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Biomedical subjects

M Mohan

Publications and source records attributed to M Mohan.

At least 37 records · Page 2Linked to original sources

Prevalence of symptomatic BPE among Malaysian men aged 50 and above attending screening during prostate health awareness campaign.

OBJECTIVE: To study the prevalence of symptomatic BPE among Malaysian men age 50 and above attending prostate health awareness campaign and to identify differences in prevalence between different ethnic groups residing within metropolitan Kuala Lumpur. MATERIALS AND METHODS: Demographic data and the completed International Prostate Symptom Score (IPSS), maximal uroflow rate (Qmax) and prostate size of volunteers, aged 50 and above, who attended the prostate health awareness campaign were analyzed. Subjects with known prostate diseases or prostate surgery, bladder disorders and neurological disorders were excluded. RESULTS: 2086 volunteers attended the campaign. 575 men fulfilled the inclusion criteria and their demographic data, IPSS; peak flow rate and prostate volume were analysed. Overall, 18.9% and 39.6% of the men were severely and moderately symptomatic, respectively. The prevalence of moderate to severe lower urinary tract symptoms (LUTS) in Malays, Chinese and Indians were 70%, 59% and 50% respectively (p = 0.004). The commonest bothersome symptoms were nocturia (56%), frequency (50.4%) and sense of incomplete voiding (43.5%). The mean peak flow rate of the subjects was 15.4 ml/s. 20.9% and 55.2% of the subjects had peak flow less than 10 ml/sec and 15 ml/sec respectively. The mean prostate size was 25.1 cc. There is no significant difference in term of maximal flow rate and prostate size among Malays, Chinese and Indians in Malaysia. A good correlation was found between the total symptom score and the single disease-specific quality of life question (r = 0.69, p < 0.001). The correlation between IPSS and peak flow rate (r = -0.22, p < 0.001) and prostate volume (r = 0.11, p = 0.009) was weak. There was no correlation between IPSS and age (r = 0.06, p = 0.17). The prevalence of symptomatic benign prostate enlargement (BPE) was 39.3%. The prevalence increased 8% per decade from 41.7% for men aged 50 to 59 to 65.4% for men aged 70 or more. There is no significant difference in prevalence of symptomatic BPE among the three ethnic groups. The Prevalence of BPO was 15.8%. CONCLUSION: The correlation between symptom score, maximal flow rate and prostate size was poor and one cannot predict the value of one parameter by knowing one or more of the other parameters. There is a high prevalence of LUTS suggestive of benign prostatic obstruction in the apparently healthy Malaysian aged 50 and above attending the prostate health awareness campaign.

Age Factors↗

An AFLP marker that differentiates biotypes of the Asian rice gall midge (Orseolia oryzae, Wood-Mason) is sex-linked and also linked to avirulence.

In an attempt to identify a specific marker for biotype 2 of the Asian rice gall midge (Orseolia oryzae, Wood-Mason), we used AFLP (amplified fragment length polymorphism) fingerprinting. We identified an AFLP marker that is specifically amplified in biotypes 1, 2 and 5 of the rice gall midge, but not in biotype 4. Biotypes 1, 2 and 5 are avirulent to hosts bearing the Gm2 resistance gene (found in rice variety Phalguna), whereas biotype 4 is virulent to Gm2. Based on the sequence of this AFLP marker, SCAR (sequence characterized amplified region) primers were designed and used in combination with previously developed SCAR primers to distinguish effectively all five biotypes in a multiplex PCR-based assay. The inheritance pattern of this marker in the progenies of inter-biotype crosses between biotypes 1, 2 and 4 shows that the marker can be amplified by PCR from all F1 females, irrespective of the biotype status of their parents. However, the marker is present only in those male progenies whose mother was of a Gm2 avirulent biotype. The specific amplification of this marker in the avirulent biotypes and its pattern of inheritance show that avirulence with respect to carriers of the Gm2 gene in rice gall midge is sex-linked.

Animals↗

Perineal application of talc and cornstarch powders: evaluation of ovarian cancer risk.

Some epidemiologic studies have reported associations between perineal talc exposure and epithelial ovarian cancer, which raises parallel questions about the consequences of perineal exposure to cornstarch. Cornstarch powder is an alternative to talc powder that by its nature is a completely different substance. In this review of the literature the epidemiologic data on ovarian cancer risk and perineal application of both powders are reviewed, and the chemical natures of the two powders are compared. All available data indicate that whereas associations between talc exposure and ovarian cancer have suggested but not proved a casual relationship, the application of perineal powder containing cornstarch exclusively is not predicted to be a risk factor for ovarian cancer.

Emollients↗

Modulation of feeding and drinking behaviour by catecholamines injected into nucleus accumbens in rats.

Nucleus accumbens is proposed as one of the centers in the neural circuitry involved in the regulation of feeding and drinking behaviour in rats. Injection of dopamine and angiotensin-II into this nucleus has been documented to affect water and food intake in rats. Reports on the effect of intracerebral injection of catecholamines on feeding and drinking behaviour in animal models are conflicting. Therefore, in the present study the effect of adrenaline and noradrenaline injected into nucleus accumbens on food and water intake in rats was assessed. 24 h basal food and water intakes were recorded in Wistar rats and were found to be 12.3 +/- 0.46 g and 21.7 +/- 1.03 ml respectively. Stainless steel cannulae were implanted stereotaxically into the nucleus accumbens. Four different doses (0.1 microgram, 0.5 microgram, 1 microgram, and 2 micrograms) of adrenaline and noradrenaline were injected into the nucleus accumbens through the implanted cannulae in different group of animals and their 24 h food and water intakes were recorded following these injections. No change in food and water intake was observed following the administration of different doses of adrenaline. A significant increase in 24 h water intake reaching a maximum of 28.88 +/- 1.45 ml at 1 microgram dose, without change in food intake was observed following administration of different doses of noradrenaline. The noradrenaline-facilitated water intake was blocked when noradrenaline was injected following injection of phentolamine, an alpha-receptor blocker. The bilateral lesions of nucleus accumbens resulted in a significant and sustained inhibition of water intake (16.61 +/- 0.67 ml) without change in food intake. These observations suggest that noradrenaline facilitates water intake without affecting food intake when injected into the nucleus accumbens in rats and the dipsogenic effect of noradrenaline is mediated by alpha-receptors. Adrenaline does not affect these ingestive behaviours when injected into the nucleus accumbens in rats.

Adrenergic Agonists↗

Effect of head-up tilt on cardiovascular responses in normal young volunteers.

Since the cardiovascular effects of tilting are influenced by degree as well as duration of the tilt, we planned to study the time course of blood pressure and heart rate (HR) responses during 30 degrees, 60 degrees, 80 degrees head up tilt (HUT). The study was conducted on 20 volunteers aged 18-20 y who were tilted on a tilting table. Blood pressure was determined by sphygmomanometer and HR was calculated from R-R interval of ECG. 30 degrees HUT produced an insignificant decrease in systolic pressure (SP) and pulse pressure (PP) while diastolic pressure (DP), mean pressure (MP) and rate-pressure-product (RPP) registered an insignificant rise. The changes produced by 60 degrees and 80 degrees HUT were more marked than those produced by 30 degrees HUT. While SP and PP decreased significantly, HR and RPP increased significantly. In conclusion, 30 degrees HUT produces insignificant changes while 60 degrees and 80 degrees HUT produce significant changes in SP, PP and RPP.

Adolescent↗

Association of maternal IgM concentrations above the median at 15-19 weeks of gestation and early preterm delivery.

IgM concentrations greater than the median in maternal serum collected at 15-19 weeks of pregnancy were strongly associated (odds ratio 15.6) with delivery before 29 weeks. Our results suggest that the postulated inflammatory component in the aetiology of very preterm delivery may elicit a measurable maternal humoral response as early as mid-trimester.

Case-Control Studies↗

Spontaneous absorption of a cataractous lens.

A case of spontaneous absorption of a cataractous lens is presented. A 37-year-old woman with Down's syndrome presented with bilateral cataracts. On follow-up, the cataract in her right eye was found to be absorbed with no secondary uveitis or glaucoma. Surgical capsulotomy was performed on the remnant anterior and posterior capsules. Such absorption is known in juveniles and in hypermature cataract, but is rare in adults in the absence of injury or inflammation. Absorption occurred over a period of one year.

Absorption↗

Differentiation of Asian rice gall midge, Orseolia oryzae (Wood-Mason), biotypes by sequence characterized amplified regions (SCARs).

We developed a polymerase chain reaction (PCR)-based assay that distinguished five different biotypes of the Asian gall midge (Orseolia oryzae), a major insect pest of rice. A total of 400 random primers were screened using random amplified polymorphic DNAs (RAPDs). Five diagnostic PCR products were isolated, cloned, sequenced and converted to sequence characterized amplified regions (SCARs). Primers specific to these SCARs were able to amplify specific DNA fragments from genomic DNAs of five biotypes of gall midge in a multiplexed-PCR-based assay. The amplified DNA fragments were used as diagnostic markers to identify different biotypes of gall midge. The SCAR primers were also capable of differentiating the Asian from the African rice gall midge (Orseolia oryzivora) as well as detecting a variant of biotype 5 which caused an outbreak in Kerala, India. Unlike the use of plant host differentials and midge feeding behaviour for identifying biotypes, this assay is fast, reliable and unaffected by environmental factors.

Animals↗

Effects of unilateral ovariectomy on follicular development and ovulation in cattle.

In a study of 4 cyclic dry cows (Trial I) and 6 cyclic puberal heifers (Trial II), unilateral ovariectomy increased the number of ovulatory follicles, did not alter the hormone profile, cycle length or the number of follicular waves. Ovarian follicular development in all 4 cows was monitored daily using transrectal ultrasonography until the day of ovulation, during which period daily blood samples were also taken from the tail vein for determination of plasma FSH, LH and P4 concentrations. Unilateral ovariectomy was performed on the day after ovulation and ovarian activity was again monitored daily (ultrasonography and blood sampling for FSH, LH and P4) for 2 consecutive cycles (8 cycles in all). Estrus in all 6 heifers was synchronized using 2 injections of PGF2 alpha given 12 d apart. Similarly, ovarian activity in the 6 puberal heifers was monitored daily using ultrasonography and blood sampling for 1 complete control cycle. Following estrus and ovulation the left ovary was removed in all the animals, and thereafter 1 complete cycle was followed. Mean cycle length, FSH, LH and P4 concentrations before and after unilateral ovariectomy were compared using paired sample t-test. The results show that unilateral ovariectomy neither altered the cycle length nor the number of follicular waves in the cows, but it increased the number of ovulatory follicles (2 follicles developed and ovulated in 6 of the 8 cycles). The mean diameter of the largest follicle was 16.1 +/- 0.9 mm and the second largest 12.5 +/- 0.9 mm. No significant (P > 0.05) differences were observed in FSH (0.72 +/- 0.09 vs 0.71 +/- 0.07), LH (0.42 +/- 0.1 vs 0.37 +/- 0.07) and P4 (2.8 +/- 0.6 vs 2.6 +/- 0.4) levels before and after unilateral ovariectomy. Of the 6 heifers, 5 had 2 waves and 1 heifer had 3 waves of follicular growth during the control cycle, and this pattern did not change after the procedure. Mean cycle length (20.7 +/- 0.9 vs 21 +/- 0.9) did not differ before and after unilateral ovariectomy, and 4 of the 6 heifers ovulated twin follicles following ovariectomy. The mean diameter of the largest follicle was 14.5 +/- 0.7 mm and second largest measured 12.1 +/- 0.8 mm. No significant (P > 0.05) differences were observed in FSH (0.16 +/- 0.09 vs 0.21 +/- 0.07), LH (0.11 +/- 0.1 vs 0.15 +/- 0.07) and P4 levels (3.6 +/- 0.26 vs 3.8 +/- 0.29) before and after unilateral ovariectomy. Based on these results, we conclude that unilateral ovariectomy is an ideal method for obtaining twin ovulations in cows and heifers.

Animals↗

Potential health risks related to carcinogens in the atmospheric environment in India.

In India, rapid urbanization and industrialization have contributed positively toward meeting the materialistic needs of the citizens, but have also resulted in contamination of the atmospheric environment. This paper deals with the assessment of potential health risks posed by carcinogenic substances, namely cadmium, chromium, and nickel, present in certain atmospheric environments in India. Average air concentrations of these carcinogenic metals have been assessed for different states and regions of India (C. R. Krishnamurti and P. Vishwanathan, Toxic Metals in the Indian Environment, Tata/McGraw-Hill, New Delhi, 1991). Based on these assessments, both individual and societal risks have been estimated in different states of the country, and comparisons were made. Reported concentration, release sources, potential health risks including cancer risk estimates, and ambient air interim guidelines are discussed. The reported environmental releases and cancer risk from cadmium are minimal. There is a potential for increased respiratory cancer risk from exposure to chromium and nickel in some northern Indian states. These metals are irritants to nasal passages and the respiratory tract. Chromium is also corrosive to mucus membranes. They have the potential to cause chronic respiratory problems. Since it appears that these metals may cause some adverse health effects in humans, exposure to these ambient air pollutants should be minimized by managing the release of these contaminants to the environment. There is a need for the development and strict enforcement of national and state regulatory standards.

Air Pollutants↗

Chalcone synthase in rice (Oryza sativa L.): detection of the CHS protein in seedlings and molecular mapping of the chs locus.

The chalcone synthase is a key enzyme that catalyses the first dedicated reaction of the flavonoid pathway in higher plants. The chs gene and its protein product in rice has been investigated. The presence of a chalcone synthase (CHS) protein in rice seedlings and its developmental stage-specific expression has been demonstrated by western analysis. The chalcone synthase of rice was found to be immunologically similar to that of maize. A rice cDNA clone, Os-chs cDNA, encoding chalcone synthase, isolated from a leaf cDNA library of an indica rice variety Purpleputtu has been mapped to the centromeric region of chromosome 11 of rice. It was mapped between RFLP markers RG2 and RG103. RG2 is the nearest RFLP marker located at a genetic distance of 3.3 cM. Some segments of chromosome 11 of rice including chs locus are conserved on chromosome 4 of maize. The markers, including chs locus on chromosome 11 of rice are located, though not in the same order, on chromosome 4 of maize. Genetic analysis of purple pigmentation in two rice lines, Abhaya and Shyamala, used in the present mapping studies, indicated the involvement of three genes, one of which has been identified as a dominant inhibitor of leaf pigmentation. The Os-chs cDNA shows extensive sequence homology, both for DNA and protein (deduced), to that of maize, barley and also to different monocots and dicots.

Acyltransferases↗

The effects of corticosteroid and reduced glutathione on the endothelial viability during culture in MK medium. A light microscopy study.

The effect of addition of dexamethasone and reduced glutathione to MK medium, in a concentration of 10(-3) Molar and 0.92 g/l, respectively, was evaluated. The post preservation corneal endothelial viability was assessed using light microscopy. Our results showed that the addition of dexamethasone to MK medium increased the preservation time of dog cornea from 7 to 10 days and that reduced glutathione could further increase the storage period to 12 days. It can be concluded that the addition of reduced glutathione to MK medium is an excellent means for intermediate term corneal preservation.

Animals↗