Vitamin D and bone health status in beta thalassemia patients-systematic review.

Thalassemia is a chronic congenital disease characterized by a combination of endocrine and metabolic disorders. Bone disease is a very common complication related to the poor absorption of calcium, the secondary chronic renal disease with low vitamin D, as well as multiple endocrine risk factors. The aim of this systematic review was to estimate the prevalence of vitamin D deficiency in thalassemia, as well as its association with osteoporosis/low bone mass. A systematic review was carried out using PubMed/Medline, Cochrane, and EBSCO databases. The methodological quality of the included studies was assessed with the validated Newcastle-Ottawa Quality Assessment Scale adapted for cross-sectional studies and cohort studies respectfully and the Cochrane Collaboration for clinical trials. After application of predetermined exclusion criteria compatible with the PICOS process, a total of 12 suitable articles were identified. The prevalence of vitamin D deficiency varied considerably. Only five of the reviewed studies examined the correlation between vitamin D levels and BMD of which just three showed a statistically significant positive association of mild/moderate grade. Vitamin D deficiency is a common comorbidity in patients with thalassemia. However, both its prevalence and its severity vary considerably in different populations, and existing evidence is insufficient to conclude whether vitamin D supplementation is also associated with BMD improvement in this special population group.

Effectiveness of current teaching methods in Cardiology: the SKILLS (medical Students Knowledge Integration of Lower Level clinical Skills) study.

INTRODUCTION: The aim of the study is to assess reported changes in medical students' capacity to attain five basic cardiological clinical skills, following a one-month intensive cardiology course provisioned in the core curriculum. MATERIALS AND METHODS: An anonymous questionnaire comprising self reported performance in the five skills, namely 1) arterial blood pressure measurement, 2) cardiac auscultation, 3) electrocardiogram (ECG) carry out, 4) ECG interpretation and 5) defibrillation, was distributed to 177 fifth year students of the Athens Medical School upon initiating the cardiology course (pre-training group) and to 59 students matched for sex, age, year of study and training centre, following completion of the course (post training group). Comparison of pre- and post- training performance was evaluated using the χ(2) test. RESULTS: No change was noted with regards to blood pressure measurement, cardiac auscultation or defibrillation. By contrast, a statistically significant improvement was reported for ECG execution (54.3 versus 81.4%; p<0.001) and interpretation (from 33.1 to 89.8%; p<0.001). CONCLUSIONS: Improvement in the execution and interpretation of ECGs seems to be among the strengths of the cardiology training program. Further studies including larger samples from multiple medical schools and objective assessment of skill execution might facilitate accurate training evaluation and define opportunities for improvement.

Investigating ROS sources in male infertility: a common end for numerous pathways.

Reactive oxygen species (ROS) are active byproducts of aerobic metabolism. Although they are constantly produced during normal cellular activities in the mitochondria, their action is counteracted by inherent antioxidant systems. This equilibrium is distorted in the case of acute or chronic inflammation, which results in increased ROS production and, ultimately, oxidative stress. In sperm, ROS are produced by both spermatozoa and circulating leucocytes and may be part of normal adaptive reactions, such as the capacitation process. However, a number of external toxicants may also contribute to ROS production in the testis and epididymis, leading to a decrease in sperm viability and motility and, therefore, an increased onset of the male factor of infertility. Such pro-oxidative conditions include, among others, exposure to radiation, extreme temperature, certain drugs, toxins, heavy metals, smoking and biological hazards. The current review paper summarizes the available evidence incriminating ROS and oxidative stress as the underlying pathophysiological mechanism leading to the onset of reproductive toxicity in each of these settings.

Sertoli cell proliferation in the fetal and neonatal rat testis: a continuous phenomenon?

Sertoli cell population kinetics, as evidenced by semi-quantitative immunolabeling for proliferating cell nuclear antigen (PCNA) and Ki-67, in developing Wistar rat male gonads of embryos and neonates [14.5 days post conception (dpc)-7 days post partum (dpp)], was investigated. Throughout the examined period a gradual increase of immunolabeled Sertoli cell number, associated with intense mitotic activity, was observed. PCNA labeling index of Sertoli cells increased from 66.67 (at 14.5 dpc) to 89.74 (at 18.5 dpc) and then dropped to 75.24 (at 20.5 dpc). At birth, the percentage of PCNA immunoreactive Sertoli cells reached 98.70% and remained high thereafter, attaining a peak value of 99.90% at 7 dpp. The percentage of Ki-67 immunoreactive Sertoli cells in the fetal testis increased from E14.5 (43.95%) to E20.5 (77.40%). The proliferation rate did not alter considerably in the neonatal testis until 5 dpp. At this point, a significant increase of the Ki-67 labeling index was observed and a peak value of 95.76% was reached at 7 dpp. The pattern of Sertoli cell proliferation with age and the establishment of the final Sertoli cell number in vivo established in the present study was compared to the results from earlier investigations reported in the literature and the observed fluctuation of dividing cell numbers, associated with immunolabeling results throughout the examined period, complements and extends existing data. An appraisal of the timing of Sertoli cell proliferation in other species, namely mouse and man, is presented. The current investigation may be useful in evaluating the potential influence of factors interfering with normal mitotic activity of Sertoli cells, including cell selection mechanisms, such as apoptosis, senescence, DNA repair and hormonal/paracrine growth modulation.

Evaluation of immunohistochemical markers of germ cells' proliferation in the developing rat testis: a comparative study.

Germ cells' proliferation during testicular organogenesis in Wistar rat embryos and neonates [14.5, 18.5, 20.5 days post conception (dpc), birth (day 0), 1, 3, 5, 7 days post partum (dpp)] was evaluated via immunohistochemistry, using the PCNA and Ki-67 nuclear antibodies. Estimation of the reactive/total cell ratio, per visual field [labeIing index (LI)] was achieved using the Image Pro Plus Software. Immunostaining of the fetal testis, with both antibodies, revealed increasing germ cells' numbers between 14.5 dpc and birth. From birth onwards, a sharp decline of germ cells' population was observed in the first 3 days of postnatal life. Then, a transient increase of the LI, between 3 and 5 dpp, was noted. Afterwards, proliferation of germ cells ceased. These results indicate that, during fetal and neonatal life, two peaks of proliferative activity of germ cells are noticed. Following estimation of the LI for both PCNA and Ki-67, a prominent labeling for the first antibody was observed throughout the examined period. Ki-67 staining follows a similar pattern, showing, however, significant fluctuation in the obtained values, in comparison to PCNA. The significant differences observed don't seem to be simply a result of the different half lives of the two markers, but rather a consequence of additional underlying cellular activity associated with PCNA, such as DNA repair.

Casual discovery of a thoracic tumour showing histological features of undifferentiated pleomorphic sarcoma in a male Wistar laboratory rat.

Sarcomas are neoplasms of mesenchymal origin, with a predominant cell population mimicking the organization of various soft tissues and/or bones. Previous categorizations also included the possibility of the presence of tissue macrophage-like (histiocytes) neoplasm cells, in a tumour described as malignant fibrous histiocytoma, but this group has been considered as a variety of undifferentiated pleomorphic sarcomas. Although this kind of malignancy is not rare in humans, only few cases have been reported in laboratory animals. We report an unusual single case of spontaneous tumour growth, detected by casual observation, in the left thoracic area of an 18-month-old male laboratory Wistar rat. Both this individual and his ancestors were not exposed to any known carcinogenic substance or radiation, thus suggesting the development of the neoplasm as a spontaneous event. The mass was extracted surgically under general anaesthesia, and slices were examined histologically and immunohistochemically, using photon microscopy. The pathologist reported the presence of a combination of fibroblasts and undifferentiated mesenchymal cells arranged in a storiform pattern. Immunohistochemistry was performed on the tissue using specific antibodies for several proliferation (Ki-67) and differentiation (S-100, CD-34, CD-68, pan-keratin, desmin and smooth muscle actin-SMA) markers. Positive reaction was observed for S-100, Ki-67, CD-68, desmin and SMA (limited) but not for CD-34 or cytokeratin.