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R J Hay

Publications and source records attributed to R J Hay.

At least 91 records · Page 5Linked to original sources
PubMed1996

Human onchocerciasis in Nigeria: isotypic responses and antigen recognition in individuals with defined cutaneous pathology.

Antigen (Ag)-specific isotype responses to Onchocerca volvulus Ag (OvAg) were assessed by enzyme-linked immunosorbent assay and immunoblot in 123 residents of a mesoendemic area in northern Nigeria and 16 Nigerians from a nonendemic area. Individuals from an endemic area were divided into six groups on the basis of cutaneous onchocercal pathology: acute papular onchodermatitis (APOD), chronic papular onchodermatitis (CPOD), lichenified onchodermatitis (LOD), atrophy (ATR), depigmentation (DPM) and normal skin, high microfilarial load (NSHMF). Immunoglobulin (Ig)G1-4 levels were all significantly associated with residence in an endemic area after controlling for age and sex (all P values = 0.0001). Both IgG1 and IgG3 were significantly associated with onchocercal clinical category after controlling for age, sex, and microfilarial load (P = 0.0031 and 0.0035, respectively). The IgG1 and IgG3 responses were both highest in LOD and lowest in NSHMF and ATR, respectively. A significant inverse association was found between IgG1 levels and microfilarial load after controlling for age, sex, and clinical category (P = 0.0061). On immunoblotting, 20 (44.4%) of 45 individual onchocerciasis sera contained IgG4 antibodies against a band of 29-31 kD, which was not recognized by pooled sera from individuals with other filarial infections. There was heterogeneity of antigen recognition within each of the onchocercal clinical groups, which together with the small numbers examined by immunoblotting, limits interpretation. Nevertheless, some differences in patterns of antigen recognition were found between the onchocercal groups. The LOD group demonstrated prominent immunoreactivity in IgG1 and IgG3 while a general paucity of low molecular weight reactivity was seen with NSHMF in IgG1-3 subclasses, but there was no specific banding pattern that differentiated NSHMF from those with pathology. Comparison of microfilariae-positive (mf+) and mf- individuals with onchocercal skin disease revealed significantly higher levels of all IgG subclasses and higher overall scores on semiquantitative assessment of immunoblots for IgG1, IgG2, and IgG4 for mf+ individuals. Differing isotypic responses may play a role in the pathogenesis of the clinical spectrum of cutaneous onchocerciasis.

Adolescent↗
PubMed1996

A case of giant bathing trunk naevus with neurofibroma-like change.

It is recognized that cells of melanocytic naevi may resemble neuroid structures and the term neurotization has been used to describe this phenomenon. This may result in difficulty in the histological differentiation between naevi and neurofibromas. We report the case of a patient with a giant bathing trunk naevus which has undergone marked neurotization and in whom there had been diagnostic difficulty.

Adult↗
PubMed1996

Validation of the U.K. diagnostic criteria for atopic dermatitis in a population setting. U.K. Diagnostic Criteria for Atopic Dermatitis Working Party.

One reason why so little is known about the epidemiology of atopic dermatitis (AD) is lack of suitable diagnostic criteria. A simple list of diagnostic criteria for AD for use in epidemiological studies has recently been developed by a U.K. working party. These have performed well in hospital validation studies of subjects with skin diseases. This study sought to validate the newly proposed criteria for AD in a population setting by conducting a cross-sectional survey of 695 schoolchildren aged 3-11 years in three randomly selected primary schools in West Lambeth, London. As a point prevalence measure, the U.K. criteria had a sensitivity of 70%, a specificity of 93%, and a positive predictive value of 47% when compared with a dermatologist's examination findings. Subsequent analysis suggested that most children classified as false positives had suffered from AD in the last year, but were inactive at the time of examination. When adjusted for these cases, the sensitivity and specificity increased to 80 and 97%, respectively, corresponding to positive and negative predictive values of 80 and 97%, respectively. The U.K. diagnostic criteria for AD appear to work well as a 1-year period prevalence measure in London schoolchildren. Further validation in adults and other countries are needed.

Child↗
PubMed1996

Human cells and cell cultures: availability, authentication and future prospects.

The availability of well characterized, viable human cells, tissues and cell lines along with pertinent data on the specific patient donors is a prerequisite for much current transplantation and biomedical research. In the USA, institutional and multi-center networks have been established for provision of primary human cells and tissues to qualified clinicians and research scientists. Monetary support derives from government, university, institutional and fee sources. Problems involved include concern for the rights and privacy of tissue donors, cultural reservations relating to tissue provision, the need for safe and expeditious transport, short term survival and limited supply, adequate correlation of patient data with samples provided, presence of infectious viruses and microorganisms, as well as state or government regulations regarding national or international shipping. The use of human cell lines with continuous or even somewhat limited doubling potentials overcomes many of the above difficulties. National cell banks have been established to provide reference lines for use by multiple investigators. Use of such cell lines assures improved research comparability both geographically and with time. Authentication procedures are critically important for all of these programs. Verification of tissue types and conditions is required through histological, biochemical and immunological assays. Tests for microbial and viral contaminants must be applied. In addition to such procedures utilized for tissues, with cell lines the banking agency must also verify species and where possible identity, properties and functions. The literature is replete with descriptions documenting incorrect identifications and infections of proliferating cell strains used for research. The availability of viable tissue through local sources and distribution agencies in the USA is becoming more commonplace even including full family participation and collection of related, detailed histories. Increased support for this developmental activity is needed, coupled with provision of blood and normal cells and cell lines from family members in many disease categories. Modern techniques, new and improved culture ware, serum-free media, reagents such as growth, adherence and transfer factors will permit isolation, propagation and wide spread distribution not only of human tumor cells but also normal and functional human cells of most renewing and expanding tissue types. Hybridization and immortalization techniques are enhancing this capability such that virtually all human cell types should be available for short or longer-term propagation and study in the foreseeable future.

Biological Specimen Banks↗
PubMed1995

DLD-1 and HCT-15 cell lines derived separately from colorectal carcinomas have totally different chromosome changes but the same genetic origin.

Aneuploid DLD-1 and HCT-15 cell lines independently derived from a colon carcinoma by two researchers lacked a common marker chromosome or a concurrent numerical change. To further look into the genetic identity of these two cell lines, we used chromosome painting with fluorescence in situ hybridization (FISH) and confirmed the G-band identification on all chromosome changes. We have also found comparable results between these two cell lines on C-/Q- polymorphic bands of several chromosomes, and electrophoretic patterns of restriction fragment-length polymorphisms (RFLPs) from eight Y-chromosome-specific DNA probes with 13 restriction enzymes. These results strongly suggest that DLD-1 and HCT-15 are identical genetically. Clearly, cell lines bearing totally unrelated changes in karotypes can be generated from the same cancer specimen.

Blotting, Southern↗
PubMed1995

London-born black Caribbean children are at increased risk of atopic dermatitis.

BACKGROUND: Previous reports suggest that atopic dermatitis is more common in black Caribbean children born in the United Kingdom than in white children. It is unclear whether these differences are caused by selection bias or variations in the use of the word "eczema" in the groups studied. OBJECTIVE: Our objective was to explore ethnic group differences in the prevalence of atopic dermatitis in London schoolchildren. METHODS: A cross-sectional prevalence survey of 693 junior school children in three schools was performed. Atopic dermatitis was defined in three ways: (1) by a dermatologist, (2) by visible flexural dermatitis as recorded by an independent observer, and (3) by a history of flexural dermatitis according to the child's parents. RESULTS: The prevalence of atopic dermatitis according to examination by a dermatologist was 16.3% in black Caribbean children and 8.7% in white children. This increased risk was present for different methods of defining of a atopic dermatitis and persisted after adjustment for potential confounders. CONCLUSION: London-born black Caribbean children appear to be at an increased risk of having atopic dermatitis.

Black or African American↗
PubMed1995

Fungal aerobiology: how, when and where?

While there is undoubted risk of infection in certain hospitalized patients following exposure to inhaled spores of fungi such as Aspergillus, the actual risk appears to vary with the underlying condition. Secondly, the degree of exposure assessed by colony forming units (cfu) per unit of ambient air is not predictable. Thirdly, severely immunocompromised patients, mainly the severely neutropenic group, are at risk from infection at very low levels of ambient Aspergillus spores. From this it can be argued that the latter group requires some form of environmental protection or prophylaxis whatever the circumstances. At present the best approach is the use of highly filtered ward areas e.g. laminar air flow rooms. Monitoring spore loads is unlikely to affect management per se provided that the ventilation systems are regularly and effectively serviced. In non-neutropenic patients the risk of infection due to colonization, for instance of the paranasal sinuses, prior to hospital admission may be as great as that occurring due to exposure within hospital and filtration of air has a lesser value. The situation may alter, though, even in these patients if the risk level is increased by a building programme in the vicinity of ward areas.

Air Microbiology↗
PubMed1995

Antifungal drug susceptibility testing. Working Party of the British Society for Antimicrobial chemotherapy.

This article describes the current situation with regard to intrinsic and acquired resistance to antifungal compounds and progress with the development of standardized methods of susceptibility testing for amphotericin B, flucytosine, and the azoles. Recommendations for testing of isolates from patients destined to receive antifungal drug treatment, or in whom therapeutic failure or relapse is suspected, are presented.

Antifungal Agents↗
PubMed1995

Adherence of Malassezia isolates to human keratinocytes in vitro--a study of HIV-positive patients with seborrhoeic dermatitis.

Adherence of Malassezia yeast cells to human keratinocytes was assessed by a novel technique using double-sided Sellotape. Although adherence using double-sided Sellotape is still merely a model for in vivo adherence, it approximates to the conditions found on the skin surface. There were no differences in adhesive properties to human keratinocytes between Malassezia strains originating from HIV-positive and HIV-negative patients with seborrhoeic dermatitis, nor was there a relationship between the severity of seborrhoeic dermatitis and in vitro adherence to human keratinocytes.

Adult↗
PubMed1995

HIV disease and Malassezia yeasts: a quantitative study of patients presenting with seborrhoeic dermatitis.

Seborrhoeic dermatitis (SD) is a disease that affects 1-3% of the general population, 3-5% of young adults and 20-83% of patients with AIDS. Malassezia yeasts have been associated with the pathogenesis of this condition. The association between the Malassezia yeasts and HIV-related SD is still a controversial subject. The objective of our study was to investigate the role of Malassezia yeasts in the pathogenesis of SD in the HIV population comparing the number of yeasts' cells with the severity of the disease and degree of immunosuppression. We used two quantitative counting methods: direct counting with Sellotape-stripped skin and recovery of the yeasts in culture using contact plates. This investigation has demonstrated that there is a trend between numbers of yeasts present on lesional skin, severity of SD and CD4-positive T lymphocytes count in HIV-positive patients. No quantitative differences were observed between HIV-related and non-HIV related SD.

Adult↗
PubMed1995

Diffuse plane xanthomatosis and acquired palmoplantar keratoderma in association with myeloma.

We report a patient with diffuse plane xanthomatosis, acquired palmoplantar keratoderma, and myeloma. Although diffuse plane xanthomatosis is a recognized manifestation of paraproteinaemia, keratoderma is not. However, successful treatment of the myeloma in our patient coincided with a dramatic improvement in the keratoderma, suggesting a genuine association between the two disorders.

Aged↗
PubMed1995

A protocol for recording the sign of flexural dermatitis in children.

The presence of visible flexural dermatitis is a key feature in diagnosing atopic dermatitis. We describe a protocol for recording this sign in population-based studies, which could be used by suitably trained non-dermatologists. The protocol was developed using a standard set of photographs and accompanying instructions, which define the terms 'dermatitis' and 'flexural'. When assessed during a survey of skin disease in primary schoolchildren, there was excellent agreement between a trained nurse and a dermatologist with regard to the presence or absence of this sign in 73 consecutive children, with perfect agreement in 71 children (97%), and a chance corrected agreement index (kappa statistic) of 0.90 (95% confidence interval [CI] 0.77-0.99). Agreement between two nurses on 114 consecutive schoolchildren was not quite as good, with perfect agreement in 102 children (90%), and a kappa value of 0.51 (95% CI 0.26-0.77). The protocol is easy to perform, does not require children to undress, takes < 1 min to carry out, and is highly acceptable to children and staff. This protocol may be useful in standardizing the assessment of atopic dermatitis in population studies of children.

Child↗
PubMed1995

A comparison of 2 weeks of terbinafine 250 mg/day with 4 weeks of itraconazole 100 mg/day in plantar-type tinea pedis.

This double-blind, parallel group study compared a 2-week course of terbinafine 250 mg/day with a 4-week course of itraconazole 100 mg/day. A total of 190 patients were enrolled, of whom 129 were evaluable for efficacy. At week 8, 69% of patients treated with terbinafine were classified as effectively treated (mycological cure, and clinical assessment total score < or = 2) vs. 67% in the itraconazole group. At week 16, however, the rating for effective treatment increased to 71% of the terbinafine group, but decreased to 55% of the itraconazole group. This difference was of borderline statistical significance (P = 0.06). The results of this study demonstrate that both drugs can be used safely, and that 2 weeks' treatment with terbinafine 250 mg daily is as effective as 4 weeks' treatment with itraconazole 100 mg daily, but with fewer long-term relapses.

Adolescent↗
PubMed1995

Specific recognition of purified Cu,Zn superoxide dismutase from Aspergillus fumigatus by immune human sera.

Sera from 22 (84.6%) of 26 patients with confirmed Aspergillus infections recognized a purified Cu,Zn superoxide dismutase from A. fumigatus on Western blots (immunoblots). Sera from 32 (71%) of 45 patients with suspected Aspergillus infections were reactive to the superoxide dismutase. Normal human sera and sera from patients with other infections were unreactive.

Antibodies, Fungal↗