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Biomedical subjects

O Ohlsson

Publications and source records attributed to O Ohlsson.

At least 19 recordsLinked to original sources
PubMed2001

High-resolution constant-height imaging with apertured silicon cantilever probes.

We present high-resolution aperture probes based on non-contact silicon atomic force microscopy (AFM) cantilevers for simultaneous AFM and near-infrared scanning near-field optical microscopy (SNOM). For use in near-field optical microscopy, conventional AFM cantilevers are modified by covering their tip side with an opaque aluminium layer. To fabricate an aperture, this metal layer is opened at the end of the polyhedral probe using focused ion beams (FIB). Here we show that apertures of less than 50 nm can be obtained using this technique, which actually yield a resolution of about 50 nm, corresponding to lambda/20 at the wavelength used. To exclude artefacts induced by distance control, we work in constant-height mode. Our attention is particularly focused on the distance dependence of resolution and to the influence of slight cantilever bending on the optical images when scanning at such low scan heights, where first small attractive forces exerted on the cantilever become detectable.

Journal Article↗
PubMed1997

Survivors of acute leukaemia and highly malignant lymphoma--retrospective views of daily life problems during treatment and when in remission.

Fifty-four former patients, in remission after acute leukaemia or highly malignant lymphoma, responded to a questionnaire covering their physical problems, their view of the help they received, who was most helpful to them during the treatment phase, and the impact of the disease and treatment on their current life. Energy loss and nutritional problems were most troublesome during the treatment phase, signifying many other physical problems. Patients with acute leukaemia had more problems, and thought the care was worse than did patients with highly malignant lymphoma. Serious physical problems correlated with low satisfaction with practical help received, indicating that the nurses failed to meet the needs of those suffering the most. Reduced psychological and sexual energy persisted in remission, showed no correlation with the extent of physical problems during the treatment phase, but correlated with co-existing problems and sensitivity to infections, with a great need for intimate help and counselling and with a low sense of coherence. Family relationships were said to have improved, while work and finances were negatively affected. The results indicate that nursing care should actively focus on physical problems, especially on energy loss and nutritional problems. The overwhelming fatigue hinders patients in taking physical care of themselves, and may be overlooked by the nurse since their motor capability seems intact. The long-term effect of the illness means a reduced psychological and sexual energy and a high degree of existential problems and sensitivity to infections, which indicates the importance of follow-up care, and perhaps especially of counselling for the long-term reactions and disturbance of equilibrium.

Activities of Daily Living↗
PubMed1992

Increased CKMB (mass concentration) in patients without traditional evidence of acute myocardial infarction. A risk indicator of coronary death.

A study of 102 patients consecutively admitted to a coronary care unit (CCU) investigated the clinical usefulness of three different immunoenzymometrical CKMB methods: NovoClone CK-MB, ICON QSR CKMB and IMx CK-MB. Blood samples were drawn on admission and then every 6 h for 48 h. The three different methods correlated very well (r = 0.93-0.96). With discrimination levels of 10 micrograms.l-1 for NovoClone CK-MB and 5 micrograms.l-1 for the other two methods, a sensitivity of 1.0 and a still acceptable specificity (> 0.81) were achieved. In the group of patients (n = 53) with suspicion of acute myocardial infarction (AMI) but with no standard criteria for AMI, 14 patients were identified with small but significant increase of serum CKMB (mass concentration) and an increased CKMB (mass concentration)/CK ratio. During a 4 year follow-up nine out of these 14 patients died within 2 years, the majority being coronary deaths, as compared to only two out of the remaining 39 non-AMI patients with suspicion of AMI but with normal CKMB values (chi 2 = 18.47, P < 0.001). The finding of such a high mortality rate among patients with increased CKMB (mass concentration) has an important prognostic value even in patients without standard criteria for AMI.

Adult↗
PubMed1986

The effect of beta-blockade on leg blood flow in hypertensive patients with intermittent claudication.

The present study was designed to assess the short-term effects of beta-blocking antihypertensive treatment on leg blood flow in patients with peripheral artery disease. Seven patients with intermittent claudication were randomly allocated to treatment with atenolol 100 mg or pindolol 10 mg. Patients switched therapy after one month of treatment. Venous occlusion plethysmography on the calves was used to assess the effects on leg blood flow after one and two months of treatment. The average 10% reduction of the systolic and diastolic blood pressures was not associated with any reduction of blood flow at rest. There was on average 3.4 ml reduction of peak flow which had no influence on the painfree or total walking distance.

Adult↗
PubMed1984

Venous volume in offspring of hypertensive patients.

Twenty normotensive healthy male offspring of hypertensive patients were compared to 20 adequate controls regarding venous volume, the effect of ouabain on venous volume and signs of left ventricular hypertrophy. Among offspring there were slightly increased amplitudes in the orthogonal ECG as compared to controls but the differences were not statistically significant. Using a plethysmographic technique we found a significantly lower venous volume of the forearm in the offspring than in controls. There was, however, no effect of ouabain on the venous volume. The decreased venous distensibility among normotensive offspring might be an early manifestation of essential hypertension.

Adult↗
PubMed1983

Serum LD-1 activity in suspected acute myocardial infarction.

We have studied the diagnostic value of measuring lactate dehydrogenase (LD) isoenzyme 1 in serum of 331 cases of suspected acute myocardial infarction (AMI). At a discriminatory level of 200 U/L (Scandinavian Committee on Enzymes, recommended method for the determination of LD) LD 1 verified the diagnosis in 96% of the AMI cases and excluded it in 96% of the not-AMI cases when samples were drawn 24-72 h after onset of pain. The correlation between 24-h S-LD-1 and 16-h S-CK B activities was 0.94 in the AMI cases. We found that quantitation of serum LD-1 is diagnostically more reliable than the serum LD-1/LD ratio.

Acute Disease↗
PubMed1982

Whole body measurements of sodium turnover in offspring of patients with sustained essential hypertension.

The elimination rate (percent per day) of injected 22Na using a whole body measurement technique was significantly lower (5.8 +/- 1.5) in normotensive or borderline hypertensive offspring of essential hypertensive patients than in 15 age- and sex-matched, normotensive controls (7.3 +/- 1.0). There were no significant differences in exchangeable sodium, whole body potassium or in the urinary excretion of sodium, potassium and creatinine. The basis for the difference in turnover rate during week 1 is probably an alteration in the cellular handling of sodium (i.e. increased intracellular sodium) in the still normotensive offspring of patients with essential hypertension. The long-term (more than 100 days) whole body retention of 22Na was found to be only 0.1% of that injected, which justifies the use of this method on larger population groups.

Adult↗
PubMed1982

Left ventricular function after myocardial infarction.

We assessed simultaneously left ventricular filling pressure and stroke index with left ventricular ejection fraction in 22 patients who had had their first transmural myocardial infarction about 11 days before the examination. Eleven were classified as anterior myocardial infarctions and 11 as inferior. Left ventricular ejection fraction was determined by equilibrium radionuclide angiocardiography. Significant correlations between left ventricular ejection fraction and left ventricular filling pressure or stroke index were obtained both at rest and during exercise. Left ventricular dysfunction was more severe in patients with anterior myocardial infarction whose left ventricular ejection fraction at rest was 34.9+/-3.4% as compared to 52.6+/-2.1% in inferior myocardial infarction. We conclude that the radionuclide method is as sensitive as catheterization for detecting left ventricular dysfunction at rest and during exercise in patients with myocardial infarction.

Aged↗
PubMed1982

The effect on blood pressure, ECG and heart rate of psychological stress, static and dynamic muscle work. A study on members of families with known aggregation of essential hypertension.

A total of 195 relatives of patients from families with essential hypertension in at least two generations have been examined in regard to blood pressure (BP) and heart rate (HR) during muscle work and psychological stress. They were compared to controls without heredity for hypertension. The differences in BP and HR at rest between the groups were maintained throughout all tests, but during heavy dynamic muscle work systolic BP rose less in relatives than in controls. When relatives and controls were divided into subgroups, we found that BP was more related to age in relatives than in controls, both at rest and during the provocation tests. The differences in BP between the groups could thus depend on a genetic factor with greater penetration with increasing age.

Adult↗
PubMed1982

Blood pressure, cardiac output and systemic vascular resistance during rest, muscle work, cold pressure test and psychological stress. A study of male offspring from families with a history of essential hypertension for at least two generations.

Haemodynamic changes in the early phases of hypertensive diseases have mainly been described in so-called borderline hypertensives. Their cardiac output (CO) has mostly been found to be elevated, but the peripheral vascular resistance (PRI) normal. In this study of the offspring (26 subjects) of hypertensive individuals, CO and intravascular pressures were measured during rest, muscular work, psychological stress and cold pressure test. For comparison, the same measurements were performed in a control group of healthy volunteers without known hypertension in their families. The offspring had higher blood pressure at rest than the controls throughout the study except during the cold pressure test and the highest dynamic work loads. Although there was no statistically significant difference between offspring and controls as regards PRI, the resistance was slightly higher in the group of offspring throughout the study. Arterial blood pCO2 in offspring was significantly lower at rest, during psychological stress and dynamic muscle work. Possible mechanisms behind this finding are considered.

Adult↗
PubMed1982

Plasma volume and plasma volume distribution at rest, during muscular work, cold pressure test and psychological stress in male offspring from families with heavy aggregation of hypertension.

Total and central plasma volume was measured in 51 male offspring of hypertensive individuals belonging to families with a history of essential hypertension for at least two generations. They were compared to 38 age-matched individuals without known hypertension in their families for at least two generations. Central plasma volume was determined at rest and during muscle work, cold pressure test and psychological stress. The offspring had significantly lower total plasma volume than the controls. Central plasma volume was equal in offspring and controls. The quotient central/total plasma volume was thus higher in offspring than in controls, and the difference was statistically significant during psychological stress and dynamic muscle work. Possible reasons for the differences between offspring and controls are an increased transcapillary escape of plasma, an increased quotient intracellular/extracellular fluid and/or increased tone of the capacitance vessels.

Adult↗
PubMed1982

Venous volume and blood flow in hand at rest and during psychological stress in male relatives to hypertensive patients.

A total of 19 male relatives to hypertensive individuals were examined with regard to blood flow and venous volume in the hand at rest and during a psychological stress test. They were compared to 19 male controls without heredity for hypertension. There were no significant differences between the groups in hand blood flow or venous volume either at rest or during the test. The increase in vascular resistance during psychological stress was significantly higher in relatives than in controls. Possible mechanisms behind the differences in arterial vascular reactivity between the groups are discussed.

Adult↗
PubMed1982

Left ventricular function at rest and during exercise in coronary insufficiency--a simultaneous evaluation by means of radionuclide angiocardiography and catheterization.

Left ventricular function was assessed simultaneously with heart catheterization and equilibrium radionuclide angiocardiography at rest and during supine exercise in ten patients with effort angina. At rest all had normal haemodynamics. During exercise all developed angina with signs of left ventricular dysfunction in the form of high left ventricular filling pressure, 31 +/- 2 mm Hg (mean +/- SEM) and pathological decreases in left ventricular ejection fraction (11 +/- 1% units). Left ventricular end-systolic volume increased significantly (43 +/- 7%), but the increase in left ventricular end-diastolic volume (13 +/- 7%) was not significant. The discordance between the changes in left ventricular filling pressure and the changes in left ventricular end-diastolic volume is discussed. Radionuclide angiocardiography revealed left ventricular dysfunction as frequently as did heart catheterization.

Aged↗