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Redfish (Sebastes spp.) in the Northwest Atlantic (NWA) extend from Baffin Island in the north to the Gulf of Maine in the south. The two most abundant species are Sebastes mentella and Sebastes fasciatus, which are morphometrically similar and difficult to visually distinguish. Redfish are long-lived, slow-growing, late-maturing, tend to produce large year classes episodically, and have complex population structure. Intraspecific genetic groups are abundant in the NWA. They are often semipelagic and patchily distributed, which makes them difficult to survey. These are all characteristics that cause difficulties for stock assessment and for sustainable fisheries management. This was the focus of The Ocean Frontier Institute Northwest Atlantic Redfish Symposium in 2018. In this paper, we synthesize the information known about NWA redfish. To improve the scientific basis for sustainable harvest strategies, key research recommendations involve (1) improved biological sampling including species and ecotype; (2) developing integrated stock assessment models; (3) developing harvest strategies with management reference points that are appropriate for redfish; (4) improving fishing technology and practices to avoid capture of small nonmarketable redfish and other species. Les sebastes (Sebastes spp.) dans l'Atlantique Nord-Ouest (ANO) sont presents de l'ile de Baffin au Nord jusqu'au golfe du Maine au Sud. Les deux especes les plus abondantes sont Sebastes mentella et Sebastes fasciatus, semblables sur le plan morphometrique et difficiles a distinguer visuellement. Les sebastes vivent longtemps, croissent lentement, maturent tardivement, ont tendance a produire episodiquement de grandes classes d'age, et la structure de leurs populations est complexe. Des groupes genetiques intraspecifiques sont abondants dans l'ANO. Ils sont souvent semi-pelagiques et ont une repartition parcellaire, ce qui rend leur recensement difficile. Toutes ces caracteristiques sont cause de difficultes pour l'evaluation des stocks et pour la gestion durable des peches et elles constituaient le theme central du symposium sur les sebastes de l'Atlantique Nord-Ouest de 2018 de l'Ocean Frontier Institute. Nous presentons une synthese de l'information connue sur les sebastes de l'ANO. Afin d'ameliorer les fondements scientifiques de strategies de recolte durables, les principales recommandations concernant la recherche comprennent (1) l'amelioration de l'echantillonnage biologique, notamment en ce qui concerne l'espece et l'ecotype, (2) l'elaboration de modeles integres d'evaluation des stocks, (3) l'elaboration de strategies de recolte qui integrent des points de reference de gestion adaptes aux sebastes et (4) l'amelioration des technologies et pratiques de peche pour eviter la prise de sebastes et poissons d'autres especes trop petits pour etre commercialisables. [Traduit par la Redaction], 1. Introduction Redfish (Sebastes spp.) are members of the Scorpaenidae family of bony fishes that are commonly found in waters of the North Pacific and North Atlantic. In the Northwest [...]

Abstract: Morphological differentiation may allow individuals to cope with prevailing environmental conditions. Morphological differentiation in fish characterized by sagittiform shape and ambush predator behaviour, such as northern pike (Esox lucius [...]

Critical thinking is a vital skill in professional settings, contributing to increased efficiency and innovation. Recognizing its importance, this study aims to explore how critical thinking is developed and applied across various industries. It is based on qualitative interviews with professionals in Education, Health, Logistics, Tourism, and Media. The analysis utilizes thematic, comparative, and content analysis to provide a sophisticated insight into the conceptualization, learning, and practice of critical thinking skills in each industry. By examining industry-specific differences, the study emphasizes the necessity for specialized training programs tailored to the unique demands of each sector. The uniqueness of this study lies in its comprehensive cross-sectoral analysis, offering a detailed comparative perspective on the role and impact of critical thinking across diverse professional landscapes. The results highlight critical thinking as a cornerstone of professional competence, supporting the development of the "Critical Reflections" program, which aims to provide intensive training adapted to sector-specific needs. Ultimately, this research underscores the importance of critical thinking in fostering adaptability, strategic decision-making, and innovative problem-solving across diverse professional landscapes, ensuring that professionals are equipped to meet contemporary challenges effectively.

This study compares the code blue calls (CBCs) used in our hospital before and during the COVID-19 pandemic. CBCs made between 31.03.2018 and 31.03.2022 in the Samsun Maternity and Child Health Training and Research Hospital were examined retrospectively. The study period was subdivided into two sections, one from March 31, 2018, to March 30, 2020 (Group 1, the pre-pandemic period) and the other from March 31, 2020, to March 31, 2022 (Group 2, the pandemic period). Patients' demographic data, the reason for the CBC and where it was issued, the time elapsed before the team arrived on the scene, and the outcomes were then compared between the groups. Seventy-nine CBCs, 34 (43.1%) of which were ‘false,' were included in the study. Forty-six calls were made in the pre-pandemic period, 26 (56.5%) of which were true calls, while 33 calls were made during the pandemic, of which 19 (57.6%) were true calls. Twenty-seven (60%) of the 45 true CBCs were for boys and 18 (40%) for girls. The children's mean age was 73.06±66.85 months, and 57.7% of the CBCs were issued during the pre-pandemic period. No significant difference was observed between groups 1 and 2 in terms of code blue team arrival times (114.03±59.14 vs. 138.1±95.96 sec, respectively (P=.305). The total mortality rate at the end of 30 days was 13.3% (P=.679). No difference was observed in CBC results between the pre-pandemic and pandemic periods in this study. We think that some blue code parameters, such as false calls and blue code team arrival times, can be improved through effective training against potential future pandemics. [Med-Science 2023; 12(4.000): 1206-9]

The southern Gulf of St. Lawrence (sGSL) White Hake Designatable Unit (DU) has been assessed as Endangered by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). This DU consists primarily of White Hake occurring in the Northwest Atlantic Fishery Organization (NAFO) Division 4T. The Recovery Potential Assessment for this stock found that extremely high natural mortality was preventing the recovery of this stock, while fishing mortality with a bycatch limit of 30 t has a negligible effect on the population trajectory. However, if fishing effort is increased as proposed with the expansion of the Redfish fishery, the impacts of bycatch fisheries on this population may no longer be considered negligible. This report aimed to examine existing information from surveys and fisheries to evaluate whether increased catch levels of Redfish would result in increased bycatch of White Hake. Significant overlap in the spatial distribution of White Hake and Redfish was noted in along the deep waters of the Laurentian Channel. This is partly the result of diet interdependencies among these species and the shift of White Hake to deeper waters to avoid predation. Bycatch of White Hake associated with Redfish was lower at depths greater than 380 m, whereas bycatch was much greater in the months of June, July, and December. Bycatch did not differ significantly based on gear type, however bycatch was overall greater in the southern region of the Laurentian Channel. Overall, the mean value of bycatch was 10.5% in the Redfish fishery. Even in the absence of fishery removals, the sGSL White Hake stock is expected to decline due to extremely high natural mortality. The sGSL White Hake population was projected forward 25 years assuming that productivity would remain at recent levels. SSB was estimated to decline by 38.7% with no catch and 39.3% with annual bycatch of 20 t, the recent level. With annual bycatch of 150 t to 350 t, SSB was estimated to decline by 43% to 48%. With bycatch of 500 t to 1,500 t, SSB declined by 53% to 70%. At present, the White Hake stock is sustained by unusually high recruitment rates which depend largely on a single cohort each year (age 4). The extinction risk for this stock (below 2,000 t) is 22 to 26% with no bycatch up to 150 t, and increases to 30% and 49% at bycatch levels of 350 t to 1,500 t respectively. If recruitment rates were to decline even slightly to the levels seen in the 2000s, the extinction risk for this stock would increase. At the present 30 t bycatch limit for White Hake, White Hake will become a choke species for the future Redfish fishery. [ABSTRACT FROM AUTHOR]

Objective:This study was carried out to determine the effect of video-assisted breast milk and breastfeeding training given to the mothers of hospitalized newborns on the breastfeeding self-efficacy and success.Methods:This was a non-randomized semi-experimental study with a pretest-posttest design including two groups. It was carried out with a total of 84 mothers who met the inclusion criteria including 41 mothers in the experimental group and 43 mothers in the control group. Data were collected by a breastfeeding Charting System and Documentation Tool (LATCH) and Postpartum Breastfeeding Self-Efficacy Scale-Short Form (PBSES-SF). While experimental group was given a video-assisted breastfeeding training together with an educational booklet on breastfeeding, control group was given a training only through an educational booklet on breastfeeding. Descriptive statistics were used in statistical analysis; besides, one-way analysis of variance (ANOVA) was used for the comparison of LATCH and PBSES-SF scores between the groups and paired samples t-test was used for comparisons within groups.Results:Mean pretest breastfeeding self-efficacy and breastfeeding success scores were similar between the groups (p>0.05); however, breastfeeding self-efficacy and breastfeeding success scores were found to be higher in the experimental group compared to the control group (p=0.00). Moreover, it was found that mean breastfeeding self-efficacy score following the training in the experimental group was significantly increased compared to the score before the training (p=0.00). A moderate level, positive and significant correlation was found between the differences in the breastfeeding self-efficacy and breastfeeding success scores of the mothers before and after the intervention (r=0.470, p

Background: Transcatheter closure of perimembraneous ventricular septal defect still poses a challenge due to the adjacent structures of the tricuspid and aortic valves and the risk of atrioventricular block. We report our experience at 2 centers using the KONAR-MF (multifunctional occluder) ventricular septal defect device, which gained its CE mark in May 2018. Methods: A retrospective study was carried out on all patients who underwent transcatheter ventricular septal defect closure with the KONAR-MF (multifunctional occluder) ventricular septal defect device at 2 centers. Results: A total of 47 patients were identified. The median age and weight of the patients were 25.8 months and 11 kg. The ventricular septal defects that were closed in 5 cases were post-operative hemodynamically significant residual ventricular septal defects. Forty-eight devices were used in the 47 cases. As for the location of the ventricular septal defect, 40/48 (83.33%) ventricular septal defects were perimembranous and 8/48 (16.66%) were muscular. The percutaneous device closure was successful in 46 procedures (95.8%). Device embolization was observed in 2 patients, and a significant residual shunt was observed in 2 cases. In the follow-up, there was no enhancement in the residual shunt in the remaining cases. Temporary atrioventricular block occurred in 2 cases during the procedure and improved after long sheath withdrawal. Conclusion: Soft, flexible, and low-profile KONAR-MF (multifunctional occluder) occluders ensure easy and safe implantation, and small sheath sizes allow for their use in small infants. Although near and mid-term follow-ups did not indicate any permanent atrioventricular block, a larger sample of patients and a longer follow-up period is necessary to understand long-term outcomes.

Abstract Background Short-term sintering may offer advantages including saving time and energy but there is limited evidence on the effect that altering sintering time has on the accuracy of monolithic zirconia crowns. The purpose of this in vitro study was to investigate the effect of shortened sintering time on the marginal and internal fit of 3Y-TZP and 4Y-TZP monolithic crowns. Methods Sixty monolithic zirconia crowns were fabricated for the maxillary first molar tooth on the prefabricated implant abutment. Groups were created according to the material composition: 3Y-TZP Generation 1, 3Y-TZP Generation 2 and 4Y-TZP. Two different sintering protocols were performed: same final sintering temperature (1500 °C) and various rates of heating (10 °C/min and 40 °C/min), cooling down speed (− 10 °C/min and − 40 °C/min), holding time (45 and 120 minutes), and total sintering time (approximately 2 and 7 hours, respectively). The marginal and internal fit of the crowns were determined using the silicone replica technique. Comparisons between groups were analyzed using two-way ANOVA. Pairwise multiple comparisons were performed using t-test (p

Objective:Dehydroepiandrosterone (DHEA) and its sulfate derivative DHEA-sulfate (DHEA-s) are major androgen hormones which are synthesis from the adrenal origin. The purpose of this study was to investigate DHEA-s levels in male patients with idiopathic hypogonadotropic hypogonadism (IHH) and to determine whether DHEA-s level are a useful marker for diagnosis of IHH.Methods:A total of 91 subjects, 31 males with IHH (mean age 19.7±2.6 years) and 60 healthy males (mean age 20.7±2.6 years), were enrolled in this study. The patients with IHH were selected from the subjects who had not yet started treatment for hypogonadism and who had no additional disease, while the healthy control group consisted entirely from individuals admitted to the same hospital outpatient clinic for routine check-ups. Both groups’ blood sampling, anthropometric measures, and physical examination were undertaken.Results:Mean DHEA-s level was 133.4±56.5 μg/dL in the IHH group and 433.3±160.3 μg/dL in the control group (p=0.000). The low DHEA-s level in patients with IHH was independent of age, cortisol, and adrenocorticotropic hormone (ACTH) at multivariate logistic regression analysis. The ROC analysis showed that DHEA-s ≤38.2 μg/dL supports a diagnosis of IHH with 100% specificity and 100% sensitivity. DHEA-s was as predictive as total testosterone which is used in the diagnosis of patients with IHH.Conclusion:DHEA-s level was significantly lower in the males with IHH compared to controls. Therefore, DHEA-s may be a potential predictive marker for diagnosis of IHH.

Background and Objectives: Total knee arthroplasty (TKA) is a commonly performed orthopedic procedure, and is often accompanied by significant postoperative pain. The supra-inguinal fascia iliaca block (SIFIB), similar to an anterior lumbar plexus block, is frequently used in hip surgeries. The interspace between the popliteal artery and capsule of the posterior knee (IPACK) block is a regional anesthesia technique that targets the posterior innervation of the knee capsule. This retrospective study aimed to compare the analgesic effects of SIFIB and SIFIB + IPACK on patients undergoing TKA under spinal anesthesia. Materials and Methods: This retrospective study revealed the data collected from a tertiary hospital. Patient data were gathered for individuals who underwent unilateral TKA under spinal anesthesia during the period between 1 January 2023 and 1 September 2023. Inclusion criteria comprised patients falling within ASA class I–III, those following a standardized perioperative analgesia regimen, and individuals receiving opioids via a patient-controlled analgesia device (PCA) as part of their postoperative pain management strategy. Patients were grouped as SIFIB and SIFIB + IPACK according to the performed regional anesthesia technique. Results: In the study, the data of 88 patients in total, 61 in the SIFIB group and 27 in the IPACK group, were analyzed. The 24 h cumulative morphine consumption was similar in the SIFIB and SIFIB + IPACK groups (10.62 ± 6.58 mg vs. 12.55 ± 8.84 mg, respectively; p: 0.258). The NRS scores of the groups were similar in all time frames. Conclusions: Our study reveals that combining IPACK with SIFIB in the multimodal analgesia plan does not provide additional benefits in terms of postoperative opioid consumption and pain scores in patients undergoing unilateral THA under spinal anesthesia.

Adequate hydration is an essential component of health at every stage of life. Although many factors such as age, gender, physical activity, drug use, and illness affect hydration status, it is vital to maintain water balance, especially in infectious diseases. This study was conducted to estimate the hydration status of young adults living in Turkey during the COVID-19 pandemic. The total water intake (TWI) and total water loss of the individuals were determined using the Water Balance Questionnaire (WBQ), which consists of questions about physical activity status, frequency of food and beverage consumption, water consumption, and water loss with urine and feces. The TWI of men and women was found to be 4,776.1 and 4,777.3 mL/day, respectively (p > 0.05). It was determined that 29% of the total water was obtained from drinking water, 49% from other beverages, and 22% from food. A positive net water balance was found in all body mass index (BMI) groups, men, and women. The net water balance was statistically lower in men (2,230.6 mL) than women (2,783.8 mL) (p < 0.05). As the COVID-19 pandemic continues, studies should be done on hydration status in the more balanced populations in terms of BMI and age groups. HIGHLIGHTS The present findings show that there is a positive net water balance in all body mass index groups, men and women.; It was determined that 74.5% of men and 93.5% of women met the Dietary Reference Intake recommendation in terms of total water intake.; Individuals' total energy intake (TEI) was found to be 2,538 kcal/day and the effect of energy taken from beverages on TEI was 7.6%.;

İmaj, bir kişi, kurum, marka, obje ya da düşüncenin zihinlerde isteyerek ya da istemeyerek bırakmış olduğu fikir ve izlenimlerdir. Profesyonel kimlik kavramı ise hemşirenin hasta ile etkileşimlerine, eylemlerine ve hemşirenin düşünme şekline rehberlik eden, hemşire tarafından sahip olunan değerler ve inançlar olarak da tanımlanmaktadır. Profesyonelliğin en önemli ölçütü işini en iyi şekilde yapabilmektir. Hemşirenin profesyonel nitelikleri hemşire imajına katkı veren niteliklerdir. Literatürde hemşirelik imajı ile ilgili yaşanan sorunların ve hemşire yetersizliğinin temel nedeninin hemşirelerin profesyonel kimlikleri ile doğrudan ilişkili olduğu belirtilmektedir. Çocuk sağlığı ve hastalıkları hemşireliği günümüzde profesyonel bir statü kazanmıştır.

Resimler çocukla sözel olmayan bir iletişim sağlar ve çocuğun duygularını ifade edebilmesine yardımcı olur. Çocuklar bir resim çizmeleri istendiğinde, sıklıkla kendileri için önemli olan durumları ve bu durumu nasıl algıladıklarını çizer. Resimler bize çocukların korkuları, algıları, fantazileri ve yanlış anlamaları hakkında ipucu verir. Çocukların resim yapmaları ile ilgili yöntemlerin psikoloji başta olmak üzere çeşitli bilim dalları tarafından "tanı" aracı olarak kullanılmakta olduğu bilinmektedir. Hastalık, gelişen her çocuğun başına gelebilecek en yaygın, en genel stres kaynaklarından biridir. Kısa süreli basit hastalıklar nadiren çocuğun üzerinde büyük etkiler veya uzun süreli duygusal bozukluklar bırakır. Oysa kronik hastalıklar gelişmekte olan çocuğun bilişsel ve duygusal gelişimi üzerinde kalıcı etkiler bırakabilir. Bilinmeyenden korkma ve kendini kontrol duygusunun tehdit altında olduğunu algılaması okul çocuğunun sağlık personeline ilişkin diğer korkularını oluşturur. Çocuk hastalığıyla ilgili her şeyi tam olarak anlamadığı için bilgideki boşlukları fantezilerle doludur. Çocuklarla çalışan hemşire çocuğun yaş ve gelişim düzeyine göre sözel ve sözel olmayan iletişim tekniklerini kullanabilmelidir. Çocuğa resim çizdirme onun hastane deneyimlerini ve bu deneyimlerinin akut veya kronik hastalıkta etkisi hakkında bilgi edinilmesini sağlayabilir. Sağlık bilincinin oluşmasında çevrenin yanı sıra deneyimlerin ve hekim-hemşire-çocuk ilişkisinin önemli rolü olmaktadır.

Studies attempting to describe fish community structure in shallow riverine environments typically rely on electrofishing and/or visual (snorkelling) surveys, but few have addressed the relative efficiencies of these two methods at estimating fish density and biomass across wide ranges of geography, taxonomy and life history stages. Multiple paired electrofishing and visual surveys were conducted in 18 temperate Canadian rivers in order to obtain community-wide density and biomass estimates from both methods. Partial canonical multivariate analyses were applied to the paired fish community matrices comparing the results of both surveying methods at the taxonomic levels of family, genus and species, as well as size classes within families and species, to assess the particular effectiveness of each sampling method. Although electrofishing estimates of family and species richness were generally greater, snorkelling surveys tended to generate higher density and biomass estimates for different size classes of many salmonid and cyprinid species. Moreover, mean river biomass estimates derived from visual surveying matched those obtained from our best mean river biomass estimates arising from the two methods combined. This study provides empirical evidence that electrofishing and visual survey methods generate different types of information when assessing fish community structure at the family level or by size classes. Our results provide ample background information for determining the most accurate sampling method for a particular fish community assemblage, which is fundamental to fisheries management and research. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Mining can be defined as the work of extracting any material that has an economic value such as ore, industrial raw material, coal and petroleum in the earth’s crust and providing necessary raw material. Today, interest in the mining sector has been increased in order to meet the developing technology and the increasing energy needs. However, since there is no serious environmental management system applied to mining activities, these activities have significant harmful effects. One of these effects is the air pollution caused by the vehicles during transportation of the extracted raw material. This study investigates the emissions of CO, NOx and PM10 due to traffic from the point where ore is extracted to the operation site in the copper mine which was established at Cerattepe location, Artvin city of Eastern Black Sea region. Within the scope of the study, the mentioned road route was divided into 5 regions and the emissions due to traffic before and after the establishing of the mine in each region were modeled by CAL3QHCR module in CALROADS 4.0 program and pollution distribution maps were created. Emission rates are calculated using CORINAIR's task-based emission factors. In order to evaluate the data obtained as a result of the modeling, the percentage increase in concentration was calculated and the results for each of the three pollutants were examined by a two-way ANOVA test. The results of the ANOVA test indicate that the traffic that will be formed after the mine has an adverse effect on the pollution effect with 95% reliability.

This study was aimed to evaluate the water quality and pollution sources in Sapanca Lake and its tributaries by applying multivariate statistical techniques to physicochemical parameters and toxic metals. For this purpose, the multivariate statistical methods such as principal component analysis (PCA) and absolute principal component score-multiple linear regression (APCS-MLR) model have been employed. It was tried to determine the seasonal pollution sources of physicochemical parameters and toxic metals obtained from 22 different sampling points between the years of 2015 and 2017. PCA was applied to the datasets, and 6 varimax factors describing 84%, 80%, 76%, and 79% of the total variance for each season were extracted. The obtained factors were analyzed using the APCS-MLR model for the apportionment of various pollution sources affecting physicochemical parameters and toxic metals. The results show that the natural soil structure, municipal-industrial wastewater, agricultural-atmospheric runoff, highways, and seasonal effects are the major pollution sources for toxic metals and physicochemical parameters. The material contribution of pollutant sources to toxic metals and physicochemical parameters was calculated and verified by the concentrations analyzed. Consequently, multivariate statistical techniques are useful to determine the physicochemical parameters and toxic metals through reciprocal correlation and assess the seasonal impact of pollutant sources in the basin. This study also provides a basis for the creation of measurement programs, determination of pollution sources, and provision of sustainable watershed management regarding other water resources.

Background/purpose: To prepare the post apace, some of the root-canal filling material has to be removed, which can affect the apical seal. The aim of this study was to compare the effect of immediate post space preparation to that of delayed post space preparation on apical sealing using three different endodontic sealers and obturation techniques. Materials and methods: In total, 90 decrowned single-rooted human teeth were studied. After root canals were prepared with 0.06 tapered nickel–titanium rotary files to size 30, the roots were categorized randomly into three experimental groups according to the obturation material: (1) AH plus/gutta-percha; (2) Sealite Ultra/gutta-percha; and (3) Epiphany/Resilon. Furthermore in all groups, specimens were categorized randomly into three subgroups according to the obturation technique (n = 10): (1) single cone; (2) cold lateral compaction; and (3) System B + Obtura. After root-canal filling, post space preparation was immediately performed in Group 1, after 24 hours in Group 2, and after 7 days in Group 3. Apical leakage was measured using the fluid-filtration method. Statistical analysis was performed using the Kruskal–Wallis test and Wilcoxon signed ranks test at P Sealite Ultra/gutta-percha > AH plus/gutta-percha (P

This study was conducted to investigate the dispersion of spatial source CO and NOx emissions with the help of different models in Korfez District, Kocaeli Province. Emissions from residential areas were chosen as the spatial source in the region and residents were divided into four different sections. The residential area is 5.31 km2 and natural gas, fuel-oil, wood, and coal are used as heating fuels in this district. With the help of the obtained data, emission rates were calculated using the mass-based emission factors of U.S. Environmental Protection Agency. These ratios were divided into residential areas and data were obtained in g/s.m2 and these data were entered to AERMOD, ISCST-3 and CALPUFF VIEW programs for the purpose of modelling. As a result of the modelling study, daily and annual dispersion maps were obtained. When the maps were examined, with AERMOD, the daily maximum concentrations of CO and NO were estimated to be 651,27 μg/m3, 18,29 μg/m3 while the annual concentrations were found as 128,47 μg/m3 and 2,90 μg/m3, respectively. The obtained daily maximum CO and NOx values with the help of ISCST-3 program were as 290,29 μg/m3 and 11,77 μg/m3 and the maximum annual values were as 86,48 μg/m3 and 1,95 μg/m3, respectively. The values of CO and NOx emissions obtained with the help of CALPUFF modelling program were as 692,67 µg/m3 and 15,64 µg/m3 , respectively, on daily basis and as 124,08 µg/m3 and 4,53 µg/m3 respectively, on annual basis. While there seemed to be a similarity in all three programs for CO when considering dispersion directions on the distribution maps, it was pointed out that the concentrations dispersed in the direction of east and west of Korfez district on AERMOD and CALPUFF maps as this dispersion was towards to the west of the county on ISCST-3 map. On NOx distribution maps, the residential areas of Korfez district were observed as the locations of density for NOx. The concentration propagation directions were same for all three programs particularly for annual dispersions maps and the concentration levels at receiver points in these directions were also determined as equal.

Amaç: Bu klinik çalışmanın amacı alt iki implant üstü locator tutuculu ve üst konvansiyonel tam protez kullanan hastaların bir yıl boyunca klinik değerlendirmesinin yapılmasıdır.Gereç ve Yöntem: Toplam 18 dental implant 9 tam dişsiz hastada alt çene ön bölgeye yerleştirildi. İyileşme sürecini takiben erken yükleme protokolü uygulanarak alt çene implant üstü locator tutuculu ve üst çene konvansiyonel tam protezler üretildi. Bir yıl süre içinde üç ayda bir kontrol randevuları yapıldı. İmplant başarı oranı, protezde görülen mekanik komplikasyonlar, periimplant dokular (marjinal kemik kaybı, diş taşı mevcudiyeti) ve hasta memnuniyeti değerlendirildi.Bulgular: İki implant üstü locator tutuculu tam protez kullanan hastaların memnuniyeti, daha önce kullandıkları konvansiyonel total protezlerden belirgin olarak daha yüksektir. İmplant başarı oranı %100’dür. Ancak 7 implant üstü locator tutuculu alt tam protezde herhangi bir mekanik komplikasyon görülmezken, 6. Ay kontrolde iki protezde locator patrikslerinde deformasyon görüldü. Patriksler daha az tutuculuğa sahip farklı renkteki plastik parçalar ile değiştirildi. Sonuç: İki implant üstü alt çene tam protezlerde locator tutucular başarılı bir tedavi seçeneğidir.

Dental implantların uzun dönem başarısı,implant etrafındaki krestal kemik desteğinebağlıdır. Krestal kemik miktarının korunmasındaplatform switch konseptinin etkili olduğudüşünülmektedir. Bu derlemede platform switchkonsepti ve onunla ilgili olan kullanılarak Pubmed ve Google Akademik veritabanında literatür taraması yapıldı. Elde edilenliteratürlerle konseptin etkisi üç ana başlık(biyomekanik davranış, krestal kemik seviyesi,yumuşak doku seviyesi) altında değerlendirildi.Platform switch konseptinin krestal kemik kaybınıazalttığı ve daha estetik sonuçların alındığınıgösteren çalışmaların yanısıra herhangi bir etkisininolmadığını gösteren çalışmalar da bulunmaktadır.Platform switch konseptinin etkinliğinindeğerlendirilmesi için uzun dönemli randomizeklinik çalışmalara ihtiyaç duyulmaktadır.

Rahnella aquatilis is an infrequently isolated Gram-negative rod within the Enterobacteriaceae family. The organism’s natural habitat is water. The organism is rarely isolated from clinical specimens and it seldom causes infection in immunocompetent individuals. Here we present a one-month-old boy who was born prematurely at 27th week of gestation by cesarean section with a birth weight of 730 g. He developed sepsis caused by Rahnella aquatilis during the treatment for ventilator associated pneumonia due to Stenotrophomonas maltophilia with ciprofloxacin. He was successfully treated with a combination of amikacin plus meropenem. Although R. aquatilis is one of the saprophyticus organisms, it may cause life-threatening infection in newborn.

Aim. To investigate obstetric features of pregnant women with thyroid disorders and thyroid function tests of their newborn infants. Methods. Women with hypothyroidism and having anti-thyroglobulin (ATG) and anti-thyroid peroxidase (anti-TPO) antibodies were assigned as group I, women with hypothyroidism who did not have autoantibodies were assigned as group II, and women without thyroid problems were assigned as group III. Results. Pregnant women with autoimmune hypothyroidism (group I) had more preterm delivery and their babies needed more frequent neonatal intensive care unit (NICU) admission. In group I, one infant was diagnosed with compensated hypothyroidism and one infant had transient hyperthyrotropinemia. Five infants (23.8%) in group II had thyroid-stimulating hormone (TSH) levels >20 mIU/mL. Only two of them had TSH level >7 mIU/L at the 3rd postnatal week, and all had normal free T4 (FT4). Median maternal TSH level of these five infants with TSH >20 mIU/mL was 6.6 mIU/mL. In group III, six infants (6.5%) had TSH levels above >20 mIU/mL at the 1st postnatal week. Conclusion. Infants of mothers with thyroid problems are more likely to have elevated TSH and higher recall rate on neonatal thyroid screening. Women with thyroid disorders and their newborn infants should be followed closely for both obstetrical problems and for thyroid dysfunction.

Dental implantların uzun dönem başarısı, implant etrafındaki krestal kemik desteğine bağlıdır. Krestal kemik miktarının korunmasında platform switch konseptinin etkili olduğu düşünülmektedir. Bu derlemede platform switch konsepti ve onunla ilgili olan anahtar kelimeler kullanılarak pubmed ve google akademik veri tabanında literatür taraması yapıldı. Elde edilen literatürler üç ana başlık (biyomekanik davranış, krestal kemik seviyesine etkisi, yumuşak dokuya etkisi) altında değerlendirildi. Platform switch konseptinin krestal kemik kaybını azalttığını ve daha estetik sonuçların alındığını gösteren çalışmaların yanısıra etkisi olmadığını gösteren çalışmalar da bulunmaktadır. Platform switch konseptinin etkinliğinin değerlendirilmesi için uzun dönemli randomize klinik çalışmalara ihtiyaç duyulmaktadır.

Life-history traits, such as size-at-maturity, are key parameters to model population dynamics used to inform fisheries management. Fishery-induced evolution, density-dependent effects, and global warming have been shown to affect size- and age-at-maturity, and resulting spawning stock biomass (SSB) in a wide range of commercial fish stocks. Marked changes in redfish biomass and environmental conditions in the Gulf of St. Lawrence and Laurentian Channel over the past decade called for a review and update of size-at-maturity for commercially important deepwater redfish Sebastes mentella and Acadian redfish Sebastes fasciatus stocks. Following a 25-year moratorium, local redfish biomass has recently reached unprecedented levels, co-occurring with an overall warming of bottom water temperatures. Our objectives were (1) to perform a histological assessment of redfish reproduction stages, including the validation and fine-tuning of a robust visual chart to facilitate monitoring of size-at-maturity and SSB in a transforming environment, and (2) to evaluate changes in size-at-maturity in unprecedentedly strong cohorts of redfish, and consequences for stock status assessment and fisheries management. Each specimen was genetically identified to species, and gonad reproduction stages were determined by histology and macroscopic appearances. The present study enabled a robust visual chart for continued and cost-effective monitoring of redfish reproduction stages to be refined and validated, and has shown a large decrease in redfish length when 50% of the individuals are considered mature that led to an increase in estimates of SSB during the 2011-2021 period for S. mentella and S. fasciatus. These changes modified the perception of stock status, thus having significant implications for fisheries management. Given that fishery-induced evolution and community structure changes along with global warming are affecting numerous stocks worldwide, the present study outlines a major and global challenge for scientists and resources managers. As shown by our results, the monitoring and frequent updates of life-history traits in transforming environments are needed to provide reliable science advice for sustainable fisheries., (© 2024 His Majesty the King in Right of Canada. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of Fisheries Society of the British Isles. Reproduced with the permission of the Minister of Fisheries Society of the British Isles.)

UV absorbents (UVAs), such as organic UV filters (UVFs) and benzotriazole UV stabilizers (BZT-UVs), are used in a wide range of consumer and industrial products and they are contaminants of emerging concern in the environment. However, their occurrence and fate in the deep-sea environments are inadequately understood. This study investigated the occurrence and distribution of five UVFs and ten BZT-UVs in the muscle (n = 127) of 2019-collected deepwater redfish (Sebastes mentella) from the St. Lawrence Estuary and Gulf (SLEG) (Canada) to better understand the accumulation of these contaminants in deep-sea fish. Small redfish (<30 cm) tended to have higher concentrations of UVAs in the muscle than that of larger specimens (>30 cm). The UVF 2-hydroxy-4-methoxybenzophenone (BP3) was the most frequently detected (present in 34 % of all samples) target UVA, with concentrations as high as 413 ng/g (dry weight). According to the δ 15 N and δ 13 C data, pelagic-eating redfish, and individuals with lower trophic levels had higher lipid content and accumulated more BP3 in their muscles. Four BZT-UVs were detected in redfish muscle, but the detection frequency was lower than 30 %. The estimated hazard quotient for these contaminants was <2.3 × 10 -2 for general Canadian populations, indicating that they are unlikely to pose health risks to humans through redfish consumption. Factors influencing UVAs bioaccumulation in redfish, as well as the effects UVAs may have on deep-sea species, should be researched further., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Mercury (Hg) pollution poses a significant threat to the environment, particularly in the form of methylmercury (MeHg). However, little is known about the distribution and influencing factors of Hg in deep-sea (>200m) fish, which is crucial for assessing potential health risks to fish and humans. In Canada, the deepwater redfish (Sebastes mentella) has been designated as an endangered species. After a 25-year fishing moratorium, the redfish population in the St. Lawrence Estuary and Gulf is recovering, and resuming of commercial fishing and human consumption are expected. This study aimed to investigate the distribution of MeHg and total Hg (THg) in the muscle of redfish, as well as the factors influencing its distribution, and to assess the potential human health risks associated with redfish consumption. The redfish samples (n = 123) were collected by Fisheries and Oceans Canada in 2019. The concentrations of THg and MeHg in redfish muscle were determined to be 93.3 ± 183 ng/g (mean ± SD, wet weight) and 78.2 ± 149 ng/g, respectively. Large redfish (>30 cm) accumulated 20 to 30 times more Hg than small redfish (17-30 cm). Small redfish from the Estuary-Western Gulf had higher levels of MeHg and THg than those from the Laurentian Channel and the Northeast Gulf, but the Hg availability to redfish among the three areas were similar. Significant predictors of MeHg concentrations in redfish muscle were determined to be fish length, muscle moisture, δ 15 N, and N%. MeHg consumption by the general population with an average fish consumption rate is not anticipated to have adverse effects. This study establishes a baseline for future Hg monitoring in the deep water environments in this region. Further research is required to elucidate the cause-effect relationships between various environmental/biological parameters and Hg accumulation in deep-sea biota., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Understanding the processes shaping population structure and reproductive isolation of marine organisms can improve their management and conservation. Using genomic markers combined with estimation of individual ancestries, assignment tests, spatial ecology, and demographic modeling, we (i) characterized the contemporary population structure, (ii) assessed the influence of space, fishing depth, and sampling years on contemporary distribution, and (iii) reconstructed the speciation history of two cryptic redfish species, Sebastes mentella and S. fasciatus . We genotyped 860 individuals in the Northwest Atlantic Ocean using 24,603 filtered single nucleotide polymorphisms (SNPs). Our results confirmed the clear genetic distinctiveness of the two species and identified three ecotypes within S. mentella and five populations in S. fasciatus . Multivariate analyses highlighted the influence of spatial distribution and depth on the overall genomic variation, while demographic modeling revealed that secondary contact models best explained inter- and intragenomic divergence. These species, ecotypes, and populations can be considered as a rare and wide continuum of genomic divergence in the marine environment. This acquired knowledge pertaining to the evolutionary processes driving population divergence and reproductive isolation will help optimizing the assessment of demographic units and possibly to refine fishery management units., (© 2020 Her Majesty the Queen in Right of Canada. Evolutionary Applications published by John Wiley & Sons Ltd. Reproduced with the permission of the Minister of Fishers and Ocean.)

Morphological differences (size and shape) across habitats are common in lake fish where differences relate to two dominant contrasting habitats: the pelagic and littoral habitat. Repeated occurrence of littoral and pelagic morphs across multiple populations of several lake fish species has been considered as important evidence that polymorphism is adaptive in these systems. It has been suggested that these habitat-based polymorphic differences are due to the temporal stability of the differences between littoral and pelagic habitats. Although streams are spatially heterogeneous, they are also more temporally dynamic than lakes and it is still an open question whether streams provide the environmental conditions that promote habitat-based polymorphism. We tested whether fish from riffle, run and pool habitats, respectively, differed consistently in their morphology. Our test compared patterns of morphological variation (size and shape) in 10 fish species from the three stream habitat types in 36 separate streams distributed across three watersheds. For most species, body size and shape (after controlling for body size) differed across riffle, run and pool habitats. Unlike many lake species, the nature of these differences was not consistent across species, possibly because these species use these habitat types in different ways. Our results suggest that habitat-based polymorphism is an important feature also in stream fishes despite the fact that streams are temporally variable in contrast to lake systems. Future research is required to assess whether the patterns of habitat-based polymorphism encountered in streams have a genetic basis or they are simply the result of within generation phenotypic plasticity., (© 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.)

The formation of the Mtr2-Mex67 heterodimer is essential for yeast mRNA export as it constitutes a key nuclear component for shuttling mRNA between the nuclear and cytoplasm compartments through the nuclear pore complex. We report the crystal structures of apo-Mtr2 from the human pathogen Candida albicans and of its complex with the Mex67 NTF2-like domain. Compared with other members of the NTF2 fold family, Mtr2 displays novel structural features involved in the nuclear export of the large ribosomal subunit and consistent with a dual functional role of Mtr2 during yeast nuclear export events. The structure of the Mtr2-Mex67 NTF2-like domain complex, which overall is similar to those of the human and Saccharomyces cerevisiae homologs, unveils three putative Phe-Gly repeat binding sites, of which one contributes to the heterodimer interface. These structures exemplify an unrecognized adaptability of the NTF2 building block in evolution, identify novel structural determinants associated with key biological functions at the molecular surface of the yeast Mtr2-Mex67 complex, and suggest that the yeast and human mRNA export machineries may differ.

The human UDP-glucuronosyltransferase 1A6 (UGT1A6) isoform is actively involved in the detoxication of phenolic compounds. In an effort to gain insight on active-site amino acids, we investigated the functional relevance of cysteinyl residues in the glucuronidation process. The enzyme was irreversibly inactivated upon exposure to thiol-specific reagents, especially N-phenylmaleimide. Site-directed mutagenesis of the conserved Cys126 into valine led to a fully inactive mutant, whereas conservative substitution with serine significantly restored the glucuronidation activity toward 4-methylumbelliferone used as a reference substrate. This mutant exhibited a reduced affinity toward the acceptor substrate, as evidenced by a 10-times increase in K(m) value, compared to the wild-type enzyme. The two mutations did not alter the stability of UGT1A6 nor change the subcellular localization of the protein in the endoplasmic reticulum of recombinant cells. These results support the conclusion that Cys126 is an essential residue for the integrity of the substrate binding site of UGT1A6.

The D-glucuronyltransferase and N-acetyl-D-glucosaminyltransferase reactions in heparan sulfate biosynthesis have been associated with two genes, EXT1 and EXT2, which are also implicated in the inherited bone disorder, multiple exostoses. Since the cell systems used to express recombinant EXT proteins synthesize endogenous heparan sulfate, and the EXT proteins tend to associate, it has not been possible to define the functional roles of the individual protein species. We therefore expressed EXT1 and EXT2 in yeast, which does not synthesize heparan sulfate. The recombinant EXT1 and EXT2 were both found to catalyze both glycosyltransferase reactions in vitro. Coexpression of the two proteins, but not mixing of separately expressed recombinant EXT1 and EXT2, yields hetero-oligomeric complexes in yeast and mammalian cells, with augmented glycosyltransferase activities. This stimulation does not depend on the membrane-bound state of the proteins.

A novel fluorescent photoactive probe 7-azido-4-methylcoumarin (AzMC) has been characterized for use in photoaffinity labeling of the substrate binding site of human phenol sulfotransferase (SULT1A1 or P-PST-1). For the photoaffinity labeling experiments, SULT1A1 cDNA was expressed in Escherichia coli as a fusion protein to maltose binding protein (MBP) and purified to apparent homogeneity over an amylose column. The maltose moiety was removed by Factor Xa cleavage. Both MBSULT1A1 and SULT1A1 were efficiently photolabeled with AzMC. This labeling was concentration dependent. In the absence of light, AzMC competitively inhibited the sulfation of 4MU catalyzed by SULT1A1 (Ki = 0.47 +/- 0.05 mM). Moreover, enzyme activity toward 2-naphthol was inactivated in a time- and concentration-dependent manner. SULT1A1 inactivation by AzMC was protected by substrate but was not protected by cosubstrate. These results indicate that photoaffinity labeling with AzMC is highly suitable for the identification of the substrate binding site of SULT1A1. Further studies are aimed at identifying which amino acids modified by AzMC are localized in the binding site.

7-Azido-4-methylcoumarin (AzMC) is a fluorescent photoactive compound structurally related to 4-methylumbelliferone (4-MU), a marker substrate of the human liver recombinant UDP-glucuronosyltransferase (UGT) 1A6. AzMC was synthesized and utilized to label the substrate binding site of UGT1A6. AzMC exhibits a fluorescence spectrum with maximum excitation and emission wavelengths of 380 and 442 nm, respectively. Upon irradiation, the probe irreversibly inhibited glucuronidation activity measured with para-nitrophenol (pNP) as substrate and interacted with UGT1A6 according to a saturable process indicative of reversible binding before covalent incorporation of the photoaffinity label. This inhibition was both time and concentration dependent and led to the calculation of an inhibition constant, k(2) = 0.113 mM min(-1), and dissociation constant, K(d) = 2.89 mM, for the reaction. Partial photoinactivation of UGT1A6 with AzMC revealed that the probe decreased the apparent V(max) of the pNP glucuronidation reaction, but not the K(m). Moreover, inhibition was partially prevented by 1-naphthol, a surrogate substrate for the enzyme, or by preincubation with an active-site directed inhibitor, 5'-O-[[(2-decanoylamino-3-phenyl-propyloxycarbonyl)amino]-su lfonyl]-2 ',3'-O-isopropylideneuridine. In contrast, UDP-glucuronic acid (UDP-GlcUA) did not have any protective effect against photoinactivation and AzMC did not affect the photoaffinity labeling of UGT1A6 by 5-[beta-(32)P]N(3)UDP-GlcUA, a photoaffinity analog of UDP-GlcUA. Additionally, in the absence of irradiation, AzMC was found to be a competitive inhibitor of 4MU glucuronidation. Collectively, these results strongly indicate that AzMC specifically binds to the UGT1A6 aglycon binding site. Amino acid alignment of phenol-binding proteins revealed a conserved motif, YXXXKXXPXP. It is possible that this motif is involved in phenol binding to UGT1A6 and other phenol-accepting proteins., (Copyright 1999 Academic Press.)

Acylglucuronides formed from carboxylic acids by UDP-glucuronosyltransferases (UGTs) are electrophilic metabolites able to covalently bind proteins. In this study, we demonstrate the reactivity of the acylglucuronide from the nonsteroidal anti-inflammatory drug, ketoprofen, toward human and rat liver UGTs. Ketoprofen acylglucuronide irreversibly inhibited the glucuronidation of 1-naphthol and 2-naphthol catalyzed by human liver microsomes or by the recombinant rat liver isoform, UGT2B1, which is the main isoform involved in the glucuronidation of the drug. A decrease of about 35% in the glucuronidation of 2-naphthol was observed when ketoprofen acylglucuronide was produced in situ in cultured V79 cells expressing UGT2B1. Inhibition was always associated with the formation of microsomal protein-ketoprofen adducts. The presence of these covalent adducts within the endoplasmic reticulum of cells expressing UGT2B1 was demonstrated following addition of ketoprofen to culture medium by immunofluorescence microscopy with antiketoprofen antibodies. Immunoblots of liver microsomes incubated with ketoprofen acylglucuronide and probed with antiketoprofen antibodies revealed the presence of several protein adducts; among those was a major immunoreactive protein at 56 kDa, in the range of the apparent molecular mass of UGTs. The adduct formation partially prevented the photoincorporation of the UDP-glucuronic acid (UDP-GlcUA) analog, [beta-32P]5N3UDP-GlcUA, on the UGTs, suggesting that ketoprofen glucuronide covalently reacted with the UDP-GlcUA binding domain. Finally, UGT purification from rat liver microsomes incubated with ketoprofen glucuronide led to the isolation of UGT adducts recognized by both anti-UGT and antiketoprofen antibodies, providing strong evidence that UGTs are targets of this metabolite.

To investigate the glucuronidation on the hydroxyl group of carbohydrate-containing drugs, the in vitro formation of glucuronides on the thioxyloside ring of the antithrombotic drug, LF 4.0212, was followed in rat and human liver microsomes and with recombinant UDP-glucuronosyltransferases (UGT). The reaction revealed a marked regioselectivity in rat and humans. Human liver microsomes glucuronidated the compound mainly on the 2-hydroxyl position of the thioxyloside ring, whereas rat was able to form glucuronide on either the 2-, 3-, or 4- hydroxyl group of the molecule, although to a lower extent. LF 4.0212 was a much better substrate of human UGT than the rat enzyme (Vmax/Km 30.0 and 0.06 microl/min/mg, respectively). Phenobarbital, 3-methylcholanthrene, and clofibrate enhanced the glucuronidation of LF 4.0212 on positions 2, 3, and 4 of the thioxyloside ring, thus indicating that several UGT isoforms were involved in this process. The biosynthesis of the 2-O-glucuronide isomer was catalyzed by the human UGT1A9 and 2B4, but not by UGT1A6 and 2B11. By contrast, the rat liver recombinant UGT1A6 and 2B1 failed to form the 2-O-glucuronide isomers. From all the recombinant UGTs tested, none catalyzed the formation of the 3-O-glucuronide isomer. Interestingly, glucuronidation on the 4-position was found in all the metabolic competent V79 cell lines considered, including the nontransfected V79 cells, suggesting the presence of an endogenous UGT in fibroblasts able to actively glucuronidate the drug. This activity, which was nonsensitive to the inhibitory effect of 7,7,7-triphenylheptanoic acid, a potent UGT inhibitor, could reflect the existence of a different enzyme.

Sodium periodate reacts with UDP-glucuronic acid (UDP-GlcUA) to generate a reactive derivative [periodate-oxidized UDP-GlcUA (o-UDP-GlcUA)]. The ability of this analog of UDP-GlcUA to inactivate and label the human recombinant UDP-glucuronosyltransferase (UGT) UGT1A6 via the UDP-GlcUA binding site was investigated. At an o-UDP-GlcUA concentration of 20 mM, the enzymatic activity of UGT1A6 was totally inactivated after 30 min of incubation at pH 7.4. Inhibition was irreversible, time-dependent, and concentration-dependent and exhibited pseudo-first order kinetics (kinact = 4.0 M-1.min-1). Cosubstrate protection with UDP-GlcUA was biphasic, with no protection in the first phase and almost total protection in the second phase, suggesting that at least 65% of the cross-linking occurs at the cosubstrate binding site. Partial inactivation by o-UDP-GlcUA led to a decrease in Vmax, suggesting that o-UDP-GlcUA can act as an active site-directed inhibitor. Furthermore, proteins, including the UGTs, from membrane fractions of a recombinant V79 cell line expressing the UGT1A6 enzyme and from rat liver microsomes were cross-linked by in situ periodate oxidation of [beta-32P]UDP-GlcUA. The present results suggest that periodate-oxidized UDP-GlcUA, which inactivates UGT1A6 by the possible formation of a Schiff base adduct with active site lysyl residues, can be used as a new affinity label for the UDP-GlcUA binding site.

Recombinant human liver UDP-glucuronosyltransferase (UGT), UGT1*6, which catalyzes the glucuronidation of small phenols, previously expressed in a V79 cell line (1) was photolabeled with [beta-32P]5N3UDP-glucuronic acid ([beta-32P]5N3UDP-GlcUA). Two polypeptides with an approximate molecular weight of 54 kDa were extensively photolabeled in the recombinant cell line while the nontransfected cell line showed no photoincorporation in this area. The identity of the two polypeptides as UGTs, which correspond to two different glycosylation forms of the same enzyme, was confirmed by Western blot using a polyclonal monospecific antibody directed against the 120 amino acids of the N-terminal end of UGT1*6. Preincubation with UDP-glucuronic acid (UDP-GlcUA) inhibited the photoincorporation of the probe into the polypeptides indicating competition of both the photoprobe and the nucleotide-sugar for the same binding site. It was further shown that photoincorporation of [beta-32P]5N3UDP-GlcUA into the UDP-GlcUA-binding site was saturable. The lack of photoincorporation of a related photoprobe, [beta-32P]5N3UDP-glucose ([beta-32P]5N3UDP-Glc), into UGT1*6 demonstrated specificity of this enzyme for UDP-GlcUA. In enzymatic assays, unlabeled 5N3UDP-GlcUA was shown to be an effective cosubstrate of the glucuronidation of 4-nitrophenol catalyzed by UGT1*6. The studies were further extended by demonstrating that photolabeling of UGT1*6 was inhibited by several active site-directed inhibitors. Finally, photoaffinity labelling was used in the purification of the labeled UGT1*6 using preparative gel electrophoresis. In conclusion, we have demonstrated that photoaffinity labeling with [beta-32P]5N3UDP-GlcUA is an effective tool for the characterization of enzymes such as recombinant UGTs that use UDP-GlcUA.

The hepatic UDP-glucuronosyltransferase UGT1*6 is actively involved in the glucuronidation of short and planar phenols in humans. Based on the irreversible inhibition of the enzyme on chemical modification by 2,3-butanedione and diethyl pyrocarbonate, the roles of His54 and Arg52 were investigated by oligonucleotide site-directed mutagenesis. These amino acids belong to a consensus sequence LX2-R52-G-H54-X3-V-L located in a conserved hydrophobic region of the variable amino-terminal domain of UGT. Arg52 was replaced by alanine (mutant R52A), and His54 was replaced by alanine or glutamine (mutants H54A and H54Q). The immunological and catalytic properties of UGT1*6 and mutants were examined after stable expression in V79 cell lines. Immunoblots and immunoprecipitation studies revealed that the mutant and UGT1*6 proteins were expressed in the microsomal membranes in similar amounts. However, replacement of His54 by glutamine led to a complete loss of activity toward 4-methylumbelliferone, and the Vmax value was decreased 4-5-fold in the mutants R52A and H54A compared with the wild-type enzyme. The dissociation constants that characterize the binding of 4-methylumbelliferone and UDP-glucuronic acid to UGT1*6 were not greatly affected by the mutations. Interestingly, H54Q was not recognized by specific antibodies to the amino-terminal portion of UGT1*6, thereby indicating that this amino acid was critical to antibody recognition. In contrast, the mutants R52A and H54A could not be differentiated from the wild-type protein by pH optimum or thermal denaturation. Furthermore, these mutants were still sensitive to irreversible inhibition by diethyl pyrocarbonate and 2,3-butanedione, with second-order inactivation constant values similar to those obtained for UGT1*6. Altogether, the strict conservation of His54 and Arg52 and the mutational analysis of these residues suggest that these amino acids in the hydrophobic amino-terminal consensus sequence LX2-R52-G-H54-X3-V-L are important for the function and the structure required for optimal catalytic efficiency of UGT1*6.

The treatment of UDP-glucuronosyltransferase UGT1*6 stably expressed in V79 cells with three carboxyl-specific reagents, dicyclohexylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide and N-ethyl-5-phenylisoxazolium-3'-sulfonate (Woodward's reagent K), resulted in a fast, dose-dependent decrease of the 4-methylumbelliferone glucuronidation. The inactivation reactions followed pseudo-first order kinetics. The pKa of the modified residue was close to 5.0. A partial protection against inactivation by Woodward's reagent was observed at pH 7.4 in the presence of UDP-glucuronic acid, UDP, and, to a lesser extent, in the presence of 4-methylumbelliferone. Dicyclohexylcarbodiimide significantly decreased the Vmax, without affecting the apparent Km towards UDP-glucuronic acid and 4-methylumbelliferone. The results support the involvement of a carboxyl group in the catalytic process.