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Biomedical subjects

C Spieker

Publications and source records attributed to C Spieker.

At least 73 records · Page 4Linked to original sources
PubMed1988

Age-dependent increase in arterial smooth muscle calcium in spontaneously hypertensive rats.

Alterations in cellular calcium metabolism in essential hypertensive and in the SHR have been described. In the present study, particle-induced X-ray emission (PIXE) was used to get some information on the spatial distribution of Ca2+ in aortas of spontaneously hypertensive rats (SHR) and normotensive controls aged 1 week, 4 weeks, and 12 weeks. It was found that the Ca2+ content was not elevated in the aortic smooth muscle of SHR aged 1 week (n = 9) as compared to normotensive controls (n = 8) (186.8 +/- 89.9 micrograms Ca2+/g tissue vs 254.0 +/- 73.7 micrograms Ca2+/g tissue. The Ca2+ content was significantly raised in the aortic smooth muscle of SHR aged 4 weeks (n = 9) as compared to 4-weeks-old WKY rats (n = 12) (726.0 +/- 130.4 Ca2+/g tissue vs 440.3 +/- 214.4 Ca2+ micrograms/g tissue and in SHR aged 3 months (n = 15) as compared to WKY rats (n = 12), respectively (3317.0 +/- 734.0 micrograms Ca2+/g tissue vs. 1632.0 +/- 569.6 micrograms Ca2+/g tissue). The results confirm the age-related increase in the arterial Ca2+ content in normotensive rats and demonstrate additionally that this age-related rise in arterial Ca2+ content is accelerated in SHR.

Aging↗
PubMed1988

Effect of hypertensive plasma on Ca2+ transport in human neutrophils.

The effects of plasma fractions from essential hypertensives (n = 17) and normotensives (n = 17) on Ca2+ transport in permeabilised human neutrophils were studied using an ion-selective electrode. The plasma fractions were obtained by gel filtration and contained substances with a molecular weight in the range of 1000-1500 Da. When isolated from essential hypertensives, this fraction had been shown to increase blood pressure after intravenous injection in the rat. The rate of Ca2+ uptake by permeabilised neutrophils after addition of extracellular Ca2+ was significantly accelerated during incubation of the cells with the hypertensive fraction (855.9 +/- 812.3% vs 218.0 +/- 294.3% of the control value, P less than 0.05). In a suspension with intact neutrophils hypertensive plasma fractions (n = 7) caused an increase of extracellular pCa by 0.479 +/- 0.115 (P less than 0.01), whereas the normotensive fractions did not change pCa significantly. It is concluded that the hypertensive plasma fraction increases Ca2+ accumulation in subcellular particles. Additionally the Ca2+ influx through the plasma membrane is increased by the circulating hypertensive factor.

Adult↗
PubMed1988

Effect of plasma from hypertensive subjects on Ca2+ transport in permeabilized human neutrophils.

1. The effects of plasma fractions from essential hypertensive subjects (n = 14) and normotensive subjects (n = 14) on Ca2+ transport in permeabilized human neutrophils was studied using an ion-selective electrode. 2. Plasma fractions were obtained by gel filtration and contained substances with a molecular mass in the range 1000-1500 daltons. This fraction isolated from essential hypertensive subjects has been shown to increase blood pressure after intravenous injection in the rat. 3. The rate of Ca2+ uptake by permeabilized neutrophils after addition of extracellular Ca2+ was significantly accelerated during incubation of the cells with the hypertensive fraction (1049.3 +/- 807.7% vs 242.5 +/- 320.9% of the control value, mean +/- SD, P less than 0.05). 4. It is concluded that the hypertensive plasma fraction increases Ca2+ accumulation in subcellular particles, so that under excitatory conditions Ca2+ release in arterial smooth muscle might be enhanced.

Adult↗
PubMed1988

Transdermal beta-blocker therapy in essential hypertension.

Transdermal drug delivery has been applied to various agents in an effort to decrease the frequency of drug administration and increase the patients compliance. In our study, we demonstrated that transdermal application of a beta-blocker (20 mg mepindolol) in patients with essential hypertension led to effective blood pressure lowering effect within 1 week (160.1 +/- 6.1 mm Hg/95.8 +/- 8.3 mm Hg vs 136.8 +/- 7.2 mm Hg/84.3 +/- 5.0 mm Hg; P less than 0.05). A controlled study of transdermal versus oral beta-blocker administration in hypertensives is necessary before this new therapeutic system is introduced in antihypertensive treatment.

Administration, Cutaneous↗
PubMed1988

Analysis of Ca2+ in aortic tissue: age-dependent Ca2+ content in spontaneously hypertensive rats and in normotensive controls.

In the present study particle-induced X-ray emission (PIXE) was used to analyse the spatial distribution of Ca2+ in aortic tissue of spontaneously hypertensive rats (SHR) and normotensive controls aged 1 week, 4 weeks and 12 weeks. Ca2+ was not elevated in the aortic smooth muscle of SHR aged 1 week (n = 9) compared with normotensive controls (n = 8; 186.8 +/- 89.9 micrograms Ca2+/g tissue). Ca2+ was significantly increased in the aortic smooth muscle of SHR aged 4 weeks (n = 9) compared with 4-week-old Wistar-Kyoto (WKY) rats (n = 12; 726.0 +/- 130.4 micrograms Ca2+/g tissue versus 440.3 +/- 214.4 micrograms Ca2+/g tissue) and in SHR aged 3 months (n = 15) compared with WKY (n = 12), (3317.0 +/- 734.0 tissue versus 1632.0 +/- 569.6 micrograms Ca2+/g tissue, respectively). The results confirm an age-related increase in arterial Ca2+ in normotensive rats and demonstrate that this age-related rise is accelerated in SHR.

Animals↗
PubMed1988

Assessment of intracellular sodium and calcium in essential hypertension during diuretic treatment.

In 87 essential hypertensive patients, torasemide (1- isopropyl-3-([4-(3-methyl-phenylalmino)pyridine]-3-sulfonyl)urea), a new long-acting high-ceiling diuretic, was applied for 6 months in order to assess its effects on blood pressure and intracellular electrolytes. In a randomized trial 42 patients received 2.5 mg and 45 patients 5 mg torasemide once daily. In all patients, diastolic blood pressure was greater than 100 mm Hg before treatment. Blood pressure normalisation (diastolic blood pressure greater than or equal to 90 mmHg) was observed in 21 out of 42 patients receiving 2.5 mg torasemide daily and in 26 out of 42 patients with 5 mg torasemide throughout the study. In both groups doubling of the dosage was performed in these patients who had an insufficient blood pressure control after 4 weeks. In the majority of these non-responders blood pressure normalisation was achieved during the higher dosages. In the total group of patients there was an elevation of the intracellular sodium and a decrease of the intracellular calcium, measured with the ion-selective electrode in red blood cells. It could be shown that the decrease in blood pressure induced by torasemide was accompanied by a decrease of intracellular Ca2+, thus supporting the hypothesis that intracellular free Ca2+ is an important regulator of vascular tone in essential hypertension.

Adult↗
PubMed1987

[Computer-assisted assessment of the 24-hour blood pressure profile in essential and secondary hypertensive patients].

In 17 essential hypertensives, 13 secondary hypertensives and 9 normotensives, noninvasive 24 h blood pressure monitoring was performed. By a computer-aided evaluation according to the Cosinor method, circadian periodicity was quantified and expressed as a coefficient of periodicity in %. This coefficient for systolic pressure was higher in essential hypertensives and normotensives than in secondary hypertensives (42.9 +/- 18.0 et 43.0 +/- 16.7 versus 28.2 +/- 17.7; p less than 0.05). The circadian periodicity of diastolic pressure showed no significant differences. Despite the large overlap, coefficients of periodicity below 20% for systolic pressure may suggest secondary hypertension.

Adult↗
PubMed1987

Cadmium and hypertension.

Cadmium, an environmental trace metal, has been implicated as a possible factor in human hypertension. Although the epidemiological studies on humans exposed to cadmium are biased by certain additional factors, more detailed information is available from animal studies and in vitro experiments. The results demonstrate that cadmium influences the vasopressor-induced reactivity and the stress strain characteristics of the blood vessel wall. Thus, it is conceivable that cadmium might contribute to the elevation of blood pressure. But still more convincing data are necessary to clarify the link between cadmium exposure and the development of human hypertension.

Animals↗
PubMed1987

Taste sensitivity for sodium chloride in hypotensive, normotensive and hypertensive subjects.

The taste sensitivity for sodium chloride was examined in 103 normotensive, 55 hypertensive and 36 hypotensive subjects. The examination was performed on five areas of the tongue using four different concentrated NaCl solutions (2.5, 5.0, 7.5 and 15%). The results indicate that hypotensive subjects show a much higher salt sensitivity compared to normotensive or hypertensive subjects. The enhanced sensitivity of hypotensives to sodium chloride may reflect a regulatory factor tending to normalize blood pressure. In contrast, the lower sensitivity of hypertensives points to a salt dependency of high blood pressure in these patients.

Diet, Sodium-Restricted↗
PubMed1987

Intracellular calcium in secondary hypertension.

In 13 essential hypertensives, 15 renal hypertensives, 16 patients with phaeochromocytoma, 6 patients with renal artery stenosis and in 21 normotensive controls the Ca2+ and K+ content in the asked material from red blood cells was determined by flame photometry. Furthermore, intracellular K+ concentration was measured in the haemolysate. The ratio between Ca2+ and K+ concentration in ashed red blood cells (Cai2+/Ki+) was 2.07 +/- 0.9110-3 in normotensives, 4.58 +/- 1.68 10(-3) in essential hypertensives (p less than 0.01), 3.13 +/- 1.90 10(-3) in renal hypertensives (p less than 0.05), 2.15 +/- 1.62 in patients with phaeochromocytoma and in patients with renal artery stenosis 2.25 +/- 1.25. Intracellular K+ concentration was 94.3 +/- 3.1 mumol/l in normotensives, 94.7 +/- 3.8 mumol/l in essential hypertensives and 93.8 +/- 3.9 mumol/l in renal hypertensives, 198.2 +/- 149.1 mumol/l in patients with phaeochromocytoma and 201.1 +/- 139.1 mumol/l in patients with renal artery stenosis. Therefore, intracellular total Ca2+ concentrations is concluded to be increased in red blood cells from essential hypertensives and, to a lesser extent, in those from renal hypertensives. The method to determined Cai2+/Ki+ in the red blood cells may thus be suitable to assess cellular Ca2+ content in hypertension.

Adrenal Gland Neoplasms↗
PubMed1987

Differences in plasma and tissue aluminum concentrations due to different aluminum-containing drugs in patients with renal insufficiency and with normal renal function.

The gastrointestinal absorption of aluminum from orally administered aluminum-containing drugs is well documented. Retention of the absorbed aluminum leads to elevated levels of this metal in the tissue of patients with renal failure. We studied two groups of dialysis patients who had received equal amounts of the different aluminum-containing phosphate-binders Aludrox and Antiphosphat. It has recently been shown that Antiphosphat releases only a few aluminum ions in an environment of low pH. Consistent with this finding, we found the aluminum levels to be significantly higher in the plasma, bone, and hair of patients who had received Aludrox as phosphate binder. Subjects with normal renal function excreted most of the ingested and absorbed aluminum. No data are available concerning the tissue load of the element in these subjects. We studied two groups of patients with normal renal function who had received antacid drugs prior to neurosurgery on a brain tumor. The first group of patients were treated with an aluminum-rich antacid (Maalox 70); the other group received an aluminum-poor drug (magaldrate) for 10 days prior to the operation. Analysis of the brain-tissue removed revealed twofold higher aluminum levels in the patients who had received Maalox 70. These results indicate that administration of aluminum-containing drugs leads to a tissue load of aluminum in patients with an impaired renal function as well as in those with a normal function. The extent of the aluminum load depends on the aluminum content and the liberation rate of the drug.

Aluminum↗
PubMed1987

Effects of drugs on magnesium requirements.

A number of drugs can influence Mg metabolism and produce changes in serum Mg concentrations. These alterations must always be considered in the differential diagnosis of cases with Mg disturbances. Hypermagnesemia is seen, particularly after administration of Mg-containing drugs in renal insufficiency. Marked hypomagnesemia can be observed in a great number of patients, particularly in those treated with loop diuretics, osmotic substances and with antineoplastics, such as cisplatin.

Anti-Bacterial Agents↗
PubMed1986

[Hemangiosarcoma of the heart].

The clinical appearance, typical localization, diagnostic procedure and the treatment of hemangiosarcoma--the most frequent malignant tumor of the heart are reported by the case of a 27 years old woman. The patient suffered from dyspnea, congestion of the superior caval vein and paroxysmal tachycardia. X-ray showed cardiac enlargement due to pericardial effusion. Echocardiography revealed a large tumor in the right atrium. Computertomography and angiocardiography showed tumor masses at the orifice of the superior caval vein and a bypass of the blood flow via the azygos vein. Thoracotomy yielded an inoperable hemangiosarcoma. By the combined treatment of irradiation and chemotherapy the cardiac tumor completely disappeared, the patient was temporary symptomless. Later metastases occurred and the patient died 13 months after diagnosis.

Adult↗
PubMed1986

Ca2+i:K+i ratio and total intracellular calcium in essential and renal hypertension.

The calcium ion (Ca2+) and potassium ion (K+) content in the ashed material from red blood cells was determined by flame photometry in 61 essential hypertensives, 11 renal hypertensives and in 47 normotensive controls, and intracellular K+ concentration was measured in the haemolysate. The ratio between Ca2+ and K+ content in ashed red blood cells (Ca2+i:K+i) was 2.07 +/- 0.91 X 10(-3) in normotensives, 4.91 +/- 2.17 X 10(-3) in essential hypertensives (P less than 0.01) and 3.48 +/- 2.04 X 10(-3) in renal hypertensives (P less than 0.05). Intracellular K+ concentration was 94.3 +/- 3.1 mmol/l in normotensives, 94.7 +/- 3.8 mmol/l in essential hypertensives and 93.8 +/- 3.9 mmol/l in renal hypertensives. Therefore intracellular total Ca2+ concentration is increased in the red blood cells from essential hypertensives and, to a lesser extent, in the red blood cells from renal hypertensives. The use of Ca2+i:K+i ratios in red blood cells may thus be useful in assessing cellular Ca2+ content in hypertension.

Adult↗