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M Riedl

Publications and source records attributed to M Riedl.

53 records · Page 3Linked to original sources
PubMed1994

Iodine-123-IBZM-SPECT: studies in 15 patients with pituitary tumors.

Single photon emission computerized tomography (SPECT) using the Iodine 123 labeled dopamine D2 receptor antagonist S(-)Iodobenzamide [S (-)IBZM] was performed in 15 patients with pituitary tumors. Among them there were five prolactinoma patients with macroadenoma and two acromegalic patients with macroadenoma. Specific binding in the area of the adenoma was only observed in one subject, a macroprolactinoma patient, who was responsive to dopaminergic treatment. None of the other patients, among them one macroprolactinoma patient responsive to dopaminergic treatment showed specific binding in the area of the tumor. IBZM-binding in the striatum was found to be significantly lower in the group of pituitary tumor patients as compared to controls. The results show that D2 receptors in pituitary adenomas can be visualized using SPECT. However, the sensitivity of IBZM-SPECT appears to be too poor to visualize PRL- and GH- secreting macroadenomas in general.

Adenoma↗
PubMed1994

Effect of elevated growth hormone concentrations on the phenotype and functions of human lymphocytes and natural killer cells.

Over the past decades, strong evidence has accumulated that growth hormone (GH) has immunostimulatory properties. Therefore, an investigation was conducted on 10 acromegalic patients and 9 age- and sex-matched healthy controls to determine whether plasma GH concentrations correlate with changes in several immune parameters, including serum concentrations of immunoglobulins, lymphocyte subsets, lymphocyte transformation with phytohemagglutinin (PHA), natural killer (NK) cell activity as well as phagocytic and metabolic burst activity. While NK cell activity, serum concentrations of immunoglobulins (IgG, IgM, IgA) and metabolic burst activity were within the normal range in both groups, a significantly enhanced phagocytic activity was observed in the acromegalic patients. Surface markers on T lymphocytes (CD3, CD4, CD8), B lymphocytes (CD19) and NK cells (CD16/56) were normal in both groups; however, in the acromegalic subjects, CD4+ and CD8+ cells showed a significant higher expression of transferrin receptors (CD71), indicating enhanced T-cell activity. The lymphocyte transformation response to PHA at the highest concentration tested showed a tendency to be elevated in acromegalics; however, the difference failed to be significant. Long-lasting and pronounced elevation of GH in acromegaly induces significantly enhanced phagocytic activity, but only negligible changes in most patients in lymphocyte phenotype and in the lymphocyte response to PHA.

Acromegaly↗
PubMed1991

Laser angioplasty: results of a prospective, multicenter study at 3-year follow-up.

A prospective multicenter trial was initiated to evaluate the efficacy and safety of laser angioplasty. Laser recanalization was performed in 338 patients with arteriosclerotic femoropopliteal artery occlusions (average length, 8.5 cm). Neodymium-yttrium-aluminum-garnet lasers were used in combination with sapphire probe catheters. The initial recanalization rate was 85%. Complications were observed in 14% of the patients. Emergency surgery was required in 1.5%. The cumulative long-term patency rate of the successfully recanalized arteries was 80%, 70%, 62%, and 57% at 6 months, 1 year, and 2 and 3 years, respectively. The patency rates were not affected by the length of the occlusion and the long-term medication (platelet inhibition vs anticoagulation), but patients with a normal runoff had significantly better patency rates than those with reduced runoff (63% vs 52%, P less than .01). The study has shown that laser-assisted angioplasty is safe and at least as effective as conventional angioplasty.

Adult↗
PubMed1991

[The treatment of septicemia in childhood using time-spaced administration of antibiotic combinations].

Theoretical consideration, empirical findings since 1972 and in vitro results had suggested that a combination of antibiotics for treatment of sepsis is more effective if the 2 or 3 antibiotics are not applied simultaneously but individually and sequentially at short intervals of 4 hours. Between January 1986 and March 1990 100 children were treated with spaced administration of antibiotic combinations at the University Hospital Innsbruck (Department of Paediatric). Causative agents isolated compared well to data published for other institutions; staphylococci were the dominating species. Anaerobic bacteria and fungi accounted for only 1% each, 60% of the cases were nosocomial infections. Overall, the fatality was 4%, a result significantly below the values reported in the literature for conventional therapeutic regimens.

Anti-Bacterial Agents↗
PubMed1990

[Femoropopliteal laser recanalization--a multicenter study].

Laser-assisted angioplasty was performed in four different hospital centers, following the same treatment protocol and using an Nd-YAG laser with a sapphire-probe catheter. The initial recanalization rate of 259 femoro-popliteal occlusions with a mean length of 7.5 cm was 84%. Dissections or perforations were observed in 10%. An emergency surgical intervention was required in 1.1%. The long-term patency rate of the successfully recanalized arteries was 74% after 2 years. The cumulative cure rate of all 259 patients was 62%.

Adult↗
PubMed1989

Spinal traumas: some postoperative complications in experimental animals.

Animals with severe spinal traumas show paraplegic syndrome and various somatic and autonomic dysfunctions. Of the various dysfunctions those related to hypothermia, bladder problems, and autophagia are of serious nature. The condition of animals with these complications deteriorates rapidly, and the animals are sacrificed for histological and pathological analyses. The findings show that the postoperative complications are related to the degree of severity of the trauma, and that 50-80% animals are lost due to these complications. Most of these animals are lost during the first two weeks after surgery, and the remaining at later stages. Transplantation of neural tissue at the site of lesion does not ameliorate these postoperative complications and improve the survival rate of the animals.

Animals↗
PubMed1989

N-hydroxy-N-arylacetamides. V. Differences in the mechanism of haemoglobin oxidation in vitro by N-hydroxy-4-chloroacetanilide and N-hydroxy-4-chloroaniline.

1. Autoxidation of N-hydroxy-4-chloroaniline(I) in buffer pH 7.4 was rapid and yielded 4,4'-azoxybischlorobenzene, 4-chloronitrosobenzene, 4-chloronitrobenzene, and 4-chlorophenyl nitroxide. In contrast, autoxidation of N-hydroxy-4-chloroacetanilide(II) was very slow, since in ether and water 78 and 92%, respectively, had decomposed in six months. 2. Haemoglobin(HbO2)-catalysed autoxidation of (I) occurred at a molar ratio of haemoglobin-Fe2+ to (I) of less than 0.25 and was accompanied by ferrihaemoglobin(HbFe3+)-formation and oxygen consumption. Coupled oxidation of HbO2 with (I) occurred at a molar ratio of greater than 0.2 and was accompanied by liberation of oxygen and the formation of HbFe3+, haemoglobin-4-chloronitrosobenzene complex, HbO2, desoxyhaemoglobin, 4-chloronitrosobenzene, 4-chloronitrobenzene, 4-chloroaniline, 4,4'-azoxybischlorobenzene, and 4-chlorophenyl nitroxide. At an equimolar ratio of 10(-3) M haemoglobin-Fe2+ to (I), 96% HbO2 was converted into HbFe3+ (50%) and haemoglobin-4-chloronitrosobenzene complex in the initial fast phase of the reaction, but only 34% of the bound oxygen was liberated, the rest was sequentially reduced to water. (I) completely disappeared, and 4-chloronitrosobenzene was the major metabolite, mainly bound to haemoglobin. 3. Chemical oxidation of (II) by PbO2 in benzene produced acetyl 4-chlorophenyl nitroxide, whose spontaneous decomposition gave 38% 4-chloronitrosobenzene, 33% N-acetoxy-4-chloroacetanilide, 10% 4-chloroacetanilide, and 8% 4-chloronitrobenzene. Its spontaneous decomposition in water also followed second order kinetics, K = 350 l mol-1 sec-1 and yielded N-(2-acetylamino-5-chlorophenyl)-p-benzo-quinoneimine-N-oxide in addition. 4. In the coupled oxidation of 10(-3) M haemoglobin-Fe2+ with 10(-3) M (II), 75% HbFe3+ was formed after 1 h, but only one third of the equivalent of oxygen was released, and two thirds were reduced to water. Concentration of (II) decreased by 5% only, indicating that one mol of (II) had catalysed the oxidation of 15 equivalents of haemoglobin-Fe2+. The identity of the product pattern formed with HbO2 with that produced by chemical one-electron oxidation indicated that oxygen bound to haemoglobin also functions as an acceptor for electrons from (II) as from (I), but the different redox potentials can explain why the secondary aromatic nitroxide was catalytically active and the primary nitroxide was not.

Acetanilides↗
PubMed1989

[A case of prepuberty periodontitis--a classification based on laboratory results].

The rare entity of periodontitis in a 4 1/2-year old child and subsequent changes over a 4-year follow-up period will be presented. Various examinations (among other immunological tests, biochemical differentiation of dermal fibroblasts, and ultrastructural skin biopsies) were made to identify whether this was a case of genuine prepuberty periodontitis or of periodontitis secondary to a general disease. On the basis of the results the case was diagnosed as Ehlers-Danlos Disease Type VIII, although at the same time signs of impaired granulocyte function were observed.

Aggressive Periodontitis↗
PubMed1986

Specificity of ganglioside binding to rat macrophages.

The binding specificity of rat alveolar macrophages (AM phi) for sheep erythrocytes (E) coated with gangliosides GM1, GM2, GM3, GD1a, GD1b or GT1b was analyzed in a rosette assay by studying the inhibitory effect of gangliosides, various carbohydrates, IgG, C3b-like C3, and fibronectin in this assay. The uptake of gangliosides by E was calculated from radioactivity measurements using 3H-labeled gangliosides. The different gangliosides were taken up by E at 37 degrees C to a similar extent. Uptake of 3H-labeled GM2 correlated linearly to its concn in the incubation medium. Erythrocytes pretreated with the same molar concn of GM2, GD1a, GD1b or GT1b were bound to AM phi to the same degree reaching a maximum of about 90% rosette forming cells. A mean of 17.8% AM phi-bound GM3-coated E. Treatment of E with asialo-GM2 (GA2) or GM1 did not induce significant rosette formation. A dose-dependent inhibition of rosette formation was observed when AM phi were preincubated at 0 degree C with GM2, GM3, GD1a, GD1b or GT1b, but not with GM1 or GA2 Of the tested carbohydrates, sialyl-lactose had a strong inhibitory effect, while lactose was completely ineffective. N-acetyl-neuraminic acid, N-glycolyl-neuraminic acid and N-acetyl-galactosamine were slightly inhibitory. A series of other carbohydrates including highly negatively charged compounds, as well as fibronectin, IgG or C3b-like C3 did not show significant inhibition. Our data indicate the expression of a receptor on rat AM phi recognizing carbohydrates containing sialic acid at or near the non-reducing terminus.

Animals↗
PubMed1984

Ganglioside receptor of rat macrophages. Modulation by enzyme treatment and evidence for its protein nature.

Previous experiments have shown that rat macrophages (M phi) bind specifically sheep erythrocytes (E) coated with various gangliosides (EG). To study the nature of this receptor-like structure, M phi were treated with proteinases, and their capacity to bind EG and/or E was analyzed in a rosette assay. Within 10 min of incubation with appropriate doses of enzymes, a clear enhancement of EG-binding activity was observed. In addition, enzyme-treated M phi bound uncoated E. Inhibition studies with gangliosides and carbohydrates, and enzyme treatment of E showed that this binding is mediated by the same M phi ganglioside receptor. The kinetics of the modulation of binding activity of M phi during trypsin treatment were similar for both E and EG. At optimal enzyme concentration a triphasic effect was noted. Enhancement of EG-binding and appearance of E-binding activity after 10-20 min was followed by a reduction of rosette-forming cells (RFC) with a minimum at about 1 hr and then by an increase of both E-RFC or EG-RFC up to 5 hr. Simultaneous incubation of M phi with trypsin and cycloheximide abrogated the second rise of binding activity and abolished binding on prolonged incubation. When these cells were washed and further incubated in fresh medium, they regained their initial E- and EG-binding capacity after 4-5 hr incubation. Taken together, these results are consistent with the idea that rat M phi bear a ganglioside receptor-like structure which seems to be a membrane protein and which is modulated by enzyme treatment.

Animals↗
PubMed1982

The human thyrocervical trunk: configuration and variability reinvestigated.

Reinvestigation of the configuration of the human thyrocervical trunk revealed, that in the presently investigated specimens the dorsal scapular artery is a direct branch of the subclavian artery in approximately 75% of the cases, whereas in the remaining 25% it is derived from the thyrocervical trunk, either directly or via the transverse cervical artery (Nomina anatomica 1977). The internal thoracic artery participates in the thyrocervical trunk in more than 10% of the observed cases. Thus, both dorsal scapular and internal thoracic artery have to be considered as facultative branches of the thyrocervical trunk. According to our results, the subclavian artery must be considered as the most common site of origin of the dorsal scapular artery. This vessel may be replaced by another artery in about one fourth of the cases. A survey of studies on the origin of the dorsal scapular artery clearly demonstrates that it is not warranted to give an overall numerical proportion for the main modes of branching. As yet no satisfactory explanation for the high degree of variability of these subclavian branches has been given. Especially the widely held notion of differences related to race, which is based on Adachi's (1928) work, has turned out to be invalid. Interpretation of variability may rather be based, as a general concept, on the late acquisition of a thyrocervical trunk in phylogeny as well as in ontogeny.

Arteries↗
PubMed1982

Antigenic heterogeneity of rat macrophages. A monoclonal antibody reacting only with alveolar but not with other types of macrophages.

Hybridoma antibodies were produced by fusing spleen cells from mice immunized with rat alveolar macrophages (AM) with P3 x 63Ag8/653 myeloma cells. Some of the hybridomas were processed to achieve monoclonality. Reactivity was tested in an indirect membrane immunofluorescence assay. One of the monoclonal antibodies, called VEP6 antibody, reacted with rat AM but not with peritoneal or splenic macrophages and not with peripheral blood monocytes of this species. It was also unreactive with cells from thymus, bone marrow, non-adherent spleen cells, granulocytes and erythrocytes, but it reacted with thrombocytes. Corynebacterium parvum activated AM were slightly less reactive then 'resident' AM, as determined in a fluorescence activated cell sorter. The VEP6 antigen was studied in polyacrylamide gel electrophoresis after immunoprecipitation from 125I-surface-labelled-macrophage NP40-lysates. Four specific radioactive bands were seen in the precipitates corresponding to molecular weights of 31, 33, 35 and 37,000. A slurred band was seen in this molecular weight range when immunoprecipitates of surface labelled thrombocytes were analysed. This study confirms the heterogeneity of macrophages by showing that certain antigens may be expressed only on a subpopulation of macrophages.

Absorption↗
PubMed1982

A ganglioside-dependent cellular binding mechanism in rat macrophages.

A rosetting assay was performed with rat alveolar and peritoneal macrophages and sheep red blood cells (SRBC) treated with gangliosides. SRBC incubated with GM2, GD1a, and a mixture of bovine brain gangliosides (BBG) showed binding to rat macrophages. The extent of binding was dependent on the concentration of gangliosides. Binding induced by GM2 was stronger than that induced GD1a and BBG. GM1 and GA2 did not induce rosette formation. Inhibition studies with gangliosides, sialyllactose, lactose, and neuraminic acid suggested that the macrophage binding site recognizes neuraminic acid in conjunction with neighboring carbohydrates showing highest affinity for GM2. Sodium azide, sodium fluoride, ethylenediaminetetraacetate, cytochalasin B, and colchicine did not inhibit rosette formation. The percentage of peritoneal macrophages binding ganglioside-treated SRBC was lower than that of alveolar macrophages. Proteose-peptone-stimulated peritoneal macrophages, however, showed an increase of rosette formation. Around 30% of adherent spleen cells also had binding activity for GM2-treated SRBC. Peripheral blood mononuclear cells did not bind ganglioside-treated SRBC. Phagocytosis of GM2-treated SRBC attached to alveolar macrophages could not be observed. It is suggested that macrophages may express recognition sites for certain gangliosides that might be important in cell-cell interaction.

Animals↗