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Nalaganje maščevja je kompleksna lastnost, na katero med drugim vplivajo številni okoljski dejavniki in genetske razlike med posamezniki. Za preučevanje genetskih dejavnikov so najbolj primerni mišji poligeni modeli. V našem postopku smo uporabili liniji, ki sta bili selekcionirani na visok (debela linija) ali nizek (vitka linija) odstotek telesnega maščevja. Prejšnje študije so nakazale, da je gen Pla2g4e eden od potencialnih kandidatnih genov, ki lahko razloži del fenotipske razlike med linijama. Zato smo si kot prvi cilj zadali analizo izražanja Pla2g4e v hipotalamusu med vitko in debelo linijo, ki sta bili krmljeni s krmama z različno vsebnostjo maščob. Dokazali smo statistično značilno povišano izražanje gena v hipotalamusu debele linije miši, ne glede na vrsto krme. Drugi cilj je bil okarakterizirati gen Pla2g4e s sodobnimi bioinformacijskimi metodami, predvsem z vidika identifikacije polimorfizmov med vitko in debelo linijo, ki bi bili lahko odgovorni za diferencialno izražanje. Pri debeli liniji smo našli polimorfizme, zaradi katerih se lahko izgubijo vezavne regije za miRNA in transkripcijski represor CTCF, kar predvidevamo, da lahko pri tej liniji vodi v povišano izražanje gena Pla2g4e in posledično povišano raven nalaganja telesne maščobe. Pridobljeni rezultati kažejo, kako pomembno je genetsko ozadje pri debelosti in predstavljajo osnovo za razvoj potencialnih novih biooznačevalcev za nalaganje maščobe. Fat accumulation is a complex trait influenced by many environmental factors and genetic differences between individuals. Mouse polygenic models are best suited to study genetic factors. In our experiment, we used two lines selected for high (fat line) or low (lean line) body fat percentage. Previous studies have suggested that the gene Pla2g4e is one of the potential candidate genes that may explain part of the phenotypic difference between the lines. Therefore, as a first aim, we set out to analyse the expression of Pla2g4e in the hypothalamus between the lean and fat lines that were fed diets containing different levels of fat. We demonstrated a statistically significant increased gene expression in the hypothalamus of the obese mouse line, irrespective of the diet type or sex. The second objective was to characterise the gene Pla2g4e using bioinformatics methods with the objective of identifying polymorphisms between the lean and the obese lines that might be responsible for the differential expression. In the obese line, we found polymorphisms that may result in a loss of binding regions for miRNA and the transcriptional repressor CTCF, which we hypothesise may lead to increased expression of the gene Pla2g4e and consequently increased levels of body fat deposition in this line. These results demonstrate the importance of genetic background in obesity and provide a basis for the development of potential new biomarkers for fat deposition.

High-throughput multiplexed assays are needed to simplify detection of Helicobacter species in experimental infection and routine health monitoring of laboratory mice. Therefore, fluorescent bead-based hybridization assays for Helicobacter sp. DNA and serology were developed. Multiplex PCR amplicons (H. hepaticus, H. bilis, H. typhlonius, H. pylori, H. muridarum, H. pullorum, H. cinaedi, H. heilmanii, C. jejuni) and antibodies against H. pylori, H. hepaticus, H. bilis were assessed in naturally and experimentally infected mice, and results compared to conventional PCR. Species-specific and sensitive detection of seven Helicobacter spp.

Relevance. Fulvestrant is used for the treatment of breast cancer in combination with other drugs. The aim of the study was to determine the effect of the prenatal action of fulvestrant on the ovaries of the offspring of laboratory mice. Materials and Methods. The experimental animals were divided into 4 groups: intact, control and 2 experimental, 5 animals in each group. Injections were administered to females after fertilization at the gestational stage E 11.5 once intramuscularly. In the control group (n=5), sterile castor oil was administered at a dose of 0.8 mcg/kg. In the first experimental group (n=5), an antiestrogen was introduced in the form of an oil solution of fulvestrant 0.08 ml 0.0005% at a dose of 20 mcg/kg. In the second group (n=5), an antiestrogen was introduced in the form of an oil solution of fulvestrant 0.4 ml 0.0005% at a dose of 100 mcg/kg. Results and Discussion . The study revealed that in the ovaries when the drug was administered at a dose of 20 mcg/kg (F-20), the number of primordial follicles was reduced. Accordingly, the number of follicles of subsequent generations decreased. With the introduction of the drug fulvestrant 100 mcg/kg (F-100) on the section of the ovary, sclerosis of the stromal component is observed, accompanied by a rearrangement of the vascular network with signs of atresia and cystic degeneration of the follicular epithelium in the secondary and tertiary follicles, formed cysts are observed in the ovarian parenchyma. Conclusion. The prenatal effect of the drug fulvestrant on the maternal body during pregnancy leads to persistent structural changes in the ovaries of the offspring, manifested in the late stages of ontogenesis, which, in turn, can lead to violations of reproductive function. The depth and scale of these changes are dose-dependent.

Purpose Suicidality can be a serious feature of psychiatric symptoms in encephalitis. Investigating the psychiatric behavior associated with suicidality in animal models of encephalitis is important; thus, determining whether normal laboratory animals are aware of death is necessary. Methods To examine the behavioral and brain activity changes associated with death of conspecifics, laboratory mice were exposed to a cadaveric mouse or an anesthetized mouse. Behavioral tasks associated with anxiety and locomotion were conducted after repeated exposure. Neural activity in the medial prefrontal cortex during the cadaver exploration was investigated using electroencephalographic recordings. Results During repeated exposure, mice in the cadaver group showed a gradual decrease in time exploring the cadaver, which was not observed in mice in the anesthesia group. The cadaver group also exhibited increased levels of anxiety in the light/dark transition and elevated plus maze tasks and displayed increased locomotor activity in the open field test. In an electrophysiological study, different brain oscillations were observed when mice were exposed to a cadaveric mouse and an anesthetized mouse. Enhanced delta-band activity and reduced theta- and alpha-band activities were observed during cadaver exploration. Conclusion The present study results showed that experiences involving dead conspecifics strongly affect mouse behavior and brain activity. These findings may be helpful in treating patients with psychiatric symptoms and aid in understanding the concept of death recognition/awareness in laboratory animals.

Background Health surveillance of murine colonies employed for scientific purposes aim at detecting unwanted infection that can affect the well-being of animals and personnel, and potentially undermine scientific results. In this study, we investigated the use of a next-generation sequencing (NGS) metagenomic approach for monitoring the microbiota composition and uncovering the possible presence of pathogens in mice housed in specific pathogen-free (SPF) or conventional (non-SPF) facilities. Results Analysis of metagenomic NGS assay through public and free algorithms and databases allowed to precisely assess the composition of mouse gut microbiome and quantify the contribution of the different microorganisms at the species level. Sequence analysis allowed the uncovering of pathogens or the presence of imbalances in the microbiota composition. In several cases, fecal pellets taken from conventional facilities were found to carry gene sequences from bacterial pathogens (Helicobacter hepaticus, Helicobacter typhlonius, Chlamydia muridarum, Streptococcus pyogenes, Rodentibacter pneumotropicus, Citrobacter rodentium, Staphylococcus aureus), intestinal protozoa (Entamoeba muris, Tritrichomonas muris, Spironucleus muris) nematoda (Aspiculuris tetraptera, Syphacia obvelata), eukaryotic parasites (Myocoptes musculinus) and RNA virus (Norwalk virus). Thus, the use of NGS metagenomics can reduce the number of tests required for the detection of pathogens and avoid the use of sentinel mice. Conclusions In summary, in comparison with standard approaches, which require multiple types of test, NGS assay can detect bacteria, fungi, DNA and RNA viruses, and eukaryotic parasites from fecal pellets in a single test. Considering the need to protect animal well-being and to improve the success and reproducibility of preclinical studies, this work provides the proof-of-concept that the use of NGS metagenomics for health monitoring of laboratory mice is a feasible and dependable approach, that is able to broaden the current concept of health monitoring of laboratory mice from “pathogen surveillance” to a more inclusive “microbiota surveillance”.

Cilj naloge je bil zbrati in analizirati podatke iz postopka krmljenja vitke linje miši (FHI) in debele linije miši (FLI). Liniji sta bili krmljeni z krmama, kjer ima ena večjo vsebnost maščob kot druga. Zanimalo nas je ali imata ta dva tipa krme vpliv na diferencialno prirast miši in maščobnih depojev v odvisnosti od genotipa. Debelost je povezana z rezistenco na inzulin. Raziskave kažejo, da imajo maščobna tkiva pomembno vlogo pri nastanku in napredovanju bolezni povezanih z debelostjo. Visok vnos maščob vodi do sprememb v presnovi v maščobnih tkivih, te pa povečajo raven prostih maščobnih kislin v krvi. V postopku smo uporabili 42 miši linij FHI in FLI (24 FHI, 18 FLI). Miši so bile vključene v postopek pri starosti 21-25 dni. Miši so bile ločene v dve skupini pri vsaki liniji in so dobivale dve vrsti krme. Ena skupina je dobivala krmo z nizko vsebnostjo maščobe (LFD). Druga skupina pa je dobivala krmo z visoko vsebnostjo maščob (HFD). Upoštevajoč dobljene rezultate, lahko sklepamo, da se genotipa v merjenih lastnostih nista razlikovala pri krmi LFD. Pri skupini, ki je bila krmljena z HFD krmo, pa je vpliv genotipa statistično značilen. The aim of this study was to collect and analyze data from an experiment in which we fed isocaloric diets to a lean line (FHI) and a fat line (FLI) of mice, but with different compositions-a high fat diet (HFD) and a low fat diet (LFD). We were interested in whether these two types of diets had an effect on the difference in growth of the mice and fat deposition depending on the genotype FHI or FLI. Obesity is associated with insulin resistance. Research shows that adipose tissue plays an important role in the development and progression of diseases related to obesity. High fat intake leads to changes in adipose tissue metabolism, increasing the level of free fatty acids in the blood, which has a negative effect on metabolism. We used 42 mice of the FHI and FLI lines (24 FHI, 18 FLI) for the procedure. The mice were enrolled in the study at 21-25 days of age. They were divided into two groups for each line. One group was fed low-fat diet and the other high fat diet. The results showed that the effect of genotype was not significant in the low-fat treatment. In the group fed high fat diet, we found statistically significant differences in the measured traits between FLI and FHI genotypes.

V kmetijstvu je danes izredno pomembno, da živali priraščajo hitro, so zdrave ter pri tem porabijo karseda malo krme. Zato se iščejo alternative, kjer bi dosegli dobre parametre rasti in razvoja živali. Namen diplomskega dela je bil ugotoviti, ali tehnologija vpihovanja nanomehurčkov v pitno vodo vpliva na rast in razvoj živali. S tega področja je bilo opravljenih nekaj raziskav, ki so dokazale pozitiven učinek nanomehurčkov na rast, razvoj in izkoriščanje krme. Mi smo za namene poskusa uporabili za modelni organizem laboratorijske miši, saj imajo hiter generacijski interval in so enostavne za rokovanje. Poskus smo izvedli s 36 laboratorijskimi mišmi, ki so bile ločene po spolu, liniji (debela/vitka) ter po vrsti tretmaja. Ena skupina miši je zauživala vodo z vpihanimi nanomehurčki, druga skupina pa navadno vodo (iz vodovoda). Poskus smo začeli pri miškah, starih 3 tedne in ga končali pri starosti 8 tednov. Miši smo tedensko tehtali, merili količino zaužite krme, izračunali izkoriščanje zaužite krme ter menjavali vodo dnevno. Prav tako smo pri 7. tednu iz nastila v kletkah zbrali blato, da smo lahko izračunali prebavljivost surovih beljakovin in surovih maščob. Ugotovili smo, da v večini ne moremo potrditi pozitivnega učinka nanomehurčkov na rast in razvoj ter izkoriščanje krme pri laboratorijskih miših. Glede na dejstvo, da je bila povprečno poraba krme pri miših iz skupine z nanomehurčki manjša ter da so se povprečni prirasti pri miših iz skupine z nanomehurčki povečevali proti koncu poskusa, je možno, da bi ob daljšem poskusu ali uporabi več živali dobili boljše rezultate. In agriculture today it is extremely important that animals grow quickly, are healthy, and consume little feed. Therefore, alternatives are sought to achieve good parameters for the growth and development of animals. The aim of B. Sc. Thesis was to determine whether the technology of injecting nanobubbles into drinking water affects the growth and development of animals. Some researchers have already been carried out in this field. The positive effect of nanobubbles on the growth, development, and utilization of feed was demonstrated. For the experiment, we used laboratory mice as model organisms because they have a fast generation interval and are easy to handle. We experimented with 36 laboratory mice that were separated by sex, line (fat/lean), and type of treatment. One group of mice received water infused with nanobubbles, and the other group received normal water (from the tap). We started the experiment in mice, at 3 weeks of age and ended it at 8 weeks of age. We weighed the mice weekly, measured the amount of feed consumed, calculated the efficiency of the feed consumed, and changed the water daily. We also collected feces from the bedding in the cages at week 7 to calculate the digestibility of crude protein and crude fat. We found that in most cases, we could not confirm the positive effect of nanobubbles on growth and development as well as feed conversion in laboratory mice. Since the average feed consumption of mice in the nanobubble group was lower and the average gains of mice in the nanobubble group increased toward the end of the experiment, a longer experiment or the use of more animals might provide better results.

The genus Corynebacterium, composed of Gram-positive diphtheroid rod-shaped bacteria, induces severe diseases, such as Corynebacterium-associated hyperkeratosis and pseudotuberculosis, in immunodeficient mice. We isolated and identified a total of 165 strains of Corynebacterium species from experimental mice in Korean laboratories, diagnosed using several methods. When identified based on molecular methods, namely, 16S rRNA and rpoB gene sequence analysis, the main Corynebacterium species isolated in Korean laboratory mice were C. mastitidis (44.8%, n = 74), C. bovis (25.5%, n = 42), C. lowii (21.2%, n = 35), and C. amycolatum (8.5%, n = 14). Diagnoses were also performed using matrix-assisted laser desorption/ionization–time of flight mass spectrometry (MALDI-TOF MS) and biochemical methods. MALDI-TOF MS yielded results that were 77.9% identical to the molecular identification results, whereas biochemical methods showed only 15.5% identical to molecular identification, partly owing to difficulties in distinguishing among C. mastitidis strains. Collectively, our findings indicate that molecular biological methods are better suited for detecting and identifying Corynebacterium species candidates isolated from mice than biochemical methods. Because of limitations associated with the use of MALDI-TOF MS, more precise results will be obtained by complementing this approach with other methods when used for rapid identification testing.

Purpose Laboratory animal workers (LAW) working with laboratory mice are exposed to mouse allergens (MA). If MA are spread to home environments, this might increase the risk for allergies in LAW and their families. This study aimed to assess 1. whether spreading of MA from workplace to home environment takes place; 2. which factors increase spreading of MA. Methods In a cross-sectional study, dust samples were taken on the mattress and seating in homes of LAW (n = 105) and an unexposed comparison group (n = 13). From 89 LAW, additional dust samples were taken from their workplaces. Samples were analysed using Mus m1 ELISA kits [detection limit (DL) 0.2 ng mus m1/ml]. Sociodemographic data, personal history of allergies and cleaning habits, as well as work-related characteristics (LAW only) were assessed by questionnaire. Latent factors were assessed via factor analysis. Tobit models were fitted to analyse the latent factors’ contribution to MA spreading. Results MA concentration on the seating was significantly higher in home environments of LAW (median = 1.28 ng mus m1/m2) than in the comparison group (median p = 0.019). The highest workplace MA concentration was found on the floor of the scullery (median = 140,000.00 ng mus m1/m2), followed by hair-covering caps (median = 76.02 ng mus m1/m2). Cage and mouse facility cleaning tasks and infrequent changing of bed linen at home were statistically significantly associated with higher MA concentrations at home. Conclusions Spreading of MA from LAW’s workplace to their home environment takes place, especially among LAWs involved in cleaning tasks.

The purpose of the research is to study the effect of extractive substances from a complex of herbs (R. Carthamoides, S. Coronate, F. ulmaria )on individual indicators of the metabolism of laboratory mice, pregnant sows and piglets obtained from them. A phytoextract containing ecdysteroids and flavonoids was orally administered to white mice ( three experimental and one control group of 15 mice) in doses of 0.1; 0.2 and 0.3 ml during 14 days that provided an increase in the average daily weight gain by 20.8-48.5% (P 0.05). It has been established that the phytoextract had an anabolic effect on white mice, did not cause a negative effect on the studied biochemical parameters of metabolism in pregnant sows, and contributed to an increase in the number of live newborns in comparison with the control.

Актуальность. Важным аспектом нарушения естественного нормального течения эмбриогенеза является влияние в пренатальный период факторов внешней и внутренней среды, которые оказывают воздействие на дифференцировку органов репродуктивной системы во взрослом организме мужского и женского пола. Цель исследования изучить и оценить результаты изменений соматометрических показателей потомства лабораторных мышей при пренатальном воздействии фулвестранта. Материалы и методы исследования. Экспериментальные исследования выполнялись на потомстве лабораторных мышах, матерям которых в отдельности на 11 сутки беременности пренатального периода в одно и то же вечернее время суток вводили исследуемый препарат. Полученное потомство лабораторных мышей были разделены на 5 групп. Интактная группа без воздействия. Контрольной группе вводили касторовое масло в дозе 0,8 мкг/кг (n=5; «МК»), первой экспериментальной группе вводили однократно, внутримышечно фулвестрант в виде 0,08 мл 0,0005% в дозе 20 мкг/кг (n=5; «Ф-20»), второй экспериментальной группе вводили однократно, внутримышечно фулвестрант 0,4 мл 0,0005% в дозе 100 мкг/кг (n=5; «Ф-100»), третьей экспериментальной группе вводили однократно, внутримышечно фулвестрант 0,8 мл 0,0005% в дозе 200 мкг/кг (n=5; «Ф-200»). У полученного потомства проводились соматометрические исследования. Результаты и их обсуждение. При однократном внутримышечном пренатальном воздействии препарата фулвестранта в потомстве мужского пола наблюдается усиление маскулинизирующего эффекта, в результате чего блокируются эстрогеновые рецепторы и работают только андрогеновые, тогда как в потомстве женского пола проявляется феминизирующий отсроченный эффект. Изучение дозозависимых эффектов пренатального введения эстрогенов продемонстрировало как стимулирующее, так и ингибирующее воздействие гормонов на соматометрические показатели потомства. Заключение. В результате пренатального воздействия эстрогенов в раннем постнатальном онтогенезе наблюдались изменения соматометрических показателей, обусловленные воздействием различных доз эстрогенов. Лимитирование дозозависимого действия эстрогенных препаратов во время беременности позволит избежать неблагоприятных эффектов в постнатальном онтогенезе., Relevance. An important aspect of the violation of the natural normal course of embryogenesis is the influence of external and internal environmental factors in the prenatal period, which affect the differentiation of the organs of the reproductive system in the adult male and female body. The research purpose was to study and to evaluate the results of changes in somatometric parameters of the offspring of laboratory mice under prenatal exposure to fulvestrant. Materials and methods of research. Experimental studies were performed on the offspring of laboratory mice, whose mothers were separately injected with the test drug on the 11th day of pregnancy of the prenatal period at the same evening time of the day. The resulting offspring of laboratory mice were divided into 5 groups. Intact group was without exposure. The control group was administered castor oil at a dose of 0.8 mcg / kg (n= 5; "MK"), the first experimental group was administered once, intramuscularly fulvestrant in the form of 0.08 ml 0.0005% at a dose of 20 mcg / kg (n=5; "F -20. The second experimental group was administered once, intramuscularly fulvestrant 0.4 ml 0.0005% at a dose of 100 mcg / kg (n=5; "F-100"), the third experimental group was administered once, intramuscularly fulvestrant 0.8 ml 0.0005% at a dose of 200 mcg / kg (n=5; "F-200"). Somatometric studies were carried out in the resulting offspring. Results and its discussion. With a single intramuscular prenatal exposure to fulvestrant in male offspring, an increase in the masculinizing effect is observed, as a result of which estrogen receptors are blocked and only androgen ones work, whereas in female offspring a feminizing delayed effect is manifested. The study of dose-dependent effects of prenatal administration of estrogens demonstrated both stimulating and inhibitory effects of hormones on the somatometric parameters of offspring. Conclusion. As a result of prenatal exposure to estrogens in early postnatal ontogenesis, changes in somatometric parameters were observed due to exposure to various doses of estrogens. Limiting the dose-dependent effect of estrogenic drugs during pregnancy will help to avoid adverse effects in postnatal ontogenesis.

Simple Summary Stressful events can trigger body temperature variations in mammals. The most commonly used methods for measuring temperature in laboratory mice are stressful and invasive in nature, and can themselves cause stress-induced hyperthermia (SIH). This raises concerns regarding both animal welfare and research output. Infrared thermography (IRT) offers a non-invasive alternative, if proven to accurately identify SIH. We exposed mice to mild handling-induced stress, by either tail-picking or the reportedly less-impactful tunnel-handling technique. Temperature was measured by reading microchip devices (PIT-tags) implanted subcutaneously (Tsc), and by a thermal camera to measure mean body surface temperature (Tbody) and mean tail surface temperature (Ttail). As expected, during acute stress exposure, both Tsc and Tbody increased, while Ttail decreased. No differences in stress-induced hyperthermia were found between the two handling techniques. This suggests that such differences may not be detectable in the context of co-occurring stressful events, such as opening of the cage lid, exposure to light, or presence of the handler. Within the same cage, animals handled last consistently showed higher body temperatures than those handled first, raising the issue of minding the order by which animals are tested. Our results suggest IRT offers a reliable non-invasive method for assessing SIH in laboratory rodents. Abstract Stress-induced hyperthermia (SIH) is a physiological response to acute stressors in mammals, shown as an increase in core body temperature, with redirection of blood flow from the periphery to vital organs. Typical temperature assessment methods for rodents are invasive and can themselves elicit SIH, affecting the readout. Infrared thermography (IRT) is a promising non-invasive alternative, if shown to accurately identify and quantify SIH. We used in-house developed software ThermoLabAnimal 2.0 to automatically detect and segment different body regions, to assess mean body (Tbody) and mean tail (Ttail) surface temperatures by IRT, along with temperature (Tsc) assessed by reading of subcutaneously implanted PIT-tags, during handling-induced stress of pair-housed C57BL/6J and BALB/cByJ mice of both sexes (N = 68). SIH was assessed during 10 days of daily handling (DH) performed twice per day, weekly voluntary interaction tests (VIT) and an elevated plus maze (EPM) at the end. To assess the discrimination value of IRT, we compared SIH between tail-picked and tunnel-handled animals, and between mice receiving an anxiolytic drug or vehicle prior to the EPM. During a 30 to 60 second stress exposure, Tsc and Tbody increased significantly (p < 0.001), while Ttail (p < 0.01) decreased. We did not find handling-related differences. Within each cage, mice tested last consistently showed significantly higher (p < 0.001) Tsc and Tbody and lower (p < 0.001) Ttail than mice tested first, possibly due to higher anticipatory stress in the latter. Diazepam-treated mice showed lower Tbody and Tsc, consistent with reduced anxiety. In conclusion, our results suggest that IRT can identify and quantify stress in mice, either as a stand-alone parameter or complementary to other methods.

Актуальность. Для регуляции овариально-менструального цикла, зачатия, поддержания, разрешения и предупреждения беременности применяют эстрогены. В связи со значительными успехами молекулярной биологии у морфологов появилась возможность иммуноцитохимически маркировать клетки при различных фазах клеточного цикла. Большое внимание уделяется изучению молекулярно-биологическому маркеру, характеризующий пролиферацию белок Ki-67, который является наиболее информационным, адекватным, удобным в использовании. Цель исследования изучение прогностического значения маркера Ki-67 при пренатальном воздействии различных доз синтетического аналога эстрогена синэстрола на яичники потомства лабораторных мышей. Материалы и методы исследования. Эксперимент выполнен на потомстве лабораторных мышей, матерям которых на стадии гестации £11.5 внутримышечно однократно вводили экспериментальные дозы синтетического аналога эстрогена синэстрола. Иммуногистохимический анализ проводили на срезах с парафиновых блоков яичников потомства, предназначенных для стандартного морфологического исследования. Оценку окрашенных препаратов проводили с использованием светового микроскопа Leica. В 10 полях зрения каждого образца при увеличении х400 производили подсчет иммунопозитивных клеток с положительной реакцией по коричневому окрашиванию ядра. Среднее число Ki-67 иммунопозитивных клеток вычисляли соотношением позитивно окрашенных клеток к негативно окрашенным клеткам (на 100 просчитанных клеток). Экспрессию маркера определяли в следующих показателях яичников потомства: в первичных, вторичных, третичных фолликулах; в желтом теле; в строме органа. Результаты и их обсуждение. В первой экспериментальной группе «С-25» во всех исследуемых показателях наблюдалось снижение митотической активности клеток при экспрессии маркера Ki-67, свидетельствующее об ускоренной физиологической гибели клеток. Во второй экспериментальной группе «С-40» уровень экспрессии белка Ki-67 в желтых телах достоверно уменьшился, но вместе с тем увеличение экспрессии произошли в остальных показателях, демонстрирующие о снижении процесса естественной гибели клеток. В третьей экспериментальной группе «С-50» наблюдался однонаправленный процесс роста количества иммунопозитивно-окрашенных клеток во всех исследуемых показателях, свидетельствующие о снижении процесса естественной гибели клеток. Заключение. Веденные исследуемые дозы синтетического эстрогена синестрола в пренатальный период вызывают морфофункциональные нарушения в яичниках потомства. Дозазависимость эстрогенов может служить фоном для развития структурных изменений в яичниках потомства, о чем свидетельствует экспрессия маркера Ki-67., Relevance. Estrogens are used to regulate the ovarian-menstrual cycle, conception, maintenance, resolution and prevention of pregnancy. Due to significant advances in molecular biology, morphologists have the opportunity to immunocytochemically label cells at various phases of the cell cycle. Much attention is paid to the study of the molecular biological marker that characterizes proliferation the protein Ki-67, which is the most informative, adequate, and convenient to use. The research purpose was to study the prognostic value of the Ki-67 marker during prenatal exposure of various doses of synthetic estrogen analog synestrol to the ovaries of offspring of laboratory mice. Materials and methods. The experiment was performed on the offspring of laboratory mice, whose mothers at the stage of gestation E11.5 were intramuscularly administered experimental doses of the synthetic analogue of estrogen synestrol once. Immunohistochemical analysis was performed on sections from paraffin blocks of ovaries of offspring intended for standard morphological examination. The stained preparations were evaluated using a Leica light microscope. In 10 fields of view of each sample, at an increase of x400, immune-positive cells with a positive reaction to the brown staining of the nucleus were counted. The average number of Ki-67 immunopositive cells was calculated by the ratio of positively colored cells to negatively colored cells (per 100 calculated cells). The expression of the marker was determined in the following indicators of the ovaries of the offspring: in primary, secondary, tertiary follicles; in the corpus luteum; in the stroma of the organ. Results and its discussion. In the first experimental group "C-25", a decrease in mitotic activity of cells was observed in all the studied parameters with the expression of the Ki-67 marker, indicating accelerated physiological cell death. In the second experimental group "C-40", the expression level of the Ki-67 protein in yellow bodies significantly decreased, but at the same time, an increase in expression occurred in the remaining indicators, demonstrating a decrease in the process of natural cell death. In the third experimental group "C-50", a unidirectional process of increasing the number of immunopositive-stained cells was observed in all the studied indicators, indicating a decrease in the process of natural cell death. Conclusion. The studied doses of synthetic estrogen synestrol in the prenatal period cause morphofunctional disorders in the ovaries of offspring. The dose dependence of estrogens can serve as a background for the development of structural changes in the ovaries of offspring, as evidenced by the expression of the Ki-67 marker.

To investigate the prevalence of murine astrovirus (MuAstV) in mice in laboratory animal facilities in Japan, a polymerase chain reaction (PCR) test targeting the RNA-dependent RNA polymerase (RdRP) gene was performed on the cecum contents of 1,212 mice (1,183 immunocompetent mice and 29 immunodeficient mice) from 226 facilities. The results showed that 118 (52.2%) of the 226 facilities were positive for MuAstV. Out of the 1,212 mice, 424 (35.0%) were positive. No gross lesions were observed in any of the mice examined. A phylogenetic analysis for 15 selected strains revealed that 13 strains formed one cluster, while two were genetically distant from that cluster. These results suggest that multiple strains are prevalent in laboratory mice in Japan.

Small animal models are of crucial importance for assessing COVID-19 countermeasures. Common laboratory mice would be well-suited for this purpose but are not susceptible to infection with wild-type SARS-CoV-2. However, the development of mouse-adapted virus strains has revealed key mutations in the SARS-CoV-2 spike protein that increase infectivity, and interestingly, many of these mutations are also present in naturally occurring SARS-CoV-2 variants of concern. This suggests that these variants might have the ability to infect common laboratory mice. Herein we show that the SARS-CoV-2 beta variant attains infectibility to BALB/c mice and causes pulmonary changes within 2-3 days post infection, consistent with results seen in other murine models of COVID-19, at a reasonable virus dose (2 x 10(5) PFU). The findings suggest that common laboratory mice can serve as the animal model of choice for testing the effectiveness of antiviral drugs and vaccines against SARS-CoV-2.

Simple Summary Different forms of environmental enrichment are used to increase the wellbeing of laboratory animals. These forms include extending the available cage space, housing a large group of animals within the same unit and adding stimulating physical objects. The semi naturalistic environment (SNE) used in this study implements all of these enhancements. However, there is debate as to whether such variation in housing standards increases the variability of experimental data. Indeed, it has been shown that mice living in the SNE developed individual differences in activity and behavioral parameters. Here, we investigated whether housing in the SNE enhances individual differences in aged animals and whether these differences are reflected in certain physiological parameters. These aspects were considered to assess the suitability of the SNE as a reference system in future studies. We found that the individual-level activity patterns of the animals stabilized during the housing period in the SNE. These behavioral characteristics did not correlate with the measured physiological parameters. Considering the variance of the measured data, which is comparable to the literature, the SNE seems to be a suitable system for studies comparing different housing systems in terms of animal welfare. Abstract Despite tremendous efforts at standardization, the results of scientific studies can vary greatly, especially when considering animal research. It is important to emphasize that consistent different personality-like traits emerge and accumulate over time in laboratory mice despite genetic and environmental standardization. To understand to what extent variability can unfold over time, we conducted a long-term study using inbred mice living in an exceptionally complex environment comprising an area of 4.6 m2 spread over five levels. In this semi-naturalistic environment (SNE) the activity and spatial distribution of 20 female C57Bl/6J was recorded by radio-frequency identification (RFID). All individuals were monitored from an age of 11 months to 22 months and their individual pattern of spatial movement in time is described as roaming entropy. Overall, we detected an increase of diversification in roaming behavior over time with stabilizing activity patterns at the individual level. However, spontaneous behavior of the animals as well as physiological parameters did not correlate with cumulative roaming entropy. Moreover, the amount of variability did not exceed the literature data derived from mice living in restricted conventional laboratory conditions. We conclude that even taking quantum leaps towards improving animal welfare does not inevitably mean a setback in terms of data quality.

Accumulating studies show that the host microbiome influences the development or progression of many diseases. The eukaryotic virome, as a key component of the microbiome, plays an important role in host health and disease in humans and animals, including research animals designed to model human disease. To date, the majority of research on the microbiome has focused on bacterial populations, while less attention has been paid to the viral component. Members of the eukaryotic virome interact with the commensal bacterial microbiome through trans-kingdom interactions, and influence host immunity and disease phenotypes as a collective microbial ecosystem. As such, differences in the virome may affect the reproducibility of animal models, and supplementation of the virome may enhance the translatability of animal models of human disease. However, there are minimal empirical data regarding differences in the virome of mice from different commercial sources. Our hypotheses were that the mice obtained from pet store sources and lab mice differ in their eukaryotic virome, and that lab mice from different sources would also have different viromes. To test this hypothesis, the ViroCap platform was used to characterize the eukaryotic virome in multiple tissues of mice from different sources including three sources of laboratory mice and two pet stores. As expected, pet store mice harbored a much greater diversity within the virome compared to lab mice. This included an ostensibly novel norovirus strain identified in one source of these mice. Viruses found in both laboratory and pet store populations included four strains of endogenous retroviruses and murine astrovirus with the latter being restricted to one source of lab mice. Considering the relatively high richness virome within different samples from healthy humans, these data suggest that mouse models from alternative sources may be more translational to the human condition. Moreover, these data demonstrate that, by characterizing the eukaryotic murine virome from different sources, novel viruses may be identified for use as field strains in biomedical research.

Laboratory mice are predominantly used for one experiment only, i.e., new mice are ordered or bred for every new experiment. Moreover, most experiments use relatively young mice in the range of late adolescence to early adulthood. As a consequence, little is known about the day-to-day life of adult and aged laboratory mice. Here we present a long-term data set with three consecutive phases conducted with the same male mice over their lifetime in order to shed light on possible long-term effects of repeated cognitive stimulation. One third of the animals was trained by a variety of learning tasks conducted up to an age of 606 days. The mice were housed in four cages with 12 animals per cage; only four mice per cage had to repeatedly solve cognitive tasks for getting access to water using the IntelliCage system. In addition, these learner mice were tested in standard cognitive tests outside their home-cage. The other eight mice served as two control groups living in the same environment but without having to solve tasks for getting access to water. One control group was additionally placed on the test set-ups without having to learn the tasks. Next to the cognitive tasks, we took physiological measures (body mass, resting metabolic rate) and tested for dominance behavior, and attractivity in a female choice experiment. Overall, the mice were under surveillance until they died a natural death, providing a unique data set over the course of virtually their entire lives. Our data showed treatment differences during the first phase of our lifetime data set. Young learner mice showed a higher activity, less growth and resting metabolic rate, and were less attractive for female mice. These effects, however, were not preserved over the long-term. We also did not find differences in dominance or effects on longevity. However, we generated a unique and valuable set of long-term behavioral and physiological data from a single group of male mice and note that our long-term data contribute to a better understanding of the behavioral and physiological processes in male C57Bl/6J mice.

We report on the first detection and isolation of B. pseudohinzii (Bordetella pseudohinzii) in laboratory mice in China. Forty‐one B. pseudohinzii strains were isolated from 3094 mice in 33 different laboratory animal facilities in southern China. The isolates were identified through culture and genome sequenceing. Phylogenetic analysis based on the sequences of 16S rRNA and OmpA genes demonstrated that these strains were on the same clade as other B. pseudohinzii strains isolated from mice. Experimental infected mice presented an asymptomatic infection. B. pseudohinzii replicated in both the respiratory tract and the digestive tract. Most importantly B. pseudohinzii shed via feces and infected a group of sentinel mice in a separate cage via cage padding contaminated with B. pseudohinzii‐positive feces, indicating that B. pseudohinzii could transmit efficiently among mice and contaminate environmental facilities. Our study highlights the importance of routine monitoring of the pathogen in laboratory mice and provides vital insights into the transmission of Brodetellae in rodents and human.

The neurobiology of environmentally induced stereotypic behaviours (e.g. pacing in zoo carnivores, crib-biting in horses) is hypothesized to involve the disruption of coordinated function within the basal ganglia (’Basal Ganglia [BG] Pathways Hypotheses’) and/or between the basal ganglia and the cortex (‘Cortico-Striatal-Thalamo-Cortical [CSTC] Circuits Hypotheses‘). However, these hypotheses have not yet been fully supported by the current research. Currently tests of these hypotheses in mice (Mus musculus) are incomplete: missing regions of interest, housing, or individual difference effects. My research used cytochrome oxidase histochemistry to examine neuronal activity in each of the basal ganglia nuclei for enriched versus barren housed mice and assessed whether basal ganglia activity correlated with SBs. None of the BG Pathways hypotheses were supported. Thus, the neurobiological mechanism for mouse SBs remains unknown. Further research is important for understanding the impact of captivity on animals’ functioning, and whether SBs are a sign of pathology. Queen Elizabeth II Graduate Scholarship in Science and Engineering; Ontario Graduate Scholarship

To maintain and foster the welfare of laboratory mice, tools that reliably measure the current state of the animals are applied in clinical assessment. One of these is the Mouse Grimace Scale (MGS), a coding system for facial expression analysis. Since there are concerns about the objectivity of the MGS, we further investigated its reliability. Four observers (two experienced and two inexperienced in use of the MGS) scored 188 images of 33 female and 31 male C57BL/6JRj mice. Images were generated prior to, 150 min, and two days after ketamine/xylazine anesthesia. The intraclass correlations coefficient (ICC = 0.851) indicated good agreement on total MGS scores between all observers when all three time points were included in the analysis. However, interrater reliability was higher in the early post-anesthetic period (ICC = 0.799) than at baseline (ICC = 0.556) and on day 2 after anesthesia (ICC = 0.329). The best agreement was achieved for orbital tightening, and the poorest agreement for nose and cheek bulge, depending on the observers&rsquo, experience levels. In general, experienced observers produced scores of higher consistency when compared to inexperienced. Against this background, we critically discuss factors that potentially influence the reliability of MGS scoring.

A comparison of whole-fish polychlorinated biphenyl (PCB) and total mercury (Hg) concentrations in mature males with those in mature females may provide insights into sex differences in behavior, metabolism, and other physiological processes. In eight species of fish, we observed that males exceeded females in whole-fish PCB concentration by 17 to 43 %. Based on results from hypothesis testing, we concluded that these sex differences were most likely primarily driven by a higher rate of energy expenditure, stemming from higher resting metabolic rate (or standard metabolic rate (SMR)) and higher swimming activity, in males compared with females. A higher rate of energy expenditure led to a higher rate of food consumption, which, in turn, resulted in a higher rate of PCB accumulation. For two fish species, the growth dilution effect also made a substantial contribution to the sex difference in PCB concentrations, although the higher energy expenditure rate for males was still the primary driver. Hg concentration data were available for five of the eight species. For four of these five species, the ratio of PCB concentration in males to PCB concentration in females was substantially greater than the ratio of Hg concentration in males to Hg concentration in females. In sea lamprey (Petromyzon marinus), a very primitive fish, the two ratios were nearly identical. The most plausible explanation for this pattern was that certain androgens, such as testosterone and 11-ketotestosterone, enhanced Hg-elimination rate in males. In contrast, long-term elimination of PCBs is negligible for both sexes. According to this explanation, males not only ingest Hg at a higher rate than females but also eliminate Hg at a higher rate than females, in fish species other than sea lamprey. Male sea lamprey do not possess either of the above-specified androgens. These apparent sex differences in SMRs, activities, and Hg-elimination rates in teleost fishes may also apply, to some degree, to higher vertebrates including humans. Our synthesis findings will be useful in (1) developing sex-specific bioenergetics models for fish, (2) developing sex-specific risk assessment models for exposure of humans and wildlife to contaminants, and (3) refining Hg mass balance models for fish and higher vertebrates.

The accepted norm in most laboratories around the globe is feeding laboratory mice an ad libitum diet, although several health impairments are well-established. In contrast, reducing the animals' body weight by feeding them less food once per day (referred to as 24 h schedule) has been shown to enhance life span and reduce disease susceptibility. Against this background, this study aimed at systematically investigating the effects of different feeding routines. Therefore, three feeding routines were compared to the standard ad libitum feeding and effects on body weight development and welfare were investigated in male C57BL/6J mice. In particular, a 24 h schedule group, an AUTO group, characterized by an automated supply of small pieces of food all over the day, and a 4 h removal group, characterized by daily removal of food for 4 h, were studied. While the removal of food for 4 h per day did not lead to a reduction of body weight, and hence is unlikely to prevent negative effects of overfeeding, both the 24 h schedule group and the AUTO group led to the aspired body weight reduction. In the AUTO group, however, higher levels of corticosterone metabolites and stereotypies were observed, implying a rather negative impact on welfare. By contrast, no distinct negative effects of a 24 h schedule were found. Studies like this underline the general need for evidence-based severity assessments of any procedure involving living animals.

Pathogenic microbial detection and control in laboratory animal facilities is essential to guarantee animal welfare, data validity and reproducibility. Helicobacter spp. are known to affect mice health, what may interfere with experimental outcomes. This study aimed to screen for Helicobacter spp. in mice from animal facilities in Rio de Janeiro, Brazil using a PCR-based method. Primers designed to specifically identify Helicobacter spp. were used to amplify feces or intestine DNA extracted of mice from four different animal facilities. The expected 375 base pairs (bp) amplicon was purified, sequenced and a similarity of 95% was observed when compared to deposited sequences of H. hepaticus and H. bilis. In our screening, Helicobacter spp. was detected in ~59% of fecal and ~70% of intestine samples. Our study is the first to screen for Helicobacter spp. in mouse facilities of a Rio de Janeiro University using a low cost, rapid molecular diagnostic test. Although Helicobacter spp. screening is not mandatory according to Brazilian animal welfare regulation it is recommended by institutional animal health monitoring programs guidelines worldwide, including ARRIVE, AAALAC and FELASA.

International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies, 11, 14, 11A14U: 1-9

Search of new approaches for harmless, non-medication treatment of body dysfunctions is still on the agenda of vet and human practitioners and researchers as well. This study presents evaluation of the effect of “Stress Relief” dietary supplement (SR) on mice behaviour under different acute short-term stress conditions and treatment duration. Five experiments were performed and in each 40 animals were randomly split into four (I–IV) groups, where I and II — non-stressed mice, III and IV — stressed animals, I and III received water with trace mineral solution (TMS), II and IV received water with SR. As stress factors, forced swimming, rodent predator odour or both together were applied. Locomotor activity under normal and stress conditions in Open Field were observed and measured by a SMART video-tracking system. Blood glucose level was measured as well. SR showed a reversal of stress-decreased locomotor activity in all stress models — distance walked increased almost twice (p < 0.0001), central zone crossings and time spent in it were 2–4 times greater than in the control group (p < 0.0001 and p = 0.0002, respectively), and fast movement episodes and maximal speed increased by 50–200%. In addition, complete normalisation of stress-induced elevation of blood glucose level (p < 0.0001) was noted. These results demonstrate for the first time that the effect of “Stress Relief” formula (water additives–minerals processed by know-how way in Vital Force Technology using Dr. Yury Kronn method) can be observed in laboratory animals, and that the effects are significant and repeatable. SR shows fear- and stress-reducing activity, which does not sufficiently differ between 7-, 9-, 14-, 28- and 32-day treatment regimes.

The poor predictive quality of currently used animal models in preclinical research is an important cause of the high attrition of promising drug candidates for human autoimmune disease in clinical trials. Examples from own work in a primate multiple sclerosis (MS) model illustrate that important lessons can be learned from a critical reassessment of failed drugs in the animal model, which can help improve the animal model and better understand the targeted disease.

Aim. Experimental evaluation of effect of E. coli LPS fractions on phagocyte and metabolic activity of blood neutrophils of laboratory mice with induced immune deficiency. Materials and methods. Phagocyte activity was evaluated by phagocyte number (PN), phagocyte index (PI) and integral phagocyte index (IPI), intensity of metabolism and energetic processes of enzyme systems - by test of tetrazolium nitro blue (TNB), mean cytochemical coefficient (MCC) in spontaneous and induced tests and stimulation index (SI). Results. LPS-3 substance administration into mice with secondary immune deficiency has resulted in a significantly highest increase of PN (15.8%), IPI (17.7%), TNB-IN (10.3%), cytochemical coefficients MCC-IN (u.) and IS (u.) - 14.8 and 10.9%, respectively, compared with the parameters of immune deficient mice that had received licopid. Conclusion. Some fractions of E. coli M17 polysaccharide have immune stimulating activity.

In recent years, the microalgae (Chlorella vulgaris) have increasingly attracted great interest as a potential source of pharmacologically active compounds. Showing anticoagulation, antioxidant and antitumor activities of Chlorella revealed its hypotensive properties. The aim of this study was to evaluate the effects of Chlorella suspension on the weight of the animals, their moving activity, and erythropoiesis. The study was performed on males and females of ICR mice. The animals from the experimental group drank only the Chlorella suspension during 3 weeks and were given standard food. Control animals drank during this period only water and had the same food. The body weight of males in the control and the experimental group with Chlorella did not change, while females in the experimental group showed an increase of body weight in a week. A similar pattern was obtained for estimation of animal body weight changes relative to food consumption. The number of red blood cells in females and males from group with Chlorella increased only after 3 weeks after the start of the experiment. Hemoglobin also increased only after 3 weeks after the start of Chlorella consumption, but only for females. All groups of animals had the same motor activity during experiment. Blood sampling resulted in a reduction of activity in control males and females as well as in males with Chlorella. The motor activity of females with Chlorella after blood sampling did not change. So, consumption of the Chlorella suspension by females leads to more effective digestion and resulted in increased body weight, improved erythropoiesis resulted in increased red blood cells and hemoglobin and also increased their resistance to acute stress. The males in the same situation increased only the erythropoiesis.

Delo z laboratorijskimi živalmi zahteva dnevni stik miši s skrbnikom. Trenutno se za vsakodnevno rokovanje uporablja klasična metoda prijem za rep. Znano je, da prijem za rep mišim povzroča nelagodje in stres. Žival, ki je med izvajanjem poskusov pod stresom, ne bo izrazila naravnega obnašanja. To ima lahko vpliv na pridobljene rezultate. Uvajata se dve novi metodi rokovanja, ki naj bi bili za miši manj stresni ter spodbujali prostovoljno približevanje rokovalcu. To sta metoda rokovanja z odprto dlanjo in rokovanje s tunelom. Tekom diplomskega dela smo poskušali potrditi pozitiven vpliv obeh novih metod, tako da smo devet dni zaporedoma, izvajali vse tri prej omenjene načine rokovanja. Prvi, peti in deveti dan smo izvedli preizkus interakcije. Z merjenjem časa, ki so ga miši preživele v interakciji z rokovalcem smo določili vpliv posamezne metode. V poskusu smo uporabili tri različne linije ter oba spola živali. Tako smo lahko analizirali tudi vpliv linije in spola na prilagoditev posamezni metodi rokovanja. Izkazalo se je, da se miši najhitreje privadijo rokovanju s tunelom, sledi metoda z odprto dlanjo in kot zadnja je klasična metoda prijema za rep. Working with laboratory animals requires daily contact of mice with the handler. At that moment the most common method to handle laboratory mice is to pick up and restrain the mouse by tail. Picking up by tail is known to cause the anxiety and stress. The animal, which is under pressure during the experiment, will not express its natural behavior. This can have an impact on the results. There are two new methods of handling that led to voluntary approach and low anxiety. These are handling by tunnel and cupping mice on the open hand. In the B. Sc. Thesis we tried to confirm positive influence of both new methods. We performed all handling methods of handling for nine consecutive days. We made the interaction test on the first, fifth and ninth day. We determine the influence of each method by measuring the time that mice stay in interaction with the handler. In the experiment, we used three different lines and both genders. So we were able to analyse the influence of the line and gender to the different handling methods. Results showed the best responses to the handling by tunnel, followed by open hand and as expected the last picking up by tail.

Individually ventilated caging (IVC) systems for rodents are increasingly common in laboratory animal facilities. However, the impact of such substantial change in housing conditions on animal physiology and behavior is still debated. Most importantly, there arise the questions regarding reproducibility and comparison of previous or new phenotypes between the IVC and open cages. The present study was set up for detailed and systematic comparison of behavioral phenotypes in male and female mice of three widely used inbred strains (C57BL/6JRccHsd, DBA/2JRccHsd, 129S2/SvHSd) after being kept in two housing environments (IVC and open cages) for 6 weeks (since 4 weeks of age) before behavioral testing. The tests addressed exploratory, anxiety‐like and stress‐related behavior (light‐dark box, open field, forced swim test, stress‐induced hyperthermia), social approach and species‐specific behavior (nest building, marble burying). In all tests, large and expected strain differences were found. Somewhat surprisingly, the most striking effect of environment was found for basal body temperature and weight loss after one night of single housing in respective cages. In addition, the performance in light‐dark box and open field was affected by environment. Several parameters in different tests showed significant interaction between housing and genetic background. In summary, the IVC housing did not invalidate the well‐known differences between the mouse strains which have been established by previous studies. However, within the strains the results can be influenced by sex and housing system depending on the behavioral tasks applied. The bottom‐line is that the environmental conditions should be described explicitly in all publications., The individually ventilated caging housing did not invalidate the well‐known differences between the mouse strains established by previous studies. However, within the strains the results can be influenced by sex and housing system depending on the behavioral tasks applied.

Background: The key point in the production procedure of inbred animals is checking the genetic purity. Skin grafting and coat color test are used traditionally to prove genetic purity, but they have some disadvantages. Recent advances in DNA profiling have enabled scientists to check easily the genetic purity of laboratory animals. In the current study, a set of microsatellite markers was designed to check the purity of inbred laboratory mice. Materials and Methods: Twenty microsatellites located on 20 chromosomes were employed to create a distinctive genetic profile for parentage analysis. Each individual primer was designed based on distinguishable colors and separable sizes. Results: Twenty specific microsatellite markers were used in the polymerase chain reaction mixture to identify inbred BALB/cJ strains. Our results confirmed that the designed microsatellites are excellent genetic markers for testing inbred BALB/cJ strain in laboratories. Conclusion: Our study showed that genetic profiling using microsatellite markers allows us to detect the genetic differences of laboratory mouse species in quality control tests and validation steps.

The aim of the study was to determine the bioavailability of minerals and oxidation-antioxidant status in the laboratory animals fed with bread from regular and bioactivated wheat grain. Material and Methods ― Studies were conducted for 21 days on white inbred BALB/с mice. The animals were organized in three groups with 30 mice in each one. Group 1 (control group) was given the complete compound feed; Group 2 was fed with regular whole wheat bread; and Group 3 was given the bread from the bioactivated wheat grain. Their blood plasma was tested for total protein, cholesterol, glucose, low and high density lipoproteins, phosphorus, calcium, magnesium, iron, zinc, malondialdehyde (MDA) levels, and the activity of superoxide dismutase (SOD). Calcium was detected histochemically using McGee-Russell’s method with Alizarin red S. Results ― It was established that the levels of glucose, total protein, cholesterol, and lipids in the blood plasma of animals in all groups were within the physiological norms. There were no significant reliable deviations in the levels of mineral substances in the blood plasma of the animals in the study groups. However, the histochemical response of the bone tissue calcium to the Alizarin red S revealed significant differences in its content in the tissues between the animals of the three groups. At the 21st day of the experiment, the maximum light absorption of the colored specimen was observed in Group 3 which indicated higher calcium content in the bone tissue of the animals fed with the bread from the bioactivated wheat grain. The oxidation-antioxidant status of the animals in Groups 2 and 3 was higher than that of the control group. On the 21st day of the experiment, MDA content in the blood plasma of the animals in Group 3 was 0.04±0.017 mmol/L which is 2.0 and 1.5 times less as compared to Groups 1 and 2 respectively. The activity of SOD in the blood plasma on the 21st day of the experiment was the highest in Group 3 animals. Conclusion ― The experiment on the laboratory mice has shown that the use of the bread from the bioactivated wheat grain makes it possible to improve the bioavailability of minerals and increase the antioxidant activity of blood plasma.

AMP-activated protein kinase (AMPK) activation is an established treatment for diabetes. Here the effects of anthocyanin extract from blood orange juice, i.e. cyanidin-3- O -β-glucoside (C3G) and its secondary metabolite protocatechuic acid (PCA), on AMPK signalling in murine hepatic cell line and in the liver of C57BL/6 mice were investigated. Results showed for the first time that C3G and PCA activate AMPK and suppress its downstream kinase mTOR/S6K both in vitro and in vivo systems. Then, C3G and particularly PCA increased expression of glut 1 and glut 4 in the liver and improved glucose tolerance in normal and obese mice. Finally, the consumption of blood orange juice was observed to increase insulin sensitivity in mice. These findings indicate that C3G and PCA are natural AMPK activators and dietary consumption of food sources of C3G and PCA improves glucose homeostasis. Mainly, blood orange juice has beneficial effect for type 2 diabetes.

Helicobacter sp. MIT 01-6451 has been detected in SPF mice kept in Japan. To characterize strain MIT 01-6451, its infection route during fetal and neonatal life and effects on pregnancy were investigated using immunocompetent and immunodeficient mouse strains (BALB/c, C57BL/6, and SCID). MIT 01-6451 was detected in the uterus, vagina, and mammary glands of 50% of infected SCID mice, whereas these tissues were all negative in immunocompetent mice. No fetal infections with MIT 01-6451 were detected at 16?18 days after pregnancy in any mouse strain. In newborn mice, MIT 01-6451 was detected in intestinal tissue of C57BL/6 and SCID mice at 9?11 days after birth, but not in BALB/c mice. The IgA and IgG titers to MIT 01-6451 in sera of C57BL/6 female mice were significantly lower than those of BALB/c mice. Although no significant differences in the number of newborns per litter were observed between MIT 01-6451-infected and MIT 01-6451-free dams, the birth rate was lower in infected SCID mice than in control SCID mice. The present results indicated that MIT 01-6451 infects newborn mice after birth rather than by vertical transmission to the fetus via the placenta and that MIT 01-6451 infection shows opportunistically negative effects on the birth rate. In addition, the maternal immune response may affect infection of newborn mice with MIT 01-6451 through breast milk., Experimental Animals, 64(4), pp.375-382; 2015

Background & objectives: For detection and molecular characterization of Babesia microti in laboratory mice from India. Methods: A total of 625 mice were screened by peripheral blood smear examination and subsequently was confirmed by PCR using a piroplasm conserved primer set (Piro A/B). Nested PCR was done using a species-specific primer targeting the gene encoding the small subunit ribosomal RNA (18S rRNA). The PCR products were cloned, purified and sequenced. A total of 12 isolates were obtained. The sequences were aligned and phylogenetic trees were prepared with other published Babesia spp. sequences. Results: B. microti was detected with a total infection rate of 8.80%. The higher rate of infection was observed by species specific PCR (8.80%) than examined by blood smear (7.20%). Sequence and phylogenetic analysis showed that Babesia species detected in mice were genetically identical to the genotypes of B. microti and can be easily distinguished from other genotypes of Babesia parasites by neighbour joining and maximum likelihood method. Intra-species analysis indicated that all the twelve isolates from six North-Eastern states of India have a close identity but inter-species showed genetic reservoir host for transmission of babesial infection to humans. Interpretation & conclusion: The detection of Babesia microti may suggest that laboratory mice may serve as potential reservoir host for human infection and possibility of innovative way of diagnosing and control of human babesiosis.

In the European Union (EU) millions of laboratory mice are used and killed for experimental and other scientific purposes each year. Although controversially discussed, the use of carbon dioxide (CO2) is still permitted for killing rodents according to the Directive 2010/63/EU. Within the scope of refinement, our aim was to investigate if isoflurane and sevoflurane are an appropriate alternative killing method to CO2 in mice. Different concentrations of CO2 (filling rates of 20%, 60%, 100%; CO2 20, 60, 100), isoflurane (Iso 2%, 5%) and sevoflurane (Sevo 4.8%, 8%) were compared in two mouse strains (NMRI, C57Bl/6J) using a broad spectrum of behavioral parameters, including the approach-avoidance test, and analyzing blood for stress parameters (glucose, adrenaline, noradrenaline). We focused in our study on the period from the beginning of the gas inlet to loss of consciousness, as during this period animals are able to perceive pain and distress. Our results show that only higher concentrations of CO2 (CO2 60, 100) and isoflurane (5%) induced surgical tolerance within 300 s in both strains, with CO2 100 being the fastest acting inhalant anesthetic. The potency of halogenated ethers depended on the mouse strain, with C57Bl/6J being more susceptible than NMRI mice. Behavioral analysis revealed no specific signs of distress, e. g. stress-induced grooming, and pain, i. e. audible vocalizations, for all inhalant gases. However, adrenaline and noradrenaline plasma concentrations were increased, especially in NMRI mice exposed to CO2 in high concentrations, whereas we did not observe such increase in animals exposed to isoflurane or sevoflurane. Escape latencies in the approach-avoidance test using C57Bl/6J mice did not differ between the three inhalant gases, however, some animals became recumbent during isoflurane and sevoflurane but not during CO2 exposure. The rise in catecholamine concentrations suggests that CO2 exposure might be linked to a higher stress response compared to isoflurane and sevoflurane exposure, although we did not observe a behavioral correlate for that. Follow-up studies investigating other fast-acting stress hormones and central anxiety circuits are needed to confirm our findings.

Wild animals' immune responses contribute to their evolutionary fitness. These responses are moulded by selection to be appropriate to the actual antigenic environment in which the animals live, but without imposing an excessive energetic demand which compromises other component of fitness. But, exactly what these responses are, and how they compare with those of laboratory animals, has been little studied. Here, we review the very small number of published studies of immune responses of wild rodents, finding general agreement that their humoral (antibody) responses are highly elevated when compared with those of laboratory animals, and that wild rodents' cellular immune system reveals extensive antigenic exposure. In contrast, proliferative and cytokine responses of ex vivo-stimulated immune cells of wild rodents are typically depressed compared with those of laboratory animals. Collectively, these responses are appropriate to wild animals' lives, because the elevated responses reflect the cumulative exposure to infection, while the depressed proliferative and cytokine responses are indicative of effective immune homeostasis that minimizes immunopathology. A more comprehensive understanding of the immune ecology of wild animals requires (i) understanding the antigenic load to which wild animals are exposed, and identification of any key antigens that mould the immune repertoire, (ii) identifying immunoregulatory processes of wild animals and the events that induce them, and (iii) understanding the actual resource state of wild animals, and the immunological consequences that flow from this. Together, by extending studies of wild rodents, particularly addressing these questions (while drawing on our immunological understanding of laboratory animals), we will be better able to understand how rodents' immune responses contribute to their fitness in the wild.

There is a strong need to gain systematic knowledge about the potential impact of routine procedures on laboratory animals to ensure animal welfare and reliability of experimental results. Blood sampling is a frequently used procedure within laboratory animal research. Two of the most common anesthesia-free techniques to obtain blood in mice are the saphenous venipuncture and submandibular bleeding. It is common practice that these methods are applied repeatedly to 1 individual. The impact of both techniques, either performed singly or repeatedly, on the animal’s welfare is not fully known yet. We directly compared the effects of both sampling methods on physiological stress responses, behavior, tissue damage, and procedure duration in 2 frequently used mouse strains: C57BL/6 and BALB/c mice (n = 45/strain). The mice were randomly assigned to 3 treatment groups (saphenous venipuncture, submandibular bleeding, control) of 15 mice/strain and were sampled weekly (80 μl/ blood sample) during 4 wk for the experimental groups and 5 wk for the control group. To evaluate the acute physiological stress response, plasma corticosterone levels were determined. As an indicator of chronic stress, body weights were recorded once a week and the thymus was weighed after necropsy. Behavior was recorded using video cameras in front of the cages and afterwards analyzed by a well-trained observer using event logging software. Tissue damage was evaluated by scoring pre-and postmortem hemorrhages and hematomas at the injection site and by measuring alanine transaminase, aspartate aminotransferase, and creatine kinase plasma levels. Submandibular bleeding appeared to be less time consuming (P

The poor predictive quality of currently used animal models in preclinical research is an important cause of the high attrition of promising drug candidates for human autoimmune disease in clinical trials. Examples from own work in a primate multiple sclerosis (MS) model illustrate that important lessons can be learned from a critical reassessment of failed drugs in the animal model, which can help improve the animal model and better understand the targeted disease.

Whether mice are an appropriate model for S. aureus infection and vaccination studies is a matter of debate, because they are not considered as natural hosts of S. aureus. We previously identified a mouse-adapted S. aureus strain, which caused infections in laboratory mice. This raised the question whether laboratory mice are commonly colonized with S. aureus and whether this might impact on infection experiments. Publicly available health reports from commercial vendors revealed that S. aureus colonization is rather frequent, with rates as high as 21% among specific-pathogen-free mice. In animal facilities, S. aureus was readily transmitted from parents to offspring, which became persistently colonized. Among 99 murine S. aureus isolates from Charles River Laboratories half belonged to the lineage CC88 (54.5%), followed by CC15, CC5, CC188, and CC8. A comparison of human and murine S. aureus isolates revealed features of host adaptation. In detail, murine strains lacked hlb-converting phages and superantigen-encoding mobile genetic elements, and were frequently ampicillin-sensitive. Moreover, murine CC88 isolates coagulated mouse plasma faster than human CC88 isolates. Importantly, S. aureus colonization clearly primed the murine immune system, inducing a systemic IgG response specific for numerous S. aureus proteins, including several vaccine candidates. Phospholipase C emerged as a promising test antigen for monitoring S. aureus colonization in laboratory mice. In conclusion, laboratory mice are natural hosts of S. aureus and therefore, could provide better infection models than previously assumed. Pre-exposure to the bacteria is a possible confounder in S. aureus infection and vaccination studies and should be monitored.

To determine the prevalence of drug resistant bacteria colonizing laboratory mice, we isolated and characterized vancomycin-resistant Enterococcus species (VRE) from commercially available mice. A total of 24 VRE isolates were obtained from 19 of 21 mouse strains supplied by 4 commercial breeding companies. Of these, 19 isolates of E. gallinarum and 5 isolates of E. casseliflavus possessing the vanC1 and vanC2/3 genes intrinsically, exhibited intermediate resistance to vancomycin respectively. In addition, these isolates also exhibited diverse resistant patterns to erythromycin, tetracycline, and ciprofloxacin, whereas the use of antibiotics had not been undertaken in mouse strains tested in this study. Although 6 virulence-associated genes (ace, asa, cylA, efaA, esp, and gelE) and secretion of gelatinase and hemolysin were not detected in all isolates, 23 of 24 isolates including the isolates of E. casselifalvus secreted ATP into culture supernatants. Since secretion of ATP by bacteria resident in the intestinal tract modulates the local immune responses, the prevalence of ATP-secreting VRE in mice therefore needs to be considered in animal experiments that alter the gut microflora by use of antibiotics., Experimental Animals, 63(3), pp.297-304; 2014

To determine the prevalence of drug resistant bacteria colonizing laboratory mice, we isolated and characterized vancomycin-resistant Enterococcus species (VRE) from commercially available mice. A total of 24 VRE isolates were obtained from 19 of 21 mouse strains supplied by 4 commercial breeding companies. Of these, 19 isolates of E. gallinarum and 5 isolates of E. casseliflavus possessing the vanC1 and vanC2/3 genes intrinsically, exhibited intermediate resistance to vancomycin respectively. In addition, these isolates also exhibited diverse resistant patterns to erythromycin, tetracycline, and ciprofloxacin, whereas the use of antibiotics had not been undertaken in mouse strains tested in this study. Although 6 virulence-associated genes (ace, asa, cylA, efaA, esp, and gelE) and secretion of gelatinase and hemolysin were not detected in all isolates, 23 of 24 isolates including the isolates of E. casselifalvus secreted ATP into culture supernatants. Since secretion of ATP by bacteria resident in the intestinal tract modulates the local immune responses, the prevalence of ATP-secreting VRE in mice therefore needs to be considered in animal experiments that alter the gut microflora by use of antibiotics.

Prevalence of Helicobacter is mostly unknown in laboratory animals in Thailand. The 221 mice feces/cecum from 8 universities, 2 pharmaceutical companies and 3 research institutions in Thailand were surveyed for the prevalence and distribution of Helicobacter species by using the Electrochemical DNA chip. Helicobacter were detected 23/46 samples in Specific Pathogen Free (SPF) and 168/175 in conventional condition. Prevalence of Helicobacter were 98%, 96%, 92% and 78% in South (n=40), Northeast (n=40), North (n=25) and Central area (n=116), respectively. Only Central area holds SPF facility resulting in Helicobacter prevalence that seems to be lower than other areas. Three species of Helicobacter were detected in feces/cecum samples by sequence analysis: H. rodentium (67.0%, 148 samples), Helicobacter sp. MIT 01-6451 (15.4%, 34 samples), and unidentified Helicobacter species (14.1%, 9 samples). The results suggested that H. rodentium is the most common species of Helicobacter in laboratory mice in Thailand.

According to the heat dissipation limit theory, maximum metabolic turnover is limited by the capacity of the body to dissipate excess heat. Small mammals, including common voles (Microtus arvalis), face a heat dissipation limitation during lactation. Pup growth and milk production are reduced under higher ambient temperatures. Heat dissipation problems might in part be alleviated by modifying behavior, such as reducing nest attendance and being active at energetically optimal times of day. According to the circadian thermo-energetics hypothesis, animals can make use of daily ambient temperature fluctuations to alter their energetic expenditure. In this study we test whether heat challenged (housing at 30 degrees C compared to 21 degrees C) lactating common voles allocate their time differently among behaviors and whether their ultradian and circadian behavioral rhythmicity are altered. Behavior was scored every 13 min from automated picture recordings, while general locomotor activity was measured by passive infrared detectors to assess ultradian and circadian organization. The effects of ambient temperature on the ultradian organization of behavior were assessed by determining the ultradian period length and the distribution of activity within the ultradian bout. Changes in circadian organization were assessed by the distribution of activity over the light and dark phase. As a complementary measure nest temperature recordings were used to quantify nest attendance distribution between day and night.Lactating dams at 30 degrees C reduced the fraction of time spent on the nest while increasing the fraction of time resting without pups away from the nest. The ultradian period of locomotor activity was longer in voles housed at 30 degrees C during pregnancy and lactation, but not after weaning when the pups were removed. No differences in the distribution of activity within the ultradian bout could be detected. The circadian organization was also modulated by ambient temperature. lactating voles housed at 30 degrees C became more day active and a loss of day-night differences in nest temperature suggests a shift of nest attendance towards the night.Reducing the time attending the nest can reduce the risk of hyperthermia, and may be the behavioral component resulting in lower milk production and hence reproductive output. Becoming more day active allows feeding and nursing of the pups during the rest phase to occur during the night at which lower ambient temperatures are expected in the field. In natural situations this strategy will increase heat dissipation and lactation capacity. Whether there are similar benefits associated with a longer ultradian period is currently unknown, but these are likely to result from decreased energy turnover at 30 degrees C. In conclusion, our study shows that lactating common voles facing heat dissipation problems re-organize their behavior in a way that can maximize heat dissipation capabilities and thereby optimize lactation capacity. (C) 2014 Elsevier Inc. All rights reserved.

Isolates of 24 enterococci, 5 Enterococcus casseliflavus and 19 Enterococcus gallinarum, possessing vanC genes and showing low-level resistance to vancomycin were obtained from mice from commercial mouse breeding companies. Since some of these isolates showed resistance to other antibiotics, the purpose of this study was to clarify the resistant profiles of these isolates. One E. casseliflavus isolate showed resistance to erythromycin with a minimal inhibitory concentration (MIC) of 8 μg/mL and also showed apparent resistance to fluoroquinolones with an MIC of 32 μg/mL for ciprofloxacin. The MICs of 2 other fluoroquinolone-resistant E. casseliflavus and E. gallinarum isolates were 3 and 6 μg/mL, respectively. These 3 resistant isolates showed an absence of macrolide- and fluoroquinolone-resistant genes, including amino acid substitutions in the quinolone resistance determining regions of DNA gyrase and topoisomerase IV. Resistance to tetracycline was detected in 2 E.gallinarum isolates that were highly resistant, exhibiting MICs of 48 and 64 μg/mL and possessing tet(O) genes.The results indicate that antibiotic-resistant enterococci are being maintained in some laboratory mouse strains that have never been treated with an antibiotic., Journal of veterinary science, 20(2), e13; 2019

Natural products are used to prevent and treat large series of affections because of their curative and immunity stimulating proprieties. The study herein focused on the effects of natural product „Imunitate cu 7 ciuperci” produced by Fares Romania, on the immunity of laboratory mice. After a chronic administration of this product for three months, the weight of all animals was determined: for the blood collected from the control group and the experimental group, the total number of leucocytes/mm³ was determined, and, on blood smears, so was the leukocyte formula. After sampling and staining, the blood smears ware examined with the optical microscope; on the blood smears was determined the number of figurative elements of blood: lymphocytes, neutrophiles, eosinophiles, monocytes and basophiles. Weight control data showed that the product does not induce weight gain. Data processing does not evidence significant differences in the total number of leucocytes/mm³ between the two mice groups; as about the leukocyte types, significant differences were found only in the case of eosinophyles. These results do not plead for an immunity stimulating effect on the laboratory mice, which means that more tests are necessary.

Feeding a diet high in fat and sucrose (HFS) during pregnancy and lactation is known to increase susceptibility to develop metabolic derangements later in life. A trait for increased behavioral activity may oppose these effects, since this would drain energy from milk produced to be made available to the offspring. To investigate these interactions, we assessed several components of behavioral energetics during lactation in control mice (C) and in mice of two lines selectively bred for high wheel-running activity (S1, S2) subjected to a HFS diet or a low-fat (LF) diet. Energy intake, litter growth, and milk energy output at peak lactation (MEO; assessed by subtracting maternal metabolic rate from energy intake) were elevated in HFS-feeding dams across all lines compared with the LF condition, an effect that was particularly evident in the S dams. This effect was not preceded by improved lactation behaviors assessed between postnatal days 1 and 7 (PND 1–7). In fact, S1 dams had less high-quality nursing, and S2 dams showed poorer pup retrieval than C dams during PND 1–7, and S dams had generally higher levels of physical activity at peak lactation. These data demonstrate that HFS feeding increases MEO underlying increased litter and pup growth, particularly in mice with a trait for increased behavioral physical activity.

Introduction: There is not much data on parasitic infections of laboratory animals that are kept in conventional conditions in Iran. The present study was designed to investigate intestinal helminths infections in laboratory colonies of rats and mice. Methods: Droppings from 110 mice and 110 rats (each animal one dropping) belonging to experimental and breeding groups in four animal houses were collected. Experimental groups were being used in biomedical researches and breeding groups were not under any experiment. The droppings were preserved in formaldehyde 10% individually and examined by microscopy with 10x magnification. Results: Out of 220 droppings examined, 96 (43.6%) harbored helminths eggs; 53 (48.1%) belonged to mice and 43 (39.09%) to rats. Four helminthes species including, Syphacia obvelata, Syphasia muris, Hymenolepis nana, and Hetrakis spumosa were identified in the both animals, while Aspicularis tetraptera was merely seen in mice. H. nana was the most frequent helminth infection in mice and rats and infection with H. spumosa and A. tetraptera, showed the lowest rates in droppings of mice and rats, respectively. Mixed infections with ≥ two species was observed in 21 (9.5%) of 220 droppings, 14 (12.7%) belonged to mice and 7 (6.3%) to rats. Conclusion: The present results emphasizes more careful monitoring in laboratory animal houses, such as improving the cleaning and ventilating systems as well as adopting therapeutic measures, when required.