Estimation of the secondary attack rate for delta hepatitis coinfection among injection drug users

The secondary attack rate for delta hepatitis coinfection was estimated among a cluster of injection drug users (IDUs). The infections occurred during an epidemic of hepatitis B in a rural area of Nova Scotia in 1988 and 1989. Six IDUs formed a cluster of delta hepatitis coinfections, representing the first reported outbreak of delta hepatitis in Canada. Contact-tracing was used to identify a cluster of 41 IDUs potentially exposed to delta hepatitis. The index case of delta hepatitis coinfection was presumed to have led to five secondary cases. The secondary attack rate was estimated to be 13.2% (95% confidence interval 0.044 to 0.281). The estimated secondary attack rate may be a useful predictor of disease due to delta hepatitis coinfection in similar IDU populations.

Elevated serum cytokines in patients with malignancy and weight-loss

Tumour necrosis factor (TNF) has been implicated in the pathogenesis of cachexia in neoplastic and infectious diseases. In our study, the relationship between TNF and other cytokines in patients with malignancy was studied by measuring the serum levels of TNF, Interleukin-I (IL-1), Interleukin-2 (IL-2), and Interleukin-6 (IL-6). Eight patients with cancer had weight loss >10% of their body weight prior to starting anticancer therapy, and their weight loss was not attributable to gastrointestinal disorder, or other medical conditions. Seven patients with malignancy and no weight loss, as well as three normal donors without malignancy were also tested as controls. TNF, IL-1, IL-2 and IL-6 serum levels were determined using a quantitative ELISA test. Elevated levels of TNF, IL-1, IL-2 and IL-6 were detected in 25%, 12.5%, 12.5% and 50% of patients, respectively. In contrast, TNF levels were elevated in 28.5% of seven patients with cancer and no weight loss. In these patients, IL-1, IL-2 and IL-6 levels were undetectable. No TNF, IL-1, IL-2 or IL-6 could be detected in the sera of normal controls. Elevated cytokines serum levels, and especially IL-6, are detected in patients with cancer-cachexia. The determination of such cytokines may have a prognostic value.

Antimalarial drug utilization by women in Ethiopia: a knowledge-attitudes-practice study

A survey was undertaken between December 1991 and February 1992 to assess the knowledge, attitudes, and practices with respect to malaria of 300 women from six randomly selected rural communities in central Ethiopia. A total of 85% were able to recognize one or more of the common symptoms of the disease; however, the modes of transmission were generally misunderstood and only 23% believed that transmission could be prevented. More women preferred to obtain antimalarials from government clinics rather than from private drug shops, mission clinics, unofficial suppliers of injections, open markets, or from leftover sources. Under-5-year-olds were identified as the most malaria-vulnerable group and given priority for treatment; severity of illness was the principal determinant in seeking treatment. Decisions about treatment were generally made jointly by both parents. Knowledge about the transmissibility of malaria decreased with increasing distance from a health unit (odds ratio: 0.48; 95% confidence interval: 0.27, 0.86). A logistic regression analysis indicated that literacy and village were the most important variables associated with knowledge about preventing malaria.

Underfeeding and body weight regulation in normal-weight young men

The mechanisms of energy regulation invoked by moderate dietary restriction were investigated in seven healthy young men of normal body weight leading unrestricted lives. Following a baseline period of weight maintenance, subjects were underfed by 806 +/- 162 (mean +/- SE) kcal/day for 21 days. Changes in total energy expenditure (TEE) and resting energy expenditure (REE) and subsequent voluntary nutrient intakes were measured. The REE, averaged for fasting and fed states, decreased during underfeeding by 100 +/- 29 kcal/day (P less than 0.01). TEE decreased nonsignificantly by 296 +/- 170 kcal/day, equivalent to an average of 37% of the decrease in energy intake. Body energy stores were estimated to decrease by 510 +/- 172 kcal/day (P less than 0.03), thus compensating for 63% of the dietary energy deficit on average. Voluntary energy intake following dietary restriction increased above the initial amount required for body weight maintenance, was proportional to the weight loss during underfeeding (P less than 0.03), and was associated with a rapid regain of weight lost during underfeeding. These results indicate that energy balance is regulated by adaptive variations in both energy intake and energy expenditure in normal-weight young men leading unrestricted lives but do not support the hypothesis that energy-wasting mechanisms contribute substantially to body energy regulation.

The hepatitis B immunization strategy in Nova Scotia: is it effective?

Since 1987, both hepatitis B disease and hepatitis B vaccine utilization have increased dramatically in Nova Scotia. We present a review of hepatitis B vaccine utilization relative to the occurrence of disease in Nova Scotia. In the two regions with the highest incidence rates, cases have been increasingly associated with lifestyle-related risk factors. Vaccine utilization was primarily for occupational risks. The current provincial hepatitis B immunization strategy is to recommend immunization to targeted high-risk groups. This strategy was judged to be ineffective. The cost of the vaccine is the most important deterrent for adopting an expanded or universal immunization strategy. The pooling of hepatitis B vaccine orders across Canada is suggested as a means to effect significant reductions in the cost of vaccine. Provincial programs would then be able to expand coverage to include populations at immediate risk and youngsters prior to the start of high-risk activity.

An epidemic of hepatitis B among injection drug users in a rural area

An epidemic of hepatitis B occurring in a rural area of Nova Scotia in 1988 and 1989 was investigated. This epidemic identified injection drug use (IDU) as the major determinant of transmission and was the first highly visible indication of IDU in rural Nova Scotia. Contact-tracing was used to identify 186 injection drug users (IDUs), of whom 153 (82%) were interviewed. Of 133 (72%) IDUs who underwent serological testing, 78 had serological evidence of hepatitis B infection. Using epidemiological criteria, 57 IDUs formed a cluster of hepatitis B infections. Using logistic regression techniques, age (O.R. = 1.1), the total number of IDU-contacts named (O.R. = 1.1), and the number of hepatitis B seropositive IDU-contacts named (O.R. = 1.3), were identified as risk factors predictive of an IDU being a cluster case. The characterization of this epidemic may be useful as a model for the spread of hepatitis B and other viral infections among IDUs in rural areas.

The benefits of treating hyperlipidemia to prevent coronary heart disease. Estimating changes in life expectancy and morbidity

OBJECTIVE

To evaluate the lifetime benefits of reducing total serum cholesterol levels to prevent coronary heart disease (CHD).

DESIGN

We developed a CHD primary prevention computer model to estimate the benefits associated with lifelong risk factor modification. We validated the model by comparing the computer estimates with the observed results of three primary CHD prevention trials.

PATIENTS

Men and women age 35 to 65 years who are free of CHD, with total serum cholesterol levels ranging from 5.2 to 7.8 mmol/L (200 to 300 mg/dL), with or without additional CHD risk factors.

INTERVENTIONS

Serum cholesterol reduction through dietary modification or diet and medications.

MAIN OUTCOME MEASURES

Changes in life expectancy and the delay of symptomatic CHD.

RESULTS

The computer forecasts for CHD end points closely matched the observed results of the Lipid Research Clinics Trial, the Helsinki Heart Study, and MRFIT. We then applied the computer model to low-risk and high-risk men and women with total serum cholesterol levels between 5.2 and 7.8 mmol/L (200 and 300 mg/dL) and estimated that, after reducing serum cholesterol levels 5% to 33%, the average life expectancy would increase by 0.03 to 3.16 years. We also forecast that the average onset of symptomatic CHD would be delayed among these patient groups by 0.06 to 4.98 years.

CONCLUSION

We conclude that this computer model accurately estimates the results of clinical trials and can be used to forecast the changes in life expectancy and morbidity (the development of CHD) associated with specific CHD risk reduction interventions. The wide variation surrounding these estimates underscores the need to better define which groups of individuals will gain the most from cholesterol reduction.

Phospholipid composition of cultured human endothelial cells

Detailed analyses of the phospholipid compositions of cultured human endothelial cells are reported here. No significant differences were found between the phospholipid compositions of cells from human artery, saphenous and umbilical vein. However, due to the small sample sizes, relatively large standard deviations for some of the phospholipid classes were observed. A representative composition of endothelial cells is: phosphatidylcholine 36.6%, choline plasmalogen 3.7%, phosphatidylethanolamine 10.2%, ethanolamine plasmalogen 7.6%, sphingomyelin 10.8%, phosphatidylserine 7.1%, lysophosphatidylcholine 7.5%, phosphatidylinositol 3.1%, lysophosphatidylethanolamine 3.6%, phosphatidylinositol 4,5-bisphosphate 1.8%, phosphatidic acid 1.9%, phosphatidylinositol 4-phosphate 1.5%, and cardiolipin 1.9%. The cells possess high choline plasmalogen and lysophosphatidylethanolamine contents. The other phospholipids are within the normal biological ranges expected. Phospholipids were separated by high-performance liquid chromatography and quantified by lipid phosphorus assay.

Accelerated fractionation for high-grade cerebral astrocytomas. Preliminary treatment results

A Phase I/II accelerated fractionation study for high-grade cerebral astrocytomas began in October 1987. Forty-two patients, 25 men and 17 women, were entered in the study. Median age was 58.5 years of age (range, 32 to 78 years). Performance status was 0, 1, 2, and 3 on Eastern Cooperative Oncology Group (ECOG) scale for 13, 19, 9, and 1 patients, respectively. Thirty-six patients had undergone partial resection, and six had stereotactic biopsy only. All patients had histologically proven astrocytomas (6 Grade 3, and 36 Grade 4). Treatment consisted of radiation therapy doses of 4400 cGy in 22 daily fractions to the whole brain plus a boost of 1600 cGy in 8 fractions given concomitantly with the last 8 whole-brain treatments using a twice daily schedule with an interfraction interval of 8 hours. Median survival time was 57 weeks from the date of starting irradiation. Survival was 50% and 28% at 1 and 2 years, respectively. Alopecia and scalp erythema were seen in all patients; nine patients had localized areas of moist desquamation in the retroauricular region. Decreased hearing and serous otitis media were seen in five patients within 1 to 2 months from the end of treatment. Increasing somnolence was marked in eight patients with progressive deterioration of performance status; computerized axial tomography (CAT) scan studies in all eight patients showed evidence of disease recurrence with associated brain edema and mass effect. Three patients had a second resection for a recurrent tumor with no evidence of brain necrosis at craniotomy. To date, the accelerated fractionation schedule appears to be well tolerated with valuable shortening of overall treatment time. The preliminary results are encouraging, and longer follow-up time is required to evaluate tumor control and toxicity.

Early detection and treatment of hyperlipidemia: physician practices in Canada

We surveyed primary care physicians in Canada to determine their current practices regarding the detection and treatment of hyperlipidemia in asymptomatic adults 20 years of age or more and to determine the role of selected patient characteristics (age, sex and the presence of coronary heart disease [CHD] risk factors) in their management decisions. The self-administered questionnaire was completed by 428 of 804 family physicians and general practitioners. The proportion of physicians who reported having tested at least 50% of their adult patients varied from 29% to 85% and was related to the number of CHD risk factors present and the patient's age. The proportion of respondents who reported starting dietary or drug therapy among patients with a cholesterol level of 6.2 mmol/L or less increased as the number of CHD risk factors increased and was not related to patient age or sex. According to the factors examined our results suggest that primary care physicians in Canada select patients for screening and treatment mainly on the basis of CHD risk factors present and that their approach is more conservative than that recommended by the Canadian and US consensus conferences.

Energy expenditure and subsequent nutrient intakes in overfed young men

We investigated the mechanisms of body weight regulation in young men of normal body weight leading unrestricted lives. Changes in total and resting energy expenditure, body composition, and subsequent voluntary nutrient intakes in response to overeating by 4,230 +/- 115 (SE) kJ/day (1,011 +/- 27 kcal/day) for 21 days were measured in seven subjects consuming a typical diet. On average, 85-90% of the excess energy intake was deposited (with 87% of this amount in fat and 13% in protein on average). There was no detectable difference between individuals in susceptibility to energy deposition. The resting metabolic rate, averaged for fasting and fed states, increased during overfeeding (mean +/- SE, 628 +/- 197 kJ/day, P less than 0.01), but at least some of this amount was obligatory expenditure associated with nutrient assimilation. No significant increase in energy expenditure for physical activity or thermoregulation resulted from overfeeding. Thus energy expenditure did not substantially adapt to increased energy intake. However, significant decreases in voluntary energy intake (1,991 +/- 824 kJ/day, P less than 0.05) and fat intake (48 +/- 11 g/day, P less than 0.01) followed overeating, indicating that adaptive changes in nutrient intakes can contribute significantly to body weight regulation after overeating.

Is multiple sclerosis an infectious disease? Inference about an input process based on the output

The output process of an infinite-server queue with a Poisson process input is observed starting at time 0 with an empty queue. It is assumed that the service time distribution is known. This article discusses statistical inference about the input intensity. A controversial issue in the study of multiple sclerosis is addressed as a motivation for the model and methods developed.

Smoking--the effects on cerebral vascular circulation. A variable in patient decision making

Stroke, caused by either infartion or subarachnoid haemorrhage, can have devastating and debilitating effect on its victims. Traditional therapy has focused on the risk factors of hypertension, hyperlipidemia, atherosclerotic heart disease and diabetes milletus. More recently, the literature has focused on smoking and the short and long term effects of cerebral blood flow. The purpose of this paper will be to review the most recent research literature on both the chronic and acute effects of smoking on the cerebral vascular system. More specifically, there will be an examination of the effect of smoking on the outcome of a carotid endarterectomy, subarachnoid haemorrhage and the progression of atherosclerosis. Smoking is harmful and its cumulative effects, along with additive effects must be recognized. Despite increased risk, people continue to smoke affecting disease progression and treatment. Two models will be discussed--the health belief model and the health decision model. These models can provide a basis for nursing to develop and assess comprehensive smoking cessation programmes.

First report of the Australian Corneal Graft Registry

In the Australian Corneal Graft Registry's first 18 months of operation, May 1985 to November 1986, data supplied by 53 surgeons relating to 322 graft recipients have been entered and analysed with respect to: the most common presenting diseases (primarily keratoconus, bullous keratopathy and corneal opacities), risk factors (especially prior sensitisation to HLA antigens, corneal vascularisation, past or present anterior segment inflammation and history of raised intraocular pressure [IOP]), donor and recipient sex, cause of donor death, storage procedures for donor eyes, operative procedures accompanying the grafts themselves, and preliminary indications of overall graft survival by actuarial analysis. It is hoped that the establishment of this Registry will not only reinforce the use of actuarial graft survival analysis as the method of choice for transplantation surgeons wishing to monitor the survival of their patients and grafts, but will also provide a useful service for the Australian ophthalmic community in general.

Characteristics of schizophrenic patients and the outcome of fluphenazine and of electroconvulsive treatments

We examined the outcome with fluphenazine treatment and ECT in a group of 120 patients according to the incidence of psychopathological symptoms, the patients' status on a variety of sociodemographic and anamnestic variables, and their diagnoses according to 13 systems for diagnosing schizophrenia. All had previously been considered to be schizophrenic patients at least once in hospital settings. The outcome with fluphenazine was better in patients with passivity feelings, auditory hallucinations and other hallucinations and delusions. The outcome with patients who had ECT, as judged from the hospital files, was better in those who were preoccupied with delusions or hallucinations and less successful in those who had been diagnosed as having schizophrenia on the first previous occasion when they had been discharged from the hospital.

Sorption studies of heavy metal ions on a novel chelating resin and its application in the stripping of mercury (II)

A chelating resin containing a stable thiol group was synthesised, using polystyrene as the starting material. The resin is stable towards conc. HCl, 0.1M HNO(3) and 0.1M NaOH. The resin shows affinity towards Ag(+), Hg(2+), Bi(3+), Pb(2+), Cu(2+), Zn(2+) and Cd(2+). Extraction of these metal ions as a function of pH, kinetics of exchange and breakthrough capacities is evaluated. The selectivity of the resin for the metal ions is in the order Ag(+) > Hg2+ > Cu2+ > Pb2+ > Cd2+ > Zn2+. The equilibrium constants for exchange and kinetics of exchange are favourable for the recovery of mercury from lean sources. Application of the resin in the stripping of mercury from chlor-alkali plant affluent, and in the enrichment of mercury from seawater, have been investigated. Mercury sorbed resin can be regenerated using 5% thiourea in 0.1M HCl.

Comparison of T8+ cell-mediated suppressor and cytotoxic functions in multiple sclerosis

Patients with progressive multiple sclerosis (MS) and controls were compared with regard to: (a) in vitro pokeweed mitogen (pwm)-induced IgG secretion, as an indirect measure of T8+ cell-mediated suppressor function; (b) alloantigen-directed cytotoxic activity, a predominantly T8+ cell-mediated function. The MS group had increased IgG secretion (4790 +/- 372 ng/ml vs. 1866 +/- 233 ng/ml, P less than 0.001) compared to controls. In contrast, alloantigen-directed cytotoxic activity did not differ between MS and control groups. These results suggest a selective defect of suppressor cell function in MS rather than a generalized dysfunction of T8+ cells. Defective immunoregulatory control coupled with preserved effector functions may contribute to the autoimmune process, suspected to underlie the pathogenesis of MS.

Dissociation of T8+ cell-mediated cytolytic and suppressor functions in young adults

In the normal young adult population, in vitro levels of polyclonally-induced IgG secretion by mononuclear cells (MNCs) vary widely amongst individuals. Levels of IgG secretion correlate with functional suppressor activity of T8+ cells but not with their proportion within the MNCs either prior to culture, or as found in this study, at the end of the culture period. The current study also demonstrates a lack of correlation between T8+ cell-mediated suppressor (Ts) function and a second predominantly T8+ cell-mediated function, alloantigen-directed cytolytic (Tc) activity. Whether this dissociation between Ts and Tc functions reflects quantitative differences in subsets contained within the T8+ population or qualitative differences in the mechanisms required for induction or generation of Ts and Tc remains to be established.

Motility of the human ureter, with special reference to the effect of indomethacin

Ureteral motility was studied in isolated preparations obtained from 19 patients at surgery. Contraction was monitored in an organ bath and contraction recorded isometrically. In all but one patient rhythmic activity with a frequency of 2.0 +/- 0.3 contractions/min was recorded. In 6 patients contractions had to be elicited by stimulation with prostaglandin E2 or F2 alpha. In the remaining cases motility started spontaneously within 30 min. In patients with bilharzia nephropathy various pathological types of contraction were recorded. Motility was dose-dependently inhibited with indomethacin.

Intramammary arterial calcifications associated with diabetes

Arterial calcification was seen on the mammograms of 37 of 319 patients. Twenty-eight patients were known diabetics, while 7 had an abnormal fasting blood sugar level or glucosuria but were not being treated for diabetes. Eighteen (51%) of the 35 diabetic and borderline diabetic patients had breast arterial calcification, compared to only 19 (6.7%) of the 284 nondiabetics (p greater than 0.01). These findings suggest that arterial calcification on mammograms may be a sign of co-existing diabetes.