1,096 research outputs found

    Aging changes of the testis in albino rat: light, electron microscopic, morphometric, immunohistochemical and biochemical study

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    Background: Aging has a deleterious effect on the morphology of the male reproductive system which might, in turn, lead to changes in spermatogenesis and consequently, decrease in both quality and quantity of spermatozoa. Materials and methods: The present study elucidated the histological and ultrastructural changes of testes of adult albino rats during aging and applied morphometric measures to obtain quantitative data for these changes. The oxidative and antioxidative markers of aged testes were also assessed. Results: The results documented the presence of age-related regressive structural changes of the testis accompanied with an increase in the apoptosis and a decrease in the proliferative capacity. Conclusions: The biochemical results gave evidence of an imbalance between the oxidative damage and the antioxidant defence indicating increased oxidative stress of aged testis

    Anatomical variations of hepatic artery using the multidetector computed tomography angiography

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    Background: The frequency of normal and aberrant hepatic arteries differs among ethnicities. The aim of our work was to study the frequency of normal and aberrant hepatic arteries among Egyptians using multidetector computed tomography (MDCT) and to compare our prevalence with the prevalence of other nationalities. In addition, the gender differences of such variations were clarified. Moreover, the arterial feeding of hepatic segment IV was determined. Materials and methods: The present study was carried out on 500 patients (409 males and 91 females). Abdominal CT was performed using two MDCT systems, a 64-row, and a 256-slice system. Results: According to Michel’s classification, the normal anatomy (type I) was observed in 369 (73.8%) cases, while anomalous hepatic arterial pattern was detected in 131 (26.2%) cases. These anomalies were distributed as follows: type II in 36 (7.2%) cases, type III in 60 (12%) cases, types IV and V in 5 cases for each (1% each), type VI in 14 (2.8%) and types VIII and IX in a single case for each (0.2% each). Neither type VII nor type X was detected. Nine (1.8%) unclassified cases were observed. According to Hiaat’s classification, the anomalies were distributed as follows: type II in 41 (8.2%) cases, type III in 74 (14.8%) cases, type IV in 6 (1.2%) cases, type V in a single case (0.2%) and type VI in 2 (0.4%) cases. Finally, 7 (1.4%) unclassified cases were observed. Common hepatic artery (CHA) originated from coeliac trunk in 98% (79.8% males and 18.2% females). It originated from the abdominal aorta in 0.4% and from the superior mesenteric artery (SMA) in 0.4%. It was absent in 1.2%. Right hepatic artery (RHA) originated from the CHA in 86.6% (69.8% males and 16.8% females) and from the SMA in 13.2% (11.8% males and 1.4% females) and from the abdominal aorta in 0.2% (a single male case). Left hepatic artery (LHA) originated from the CHA in 91.2% and from the left gastric artery (LGA) in 8.8%. The most common origin of the segment IV blood supply was the LHA in 60.8%, followed by the RHA in 35%. Less commonly, blood supply derived from the hepatic artery proper (HAP) in 1%. Combined supply derived from RHA and LHA in 0.8%, from the LHA and HAP in 2% and the least encountered was from the RHA and HAP in 0.4%. Conclusions: Hepatic artery variations among Egyptians have a different distribution when compared to such variations among other species. The normal hepatic arterial pattern was observed in 73.8%, while the anomalous was detected in 26.2%. The CHA originated from the coeliac trunk in 98%, the RHA originated from the CHA in 86.6% and the LHA originated from the CHA in 91.2%. The most common arterial supply of the hepatic segment IV is derived from the LHA (60.2%)

    First record of Taningia danae (Cephalopoda: Octopoteuthidae) in the Mediterranean Sea

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    The capture of a specimen of the oceanic cephalopod Taningia danae Joubin, 1931, caught during a bottom trawl survey carried out off the Algerian coast, is reported for the first time in the Mediterranean Sea. The individual, which was taken at 385-395 m depth, was a juvenile with a 55.6 mm mantle length and age of 132 days. This finding is important as there are few worldwide records of this speciesPublicado

    Charged Excitons in Self-assembled Quantum Dots

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    11 páginas, 8 figuras.-- 2002 Mrs Fall Meeting, Boston.-- Victor I. Klimov, Jillian M. Buriak, Wayner Danial D. M., Francesco Priolo, Bruce White (Eds.).We have succeeded in generating highly charged excitons in InAs self-assembled quantum dots by embedding the dots in a field-effect heterostructure. We discover an excitonic Coulomb blockage: over large regions of gate voltage, the exciton charge remains constant. We present here a summary of the emission properties of the charged excitons.This work was funded by EPSRC and the DFG (SFB348).Peer reviewe

    Ambient particulate pollution and the world-wide prevalence of asthma, rhinoconjunctivitis and eczema in children: Phase One of the International Study of Asthma and Allergies in Childhood (ISAAC)

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    Objectives: To investigate the effect of ambient particulate matter on variation in childhood prevalence of asthma, rhinoconjunctivitis and eczema. Methods: Prevalences of asthma, rhinoconjunctivitis and eczema obtained in Phase One of the International Study of Asthma and Allergies in Childhood (ISAAC) were matched with city-level estimates of residential PM10 obtained from a World Bank model. Associations were investigated using binomial regression adjusting for GNP per capita and for clustering within country. For countries with more than one centre, a two stage meta-analysis was carried out. The results were compared with a meta-analysis of published multi-centre studies. Results: Annual concentrations of PM₁₀ at city level were obtained for 105 ISAAC centres in 51 countries. After controlling for GNP per capita, there was a weak negative association between PM₁₀ and various outcomes. For severe wheeze in 13-14-year-olds, the OR for a 10 μg/m³ increase in PM₁₀ was 0.92 (95 CI 0.84 to 1.00). In 24 countries with more than one centre, most summary estimates for within-country associations were weakly positive. For severe wheeze in 13-14-year-olds, the summary OR for a 10 μg/m³ increase in PM₁₀ was 1.01 (0.92 to 1.10). This result was close to a summary OR of 0.99 (0.91 to 1.06) obtained from published multi-centre studies. Conclusions: Modelled estimates of particulate matter at city level are imprecise and incomplete estimates of personal exposure to ambient air pollutants. Nevertheless, our results together with those of previous multi-centre studies, suggest that urban background PM₁₀ has little or no association with the prevalence of childhood asthma, rhinoconjunctivitis or eczema either within or between countries

    Asthma Prevalence, Knowledge, and Perceptions among Secondary School Pupils in Rural and Urban Costal Districts in Tanzania.

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    Asthma is a common chronic disease of childhood that is associated with significant morbidity and mortality. We aimed to estimate the prevalence of asthma among secondary school pupils in urban and rural areas of coast districts of Tanzania. The study also aimed to describe pupils' perception towards asthma, and to assess their knowledge on symptoms, triggers, and treatment of asthma. A total of 610 pupils from Ilala district and 619 pupils from Bagamoyo district formed the urban and rural groups, respectively. Using a modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire, a history of "diagnosed" asthma or the presence of a wheeze in the previous 12 months was obtained from all the studied pupils, along with documentation of their perceptions regarding asthma. Pupils without asthma or wheeze in the prior 12 months were subsequently selected and underwent a free running exercise testing. A >= 20% decrease in the post-exercise Peak Expiratory Flow Rate (PEFR) values was the criterion for diagnosing exercise-induced asthma. The mean age of participants was 16.8 (+/-1.8) years. The prevalence of wheeze in the past 12 months was 12.1% in Bagamoyo district and 23.1% in Ilala district (p < 0.001). Self-reported asthma was found in 17.6% and 6.4% of pupils in Ilala and Bagamoyo districts, respectively (p < 0.001). The prevalence of exercise-induced asthma was 2.4% in Bagamoyo, and 26.3% in Ilala (P < 0.002). In both districts, most information on asthma came from parents, and there was variation in symptoms and triggers of asthma reported by the pupils. Non-asthmatic pupils feared sleeping, playing, and eating with their asthmatic peers. The prevalence rates of self-reported asthma, wheezing in the past 12 months, and exercise-induced asthma were significantly higher among urban than rural pupils. Although bronchial asthma is a common disease, pupils' perceptions about asthma were associated with fear of contact with their asthmatic peers in both rural and urban schools

    Far-infrared study of the Jahn-Teller distorted C60 monoanion in C60 tetraphenylphosphoniumiodide

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    We report high-resolution far-infrared transmission measurements on C(60)-tetraphenylphosphoniumiodide as a function of temperature. In the spectral region investigated (20-650 cm(-1)), we assign intramolecular modes of the C(60) monoanion and identify low-frequency combination modes. The well-known F(1u)(1) and F(1u)(2) modes are split into doublers at room temperature, indicating a D(5d) or D(3d) distorted ball. This result is consistent with a dynamic Jahn-Teller effect in the strong-coupling limit or with a static distortion stabilized by low-symmetry perturbations. The appearance of silent odd modes is in keeping with symmetry reduction of the hall, while activation of even modes is attributed to interband electron-phonon coupling and orientational disorder in the fulleride salt. Temperature dependences reveal a weak transition in the region 125-150 K in both C(60)(-) and counterion modes, indicating a bulk, rather than solely molecular, effect. Anomalous softening (with decreasing temperature) in several modes may correlate with the radial character of those vibrations. [S0163-1829(98)03245-7]

    Angiogenesis in urinary bladder carcinoma as defined by microvessel density (MVD) after immunohistochemical staining for Factor VIII and CD31

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    Background: Among the patients with bladder cancer, a group is still at risk of disease recurrence, progression, and death from their cancer after curative treatment. Angiogenesis is a crucial pathogenic mechanism for this type of urothelial carcinoma and is a potential therapeutic target. Objectives: To quantify tumor angiogenesis in bladder cancer and determine whether it correlates with tumor stage and grade. Patients and methods: A series of 42 archival samples from carcinomas of the urinary bladder were graded, staged, and analyzed for microvessel density (MVD) by a double immunohistochemical technique using Factor VIII (FVIII) and CD31 antibodies. The correlation between MVD and histopathological grade and tumor stage was evaluated. Results: FVIII and CD31 immunoreactivity was observed in 100% of cases and more intensely with CD31. Significantly higher MVD was determined in invasive tumors than in superficial tumors (p&#60;0.05). MVD increased with tumor grade and stage (p&#60;0.05); MVD was not affected by age or sex of the patients. Conclusion: These data demonstrate that MVD in bladder carcinoma correlates with the tumor grade and stage. Quantification of tumor angiogenesis may allow selection of the type of treatment for bladder cancer patients

    JunD/AP-1-Mediated Gene Expression Promotes Lymphocyte Growth Dependent on Interleukin-7 Signal Transduction

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    Interleukin-7 (IL-7) is an essential cytokine for lymphocyte growth that has the potential for promoting immune reconstitution. This feature makes IL-7 an ideal candidate for therapeutic development. As with other cytokines, signaling through the IL-7 receptor induces the JAK/STAT pathway. However, the broad scope of IL-7 regulatory targets likely necessitates the use of other signaling components whose identities remain poorly defined. To this end, we used an IL-7 dependent T-cell line to examine how expression of the glycolytic enzyme, Hexokinase II (HXKII) was regulated by IL-7 in a STAT5-independent manner. Our studies revealed that IL-7 promoted the activity of JNK (Jun N-terminal Kinase), and that JNK, in turn, drove the expression of JunD, a component of the Activating Protein 1 (AP-1) transcription factors. Gel shifts showed that the AP-1 complex induced by IL-7 contained JunD but not c-Fos or c-Jun. Inhibition of JNK/JunD blocked glucose uptake and HXKII gene expression, indicating that this pathway was responsible for promoting HXKII expression. Because others had shown that JunD was a negative regulator of cell growth, we performed a bioinformatics analysis to uncover possible JunD-regulated gene targets. Our search revealed that JunD could control the expression of proteins involved in signal transduction, cell survival and metabolism. One of these growth promoters was the oncogene, Pim-1. Pim-1 is an IL-7-induced protein that was inhibited when the activities of JNK or JunD were blocked, showing that in IL-7 dependent T-cells JunD can promote positive signals transduced through Pim-1. This was confirmed when the IL-7-induced proliferation of CD8 T-cells was impaired upon JunD inhibition. These results show that engagement of the IL-7 receptor drives a signal that is more complex than the JAK/STAT pathway, activating JNK and JunD to induce rapid growth stimulation through the expression of metabolic and signaling factors like HXKII and Pim-1

    Estimation of proteinuria as a predictor of complications of pre-eclampsia: a systematic review

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    Background Proteinuria is one of the essential criteria for the clinical diagnosis of pre-eclampsia. Increasing levels of proteinuria is considered to be associated with adverse maternal and fetal outcomes. We aim to determine the accuracy with which the amount of proteinuria predicts maternal and fetal complications in women with pre-eclampsia by systematic quantitative review of test accuracy studies. Methods We conducted electronic searches in MEDLINE (1951 to 2007), EMBASE (1980 to 2007), the Cochrane Library (2007) and the MEDION database to identify relevant articles and hand-search of selected specialist journals and reference lists of articles. There were no language restrictions for any of these searches. Two reviewers independently selected those articles in which the accuracy of proteinuria estimate was evaluated to predict maternal and fetal complications of pre-eclampsia. Data were extracted on study characteristics, quality and accuracy to construct 2 × 2 tables with maternal and fetal complications as reference standards. Results Sixteen primary articles with a total of 6749 women met the selection criteria with levels of proteinuria estimated by urine dipstick, 24-hour urine proteinuria or urine protein:creatinine ratio as a predictor of complications of pre-eclampsia. All 10 studies predicting maternal outcomes showed that proteinuria is a poor predictor of maternal complications in women with pre-eclampsia. Seventeen studies used laboratory analysis and eight studies bedside analysis to assess the accuracy of proteinuria in predicting fetal and neonatal complications. Summary likelihood ratios of positive and negative tests for the threshold level of 5 g/24 h were 2.0 (95% CI 1.5, 2.7) and 0.53 (95% CI 0.27, 1) for stillbirths, 1.5 (95% CI 0.94, 2.4) and 0.73 (95% CI 0.39, 1.4) for neonatal deaths and 1.5 (95% 1, 2) and 0.78 (95% 0.64, 0.95) for Neonatal Intensive Care Unit admission. Conclusion Measure of proteinuria is a poor predictor of either maternal or fetal complications in women with pre-eclampsia
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