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Biomedical subjects

A Kumar

Publications and source records attributed to A Kumar.

At least 127 records · Page 7Linked to original sources
PubMed1991

Evaluation of intraosseous vs intravenous antibiotic levels in a porcine model.

OBJECTIVES: To compare intraosseous vs intravenous routes of administration and their effects on serum levels of four antibiotics in an animal model. DESIGN: Prospective controlled study comparing two routes of drug administration. SETTING: Research laboratories of a large pharmaceutical company. PARTICIPANTS: Twenty male and female domestic swine weighing 10 to 20 kg. INTERVENTIONS: The animals were anesthetized and treated with controlled ventilation. The animals were divided into one of four groups: (1) intravenous and intraosseous cefotaxime sodium (50 mg/kg), (2) intravenous and intraosseous chloramphenicol sodium succinate (25 mg/kg), (3) intravenous and intraosseous vancomycin hydrochloride (15 mg/kg), or (4) intravenous and intraosseous tobramycin sulfate (2.5 mg/kg). There was a 24-hour clearance period for groups 1 and 2 and a 48-hour clearance period for groups 3 and 4. Serum drug levels were measured at 1, 15, 30, 45, 60, 90, and 120 minutes after intravenous and intraosseous administration of the respective antibiotics. Control and treated tibias were sampled for drug levels at the end of the experiment. MEASUREMENTS AND MAIN RESULTS: - Peak serum concentrations for intravenously administered antibiotics were within the therapeutic range. Peak serum levels after intravenous and intraosseous administration were 102 and 82 mg/L, respectively for cefotaxime; 13.9 and 6.3 mg/L, respectively, for chloramphenicol; 24.5 and 3.8 mg/L, respectively, for vancomycin; and 7.1 and 1.3 mg/L, respectively, for tobramycin. CONCLUSIONS: Cefotaxime may be administered intraosseously when intravenous access is not possible. We cannot recommend chloramphenicol or vancomycin for intraosseous administration, because serum levels were not comparable with those following intravenous administration. Findings with tobramycin suggested a lack of achievement of serum levels comparable with those following intravenous administration.

Animals↗
PubMed1991

Immunoglobulin heavy chain constant-region gene polymorphism in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is associated with immunoglobulin allotypes in several ethnic groups. In this study, we investigated the association of a Bst EII immunoglobulin heavy chain constant-region gene restriction fragment length polymorphism with SLE in patients from the US and Mexico. A 3-kb restriction fragment was observed with significantly decreased frequency in randomly selected Mexican SLE patients and in Mexican SLE patients in multiplex families. However, no such association was observed in SLE patients from the US. Thus, the absence of a 3.0-kb Bst EII restriction fragment from immunoglobulin heavy chain constant-region genes provides a marker for SLE in Mexican individuals.

Blotting, Southern↗
PubMed1991

Cytomegalovirus infection and excretion in residents of a nursing home.

Cytomegalovirus (CMV), following primary infection, usually remains latent with the potential for reactivation and excretion in saliva and urine. The prevalence of CMV excretion has not been studied among the elderly. This study followed 54 nursing home residents (mean age 83 years and medically stable, but with a wide spectrum of medical conditions). Over a 6 month period these subjects were serially tested for viral excretion in saliva and urine and for CMV antibody. While approximately 93% of the residents tested were sero-positive, indicating previous CMV infection, there was no evidence of viral excretion in any resident during the study period. Therefore, it is unlikely that the elderly nursing home residents will prove to be a source of CMV to the health care workers or to their family members.

Aged↗
PubMed1991

The Moloney murine leukemia virus enhancer and its flanking sequences collaborate to determine virulence in T-cell lymphomagenesis.

A panel of recombinant virus genomes was constructed by exchanging homologous genome fragments between the potent T-cell lymphoma inducer Moloney murine leukemia virus (MoMuLV) and its closely related but significantly less virulent relative MoMuLV-TB. Testing of these recombinant viruses in BALB/c mice established that only nucleotide changes within the Clal(-590)-Kpnl(36) fragment altered virulence. Fine analysis of this fragment showed that while mutations within the enhancer of MoMuLV-TB attenuated the latency period most, mutations within the MoMuLV-TB fragments flanking the enhancer also helped reduce the virulence of MoMuLV. The present study also suggests that the small difference in the relative number of lymphomas that developed primarily in the spleens of MoMuLV- or MoMuLV-TB-infected mice may correlate with nucleotide differences between the Clal-Kpnl fragments of the two viruses. However, the significantly greater proportion of premature death observed in MoMuLV-TB-relative to MoMuLV-infected mice could not be correlated with nucleotide differences in a specific genome fragment.

Animals↗
PubMed1991

Postinfantile giant cell hepatitis in association with hypereosinophilia.

Fatal giant cell hepatitis and hypereosinophilia developed in a 39-year-old man. The coexistence of these two rare disorders has not been previously described. Despite extensive testing, no specific causes could be identified. Evidence for a viral etiology of some cases of giant cell hepatitis is briefly reviewed.

Adult↗
PubMed1991

DR3 and nonDR3 associated complement component C4A deficiency in systemic lupus erythematosus.

The molecular basis of complement component C4A deficiency in white U.S. and Mexican patients with systemic lupus erythematosus (SLE) was studied. Genomic DNA from SLE patients and non-SLE controls was analyzed for restriction fragments using HindIII and a 5' C4 cDNA probe. C4A gene deletion was recognized by the loss of a 15-kb restriction fragment and the appearance of a 8.5-kb fragment. Thirty-two selected U.S. SLE patients, 7 nonSLE controls, and 11 Mexican SLE patients and 9 relatives were studied. The deletion was recognized in all of the 14 HLA-B8;DR3 SLE patients with a C4A protein deficiency. Two SLE patients with DR3 but without B8 also had this gene deletion. None of the 3 U.S. SLE nonDR3, C4A protein deficient patients nor 20 C4A protein deficient Mexican individuals (11 SLE patients and 9 relatives; none had B8 and/or DR3) showed this deletion. Thus the C4A gene deletion failed to account for the C4A protein deficiency in all the nonDR3 Mexicans and in some U.S. SLE patients. To determine whether gene conversion at the C4A locus would encode a C4B-like protein and be responsible for the C4A protein deficiency (in nonDR3 patients), the C4d region of the gene was amplified by polymerase chain reaction and subjected to Nla IV digestion, and restriction fragment analysis was performed using a C4d region-specific probe. The resulting restriction fragment length polymorphism pattern revealed no changes in the isotype-specific region of the gene as characterized by C4A-specific 276- and 191-bp fragments in Dr3 or nonDR3 individuals. Thus, homoexpression of C4B at both loci was not responsible for C4A deficiency in nonDR3 SLE patients without C4A gene deletion.

Alleles↗
PubMed1991

Actinomycosis of the thigh presenting as a soft-tissue neoplasm.

A 14-year-old boy presented with a mass measuring 6 cm x 9 cm, proximal to the patella on the anterior aspect of the knee. Magnetic resonance imaging revealed a 6 x 8 x 4 cm smoothly marginated slightly heterogeneous ellipsoidal mass which displaced musculature, the adjacent cutaneous fat and the quadriceps tendon. At surgery, the mass was noted not to penetrate the superficial surface of the quadriceps tendon and was full of slimy fluid. Histological examination revealed multiple basophilic lobulated granules with homogeneous centres and eosinophilic peripheral clubbed projections. The organisms grown anaerobically were identified as Actinomyces species. The anatomical site of the lesion is very unusual for actinomycosis and the exact route of infection in this patient remains unclear.

Actinomycosis↗
PubMed1991

Neurogenic tumours of the parapharyngeal space in the paediatric age group.

Two cases of neurogenic tumours of parapharyngeal space in children of 7 years old are presented. Difficulties during the diagnosis, investigations and management are discussed along with a review of the available literature. CAT scan with sialography, carotid angiography during surgery, angle mandibulectomy and liberal incision to expose the great vessels for better control of bleeding are stressed to minimise the peri-operative complication and to assist in complete removal of the tumours.

Child↗
PubMed1991

Treatment of ureteral calculi with extracorporeal shock wave lithotripsy using the Lithostar device.

Shock wave requirements for fragmentation and the ultimate outcome after extracorporeal shock wave lithotripsy (ESWL) with the Lithostar device were analyzed in 107 renal units with solitary ureteral calculi. In situ treatment was done in 54 stones without prior manipulation and in 15 after failure of endoscopic manipulation. A total of 25 ureteral calculi was treated after bypass with a ureteral catheter or stent and 13 after push back to the pelvicaliceal system. Shock wave requirement for fragmentation was significantly higher for calculi of 101 to 400 mm. X mm. when compared with the requirement for smaller calculi. Shock wave requirement was also significantly higher for patients with similar sized stones treated in the prone compared to the supine position. The average number of shock waves required for disintegration was not significantly different among in situ or any of the manipulation categories of similar sized stone populations. Over-all satisfactory clearance was achieved in 77.5% of the treated ureteral calculi. Clearance status was unaffected by size up to 400 mm. X mm. and the position of the patient during treatment (prone or supine). Clearance of ureteral stones treated in situ without prior manipulation (76.5%) was numerically inferior, although statistically insignificant, to that for successfully manipulated calculi (bypassed 88% and pushed back 92.3%) but it was significantly better than the outcome obtained after failed manipulation (46.2%). ESWL with the Lithostar device is a successful mode of treatment within the entire ureteral length, and a vigorous attempt at push back before lithotripsy is unnecessary.

Humans↗
PubMed1991

Peribulbar anesthesia and optic nerve conduction.

Serial recordings of distance visual acuity and visually evoked potentials (VEPs) after peribulbar anesthesia in three patients are reported. Visual acuity was not markedly affected but the latency and amplitude of VEPs were. This study concludes that optic nerve conduction is not significantly affected by peribulbar anesthesia.

Adolescent↗
PubMed1991

Heterosis and the lack of coadaptation in Drosophila nasuta.

Natural populations of Drosophila nasuta are polymorphic for several paracentric inversions. Two non-overlapping inversions on the third chromosome (III-2 and III-35) are heterotic in both laboratory and natural populations and display an extreme case of linkage disequilibrium. Intra- and interpopulation crosses involving standard and inverted gene orders of the III-2 and III-35 inversions were made to test if the polygenic complexes within these inversions are coadapted. The inversion heterozygotes formed by the two chromosomes derived from different localities exhibited heterosis since the viability of the heterozygotes was greater than that of either of the two homozygotes. In intrapopulation crosses, the heterozygotes were also heterotic. The present results thus indicated a lack of coadaptation among polygenic complexes within the inversions of D. nasuta. The data suggest that the heterosis produced by these linked inversions is the result of natural selection and epistasis.

Adaptation, Physiological↗
PubMed1991

TestPack Strep A kit for the rapid detection of group A streptococci on 11,088 throat swabs in a clinical pathology laboratory.

Results obtained with Abbott Laboratories' TestPack Strep A, a rapid test kit to detect group A streptococcal antigen on throat swabs, were compared with the culture results. All tests were performed by American Society of Clinical Pathology-registered technologists in a large clinical laboratory. A total of 11,088 throat swabs were tested; 9,161 belonged to pediatric patients and 1,927 to adults. For TestPack Strep A, the study demonstrated a sensitivity value of 0.91 and a specificity value of 0.96; positive predictive value and negative predictive values were 0.82 and 0.98, respectively. These data indicate that even when performed by experienced technologists, in a laboratory setting, approximately 1 of 10 patients with group A streptococcal tonsillopharyngitis will be missed if physicians rely solely on this direct antigen test. A backup culture on all patients who are negative by a rapid antigen detection test is recommended.

Adolescent↗
PubMed1991

An investigation of environmental impact on health of workers at retail petrol pumps.

Ninety-four male pump workers, employed in 41 petrol filling stations in Kanpur (formerly Cawnpore) and Lucknow--both in the Ganges plain of north India--were clinically examined. Headache, redness in eyes, lacrimation and signs like coated and/or furred tongue, throat and/or conjunctival congestion and carious teeth were significantly higher (P less than 0.05) in workers exposed to petrol fumes than in controls, as also was the level of phenol in urine (P less than 0.01). Environmental measurements revealed higher concentrations of benzene, sulphur dioxide and photoionizable dust in the air at petrol stations, and most of the symptoms and signs could be attributed to petrol fumes and other environmental pollution.

Adolescent↗