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Biomedical subjects

P Neumann

Publications and source records attributed to P Neumann.

At least 109 records · Page 6Linked to original sources
PubMed1987

Fatty acid metabolism in symptomatic patients with mitral valve prolapse but without coronary artery disease--comparison with 201Tl myocardial perfusion scintigraphy.

Using 123I-omega-heptadecanoic acid (HDA) and 201Tl, respectively, myocardial fatty acid metabolism and perfusion were studied in 51 symptomatic patients with mitral valve prolapse (MVP) as diagnosed by ventriculography, and no evidence of coronary artery disease. Twelve subjects with normal coronary arteries and normal ventriculogram served as a control group for the evaluation of elimination kinetics of HDA. In the control group, the mean elimination half-life was 26.1 +/- 3.6 min, whereas the patients with MVP had a mean value of 25.0 +/- 6.4 min. In patients with MVP, a high incidence concerning abnormalities of accumulation and/or elimination of HDA occurred, namely accumulation defects in 31% and both prolonged and shortened elimination half-lives in 16% and 29%, respectively. Myocardial perfusion scintigraphy using 201Tl showed abnormalities in 76%. Correlations were found between decreased uptake of HDA and prolonged elimination half-life as well as defects by 201Tl, presumably due to ischemia based on small-vessel disease or abnormalities of cellular metabolism.

Adult↗
PubMed1986

Pseudo-Zellweger syndrome: deficiencies in several peroxisomal oxidative activities.

We describe an infant girl with a clinical, chemical, and pathologic syndrome remarkably similar to Zellweger cerebrohepatorenal syndrome but whose liver parenchymal cells contained abundant peroxisomes. Peroxisomal L-alpha hydroxy acid oxidase, catalase, and the plasmalogen synthesizing enzyme dihydroxy acetone phosphate-acyl transferase activities were normal; other peroxisomal enzymatic activities, including fatty acyl-CoA oxidase and D-amino acid oxidase, were reduced by 80% to 85%. Oxidation of bile acids and pipecolic acid was also deficient. Autopsy revealed the presence of neuronal heterotopia, renal cortical cysts, adrenal atrophy, and accumulation of very long chain fatty acids. The clinical and pathologic features of this case of "pseudo-Zellweger syndrome" reflect a deficiency in multiple peroxisomal activities rather than a defect in peroxisomal biogenesis. The deficient enzymatic activities require flavin adenine dinucleotide, and the underlying defect may be in the utilization of this cofactor.

Acyl-CoA Oxidase↗
PubMed1986

Dedifferentiated chondrosarcoma: an ultrastructural study of two cases, with immunocytochemical correlations.

The clinicopathologic features of two cases of dedifferentiated chondrosarcoma (DCS) are presented, in which anaplastic components showed the electron microscopic features of malignant fibrous histiocytoma, as well as immunoreactivity for alpha-1-antitrypsin and alpha-1-antichymotrypsin. Rare cells also displayed S100 protein in high-grade areas of the primary tumors, but a pulmonary metastasis lacked this determinant. These findings could be interpreted as reflecting a retained potential for primitive chondrogenesis in primary DCS, which may be lost in its metastases. In all other respects, this tumor appears to assume the morphological and immunocytochemical attributes of a fibrohistiocytic neoplasm.

Bone Neoplasms↗
PubMed1985

Mitral valve prolapse in the ventriculogram: scintigraphic, electrocardiographic, and hemodynamic abnormalities.

Patients with mitral valve prolapse (MVP) frequently have chest pain, which may be difficult to differentiate from angina pectoris in coronary artery disease (CAD). We performed resting and exercise ECGs, pulmonary arterial pressure measurements, radionuclide ventriculography (99mtechnetium), and perfusion scintigrams (201thallium) in 56 patients with angiographically proven MVP and no CAD. Pathological results were obtained in 31% of exercise ECGs, 33% of pulmonary arterial pressure measurements during exercise, 22% of radionuclide ventriculographies, and in 75% of thallium perfusion scintigrams. A significant correlation in pathological results was found only between exercise ECG and both radionuclide ventriculography and pulmonary arterial pressure measurements. Because of the high prevalence of false-positive perfusion scintigrams in patients with typical or atypical chest pain, the use of exercise 201Tl imaging as a screening method to separate patients with MVP from those with CAD will not be appropriate. The variability of cardiac abnormalities in our patients with MVP and angiographically normal coronary arteries suggests that the MVP syndrome may represent a variable combination of metabolic, ischemic, or myopathic disorders.

Coronary Disease↗
PubMed1985

Underestimation of left-ventricular ejection fraction by radionuclide ventriculography in patients with aneurysm.

The left-ventricular ejection fraction (LVEF) of 72 patients with aneurysm of the anterior wall was measured by multiple gated blood pool acquisition (MUGA) in the anterior and left anterior oblique (LAO) positions, and by cineangiography (CA) in right anterior oblique (RAO) and LAO projections of 30 degrees and 60 degrees, respectively. The LVEF was overestimated by CA in the LAO projection and by MUGA in the anterior position, but underestimated by CA in the RAO projection (6.1 percentage points) and by MUGA in the LAO position (6.2 percentage points). In 50 patients without aneurysm, no systematical error occurred using MUGA. The underestimation of the LVEF in patients with aneurysm by MUGA in the LAO position is due to differences of photon attenuation in various parts of the cardiac blood pool. This systematical error can be overcome by biplane MUGA.

Cardiac Output↗
PubMed1985

Improved quality and information in thyroid scintigraphy.

We compared rectilinear scanning, analogous gamma-camera imaging and imaging using a gamma camera interfaced to a computer in order to determine which of these techniques is superior for thyroid scintigraphy. Forty patients with and without goitre and irregular activity distribution were imaged using each of the three techniques. The sets of three scintigrams per patient were rated by seven physicians. These ratings were statistically analysed using a new distribution-free test. Thyroid scintigraphy using a gamma camera interfaced to a computer turned out to be the best method, especially for detecting circumscribed areas of increased uptake. We conclude that this was due to a combination of the following factors: a computer matrix of 128 X 128 pixels in combination with an acquisition zoom of 1.5, the high count density of the scintigrams, computer-controlled documentation after data acquisition and the use of a continuous grey scale for documentation. The improved quality and information content of the scintigrams obtained using a gamma-camera/computer system could improve the diagnostic value of thyroid scintigraphy, especially when the scintigrams are also evaluated quantitatively.

Humans↗
PubMed1985

Long-term follow-up after intracoronary streptokinase therapy for acute myocardial infarction.

This article describes the effects on patients treated with intracoronary streptokinase during acute myocardial infarction and long-term follow-up. The mortality and the incidence of cardiac events were assessed during a follow-up period of 35 +/- 5 months. Coronary artery bypass grafting was undertaken in 37% of the patients. Hospital mortality was 11%, (n = 8); none of these deaths was due to myocardial rupture. The postdischarge mortality was 10%; three of these patients experienced sudden death. Serial assessment of left ventricular function in 35 patients showed an increase of angiographic ejection fraction prior to intervention from 50 +/- 4% to 58 +/- 12% (p = 0.005) 36 +/- 53 days later. Gated-blood pool imaging after 16 +/- 7 months (n = 35) and 32 +/- 9 months (n = 31) revealed no change in ejection fraction. Angina pectoris recurred in four of the 35 patients. We studied a historical comparison group, that consisted of 66 patients, who were treated at the same institution prior to the advent of intracoronary intervention techniques; this group was followed for 48 +/- 9 months. Baseline clinical and angiographic parameters were comparable in the two groups. Coronary artery bypass grafting was performed in only 18 of these patients. Mortality during hospitalization and postdischarge was not significantly different in the two groups. Ejection fraction decreased significantly in the comparison group from the first to the second evaluation and remained unchanged during the follow-up period. We conclude that no major adverse effects were associated with intracoronary streptokinase infusion over a long follow-up period. This may be related to the high frequency of coronary artery bypass surgery following reperfusion.

Aged↗
PubMed1985

A controlled study on the effect of epidural analgesia with local anaesthetics and morphine on morbidity after abdominal surgery.

A hundred patients scheduled for elective abdominal surgery were randomized to either general anaesthesia (low-dose fentanyl) and systemic morphine for postoperative pain or combined general anaesthesia and epidural analgesia with etidocaine 1.5% intraoperatively (T4-S5) and bupivacaine 0.5% 5 ml/4 h for 24 h and morphine 4 mg/12 h for 72 h. Postoperative pain was better controlled by the epidural regimen (P less than 0.0001). We found no significant reduction in postoperative mortality (6% to 2%), pneumonia (28% to 20%), cardiac dysrhythmia (10% to 5%) and wound complications (14% to 11%) by the epidural analgesic regimen. The incidence of deep venous thrombosis (125I-fibrinogen scan) was 32% after general anaesthesia and low-dose heparin and 34% after epidural analgesia with no prophylactic antithrombotic treatment (P greater than 0.9). Postoperative weight loss and decrease in serum-albumin and serum-transferrin, as well as the reduction in haemoglobin and the need for postoperative transfusions, were similar in the two groups. Convalescence, as assessed by postoperative fatigue, restoration of bowel function (flatus, bowel movement and food intake) and the time until the patients were self-aided at their preoperative level, was not reduced by epidural analgesia. Since 50% of the patients in each group suffered from one or more of the above-mentioned postoperative complications, this epidural regimen was not effective in reducing postoperative morbidity after major abdominal surgery despite the achievement of adequate pain relief.

Abdomen↗
PubMed1985

[Alcohol consumption and chronic gastritis].

History of alcohol intake was evaluated in 1,500 patients who had gastroscopy for different reasons. Alcohol intake was related to histological findings of antrum and corpus mucosa. No statistically significant correlation between lesions and alcohol intake could be found. There was a correlation between incidence and severity of gastritis on the one hand and increasing age on the other. The patients under investigation were beer drinkers in the first line. For this reason our findings do not allow any conclusions in regard to persons, who usually drink higher concentrated alcohol beverages. The conclusion can be drawn however that even excessive drinking of beer does not seem to cause chronic gastritis.

Adolescent↗
PubMed1985

[Follow-up of patients with anterior wall aneurysms using radionuclide ventriculography].

32 patients with a large anterolateral aneurysm were studied by using biplane ventricular angiography and rest and exercise radionuclide ventriculography (gated-blood-pool method). The correlation coefficient of biplane ejection fraction by angiography and radionuclide ventriculography was poor (r = 0.65), but repeated investigations and interobserver comparison showed nearly identical values, therefore we used the gated-blood-pool method (GBP) for follow-up investigations in patients with an aneurysm of the anterolateral wall. 11 patients were studied before and 17 +/- 6 months after left ventricular aneurysmectomy. Resting ejection fraction (LVEF) increased significantly from 28 +/- 8 to 38 +/- 8% (p less than 0.005), but exercise LVEF did not. In 21 patients with medical therapy the second GBP measurement after 16 +/- 6 months showed so significant changes in biplane LVEF (33 +/- 9 and 31 +/- 7%, respectively). During exercise LVEF remained unchanged after aneurysmectomy but increased slightly by 5% (p less than 0.05) in the medically treated group. The regional wall motion was unchanged in patients with medical therapy, but after aneurysmectomy there was a significant increase in local ejection fractions in the anterolateral, apical and posterolateral region. The gated-blood-pool methods is suitable for the determination of left ventricular function in patients with anterolateral aneurysm and may be used for follow-up studies. Left ventricular aneurysmectomy is effective in improving resting ventricular function, whereas in patients with medical therapy LV function remains unchanged.

Cardiac Output↗
PubMed1984

Analysis of left ventricular regional motility: a comparison of different methods.

Multiple gated blood pool (MUGA) and contrast ventriculographic studies were performed within 24 h in 80 patients, 20 with 120 normokinetic wall segments and 60 with wall motion abnormalities in 239 of 360 wall segments. Three methods of evaluation of the radionuclide ventriculograms were compared with the results of the biplane contrast ventriculography which served as a standard: (1) qualitative analysis of the cine mode, (2) analysis of parametric scans (amplitude and phase images) and the phase histogram obtained by Fourier analysis, (3) quantitative determination of regional ejection fraction. Normal values were obtained from 20 patients with normal wall motion in the contrast angiogram. The overall sensitivity for the detection of wall motion abnormalities of high degree was 96% for method 1, 95% for method 2, and 90% for method 3, for those of low degree 72% for method 1, 63% for method 2, and 75% for method 3. Combining methods 2 and 3 the sensitivity was increased to 99% for high grade and to 81% for low grade wall motion abnormalities. The two methods showed a complementary effect because of different sensitivities in dependence of the localization of the wall motion abnormality. Although a high efficiency for the evaluation of left ventricular function was provided by the qualitative analysis of the cine mode the combination of Fourier analysis and the determination of regional ejection fraction should be preferred. It increases the sensitivity for the detection of wall motion abnormalities. Moreover, it offers quantitative data which improve the reproducibility and decrease the observer variability.

Angiography↗
PubMed1984

Failure of epidural analgesia to modify postoperative depression of delayed hypersensitivity.

Delayed hypersensitivity to four common antigens was assessed in 32 patients undergoing major abdominal surgery randomly allocated to either general anesthesia (fentanyl + O2/N2O + postoperative pain relief with systemic opiates) or general anaesthesia + epidural analgesia (local anaesthetics + morphine) continued for 72 h. Skin-test responses were performed 2 days before surgery and 1 day after surgery and compared to a similar retesting schedule in 16 comparable non-operative control patients. Cumulated mean skin-test responses increased from 1290 to 2330 mm2 (P less than 0.0001) during retesting in the non-operative control group. In contrast, mean skin-test responses in patients operated during general anaesthesia + systemic opiates for postoperative pain relief fell from 1422 to 1227 mm2 (P = 0.3) and in patients receiving epidural analgesia from 1228 to 890 mm2 (P = 0.06), without statistically significant differences between these two groups (P greater than 0.5). Thus, surgery leads to depression of delayed hypersensitivity and this impairment in immunofunction is not modified by an epidural analgesic regimen providing adequate pain relief.

Aged↗
PubMed1983

[Comparison of various tuberculin tests].

In 188 children results of the Mendel-Mantoux (10 or 100 IU) tuberculin test given intracutaneously were compared with ointment and patch tests as well as with three multipuncture tests using dried or fluid old or purified tuberculin. The new and easily performed multipuncture test with liquid old-tuberculin was significantly superior at 89.4% positive reactions to the other tests (Mendel-Mantoux test as standard at 100%). There were no false-positive results.

BCG Vaccine↗
PubMed1983

Mutagenicity evaluation of amino-oxazoline derivatives using in vitro and in vivo short-term tests.

During routine investigation of potential drugs it was found that 1-methyl-4-(2-oxazoline-2-ylamino)-indazole (1) compound 1 was mutagenic for Salmonella typhimurium TA1535 and TA100. The genotoxicity of compound 1 was confirmed by the following in vitro test systems: V79 Chinese hamster cells (HGPRT-locus), Saccharomyces cerevisiae D7 (mitotic gene conversion, mutations, aberrations), and Escherichia coli (rec-assay). On the other hand, when compound 1 was tested in vivo (micronucleus test in mice and sister chromatid exchange in Chinese hamsters) it did not show evidence of genotoxic activity. In order to study structure/activity relationships, different analogues of compound 1 were tested in Salmonella typhimurium TA1535. The tests showed that (1) most 2-amino-oxazolines were mutagenic for the test organism; (2) the 2-amino-imidazoline and 2-amino-thiazolidine derivatives tested were not mutagenic; (3) substituents bound to the extranuclear nitrogen of the 2-aminooxazoline ring had only a weak influence on the mutagenic potential; and (4) methylation of the oxazoline ring, most conspicuously at the carbon in position 5, strongly reduced the mutagenic effect. From these observations it is concluded that the reaction of nucleophilic DNA sites with the most electrophilic site of the oxazoline ring, ie, the carbon in position 5, is responsible for the genotoxicity of amino-oxazoline compounds. Due to the genotoxicity observed in these in vitro tests this class of compounds was no longer developed, but dropped, even without performing a long-term carcinogenicity study or considering the negative in vivo findings.

DNA Repair↗
PubMed1983

Visualizing cardiac blood pool: comparison of three labeling methods.

The quality of three different labeling methods of visualizing the cardiac blood pool was investigated in 72 patients: 99mtechnetium labeling of red blood cells in vivo or in vitro and human serum albumin. By the simplified technique of in vitro labeling of RBC from the view point of (1) labeling efficiency, (2) activity in the blood, (3) count rates in a standard ROI over the left ventricle and the paracardiac background, (4) ratio of these count rates, and (5) evaluation of image quality, the best results were obtained. HSA and in vivo labeled RBC led to satisfactory results for visual assessment of ventricular performance in most cases. In spite of the slightly higher technical investment involved in the in vitro labeling method this technique appears to be preferable for gated cardiac blood pool studies in view of the excellent labeling quality.

Coronary Circulation↗
PubMed1983

Branchial ion exchange and acid-base regulation after strenuous exercise in rainbow trout (Salmo gairdneri).

Specimens of rainbow trout (Salmo gairdneri) were electrically stimulated to exhausting activity in a closed water recirculation system and the changes in dorsal aortic plasma pH, PCO2, PO2, O2 content, [Na+], [Cl-], [K+], [Lactate-] and Ht were measured during a 24 h recovery period. Net transfer of H+, Na+, Cl- and ammonia between fish and environment were determined by measurement of the concentration changes in the recirculating water. Strenuous exercise resulted in a severe lactacidosis which was corrected by transient net transfer of H+ ions to the environmental water within 4 h, about 6-8 h before the lactate was metabolically removed. The net transfer of H+ ions was achieved in part by branchial HCO3-/Cl- ion exchanges, but to a larger extent by branchial exchange of H+ and/or NH4+ against Na+. The excretion of ammonia, which was considerably enhanced during the first 4 h after exercise, was at least partially due to non-ionic diffusion across the gill epithelium. The observed elevation in ammonia excretion was probably the result of an exercise-induced increase in nitrogen metabolism rather than of production of ammonia for the purpose of acid-base regulation.

Acid-Base Equilibrium↗
PubMed1983

In vitro effects of calcium antagonists PN 200-110, nifedipine, and nimodipine on human and canine cerebral arteries.

PN 200-110 [4-(2,1,3-benzoxadiazol-4-)-1,4-dihydro-2,6-dimethyl-pyridine-3,5-dicarboxylic acid methyl 1-methylethyl ester], a new dihydropyridine derivative, was investigated by recording isometric tension on spiral strips from human and canine arteries in tissue baths at 37 degrees C. Responses to increasing concentrations of CaCl2 were investigated in calcium-free depolarizing solution (60 mmol/L KCl in equimolar replacement for NaCl, 50 mmol/L TRIZMA buffer, pH 7.4). Comparison of those concentrations that reduced the vasoconstrictor response to 1.6 mmol/L CaCl2 by 50% revealed the following order of potencies on both human and canine arteries: PN 200-110 greater than nimodipine greater than nifedipine. Responses to 5-hydroxytryptamine (5-HT) and blood were investigated in Krebs-Henseleit solution (NaHCO3 buffer). On canine arteries, PN 200-110 antagonized responses to 5-HT when used at 10-30 pmol/L; it was approximately 70 times more potent on basilar than on mesenteric arteries, whereas both nifedipine and nimodipine were, respectively, approximately 10 and 6 times more potent on basilar than on mesenteric arteries. When canine basilar arteries were constricted by the addition of blood to the organ bath, each of the investigated dihydropyridine derivatives elicited concentration-dependent relaxation, producing the following order of potencies: PN 200-110 greater than nifedipine = nimodipine. On human anterior cerebral arteries, the blood-induced contractions were counteracted in the following rank order: PN 200-110 = nimodipine greater than nifedipine. The results suggest that due to its potent calcium-blocking activity on cerebral arteries, PN 200-110 might be of value for the prevention and treatment of cerebrovascular spasms following subarachnoid hemorrhage.

Animals↗