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Biomedical subjects

H Prabhakar

Publications and source records attributed to H Prabhakar.

At least 19 recordsLinked to original sources

Dengue haemorrhagic fever outbreak in October-November 1996 in Ludhiana, Punjab, India.

An epidemic of haemorrhagic fever broke out in Ludhiana in October and November 1996. Persons of all age groups were affected with preponderance of young adults. Haemorrhagic manifestations like rashes, epistaxis, bleeding from the gums and haematemesis were observed. The cause of fever was investigated. Serum samples collected at random from 71 patients were tested by ELISA for dengue types 1-4 IgM antibodies. These were positive in 96.7 per cent of cases. Immunoblot testing for IgM and IgG for all serotypes of dengue virus were positive in 90.2 and 73.2 per cent of the serum samples respectively. The haemorrhagic fever was serologically proven to be due to dengue virus.

Adult

Prevalence of multi-drug resistant Salmonella typhi in Ludhiana Punjab.

A total of 945 strains of S. typhi isolated from blood cultures during 1989 to 1994 were studied. Their antibiotic susceptibility showed 580 (61.4%) of strains to be multidrug resistant. The 464 strains tested for their susceptibility to ciprofloxacin were all sensitive to the drug. Twenty three (17.9%) of the 128 strains of S. paratyphi A were resistant to chloramphenicol. The sole isolate of S. paratyphi B was sensitive to all antibiotics tested.

Drug Resistance, Multiple

Prevalence of hepatitis A, B, C & D in Ludhiana.

172 sera were tested for serological markers of hepatitis A, hepatitis B, hepatitis C and hepatitis D to define the aetiology of acute viral hepatitis by Enzyme immunoassays. The viral aetiology could be decided in 60.5% (104/ 172) of patients. Hepatitis B infection was present in 34.9%, hepatitis A in 10.5%, hepatitis C in 9.3% and hepatitis D in 5.8% of cases. Delta hepatitis associated with HBsAg positive hepatitis was detected in 10% (6/60) of the patients. The aetiology remained undecided in 39.5% of patients.

Acute Disease

Predictive utility of clinical and stool parameters in bacterial diarrhoea in children.

A prospective one year study was conducted on children between the ages of 1 month to 5 years hospitalised in the pediatric ward of Christian Medical College, Ludhiana, with the aim of determining the predictive utility of certain clinical and stool parameters in diagnosing bacterial diarrhoea. Among the 204 children enrolled in the study, fever was observed in 40% in both the culture positive and negative groups. Clinical features such as abdominal distension, vomiting and oliguria although had low positive predictive values, their negative predictive values were high. Among the stool parameters, watery consistency and pus cells > 5 HPF were significantly more often observed in culture positive cases. The presence of mucus and pus cells > 5 HPF had good sensitivity (70-80%) but poor specificity (27-40%), while the reverse was true of blood (sensitivity 23%, specificity 89%). Again the positive predictive values were uniformly low while the negative ones were high. In conclusion the clinical and stool parameters were found to be more useful by their absence than by their presence in excluding a positive stool culture.

Bacterial Infections

Shigella isolates in stool.

A total of 447 Shigella strains were isolated from stool samples during 1989-1991. Of these 270 (60%) were from children. Among the different species and serotypes Sh. flexneri 60 (13.4%) and Sh. sonnei Phage 139 (65%) were the most frequently isolated strains. 154 (34.4%) strains were resistant to three and 179 (40%) to more than three antibiotics. Some strains of Shigella were found to be resistant to furazolidine and neomycin.

Adult

Acinetobacter meningitis.

10,468 CSF samples from cases of meningitis in different age groups were cultured during 1988-1991. Acinetobacter calcoaceticus was isolated in 12 (5.6%) of 211 positive cultures. The strain were 100% resistant to ampicillin, cotrimoxazole and tetracycline 50% resistant to cephazolin gentamicin and kanamycin but 100% susceptible to chloramphenicol.

Acinetobacter

Physical factors contributing to the partition coefficient and retention time of 2',3'-dideoxynucleoside analogues.

Acquired immunodeficiency syndrome (AIDS) is an immunosuppressive disease characterized by an immune impairment and a high susceptibility to unusual forms of certain neoplasms. Since the brain is an important site of the infection, it is necessary to explore new classes of drugs that have the ability to penetrate across the blood-brain barrier, and the potency to suppress viral replication within the central nervous system (CNS). Therefore, the ability to predicate the lipophilicity of the potent anti-AIDS drugs may provide useful information about the potential of the drugs to enter CNS. In this paper, the correlations of log P (octanol-buffer partition coefficient) and log tR (retention time in HPLC; Rt was used by Balzarini et al.) with some physical constants like log MW (molecular weight), hydrogen bond forming ability (HB) of the substituents, and the substituent group dipole moments (mu) are analyzed. Good correlations of log P and log tR with log MW, HB, and mu have been obtained.

Antiviral Agents

Anaerobic bacterial flora of wound sepsis.

Two hundred specimens from wound infection (surgical and non-surgical) were cultured for the isolation of anaerobic and aerobic bacteria. Positive cultures were obtained in 174 (87%) and 26(13%) were sterile. Anaerobes were isolated from 31(17.8%), as single culture in 6(3.4%) and as mixed culture with aerobes in 25(14.3%). Amongst anaerobes, anaerobic cocci were predominant (45.9%). Of aerobes Staph pyogenes (35%) was predominant. Metronidazole was the most effective drug against anaerobes and gentamicin against aerobes. No significant difference was noted in antimicrobial susceptibility of anaerobes of surgical and non-surgical wounds. Among aerobes high resistance was observed in surgical wounds.

Bacteria, Aerobic

Haemagglutination antibody titres & immunoglobulin levels in cases of Plasmodium infection.

Malarial antibody estimation was done in patients with malaria (50), and fever (malaria negative, 50) and in 50 healthy controls who gave no history of malaria for the last one year, using the indirect haemagglutination test (IHA). Seropositivity was 78, 32 and 4 per cent respectively. Levels of IgG and IgM were found to be significantly higher in patients as compared to controls and a significant fall was observed in IgA levels in patients of malaria. Although the malarial antibody titre showed good correlation with IgG (P less than 0.01) and IgM (P less than 0.05) not all patients with a negative haemagglutination antibody titre had normal immunoglobulin levels.

Animals

Carcinogen induced DNA damage in isolated rat liver nuclei.

Alkali-labile DNA lesions were detected by a hydroxylapatite batch assay following incubation of isolated rat liver nuclei with direct and indirect-acting alkylating agents. N-Methyl-N'-nitro-N-nitrosoguanidine (MNNG) (20-200 microM) produced a steep, concentration-related decrease in double stranded DNA. In contrast, only minimal effects on DNA integrity were observed with methylmethane sulfonate (200 microM). The bifunctional alkylating agent, mechlorethamine produced an apparent increase in double-stranded DNA in accord with its ability to induce interstrand DNA crosslinks. The indirect-acting alkylating agent, dimethylnitrosamine (DMN) induced DNA damage only when an NADPH generating system was included in the incubation mixture. These results suggest that isolated rat liver nuclei may be a useful model for studying the effects of mutagenic and carcinogenic chemicals on the integrity of chromosomal DNA.

Animals