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1.
We compared the biological traits of insecticide resistant and susceptible field populations of tea mosquito bug Helopeltis theivora Waterhouse. The insecticide resistant population of the conventional Tea Estate “Chuapara” of the Dooars, Jalpaiguri, differed significantly from the susceptible strain of the organic Tea Estate “Makibari” of Darjeeling. Both these tea plantation areas are located in the northern part of West Bengal, India. Adverse changes in biological and developmental traits were observed mainly in: (i) reduction in oviposition period; (ii) fecundity; and (iii) prolongation of nymphal and total developmental period. However, all other parameters such as pre- and post oviposition periods, egg incubation period, hatchability and adult longevity were not significantly different. These results clearly demonstrated that only certain fitness components in the resistant strains appear to be adaptively changed and lowered.  相似文献   
2.
Animal experiments continue to play an integral role in Indian undergraduate medical education, even though alternatives are becoming increasingly available. In this context, this study aimed to assess the perceptions of pharmacology faculty members from medical colleges in southern India regarding the use of animals and alternatives in experimental pharmacology, and to determine the association between these perceptions and the socio-demographic characteristics of the participants. Data were collected from 59 faculty members of 15 medical colleges in southern India. The response rate was 84.3%. A 30-statement, five-domain questionnaire was used, with a global score of 120. The mean ± SD global score was 60.9 ± 17.3. Significant differences were observed in domain scores and individual statement scores with respect to the extent of teaching experience. There were no statistically significant differences in perceptions with respect to age, gender or educational qualifications. All the participating colleges were conducting at least 3-8 animal experiments per year on the rabbit, rat, mouse and frog/toad. The pharmacology faculty members in the southern India medical colleges included in the study (especially the more experienced teachers) supported animal use in undergraduate medical education, in spite of being aware of the drawbacks of animal experiments and the availability of alternatives.  相似文献   
3.
Eukaryotic cells utilize oxygen for different functions of cell organelles owing to cellular survival. A balanced oxygen homeostasis is an essential requirement to maintain the regulation of normal cellular systems. Any changes in the oxygen level are stressful and can alter the expression of different homeostasis regulatory genes and proteins. Lack of oxygen or hypoxia results in oxidative stress and formation of hypoxia inducible factors (HIF) and reactive oxygen species (ROS). Substantial cellular damages due to hypoxia have been reported to play a major role in various pathological conditions. There are different studies which demonstrated that the functions of cellular system are disrupted by hypoxia. Currently, study on cellular effects following hypoxia is an important field of research as it not only helps to decipher different signaling pathway modulation, but also helps to explore novel therapeutic strategies. On the basis of the beneficial effect of hypoxia preconditioning of cellular organelles, many therapeutic investigations are ongoing as a promising disease management strategy in near future. Hence, the present review discusses about the effects of hypoxia on different cellular organelles, mechanisms and their involvement in the progression of different diseases.  相似文献   
4.
Diabetes mellitus impairs testicular activity and leads to infertility. Leptin is one of the endogenous regulators of the male reproductive functions, but the role of leptin and its receptor (LEPR/Ob‐R) in the control of testosterone production and testicular proliferation has not been investigated so far, especially in the Type 1 diabetes mellitus (DM1). Metformin is an anti‐hyperglycemic drug which is beneficial for treating the both DM2 and DM1. The aim of this work was to study the possible role of leptin and Ob‐R in the regulation of steroidogenesis and proliferation in the testes of mice with streptozotocin‐induced DM1 (75 mg/kg/day, 4 days) and to estimate the restoring effect of metformin treatment (500 mg/kg, 2 weeks) on the diabetic testes. In the diabetic testes, the plasma and intratesticular leptin levels and plasma testosterone levels were reduced and completely restored by metformin treatment. Metformin also restored the expression of the steroidogenic transport protein steroidogenic acute regulatory protein reduced in DM1. In the diabetic testes, the expression of Ob‐R was downregulated and the immunolocalization of Ob‐R showed weak staining in the Leydig cells, the primary spermatocytes and the round spermatids. The germ cell proliferation was also reduced in DM1, as noticed with proliferating cell nuclear antigen (PCNA) expression. Metformin increased the Ob‐R expression and immunostaining in the different cell types and improved the PCNA expression. Thus, DM1 impairs the testicular steroidogenesis and proliferation by inhibiting the leptin signaling, causing a decrease in leptin levels and Ob‐R expression in the testes of diabetic mice, while metformin improves the leptin signaling and restores testosterone production and testicular proliferation.  相似文献   
5.
The present study aimed to investigate the effects of vitamin D3 in the epididymal sperm cells of D ‐gal‐induced aged rats. It is well known that during aging sperm quality and quantity declines and leads to age‐related infertility problems in males. The results of the present study showed that there were elevated levels of oxidative stress and poor DNA integrity of sperm of aged rats. The expression of BCL2 also showed a significant decline in the sperm of aged rats, however, the expression of BAX and active caspase‐3 did not show significant change compared with the control group. The treatment of vitamin D3 at lower doses to aged rats showed increased expression of BAX and active caspase‐3 in the sperm, this finding suggests that increased apoptosis may be responsible for removal of poor quality sperm during aging. Vitamin D3 treatment at both doses showed improvement in the oxidative stress and DNA integrity in the sperm of aged rats. We also investigated the expression of AGER, visfatin, and HSPA1A in the epididymal sperm. It has been found that expression of AGER, visfatin, and HSPA1A increased in the sperm aged rats and vitamin D3 treatments at both doses decreased its expression. Thus, it might be suggested that during aging vitamin D3 treatment would be important for managing the sperm quality by regulating the apoptosis, antioxidant system and DNA integrity via modulation of visfatin and HSPA1A.  相似文献   
6.
Physical forces direct the orientation of the cell division axis for cells cultured on rigid, two-dimensional (2D) substrates. The extent to which physical forces regulate cell division in three-dimensional (3D) environments is not known. Here, we combine live-cell imaging with digital volume correlation to map 3D matrix displacements and identify sites at which cells apply contractile force to the matrix as they divide. Dividing cells embedded in fibrous matrices remained anchored to the matrix by long, thin protrusions. During cell rounding, the cells released adhesive contacts near the cell body while applying tensile forces at the tips of the protrusions to direct the orientation of the cell division axis. After cytokinesis, the daughter cells respread into matrix voids and invaded the matrix while maintaining traction forces at the tips of persistent and newly formed protrusions. Mechanical interactions between cells and the extracellular matrix constitute an important mechanism for regulation of cell division in 3D environments.  相似文献   
7.
The interactions between biochemical processes and mechanical signaling play important roles during various cellular processes such as wound healing, embryogenesis, metastasis, and cell migration. While traditional traction force measurements have provided quantitative information about cell matrix interactions in two dimensions, recent studies have shown significant differences in the behavior and morphology of cells when placed in three-dimensional environments. Hence new quantitative experimental techniques are needed to accurately determine cell traction forces in three dimensions. Recently, two approaches both based on laser scanning confocal microscopy have emerged to address this need. This study highlights the details, implementation and advantages of such a three-dimensional imaging methodology with the capability to compute cellular traction forces dynamically during cell migration and locomotion. An application of this newly developed three-dimensional traction force microscopy (3D TFM) technique to single cell migration studies of 3T3 fibroblasts is presented to show that this methodology offers a new quantitative vantage point to investigate the three-dimensional nature of cell-ECM interactions.  相似文献   
8.
In India, animal experiments play an integral role in both undergraduate medical education (UGME) and postgraduate medical education (PGME) in the discipline of Pharmacology. Therefore, we aimed to compare the perceptions of pharmacology faculty members in southern India with regard to the use of animal experiments and alternatives in UGME and in PGME. We also determined the association between these perceptions and the socio-demographic characteristics of the participants. Pharmacology faculty members in 15 medical colleges located in southern India answered a 27-statement, 5-domain questionnaire with a total score of 108. The means of the total, domain and statement scores were analysed by the Wilcoxon signed-rank test. The mean total score obtained for faculty members (n = 52) was significantly higher (p < 0.001) for PGME (61.2/108) than that for UGME (51.9/108). Significant differences were observed in the mean total and in the domain scores for PGME when compared to UGME in all of the socio-demographic groups, except for male faculty members and those without an MD or doctoral degree. The mean individual statement scores also indicated that there is more support for animal use in PGME. Overall, it was apparent that pharmacology faculty members in southern Indian medical colleges support animal use in PGME more than in UGME. Increased awareness is required among faculty members concerning alternatives to animal experiments in medical education, especially in PGME.  相似文献   
9.
The present study illustrates an optimized sample preparation method for an efficient DNA isolation from low quantities of honey samples. A conventional PCR-based method was validated, which potentially enables characterization of plant species from as low as 3 ml bee-honey samples. In the present study, an anionic detergent was used to lyse the hard outer pollen shell, and DTT was used for isolation of thiolated DNA, as it might facilitate protein digestion and assists in releasing the DNA into solution, as well as reduce cross-links between DNA and other biomolecules. Optimization of both the quantity of honey sample and time duration for DNA isolation was done during development of this method. With the use of this method, chloroplast DNA was successfully PCR amplified and sequenced from honey DNA samples.  相似文献   
10.
Cadmium (Cd) is one of the heavy metal pollutants present in the environment due to human intervention. It is well known that Cd causes toxicological effects on various organs, including the testes. Morin hydrate is a plant-derived bioflavonoid with antioxidant, anti-inflammatory, and anti-stress properties. Thus, the question can be raised as to whether Morin has an effect on Cd-intoxication-induced testicular impairment. Therefore, the aim of this study was to investigate the role of Morin on Cd-mediated disruption of testicular activity. Mice were divided into three groups: group 1 served as the control group, group 2 was given Cd (10 mg/kg) orally for 35 days, and group 3 was given Cd and Morin hydrate (100 mg/kg) for 35 days. To validate the in vivo findings, an in vitro study on testicular explants was also performed. The results of the in vivo study showed that Cd-intoxicated mice had testicular disorganization, reduced circulating testosterone levels, decreased sperm density, and elevated oxidative stress and sperm abnormality. The expression of the germ cell proliferation marker, germ cell nuclear acidic protein (GCNA), and adipocytokine visfatin were also downregulated. It was observed that Morin hydrate upregulated testicular visfatin and GCNA expression in Cd-intoxicated mice, along with improvement in circulating testosterone, testicular histology, and sperm parameters. Furthermore, the in vitro study showed that Cd-mediated downregulation of testicular visfatin and GCNA expression, along with the suppressed secretion of testosterone from testicular explants, was normalized by Morin treatment, whereas visfatin expression was not. Overall, these data indicate that environmental cadmium exposure impairs testicular activity through downregulation of visfatin and GCNA expression, and Morin might play a protective role against Cd-induced testicular toxicity.  相似文献   
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