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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Suppression of renin release by beta-adrenoceptor blocking drugs has been advocated as the prime blood pressure lowering mechanism of these agents. The present report casts doubt on this proposition in three ways. In the first study, involving 22 patients with borderline hypertension, patients with elevated plasma renin levels showed normalization of the blood pressure after pharmacological autonomic blockade with intravenous atropine, propranolol and phentolamine, the time course of the pressure fall being such as to exclude suppression of renin release as the antihypertensive mechanism. It is clear that in patients with mild hypertension and high plasma renin levels, the elevation of blood pressure is maintained by a neurogenic mechanism, the elevated plasma renin having no direct role in sustaining the higher blood pressure. In two additional studies involving 21 patients in all with mild to moderately severe essential hypertension, to whom propranolol was administereed by mouth for 1--3 months, two findings were of interest:1) patients with low-renin essential hypertension showed a good antihypertensive response to propranolol, and 2) in some patients a dosedependent dissociation of the renin and blood pressure lowering action of propranolol could be demonstrated. These findings militate against the assumption that propranolol selectively lowers the blood pressure in "renin-dependent" hypertension, and strongly suggest that the antihypertensive action of this drug is not mediated by depression of plasma renin activity.
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PMID:Dissociation of the renin lowering and antihypertensive actions of propranolol. 103 70

Because of the multiplicity of disease conditions and diminished tolerance for drugs in the aged, it is necessary to know concomitant pathologic conditions to determine which antihypertensive drug to use. In the Philadelphia Geriatric Center, there are about 1,000 residents, between 70 and 100 years of age. About 40% have hypertension; almost 50% have or once had depression; there are many cases of hiatal hernia and/or peptic ulcer; in one subdivision of residents, almost 40% have renal disease with BUN above 30 mg/100 ml. In antihypertensive treatment, some individuals respond fairly well to reassurance and weight reduction, when obese, even without drugs. All are given a low-salt diet. A diuretic is first used--thiazide in cases of good renal function, furosemide with impaired renal function. Liquid potassium supplements are given. If there is but little reduction in blood pressure in several weeks, methyldopa is added in ascending doses, in cases with or without renal impairment. In hypertension with impaired renal function, furosemide and/or methyldopa were especially valuable. Furosemide as an antihypertensive drug was also noted to delay the onset of congestive heart failure. Since reserpine can aggravate peptic ulcer and can precipitate or aggravate depression, it should seldom be used to treat hypertension in the aged. Guanethidine is rarely used, since it can cause cerebrovascular insufficiency and marked weakness. High blood pressure should be reduced slowly in the aged, to avoid untoward effects.
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PMID:An approach to the treatment of hypertension in the aged. 105 27

Blood pressure measurements were recorded in 522 adults and 141 10-19 year-old full and part blood Aborigines in five communities. The means for systolic and diastolic blood pressures at 40 years were close to those reported for Europeans, although below this age, values tended to be lower, and above 40 years tended to be higher than those reported in the Tecumseh study. Hypertension, as defined by the Princeton criteria, was present in 29%, more often in the men (1-6 to 1-0), and eight subjects satisfied the criteria for hypertensive heart disease (HHD). 522 electrocardiograms were recorded on adult subjects at five Aboriginal communities and classified according to categories of the Minnesota code. Of the 210 abnormalities observed, minor T wave inversions and minor S-T segment depression were the most commonly encountered, and were more frequent in female subjects. Q wave changes typical of myocardial infarction was found in 5% of the tracings and occurred mainly in older men. If hypertension and certain ECG codes are assumed to be "risk factors" for the development of clinical ischaemic heart disease (IHD), the urbanized Aboriginal had a higher prevalence compared with Caucasian subjects of the Busselton study. "Probable" and "suspect" ECG changes of IHD, although mainly in the older subjects, were found to be associated with hyperglycaemia, as recognised in Western society. It is postulated that urbanized Aborigines are prone to cardiovascular degenerative disease to a similar or possibly larger extent than Caucasians.
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PMID:Blood pressures and electrocardiographic findings in the South Australian Aborigines. 106 18

1. Propranolol, when used for treating arterial hypertension, may influence determinants of both cardiac and vascular function; the consequent changes in cardiac performance may result from the interaction of different and possibly opposite effects. 2. Cardiac funtion was investigated in fifty-four primary hypertensive men in the pretreatment state and after 3 weeks of propranolol therapy at a daily dose of 320 mg. 3. beta-Receptor blockade caused depression of pre-injection left ventricular function, which was unrelated to the direction and the extent of changes in peripheral circulation. 4. The ejection left ventricular function could be either depressed or improved depending on the direction to which treatment shifted the vascular resistance, and consequently, the impedance to left ventricular ejection. 5. Withdrawal of the adrenergic support is probably the major factor responsible for the poor ventricular adaptation to an augmented impedance.
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PMID:Cardiac function in the treatment of arterial hypertension with propranolol. 107 80

Reports of complications due to estrogen-progestagen combinations are summarized. Common minor symptoms include nausea, abdominal distress, headache, depression, and weight gain. Some of these are directly due to the pill, but others are not; for instance, depression may result from pyrodoxine deficiency, but psychodynamic factors explain the problem in others. Effects on the reproductive organs include secondary amenorrhea in about 2 of every 1000 women; structural and functional changes of the ovaries, uterus, and cervix; increase in incidence of yeast vulvovaginitis; and inhibition of lactation. Most changes in laboratory values of various constituents of blood and other body fluids reflect changes in hepatic function. Thromboembolic diseases, hypertension, and hypertriglyceridemia are rare but more serious conditions for which the pill may be responsible in some cases. Contribution of the pill to carcinogenesis and fetal abnormalities has not been proven.
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PMID:Clinical complications of oral contraceptives. 109 Jan 18

The literature data and personal experience with high - and very high - risk patients show that the association of enflurane as anaesthetic and pancuronium as muscle-relaxant constitutes a positive advance in balanced general anaesthesia. Cardiocirculatory depression is not encountered; if anything, there is an improvement of homeostatic conditions. This results in increased safety, even for patients regarded as inoperable. Confirmation of the reasons for associating these two drugs has certainly been obtained. The method cannot, however, be employed indiscriminately, but, at least in theory, should be avoided in patients with serious hypertension or a myocardium that is particularly sensitive to endogenic catecholamine incretion. In hypotension, on the other hand, cases of imminent or frank shock, or situations where surgery cannot be postponed, the association is, paradoxically, a true pharmacological "support", backed up, of course, by other usual procedures. This contradiction of modern views concerning the peripheral circulation is only apparent, since the duration of anaesthesia is reduced; main aim in this period is the maintenance of sufficient circulation to the more important organs. Comparison with associations combining d-Tubocurarine, halothane and methoxyfluorane is still an open question as far as objective assessment of their usefulness is concerned. There can be no doubt, however, that the association of enflurane and pancuronium has eliminated a large sector of contraindications in the field of general anaesthesia.
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PMID:[Enflurane-pancuronium combination: real progress toward greater safe conditions in general anesthesia]. 111 99

Periodic sleep apnea may be due to repeated episodes of upper airway obstruction in patients who have a short thick neck and/or large jowls. Apnea due to complete cessation of breathing may occur to a lesser extent. Anaylsis of the sleep electroencephalogram shows that these patients rarely achieve deep sleep and have less stage 1-REM sleep than normal subjects of comparable age. They are chronically sleep-deprived, a manifestation expressed by daytime somnolence, chronic fatigue and often by personality disturbances marked by paranoia, agitated depression and hostility. The definitive diagnosis of this syndrome may be established by monitoring during sleep, the electroencephalogram, measuring abdominal excursions through a mercury-in-Silastic-strain gauge and recording air flow at the nose by means of a thermocouple. As demonstrated by other investigators, chronic hypoventilation during sleep leads to both pulmonary and systemic arterial hypertension, which may produce generalized cardiac enlargement and congestive heart failure. The abnormalities in the periodic sleep apnea syndrome are abolished by establishing a patent airway either through tracheostomy or weight reduction.
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PMID:Periodic sleep apnea: chronic sleep deprivation related to intermittent upper airway obstruction and central nervous system disturbance. 111 91

The effect of prostaglandin E2 on the biosynthesis of corticosteroids was studied in intact rabbits and in the ones with vasorenal hypertension in different periods of its development (1st group) and in the animals subjected to a spurious operation (2nd group). Prostaglandin added to an incubation medium was found to produce in intact rabbits a significant depression of the 11-dehydrocorticosterone and cortisone biosynthesis from progesterone-C14. In rabbits operated upon (1st and 2nd groups) prostaglandin E2 brought changes in the production of corticosteroids no sooner than in 1 month after surgery. In rabbits with vasorenal hypertension brought about through unilateral constriction of the renal artery with an intact second kidney the content of the labeled 11-desoxycorticosterone and 11-desoxycorticosol materially decreased under the effect of prostaglandin E2, while the biosynthesis of the end fractions--11-desoxycorticosterone, aldosterone and cortisone, would gain in intensity. These changes preceded somewhat the most significant rise of the arterial pressure. In the rabbits spuriously operated upon prostaglandin E2 increased the production of corticosteroids and 11-dehydrocorticosterone, low at that time. It is presumed that prostaglandin E2 produces a regulating influence on the processes of the corticosteroids biosynthesis both in normalcy and in vasorenal hypertension.
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PMID:[Changes in the biosynthesis of corticosteroids from progesterone-C14 under the effect of prostaglandin E2 in rabbits with vasorenal hypertension]. 111 13

Impact between the brain and the cristae of the base normally results as a consequence of inertia when an obstacle is hit, followed by contusion, or intra-, sub- or extradural haematoma. The skull itself may be briken (usually at the interpilasters or the weak points of the pilasters) or dented. Denting resulted in the depression of a circular fragments or fragments, with compression of the dura mater or brain; this, in turn, may be contused, lacerated or even crushed. Spinal crash fractures usually involve the lumbar region. Neck fractures are rare. The picture may be one of clinical silence (local pain) or marked neurological involvement. Damage to the cord is expressed in the form of shock, complete flaccid para- or tetraplegia, complete loss of sensation below the lesion, loss of deep and superficial reflexes, urinary retention and rectal incontinence. Treatment is rendered complicated by profuse scalp haemorrhages, respiratory insufficiency requiring orotracheal intubation and assisted respiration, convulsions, which should be handled with care, since ordinary anti-epilepsy products may mask the onset of hypertension and haematoma. Swelling should be reduced with cortisones. Diuretics may be too brusque and lead to intracerebral haematoma. In the case of spinal injuries, particular care should be excercised in shifting the patient and conveying him to hospital. Where high neck lesions are suspected, the possibility of damage to the originating segments of the phrenic nerve must be borne in mind.
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PMID:[Aeromedical problems in cranio-vertebral injuries]. 112 65

Regional cerebral blood flow (rCBF) measurements were performed over the contralateral hemisphere by the 133Xe intracarotid injection method in 20 patients with acute cerebral infarction in the territory of the internal carotid artery. The rCBF was found to be reduced, sometimes remarkably, in all of the patients. The mean reduction was 30 percent to 36 percent from the lowest normal value for the mean age of these patients. In the younger age group (40 to 59) the reduction was greater, 40 percent to 47 percent from the lowest normal value for this age. tthe rCBF depression was not related to cerebral dominance, previous hypertension or arterial PCO2 levels. The occurred in both patients who were fully alert and those with disturbances or consciousness, although it tended to be more diminished in the latter. tit can be assumed that the flow reduction in the nonaffected hemisphere is part of a general phenomenon affecting the entire brain and caused by globally reduced cerebral metabolism.
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PMID:The effect of cerebral infarction on the regional cerebral blood flow of the contralateral hemisphere. 112 15


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