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Biomedical subjects

A Bansal

Publications and source records attributed to A Bansal.

At least 19 recordsLinked to original sources
PubMed1992

Portal-vein obstruction in children leads to growth retardation.

The portal vein is the main source of blood and hepatotrophic factors to the liver. Partial portal-vein ligation in rats results in reduced growth compared with that in control rats. To investigate whether extrahepatic portal vein obstruction occurring in early childhood influences growth in humans, anthropometric and nutritional assessments were prospectively carried out in 61 patients with extrahepatic portal vein obstruction. Comparisons were made with 183 matched healthy controls using National Center of Health Statistics reference. Fifty-one percent of children with extrahepatic portal vein obstruction had stunted growth (height for age less than 90% of normal), compared with 16% of controls (p less than 0.01). Growth retardation was severe in patients with longer (greater than 5 yr) than with shorter (less than 2.5 yr) duration of clinical portal hypertension (height for age, 88.0 +/- 3.2 vs. 95.1 +/- 3.0; p less than 0.01). Little difference was seen in the energy intake (1,302 +/- 463 kcal/day vs. 1,335 +/- 449 kcal/day; p = not significant) and weight for height index (83.6 +/- 9.3 vs. 88.0 +/- 7.9; p = not significant) between extrahepatic portal vein obstruction patients and controls. This suggested that despite comparable nutrition, marked growth retardation occurred in extrahepatic portal vein obstruction patients. Incremental growth velocity was studied in 31 patients; in 24 (73%) the baseline Z score (-2.1 +/- 0.2) had decreased further (-2.4 +/- 0.2) at the end of follow-up (15.5 +/- 1.6 mo). Although the incremental height velocity was only 56% of the expected height, incremental weight gain was 98% of the expected weight for the attained height.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Soluble CD23 levels are elevated in the serum of patients with primary Sjögren's syndrome and systemic lupus erythematosus.

The low affinity IgE receptor Fc epsilon RII (CD23) is important in several aspects of T and B cell function. In this study serum levels of soluble CD23 (sCD23) were measured in three groups: 26 female patients with systemic lupus erythematosus (SLE), 21 females with primary Sjögren's syndrome (pSS) and 25 normal healthy females. The concentration of sCD23 was determined using an enhanced chemiluminescent sandwich ELISA developed in this laboratory. Increased levels of sCD23 were observed in pSS and in SLE patients compared with controls (median 23.0 versus 8.6, P less than 0.0002 and 18.1 versus 8.6, P less than 0.002 respectively). While the median level of sCD23 was found to be higher in pSS than in SLE the difference was not statistically significant. Patients with SLE and pSS on glucocorticoid treatment had significantly lower levels of sCD23 than patients not on this treatment (median 28.9 versus 14.4, P less than 0.05). Amongst the control patients sCD23 was inexplicably lower in the female members relative to the males (median 8.5 versus 12.3, P less than 0.05). Although serum IgG and IgA levels were significantly elevated in pSS and SLE patients relative to controls there was no direct correlation between sCD23 and the serum levels of these immunoglobulins. We conclude that B cell hyperactivity which occurs in both pSS and SLE is associated with raised levels of sCD23.

Adult↗
PubMed1992

Characterization of the binding of a potent, selective, radioiodinated antagonist to the human neurokinin-1 receptor.

We have synthesized a potent, selective, radioiodinated antagonist of the human neurokinin-1 (NK1) receptor and have characterized its binding to the cloned receptor expressed in Chinese hamster ovary cells. (cis)-2-(Diphenylmethyl)-N-[(2-iodophenyl)-methyl]-1- azabicyclo[2.2.2]octan-3-amine (L-703606) inhibits binding of 125I-Tyr8-substance P to the human NK1 receptor with an IC50 of 2 nM. This compound is a competitive antagonist of substance P-induced inositol phosphate generation, with a Kb of 29 nM. [125I]L-703606 binds to a single class of high affinity binding sites in human NK1/Chinese hamster ovary cell membranes (Kd = 0.3 nM). Substance P inhibits the binding of [125I]L-703606 to 65% of the NK1 receptor sites with a Kd of 0.04 +/- 0.03 nM and to the remaining 35% of the sites with a Kd of 1.5 +/- 0.7 nM. Addition of the nonhydrolyzable GTP analog guanylyl-5'-(beta, gamma-imido)diphosphate [Gpp(NH)p] shifts greater than 90% of the binding sites to the lower affinity state. In addition, Gpp(NH)p markedly alters the dissociation of substance P from the NK1 receptor by increasing the number of sites in the low affinity, rapidly dissociating state. However, Gpp(NH)p does not affect the rate of dissociation of [125I]L-703606. These data suggest that the pharmacological properties of [125I]L-703606 binding to the human NK1 receptor are similar to those of antagonists of nonpeptide guanine nucleotide-binding protein-coupled receptors and that this ligand will be useful for the biochemical and pharmacological characterization of the human NK1 receptor.

Amino Acid Sequence↗
PubMed1991

The NPXY internalization signal of the LDL receptor adopts a reverse-turn conformation.

Peptides corresponding to the proposed coated pit internalization signal of the native low density lipoprotein receptor, NPVY, take up in aqueous solution a reverse-turn conformation with the Asn in position i and the Tyr in position i + 3. By contrast, peptides derived from receptors that are defective for endocytosis do not adopt the reverse turn. These internalization-defective receptors include those with a nonaromatic residue substituted for the Tyr and those with Asn----Ala or Pro----Ala substitutions. While the tendency of an Asn-Pro sequence to induce a reverse turn was anticipated, the structural importance of an aromatic residue in position i + 3 was not. The sequences associated with the internalization signal thus appear to play a critical conformational role that is required for endocytosis, probably by enabling binding to adaptor molecules. With the results presented in the accompanying paper on lysosomal acid phosphatase, we now have direct evidence for previous proposals of a general correlation of internalization signals with a turn conformational motif.

Amino Acid Sequence↗
PubMed1990

Infant feeding practices in educated mothers from upper socio-economic status.

One hundred and twenty mothers from upper socio-economic status and education up to graduation level were assessed for infant feeding practices using a pre-tested questionnaire. Prelacteal feed of honey was administered by 51.7% and initiation of breast feeding delayed by more than 24 hours by 68.3% of mothers. Colostrum was discarded by 53% mothers; 83% introduced bottle feeding in the first month of life; and poor bottle hygiene was seen in 54% cases. Addition of semisolids was delayed by almost 50% of mothers, the reason given being fear of liver disorders. These observations highlight ignorance about basic infant feeding practices in the educated elite section of our country. Health education in schools, colleges, non formal gatherings and during the antenatal period are suggested as means to remove this ignorance.

Bottle Feeding↗
PubMed1989

Affinity labeling of a glutamyl peptide in the coenzyme binding site of NADP+-specific glutamate dehydrogenase of Salmonella typhimurium by 2-[(4-bromo-2,3-dioxobutyl)thio]-1,N6-ethenoadenosine 2',5'-bisphosphate.

NADP+-specific glutamate dehydrogenase from Salmonella typhimurium, cloned and expressed in Escherichia coli, has been purified to homogeneity. The nucleotide sequence of S. typhimurium gdhA was determined and the amino acid sequence derived. The nucleotide analogue 2-[(4-bromo-2,3-dioxobutyl)thio]-1,N6-ethenoadenosine 2',5'-bisphosphate (2-BDB-T epsilon A-2',5'-DP) reacts irreversibly with the enzyme to yield a partially inactive enzyme. After about 60% loss of activity, no further inactivation is observed. The rate of inactivation exhibits a nonlinear dependence on 2-BDB-T epsilon A-2',5'-DP concentration with kmax = 0.160 min-1 and KI = 300 microM. Reaction of 200 microM 2-BDB-T epsilon A-2',5'-DP with glutamate dehydrogenase for 120 min results in the incorporation of 0.94 mol of reagent/mol of enzyme subunit. The coenzymes, NADPH and NADP+, completely protect the enzyme against inactivation by the reagent and decrease the reagent incorporation from 0.94 to 0.5 mol of reagent/mol enzyme subunit, while the substrate alpha-ketoglutarate offers only partial protection. These results indicate that 2-BDB-T epsilon A-2',5'-DP functions as an affinity label of the coenzyme binding site and that specific reaction occurs at only about 0.5 sites/enzyme subunit or 3 sites/hexamer. Glutamate dehydrogenase modified with 200 microM 2-BDB-T epsilon A-2',5'-DP in the absence and presence of coenzyme was reduced with NaB3H4, carboxymethylated, and digested with trypsin. Labeled peptides were purified by high performance liquid chromatography and characterized by gas phase sequencing. Two peptides modified by the reagent were isolated and identified as follows: Phe-Cys(CM)-Gln-Ala-Leu-Met-Thr-Glu-Leu-Tyr-Arg and Leu-Cys(CM)-Glu-Ile-Lys. These two peptides were located within the derived amino acid sequence as residues 146-156 and 282-286. In the presence of NADPH, which completely prevents inactivation, only peptide 146-156 was labeled. This result indicates that modification of the pentapeptide causes loss of activity. Glutamate 284 in this peptide is the probable reaction target and is located within the coenzyme binding site.

Adenosine Diphosphate↗
PubMed1989

Fortified high calorie human milk for optimal growth of low birth weight babies.

This study was undertaken with the aim of providing adequate calories for optimal growth in low birth weight (LBW) by fortifying human milk with medium chain triglycerides and sugar. Twenty-one LBW babies with birth weight between 1.0 and 1.75 kg and gestational age 28-36 weeks constituted the study material. They were administered expressed human milk, initially with gavage and then by spoon. Coconut oil and sugar were added to increase the caloric density to (0.8 cal/ml). The aim was to achieve a caloric intake of 200 cal/kg. This was achieved between 6 and 11 days of birth. Additionally, vitamin C (50 mg) and vitamin E (25 IU/kg/day) were administered. Weight was recorded daily to the nearest 50 g. Head circumference was measured weekly using a non-stretch tape measure. Blood urea nitrogen was measured once the neonate started taking high calorie feeds. Stools were examined daily for the presence of fat globules and reducing substances and for the pH. All but one neonate tolerated the feeds well and there were no complications, such as vomiting, diarrhoea, abdominal distension, or necrotizing enterocolitis. The weight gain recorded was 17.29 +/- 5.30 g/day or 13.95 +/- 5.52 g/kg/day. The study demonstrates that optimal growth can be achieved within the metabolic tolerance of low birth weight infants by administering fortified high calorie breast milk.

Energy Intake↗
PubMed1989

Gastroesophageal reflux in infants and children.

Seventy-five infants and children presenting during the period December 1984 to December, 1987 with the clinical features of vomiting, failure to thrive, chronic cough, recurrent pneumonia and atypical asthma were evaluated for gastroesophageal reflux by standard barium esophagram. Fifty six cases (74.7%) and as many as 80% of the infants studied had gastroesophageal reflux; Grade II reflux was seen in 12 cases, Grade III in 30 and Grade IV in 14 cases. The patients with gastroesophageal reflux were put on medical treatment. All the patients had subjective improvement after 6 weeks to 6 months of conservative treatment and none of them developed further complications of gastroesophageal reflux during a follow-up period varying from two months to fifteen months. Anti-reflux surgery was not considered owing to the subjective improvement in all the patients on conservative treatment. We conclude that gastroesophageal reflux is very common in infants and children and urge the need to evaluate the patients presenting with the symptoms suggesting gastroesophageal reflux by barium esophagram; conservative treatment is the mainstay in the management of these children.

Barium↗