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Biomedical subjects

R K Chawla

Publications and source records attributed to R K Chawla.

At least 73 records · Page 4Linked to original sources
PubMed1975

Observations on the lipolytic and melanotropic properties of neurophysin proteins.

Previous work indicated that brain contains 3 types of lipolytic-melanotropic peptide: (1) in adenohypophysis: ACTH, alpha-MSH, beta-MSH, peptide I, peptide L', beta-lipotropin and gamma-lipotropin; (2) in neurohypophysis: peptide 7D6, also termed neurophysin I, peptide II or Wuu-Saffran peptide; (3) in extrahypophyseal regions: peptide IIF. Bovine and human neurophysin I prepared by R. Walter has now been found devoid of lipolytic and melanotropic activities. Porcine and bovine peptide 7D6, closely similar or identical to bovine neurophysin I in electrophoretic mobility and amino acid composition, were therefore reexamined to determine whether their lipolytic-melanotropic property resided in a contaminating factor. When peptide 7D6 was analyzed in 100 transfer counter current distribution (1 butanol/0.1M NH4 HCO3), the neurophysin was recovered in tubes 1-9 (7D6-alpha) representing 95% of 7D6. 7D6-alpha was inactive in lipolytic and melanotropic assays. The biologic activities of 7D6 were recovered instead in tubes 50-70 (labeled 7D6-beta), representing 5% of 7D6. 7D6-beta proved to be a peptide with MW 1000-3000, closely similar to peptide IIF in amino acid composition, MW, and Rf values in 4 systems of paper chromatography.

Amino Acids↗
PubMed1975

Efficiency of alpha-ketoisocaproic acid as a substitute for leucine in the diet of the growing rat.

Immature male albino rats (70-80 g), eating a diet furnishing all nutrients for optimal growth and containing 84.6 mumoles of leucine/g, gained weight at an average rate of 5.9 g/day. Removal of leucine caused an average daily weight loss of 1.3 g. Addition of leucine to the diet in graduated amounts corrected this weight loss, the improvement in body weight (BW) being proportional to the dietary content of leucine. Addition of alpha-ketoisocaproic acid in place of leucine to the leucine-free diet also prevented loss of BW. Percentage efficiency of alpha-ketoisocaproic acid as a dietary substitute for leucine was calculated as: (see article). Efficiency of such substitution varied from 27% for a diet containing 84.6 mumoles of alpha-ketoisocaproic acid/g to 20% for a diet containing 169.2 alpha-ketoisocaproic acid/g.

Amino Acids, Essential↗
PubMed1975

Melanotropic activity in extrahypophyseal regions of rodent brain: effect of age, hormones, and drugs.

Two or more melanotropic peptides are present in extrahypophyseal regions of mammalian brain. Previous studies showed that extrahypophyseal melanotropic activity is not influenced by hypophysectomy, adrenalectomy, or exogenous glucocorticoid. The present study investigated the possible influence of the following factors on the level of melanotropic activity in whole brain, cerebral cortex, cerebellum, midbrain, and brainstem of mouse and rat: age, sex, starvation; and of the following hormones or drugs administered by the intraperitoneal or intracerebral route: norepinephrine, dihydroxyphenylalanine, pargyline, 6-hydroxy-dopamine, alpha-methyltyrosine methyl ester, reserpine, acetylcholine, pilocarpine, atropine, serotonin, p-chlorophenylalanine, pentobarbital, pentylenetetrazol, insulin, melatonin, and cycloheximide. Only age influenced extrahypophyseal melanotropic activity. The activity per unit of tissue wet weight or of tissue protein increased in all regions progressively from birth to 1 yr of age. Extrahypophyseal melanotropic activities perunit wet weight of tissue at 50 wk averaged 4.3 times those at birth. When brain of adult rodents was fractionated by differential centrifugation, the major proportion of melanotropic activity was recovered in myelin (27-35 percent), nerve endings (20-22 percent), and mitochondria (25-30 percent). The lower activity in newborn brain resulted not onlyfrom absence of a myelin fraction, but also from lower activity at birth in nerve endings and mitochondria.

Acetylcholine↗
PubMed1974

Isolation of a novel glycoprotein from the urine of a patient with chronic myelocytic leukemia.

Patient B. J. with chronic myelocytic leukemia excreted 0.5-1.1 g protein per day in the urine. Gel filtration on Sephadex G-75 showed about one-third of this protein to be in molecular weight range 20,000-40,000 (fraction BJC). BJC, prepared from 9 liters of urine by gel filtration, was chromatographed on carboxymethylcellulose. Two proteins were eluted from the resin in pure form (as shown by zone and immunoelectrophoresis) in yields representing 8 and 3 mg/liter of urine: BJC1 and BJC2. Their amino acid compositions were identical. BJC1 contained 61% carbohydrate (33% hexose, 11% sialic acid, 13% glucosamine, 5% galactosamine). BJC2 contained one-fourth to one-half as much of each carbohydrate. Molecular weight of BJC1 was estimated at 29,000 by gel filtration. Neither glycoprotein reacted with rabbit antiserum to normal human serum.Antiserum to BJC1 was made in the rabbit. Immunoelectrophoresis with this antiserum showed a faint precipitin line, corresponding in mobility to BJC1, in normal human plasma, and a stronger line in most leukemic plasmas. By immunodiffusion, BJC1 was not detectable in normal human urine, but a positive reaction occurred in the following conditions: leukemia, 64-72%; other types of disseminated neoplastic disease, 36-78%; regional ileitis, 45%; ulcerative colitis, 38%; tuberculosis, 33%; during the 1st wk after major surgery, 33%.BJC2 was found in the urine by immunoelectrophoresis in 10% of patients with neoplastic disease and was not observed in urine of other patients or in human plasma. Amino acid composition, carbohydrate content, and antigenic specificity indicate BJC1 is a previously unrecognized member of the system of normal human plasma glycoproteins. Like certain other glycoproteins, its plasma concentration frequently increases in patients with neoplastic disease, chronic inflammatory disease, or tuberculosis and after surgery. Because molecular weight is 29,000, increased plasma concentration readily causes its appearance in the urine.

Aged↗
PubMed1974

Orosomucoid content of pleural and peritoneal effusions.

22 nonneoplastic, noninflammatory effusions (cirrhosis and congestive heart failure), 12 non-neoplastic inflammatory effusions (tuberculosis, lupus erythematosus, rheumatoid arthritis, and idiopathic pleuropericarditis), and 58 neoplastic effusions (cancer of lung, breast, ovary, and pancreas, and lymphoma) were analyzed by radial immunodiffusion for orosomucoid concentration. The average concentration +/-SE was 35+/-4, 65+/-17, and 130+/-13 mg/100 ml in the three types of effusion, respectively. By gel filtration and ion exchange chromatography, orosomucoid was isolated from 12 nonmalignant and 14 malignant fluids. The orosomucoid preparations reacted as single components in acrylamide gel electrophoresis at pH 9.0, and in immunodiffusion and immunoelectrophoresis against antisera to human serum and to human plasma orosomucoid. In radial immunodiffusion, the slope of the line relating concentration to the square of the diameter of the precipitate area was identical for orosomucoid isolated from normal human plasma and from nonneoplastic effusions, but was subnormal for orosomucoid isolated from neoplastic fluids. All orosomucoid preparations had normal amino acid composition. Orosomucoid from the nonmalignant effusions had normal carbohydrate content. 11 of 14 samples of orosomucoid isolated from neoplastic fluids had abnormalities in carbohydrate composition, consisting of subnormal content of sialic acid (11 of 14), hexose (10 of 14), and hexosamine (3 of 14), and abnormally high content of hexosamine (4 of 14). Discriminant analysis showed that concentration of orosomucoid distinguished between neoplastic and nonneoplastic noninflammatory effusions more effectively than concentration of total protein, albumin, alpha(1), alpha(2), beta, or gamma-globulin.

Albumins↗
PubMed1974

Utilization of alpha-keto and alpha-hydroxy analogues of valine by the growing rat.

When 70-80-g male albino rats eat a diet furnishing daily requirement of valine for optimal growth (70 mumol/g) and all other nutrients ("complete diet"), they gain weight at an average rate of 3.0 g/100 g body wt/day. When valine is removed, they lose weight at an average 2.1 g/100 g body wt/day. The growth retardation is improved or corrected by adding valine to the diet, daily weight gain being proportional to dietary valine content over a range of 0-70 mumol/g. Addition of alpha-ketoisovaleric acid instead of valine to the valine-free diet also improves or corrects the growth failure. Percent efficiency of alpha-ketoisovaleric acid as a substitute for valine was calculated as: 100 x (micromole valine per gram diet required to produce specified growth response)/(micromole alpha-ketoisovaleric acid per gram diet required to produce the same response). Efficiency of the substitution is inversely related to dietary content of the keto analogue, being 80% when diet contains 17.5 mumol/g (molar equivalent of (1/4) the daily requirement of valine), and 37% when diet provides 140 mumol/g (molar equivalent of twice the daily requirement of valine).alpha-Hydroxyisovaleric acid also substitutes for valine. Efficiency of the substitution at the single ration tested, 70 mumol/g diet, is 45%, similar to that for the keto analogue under the same conditions. When [1-(14)C]alpha-ketoisovaleric acid is injected intravenously, 30-80% of the administered radioactivity is exhaled as (14)CO(2) within 24 h. This finding suggests that inefficiency of alpha-ketoisovaleric acid as a substitute for valine results in part from degradation of the keto acid to isobutyric acid by branched chain dehydrogenase-decarboxylase. Oral administration of neomycin, polymyxin, and bacitracin reduces efficiency of alpha-ketoisovaleric acid as a substitute for valine by (1/4)-(1/2). This effect suggests that transamination of the keto acid may be performed in part by gastrointestinal microbes.

Animals↗
PubMed1973

Ineffectiveness of an oral killed typhoid vaccine in a field trial.

A field trial was carried out with a vaccine containing 300x10(9) killed S. typhi (strain Ty58) per tablet. A total of 12 564 children aged 1-15 years were given 3 tablets of the vaccine or a placebo at the rate of one tablet on each of 3 consecutive days. The results indicated that the vaccine, in its present form and at this dosage, gives no protection.

Administration, Oral↗
PubMedDate not supplied

Branchiogenic cyst of larynx.

An extremely rare case of branchiogenic cyst of the larynx in young adult male is reported. Relevant literature is reviewed.

Adult↗
PubMedDate not supplied

Effect of bromhexine on nasal mucus clearance in chronic maxillary sinusitis.

Nasal mucus clearance (NMC) was studied in seventy patients with chronic maxillary sinusitis. Forty-five patients were treated with oral administration of bromhexine tablets along with oral antibiotics and nasal decongestants. Twenty-five patients received the same treatment but without bromhexine to evaluate the results. NMC was also studied in hundred healthy controls.

Bromhexine↗