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Biomedical subjects

S Banerjee

Publications and source records attributed to S Banerjee.

At least 37 records · Page 2Linked to original sources
PubMed1998

APIC and CDC survey of Mycobacterium tuberculosis isolation and control practices in hospitals caring for children. Part 2: Environmental and administrative controls. Association for Professionals in Infection control and Epidemiology, Inc.

BACKGROUND: The 1994 Centers for Disease Control and Prevention draft Guidelines for Preventing the Transmission of Mycobacterium tuberculosis in Health-Care Facilities did not exempt pediatric facilities from instituting controls to prevent nosocomial tuberculosis (TB) transmission. Many researchers contend that TB disease in children does not require such rigid controls. We surveyed acute-care pediatric facilities in the United States to determine adherence to environmental and administrative control recommendations. METHODS: The study included 4 mailings of a survey to infection control professionals at 284 US children's hospitals and adult acute-care hospitals with > 30 pediatric beds. RESULTS: Isolation rooms (IRs) generally conformed to recommended guidelines; 92% of respondents reported IRs with > or = 6 air changes per hour, 90% reported 1-pass air and negative pressure, and 89% reported that IRs were private rooms. A sufficient number of inpatient IRs were reported by 88%, but only 42% had IRs in outpatient areas, and 19% had IRs in off-site clinics. Employee tuberculin skin-test programs were in place at 98% of facilities, but policies pertaining to implementation varied. Employees' use of personal respirators increased at respondent hospitals from 1991 to 1994, but as late as 1994, nearly one third still used surgical masks for high-risk procedures. CONCLUSIONS: Environmental and administrative controls used by respondent hospitals largely conformed to published guidelines. Because definitive studies that quantify the risk of nosocomial M tuberculosis transmission in pediatric settings have yet to be performed, pediatric facilities are required to have the same protections in place as do their adult counterparts.

Adult↗
PubMed1998

The role of ophthalmic triage and the nurse practitioner in an eye-dedicated casualty department.

PURPOSE: To evaluate the appropriateness of triage decisions in a busy ophthalmic casualty department and to assess the diagnostic and management skills of eye-dedicated nurse practitioners. METHODS: Three hundred and one consecutive patients attending the Birmingham and Midland Eye Centre (BMEC) accident and emergency (A&E) department over a 2 week period were included in this prospective study. Patients were categorised in terms of urgency in concordance with strict guidelines, and the agreement between the final diagnosis and this system of prioritisation was then investigated. To evaluate nurse practitioner (NP) skills, all patients seen and managed by a NP were also assessed by the most senior doctor in casualty at the time in a masked fashion. Waiting times and a breakdown of waiting times were also calculated. RESULTS: Upon establishment of a diagnosis, triage category allocation was found to be appropriate in all 301 cases. Fifty patients (16.67%) were seen by the NP. Of these the supervising doctor concurred with the NP diagnosis in all cases and with the proposed management in 96% of cases. The mean waiting time (+/- SD) was 83.43 +/- 45.84 min, with a range of 5-335 min. The delay before being attended to was greater for less urgent cases as categorised by the triage system. CONCLUSION: This study confirms the high standard of diagnostic and management skills of the ophthalmic NP and indicates that the triage system of patient prioritisation is accurate. Waiting times in the A&E department remain unacceptable and ways of addressing this include improved ophthalmic training of general practitioners, diverting a greater proportion of non-acute cases to the primary care clinic and expanding the role of the NP.

Adolescent↗
PubMed1998

The effect of age-dependent increase in fat mass on peripheral insulin action is saturable.

Insulin resistance and increased fat mass (FM) are common in human aging. We aimed to investigate the relationship between the age-dependent increase in FM and insulin resistance (by euglycemic hyperinsulinemic clamp technique), in a homogenous rodent model. The decline in insulin responsiveness was linear until late adulthood when body weight, FM, and epididymal fat reached a critical amount (r > .750, for all). Above this critical point, there was no further decline in insulin responsiveness with aging and with increased BW (p < .00001 for all spline curve analyses). This decline in insulin-mediated glucose uptake was accounted for by a decrease in whole body glycolytic rate with no change in the rate of glycogen synthesis. Thus, in this homogenous model, an early increase in FM is associated with impairment in insulin action until a critical FM is achieved, after which there is no additional insulin resistance with aging. We suggest that decreasing insulin responsiveness, in a heterogeneous group such as humans, will only occur within a specific accretion of visceral or total FM.

Adipose Tissue↗
PubMed1998

Differential expression and regulation of a human transgene, HLA-B27, in mouse placental and embryonic cell lines.

Unlike other somatic cells, human placental trophoblast cells do not express the highly polymorphic HLA-A and HLA-B human leukocyte major histocompatibility antigens that would stimulate maternal immunological rejection of the fetus. To investigate mechanisms underlying cell lineage-specific expression, cell lines were generated from homozygous matings of HLA-B27 transgenic mice. Trophoblast cell lines were generated from gestation day 10 placentas and fibroblasts were cultured from gestation day 13/14 embryos. Polymerase chain reaction (PCR) readily identified HLA-B DNA in transgenic trophoblastic cells but specific mRNA was of low abundance, being detectable by reverse transcriptase PCR but not by Northern blot hybridization. HLA-B-specific protein in/on the trophoblast cells was undetectable by cell enzyme-linked immunosorbent assay and the protein was not induced by exposing the trophoblastic cells to interferon-gamma (IFN-gamma). Restricted expression was specific for the HLA-B transgene and its antigen; IFN-gamma-inducible endogenous H-2Db class I antigens were detectable on the trophoblast cells. In contrast to the trophoblastic cells, HLA-B27 transgenic fibroblasts expressed IFN-gamma-inducible HLA class I antigens as well as H-2Db antigens. Thus, the mechanism(s) regulating expression of the polymorphic HLA-B antigen in trophoblastic cells is gene-specific, IFN-gamma-resistant and operative at the level of transcription or immediate post-transcription.

Animals↗
PubMed1998

Age-dependent and lobe-specific spontaneous hyperplasia in the brown Norway rat prostate.

We showed previously that exogenously administered testosterone caused age- and lobe-specific overgrowth of the prostate in Brown Norway rats. A common feature observed in testosterone-treated animals was cell hypertrophy in each of the ventral, dorsal, and lateral lobes of both young (6 mo old) and old (24 mo old) rats. By contrast, hyperplasia was seen only in the dorsal and lateral lobes of old rats treated with testosterone. These observations prompted us to examine whether age- and lobe-specific overgrowth might also occur in untreated rats as a consequence of the endogenous hormonal milieu. To this end, blood and prostates were collected from a large number (25-30 rats per group) of 4- to 6-mo-old (young) and 21- to 24-mo-old (old) Brown Norway rats. Both serum testosterone (-45%) and estradiol (-22%) concentrations decreased significantly with age, but the greater magnitude of the decrement in testosterone relative to estradiol led to a reduction in the serum testosterone:estradiol ratio. Paradoxically, although the prostate is androgen dependent, the wet weight, protein, and DNA contents increased significantly with age in the dorsal and lateral lobes of old rats despite the decrease in testosterone level. Histologic examination revealed that the increased weights and DNA contents of the dorsal and lateral lobes in old rats coincided with an increased number of epithelial cells in the distal and intermediate segments of these lobes, indicative of hyperplasia but independent of change in cell size. Taken together, these results show a spontaneous age-related overgrowth of cells in the dorsal and lateral prostatic lobes of old Brown Norway rats despite diminished serum testosterone concentrations. The aging Brown Norway rat, therefore, may be a useful model for studies of some aspects of the pathogenesis underlying spontaneous age-related prostatic hyperplasia.

Aging↗
PubMed1998

A PC-based Braille library system for the sightless.

This paper presents a novel multiclient braille reading system developed around a single low cost personal computer. The system primarily addresses the needs of the Braille libraries, where different texts are needed to be read by different users simultaneously. Moreover, the system can simultaneously cater to different texts written in different languages. This feature makes it specially suitable for use by multilingual nationalities. The major advantage of this system is its low cost, compared to the other systems available and is specially attractive for the developing or underdeveloped countries. The paper describes the system, first from the user point of view and then presents the hardware and software design details. The system performance has been evaluated by the sightless users and has shown encouraging results.

Blindness↗
PubMed1998

Refractory status epilepticus in children: role of continuous diazepam infusion.

To determine efficacy of continuous diazepam infusion in the treatment of refractory status epilepticus in a retrospective study, we analyzed data of 62 children admitted consecutively to our Pediatric Intensive Care Unit with a diagnosis of refractory status epilepticus. The unit followed a standard treatment protocol for diazepam infusion; if it failed, thiopental infusion was used. The mean age of patients was 2.80 years (range, 1.5 to 11.5 yr). Thirty-six patients (60%) had acute infections of the central nervous system and 10 (16%) had idiopathic epilepsy. Diazepam infusion was used in 57 patients. This treatment controlled seizures in 86% of patients (49/57), on average within 40 minutes (median, 30 min; range, 10-120 min), at a mean infusion rate of 0.017 mg/kg/min (range, 0.01-0.03 mg/kg/min). The mean total duration of infusion was 68 hours (range, 12-220 hr). Diazepam infusion was associated with hypotension in one patient, respiratory depression requiring ventilatory support in 12% of patients (6/49), and death in 14% of patients (7/49). Thiopental infusion was used in nine patients, including eight in whom diazepam infusion had failed. Thiopental infusion controlled seizures in all nine patients, but all of them needed mechanical ventilation, and seven needed vasopressor support for hypotension; four patients (44%) died. We conclude that continuous diazepam infusion is a reasonably effective modality to control refractory status epilepticus in children and is associated with reduced need for ventilatory and vasopressor support.

Anticonvulsants↗
PubMed1998

Culturally sensitive validation of screening questionnaires for depression in older African-Caribbean people living in south London.

BACKGROUND: We tested the validity of two screens for depression in older African-Caribbean adults, the 15-item Geriatric Depression Scale (GDS) and a new Caribbean Culture-Specific Screen for emotional distress (CCSS). Two independent criteria were used for validity: (a) a psychiatric diagnosis derived from GMS-AGECAT, and (b) a culturally sensitive assessment of mental disorder, derived from a tool developed with local African-Caribbean religious healers. METHOD: One hundred and sixty-four consecutive African-Caribbean primary care users, aged 60 years or older, were screened with the GDS and the CCSS. Diagnostic interviews were carried out on 80% of high scorers and 20% of low scorers. RESULTS: The number of cases detected by the two separate diagnostic approaches was similar. However, the agreement between who was and who was not a case was only modest. At a cut-off of > or = 5, the GDS was an adequate case detector for psychiatric depression, and, at a cut-off of > or = 4, for 'depressed/lost spirit', as defined by culture-specific criteria. It performed as well as the new CCSS. CONCLUSIONS: At a cut-off of > or = 4 the 15-item GDS can be recommended as a case detector for significant forms of depression in older African-Caribbean people living in south London.

Aged↗
PubMed1998

Lobe-specific telomerase activity in the intact adult brown Norway rat prostate and its regional distribution within the prostatic ducts.

It is generally established that telomerase activity is present in most cancer cells, germ line cells, and established cell lines but typically is not present in normal somatic cells. Among the few exceptions, telomerase activity has been detected in hematopoietic stem cells and in physiologically renewable epithelial cell populations (e.g. skin, small intestine). The adult rat prostate gland is a tissue that has the ability to regenerate in response to androgen. We hypothesized, therefore, that telomerase activity should be present in the normal adult rat prostate. In this study, using a highly sensitive PCR-based telomerase assay [the telomerase repeat amplification protocol (TRAP) assay], we tested this hypothesis by measuring telomerase activity in the ventral, dorsal, lateral, and anterior lobes of the adult rat prostate. We show herein that telomerase activity indeed is present in whole tissue extracts of the ventral, dorsal, and anterior lobes, though at differing levels, but not the lateral lobe. However, lateral lobe prostatic fluid was found to contain one or more factors inhibitory for the TRAP reaction, and therefore, telomerase activity was detected after removal of this fluid. Telomerase activities were not uniform within the prostatic ducts, but rather telomerase positive cells are regionally distributed within the distal, intermediate, and proximal ducts of the microdissected segments of each of the lobes. We speculate from these results that androgen-stimulated regeneration of rat prostate following androgen ablation may depend upon the telomerase-positive regenerating pool of cells present within specific regions of the ductal network.

Animals↗
PubMed1998

Telomerase activity in normal adult Brown Norway rat seminal vesicle: regional distribution and age-dependent changes.

Telomerase activity is essential for protection of cells against the telomere erosion that occurs with each round of cell replication, and thus appears to play a role in the indefinite replication potential of some, but not all, eukaryotic cells. In this regard, some tissues contain stem cells that have a long proliferative life-span and are capable of regenerating or renewing the somatic epithelial cell population within the tissue. Because the adult seminal vesicle exhibits the ability to regenerate during androgen-replacement after castration, we hypothesized that a pool of cells with regenerating potential is present in the adult seminal vesicle, which expresses telomerase activity. In this study, we used a highly sensitive PCR-based telomerase assay [the telomeric repeat amplification protocol (TRAP) assay] to detect telomerase activity in rat seminal vesicle. Our results show that telomerase activity is, indeed, present in the normal adult rat seminal vesicle, but that, in the presence of seminal vesicle fluid, telomerase activity cannot be detected. In fact, seminal vesicle fluid was found to contain some factor(s) that is inhibitory for the TRAP assay. In addition, we found that telomerase activity in the seminal vesicle changes with age and is regionally distributed within the distal, intermediate, and proximal segments of the duct. These results suggest that as is the case for the rat prostate, a population of telomerase-positive cells is present within the adult rat seminal vesicle, and thereby, this organ retains throughout life the potential to regenerate in response to androgen replacement following castration-induced apoptotic cell death.

Age Factors↗
PubMed1998

Regional expression of transforming growth factor-alpha in rat ventral prostate during postnatal development, after androgen ablation, and after androgen replacement.

The prostate is a highly heterogeneous organ, composed of different types of epithelial and stromal cells organized regionally along the ductal network. Although androgen-stimulated growth and maintenance of the prostate gland primarily involve epithelial cells, it is unclear whether all epithelial cells are androgen dependent. Moreover, the actions of androgens may not be direct; a number of polypeptide growth factors, including transforming growth factor-alpha (TGFalpha), are postulated to mediate androgen action in the rat prostate. In this investigation, using an immunohistochemical technique, we examined the cellular and regional expression of TGFalpha in the rat ventral prostate during postnatal development to adulthood. TGFalpha-immunopositive cells were located throughout the ductal epithelium from postnatal days 5-20. By day 45 and thereafter, regional variation in TGFalpha expression became apparent; epithelial cells in the proximal segment exhibited intense staining, whereas those in the distal segment exhibited negligible staining. These observations were coincident with increased serum testosterone concentrations at puberty. To understand the role of androgen in the expression of TGFalpha in the epithelial cells of the distal and proximal segments of the adult rat ventral prostate, androgen was withdrawn by castration, and testosterone subsequently was administered. Androgen receptor protein expression decreased after castration and reappeared after androgen replacement in both the distal and proximal segments. TGFalpha staining was negligible in epithelial cells of the distal segment of intact adult rats, became prominent by 7 days after castration, but then diminished after the administration of testosterone. Western blot analyses revealed the presence of a specific 30-kDa immunoreactive form of TGFalpha in rat ventral prostate, and its quantity reflected the staining intensities observed in the immunohistochemical studies. These results suggest that TGFalpha expression is negatively regulated by androgen in epithelial cells of the distal segment. In contrast, staining for TGFalpha in epithelial cells of the proximal segment did not change with castration or testosterone administration, suggesting that TGFalpha is not regulated by androgen in this region of the ventral prostate. In summary, TGFalpha expression is differentially regulated among epithelial cells localized in two different regions of the ventral prostate. We hypothesize that TGFalpha may function as a survival factor for epithelial cells which, as a consequence of its expression, become androgen independent and thus escape apoptotic cell death after androgen ablation.

Aging↗
PubMed1998

Hormonal findings in African-American and Caribbean Hispanic girls with premature adrenarche: implications for polycystic ovarian syndrome.

BACKGROUND: Premature adrenarche refers to the early maturation of the adrenal zona reticularis such that the resultant modest hyperandrogenism causes the early appearance of pubic hair before the age of 8 years in girls and 9 years in boys. The precise etiology of premature adrenarche is not known. However, recent studies indicate that certain girls with premature adrenarche are at risk of developing functional ovarian hyperandrogenism, polycystic ovarian syndrome, and hyperinsulinism. Caribbean Hispanic women in general are at increased risk of developing polycystic ovarian syndrome, and African-Americans are at increased risk of developing the complications of hyperinsulinism. Previously, girls with premature adrenarche were reported to have androgens in the range found in normal children in the early stages of puberty. We noted that many of our African-American and Caribbean Hispanic patients with premature adrenarche had androgens that were much higher than what has been reported previously. OBJECTIVE: This retrospective study was performed to characterize the adrenocorticotropin-stimulated androgen response in an African-American and Caribbean Hispanic population of girls with premature adrenarche. METHODOLOGY: The androgen response to adrenocorticotropin stimulation in 72 African-American and Caribbean Hispanic girls with premature adrenarche was compared with those reported for normal girls in early puberty (Tanner stages II and III). The mean age was 6.8 +/- 0.8 years, bone age was 8 +/- 1.5 years, pubic hair was Tanner stages II and III, and body mass index was 18.6 +/- 4. RESULTS: Of the girls, 28% were found to have elevated stimulated 17OHPregnenolone (17OHPreg) levels that were >2 SD units above the mean for normal early pubertal children. The stimulated ratio of 17OHPreg/17OHProgesterone also was elevated in 18% of the girls and showed a modest correlation with body mass index. CONCLUSION: In contrast to previous studies of girls of mixed ethnic backgrounds with premature adrenarche, 28% of the 72 African-American and Caribbean Hispanic girls with premature adrenarche had adrenocorticotropin-stimulated 17OHPreg levels that were significantly higher than those seen in early pubertal girls. Because 17OHPreg hyperresponsiveness has been described previously in women with hirsutism or polycystic ovarian syndrome, the similar finding in many African-American and Caribbean Hispanic girls with premature adrenarche suggests that the two conditions may share a common mechanism for their hyperandrogenism. Therefore, the hyperandrogenism in certain African-American and Caribbean Hispanic girls with premature adrenarche may not be benign and may be the first presentation of polycystic ovarian syndrome.

Black or African American↗
PubMed1998

The prevalence of Tourette syndrome in a mainstream school population.

The aim of this study was to ascertain accurately the prevalence of Tourette syndrome (TS) in a mainstream school population. All year 9 pupils (aged 13 to 14 years) in a mainstream secondary school were investigated using a two-stage procedure. Standardized questionnaires were completed by parents, teachers, and pupils. Class observations were also carried out to identify tics. Those pupils identified as having tics underwent a semistructured interview to determine whether they had TS according to DSM-III-R criteria. Data were available from at least one source (parent, teacher, or self-reports) on 166 of the 167 pupils in the year. Five subjects were identified as having TS according to DSM-III-R criteria, yielding a prevalence estimate of 299 per 10,000 pupils in this age group. The results of this study suggest that TS in the community as a whole is more common and milder than those prevalence estimates and descriptions of the disorder based on TS encountered in secondary or tertiary health-care service settings.

Adolescent↗
PubMed1998

Autoimmunity to cartilage link protein in patients with rheumatoid arthritis and ankylosing spondylitis.

OBJECTIVE: To determine whether patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS) express cellular immunity to cartilage link protein (LP). METHODS: LP was purified from human fetal epiphyseal and bovine adult nasal cartilage. It was used in proliferation assays with the peripheral blood lymphocytes (PBL) isolated from 83 patients with RA, 21 patients with AS, and 30 healthy controls. RESULTS: Patients with RA (34%) and AS (71%) expressed a significantly higher prevalence of cellular immune responses to human LP compared with the healthy control group (13%). Such significant differences were not observed for bovine LP. Half the patients with RA responding to LP exhibited cellular immunity to both human and bovine protein. In the AS group, PBL from a majority of responders to LP recognized only human LP. CONCLUSION: These data suggest that LP is a potential autoantigen in the development of RA and AS and that cellular immune reactivity to common and distinct LP epitopes in patients with RA and AS may play a role in the pathogenesis of these diseases.

Adult↗