Cathepsin B and middle cerebral artery occlusion in the rat

Lysosomal proteases, although tightly regulated under physiological conditions, are known to contribute to cell injury after various forms of tissue ischemia have occurred. Because cathepsin B is a prominent lysosomal protease found in brain parenchyma, the authors hypothesized that it may contribute to neuronal cell death after focal cerebral ischemia. The authors measured the expression and spatial distribution of cathepsin B within the ischemic brain in 43 animals by means of immunohistochemical analysis in a rat model of transient middle cerebral artery (MCA) occlusion. Cathepsin B activity was also measured within specific ischemic brain regions by using an in vitro assay (22 animals). In addition, the authors tested the therapeutic effect of preischemic intraventricular administration of stefin A, a cysteine protease inhibitor, on the volume of cerebral infarction after transient MCA occlusion (15 animals). Increased cathepsin B immunoreactivity was detected exclusively within the ischemic neurons after 2 hours of reperfusion following a 2-hour MCA occlusion. Cathepsin B immunolocalization in the ischemic region decreased by 24 hours of reperfusion, but then increased by 48 hours of reperfusion because the infarct was infiltrated by inflammatory cells. Increased immunolocalization of cathepsin B in the inflammatory cells located in the necrotic infarct core continued through 7 days of reperfusion. Cathepsin B enzymatic activity was significantly increased in the ischemic tissue at 2, 8, and 48 hours, but not at 24 hours of reperfusion after 2 hours of MCA occlusion. Continuous intraventricular infusion of stefin A, before 2 hours of MCA occlusion (15 animals), significantly reduced infarct volume compared with control animals (12 animals): the percentage of hemispheric infarct volume was 20+/-3.9 compared with 33+/-3.5 (standard error of the mean; p = 0.025). These data indicate that neuronal cathepsin B undergoes increased expression and activation within 2 hours of reperfusion after a 2-hour MCA occlusion and may be a mechanism contributing to neuronal cell death. Intraventricular infusion of stefin A, an inhibitor of cathepsin B, significantly reduces cerebral infarct volume in rats.

Traumatic grief as a risk factor for mental and physical morbidity

OBJECTIVE

The aim of this study was to confirm and extend the authors' previous work indicating that symptoms of traumatic grief are predictors of future physical and mental health outcomes.

METHOD

The study group consisted of 150 future widows and widowers interviewed at the time of their spouse's hospital admission and at 6-week and 6-, 13-, and 25- month follow-ups. Traumatic grief was measured with a modified version of the Grief Measurement Scale. Mental and physical health outcomes were assessed by self-report and interviewer evaluation. Survival analysis and linear and logistic regressions were used to determine the risk for adverse mental and physical health outcomes posed by traumatic grief.

RESULTS

Survival and regression analyses indicated that the presence of traumatic grief symptoms approximately 6 months after the death of the spouse predicted such negative health outcomes as cancer, heart trouble, high blood pressure, suicidal ideation, and changes in eating habits at 13- or 25-month follow-up.

CONCLUSIONS

The results suggest that it may not be the stress of bereavement, per se, that puts individuals at risk for long-term mental and physical health impairments and adverse health behaviors. Rather, it appears that psychiatric sequelae such as traumatic grief are of critical importance in determining which bereaved individuals will be at risk for long-term dysfunction.

A comparison of the performance and impact of breast cancer screening programmes in East Anglia, U.K. and Bouches du Rhône, France

The purpose of this study was to compare results from the first screening round of two breast cancer screening programmes of similar design implemented in different health care settings. The East Anglian programme is part of the U.K. National Health Service Breast Screening Programme, which is a centralised programme with a limited number of dedicated screening units. The Bouches du Rhône programme is one of 13 French programmes based on a decentralised model using existing radiology clinics. Compliance and cancer detection rates were lower in the Bouches du Rhône programme. Detection rates for small invasive cancers (< or = 10 mm) were similar in the two programmes, although larger cancers (> or = 20 mm) were detected in the Bouches du Rhône programme. Significantly, the shift towards more favourable distribution of prognostic characteristics associated with screen-detected breast cancers compared with those arising outside the programme is less marked in the Bouches du Rhône programme. This is probably due to the more favourable underlying disease status in the district resulting from a long history of breast awareness and spontaneous mammography.

Retrospective study of reasons for improved survival in patients with breast cancer in east Anglia: earlier diagnosis or better treatment

OBJECTIVES

To investigate the recent fall in mortality from breast cancer in England and Wales, and to determine the relative contributions of improvements in treatment and earlier detection of tumours.

DESIGN

Retrospective study of all women with breast cancer registered by the East Anglian cancer registry and diagnosed between 1982 and 1989.

SUBJECTS

3965 patients diagnosed 1982-5 compared with 4665 patients diagnosed 1986-9, in three age groups 0-49, 50-64, > or = 65 years, with information on stage at diagnosis and survival.

MAIN OUTCOME MEASURES

Three year relative survival rates by time period, age group, and stage; relative hazard ratios for each time period and age group derived from Cox's proportional hazards model, adjusted for single year of age and stage.

RESULTS

Survival improved in the later time period, although there was little stage specific improvement. The proportion of early stage tumours increased especially in the 50-64 year age group, and adjustment for stage accounted for over half of the improvement in survival in women aged under 65 years.

CONCLUSION

Over half of the drop in mortality in women aged under 65 years seems to be attributable to earlier detection of tumours, which has been observed since the mid-1980s. This could have resulted from an increase in breast awareness predating the start of the breast screening programme.

Asymptomatic lymphoma associated with elevation of immunoglobulin E

BACKGROUND

Elevation of immunoglobulin E (IgE) is rarely detected in patients with underlying malignancy. There has been only one report of such a finding in a patient with a T cell lymphoma and none to our knowledge in association with a B-cell lymphoma.

OBJECTIVE

To report a patient with elevation of IgE associated with a B-cell lineage lymphoma.

MATERIAL AND METHODS

Case report and review of literature.

RESULTS

A 73-year-old woman was found to have elevated IgE (11,766 IU/mL) in a routine evaluation for rhinitis. No underlying allergic diathesis or disease associated with IgE elevation was noted. Because of an abnormal lymphocyte profile, an extensive malignancy evaluation was performed which revealed a B-cell lymphoma.

CONCLUSION

B-cell lineage lymphoma can be associated with elevated of IgE and should be included in the differential diagnosis in a patient presenting with this finding.

The effects of prenatal alcohol exposure

Exposure to alcohol during gestation can cause persistent abnormalities in physical and cognitive development. Children who meet the clinical definition of fetal alcohol syndrome (FAS) are small for their age, exhibit characteristic facial anomalies, and demonstrate deficits in central nervous system development. Alcohol effects in children with prenatal exposure, but not FAS, are similar, although of smaller magnitude and not necessarily present in all three systems. The degree to which a person is affected by prenatal alcohol exposure depends on the amount, timing, and duration of the mother's alcohol consumption during pregnancy as well as maternal characteristics (e.g., age and comorbid psychiatric disorders) and environmental factors (e.g., socioeconomic status and family problems). Some exposure-related effects, such as growth deficits, are directly related to the amount of alcohol consumed, however, so that even a small amount of alcohol may affect child development. Therefore, the best policy continues to be abstinence during pregnancy.

Environmental acidity and white muscle recruitment during swimming in the brown trout (Salmo trutta)

Electromyographic recordings show that, for adult brown trout swum up to their critical swimming speed (Ucrit) in a flume at neutral pH, white muscle recruitment occurred when speeds approached 1 body length s-1 (BL s-1) and continued to Ucrit (approximately 2 BL s-1) at both winter (5 &deg;C) and summer (15 &deg;C) acclimation temperatures. However, in the majority of fish swum up to Ucrit at sublethal acidic pH, continuous white muscle recruitment did not occur, although all swam above 1 BL s-1. Any observed electrical activity of the white muscle in these individuals was, at best, intermittent. Consequently, the mean Ucrit of these fish was approximately half that of fish swum at neutral pH. In all fish at sublethal pH, red muscle activity was observed for the whole duration of the exercise period, showing that swimming speeds greater than 1 BL s-1 were achieved largely aerobically. Fish that were chased around a tank at sublethal pH appeared lethargic in their escape response, exhibiting little or no burst swimming. Other observed effects of exposure to sublethal pH, which may have affected swimming capacity, included increases in the resting levels of blood and muscle ammonia, reduced muscle glycogen stores and reduced muscle ion concentrations.

An aldose reductase inhibitor but not myo-inositol blocks enhanced polyphosphoinositide turnover in peripheral nerve from diabetic rats

Experimental diabetic neuropathy, whether chemically induced or present in several spontaneously diabetic animal models, is characterized by sorbitol accumulation and myo-inositol depletion and usually also by enhanced turnover of the monoesterified moieties of polyphosphoinositides, particularly phosphatidylinositol-4,5-bisphosphate (PIP2). This study examined the relationship of these alterations by assessing the effects of myo-inositol and the aldose reductase inhibitor, sorbinil, supplied as dietary supplements, on sorbitol and myo-inositol concentrations and incorporation of 32P into polyphosphoinositides in sciatic nerve from rats killed 8 weeks after induction of diabetes with streptozotocin. Nerves from diabetic rats killed after 8 weeks of disease exhibited 52% to 76% greater PIP2 labeling, markedly elevated sorbitol levels, and 30% less myo-inositol when compared with age-matched normal rats. Incorporation of isotope into PIP2 in nerves from animals fed a myo-inositol supplement, added to either a high-sucrose diet or standard rat chow beginning immediately after induction of diabetes, remained substantially elevated, whereas myo-inositol levels were corrected to normal. Essentially the same results were obtained when rats were fed the myo-inositol-containing diet beginning 4 weeks after streptozotocin injection. In contrast, PIP2 labeling in nerves from diabetic rats that received the sorbinil-supplemented diet for either 4 or 8 weeks was not different from that in controls. myo-Inositol levels in these animals were also restored to normal, whereas sorbitol levels remained elevated, albeit reduced by approximately 30%. These results indicate that myo-inositol administration is unable to completely counteract the impact of diabetes on the turnover of monoesterified phosphate groups in PIP2. In contrast, sorbinil can correct this abnormality, but this beneficial effect is not dependent on the presence of normal sorbitol concentrations.

Molecular and epidemiological approaches to the etiology of urinary tract tumors in an area with Balkan endemic nephropathy

Recently, we completed a second biostatistical study of urinary tract tumors (UTT) in areas with Balkan endemic nephropathy (BEN) in the Vratza district, Bulgaria, during the period 1975 to 1991. We confirmed the positive correlation between the incidence of urinary tract tumors (UTT) and BEN demonstrated in our first population-based case control 1977 study. A UTT incidence of 98.9 per 100,000 men and 74.7 per 100,000 women was found in villages most affected by BEN when compared with 11.0 and 6.7 for men and women, respectively, in nonendemic villages. The relative risk (RR) of UTT in BEN villages showed tumors of kidney pelvis and ureters-29 in men and 35 in women and urinary bladder tumors-4 in men and 11 in women. The percentage of food and blood samples containing nephrotoxic and carcinogenic mycotoxin Ochratoxin A (OTA) correlated with the origin of the samples. The most contaminated samples were found in BEN villages and households, and the urinary excretion of OTA was higher in the group of BEN/UTT patients. The UTT DNA's were studied by the 32P-postlabeling method for the presence of OTA-DNA adducts. Some OTA-DNA adducts characteristic for endemic UTT and absent in control nonendemic UTT and nontumorous tissues were described for the first time.

Monitoring interval cancers in breast screening programmes: the east Anglian experience. Quality Assurance Management Group of the East Anglian Breast Screening Programme

Interval cancer rates are a major determinant of the success of a screening programme. In the Swedish two county study, on which the United Kingdom programme is based, a 39% reduction in mortality was observed in screened women aged 50-64. Using data from the Swedish study, the relationship between interval cancer incidence and the likely future effect on breast cancer mortality was quantified. In East Anglia, as elsewhere in the United Kingdom, interval cancers rates are nearly double those obtained in Sweden: interval cancer rates in the first, second, and third years respectively, after a negative screen were 24%, 59%, and 79% of the expected underlying incidence in the absence of screening. The corresponding figures from the two county study were 17%, 30%, and 56%. From these it was estimated that the mortality reduction in East Anglia will be 21%, which is lower than the 35% observed in invited women in this age group in the Swedish two county study and the 25% specified in the Health of the Nation target. In a rereading exercise, using screening mammograms from women who were screen normal, who had screen detected cancers, or who subsequently developed interval cancers, four out of five radiologists recommended recall for around 70% of the original mammograms (classed as screen normal at time of screening) from 33 interval cancers. This suggests that sensitivity is a contributory factor to the higher interval cancer rates in East Anglia.

Cost-effectiveness of alternative interventions for the prevention and treatment of coronary heart disease

Although mortality from coronary heart disease (CHD) in Australia has fallen dramatically since the 1960s, it still remains the major cause of death in Australia and poses a significant burden on the economy. Even though a number of studies have concluded that prevention has been the main determinant of the declines in CHD, a disproportionate amount of health-care expenditure is devoted to treatment rather than prevention. This paper reviews the international literature on the economic appraisal (costs and benefits) of alternative interventions for the treatment and prevention of CHD with the view of assessing whether there is sufficient evidence to justify a reallocation of resources away from treatment to prevention. First, few studies on the economic evaluation of CHD prevention and treatment programs have been undertaken in Australia, with most being from the United States and Europe. Second, assumptions about the specification, measurement and valuation of costs, and the epidemiological evidence on program effectiveness have varied. Third, health promotion and prevention programs are not necessarily more cost-effective than drug or surgical treatments for CHD. Individual interventions must be judged on their own merits. There is a need for a systematic evaluation of interventions for CHD using primary Australian data to better inform decision making on resource-allocation priorities. Such an evaluation should incorporate economic evaluation techniques.

Intraleucocytic malaria pigment and prognosis in severe malaria

The quantity of malaria pigment liberated into the circulation at schizogony reflects the pathogenic sequestered parasite burden in Plasmodium falciparum malaria, and may therefore be a measure of disease severity. Among 300 consecutive adult patients with severe falciparum malaria, the 40 who died had significantly higher proportions of malaria pigment-containing neutrophils on admission (mean = 7.7%, standard deviation (SD) = 5.9%) and pigment-containing monocytes (mean = 8.6%, SD = 5.9%) than did survivors (mean 3.2%, SD = 4.1% and mean 4.8%, SD = 4.6%, respectively) (P < 0.0001). This proved a better indicator of prognosis than the peripheral parasite count. A count of peripheral neutrophils containing visible pigment > or = 5% predicted a fatal outcome with 73% sensitivity and 77% specificity (relative risk 6.2, 95% confidence interval (CI) 3.2-11.8) compared to 60% sensitivity and 57% specificity for parasitaemia > 100,000/microL (relative risk 1.8, 95% CI 1.0-3.3). The peripheral blood count of pigment-containing neutrophils in severe malaria is a rapid, simple, and practical prognostic test.

A longitudinal study of prenatal marijuana use. Effects on sleep and arousal at age 3 years

OBJECTIVE

To test the hypothesis that sleep disruptions would be evident in 3-year-old children with a history of prenatal marijuana exposure.

DESIGN

A prospective study using stratified random sampling beginning in the fourth month of pregnancy. Marijuana and other substance use were assessed by interviews at multiple time points. Offspring were followed up through age 3 years with multidomain assessments at fixed time points, including electroencephalographic sleep studies in the newborn period and at age 3 years.

SETTING

Primary care, prenatal clinic at a university hospital.

SUBJECTS

The sample included 18 children with prenatal marijuana exposure (mean [+/- SD] age, 39.0 +/- 4.4 months) and 20 control children (mean [+/- SD] age, 39.7 +/- 4.4 months). The two groups were similar in relationship to maternal age, race, income, education, or maternal use of alcohol, nicotine, and other substances in the first trimester.

MAIN OUTCOME MEASURE

Sleep variables from polysomnographic recordings at age 3 years.

RESULTS

Children with prenatal marijuana exposure showed more nocturnal arousals (mean [+/- SD], 8.2 +/- 5.3 vs 3.2 +/- 4.6; P < .003), more awake time after sleep onset (mean [+/- SD], 27.4 +/- 20.0 vs 13.7 +/- 12.4 min; P < .03), and lower sleep efficiency (mean [+/- SD], 91.0 +/- 3.8 vs 94.4 +/- 2.1; P < .03) than did control children.

CONCLUSION

Prenatal marijuana exposure was associated with disturbed nocturnal sleep at age 3 years.

THE RELATIONSHIP BETWEEN INTRACELLULAR pH AND SEASONAL TEMPERATURE IN THE BROWN TROUT SALMO TRUTTA

Early studies on reptiles demonstrated that plasma pH increases as body temperature falls (Robin, 1962). Rahn (1967) proposed that plasma pH in all poikilothermic vertebrates is regulated as body temperature changes so as to maintain a constant relative alkalinity, i.e. a constant [OH-]/[H+] ratio, and Reeves (1972) suggested a way in which this could be achieved. Known as the ‘imidazole alphastat hypothesis’, it postulates that PCO2 is regulated (by way of ventilation) so that the fractional dissociation (alpha) of the imidazole moiety of histidine is kept constant. As the pK' of imidazole changes with temperature in about the same manner as the neutral pH of water (Heisler, 1986), the alphastat hypothesis is consistent with that of constant relative alkalinity.

THE RELATIONSHIP BETWEEN INTRACELLULAR pH AND SWIMMING PERFORMANCE OF BROWN TROUT EXPOSED TO NEUTRAL AND SUBLETHAL pH

Adult brown trout were acclimated for 2–4 weeks to artificial soft water ([Ca2+] 25 micromolar) at neutral pH and at summer (15°C) temperature. During this period they swam against a current of approximately 0.25 m s-1. They then had their dorsal aorta cannulated and were exposed to neutral or sublethal pH (4.5) for 4 days in still water. After 4 days of exposure to sublethal pH, critical swimming speed (Ucrit) was 35 % lower than that for fish at neutral pH. There were significant increases in arterial PCO2 and in blood lactate concentrations at Ucrit compared with the values in resting fish at neutral pH and these led to significant reductions in plasma pH. There were no such changes in fish at sublethal pH. There were no significant changes in intracellular pH (pHi) of red blood cells at Ucrit, probably as a result of increases in the levels of plasma catecholamines. There were significant reductions in pHi of red and white muscle fibres at Ucrit. It is argued that these values were not as low in the white fibres as those seen in previous studies after fish have been chased to exhaustion and, therefore, that the fish in the present study were not completely exhausted, although they would no longer swim at a steady speed. As pHi of the red muscle was the same at Ucrit for fish at neutral and at sublethal pH, it is suggested that Ucrit (fatigue) coincides with a particular pHi of the red muscles and possible mechanisms are discussed.

The effects of prenatal tobacco and marijuana use on offspring growth from birth through 3 years of age

This is a prospective study of prenatal substance use. Women were interviewed during their fourth and seventh months of pregnancy, at delivery, and at 8, 18, and 36 months postpartum. At birth, there were 763 liveborn, singleton offspring in the sample. At each phase, the offspring were examined and measured for growth. Data are presented on the relationship between tobacco and marijuana use and the size of the offspring at birth, 8, 18, and 36 months of age. At birth, there was a significant inverse relationship between tobacco use and weight, length, and head circumference. At 8 months of age, only length continued to be associated with prenatal tobacco exposure. By 18 months of age, there was no relationship between prenatal tobacco exposure and size of the offspring. Prenatal marijuana exposure was only associated with decreased length at birth. Neither tobacco nor marijuana use predicted gestational age or morphological abnormalities.

Methodological issues in screening for dementia

Screening for dementia in populations presents particular difficulties for researchers. In the absence of gold standards for diagnosis, the methods used must be determined by the purposes of the study. In two-stage epidemiological study the screening wave and the diagnostic instrument should be considered together in relation to a third proxy gold standard such as progression of the disorder to moderate and greater severity and neuropathological diagnosis. This provides a measure of the predictive performance of the original screening method and its diagnostic phase. To reduce the variance of estimates of prevalence and incidence it is suggested that the screening interview be a subset of the diagnostic interview.

Prenatal marijuana use and neonatal outcome

In a longitudinal study of marijuana and other substance use during pregnancy, women were interviewed at each trimester of pregnancy. Growth parameters, morphological abnormalities and gestational age were assessed for the 519 liveborn singletons. There were few significant effects of marijuana use during pregnancy on birth weight, head or chest circumference, gestational age, or growth retardation after adjustment for covariates using a regression model for analysis. There was a small but significant negative effect of marijuana use during the first two months of pregnancy on birth length and a positive effect of marijuana use during the third trimester on birth weight.