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Biomedical subjects

J Chatterjee

Publications and source records attributed to J Chatterjee.

At least 19 recordsLinked to original sources
PubMed2000

Primary malignant giant cell tumour of bone--a study of two cases with short review.

Primary malignant giant cell tumour of bone is extremely rare. It is distinctly separate from benign metastasising giant cell tumour of bone and secondary malignant giant cell tumour which occurs in response to radiotherapy and repeated curettage of benign giant cell tumor. The tumor has high mortality rate. It usually affects lower end of femur and upper end of tibia. Two usually affects lower end of femur and upper end of tibia. Two cases, on involving upper end of tibia and other in vertebra are discussed. Extreme paucity of literature prompted to publish this article. A short review of radiological appearance, histopathological findings and treatment modalities is highlighted.

Adult↗
PubMed1999

Ultrastructural and trace metal studies on radiographers' hair and nails.

Scalp hair and fingernail samples of 42 medical radiographers and 42 nonradiographers (control) with matching age groups and food habits were collected for this study. Trace metal estimation by atomic absorption spectrometry (AAS) has indicated a significant increase (P < 0.001) in Zn, Cu, and Cd contents in the radiographers' hair and nails. Scanning electron microscopy (SEM) revealed structural changes in the hair and nails of radiographers. Significant alterations in the Zn and Cd contents along with extensive structural damage in the hair and nails probably indicate that low-dose X-radiation imposes stress on these radiation workers.

Adult↗
PubMed1997

Hepatotoxicity of diazepam. Structural and trace metal studies in rat.

Studies of effects of diazepam on liver parenchyma are very scanty. In this study, adult albino rats were treated with diazepam in two different doses (0.25 mg and 0.30 mg/kg body wt) daily for 30 and 60 d. Through light microscopy and electron microscopy, prenecrotic and necrotic changes were noted in the high-dose group. Trace metal analysis indicated that zinc (Zn) was reduced by 30 and 60 day under both the doses, whereas iron (Fe) and copper (Cu) were reduced significantly in these groups only after 60 d of treatment. This reduction in metal contents may have some correlations with necrotic changes in liver parenchyma.

Animals↗
PubMed1997

A trace metal (zinc and iron) study on low dose x-radiation response in rat skin.

There is no reliable bio-dosimeter regarding low dose radiation effects in mammalian systems. In this study, chronic low dose (< 1 cGy) whole body x-irradiated rat skin have shown altered trace metal (zinc and iron) content which clearly indicated the redistribution of these metals in the integumentary system. The decreased zinc to iron ratios suggested enhanced oxidative stress of the tissue. Changes in trace metal content in irradiated rat skin, as a biological response to low dose radiation, were non-linear. Moreover, the lowered zinc content of E2, E3, E4 and E5 dose groups suggested a different steady state, compared to the control. The Zn: Fe ratio decreased with increasing radiation dose.

Animals↗
PubMed1996

Zinc and iron as bioindicators of precancerous nature of oral submucous fibrosis.

Oral Submucous Fibrosis (OSF) is a precancerous condition of oral cavity and oropharynx. Its etiopathogenesis is still obscure. Epithelial dysplasia is considered an important indicator of it. In the present study, the authors try to ascertain bioinorganic parameters as alternate indicators of malignant potential of OSF along with other clinicopathological attributes. They also try to identify causative factors. Thirty-six OSF patients, showing different degrees of epithelial dysplasia, and 12 normal individuals are studied with special reference to trace metal contents (Zn and Fe) in oral tissues. Statistical analyses of data indicate that trace metal contents can be regarded as an alternate indicator of the precancerous nature of OSF. Some clinicopathological attributes that are easier and cheaper to measure may also indicate OSF.

Adult↗
PubMed1996

The role of lux autoinducer in regulating luminescence in Vibrio harveyi; control of luxR expression.

Analysis of Vibrio harveyi dark autoinducer mutants has demonstrated that the level of LuxR was much lower than that observed in wild-type cells. Complementation with luxR fully restored luminescence suggesting that the lux autoinducer may control expression of the luxR regulatory gene. By primer extension, the transcriptional start site of luxR was located 78 bp from the initiation codon. The level of the primer-extended product was enhanced upon addition of the lux autoinducer to the autoinducer mutants, which was confirmed by hybridization of lux mRNA with specific probes. By using chloramphenicol acetyltransferase as a reporter gene in a transcriptional fusion with luxR, the stimulatory effect of autoinducer on luxR expression was shown to occur at the level of the luxR promoter. The results provide evidence that the autoinducer signal in V. harveyi can be transduced through luxR, resulting in stimulation of luminescence.

Bacterial Proteins↗
PubMed1996

Autoregulation of luxR: the Vibrio harveyi lux-operon activator functions as a repressor.

Mobility-shift assays have been used to demonstrate that the activator of the Vibrio harveyi lux operon, LuxR, binds independently, and with similar affinity, to two sites upstream of its own open reading frame. One site was located between 52 and 107 bp upstream of, and the other site in a region 25 bp downstream of, the transcriptional start site. The luxR promoter, in a transcriptional fusion with the chloramphenicol acetyl transferase (cat) gene, could readily be expressed in Escherichia coli as well as V. harveyi in the absence of LuxR. In both species, the presence of the luxR gene product resulted in repression of luxR promotion. These results show that LuxR directly regulates its own expression by functioning as an autorepressor. A mechanism for this repression is suggested by evidence showing that LuxR has a negative effect on RNA polymerase binding to the luxR promoter. In light of the fact that LuxR is also part of a regulatory family of repressors, the mechanism by which LuxR functions as a transcriptional activator of the lux operon has been re-examined.

Bacterial Proteins↗
PubMed1995

Historical introduction of acupuncture in India.

Acupuncture, though originated in oriental countries in the ancient times but, its philosophical understanding is amazingly wide open to the modern medical science. Historically, records are there regarding its Indian origin. However, acupuncture practised today in Indian sub-continent mainly shows Chinese origin and its introduction to India was pioneered by Dr. B.K. Basu, the first Indian who learned Chinese acupuncture from mainland China during 1959. It is interesting enough to note that though acupuncture is successfully practised in India in a rejuvenated form for the last few decades but due to lack of proper Governmental support this thereby suffers from under utilization and under development. While WHO suggested for its wider application and development through concerted Governmental efforts.

Acupuncture Therapy↗
PubMed1994

Low-level X-ray exposures on rat skin. Hyperkeratinization and concomitant changes in biometal concentration.

Integumentary structures naturally are more exposed to solar radiation than other body tissues, so there is a big question regarding the biological threshold of skin in respect to low-dose ionizing radiation. In this study, adult male albino rats were exposed chronically to low-dose (0.015 cGy/sec) X-rays for 9 and 18 mo, with total X-ray dose of 2.025 and 4.050 cGy, respectively. In both the dose groups, hyperkeratinization was noted in skin by transmission electron microscopic (TEM) study. Atomic absorption spectrometric (AAS) study revealed decreased zinc concentration (p < 0.01), increased iron concentration (p < 0.001), and status quo cadmium concentration. Moreover, the ratio between zinc and iron became highly depleted in both the irradiated groups. Hence it may be stated that chronic low-level X-rays induce redistribution of biometals in the skin. Nevertheless, specific concentrations of biometals indicate the risk-prone status of irradiated skin.

Animals↗
PubMed1994

Trace metal levels of X-ray technicians' blood and hair.

Medical X-ray technicians are exposed to low-level ionizing radiation in their occupational field. There are very few data on low-dose radiation effects. The present study was designed to estimate few vital trace metals (Zn, Cu, Fe) in indicator tissues (blood and hair) of X-ray technicians and non-X-ray technicians (hospital employees were used as controls) by Atomic Absorption Spectrometry (AAS). This analysis noted a significant increase in Zn, Cu, and Fe concentrations in X-ray technicians' hair. But in blood, Zn and Cu were depleted, whereas Fe was increased. Such changes in trace metal concentrations among X-ray technicians were noted where occupational exposure to radiation was for longer than three years. Through composite risk analysis, by using Zn:Fe as an indicator, it was noted that blood gave a stronger indication than hair in analyzing and estimating risk.

Adult↗
PubMed1994

Alteration of spermatozoal structure and trace metal profile of testis and epididymis of rat under chronic low-level X-ray irradiation.

This study investigates the short-term as well as long-term effects of low-level X-ray irradiation on the Spermatozoal structure and trace metal (Zn, Fe, Cu, and Cd) contents in the testis and epididymis of whole-body irradiated albino rats. Male rats were exposed to 0.675, 1.350, 2.700, and 4.050 cGy of X-ray intermittently in 45, 90, 180, and 270 equal fractions (each fraction of 0.015 cGy s-1), respectively. SEM study had revealed numerous fusiform swelling in sperm tail in most of the x-irradiated groups. Moreover, in 2.700 and 4.050 cGy dose groups, the tail sheath of several sperm were eroded out. In the TEM study, damage in microtubules of sperm tail in 4.050 cGy irradiated group was noted. The AAS study showed a transient increase in Zn content in 0.675 and 1.350 cGy dose groups, but its concentration was decreased in 2.700 and 4.050 cGy dose groups. Fe concentration was increased in all the cases in comparison to that of control group. Nevertheless, Cu and Cd contents were increased mostly in 2.700 and 4.050 cGy doses. Thus present findings probably throw some light regarding mammalian response threshold at low-level X-ray irradiation. Moreover, it raises questions regarding the validity of "safe dose ionizing radiation."

Animals↗
PubMed1994

99Tcm-cystine, a renal function and imaging agent: a comparative study in dog with 131I-hippurate and 99Tcm-glucoheptonate to evaluate its functional and imaging characteristics.

99Tcm-cystine, which has been proposed as a renal radiopharmaceutical for evaluating renal morphology and function in a single experiment, is compared with 131I-orthoiodohippurate (OIH) with respect to its renal clearance and extraction parameters and with 99Tcm-glucoheptonate (GHA) regarding its imaging characteristics. In spite of its comparable renal accumulation with 131I-OIH, its clearance (10.1 +/- 1.0 ml min-1 kg-1) was lower than that of 131I-OIH (21.5 +/- 0.9 ml min-1 kg-1) but was higher than that of 125I-iothalamate (5.4 +/- 0.6 ml min-1 kg-1). Extraction efficiencies of 99Tcm-cystine, 131I-OIH and 125I-iothalamate were 39 +/- 5, 64 +/- 4 and 27 +/- 3, respectively. The glomerular filtration components of 99Tcm-cystine and 131I-OIH were 26 and 16% of their respective clearances. In probenecid-treated animals the clearance of both agents was affected to a similar extent and fell to half of their respective control values, whereas tubular secretory components were found to be 19 and 31% of the controls. The kidney images obtained with 99Tcm-cystine were superior to those obtained with 99Tcm-GHA at different time points. Therefore, considering both renal function and imaging properties of 99Tcm-cystine it appears that this radiopharmaceutical offers some definite advantages over the currently available renal agents and commands further study.

Animals↗
PubMed1994

Reply to Gray.

Explore the source record for details and available documents.

Association↗
PubMed1993

Cysteine, a chelating moiety for synthesis of technetium-99m radiopharmaceuticals--Part IV. Benzyl cysteine and derivatives.

To explore the possibility of utilizing cysteine derivatives for technetium-99m radiopharmaceutical preparation with clinical potential, we synthesized two benzyl substituted cysteine compounds, namely, S-benzyl cysteine 1 and cysteine benzyl ester 3. It was expected, from our previous studies on benzoyl cysteines, that the above two ligands after chelation with 99mTc would be excreted by the hepatobiliary pathway. Although for 99mTc-3 the above expectation was realized, 99mTc-1 behaved in a most unexpected way by affixing itself with kidney and selecting the renal tubular secretory pathway for its excretion. It is anticipated that the affinity of 99mTc-1 for kidney is due to its interaction with the kidney sulphhydryl group and it also formed an adduct with other sulphydryl containing compounds like thiophenol. In terms of the kidney-to-background ratio, 99mTc-1 showed some superiority over other kidney structure agents, like 99mTc-dimercaptosuccinic acid and 99mTc-glucoheptanoic acid and, therefore, the chelate (99mTc-1) may have the potential to replace the above two radiopharmaceuticals in clinical use.

Animals↗
PubMed1993

Detection of structural and trace metal changes in scalp hair of radiographers.

Human scalp hair samples were collected from 24 medical radiographers and from 24 nonradiographers (control group) of matching age groups belonging to both sexes. Changes in zinc, copper, and iron content, as well as structural morphology of hair, were studied by atomic absorption spectrometry and scanning electron microscopy, respectively. Such studies revealed increases in zinc, copper, and iron concentrations along with varied types of cuticular damage in the radiographers' hair compared to that of nonradiographers. Present observations indicate the possibility of radiation hazards for radiation workers.

Adult↗
PubMed1993

Collagen, zinc & iron contents of rat skin irradiated with chronic low-dose X-ray.

The effects of very low-dose X-ray on collagen and Zn and Fe contents of rat skin were studied. CFS male rats were exposed to chronic, intermittent low dose X-radiation at the dose rate of 0.015 cGy/sec/day (7 days irradiation alternating with 7 days rest) for periods of three months and six months. Transmission electron microscopy showed hyalinization collagen on days 180 and 360 in the six months group. Atomic absorption spectrometry revealed significantly decreased zinc levels (P < 0.001) only on day 360 in six months group whereas iron increased significantly (P < 0.001) in all treated groups. This radiation induced redistribution of zinc and iron and subsequent changes in dermal collagen possibly confirm the hazardous effect of long term exposure to X-rays. Our findings also provide some information on the mammalian response threshold at low dose X-irradiation.

Animals↗
PubMed1985

Attitudes of Asian patients in Birmingham to general practitioner services.

Attitudes of Asian patients to the delivery of primary health care in two Birmingham general practices were investigated by questionnaires administered by an Asian ethnic minorities worker who spoke dialects appropriate to the population under investigation. One practice was staffed by Asian doctors the other by British doctors. The responses to the questionnaires were analysed with reference to religion - Sikh, Hindu and Muslim and to the two practices. Choice of doctor appears to be determined more by the proximity of the patient's home to the practice premises than by ethnic considerations. Reported failures to meet the special needs of Asian patients were those inherent in the difficulties of British general practice and were not peculiar to Asian patients. The need for help from an interpreter did not seem to be important.

Adult↗