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S Das

Publications and source records attributed to S Das.

At least 307 records · Page 17Linked to original sources
PubMed1997

A novel and simple technique for ectopic transplantation of the pituitary gland.

Sites for ectopic transplantation of the pituitary include the kidney capsule of mammals, the anterior eye chamber, the so-called hypophysiotropic area of the brain, the third cerebral ventricle, and the tail of the amphibian tadpole. Transplantation of pituitary in the kidney capsule of mammals is a simple technical procedure but most nonmammalian species do not offer such a convenient site. Transplantation of pituitaries at other ectopic sites involves technical sophistication and cannot be undertaken by all investigators, and retrieving the transplant is often difficult. A new technique is described to overcome these difficulties. Silastic tube pieces (7-10 mm) were ligated at both ends and cut longitudinally, and pituitaries taken from sister animals (homologous donors) were inserted through the incision. The Silastic tubes were then implanted either in the abdominal cavity or in the liver of rat, Japanese quail, and toad. They were retrieved after 7 or 14 days (in the case of rat and Japanese quail) or after 10 or 20 days (in the case of toad), and the pituitary was sectioned and stained immunocytochemically using rat and human prolactin (PRL) antisera. Taking the preponderance of PRL cells in the pars distalis as a parameter for determining the viability and functional status of the transplants (because ectopically transplanted pituitaries secrete abundant PRL), it was found that 13 of 16 pituitary homografts had been well established and there was no visible host-graft incompatibility. The technique reported is novel and simple, and it ensures quick delivery of the grafts and their easy retrieval without any loss whatsoever. It is expected that the technique would be very useful and would find wider application because it can also be employed for transplanting other organs/tissues into a wide range of animals, including invertebrates.

Animals↗
PubMed1997

Immunocytochemistry of the pars tuberalis of the pituitary gland in some Indian wild birds: a comparative study.

Immunohistochemistry has been applied to the cells of the pars tuberalis (PT) of the pituitary gland of three species of Indian wild birds (Halcyon smyrnensis perpulchra, Lonchura striata striata, Dicrurus adsimilis macrocercus). As in the pars distalis (PD), five types of immunoreactive cells (gonadotropic, GTH; thyrotropic, TSH; lactotropic/prolactin, PRL; growth hormone/somatotropic, STH; and cortico-melanotropic, ACTH/MSH cells) are present in the PT of these birds. In addition to the GTH cells, immunoreactive TSH, PRL, STH, and ACTH/MSH cells are present in the avian PT. The GTH cells are the predominant cell population of the PT. Other immunoreactive cells, though less numerous, are also present, unlike their inconsistent occurrence in several mammalian PTs. Though immunologically related, the PT cells distinctly differ from their counterparts in the PD with regard to their morphology, intensity of immunoreaction, and cellular arrangement.

Adrenocorticotropic Hormone↗
PubMed1997

Clinical evaluation of technetium-99m infecton for the localisation of bacterial infection.

The aim of the study was to distinguish infection from inflammation in patients with suspected infection using technetium-99m Infecton. Ninety-nine patients (102 studies) referred for infection evaluation underwent imaging with 400 MBq 99mTc-Infecton at 1 and 4 h. Most patients had appropriate microbiological tests and about half (56) had radiolabelled white cell scans as well. No adverse effects were noted in any patient. The clinical efficacy of 99mTc-Infecton depended in part on whether imaging was undertaken during antibiotic therapy for infection or not. In consultation with the microbiologist, 5-14 days of appropriate and successful antibiotic therapy was considered adequate to classify some results as true-negatives. The figures for sensitivity and specificity of 99mTc-Infecton for active or unsuccessfully treated infection were 83% and 91% respectively. It is concluded that 99mTc-Infecton imaging contributed to the differential diagnosis of inflammation. It is being used as the first imaging modality when bacterial infection is suspected.

Adolescent↗
PubMed1997

Variable histomorphology of muscle in congenital muscular dystrophy.

Congenital muscular dystrophy (CMD) is a relatively uncommon disease with a controversial nosological status. That collagen synthesis could be the primary abnormality has been suggested earlier (Fidzianska et al., 1982). Amongst eighteen cases of CMD diagnosed during the past twelve years, muscle biopsy in three cases revealed prominence of myofibre necrosis and phagocytosis, and serum CPK was markedly elevated suggesting a rapidly progressive form. In twelve cases, marked increase in endomysial collagen, pronounced fallout of myofibres and significant fibre diameter variation was seen. This was associated with myonecrosis and regenerative activity of mild degree resembling the classical form of CMD. In the remaining three cases, polyfocal, polyphasic necrosis was noticed. Fibre splitting was more frequently observed, better delineated in the enzyme histochemical preparations, affecting both fibre types, while endomysial fibrofatty tissue was only moderately increased. The histomorphology in the latter group resembled that of limb girdle dystrophy. Ultrastructural findings in all the eighteen cases correlated well with light microscopic observations. lmmunohistochemical studies done on three of the eighteen cases showed normal localization of dystrophin protein. Such variable histomorphology, revealing a spectrum of myopathic features, suggests that the primary change in CMD is likely to be in the myofibre rather than in collagen synthesis.

Biopsy↗
PubMed1997

Functional brain imaging and neuropsychological testing in Lyme disease.

Differentiating neuropsychiatric Lyme disease from a primary psychiatric disorder can be a daunting task. This article describes how functional brain imaging and neuropsychological testing can be particularly valuable in helping to make diagnostic distinctions. In addition to a review of the relevance of functional imaging to neuropsychiatry in general, recent findings are presented regarding the use of single photon emission computed tomographic (SPECT) imaging in Lyme disease.

Brain↗
PubMed1997

Correlation between binding affinities of C21 steroids for the maturation-inducing steroid membrane receptor in spotted seatrout ovaries and their agonist and antagonist activities in an oocyte maturation bioassay.

The relative binding affinities of steroids for the maturation-inducing steroid (MIS) plasma membrane receptor in spotted seatrout (Cynoscion nebulosus) ovaries were compared to their relative potencies in inducing final oocyte maturation (FOM) of seatrout oocytes in vitro. The MIS receptor is specific for C21 steroids (pregnenes) lacking ketone or hydroxyl (OH) groups at the 11 position. The addition of single OH groups at the 17, 20, or 21 positions and two OHs at the 17, 20 and at the 17, 21 positions of both progesterone and pregnenolone derivatives decreased binding affinity. In contrast, the combination of OH at the 20beta and 21 positions increased affinity, and greatest binding affinity for a progesterone derivative was observed with three OHs at positions 17, 20beta, and 21 (17,20beta,21-trihydroxy-4-pregnen-3-one; 20beta-S), the natural MIS in this species. Germinal vesicle breakdown (GVBD) bioassays showed that 1-min exposure to 290 nM 20beta-S or 17,20beta-dihydroxy-4-pregnen-3-one (17,20beta-P) in vitro was sufficient to induce final maturation of follicle-enclosed oocytes of seatrout and a closely related species, Atlantic croaker (Micropogonias undulatus), whereas the other steroids tested were ineffective. 20Beta-S was more potent than 17,20beta-P in inducing GVBD after 1-min exposure at lower steroid concentrations (5 nM-100 nM), even though the follicular uptake of the two steroids was similar. Coincubation of seatrout oocytes for 1 min with other steroids at concentrations capable of displacing more than 80% of the bound 20beta-S from its receptor effectively blocked the induction of GVBD by 5 nM 20beta-S. The binding affinities of steroids for the MIS receptor correlated in general with either their agonist or their antagonist activities in the GVBD bioassays. These findings strongly support the concept that induction of FOM by the MIS in spotted seatrout is mediated solely through the ovarian plasma membrane 20beta-S receptor.

Animals↗
PubMed1997

Spinal intramedullary cysticercosis.

OBJECTIVE: Spinal intramedullary cysticercosis is an uncommon manifestation of neurocysticercosis. We review our experience with eight cases of intramedullary cysticercosis. METHODS: Eight patients who were surgically treated for spinal intramedullary cysticercosis between 1982 and 1991 were retrospectively reviewed, and the final outcomes were assessed. RESULTS: In six patients, the cysticercosis involved the thoracic cord, whereas in the other two, the cysticercosis was cervical in location. Only one patient had multiple soft tissue calcifications, as revealed by plain radiography. Myelography indicated an intramedullary lesion in each of seven patients; two of the seven patients had partial myelographic block, suggesting the segmental nature of the lesion. Cerebrospinal fluid studies were noncontributory. One patient had three cysts, whereas the other seven had one cyst each. Four patients had adjacent soft purulent materials, which were revealed by histopathological examination to be granulation tissue. The neurological statuses of seven patients improved after surgery. Six patients were followed up for a mean of 30.6 months (3 mo-5 yr). Three could resume their previous occupations, two others could manage their daily activities, and one required only minimal assistance for daily activities. CONCLUSION: The outcome of intramedullary cysticercosis is not as dismal as reported earlier, and patients with paraplegia also have favorable outcomes. A preoperative diagnosis of cysticercosis can be suspected in an endemic area in the presence of multiple soft tissue calcifications and segmental lesions revealed by myelography or magnetic resonance imaging studies.

Activities of Daily Living↗
PubMed1997

Experimental apexigenesis in baboons.

Apexification with calcium hydroxide is a routine procedure. However, some clinical reports suggest that root completion can occur by controlling the infection without use of a catalyst. The present study investigated the use of tetracycline treatment (in root canals) on root growth in immature teeth, rendered non-vital experimentally. Incisors in 3 young baboons were exposed and canals were left open. After 2 months all canals were cleaned and treated with either tetracycline or formocresol. Some canals in each group were filed. Animals were sacrificed after 6 months. Bacterial evaluations were done before placing medications, one week later and six months after that. The number of bacteria were reduced in all treatment groups. Root growth almost near completion was observed in more teeth treated with tetracycline than in the formocresol group.

Animals↗
PubMed1997

Cariostatic effect of aspartame in rats.

This study examined the effects of aspartame (APM) on caries and the Streptococcus sobrinus population. Six groups of rats (20 in each group) colonized with S. sobrinus were fed varying amounts of sucrose (SU) and APM in their diets as follows: 1-0.15% APM, 2-0.30% APM, 3-30% SU, 4-30% SU + 0.15% APM, 5-50% SU and 6-50% + 0.15% APM. Ten from each group were sacrificed at 6 weeks and 10 at 12 weeks. S. sobrinus populations at both intervals were negligible in groups 1 and 2 and had no differences between groups 3, 4, 5 and 6. No caries were found in groups 1 and 2 Animals fed SU plus APM had significantly lower caries than animals fed the same amounts of SU (p = 0.001-0.0002). We conclude that APM is noncariogenic and anticariogenic.

Analysis of Variance↗
PubMed1997

Radiation-induced double-strand modification in calf thymus DNA in the presence of 1,2-dihydroxy-9,10-anthraquinone and its Cu(II) complex.

When cells or DNA is exposed to ionizing radiation, the radicals produced in the irradiated sample will modify the base-pair region of the double strands. Effects of 1,2-dihydroxy-9,10-anthraquinone (DHA) and its Cu(II) complex on the radiation-induced modification of double-strands in calf thymus DNA were studied using ethidium bromide as a fluorescent probe. Our results show that the Cu(II)-DHA complex is more efficient in modifying the base-pair region in double-stranded DNA compared to free DHA.

Animals↗
PubMed1997

Effect of premenstrual stress on audiovisual reaction time and audiogram.

A study of weight, auditory reaction time (ART), visual reaction time (VRT) and audiogram was carried out on 105 healthy female subjects between the age of 17-20 years during the premenstrual and post-menstrual phase. A significant increase in weight and prolongation in auditory reaction time (ART) and visual reaction time (VRT) were observed during premenstrual phase. A slight increase in decibel loss was also observed during premenstrual phase in audiogram though not significant. These changes could be attributed to fluid and salt retention due to overain steroids leading to decrease in the processing capability of central nervous system.

Acoustic Stimulation↗
PubMed1997

Insulin sensitizers.

Explore the source record for details and available documents.

Diabetes Mellitus, Type 1↗
PubMed1997

Histopathological & immunohistochemical evaluation of ageing changes in normal human brain.

As age related changes in the brain have not been systematically studied in the Indian population though there is an impression that they are less frequent, we studied 52 brains collected at autopsy from individuals above the age of 60 yr. The incidence of senile plaques (SPs) and neurofibrillary tangles (NFTs) together were found to increase with age from 21 per cent in the seventh decade to 33 per cent in the eighth decade and 54 per cent in the ninth decade, the increasing incidence of NFTs being statistically significant. The SPs were found both in the hippocampus and frontal cortex while NFTs were seen only in the hippocampus in non-demented aged individuals. In contrast, in the three cases of Alzheimer's disease (symbol: see text) AD studied, the NFTs and SPs were found in high density in both hippocampus and frontal cortex. By immunohistochemistry, various morphological forms of SPs were found to have beta amyloid protein consistently, while ubiquitin and phosphorylated neurofilament occurred variably. More number of SPs could be labelled by amyloid immunostaining than by conventional silver stains. The NFTs contained ubiquitin and phosphorylated neurofilament protein as the antigenic components, both in AD and normal ageing. The incidence of age related changes and their antigenic character in the limited sample studied from south India appears to be comparable to findings from the West. Multicentric studies on a large sample derived from different ethnic groups in India are needed to further evaluate these features.

Aged↗
PubMed1997

Chediak-Higashi syndrome--a case report with ultrastructural and cytogenetic study.

We report the ultrastructural abnormalities of the leukocyte granules and the cytogenetic findings in a patient of Chediak-Higashi syndrome (CHS), who presented with cutaneous melanosis as the only clinical feature. The diagnosis of CHS was established by peripheral smear and bone marrow examination. Chediak-Higashi syndrome, a rare autosomal recessive disorder is characterized by enlarged abnormal organelles in leukocytes and other cells. An interesting aspect of our patient was the absence of recurrent infections or any other clinical stigmata. Ultrastructurally, the leukocytes and their precursors in the bone marrow showed characteristic homogenous and heterogenous giant inclusions of variable sizes and shapes. These represent the primary granules which enlarge to attain the giant abnormal size by fusion with other primary or secondary granules. Cytogenic study of the bone marrow cells showed monosomy of chromosomes 8 and 17 in 20 percent of the metaphases. Neither the gene nor the chromosomal abnormalities specific for CHS have been identified as yet and thus the significance of our cytogenetic finding is presently not clear.

Bone Marrow Cells↗
PubMed1997

Effects of sequential reagent addition on technetium-99m red blood cell labeling efficiency using the UltraTag kit.

OBJECTIVE: The purpose of this study was to investigate how the reagent-adding sequence affects 99mTc red blood cell (RBC) labeling efficiency using the UltraTag RBC kit. METHODS: The package insert for preparation and quality control was followed during the experiment. The reagent-adding sequences were then altered during preparation. RESULTS: If acid-citrate dextrose is added before the NaOCl, the labeling efficiency decreases dramatically. However, the order of addition of Na 99mTcO4 and acid-citrate dextrose did not affect the labeling efficiency. CONCLUSION: Addition of the NaOCl solution before the acid-citrate dextrose solution is imperative for proper labeling efficiency.

Erythrocytes↗