ISSN:0263-6352    

出版商:OVID    

年代:1991

数据来源: OVID

ISSN:0263-6352    

出版商:OVID    

年代:1991

数据来源: OVID

ISSN:0263-6352    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

In an attempt to study and prevent the development of hypertension, there is a growing interest in measuring blood pressure in children. The aim of this is to detect and monitor those with a relatively high level of blood pressure. Until now, reference values on blood pressure in children are based on data from North-American youngsters. The present study provides percentile charts based on pooled data from studies on blood pressure conducted in six North-West European countries among 28043 children. These blood pressure centiles are presented as age-, height- and gender-specific. Brief guidelines for blood pressure measurements in childhood and for detection of children with a relatively high blood pressure are included

ISSN:0263-6352    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Ambulatory blood pressure has been shown to be more reproducible than office blood pressure and thus to be more suited for studying the efficacy of antihypertensive drugs. In 34 untreated essential hypertensive subjects, we measured office and 24-h non-invasive or intra-arterial blood pressure twice over a 4-week interval; 24-h intra-arterial blood pressure was obtained by the Oxford method whereas 24-h non-invasive blood pressure was obtained by the automatic SpaceLabs 5300 device, with a 10min (daytime) or 20min (night-time) interval between measurements. The standard deviation of the mean difference (s.d.d.) between blood pressures obtained in each recording was taken as the reciprocal of blood pressure reproducibility. The s.d.d. was highest for office blood pressure and for single blood pressure readings taken from 24-h non-invasive recordings. The s.d.d. fell when the two 24-h average non-invasive blood pressures were considered. The fall was progressively greater as the number of ambulatory readings on which the average was calculated increased from two to 24, no further fall being observed when more than 24 values were considered. The maximal reduction in s.d.d. was 59% (systolic) and 42% (diastolic) as compared with the office s.d.d. The two 24-h mean values obtained by the intra-arterial approach were slightly more closely correlated than those obtained non-invasively. However, at comparable sampling rates, the s.d.d. was not substantially lower with 24-h intra-arterial blood pressure and including in the calculation the average of the thousand readings provided by this approach did not cause any further improvement. Thus, 24-h average blood pressure is more reproducible than office blood pressure. The increased reproducibility is a function of the number of ambulatory blood pressure readings, but a maximal advantage can be obtained at a relatively low sampling rate. This means that in therapeutic trials there may be no need to assess blood pressure too frequently or to consider the huge number of values provided by intra-arterial monitoring

ISSN:0263-6352    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Brief bilateral carotid artery ligation in adult spontaneously hypertensive rats (SHR) induced locomotor hyperactivity and lesions of the CA-, region of the hippocampus but had no effect in Wistar normotensive rats. This result suggests that high blood pressure amplifies the consequences of cerebral ischaemia. Treatment for 7 weeks with the calcium entry-blocker isradipine (5 mg/kg per day, subcutaneously) normalized blood pressure and attenuated the behavioural and histological consequences of cerebral ischaemia. Chronic treatment with hydralazine (25 mg/kg per day, subcutaneously) also normalized blood pressure but afforded no protection against the consequences of cerebral ischaemia. This suggests that the protective effect of antihypertensive treatment depends not only on the blood pressure—Slowering action but may also be linked to the mechanism of action of the drug used

ISSN:0263-6352    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Diagnosis and management of hypertension by physicians in two large cities in the northwest of Germany were studied in 1988. Three hundred and fifteen out-of-hospital physicians (71%) responded to a mailed questionnaire. Sixty-eight per cent reported measuring blood pressure at almost each patient visit and 36% involved allied health professionals in the measurement process. Only 63% used disappearance of sound for the diastolic reading (phase V). A comparison with US data from 1987 showed that German physicians started drug therapy at higher levels of diastolic blood pressure than their American colleagues. Only 43% of the German physicians initiated antihypertensive medication at diastolic blood pressure values below l00mmHg; this compares with 92% for US physicians. In Germany, (β -blockers were clearly preferred as step-one therapy for young patients, while diuretics were prescribed for the majority of the older patients. Forty per cent reported reducing or stopping antihypertensive medication when the blood pressure was controlled

ISSN:0263-6352    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

The possible point-mutational activation of the ras oncogene, which probably contributes to the evolution of aldosterone-producing adenomas and ectopic reninoma, was evaluated. Chromosomal DNA was extracted from six aldosteroneproducing adenomas and one renin-secreting liver carcinoma, using the standard method with phenol: chloroform: isoamyl alcohol. One microgram of sample DNA, forward and reverse primers, Taq I polymerase and deoxyribonucleotide triphosphates (dNTPs) were mixed and the ras gene was amplified by the polymerase chain reaction. Point mutations at ras-12 or ras-61 sites of amplified DNA were tested by dot-blotting, using H-, N- and K-ras oligonucleotide probes with mutations at codons 12 or 61. However, there were no point mutations at amino acid codons 12 or 61 of c-Hi-ras, c-Ki-ras and N-ras oncogenes in all aldosterone-producing adenomas and the one ectopic reninoma. These results indicate that point-mutational activation of ras oncogenes does not contribute, at least in this series, towards the evolution of aldosterone-producing adenomas and the reninoma

ISSN:0263-6352    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Normotensive young men (36 ± 5 years old) with positive family histories of hypertension (n=11) and age-matched controls (n=21) with negative family histories of hypertension were examined. The control group was divided into one group matched for body mass index with those subjects with positive family histories (n=10) and one group with normal body mass index (n=11). Blood pressure, central venous pressure (CVP), plasma atrial natriuretic peptide (ANP) and serum aldosterone were examined at a baseline and during an acute volume load with 1000 ml saline solution. Subjects with positive family histories and controls matched for body mass index had a higher blood pressure at baseline than controls with normal body mass index. CVP and serum aldosterone did not differ between the three groups, while sodium intake and plasma concentrations of ANP were significantly higher in subjects with positive family histories. During volume loading, CVP increased significantly more in subjects with positive family histories as compared with the two control groups. A blunted response to ANP was observed during volume loading in subjects with positive family histories, while subjects in the two control groups demonstrated comparable and significant increases in circulating ANP. Serum aldosterone, however, decreased during volume loading in all three groups, with no difference between the groups. We conclude that normotensive subjects with positive family histories are characterized by increased basal concentrations of ANP and exhibit a blunted response to an acute volume load. One possible explanation for the higher basal circulating ANP in subjects with positive family histories could be a higher sodium intake, while the blunted response may represent a primary or an early inability to respond to and excrete a volume load

ISSN:0263-6352    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Neutrophils possess a plasma-membrane-bound reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase which catalyzes superoxide (O2¯ ) formation and is activated by a variety of stimuli. Recently, neutrophils of patients with essential hypertension (EHT) have been reported to generate O2¯ at rates up to fourfold higher than those of normotensive (NT) subjects upon exposure to the chemotactic peptide N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMet-Leu-Phe). We studied regulation of O2¯ formation in neutrophils of 25 EHT subjects and 25 age- and sex-matched NT subjects. The intercellular signal molecules fMet-Leu-Phe, platelet-activating factor and leukotriene B4 activated O2¯ formation in neutrophils, but the latter two receptor agonists were less effective than the former. fMet-Leu-Phe activated O2¯ formation with a 50% effective concentration (EC50) of about 30nmol/l, the effect of the chemotactic peptide being maximal at 0.1-1 umol/l. fMet-Leu-Phe-induced O2¯ formation was potentiated by platelet-activating factor, adenosine 5'-[γ -thio]triphosphate and cytochalasin B and was inhibited by the activators of adenylyl cyclase, isoproterenol, prostaglandin E1 and histamine. 4(β -Phorbol 12-myristate 13-acetate, 1,2-dioctanoyl-sn-glycerol, y-hexachlorocyclohexane and arachidonic acid, which circumvent receptor stimulation, also activated O2¯ formation. Significant differences between NT and EHT subjects were not evident in respect of any of the parameters studied. Our data suggest that regulation of the neutrophil NADPH oxidase is not disturbed in EHT and that altered O2¯ formation does not represent a genetic marker for abnormalities in plasma-membrane signal transduction in EHT

ISSN:0263-6352    

出版商:OVID    

年代:1991

数据来源: OVID