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Biomedical subjects

A Gupta

Publications and source records attributed to A Gupta.

At least 811 records · Page 45Linked to original sources
PubMed1989

Hydration and tissue solid content of the lean body on prolonged exposure to altitude.

Using densitometric, hydrometric and anthropometric techniques, body fat, tissue solids, water and mineral content were quantitatively measured on two groups each of 26 young and healthy Indian soldiers of mixed ethnic composition. The experimental group was exposed to 3500 m altitude for 2 years and the experiments were carried out after 48 h and 3 weeks rehabilitation in Delhi (300 m). The control group was never exposed to high altidues. Inspite of the experimental group being fed with superior rations at high altitude, this group showed significantly hyperhydrated lean body with reduced tissue solids in comparison to the control group which was fed with identical rations in Delhi. The calculated mean density of the fat free body had declined to 0.092 x 10(3) kg/m3. The 3 week stay at low altitude had little influence on body composition. Hyper-hydration, with reduced tissue solids, would cause reduction in the density of fat free body, and would thus interfere with the estimates of total body fat based on densitometric procedures alone. In the hyperhydrated state, Siri's formula overestimated fat by 22.8% of the true value.

Adipose Tissue↗
PubMed1989

Fractures of the hook of the hamate.

Fractures of the hook of the hamate have been infrequently reported in the literature. A high index of suspicion is required if the correct diagnosis is to be established. We report three cases of fractures of the hook of the hamate and postulate a mechanism of injury in sportsmen. Once established, an excision of the hook is usually necessary to resolve the discomfort.

Adult↗
PubMed1989

The induction of intercellular adhesion molecule 1 (ICAM-1) expression on human fetal astrocytes by interferon-gamma, tumor necrosis factor alpha, lymphotoxin, and interleukin-1: relevance to intracerebral antigen presentation.

Antigen presentation reactions are dependent upon the expression of the class II major histocompatibility antigens (MHC), the T-cell receptor, and the presented antigen. Recent studies demonstrate that such processes also require the presence of adhesion molecules such as lymphocyte functional antigen 1 (LFA-1) and its cell surface ligand, intercellular adhesion molecule 1 (ICAM-1). It has been suggested that the brain astrocyte can function as a facultative antigen presenting cell (APC). This hypothesis is based upon the ability to induce the expression of the class II MHC antigens on astrocytes, and on their ability to present myelin basic protein to encephalitogenic T-cells in vitro. The best in vivo data showing that astrocytes serve as intracerebral APCs is the finding that astrocytes in multiple sclerosis plaques are DR+ (class II MHC in human). However, it still remains to be resolved whether the in vivo expression of the MHC antigens in disease states is instrumental to antigen presentation mechanisms or whether these cell surface glycoproteins are expressed secondary to brain immune responses. If astrocytes function as immunocompetent APCs within the brain, it would seem that they would also be able to express molecules important for intercellular adhesion. Here, we present the first data that indicates that human astrocytes are capable of expressing ICAM-1 in response to cytokines that either induce or upregulate the expression of DR. In essence, cytokines derived from different cell types seem to exert similar pleiotropic effects on the modulation of MHC and ICAM-1 expression on astrocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigen-Presenting Cells↗
PubMed1989

Comparison of endothelial damage produced by control and surface modified poly(methyl methacrylate) intraocular lenses.

Biological studies were performed on control and surface modified (passivated) poly(methyl methacrylate) (PMMA) intraocular lenses (IOLs). In acute corneal touch studies in cats, surface modified IOLs caused little endothelial damage and only single cells or small debris were seen adhering to the IOL. In contrast, control IOLs caused major endothelial damage and large sheets of endothelial cells were seen adhering to the control IOL surface. Use of the surface modified IOLs may help reduce the associated endothelial damage during cataract surgery.

Animals↗
PubMed1989

Minitracheotomy in the early respiratory management of patients with spinal injuries.

Minitracheotomy is a new technique of tracheal suction by the introduction under local anaesthetic of a small bore tube into the trachea through the cricothyroid membrane. The use of minitracheotomy in the early management of respiratory problems in patients with spinal injuries is described with a few illustrative cases. This technique is an adjunct to good physiotherapy in clearing secretions from the trachea. Its advantages and disadvantages are discussed.

Adult↗
PubMed1989

Efficacy of lignocaine in the suppression of the intra-ocular pressure response to suxamethonium and tracheal intubation.

The effect of lignocaine pretreatment on the intra-ocular pressure response to suxamethonium and tracheal intubation was studied in 80 adult patients, divided randomly into four groups of 20 each. These groups received respectively normal saline (10 ml), lignocaine 1 mg/kg, 1.5 mg/kg and 2 mg/kg as pretreatment, in a double blind manner, one minute before anaesthetic induction with thiopentone and suxamethonium 1.5 mg/kg. Lignocaine pretreatment caused a significant decrease in intra-ocular pressure. Suxamethonium caused a significant increase, but lignocaine pretreatment in doses of 1.5 mg/kg and 2 mg/kg effectively kept the postsuxamethonium pressure below control values. Tracheal intubation further aggravated the postsuxamethonium increase in intra-ocular pressure. Lignocaine, in doses of 1.5 mg/g and 2 mg/kg also effectively kept the postintubation pressure values below control levels. Lignocaine, in dose of 1 mg/kg, only partially attenuated the postsuxamethonium and postintubation increase in intra-ocular pressure. In conclusion, lignocaine pretreatment, in a dose of 1.5 mg/kg, offers protection against suxamethonium- and tracheal-intubation initiated increases in intra-ocular pressure, without causing any significant decrease in arterial pressure.

Adolescent↗
PubMed1989

Control of phosphate transport in flounder renal proximal tubule primary cultures.

Unidirectional mucosal-to-serosal (Jm----s) and serosal-to-mucosal (Js----m) transepithelial phosphate fluxes across monolayers of flounder (Pseudopleuronectes americanus) renal proximal tubule cells in primary culture were examined for effects of diacylglycerols, phorbol ester, A23187, forskolin, and extracellular phosphate availability. Tissues were cultured on floating collagen rafts and studied short circuited in Ussing chambers. Transepithelial electrical properties were continuously monitored and were unaffected by any of the treatments compared with paired controls. Under usual conditions (phosphate = 0.4 mM) tissues invariably displayed net phosphate reabsorption [Js----m = 2.3 +/- 0.52; Jm----a = 7.1 +/- 1.77; Jnet = 4.9 +/- 1.45 (SE) nmol.cm-2.h-1]. Acute elevation of bath phosphate concentration above 0.5 mM stimulated net secretion. Exposure to 100 microM 1,2-dihexanoyl-sn-glycerol stimulated net phosphate secretion within 30 min, the result of a fivefold increase in Js----m. Phorbol-12,13-didecanoate stimulated net phosphate secretion by increasing Js----m and decreasing Jm----s. The inactive diacylglycerol, 1,3-didecanoyl-rac-glycerol (100 microM), had no effect on phosphate fluxes. A23187 stimulated net phosphate secretion; Jm----s was reduced almost fourfold while Js----m was increased threefold. Forskolin (10 microM) stimulated net reabsorption more than threefold after a long latency (2 h). These data indicate that renal phosphate secretion and reabsorption may be regulated by several putative intracellular messengers. In addition, extracellular phosphate availability may modulate renal phosphate handling.

Animals↗
PubMed1989

Evidence for prostaglandins and leukotrienes as mediators of phase I of estrogen action in implantation in the mouse.

The inhibition of the cyclooxygenase and/or the lipoxygenase pathways by indomethacin or nordihydroguaiaretic acid during Phase I of estrogen action interfered with estriol-induced initiation of implantation, but not uterine macromolecular uptake and water imbibition. This inhibition of implantation was completely reversed by supplementation with prostaglandin E2 or leukotriene C4. These results suggest that estrogen-induced initiation of implantation in a progesterone-primed uterus is mediated via prostaglandins and leukotrienes as components of Phase I of estrogen action.

Animals↗
PubMed1989

Multilevel spinal injuries. Incidence, distribution and neurological patterns.

Spinal injury at more than one level is not uncommon. Awareness of multilevel injury of the spine and associated neurological patterns is important for the proper initial management of the patient. This study presents the incidence, pattern of signs and the neurological consequences of multilevel spinal injury. A review of 935 patients with spinal injuries revealed that lesions occurred in multiple levels in 9.7%; in over half of the cases, neurological lesions were incomplete. Multiple level non-contiguous lesions at more than two levels had the worst prognosis with 70% of patients suffering complete paraplegia.

Fractures, Bone↗
PubMed1989

Acute renal failure in infants in the tropics.

This study records our experience with 40 infants who developed acute renal failure in a tropical environment over a period of 2 years. All the patients required intermittent peritoneal dialysis. Septicaemia (88%) and acute gastroenteritis (55%) constituted the leading causes of acute renal failure. Haemolytic uraemic syndrome was present in six (18%) patients. An elevated serum creatinine (85%), metabolic encephalopathy (75%), uncompensated metabolic acidosis (75%) and hyperkalaemia (48%) were the major indications for dialysis, while fluid overload was present in only 18% of the infants. Intermittent peritoneal dialysis was used in all the patients and was found to be effective. Procedural complications were minor and infrequently encountered. The clinical course and laboratory data consistent with haemolytic uraemic syndrome was observed in six patients, and acute tubular necrosis was the predominant renal lesion in the remainder. Mortality was 75%. The aetiology of acute renal failure in infants in the tropics differs significantly from that in the West, and even within a given country marked regional variations exist.

Acute Kidney Injury↗