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Biomedical subjects

A Aggarwal

Publications and source records attributed to A Aggarwal.

At least 109 records · Page 6Linked to original sources
PubMed1996

A gene map of the human genome.

The human genome is thought to harbor 50,000 to 100,000 genes, of which about half have been sampled to date in the form of expressed sequence tags. An international consortium was organized to develop and map gene-based sequence tagged site markers on a set of two radiation hybrid panels and a yeast artificial chromosome library. More than 16,000 human genes have been mapped relative to a framework map that contains about 1000 polymorphic genetic markers. The gene map unifies the existing genetic and physical maps with the nucleotide and protein sequence databases in a fashion that should speed the discovery of genes underlying inherited human disease. The integrated resource is available through a site on the World Wide Web at http://www.ncbi.nlm.nih.gov/SCIENCE96/.

Amino Acid Sequence↗
PubMed1996

Takayasu's arteritis: role of Mycobacterium tuberculosis and its 65 kDa heat shock protein.

BACKGROUND: Mycobacterium tuberculosis has been implicated in the pathogenesis of Takayasu's arteritis (TA). Recently, its 65 kDa heat shock protein (HSP) has been implicated in the pathogenesis of other autoimmune diseases. We thus decided to study humoral immune response to Mycobacterium tuberculosis antigens in patients with TA. AIM: To study humoral immune response to Mycobacterium tuberculosis and its 65 kDa HSP, a putative autoantigen, in patients with TA. METHODS: Antibodies to sonicated Mycobacterium tuberculosis extract (MBA) and its recombinant 54 kDa protein were measured using ELISA in 36 patients with TA and 35 healthy controls. Levels exceeding mean +2 S.D. of the controls were taken as positive responses. RESULTS: Abnormally elevated levels of IgG, IgM and IgA antibodies against MBA were present in 6, 20 and 7 patients respectively whereas those against r65 kDa protein were present in 6, 7 and 33 patients, respectively. Though the levels of IgG antibodies were also elevated, those of IgM and IgA antibodies were elevated to a greater extent. CONCLUSIONS: Patients with TA have heightened immune response to Mycobacterium tuberculosis antigens, in particular to its 65 kDa HSP, suggesting that this organism may have a role in the immunopathogenesis of this disease.

Adolescent↗
PubMed1996

IgM rheumatoid factor estimation by ELISA in seronegative rheumatoid arthritis before and after IgM fractionation: does seronegative RA exist?

We looked for the presence of IgM rheumatoid factor (RF) using an enzyme-linked immunosorbent assay (ELISA) in 25 patients with active seronegative rheumatoid arthritis. In unfractionated sera, 12 patients (48%) were positive for IgM RF (classical), but after IgM fractionation of 23 samples (2 samples were not available) using high performance liquid chromatography for fractionating IgM, 12 patients were positive for RF by ELISA indicating the presence of hidden RF. Finally, three patients were labelled as truly seronegative for IgM RF. Classical IgM RF as detected by ELISA correlated significantly with erosive disease. Hidden RF did not correlate with disease activity or severity in this cross-sectional study, and though its presence was associated with shorter disease duration this did not reach statistical significance.

Adolescent↗
PubMed1996

Electrosurgery-induced ventricular fibrillation during pacemaker replacement--a unique mechanism.

Arrhythmias and pacemaker malfunction are known to occur from the use of an electrosurgical device. The present case report describes a patient with sick sinus syndrome who experienced ventricular fibrillation while undergoing surgery. During replacement of his non-functioning cardiac pacemaker under general anesthesia, electrosurgery was used to ensure hemostasis. Electric current may have stimulated myocardial leads present in the surrounding tissue, leading to ventricular fibrillation. The patient was resuscitated from the episode without any residual sequelae. Microshock and possible mechanisms that can lead to ventricular arrhythmias in patients with pacemakers during electrosurgery are discussed.

Adult↗
PubMed1996

Gluteus maximus island flap for the repair of sacral pressure sores.

Surgical management of decubitus ulcers in spinal cord injured patients (SCI) has been considerably improved by the application of muscle, myocutaneous and fasciocutaneous flaps. The goal of the present study was to do a critical analysis of the use of a gluteus maximus island flap for sacral pressure sores in paralysed as well as nonparalysed patients. In a prospective study, 34 patients with sacral pressure sores from grade V to VII were treated by gluteus maximus myocutaneous island flaps. Follow up ranged from 1.8 years to 6.2 years. Results were evaluated according to criteria based on (i) extent of wound dehiscence (ii) flap necrosis (iii) recurrence. Final results were excellent to good in 30 cases (88.3%). Poor results occurred in two patients (5.8%) and recurrence in one (2.9%) due to a major flap necrosis. Postoperative infection and wound dehiscence occurred in two cases each. No systemic complications occurred except for one patient who died from uraemia. The rehabilitation of these patients was improved. The postoperative duration of stay in hospital was from 18 to 32 days (mean: 22.5 days). The majority of the patients were quite pleased with the operation.

Anesthesia↗
PubMed1996

Effect of epidural buprenorphine and clonidine on vesical functions in women.

Buprenorphine (4 micrograms/kg body weight) and clonidine (3 micrograms/kg body weight) were administered epidurally to investigate their effect on vesical function in 20 American Society of Anaesthesiologists Classification I (ASA I) adult females. Cystometry was performed before and 30 minutes following epidural administration of drugs. Epidural administration of buprenorphine increased the maximum cystometric capacity from 352 +/- 98.5 - 462.8 +/- 167.3 ml (p < 0.05). There was no significant change in detrusor pressure at maximum cystometric capacity, in vesical compliance, maximum flow rate, and in the mean flow rate. Epidural administration of clonidine did not produce any significant change in the above urodynamic parameters. None of the patients in both groups developed retention of urine.

Adrenergic alpha-Agonists↗
PubMed1996

Type B lactic acidosis in an AIDS patient treated with zidovudine.

Human immunodeficiency virus type 1 (HIV 1) infection has been shown to cause myopathy. Zidovudine, a nucleoside analogue, has also been shown to cause myopathy in HIV-infected patients. Dalakas et al., were unable to distinguish the myopathy associated with HIV infection from the toxic mitochondrial myopathy caused by zidovudine. In a recent report, Chattha et al., described seven patients with Acquired Immunodeficiency Syndrome (AIDS) who developed type B lactic acidosis. Four of these patients were treated with zidovudine. A 100% mortality over a period of 15 months was observed. Zidovudine disrupts the mitochondrial deoxyribonucleic acid (DNA) that encodes for the respiratory chains, inhibiting the transport of lactate into the mitochondria. This may cause the accumulation of lactate in the cytoplasm, producing a severe metabolic acidosis. We present an AIDS patient with servere type B lactic acidosis which could have been associated with, or precipitated by, zidovudine.

Acidosis, Lactic↗
PubMed1996

Cervical spine involvement in rheumatoid arthritis: prevalence and relationship with overall disease severity.

Rheumatoid arthritis (RA) affects the cervical spine in 20-90% of patients in Western countries. We report the prevalence of cervical spine involvement in RA and its relationship with duration of disease, seropositivity, hand joint erosions and symptoms and signs suggestive of cervical spine involvement. 100 patients with RA criteria were included. Apart from clinical history and examination, study included X-rays of the cervical spine in AP, open mouth and lateral views and posteroanterior view of hands and rheumatoid factor estimation. All X-rays were read by a radiologist who was unaware of the clinical details. Cervical spine involvement was seen in 65% of patients. The commonest abnormality was erosions of the odontoid process (47%), followed by atlanto-axial dislocation and apophyseal joint involvement (24%). Only 5% of patients had abnormalities of spinous processes or vertebral bodies. Patients with abnormal cervical spine radiographs had higher prevalence of rheumatoid factor and erosions on hand radiographs. Severity of cervical spine changes was related to duration of disease (> 5 years). No correlation was seen between symptoms and radiological abnormalities except when neurological deficit was present. Patients with seropositivity, erosive disease and disease duration greater than five years should be screened for cervical spine disease.

Adolescent↗
PubMed1995

Highly attenuated HIV type 2 recombinant poxviruses, but not HIV-2 recombinant Salmonella vaccines, induce long-lasting protection in rhesus macaques.

Immunization schemes employing priming with vector-based vaccine candidates followed by subunit booster administrations have been explored and shown to have merit in the human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus systems. In this study, we have assessed the priming capacity of highly attenuated poxvirus vector (NYVAC and ALVAC)-based HIV-2 recombinants, as well as Salmonella typhimurium HIV-2 recombinants in rhesus macaques. ALVAC- and NYVAC-based vaccine candidates expressing the HIV-2 gag, pol, and env genes or NYVAC-based recombinants expressing either gp160 or gp120 were used to immunize rhesus macaques in combination protocols with alum-adjuvanted HIV-2 rgp160. Following intravenous challenge exposure with 100 infectious doses of the HIV-2SBL6669 parental virus genotype mixture, seven of eight animals were protected from infection. The seven protected animals were rechallenged 6 months postprimary challenge, without additional booster inoculations, with the same dose of the HIV-2SBL6669 parental virus. Five of the seven animals remained protected against HIV-2 infection at 6 months following the second challenge. In contrast, oral immunization with recombinant Salmonella expressing the HIV-2 gag and the gp120 portion of the envelope either alone or in combination with alum-adjuvanted rgp160 failed to confer protection. These results suggest that the NYVAC- and ALVAC-based recombinants may confer long-lasting protection and that these two highly attenuated poxvirus vaccine vectors may represent promising candidates for developing an acquired immunodeficiency syndrome vaccine.

Amino Acid Sequence↗
PubMed1995

Compound heterozygosity of HLA-DR4 and DR1 antigens in Asian Indians increases the risk of extra-articular features in rheumatoid arthritis.

The relationship of HLA-DR antigens in rheumatoid arthritis (RA) patients with the presence of rheumatoid factor (RF), extra-articular features, joint erosions, functional status and response to disease modifying anti-rheumatic drugs (DMARDs) was studied. Seventy-four patients with RA were serologically typed for class II antigens. Clinical features were recorded before starting DMARDs and during follow-up to assess response and side-effects. HLA-DR1 and DR4 antigens were present more frequently in patients with RA than in the general population. The presence of DR4 correlated with RF seropositivity (P < 0.001) while DR1 was associated with seronegativity (P < 0.02). Ten of the 11 patients with extra-articular features had DR1 and/or DR4. Patients with both DR4 and DR1 had a significantly higher frequency of extra-articular features compared with those with only one of these (P < 0.01). HLA-DR4 and DR1 had no relation with the presence of subcutaneous nodules, erosive changes, deformities, response to drugs and side-effects of DMARDs.

Adult↗
PubMed1995

Additive cardiac depression by volatile anesthetics in isolated hearts after chronic amiodarone treatment.

Some patients undergoing general anesthesia may be chronically receiving the antidysrhythmic drug amiodarone. The half-life of this drug is very long and it may not be advisable or possible to discontinue its administration prior to anesthesia. We examined depressant effects of three volatile anesthetics in hearts isolated from guinea pigs chronically treated with amiodarone. Hearts were isolated and perfused retrogradely through the aorta with oxygenated Krebs-Ringer solution at 37 degrees C at constant pressure. Variables measured in 26 hearts were heart rate (HR), atrioventricular, intraatrial, and intraventricular conduction times (AVCT, IACT, IVCT) during pacing at 240 bpm, coronary flow, and left ventricular pressure (LVP). Amiodarone (20 mg intraperitoneally) or placebo (Group 1) was given once daily for 1 (Group 2) or 4 (Group 3) wk. Cardiac tissue concentrations of amiodarone were similar (12.1 micrograms/g wet weight) in hearts in Groups 2 and 3 but serum levels were twice as high in hearts in Group 3 as in Group 2 (0.33 vs 0.17 microgram/mL). Before anesthetic exposure, all variables for hearts in Group 2 were not significantly different from those in Group 1. Significantly, for hearts in Group 3, compared to those in Group 1, HR was slower (-14%), conduction times were longer (IACT + 5 ms, IVCT + 4 ms, AVCT + 9 ms), coronary flow was higher (+23%), and LVP was lower (-12%). After control measurements, hearts were exposed to 0.5 and 1 minimum alveolar anesthetic concentration (MAC) halothane, enflurane, and isoflurane in random order.(ABSTRACT TRUNCATED AT 250 WORDS)

Amiodarone↗
PubMed1995

Timing and dose of BCG vaccination in infants as assessed by postvaccination tuberculin sensitivity.

Tuberculosis is an important public health problem in developing countries and BCG plays an important role in preventing serious form of the disease in children. BCG induced tuberculin sensitivity is a quantitative characteristic and has been used to compare vaccine efficacy. The standard dose of BCG vaccine is 0.1mg in 1 ml though manufacturers of certain strains of BCG, i.e., Copenhagen 1331 recommend half dose in infants. There are also varying ideas about the optimum time to vaccinate babies and some studies suggest that late vaccination confers a high degree of protection. This study was carried out to evaluate tuberculin sensitivity and side effects following 0.05 ml and 0.1 ml of BCG at birth and 0.1 ml of BCG at 4-6 weeks of age. Two hundred and thirty eight newborns were vaccinated randomly with 0.05 ml and 0.05 ml and 0.1 ml of BCG vaccine (Copenhagen 1331 strain) containing .69 million culturable particles per ml. One hundred and eight infants 4-6 weeks of age were vaccinated with 0.1 ml of BCG. One hundred and fifty five (44.7%) infants were evaluated by Mantoux test using 1TU PPD RT23 10-12 weeks after vaccination and 105 (30.6%) followed up till 6 months for any side effects. No significant difference in mean tuberculin reaction, tuberculin positivity and mean scar size was observed in groups receiving 0.1 ml at birth or 4-6 weeks of age. However, the group receiving 0.05 ml at birth had a significantly lower mean tuberculin reaction, tuberculin positivity and mean scar size. No locoregional side effects were observed. Hence the present practice of giving 0.1 ml of BCG at birth should be continued.

Age Factors↗
PubMed1995

Evaluation of cold chain system in rural areas of Haryana.

Evaluation of cold chain system was done in a time bound study during August and September months of 1992 in two districts of Haryana as there were frequent breakdowns of icelined refrigerators during the previous year. The study revealed that defective stabilizers and electricity plugs and sockets were the reason of breakdown in many cases. Temperature maintenance and functioning of deep freezers was satisfactory. Retrospective analysis showed that the polio vaccine samples picked up during 1990-92 were found to be satisfactory by CRI, Kasauli. Use of two ice-pick carrier and thermos flasks was associated with poor temperature maintenance. Seven vaccine carriers out of 25 examined had cracked wall lining. Lids of carriers were also not kept tight during vaccination sessions. Response lag of the health workers and medical officers in case of breakdowns was delayed. A one day refresher course exclusively on cold chain maintenance at community health centre level is recommended.

Drug Storage↗