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Biomedical subjects

G Willis

Publications and source records attributed to G Willis.

At least 19 recordsLinked to original sources
PubMed2005

Audio computer assisted interviewing to measure HIV risk behaviours in a clinic population.

OBJECTIVES: To examine whether audio computer assisted survey interviewing (ACASI) influenced responses to sensitive HIV risk behaviour questions, relative to interviewer administration of those questions (IAQ), among patients attending a sexually transmitted infection (STI) clinic and whether the impact of interview mode on reporting of risk behaviours was homogeneous across subgroups of patients (defined by age, sex, and previous STI clinic experience). METHODS: 1350 clinic patients were assigned to complete a detailed behavioural survey on sexual risk practices, previous STIs and symptoms, condom use, and drug and alcohol use using either ACASI or IAQ. RESULTS: Respondents assigned to ACASI were more likely to report recent risk behaviours such as sex without a condom in the past 24 hours (adjusted OR = 1.9), anal sex (adjusted OR = 2.0), and one or more new partners in the past 6 months (adjusted OR = 1.5) compared to those interviewed by IAQ. The impact of ACASI varied by sex but, contrary to expectations, not by whether the patient had previously visited an STI clinic. Mode of survey administration made little difference within this population in reports of STI knowledge, previous STIs, STI symptoms, or illicit drug use. CONCLUSION: ACASI provides a useful tool for improving the quality of behavioural data in clinical environments.

Adolescent↗
PubMed2002

HFE mutations in an inflammatory arthritis population.

OBJECTIVES: To determine the value of screening patients with inflammatory arthritis for haemochromatosis-associated mutations in the HFE gene. METHODS: We screened 1000 patients with inflammatory arthritis and 1000 controls for the HFE gene mutations that are associated with haemochromatosis. The arthritis patients were diagnosed between 1989 and 1995 and their blood DNA was archived as part of the Norfolk Arthritis Register project. RESULTS: Five out of 1000 (0.005) patients in the arthritis group were homozygous for the HFE C282Y mutation. This frequency is the same as the frequency of 5/1000 (0.005) for C282Y homozygosity observed in the normal population. It is slightly above the predicted frequency of homozygosity of 0.0044 derived from the gene frequency in the normal population. CONCLUSIONS: These data suggest that most of the C282Y homozygotes occurred in this arthritis group by chance and that their arthritis was incidental to their HFE genotype. This implies that screening for HFE mutations among patients with inflammatory arthritis would infrequently identify patients whose arthritis might benefit from additional treatment.

Adult↗
PubMed2001

Increased DNA oxidative susceptibility without increased plasma LDL oxidizability in Type II diabetes: effects of alpha-tocopherol supplementation.

In vivo supplementation studies of the antioxidant alpha-tocopherol in human Type II diabetes have used surrogate, rather than direct, markers of oxidative damage/antioxidant protection and have used higher doses of alpha-tocopherol than used in coronary secondary prevention trials. We tested the hypothesis that oral alpha-tocopherol in a dosage regimen used in secondary prevention trials would reduce directly observed oxidatively induced single-strand breaks in lymphocyte DNA in Type II diabetes. We studied 40 people with Type II diabetes and 30 controls in a randomized, double-blind, placebo-controlled trial of 400 i.u. of oral alpha-tocopherol daily for 8 weeks. Lymphocyte DNA single-strand breaks and low-density lipoprotein (LDL) particle size and oxidizability were measured at baseline, after 8 weeks, and after 4 weeks washout. Polymorphisms in the gene for the antioxidant enzyme paraoxonase-1 gene (position 192) were measured. The diabetics had increased DNA oxidative susceptibility (P=0.008), without increased LDL oxidative susceptibility. There was a direct relationship between DNA oxidative susceptibility and baseline plasma alpha-tocopherol in the diabetes group alone (r=0.421, r(2)=0.177 and P=0.023), but DNA and LDL oxidative susceptibility were not influenced by alpha-tocopherol supplementation in either group in this regimen. Paraoxonase-1 gene polymorphisms did not contribute to LDL or DNA oxidative susceptibility or response to alpha-tocopherol. Increased DNA oxidative susceptibility, therefore, can occur in Type II diabetes without increased LDL oxidative susceptibility, but alpha-tocopherol supplementation in this regimen has no influence on DNA or LDL oxidative susceptibility in Type II diabetes or controls. Polymorphisms in the paraoxonase gene (position 192) are not associated with differences in oxidative susceptibility or responses to alpha-tocopherol.

Adult↗
PubMed2000

Incidence of liver disease in people with HFE mutations.

BACKGROUND: Most patients with haemochromatosis have mutations of the HFE gene. However, the risk to people with HFE mutations of developing disease manifestations of haemochromatosis is not known. AIMS: To determine the risk of developing cirrhosis and liver cancer in individuals with HFE mutations in a population where few people were being treated for haemochromatosis. METHODS: 215 archive biopsy specimens of liver cancer (n=34) and cirrhosis (n=190) were retrieved from histology archives. Blood samples from 1000 individuals from the normal population were also collected. DNA was extracted from the biopsy specimens and exons 2 and 4 of the HFE gene were amplified using polymerase chain reaction. The products were analysed for the C282Y (845A) and H63D (187G) mutations. RESULTS: Three (8.8%) patients from the liver cancer group were homozygous for the C282Y mutation. Five (2.6%) patients from the cirrhosis group were homozygous for the C282Y mutation. One case fell in both the liver cancer and cirrhosis groups. C282Y homozygosity was thus significantly more frequent in both groups than in the normal population. These 215 cases are representative of a population of about 250 000 over 20 years. During this period we estimate that about 260 births or deaths of C282Y homozygous individuals occurred within this population. CONCLUSIONS: A diagnosis of liver cancer or cirrhosis is rare in the lifetime of individuals from this population who are homozygous for the C282Y mutation (2.5%; upper 95% confidence interval (CI) = 8%). Similarly liver disease is rare among C282Y/H63D compound heterozygotes (1%; upper 95% CI = 3.5%).

Adolescent↗
PubMed1998

Readmissions to drug abuse treatment and HIV risk behavior.

The objectives of the study were (a) to investigate the characteristics of drug abuse treatment clients who return to treatment and (b) among those with readmissions, to describe changes over time in risk behavior for human immunodeficiency virus (HIV) infection and to identify factors associated with behavior change. Data were derived from a multisite HIV surveillance program in a single community; the program used a unique identifier to link HIV test results and behavioral information from multiple contacts. During a 30-month period, 1994 clients were admitted to three satellite facilities of a single treatment agency: detoxification, long-term residential, and outpatient. Of these clients, 574 (29%) had one or more readmissions to the same or a different facility during the 24 months following the index admission. Drug injectors, those tested for HIV, and those living in the community were more likely to be readmitted to treatment. There was little overall change in HIV risk behavior between the index admission and the readmission furthest in time from the index admission. Clients whose index visit was at the residential facility were more likely to reduce their injection risk behavior than those admitted to the other facilities. Clients readmitted to either the residential or the outpatient facility were more likely to have reduced their injection risk behavior than those readmitted to detoxification. Treatment facility was not associated with sexual risk behavior change. Men were more likely than women to reduce their high-risk sexual behaviors. The results underscore the need for treatment programs to make HIV testing readily available to their clients and to make special efforts to assist female clients to reduce their HIV risk.

Adolescent↗
PubMed1997

A high prevalence of HLA-H 845A mutations in hemochromatosis patients and the normal population in eastern England.

We have examined normal individuals and all the patients currently being treated for hemochromatosis at the Norfolk and Norwich hospital for mutations in the HLA-H gene. We found a gene frequency in 200 normal subjects for teh 845A (C282Y) allele of 0.085, corresponding to a carrier frequency of 17% which is among the highest reported anywhere in the world. The frequency for the less penetrant 187G (H63D) allele was 0.16 among 58 of the normal subjects, which corresponds to a carrier frequency of 32%. All 18 hemochromatosis patients were homozygous for the 845A allele which is not significantly different from other reports in our subset of 12 unrelated patients. These findings present a snapshot of a relatively stable population containing a predicted 3,500 individuals homozygous for the 845A allele but not diagnosed with hemochromatosis. This population will be an excellent model for studies on the penetrance of the 845A homozygous genotype and population screening.

Alleles↗
PubMed1997

A differential PCR assay for the detection of c-erbB 2 amplification used in a prospective study of breast cancer.

AIMS: To establish a robust differential polymerase chain reaction (PCR) assay for the detection of c-erbB 2 amplification in breast cancer that can be used in a routine pathology laboratory. Once established, the assay was used in a prospective study of breast tumours to investigate the relation between c-erbB 2 amplification and both recognised prognostic features and short term clinical outcome. METHODS: The differential PCR was used for the co-amplification of c-erbB 2 and a reference gene from 48 tumour DNA samples and control DNA samples. The ratio of the two genes was determined by image analysis of the PCR products electrophoresed on a highly resolving agarose gel. RESULTS: The differential PCR assay was shown to be accurate and reproducible using the conditions outlined. Twenty six per cent of the breast cancer patients were shown to have c-erbB 2 amplification in their tumour biopsies. Twenty eight per cent of the patients died of their disease or had disease recurrence during the follow up period and 73% of these patients had amplification of c-erbB 2. CONCLUSIONS: A significant association was found between c-erbB 2 amplification and early disease recurrence. This assay could be used to provide a marker for poor prognosis in breast cancer.

Adult↗
PubMed1996

Community-wide HIV counselling and testing in central Massachusetts: who is retested and does their behavior change?

HIV counselling and testing was provided to 4267 individuals between September 1987 and June 1992 at a multi-site program, including community clinics, drug treatment programs, and a men's prison in central Massachusetts. Half of those tested reported the risk behaviors targeted by the programs: injection drug use (38.1%) and sexual contact with a drug injector (12.6%). The objectives of this study were to examine 1) factors associated with repeat HIV testing among these initially seronegative, and 2) behavior change following counselling and testing. Initially 7.4% were HIV positive, and 12.4% of those testing negative were retested within one year. Risk behavior was the only strong independent predictor of retesting (odds ratios of 3.8 and 4.2 for men reporting sex with men and recent drug injectors, respectively). Changes in risk behaviors between the time of the initial test and the second test were assessed (n = 207). Among those who continued to inject drugs at follow-up there was a reduction in the percent visiting shooting galleries (p = 0.05); no other significant behavior changes were reported. While selection bias may be responsible in part for the minimal behavior change observed, continued monitoring of risk behavior and counselling are warranted.

Adolescent↗
PubMed1993

Analysis of ras point mutations and human papillomavirus 16 and 18 in cervical carcinomata and their metastases.

Paraffin-wax-embedded samples of normal cervical tissue and of primary cervical carcinomata and nodal metastases were obtained from each of 15 patients. They were analyzed for the presence of ras point mutations and human papillomavirus (HPV) types 16 and 18 using the polymerase chain reaction (PCR) and hybridization to oligomer probes. Only 1 patient was found to have a ras mutation: a codon 13 mutation of Ki-ras which was present in only two lymph node metastases, but not in the primary tumor or in a third metastasis. These results suggest that ras point mutation is not a common factor in the development of primary or metastatic cervical cancer. HPV 16 was detected in 7 of the 15 patients and was present in both primary and metastatic tumors in 6 of these 7 cases. HPV 18 was not detected in any of the 15 patients. These results do not suggest a role for HPVs 16 and 18 in producing metastatic behavior.

Adult↗
PubMed1992

Use of a portable manometer as a screening procedure in voice rehabilitation.

Abnormal tone in the pharyngo-oesophageal (PO) segment may lead to failure in developing oesophageal speech. Videofluoroscopy may give a qualitative assessment of the PO segment but is expensive, time consuming and lacks quantification. A custom built PO segment manometer was therefore assessed as a means of predicting eventual oesophageal speech outcome. Two groups of patients were studied. In group 1 (18 patients) the PO segment pressures were compared to their videofluoroscopy findings. Videofluoroscopy categorized the patients into four groups. The PO pressures corresponded to this grouping, pressures above 20 mmHg being associated with voice failure. In group 2 (12 patients) the PO pressures in the early post-operative period were compared to their eventual speech outcome. In all cases the pressures predicted the eventual speech outcome. The pressure manometer is a simple, cheap and portable device which is a reliable screening test to predict the potential for oesophageal speech.

Esophagus↗
PubMed1988

Immune response of sheep to oral and subcutaneous administration of live aromatic-dependent mutant of Salmonella typhimurium (SL1479).

The major objective of the present study was to determine whether oral immunization with a live aromatic-dependent strain of Salmonella typhimurium (SL1479) was capable of stimulating an intestinal immune response in sheep similar to that induced by combined intraperitoneal injection followed by oral boosting. The results showed that repeated oral immunization was incapable of stimulating an anti-flagella antibody containing cell (ACC) response in the lamina propria of the intestine even though primary oral administration of 5 x 10(9) live SL1479 gave rise to an ACC response in intestinal lymph which was predominantly of the IgM isotype. ACC reached a peak 9-10 days after oral administration when ACC comprised 0.5-1% of total lymphocytes in lymph. An ACC response of similar isotope specificity also occurred in popliteal prefemoral lymph of unprimed sheep following regional subcutaneous injection of SL1479. Oral administration of SL1479 to orally primed sheep did not reinvoke an ACC response in lymph although IgG1-ACC were observed in medullary cords of mesenteric lymph nodes of sheep 6-8 days after the booster dose of SL1479. The results suggest that the protective immunity elicited by oral administration of SL1479 cannot be attributed to induction of a local intestinal antibody production.

Administration, Oral↗
PubMed1988

Lymphocyte phenotypes in the intestinal mucosa of sheep infected with Trichostrongylus colubriformis.

Monoclonal antibodies to ovine lymphocyte surface antigens were used in an immunohistochemical study of the intestine of sheep. In the epithelium CD8+ cells predominated whereas the majority of lamina propria T lymphocytes were CD4+. Infection of sheep with the parasitic nematode Trichostrongylus colubriformis including sufficiently large numbers of parasites to induce protective immunity did not alter the number of CD4+ or CD8+ lymphocytes in the intestinal mucosa. In contrast, exposure of naive sheep to a single large infection of T. colubriformis resulted in a substantial decrease in number of CD8+ cells and moderate decreases in number of CD4+ cells in the duodenal but not the jejunal mucosa. MHC class II antigens were not detected either in or on epithelial cells of the sheep small intestine.

Aging↗
PubMed1987

The urban homeless: estimating composition and size.

Although homelessness has been recognized as a serious and growing urban social problem, scientifically acceptable methods for estimating the composition and size of the homeless population have been lacking. A new research approach to estimating the size and composition of undomiciled urban populations is presented, and its utility is illustrated through a description of the literal homeless of Chicago. The homeless in the Chicago sample are unaffiliated persons living in extreme poverty, with high levels of physical and mental disability. Homelessness is interpreted as a manifestation of extreme poverty among persons without families in housing markets with declining stocks of inexpensive dwelling units suitable for single persons.

Chicago↗
PubMed1987

Living with the mentally ill: factors affecting household complaints.

Data provided by case managers in community support programs are used to analyze the problems of families providing shelter to mentally ill relatives. Factors affecting complaints in 345 family households are contrasted with factors leading to complaints in a subsample of 622 other residential alternatives. Behavioral problems are the best predictors of complaints from all households regardless of type, but some causal factors identified are unique to family residences, notably failure to perform household chores and infrequently socializing with friends. Active and passive rule violations, encompassing both do's and don'ts, are more important than clinical history and social background in understanding complaints.

Activities of Daily Living↗
PubMed1985

Ribavirin small-particle aerosol treatment of infections caused by influenza virus strains A/Victoria/7/83 (H1N1) and B/Texas/1/84.

In a double-blind study of influenza in a population of college students in 1984, ribavirin small-particle aerosol treatment of 38 patients (18 treated, 20 control) infected with a new antigenic variant, influenza virus strain A/Victoria/7/83 (H1N1), was associated with statistically significant reductions in the height and duration of fever, systemic symptoms, and virus shedding. Patients received a total of 2.4 g of ribavirin over 42 h during 68 h of hospitalization without any side effects. In addition, in a study of patients infected with influenza virus strain B/Texas/1/84 (seven treated, eight control) treated with ribavirin aerosol showed a trend of more rapid recovery than control patients.

Aerosols↗