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Biomedical subjects

L Hansson

Publications and source records attributed to L Hansson.

At least 361 records · Page 20Linked to original sources
PubMed1989

Analysis of treatment outcomes. Why is benefit not larger?

The benefits of antihypertensive treatment are well-known. In malignant hypertension antihypertensive therapy has markedly improved prognosis and increased 5-year survival from 0% to 75%. In addition, the incidence of this severe form of hypertension has been shown to decrease significantly in some centers. In nonmalignant hypertension prognosis is also markedly improved thanks to antihypertensive therapy, with substantial reductions in the incidence of stroke and congestive heart failure, whereas the beneficial effects against coronary heart disease are less obvious. In addition, during recent years there has been some discussion about the J-curve phenomenon. There are several conceivable explanations behind the less than optimal outcome of antihypertensive therapy. Some of these will be discussed here, e.g. the fact that hypertension-induced pathology is only partially reversible. Moreover, in several intervention studies strict normotensive blood pressures have not been obtained during treatment. In addition, some of the antihypertensive drugs used may cause potentially negative effects, e.g. by increasing serum lipoproteins. Finally, the pathophysiology behind stroke and myocardial infarcts differ in several respects, and this may contribute to the less favourable effects of antihypertensive treatment on coronary artery disease-morbidity as compared to stroke-morbidity.

Animals↗
PubMed1989

Antipathological potential of beta-blockers.

Today, beta-blockers are frequently the drugs of first choice for the treatment of hypertension. It had been hoped that beta-blocker therapy would confer a primary preventive effect against coronary artery disease (CAD), but so far a positive effect has been shown only in open trials. In addition to a primary preventive effect (which remains to be shown in a controlled trial), it is anticipated that in the future treatment of hypertension the bea-blockers will have vascular protective potential. The regression of hypertension-induced structural arteriolar changes has already been demonstrated when a vasodilating component is present, while in experimental animals subjected to stress and a high cholesterol intake beta-blockers prevent or reduce the degree of coronary atheromatosis. For such reasons it seems logical to predict that beta-blockers, especially those with a vasodilating action, afford potential cardiovascular protection. Thus, in addition to their antihypertensive effects, regression of cardiovascular hypertrophic changes can be expected, presumably with a primary preventive action against CAD and atherosclerotic changes. Clinical trials to evaluate these highly desirable prospects should be given high priority.

Adrenergic beta-Antagonists↗
PubMed1989

Beta-blockers with ACE inhibitors--a logical combination?

Although there is no obvious pharmacological rationale for the combined use of an ACE inhibitor and a beta-blocker in the treatment of hypertension, this combination has proved to be more effective than monotherapy in a number of studies, some of which are reviewed. Moreover, there is evidence that this combination may be beneficial after myocardial infarction. Combined use of ACE inhibitor and beta-blocker therapy therefore warrants further investigation.

Adrenergic beta-Antagonists↗
PubMed1989

Increased secretion of immunoglobulins in malignant hypertension.

Recent evidence suggests that immunogenic factors may be of importance for development and maintenance of severe hypertension. Twenty-three patients with a previously malignant phase of hypertension (MH) were investigated with respect to serum levels as well as actual production of immunoglobulins (lgs) and compared with a group of 22 patients with non-malignant hypertension (NMH) and 45 matched normotensive control subjects (C). Patients with MH had a significantly elevated secretion of IgG and IgA as compared with C. Total serum concentration of lgs did not differ between the groups, but a raised level of the subclass IgG3 was found in MH. There was a significant positive correlation between systolic blood pressure (SBP) and secretion of IgA and IgG when all hypertensive patients were studied. Six patients were subjected to repeated investigations during the first year after malignant phase. If examined in an early phase of MH (within 4 months) the secretion of IgG, IgA and IgM was enhanced compared with later stages (after 5-12 months). The results suggest that an immunological process is involved in MH. This could either be a primary immunological disturbance or more plausibly secondary effects due to the vascular damage caused by the very high blood pressure.

Antihypertensive Agents↗
PubMed1989

Atomic absorption spectrometric determination of selenium in human blood components.

We separated blood from five healthy blood donors into plasma, erythrocytes, platelets, and leukocytes; counted the number of cells in each fraction; and determined the selenium content of each component by hydride generation atomic absorption spectrometry. The mean (+/- SD) selenium concentrations and amounts measured were as follows: whole blood 102.3 +/- 16.1 micrograms/L, plasma 76.9 +/- 10.6 micrograms/L, erythrocytes 13.7 +/- 2.8 ag per cell, platelets 4.8 +/- 1.1 ag per cell, and leukocytes 99 +/- 26 ag per cell.

Blood Platelets↗
PubMed1988

Human tissue-type plasminogen activator synthesized by using a baculovirus vector in insect cells compared with human plasminogen activator produced in mouse cells.

A cDNA fragment encoding the human tissue-type plasminogen activator was inserted into the baculovirus Autographa californica nuclear polyhedrosis virus downstream from the polyhedrin promoter. The induction kinetics of t-PA was followed, after infection of Spodoptera frugiperda cells, at both mRNA and protein levels. Fibrinolytically active plasminogen activator accumulated in the culture medium and reached 2.5 micrograms/ml after 120 h. The protein was compared with recombinant plasminogen activator produced in mouse cells and was found to be slightly smaller. This difference in size was found to be caused by N-linked oligosaccharides which are shorter in the recombinant activator obtained from insect cells. The molecules produced in such cells contain at least two different types of N-linked glycans, since only one out of three oligosaccharides is sensitive to endoglycosidase H. However, all glycan structures bind strongly to concanavalin A-Sepharose.

Animals↗
PubMed1988

Current and future strategies in the treatment of hypertension.

Treatment of arterial hypertension is an important part of the medical care provided in industrialized countries today. Its rationale comes from large-scale intervention trials which have shown that lowering of elevated blood pressure reduces cardiovascular morbidity and mortality. Nevertheless, during the last few years it has been shown that treated hypertensive patients are still at an increased risk of cardiovascular morbidity and mortality compared with untreated normotensive subjects of the same age and sex. Possible explanations for this disappointing finding are that blood pressure has not been lowered to strictly normotensive levels; that some elements of the excess morbidity and mortality are not prevented by antihypertensive therapy, e.g., the part attributable to coronary artery disease; or that the drugs used may themselves have negative effects, e.g., on serum lipids, which may offset the positive effects of lowered blood pressure. It is desirable that antihypertensive treatment produces a reversal of hypertension-induced structural cardiovascular changes such as left ventricular hypertrophy or increased wall/lumen ratio in the precapillary blood vessels, but many of the current antihypertensive drug regimens have no effect on structural cardiovascular changes. Against this background it would appear logical to make renewed efforts to reduce blood pressure into the clearly normotensive range in an attempt to lower the excess risk demonstrable in treated hypertensive patients. It would also seem logical to use antihypertensive drugs that could also be expected to have positive effects on hypertension-induced structural cardiovascular changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1988

Implications of doxazosin therapy on risk of coronary heart disease.

Antihypertensive treatment is known to reduce mortality in severe hypertension and cardiovascular morbidity in mild and moderately severe hypertension, for example, from stroke and left ventricular failure. However, treated hypertensive patients still have significantly higher mortality and morbidity than matched control subjects. In particular, risk of coronary heart disease is affected little by antihypertensive treatment. There may be several explanations for these less than optimal results. For example, blood pressure may not have been brought down to strictly normotensive levels or an antihypertensive agent, which adversely affects serum lipoproteins, may have been used, thereby offsetting the intended therapeutic effect. Doxazosin, a new selective alpha 1-inhibitor, offers both effective antihypertensive action and a favorable lipid effect. Both of these effects could have a positive impact on risk of coronary heart disease and therefore may prove to be more effective than previously used antihypertensive treatments.

Adrenergic alpha-Antagonists↗
PubMed1988

Nocturnal hypoxaemia in severe scoliosis.

The relationship between spirometry and daytime blood gases on the one hand and hypoxaemia during sleep on the other was studied in 13 patients with severe thoracic scoliosis. Eight patients had hypoxaemia (mean Sao2 less than 90%) during sleep. They were characterized by a lower vital capacity (30 versus 50% of predicted, P less than 0.01) and by a greater fall in vital capacity from sitting to supine (26 versus 7% of sitting VC, P less than 0.05). All patients with hypoxaemia during sleep were hypercapnic during the daytime. The fall in Sao2 with sleep was related to the increase in transcutaneous PCO2, indicating hypoventilation as the main mechanism behind hypoxaemia during sleep in scoliosis patients.

Adult↗
PubMed1988

Controlled trial of enalapril and hydrochlorothiazide in 200 hypertensive patients.

In a multicenter, multinational study, 200 patients with essential hypertension were treated with a fixed dose of Enalapril (E) 20 mg/day after a 2- to 4-week placebo period. All had diastolic blood pressure (DBP) 100 to 120 mm Hg at the end of the placebo period. They were then given E for 6 weeks. If DBP after this was greater than 90 mm Hg they were randomized double-blind to added therapy with hydrochlorothiazide (H) either 25 mg/day (E + H 25) or 12.5 mg/day (E + H 12.5) or placebo (E + P) for 4 weeks. Blood pressure was measured approximately 24 hours after taking the medication. In the whole group, BP fell from 171/107 to 156/97 mm Hg during monotherapy with E (P less than 0.001). Sixty-six patients reached DBP less than or equal to 90 mm Hg on E alone. Of the remainder, 42 were randomized to E + P. In these, BP fell by 5.9/3.4 mm Hg (P less than 0.05). Forty-two patients received E + H 12.5 and BP fell by 9.0/6.9 mm Hg (P less than 0.001). Forty-one patients received E + H 25 and BP fell by 5.6/6.3 mm Hg (P less than 0.05/0.01). The proportion of patients who reached DBP less than or equal to 90 mm Hg was 26% in the E + P group, 48% in the E + H 12.5 group (P less than 0.05 compared to E + P group), and 38% in the E + H 25 group. There were no other significant differences between the E + H 12.5 and E + H 25 groups except that S-potassium fell significantly (-0.2 mmol/L) in E + H 25. Both regimens were remarkably well tolerated. It can be concluded that H 12.5 mg/day potentiates the effect of Enalapril 25 mg/day at least as well as H 25 mg/day and better than placebo.

Adult↗
PubMed1988

What are we really achieving with long-term drug therapy?

Hypertension-induced morbidity and mortality can be positively affected by antihypertensive treatment. This was first shown in malignant phase hypertension and it is now clearly established that not only total mortality but also morbidity from stroke, left ventricular failure, and progressive renal failure can be positively affected by pharmacological lowering of arterial pressure. Benefits of treatment for coronary artery disease are less obvious. In spite of the positive effects of antihypertensive therapy briefly mentioned here, recent data from several centers show that hypertension-induced risks in treated hypertensive patients are not reduced down to the level seen in comparable normotensive subjects. There could be several reasons for this. Some of the hypertension-induced cardiovascular changes are irreversible, or that antihypertensive pharmacological agents may have some adverse effects that would partially offset the advantages obtained through a reduction in blood pressure, or that treated arterial blood pressure usually has not been brought down to strictly normotensive levels. Therefore, the risks associated with hypertension have not been lowered to those seen in normotensive subjects. This latter point assumes particular significance in view of some recent suggestions that a too drastic lowering of blood pressure in hypertensive subjects may be associated with an increased risk, particularly for coronary artery disease mortality.

Antihypertensive Agents↗
PubMed1988

Blood pressure does not predict mortality in the elderly.

The purpose of our study was to estimate the extent to which casual blood pressure measurements can predict mortality in elderly people in a defined population. A random sample of subjects born between 1890 and 1914 was extracted and their medical records were studied. Their earliest blood pressure record was chosen, provided the patient was at least 60 years old at the time of measurement. The population consisted of 961 patients (49.8% women), 560 of whom died between 1968 and 1987. Their mean age was 70.1 years and the total number of person-years involved was 8625. The mortality risk was estimated as a function of sex, present age, systolic (SBP) and diastolic (DBP) blood pressures, by a version of the Cox regression model. On the basis of close confidence intervals we conclude that blood pressure in the elderly is a very weak predictor of mortality.

Aged↗
PubMed1988

Antihypertensive effect of felodipine or hydralazine when added to beta-blocker therapy.

In a double-blind randomized study, hydralazine (n = 59) or the new dihydropyridine calcium antagonist felodipine (n = 61) was added to previous treatment with beta-adrenoceptor blocking agents in a group of 120 patients with essential hypertension. Active treatment with either hydralazine or felodipine was given for 8 weeks after a 4-week placebo run-in period, at the end of which all patients had supine diastolic blood pressures greater than 95 mm Hg. Assessment of the results according to the intention to treat principle showed that felodipine was significantly more effective than hydralazine at the doses employed, reducing systolic blood pressure 10-19 mm Hg more than hydralazine and reducing diastolic blood pressure 5-11 mm Hg more than hydralazine (95% confidence intervals). The number of patients complaining of side effects, the number of complaints, and the number of patients that had to be withdrawn from treatment were numerically higher during treatment with hydralazine than with felodipine, but these differences were not statistically significant. Against this background it is concluded that felodipine is superior to hydralazine when added to an antihypertensive regimen consisting of beta-adrenoceptor blocking agents.

Adrenergic beta-Antagonists↗
PubMed1988

Calcium antagonists combined with beta-blockers or ACE inhibitors in the treatment of hypertension.

During the last few years, there has been a growing awareness that treated hypertensive patients are still at substantially increased risks for cardiovascular morbidity and mortality and that one conceivable explanation for this is that their blood pressure has not been lowered to strictly normotensive levels. To obtain normotensive blood pressures, it may be necessary to skillfully combine antihypertensive drugs much more frequently than has been common so far. In this context, calcium antagonists in combination with beta-blockers are of special interest, since several controlled studies have shown that a combination between a beta-blocker and nifedipine, nitrendipine, isradipine, or felodipine have been remarkably potent as regards their antihypertensive effect. In controlled trials, such combinations have also been shown to be more effective and better tolerated than a combination between a beta-blocker and hydralazine. Marked efficacy has also been noted when a calcium antagonist has been combined with an angiotensin converting enzyme (ACE) inhibitor. So far, most studies have dealt with small numbers of patients and study design has not always been optimal. Results from controlled studies will presumably be ready for presentation in the near future. It can be concluded that combination therapy between calcium antagonists and beta-blockers or ACE inhibitors appear to be markedly effective and well tolerated. This would offer the possibility of reducing elevated arterial pressure to normotensive levels in many hypertensive patients.

Adrenergic beta-Antagonists↗
PubMed1988

Predictors of stroke in the elderly.

Hypertension, diabetes mellitus, coronary heart disease and cigarette smoking have repeatedly been identified as risk factors for stroke in young and middle-aged individuals. In order to find predicting factors for stroke in the elderly we assessed health characteristics in 55 stroke victims in the age range 65-75 years (mean 70.7 +/- 2.7) allocated to our stroke unit at Ostra University Hospital in Gothenburg. For comparison we used data from 2,009 individuals participating in the ongoing longitudinal population study "70-year-old people in Gothenburg, Sweden". Among the stroke victims we found a higher prevalence of hypertension (63.5% vs. 27.8%, p less than 0.001), diabetes mellitus (21.8% vs. 6.2%, p less than 0.001) and a history of previous myocardial infarction (12.7% vs. 4.8%, p less than 0.01), thus confirming previous findings. There was no difference with regard to smoking habits (32.7% vs. 27.5%, NS), which is at variance with findings in the young and middle-aged.

Age Factors↗