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Biomedical subjects

L Srivastava

Publications and source records attributed to L Srivastava.

At least 19 recordsLinked to original sources
PubMed2005

Characterization and changing minimum inhibitory concentration (MIC) of Acinetobacter species from a tertiary care setup.

128 isolates of Acinetobacter species from admitted and outdoor patients were subjected to biotyping and resistotyping. Resistance phenotype analysis included nine antibiotics and two betalactam inhibitor combination drugs. In 100 strains of Acinetobacter spp. ciprofloxacin, amikacin, cefotaxime and cefepime minimum inhibitory concentration (MIC) was done by agar dilution using NCCLS 2002 criteria. In forty-nine isolates MIC level was determined by E-strip also. Extended spectrum beta lactamase (ESBL) production was detected by double disc synergy technique. Inducible beta lactamases (IBL's) were detected by disc approximation method. The relationship between biotypes and resistance phenotype was analyzed. Majority of isolates (93.75%) were from admitted patients. The biotyping revealed Acinetobacter calcoaceticus-Acinetobacter baumannii complex (87.2%) to be the predominant species and they were isolated from tracheal aspirates of patients with ventilator associated pneumonia. By Kirby Bauer disc diffusion antimicrobial sensitivity testing Acinetobacter spp. were most sensitive to the combination of drug cefoperazone-sulbactam (95.6%) followed by meropenem (94.6%), piperacillin-tazobactam (92.6%). On screening incidence of Imipenem Nonsensitive Acinetobacter spp. (INSA) was (5.4%). Acinetobacter spp. were typable by six resistance phenotypes and six biotypes. Most common (66.6%) resistant phenotype of A. calcoaceticus-A. baumannii complex was susceptible to cefoperazone-sulbactam and or meropenem and or piperacillin-tazobactam. ESBL production was seen in 6% and IBL (Inducible Beta Lactamase) production was seen in 7% of Acinetobacter spp. The MIC90 for ciprofloxacin was =256 microg/ml, cefotaxime 512 microg/ml, cefepime 512 microg/ml, and amikacin 32 microg/ml. Multidrug resistance was seen in more than 90% of A. calcoaceticus-A. baumannii complex and 20% of Acinetobacter lwoffii. Acinetobacter spp. has other emerging novel mechanism of resistance that requires continuous research. Simpler, reproducible and reliable methods of biotyping and their subsequent correlation with resistotyping are more cost effective than molecular methods, which are available only in reference laboratories.

Acinetobacter↗
PubMed2000

Fasciolopsiasis--a persisting problem in eastern U.P.--a case report.

Fasciolopsiasis, or infection by the intestinal fluke, Fascilopsis buski, is endemic in the eastern states of our country. While it is by no means a rarity, especially in the rural set up, awareness regarding this common parasitic infestation is still a much-needed entity. The importance of a strong degree of suspicion and early diagnosis cannot be over emphasised, if a successful campaign is to be launched in its control. With this as our central theme, we proceed to report a case of and unsually heavy Fasciolopsis buski infection in our hospital, which had failed to be diagnosed in a semi urban setup in UP.

Adult↗
PubMed1999

Etiology of infantile autism: a review of recent advances in genetic and neurobiological research.

The etiology of autism is complex, and in most cases the underlying pathologic mechanisms are unknown. Autism is a hetereogeneous disorder, diagnosed subjectively on the basis of a large number of criteria. Recent research has investigated genetics, in utero insults and brain function as well as neurochemical and immunological factors. On the basis of family and twin studies, there appears to be a genetic basis for a wide "autistic syndrome." About a quarter of cases of autism are associated with genetic disorders such as fragile X syndrome or with infectious diseases such as congenital rubella. Genetic studies have shown an association between autism markers of brain development such as 3 markers of the c-Harvey-ros oncogene and the homeobox gene EN2. In some cases, autism is associated with insults early in gestation, including thalidomide embryopathy. Autism may arise from abnormal central nervous system functioning, since most autistic patients have indications of brain dysfunction, and about half of them have abnormal electroencephalograms. Similarly, the pattern of evoked response potentials and conduction time is altered in autistic children. There is substantial evidence from neuroimaging studies that dysfunctions in the cerebellum and possibly the temporal lobe and association cortex occur in autistic symptoms. Neurochemical studies have investigated the role of serotonin, epinephrine and norepinephrine, since levels of these neurotransmitters are altered in autism, although other hypotheses implicate overactive brain opioid systems and changes in oxytocin neurotransmission. Autoimmunity may also play a role; antibodies against myelin basic protein are often found in children with autism, who also have increased eosinophil and basophil response to IgE-mediated reactions. In summary, the prevailing view is that autism is caused by a pathophysiologic process arising from the interaction of an early environmental insult and a genetic predisposition.

Autistic Disorder↗
PubMed1999

Detection of mycobacterial antigen in circulating immune complexes in patients with childhood tuberculosis.

The presence of both components (antigen and antibody) in circulating immune complexes (CIC) were detected in tuberculosis in children. Fifty two patients with pulmonary and extrapulmonary tuberculosis showed the presence of either components or both. CIC--antigen was present in 92.3% (48/52) and CIC antibody in 88.96% (46,52). Out of these 52 patients, 20 were proved cases, CIC antigen (ag) and CIC--antibody (ab) were present in 100% (20/20). In the control group both CIC-ag and CIC-ab and CIC = ab can be taken as an additional marker in diagnosis of tuberculosis.

Antibodies, Bacterial↗
PubMed1996

Plasma platelet-derived growth factor: preliminary study of a potential marker in head and neck cancer.

The role of growth factors in the development and spread of head and neck cancers has received little attention. Platelet-derived growth factor (PDGF) is a potent mitogen that is released normally in wound healing, but is also secreted by human malignant epithelial cells. In breast and ovarian carcinomas, elevated plasma PDGF has correlated with a poorer prognosis. This preliminary study was designed 1) to determine if PDGF is elevated in the plasma of patients with squamous cell carcinoma of the head and neck and 2) to determine whether there is any change in levels following surgical ablation. The PDGF was measured by radioimmunoassay in 18 patients with head and neck squamous cell carcinoma and in 12 normal controls. In the control group the mean level was 7.4 fmol/100 microL (range 2.8 to 12.5, median 7.6), in spite of the fact that PDGF is reportedly not measurable in normal subjects. The mean PDGF level in the cancer patients was 20.4 fmol/100 microL (range 4.1 to 35.7, median 20.5) and as compared to the control group was significantly elevated (median two-sample test, p < .001). Of the 20 cancer patients, only 4 had levels less than 12.5 fmol/100 microL. Moreover, 2 of these had undergone prior radiotherapy. In all cases, PDGF levels decreased significantly after surgery. These results support the importance of the further investigation of plasma PDGF levels as a potential biomarker to evaluate efficacy of treatment, possibly to aid in the detection of tumor recurrence, and even to be a potential indicator of tumor aggressiveness.

Biomarkers, Tumor↗
PubMed1994

Adrenal effects of low-dose aminoglutethimide when used alone in postmenopausal women with advanced breast cancer.

Aminoglutethimide (Ag) is a potent aromatase-enzyme inhibitor used in the treatment of patients with breast cancer. In the past, it has been administered in doses of 1,000 mg/d (usually with 40 mg hydrocortisone). At these dose levels, the drug also affects multiple cytochrome P-450 enzymes, including enzymes for adrenal steroid biosynthesis. Recently, lower-dose regimens (500 mg/d) of Ag have been found to be just as effective for breast cancer therapy, but less toxic than the higher conventional dose. There is limited information on the adrenal effects at the lower dosages, and it is not known whether these effects are clinically significant. We measured basal and synthetic corticotropin (Cortrosyn)-stimulated levels of adrenal steroids in postmenopausal breast cancer patients before and during treatment with low-dose Ag (500 mg/d) administered without a glucocorticoid preparation. Basal levels of progesterone, 17-OH progesterone, and 11-deoxycortisol were higher after 2 months' treatment (P < .01). After ACTH injection, peak levels of progesterone and 17-OH progesterone were higher (P < .01), but in contrast, peak levels of 18-OH corticosterone were lower during treatment (P < .02). Basal and peak levels of cortisol, aldosterone, and all other adrenal steroids were unchanged during treatment. We conclude that low-dose Ag treatment leads to partial inhibition of the 21-hydroxylase, 11-hydroxylase, and 18-hydroxylase adrenal enzymes. Since cortisol and aldosterone secretion remained normal with minimal shunting to or accumulation of adrenal androgen compounds, we believe that the mild inhibition was compensated for by further endogenous ACTH stimulation.

17-alpha-Hydroxyprogesterone↗
PubMed1994

Diagnosis of tuberculous meningitis by ELISA test.

Detection of IgG antibodies to Mycobacterium tuberculosis H37 Ra antigen in cerebrospinal fluid (CSF), by ELISA test appears to be highly sensitive. In 90 per cent (18/20) of proven cases of tuberculous meningitis (TBM), antibodies were present in CSF; in 75 per cent (15/20) antibodies were also present in the sera. In the patients clinically suspected to have TBM, antibodies in CSF and sera were present in 87.5 per cent (42/48) and 70.8 per cent (34/48) respectively, whereas in the control group antibodies were present in only one serum sample and in none of the CSF samples. The results indicate that ELISA test using sonicated M. tuberculosis H37 Ra as antigen is a sensitive and specific test for diagnosis of TBM.

Adolescent↗
PubMed1991

Role of bacteriological monitoring of the hospital environment and medical equipment in a neonatal intensive care unit.

The aim of this study was to evaluate the usefulness of performing routine monthly bacteriological surveillance of the nursery environment, resuscitation equipment, baby placement sites, medications, formula feeds, cleansing solutions and miscellaneous medical items such as intravenous cannulae in relation to development of hospital-acquired bacteraemia in a Neonatal Intensive Care Unit (NICU) over a period of 19 months. The study is based on a retrospective review of records from the neonatal division and the microbiology laboratory. On discriminant analysis, only three NICU sites, namely baby placements, resuscitation equipment and various cleansing solutions were found to be significantly associated with hospital-acquired infections (HAI) (P less than 0.001). The probability that a batch of newly admitted babies would develop HAI if all three sites were colonized was 0.602. Similarly, the probability if none of these sites was colonized was 0.10. On multiple logistic regression analysis, however, the relative risk of infection was greatest if baby placement sites were colonized (Odds ratio = 7.48; P less than 0.01). In contrast, pathogens present in the inanimate NICU environment, e.g. floors, walls, sink-drains or furniture were not associated with HAI. Routine bacteriological surveillance of the inanimate nursery environment, is not therefore justified. However, our results suggest that routine bacteriological monitoring of medical equipment and cleansing solutions may have a role in the prevention of HAI.

Bacterial Infections↗
PubMed1991

Coagulase negative staphylococcal septicemia in newborns.

The case records of 2177 newborn infants admitted in the Neonatal Intensive Care Unit (NICU) from January, 1989, through July, 1990, with positive blood cultures for coagulase-negative staphylococci (C-NS) were evaluated. Seventy four (3.4%) neonates yielded C-NS in blood cultures during the study period. Of these, 58 (2.7%) infants had clinical and hematological features compatible with the diagnosis of septicemia. Remaining 16 babies with positive cultures had no evidence of sepsis, and were designated as "C-NS bacteremia". The age at which positive cultures were obtained differed between the bacteremic and septicemic groups. In bacteremic group, the onset occurred between one to four days of age. In contrast, in septicemic group the range was 6-20 days, with a mean of 10.22 (+/- 3.53) days. More than two third of total cases of C-NS sepsis were premature and low birth weight (LBW). Prominent clinical features included lethargy, poor feeding and fever. Besides this apneic spells were seen predominantly in babies weighing less than 1500 g. Further, before the diagnosis of C-NS sepsis, more than half of neonates had received prolonged intravenous fluid therapy, a quarter had undergone umbilical catheterization and a further quarter needed a ventilator support. Overall mortality in C-NS sepsis was 17.24%, distinctly higher in neonates with RDS and those requiring mechanical ventilation (p less than 0.05). Only 1.34% C-NS isolates were resistant to all routinely used antibiotics and sensitivity was maximum with newer cephalosporins, ciproflox and amikacin.

Bacteremia↗
PubMed1990

An epidemic of dengue haemorrhagic fever and dengue shock syndrome in Delhi: a clinical study.

Twenty-four cases of dengue haemorrhagic fever/dengue shock syndrome were studied in Delhi in the months of September and October, 1988. The majority of these cases were boys aged 6-10 years. Classical symptoms of dengue (fever, headache, aesthesia, myalgia) occurred in all the patients. Digestive symptoms (nausea, vomiting, anorexia, abdominal pain and hepatomegaly) were also common. Haemorrhagic manifestations were present in 41.7% of the cases. Of these, 90% had gastrointestinal haemorrhages. Shock occurred in 17 cases (70.8%). Thrombocytopenia and prolongation of coagulation profile were found in 62.5% of cases. Three patients (12.5%) who presented with encephalopathy died. The other 21 patients recovered after an average period of 2-8 days.

Child↗
PubMed1990

Salmonella senftenberg outbreak in a neonatal unit.

Salmonella senftenberg was isolated from the stools of 35 newborns between June, 1987 and September, 1988. Twenty nine (82.8%) babies were preterms and twenty six (74%) babies were less than 2,000 grams in weight. All of them were symptomatic within 6 days of life, 74.3% (26) within 4 days. All of them had loose stools and weight loss. Other features were sclerema, jaundice and paralytic ileus. The organism was sensitive to nalidixic acid (100%), amikacin (94.6%), gentamicin (72.9%), cephaloridine (56.7%), and chloramphenicol (29.8%) and resistant to benzyl penicillin and ampicillin. Babies showed good response to a combination of cephaloridine and amikacin along with supportive care. Five babies died, 4 of septicemic shock and one of pulmonary hemorrhage.

Cross Infection↗
PubMed1989

Detection of antigen specific circulating immune complexes in Indian kala-azar.

The sera of active and treated cases of kala-azar were tested for circulating immune complexes (CIC) by antigen-specific enzyme linked immunosorbent assay (ELISA). All (100%) of proved cases had elevated CIC; 64.3% of clinically diagnosed cases and 58.8% of treated cases were also positive for CIC. A fall in the level of CIC was observed after treatment. Detection of antigen-specific CIC may be useful in monitoring the therapeutic effect and recovery.

Animals↗
PubMed1989

Comparative evaluation of serological tests in diagnosis of kala azar.

Four serological tests, viz., counter immunoelectrophoresis (CIEP), indirect fluorescent antibody (IFA) test, enzyme linked immunosorbent assay (ELISA) and dot-enzyme linked immunosorbent assay (dot-ELISA) were compared for their sensitivity and specificity for diagnosis and epidemiological studies of kala azar. Sera from patients who were parasite positive (58), parasite negative (16), clinically diagnosed (53), treated (31) and from healthy controls (42) were tested for presence of antibodies by these techniques. Antibodies were detected in treated patients even after 18-24 months by ELISA (77.4%) and dot-ELISA (74.19%). In clinically diagnosed patients antibodies were present in 90.56 per cent by both the tests. The sensitivity and specificity of CIEP was 0.77 and 1.0, for IFA 0.87 and 0.95 respectively and for ELISA and dot-ELISA 0.92 and 0.9 respectively. Due to the requirement of small quantity of reagents and simplicity of the test, dot-ELISA is found to be more suitable for use in peripheral laboratories both for diagnosis and seroepidemiology.

Counterimmunoelectrophoresis↗
PubMed1988

Diagnosis of Indian kala-azar by dot enzyme-linked immunosorbent assay (dot-ELISA).

Serodiagnosis of kala-azar was determined by dot-ELISA under variable conditions such as may be encountered in the field, for example, in the nature of the antigen, the preservation of antigen at different temperatures, variation in incubation temperature and so on. The test was found to be useful under field conditions, and the correlation between ELISA and dot-ELISA was significant. Dot-ELISA has definite advantages over the ELISA test, as it is easy to perform, is stable and does not require expensive equipment. The test can be used for large-scale screening of sera in sero-epidemiological studies.

Animals↗
PubMed1987

Synthesis of neuropeptide Y.

Neuropeptide Y (NPY), a hexatriacontapeptide amide, was synthesized on benzhydrylamine resin. The peptide product obtained by HF treatment contained 63% of the target peptide, NPY. A comparison of the chemical, immunochemical and biological properties of the synthetic peptide with natural NPY indicated that they were identical.

Amino Acid Sequence↗
PubMed1986

Serological diagnosis of typhoid fever by enzyme-linked immunosorbent assay (ELISA).

Serum sample from 22 bacteriologically proved cases of typhoid fever, 41 febrile cases who were culture negative and 70 sick and healthy age-matched controls were tested for enzyme-linked immunosorbent assay (ELISA) IgG and IgM antibodies using Salmonella typhi LPS antigen. IgG and IgM antibodies were present in 72.7% and 81.8% respectively as against Widal test which was positive in 40.9% in proved cases. In febrile controls IgG and IgM ELISA antibodies were present in 80.4% and 60.9% respectively as against 53.6% by Widal test. This difference between the two tests was statistically significant P less than 0.001. ELISA test was more sensitive than the Widal test and hence it may be useful in rapid serodiagnosis of typhoid fever and also in circumstances where bacteriological techniques are not available.

Enzyme-Linked Immunosorbent Assay↗