Biomedical subjects

A Kumar

Publications and source records attributed to A Kumar.

At least 667 records · Page 37Linked to original sources

PubMed1998

Mutation and polymorphism analysis in the tuberous sclerosis 2 (TSC2) gene.

Tuberous sclerosis complex (TSC) is an autosomal dominant multi-system disorder with two known disease loci on chromosomes 9q34 (TSC1) and 16p13.3 (TSC2). TSC has a prevalence of approximately 1 in 5,000-6,000, exhibits incomplete penetrance, and occurs in all racial groups. Our laboratory has undertaken the complete mutation analysis of the TSC2 gene in 42 TSC families using single-strand conformation polymorphism analysis and reverse transcription-polymerase chain reaction. Of the total of 42 families, 16 show evidence of linkage to the chromosome 16 TSC2 locus and 26 are either sporadic or too small to establish chromosome linkage. The TSC2 gene spans at least 45 kilobases of genomic DNA, has 41 known exons, and codes for a 5,474-base pair transcript. After complete gene analysis, 16 TSC2 mutations have been identified, including DNA insertions, deletions, splice site mutations, and amino acid substitutions. The majority of putative TSC2 mutations were found in sporadic rather than TSC2-linked families. We have also detected 15 polymorphisms which occur in the TSC2 gene.

Amino Acid Substitution↗

PubMed1998

Studies on tractor related injuries in northern India.

Epidemiological studies were conducted in two phases each of 1 year duration in nine and 30 villages, respectively, in two northern states of India. Investigations were carried out to determine the causal factors, the activities involved and severity of injuries for farming and non-farming activities in tractor related accidents. A total of 76 cases involving five fatalities and 71 non-fatal injuries were recorded. The pattern of tractor related injuries in India have been found to be very different compared to those reported from highly industrialized countries. Fifty-four percent of tractor related injuries in the first phase and 49% in the second phase were because of non-farming activities. Of the total injuries recorded in both the phases only 1 and 6% were tractor related. A major cause of tractor related injuries were collisions. In the two phases 28 and 40% injured were passengers on tractor or trailer.

Accidents, Traffic↗

PubMed1998

Randomized trial of intraoperative mitomycin C in surgery for pterygium.

PURPOSE: To report the efficacy and safety of intraoperative application of mitomycin C in surgery for pterygium. METHODS: In a prospective randomized and double-blind study done within a span of 2.5 years in 50 eyes (50 patients) with primary progressive pterygium, mitomycin C in a concentration of 0.02 mg/ml soaked in a sterile 5 x 5-mm sponge was applied over the bare sclera intraoperatively as an adjuvant therapy in 25 eyes after pterygium excision. These cases were compared with another 25 similar eyes that underwent the same procedure but in which gentamicin solution 0.3% was used instead of mitomycin C solution. RESULTS: Three eyes (12%) in the mitomycin C group showed recurrence within 7 months of surgery compared with eight eyes (32%) of the gentamicin control group within 3 to 5 months. Mild side effects, such as pain, photophobia, and delayed wound healing, were observed within the first 1 to 2 weeks postoperative in both groups. In the mitomycin C-treated group, corneal changes in the form of superficial punctate keratitis (three eyes) and limbal avascularity (two eyes) subsided within 2 weeks postoperatively. Follow-up time for these cases ranged from 18 to 21 months. CONCLUSIONS: A diluted solution of mitomycin C, 0.02 mg/ml, with an accurate size of sterile sponge applied to bare sclera after primary pterygium excision decreases the rate of recurrence to a greater extent than does gentamicin solution and is not associated with severe complications.

Adult↗

PubMed1998

Intractable hiccups during stroke rehabilitation.

OBJECTIVE: To study the frequency of intractable hiccups during stroke rehabilitation and the impact on rehabilitation management. DESIGN: Case series, retrospective chart review. SETTING: Inpatient stroke rehabilitation floor within a tertiary care teaching hospital. PATIENTS: Three patients admitted for stroke rehabilitation with hiccups of at least 48 hours out of 270 consecutive cases. INTERVENTIONS: None. MAIN OUTCOME MEASURE: Response to pharmacologic treatment. RESULTS: All three subjects had pontine infarcts and required gastrostomy tube feedings and lengthy rehabilitation stays. Subjects suffered from significant complications including aspiration pneumonia, respiratory arrest, and nutritional depletion. Chlorpromazine treatment was terminated in all three subjects because of sedation that interfered with therapies. Treatment with carbamazepine was successful in only one patient; in the other two subjects, their hiccups were controlled with haloperidol or baclofen. All subjects were ultimately managed with a single agent. CONCLUSIONS: Pharmacologic interventions for intractable hiccups must be tailored to the unique circumstances of the stroke rehabilitation patient. Intractable hiccups can be associated with potentially fatal consequences, and safe management may require an inpatient rehabilitation setting and multidisciplinary team approach to optimize the feeding management of this challenging population.

Aged↗

PubMed1998

Energetics of quasiequivalence: computational analysis of protein-protein interactions in icosahedral viruses.

Quaternary structure polymorphism found in quasiequivalent virus capsids provides a static framework for studying the dynamics of protein interactions. The same protein subunits are found in different structural environments within these particles, and in some cases, the molecular switching required for the polymorphic quaternary interactions is obvious from high-resolution crystallographic studies. Employing atomic resolution structures, molecular mechanics, and continuum electrostatic methods, we have computed association energies for unique subunit interfaces of three icosahedral viruses, black beetle virus, southern bean virus, and human rhinovirus 14. To quantify the chemical determinants of quasiequivalence, the energetic contributions of individual residues forming quasiequivalent interfaces were calculated and compared. The potential significance of the differences in stabilities at quasiequivalent interfaces was then explored with the combinatorial assembly approach. The analysis shows that the unique association energies computed for each virus serve as a sensitive basis set that may determine distinct intermediates and pathways of virus capsid assembly. The pathways for the quasiequivalent viruses displayed isoenergetic oligomers at specific points, suggesting that these may determine the quaternary structure polymorphism required for the assembly of a quasiequivalent particle.

Animals↗

PubMed1998

Pyogenic liver abscess in children--South Indian experiences.

PURPOSE: Eighteen cases of pyogenic liver abscess (PLA) admitted at JIPMER hospital, South India, over a 6-year period were analyzed to document the clinical profile and to evaluate the management of PLA among children. METHODS: Records of all these patients were reviewed for presenting signs and symptoms, any associated condition, investigative results, management, and follow-up findings. RESULTS: The overall incidence of PLA was 78.9 per 100,000 pediatric (under 12 years) admissions. One patient had aplastic anemia and was on long-term steroid therapy, whereas another had measles in recent past. Moderate to severe malnutrition was present in five (27.8%) and ascariasis in seven (38.9%) children. Common presentations were fever (100%), abdominal pain (76.9%), and tender hepatomegaly (83.3%). Ultrasonography results were positive in all cases. Fourteen patients (77.8%) had solitary liver abscess, and four had multiple abscesses. Organism was isolated in 11 cases (63.6%), and Staphylococcus aureus was the commonest isolate (66.7%). All patients received antibiotics. Twelve cases were managed conservatively with antibiotics alone, of these only two (16.7%) required drainage later on. Percutaneous aspiration was also undertaken in four additional (22.2%) cases and open drainage in two (11.1%), at presentation. The overall mortality rate was 11.1%. Time taken for complete resolution ranged from 10 days to 40 days. CONCLUSIONS: Any child presenting with fever, abdominal pain, and tender hepatomegaly should be subjected to ultrasound scan for early detection of PLA. S aureus is the commonest causative agent. Enterobacteriaceae contribute significantly during infancy. A combination of cloxacillin and gentamicin or a third generation cephalosporine and gentamicin, especially in infants, is a satisfactory initial coverage. Therapeutic drainage is not a must in all cases of PLA. When required, percutaneous needle aspiration is safe and effective. Resolution and significant reduction in mortality has been made possible by early detection and optimum antibiotics therapy.

Child↗

PubMed1998

Awareness of diagnosis and psychiatric morbidity among cancer patients--a study from South India.

Awareness regarding cancer diagnosis and its relationship to psychiatric morbidity was studied in 294 newly admitted cancer patients at an oncology center in South India. Fifty-four percent of patients were aware that they had cancer and were able to discuss their diagnosis; 46% of patients reported nonawareness of diagnosis. Discriminant function analysis revealed that oral cancers and relatives' awareness of the cancer was more prevalent in the group aware of diagnosis. More patients in the "unaware" group refused treatment for psychological distress. There was no difference between the two groups in patterns and prevalence of psychiatric morbidity. The study emphasizes the complexities in assessing awareness in cancer patients and a need to study its various components and relationship to psychological distress.

Adaptation, Psychological↗

PubMed1998