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Biomedical subjects

L Kumar

Publications and source records attributed to L Kumar.

At least 19 recordsLinked to original sources
PubMed2006

Incidence and characterization of Clostridium perfringens isolated from antibiotic-associated diarrhoeal patients: a prospective study in an Indian hospital.

Clostridium perfringens has been reported as causing between 2-15% of all cases of antibiotic-associated diarrhoea (AAD), and may be diagnosed by detection of enterotoxin in faeces. A prospective study comprising 150 diarrhoeal patients and 100 non-diarrhoeal controls was undertaken to assess the incidence of C. perfringens-associated diarrhoea in an Indian hospital. Methods used included C. perfringens culture, reverse passive latex agglutination (RPLA) and enzyme-linked immunosorbent assay (ELISA) for detection of enterotoxin, and polymerase chain reaction (PCR) assay for the presence of enterotoxin gene. Attempts were made to type the isolates by multiplex PCR. Of the 150 diarrhoeal stool samples tested, 13 were culture positive. Of these, four were positive for C. perfringens enterotoxin by RPLA, two were positive by PCR and two were positive by RPLA and ELISA. Twenty-seven samples were positive for culture of C. perfringens in non-diarrhoeal controls but none were positive for enterotoxin either by RPLA or by PCR. The average incidence of C. perfringens AAD using these methods was 2.6%. Toxin typing showed that all the isolates belonged to type A. To conclude, the relatively low incidence of toxigenic C. perfringens suggests that enterotoxigenic C. perfringens is not a major cause of AAD in this population.

Adolescent↗
PubMed2006

A case of Hodgkin's disease presenting with recurrent laryngeal nerve palsy and tracheoesophageal fistula.

Malignancy is the most common cause of tracheoesophageal fistulas. The malignancies commonly implicated in the development of tracheoesophageal fistulas are primary bronchial or esophageal carcinomas. Hodgkins disease rarely leads to such a fistula. We report a case of Hodgkin's disease with a tracheoesophageal fistula as well as a left recurrent nerve palsy at presentation. This presentation has no precedent in literature. The patient was treated with systemic chemotherapy and involved field radiotherapy. On follow up 1 year after the completion of treatment, he was clinically and radiologically disease free.

Adult↗
PubMed2005

Prevalence and risk factors for transmission of infection among children in household contact with adults having pulmonary tuberculosis.

AIMS: To study the prevalence of tuberculosis infection among children in household contact with adults having pulmonary tuberculosis, and identify the possible risk factors. METHODS: Children under the age of 5 years who were in household contact with 200 consecutive adults with pulmonary tuberculosis underwent tuberculin skin testing. Transverse induration of greater than 10 mm was defined as positive tuberculin test suggestive of tubercular infection. Infected children underwent chest radiography and analysis of gastric lavage fluid or induced sputum for detection of acid fast bacilli. RESULTS: Tuberculin test was positive in 95 of 281 contacts (33.8%), of which 65 were contacts of sputum positive patients, while 30 were contacts of sputum negative patients. Nine of these children were diagnosed as having tuberculosis based on clinical features and/or recovery of acid fast bacilli; seven were in contact with sputum positive adults. The important risk factors for transmission of infection were younger age, severe malnutrition, absence of BCG vaccination, contact with an adult who was sputum positive, and exposure to environmental tobacco smoke. CONCLUSION: The prevalence of tuberculosis infection and clinical disease among children in household contact with adult patients is higher than in the general population, and risk is significantly increased by contact with sputum positive adults.

Adult↗
PubMed2004

Evaluation of quality of life in indian children with bronchial asthma using a disease-specific and locally appropriate questionnaire.

AIM: To evaluate quality of life (QOL) in Indian children with bronchial asthma. METHODS: A disease-specific, locally appropriate QOL questionnaire was administered in asthmatic children and compared with FEV1, FVC, PEFR and asthma symptom score, on three occasions. RESULTS: QOL score had strong negative correlation with symptom score and weaker positive correlation with pulmonary function tests. CONCLUSION: Disease-specific QOL score correlates inversely with symptom score in children with bronchial asthma.

Asthma↗
PubMed2004

Randomized controlled trial of intrapleural streptokinase in empyema thoracis in children.

AIM: To compare intrapleural streptokinase and placebo in paediatric empyema. METHODS: Children with empyema greater than stage 5 received intrapleural streptokinase (n = 19) or normal saline (n = 21) along with intercostal drainage. Clinical and serial sonographic outcomes were compared. RESULTS: Although there was no difference in clinical and sonographic outcome, none of the children with stage 7 empyema (multi-loculated empyema) who received streptokinase developed pleural thickening 30 d later. CONCLUSION: There is no short-term clinical benefit of intrapleural streptokinase in paediatric empyema; this therapy may be reserved for those with stage 7 empyema to prevent pleural thickening in the long term.

Anti-Bacterial Agents↗
PubMed2004

Assessment of allergenicity to Mallotus phillipensis pollen in atopic patients in India: a new allergen.

OBJECTIVE: Pollen grains of the Euphorbiaceae family are well known causative agents of respiratory allergies in India, European countries and USA. Mallotus phillipensis belongs to the same family and may have some common allergenic properties. It has thus been evaluated for the first time in Indian population for its pollinosis causing properties. METHODS: Pollen antigen of Mallotus phillipensis (MP) was extracted and characterized for its protein components by biochemical methods. Pollinosis potency of crude extract of MP pollen was evaluated by skin prick test on population residing in different parts of India. Specific IgE binding characteristics of the extract were determined by ELISA and Immunoblot. RESULTS: Marked skin reactivity in 5.7% atopic population was recorded and subjects constituting 23.8% of the total patients tested showed skin sensitivity to the MP pollen antigen. Significantly raised specific IgE against MP pollen were recorded in 50% of the skin test positive patients. A number of protein bands were detected in a wide Molecular weight range as well as in acidic pI range, by SDS-PAGE and IEF, respectively. A total 11 protein fractions were detected by the specific IgE antibodies on immunoblotting with patient's sera and were considered allergenic. CONCLUSION: Patients from different geographical regions have shown sensitization to MP pollen antigen. Many proteins have similar molecular weights and pI as other allergenic members of the family (Ricinus communis and Putranjiva roxburghii) found in India, which constitutes a good reason for studying cross reactivity among the members of family Euphorbiaceae, in the future.

Allergens↗
PubMed2003

Paraoxon induces apoptosis in EL4 cells via activation of mitochondrial pathways.

The toxicity of organophosphorus compounds, such as paraoxon (POX), is due to their anticholinesterase action. Recently, we have shown that, at noncholinergic doses (1 to 10 nM), POX (the bioactive metabolite of parathion) causes apoptotic cell death in murine EL4 T-lymphocytic leukemia cell line through activation of caspase-3. In this study, by employing caspase-specific inhibitors, we extend our observations to elucidate the sequence of events involved in POX-stimulated apoptosis. Pretreatment of EL4 cells with the caspase-9-specific inhibitor zLEHD-fmk attenuated POX-induced apoptosis in a dose-dependent manner, whereas the caspase-8 inhibitor zIETD-fmk had no effect. Furthermore, the activation of caspase-9, -8, and -3 in response to POX treatment was completely inhibited in the presence of zLEHD-fmk, implicating the involvement of caspase 9-dependent mitochondrial pathways in POX-stimulated apoptosis. Indeed, under both in vitro and in vivo conditions, POX triggered a dose- and time-dependent translocation of cytochrome c from mitochondria into the cytosol, as assessed by Western blot analysis. Investigation of the mechanism of cytochrome c release revealed that POX disrupted mitochondrial transmembrane potential. Neither this effect nor cytchrome c release was dependent on caspase activation, since the general inhibitor of the caspase family zVAD-fmk did not influence both processes. Finally, POX treatment also resulted in a time-dependent up-regulation and translocation of the proapoptotic molecule Bax to mitochondria. Inhibition of this event by zVAD-fmk suggests that the activation and translocation of Bax to mitochondria is subsequent to activation of the caspase cascades. The results indicate that POX induces apoptosis in EL4 cells through a direct effect on mitochondria by disrupting its transmembrane potential, causing the release of cytochrome c into the cytosol and subsequent activation of caspase-9. Inhibition of this specific pathway might provide a useful strategy to minimize organophosphate-induced poisoning.

Animals↗
PubMed2003

Colony-stimulating activity of fetal liver cells: synergistic role of stem cell factor in bone marrow recovery from aplastic anemia.

Previously, we and others have shown that fetal liver infusion (FLI) leads to autologous hematopoietic improvement in 40-54% of patients with aplastic anemia. However, whether this recovery was spontaneous or the effect of the infused liver cells was not clear. To dissect the role of FLI in autologous hematopoietic recovery, the colony-supporting potential of fetal liver-conditioned medium (FLCM) was evaluated in bone marrow (BM) cells of normal adult and aplastic anemia patients. In both cases, each sample of FLCM supported the growth of colony-forming cells in semi solid culture medium. The FLCM was assayed for the presence of four principal colony-stimulating cytokines, namely stem cell factor (SCF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and erythropoietin (Epo). While GM-CSF, IL-3, and Epo were present in insignificant amounts or were altogether absent, 50-635 pg/ml of SCF was found in 8 of the 13 FLCM samples tested. Preliminary results of bioneutralization assay indicated the possible role of SCF, secreted by the FL cells, in colony-supporting activity of aplastic anemia and normal BM cells. Overall, our in vitro study implicates the paracrine role of infused FL cells in regenerating autologous hematopoiesis in aplastic anemia patients.

Anemia, Aplastic↗
PubMed2003

Empyema thoracis: a 10-year comparative review of hospitalised children from south Asia.

AIMS: To study the clinical and microbial profile of childhood empyema in South Asia and to identify the changes over the past three decades. METHODS: A total of 265 children (aged 1 month to 12 years) with empyema admitted to the Advanced Pediatric Center, PGIMER, Chandigarh, India in 1989-98, were reviewed retrospectively. RESULTS AND CONCLUSIONS: One third of children were under 5. Culture positivity had decreased significantly (48% v 75%) over the years. Staphylococcus aureus continues to be the commonest (77%) aetiological agent; clustering was seen during hot and humid months (46%). Culture positive Streptococcus pneumoniae cases also decreased (9% v 27%); all were seen during the winter and spring season. Gram negative rods grew in more patients (11% v 7%). Community acquired methicillin resistant S aureus (MRSA) was isolated in three patients. Most children (93%) were treated with parenteral cloxacillin and an aminoglycoside. Tube drainage (TD) was used in 92% of fibropurulent cases, and was successful in 79%. Of 48 patients with failed TD, 12 needed decortication; limited thoracotomy was sufficient in the remaining 36. Surgery was mainly required by children with persistent pleural sepsis after 10 days of TD. Delaying surgery until 14 days had a significantly higher potential of requiring decortication. Early change to oral antibiotics (after 1-2 weeks of parenteral therapy) reduced the hospital stay significantly (17+7 v 23+7 days) without compromising long term outcome. Twenty two patients presenting late in the chronic stage underwent decortication at admission.

Anti-Bacterial Agents↗
PubMed2002

Reconstitution of naïve T cells and type 1 function after autologous peripheral stem cell transplantation: impact on the relapse of original cancer.

BACKGROUND: Phenotypic and functional reconstitution of T cells after peripheral blood stem cell transplantation (PBSCT) and its influence on posttransplant immune status is important in terms of immune surveillance and relapse of original cancer. We investigated the relationship between the dominant immune reconstitution pathway and the immune surveillance. We also tested the cytokine bias acquired by T cells after transplantation and its possible influence on relapse of original malignancy. METHODS: Immunophenotyping of naïve and memory T cells was performed by flow cytometry on patients who underwent PBSCT for various cancers. Cytokine production by peripheral memory helper (CD4) and cytotoxic (CD8) T cells was investigated at various pretransplant and posttransplant time points with fluorescein isothiocyanate-based intracellular cytokine assay after short-term in vitro mitogenic stimulation (phorbol myristate acetate + ionomycin). Data on T-cell subsets and polarized cytokines gamma-interferon (Ifn) and interleukin 4 produced by memory T cells were compared with that of healthy controls. RESULTS: The reconstitution of naïve T cells and gamma-Ifn-producing memory cells was significantly lower in patients who experienced relapse of original cancer within 1 year of PBSCT compared to those who showed no signs of relapse even after 2 years and compared to normal subjects. The results indicate that efficient reconstitution of naïve T cells and type 1 function of memory T cells are important in maintaining T-cell repertoire diversity after PBSCT. It also confers appropriate levels of immune surveillance against diverse neoantigens that evolve from residual tumor burden. The data reveal that chemotherapy-induced thymic injuries may impair regeneration of naïve cells that result in a naivopenic state in a susceptible host. CONCLUSIONS: The study highlights the importance of naïve T-cell reconstitution and points towards cell replacement strategies for improving immune surveillance after PBSCT.

Adult↗
PubMed2002

Disabling pansclerotic morphea of childhood and hypogammaglobulinemia: a curious association.

This communication describes a 1.5-year-old girl who presented with multiple episodes of infection since early infancy and stiffening of limbs for 2 months. Biopsy of the involved areas showed features consistent with pansclerotic morphea. Immunoglobulin estimation revealed hypogammaglobulinemia. This unique combination of pansclerotic morphea with hypogammaglobulinemia has not been reported before.

Agammaglobulinemia↗
PubMed2002

Mortality patterns in childhood lupus--10 years' experience in a developing country.

Over the last 10 years we have seen 31 children with systemic lupus: 10 (32%) of these have died. The commonest primary determinant of mortality was uncontrolled disease activity (60%), possibly contributed to by late referrals leading to delays in diagnosis and the institution of therapy. Thromboembolic disease was responsible for two deaths and tuberculosis for one. The major contributory factors were nephritis in two patients and myocarditis, endocarditis, lupus pneumonia and CNS disease in one patient each. Concomitant infections, predominantly nosocomial, occurred in a significant proportion of patients (40%) but were only cofactors in mortality. Autopsies were done in three cases. These patterns of death are significantly different from those seen in the developed world, where disease activity has ceased to be an important factor owing to early recognition of cases. Avoiding late referrals and delays in diagnosis can reduce mortality in childhood-onset lupus.

Cause of Death↗
PubMed2002

Remifentanil and propofol sedation for retrobulbar nerve block.

We studied remifentanil and propofol for analgesia and sedation during the placement of an ophthalmic block. Eighty ASA I or II patients undergoing elective cataract surgery under a retrobulbar block in a rural camp setting were included in the study. Patients were randomly divided into four groups and received different drug combinations as follows: Group I--remifentanil 1 microg/kg, Group II--remifentanil 0.5 microg/kg and propofol 0.5 mg/kg, Group III--remifentanil 1 microg/kg with propofol 0.5 mg/kg and Group IV--saline 0.1 ml/kg. Patients were observed for degree of movement, sedation, pain, recall and respiratory depression. No patient in the study groups reported pain or displayed movement whereas most of the patients in the control group had significant pain during the placement of the block. Also, seven (35%) patients in the control group showed significant movement which may have led to failure of block in two patients and retrobulbar haemorrhage in one patient. Incidence of significant respiratory depression was maximum in Group III patients (60%), followed by Group I (20%) and least in Group II (5%). All patients in the study groups remained cooperative and obeyed commands except four patients in group III (OAA/S-4). Postoperatively, other than the control group, recall was maximum in Group I (55%) and least in Group II (5%). Hence, a combination of remifentanil 0.5 microg/kg with propofol 0.5 mg/kg as a bolus was considered to provide excellent relief of pain and anxiety with least adverse effects for the placement of ophthalmic blocks.

Analgesics, Opioid↗
PubMed2002

A study of bacteremia in febrile neutropenic patients at a tertiary-care hospital with special reference to anaerobes.

Patients with hematological malignancies who are receiving chemotherapy suffer prolonged periods of neutropenia, which leads to a greater risk of infection and mortality. A prospective study was conduced to determine the incidence of bacteremia in patients of hematological malignancies over a 2-yr period. A total of 119 episodes of febrile neutropenia occurred among 96 consecutive patients, of which 35 episodes were associated with bacteremia. Forty-four percent of the isolated bacteria were Gram-positive aerobes and 46% were Gram-negative aerobes. Staphylococcus aureus, Enterococcus spp., and Escherichia coli were the most common isolates. Gram-negative bacteremia was associated with a higher mortality. Anaerobes accounted for 4.4% of all isolates. The episodes of anaerobic bacteremia were polymicrobial and had a fatal outcome. A high incidence of antimicrobial resistance among aerobic and anaerobic bacteria was also recorded. Compared to previous years, a shift from a predominating Gram-negative to a Gram-positive etiology was noted. The initial empiric antibiotic regimens should be based on a local knowledge of the most common causative microorganisms, their sensitivity pattern, and the outcome of bacteremia.

Adolescent↗