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Biomedical subjects

B Singh

Publications and source records attributed to B Singh.

At least 343 records · Page 19Linked to original sources
PubMed1997

Family caregiving: measurement of emotional well-being and various aspects of the caregiving role.

BACKGROUND: Past research and instrument development in caregiving have focused on specific aspects of caregiving or specific disability groups. This paper reports the scale characteristics of a new generic instrument developed to assess the experience of caregiving, and the social and emotional well-being of caregivers and a comparison group of 'non-caregivers'. METHODS: Using computer-assisted telephone technology, a random survey of 26000 households was conducted in Victoria, Australia to identify and interview 976 caregivers of people who were aged or had a long-term illness or disability of any kind, and 219 non-caregivers. Both groups were re-interviewed after 15 months. Scales administered on each occasion to caregivers and non-caregivers included life satisfaction, positive and negative affect, social support and overload; and to caregivers, caring role satisfaction, resentment and anger, and, in relation to the care recipient, measures of help provided and needed, severity of disability and behaviour problems. RESULTS: On each occasion and with each sample all scales demonstrated a satisfactory reliability. With a subsample of caregiver-care-recipient dyads (N = 67), caregiver reports of severity of disability, level of helped needed and provided were validated externally by clinician assessments. CONCLUSIONS: A comprehensive instrument to assess the experience of caregiving was developed. It is relevant to a broad range of ages, levels and types of disability and care provided; and, in assessing health and well-being, to both caregivers and non-caregivers. Scales, including both positive and negative dimensions, have demonstrated good internal consistency on two occasions. The instrument is potentially useful in a range of research and practical settings.

Activities of Daily Living↗
PubMed1997

Transgenic plants expressing autoantigens fed to mice to induce oral immune tolerance.

Oral administration of protein can induce antigen-specific immune hyporesponsiveness. However, the utility of oral tolerance to autoantigens in the treatment of autoimmune diseases may be limited when candidate autoantigens cannot be produced by conventional systems in quantities sufficient for clinical studies. Plants may be ideally suited for this purpose, as they can synthesize, glycosylate and assemble mammalian proteins to provide huge quantities of relatively low cost soluble proteins. Furthermore, edible transgenic plants could provide a simple and direct method of autoantigen delivery for oral tolerance. Therefore, the aim of this study was to determine whether a transgenic plant expression system was capable of synthesizing the diabetes-associated autoantigen, glutamic acid decarboxylase (GAD) in an immunogenic form and whether the oral administration of an autoantigen expressed by a plant could directly induce protective immune responses in a mouse model of diabetes. We show that a GAD-expressing transgenic plant, given as a dietary supplement, inhibits the development of diabetes in the non-obese diabetic (NOD) mouse.

Agrobacterium tumefaciens↗
PubMed1997

Preliminary studies on tannin degradation by Aspergillus niger van Tieghem MTCC 2425.

A tannin-degrading strain of Aspergillus niger van Tieghem was grown at pH 5.0 and 30 degrees C in a defined medium where tannins were the sole source of carbon and energy. The fungus had variable growth in tannic acid- and quebracho tannin-medium and could tolerate these tannins even up to 150 g-1 without showing any growth inhibition.

Aspergillus niger↗
PubMed1997

Butyrate can act as a stimulator of growth or inducer of apoptosis in human colonic epithelial cell lines depending on the presence of alternative energy sources.

In vivo, butyrate is a major energy source for the colonic epithelium and is thought to stimulate proliferation. In contrast, butyrate in vitro has been shown to inhibit proliferation and induce differentiation and apoptosis in colonic epithelial cells. Most colon cell cultures are grown in medium containing high concentrations of glucose, whereas in vivo, the main energy source used by the colon cells is butyrate. The aim of this study was to determine whether the apparent contrasting roles of butyrate in vivo and in vitro could be as a consequence of differences in glucose availability. The sensitivity of two human colorectal tumour cell lines, one adenoma (S/RG/C2) and one carcinoma (HT29) to butyrate-induced growth inhibition and apoptosis was investigated to determine whether these cellular effects were altered under glucose depleted culture conditions. Glucose depletion resulted in increased apoptosis in both cell lines in the absence of butyrate. Butyrate in standard culture conditions (containing 25 mM glucose and 1 mM pyruvate) inhibited growth and induced apoptosis in both cell lines. However, low concentrations of butyrate in glucose depleted culture conditions (i.e. standard growth medium without glucose and pyruvate supplements) were found to reduce apoptosis induced by glucose deprivation and increase cell yield in both cell lines. The results show that in glucose depleted culture conditions, butyrate at low concentrations (0.5 mM for S/RG/C2, and 0.5 and 2 mM for HT29 cells) was found to be growth stimulatory whereas in the presence of glucose, these same concentrations of butyrate induced apoptosis. Thus, whether butyrate is growth stimulatory or growth inhibitory may depend on the availability of other energy sources. These observations may, in part, provide an explanation for the apparent opposite effects of butyrate on proliferation reported in vivo and in vitro.

Adenoma↗
PubMed1997

Insulin-like growth factor-1, a component of serum that enables porcine cumulus cells to expand in response to follicle-stimulating hormone in vitro.

The present study was aimed at determining whether insulin-like growth factor-1 (IGF-1) is a component of fetal bovine serum (FBS) that enables porcine cumulus cells to expand in response to FSH in vitro. Cumulus-oocyte complexes (COC) obtained from 4- to 6-mm follicles of prepubertal gilts were cultured at 39 degrees C for 24 h in media that contained human recombinant IGF-1 (50 ng/ml), FBS (15% v:v), or their combination, with or without FSH (1.5 microg/ml), and cumulus expansion was scored microscopically. Expansion was FSH dependent and was observed only when IGF-1, FBS, or both were present. The proportion of FSH-stimulated COC exhibiting full expansion in response to IGF-1 alone did not differ significantly (p > 0.05) from the proportion in those cultured with FBS or IGF-1+FBS (79 +/- 2.8% vs. 84 +/- 2.2% or 76 +/- 6.2%, respectively). In a concentration-response study, FSH-stimulated expansion was observed in a significant proportion of COC (32 +/- 2.8% vs. 0% control) at 1 ng/ml IGF-1, with the proportions increasing dose-dependently to maximal values between 10 and 75 ng/ml IGF-1, and decreasing at higher IGF-1 concentrations. Exposure of COC to an IGF-1 receptor (IGF-1R)-neutralizing antibody (Ab) for 90 min before addition of FSH and FBS dose-dependently inhibited cumulus expansion, with maximal inhibition at 10 microg/ml (1 +/- 1.0% vs. 68 +/- 1.1% control). In the absence of FBS or IGF-1, some COC had a tendency toward slight expansion when cultured with FSH, and the Ab completely inhibited that effect, suggesting that this may be due to endogenous IGF-1 production by the COC. The Ab effect was reversible and was eliminated by washing twice with fresh medium followed by culture for an additional 24 h in the presence of FSH and FBS. Expression of IGF-1R mRNA in the isolated oocyte and cumulus cells was determined by reverse tramscriptase polymerase chain reaction using sequence-specific primers. The IGF-1R message was detected in both the oocyte and cumulus cells. Collectively, these observations suggest that IGF-1 is a component of serum that enables cumulus cells to expand in response to FSH in vitro, and that the effect is receptor mediated. Since IGF-1 is present in the follicle in vivo, it may have a physiological role during gonadotropin-induced cumulus expansion.

Animals↗
PubMed1997

Membranous fat necrosis in lipomas.

Membranous fat necrosis (MFN) is an under-recognized variant of fat necrosis (FN) that is characterized by the presence of membranocystic foci in which cysts are lined by an eosinophilic, homogeneous membrane with pseudo-papillary luminal projections. Although MFN has been described in systemic adipose tissue, it has not been described in lipomas. We report the rare occurrence of MFN in four lipomas. The lipomas ranged in size between 9 and 22 cm and occurred in menopausal women in the left shoulder, right upper back, right thigh, and gluteal regions. In two cases the membranocystic foci were identified macroscopically, whereas in the other two cases MFN was only identified on histologic assessment. Apart from the typical histologic appearance of the membranocystic foci, the membranes have a distinct histochemical profile that includes consistent Sudan black positivity and either periodic acid-Schiff or Ziehl-Neelsen positivity. In all cases, there was autofluorescence of the membranes on immunofluorescent examination of unstained sections. These membranocystic foci have the typical staining reactions of ceroid pigment. The exact cause of MFN in lipomas is not known, but in view of their large sizes, traumatic and ischemic etiologies are proposed.

Aged↗
PubMed1997

Validation of the Charlson comorbidity index in patients with head and neck cancer: a multi-institutional study.

Comorbid conditions are medical illnesses that accompany cancer. The impact of these conditions on the outcome of patients with head and neck cancer is well established. However, all of the comorbidity studies in patients with head and neck cancer reported in the literature have been performed using the Kaplan-Feinstein index (KFI), which may be too complicated for routine use. This study was performed to introduce and validate the use of the Charlson comorbidity index (CI) in patients with head and neck cancer and to compare it with the Kaplan-Feinstein comorbidity index for accuracy and ease of use. Study design was a retrospective cohort study. The study population was drawn for three academic tertiary care centers and included 88 patients 45 years of age and under who underwent curative treatment for head and neck cancer. All patients were staged by the KFI and the CI for comorbidity and divided into two groups based on the comorbidity severity staging. Group 1 included patients with advanced comorbidity (stages 2 or 3), and group 2 included those with low-level comorbidity (stages 0 or 1). Outcomes were compared based on these divisions. The KFI was successfully applied to 80% of this study population, and the CI was successfully applied in all cases (P < 0.0001). In addition, the KFI was found to be more difficult to use than the CI (P < 0.0001). However, both indices independently predicted the tumor-specific survival (P = 0.007), even after adjusting for the confounding effects of TNM stage by multivariate analysis. Overall, the CI was found to be a valid prognostic indicator in patients with head and neck cancer. In addition, because comorbidity staging by the CI independently predicted survival, was easier to use, and more readily applied, it may be better suited for use for retrospective comorbidity studies.

Adult↗
PubMed1997

A profile of Australian family caregivers: diversity of roles and circumstances.

Research on family caregiving has been based largely on small samples, often drawn from support organisations or services, and has tended to focus on particular disability groups. Our study was population-based and included all ages and disabilities. As the first stage in a longitudinal research and health promotion program for informal caregivers, a statewide random survey of over 26,000 households was conducted by telephone: 78 per cent of self-identified carers (N = 976) agreed to participate in a one-hour interview. This paper presents a sociodemographic profile of Australian caregivers. Four types of relationship between carers and care recipients (adult offspring, spouses, parents and other relatives and friends) provide the framework for results. Group differences were observed on most characteristics: for example, age, living arrangements, work status and duration of care. Care recipient characteristics, including difficult behaviours and need for assistance, are also reported, as well as use of and need for community services. What the findings reflected most was the heterogeneity of both caregivers and care recipients and the diversity of caregiving roles and circumstances.

Adolescent↗
PubMed1997

The role of general practitioners and pharmacists in information exchange with family carers.

As a trial of the provision of community-service information to family carers, general practitioners and pharmacists from the Western region of Melbourne were supplied with tear-off pads listing suburb-specific community services, and were encouraged to discuss service needs with carers of people with disabilities and distribute the lists to carers accordingly. One hundred and nine general practitioners and 58 pharmacists participated in pretrial and post-trial interviews assessing their knowledge of community services and frequency of discussion with carers. Before the trial, general practitioners had significantly higher self-rated knowledge of community services and reportedly discussed these with carers more often than did pharmacists. After the five-month trial period, pharmacists showed a significant increase in self-rated knowledge and frequency of discussion. General practitioners' knowledge and discussion showed a nonsignificant increase. After the trial, the two did not differ in knowledge of services; however, general practitioners maintained a higher reported frequency of discussion about services with carers. General practitioners and pharmacists appear to be well placed to act as a service link for family carers. However, additional high-intensity strategies are needed to assist them in this role.

Caregivers↗
PubMed1997

The dental identification of victims of an aircraft accident in Malaysia.

On 15 September 1995 a Malaysian Airlines (MAS) Fokker 50 plane plunged while descending and crashed, killing thirty-four passengers aboard. The dental disaster victim identification team comprising dental surgeons from the Dental faculty, University of Malaya; Ministry of Health, Sabah; and the Malaysian Defence Forces played an active role in the identification process. Most of the bodies were badly mutilated, disfigured and severely incinerated. Problems were encountered due to inadequate facilities and space at the mortuary. Difficulties were also encountered during the procurement and deciphering of information from dental records. This disaster has however created greater awareness amongst Malaysians of the important role of forensic odontology in mass disasters.

Accidents, Aviation↗
PubMed1997

Dorsal penile frenulum.

A dorsal frenulum with a normal penis lacks description in the available English literature. We report 1 such case and its genesis is also postulated.

Adult↗
PubMed1997

Complications associated with 327 foreign bodies of the pharynx, larynx, and esophagus.

We intended to identify the types and incidence of complications associated with foreign bodies (FBs) impacted in the upper aerodigestive tract (UADT) and to ascertain factors predisposing to the development of these complications. The design was a retrospective cohort study of 327 patients with UADT foreign bodies admitted to a tertiary care center. The overall incidence (7.6%) and types of complications varied by age. Complications developed in 4.8% of 208 patients 10 years of age and under, with pulmonary complications being most common. In contrast, complications occurred in 12.6% of 119 older patients, with retropharyngeal abscess being the most common (p < .0001). Delayed presentation (> 24 hours after the onset of symptoms) was the only factor associated with an increase in the incidence of complications in the younger patients (p = .02). In contrast, pharyngeal location of the FB (p = .0004), the FB's being a fish bone (p = .006), and radiolucency (p = .02) were all associated with an increased incidence of complications in patients over 10 years of age. A significant risk for complications is present for patients admitted for the management of FBs in the UADT. Older patients with sharp FBs are at greatest risk. In this group of patients, close observation in the perioperative period is required, especially if there is evidence of mucosal injury.

Adolescent↗