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Biomedical subjects

R Gupta

Publications and source records attributed to R Gupta.

At least 307 records · Page 17Linked to original sources
PubMed1999

Cost effectiveness analysis of antenatal HIV screening in United Kingdom.

OBJECTIVE: To assess the cost effectiveness of universal antenatal HIV screening compared with selective screening in the United Kingdom. DESIGN: Incremental cost effectiveness analysis relating additional costs of screening to life years gained. Maternal and paediatric costs and life years were combined. SETTING: United Kingdom. MAIN OUTCOME MEASURES: Number of districts for which universal screening would be cost effective compared with selective screening under various conditions. RESULTS: On base case assumptions, a new diagnosis of a pregnant woman with HIV results in a gain of 6.392 life years and additional expenditure of 14 833 pounds. If decision makers are prepared to pay up to 10 000 pounds an additional life year, this would imply a net benefit of 49 090 pounds (range 12 300 pounds- 59 000 pounds), which would be available to detect each additional infected woman in an antenatal screening programme. In London, universal antenatal screening would be cost effective compared with a selective screening under any reasonable assumptions about screening costs. Outside London, universal screening with uptake above 90% would be cost effective with a 0.60 pounds HIV antibody test cost and up to 3.5 minutes for pretest discussion. Cost effectiveness of universal testing is lower if selective testing can achieve high uptake among those at higher risk. A universal strategy with only 50% uptake may not be less cost effective in low prevalence districts and may cost more and be less effective than a well run selective strategy. CONCLUSIONS: Universal screening with pretest discussion should be adopted throughout the United Kingdom as part of routine antenatal care as long as test costs can be kept low and uptake high.

Anti-HIV Agents↗
PubMed1999

Nucleotide excision repair in a constitutive and inducible gene of a yeast minichromosome in intact cells.

Repair of UV-induced cyclobutane pyrimidine dimers (CPDs) was measured in a yeast minichromosome, having a galactose-inducible GAL1:URA3 fusion gene, a constitutively expressed HIS3 gene and varied regions of chromatin structure. Transcription of GAL1:URA3 increased >150-fold, while HIS3 expression decreased <2-fold when cells were switched from glucose to galactose medium. Following galactose induction, four nucleosomes were displaced or rearranged in the GAL3-GAL10 region. However, no change in nucleosome arrangement was observed in other regions of the minichromosome following induction, indicating that only a few plasmid molecules actively transcribe at any one time. Repair at 269 cis-syn CPD sites revealed moderate preferential repair of the transcribed strand of GAL1:URA3 in galactose, consistent with transcription-coupled repair in a fraction of these genes. Many sites upstream of the transcription start site in the transcribed strand were also repaired faster upon induction. There is remarkable repair heterogeneity in the HIS3 gene and preferential repair is seen only in a short sequence immediately downstream of the transcription start site. Finally, a mild correlation of repair heterogeneity with nucleosome positions was observed in the transcribed strand of the inactive GAL1:URA3 gene and this correlation was abolished upon galactose induction.

Chromatin↗
PubMed1999

Costs and benefits to the mother of antenatal HIV testing: estimates from simulation modelling.

OBJECTIVE: To assess the health service costs and benefits for the woman of an earlier HIV diagnosis as a result of antenatal HIV testing. DESIGN: A model of maternal disease progression was developed based on the rate of decline in CD4 cell counts and applied to two matched simulated cohorts of women with identical initial CD4 cell levels and decline rates but whose HIV diagnosis occurred at different times as a result of antenatal HIV testing. UK data on CD4 cell count at HIV diagnosis and annual health service costs of care excluding antiretroviral therapy (ART) incurred at defined states of CD4 cell count were taken from published UK data. Costs of triple ART were added and effectiveness modelled by retarding the rate of CD4 cell count decline. Discounting costs at 6% and life-years at 2% per year, the additional costs per life-year gained by screening were calculated. Uncertainty was explored using sensitivity analysis. RESULTS: Costs per life-year gained by antenatal diagnosis of women were pound sterling 51258 ($76887) assuming untested women were diagnosed a median of 20.4 months later than tested women, ART was initiated at a CD4 cell count of 350x10(6) cells/l and ART efficacy retarded decline in CD4 cell counts by 40% for life. Sensitivity analyses showed results were most sensitive to the assumed efficacy of lifetime ART and time assumed to HIV diagnosis for women not tested in pregnancy. CONCLUSION: This model provides a way of estimating the additional costs and benefits of future care for the woman resulting from an earlier HIV diagnosis through antenatal testing. These should be included with the paediatric costs averted and life-years gained from interventions to reduce mother-to-child transmission in order to evaluate the cost-effectiveness of antenatal screening in different populations and settings.

CD4 Lymphocyte Count↗
PubMed1999

Characterization of a single-copy Arabidopsis gene encoding a protein showing limited similarity to the N-terminus of the mammalian clathrin-assembly protein AP180.

The Arabidopsis 194 gene encoding a protein containing sequence similarity to an N-terminal region of the clathrin-assembly protein AP180 has been identified in a 4.9-kb region of genomic DNA upstream of the gene encoding the high mobility group protein HMG-I/Y. The gene consists of 12 exons and 11 introns, identified by comparison with partial cDNAs and using the NetPlantGene programme, and encodes a protein of 584 amino acid residues. The C-terminal region of the protein contains 8 tandem repeats of a 17-amino-acid-residue sequence. Southern blot analysis of genomic DNA from Columbia and Landsberg ecotypes of Arabidopsis indicates the presence of a single copy of the 194 gene. The 194 gene is expressed in all organs of Arabidopsis including roots, stems, leaves, flowers, and developing siliques, as determined by northern blot analysis.

Adaptor Proteins, Vesicular Transport↗
PubMed1999

Protein stability: functional dependence of denaturational Gibbs energy on urea concentration.

Determination of protein stability (DeltaGD0) from the conformational transition curve induced by a chemical denaturant is problematic; for different values of DeltaGD0, the value of the Gibbs energy change on denaturation (DeltaGD) in the absence of the denaturant are obtained when different extrapolation methods are used to analyze the same set of (DeltaGD, denaturant concentration) data [Pace, C. N. (1986) Methods Enzymol. 131, 266-280]. We propose a practical solution to this problem and use it to test the dependence of DeltaGD of lysozyme, ribonuclease-A, and cytochrome-c on [urea], the molar urea concentration. This method employs (i) measurements of the urea-induced denaturation in the presence of different guanidine hydrochloride (GdnHCl) concentrations which by themselves disrupt the native state of the protein at the same temperature and pH at which denaturations by urea and GdnHCl have been measured; (ii) estimation of DeltaGDcor, the value of DeltaGD corrected for the effect of GdnHCl on the urea-induced denaturation using the relation (DeltaGDcor = DeltaGD + mg [GdnHCl] = DeltaGD0 - mu [urea], where mg and mu are the dependencies of DeltaGD on [GdnHCl] and [urea], respectively) whose parameters are all determined from experimental denaturation data; and (iii) mapping of DeltaGDcor onto the DeltaGD versus [urea] plot obtained in the absence of GdnHCl. Our results convincingly show that (i) [urea] dependence of DeltaGD of each protein is linear over the full concentration range; (ii) the effect of urea and GdnHCl on protein denaturation is additive; and (iii) KCl affects the urea-induced denaturation if the native protein contains charge-charge interaction and/or anion binding site, in a manner which is consistent with the crystal structure data.

Animals↗
PubMed1999

Selective versus universal antenatal HIV testing: epidemiological and implementational factors in policy choice.

OBJECTIVE: To develop an epidemiological basis for economic analyses of selective and universal antenatal screening strategies, and to apply it to the UK. METHODS: The prevalence of higher-risk women and the prevalence of undiagnosed infection within groups of high-risk and low-risk women was estimated from surveillance and survey data. The numbers of women tested and the numbers of infected women who would be identified by universal and selective strategies were then calculated under a range of assumptions about the identification of higher-risk women and acceptance of testing. RESULTS: In higher-risk women estimated prevalence of undiagnosed infection was between 0.06% and 2.8%, comparing well with independent estimates. In low-risk women, estimates ranged from 0.014% in London to 0.002% in the rest of the UK. If uptake among the high-risk women was the same in selective and universal strategies, universal testing would entail testing between 7100 (London) and 50000 (rest of England) additional women to detect an additional case. However, if selective screening identified only 60% of those at high risk and achieved only 60% acceptance compared with a universal programme, then universal screening would require only 1150 additional women to identify one additional case in London, compared to 6470 in Scotland and 13140 in the rest of the UK. CONCLUSIONS: Overall prevalence does not form an adequate basis for determining screening strategy. Instead, universal screening can be justified either because the prevalence of HIV in the low-risk group is sufficiently high, or because it achieves sufficiently higher uptake relative to selective screening among those at higher risk.

Female↗
PubMed1999

O-GLYCBASE version 4.0: a revised database of O-glycosylated proteins.

O-GLYCBASE is a database of glycoproteins with O-linked glycosylation sites. Entries with at least one experimentally verified O-glycosylation site have been compiled from protein sequence databases and literature. Each entry contains information about the glycan involved, the species, sequence, a literature reference and http-linked cross-references to other databases. Version 4.0 contains 179 protein entries, an approximate 15% increase over the last version. Sequence logos representing the acceptor specificity patterns for GalNAc, GlcNAc, mannosyl and xylosyl transferases are shown. The O-GLYCBASE database is available through the WWW at http://www.cbs.dtu.dk/databases/OGLYCBASE/

Acetylgalactosamine↗
PubMed1999

A PstI polymorphism detects the mutation of serine128 to arginine in CD 62E gene - a risk factor for coronary artery disease.

The mutation of serine128 to arginine in the CD 62E gene is a risk factor for coronary artery disease (CAD). We designed a new method to detect this mutation based on the observation that it is due to a transversion of nucleotide A561 to C, which abolishes a PstI recognition site. Two alleles, A and C, are easily typed when genomic DNA is amplified by PCR, digested with PstI, and separated on agarose gels. Among 153 people who underwent an elective, diagnostic arteriography in Johns Hopkins Hospital, we found that the C allele accounts for 19.5% in angiographically documented CAD patients (n = 82). It is significantly higher than the 10.6% frequency observed in normal controls (n = 71, p < 0.05). It indicates that the C allele is associated with early-onset CAD. This new method should facilitate the screening of this mutant allele in large populations and contribute to the understanding of the molecular mechanism underlying the association of this mutation with CAD.

Alleles↗
PubMed1999

Sorption and desorption of cobalt by Oscillatoria anguistissima.

Oscillatoria anguistissima rapidly adsorbs appreciable amounts of cobalt from the aqueous solutions within 15 min of initial contact with the metal solution. O. anguistissima showed a high sequestration of cobalt at low equilibrium concentrations, and it followed the Freundlich model of adsorption. The adsorption is a strongly pH-dependent and temperature-independent phenomenon. The presence of Mg2+ and Ca2+ (100-200 ppm) resulted in decline in Co2+ adsorption capacity of Oscillatoria biomass. Sulphate and nitrate (0. 75-10 mM) drastically reduced the extent of Co2+ biosorption. The biosorption of cobalt is an ion-exchange process as the Co2+ binding was accompanied by release of a large amounts of Mg2+ ions. Na2CO3 (1.0 mM) resulted in about 76% desorption of Co2+ from the loaded biomass.

Adsorption↗
PubMed1999

Frequency of occurrence and antimicrobial susceptibility of bacterial pathogens associated with skin and soft tissue infections during 1997 from an International Surveillance Programme. SENTRY Participants Group.

The SENTRY Antimicrobial Surveillance Programme was established to provide a coordinated, standardised, international surveillance on antimicrobial resistance. In one part of the programme, isolates from skin and soft tissue infections sent from 20 hospitals in 12 different European countries were investigated in the European coordinating centre. Of 1013 isolates, Staphylococcus aureus and Pseudomonas aeruginosa were the most significant species, constituting almost 50% of the referred isolates. Methicillin resistance in Staphylococcus aureus averaged 22% across Europe, only slightly less than that in isolates derived from blood. Less than 5% of the enterococcal isolates were resistant to vancomycin. Piperacillin/tazobactam was the most active penicillin-derived beta-lactam compound against Pseudomonas aeruginosa, inhibiting 91.3% of the isolates, while ceftazidime and cefepime were the most active cephalosporins, inhibiting 85.8% and 80.3% of the isolates, respectively. Putative extended-spectrum beta-lactamase production was not detected in Escherichia coli and was found in only 5.1% of the Klebsiella pneumoniae isolates. In general, strains of the family Enterobacteriaceae remained mostly susceptible to carbapenems, cefepime, and amikacin.

Anti-Bacterial Agents↗
PubMed1999

Expectant management of haemoperitoneum.

Nonoperative management was successful in 81 of the 90 patients including two patients with penetrating injury. Nine patients were operated on after an initial period of observation, eight because of continued bleeding and one because of features of peritonitis. There were four deaths. These were due to multisystem injuries and not directly related to haemoperitoneum alone. Nonoperative management is a relatively safe and effective method in management of selected cases of haemoperitoneum.

Abdominal Injuries↗
PubMed1999

Allergens of Curvularia lunata during cultivation in different media.

BACKGROUND: Despite enormous efforts toward the standardization of fungal extracts, only a few extracts have been characterized that are relevant for the diagnosis and immunotherapy of allergy-associated disorders. OBJECTIVE: The goal of this study was to determine the optimum growth condition of Curvularia lunata, an important fungal allergen for quality raw material, and to analyze the C lunata extract for IgE- and IgG-binding proteins. METHODS: C lunata was grown in synthetic (Czapeck Dox medium), semisynthetic (Sabouraud's broth [SB]), and natural media (potato dextrose [PD]) for different periods of time. The extracts were probed for allergenic and antigenic activity, with pooled patient sera and polyclonal antibodies raised against C lunata by means of ELISAs, immunoblots (in vitro), and intradermal tests (in vivo). RESULTS: The growth of C lunata was better in semisynthetic media (ie, SB) compared with other types of media. Dry weight and protein content was maximum in the 7-day culture of SB. ELISA with pooled sera from C lunata-sensitive patients exhibited that cultures grown in SB for 11 to 13 days and PD plus 1.0% agar for 5 days were the most potent. Intradermal tests with 11- to 13-day SB culture extract showed maximum skin reactivity in allergy patients. Immunoblots with patient sera showed 10 to 14 IgE-binding proteins in 5- to 15-day SB cultures. Analysis of 5- to 15-day SB extract with rabbit sera showed 10 to 16 IgG-binding proteins. CONCLUSIONS: The extract from 11- to 13-day SB cultures were most biologically potent (intradermal tests) and showed high antigenic and allergenic reactivity (ELISA and immunoblot). The addition of yeast extract did not affect the dry weight and protein content of the C lunata extract. Furthermore, addition of agar in PD medium increases the dry weight and protein content of the fungal mat. Synthetic media was not suitable for mass cultivation of C lunata.

Allergens↗