Infection of laying hens with Salmonella enteritidis PT4 by conjunctival challenge

The direct administration of either 103 or 108 cells of Salmonella enteritidis phage type 4 on to the conjunctiva of laying hens resulted in systemic infection. The bacterium was isolated from a variety of tissues, including the ovary and oviduct, and it was excreted in faeces for at least 27 days after infection.

Postmarketing surveillance of captopril for hypertension

1. A scheme for augmented spontaneous reporting of adverse drug events using advanced view data systems was developed and applied to study 67,698 consecutive patients prescribed captopril in general practice for the treatment of hypertension. 2. Captopril was an effective hypotensive agent in this population, as only 1.9% of patients were withdrawn because of apparent inefficacy. 3. Adverse effects of captopril resulted in withdrawal of treatment in 8.9% of recipients, and such effects were more frequent in elderly and female recipients. 4. Skin reactions--usually maculopapular rashes--tended to occur early during therapy whereas cough occurred much later and was reported more frequently in non-smokers. 5. Some 1.1% of recipients died during follow-up. There was no evidence of any unusual or unexpected causes of death which might be partially or totally captopril-related in the study cohort. 6. The study confirms the feasibility of large scale postmarketing surveillance studied in general practice and allowed risk benefit assessments to be made on the use of captopril for treating hypertension.

Techniques for the isolation of salmonellas from eggs

1. When the contents of 4 or more naturally-contaminated intact eggs were combined, the isolation rate of Salmonella enteritidis was improved by extending incubation at 37 degrees C from 24 to 48 h before sub-culture. 2. The isolation rate of salmonellas from raw homogenised whole egg was significantly increased by the inclusion of Novobiocin and Cefsulodin in the primary culture media. 3. Rappaport Vassiliadis broth was found to be superior to Selenite as a selective enrichment medium.

Airborne infection of laying hens with Salmonella enteritidis phage type 4

Hens were exposed to small-particle aerosols containing different concentrations of Salmonella enteritidis phage type 4. They developed a systemic infection and some birds were still excreting the organism in the faeces when killed 28 days after infection. S enteritidis was present for a similar period in a wide range of alimentary tract issues and in the ovary and oviduct.

Statistical evaluation of the fixed-dose procedure

The fixed-dose procedure (FDP) was proposed by the British Toxicology Society in 1984 as an alternative to the LD50 study in the assessment of the acute oral toxicity of a substance. This paper presents a statistical evaluation of this procedure. A mathematical description of the FDP shows that the starting dose can affect the toxic classification of a substance. The toxic classification based on the FDP is compared with that based on an LD50 test. This shows that, in general, the FDP is likely to result in the same classification or a less toxic one than the LD50 procedure. However, for substances with very shallow dose-response slopes, the FDP is likely to result in the same classification or a more toxic one. The expected number of animals that will be tested and will die using the FDP will be reduced compared with the LD50 study. The results from the international validation study carried out in 1989 showed agreement with the results predicted from the mathematical model.

Salmonella enteritidis PT4 infection in specific pathogen free hens: influence of infecting dose

The period during which specific pathogen free hens, infected by direct introduction into the crop of either 10(3), 10(6) or 10(8) cells of Salmonella enteritidis PT4, excreted the organism in faeces was closely related to the size of the inoculum, with the birds excreting for mean periods of 3.4, 16.4 and 36.8 days, respectively. The production of either IgG or IgM was also dose related with the birds which received 10(3) cells having lower antibody levels than those in the other two groups. In contrast, there was no relationship between the contamination of egg contents and either antibody status, faecal excretion, or the dose administered.

A general parametric approach to the meta-analysis of randomized clinical trials

Meta-analysis provides a systematic and quantitative approach to the summary of results from randomized studies. Whilst many authors have published actual meta-analyses concerning specific therapeutic questions, less has been published about comprehensive methodology. This article presents a general parametric approach, which utilizes efficient score statistics and Fisher's information, and relates this to different methods suggested by previous authors. Normally distributed, binary, ordinal and survival data are considered. Both the fixed effects and random effects model for treatments are described.

Numbers of Salmonella enteritidis in the contents of naturally contaminated hens' eggs

Over 5700 hens eggs from 15 flocks naturally infected with Salmonella enteritidis were examined individually for the presence of the organism in either egg contents or on shells. Thirty-two eggs (0.6%) were positive in the contents. In the majority, levels of contamination were low. Three eggs, however, were found to contain many thousands of cells. In eggs where it was possible to identify the site of contamination, the albumen was more frequently positive than the yolk. Storage at room temperature had no significant effect on the prevalence of salmonella-positive eggs but those held for more than 21 days were more likely (P less than 0.01) to be heavily contaminated. In batches of eggs where both shells and contents were examined, 1.1% were positive on the former site and 0.9% in the latter.

Pharmacokinetics of haloperidol and fluphenazine decanoates in chronic schizophrenia

In a double-blind comparison of haloperidol decanoate and fluphenazine decanoate given 4-weekly for 60 weeks as maintenance therapy in 38 chronic schizophrenic in-patients, plasma haloperidol, fluphenazine and prolactin levels were measured at regular intervals by radioimmunoassay. After the first injection, the mean plasma haloperidol level was highest at week 1 and fell gradually towards week 4. Mean pre-dose haloperidol levels changed little after week 8. Results suggested an absorption half-life of 4 weeks, although, in three cases steady state was only achieved after 11 monthly injections. Steady state levels of both haloperidol and fluphenazine correlated highly with dose. In two sub-groups observed at steady state, both drugs produced a biphasic pattern of plasma drug concentration between injections, a rapid rise on day 1 followed by stable elevated levels and a gradual return to pre-injection concentration by the end of week 4. In the fluphenazine sub-group there was a second peak on day 7 and a steeper decline, so that the mean area-under-curve in week 4 was 64% of that in week 1. Drug injections at steady state induced an increase in prolactin secretion in all of the fluphenazine sub-group and in half of those receiving haloperidol. Plasma prolactin changes resembled those for drug concentrations, but differences in times of peaks on day 1 resulted in weak correlations. Fluphenazine appeared more potent than haloperidol in provoking prolactin secretion.

Allopurinol dosage selection: relationships between dose and plasma oxipurinol and urate concentrations and urinary urate excretion

1. Allopurinol usage in 50 patients of a city teaching hospital was surveyed. 2. The plasma concentrations of oxipurinol and uric acid and the urinary production of uric acid were examined. 3. The daily doses of allopurinol ranged from 50 to 1200 mg but 83% of patients were taking 300 mg daily. 4. A wide range of plasma oxipurinol concentrations was observed from 2.8 to 55.8 mg l-1 with a mean +/- s.d. of 15.2 +/- 11.7 mg l-1. 5. The population studied included a high proportion of patients with renal impairment and creatinine clearance was a significant determinant of oxipurinol concentrations (P less than 0.005). 6. There was no significant correlation between plasma urate and plasma oxipurinol concentrations and only a few plasma urates were above the upper limit of the reference range of the laboratory. 7. It was apparent that many patients were taking unnecessarily high daily doses of allopurinol and that renal status was not always considered when deciding dosage regimens of allopurinol.

Relationship between plasma oxipurinol concentrations and xanthine oxidase activity in volunteers dosed with allopurinol

1. 1-methyl xanthine (1-MX) is metabolized exclusively to 1-methyl uric acid (1-MU) by the enzyme xanthine oxidase. 2. The ratio of 1-MU to 1-MX in the urine, following a dose of 50 mg of 1-MX infused intravenously over 20 min, was used to measure the inhibition of xanthine oxidase induced by different doses of allopurinol. 3. Normal volunteers (n = 8) were given allopurinol 50, 100, 300 and 600 mg daily for 1 week each, in random order and 1 week separated each treatment. Inhibition of xanthine oxidase was assessed twice, on the last 2 days of each treatment week. 4. Steady-state oxipurinol concentrations increased linearly with increasing dose of allopurinol. 5. There was a hyperbolic relationship between the 1-MU/1-MX ratio and plasma oxipurinol concentrations, with an initial steep decline in the ratio which plateaued when plasma oxipurinol was around 4-6 mg l-1. This reduction in the ratio was quickly reversible upon cessation of allopurinol. 6. The 50% and 90% effective inhibitory oxipurinol concentrations, in relation to the 1-MU-/1-MX ratio were 1.4 +/- 0.46 and 4.08 +/- 2.03 mg l-1 respectively. 7. The concentration of oxipurinol required for almost complete inhibition of the enzyme was substantially less than those often observed in clinical practice.

Efficient selection of controls for multi-centered collaborative studies of rare diseases

An increasing number of epidemiologic studies of rare diseases are being conducted as collaborative ventures among several institutions in different geographic areas. Geographic area must be accounted for in the analysis, along with age and other potential confounders. This paper shows that it may not be possible to accurately predict the distribution of persons with rare diseases by age and geographic area. Therefore, selecting controls by matching on age group and geographic area is more efficient than selecting controls in all age and geographic area strata based on prior estimates of expected numbers of cases.

Factors related to successful outcome in the treatment of sexually unresponsive women

Couples in whom the main complaint was of a lack of female sexual response were treated using a practical counselling approach. A number of pre-treatment measures were studied to determine which factors were predictive of treatment outcome. While age and chronicity were not predictive, the quality of the general relationship and measures of sexual attitude did give useful indications of likely outcome.

The assessment of cardiac hypertrophy at autopsy

The total weight of the normal adult human heart as well as that of each ventricle is proportional to body size. Body weight is superior to height as a predictor of total heart and isolated ventricular weights. Ventricular wall thickness is an insensitive means of assessing ventricular hypertrophy. Heart weight is a poor predictor of isolated right ventricular mass but a slightly better predictor of isolated left ventricular mass. The only method of determining the presence or absence of hypertrophy with confidence is to use the Fulton technique for isolated ventricular weights. The use of an arbitrary upper and lower limit, as currently used, for isolated ventricular weights obtained by Fulton's method may, however lead to errors in determining the presence or absence of ventricular hypertrophy.

Invasive cervical cancer and depot-medroxyprogesterone acetate. WHO Collaborative Study of Neoplasia and Steroid Contraceptives

Preliminary results of a study of the possible relationship of depot-medroxy-progesterone acetate (DMPA) to invasive cervical cancer are presented. The findings are based on data from three participating centres in Thailand and one in Mexico. A relative risk for cervical cancer of 1.2 was observed in women who had ever used DMPA; this was not statistically significant. No consistent increase in risk with duration of use was observed, although a relative risk of 2 was found in women who had used DMPA for more than 5 years. This observed increase in risk was confined to women who were aged under 46 years or who had first been exposed to DMPA before 30 years of age. These findings are based on small numbers of subjects, and may not represent a causal relationship.

Breast cancer and depot-medroxyprogesterone acetate. WHO Collaborative Study of Neoplasia and Steroid Contraceptives

The preliminary results of a study of the incidence of breast cancer in relation to use of depot-medroxyprogesterone acetate (DMPA) are presented. The findings are based on data from three participating centres in Thailand, and one each in Kenya and Mexico. A relative risk for breast cancer of 0.7 was observed in women who had ever used DMPA; this was not statistically significant. Although no consistent decrease in risk with duration of use was observed, the lowest relative risk (0.5) was observed in women who had used DMPA for three or more years. These findings are based on small numbers and must be considered preliminary. However, they provide no evidence that DMPA increases the risk of breast cancer, and suggest that it may exert a protective effect, particularly in long-term users.

Psychological and hormonal factors in the treatment of female sexual dysfunction

Forty-eight couples with a presenting problem of female sexual unresponsiveness were treated in a controlled study using a balanced factorial design. The factors varied in this design were medication (testosterone or placebo), treatment frequency (weekly or monthly sessions), and the number of therapists involved (one female or a male/female pair). All counselling was adapted from that described by Masters & Johnson (1970) and Heiman et al. (1976). Results were assessed before and after a 3-month treatment period, and again 6 months later. Contrary to expectations from earlier work, there was no benefit attributable to testosterone or to the use of two therapists; self-ratings favoured weekly sessions with one therapist. It was concluded that testosterone (at least in the dosage used) is unlikely to have a useful place in the treatment of sexually unresponsive women, but that weekly counselling sessions with a single therapist is a reasonably effective and economic form of sex therapy. Findings from this research suggest the need for a clearer understanding of aetiological and treatment mechanisms.

Outcome in elderly psychiatric patients: implications of cognitive changes

Elderly psychiatric patients who were in contact with the hospital service one year after admission were reassessed using clinical and psychometric measures. Outcome was determined by survival over the following four years. On the psychometric tasks, there was a differential tendency for those who subsequently died to show declining levels of functioning over the year.

Elderly psychiatric patients: a five-year prospective study

In a prospective study, 200 elderly psychiatric patients were followed for 5 years. A poor outcome–death or continuing major reliance on the hospital based services – was associated with poor intellectual functioning on admission. Continued use of the hospital services was also related to past psychiatric history.