Multivariate logistic analysis of risk factors for stroke in Tilburg, The Netherlands

By means of a case-control study conducted between October 1, 1978, and July 31, 1981, in Tilburg, The Netherlands, various characteristics and events, including personal data, health-related behavior, and medical history, were evaluated as risk factors for stroke. The study subjects included 132 stroke patients and 239 age- and sex-matched control patients interviewed at the two city hospitals. To assess joint effects and possible interactions, and to control for multiple confounding factors, a series of multivariate logistic models for matched data were studied. From this analysis, it appeared that hypertension, acute myocardial infarction, cardiac arrhythmias, transient cerebral ischemic attacks, obesity, physical activity during leisure time, education of head of household, and Rhesus factor were all significant stroke risk factors. These risk determinants demonstrated a multiplicative effect in general; however, the influence of some variables on stroke risk was not constant with age (hypertension, acute myocardial infarction, cardiac arrhythmias, obesity, and Rhesus factor) and sex (hypertension and education of head of household). The relationship of diabetes mellitus to stroke slightly decreased and became nonsignificant after adjustment for factors besides age and sex. Stroke risk was not associated with cigarette and alcohol use, family history of stroke and related disorders, marital status, and ABO blood typing.

Ligand-induced rapid redistribution of lysosomes is temporally distinct from endosome translocation

When many ligands bind to cell-surface receptors, ligand-receptor complexes are internalized via clathrin coated pits by a process called receptor-mediated endocytosis. The cytoplasmic fate of ligands internalized within endocytic vesicles or endosomes is variable. For example, maternal immunoglobulins are transported through the cytoplasm of neonatal intestinal epithelial cells and are exocytosed at the basolateral surface. However, other ligands are degraded as a result of their delivery to the lysosomal compartment of cells. Although the translocation of endosomes to the Golgi region in the cell centre seems to be a general phenomenon presumably coupled to ligand degradation by lysosomes and endosomes and lysosomes undergo saltatory movements within the cytoplasm, the spatial control of interaction between the two structures is not understood. To address this problem we have begun to examine the spatial and temporal intracellular distribution of endosomes and lysosomes. Utilizing a new fluorescent microscopic approach, we have now been able simultaneously to visualize endosome and lysosome populations in living cells. Our results suggest that a specific relocation of lysosomes is rapidly induced upon binding of different types of ligands to the cell surface; this migration of lysosomes to the Golgi region of the cell precedes the translocation of endosomes into the same area.

The effects of taxol on the organization of the cytoskeleton in cultured ovarian granulosa cells

Exposure of ovarian granulosa cells to taxol, a potent microtubule assembly promoting and stabilization agent, results in a time and dose-dependent alteration in the organization of cytoplasmic filaments (microtubules, microfilaments, intermediate filaments) and organelles. Transmission electron microscopy and fluorescence microscopy are used in conjunction with various antimitotic drugs to evaluate the action of taxol on suspension and monolayer cultures. Taxol treatment (1.0 microM) of freshly isolated suspended cells for 4 h leads to the formation of multiple bundles of microtubules emanating from a single centrosomal organizing center. Within 4 h after addition to monolayer cultures, 1.0 microM taxol induces a lateral aggregation of microtubules which, by 12 to 24 h of treatment, results in the appearance of dense bundles of tightly-packed microtubules located near the centrosome, close to the outer nuclear envelope, and at peripheral cytoplasmic sites. By electron microscopy, both lateral and end-on associations between bundled microtubules and the nuclear envelope are apparent. During the course of taxol-induced bundling, intermediate filaments are altered from a normally dispersed fibrous network into perinuclear aggregates. Microtubule bundling is also associated with a rearrangement of actin filaments from stress fibers into a marginal distribution, and actin appears to be excluded from sites of bundle formation. When granulosa cells are treated with equivalent concentrations of the microtubule-disrupting drugs, colchicine or nocodazole, either before or during taxol treatment, bundle formation is prevented suggesting that an intact microtubule network is required for taxol-induced bundling. Colchicine, but not nocodazole, is able to reverse the effects of taxol on bundle formation. The data suggest that the cellular distribution of cytoplasmic organelles, intermediate filaments, and microfilaments are regulated by the cytoplasmic microtubule complex.

Epidemiology of stroke in Tilburg, the Netherlands. The population-based stroke incidence register: 2. Incidence, initial clinical picture and medical care, and three-week case fatality

The results of a prospective population study of stroke in Tilburg are reported. The average annual over-all incidence (per 100,000 population) for the period October 1, 1978-September 30, 1980 was 174 for total cases, 145 for first-ever cases. Males and older persons were at greater risk for a stroke. The vast majority of strokes were thrombo-embolic infarctions. Hemiplegia was the predominant neurological deficit resulting from an insult. Patients with speech problems, as opposed to those without, demonstrated more extreme motor deficit when such occurred. Seventy-four per cent of stroke cases had hypertensive blood pressure readings shortly after onset. Most patients were under hospital care during the initial phase of their attacks. The presence of such handling was related to specific patient characteristics. Three-week stroke case fatality was 30% for all patients registered, and varied significantly by age, sex and diagnostic type.

An evaluation of risk factors for stroke in a Dutch community

The objective of the present epidemiological study was to reevaluate the relationship of various suspect risk factors to stroke within a Dutch community. The Tilburg study lends support to findings in other countries concerning the greater stroke risk of persons with high blood pressure, heart disorders, and diabetes mellitus. Significant interactions of both age and a history of myocardial infarction with hypertension on stroke risk were noted. The presence of overweight and possible transient ischemic attacks (TIA) were found related to stroke onset. No increase in stroke risk was associated with cigarette smoking. The extent of leisure time physical activity during one's lifetime was found inversely related to one's chances for stroke.

The intracellular movement of endocytic vesicles in cultured granulosa cells

Ligand binding to cell surface receptors induces rapid internalization of ligand-receptor complexes by receptor mediated endocytosis. We have examined the intracellular movement of endocytic vesicles, induced by the lectin concanavalin A (Con A), in cultured rat ovarian granulosa cells using fluorescence and electron microscopy. Within 20 minutes of ligand treatment at 37 degrees C, numerous Con A-containing endocytic vesicles form, which migrate to the cell center by 60 minutes. Double label fluorescence microscopy, using fluorescein-Con-A and rhodamine immunofluorescent staining of tubulin or vimentin, indicates that during vesicle migration microtubules and 10-nm filaments are altered in their organization. By 30 minutes, vesicles are associated with microtubule bundles, which subsequently collapse around the nucleus. Similarly, 10-nm filaments accumulate around the nucleus in conjunction with the perinuclear aggregation of endocytic vesicles. Electron microscopy of Con A-horseradish peroxidase-labeled cells demonstrates that endocytic vesicles fuse to form large receptosome-like structures during intracellular migration and these structures are associated with cytoplasmic microtubules and 10-nm filaments. Taxol, a drug that stabilizes microtubules, prevents endocytic vesicle translocation to the Golgi region. Nocodazole, which causes microtubule disassembly, results in the collapse of 10-nm filaments and the central aggregation of endocytic vesicles. The data indicate that the cytoskeleton participates in the directed intracellular movement of endocytic vesicles; the possible subcellular basis for this movement is discussed.

Unexpected trends in the analysis of a questionnaire and interview procedure to detect transient cerebral ischemic attack in a female population

By means of a case-control study, social and biomedical factors were considered in relation to transient cerebral ischemic attack occurrence as determined by questionnaire and interview among a population of females ( greater than 50 years of age) residing in the city of utrecht and surroundings. Contrary to earlier expectations, a greater TIA risk was found associated with: lower systolic and diastolic blood pressure, a low-salt diet for high blood pressure, lower body weight, smaller body surface, and use of medicines for cardiac insufficiency/arrhythmias and chronic anxiety. The importance of hemodynamic processes (i.e. hypotensive episodes of cerebral circulation) for TIA within the general population is emphasized.

Epidemiology of stroke in Tilburg, The Netherlands. The population-based stroke incidence register: 1. Introduction and preliminary results

We present the methodology and some preliminary findings of a population-based stroke incidence register operating in Tilburg (about 150,000 persons), The Netherlands. From October 1, 1978 to March 31, 1979, 152 new strokes occurred giving an estimated overall incidence (per 100,000 population) for total and first attacks of 202 and 162, respectively. No major sex difference in stroke risk (all ages) was noted, although males did have a significantly higher incidence at 55--64 years of age. Stroke incidence increased strikingly with age. Thromboembolic infarcts comprised 83% and intracranial hemorrhage 13% of attacks. Males and females differed little in distribution of stroke types. The proportion of cerebral infarction was higher among older than younger cases. The opposite was true regarding intracranial hemorrhage. Embolic infarcts constituted a significantly higher proportion of cases at 65--74 years of age than at other ages. Hemiplegia and speech deficits dominated the clinical picture at onset. The 3-week case fatality for all strokes was 26%. Both a lowering of consciousness (found among 38% of cases during the first 24 hours) and a history of prior stroke were found related to a reduction in survival. Of patients surviving 3 weeks 25% were completely dependent and 25% partially dependent upon others for personal care.

[Evolution of motor nerve conduction and Hoffmann reflex in 100 patients with chronic renal failure treated by periodic hemodialysis (author's transl)]

The study of motor nerve conduction (MNC) and H. reflex was carried out on 100 chronic uraemic patients, fifty-four males and fourty-six females, treated by periodic hemodialysis. The MNCV is more frequently normal in females than in males. Periodic hemodialysis improves MNCV but sometimes uraemic neuropathy appears with hemodialysis. The MNCV is oftener improved than H. reflex latency. Results are neither significantly improved by a greater number of hemodialysis seances nor in function of the different dialyzers. Any kidney activity does not modify the nerve conduction.

Risk of infection in prolonged central venous catheterization

Classically, duration of infusion was thought to increase the rate of contamination by catheters. The results of this study show that this is not true and that, to the contrary, there is a definite difference in contamination rates between the basilic and the jugular and subclavian veins. The advantage of the basilic way which exists whatever the pathologic condition must undoubtedly determine the choice of this way of catheterization rather than any other.

The biology of social attachments: opiates alleviate separation distress

The possibility that brain opiate systems participate in the control of social affect was assessed by determining capacity of low doses of exogenous opiates (0.125-0.50 mg/kg oxymorphone, and 0.10-0.50 mg/kg morphine sulfate) to reduce distress vocalizations of socially isolated puppies. Low doses of opiates were capable of profoundly reducing crying as well as the motor agitation they exhibit during brief periods of social isolation. Since reductions in crying could be obtained with morphine in the absence of any gross behavioral disturbances, the possibility is entertained that brain opiates may function to control the intensity of emotions arising from social separation. Possible parallels between the biological nature of narcotic addiction and the formation of social bonds are discussed.

Histiocytoma; histiocytoma proliferans; histiocytoma malignum: (clinical and morphological observations)

In a group of 112 cases of histiocytic neoplasms treated 1960--1973 103 benign tumors (histiocytoma), 3 semimalignant tumors (histiocytoma proliferans), and 6 malignant ones (histiocytoma malignum) were diagnosed. Clinical and morphological examinations indicate that under the influence of stimuli histiocytoma may undergo a biological transformation developing into less mature forms such as histiocytoma proliferans and histiocytoma malignum. The treatment of malignant tumors consisted in their removal together with a wide margin or adjacent tissues. In 2 cases enlarged lymph nodes were removed but no metastases were found. In one case death occurred 3 years after operation as a result of distant metastases.