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Biomedical subjects

B Hesse

Publications and source records attributed to B Hesse.

At least 73 records · Page 4Linked to original sources
PubMed1991

Detection of deep venous thrombosis with indium 111-labelled monoclonal antibody against tissue plasminogen activator.

The administration of a radiolabelled monoclonal antibody against tissue plasminogen activator allows detection of areas with increased fibrinolytic activity, i.e. those with an active thrombotic lesion. Eight patients with phlebographically verified deep venous thrombosis were examined. At the time of immunoscintigraphy study they were examined receiving anticoagulant therapy. Some 75-85 MBq indium 111-labelled antibody were injected, and scintigrams were obtained after 30 min and after 24 h. The precise site of the thrombus could not be visualized after 30 min due to high background activity, whereas after 24 h it was detectable in all patients. The thrombus/background ratios achieved are twice as high as those observed in a human antifibrin antibody study. These preliminary data suggest a high sensitivity of our t-PA-specific antibody for the detection of active deep venous thrombosis in man, and our antibody seems to offer theoretical advantages over both platelet and fibrin-specific antibodies.

Antibodies, Monoclonal↗
PubMed1991

EA-1, a novel adhesion molecule involved in the homing of progenitor T lymphocytes to the thymus.

The mouse progenitor T lymphocyte (pro-T) cell line FTF1 binds in vitro to thymus blood vessels, the thymic capsule, and liver from newborn mice. A mAb, EA-1, raised against an embryonic mouse endothelial cell line, blocked adhesion. The antibody also interfered with pro-T cell adhesion to a thymus-derived mouse endothelial cell line; it had no effect on the adhesion of mature T lymphocytes and myeloid cells. The antigen recognized by EA-1 is located on the vascular endothelium of various mouse tissues and absent on pro-T cells. EA-1 antibody precipitates molecules with apparent molecular weights of 110,000, 140,000, 160,000, and 200,000. Immunoclearing and binding-inhibition studies with antibodies against known adhesion molecules suggest that the EA-1 antigen is a novel adhesion molecule involved in colonization of the embryonic thymus by T cell progenitors.

Animals↗
PubMed1991

Fallacy in direct cystourethrography.

Voiding cystourethrography is widely used in children to detect vesicoureteral reflux disease. A case of radionuclide voiding cystourethrography is reported, where the initial location of the catheter tip in an open ureter ostium might have lead to erroneous interpretation. Recommendations for catheter technique and control of imaging in voiding cystourethrography are given.

Child↗
PubMed1991

Oesophageal transit in patients with autonomic dysfunction. The effect of treatment with fludrocortisone.

Oesophageal function was examined by radionuclide transit measurements in 15 patients with severe autonomic deficiency and orthostatic hypothension and 23 healthy volunteers. Seven of the patients were re-examined after treatment for 3 weeks with fludrocortisone acetate (Florinef). Six patients and five control subjects were evaluated before and after i.v. administration of atropine. The mean transit time (MTT) was prolonged (P less than 0.007) and the residual activity increased (P = 0.038) in the patients compared with the control group. Prolonged MTT was associated with oesophageal symptoms. Treatment of orthostatic hypotension with fludrocortisone acetate significantly reduced MTT. Atropine increased MTT and residual activity. The increase in heart rate after atropine was correlated in the patients with MTT before treatment. The results demonstrate the frequent presence of impaired oesophageal function in patients with severe autonomic dysfunction, irrespective of aetiology. The impairment seems to be closely related to parasympathetic insufficiency. The improvement after fludrocortisone may suggest an influence of ion balance on oesophageal function in these patients.

Adult↗
PubMed1990

Prognosis and diagnostic work-up in patients admitted for, but without, myocardial infarction--the value of nuclear medicine examinations.

Patients admitted for acute myocardial infarction that is not confirmed (non-AMI) have a prognosis only slightly better than that of patients with confirmed infarction. In a prospective, prognostic study of 158 patients with non-AMI the combination of exercise ECG and transient defects demonstrated at 201thallium scintigraphy identified low- and high-risk groups better than either examination alone. The purpose of a new, still ongoing study of non-AMI patients is to establish a relevant, cost-effective examination programme in order to arrive at a positive diagnosis in each non-AMI patient. Preliminary results of lung perfusion/ventilation scintigraphy suggest a rather low frequency of pulmonary embolism. Preliminary data of oesophageal scintigraphy suggest that about 25% of the non-AMI patients have abnormal mean transit times. The clinical significance of these data are discussed.

Coronary Disease↗
PubMed1990

Influence of the renin-angiotensin system on human forearm blood flow.

Although angiotensin II is a potent vasoconstrictor agent in all tissues, including the human forearm, equivocal effects on forearm blood flow (FBF) have been found after angiotensin blockade. In 13 healthy Na(+)-depleted subjects FBF was measured by the 133Xe washout technique; subcutaneous and muscle blood flows were determined separately. FBF was measured during supine rest, after the arm was lowered, and during lower body negative pressure (LBNP). The measurements were repeated during intra-arterial saralasin infusion in six subjects and after intravenous administration of enalapril in seven subjects. FBF decreased and forearm vascular resistance (FVR) increased during arm lowering and LBNP, as the result of local and central adrenergic reflexes, respectively. We observed similar FBF and FVR values after both saralasin and enalapril, except for a decrease in FVR at rest after enalapril. It is concluded that, in the human forearm, angiotensin II is not necessary for sympathetic vasoconstrictor reflexes but may, through a central effect, have some influence on arteriolar tone at rest.

Adult↗
PubMed1989

Effects of angiotensin blockade on the splanchnic circulation in normotensive humans.

The effects of angiotensin-converting enzyme inhibition (ACE-I) by enalapril on splanchnic (n = 10) and central hemodynamics (n = 9) were examined in moderately salt-depleted healthy volunteers, at rest and during 15-20 min of lower body negative pressure (LBNP), reducing mean arterial pressure by 10 mmHg. During LBNP before ACE-I, both splanchnic and total peripheral vascular resistances increased. During ACE-I, splanchnic and total peripheral vascular resistances decreased. After enalapril administration, splanchnic vascular resistance did not increase during LBNP. Total peripheral vascular resistance still increased but not to the same extent as during LBNP before ACE-I. The increases in heart rate and plasma norepinephrine during LBNP were attenuated after ACE-I compared with LBNP before ACE-I. The effectiveness of the ACE-I was clearly demonstrated by unchanged and low plasma angiotensin II levels during ACE-I. We conclude that, in normal sodium-depleted humans, acute ACE-I decreases splanchnic vascular resistance at rest and abolishes splanchnic vasoconstriction during LBNP. Furthermore, it may interfere with autonomic nervous system control of the circulation.

Adult↗
PubMed1989

Abnormal oesophageal function in patients with non-toxic goiter or enlarged left atrium, demonstrated by radionuclide transit measurements.

In 10 patients with enlarged atrium and in 29 patients with goiters and neck discomfort dynamic oesophageal scintigraphy was performed. The passage of water and capsules, containing 99mTc-pertechnetate, was studied with the patients in the supine and in the sitting positions. As a reference group we examined 35 healthy, age-matched volunteers. Mean transit time (MTT) was calculated, residual activity was expressed as a percentage of maximum activity, and the number of spikes in the curves was defined by visual analysis. Both in patients with enlarged left atrium and in those with large goiters the studies showed significantly prolonged MTT, increased residual activity, and a higher frequency of spikes, compared with healthy volunteers and with patients with small goiters. There was no relationship between symptoms and abnormal scintigraphic results. The passage of capsules was impaired only in cardiac patients. It is concluded that abnormal oesophageal function is often present in patients with enlarged left atrium and in patients with large, but not with small, goiters. Inhibition of oesophageal transit appears to be dependent on mechanical compression, but the nature of oesophageal impairment may vary with the level of compression. The frequent complaints of neck sensations in patients with goiters are probably not of oesophageal origin.

Adult↗
PubMed1988

The reliability of measuring left ventricular ejection fraction by radionuclide cardiography: evaluation by the method of variance components.

A statistical model based on the method of variance components was applied to obtain confidence statements for single and repeat determinations of left ventricular ejection fraction by radionuclide techniques. With this approach variance caused by individual factors in the measurement procedure is estimated to allow calculation of confidence intervals based on single measurements and the detection limits for changes. Six study groups made up of a total of 143 subjects were examined by both multigated equilibrium and first pass imaging. Under favourable conditions (with an updated gamma camera and experienced observer) the 95% confidence interval with a single measurement of left ventricular ejection fraction by equilibrium imaging was +/- 3 ejection fraction units, compared with +/- 6 units with the first pass technique (one ejection fraction unit = 1/100 of the possible values from 0.00 to 1.00). The minimal significant changes (at the 5% level) in measured equilibrium left ventricular ejection fraction at intervals of 15 min, 3 days, 1, 3, and 4 weeks were +/- 4, +/- 4, +/- 5, +/- 5, and +/- 6 units, respectively. The corresponding minimal detectable changes in a subject's "true" left ventricular ejection fraction for the same intervals were +/- 7, +/- 7, +/- 10, +/- 10, and +/- 12 units respectively. With first pass imaging, only average values for the variation at repeat determination could be calculated. The minimal significant change in measured first pass left ventricular ejection fraction was +/- 7 units, and the minimal detectable change in "true" left ventricular ejection fraction was +/- 14 units. Measurements of left ventricular ejection fraction by equilibrium technique were generally more reproducible than first pass determinations because the variability caused by study acquisition, observer analysis, and residual errors was smaller. The method of variance components appears to be well suited to the evaluation of quantitative biological measurements in clinical use. The popularity of established procedures may obscure the lack of basic information about method evaluation.

Adult↗
PubMed1988

The diagnostic value of computerized short-term oesophageal pH-monitoring in suspected gastro-oesophageal reflux.

In 109 consecutive patients suspected of having gastro-oesophageal reflux (GOR) a 3.5-h pH-monitoring in the oesophagus was performed during the daytime. The data were stored in a portable recording system, and three different variables (mean pH, mean acid clearance rate, and number of spikes) were calculated. Compared with a combined endoscopic-histologic score for the diagnosis of oesophagitis, assumed to be due to GOR, the 3.5-h pH-monitoring had a sensitivity of 85% and a specificity of 81%. The data suggest that the short-term pH-monitoring is almost as accurate as the traditional 24-h pH-monitoring and more convenient both for the patient and the gastroenterologic unit.

Adolescent↗
PubMed1987

Uniform detection of immunoglobulin-gene rearrangement in benign lymphoepithelial lesions.

The term "benign lymphoepithelial lesion" is used to describe the salivary-gland lymphocytic infiltration and epithelial changes typically found in association with Sjögren's syndrome. We used Southern blot hybridization techniques to examine the immunoglobulin genes in salivary-gland tissue derived from eight patients with benign lymphoepithelial lesions. Three of these patients had intrasalivary non-Hodgkin's lymphoma complicating the lesions, whereas the lesions in the remaining five were all histologically benign. Ten samples from the eight patients all revealed rearrangement of both the heavy-chain and light-chain immunoglobulin genes. In one of the patients in whom non-Hodgkin's lymphoma involved both the salivary-gland lesion and an ipsilateral lymph node, the rearrangements of the heavy-chain and light-chain immunoglobulin genes detected at the two sites were identical. One other patient had two distinct benign lymphoepithelial lesions removed two years apart. The rearrangements of the heavy-chain as well as the kappa light-chain genes detected in these two lesions were entirely different. These data suggest that B-cell clonal expansion has an integral role in the pathophysiology of the benign lymphoepithelial lesion and may explain the increased incidence of lymphoma noted in association with this disorder.

Adult↗
PubMed1987

[The action of benzydamine on phospholipase activation].

The effects of the antiinflammatory drug benzydamine (Tantum) on phospholipase activities were determined in vitro, employing various enzyme preparations (rat liver plasma membranes, endoplasmic reticulum, lysosomes; human seminal plasma) and stereospecifically radiolabeled phosphatidylethanolamines as substrates. Fatty acid release from the sn-2 position was inhibited at drug concentrations above 10(-5) mol/l. Concerning the mode of inhibition, a mixed type was found for the soluble phospholipase A2. Impaired fatty acid release from the sn-2 position might contribute to the mechanism of antiinflammatory action of benzydamine by rendering less free precursor acid available for the synthesis of eicosanoids. Fatty acid release from the sn-1 position was inhibited at benzydamine concentrations from 10(-6)-10(-2) mol/l only in lysosomes, whereas in plasma membranes and endoplasmic reticulum it was stimulated, maximally (at 10(-3) mol/l) about 25% and 50%, respectively.

Animals↗
PubMed1986

Diacylglycerol hydrolysis in rat liver lysosomes.

The matrix of rat liver lysosomes exhibits high hydrolytic activity towards 1,2-diacylglycerol with an optimum at pH 4.0. The lipolytic reaction follows Michaelis-Menten kinetics (apparent Vmax 470 nmol hydrolysed/min per mg protein; apparent Km 71 microM 1,2-dioleoylglycerol). Formation of 1- and 2-monooleoylglycerols indicates an initial attack at both the primary and secondary ester bonds. The lysosomal matrix also catalyses (re)acylation reactions, i.e. the formation of 1,2-diacylglycerol from 2-monoacylglycerol and free fatty acid. However, (re)acylation proceeds at a far lower rate than deacylation of diacylglycerol. Lysosomal diacylglycerol hydrolysis is sensitive towards non-ionic detergents, cationic amphiphilic drugs and the lipase inhibitor RHC 80267.

Acid Phosphatase↗
PubMed1986

Renal handling of angiotensins I and II in patients with renovascular hypertension.

Plasma renin (PRC) and angiotensin I (pANG I) and II (pANG II) concentrations were determined at renal vein catheterization in 38 hypertensive patients suspected of renal or renovascular aetiology. Veno-arterial differences in pANG I across the affected kidney in patients with lateralization of the renin secretion indicated release of angiotensin I (ANG I) in considerable amounts. Veno-arterial differences in pANG II of around zero indicated that generation and elimination of angiotensin II (ANG II) were equal in that kidney. Across the contralateral kidney the veno-arterial differences in PRC and pANG II were both close to zero, while negative differences in pANG II indicated the removal of ANG II. In patients without lateralization of the renin secretion the veno-arterial differences in pANG I were close to zero or positive, those of pANG II being close to zero or negative. In 14 of the 38 patients, data were obtained either during maintenance treatment with captopril or after a single dose of this converting enzyme inhibitor. Systemic PRC and pANG I values were extremely high and pANG II values low. The pANG I gradient across the affected kidney was further increased compared with pre-captopril levels, whereas the contralateral kidney still eliminated ANG I.

Adolescent↗