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Biomedical subjects

P Cowen

Publications and source records attributed to P Cowen.

At least 19 recordsLinked to original sources
PubMed2001

A weighted composite dose-response model for human salmonellosis.

This article describes the development of a weighted composite dose-response model for human salmonellosis. Data from previously reported human challenge studies were categorized into two different groups representing low and moderately virulent/pathogenic Salmonella strains based on a disease end point. Because epidemiological data indicate that some Salmonella strains are particularly pathogenic, and in the absence of human feeding study data for such strains, Shigella dysenteriae was used as a proxy for highly virulent strains. Three single-hit dose-response models were applied to the human feeding study data and evaluated for best fit using maximum likelihood estimation: (1) the exponential (E-1pop), (2) the two-subpopulation exponential (E-2pop), and (3) the Beta-Poisson (BP). Based on the goodness-of-fit test, the E-1pop and BP were the best-fit models for low and moderately virulent/pathogenic Salmonella strains, and the E-2pop and BP models were better for highly virulent/pathogenic strains. Epistemic analysis was conducted by determining the degree of confidence associated with the selected models, which was found to be 50%/50% (E-1pop/BP) for low and moderately pathogenic Salmonella strains, and 9.8%/90.2% (E-2pop/BP) for highly virulent strains. The degree of confidence for each component model and variations in the proportion of strains within each virulence/pathogenicity category were incorporated into the overall composite model. This study describes the influence of variation in strain virulence and host susceptibility on the shape of the population dose-response relationship.

Colony Count, Microbial↗
PubMed2001

Management of psoriasis.

BACKGROUND: Psoriasis affects more than 6% of Australian adults. While rarely life threatening it can have an enormous psychosocial impact on sufferers. OBJECTIVE: To outline the treatment options for psoriasis. DISCUSSION: Localised psoriasis can usually be managed by topical therapy but more widespread psoriasis will require stronger treatments such as ultraviolet light, or various oral therapies. There is a great deal of psoriasis research underway and a number of new treatments have evolved over the past few years, some of which have yet to be released in Australia. As with any medical therapy the risks of the treatment must be weighed against the likely benefits. The patient needs to have an informed, sympathetic doctor to discuss the various available options.

Administration, Oral↗
PubMed1998

Plasma levels of von Willebrand factor antigen in acute bronchitis and in a normal population.

von Willebrand factor (vWF) is a large glycoprotein secreted predominantly by endothelial cells in both the systemic and pulmonary circulations and has a central role in the formation of the platelet plug. It has been put forward as a possible marker of endothelial cell injury, but is not ideal in that it is not specific for either the pulmonary or systemic circulation and may be released as part of the acute phase response from otherwise healthy endothelial cells. We undertook two studies (i) to assess within-subject to assess within-subject variation in plasma von Willebrand factor antigen (vWF:Ag) levels over time and to assess between-subject variation in a healthy patient population, and (ii) as part of a descriptive study of acute bronchitis, to assess whether plasma vWF:Ag levels altered in such a common and minor insult. A random sample of patients aged 45-74 years were taken from a local general practice. vWF:Ag levels were measured on three occasions, and spirometry was performed. The descriptive study was undertaken on patients in the general practice diagnosed with acute bronchitis without pre-existing pulmonary disease. Plasma vWF:Ag was measured on presentation and 14 and 42 days later. In 219 randomly selected patients the mean plasma vWF:Ag was similar at all three visits, the within-subject standard deviation being 0.09 U ml(-1) and 1.12 U ml(-1) respectively). There was no correlation between plasma vWF:Ag and C-reactive protein on presentation. We conclude that there is relatively little variation in an individual's plasma vWF:Ag level but that levels increase significantly with age. The observed elevation occurring with acute bronchitis is a true phenomenon; the absence of an associated acute phase response suggests that endothelial cell injury is the mechanism for the rise. These observations are important in the context of vWF as a marker of endothelial cell damage, as a common and supposedly minor insult such as acute bronchitis may markedly raise plasma levels.

Acute Disease↗
PubMed1998

Comparison of one week of oral terbinafine (250 mg/day) with four weeks of treatment with clotrimazole 1% cream in interdigital tinea pedis.

Treatment of interdigital tinea pedis often involves long-term therapy with topically applied preparations. Effective oral preparations, such as the allylamine terbinafine (Lamisil), taken over a shorter period, could provide a useful therapeutic alternative. A total of 269 patients from five centres with clinically diagnosed interdigital tinea pedis were entered into this double-blind, randomized, double-dummy, parallel-group study comparing oral terbinafine 250 mg once daily for 1 week with 1% clotrimazole (Canesten) cream applied twice daily for 4 weeks. Of these, 137 patients were evaluable for efficacy (confirmed dermatophyte infection by microscopy and culture): 63 terbinafine and 74 clotrimazole. At week 4, the mycological cure rates (negative culture at week 1 and negative results on microscopy and culture at week 4 onwards) were very similar (71% for clotrimazole and 72% for terbinafine). There was a faster response rate in the terbinafine group with respect to signs and symptoms at week 1. Both treatments were equally well tolerated; adverse events occurred equally in the two groups. In conclusion, oral terbinafine in a single daily dose of 250 mg for 1 week is as effective and as well tolerated as 1% clotrimazole cream applied twice daily for 4 weeks in the treatment of interdigital tinea pedis.

Adolescent↗
PubMed1997

Pityriasis rubra pilaris and focal acantholytic dyskeratosis.

A 65-year-old man presented with a widespread erythematous maculopapular eruption. Skin biopsy showed spongiosis and focal acantholytic dyskeratosis consistent with Grover's disease. Clinically the eruption evolved to erythroderma with typical features of pityriasis rubra pilaris. On review of the histology, changes consistent with this diagnosis were also present in addition to the acantholytic dyskeratosis.

Acantholysis↗
PubMed1997

Haber's syndrome.

Haber's syndrome is a rare genodermatosis characterised by an early onset rosacea-like eruption associated with multiple truncal keratotic lesions. The present study reports the clinical presentation, histology and response to therapy of two cases of Haber's syndrome. The cases presented with the typical features of Haber's syndrome. Case 1 also had diffuse palmoplantar keratoderma and prominent nail cuticles, and case 2 had diffuse palmar keratoderma. These features have not been previously reported in Haber's syndrome. In the present study Haber's syndrome is reviewed, and its relationship to Dowling-Degos disease and acropigmentation of Kitamura are discussed.

Adolescent↗
PubMed1996

The relationship between asthma admission rates, routes of admission, and socioeconomic deprivation.

This study aimed to explore the relationship between hospital admissions for asthma and socioeconomic deprivation. A retrospective study examined one year of hospital admissions for asthma in the West Midlands region of England (n = 10,044), and in one of the region's wealthier districts, Worcester (n = 251). Age standardized admission ratios (SARs) for asthma, and the routes of hospital admission, were compared with the Towns- end Deprivation Index for the place of residence. Asthma SAR was strongly associated with deprivation as measured by the Towns end Index for the district of residence (Spearman rank correlation coefficient rho = 0.65; p = 0.004). Asthma admission rates for all age groups, except those aged over 65 yrs, were higher in poorer districts. A significantly greater proportion of emergency admissions in poorer districts came via Accident and Emergency departments, rather than general practitioner referrals (rho = 0.76; p < 0.001). Within Worcester District, SAR was associated with Townsend Index for the ward of residence (rho = 0.39; p < 0.001). This remained significant after excluding repeat admissions (rho = 0.45; p < 0.001). We conclude that asthma admissions are strongly associated with deprivation in the community. Differences in the health care received during acute exacerbations by asthma patients from different economic backgrounds is likely to be an important factor in this relationship.

Adolescent↗
PubMed1996

New horizons in the treatment of psoriasis and cutaneous fungal infections.

This article takes a historical perspective and makes an assessment of current and future changes in the treatment of psoriasis and cutaneous fungal infections. Both medical and physical therapies in the management of psoriasis are reviewed and an assessment of the new approaches, compared with the old, is made. The vexing problem of cutaneous fungal infections is considered and the newer topical preparations are reviewed. With the arrival of these newer products improved outcomes for psoriasis and cutaneous fungal infections are being found.

Antifungal Agents↗
PubMed1995

Bullous pemphigoid in an infant.

An acral blistering eruption in a 10 week old baby was found on histology and direct immunofluorescence to be bullous pemphigoid. Circulating auto-antibodies were not detected. He responded quickly to oral prednisolone and there have been no sequelae.

Autoantibodies↗
PubMed1994

A research feasibility assessment of regulatory information systems capacities for investigation of epidemiologic factors in pseudorabies.

Pseudorabies (PR) outbreak-investigation forms from 10 states having the most PR-infected herds were evaluated for agreement in question response-data type, information intent, and outbreak information categories. A question randomly selected from an investigation form had 0.6304 probability of being unique to a single state, and 0.0062 probability of being common to all states. Analysis of outbreak forms, on the basis of information intent, revealed that the probability of a randomly selected question being derived from an information category unique to a single state was 0.0323, whereas the probability of a question being derived from an information category shared by all states was 0.1935. A telephone survey revealed that state PR control officials did not believe additional research on between-herd spread of PR was necessary to successfully complete the eradication program. However, officials believed a better understanding of PR risk factors would enhance program effectiveness and build producer confidence.

Animals↗
PubMed1994

Developing an information resources management strategy for regulatory veterinary medicine: a national imperative.

Lack of a standardized information technology management strategy has resulted in state and federal information systems evolving separately, rather than in tandem. Absence of an information management strategy will eventually affect regulatory program management, epidemiologic research, and domestic and international livestock trade. Producers will ultimately pay the price for the lack of regulatory coordination of US animal health and disease information. The longer the development of state and federal information technology management strategies is postponed, the more cost-, labor-, and time-intensive correcting the deficiency will be. Development of a national information resources management environment is the first step in constructing state and federal information technology strategies.

Animal Diseases↗
PubMed1993

Peritonitis in horses: 67 cases (1985-1990).

Peritonitis was diagnosed in 67 horses between 1985 and 1990: 14 horses developed septic peritonitis after intestinal rupture, 25 horses developed peritonitis after abdominal surgery, and 28 horses had peritonitis not associated with intestinal rupture or abdominal surgery. Forty of 67 horses (59.7%) did not survive. Nonsurvivors had higher heart rates (P = 0.01), RBC count (P = 0.039), serum creatinine concentration (P = 0.036), PCV (P = 0.007), and anion gap (P = 0.005); lower venous blood pH (P = 0.002); and a greater number of bacterial species cultured from peritoneal fluid samples (P = 0.054), compared with those from survivors. Nonsurvivors were more likely to have signs of abdominal pain (P < 0.000), circulatory shock (P = 0.009), and bacteria in peritoneal fluid samples (P = 0.042). Physical examination and peritoneal fluid analysis were the most valuable diagnostic aids for intestinal rupture. Peritonitis after abdominal surgery resulted in high mortality (56%); peritonitis not associated with intestinal rupture or abdominal surgery had lower mortality (42.9%). Clinical and laboratory indices can be of value in determining the prognosis for horses with peritonitis.

Animals↗
PubMed1993

A unique presentation of multicentric reticulohistiocytosis in pregnancy.

We describe a patient with multicentric reticulohistiocytosis who presented, during the second trimester of pregnancy, with symmetric polyarthritis, marked erythematous, pulsatile synovial swelling of the distal interphalangeal joints of both hands, and widespread telangiectasias. She did not have the typical skin manifestations of multicentric reticulohistiocytosis. The erythema and pulsatility of the synovial swellings of the distal interphalangeal joints resolved after delivery, but she continued to have widespread active synovitis, which did not resolve until treatment with low-dose oral methotrexate was instituted.

Adult↗
PubMed1993

Low serum cholesterol and suicide.

"Primary prevention trials which have shown that the lowering of serum cholesterol concentrations in middle-aged subjects by diet, drugs, or both leads to a decrease in coronary heart disease have also reported an increase in deaths due to suicide or violence. There has been no adequate explanation for this association. I have reviewed the relevant published work and describe a physiological mechanism that might account for this curious finding. One of the functions of serotonin in the central nervous system is the suppression of harmful behaviour impulses. When mouse brain synaptosomal membrane cholesterol is increased there is a pronounced increase in the number of serotonin receptors. Low membrane cholesterol decreases the number of serotonin receptors. Since membrane cholesterol exchanges freely with cholesterol in the surrounding medium, a lowered serum cholesterol concentration may contribute to a decrease in brain serotonin, with poorer suppression of aggressive behaviour".

Brain↗
PubMed1992

Fatal myocardial infarction and use of psychotropic drugs in young women.

We have observed an unexpected 17-fold increase in risk of fatal [corrected] myocardial infarction (relative risk 16.9, 95% confidence interval 3.9-72.8) associated with current use of psychotropic drugs. This incidental finding, in a case-control study of cardiovascular mortality in women aged 16-39 not designed to test any hypothesis about psychotropic drugs, should be treated cautiously. There is, however, evidence of a relation between psychiatric morbidity and cardiovascular disease and the association recorded here requires further investigation.

Adolescent↗