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Biomedical subjects

H Barth

Publications and source records attributed to H Barth.

At least 91 records · Page 5Linked to original sources

A Double-Blind Multicenter Comparison of the Efficacy and Safety of Saruplase and Urokinase in the Treatment of Acute Myocardial Infarction: Report of the SUTAMI Study Group.

Background: Urokinase or two-chain urokinase-type plasminogen activator has been shown to be effective in the treatment of acute myocardial infarction. Its parent molecule, single-chain urokinase-type plasminogen activator (scu-PA), unlike urokinase, can selectively activate fibrin-bound plasminogen. The induced clot lysis is amplified by plasmin-triggered conversion of scu-PA to urokinase and by further plasmin generation. The aim of our study was to compare the efficacy and safety of recombinant unglycosylated scu-PA, or saruplase, and urokinase at doses considered optimal in patients with acute myocardial infarction within 6 hours of onset of pain. Methods and results: In a double-blind trial 543 patients were randomized to saruplase (20 mg bolus + 60 mg/hr) or urokinase (1.5 million unit bolus + 1.5 million units/hr). Primary endpoint: The patency rates at 24-72 hours were 75.4% (95% CI 70.3-80.5%) for saruplase and 74.2% (95% CI 69.0-79.4%; P = 0.77) for urokinase. Secondary endpoint: The incidence of bleeding events in both groups was 10.7%. There were three hemorrhagic strokes in the saruplase group (ns). Other efficacy and safety evaluations: Apart from the generation of more fibrinogen degradation products under saruplase, the changes in hemostatic parameters did not differ. Hospital mortality was 4.4% for saruplase and 8.1% for urokinase. This nonsignificant difference was maintained for 1 year. Conclusion: The efficacy and safety of saruplase and urokinase in the regimens used are very similar.

Journal Article↗

Lack of an effect of novel inhibitors with high specificity for protein kinase C on the action of the phorbol ester 12-O-tetradecanoylphorbol-13-acetate on mouse skin in vivo.

The inhibitory effects of three novel staurosporine-derived compounds were tested with five different types of protein kinases, including protein kinase C (PKC). IC50 values of two of these compounds were found to be 300 to > 5000 times lower for PKC alpha beta gamma (a mixture of the PKC isoenzymes alpha, beta and gamma) than for any of the other protein kinases. The inhibitory action of the most selective inhibitor was tested also with the Ca(2+)-unresponsive PKC isoenzyme delta and was found to suppress PKC alpha beta gamma and PKC delta differentially. The highly specific PKC inhibitors are active both in cell culture and in vivo. They inhibit the PKC-catalyzed phosphorylation of the specific PKC substrate MARCKS in Swiss-3T3 fibroblasts and the okadaic acid-induced edema of the mouse ear. However, the more complex biological processes triggered by the phorbol ester 12-O-tetradecanoylphorbol-13-acetate in mouse skin, such as inflammation, stimulation of cellular hyperproliferation and tumor promotion, remain largely unaffected upon topical application of these compounds.

3T3 Cells↗

[Abnormal origin of the right coronary artery from the pulmonary artery. A case report].

An asymptomatic 4-year-old girl with anomalous origin of the right coronary artery from the pulmonary trunk is reported. Echocardiography showed overall dilated coronary arteries with anomalous course of the right coronary artery anterior to the aortic root. During heart catheterization the catheter could be moved from the proximal pulmonary trunk into the aberrant right coronary artery. Because of the coronary-pulmonary steal phenomenon corrective surgery with aortic reimplantation of the right coronary artery is recommended even in asymptomatic patients.

Aortography↗

Phorbol ester TPA rapidly prevents activation of p34cdc2 histone H1 kinase and concomitantly the transition from G2 phase to mitosis in synchronized HeLa cells.

HeLa cells in G2 phase are temporarily inhibited and prevented from entering mitosis by treatment with the phorbol ester TPA (12-O-tetradecanoylphorbol-13-acetate), whereas cells in mitosis are refractory to TPA and divide. In this study the possibility was tested that TPA may interfere with the regulatory cycle of MPF (mitosis promoting factor), the rate-limiting protein kinase for cell division. MPF, consisting of the catalytic subunit p34cdc2 and the regulatory subunit Cyclin B, is known to be activated at the transition from G2 phase to mitosis through dephosphorylation at Tyr15 and to become inactivated after metaphase by proteolysis. Treatment of HeLa cells (synchronized around the G2-M transition) with TPA (10(-7) M) has now been shown to induce an overall decrease of the histone H1 kinase activity associated with anti-p34cdc2 immunoprecipitates after about 20 to 30 min. In metaphase cells, the histone H1 kinase activity of p34cdc2 was shown to remain unaffected by TPA treatment. In cultures enriched in G2 cells neither the amount of p34cdc2 protein nor that of Cyclin B was influenced by TPA. Moreover, the p34cdc2/Cyclin B complex formation was also unaffected. However, p34cdc2 from cultures treated with TPA was more intensely stained by anti-phosphotyrosine antibodies than that of control cells, indicating that TPA treatment probably prevented the tyrosine dephosphorylation required for expression of the histone H1 kinase activity of the complex. The results indicate that TPA treatment of HeLa cultures rapidly stops the G2-M transition because it very rapidly prevents the p34cdc2/Cyclin B complex in G2 cells from developing histone H1 kinase activity.

CDC2 Protein Kinase↗

[Intracerebral hematoma as an acute manifestation of intracranial tumors].

Sixteen patients with spontaneous intracerebral haematoma due to intracranial tumours are discussed. The total number of patients with intracranial tumour treated in the period concerned was 594, so the incidence of tumour haemorrhage was 2.7%. In most of the patients we found metastatic neoplasm (n = 6) and glioblastoma (n = 3). All patients were acute admissions. Seven were comatose, seven were somnolent, and two patients were alert. In ten patients the haemorrhage represented the first reliable clinical sign. In six patients a tumour disease was known. Fourteen patients were operated on. Six patients died. Extensive neuro-radiological examination is very important, particularly since 30% of these acute intracerebral haemorrhages occur in patients with benign intracranial tumours.

Acute Disease↗

Anti-inflammatory properties of the protein kinase C inhibitor, 3-[1-[3-(dimethylamino)propyl]-1H-indol-3-yl]-4-(1H-indol-3-yl)-1H- pyrrole-2,5-dione monohydrochloride (GF109203X) in the PMA-mouse ear edema model.

Protein kinase C (PKC) mediates a number of intracellular signal transduction pathways implicated in the pathogenesis of inflammation, including phospholipase A2-dependent arachidonic acid release and eicosanoid production. Recent studies demonstrate that the PKC inhibitor GF109203X significantly reduces a number of inflammatory processes resulting from PKC activation by the topical application of phorbol myristate acetate (PMA) to mouse ears. In this model, GF109203X significantly reduced edema at doses similar to the PKC inhibitor staurosporine, and more effectively than indomethacin, zileuton, or sodium meclofenamate. Histological and biochemical analysis of biopsies from control and drug-treated ears revealed a marked reduction in edema, infiltrating neutrophils, and levels of the neutrophil-specific marker, myeloperoxidase, in GF109203X-treated mice. Prostaglandin E2 levels were also reduced in ears treated with GF109203X. These data suggest that GF109203X is an effective antiinflammatory agent as evaluated in the PMA model of edema, and implicates PKC as a potential target in the development of novel anti-inflammatory agents.

Animals↗

The effect of taprostene in patients with acute myocardial infarction treated with thrombolytic therapy: results of the START study. Saruplase Taprostene Acute Reocclusion Trial.

Taprostene is a prostacyclin analogue that inhibits platelet aggregation and thus might be a useful adjuvant to thrombolytic agents in acute myocardial infarction. In a placebo-controlled dose rising study, taprostene or placebo was intravenously infused in 80 patients treated with the thrombolytic agent saruplase (rscu-PA) for acute myocardial infarction. Three doses of taprostene were used: 6.25; 12.5; or 25.0 ng.kg-1 x min-1. Taprostene or placebo was infused for 48 h, followed by a 24 h tapering period. All 80 patients had short symptom-to-treatment delay and marked ST segment elevation. Patency at 90 min was documented in 58/78 patients (two patients had no angiography). Success rate varied from 67-82% in the four treatment arms (P = 0.33). Patency after rescue PTCA was seen in 10 out of 13 patients. Of the 58 patients having a patent artery at 90 min, none of the 43 taprostene patients and one of the 15 placebo patients had a re-occluded artery at the second angiography at 32-48 h (5/58 patients had no recatheterization). Conversely, of nine patients who had successful rescue PTCA, three of four placebo patients had a re-occluded artery at the second angiography compared to one of five taprostene patients (one placebo patient had no recatheterization) (P = 0.33). Safety evaluation revealed no major difference between the placebo plus saruplase and the taprostene plus saruplase groups. Taprostene was well tolerated up to 25 ng.kg-1 x min-1. Although taprostene did not affect 90 min patency, there was a trend to better maintenance of patency after rescue PTCA.

Angioplasty, Balloon, Coronary↗

Synthesis and biological activity of 4-(diphenylmethyl)-alpha-[(4-quinolinyloxy)methyl]-1-piperazineethanol and related compounds.

A series of 4-(diphenylmethyl)-alpha-[(4-quinolinyloxy)methyl]-1-pipe razineethanol and closely related compounds was synthesized and evaluated for cardiac and vascular activity in isolated perfused rat and guinea pig hearts. Compound 1 produced greater inotropic effects in rat hearts than in guinea pig hearts, a phenomenon which was also observed with the prototype agent DPI 201-106. Compound 15 produced an inotropic effect with one-tenth the potency of compound 1. Both compounds 1 and 15 demonstrated direct inotropic and vasodilatory effects when administered iv in anesthetized dogs, although the vasodilatory activity was more pronounced with compound 15 than 1 and DPI compound. Compound 1 lacks the CN moiety which is a key structural requirement in DPI for positive inotropic activity. The synthesis, in vitro, and in vivo evaluations of these agents, and comparative data with DPI-201-106 (compound 17) are reported.

Animals↗

Group conduction velocities and nerve fibre diameters of alpha and gamma-motoneurons from lower sacral nerve roots of the dog and humans.

Single action potentials and their conduction times were recorded extracellularly from dog and human lower sacral nerve roots. Conduction velocity frequency distribution histograms were constructed and peaks of single extrafusal and intrafusal motoneuron distributions were identified. The electrophysiologically measured roots were removed and morphometrically analysed. Nerve fibre diameter frequency distribution histograms were constructed with respect to 3 myelin sheath thickness ranges, and peaks of single motoneuron group distributions were identified. The identified motoneuron classes, characterized by their group peak values of conduction velocity at about 36 degrees C and fibre diameter were: dog: intrafusal: gamma 22(23ms-1/4.8 microns),gamma 21(33/5.7), gamma 1 (43/6.7),gamma beta?(54/10.1) extrafusal: alpha 3(61ms-1/11.7 microns),alpha 2(72/13.6), alpha 11 (81/15.2), alpha 12(86/16.8),alpha 13(95/19) human: intrafusal: gamma 21(15ms-1/5.8 microns), gamma 1(20/6.8), gamma beta?(27/7.2) extrafusal: alpha 3(37ms-1/8.3 microns),alpha 2(50/10.2), alpha 1(60/13.1) The 60 (alpha 3) to 30% (alpha 1-motoneurons) higher conduction velocities in dogs as compared to humans seem to originate in the 40 (alpha 3) to 30% (alpha 1-motoneurons) larger nerve fibre diameters. However, the myelin sheath seemed to be 0.1 to 0.2 microns thinner in dogs than in humans. The pair-values "conduction velocity-fibre diameter" of the alpha and gamma-motoneuron groups were lying on different correlation curves in the velocity-diameter plane indicating structural and/or geometrical differences between alpha and gamma-motoneurons.

Action Potentials↗

Extracorporeal lung assist with heparin-coated systems.

Extracorporeal lung assist (ELA) has been recommended for the treatment of ARDS if conventional therapy fails. However, the need for nearly complete anticoagulation is a major risk factor for hemorrhagic complications. We describe our experience with 13 ARDS patients treated with ELA using heparin-coated systems (Carmeda). Maintaining partial thromboplastin time and activated clotting time within or close to the normal range, even major surgery (20 thoracotomies and 2 laparotomies) could be performed without undue bleeding complications related to anticoagulation during extracorporeal support. Eight of the 13 patients survived. The use of heparin-coated systems allows prolonged ELA with nearly physiological coagulation function, permitting major surgical intervention. It enhances the safety margin of extracorporeal gas exchange and may ultimately extend its indications.

Adult↗

[Anomalous origin of the left coronary artery from the pulmonary artery. Variability of clinical aspects, echocardiography and angiography findings].

OBJECTIVES: Analysis of symptoms, diagnostical difficulties and follow-up in infants and children with anomalous origin of the left coronary artery from the pulmonary artery. METHODS: Retrospective study; 12 children between 3 weeks and 2 years old; time period: 1980-1991. RESULTS: Three infants were detected on routine examination because of a new cardiac murmur, the others presented with signs of cardiac failure. Cross sectional echocardiography and color Doppler flow mapping allowed to verify the suspected diagnosis. However, in one infant a false-negative cross sectional echocardiographic result was obtained. In this case nuclear magnetic resonance imaging was able to delineate the exact anatomy. Mean preoperative left ventricular ejection fraction: 33 +/- 4%; percentage of infants below the age of 6 months: 92%; surgery related mortality: 66%; mean follow-up of the remaining 4 patients being in good clinical condition: 2.9 +/- 1 years. CONCLUSIONS: 1. An anomalous origin of the left coronary artery should be included into the differential diagnosis when a new cardiac murmur is detected. 2. Possibility of false-negative echocardiographic results is emphasized. 3. With early symptoms and highly reduced left ventricular function, the mortality is still high.

Angiocardiography↗

Dose-related healing of duodenal ulcer with the proton pump inhibitor lansoprazole.

Lansoprazole (AG 1749) is a novel substituted benzimidazole which inhibits gastric acid secretion by blocking H+,K(+)-ATPase. This randomized, double-blind multicentre trial studied the dose-response relationship of lansoprazole on ulcer healing and compared it with ranitidine in 314 out-patients with endoscopically assessed, symptomatic duodenal ulcer. Cumulative healing rates with Lansoprazole 7.5, 15, and 30 mg o.m. were 48, 59, and 74% at 2 weeks and 75, 84, and 95% at 4 weeks, respectively (intention-to-treat); the difference of the healing rates between 7.5 and 30 mg groups was significant (P less than 0.001). Corresponding healing rates for 300 mg ranitidine nocte were 51 and 89%. Pain relief was similar in all treatment groups. Lansoprazole was well tolerated. During a follow-up of 6 months relapse rates after lansoprazole 7.5, 15, and 30 mg were 21, 29, and 22%, respectively; the relapse rate after ranitidine 300 mg was 20%. In conclusion, lansoprazole provides faster healing of duodenal ulcer than ranitidine and a similar relapse pattern. For further trials in peptic ulcer disease a daily dose of lansoprazole 30 mg o.m. is recommended.

2-Pyridinylmethylsulfinylbenzimidazoles↗

Effects of taprostene, a stable prostacyclin analogue, on haemodynamics, platelet function and arachidonate metabolism in healthy volunteers.

In order to assess the effect of taprostene on haemodynamics, platelet function and arachidonate metabolism in 4 healthy volunteers an intravenous infusion of 25 ng.kg-1.min-1 was given for 6 h. During the infusion period systolic blood pressure dropped from 130 to 111 mm Hg and diastolic blood pressure from 77 to 69 mm Hg. The heart rate rose from 77 to 84 beats/min. During the taprostene infusion the slope and height of the ADP and collagen induced platelet aggregation curves were significantly inhibited and the sensitivity of platelets to PGI2 and PGE1 was increased. Plasma and serum thromboxane B2, conversion of exogenous radiolabelled arachidonic acid, WU-test, circulating endothelial cell count, concentration of platelet factor 4, beta-thromboglobulin, malondialdehyde and the PGI2-synthesis stimulating plasma factor did not show any clear drug-related alteration. It is concluded that infusion of taprostene 25 ng.kg-1.min-1 caused measurable inhibition of platelet function ex vivo.

Adult↗

[Malignant neurinoma of the suprascapular nerve].

Malignant neurinomas are rare. The clinical symptoms are determined by the location of the tumor and are uncharacteristic. Therefore, the case of an 27-year-old male patient is described who was operated on a malignant neurinoma of the suprascapular nerve. The treatment of choice is radical surgery. In addition, radiation and chemotherapy are indicated in some cases.

Amputation, Surgical↗

Effects of taprostene, a chemically stable prostacyclin analogue, in patients with ischaemic peripheral vascular disease: a placebo controlled double-blind trial.

Thirty patients with ischaemic peripheral vascular disease and intermittent claudication were randomly allocated to receive either placebo or taprostene, a chemically stable prostacyclin analogue, intravenously at a rate of 25 ng/kg/min for 6 hours daily on 5 consecutive days. Taprostene produced a significant (p less than 0.05) increase in absolute walking time compared to placebo on one day after infusion and at 1, 4 and 8 weeks (14% vs 2.8%) later. Taprostene also produced a significant (p less than 0.05) increase in the pain-free walking time compared to placebo in the follow-up period (8 weeks after infusion: 23% vs 3.8%). During the infusion period systolic and diastolic blood pressure decreased (p less than 0.05) and heart rate was accelerated (p less than 0.05) in the taprostene treated group whereas no change was monitored in the placebo group. The ankle/brachial Doppler index was unaffected by taprostene. The platelet half-life was significantly (p less than 0.05) prolonged following taprostene-infusion (72.6 +/- 9.35 vs 77.9 +/- 7.44 hours). However, no change on platelet half-life was found in the placebo group (p less than 0.05). Various measures of platelet function parameters followed in vitro (ADP-induced aggregation, platelet sensitivity to PGI2, PGE1, PGD1 and taprostene, concentrations of platelet factor 4 and beta-thromboglobulin) showed no change with taprostene. Measures of circulating platelet aggregates and endothelial cells count showed no changes during the 2 months follow-up period too. It is assumed that taprostene may be of clinical benefit in patients with ischaemic peripheral vascular disease. However, future investigations have to be carried out to assess the optimal dose regime.

Alprostadil↗