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Aim: The aim of this study was to evaluate the effects of Bdellovibrio bacteriovorus HD100 on experimental periodontitis (EP) in rats., Methods: Thirty-two rats were divided into four groups: control, C-HD100 (B. bacteriovorus), EP, and EP-HD100. On day 0, EP was induced by the placement of cotton ligatures around the mandibular first molars (MFMs) in the EP and EP-HD100 groups. In the C-HD100 and EP-HD100 groups, suspensions containing 1 × 10 9  PUF/ml of B. bacteriovorus HD100 were topically administered to the subgingival region of MFMs on days 0, 3, and 7. Animals were euthanized on day 14. Morphometrics analyses were performed in hemimandibles. The levels of tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, monocyte chemoattractant protein (MCP)-1, IL-10, IL-1β, transforming growth factor beta (TGF-β), macrophage colony-stimulating factor (M-CSF) and regulated on activation and normal T cell expressed and secreted (RANTES) were determined by enzymatic immunoassays in gingival tissues. Beta defensin (BD)-1, BD-2, and BD-3, Toll-like receptors (TLR)-2 and TLR-4, and a cluster of differentiation (CD)-4, CD-8 and CD-57 were analyzed by immunohistochemistry in hemimandibles. Data were statistically analyzed., Results: The EP group showed greater alveolar bone loss than EP-HD100 (p < .05). The EP-HD100 group showed higher levels of MCP-1, RANTES, IL-10, and TGF-β, lower levels of TNF-α than the EP group (p < .05). No differences were observed in IL-1β, IL-6, and M-CSF levels between EP and EP-HD100 groups. The C-HD100 group had higher IL-6, TNF-α, RANTES, and MCP-1 levels than the control group (p < .05). Regarding BD, the EP-HD100 group showed a larger immunolabeling pattern for BD-1, BD-2, and BD-3 than the EP group (p < .05). No significant differences in the immunolabeling pattern were observed for TLR-2, TLR-4, CD-4, CD-8, and CD-57 between EP and EP-HD100 groups., Conclusion: The topical use of B. bacteriovorus HD100 reduces alveolar bone loss, increases expression of BD, and modulates the cytokines levels on periodontal tissues in rats with EP., (© 2022 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with a hyperinflammatory state and lymphocytopenia, a hallmark that appears as both signature and prognosis of disease severity outcome. Although cytokine storm and a sustained inflammatory state are commonly associated with immune cell depletion, it is still unclear whether direct SARS-CoV-2 infection of immune cells could also play a role in this scenario by harboring viral replication. We found that monocytes, as well as both B and T lymphocytes, were susceptible to SARS-CoV-2 infection in vitro, accumulating double-stranded RNA consistent with viral RNA replication and ultimately leading to expressive T cell apoptosis. In addition, flow cytometry and immunofluorescence analysis revealed that SARS-CoV-2 was frequently detected in monocytes and B lymphocytes from coronavirus disease 2019 (COVID-19) patients. The rates of SARS-CoV-2-infected monocytes in peripheral blood mononuclear cells from COVID-19 patients increased over time from symptom onset, with SARS-CoV-2-positive monocytes, B cells, and CD4+ T lymphocytes also detected in postmortem lung tissue. These results indicated that SARS-CoV-2 infection of blood-circulating leukocytes in COVID-19 patients might have important implications for disease pathogenesis and progression, immune dysfunction, and virus spread within the host., (© The Author(s) (2022). Published by Oxford University Press on behalf of Journal of Molecular Cell Biology, CEMCS, CAS.)

Membrane lipids are generally viewed as inert physical barriers, but many vital cellular processes greatly rely on the interaction with these structures, as expressed by the membrane hypothesis that explain the genesis of schizophrenia, Alzheimer's and autoimmune diseases, chronic fatigue or cancer. The concept that the cell membrane displays transient membrane microdomains with distinct lipid composition providing the basis for the development of selective lipid-targeted therapies, the membrane-lipid therapies (MLTs). In this concern, medicinal chemists may design therapeutically valuable compounds 1) with a higher affinity for the lipids in these microdomains to restore the normal physiological conditions, 2) that can directly or 3) indirectly (via enzyme inhibition/activation) replace damaged lipids or restore the regular lipid levels in the whole membrane or microdomain, 4) that alter the expression of genes related to lipid genesis/metabolism or 5) that modulate the pathways related to the membrane binding affinity of lipid-anchored proteins. In this context, this mini-review aims to explore the structural diversity and clinical applications of some of the main membrane and microdomain-targeted lipid drugs., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Oropouche virus (OROV) is an emerging arbovirus in South and Central Americas with high spreading potential. OROV infection has been associated with neurological complications and OROV genomic RNA has been detected in cerebrospinal fluid from patients, suggesting its neuroinvasive potential. Motivated by these findings, neurotropism and neuropathogenesis of OROV have been investigated in vivo in murine models, which do not fully recapitulate the complexity of the human brain. Here we have used slice cultures from adult human brains to investigate whether OROV is capable of infecting mature human neural cells in a context of preserved neural connections and brain cytoarchitecture. Our results demonstrate that human neural cells can be infected ex vivo by OROV and support the production of infectious viral particles. Moreover, OROV infection led to the release of the pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-α) and diminished cell viability 48 h post-infection, indicating that OROV triggers an inflammatory response and tissue damage. Although OROV-positive neurons were observed, microglia were the most abundant central nervous system (CNS) cell type infected by OROV, suggesting that they play an important role in the response to CNS infection by OROV in the adult human brain. Importantly, we found no OROV-infected astrocytes. To the best of our knowledge, this is the first direct demonstration of OROV infection in human brain cells. Combined with previous data from murine models and case reports of OROV genome detection in cerebrospinal fluid from patients, our data shed light on OROV neuropathogenesis and help raising awareness about acute and possibly chronic consequences of OROV infection in the human brain., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Almeida, Souza, Mendes, Pontelli, Pinheiro, Nogueira, Cardoso, Paiva, Ferrari, Veras, Cunha, Horta-Junior, Alberici, Cunha, Podolsky-Gondim, Neder, Arruda and Sebollela.)

Cholesteatomas are frequent middle ear benign tumors of unknown etiology. Infectious agents have been considered as possible contributing factors in the pathogenesis of cholesteatomas. Aiming to investigate the presence of respiratory viruses in primary cholesteatoma tissues, 26 formalin-fixed paraffin-embedded primary cholesteatoma tissues obtained from patients seen at the of the Clinical Hospital of the University of São Paulo School of Medicine, in Ribeirão Preto, Brazil were tested by real-time polymerase chain reaction (PCR). Considering the PCR results, 35% of the tissues were positive for human rhinovirus (HRV), 15.3% for human enterovirus (EV), 3.8% for human metapneumovirus (HMPV), and 3.8% for human bocavirus (HBoV). Serial immunohistochemistry for virus antigens and cell surface markers evidenced that the viruses were associated with fibroblasts, dendritic cells, macrophages, B lymphocytes, CD4 + , and CD8 + T lymphocytes. These findings indicate for the first time the presence of active respiratory virus infection in primary cholesteatoma tissues, suggesting that persisting virus infection in the middle could play a role in the pathogenesis and evolution of cholesteatomas., (© 2021 Wiley Periodicals LLC.)

Intense human use and high construction density in coastal areas are stressors to sandy beaches. Pollution by marine debris is a major problem on beaches worldwide. This study pioneered an assessment of marine debris characterization over time on beaches with different levels of access. In two periods and seasons, marine debris was sampled on nine sandy beaches of Rio de Janeiro, grouped by levels of access. The general marine debris density has decreased over time, accompanied by an improvement in public cleaning mechanisms. The most important predictor for the majority of marine debris items is related to accessibility; beaches with restricted access showed a reduction in the abundance of most items. High marine debris densities, even on beaches with restricted access, showed that all evaluated beaches can be sinks for marine debris circulating in marine waters. Beach cleaning strategy improvements will be inefficient unless integrated marine debris management is implemented., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Human respiratory syncytial virus (HRSV) envelope glycoproteins traffic to assembly sites through the secretory pathway, while nonglycosylated proteins M and N are present in HRSV inclusion bodies but must reach the plasma membrane, where HRSV assembly happens. Little is known about how nonglycosylated HRSV proteins reach assembly sites. Here, we show that HRSV M and N proteins partially colocalize with the Golgi marker giantin, and the glycosylated F and nonglycosylated N proteins are closely located in the trans-Golgi, suggesting their interaction in that compartment. Brefeldin A compromised the trafficking of HRSV F and N proteins and inclusion body sizes, indicating that the Golgi is important for both glycosylated and nonglycosylated HRSV protein traffic. HRSV N and M proteins colocalized and interacted with sorting nexin 2 (SNX2), a retromer component that shapes endosomes in tubular structures. Glycosylated F and nonglycosylated N HRSV proteins are detected in SNX2-laden aggregates with intracellular filaments projecting from their outer surfaces, and VPS26, another retromer component, was also found in inclusion bodies and filament-shaped structures. Similar to SNX2, TGN46 also colocalized with HRSV M and N proteins in filamentous structures at the plasma membrane. Cell fractionation showed enrichment of SNX2 in fractions containing HRSV M and N proteins. Silencing of SNX1 and 2 was associated with reduction in viral proteins, HRSV inclusion body size, syncytium formation, and progeny production. The results indicate that HRSV structural proteins M and N are in the secretory pathway, and SNX2 plays an important role in the traffic of HRSV structural proteins toward assembly sites. IMPORTANCE The present study contributes new knowledge to understand HRSV assembly by providing evidence that nonglycosylated structural proteins M and N interact with elements of the secretory pathway, shedding light on their intracellular traffic. To the best of our knowledge, the present contribution is important given the scarcity of studies about the traffic of HRSV nonglycosylated proteins, especially by pointing to the involvement of SNX2, a retromer component, in the HRSV assembly process., (Copyright © 2020 Cardoso et al.)

Background: Short-term (ST) and long-term tunneled (LTT) central venous catheters for hemodialysis (CVCH) are critical for hemodialysis therapy. However, few studies have been conducted in Brazil to investigate the incidence of complications with these two types of catheters., Objectives: To analyze complications and duration of CVCH in a hemodialysis center at a teaching hospital., Methods: Single-center, longitudinal, and retrospective study of 115 consecutive patients undergoing hemodialysis catheter placement (67 ST and 48 LTT) over a 2-year period, analyzing overall survival, patency, loss of access, and incidence of complications., Results: Sixty percent of the patients were male and mean age was 62 years. The most common puncture site was the right internal jugular vein. Systemic arterial hypertension was present in 95% of cases. Median catheter in-place duration was 50 days (ST) vs. 112 days (LTT; p < 0.0001). There was no difference in overall survival. Incidence of catheter-related infection was higher in ST CVCH, with Staphylococcus sp. the microorganism most often found. The infection rate per 1000 days was higher in ST than in LTT catheters (16.7 events/1000 days vs. 7.0 events/1000 days). Low income was the only factor related to higher incidence of infection., Conclusions: The in-place duration of long-term catheters was significantly longer compared to short-term CVCH, but still below the values reported in the literature and without impact on overall survival. Low income was a factor associated with catheter infection., Competing Interests: Conflicts of interest: No conflicts of interest declared concerning the publication of this article.

Background: The use of unfractionated heparin in hypovolemic shock, aortic clamping, and visceral reperfusion is still not established, despite evidence of inhibition of early cell damage. This study investigated the potential protective effect of unfractionated heparin on hepatic and renal apoptosis in a porcine ischemia and reperfusion model., Methods: Twenty-one male swine (Sus scrofa) were divided into 3 groups: sham (n = 5), heparin (n = 8), and nonheparin (n = 8). The heparin and nonheparin groups underwent hypovolemic shock for 30 min, supraceliac aortic clamping for 1 h and reperfusion for 3 h. Unfractionated heparin 200 mg/kg was administered to the heparin group during aortic clamping. Hemodynamic and laboratory parameters were monitored, including aminotransferase and serum urea. Histological lesion scores were applied to hematoxylin and eosin-stained liver and kidney sections. Apoptosis quantification was performed by caspase-3 immunohistochemistry., Results: The proposed model caused a severe cardiocirculatory disturbance in the heparin and nonheparin groups, observed by the carotid-femoral pressure gradient and lactic acidosis. There was no significant difference in hemodynamic and laboratory parameters between these two groups. The mean values of liver and renal histological lesion scores did not present any significant differences. Caspase-3 immunoexpression was lower in the heparin than the nonheparin group for both liver and kidney., Conclusions: Attenuation of liver and kidney cell apoptosis in pigs undergoing systemic heparinization suggests a potential use for heparin in modulating cell death under critical hemodynamic conditions., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objectives: This study evaluated the influence of thermo-mechanical cycling (TMC) on the bond strength (BS) of a universal adhesive system (UAS - Adper Single Bond Universal, 3M ESPE) to dentin treated or not with 0.2% chlorhexidine (CHX)., Methods: Eighty human molars were flattened until reach the dentin and separated into 4 groups according to the bonding protocol: ENR Group: 37% phosphoric acid + 3-step etch-and-rinse adhesive system (ENR); UAS Group: UAS in self-etch mode; ENR + CHX Group: 37% phosphoric acid + CHX + ENR; UAS + CHX Group: CHX + UAS in self-etch mode. After treatments, teeth were restored (Filtek Z350, 3M ESPE). Samples (n = 10) were submitted to aging process: stored in distilled water at 37°C/30 days or TMC (ERIOS - 98N/1.6Hz + thermal cycling 5/37/55 °C - 1,200,000 cycles). Specimens were sectioned into sticks (1.0 mm 2 ) and submitted to the microtensile test (Mechanical Test Machine - 0.5 mm/min). Fracture patterns and hybrid layer integrity were analyzed under Stereomicroscope and Scanning Electron Microscopy (SEM)., Results: The BS results (3-way ANOVA, Bonferroni's test, α = 5%) showed that groups treated with CHX presented higher BS values than control groups; significant in all cases (p < .05), except for ENR submitted to TMC (p > .05). When CHX was applied and samples were cycled, UAS revealed higher BS (p < .05) than ENR. After TMC, cohesive fractures increased for UAS, regardless of CHX application. SEM analysis demonstrated different hybridization patterns for the adhesive systems tested., Conclusion: The performance of the universal adhesive system used in self-etch mode was better than that of the 3-step etch-and-rinse adhesive system., Clinical Significance: Universal adhesive systems have been developed in order to simplify the dentin hybridization protocol. It is important to determine the longevity of the adhesive interface using these bonding materials after chewing., (© 2020 Published by Elsevier Ltd.)

Influenza A viruses (IAVs) cause more than 2 million annual episodes of seasonal acute respiratory infections (ARI) and approximately 500,000 deaths worldwide. Depending on virus strain and host immune status, acute infections by IAV may reach sites other than the respiratory tract. In the present study, IAV RNA and antigens were searched for in tissues of palatine tonsils and adenoids removed from patients without ARI symptoms. A real-time reverse transcriptase PCR (RT-PCR) screening revealed that 8 tissue samples from 7 patients out of 103 were positive for IAV. Positive samples were subjected to next-generation sequencing (NGS) and 3 of 8 tissues yielded complete IAV pH1N1 genomes, whereas in 5 samples, the PB1 gene was not fully assembled. Phylogenetic analysis placed tonsil-derived IAV in clusters clearly segregated from contemporaneous Brazilian viruses. Flow cytometry of dispersed tissue fragments and serial immunohistochemistry of paraffin-embedded sections of naturally infected biopsies indicated that CD20 + B lymphocytes, CD8 + T lymphocytes, and CD11c + cells are susceptible to IAV infection. We sought to investigate whether these lymphoid tissues could be sites of viral replication and sources of viable virus particles. MDCK cells were inoculated with tissue lysates, enabling recovery of one IAV isolate confirmed by immunofluorescence, reverse transcriptase quantitative PCR (RT-qPCR), and NGS. The data indicate that lymphoid tissues not only harbor expression of IAV proteins but also contain infectious virus. Asymptomatic long-term infection raises the possibility of IAV shedding from tonsils, which may have an impact on host-to-host transmission. IMPORTANCE Influenza A virus (IAV) infections are important threats to human health worldwide. Although extensively studied, some aspects of virus pathogenesis and tissue tropism remain unclear. Here, by different strategies, we describe the asymptomatic infection of human lymphoid organs by IAV in children. Our results indicate that IAV was not only detected and isolated from human tonsils but displayed unique genetic features in comparison with those of contemporaneous IAVs circulating in Brazil and detected in swabs and nasal washes. Inside the tissue microenvironment, immune cells were shown to be carrying IAV antigens, especially B and T CD8 + lymphocytes. Taken together, these results suggest that human lymphoid tissues can be sites of silent IAV infections with possible impact on virus shedding to the population., (Copyright © 2020 American Society for Microbiology.)

The purpose of this study was to evaluate the effects of systemic administration of the probiotic Bifidobacterium animalis subsp. lactis HN019 (HN019) on ligature-induced periodontitis in rats with experimental rheumatoid arthritis (RA). 28 rats were divided into four groups (n=7): RA (rheumatoid arthritis), RA/PROB (probiotic), RA/EP (experimental periodontitis) and RA/EP/PROB. From day zero, HN019 was added daily to the water of the PROB groups animals until the end of the experiment. From day seven, RA was induced. On day 28, in EP groups, ligatures were positioned around mandibular first molars and remained in position for 11 days, in order to induce periodontitis. The animals were euthanised on day 39. Microtomographic, histomorphometric, immunoenzymatic and microbiological analyses were performed. Data were statistically analysed ( P <0.05). Group RA/EP/PROB presented reduced alveolar bone loss, tumour necrosis factor-α and interleukin (IL)-6 levels and increased IL-17 levels when compared with group RA/EP. There were no significant differences regarding connective tissue attachment level and IL-10 levels between groups RA/EP and RA/EP/PROB. Group RA/PROB showed decreased anti-citrullinated protein antibodies levels when compared with groups RA and RA/EP. Group RA/EP/PROB presented a higher rate of aerobic/anaerobic bacteria than group RA/EP. Systemic administration of HN019 promoted a protective effect against periodontal tissue destruction, decreasing both bone loss and inflammatory mediators and increasing the proportion of bacteria compatible with periodontal health, in rats with experimental RA and EP.

Background: This study evaluated the effects of topical administration of Bdellovibrio bacteriovorus HD100 on experimental periodontitis (EP) in rats., Methods: Thirty-two rats were divided into groups C (control), EP, C-HD100, and EP-HD100. At day 0, animals of groups EP and EP-HD100 received cotton ligatures around mandibular first molars (MFM). In groups C-HD100 and EP-HD100, 1 mL of suspensions containing B. bacteriovorus HD100 was topically administered in the subgingival region of MFMs at days 0, 3, and 7. Animals were euthanized at day 14. Gingival tissue, hemimandibles, and oral biofilm were collected. Data were statistically analyzed., Results: Group EP-HD100 presented greater bone volume and lower connective tissue attachment loss (CTAL) than group EP (P < 0.05). Group EP-HD100 presented greater proportions of Actinomyces and Streptococcus-like species and lower proportions of Prevotella intermedia, Peptostreptococcus micros, Fusobacterium nucleatum, Fusobacterium polymorphum, Eikenella corrodens, Eubacterium nodatum, Campylobacter gracilis, Capnocytophaga sputigena, and Veillonella parvula-like species than group EP. Group EP-HD100 presented greater levels of osteoprotegerin and gene expression of interleukin (IL)-17, IL-10, and forkhead box P3 than group EP (P < 0.05)., Conclusion: Topical use of B. bacteriovorus HD100 promotes a protective effect against alveolar bone loss and CTAL in rats with EP., (© 2019 American Academy of Periodontology.)

Introduction: Perforator veins (PVs) play an important role in the development of chronic venous insufficiency and ulceration. Procedures to eliminate incompetence and reflux in PV may include open surgery, subfascial endoscopic surgery, intravenous ablation techniques and sclerotherapy. With the aim of filling the evidence gap, this is a protocol for a systematic review that will assess the effects of any form of intervention for the treatment of pathologic PVs of the lower limbs in patients with chronic venous disease., Methods and Analysis: Systematic searches will be carried out in MEDLINE, EMBASE, Cochrane CENTRAL, IBECS and LILACS databases at a minimum without date or language restrictions for relevant randomised controlled trials (RCTs) and quasi-RCTs (trials in which the method of allocation is not truly random). In addition, a search will also be carried out in the WHO International Clinical Trials Registry Platform, in the clinical trial registries of ClinicalTrials.gov and in the grey literature source OpenGrey.eu. The RCT and quasi-RCT comparison techniques isolated or in combination for treating PVs will be considered. Three review authors will independently perform data extraction and quality assessments of data from included studies, and any disagreements will be resolved by discussion. The primary outcomes will be wound healing and pain. Secondary outcomes will include oedema, adverse events, recurrence or recanalisation, quality of life and economic aspects. The Cochrane handbook will be used for guidance. If the results are not appropriate for a meta-analysis in RevManV.5 software (eg, if the data have considerable heterogeneity and are drawn from different comparisons), a descriptive analysis will be performed., Ethics and Dissemination: Ethics committee approval is not necessary. We intend to update the public registry used in this review, report any important protocol amendments and publish the results in a widely accessible journal., Prospero Registration Number: CRD42018092974., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective  To evaluate the mechanical properties of sutures commonly used in orthopedic surgeries, characterizing their behavior through tensile tests and determining which one has greater mechanical strength. Method  Tensile tests of different sutures were performed in a mechanical testing machine BME 10 kN, using a 50 kgf maximum capacity loading cell. Seven samples from each suture material were tested. Both ends of the sample material were fixed in the proper metal claw, maintaining an initial length of 5 cm. Tests were performed at a speed of 20 mm/minute and at room temperature, recording data for maximum displacement and maximum force at the rupture point. Results  FiberWire® #2 (Artrhex, Naples, FL, USA) presented the highest mean strength of rupture (240.17 N), followed by HiFi® #2 (Conmed, Utica, NY, USA) (213.39N) and Ethibond® #5 (Ethicon Inc., Somerville, NJ, USA) (207.38 N). Ethibond® #2 (Ethicon Inc., Somerville, NJ, USA) had the lowest mean strength of rupture (97.8 N). Conclusion  Non-absorbable braided polyblend sutures, more recently introduced, are superior to conventional, braided polyester sutures, and FiberWire® #2 is the most resistant suture evaluated in the present study.

The relationship between metal accumulation and feeding behavior of macrofauna species is a key concept to understand the bioavailability of different metals in the marine environment. We examined and compared the concentrations of eight heavy metals (Cr, Zn, Pb, Ni, Cu, Cd, Co and V) in different feeding guilds of macrofauna species, from a data set including 68 sandy beaches along the Rio de Janeiro coast. For this purpose, macrofauna species were classified in five feeding guild categories: carnivorous, herbivorous, detritivorous, suspensivorous and filter feeders. The coast of Rio de Janeiro was divided into seven regions according to environmental characteristics and historical human activities. For each region, generalized linear models were adjusted to test for differences between feeding guild abundances. Redundancy Analysis was performed to explore the relationship among the feeding guilds composition and the environmental variables. We found high variability in abundance and composition among feeding guilds, linked with environmental heterogeneity. In general, carnivorous species showed a higher heavy metal concentrations compared to other trophic guilds evaluated. However, bioaccumulation across the feeding guild was not the rule and patterns varied across regions. Our hypothesis is that variations are probably related to the different magnitudes of metal contamination along the coast as also in to the trophic structure found in each beach. This data highlighted the crucial role of the relationship between variability of environmental drivers and bioaccumulation in macrofauna species in sandy beaches ecosystem., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Infrarenal abdominal aortic aneurysms (AAA) are responsible for high rates of rupture-associated morbidity and mortality and can be treated by open or endovascular surgery., Objectives: To analyze risk factors and survival associated with surgical and endovascular AAA treatment methods., Methods: A retrospective, longitudinal study involving 41 patients who underwent endovascular or open AAA repair, whether elective or emergency, over a 48-month period, with analysis of preoperative comorbidities, 30-day and 1-year survival, in-hospital mortality, length of hospital stay, transfusion of blood products, duration of surgery, and development of acute kidney failure. Inferential statistics and survival analysis considered a 95% CI and p < 0.05 as significant., Results: Twelve of the 41 patients were treated with open surgery and 29 with endovascular techniques. The majority were male (75%), with an average age of 71 (range: 56 - 90 years). There were no differences in demographic or risk factors between the groups. Overall survival rates for open and endovascular repair were different for both 30 days (37 vs. 72%, p = 0.01) and 360 days (37 vs. 67%, p = 0.01). However, survival rates in elective cases were similar at 30 days (71 vs. 76%, p = 0.44) and 360 days (both 71%, p = 0.34). Endovascular repair showed shorter length of hospital stay (3.0 vs. 4.4 days; p = 0.02) and duration of surgery (111 vs. 163 min; p < 0.01) compared to open repair., Conclusions: There was no difference in short- or medium-term survival of AAA patients treated electively with endovascular or open surgery. Hospital stays and duration of surgery were both shorter with minimally invasive treatment., Competing Interests: Conflicts of interest: No conflicts of interest declared concerning the publication of this article.

Bats (Order: Chiroptera) harbor a high diversity of emerging pathogens presumably because their ability to fly and social behavior favor the maintenance, evolution, and dissemination of these pathogens. Until 2012, there was only one report of the presence of Hantavirus in bats. Historically, it was thought that these viruses were harbored primarily by rodent and insectivore small mammals. Recently, new species of hantaviruses have been identified in bats from Africa and Asia continents expanding the potential reservoirs and range of these viruses. To assess the potential of Neotropical bats as hosts for hantaviruses and its transmission dynamics in nature, we tested 53 bats for active hantaviral infection from specimens collected in Southeastern Brazil. Part of the hantaviral S segment was amplified from the frugivorous Carollia perspicillata and the common vampire bat Desmodus rotundus. DNA sequencing showed high similarity with the genome of Araraquara orthohantavirus (ARQV), which belongs to one of the more lethal hantavirus clades (Andes orthohantavirus). ARQV-like infection was detected in the blood, urine, and organs of D. rotundus. Therefore, we describe a systemic infection in Neotropical bats by a human pathogenic Hantavirus. We also propose here a schematic transmission dynamics of hantavirus in the study region. Our results give insights to new, under-appreciated questions that need to be addressed in future studies to clarify hantavirus transmission in nature and avoid hantavirus outbreaks.

Background Sclerotherapy has been gaining increased acceptance and popularity as an effective therapy for the treatment of varicose veins. This attention has fed growing interest into the safety and potential complications of this procedure. There is no evidence of pulmonary complications from foam sclerotherapy in humans; however, animal studies have shown possible damage. The aim of this study is to show the changes in rat pulmonary parenchyma after the injection of 1% polidocanol Tessari foam into the peripheral vein using histological analysis of the inflammatory and fibrosis processes. Methods Twenty-four Wistar rats were divided into the following four groups: 24 h polidocanol, seven-day polidocanol, 28-day polidocanol, and control group. After the foam was injected into the lateral saphenous vein, the lungs of the rats were removed for histological analysis. Results Alveolar edema was observed in only the 24 h group (P < 0.005). Vessel thickening was observed in the seven-and 28-day groups (P < 0.001). Interstitial fibrosis was found in only the 28-day group (P = 0.006). There was no evidence of venous or arterial thrombosis in either group. Conclusion Polidocanol Tessari foam injection into rat peripheral veins causes alveolar edema, vessel thickening, and interstitial fibrosis.

Preservation of the knee joint has enormous advantages in terms of mobility and rehabilitation of an amputee. Any cause of breakdown requiring revision to an above-knee amputation is a major setback because it reduces the patient's rehabilitative potential. We report a case of intra-arterial thrombolysis use to save a below-knee amputation stump with acute ischemia. A 56-year-old man who sought the emergency department with 1-day history of acute pain on his right below-knee stump. The angiography confirmed popliteal artery occlusion. Pharmacomechanical thrombectomy, with Aspirex (rotational catheter to restore blood flow in occluded vessel, by removing occlusion material from the vessel) and recombinant tissue plasminogen activator, was performed. After 9 years of follow-up the patient remained asymptomatic, capable of independent ambulation with prosthetic limb. Intra-arterial fibrinolysis seems to be a safe and effective treatment for cases of acutely ischemic amputation stump.

Competing Interests: Conflito de interesse: Os autores declararam não haver conflitos de interesse que precisam ser informados.

We evaluated concentrations of eight heavy metals Cr, Zn, Pb, Ni, Cu, Cd, Co and V, in tissues of representative macrofauna species from 68 sandy beaches from the coast of Rio de Janeiro state. The links between contamination levels and community descriptors such as diversity, evenness, density and biomass, were also investigated. Metal concentrations from macrofaunal tissues were compared to maximum permissible limits for human ingestion stipulated by the Brazilian regulatory agency (ANVISA). Generalized linear models (GLM's) were used to investigate the variability in macrofauna density, richness, eveness and biomass in the seven different regions. A non-metric multidimensional scaling analysis (n-MDS) was used to investigate the spatial pattern of heavy metal concentrations along the seven regions of Rio de Janeiro coast. Variation partitioning was applied to evaluate the variance in the community assemblage explained by the environmental variables and the heavy metal concentrations. Our data suggested high spatial variation in the concentration of heavy metals in macrofauna species from the beaches of Rio de Janeiro. This result highlighted a diffuse source of contamination along the coast. Most of the metals concentrations were under the limits established by ANVISA. The variability in community descriptors was related to morphodynamic variables, but not with metal contamination values, indicating the lack of direct relationships at the community level. Concentration levels of eight heavy metals in macrofauna species from 68 sandy beaches on Rio de Janeiro coast (Brazil) were spatially correlated with anthropogenic activities such as industrialization and urbanization., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Objective: Syncytia formation is the hallmark of the cytopathic effect caused by human respiratory syncytial virus (HRSV), which is the most important viral respiratory pathogen in children. This article reports methodological improvements in primary HRSV isolation and the importance of syncytia formation and mRNA levels of F protein for the progeny yield, using clinical isolates of HRSV., Methods: The A and B strains of HRSV were isolated in HEp-2 cell cultures from fresh and frozen nasopharyngeal aspirates. The formation of syncytia was evaluated using 2 different assays. Levels of F protein mRNA were quantified by real-time PCR while HRSV progeny titration was done by plaque assay., Results: HRSV was primarily isolated from 238 of 312 (90.7%) samples, and 13 of these (12 HRSV-A and 1 HRSV-B) were continuously passaged in vitro. The quantity and size of syncytia formed by 6 pure HRSV-A clinical isolates were different, as were the levels of F protein mRNA., Conclusion: There is a direct correlation of quantities of syncytia and inoculum size, but not with mRNA levels of HRSV-A F protein. Importantly, levels of F protein mRNA were directly related to progeny production., (© 2017 S. Karger AG, Basel.)

Competing Interests: Conflito de interesse: Os autores declararam não haver conflitos de interesse que precisam ser informados.

The Consensus on restless legs syndrome is an effort of neurologists from several Brazilian states, which tirelessly reviewed the literature of recent years in search of evidence, both in regard to diagnosis and treatment, according to the Oxford Centre for Evidence-based Medicine.

The primary trigger to periodic limb movement (PLM) during sleep is still unknown. Its association with the restless legs syndrome (RLS) is established in humans and was reported in spinal cord injury (SCI) patients classified by the American Spinal Injury Association (ASIA) as A. Its pathogenesis has not been completely unraveled, though recent advances might enhance our knowledge about those malfunctions. PLM association with central pattern generator (CPG) is one of the possible pathologic mechanisms involved. This article reviewed the advances in PLM and RLS genetics, the evolution of CPG functioning, and the neurotransmitters involved in CPG, PLM and RLS. We have proposed that SCI might be a trigger to develop PLM.

Background: The continued increase in tuberculosis (TB) rates and the appearance of extremely resistant Mycobacterium tuberculosis strains (XDR-TB) worldwide are some of the great problems of public health. In this context, DNA immunotherapy has been proposed as an effective alternative that could circumvent the limitations of conventional drugs. Nonetheless, the molecular events underlying these therapeutic effects are poorly understood., Methods: We characterized the transcriptional signature of lungs from mice infected with M. tuberculosis and treated with heat shock protein 65 as a genetic vaccine (DNAhsp65) combining microarray and real-time polymerase chain reaction analysis. The gene expression data were correlated with the histopathological analysis of lungs., Results: The differential modulation of a high number of genes allowed us to distinguish DNAhsp65-treated from nontreated animals (saline and vector-injected mice). Functional analysis of this group of genes suggests that DNAhsp65 therapy could not only boost the T helper (Th)1 immune response, but also could inhibit Th2 cytokines and regulate the intensity of inflammation through fine tuning of gene expression of various genes, including those of interleukin-17, lymphotoxin A, tumour necrosis factor-alpha, interleukin-6, transforming growth factor-beta, inducible nitric oxide synthase and Foxp3. In addition, a large number of genes and expressed sequence tags previously unrelated to DNA-therapy were identified. All these findings were well correlated with the histopathological lesions presented in the lungs., Conclusions: The effects of DNA therapy are reflected in gene expression modulation; therefore, the genes identified as differentially expressed could be considered as transcriptional biomarkers of DNAhsp65 immunotherapy against TB. The data have important implications for achieving a better understanding of gene-based therapies., ((c) 2008 John Wiley & Sons, Ltd.)

Background: Mycelium-to-yeast transition in the human host is essential for pathogenicity by the fungus Paracoccidioides brasiliensis and both cell types are therefore critical to the establishment of paracoccidioidomycosis (PCM), a systemic mycosis endemic to Latin America. The infected population is of about 10 million individuals, 2% of whom will eventually develop the disease. Previously, transcriptome analysis of mycelium and yeast cells resulted in the assembly of 6,022 sequence groups. Gene expression analysis, using both in silico EST subtraction and cDNA microarray, revealed genes that were differential to yeast or mycelium, and we discussed those involved in sugar metabolism. To advance our understanding of molecular mechanisms of dimorphic transition, we performed an extended analysis of gene expression profiles using the methods mentioned above., Results: In this work, continuous data mining revealed 66 new differentially expressed sequences that were MIPS(Munich Information Center for Protein Sequences)-categorised according to the cellular process in which they are presumably involved. Two well represented classes were chosen for further analysis: (i) control of cell organisation - cell wall, membrane and cytoskeleton, whose representatives were hex (encoding for a hexagonal peroxisome protein), bgl (encoding for a 1,3-beta-glucosidase) in mycelium cells; and ags (an alpha-1,3-glucan synthase), cda (a chitin deacetylase) and vrp (a verprolin) in yeast cells; (ii) ion metabolism and transport - two genes putatively implicated in ion transport were confirmed to be highly expressed in mycelium cells - isc and ktp, respectively an iron-sulphur cluster-like protein and a cation transporter; and a putative P-type cation pump (pct) in yeast. Also, several enzymes from the cysteine de novo biosynthesis pathway were shown to be up regulated in the yeast form, including ATP sulphurylase, APS kinase and also PAPS reductase., Conclusion: Taken together, these data show that several genes involved in cell organisation and ion metabolism/transport are expressed differentially along dimorphic transition. Hyper expression in yeast of the enzymes of sulphur metabolism reinforced that this metabolic pathway could be important for this process. Understanding these changes by functional analysis of such genes may lead to a better understanding of the infective process, thus providing new targets and strategies to control PCM.

In this study, we observed the occurrence of TRBV8.1-DB2.1 V(D)J recombination in murine fetal thymus organ culture (FTOC), in which the thymic microenvironment is mimicked. Since ionizing radiation affects T-cell development, we irradiated FTOCs with gamma rays to evaluate the modulation of genes implicated in TRBV8.1-BD2.1 rearrangements. The nylon cDNA microarray method was employed to monitor the expression of 9216 genes, which were organized in coexpression clusters. Clustering analysis showed similar expression profiling of genes implicated in the V(D)J recombination and DNA double strand break (DSB) repair processes such as XRCC4, RAG-2, Artemis and DNA-PK-cs, thus suggesting overlap between the two processes. The RUNX3 gene, whose coded protein binds to the enhancers of TR genes, was also modulated and the DNA cross-linking LR1 gene, which plays a role in the opening of hairpin DNA structures and whose expression pattern is similar to Artemis, may play a role in the control of V(D)J recombination. Furthermore, our data demonstrate that the FTOC model system and cDNA microarray method are useful tools to evidentiate genes that may play a role in both processes V(D)J recombination and DNA repair.

The aim of this study was to determine whether subcutaneous injection of tumor cells into Balb-c mice, which induces a fibrosarcoma at the site of injection, produced a differential expression profile in the thymus that could be correlated with tumor growth. A dynamic transcriptional profile of the thymus in response to tumor development was observed using nylon cDNA microarrays. The Cluster-Tree View and the SAM programs were used to reveal induced and repressed genes during tumor growth. This experimental model-system showed that this approach is adequate to detect the presence of tumor cells in vivo., ((Mol Cell Biochem 276: 81-88, 2005).)

Paracoccidioides brasiliensis is the causative agent of paracoccidioidomycosis, a disease that affects 10 million individuals in Latin America. This report depicts the results of the analysis of 6,022 assembled groups from mycelium and yeast phase expressed sequence tags, covering about 80% of the estimated genome of this dimorphic, thermo-regulated fungus. The data provide a comprehensive view of the fungal metabolism, including overexpressed transcripts, stage-specific genes, and also those that are up- or down-regulated as assessed by in silico electronic subtraction and cDNA microarrays. Also, a significant differential expression pattern in mycelium and yeast cells was detected, which was confirmed by Northern blot analysis, providing insights into differential metabolic adaptations. The overall transcriptome analysis provided information about sequences related to the cell cycle, stress response, drug resistance, and signal transduction pathways of the pathogen. Novel P. brasiliensis genes have been identified, probably corresponding to proteins that should be addressed as virulence factor candidates and potential new drug targets.

Non-manipulated inbred mouse strains constitutes an interesting model-system for in vivo studies on thymus ontogeny due to the possibility to observe the molecular events of the thymocyte maturation. In previous studies, using RT-PCR method, we have found that several immune system genes such as interleukins and MHC are differentially expressed during ontogeny of the thymus whose genes act as modulators of T-cell differentiation. To determine which other genes are modulated on a large-scale basis, we measured the levels of mRNA expression in mouse fetal thymus (14-17 days of gestation) by hybridization with cDNA microarrays containing 1,576 cDNA sequences derived from the IMAGE MTB library. T-cell maturation was monitored by detection of the T-cell receptor beta TRBV8.1-BD2.1 rearranged DNA segment. Each developmental phase of thymus, displayed a characteristic expression profile, as evaluated by the Cluster and Tree-View softwares. Genes differentially and significantly expressed were selected on the basis of significance analysis of the microarray data (SAM program). With the reclustering of only significantly expressed genes, it was possible to characterize the phases of thymus ontogeny, based on the differential profile of expression. Our method provided the detection of genes implicated in the cell signaling, such as the hematopoietic cell signal transducer gene, genes implicated in T-cell calcium influx (tyrosine phosphatase) and calcium signaling proteins (vesicle transport binding protein 3, proline rich Gla, casein kinase alpha 1 and Down syndrome homolog protein 1) and a gene important for the protein transport, including T-cell receptors chains, towards the cell membrane (Golgi SNAP receptor complex member 2). The results demonstrate that the cDNA microarray used to explore the gene expression was useful for understanding the modulation of several cell-signaling genes, including the calcium cascade pathway, which is important for individual stages of T-cell maturation and control of anergy during thymus ontogeny.

To evaluate the T-cell large-scale differential gene expression in systemic lupus erythematosus (SLE) patients presenting with glomerulonephritis we studied SLE patients before and after immunosuppressive treatment. Large-scale gene expression of peripheral blood mononuclear T cells was evaluated using cDNA microarray nylon membranes containing 5184 cDNAs. Data were analysed using the SAM and Cluster and Treeview software. When untreated patients were compared to healthy individuals, 38 genes, most of them located on chromosomes 1, 3, 6, 17 and 19, were repressed, and when untreated patients were compared to treated ones, 154 genes, located on chromosomes 1, 6, 7, 12 and 17, were induced. In terms of biological function of coded proteins, the differentially expressed genes were associated with apoptosis, cell cycle, chromosomal scaffold, cytokine/chemokine, DNA repair/replication, Golgi/mitochondrial proteins, mRNA processing, signalling molecules and tumour suppressors. Two autoantigen genes related to RNA splicing (small nuclear riboprotein 70,000 MW-U1 SNR, and splicing factor 3a, 60,000 MW), and the tetranectin-plasminogen-binding protein were repressed. The Fc fragment of immunoglobulin G low affinity IIb, apoptotic protease activating factor-1, two subunits of cytochrome c, caspase 8, complement C5a, HLA-DRA, HLA-DQB1, transforming growth factor-beta receptor II, small nuclear ribonucleoprotein polypeptide N (Sm protein N) genes, heterogeneous nuclear riboprotein-C, and argininosuccinate lyase genes, among others, were induced. A total of 10 genes were repressed in untreated patients and induced in treated ones, among them tumour necrosis factor (ligand) superfamily member 9, tumour protein p53, mannosidase alpha class IA, and CD22. Although some of these differentially expressed genes are typically expressed in B cells, CD22 and CD32 have also been reported in T cells and may provide regulatory signals to B cells. Assessment of differential gene expression may provide hybridization signatures that may identify susceptibility, diagnostic and prognostic markers of SLE.

The CBA/J inbred mouse strain constitutes an interesting in vivo model-system for studies on molecular genetics of thymus ontogeny. Using RT-PCR method we have found previously that several immune system related genes as interleukins and MHC are differentially expressed. During this period the onset of T-cell receptor beta rearrangements also occur. To know which other genes are modulated during the ontogeny of the thymus, the mRNA expression levels of fetal thymus (15 and 16 days gestation) of CBA/J mouse strain were measured by hybridization with a set of four macroarrays containing a panel of 6,144 IMAGE cDNA clones from MTB thymus library. We found 145 differentially expressed sequences; 44 were up- and 101 down-regulated in the thymus at 15-16 days gestation. Among these sequences, only 20 are identified as genes whose functions are known and 125 are still unknown. Our data demonstrated that, despite intense research on maturation of the immune system focusing on the activity of several well-characterized genes, the large scale expression profile during thymus ontogeny is still an open matter. The use of cDNA-array technology is an affordable method to identify new genes that may play a role in this phenomenon.

Cell response to genotoxic agents is complex and involves the participation of different classes of genes (DNA repair, cell cycle control, signal transduction, apoptosis and oncogenesis). In this report, we present three approaches to document gene expression profiles, dealing with the evaluation of cellular responses to genotoxic agents (gamma-rays from 60Cobalt and cyclophosphamide). We used the method of cDNA arrays to analyze the differential gene expression profiles that were displayed by lymphocytes from radiation-exposed individuals, a human fibroblast cell line, and T lymphocytes from systemic lupus erythematosus (SLE) patients who were treated with cyclophosphamide. A preliminary analysis performed in lymphocytes from three radiation-workers showed that several induced genes can be associated with cell response to ionizing radiation: TRRAP (cell cycle regulation), Ligase IV (DNA repair), MAPK8IP1 and MAPK10 (signal transduction), RASSF2 (apoptosis induction/tumorigenesis), p53 (damage response/maintenance of genetic stability). The in vitro irradiated normal VH16 cell line (primary) showed a complex response to the genotoxic stress at the molecular level. Many apoptotic pathways were concomitantly induced. In addition, several genes involved in signaling and cell cycle arrest/control were significantly modulated after irradiation. Many genes involved in oxidative damage were also induced, indicating that this mechanism seems to be an important component of cell response. After treatment of the SLE patients with cyclophosphamide, 154 genes were differentially and significantly induced. Among them, we identified those associated with drug detoxification, cell cycle control, apoptosis, and tumor-suppressor. These findings indicate that at least two apoptotic pathways were induced after cyclophosphamide treatment. The induction of APAF1 and two genes coding for two subunits of cytochrome c supports a previous report showing increased apoptosis in lymphocytes from SLE patients. The present study provides new information on the molecular mechanism underlying the cell response to genotoxic stress, with relevance to basic and clinical research.

The V(D)J recombination of TCRalpha and beta in early developing T-cells is a highly modulated phenomenon initiated and completed by recombinase complex (RAG-1 and RAG-2), and regulated by other gene products such as interleukins. To further evaluate the association of several other gene products with the evolution of TCRVbeta8.1 V(D)J rearrangements in vivo, the mRNA expression levels of seven interleukins, three cytokines, receptors TCRVbeta8.1 and IL-2Rbeta, MHC-I/MHC-II, RAG-1/ RAG-2 and retroviral superantigen MMTV(SW) were measured by RT-PCR during the fetal development of the thymus of three inbred mouse strains (Balb-c, C57B1/6 and CBA/J). Clustering using the Tree View software, was used to organize these genes based on similarity of expression patterns. Each strain displayed a different expression profile during thymus ontogeny. During the late developmental stage the most evident association was the kinetics of MMTV(SW) retrovirus, IL-2Rbeta and IL-7 overexpression with reduction of TCRVbeta8.1-D1beta2.1 rearrangement in the thymus of CBA/J mice. These data suggest a susceptibility of this strain to expression of MMTV(SW) upon reduction of the rearranged TCRVbeta8.1-Dbeta2.1 segment in developing thymocytes, with parallel IL-7 overexpression.

A cytogenetic study was carried out with 5-azacytidine (5-azaC) and etoposide (VP-16) in CHO-K1 and XRS-5 (mutant cells deficient for double-strand break rejoining) cell lines to verify the interaction effects of the drugs in terms of induction of chromosomal aberrations. 5-azaC is incorporated into DNA causing DNA hypomethylation, and VP-16 (inhibitor of topoisomerase II enzyme) is a potent clastogenic agent. Cells in exponential growth were treated with 5-azaC for 1 h, following incubation for 7 h, and posttreatment with VP16 for the last 3 h. In K1 cells, the combined treatments induced a significant reduction in the aberrations induced in the X and "A" (autosome) chromosomes, which are the main target for 5-azaC. However, in XRS-5 cells, the drug combination caused a significant increase in the aberrations induced in those chromosomes, but with a concomitant reduction in the randomly induced-aberrations. In addition, each cell line presented characteristic cell cycle kinetics; while the combined treatment induced an S-arrest in K1 cells, alterations in cell cycle progression were not found for XRS-5, although each drug alone caused a G2-arrest. The different cell responses presented by the cell lines may be explained on the basis of the evidence that alterations in chromatin structure caused by 5-aza-C probably occur to a different extent in K1 and XRS-5 cells, since the mutant cells present a typical hyper-condensed chromosome structure (especially the X- and "A" chromosomes), but, alternatively, 5-aza-C could induce reactivation of DNA repair genes in XRS-5 cells., (Copyright 2003 Wiley-Liss, Inc.)

3-Aminobenzamide (3AB) is an inhibitor of poly (ADP-ribose) polymerase (PARP), an enzyme implicated in the maintenance of genomic integrity, which is activated in response to radiation-induced DNA strand breaks. cDNA macroarray membranes containing 1536 clones were used to characterize the gene expression profiles displayed by mouse BALB/3T3 fibroblasts (A31 cell line) in response to ionizing irradiation alone or in combination with 3AB. A31 cells in exponential growth were pre-treated with 3AB 4mM 1h before gamma-irradiation (4Gy), remaining in culture during 6h until harvesting time. A31 cells treated with 3AB alone presented a down-regulation in genes involved in protein processing and cell cycle control, while an up-regulation of genes involved in apoptosis and related to DNA/RNA synthesis and repair was verified. A31 cells irradiated with 4Gy displayed 41 genes differentially expressed, being detected a down-regulation of genes involved in protein processing and apoptosis, and genes controlling the cell cycle. Concomitantly, another set of genes for protein processing and related to DNA/RNA synthesis and repair were found to be up-regulated. A positive or negative interaction effect between 3AB and radiation was verified for 29 known genes. While the combined treatment induced a synergistic effect on the expression of LCK proto-oncogene and several genes related to protein synthesis/processing, a negative interaction effect was found for the expression of genes related to cytoskeleton and extracellular matrix assembly (SATB1 and Anexin III), cell cycle control (tyrosine kinase), and genes participating in DNA/RNA synthesis and repair (RNA helicase, FLAP endonuclease-1, DNA-3 glycosylase methyladenine, splicing factor SC35 and Soh1). The present data open the possibility to investigate the direct participation of specific genes, or gene products acting in concert in the mechanism underlying the cell response to radiation-induced DNA damage under the influence of PARP inhibitor.

Chromosomal instability involving telomeric DNA sequences was studied in mouse Balb/3T3 fibroblasts transfected with a mutated human c-Ha-ras-1 gene (B61 cells) and spontaneously immortalized normal parental cells (A31 cells), using fluorescence in situ hybridization (FISH). FISH analysis with a telomeric probe revealed high frequencies of chromosome alterations involving telomeric regions, mainly stable and unstable Robertsonian fusion-like configurations (RLC) (0.25 and 1.95/cell in A31 and B61 cells, respectively) and chromosome ends lacking telomeric signals in one (LTS') or both chromatids (LTS") (5.9 and 17.5/cell for A31 and B61 cells, respectively). Interstitial telomeric sequences (ITS) were also detected at both non-telomeric sites and in the centromeres of RLC. The frequencies of RLCs with ITS located in the centromeres were 3-fold higher in B61 compared with A31 cells. We demonstrated a high level of chromosome instability involving telomeric DNA sequences in ras-transfected cells overexpressing ras mRNA, which could be a consequence of rapid cell cycle progression associated with a deficient telomere capping mechanism.

Cytogenetic analysis was performed in peripheral blood lymphocytes from hospital workers chronically exposed to ionizing radiation in comparison to matched non-exposed individuals. The accumulated absorbed doses calculated for the radiation workers ranged from 9.5 to 209.4 mSv. The endpoints used were chromosomal aberrations (CA), micronuclei (MN), and sister chromatid exchanges (SCE). The frequencies of CA/100 cells observed for the exposed group were significantly (P=0.018) higher than in the control group: 3.2 and 2.6, respectively. Similarly, the mean numbers of SCE per cell were statistically higher (P=0.025) in the exposed group (6.2) in comparison with the control group (5.8). In the case of micronuclei analysis, no significant (P=0,06) difference between both groups was found, but these data should be cautiously interpreted since an increase in the frequencies of MN was found for radiation workers (3.0 MN/100 cells), compared to the control group (2.6 MN/100 cells) and this increase occur in parallel to CA and SCE frequencies. The difference between the results could be explained by the nature of CA and MN generation. The increased frequencies of CA and SCE in radiation workers indicate the cumulative effect of low-level chronic exposure to ionizing radiation, and the relevance of conducting cytogenetic analysis in parallel to physical dosimetry in the working place., (Copyright 2001 Wiley-Liss, Inc.)