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Biomedical subjects

F Ruschitzka

Publications and source records attributed to F Ruschitzka.

27 records · Page 2Linked to original sources
PubMed1995

Effects of endothelin on hemodynamics, prostaglandins, blood coagulation and renal function.

The interaction of the endogenous vasoconstrictors endothelin (ET), angiotensin II (Ang II) and catecholamines with the kallikrein-kinin-, prostaglandin and renin-aldosterone systems in the pathogenesis of acute renal failure (ARF) is still to be defined. In 18 anesthesized pigs the influence of i.v. bolus applications of ET (2 micrograms/kg), Ang II (10 micrograms/kg) and norepinephrine (NE; 20 micrograms/kg) on hemodynamics, plasmatic coagulation and fibrinolysis system, prostaglandins and renal function was studied. ET induced a biphasic change in blood pressure, starting with an initial short-lasting reduction followed by a long-lasting elevation of systolic and diastolic blood pressure. Endothelin bolus resulted in a significant increase of 6-keto-PGF1 alpha, PGE2 and TXB2 plasma levels (P < 0.05 against preinjection values), whereas prostaglandins remained unchanged in the Ang II and NE groups. There was a distinct correlation between the plasma ET and 6-keto-PGF1 alpha levels (r = 0.82). In contrast to Ang II or NE, ET induced a shortening of the activated partial thromboplastin time (aPTT) and increase of antithrombin III levels (ATIII), fibrin monomers (FM), prekallikrein (PKK) and factor VIII activity at the beginning. Finally a pronounced decrease of ATIII, FM and PKK occurred, indicating a consumptive coagulopathy. At the end of the experiment, elevated plasma renin activity and pCO2, significantly decreased creatinine clearance, blood pH, pO2, base excess, HCO3-, oxygen saturation (P < 0.01), a distinct glomerular proteinuria, and a final anuria were observated. These results reveal that ET activates the plasmatic coagulation system and induces an ARF accompanied by impairment of pulmonary function.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II↗
PubMed1992

[Long-term blood pressure measurement for evaluating the first dose response of captopril and ramipril in patients with a stimulated renin system].

First-dose-response of captopril 1 x 25 mg (no prodrug) and ramipril 1 x 2.5 mg (prodrug) were compared in two groups of 17 patients with moderate or severe hypertension and stimulated renin-angiotensin system (because of continuous diuretic therapy) by means of 24-h blood-pressure measurement at the 1st and 7th day of therapy. In the ramipril-group the antihypertensive effect started after 2 h, had its maximum (mean: -13/-8 mmHg) after 4 h and remained unchanged for 8 h. The antihypertensive effect was significant for 24 h. There was a slightly but not significant improved blood-pressure reduction at the 7th day compared to the 1st. The captopril-group showed a fast and marked decrease of blood pressure within the first hour, and reached its maximum (mean: -18/-10 mmHg) after 2 h. After 7 h there was no antihypertensive effect detectable. At the 7th day blood-pressure reduction was less pronounced compared to the 1st day. The results show that initial decrease of blood pressure in risk-patients is less severe with prodrug-ACE-inhibitors with slow onset of action so that counterregulation can be activated and prevent severe, fast, ACE-inhibitor-induced hypotension. 24-h-blood-pressure measurement is a sufficient method to evaluate first-dose-response of ACE-inhibitors.

Adult↗
PubMed1992

[Diagnostic significance of absent nocturnal blood pressure decrease in 24-hour long-term blood pressure measurement].

Patients (pts) with essential hypertension normally exhibit a typical diurnal variation with a nocturnal blood-pressure (BP) decreased. A lack of this periodicity is often reported in pts with secondary hypertension. 24-h BP measurement was therefore performed in 308 pts with essential hypertension, and in 172 pts with secondary hypertension, in order to evaluate the diagnostic value of nocturnal BP decrease. Diagnoses of the secondary hypertensives were: renoparenchymatous hypertension (n = 29), diabetic nephropathy (n = 24), morbus Conn (n = 6), renal artery stenosis (n = 32), pheochromocytoma (n = 5), hemodialysis pts (n = 30), and kidney transplantation (n = 44). Pts with essential hypertension showed a mean systolic and diastolic BP decrease during the nighttime period of 22 +/- 7 mmHg and 17 +/- 5 mmHg, respectively. In contrast, the corresponding values in secondary hypertension were 5.7 +/- 9.2 mmHg (systolic decrease) and 5.2 +/- 5.9 (diastolic decrease). Pts with pheochromocytoma who had a nighttime increase in BP demonstrated the greatest difference from the essential hypertensives, followed by pts with either diabetic nephropathy or after kidney transplantation. A lack of nocturnal BP decline (less than 10% of the daytime values) was detected in 69.8% of pts with secondary hypertension, but only in 5.2% of pts with essential hypertension. In summary, these results suggest that the absence of a nighttime decline in BP during 24-h ambulatory monitoring is an indication of secondary hypertension and should lead to further investigations. Furthermore, a nightly hypertension is associated with a higher risk of complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Gland Neoplasms↗
PubMed1991

[Importance of 24-hour blood pressure monitoring in secondary hypertension].

A typical diurnal variation in blood pressure is observed in patients with essential hypertension. Attenuation or lack of circadian periodicity might be expected in patients with secondary hypertension. Therefore, non invasive ambulatory blood-pressure monitoring was performed in 172 patients with secondary hypertension and in 201 patients with essential hypertension. The following patients with secondary hypertension were investigated: renoparenchymatous nephropathy (n = 29), diabetic nephropathy (n = 24), morbus Conn (n = 6), renal artery stenosis (n = 32), pheochromocytoma (n = 5), hemodialysis patients (n = 30), and patients after kidney transplantation (n = 44). In addition, 36 pregnant women (17 normotensives, 19 hypertensives) were studied. 98.5% of patients with essential hypertension showed a nightly decline in blood pressure of at least 15 mmHg (systolic + diastolic), whereas 70% of patients with secondary hypertension showed either an attenuated circadian rhythm or no circadian rhythm. Patients with pheochromocytoma who had a nighttime increase in blood pressure demonstrated the greatest difference in the essential hypertension collective, followed by patients with diabetic nephropathy and patients after kidney transplantation. After successful treatment of the condition leading to hypertension, circadian periodicity returned in some patients. In summary, these results suggest that the absence of a nighttime decline in blood pressure during 24-h-ambulatory monitoring is an indication of secondary hypertension, which should be further investigated. As a practical consequence, antihypertensive drugs should also be applied in an evening dose in secondary hypertensives. Noninvasive ambulatory blood-pressure monitoring is recommended for treatment control, especially in patients who need an efficient blood-pressure control.

Adrenal Gland Neoplasms↗
PubMed1990

[Plasma endothelin in normal probands and patients with nephrologic-rheumatologic and cardiovascular diseases].

Plasma concentrations of the recently isolated potent vasoconstrictory peptide endothelin were measured in 382 patients. The investigations were performed by means of a sensitive radioimmunoassay specific for Endothelin-1, 2. The results from 110 healthy volunteers displayed a normal range of 44.67 +/- 3.51 pg/ml. Significantly raised levels were found in 33 patients with chronic end-stage renal failure both before and after hemodialysis. In contrast, 35 patients with compensated renal insufficiency did not differ from the normals. Sixty-five patients after kidney transplantation revealed significantly elevated levels, as did 27 patients with acute myocardial infarction, 8 after coronary bypass surgery, and 5 with liver cirrhosis. The mean values of 27 patients with untreated hypertension, 22 with secondary hypertension, of various causes and 16 with coronary artery disease were comparable to the normal population. The values were significantly decreased in 9 pregnant women with hypertension and proteinuria. A marked decline was found in 5 patients with systemic lupus erythematodes, while 20 patients with rheumatoid arthritis demonstrated only a slight decrease. The pathophysiological role of endothelin as a local or circulating hormone in regulating systemic blood pressure or release of other hormones remains to be determined.

Arthritis, Rheumatoid↗
PubMed1990

Histopathology of N-methyl-N-nitrosourea-induced mesenchymal tumours of the rat urinary bladder.

The present study reports the induction, histopathology, immunocytochemistry, growth pattern and proliferative behaviour of mesenchymal tumours of the urinary bladder of rats induced by a single intravesical dose (5 mg/kg/body weight) of N-methyl-N-nitrosourea (MNU). In 14 of 283 female Wistar rats (incidence: 4.9%). 16 non-epithelial tumours had developed after an experimental period of 14 months. The most common histological type induced was of fibrohistiocytic origin (eight benign-appearing and three malignant fibrous histiocytomas). Furthermore, two pure histiocytomas (one benign and one malignant) and three capillary and cavernous haemangiomas were produced. Since no metastases occurred and no clear-cut distinction between a merely expansive and a truly invasive growth was possible, the diagnosis of malignancy was based on the degree of cellular atypia and the mitotic activity. The benign-appearing fibrous histiocytomas showed a mean mitotic index of 0.06% and the malignant fibrous histiocytomas of 0.34%. The mitotic activity of the malignant histiocytoma was threefold (0.78%) as high as in the benign-appearing histiocytoma (0.25%). There exist close morphological similarities between the induced mesenchymal tumours in the rat and those occurring in the human bladder. Although the spectrum of histological types of mesenchymal tumours seen in the rat bladder was narrower than that encountered in man, MNU seems suitable for further studying the histogenesis, histopathology and biology of experimentally induced non-epithelial bladder neoplasms to gain information for a better understanding of the pathogenesis of human disease.

Animals↗
PubMedDate not supplied

[Longitudinal study of 24-hour blood pressure behavior in pregnancy and puerperium in patients with normal pregnancy, pre-eclampsia and HELLP syndrome].

Ante- and postpartum noninvasive 24-hour ambulatory blood pressure measurements were performed in 18 normotensive pregnants and 36 patients with mild (n = 16) or severe preeclampsia (n = 12) or HELLP-syndrome (n = 8). In contrast to normotensive pregnancy (n = 18) displaying a decline of systolic and diastolic blood pressure in comparison with normotensive non-pregnant, preeclamptic women demonstrate significantly elevated blood pressure profiles before delivery that remain elevated up to the eighth week postpartum. 9 out of 12 patients with severe preeclampsia and 6 of 8 women with HELLP-syndrome show a nocturnal increase of blood pressure within the first week postpartum and a non-dipping up to the eighth week after delivery. As a result of this, in preeclamptic women blood pressure control should be extended into the night and antihypertensive therapy should include a sufficient evening dose.

Adult↗