Biomedical subjects

A Taylor

Publications and source records attributed to A Taylor.

At least 127 records · Page 7Linked to original sources

PubMed2001

Age-specific distribution of serum prostate-specific antigen in a community-based study of African-American men.

OBJECTIVES: Previous studies have observed higher age-specific serum prostate-specific antigen (PSA) values in African-American (AA) men without prostate cancer compared to white men, leading some to recommend race-specific PSA reference ranges for the early detection of prostate cancer. The primary objective of the Flint Men's Health Study was to determine age-specific PSA reference values in a community-based sample of AA men, aged 40 to 79 years. METHODS: A probability sample of 943 AA men was selected from households in Genesee County, Michigan. Men without a prior history of prostate cancer/surgery were invited to participate in a prostate cancer screening protocol, consisting of measurement of serum total PSA, free/total PSA ratio, and digital rectal examination. Sextant biopsies were recommended, based on total PSA greater than 4.0 ng/mL and/or an abnormal digital rectal examination. RESULTS: From the sample of 943 men, 732 were eligible, 432 had blood drawn for PSA testing, and 374 completed all phases of the clinical examination. The 95th percentile PSA values were estimated to range from 2.36 ng/mL for men in the fifth decade to 5.59 ng/mL for men in the eighth decade. The 95th percentile values for age-specific PSA were comparable to those observed in a similar study of white men in Olmsted County, Minnesota. The median and 5th percentile values for free/total PSA did not vary significantly across age. CONCLUSIONS: The minor differences in PSA reference ranges between AA and white men may not be of sufficient magnitude to recommend the use of race-specific PSA reference ranges for screening.

Adult↗

PubMed2001

2001 assessment of nutritional influences on risk for cataract.

It is clear that oxidative stress is associated with compromises to the lens. Recent literature indicates that antioxidants may ameliorate that risk and may actually decrease risk for cataract. This article will briefly review the etiology of cataract. It will also review the epidemiologic information with emphasis on roles for vitamins C and E and carotenoids. More thorough recent reviews are available.

Aging↗

PubMed2001

Biodistribution and renal excretion of isomers of the cationic tracer, (99m)Tc diaminocyclohexane (DACH): biodistribution of cationic renal tracers.

The buildup of organic anions in the plasma in the uremic state can competitively inhibit the tubular extraction of para-aminohippurate or (131)I ortho-iodohippurate (OIH) and lead to spuriously low measurements of effective renal plasma flow (ERPF). This problem can be circumvented by the use of cationic tracers. The cationic renal tracer, (99m)Tc labeled diaminocyclohexane ((99m)Tc DACH), has a clearance of 80% of OIH in mice but its clearance in humans is relatively low, only 30% of OIH. The (99m)Tc DACH isomer(s) used in prior studies, however, was not clearly defined and may have consisted of a single isomer or a combination of isomers. Since the anionic isomers of some (99m)Tc renal tracers have been shown to have widely different clearances, the biodistribution and urine excretion of the (99m)Tc cis-, trans-S,S, trans-R,R and +/-trans-DACH isomers were compared in Sprague-Dawley rats at 10 minutes and 60 minutes postinjection to determine if one of the (99m)Tc DACH isomers may be a significantly better renal tracer than the others. The red cell binding of (99m)Tc +/- trans-DACH was also determined. All of the isomers showed a high degree of specificity for the kidney with minimal secretion into the gastrointestinal tract. Urine excretion of the 4 tracers, however, was only 38-48% that of OIH at 10 minutes and 66-84% that of OIH at 60 minutes. Red cell binding was 6.9%. Cationic renal tracers have the potential to provide a more accurate measurement of ERPF than anionic tracers. Based on the animal data, however, it is unlikely that any of the (99m)Tc DACH isomers will have a substantially higher clearance in humans than the form of (99m)Tc DACH originally tested. Development of alternative cationic renal tracers is warranted.

Animals↗

PubMed2001

Adolescent psychological problems, partnership transitions and adult mental health: an investigation of selection effects.

BACKGROUND: Marital status is a strong correlate of psychiatric morbidity in adulthood, but debate continues on how far this association reflects causal influences or selection effects based on prior psychological characteristics. METHOD: Prospective data from the National Child Development Study were used to examine effects of adolescent emotional and behavioural problems on transitions into and out of first partnerships, and their implications for psychiatric morbidity at age 33. RESULTS: Emotional and behavioural problems in adolescence showed systematic links with early partnership transitions (age at partnership formation, type of first partnership, and risks of first partnership breakdown). More detailed tests suggested that these effects only accounted for a modest proportion of the associations between partnership status and psychiatric morbidity at age 33. CONCLUSIONS: In a non-referred community sample selection effects associated with adolescent emotional and behavioural problems appear to play only a modest role in links between partnership status and adult mental health.

Adolescent↗

PubMed2001

Prevalence of antibodies to hepatitis C virus, HIV and human T-cell leukaemia/lymphoma viruses in injecting drug users in Tayside, Scotland, 1993-7.

The prevalence of blood-borne viruses in injecting drug users (IDUs) in Tayside, Scotland was determined by testing serum samples from IDUs who underwent attributable HIV antibody testing during 1993-7. The prevalence of antibodies to HIV was 29/802, (3.6%); to hepatitis C virus (HCV) 451/691, (65.3%); and to human T-cell leukaemia/lymphoma viruses type 1 and 2 (HTLV) 0/679, (0.0%). The prevalence of HIV and HCV antibodies were higher in subjects over the age of 25 (P = 0.03 and P = 0.001, respectively). During 1993-7 the prevalence of HCV fell only in younger female IDUs (P < 0.01). HIV prevalence has declined dramatically since 1985, when a rate of 40% was recorded in similar populations. Harm reduction measures have failed to control HCV the spread of infection among IDUs in Tayside, as indicated by the high proportion of antibody positive IDUs, particularly males under the age of 25. Future studies should address the nature and effective reduction of continuing risk taking among IDUs in Tayside.

Adolescent↗

PubMed2001

In vitro induction of CD25+ CD4+ regulatory T cells by the neuropeptide alpha-melanocyte stimulating hormone (alpha-MSH).

Recently, we have found that the neuropeptide alpha-melanocyte stimulating hormone (alpha-MSH) not only suppresses IFN-gamma production, but also induces TGF-beta1 production by activated effector T cells. These alpha-MSH- treated effector T cells function as regulatory T cells in that they suppress IFN-gamma production and hypersensitivity mediated by other effector T cells. Experimental autoimmune uveoretinitis (EAU) was suppressed in its severity and incidence in mice that were injected with primed T cells activated in vitro by APC and antigen in the presence of alpha-MSH. Moreover, it appeared that alpha-MSH had converted a population of effector T cells polarized to mediate hypersensitivity into a population of T cells that now mediated immunoregulation. To characterize these alpha-MSH- treated T cells, primed T cells were TCR-stimulated in the presence of alpha-MSH in vitro and their lymphokine profile was examined. Such effector T cells displayed enhanced levels of TGF-beta1 production and no IFN-gamma or IL-10, with IL-4 levels remaining unchanged in comparison with inactivated T cells. In addition, if soluble TGF-beta receptor II was added to cocultures of alpha-MSH-treated T cells and activated Th1 cells, the alpha-MSH-treated T cells could not suppress IFN-gamma production by the Th1 cells. These results suggest that alpha-MSH induces T cells with a regulatory lymphokine pattern, and that through their production of TGF-beta1 these cells suppress other effector T cells. Examination of the alpha-MSH-treated T cells showed that alpha-MSH did not alter the phosphorylation of CD3 molecules following TCR engagement. Primed T cells express the melanocortin 5 receptor (MC5r), a receptor that is linked to an intracellular signalling pathway shared by other cytokine receptors. Blocking the receptor with antibody prevented alpha-MSH from suppressing IFN-gamma production by the activated regulatory T cells, suggesting that alpha-MSH immunoregulation is through the MC5r on primed T cells. Surface staining and cell sorting of the alpha-MSH- treated primed T cells showed that the regulatory T cells are CD25+ CD4+ T cells. From these results we find that alpha-MSH can mediate the induction of CD25+ CD4+ regulatory T cells. These regulatory T cells require specific antigen for activation, but through non-specific TGF-beta1-mediated mechanisms they can suppress other effector T cells.

Animals↗

PubMed2001

A method to detect the incidence of hepatitis C infection among injecting drug users in Glasgow 1993-98.

OBJECTIVES: To determine the incidence of HCV infection in a selected population of Glasgow injectors during the mid-1990s, using a retrospective cohort design. METHODS: Unlinked anonymous anti-HCV testing was undertaken on serum residues collected from injecting drug users (IDUs) having two or more voluntary named HIV tests between 1993 and 1998. RESULTS: Seventy-seven percent (164/212) of IDUs had detectable HCV antibody in their first specimen collected. Of the 44 IDUs who were initially HCV seronegative and had a subsequent specimen available for testing, 11 (25%) seroconverted, giving an estimated incidence of 28.4 per 100 person-years (95% CI 15.7-51.2); the incidence of infection was greatest amongst older males. CONCLUSION: This study provides evidence of continuing transmission of HCV among Glasgow IDUs during an era of interventions to prevent the spread of bloodborne infections in this population and demonstrates the application of the unlinked anonymous testing approach to gauge incidence rather than prevalence of infection.

Adult↗

PubMed2001

Identification of functionally variant MDR1 alleles among European Americans and African Americans.

MDR1 (P-glycoprotein) is an important factor in the disposition of many drugs, and the involved processes often exhibit considerable interindividual variability that may be genetically determined. Single-strand conformational polymorphism analysis and direct sequencing of exonic MDR1 deoxyribonucleic acid from 37 healthy European American and 23 healthy African American subjects identified 10 single nucleotide polymorphisms (SNPs), including 6 nonsynonymous variants, occurring in various allelic combinations. Population frequencies of the 15 identified alleles varied according to racial background. Two synonymous SNPs (C1236T in exon 12 and C3435T in exon 26) and a nonsynonymous SNP (G2677T, Ala893Ser) in exon 21 were found to be linked (MDR1*2 ) and occurred in 62% of European Americans and 13% of African Americans. In vitro expression of MDR1 encoding Ala893 (MDR1*1 ) or a site-directed Ser893 mutation (MDR1*2 ) indicated enhanced efflux of digoxin by cells expressing the MDR1-Ser893 variant. In vivo functional relevance of this SNP was assessed with the known P-glycoprotein drug substrate fexofenadine as a probe of the transporter's activity. In humans, MDR1*1 and MDR1*2 variants were associated with differences in fexofenadine levels, consistent with the in vitro data, with the area under the plasma level-time curve being almost 40% greater in the *1/*1 genotype compared with the *2/*2 and the *1/*2 heterozygotes having an intermediate value, suggesting enhanced in vivo P-glycoprotein activity among subjects with the MDR1*2 allele. Thus allelic variation in MDR1 is more common than previously recognized and involves multiple SNPs whose allelic frequencies vary between populations, and some of these SNPs are associated with altered P-glycoprotein function.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2001

Discrimination between individual humans by domestic fowl (Gallus gallus domesticus).

1. We demonstrate that Barred-Rock and Isa-Brown hens can discriminate between the presence of 2 different humans and use this information as a cue for whether or not to make an operant response. 2. This demonstration in domestic fowl, the first of its kind in any avian subject, is consistent with a growing body of evidence that many species, including agricultural animals, are surprisingly adept at differentiating between humans. 3. Such a discriminative ability carries considerable implications for issues related to husbandry, production and welfare.

Animal Husbandry↗

PubMed2001

Trends in HCV prevalence among injecting drug users in Glasgow and Edinburgh during the era of needle/syringe exchange.

In 1998, we reported that anti-HCV prevalence among injectors from Glasgow had declined between 1990 and 1995. We set out to ascertain if the anti-HCV prevalence among injectors from Edinburgh had declined similarly during this period and if there had been any trend in prevalence among injectors from both cities since 1995. Residual sera from both cities' injecting drug users who had undergone named HIV testing were identified, linked to age band and gender information and tested anonymously for anti-HCV. Among Edinburgh's injectors, significant (p < 0.0001) decreases in anti-HCV prevalence from 69% (1989/90) to 13% (1997) and from 80% (1989/90) to 54% (1997) were seen in those aged < 25 y and > or = 25 y, respectively. Among Glasgow's injectors, a significant (p < 0.0001) decrease in prevalence from 91% (1990) to 43% (1997) was seen only among those aged < 25 y. Of both cities' 15-19 y olds, sampled during 1995-97, 17% (24/139) were anti-HCV-positive. The findings suggest that the incidence of HCV among young injectors continued to decrease during the 1990s--the era of needle/syringe exchange and other interventions--but is still too high. Further investigative and preventive work is required.

Adult↗

PubMed2001

The new MRCOG Objective Structured Clinical Examination--the examiners evaluation.

Following criticism of the clinical and viva sections of the previous Part II MRCOG examination, the Royal College of Obstetricians and Gynaecologists (RCOG) introduced an objective structured clinical examination (OSCE) in November 1998. This replaced the previous clinical and viva voce sections and was designed to allow a fairer, more reliable and more reproducible method of candidate assessment. We set out to document the examiners' response to the first MRCOG Part II OSCE and to evaluate their assessment of the new format compared to the old. We conducted a retrospective survey of all 76 examiners involved in the new style OSCE format. A questionnaire was posted to all examiners and a further questionnaire was sent out to the initial non-responders. The questionnaire was designed to determine whether or not examiners had examined for the MRCOG Part II before and if so to evaluate their assessment of the new format compared to the old. All examiners were then asked to score each OSCE station. The score represented the examiners view of the station's ability to assess the clinical skill that it had been designed to test. Median scores were determined for each question. A space was provided for general comments. Seventy-two of 76 examiners returned their questionnaires (two were excluded), a 95% response rate. Seventy-eight per cent of examiners had examined before and considered the standard of the exam to be comparable with the old format, a median score of 3 (range 1-5). In addition they found the OSCEs to be a much fairer method of candidate assessment, median score 4 (range 1-5). The majority of median scores relating to OSCE stations were 4 and 5, suggesting that examiners felt the stations assessed the candidates, clinical skills adequately. Sixty-eight of 70 (97%) examiners felt the new format should remain and 57 of 70 (81%) felt it would be suitable for adoption by other specialities. The first MRCOG Part II OSCE was generally well received by the examiners and was an organisational success. Our survey of examiners revealed that the new format was considered to be of the same standard as previous examinations, but that the new format was perceived to be much fairer. The majority of OSCE stations adequately tested the clinical skills they were designed to assess. With ongoing evaluation and development it is anticipated that this proportion will increase. The success of the new format suggests that OSCEs will remain as the final clinical examination for postgraduate obstetrics and gynaecology.

Journal Article↗

PubMed2001

A prospective controlled study of the effect of intramural uterine fibroids on the outcome of assisted conception.

BACKGROUND: Although uterine fibroids occur in 30% of women and are associated with a degree of subfertility, the effect of intramural fibroids on the outcome of IVF or ICSI treatment has not been prospectively studied. METHODS: Data were prospectively collected on 434 women undergoing IVF/ICSI in the assisted conception unit of an inner London teaching hospital. Patients were assessed for the presence of fibroids by transvaginal ultrasound and hysterosonography or hysteroscopy where appropriate. RESULTS: During the study period, 112 women with (study), and 322 women without (controls), intramural fibroids were treated. Patients were similar regarding the cause and duration of their infertility, number of previous treatments, and basal serum FSH concentration. Women in the study group were on average 2 years older (36.4 versus 34.6 years; P < 0.01). There was no significant difference in the duration of ovarian stimulation or gonadotrophin requirement, number of follicles developed, oocytes collected, embryos available for transfer or replaced. When analysing only women with intramural fibroids of < or =5 cm in size (n = 106) pregnancy, implantation and ongoing pregnancy rates were significantly reduced: 23.3, 11.9 and 15.1 respectively compared with 34.1, 20.2 and 28.3% in the control group (P = 0.016, P = 0.018 and P = 0.003). The mean size of the largest fibroids was 2.3 cm (90% range 2.1-2.5 cm). Logistic regression analysis demonstrated that the presence of intramural fibroids was one of the significant variables affecting the chance of an ongoing pregnancy, even after controlling for the number of embryos available for replacement and increasing age, particularly age > or =40 years, odds ratio 0.46 (CI 0.24-0.88; P = 0.019). CONCLUSION: This study demonstrated that an intramural fibroid halves the chances of an ongoing pregnancy following assisted conception.

Embryo Implantation↗

PubMed2001

Tc-99m mercaptoacetyltriglycine clearance: comparison of camera-assisted methods.

PURPOSE: To compare the accuracy of three camera-assisted methods for the measurement of Tc-99m mercaptoacetyltriglycine (MAG3) clearance. MATERIALS AND METHODS: MAG3 renal scintigraphy was performed in 21 adults with different degrees of renal function. Posterior views were obtained that included the heart and the kidneys in the camera field of view. The syringe for injection was imaged before and after injection. Blood samples were drawn 24 and 43 minutes after injection and plasma radioactivity was measured. Three camera-assisted techniques to measure MAG3 clearance were tested: 1) Biexponential fitting of the left ventricular curve, normalized to plasma activity at 24 minutes; 2) calculation of clearance by relating the integral of the plasma curve (normalized to plasma activity) to the kidney activity using the Rutland-Patlak space method; and 3) a regression equation measuring clearance from the percentage of the injected dose accumulating in the kidneys during the 1- to 2.5-minute period. The camera-assisted clearances were compared with the single-sample MAG3 clearances calculated using the Russell equation. Linear regression analysis was used to measure the correlation between the camera-based methods and the single-sample techniques. RESULTS: Correlation with r > 0.900 was found for all three techniques. The difference in correlation coefficients between the three methods was not significant; however, the regression line of method 3 was significantly closer to the line of identity (P = 0.005). CONCLUSION: Method 3 most closely fits the line of identity and is probably the most practical because no blood sample is needed.

Adult↗

PubMed2001

An attempt to identify the evolutionary origin of a novel serotype of Salmonella enterica isolated from harbour porpoises.

The isolation since 1991 of a new serotype of Salmonella enterica (antigenic formula 4,12:a:-) from harbour porpoises (Phocoena phocoena) at post-mortem examination raised the question of its evolutionary origin. Representative strains of S. enterica serotype 4,12:a:- and strains of eight other serotypes of serogroup 04 with phase-1 flagellar antigen H 'a' were examined by EcoRI ribotyping, IS200 fingerprinting and PCR-based profiling. Statistical analysis of results of multiple typing showed that strains of Salmonella serotype 4,12:a:- were genetically distant from those of antigenically similar salmonella serotypes, none of which seemed likely to be the progenitor of the 'porpoise' serotype.

Animals↗

PubMed2001

Review of policies and guidelines on infant feeding in emergencies: common ground and gaps.

Recent crises in regions where exclusive breastfeeding is not the norm have highlighted the importance of effective policies and guidelines on infant feeding in emergencies. In 1993, UNICEF compiled a collection of policy and guideline documents relating to the feeding of infants in emergency situations. In June 2000 Save the Children, UK, UNICEF and the Institute of Child Health undertook a review of those documents, updating the list and identifying the common ground that exists among the different policies. The review also analysed the consistency of the policy framework, and highlighted important areas where guidelines are missing or unclear. This article is an attempt to share more widely the main issues arising from this review. The key conclusions were that, in general, there is consensus on what constitutes best practice in infant feeding, however, the lack of clarity in the respective responsibilities of key UN agencies (in particular UNICEF, UNHCR and WFP) over issues relating to co-ordination of activities which affect infant-feeding interventions constrains the implementation of systems to support best practice. Furthermore, the weak evidence base on effective and appropriate intervention strategies for supporting optimal infant feeding in emergencies means that there is poor understanding of the practical tasks needed to support mothers and minimise infant morbidity and mortality. We, therefore, have two key recommendations: first that the operational UN agencies, primarily UNICEF, examine the options for improving co-ordination on a range of activities to uphold best practice of infant feeding in emergencies; second, that urgent attention be given to developing and supporting operational research on the promotion of optimal infant-feeding interventions.

Guidelines as Topic↗

PubMed2001

From policy to practice: challenges in infant feeding in emergencies during the Balkan crisis.

The preparation and dissemination of policy statements are necessary but insufficient to prevent the inappropriate use of infant-feeding products in emergencies. The widespread failure of humanitarian agencies operating in the Balkan crisis to act in accordance with international policies and recommendations provides a recent example of the failure to translate infant-feeding policies into practice. This article explores the underlying reasons behind the failures which include: (1) the weak institutionalisation of policies; (2) the massive quantities of unsolicited donations of infant-feeding products: (3) the absence of monitoring systems; (4) inadequate co-ordination mechanisms; (5) the high costs of correcting mistakes; and (6) the cumulative effects of poor practice. Efforts to uphold best practice during the crisis are also documented. Finally, the article identifies actions that could be undertaken in advance of and during future emergencies to enhance the application of infant feeding policies in emergencies.

Albania↗

PubMed2001

Predicting early fatherhood and whether young fathers live with their children: prospective findings and policy reconsiderations.

This prospective study of a birth cohort addressed three questions. Which individual and family-of-origin characteristics predict the age at which young men make the transition to fatherhood? Do these same characteristics predict how long young men live with their child? Are individual differences in the amount of time fathers spend living with their child associated with the father's psychosocial characteristics in young adulthood? In this unique study, it was found that by age 26, 19% of the 499 study men had become fathers. Individual and family-of-origin characteristics were assessed from birth until age 15 and contemporaneous characteristics were assessed at age 26. Young men who experienced a stressful rearing environment and a history of conduct problems were more likely to become fathers at an early age and to spend less time living with their child. Of those who experienced none of the risk factors, fewer than 10% had become fathers by age 26 compared to more than 60% of those who experienced five risk factors. Fathers who lived apart from their child reported the most social and psychological difficulties in young adulthood. These findings point to individual and family-of-origin characteristics that might be targeted in order to delay fatherhood and increase levels of paternal involvement. However, given their troubled life histories and poor social-psychological adjustment in young adulthood, some absent fathers might have difficulties providing positive parenting and partnering unless policy initiatives to promote intact families also support young fathers.

Adolescent↗

PubMed2001

Can women provide reliable information about their children's fathers? cross-informant agreement about men's lifetime antisocial behaviour.

It is difficult to study the contribution of fathers' antisocial behaviour to children's development because fathers with behavioural problems are often absent or reluctant to participate in research. This study examines whether mothers' reports about their children's fathers' antisocial behaviour can be substituted for interviews with fathers. Both members of 67 couples (N = 134) were interviewed separately and independently about the men's lifetime antisocial behaviour. There was strong relative agreement: the women's reports about men's antisocial behaviour and the men's self-reports about the same behaviour were highly correlated. However, there was poor agreement about absolute level: compared to men's self-reports, women reported fewer of the men's antisocial behaviours. Women's reports provide a reliable index of men's relative standing in a distribution and can be used in research about their children's fathers, but should not be used to make diagnostic decisions about men's antisocial disorders.

Adolescent↗