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Biomedical subjects

W Schulte

Publications and source records attributed to W Schulte.

At least 19 recordsLinked to original sources
PubMed1992

Head trauma and the risk of Alzheimer's disease.

A population-based case-control study of the association between head trauma and Alzheimer's disease was conducted in the Netherlands from 1980 to 1987. The study comprised 198 patients with clinically diagnosed early onset Alzheimer's disease and 198 age- and sex-matched population controls. Adjusted for sex, age, family history of dementia, and education, the odds ratio of a history of head trauma with loss of consciousness was 1.6 (95% confidence interval (CI) 0.8-3.4). The odds ratio for men was 2.5 (95% CI 0.9-7.0), and that for women was 0.9 (95% CI 0.3-2.8). The increase in odds ratio was limited to head trauma that occurred within the period of 10 years prior to the onset of dementia (odds ratio = 10.0; 95% CI 1.0-96.8). There was no evidence of effect modification by family history of dementia as measured on a multiplicative scale. However, the power to show interaction may have been low in this study. The authors' findings are compatible with the view that head trauma may be implicated in Alzheimer's disease, with a short lag time between the head trauma and the first symptoms of disease. The association needs to be confirmed in a prospective follow-up study to fully exclude the possibility of recall bias.

Aged↗
PubMed1992

Impact of antihypertensive therapy with isradipine and metoprolol on early markers of hypertensive nephropathy.

In a double-blind, randomized trial with 26 male white patients with essential hypertension in World Health Organization Stages I and II, we examined the impact of calcium entry blockade (5 to 10 mg/day isradipine, N = 14) and beta-blockade (100 to 200 mg/day metoprolol, N = 12) on early markers of hypertensive nephropathy before and after 7 weeks' treatment. Excretion of total protein, albumin, alpha 1-microglobuline, and N-acetyl-beta-glucosaminidase (NAG) were measured in the 24-h urine by radial immunodiffusion and fluorimetric method, respectively. Before therapy, 8 of 26 patients had microproteinuria (31%), six had microalbuminuria (22%), six had elevated urinary NAG activity (22%), and three had elevated alpha 1-microglobulin excretion (11%). In these subjects anti-hypertensive therapy led to a fall in proteinuria (296 +/- 56 v 127 +/- 116 mg/day, P less than .01), albuminuria (44 +/- 24 v 25 +/- 12 mg/day, P less than .05), and NAG excretion (45 +/- 22 v 28 +/- 5, P less than .05). The higher the pretreatment value, the greater the fall was in proteinuria (r = +0.55, P less than .01), albuminuria (r = 0.80, P less than .001), and NAG excretion (r = 0.60, P less than .01). We did not observe any significant difference in clinical characteristics, blood pressure, or urinary excretion of protein, albumin, or NAG between the two treatment groups, either before or after therapy. Thus, antihypertensive therapy reduced excretion of total protein, albumin, and NAG activity in hypertensive patients with elevated pretreatment values, potentially indicating reversal of early hypertensive nephropathy.(ABSTRACT TRUNCATED AT 250 WORDS)

Antihypertensive Agents↗
PubMed1992

High-speed filming of the Periotest measurement.

Periodontal disease may be diagnosed with the Periotest technique, which involves electronically controlled and reproducible percussion of tooth. The movement on percussion was investigated with high-speed film and then compared with the return of teeth after static deflection for several seconds as has been reported previously by Lukas and Scholz. The elastic and viscous properties of the periodontium and the surrounding bony tooth socket are to a large extent non-linear. The 10-20 microns deflection of the healthy tooth represents only a fraction of static tooth mobility published by Parfitt or Schulte et al. The visco-elastic properties of a healthy tooth enabling the percussion of the Periotest tapping head to be decelerated in less than 1 ms are largely lost in periodontitis. It is this essential difference which the Periotest method utilizes.

Alveolar Bone Loss↗
PubMed1992

Periotest for measuring periodontal characteristics--correlation with periodontal bone loss.

The Periotest measures the reaction of the periodontium to a defined percussive force. The percussion is applied to the tooth by an electronically controlled tapping head. Information on structural change is obtained by measurement of both the elastic and viscous characteristics of the periodontium. The latter prevent oscillations of the tooth in the alveolar bone. A value is calculated and is displayed as a "Periotest value". The following research report shows the relation of Periotest values to bone loss. Bone loss was quantitatively determined for 2312 teeth from orthopantomographic radiographs and for 900 teeth exposed to intra-oral films using the standard paralleling technique. A differentiation was made between vertical and horizontal bone loss. Clinical mobility index, pocket depth, gingival recession and papillary hemorrhagic index were also measured. There was a strong association between the Periotest value and bone loss. These results suggest that Periotest evaluation provides an objective indication of the extent of periodontal bone loss.

Adult↗
PubMed1992

The Periotest method.

The Periotest is a new instrument for the diagnosis of periodontal diseases. The 'Periotest value' depends to some extent on tooth mobility, but mainly on the damping characteristics of the periodontium. The Periotest measures the reaction to a reproducible impact applied to the tooth crown. The Periotest value is a biophysical parameter.

Electronics, Medical↗
PubMed1992

Impact of angiotensin converting enzyme inhibition on the haemodynamic profile during laboratory stress tests.

To determine the haemodynamic profile of angiotensin converting enzyme (ACE) inhibitors during stress, the cardiovascular response to various stress tests was examined in patients with essential hypertension before and after three months of therapy with lisinopril. Eighteen white patients were enrolled in the trial, of whom 12 completed the protocol. ACE inhibition with lisinopril effectively reduced systolic and diastolic pressure in the office (P less than 0.001), at rest (P less than 0.002), during mental stress (P less than 0.003), cold pressor test (P less than 0.003), and reaction time task (P less than 0.05). During physical exercise only diastolic pressure was significantly reduced (P less than 0.02). The fall in peak systolic pressure during cold pressor test and reaction time task was more pronounced than the fall in casual systolic pressure (P less than 0.05). At rest, cardiac output was unchanged, but total peripheral resistance was reduced after medication with lisinopril (P less than 0.05). During the cold pressor test, the increase in total peripheral resistance was attenuated by ACE inhibition (P less than 0.04). The haemodynamic response profile was not altered during the other tests. It is concluded that in middle-aged men ACE inhibitors reduce blood pressure during a variety of stressful events without altering the haemodynamic profile and even attenuating vasoconstriction during stress. This response pattern to ACE inhibition with lisinopril may reduce the impact of recurring stress-induced increases of blood pressure and of exaggerated vasoconstrictive stimuli on the cardiovascular system.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1992

Pharmacological modulation of stress-induced cardiovascular hyperreactivity in essential hypertension.

The effects of the calcium antagonist isradipine and the beta-blocker metoprolol, which are based on different antihypertensive therapeutic principles, were evaluated in 52 men with mild-to-moderate hypertension in a 6-week, double-blind, randomized study. Mental stress-testing was performed before and after active treatment. With isradipine (n = 26), the stress-induced responses of cardiac output and total peripheral resistance were not significantly changed, but the blood pressure (BP) response, specifically the diastolic response, was decreased. With metoprolol (n = 26), there was a decreased response of cardiac output and an increased response of total peripheral resistance, and the BP response was even greater than it had been before treatment. Thus, these results indicate that beta-blockade is effective in reducing cardiac responsiveness but, because of vascular counterregulatory mechanisms, BP responsiveness is not decreased. In contrast, calcium antagonism preserves the physiological hemodynamic profile while reducing BP responsiveness to stress.

Calcium Channel Blockers↗
PubMed1991

Continuous systemic 5-fluorouracil infusion in refractory prostatic cancer.

Twenty patients with metastatic prostatic cancer were treated on an ambulatory basis with continuous 5-fluorouracil (5-FU) infusion 250-300 mg/M2 per day through a chronic indwelling central venous catheter. All patients had symptomatic, progressive disease despite previous standard therapies. Partial remission was seen in 2 of 20 patients (10%), stable disease in 9 of 20 (45%), and progressive disease in 9 of 20 (45%); mean duration of benefit in responding and stable disease patients was six months. Improvement in pain and ECOG performance status were seen in most of the patients in the responding and stable disease categories. Forty percent of the patients experienced no significant drug toxicity; treatment interruption was necessary for stomatitis in 6 patients (30%), hand/foot syndrome in 3 patients (15%), and diarrhea in 1 patient (5%). No significant myelosuppression or other significant organ toxicities were encountered. Continuous systemic venous infusion of 5-FU may provide significant palliative effect for some patients with symptomatic, refractory carcinoma of the prostate.

Drug Evaluation↗
PubMed1991

Contribution to the functional surface structure of endosseous implants.

An endosseous implant that should allow osseointegration as well as fixation by connective tissue has been developed. A special surface structure consisting of titanium wire loops on a titanium implant was produced by diffusion bonding. The mechanical properties of this implant are investigated.

Dental Bonding↗
PubMed1990

[Significance of microproteinuria for early detection of hypertension-induced end organ damage].

To investigate the clinical importance of microproteinuria, we examined the prevalence of microproteinuria and its relation to cardiac structural adaptation in 80 male, middle-aged patients with essential hypertension. Patients with secondary causes of hypertension were ruled out. 14 out of 80 hypertensives (18 percent) were found to have microproteinuria defined as "negative" for urinary protein excretion in the conventional test, but "positive" (above the upper normal limit) in the 24-hour urine samples. Patients with microproteinuria had a similar age and body weight, but a higher systolic and diastolic pressure (161 +/- 14/104 +/- 12 vs 148 +/- 14/97 +/- 9 mmHg, p less than 0.02) and greater creatinine clearance (163 +/- 36 vs 136 +/- 33 ml/min, p less than 0.01) than those with normal protein excretion. Also, hypertensives with microproteinuria had a greater left ventricular mass (241 +/- 57 vs 207 +/- 45 g, p less than 0.05) and greater cross sectional area (22.2 +/- 2.8 vs 20.5 +/- 2.9 cm2, p less than 0.05) evaluated by 2-D guided M-mode echocardiography than the control group. A positive Sokolow-index was more prevalent in patients with microproteinuria than in those without (x2 = 6.2, p less than 0.02). Patients with essential hypertension and microproteinuria (prevalence 21 per cent) were characterized by a higher arterial pressure, by a higher degree of echocardiographic and electrographic evidence of left ventricular hypertrophy. Thus, microproteinuria might serve as a marker for early target organ damage in essential hypertension.

Adult↗
PubMed1990

Relation of hemodynamic reaction during stress to left ventricular hypertrophy in essential hypertension.

To elucidate the impact of increased afterload during physical and mental stress on myocardial hypertrophy, a homogeneous population of 73 patients with untreated mild-to-moderate essential hypertension were enrolled in the current study. Left ventricular mass and cross-sectional area, both determined by 2-D guided M-mode echocardiography, were related to blood pressure measured at rest as well as during various stress situations. Left ventricular mass and cross-sectional area correlated with systolic pressure at work site (r = 0.28 and r = 0.23 respectively, P less than .05) and systolic pressure at complete rest (r = 0.35 and r = 0.33, P less than .01). Neither the response in blood pressure to mental arithmetic or a bicycle exercise test performed in the laboratory, nor blood pressure during both stress tests were significantly related to the degree of left ventricular hypertrophy. In addition, patients with a hyperreactive response to mental arithmetic or to the physical stress test did not disclose a greater left ventricular mass than normoreactors. Examining the hemodynamic response pattern during mental arithmetic, we found that patients with vasoconstriction during mental stress had a greater left ventricular mass than individuals with vasodilation during mental stress (244 +/- 73 v 204 +/- 53 g, P less than .05), but this was due to the impact of obesity on left ventricular mass (analysis of covariance: F = 2.1, P = NS). Thus, blood pressure at work site and at rest, but not blood pressure during mental or physical stress, nor the response of blood pressure to both stress tests, was linked to the degree of left ventricular hypertrophy.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiomegaly↗
PubMed1990

[Determinants for myocardial hypertrophy in mild essential hypertension. The effect of sodium chloride on left-ventricular hypertrophy].

The impact of clinical parameters on the pathogenesis of myocardial hypertrophy was examined in 75 male patients with mild essential hypertension. Clinical parameters were age, body weight, sodium excretion (as an estimate for dietary salt intake), systolic and diastolic blood pressure at work, casual blood pressure, resting and stress blood pressure during mental stress test and physical exercise. Left ventricular mass as a parameter for the degree of left ventricular hypertrophy was assessed by 2-D guided M-mode echocardiography. Left ventricular mass correlated with body weight (r = 0.47, p less than 0.002), with body mass index (r = 0.48, p less than 0.001), with systolic blood pressure at the worksite (r = 0.28, p less than or equal to 0.05), and systolic blood pressure at rest (r = 0.35, p less than or equal to 0.01), whereas no correlation was found between casual or stress blood pressure readings during physical exercise and mental stress with the degree of left ventricular hypertrophy. Sodium excretion was related to the end-diastolic diameter of the left ventricle (r = 0.33, p less than or equal to 0.01) and to left ventricular mass (r = 0.35, p less than or equal to 0.01). Multiple regression analysis revealed that sodium excretion over 24 hours, systolic blood pressure at the worksite and body mass index were independent determinants of left ventricular mass. Thus, dietary salt intake was found to modulate the degree of left ventricular hypertrophy independently of the pressure load imposed on the myocardium.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1978

[Animal experiments on the question of healing around the Tübingen immediate implant].

In order to determine the capacity for deposition of bone, 5 Beagles were each implanted extraorally with 6 aluminium oxide cylinders into the horizontal mandibular ramus. 4 months after the first implantation a second implantation was carried out in the opposite side with similar cylinders. After six months all were removed so that in altogether 60 implants the bone deposition could be observed 4 months and 2 months after implantation. A further 14 dogs received altogether 55 Tuebinger immediate implants. All animals were regularly observed post-operatively. After 6 months all cylinder full-implants had been accepted without reaction. All tooth implants which were either not put under strain or were immediately put under pressure healed without reaction. After three months 19 implants were lost and a further 5 were lost after 8 months. All cylinder implants were histologically examined 6 months after first implantation.

Animals↗