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Biomedical subjects

O C Abraham

Publications and source records attributed to O C Abraham.

36 records · Page 2Linked to original sources

Low infectious morbidity after intensive chemotherapy and autologous peripheral blood progenitor cell transplantation in the outpatient setting for women with breast cancer.

Autologous peripheral blood progenitor cell (PBPC) transplantation is increasingly employed in the outpatient setting, yet data on early complications following PBPC transplantation are scant. We evaluated 105 women with high-risk primary or metastatic breast cancer who were treated at a single institution during 1996--1997. The mean duration of neutropenia (absolute neutrophil count, <500 cells/mm(3)) was 7.5 days. Twenty-nine percent of women remained afebrile throughout the neutropenic period. Of the remaining 71%, most (64 of 75) had fever of unknown origin. Infections, mostly of mild severity, occurred in 34% of women; these infections included bacteremia due to gram-positive organisms, catheter site infection, cellulitis, pneumonia, oral candidiasis, herpes simplex virus infection, and vaginitis. Fifty percent of PBPC transplant recipients required hospital admission, usually because of persistent fever; the mean duration of hospitalization was 3 days. No deaths or serious adverse events occurred. Such reduced infectious morbidity may be a consequence of minimal oral and/or gastrointestinal mucositis associated with the conditioning regimen and broad-spectrum antimicrobial prophylaxis used for this patient population.

Adult↗

A peptide enzyme linked immunosorbent assay (ELISA) for the detection of human immunodeficiency virus type-2 (HIV-2) antibodies: an evaluation on polymerase chain reaction (PCR) confirmed samples.

BACKGROUND: HIV-1 and HIV-2 infections differ in prognosis, and may also require different prevention and/or treatment approaches. Thus, estimating the true prevalence of HIV-1 and HIV-2 infections, as well as co-infections, is a critical step in controlling the disease. There are a few commercial ELISA and immunoblot kits, which can differentiate between HIV-1 and HIV-2 infections. However, some of these assays overestimate the prevalence of dual infection. Hence, it is necessary to develop assays capable of discriminating between the two infections. OBJECTIVES: To develop a synthetic HIV-2 env based peptide ELISA for the detection of HIV-2 specific antibodies and evaluate its performance on samples from HIV positive individuals previously tested by HIV-1 and HIV-2 PCR and HIV seronegative individuals. STUDY DESIGN: We studied 45 HIV seronegative and 63 HIV infected individuals, including 30 HIV-1 PCR and immunoblot positives, 19 HIV-2 PCR and immunoblot positives, five HIV-1 and two PCR and dual immunoblot positives, two PCR negative but positive for HIV-2 by immunoblot and seven dual immunoblot positives who were only positive for HIV-1 by PCR. RESULTS: All 24 HIV-2 PCR positive samples tested were positive by the peptide assay. Among 30 HIV-1 PCR and immunoblot positive samples, only one (3.3%) showed an absorbance value above the cut off level. The seven dual positive samples by immunoblot (only positive for HIV-1 by PCR) were negative by the HIV-2 peptide ELISA. There was a 100% concordance between HIV-2 PCR and peptide ELISA. The sensitivity, specificity, and the likelihood ratio for the peptide ELISA were 100,94.9, and 19.5, respectively when compared against the PCR findings. CONCLUSIONS: This ELISA, using a specific immunodominant epitope (11 amino acids) from the transmembrane (gp36) portion of the HIV-2 envelope glycoprotein showed a high concordance with PCR findings. This can be considered as a highly sensitive, specific and economically feasible assay for the discrimination of HIV-1 and HIV-2, and may serve as an alternative to HIV-2 PCR in epidemiological studies.

Enzyme-Linked Immunosorbent Assay↗

Isolation and in vitro susceptibility to amphotericin B, itraconazole and posaconazole of voriconazole-resistant laboratory isolates of Aspergillus fumigatus.

OBJECTIVES: To select voriconazole-resistant mutants of Aspergillus fumigatus in the laboratory from drug-susceptible clinical isolates and examine their in vitro susceptibility to amphotericin B and investigational azoles, and to compare the intramycelial accumulation of voriconazole in the resistant isolates with that in the susceptible parent. METHODS: Voriconazole-resistant Aspergillus fumigatus isolates were selected in the laboratory from three highly susceptible (MIC < or = 0.5 mg/L) clinical isolates by stepwise selection on peptone yeast extract glucose (PYG) agar containing 0.5 mg and 4 mg voriconazole/L. Twenty-three colonies that grew in the presence of 4 mg voriconazole/L on PYG agar (frequency 1.9 x 10(-8)) were tested for their in vitro susceptibility to amphotericin B, itraconazole, voriconazole and posaconazole by a broth macrodilution technique. The accumulation of voriconazole in the mycelia of two representative resistant isolates (VCZ-W42 and VCZ-W45) was determined by a previously described bioassay. RESULTS: The geometric mean MICs (mg/L) of amphotericin B, itraconazole, voriconazole and posaconazole for these isolates were 0.45 +/- 0.19, 0.69 +/- 0.45, 5.24 +/- 3.74 and 0.27 +/- 0.18, respectively. A comparison of the geometric mean MICs of the antifungals obtained for the resistant isolates to those of the susceptible parents showed 1.15-, 2.76-, 16.90- and 1.42-fold increases, respectively, for amphotericin B, itraconazole, voriconazole and posaconazole, suggesting that low-level cross-resistance exists between the azole antifungals. The susceptible parent and the resistant isolates accumulated similar amounts of voriconazole. CONCLUSIONS: These results suggest that spontaneous mutants of Aspergillus fumigatus resistant to voriconazole could emerge among clinical isolates under selection pressure and that the observed reduced in vitro susceptibility to voriconazole may not be due to reduced accumulation of the drug in the mycelia.

Amphotericin B↗

Serological evidence for the continued presence of human rickettsioses in southern India.

Rickettsiosis is generally believed to have disappeared from many parts of India. However, the serological testing of 37 residents of southern India who presented with fever of unknown aetiology in 1996-1998 confirmed that spotted fever, epidemic/endemic typhus and scrub typhus continue to occur in southern India. The epidemiology and magnitude of the problem need to be evaluated.

Adolescent↗

Correlation of CD4(+) T-Cell counts estimated by an immunocapture technique (Capcellia) with viral loads in human immunodeficiency virus-seropositive individuals.

As antiretroviral therapy becomes more affordable, valid, reliable, and inexpensive laboratory tests are also needed to monitor the progression of disease in people with human immunodeficiency virus (HIV) infection. The CD4(+) T-cell counts estimated by Capcellia, an immunocapture method, and flow cytometry were compared and were correlated with HIV type 1 (HIV-1) load. There was a significant negative correlation between the HIV-1 load and CD4(+) T-cell counts estimated by flow cytometry (r = -0.63, P = <0.001) as well as between the HIV-1 load and CD4(+) T-cell counts estimated by Capcellia (r = -0.61, P = <0.001). Capcellia is a cost-effective, user-friendly assay that correlated well with HIV-1 load determinations for individuals both with and without treatment.

Adult↗

Peripheral CD4+/CD8+ T-lymphocyte counts estimated by an immunocapture method in the normal healthy south Indian adults and HIV seropositive individuals.

BACKGROUND: Flow cytometry is the standard method for the estimation of CD4/CD8 counts, but the high initial investment for this instrument and costly reagents make it unaffordable to most of the centers in a developing country like India. OBJECTIVES: To evaluate the feasibility of an alternate system for the estimation of CD4 and CD8 counts in normal south Indian adults and validate the usefulness of this assay to monitor the counts in HIV seropositive individuals. STUDY DESIGN: Forty-six normal healthy adults and 68 HIV seropositive individuals both belonging to south Indian linguistic groups were enrolled in this cross-sectional study. The HIV seropositive individuals included 54 HIV-1, 9 HIV-2 and 5 HIV 1&2 infected individuals serologically confirmed by one of the commercial Immunoblot kits. The Capcellia CD4/CD8 whole blood assay, an immuno-capture ELISA based kit from Sanofi DIAGNOSTICS Pasteur, (France) was used with a few modifications in the procedure to measure the CD4 and CD8 counts. RESULTS: The mean CD4 cell counts were 1048 (central 95 centile only), 746 and 424 for the normal healthy adults, asymptomatic HIV seropositives and symptomatic HIV patients, respectively, and the mean CD8 counts were 595, 889 and 732, respectively. Statistically significant differences were observed in the CD4 cell counts between HIV seronegative healthy adults and asymptomatic (P < 0.001) as well as asymptomatic and symptomatic (P < 0.05) HIV infected individuals. The mean CD4 counts of asymptomatic HIV-2 infected individuals was significantly higher than the counts of asymptomatic HIV-1 infected individuals (P < 0.05). CONCLUSIONS: This is an user friendly test and can be an alternate to flow cytometry for the estimation of peripheral T-lymphocyte subsets in developing countries. The assay system has certain limitations inherent to ELISA techniques.

Adult↗

Molecular confirmation of human immunodeficiency virus (HIV) type 2 in HIV-seropositive subjects in south India.

Nested PCRs for human immunodeficiency virus type 1 (HIV-1) and HIV-2 were compared with immunoblot test results. Twelve of 13 immunoblot-positive HIV-2 samples were positive by PCR. There were five INNO-LIA (Innogenetics, Zwijnaarde, Belgium) and/or HIVBLOT 2.2 (Genelabs, Singapore) samples that tested positive for dual infection. HIV-1 PCR was positive in all samples, while HIV-2 PCR was positive in two and RIBA (Chiron Corporation, San Diego, Calif.) was positive for HIV-2 in three samples. Thus the prevalence of HIV-2 is accurately estimated by the use of immunoblotting, but that of HIV-1 and -2 dual infection may be overestimated.

Female↗

Effect of test medium on in vitro susceptibility testing results for Aspergillus fumigatus.

We examined the effect of peptone yeast extract glucose broth (PYG), RPMI 1640 and Antibiotic Medium 3 (M3) on the in vitro susceptibility of clinical isolates (n = 200) of Aspergillus fumigatusto amphotericin B (AMB), itraconazole (ITZ) and voriconazole (VCZ). The MICs (mug/mL) of various antifungal agents (geometric mean plus/minus standard deviation) obtained in PYG, RPMI 1640 and M3, respectively, were as follows; AMB: 1.64 plus/minus 0.92, 0.42 plus/minus 0.21, 0.33 plus/minus 0.16; ITZ: 0.44 plus/minus 0.54, 0.40 plus/minus 0.65, 0.17 plus or minus 0.32; VCZ: 0.70 plus/minus 0.58, 0.29 plus/minus 0.22, 0.36 plus/minus 0.21. Pairwise comparisons of the MICs of AMB, ITZ and VCZ obtained in PYG, RPMI 1640 and M3 showed no significant differences except for AMB in PYG broth compared to those obtained in RPMI 1640 and M3 (p</=0.05). These results suggest that the susceptibility of A. fumigatus to AMB, ITZ and VCZ is similar in growth media currently used for susceptibility testing.

Journal Article↗

In vitro susceptibilities of Aspergillus species to voriconazole, itraconazole, and amphotericin B.

We studied the in vitro activity of voriconazole (VCZ) itraconazole (ITZ) and amphotericin B (AMB) against 216 clinical isolates of Aspergillus spp. (142 Aspergillus fumigatus and 74 nonfumigatus Aspergillus spp. isolates) using a broth macrodilution method. The MICs (microgram/mL) (mean, range) for A. fumigatus were: VCZ 0.88, 0.25-4; ITZ 0.54, 0.25-4; AMB 2.16, 0.5-8. MIC90s were: VCZ 2, ITZ 1, AMB 4. MICs for nonfumigatus Aspergillus spp. were: VCZ 1.57, 0.25-4; ITZ 1.74, 0.25-4; AMB 2.88, 0.5-8. MIC90s for this group were: VCZ 4, ITZ 4, AMB 4. We also studied the susceptibility to VCZ of 18 AMB-resistant (mean, MIC 6.0 micrograms/mL) and 28 ITZ-resistant (mean, MIC 13.28 micrograms/mL) A. fumigatus isolates selected in the laboratory. The mean MICs of VCZ were 0.59 microgram/mL for AMB-resistant and 1.32 micrograms/mL for ITZ-resistant isolates. Our study showed that VCZ and ITZ had comparable in vitro activity against the isolates studied, except against A. fumigatus, where the MIC of ITZ was lower. The azoles had better in vitro activity than AMB against A. fumigatus and non-fumigatus spp. The non-fumigatus Aspergillus spp. were less susceptible to all three antifungals evaluated. When tested against ITZ- or AMB-resistant A. fumigatus strains, VCZ retained good activity, showing only a modest rise in the MIC against ITZ-resistant strains.

Amphotericin B↗

Transseptal approach to aortography and carotid artery stenting in pulseless disease.

We report on a patient with pulseless disease (Takayasu's arteritis) in whom access to the central circulation by extremity arterial cannulation was not possible due to absent pulses in all four limbs. The transseptal approach was used for aortography, bilateral selective carotid angiography, and successful elective stent deployment in the right common carotid artery.

Adult↗

Management of neuroleptic malignant syndrome--a series of eight cases.

Neuroleptic Malignant Syndrome (NMS) is a rare and life threatening complication of treatment with Neuroleptic medication. Phenothiazine and butyrophenones are most frequently implicated in this syndrome even though there are case reports with other drugs. In this paper we describe the classical presentation of this syndrome in eight cases who had been on either a butyrophenone, a phenothiazine or a combination of these drugs. In addition some of our patients were also on either Lithium and/or Amitrytiline for control of depressive symptoms. Fever, muscule rigidity and elevated CPK are the important criteria for diagnosis and they were noted in all our patients. In addition four of our patients fulfilled five of the six minor criteria laid down by Levenson. Both Sinemet and Bromocriptine were found to be effective in the treatment of seven of the eight cases. However treatment with Dantroline sodium was associated with severe muscle wasting in one of our cases and the drug had to be discontinued. Two of our patients developed suspected myoglobinuria with dark coloured urine and progressive renal failure. One patient died after development of renal failure, pulmonary edema and hyperkalemia as a consequence of this disorders.

Adolescent↗

Toxic strep syndrome.

Group A beta-hemolytic streptococci are known to produce infections with protean manifestations. We report here a case of toxic streptococcal syndrome in a patient who presented with a multisystemic disease. Serological and bacteriological evidence strongly suggested an infection by Group A beta hemolytic streptococci.

Cefazolin↗