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Biomedical subjects

K Vohra

Publications and source records attributed to K Vohra.

12 recordsLinked to original sources
PubMed1990

Determination of 2-methylaziridine in workplace atmospheres.

A sampling and analytical procedure was developed for the monitoring of airborne 2-methylaziridine (MA). The analyte is collected by drawing air through a solution of 2,4,6-trinitrobenzenesulphonic acid (TNBS). In situ derivatisation of MA with TNBS during sample collection provides stability to the highly reactive analyte and makes it amenable to a sensitive high-performance liquid chromatographic determination with ultraviolet detection. The purified synthetic derivative of MA with TNBS is more suitable as a calibration standard than commercially available MA.

Air Pollutants, Occupational↗
PubMed1990

Improvement of neutrophil migration by systemic vitamin C in neonates.

The effect of oral vitamin C on chemotactic and random migration of neutrophils in 20 neonates (10 normal and 10 with suspected sepsis) was evaluated. Chemotaxis and random migration were studied between 24 and 48 hours of life, before and 24 hours after the administration of 400 mg (divided in four doses) of vitamin C. Chemotactic migration improved by 65% and random migration by 57% following vitamin C administration. The significant improvement in chemotaxis (P less than .01) and random migration may justify the inclusion of vitamin C as an adjunct to the therapy of neonatal sepsis.

Ascorbic Acid↗
PubMed1989

Ischemic injury to newborn rabbit ileum: protective role of human superoxide dismutase.

The effectiveness of human superoxide dismutase (hSOD) in the prevention of reperfusion injury was evaluated in a rabbit ileal loop model. Weanling white New Zealand rabbits, 6 weeks of age and weighing 500 to 1,000 g, were used. Intraluminal administration of SOD (5 mg/kg) was studied in 12 animals with each animal serving as its own control. In an additional 12 animals, parenteral SOD in a dose of 5 mg/kg in seven animals and 10 mg/kg in five animals was evaluated, while five additional control animals received parenteral saline. The effect of reperfusion injury was evaluated in each bowel loop by interruption of blood supply for five minutes, followed by reperfusion. Blood was drawn at 0, 16, 20, 24 hours in the parenteral group for measurement of hSOD levels by radioimmunoassay. The loops were studied pathologically for extent of mucosal damage. In the intraluminal group, nine of 12 loops without SOD v three of 12 loops with SOD showed necrosis when rendered ischemic (P = .0196). In the parenteral group 22 of 24 loops were normal when pretreated with SOD and subjected to ischemia v five of ten when no SOD was given (P = .0139). In the parenteral group, mean baseline level of hSOD was 0.42 +/- 0.26 micrograms/mL. Levels peaked at 16 hours (3.64 +/- 1.75 micrograms/mL) and progressively decreased at 20 hours (2.85 +/- 1.34 micrograms/mL) and 24 hours (1.82 +/- 1.15 micrograms/mL). This preliminary animal study suggests that hSOD may be an effective method for the prevention of postischemic bowel injury, adding to the literature on the protective effects of SOD in various models of intestinal ischemia.

Animals↗
PubMed1989

Clinical consequences of a human non-fluorescent Y chromosome (Ynf).

A new case of ambiguous genitalia and immature tissue in the left gonad is presented. Cytogenetic findings with various techniques demonstrated that the distal two-thirds of the long arm of the Y chromosome is deleted. Q-banding showed a non-fluorescent Y; three positive bands were however noted when the DA/DAPI technique was applied. After a review of the literature, it was concluded that the non-fluorescent Y chromosome (Ynf) when inherited from generation to generation is a heteromorphism in normal males. However, in our case, where the proband's Y is lacking the fluorescent segment, a simple deletion does not appear to adequately explain the DA/DAPI positive bands. Possibly, a deletion followed by a structural rearrangement of the non-fluorescent segment had occurred de novo. The highly Y-specific DNA sequences present in the fluorescent segment are absent in these patients. The abnormal development in these cases is due to the presence of the 45,X cell line. The gene responsible for spermatogenesis has been localized to the non-fluorescent region in the long arm of the Y chromosome. Furthermore, it is concluded that two types of non-fluorescent Y chromosomes can be found in the population; one is a normal inherent heteromorphic variant, while the other appears to be an abnormality, especially in cases with azoospermia. Such distinctions should clearly be established prior to genetic counseling for patients with so called Ynf or del (Yd).

Chromosome Banding↗
PubMed1987

Trisomy 22: report of a patient diagnosed as a neonate.

The present case report describes the occurrence of Trisomy 22 in a neonate. This chromosomal disorder has rarely been diagnosed in the neonatal period. A review of the literature is presented to elucidate the fact that only further diagnosis of new cases of Trisomy 22 in neonates will allow a clearer delineation of this chromosomal abnormality in the neonatal period.

Abnormalities, Multiple↗
PubMed1983

Pharmacokinetics of cefoperazone in full-term and premature neonates.

The pharmacokinetics of cefoperazone were evaluated in 28 newborn infants who were being treated for sepsis. A dose of 50 mg/kg was administered intravenously on days 0 to 2 in all, with a second dose administered on days 5 to 7 in 14 infants. Cerebrospinal fluid penetration was also studied in seven neonates. The mean peak concentration of cefoperazone in the serum of premature infants less than 33 weeks of gestational age, 159 (standard deviation, +/- 22) micrograms/ml, was higher than concentrations in premature infants 33 to 36 weeks of age and full-term infants (110 +/- 41 and 109 +/- 29 micrograms/ml, respectively). The mean concentrations 24 h after dosage were similar in all three groups, 13 to 17 micrograms/ml. The mean serum half-lives were similar in the three subgroups and ranged from 7 to 9 h. After the dose at 5 to 7 days, mean blood levels in the subgroups at 0.5 h were 149, 112, and 112 micrograms/ml; 24-h levels ranged from 9 to 12 micrograms/ml. The mean serum half-lives ranged from 5 to 7 h. Cerebrospinal fluid levels in patients with meningitis ranged from 2.8 to 9.5 micrograms/ml and in patients without meningitis from 1 to 7 micrograms/ml. Peak blood levels were 15 to 1,000 times higher than the 90% minimal inhibitory concentration of common pathogens found in newborns. These observations support the potential efficacy of cefoperazone in treatment of infections, including meningitis, in newborn infants.

Cefoperazone↗
PubMedDate not supplied

Gas chromatographic determination of 2,5-hexanedione in urine as an indicator of exposure to n-hexane.

A sensitive and specific method for determination of 2,5-hexanedione in urine is described. Treatment of the urine specimen directly with n-butylamine yields n-butyl 2,5-dimethyl pyrrole. The latter is extracted into diisopropylether and analyzed by gas chromatography (GC) with flame ionization detection (FID), thermionic specific detection (TSD) (N mode), or mass spectrometric detection (MS). The minimum detectable quantities are 1 mg/L urine when employing FID with a coefficient of variation of less than 6%. Recovery of 2,5-hexanedione added to the urine at the level of 10 mg/L was 78.9%.

Chromatography, Gas↗