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Biomedical subjects

S Parveen

Publications and source records attributed to S Parveen.

At least 19 recordsLinked to original sources
PubMed2006

Geographical variation in antibiotic resistance profiles of Escherichia coli isolated from swine, poultry, beef and dairy cattle farm water retention ponds in Florida.

AIMS: The aim of this study was to assess geographical variation in multiple antibiotic resistance (MAR) profiles of livestock Escherichia coli as well as to evaluate the ability of MAR profiles to differentiate sources of faecal pollution. METHODS AND RESULTS: More than 2000 E. coli isolates were collected from water retention ponds and manure of swine, poultry, beef and dairy farms in south, central and north Florida, and analysed for MAR using nine antibiotics. There were significant differences in antibiotic resistance of E. coli by season and livestock type for more than one antibiotic, but regional differences were significant only for ampicillin. Over the three regions, discriminant analysis using MAR profiles correctly classified 27% of swine, 49% of poultry, 56% of beef and 51% of dairy isolates. CONCLUSIONS: Regional variations in MAR combined with moderate discrimination success suggest that MAR profiles of E. coli may only be marginally successful in identifying sources of faecal pollution. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrates the existence of regional and seasonal differences in MAR profiles as well as the limited ability of MAR profiles to discriminate among livestock sources.

Agriculture↗
PubMed2001

Antibodies against neural, nuclear, cytoskeletal, and streptococcal epitopes in children and adults with Tourette's syndrome, Sydenham's chorea, and autoimmune disorders.

BACKGROUND: Some cases of Tourette's syndrome (TS) are hypothesized to be caused by autoantibodies that develop in response to a preceding group A beta hemolytic streptococcal infection. METHODS: To test this hypothesis, we looked for the presence ot total and IgG antibodies against neural, nuclear, cytoskeletal and streptococcal epitopes using indirect immunofluorescent assays and Western blot techniques in three patient groups: TS (n = 81), SC (n = 27), and a group of autoimmune disorders (n = 52) and in normal controls (n = 67). Subjects were ranked after titrations of autoantibodies from 0 to 227 according to their level of immunoreactivity. RESULTS: TS patients had a significantly higher mean rank for total antineural and antinuclear antibodies, as well as antistreptolysin O titers. However, among children and adolescents, only the total antinuclear antibodies were increased in TS patients compared to age matched controls. Compared to SC patients, TS patients had a significantly lower mean rank for total and IgG class antineural antibodies, significantly lower IgG class anticytoskeletal antibodies, and a significantly higher rank for total antinuclear antibodies. Compared to a mixed group of autoimmune disorders, the TS patients had a significantly lower mean rank for total and IgG class antineural antibodies, total and IgG class antinuclear antibodies, IgG class anticytoskeletal antibodies, and a significantly higher rank for antistreptococcal antibodies. CONCLUSIONS: TS patients had significantly higher levels of total antineural and antinuclear antibodies than did controls. Their relation to IgG class antineural and antinuclear antibodies, markers for prior streptococcal infection, and other clinical characteristics, especially chronological age, was equivocal.

Adolescent↗
PubMed2001

Acetyl and butyrylcholinesterase-inhibiting triterpenoid alkaloids from Buxus papillosa.

Three triterpenoid alkaloids, buxakashmiramine [(20S)-20-dimethylamino-4',6'-dimethoxy-5'-hydroxybenzoylamino-3beta-methyl-buxan-31-ol] (1), buxakarachiamine [(20S)-20-dimethylamino-2'-hydroxy-3beta-methyl-3'-methyl-butanoylamino-9,10-seco-buxa-9(11), 10(19)-dien-31-ol] (2) and buxahejramine [(20S)-20-dimethylamino-2'-hydroxy-3beta-methyl-3'-methyl-pentanoylamino-9,10-seco-buxa-9(11), 10(19)-dien-31-ol] (3) were isolated from the leaves of Buxus papillosa. Four known bases, cycloprotobuxine-C (4), cyclovirobuxeine-A (5), cyclomicrophylline-A (6) and semperviraminol (7) were isolated for the first time from this species. Their structures were established through extensive spectroscopic studies. Most of these compounds exhibited anticholinesterase activity.

Acetylcholinesterase↗
PubMed2001

Phenotypic and genotypic characterization of human and nonhuman Escherichia coli.

Estuarine waters receive fecal pollution from a variety of sources, including humans and wildlife. Escherichia coli is one of several fecal coliform bacteria that inhabit the intestines of many warm-blooded animals that sometimes contaminate water. Its presence does not specifically implicate human fecal input, therefore it is necessary to differentiate contamination sources to accurately assess health risks. E. coli were isolated from human sources (HS) and nonhuman sources (NHS) in the Apalachicola National Estuarine Research Reserve and analyzed for fatty acid methyl ester (FAME), O-serogroup, and pulsed-field gel electrophoresis (PFGE) profiles. For FAME and PFGE analyses, there was no relationship between profile and isolate source. Human source PFGE profiles were less diverse than NHS isolates, and conversely for FAME. In contrast, O-serogrouping showed less diversity for HS vs. NHS isolates, and the predominant HS O-serogroups differed significantly (P < 0.01) from those of NHS isolates.

Animals↗
PubMed2000

Pathogenesis of infection by clinical and environmental strains of Vibrio vulnificus in iron-dextran-treated mice.

Vibrio vulnificus is an opportunistic pathogen that contaminates oysters harvested from the Gulf of Mexico. In humans with compromising conditions, especially excess levels of iron in plasma and tissues, consumption of contaminated seafood or exposure of wounds to contaminated water can lead to systemic infection and disfiguring skin infection with extremely high mortality. V. vulnificus-associated diseases are noted for the rapid replication of the bacteria in host tissues, with extensive tissue damage. In this study we examined the virulence attributes of three virulent clinical strains and three attenuated oyster or seawater isolates in mouse models of systemic disease. All six V. vulnificus strains caused identical skin lesions in subcutaneously (s.c.) inoculated iron dextran-treated mice in terms of numbers of recovered CFU and histopathology; however, the inocula required for identical frequency and magnitude of infection were at least 350-fold higher for the environmental strains. At lethal doses, all strains caused s. c. skin lesions with extensive edema, necrosis of proximate host cells, vasodilation, and as many as 10(8) CFU/g, especially in perivascular regions. These data suggest that the differences between these clinical and environmental strains may be related to growth in the host or susceptibility to host defenses. In non-iron dextran-treated mice, strains required 10(5)-fold-higher inocula to cause an identical disease process as with iron dextran treatment. These results demonstrate that s.c. inoculation of iron dextran-treated mice is a useful model for studying systemic disease caused by V. vulnificus.

Animals↗
PubMed2000

Serological response to immunization with tetanus toxoid.

A total of two hundred women were immunized with tetanus toxoid vaccine. Two batches of toxoid prepared at the Institute of Public Health (IPH), Dhaka and one batch of imported vaccines, were being used by the EPI in Bangladesh for immunization. Each hundred women were immunized by IPH and imported vaccine. Two human doses were given in one month interval. Blood samples from all the study subjects were collected on the day of 1st dose and one month after second dose. Both the preimmunized sera and the sera after vaccination were tested to determine the antibody titre against tetanus toxoid by the haemagglutination method. The preimmunized sera showed the presence of protective antibody in 50(25%) subjects who had the history of previous immunization. Including these initial antitoxin positive cases the seroconversions found among 95% and 96% of the study population respectively after immunization with IPH and imported toxoids, which were 93.05% and 94.87% when these 50 subjects were excluded. No significant difference (p = 1.0) was observed between the immunity of the subjects after receiving IPH and imported vaccine. Antibody titre of initial tetanus-antitoxin positive cases raised eight folds after getting more doses. The result gave fair indication of the antigenicity of all the toxoids used in the study.

Antigens, Bacterial↗
PubMed1999

Discriminant analysis of ribotype profiles of Escherichia coli for differentiating human and nonhuman sources of fecal pollution.

Estuarine waters receive fecal pollution from a variety of sources, including humans and wildlife. Escherichia coli is a ubiquitous bacterium in the intestines of warm-blooded animals and is used as an indicator of fecal pollution. However, its presence does not specifically differentiate sources of pollution. A total of 238 E. coli isolates from human sources (HS) and nonhuman sources (NHS) were collected from the Apalachicola National Estuarine Research Reserve, from associated sewage treatment plants, and directly from animals and tested for ribotype (RT) profile. HS and NHS isolates showed 41 and 61 RT profiles, respectively. At a similarity index of ca. 50%, HS and NHS isolates demonstrated four clusters, with the majority of HS and NHS isolates located in clusters C and D; isolates obtained directly from human and animal feces also could be grouped within these clusters. Discriminant analysis (DA) of RT profiles showed that 97% of the NHS isolates and 100% of the animal fecal isolates were correctly classified. The average rate of correct classification for HS and NHS isolates was 82%. We conclude that DA of RT profiles may be a useful method for identifying HS and NHS fecal pollution and may potentially facilitate management practices.

Animals↗
PubMed1998

Inwardly rectifying whole cell potassium current in human blood eosinophils.

1. Membrane currents were studied in single human blood eosinophils using the whole cell voltage clamp technique. The whole cell current-voltage relationship exhibited rectification about the membrane potential which followed the potassium equilibrium potential when [K+]o was raised. Elevation of [K+]o considerably potentiated inward current amplitude, and in some cells channel activity was discernible in the whole cell membrane current recordings. The single channel conductance was 24 +/- 1 pS ([K+]o, 100 mM; [K+]i, 140 mM), and eosinophils were found to have as few as three, and on average twenty, inward rectifier channels each. 2. The inward current was inhibited in a voltage-dependent manner by extracellular cations in order of potency Ba2+ > Cs+ > Na+. Intracellular acidification inhibited while alkalization augmented the inward current. Mg2+ contributed to rectification as dialysis with nominally Mg(2+)-free pipette solution was associated with an increase in the outward current during membrane polarization. 3. By reverse transcription-polymerase chain reaction (RT-PCR) using suitable primers on human eosinophils mRNA, an inward rectifier channel, Kir2.1, was identified, which is known from expression studies to have very similar properties to those found in this study. 4. Superoxide anion production or its stimulation by phorbol 12-myristate 13-acetate (PMA) was not significantly affected by depolarization with 140 mM [K+]o, or by 1 mM BaCl2. 5. It is concluded that the single channel currents and the whole cell current rectification observed in human blood eosinophils resulted from the presence of an inwardly rectifying potassium channel, probably Kir2.1.

Action Potentials↗
PubMed1998

Antibodies to Ro/La, Cenp-B, and snRNPs antigens in autoimmune hepatitis of North America versus Asia: patterns of immunofluorescence, ELISA reactivities, and HLA association.

To assess whether demography is one of the important factors determining antibody response to nuclear antigens [ANA: SSA-Ro (52K and 60K), SSB-La, snRNPs (A, 70K, B'/B), and Cenp-B], we investigated 95 and 47 sera of autoimmune hepatitis (AIH) from North America and Asia, respectively, by immunofluorescent (IF) and recombinant ELISA. Correlations among nuclear IF patterns, ELISA, and disease indices were analyzed. The frequency and titer of individual antibodies differed significantly between the groups. Patients with speckled patterns were younger in both regions and had higher aspartate aminotransferase levels only in North America. HLA-A1, B8, DQ2, and DR4 or DR3 or both in North America, and A2, B61, DQ7, and DR4 in Asia were predominant. In Asia, B61 correlated with anti-70K, and DQ7 correlated with antibodies to 52K, Cenp-B, and B'/B. In North America, A1, B8, DR3 haplotype, and DQ2 correlated with antibodies to A and 70K. Anti-B'/B and DR4 in North America, and A2 in Asia, were associated with concurrent immunologic disorder. Individual ANA clusters correlated with individual HLA in the demography, and different HLA alleles might determine disease expression as well as different ANA being produced in AIH.

Adult↗
PubMed1998

Inhibition of sCD23 and immunoglobulin E release from human B cells by a metalloproteinase inhibitor, GI 129471.

Soluble CD23 (sCD23) has been proposed to play an important role in the up-regulation of immunoglobulin E (IgE) synthesis. Production of sCD23 is dependent on the proteolytic cleavage of membrane CD23, but the protease(s) involved in this process remain unknown. Preliminary data, obtained by testing a panel of protease inhibitors, suggested that this enzyme may be a zinc-dependent metalloproteinase. Therefore, we investigated the effect of a standard hydroxamate-type Zn2+ metalloproteinase inhibitor (GI 129471) on both sCD23 and IgE release from human tonsillar B cells, stimulated with interleukin-4 (IL-4) and anti-CD40. Incubation of cells for 3 days with GI 129471 inhibited the production of sCD23 with an IC50 of 602 nm+/-3 nm (n=3), but by 14 days the activity of the compound against sCD23 had decreased by greater than threefold (IC50 2+/-0.26 microM; n=3). On the other hand, GI 129471 caused a potent inhibition of IgE production, with no apparent loss of activity over the culture period (14 days: IC50 250 nm+/-72 nm; n=3). Time-course studies showed that, despite loss of activity against sCD23, inhibition of sCD23 production early in the culture was able to cause a potent and long-lasting inhibitory effect on IgE. Furthermore, we also showed that the activity of GI 129471 is selective for IgE, as no effect was seen on immunoglobulin G1 (IgG1) or IgG4 production at test concentrations as high as 10 microM. These results support the hypothesis that metalloproteinases may be involved in the proteolytic cleavage of CD23 and subsequent regulation of IgE synthesis. Inhibition of the protease(s) responsible for such cleavage may be of value in the treatment of allergic disease.

B-Lymphocytes↗
PubMed1997

Antibodies to single-stranded and double-stranded DNA in antinuclear antibody-positive type 1-autoimmune hepatitis.

To determine the significance of antibodies to single-stranded (anti-ssDNA) and double-stranded DNA (anti-dsDNA) in antinuclear antibody (ANA)-positive type 1 autoimmune hepatitis, sera from 53 patients were tested by enzyme immunosorbent assay (ELISA) and indirect immunofluorescence using the Crithidia luciliae substrate. Anti-dsDNA were detected in 18 patients (34%) by ELISA and 12 patients (23%) by the Crithidia-based assay. Twenty patients with anti-dsDNA by either assay (38%) had higher serum levels of immunoglobulin G (3971 +/- 270 mg/dL vs. 3201 +/- 247 mg/dL, P = .05) than seronegative patients. They also had human leukocyte antigen (HLA) DR4 more commonly than other patients (83% vs. 41%, P = .006) and normal subjects (83% vs. 30%, P = .00007). In contrast to patients seropositive by the Crithidia-based assay, those seropositive by ELISA failed corticosteroid therapy more commonly (24% vs. 3%, P = .04). Anti-ssDNA were found in 45 patients (85%) and they did not distinguish patients with different clinical features or outcomes. We conclude that anti-dsDNA are common in ANA-positive type 1 autoimmune hepatitis. HLA DR4 is associated with their production, and seropositivity by ELISA characterizes patients who have a poorer immediate response to corticosteroid treatment. Anti-ssDNA are common but they do not have important clinical implications.

Animals↗
PubMed1997

Frequency and significance of antibodies to P450IID6 protein in Japanese patients with chronic hepatitis C.

BACKGROUND/AIMS: The aims of the current study were to assess the frequency and the significance of antibodies to cytochrome P450IID6 protein (anti-P450IID6) in various diseases among Japanese patients. METHODS: Sera from 541 patients were tested by indirect immunofluorescence, and the specificity of anti-P450IID6 was ascertained by either enzyme immunoassay (ELISA) or Western blot using recombinant antigen or rat liver microsomes. RESULTS: Anti-P450IID6 was found in only 6 of 235 patients (2.6%) with chronic active hepatitis (CAH) positive for hepatitis C virus (HCV) antibody and quantitative HCV-RNA with genotypes II and IV. The predominant epitopes on immunoblots were 66 and 50KD, a 10KD band being the newly underfined microsomal antigen. Even in the patients negative for autoantibodies to nuclear antigens (ANA) by routine indirect immunofluorescence test, various ANA were detected by the newly developed recombinant ELISA. These patients were younger, with lower gamma-globulin and IgG levels than patients with autoimmune hepatitis. Three of five patients with anti-P450IID6 responded well to interferon therapy and one received prednisone when interferon was ineffective. Interestingly, only this patient was diagnosed as definite autoimmune hepatitis according to the criteria proposed by the International Autoimmune Hepatitis Group (IAHG). The other five patients who did not satisfy the IAHG criteria might be considered as CAH-C with autoimmune features. No autoimmune hepatitis patients positive for anti-P450IID6 were identified in the current study, indicating that the variant is very rare in Japan. CONCLUSIONS: Anti-P450IID6 in CAH-C patients in Japan is not as rare as expected. Anti-P450IID6 among Japanese patients has uncertain significance and precludes further characterization of CAH-C with autoimmune features, which might require interferon therapy.

Adult↗
PubMed1997

Antibodies to P450IID6, SLA, PDH-E2 and BCKD-E2 in Japanese patients with chronic hepatitis.

Auto-antibodies specific to various antigens in chronic hepatitis (CH) have been detected but their specificities and implications were uncertain. The aims of the present study were to investigate the frequency and the significance of seropositivity of antibodies to P450IID6 or liver/kidney microsome 1 (LKM1), soluble liver antigen (SLA), pyruvate dehydrogenase (PDH) and branched-chain keto acid dehydrogenase (BCKD) in 188 Japanese patients with different forms of CH by western blot or enzyme immunoassay (EIA). Anti-LKM1 was also measured by indirect immunofluorescent test. Anti-P450IID6 was found in 6/188 (3.2%) CH patients including 5/104 (4.8%) with hepatitis C virus (C) infection and 1/12 (8.3%) CH-C patients with antibodies to nuclear and smooth muscle antigens and hypergammaglobulinaemia (> 2.5 g/dL). This patient was the only one diagnosed with autoimmune hepatitis (AIH). All CH patients with hepatitis B (B), hepatitis non-B non-C (NBNC) and AIH were seronegative for anti-LKM1. Antibodies to soluble liver antigen were found in two of 188 (1%) patients, one with AIH and one with CH-B. Anti-BCKD-E2 but not anti-PDH-E2 was found in four patients (2.5%), one with AIH, two with CH-C, and one with NBNC. There was no obvious difference in age, sex ratio and laboratory findings in patients with or without anti-SLA and anti-BCKD-E2. Antibodies to P450IID6, SLA, PDH-E2 and BCKD-E2 are uncommon in adult CH-C, CH-B, CH-NBNC and AIH patients in Japan. Some of these patients positive for auto-antibodies appear to have autoimmune features and might require a careful follow up. The heterogeneity of these antibodies in CH preclude further justification for subtyping of AIH by the presence of the distinct auto-antibodies.

3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)↗
PubMed1997

Association of multiple-antibiotic-resistance profiles with point and nonpoint sources of Escherichia coli in Apalachicola Bay.

A total of 765 Escherichia coli isolates from point and nonpoint sources were collected from the Apalachicola National Estuarine Research Reserve, and their multiple-antibiotic-resistance (MAR) profiles were determined with 10 antibiotics. E. coli isolates from point sources showed significantly greater resistance (P < 0.05) to antibiotics and higher MAR indices than isolates from nonpoint sources. Specifically, 65 different resistance patterns were observed among point source isolates, compared to 32 among nonpoint source isolates. Examples of this contrast in MAR profiles included percentages of isolates with resistance to chlortetracycline-sulfathiazole of 33.7% and to chlortetracycline-penicillin G-sulfathiazole of 14.5% for point source isolates versus 15.4 and 1.7%, respectively, for nonpoint source isolates. MAR profile homology, based on coefficient similarity, showed that isolates from point sources were markedly more diverse than isolates from nonpoint sources. Seven clusters were observed among point source isolates, with a coefficient value of approximately 1.8. In contrast, only four clusters were observed among nonpoint source isolates. Covariance matrices of data displayed six very distinct foci representing nonpoint source E. coli isolates. Importantly, E. coli isolates obtained directly from human and animal feces also clustered among point and nonpoint sources, respectively. We conclude that E. coli MAR profiles were associated with point and nonpoint sources of pollution within Apalachicola Bay and that this method may be useful in facilitating management of other estuaries.

Animals↗