Search PubMed⌕ Search

Biomedical subjects

S Sethi

Publications and source records attributed to S Sethi.

At least 55 records · Page 3Linked to original sources

Airway inflammation and etiology of acute exacerbations of chronic bronchitis.

STUDY OBJECTIVES: The etiologic role of bacterial pathogens isolated from sputum culture in 40 to 50% of acute exacerbations of chronic bronchitis (AECB) is controversial. If bacterial pathogens cause these AECB, they should be associated with greater neutrophilic airway inflammation than pathogen-negative exacerbations. DESIGN: This hypothesis was tested by comparing levels of interleukin (IL)-8, tumor necrosis factor (TNF)-alpha, and neutrophil elastase (NE) in 81 sputum samples obtained from 45 patients with AECB. Four groups were compared. In the first three groups, nontypable Haemophilus influenzae (n = 20), Haemophilus parainfluenzae (n = 27), and Moraxella catarrhalis (n = 14) were isolated as sole pathogens, respectively. In the fourth group, only normal flora was isolated (n = 20). Paired samples, obtained from individual patients at different times, that differed in their culture results were also compared. SETTING: An outpatient research clinic at a Veterans Affairs Medical Center. PATIENTS: These patients were participating in a prospective, longitudinal study of the dynamics of bacterial infection in chronic bronchitis, for which they were seen in the study clinic on a monthly basis as well as when they were experiencing symptoms suggestive of AECB. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: H influenzae exacerbations were associated with significantly higher sputum IL-8, TNF-alpha, and NE. M catarrhalis exacerbations demonstrated significantly higher sputum TNF-alpha and NE when compared to pathogen-negative exacerbations. H parainfluenzae-associated exacerbations had an inflammatory profile similar to pathogen-negative exacerbations. Sputum elastase level distinguished bacterial from nonbacterial AECB and correlated with clinical severity of the AECB. CONCLUSIONS: Increased airway inflammation associated with isolation of H influenzae and M catarrhalis supports an etiologic role of these pathogens in AECB.

Acute Disease↗

Evaluation of E test for susceptibility testing of Mycobacterium tuberculosis to primary anti tubercular drugs.

BACKGROUND & OBJECTIVES: Antimicrobial susceptibility tests for tuberculosis take weeks and delayed therapy can lead to an increase in disease incidence. The E test is a new concept for minimum inhibitory concentrations (MIC) determinations for antimicrobial agents that is based on a predefined antibiotic gradient on a plastic strip calibrated with a continuous logarithmic MIC scale covering 15 two-fold dilutions. The present study was undertaken to evaluate E test strips for susceptibility testing of Mycobacterium tuberculosis. METHODS: Twenty five clinical isolates of M. tuberculosis were tested for the four first line antitubercular drugs by E test and were compared with standard proportion method. The inoculum turbidity was adjusted to McFarland 3.0 standard and agar plates (Middle brook 7H11 agar) were inoculated and preincubated (37 degrees C in 7-10% CO2) for 24 h after which time, the E test strips were placed on the agar surface which were incubated under same conditions. The MIC was interpreted as the point at which the ellipse intersected the 'E test' strip as described in E test technical guide. RESULTS: Of the 25 strains, susceptibility as determined by both methods for isoniazid (INH), rifampin, ethambutol and streptomycin was found in 22 (88%), 20 (80%), 24 (96%) and 18 (72%) strains respectively. Agreement between E test and proportion method was 96 per cent for INH, 92 per cent for rifampin and 100 per cent for ethambutol and streptomycin each. However, sensitivity could be predicted after 7-10 days by E test and exact MIC could also be determined. INTERPRETATION & CONCLUSIONS: E test method was found to be rapid, accurate, reliable and easy to perform. It can be employed for routine susceptibility testing for antitubercular drugs.

Antitubercular Agents↗

Evaluation of leukergy test as an indicator of infection in hip joint in children.

This new blood test (leukergy) for infection is based on the fact that white cells agglomerate in peripheral blood of patients with inflammatory diseases. We evaluated leukergy in 25 children with proven septic arthritis of hip. It was found to be the efficient and earliest indicator of septic arthritis than the erythrocyte sedimentation rate (ESR), total leucocyte count (TLC), polymorphs and C-reactive protein (CRP). It also correlated well with the clinical severity of infection and the prognosis of disease. Thus leukergy is a simple, rapid and inexpensive slide test which was found as the best indicator profile for the presence of septic arthritis.

Arthritis, Infectious↗

Diagnostic potential of histochemical demonstration for copper-orcein stain.

The histochemical demonstration of hepatic copper is important in the diagnosis of paediatric copper storage disorders. Conflicting results have been published regarding ability of different histochemical stains to demonstrate copper storage in the liver. Hence the authors retrospectively analysed eighty-two liver biopsies from 82 patients of Indian childhood cirrhosis (ICC), 59 males and 23 females aged between 1-4 years (mean age 3.1 years). All cases were stained with orcein stain. On the basis of histological picture the liver biopsies were divided into the three histological grades I, II and III. Orcein positively was graded from I to IV. All cases showed positivity with orcein stain. Most cases showed grades II and III of orcein positivity. The association between histological and orcein grades was significant. The present study demonstrates the diagnostic utility of orcein stain in liver copper storage disorder, Indian childhood cirrhosis. Variable copper content in the same histological grade of the disease could be due to individual factors such as genetic milieu which determine the amount of copper liver can store without toxicity.

Biopsy, Needle↗

Nitric oxide-mediated augmentation of polymorphonuclear free radical generation after hypoxia-reoxygenation.

Polymorphonuclear leukocytes (PMNLs), nitric oxide (NO), calcium, and free radicals play an important role in hypoxia/ischemia and reoxygenation injury. In the present study, NO donors, sodium nitroprusside (SNP), and diethylamine-NO (DEA-NO) at low concentrations (10 and 100 nmol/L) potentiated, while higher (10 micromol/L to 10 mmol/L) concentrations inhibited free radical generation response in the rat PMNLs. Free radical generation response was found to be significantly augmented when hypoxic PMNLs were reoxygenated (hypoxia-reoxygenation [H-R]). This increase in free radical generation after reoxygenation or SNP (10 nmol/L) was blocked in the absence of extracellular calcium. SNP (10 nmol/L) or H-R-mediated increases in the free radical generation were prevented by the pretreatment of PMNLs with NO scavenger (hemoglobin), the polyadenine diphosphate (ADP)-ribosylation synthase inhibitor (benzamide) or the calcium channel antagonist (felodipine). A significant augmentation in the nitrite and intracellular calcium levels was observed during hypoxia. Hemoglobin pretreatment also blocked the increase in intracellular calcium levels due to SNP (10 nmol/L) or hypoxia. Thus, increased availability of NO during SNP treatment or H-R, may have led to an ADP-ribosylation-mediated increase in intracellular calcium, thereby increasing the free radical generation from the rat PMNLs.

Animals↗

Retroperitoneal ganglioneuroma: report of a case diagnosed by fine-needle aspiration cytology, with review of the literature.

A case of ganglioneuroma presenting as a retroperitoneal mass in a 5-yr-old girl was diagnosed by preoperative fine-needle aspiration cytology. The cytologic smears predominantly showed clusters of Schwann cells, with scattered mature ganglion cells. The cytologic diagnosis of ganglioneuroma was subsequently confirmed on histopathologic examination. To date, very few reports on the cytologic features of this tumor exist. The importance of considering a confident diagnosis by cytology, and of the uncommon age group that may be affected, is stressed. Diagn. Cytopathol. 1999;21:194-196.

Biopsy, Needle↗

Simultaneous respiratory tract colonization by multiple strains of nontypeable haemophilus influenzae in chronic obstructive pulmonary disease: implications for antibiotic therapy.

Nontypeable Haemophilus influenzae often causes exacerbations of chronic obstructive pulmonary disease (COPD), and these exacerbations are frequently treated with oral antibiotics. The goals of this study were to determine the frequency of the simultaneous presence of multiple strains of H. influenzae in sputum and to measure the MICs of antibiotics for the isolates. In a prospective study, adults with COPD were seen monthly. Sputum cultures were obtained, and individual colonies were subjected to genomic DNA typing and MIC determinations. Multiple strains of H. influenzae were present simultaneously in the sputum of 26.3% of adults with COPD. In 64.5% of these, MICs of >/=1 antibiotic varied by >/=4-fold among the strains. Therefore, multiple strains of H. influenzae are frequently present simultaneously in the sputum of adults with COPD, and the antimicrobial susceptibility of different strains in the same sputum sometimes differs.

Aged↗

Infectious exacerbations of chronic bronchitis: diagnosis and management.

Chronic bronchitis is an increasing cause of significant morbidity and mortality. Despite treatment, respiratory tract infection is the most common identifiable cause of death for patients with chronic obstructive pulmonary disease. Repeated infectious exacerbations may ultimately cause acute and chronic lung injury. The most common bacterial aetiologies of acute exacerbations of chronic bronchitis (AECB) include Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pneumoniae. Pseudomonas aeruginosa is often a nosocomial pathogen and is becoming more prevalent in patients with severe underlying disease. Viruses are responsible for approximately one-third of acute exacerbations overall. Atypical pathogens are causative pathogens in < 10% of episodes. The diagnosis of AECB is often based on clinical impression, although suspicion of bacterial infection can be enhanced by quantitative Gram's stains from appropriately obtained sputum specimens. However, a specific microbiological diagnosis is only needed in certain specific situations. Management of AECB involves non-drug interventions (e.g. smoking cessation) and antibiotic treatment. Recommendations for antibiotic use in patients with known or highly suspected AECB are still evolving. The selection of an antibiotic for treatment of an infectious episode must consider underlying patient co-morbidities, likely pathogens, resistance issues and individual antibiotic properties. Cephalosporins, beta-lactam/beta-lactamase inhibitor combinations and macrolides are all reasonable choices. However, due to the increasing prevalence of resistance to standard antibiotics among common respiratory pathogens, and increased incidence of Pseudomonas spp., fluoroquinolones should be a first-line treatment for AECB in patients who have chronic bronchitis complicated by co-morbid illness, severe obstruction (FEV1 < 50%), old age (> 65 years) or have recurrent exacerbations. In patients who do not have these risk factors (i.e. those with simple chronic bronchitis), agents such as co-trimoxazole remain useful.

Bacterial Infections↗

Isolation pattern and clinical outcome of genital mycoplasma in neonates from a tertiary care neonatal unit.

The role of genital mycoplasma in perinatal mortality and morbidity has been debated. This study was undertaken to determine the frequency of isolation of genital mycoplasma and evaluate its association with clinical outcome. Sixty-six cerebrospinal fluid (CSF) and 49 tracheal aspirates taken from 100 low birthweight infants who had suspected meningitis and/or respiratory distress respectively were cultured for genital mycoplasma. Ureaplasma urealyticum was isolated from 9 per cent of CSF and 14 per cent of tracheal aspirates. Mycoplasma hominis was isolated from CSF in one case and none at the tracheal aspirates. Three out of seven mycoplasma-infected CNS cases showed CSF pleocytosis while three out of seven patients whose tracheal aspirates grew mycoplasma had congenital pneumonia. None of the patients were treated with antimycoplasmal therapy and none developed chronic lung disease.

Female↗

Analysis of antigenic structure and human immune response to outer membrane protein CD of Moraxella catarrhalis.

Moraxella catarrhalis is an important cause of otitis media in children and lower respiratory tract infections in adults with chronic obstructive pulmonary disease (COPD). Outer membrane protein CD (OMP CD) is a 45-kDa protein which is a potential vaccine antigen to prevent infections caused by M. catarrhalis. Eight monoclonal antibodies were used to study the antigenic structure of the OMP CD molecule by assaying recombinant peptides corresponding to the sequence of the protein. This approach identified two surface-exposed epitopes, including one near the amino terminus (amino acids 25 to 44) and one in the central region of the molecule (amino acids 261 to 331). Assays with serum and sputum supernatants of adults with COPD revealed variable levels of antibodies to OMP CD among individuals. To determine which portions of the OMP CD molecule were recognized by human antibodies, three human serum samples were studied with six recombinant peptides which span the sequence of OMP CD. All three sera contained immunoglobulin G antibodies which recognized exclusively the peptide corresponding to amino acids 203 to 260 by immunoblot assay. Adsorption experiments with whole bacteria established that some of the human antibodies are directed at surface-exposed epitopes on OMP CD. We conclude that OMP CD is a highly conserved molecule which contains at least two separate epitopes which are exposed on the bacterial surface. While individual adults with COPD show variability in the immune response to OMP CD, a specific region of the OMP CD molecule (amino acids 203 to 260) is important as a target of the human immune response.

Adult↗

Study of gastric carcinomas with special reference to intestinal metaplasia.

An attempt was made to classify 61 cases of gastric carcinomas according to Lauren's classification from the period January 1992-December 1993. All the gastrectomy specimens resected for carcinoma of stomach were included in the study. Of 61 cases, 57 were classifiable according to Lauren's criteria. 38 (62.3%) were of intestinal type and 19 (31.1%) were of diffuse type. 4 cases could not be classified into either group. There were significant correlation of type III intestinal metaplasia with intestinal type gastric carcinoma.

Adenocarcinoma↗

Prevalence of Japanese encephalitis and West Nile viral infections in pig population in and around Chandigarh.

A study on sero prevalence of Japanese Encephalitis (JE) and West Nile (WN) viruses in pigs was carried out in and around Chandigarh. A total of 158 blood samples collected (June, 1995-March, 1996) from batches of pigs were screened for antibodies against JE and WN viral antigens by haemagglutination inhibition and complement fixation tests. In Chandigarh out of 13 pigs, 5 had JE and one WN HAI antibodies. Similarly, the sera of 14 and 1 pigs in Punjab and 29 and 3 pigs in Haryana were positive for JE and WN HAI antibodies respectively. In total JE specific HAI antibodies were found in 30.3% and CF antibodies in 12.5% of pigs whereas WN specific HAI antibodies were obtained in 3.2% and only one pig had CF antibodies. The results show that JE and WN viral infections are prevalent in pig population in and around Chandigarh.

Animals↗

Role of serology in the diagnosis of herpes simplex encephalitis.

Twenty one cerebrospinal fluid (CSF)/brain tissue (16 CSF and 5 brain tissue) from patients clinically suspected of herpes simplex encephalitis (HSE) were collected during one year period and was subjected for the detection of HSV type I and type II antigen by direct Immunofluorescence (DIF). Paired serum and CSF samples obtained from 12 patients were tested for herpes simplex virus antibodies by indirect immunofluorescence test. Of the 21 cases, two were positive for HSV-1 antigen in CSF and one in brain tissue by DIF. Virus specific IgG antibody in paired CSF and serum samples was positive in one case only. In none, virus could be grown in verocell line. In 2 Patients antemortem diagnosis was possible and parenteral acyclovir could be administered in one case that recovered following treatment. Thus, besides antibody detection, direct immunofluorescence is an useful and rapid method for the early diagnosis of HSE.

Adolescent↗

Serologic response to the E4, E6, and E7 proteins of human papillomavirus type 16 in pregnant women.

OBJECTIVE: In a seroepidemiologic study the effects of pregnancy and other factors on humoral response to human papillomavirus type 16 infection were examined. STUDY DESIGN: Multiple serum samples were taken at 3-month intervals for 15 months from 77 pregnant and 85 nonpregnant women. Serologic response to human papillomavirus type 16 proteins was analyzed with a peptide-based enzyme-linked immunosorbent assay. RESULTS: Seroreactivity was higher in nonpregnant women than in pregnant women, suggesting a reduced humoral immune response against human papillomavirus infections during pregnancy. Among the pregnant women a twofold to threefold decrease in mean reactivity in the E4 protein-based assay was detected between early gestation and delivery. The presence of human papillomavirus type 16 or 18 deoxyribonucleic acid was significantly associated with reactivity to the E6 protein (p = 0.0005) and the E4 protein (p = 0.06). Reactivity to the E4 protein also correlated with an abnormal Papanicolaou smear. CONCLUSIONS: The observation of changes in humoral response to genital human papillomavirus infections during pregnancy warrants further investigation with highly seroreactive assays.

Amino Acid Sequence↗