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Biomedical subjects

M Lang

Publications and source records attributed to M Lang.

At least 181 records · Page 10Linked to original sources
PubMed1987

[New thrombolytic agents in myocardial infarction].

Fibrinolysis is a physiological process which aims at dissolving intravascular thrombi and is mediated by activation of plasminogen to plasmin. Streptokinase (SK) and urokinase (UK) are non-specific plasminogen activators. They have proved effective as thrombolytic agents, but their use is limited by the risk of haemorrhages due to systemic fibrinogenolysis. More fibrin-specific drugs have recently been developed. One is a tissue plasminogen activator (t-PA), the other is a urokinase precursor (pro-UK), also called single chain urokinase plasminogen activator (scu-PA). Genetic engineering techniques have resulted in the large-scale production of a "recombinant t-PA" (rt-PA) and a "recombinant scu-PA" (r scu-PA) for therapeutic use, notably in acute myocardial infarction. In vitro, these two drugs exhibit a thrombolytic activity that is equal to, or greater than that of SK or UK. In vivo, their fibrinogenolytic effect is less pronounced, and their thrombolytic effect greater than those of SK or UK. "Acyl-enzymes" have more recently emerged. These are inactive acylated SK-plasminogen complexes which progressively become effective in plasma after deacylation. So far, the most extensively studied of these complexes is BRL 26921 (anisoylated plasminogen streptokinase activator complex, or APSAC) which is administered by bolus intravenous injection. It is more thrombolytic than SK but produces systemic fibrinogenolysis to an equivalent degree. Injected intravenously (by infusion or bolus) during the first hours of a coronary infarction these three new thrombolytic agents have proved effective in promoting coronary reperfusion, with an early coronary patency rate of 70-75%.(ABSTRACT TRUNCATED AT 250 WORDS)

Anistreplase↗
PubMed1987

[Diagnosis of primary hyperaldosteronism. Apropos of 3 cases].

Primary hyperaldosteronism (HA1) represent a rare etiology of arterial hypertension (less than 1%). It concerns, most of the time, aldosterone-producing adenomas or bilateral adrenal hyperplasias although intermediate forms have been reported. The diagnosis of HA1 is based on simple examinations, especially systematic measurement of kaliemia in every hypertensive patient with a normal sodium diet before treatment. The elevation of aldosterone blood levels associated with a low plasma renin activity confirms the autonomous nature of the hormonal secretion which is dissociated from the renin-angiotensin system. Study of the ratio aldosterone blood level/ARP and the captopril test are particularly useful in borderline cases. Once the diagnosis of HA1 is made, a topographic analysis may be undertaken; tomodensitometry and adrenal scintigraphy are currently the examinations of choice in the diagnosis of adrenal tumors. Due to biological, morphological and topographic factors, aldosterone-producing adenomas may be identified with a great deal of certainty: surgical excision ensures a cure in a large majority of cases. The treatment of bilateral hyperplasias remains medical.

Adenoma↗
PubMed1987

Slow negative potential shifts indicating verbal cognitive learning in a concept formation task.

It is well-known clinically that patients with left frontal lesions are impaired in their verbal-cognitive learning ability. Starting from such observations, it is of particular interest whether the event-related cerebral potential shifts recorded in healthy human subjects would indicate a left frontal lobe involvement in verbal-cognitive learning tasks. In a concept formation paradigm, subjects learned by trial and error to transform letters into Morse codes. This cognitive performance was accompanied by a slow negative potential shift (SP) that in frontal recordings was lateralized towards the left hemisphere. off results show in a later stage of learning, in which the experience of the preceding trial and error learning could be integrated, an increasing slow negativity over the frontal cortex. Ss also participated in a control task with already known letter/Morse code combinations. Again, a negative potential shift occurred within the stimulus-response interval, however, it was smaller in amplitude.

Adult↗
PubMed1987

[Analysis of segmental kinetics of the left ventricle after intravenous administration of urokinase in the acute phase of myocardial infarction].

From 1982 to 1984 included, 31 patients under 70 years of age were admitted during the first three hours of a primary myocardial infarction (MI) and are the subject of a randomized prospective study. 16 patients are treated with 5,000 U of heparin given in intravenous bolus, followed with 150,000 IU of urokinase (UK) in intravenous bolus, then 12,000 IU of UK/min for 90 min or a total dose of 1,230,000 IU. 15 patients are treated with heparin alone (intravenous bolus of 5,000 U). Repeated titrations of creatine phosphokinase (CPK) and the coagulation parameters are performed during the first 24 hours. A coronary angiography with ventriculography (RAO 30 degrees) is performed on the 1st day (D1) and the 3rd week (W3). Study of the left ventricular kinetics (LV) is carried out according to the Stanford method. At D1, the rate of coronary patency is 56 p cent (n = 9) in the UK (A) group and 53 p. cent (n = 8) in the control group B (heparin alone). The percentage of late re-thrombosis is 0 p. cent in group A and 12.5 p. cent in group B (heparin alone). 1 patient died in each group. The CPK peak is less high in case of coronary patency in group A than in case of thrombosis (1,444 +/- 413 vs 1,710 +/- 120 U -heparin alone) and occurs earlier (16 +/- 2 h vs 21 +/- 1 h). In group A a significant decrease of fibrinogen (p. 0.01) as well as plasminogen and alpha-2-antiplasmins (p less than 0.001), is noted. No severe haemorrhagic complications nor sustained rhythm disorders are noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1986

[Monitoring heparin therapy by thrombin time and activated partial thromboplastin time--a comparison].

In 106 plasma samples obtained from patients on heparin therapy, monitoring by 2 methods (activated partial thromboplastin time and thrombin clotting time--APTT and TT) was compared. All patients in whom APTT indicated markedly higher plasma heparin concentrations than the TT were critically ill (group B): their main diagnoses included severe infectious disease, severe liver disease and extensive myocardial infarction. Patients with lesser discrepancies between the results of APTT and TT did not suffer from such severe conditions (group A). Cardiac surgery without major postoperative problems, limited myocardial infarction and uncomplicated thromboembolism were the main diagnoses in this group. In group B, non-heparin related prolongation of APTT was thought to be the main factor responsible for the overestimation of plasma heparin concentrations by this test. We conclude that in patients with severe infectious disease, liver disease or extensive tissue necroses (i.e. myocardial infarction), APTT cannot be recommended for laboratory monitoring of heparin therapy.

Blood Coagulation Tests↗
PubMed1986

Coumarin 7-hydroxylase in inbred strains of mice: comparison with other microsomal monooxygenase activities and induction by pyrazole.

This study was carried out in order to find out the effects of pyrazole on liver drug metabolism in several inbred mice: D2, B6, BALB, and AKR and in the outbred mouse NMRI. Compared to control pyrazole treatment decreased the microsomal cytochrome P-450 content of liver to 60-70% and benzo(a)pyrene hydroxylase and ethylmorphine N-demethylase activities to 40-55% and increased 7-ethoxycoumarin O-deethylase activity to 100-200% in AKR, BALB, B6, and NMRI mice and 300% in D2 mouse. Coumarin 7-hydroxylase was increased only 200-300% in B6, AKR, and BALB mice and as much as 700% in D2 and 900% in NMRI mice compared to control. Coumarin 7-hydroxylase is under different genetic control from other monooxygenase activities and differently expressed in various strains of mice.

Animals↗
PubMed1986

Sex typing and division of labor as determinants of marital change across the transition to parenthood.

This investigation examines the proposition that wives who describe their personality in ways that deviate from sex stereotypes will become less positive and more negative about their marriage from before to after they become mothers, particularly when the transition to parenthood is accompanied by an increase in the traditionalism of marital roles. Sixty-one couples were studied longitudinally from the last trimester of pregnancy through the third postpartum month. The wives completed the Personal Attributes Questionnaire (Spence & Helmreich, 1978), which measures the extent to which they ascribe personality attributes stereotyped as "masculine" (i.e., instrumental, agentic) and "feminine" (expressive, affectional) to themselves, and several questionnaires assessing the marital relationship at both times of measurement. Results revealed that the more division of labor changed toward traditionalism, the greater the decline in wives' evaluations of the positive aspects of marriage and that changes in wives' evaluations of both positive and negative aspects of marriage can be significantly predicted by the interaction of the wives' expressivity and changes toward increased traditionalism in division of labor. Additional analyses showed that wives who do not ascribe female sex-typed attributes to themselves (relative to those who see themselves in sex-stereotyped ways) are more apt to evaluate their marriage less favorably from before to after parenthood when roles shift toward greater traditionalism.

Adaptation, Psychological↗
PubMed1986

The penems, a new class of beta-lactam antibiotics. 7. Synthesis and antimicrobial activity of 2-heterocyclylmercaptoalkyl derivatives.

2-Heterocyclylmercaptoalkyl penems were synthesized and their in vitro potency was established. The compounds exhibit moderate to strong antibacterial activity against various Gram-positive and Gram-negative bacteria. Their antimicrobial activity is related to the nature of the heterocycle, the length of the hydrocarbon spacer between the 2-position of the penem nucleus and the mercapto group, and the substitution pattern of the C-6 position of the penem skeleton.

Anti-Bacterial Agents↗
PubMed1986

[Comparative studies of CPAP systems using a respiration simulator. I. Evaluation criteria].

Assessment of the performance of modern ventilators that combine spontaneous breathing and mechanical ventilation is orientated not only towards the assessment of the inspiratory and expiratory resistance within the system, but also towards the functional criteria for the inspiratory and expiratory valves. This conclusion is particularly valid for CPAP procedures, as in this case patients must perform the entire work of breathing by themselves. As it has proved to be extremely problematic to carry out comparative testing of ventilators on patients in the intensive care unit, a breathing simulator has been developed, the use of which has enabled us to have a "patient" at our disposal who can tolerate the procedures for measuring the performance of ventilators with IMV and with CPAP without injury. The pressure-flow characteristics and the work of breathing can thus be measured under constant conditions and with various ventilation systems. Exact analysis of the pressure curve pattern under standardized conditions proved to be of value for assessing the suitability of CPAP in the case of both demand-valve systems and continuous flow systems. Appropriate assessment criteria have been worked out; the course of the test and the results for two ventilators are discussed as an example, using these criteria.

Evaluation Studies as Topic↗
PubMed1986

Electrophysiological evidence for right frontal lobe dominance in spatial visuomotor learning.

Slow negative potential shifts were recorded together with the error made in motor performance when two different groups of 14 students tracked visual stimuli with their right hand. Various visuomotor tasks were compared. A tracking task (T) in which subjects had to track the stimulus directly, showed no decrease of error in motor performance during the experiment. In a distorted tracking task (DT) a continuous horizontal distortion of the visual feedback had to be compensated. The additional demands of this task required visuomotor learning. Another learning condition was a mirrored-tracking task (horizontally inverted tracking, hIT), i.e. an elementary function, such as the concept of changing left and right was interposed between perception and action. In addition, subjects performed a no-tracking control task (NT) in which they started the visual stimulus without tracking it. A slow negative potential shift was associated with the visuomotor performance (TP: tracking potential). In the learning tasks (DT and hIT) this negativity was significantly enhanced over the anterior midline and in hIT frontally and precentrally over both hemispheres. Comparing hIT and T for every subject, the enhancement of the tracking potential in hIT was correlated with the success in motor learning in frontomedial and bilaterally in frontolateral recordings (r = 0.81-0.88). However, comparing DT and T, such a correlation was only found in frontomedial and right frontolateral electrodes (r = 0.5-0.61), but not at the left frontolateral electrode. These experiments are consistent with previous findings and give further neurophysiological evidence for frontal lobe activity in visuomotor learning. The hemispherical asymmetry is discussed in respect to hemispherical specialization (right frontal lobe dominance in spatial visuomotor learning).

Contingent Negative Variation↗