Search PubMed⌕ Search

Biomedical subjects

L Hansson

Publications and source records attributed to L Hansson.

At least 325 records · Page 18Linked to original sources
PubMed1991

Key learnings from the STOP-Hypertension study: an update on the progress of the ongoing Swedish study of antihypertensive treatment in the elderly.

The Swedish Trial in Old Patients with Hypertension (STOP-Hypertension) is an ongoing multicenter, randomized, double-blind study of antihypertensive treatment (beta-blockers or diuretics) compared to placebo in hypertensive men and women aged 70-84 years. The main trial, which is now in progress, is being carried out at approximately 120 primary health care centers in Sweden, the aim being to recruit 2000 patients, who will be studied for an average period of 3 years. The main study was preceded by a 1-year pilot study in 31 centers. Almost 5000 patients were screened in the pilot study, 55% of whom were labelled hypertensive, i.e., their recumbent blood pressure was greater than or equal to 180/105 mmHg or they were already receiving antihypertensive therapy. After 1 year, 89 patients (1.9%) had been randomized to double-blind treatment and 66 patients (1.4%) were in the run-in/washout period, whereas the remainder had not been included in the trial. The most common reason for not being included as a failure to reach the inclusion blood pressure criteria (greater than or equal to 180 mmHg systolic and/or greater than or equal to 105 mmHg diastolic) following withdrawal of previous antihypertensive medication. In the main trial, recruitment of new centers and new patients has improved gradually and by April 1989 approximately 900 patients had been randomized to double-blind treatment. In an analysis of 961 elderly patients (mean age 70.1 years), the relation between systolic and diastolic blood pressure and mortality was not significant.

Aged↗
PubMed1991

Reversal of cardiac and vascular hypertrophy by antihypertensive therapy.

Cardiovascular hypertrophy, such as left ventricular hypertrophy, and arteriolar hypertrophic changes are common in established hypertension. Left ventricular hypertrophy, in particular, markedly increases the risk of cardiovascular complications and death. The ability of an antihypertensive agent to reverse hypertrophic changes could, therefore, be greatly advantageous. Clinical studies with beta-blockers have shown them able to substantially reduce left ventricular hypertrophy. For reversal of arteriolar hypertrophy, vasodilatory beta-blockers have been shown to be preferable to ordinary beta-blockers, possibly because vasodilation reduces vascular smooth-muscle tone, which may facilitate reversal of hypertrophy. Theoretically, a vasodilatory beta-blocker, such as celiprolol, would therefore appear to offer advantages because of its ability to reverse left ventricular and arteriolar hypertrophy in addition to its antihypertensive action. The practical and clinical effects of cardiovascular hypertrophy reversal remain to be fully evaluated; however, it is logical to assume that they would be of considerable benefit to the hypertensive patient.

Arteries↗
PubMed1991

Calcium antagonists: an overview.

Calcium antagonists reduce the influx of calcium ions through the calcium channels. This causes a reduction in myocardial contractility or a fall in vascular resistance because of a lowering of vascular smooth muscle tone. Therefore, the net effect is a fall in blood pressure. The three major classes of calcium antagonists, the dihydropyridines, papaverine derivatives, and benzothiazepines, differ in molecular structure and their binding characteristics to the calcium channels. Furthermore, newer antagonists, particularly the dihydropyridines such as nicardipine, have a high affinity for vascular tissue and are highly selective for vascular smooth muscle. These compounds also have a favorable effect on hypertension mainly because of lowering of vascular resistance. In addition, they do not cause potentially negative metabolic effects on glucose or lipid levels and are generally well tolerated. Based on these findings, the Joint National Committee in the United States and the World Health Organization/International Society of Hypertension Committee on the Management of Mild Hypertension recommended the use of calcium antagonists as first-line treatment in hypertension.

Blood Pressure↗
PubMed1991

Regional sensitivity of the respiratory tract to stimuli causing cough and reflex bronchoconstriction.

Sensory nerves mediating cough and reflex bronchoconstriction have a non-uniform distribution in the respiratory tract. Afferent nerves originating in the laryngeal region differ from those of the intrapulmonary airways in their responsiveness to physical events in the breathing cycle and to chemical stimuli. Also, within each site afferents with separate characteristics are present. Studies in animals and human subjects have shown that the larynx and the carina are particularly sensitive to mechanical stimuli, whereas the intrapulmonary airways seem to be more sensitive to mediators and irritants. Based on recent data, the importance of the intrapulmonary airways to mediator/irritant-induced cough and reflex bronchoconstriction is emphasized. Inferentially, drugs inhibiting afferent neural activity arising in intrapulmonary airways would be a novel possibility in the treatment of cough and reflex bronchoconstriction.

Animals↗
PubMed1991

Shortcomings of current antihypertensive therapy.

Effective antihypertensive agents have been available for the last four decades. Their use in the treatment of hypertension has resulted in a marked decline in hypertension-induced morbidity and mortality. There are, however, some notable shortcomings with the currently available antihypertensive therapies, including disappointing effects against coronary artery disease and the fact that, even with treatment, hypertensive patients still have considerably higher cardiovascular morbidity and mortality than matched normotensives. This may be due to insufficient lowering of the elevated arterial pressure in hypertensive patients. In theory, overtreatment may also constitute a risk, considering the J-curve phenomenon. Other factors which may play a role are the different pathophysiological mechanisms in stroke and myocardial infarction, the potentially negative metabolic effects induced by some antihypertensive drugs, the importance of cardiovascular hypertrophy (in particular, left ventricular hypertrophy), and the inability of some antihypertensive agents to reverse such changes. To rectify some of these shortcomings, a more effective antihypertensive therapy is required. Ideally, an antihypertensive agent should provide effective lowering of blood pressure, in most patients to normotensive levels, while being devoid of potentially negative metabolic effects. It should also induce reversal of the changes of cardiovascular hypertrophy and, if possible, limit tissue damage if and when a vascular complication occurs.

Antihypertensive Agents↗
PubMed1991

Mental health problems in primary care before and after sectorization of psychiatric care--a study of patients utilizing both primary health care and psychiatric care.

Frequencies of noted mental health problems, diagnoses, and drug prescriptions performed by general practitioners were studied in a Swedish health district before and after the sectorization of the psychiatric care in patients (N = 252, N = 294, respectively) who had contacted both the outpatient psychiatric care and the primary health care. The frequencies of noted mental health problems before the sectorization were similar to other studies, but decreased after the sectorization. After the organizational change, psychiatric diagnoses decreased whereas psychosomatic diagnoses increased. After the sectorization, prescription of psychotropic drugs was reduced.

Ambulatory Care↗
PubMed1991

Swedish Isradipine Study in Hypertension: evaluation of quality of life, safety, and efficacy. SWISH Group.

This was a double-blind multicenter study to compare the efficacy, tolerability and effects on the quality of life with isradipine and atenolol in the treatment of essential hypertension. Of 588 patients entering the 6-week placebo run-in period, 549 were eligible for randomization to receive either isradipine or atenolol for 8 weeks. If, at the end of this period, diastolic blood pressure (DBP) remained greater than 90 mm Hg, then both agents were given in combination for a further 10 weeks. Tolerability and quality of life were assessed repeatedly during the placebo and active-treatment phases. A subgroup of 30 patients were followed by 24-h ambulatory blood pressure monitoring, and their results are now being analyzed. In another subgroup of 26 patients, maximum exercise capacity, as determined by ergometer bicycle-testing, was measured once during placebo and twice during active treatment. At the end of the 24-week study period, both isradipine and atenolol as monotherapy had produced significant decreases in blood pressure. There were no significant differences overall between the compounds in quality-of-life and side-effect profiles, although there was a relative absence of ankle edema and headache with isradipine. Furthermore, patients receiving isradipine had no change in performance on exercise testing whereas patients on atenolol had a significant decrease (p less than 0.01).

Antihypertensive Agents↗
PubMed1991

Calcium antagonists in antihypertensive combination therapy.

Calcium antagonists can be used with a number of other antihypertensive compounds. The combined use of a dihydropyridine calcium antagonist and beta-blocker is well established and is probably the most efficacious combination for routine use. Angiotensin-converting enzyme (ACE) inhibitors may also constitute a suitable addition to calcium antagonist therapy, whereas little benefit appears to be derived from the combined use of a calcium antagonist and a diuretic. Other compounds, e.g., alpha-adrenoceptor blockers, can also be given together with calcium antagonists, although this should be done with great caution because dramatic reductions in blood pressure may result. It is worth noting that in addition to the improved antihypertensive efficacy produced by some of the calcium antagonist combinations, potentially positive metabolic changes may also occur, e.g., a reduction in serum cholesterol, when a calcium antagonist and a beta-blocker are combined.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1990

Pre-eclampsia, hypertension and the premenstrual tension syndrome.

A total of 261 of 17,000 pregnancies were complicated by pre-eclampsia/hypertension in pregnancy. Seven to twelve years later 237 were available for follow-up together with 33 women, who had a normotensive pregnancy in 1969-1973. The association between pre-eclampsia/hypertension and the premenstrual tension syndrome has been studied. Women with present hypertension complained significantly (P less than 0.05) more of premenstrual sadness than the normotensive women. However, women with previous pre-eclampsia/hypertension in pregnancy did not have more premenstrual symptoms than women in general, on the contrary, women with a history of severe pre-eclampsia had less symptoms.

Adult↗
PubMed1990

Production of human tissue-type plasminogen activator in different mammalian cell lines using an Epstein-Barr virus vector.

Human tissue-type plasminogen activator (t-PA) cDNA inserted into an Epstein-Barr virus (EBV) derived expression vector was transfected into human HeLa, 293, K-562 and hamster CHO-K1 cells and the expression of t-PA was studied. The best t-PA producing cell clones were found among CHO-K1 cells (up to 11 micrograms d-1 per 10(6) cells). However, HeLa and 293 cells were most efficiently transfected, e.g. about 70% of the selected cell clones were t-PA positive. The vector DNA copy numbers correlated with the mRNA levels and the protein levels for all cell lines analysed, with the exception for the K-562 cell line, where the production of t-PA was very low. The results obtained indicated that the highest expression levels were achieved in low density cultures.

Animals↗
PubMed1990

The reliability of auscultatory measurement of arterial blood pressure. A comparison of the standard and a new methodology.

In 48 individuals with a wide range of arm circumferences blood pressure measured indirectly with two different cuffs was compared to direct intraarterial measurements. The two cuffs were a standard size cuff (12 X 35 cm) and a newly developed cuff, containing three rubber bags of different sizes, which automatically selects the appropriately sized bag in relation to arm circumference (Tricuff, Pressure Group AB, Sweden). The Tricuff correctly placed 42 of the 43 patients in the "normotensive" range, ie, diastolic blood pressure less than 90 mm Hg, whereas the standard cuff put only 33 of 44 patients in this range (P less than .005). The discrepancy was not only due to the expected better performance in patients with obese arms, but also in the subgroup of patients with arms in the range 22 to 31 cm, in which group both cuffs would measure blood pressure with a 12 cm wide rubber bag. The number of correctly identified "normotensive" patients was noticeably higher with the Tricuff than with the standard cuff (30/31 v 25/32, P = .053). The better specificity of the new cuff thus offers an improvement over the standard cuff. There are several potential clinical advantages of this, mainly that the risk of erroneously labelling normotensive individuals as hypertensive is reduced.

Adolescent↗
PubMed1990

Predicted reductions in the risk of coronary heart disease by antihypertensive therapy: the confounding effect of lipids.

The treatment of arterial hypertension confers several important benefits, e.g. reducing hypertension-induced cardiovascular morbidity and mortality. However, the preventive effect for coronary heart disease is considerably smaller than the effect of treatment on the incidence of strokes. Several factors may explain this discrepancy, but it appears likely that drug-induced increases in serum lipoproteins may, to some extent, offset the risk reduction obtained through the lowering of blood pressure. It appears that more emphasis should be put on therapeutic intervention in other risk factors in addition to the treatment of hypertension. An appropriate therapeutic aim of the treatment of hypertension should be to lower blood pressure to 'normotensive' levels, by using drugs which do not themselves increase cardiovascular risks, e.g. do not increase serum lipoproteins, and to actively intervene against other co-existing risk factors, such as hyperlipidaemia. By using this approach, it seems likely that the risk of coronary heart disease can be reduced.

Antihypertensive Agents↗
PubMed1990

Regional haemodynamic effects of endothelin-1 in rat and man: unexpected adverse reaction.

Endothelin-1 was infused into the non-dominant brachial artery in two male subjects. We then monitored intra-arterial mean blood pressure, right atrial pressure, the heart rate and forearm blood flow (by plethysmography). Endothelin-1 at a dose of 5 x 10(-14) to 5 x 10(-9) mol, infused over 5 min periods, elicited no major changes in mean arterial pressure, heart rate and right atrial pressure. We observed an initial increase in forearm blood flow, followed by dose-dependent decreases of 25, 34 and 42% at 5 x 10(-11) to 5 x 10(-9) mol. A higher dose of endothelin-1, 5 x 10(-8) mol, given to only one of the subjects, elicited sweating and vomiting. In this subject, mean arterial pressure, right atrial pressure and the heart rate did not change, while forearm blood flow increased transiently. A deep muscular pain developed in the forearm receiving the endothelin-1 infusion after 30 min (maximum 2 h, duration 10 h), and this pain was intensified by touch and muscle contractions. The force of muscle contractions in the forearm was markedly reduced and a visible oedema developed. In order to investigate the mechanisms of oedema formation, endothelin-1 (10(-10) to 5 x 10(-8) mol/l) was given intra-arterially in a rat hindquarter preparation which was perfused at a constant flow rate. In the rat, endothelin-1 increased both pre- and postcapillary resistance, leading to an increase in capillary hydrostatic pressure and a marked net transcapillary fluid transfer from the perfusate to tissue. There was no sign of increased vascular permeability.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Calcium antagonists in the treatment of hypertension: state of the art.

Treatment of hypertension constitutes an important part of all medical care provided in industrialized countries today. During the last three to four decades, several groups of effective and well-tolerated antihypertensive compounds have become clinically available, e.g., the thiazide diuretics, the centrally acting sympatholytic drugs, the vasodilators, and the beta-blockers. The calcium antagonists can be viewed as the latest important addition to the antihypertensive armamentarium. In this article we review briefly some of the aspects of calcium antagonist therapy that are of relevance for the treatment of arterial hypertension.

Animals↗
PubMed1990

Erythrocyte sodium transport in malignant hypertension.

Twenty-three patients with treated malignant hypertension (MH), 23 patients with treated non-malignant hypertension (NMH) and 46 normotensive control subjects were investigated with regard to intraerythrocyte sodium (Na) and potassium (K) levels, as well as transmembrane fluxes of sodium (Na-influx and Na-efflux rate constant). Intraerythrocyte Na and K concentrations were determined by flame photometry. The Na-influx and Na-efflux rate constant were calculated from uptake values for 22Na in vitro. In NMH the Na-influx and Na-efflux rate constant were significantly higher while intraerythrocyte Na and K levels did not differ from the controls. Patients with MH tended to have an elevated intraerythrocyte Na concentration, but an unchanged Na-influx and Na-efflux rate constant relative to controls. The increased rate of erythrocyte membrane transport of Na in treated NMH could be due to a stimulatory effect of antihypertensive treatment on cellular Na transport. Patients with treated MH do not show this effect, and in addition, tend to have an elevated intraerythrocyte Na concentration, which is compatible with the existence of a more pronounced abnormality of cellular ion transport in MH.

Biological Transport↗