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Biomedical subjects

W McCarthy

Publications and source records attributed to W McCarthy.

At least 19 recordsLinked to original sources
PubMed1998

Solar keratoses: a risk factor for melanoma but negative association with melanocytic naevi.

Solar keratoses have been associated with increased risk of squamous-cell and basal-cell carcinomas, but their association with melanoma is less clear. This study investigated solar keratoses as a risk factor for cutaneous melanoma in Australia, also associations between solar keratoses and other host factors associated with melanoma. A total-body naevus count was made of 258 melanoma cases and 281 controls recruited from New South Wales, Australia, and solar keratoses were counted on the left forearm. Solar elastosis was also assessed by clinical examination on the face and the side of the neck. Solar keratoses were a significant risk factor for melanoma in Australia. The presence of 10 or more solar keratoses on the left forearm (compared with none) was associated with an odds ratio of 4.7 (95% CI, 2.0-10.9). A highly significant association was found between number of solar keratoses and a past history of multiple basal-cell carcinomas in cases and controls respectively. Numbers of common and atypical naevi decreased significantly with age, while solar keratoses were more common in older individuals. Solar keratoses were found more commonly in men than women in cases and in controls (p < 0.0001). A negative association was found between numbers of common naevi and numbers of solar keratoses in cases and controls, and this remained significant after stratifying for age, gender and hair colour (p < 0.0001 and p < 0.0016 respectively). Solar keratoses were more common in males with melanoma on the head and neck as compared with melanoma on any other site. Solar keratoses and naevi were independently predictive of increased melanoma risk. The fact that these 2 phenotypes were found to be negatively associated suggests that susceptibility to melanoma may be expressed via 2 distinct cutaneous phenotypes which may be genetically determined.

Adolescent↗
PubMed1998

Occupational dermatitis causing days away from work in U.S. private industry, 1993.

BACKGROUND: Occupational skin disease is an important cause of disability in the workplace. The aim of this report is to estimate the incidence of occupational dermatitis cases that causes days away from work and to characterize the cases. METHODS: The Annual Survey of Occupational Injuries and Illnesses from the Bureau of Labor Statistics collects employer reports on work-related dermatitis. Descriptive data are collected on a sample of the cases that result in days away from work. Estimates of the number of cases and days away from work were calculated by industry, occupation, and exposure source. RESULTS: In 1993, there were an estimated 8,835 cases of occupational dermatitis, a rate of 1.12/10,000 workers. The largest number of cases was in health services, while the highest rate was in agricultural crops. The occupation with the largest number of cases was non-construction laborers. Cleaning/polishing agents caused the largest number of cases. Calcium hydroxide and oxides caused a median of nine days away from work. DISCUSSION/CONCLUSIONS: The survey data show that the effect of occupational dermatitis is substantial in the lives of workers. These descriptive data should be used to target interventions.

Absenteeism↗
PubMed1998

The association between naevi and melanoma in populations with different levels of sun exposure: a joint case-control study of melanoma in the UK and Australia.

Two case-control studies were set up to investigate the relationship between melanocytic naevi and risk of melanoma and to compare the naevus phenotype in two countries exposed to greatly different levels of sun exposure and different melanoma rates. In England 117 melanoma cases and 163 controls were recruited from the North-East Thames Region and 183 melanoma cases and 162 controls from New South Wales, Australia. Each subject underwent a whole-body naevus count performed by the same examiner in each country. Relative risks associated with melanocytic naevi in each country were calculated with comparison of naevus data in controls between Australia and England. Atypical naevi were strong risk factors for melanoma in both countries: the odds ratio (OR) for three or more atypical naevi was 4.6 (95% CI 2.0-10.7) in Australia compared with 51.7 (95% CI 6.5-408.4) in England. Common naevi were also significant risk factors in Australia and England with similar odds ratios in the two countries. Prevalence of atypical naevi was greater in Australian controls than in English controls: OR 9.7 (95% CI 1.2-81.7) for three or more atypical naevi in Australia compared with England. For young age groups, the median number of common naevi was greater in Australia than in the UK, whereas for older individuals this difference in naevi number between the two countries disappeared. The prevalence of naevi on non-sun-exposed sites in controls was not significantly different between the two countries. The atypical mole syndrome (AMS) phenotype was more prevalent in Australian controls (6%) than in English controls (2%). The results of this study support the role of sun exposure in the induction of atypical naevi in adults. There was a trend towards stronger risk factors associated with atypical naevi in England compared with Australia. The atypical mole syndrome, usually associated with a genetic susceptibility to melanoma, was more common in Australia than in England, suggesting genetic environmental interactions with the possibility of phenocopies induced by sunlight.

Adolescent↗
PubMed1997

Competency-based learning in traumatology.

BACKGROUND: A multidisciplinary, competency-based trauma teaching program was introduced for final year medical students (n = 67) at Royal Prince Alfred Hospital (RPAH) in 1994 to complement the surgical clerkship. METHODS: The method involved small groups rotating through a series of teaching stations each structured to address a predetermined competency. Four 3-hour sessions were held on the subject areas of resuscitation, plastic, orthopedic, and neurotrauma. Performance in the trauma section of a summative Objective Structured Clinical Examination (OSCE), 6 months after the teaching, was compared with that of a control group (n = 127) from other campuses where trauma was taught by a series of discipline-based lectures. Three trauma OSCE stations were designed to test psychomotor skills while five addressed aspects of the cognitive domain. Checklists were used to ensure standardization of scoring in a range of questions asked for skills tested at each station. RESULTS: The marks of the RPAH students (mean 78% +/- SD 9%) were significantly higher (P < 0.0005) than the controls (mean 70% +/- SD 9%) in the 8 trauma questions. There was no significant difference (P = 0.8) in marks obtained by the study group (mean 61% +/- SD 8%) and controls (mean 63% +/- SD 7%) in 22 questions sampling a wide spectrum of nontrauma subject areas. The study group performed significantly better in one of the three skills stations and three of the five problem-solving stations when compared with the control group. CONCLUSION: The innovation has the potential to fulfill a need for an integrated trauma program in the undergraduate core curriculum.

Australia↗
PubMed1997

Beta particle attenuation characteristics of CaSO4.

The beta particle mass attenuation coefficient for CaSO4 in a Teflon matrix has been estimated by two methods: an experiment using collimated sources and a collimated gas flow proportional counter and simulations using the EGS4 Monte Carlo code. The attenuation coefficient has been cast in the general form of mu/rho = aE(-b), where E is the maximum beta particle energy and a and b are fitting parameters. The a and b parameters are given as a function of the atomic number of the material.

Beta Particles↗
PubMed1995

Intermittent claudication. The natural history.

Intermittent claudication is a relatively common disorder, present in a subset of patients with lower extremity atherosclerotic disease. Although lower extremity morbidity rates are low, patients with claudication frequently have coexistent cardiovascular disease and are at significantly increased risk of adverse cardiovascular events. Data to support work-up for concomitant coronary artery disease in conservatively managed patients are not available; however, clinicians should consider the high prevalence of coronary artery disease when developing management strategies. Patients should be carefully selected for lower extremity interventional management given the generally benign lower extremity prognosis. Tobacco smokers should be urged to quit, owing to their higher rate of lower extremity and cardiovascular adverse outcomes. Functional outcomes after various treatment strategies have not yet been sufficiently studied in the claudicant.

Adult↗
PubMed1994

Cutaneous findings in HIV-1-positive patients: a 42-month prospective study. Military Medical Consortium for the Advancement of Retroviral Research (MMCARR).

BACKGROUND: Cutaneous disease is common in patients infected with HIV-1. OBJECTIVE: The aim of our study was to identify cutaneous markers associated with HIV-1 infection and disease progression as measured by Walter Reed (WR) stage. METHODS: For 42 months we have observed 912 HIV-1-positive patients in all WR stages. All patients had an extensive past and present medical history taken as well as a complete physical examination, periodic visits, and appropriate diagnostic procedures. RESULTS: Increasing dryness of the skin and seborrheic dermatitis are early findings in a large percentage of patients in WR stage 1; the occurrence and severity of both conditions increase with disease progression. Tinea infections, condylomata acuminata, and verrucae are seen early, but with disease progression, although there is no clear increase in occurrence, these infections become more diffuse and resistant to treatment. Flares in acne vulgaris and folliculitis show a peak occurrence in early and mid-stage disease with a decreased occurrence in late-stage disease. Herpes simplex infections, oral candidiasis, molluscum contagiosum, Staphylococcus aureus infections, and oral hairy leukoplakia show a marked increase in occurrence with advanced disease. Conditions that have a statistically significant association with disease progression as measured by a change in a stage include drug eruptions, seborrheic dermatitis, oral candidiasis, oral hairy leukoplakia, molluscum contagiosum, herpes zoster, and hyperpigmentation (nail, oral, skin). CONCLUSION: The most frequent and persistent cutaneous disorders were asteatosis (with or without asteatotic eczema) and seborrheic dermatitis. Conditions that were associated with a change in WR stage include drug eruptions, seborrheic dermatitis, oral candidiasis, oral hairy leukoplakia, molluscum contagiosum, herpes zoster, and hyperpigmentation. In addition to Kaposi's sarcoma, patients with HIV-1 disease have an increased potential for the development of both cutaneous epithelial and probably melanocytic malignancies. Epithelial tumors were seen in patients in all stages of disease.

AIDS-Related Opportunistic Infections↗
PubMed1994

Multiple atypical nevi: a cutaneous marker of germ cell tumors.

PURPOSE: This study assessed whether a specific association exists between atypical nevi and germ cell tumors (GCT). METHODS: A prospective comparison was performed on a cohort of 129 unselected patients with GCT and a series of 153 healthy men. Three or more of the following criteria were required for diagnosis of multiple atypical nevi: greater than 5 mm in diameter; variegated color, often speckled black/brown, with irregularly distributed pigmentation; irregular outline or indistinct border; and at least three such lesions. RESULTS: Prevalences for multiple atypical nevi in patients with GCT and in healthy controls were 37% and 15%, respectively (P < .01). Two patients with these lesions also had documented malignant melanoma. In contrast, 16% of patients with GCT had a history of testicular maldescent (the most common known risk factor), compared with 5% of healthy controls (P < .01). CONCLUSION: Multiple atypical nevi occur with a statistically significant increased prevalence in patients with GCT as compared with healthy controls, and constitute one of the most common known clinical associations with this malignancy. These data may be of relevance for our understanding of the biology of GCT and of malignant melanoma, in the design of screening programs for testis cancer, and in the follow-up evaluation of patients with each of these disorders.

Adolescent↗
PubMed1991

High resolution real-time ultrasound for the diagnosis of venous thrombosis in the rehabilitation setting.

Accurate, noninvasive testing for deep venous thrombosis (DVT) by conventional methods is often not possible in the rehabilitation patient. Lower extremity amputation, a cast or bandage, or skin problems present obstacles to standard diagnostic methods. This report describes the use of duplex ultrasound (US) scanning for noninvasive diagnosis of DVT in a seventy-year-old man with a below-knee amputation, on whom Doppler and plethysmography examinations could not be performed. As experience is gained with this technique, the use of venography for diagnosis of DVT becomes more difficult to rationalize.

Aged↗
PubMed1987

Evidence that treatment with vaccinia melanoma cell lysates (VMCL) may improve survival of patients with stage II melanoma. Treatment of stage II melanoma with viral lysates.

A total of 80 patients with melanoma metastases in regional lymph nodes were treated by i.d. injections with a vaccine prepared from a vaccinia virus-infected allogeneic melanoma cell line; 39 patients have been followed for a 2-year period. Interim results from comparison of the treated group with 151 historical controls treated without the vaccine from September 1978 to December 1981 at the same institution and 56 non-randomized concurrent controls suggest that survival was significantly prolonged in the vaccinated group. At the 2-year period overall survival was 75% in the treated compared to 57% in the historical control group. Subset analysis showed a greater apparent benefit of vaccine therapy among patients who had metastases detected at the time of treatment of the primary melanoma (synchronous metastases), while therapy appeared less effective in patients with metastases detected at some time after treatment of the primary (delayed metastases). In the latter only those with one lymph node appeared to benefit from the treatment whereas in patients with synchronous metastases patients with three or more nodes as well as one node appeared to have improved survival. The survival rates at 2 years for treated patients with synchronous metastases in one, two, three or more lymph nodes was 100%, 83% and 79% respectively compared with that of 82%, 86% and 47% respectively in the equivalent control groups. Survival rates in treated patients with delayed metastases in one, two, three or more lymph nodes was 70%, 70% and 65% compared with 47%, 42% and 35% in the equivalent control groups. Treatment and control groups appeared well matched for a number of known prognostic features, including number and size of involved nodes, sex and thickness of primary tumor. Multivariate analysis indicated the effect of treatment was independent of these factors. Despite the empiricism of this approach the present results suggest that this form of therapy warrants further evaluation in a randomized controlled trial.

Adolescent↗
PubMed1986

Immunological effects of recombinant interferon alfa-2a in patients with disseminated melanoma.

Twenty patients with disseminated melanoma were treated with interferon alfa-2a, given by intramuscular (IM) injection three times a week in escalating doses from 15 to 50 X 10(6) U/m2. Of 18 patients considered evaluable, two had complete remission and in two others the disease was stabilized. Laboratory tests 6 hours after injection of interferon alfa-2a indicated a marked lymphopenia and a reduction in natural killer (NK) cell activity. Sequential changes (measured before injection of interferon alfa-2a on days 3, 10, and 31) consisted of neutropenia, thrombocytopenia, and a slight increase in OKT4 positive T cells compared with OKT8 positive T cells. NK activity against the K562 target cells was increased in most patients during the first week of treatment, returning to near or below pretreatment levels thereafter. This response contrasted with a delayed increase against melanoma target cells in 10 patients. The latter correlated with an increase in mitogen-stimulated interleukin-2 (IL2) production, and may indicate that the cytotoxic activity resulted from lymphokine-activated killer (LAK) cells. Changes in cortisol levels may explain some effects on the immune system, such as depression of IL2 and immunoglobulin production in vitro, and the differences noted in clinical responses during the present study compared with those observed with interferon alfa-2b given by intravenous (IV) injection in 5-day cycles. These results suggest that interferon alfa-2a has antitumor activity in certain melanoma patients, in particular those with metastases to pulmonary or subcutaneous sites. Assays of IL2 production and LAK activity may assist in the selection of patients who respond to interferon alfa-2a and help to optimize treatment regimens.

Adult↗
PubMed1981

Suppressor cell activity in melanoma patients. I. Relation to tumor growth an immunoglobulin levels in vivo.

The effect of tumor growth on the suppressor cell activity of melanoma patients was examined by measurement of immunoglobulin produced in vitro in pokeweed mitogen (PWM)-stimulated cultures of B and T lymphocytes. B and T cells were separated by sheep red blood cell rosetting and suppressor cell activity was assessed by comparison of immunoglobulins produced in cultures with irradiated T cells (2,000 rads) to that with unirradiated T cells. In the majority of patients with localized melanoma, radiosensitive suppressor T cells were detected and appeared to be an augmentation of a normal physiological state. In patients with Stage I and II melanoma, removal of the tumor resulted in a significant decrease in suppressor activity against IgA and IgM but not against IgG production. Similar sequential changes in suppressor cell activity against IgA and IgM but not against IgG production. Similar sequential changes in suppressor cell activity were not generally detected in patients who had surgery for skin graft after previous removal of the primary melanoma or in patients undergoing surgery for non-malignant conditions. Sequential studies on the levels of serum immunoglobulins showed an apparent trend for immunoglobulins to increase after surgery. Of particular importance, the decrease in in vitro suppressor cell activity against IgM and IgG production after tumor removal in individual patients was significantly associated with an increase in immunoglobulin levels in the serum of these patients. It is suggested that these findings may account in part for the absence of detectable antibody responses to melanoma antigens in many patients and for the generalized immunodeficiency in patients with disseminated melanoma.

B-Lymphocytes↗
PubMed1981

Suppressor cell activity in melanoma patients. II. Concanavalin A-induced suppressor cells in relation to tumor growth and suppressor T-cell subsets.

The relative proportions of T, B and T gamma suppressor cells were determined sequentially in peripheral blood of melanoma patients before and after surgery. Concanavalin A (Con A)-induced suppression against lymphocyte mitogenesis of melanoma patients and age matched controls was measured concurrently. The mean percentage of T gamma cells was significantly higher (p less than 0.001) in melanoma patients before surgery (21.8 +/- 5.4) compared to a group of age-matched controls (14.9 +/- 5.4). There was a tendency for the proportion of T gamma cells in patients to decrease after surgery, although the relative levels of T gamma were still significantly elevated (p less than 0.05) 6-8 weeks after surgery when compared to normal controls. The mean percentage of T and B cells in melanoma patients before and after surgery was comparable to that observed in normal controls. The degree of Con-A-induced suppression in patients increased significantly after surgery particularly at 6-8 weeks (p less than 0.02). No difference in con-A-induced suppressor cell activity was observed between melanoma patients and controls before or after surgery. An inverse relationship was found between the amount of Con-A-induced suppression and percentage of T gamma cells in melanoma patients before surgery. Similar associations were not apparent in patients after surgery or in normal control populations. The inverse correlation of Con-A-induced suppression with T gamma cell numbers suggests that the former may measure potential suppressor cell activity whereas the T gamma cells may indicate active suppressor cells. The significance of these findings for the monitoring of suppressor cell activity in vivo and their role in suppression of immune responses in melanoma patients is discussed.

B-Lymphocytes↗
PubMed1980

Detection of an inhibitor of cell division in cultures of tumour cells with immunosuppressive activity in vitro.

A number of previous reports have described the presence of factors which inhibit the response of lymphoid cells to phytohaemagglutinin. The present study describes an inhibitor of cell division synthesized and released directly from cultured tumour cells which appears to have similar immunosuppressive effects in vitro. This factor(s) was detected in a wide variety of cultured tumour cells and some cultures of normal foetal tissue. It inhibited the mitogenic response of lymphocytes to PHA and also the spontaneous cell division of a variety of cultured cells including the cells producing the factor. Pulse cytophotometry showed that cells were inhibited in the G1 phase. Production of the factor increased with time and was related to the number of cells in culture. Its synthesis was inhibited by cycloheximide. DNA and RNA synthesis was not required for its production. The factor appeared to have a high degree of biological activity in terms of the number of cultured cells required for production and in regard to the number of cells inhibited. The biological significance of this factor in vivo is unknown but in vitro it was shown to inhibit immunoglobulin and mitogen-induced responses which suggests it may play an important role in suppression of the immune response against tumour cells in the host.

Cells, Cultured↗
PubMed1978

Distribution along the rat nephron of three enzymes of gluconeogenesis in acidosis and starvation.

Methods were devised or modified which made it possible to measure phosphoenolpyruvate carboxykinase, fructose-1,6-bisphosphatase, and glucose-6-phosphatase in seven defined parts of single nephrons and in patches from thin limb and papilla areas dissected from freeze-dried microtome sections of rat kidney. All three enzymes were essentially confined to the proximal tubule. In normal kidneys, the levels were highest in the proximal convoluted tubule. Glucose-6-phosphatase was 20 times higher in the early part of the convoluted segment than in the late part of the straight segment. With one exception, in acidosis, only phosphoenolpyruvate carboxykinase increased (fourfold in the proximal convoluted segment but much less in the straight portion). In starvation, phosphoenolpyruvate carboxykinase increased about as much as in acidosis in the proximal straight tubule, but not as much in convoluted portions, whereas glucose-6-phosphatase rose modestly in both parts of the proximal tubule and fructose bisphosphatase rose only in the straight tubule, especially the early segment. It is suggested that ammoniagenesis can accompany gluconeogenesis in the proximal convoluted tubule but not in the straight segment.

Acidosis↗