Biomedical subjects
R Das
Publications and source records attributed to R Das.
Atopy and airways reactivity in animal health technicians. A pilot study.
Smoking, response to allergen skin testing, and nonspecific airways reactivity in students entering a career program for animal health technicians (AHT) were studied at their entrance and 7 months into the program to determine whether such persons provide a suitable cohort to overcome the selection biases accompanying investigations of occupational asthma. Previous occupational exposure to animals (65%) was associated positively with allergic symptoms but negatively with skin response to animal allergens and to airway hyperreactivity (AR). AHTs remaining in the program were more likely than those dropping out to have (1) worked with animals, (2) positive skin responsiveness to animal allergens, and (3) AR; the latter was significantly associated with positive skin-test responses to animal allergen testing. This study demonstrates that significant exposure to animals may have occurred among workers entering animal-handling careers. Additionally, competing "healthy" and "resistant" worker effects operate among AHTs to influence the prevalence of occupational asthma in this population.
The synthesis of E-17 alpha-[131I]iodo-vinyl oestradiol and evaluation of its use as a radiotracer for oestrogen receptor positive breast tumours.
17 alpha-Iodo-vinyl oestradiol binds with high affinity to the oestrogen receptor, is metabolically stable and has been shown to accumulate in oestrogen sensitive tissues of rodents. We have synthesised this compound and its 3-acetate, labelled with carrier free 125I and shown the accumulation of both compounds in rat uterus. 17 alpha-Iodo-vinyl oestradiol-3-acetate was prepared labelled with carrier free 131I and administered to twelve patients with suspected breast cancer, approximately 1 h before surgical removal of the primary tumour mass. At the time of surgery a sample of the tumour and a peripheral blood sample were taken. The ratio of radioactivity in the tumour to blood was determined. All tumours accumulated radioactivity and ratios ranged from 1.5:1 to 3.7:1. There was no correlation between the degree of accumulation and either cytosolic oestrogen or progesterone receptor concentration in the tumour. Analysis of blood revealed a single circulating species, 17 alpha-iodo-vinyl oestradiol. The results show that 17 alpha-iodo-vinyl oestradiol is metabolically stable and accumulates in breast tumours though this accumulation is not sufficient to permit imaging.
A comparative trial of cefuroxime axetil and ampicillin plus probenecid in the treatment of acute gonococcal infection.
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Anthropological studies in Assam, India. 7. Socio-biological observations on Assamese populations.
Three population groups of Assam, viz., the Hindus, Muslims and Mongoloids have been investigated for certain bio-social variables, e.g., size and composition of family, sex distribution, menarcheal age, age at marriage, marriage distance, conception, pregnancy wastage and fertility. The results are discussed on comparative basis, and attempts are made to offer possible reasons for differences.
Evaluation of total and partial structure factors, self-diffusion coefficients, and compressibilities of the cadmium-gallium melt.
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Anthropological studies in Assam, India. 6. Differentiation processes among Assamese populations.
In 1978-79 13 Assamese populations--two Muslim groups, five Mongoloid groups and 6 Hindu caste groups--have been investigated for the distribution of anthropometric, anthroposcopic and dermatoglyphic traits as well as for the distribution of ABO blood groups and PTC taste sensitivity. Except for finger ridge patterns all traits under investigation showed a marked intergroup variability. For anthropometric, anthroposcopic and dermatoglyphic traits a clear differentiation in Mongoloid populations on one hand and Hindu caste groups on the other could be observed and be substantiated by results of corresponding distance analyses. With regard to Muslims it has to be distinguished between Marias who seem to be more closely related to Mongoloid populations and Sheikhs whose phenotypic appearance is more like that of the Hindu caste groups. The results are discussed.
Theoretical computation of coherent scattering intensities, partial structure factors, and diffusion coefficients of magnesium-bismuth melt.
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Sources of error and variability in the determination of anaerobic threshold in healthy humans.
The derivation of anaerobic threshold (AT) from the ventilatory responses to incremental exercise is associated with several sources of variability including true biological variability and the error attributable to the observer interpretation of data. To define and quantitate the sources of variability in AT determination we exercised 6 healthy volunteers 6 times and submitted plots of ventilation (Ve), CO2 production (VCO2), respiratory exchange ratio (R) and the ventilatory equivalent for oxygen (Ve/VO2) in random order to 4 independent observers. Within-subject variability in AT ranged from 7 to 55% depending on the subject, ventilatory parameter and observer with an overall mean coefficient of variability of 24%. Significant day-to-day variability was demonstrated in 4 of the 6 subjects using AT values derived from at least one of the ventilatory parameters (Anova, p less than 0.05-p less than 0.001). Mean values for AT obtained with the Ve and VCO2 plots (1.91 and 1.69 liter/min VO2) were significantly lower than those obtained from R and Ve/VO2 plots (2.28 and 2.6 liters/min VO2; p less than 0.001, Anova). Anova showed significant differences in AT values derived by one of the observers compared to the other three (p less than 0.001). A significant observer/ventilation parameter interaction was also found (p less than 0.001) due to one observer consistently estimating higher values of AT from the R plots. The observer error in deriving AT from each exercise test using the Ve plots = 24%, for VCO2 = 19% for R = 29% and for Ve/VO2 = 15%.(ABSTRACT TRUNCATED AT 250 WORDS)
Tetrazolium reduction test in diagnosis of urinary tract infections.
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Anthropological studies in Assam, India. 4. Observations on the Kalitas.
Five regional groups of the Kalitas, an Assamese caste group, have been investigated for the distribution of anthropometric and dermatoglyphic traits as well as for the distribution of ABO blood groups and PTC taste sensitivity. The intergroup variability is to some extent considerable. The possible reasons for that are discussed.
Anthropological studies in Assam, India.
Four Assamese caste groups--Jogis, Hiras, Kumars and Kaibartas--have been analysed for the distribution of anthropometric and dermatoglyphic traits as well as for the distribution of ABO blood groups and PTC taste sensitivity. The differences among these four caste groups are statistically mostly significant, which can be connected with the history of these groups and their genetic isolation from each other.
Anthropological studies in Assam, India. 3. Observations on three Brahmin groups.
Three Brahmin groups from Lower, Middle and Upper Assam (Kamrup, Darrang, Sibsagar) have been investigated for the distribution of anthropometric and dermatoglyphic traits as well as for that of ABO blood groups and PTC taste sensitivity. The intergroup variability is discussed.
Evidence of regulation of calcium uptake by phytochrome in maize protoplasts.
Red light stimulated calcium uptake in maize leaf protoplasts upto 140% over the dark control. The stimulation was maximally noticed after 120 seconds of incubation and was reversed by far red light. 5-Hydroxytryptamine also enhanced calcium uptake in dark, upto the red level. A possible role of phosphoinositide for signal transduction in calcium uptake for phytochrome mediated responses in higher plants is suggested.
Anthropological studies in Assam, India. 1. Observations on five Mongoloid populations.
Five Mongoloid population groups from Upper Assam (Ahom, Chutia, Deuri, Mishing and Moran) have been investigated for the distribution of anthropometric and dermatoglyphic traits as well as for that of ABO blood groups and PTC taste sensitivity. The results are discussed with special reference to extent and causes of intergroup variability.
Anthropological studies in Assam, India. 2. Observations on Muslims.
Six Muslim groups from various parts of Assam (Goalpara, Kamrup, Darrang, Nowgong, Sibsagar and Dibrugarh) have been analysed for the distribution of anthropometric and dermatoglyphic traits as well as for that of AB0 blood groups and PTC taste sensitivity. The intergroup variability in the distribution of all these anthropological characters is considerable. The possible reasons therefore are discussed.
Primary structure of the Streptomyces enzyme endo-beta-N-acetylglucosaminidase H.
We report the DNA and primary amino acid sequences of the Streptomyces plicatus enzyme endo-beta-N-acetylglucosaminidase H. Peptide sequence information was derived from enzyme isolated from Streptomyces culture medium using a combination of mass spectrometric methods and conventional techniques, including Edman degradation and carboxypeptidase Y digestion. The DNA sequence was determined by analysis of the Endo-beta-N-acetylglucosaminidase H gene cloned into the Escherichia coli plasmid pBR322 (Robbins, P. W., Wirth , D. F., and Hering , C. (1981) J. Biol. Chem. 256, 10640-10644). The enzyme from Streptomyces medium is 271 (or 269) amino acids in length and has a ragged NH2-terminal sequence beginning primarily with Ala-Pro-Val or Ala-Pro-Ala-Pro-Val. DNA resection experiments as well as the DNA sequence itself suggest that a proenzyme or, more probably, " prepro " enzyme may be the primary product of translation. The long 42 (or 44) residue leader sequence of the preproenzyme shows striking similarities to leader sequences found on proteins secreted by Bacillus species. The leader sequence is partially removed by E. coli and, as reported previously, endo-beta-N-acetylglucosaminidase H made in E. coli appears in both the periplasmic space and in the cell.
Transmissible antibiotic resistance among Shigella species.
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