Age-related changes in the immune system of growing rats under acute and chronic stress conditions

Objectives : To examine whether or not excess pyruvate can provide the metabolic sub~trate to support the growth of early embryos in the presence of peritoneal fluid with endometriosis or interleukin- a . Introduction : The adverse effect of peritoneal fluid with endometriosis on .early embryo growth has previously been described (1). Recent studies suggest that interleukinsmay be the embryotoxic factor mediating the effect of endometriosis. This hypothesis is supported by the presence of interleukins in the peritoneal fluid obtained from women with endometriosis (unpublished observation). A common-metabolic pathway mediating the effects. of endometriosis and interleukin could provide further support to the hypothesis. · Methodology : Two-cell mouse embryos were cultured in 1 ml Whitten's medium as previously described (1). The effects of excess pyruvate (1 mmol) on early embryo growth in the presence of peritoneal fluid with endometriosis or interleukin-8 were examined. The embryos were cultured for 3 days. Results : Both peritoneal fluid with endometriosis and interlf:)ukin-8 were found to significantly inhibit the development of early mouse embryos. The in vitro development from 2 cells to blastocysts was suppressed in the presence of peritoneal fluid with mild, moderate or severe endometriosis (p<0.001 Fisher's exact test). lnterleukin-8 (16 and 1000 pglml) however inhibited mainly the development of the later stage embryo, from morulae to blastocysts (p<0.001 Fisher's exact test). Interestingly, pyruvate was effective in reversing the embryotoxic effects of both the peritoneal fluid with endometriosis and interleukin-8. ConClusion : The ability of pyruvate to reverse the embryotoxic effects of both peritoneal fluid.with endometriosis and inter/eukin-8 suggests that a common pathway may be involved in their actions. This provides further support to the hypothesis that interleukins mediate the embryotoxic effect of peritoneal fluid in endometriosis

Structure and formation of luminescent centers in light-up Ag cluster-based DNA probes

Fluorescent beacons based on silver (Ag) clusters for DNA/RNA detection represent a new type of turn-on probe that fluoresces upon hybridization to target nucleobase sequences. Physical–chemical mechanisms of their fluorescence activation still remain poorly understood. We studied in detail the fluorescence activation of dark Ag clusters induced by interactions of Ag–DNA complexes with different DNA sequences. In all cases, the final result depends neither on the location of the precursors (dark clusters) nor on their spectral properties. The reaction of fluorescence activation is a process similar to the growth of fluorescent silver clusters on dsDNA matrices. In both cases, reactants are dark clusters and two adjacent DNA strands. The latter form a double-stranded template for cluster nucleation. We found the optimized structure of a green fluorescent Ag4+2 cluster assembled on a C3/C3 DNA dimer in two different ssDNA pairs using QM modeling. The calculated absorption spectra match nicely the experimental ones, which proves the optimized structures. We conclude that apparent fluorescence activation in the studied systems results from reassembling Ag clusters on the new dsDNA template formed upon hybridization with the target. The suggested mechanism of “fluorescence activation” offers a way to design new light-up DNA probes. Two DNA strands making up the dsDNA template providing a high yield of bright Ag clusters can be used as the halves with the “stick” tails hybridizing with the base sequence of the target DNA. In this way, we have designed a light-up Ag cluster probe for β-actin mRNA

The effects of an indigenous contraceptive herbal Formulation on the gonadotrophs of the pituitary gland Of rat (experimentat immunohistochemical research)

Objective: To observe the morphometric changes of the gonadotrophs and the plasma concentrations of follicle stimulating hormone and leutinizing hormone. Methodology : Thirty five animals were randomly divided into 5 groups. Control animals were given vehicle and experimental animals were given combined herbal extract or individual herbal extract at a dose of 540 mg/kg/day s.c for 7 days. Immune-stained gonadotrophs were studied by using image analyzer, FSH and LH serum concentrations were determined. Results: The FSH and LH concentrations were low in animals that received combined herbal extract (p<0.01) . FSH concentration was noted to be significantly low in animals that received P. rotundifolia (p<0.05). The mean cell area and cell density of gonadotrophs of animals that received combined herbal extract were significantly low compared to control group (p<0.05). Discussion : These findings were corresponded to our previous findings that the combined herbal extract reduced both estradiol and progesterone concentrations and the individual plant extracts reduced the estradiol concentration significantly but not the progesterone. Conclusion: We concluded that the herbal extracts do affect the pituitary gonadotrophs and the circulating gonadotrophins. Further evaluation is needed to verify whether the effect was directly on the pituitary or through a higher centre such as the hypothalamus

Attitude of UNIMAS Pre-Clinical Medical Students towards Online Learning and the Challenges Faced by Them

Introduction: The entire world is having a crisis on the attitudes and challenges faced by people in the e-learning areas. Online learning or e-learning carries the definition of having the education through an online basis. It is realized that online learning establishes various kinds of conceptions and barriers in achieving academic goals. Purpose: This study aims to assess the attitudes and challenges faced by the UNIMAS pre-clinical medical students concerning their academic achievements based on online medical education using e-learning systems. Methodology: In this study, the attitudes of students regarding the challenges faced by respondents and their experience during e-learning are measured. In the online survey conducted among pre-clinical medical students, the sample population was selected through convenience sampling technique taken from Year 1 and 2 medical students of UNIMAS, the data collected concerning their opinion about the experience during e-learning and the challenges faced by them. The sample data collected were statistically analysed using the T-test and Chi-Square test. Results: The results showed few significant correlations of some attitudes towards online learning and the challenges with regard to various socio-demographic factors. The results suggest that some socio-demographic factors affect the attitudes and challenges faced directly or indirectly. Most of the UNIMAS pre-clinical medical students showed a neutral attitude towards online learning while facing moderate challenges in this matter. There was no significant association between the majority variables of the socio-demographic with the respondents' attitudes except for the internet connectivity. Ethnicity and internet connectivity showed a true relationship with the challenges faced by the respondents during online learning. Conclusion: The study concludes no evidence of significant negativity among the students' attitudes with regard to their demographic background and internet connectivity. Although there were students who had faced difficulties with regard to online learning. The study suggests that online learning should have facilitated approaches in achieving total learning activities of students around the world, preparation of competent technical personnel, funding of facilitation, and collaboration between universities, specifically in developing countries

Microstructural Changes In The Thyroid Gland Of The Preweaning And Weaning Rats After Heterotypic Stress

Chronic stress modulates the activity of various neuroendocrine axes; while activation pattern of the hypothalamo-hypophyseo-adrenal axis (HHAA) is studied in details, the response of the hypothalamo-hypophyseo-thyroid axis (HHTA) is less understood, especially in terms of its response to different types of stressors by the follicular and parafollicular compartments of the thyroid gland. Recent papers presented data on the inhibitory effect of chronic stress on the HHTA, while exercise and low temperature were shown to be able to activate its function. Most studies were done on the adult experimental animals using genetic studies without consideration of the structural changes in the peripheral link of the HHTA in the growing body. Reports on the effect of the chronic variable stressors on the thyroid gland in early life are scarce, though during this period neuroendocrine axes are extremely sensitive to different adverse factors, such as stress, infection, inflammation and environmental changes. The objective of this research is to assess the microscopic changes in the thyroid gland of the preweaning and weaning rats exposed to chronic heterotypic stress compared to the homotypic one. Homo- or heterotypic stressors were chronically applied to the preweaning and weaning rat pups. After the end of the last stress session the animals were euthanized, thyroid gland was sampled, embedded in paraffin, sectioned and stained for thyroglobulin, calcitonin, proliferative cells nuclear antigen (PCNA) and caspase 3. The mucosa of the alimentary tract of the experimental animals was examined and the thymus and the adrenal glands were sampled and weighed to evaluate the depth of stress-induced changes in the body. Immunologically stained slides of the thyroid gland were assessed using Image Pro+ software. Our study showed that chronic stress resulted in the structural and immunohistochemical changes of the thyroid gland in the preweaning and weaning experimental animals which indicate an inhibition of its function in the type of stress-related pattern. Both homo- and heterotypic stressors caused microscopic alterations in the thyroid gland, the extent of which depended both on the initial age of the experimental animal and the type of the stressor applied. The number and the size of the thyroglobulin-positive cells significantly decreased, and the volume density of the apoptotic cells significantly increased in the heterotypically stressed rat pups of both age subgroups with higher level of significance in the preweaning age subgroup. The number of calcitoninocytes was significantly increased in the weaning rat pups exposed to the heterotypic stress. The number of PCNA-positive cells significantly decreased only in the heterotypic stress group of both ages with higher level of significance in the preweaning age subgroup. A positive correlation was found between the volume density of the thyroglobulin-positive cells and the severity of the accidental thymic involution. Thus, our research demonstrated that weaning period is very sensitive to chronic stress for the thyroid gland of the experimental animals which by this age becomes mature enough to differentially respond to the various types of stress (homotypic versus heterotypic) both by the thyroid follicular and parafollicular compartments, and that thymus plays an important role in the functional capacity of the thyroid gland during stress in early life

Localization of the motor neuron somata of geniohyoid muscle in rat: A horseradish peroxidase study

Aimi Nadia Binti Razlan1 | Muzammil Ullah1 | Marina Yurievna Kapitonova2 | Norhayati Binti Liaqat Ali Khan1 | Syed Baharom Syed Ahmad Fuad

MORPHOMETRIC CHARACTERISTICS OF THE MANDIBULAR CONDYLAR PROCESSES

Aim: to study the morphometric characteristics of the mandibular condylar processes to identify patterns and their classification. Materials and Methods: a study of 49 skeletonized and certified mandibular preparations was performed using a caliper and a depth gauge. During the study of the material, the forms and the main morphometric parameters of the condylar processes were determined and analyzed. Statistical data processing was carried out using the Microsoft Excel program. Results: The study of certified biological material yielded the main morphometric and morpho functional parameters of the mandibular condylar processes. We revealed characteristic differences in the anatomical structures of the studied preparations. The main variants and types of combinations of forms of condylar processes were singled out: oval, hook-shaped, diamond-shaped, L-shaped. The lowest asymmetry index is characteristic of a combination of oval and diamond–shaped forms - 2.44%., and the highest asymmetry index is characteristic of diamond–shaped and L-shaped forms of condylar processes - 7.13%. Conclusion: The presented data can help practitioners to more accurately determine the target point for Gow-Gates anesthesia; to take into account the nature of the influence of structural changes in the joint on other elements of the dental apparatus, thus preventing functional diseases of the temporomandibular joint. The methodology of studying the main morphometric parameters on skeletonized preparations of the lower jaws can be adapted for the examination of living persons using diagnostic radiology