Drosophila simulans Lethal hybrid rescue mutation (Lhr) rescues inviable hybrids by restoring X chromosomal dosage compensation and causes fluctuating asymmetry of development

The Drosophila simulans Lhr rescues lethal hybrids from the cross of D. melanogaster and D. simulans. We describe here, the phenotypes of Lhr dependent rescue hybrids and demonstrate the effects of Lhr on functional morphology of the salivary chromosomes in the hybrids. Our results reveal that the phenotypes of the 'Lhr dependent rescued' hybrids were largely dependent on the genetic background and the dominance in species and hybrids, and not on Lhr. Cytological examination reveal that while the salivary chromosome of 'larval lethal' male carrying melanogaster X chromosome was unusually thin and contracted, in 'rescued' hybrid males (C(mel)X(mel)Y(sim); A(mel)A(sim)) the X chromosome showed typical pale staining, enlarged diameter and incorporated higher rate of (3)H-uridine in presence of one dose Lhr in the genome. In hybrid males carrying simulans X chromosome (C(mel)X(sim)Y(mel); A(mel)A(sim)), enlarged width of the polytene X chromosome was noted in most of the nuclei, in Lhr background, and transcribed at higher rate than that of the single X chromosome of male. In hybrid females (both viable, e.g., C(mel)X(mel)X(sim); A(mel)A(sim) and rescued, e.g., C(mel)X(mel)X(mel); A(mel)A(sim)), the functional morphology of the X chromosomes were comparable to that of diploid autosomes in presence of one dose of Lhr. In hybrid metafemales (C(mel)X(mel)X(mel)X(sim); A(mel)A(sim)), two dose of melanogaster X chromosomes and one dose of simulans X chromosome were transcribed almost at 'female' rate in hybrid genetic background in presence of one dose of Lhr. In rescued hybrid males, the melanogaster-derived X chromosome appeared to complete its replication faster than autosomes. These results together have been interpreted to have suggested that Lhr suppresses the lethality of hybrids by regulating functional activities of the X chromosome(s) for dosage compensation.

Validity of 20 meter multi stage shuttle run test for prediction of maximum oxygen uptake in Indian female university students

BACKGROUND

The 20-meter multi stage shuttle run test (20-m MST) has not yet been used by Indian scientists and validity of the test has not been studied for use with any of the Indian population.

AIMS

The purpose of this study was to validate the applicability of the 20-m MST in Indian adult female.

MATERIALS AND METHODS

For application of direct method cross over design was followed. For validity of the results repeatability was used.

METHODS AND MATERIAL

32 female university students (age range 20.4 approximately 24.8 years) from three different universities of West Bengal, India were recruited for the study. Direct estimation of VO2 max comprised treadmill exercise followed by expired gas analysis by scholander micro-gas analyzer whereas VO2 max was indirectly predicted by the 20-m MST.

STATISTICAL ANALYSIS

Paired t-test, Pearson's product moment correlation, linear regression statistics and Bland and Altman approach for limit of agreement were adopted for statistical analysis of the data.

RESULTS

The difference between the mean (SD) VO2 max values of direct measurement (VO2 max = 32.84 +/- 2.92 ml/kg/min) and the 20-m MST (SPVO2 max = 32.60 +/- 3.40 ml/kg/min) was statistically insignificant (p>0.10). Limits of agreement analysis also suggest that the 20-m MST can be applied for use with the studied population.

CONCLUSIONS

The results suggest that the application of the present form of the 20-m MST be justified in the studied population. For better prediction of VO2 max a new equation has been computed based on present data for use with Indian female university students.

Double coins at the oesophageal inlet

Multiple foreign bodies lodged in the oesophagus are extremely rare. Here an unusual case of two coins accidentally lodged at the oesophageal inlet of a six-year-old girl is reported. The coins were successfully removed by oesophagoscopy. It is to be noted that apart from the straight x-ray (PA view) of the neck and chest, a lateral view is essential for proper characterisation and identification of the type and number of foreign bodies prior to surgical removal.

Study of plasma lipid and lipoprotein profile in elite women boxers during a six weeks' training progamme

The present study was undertaken with an objective to frame out the lipid profile of Indian Women Boxers. Women boxing is a newly recognized game and no work has been reported on elite female boxers in India till date. The study was based on a sample of 45 women boxers (age 17 ~ 24 years) attending Senior National Women Boxing Camp at Sports Authority of India. Each subject was evaluated for Lipid Profile variables at the beginning and end of the six weeks training camp. Fasting blood samples were taken from the antecubital vein by venipuncture. Before the samples drawn the subjects were asked to take rest for ten minutes. The blood sample was analyzed by HITACHI UV-2000 spectrophotometer (Japan). Standard techniques and procedures were followed for all the estimation. Volume and intensity of different components of training was measured by observational and physiological methods. Data were subjected to statistical treatment like mean and standard deviation. Test of significance't' - test (for paired sample) was applied to asses the difference in pre & post-test. Results reveal that mean (+/-SD) Cholesterol, Triglyceride, LDL, HDL - Cholesterol and Cholesterol / HDL Cholesterol ratio was 144.7 +/- 3.6 mg%, 59.7 +/- 17.5 mg% 81.4 +/- 21.1 mg% 51.3 +/- 8.2 mg% and 2.8 +/- 0.5 respectively as found in the pre-test. Significant difference (P < 0.01) was observed in Cholesterol, LDL-Cholesterol, HDL Cholesterol level in the post-test. The study concludes that women who practice sport of boxing on regular basis have a favorable lipid profile. A significant change in lipid profile of the boxers was observed after 6 weeks' training program.

Energy expenditure in women boxing

OBJECTIVES

Women boxing have got recognition recently and so far no work has been reported on energy expenditure of national women boxers in India. This study was aimed to estimate the energy expenditure in Indian female boxers during sparring.

METHODS

A total of 20 female boxers were subjected. Energy expenditure was estimated using the same individual's HR-VO2 regression equation. Heart rate was recorded through radiotelemetry.

RESULTS

Results reveal that average and maximum energy expenditure considering the total duration of boxing are 12.7 +/- 1.3 and 14.4 +/- 1.6 kcal/min.

CONCLUSIONS

It is concluded that depending on the severity of energy expenditure female boxing comes under heavy category and as it is a pioneer attempt in India, further studies in this aspect are really required which will guide the coaches regarding the energy expenditure pattern in women boxing.

Work related physical exertion and spontaneous abortion

A retrospective cohort study was undertaken among 100 women workers of 35-40 years of age to elicit the risk of spontaneous abortion. Comparison was made with a matched control group of 100 non-working women. Employed women were found at increased risk of spontaneous abortion than the control group. The difference was found statistically significant at p < 0.05, Odds ratio being 1.50 and AR% being 33.14. According to gravidity also, abortion was found to be significantly raised in working women after their joining service for first 3rd - 4th gravida. The risk then fell, to raise again for 8th or more gravida.

Validity of Queen's College step test for use with young Indian men

OBJECTIVES

To assess the suitability of the Queen's College step test (QCT) to predict maximum oxygen uptake in Indian men.

METHODS

Thirty sedentary male university students from West Bengal, India, with the same socioeconomic background and mean (SD) age, height, and weight of 22.6 (0.2) years, 166.4 (0.5) cm, and 53.8 (0.2) kg, respectively, were randomly sampled from University of Calcutta. VO2max of each participant was determined by direct procedure involving incremental bicycle exercise and also by applying indirect QCT method with a gap of 4 days between the tests.

RESULTS

The difference between the mean (SD) VO2max values directly measured (VO2max = 39.8 (1.03) ml/min/kg body mass) and indirectly predicted (PVO2max = 39.3 (1.07) ml/min/kg body mass) was statistically insignificant (p>0.10). PVO2max and VO2max values expressed as ml/min/kg body mass corroborated with previous studies in the same laboratory involving the same population, and also exhibited significant statistical correlation (r = 0.95, p<0.001) between them.

CONCLUSION

The results suggest that QCT can be applied in the studied population to produce a good estimation of maximum oxygen uptake, especially in the field where large numbers of participants are to be evaluated without a well equipped laboratory.

An unusual foreign body (Big Metallic Nut) in the nasopharynx of an infant

Foreign body in the nasopharynx is an extremely rare conidition; however a big metallic nut in the masopharynx of an infant of eight- months has not been previously reported in literature. We report an unusual case where an eight-month-old child introduced a big metallic nut through the mouth and was lodged in the nasopharynx, with a brief review of literature regarding the diagnosis and management of such case.

Patterns of tobacco use amongst school teachers

Indulgence in tobacco is a known health risk. The example of school teachers in this regard is likely to have far reaching influence on their pupils and the community. A cross sectional study among 257 teachers from 30 schools revealed that as high as 51.0% teachers consumed tobacco in one form or the other. Smoking was the most popular form of tobacco use (72%). Marked gender differences were noted with 73.9%. Male teachers hooked to tobacco habit in comparison to 13.9% of female teachers. Educational qualification had paradoxical effect on tobacco habit as fewer (20.0%) graduate teachers used tobacco in comparison to non graduate teachers (55.7%). However proportion of Post graduate teachers consuming tobacco was still higher (64.2%). Initiation to tobacco habit in majority began at age 21 years and beyond. Common reasons given for tobacco consumption were curiosity (37.9%), to be social (22.0%), enjoyment (21.2%), to relieve stress (8.17%) and improving performance (5.8%). 21.9% smokers consumed more than 20 cigarettes a day. More than four fifth teachers consciously avoided tobacco use in school premises. Nearly half (45.3%) of tobacco users reported reduction in tobacco use in preceding two years. By and large teachers (92.4%) were aware of harmful consequences of tobacco on health. But only in 29.6% it was a cause for concern. 71.2% respondents intended to give up tobacco habit. 33.7% smokers were aware of hazards of passive smoking to others.

Microbial transformations of the antimelanoma agent betulinic acid

Microbial transformation studies of the antimelanoma agent betulinic acid (1) were conducted. Screening experiments showed a number of microorganisms capable of biotransforming 1. Three of these cultures, Bacillus megaterium ATCC 14581, Cunninghamella elegans ATCC 9244, and Mucor mucedo UI-4605, were selected for preparative scale transformation. Bioconversion of 1 with resting-cell suspensions of phenobarbital-induced B. megaterium ATCC 14581 resulted in the production of the known betulonic acid (2) and two new metabolites: 3beta,7beta-dihydroxy-lup-20(29)-en-28-oic acid (3) and 3beta,6alpha, 7beta-trihydroxy-lup-20(29)-en-28-oic acid (4). Biotransformation of 1 with growing cultures of C. elegans ATCC 9244 produced one new metabolite characterized as 1beta,3beta, 7beta-trihydroxy-lup-20(29)-en-28-oic acid (5). Incubation of 1 with growing cultures of M. mucedo UI-4605 afforded metabolite 3. Structure elucidation of all metabolites was based on NMR and HRMS analyses. In addition, the antimelanoma activity of metabolites 2-5 was evaluated against two human melanoma cell lines, Mel-1 (lymph node) and Mel-2 (pleural fluid).

Biotransformation of the antimelanoma agent betulinic acid by Bacillus megaterium ATCC 13368

Microbial transformation of the antimelanoma agent betulinic acid was studied. The main objective of this study was to utilize microorganisms as in vitro models to predict and prepare potential mammalian metabolites of this compound. Preparative-scale biotransformation with resting-cell suspensions of Bacillus megaterium ATCC 13368 resulted in the production of four metabolites, which were identified as 3-oxo-lup-20(29)-en-28-oic acid, 3-oxo-11alpha-hydroxy-lup-20(29)-en-28-oic acid, 1beta-hydroxy-3-oxo-lup-20(29)-en-28-oic acid, and 3beta,7beta, 15alpha-trihydroxy-lup-20(29)-en-28-oic acid based on nuclear magnetic resonance and high-resolution mass spectral analyses. In addition, the antimelanoma activities of these metabolites were evaluated with two human melanoma cell lines, Mel-1 (lymph node) and Mel-2 (pleural fluid).

Enhanced H(2)O(2)-induced cytotoxicity in "epithelioid" smooth muscle cells: implications for neointimal regression

Vascular smooth muscle cells (SMCs) are phenotypically diverse. Although most medial SMCs can be classified as "fusiform," others are of the "epithelioid" phenotype. Proliferation and apoptosis of epithelioid SMCs may contribute importantly to neointimal formation and regression, respectively. Because reactive oxygen species (ROS) are increased in vascular injury and can induce apoptosis of SMCs, we compared the effects of ROS on epithelioid and fusiform SMCs. Epithelioid and fusiform SMC lines were clonally isolated from rat aortic media and studied under similar conditions and passage numbers. H(2)O(2) produced dose- and time-dependent cytotoxicity that was enhanced in epithelioid compared with fusiform cells. After 24-hour exposure to 50 micromol/L H(2)O(2), epithelioid cell numbers were reduced by 34+/-5% versus a 3+/-5% (P<0.05) reduction in fusiform cell numbers. Similar results were obtained whether H(2)O(2) was administered to growth-arrested or growing cells or when epithelioid and fusiform cells were exposed to extracellular O(2)(.-). To investigate whether apoptosis contributed to enhanced ROS-induced cytotoxicity in epithelioid SMCs, terminal deoxyribonucleotidyl transferase (TDT)-mediated dUTP-digoxigenin nick-end labeling (TUNEL) staining was performed. The incidence of TUNEL positivity was 5-fold increased in epithelioid versus fusiform SMCs after treatment with 50 micromol/L H(2)O(2) (19+/-1% epithelioid versus 5+/-1% fusiform, P<0.05). Enhanced H(2)O(2)-induced apoptosis in epithelioid SMCs was confirmed by DNA laddering. Furthermore, when balloon-injured aortas were exposed to H(2)O(2) ex vivo, enhanced apoptosis was observed in neointimal compared with medial SMCs. These results suggest that epithelioid SMCs exhibit enhanced sensitivity to ROS-induced apoptosis, which may play an important role in neointimal regression.

Epoxide hydrolases regulate epoxyeicosatrienoic acid incorporation into coronary endothelial phospholipids

Cytochrome P-450-derived epoxyeicosatrienoic acids (EETs) are avidly incorporated into and released from endothelial phospholipids, a process that results in potentiation of endothelium-dependent relaxation. EETs are also rapidly converted by epoxide hydrolases to dihydroxyeicosatrienoic acid (DHETs), which are incorporated into phospholipids to a lesser extent than EETs. We hypothesized that epoxide hydrolases functionally regulate EET incorporation into endothelial phospholipids. Porcine coronary artery endothelial cells were treated with an epoxide hydrolase inhibitor, 4-phenylchalcone oxide (4-PCO, 20 micromol/l), before being incubated with (3)H-labeled 14,15-EET (14,15-[(3)H]EET). 4-PCO blocked conversion of 14,15-[(3)H]EET to 14,15-[(3)H]DHET and doubled the amount of radiolabeled products incorporated into cell lipids, with >80% contained in phospholipids. Moreover, pretreatment with 4-PCO before incubation with 14,15-[(3)H]EET enhanced A-23187-induced release of radiolabeled products into the medium. In contrast, 4-PCO did not alter uptake, distribution, or release of [(3)H]arachidonic acid. In porcine coronary arteries, 4-PCO augmented 14,15-EET-induced potentiation of endothelium-dependent relaxation to bradykinin. These data suggest that epoxide hydrolases may play a role in regulating EET incorporation into phospholipids, thereby modulating endothelial function in the coronary vasculature.

Overexpression of human catalase inhibits proliferation and promotes apoptosis in vascular smooth muscle cells

The role of reactive oxygen species, such as superoxide anions (O(2). (-)) and hydrogen peroxide (H(2)O(2)), in modulating vascular smooth muscle cell proliferation and viability is controversial. To investigate the role of endogenously produced H(2)O(2), rat aortic smooth muscle cells were infected with adenoviral vectors containing cDNA for human catalase (AdCat) or a control gene, beta-galactosidase (AdLacZ). Infection with AdCat resulted in dose-dependent increases in intracellular catalase protein, which was predominantly localized to peroxisomes. After infection with 100 multiplicity of infection (MOI) of AdCat, cellular catalase activity was increased by 50- to 100-fold, and intracellular H(2)O(2) concentration was reduced, as compared with control. Infection with AdCat reduced [(3)H]thymidine uptake, an index of DNA synthesis, in cells maintained in medium supplemented with 2% serum (0.37+/-0.09 disintegrations per minute per cell [AdLacZ] versus 0.22+/-0.08 disintegrations per minute per cell [AdCat], P<0.05). Five days after infection with 100 MOI of AdCat, cell numbers were reduced as compared with noninfected or AdLacZ-infected cells (157 780+/-8413 [AdCat], P<0.05 versus 233 700+/-3032 [noninfected] or 222 410+/-5332 [AdLacZ]). Furthermore, the number of apoptotic cells was increased 5-fold after infection with 100 MOI of AdCat as compared with control. Infection with AdCat resulted in induction of cyclooxygenase (COX)-2, and treatment with a COX-2 inhibitor overcame the AdCat-induced reduction in cell numbers. These findings indicate that overexpression of catalase inhibited smooth muscle proliferation while increasing the rate of apoptosis, possibly through a COX-2-dependent mechanism. Our results suggest that endogenously produced H(2)O(2) importantly modulates survival and proliferation of vascular smooth muscle cells.