Search PubMed⌕ Search

Biomedical subjects

M Lang

Publications and source records attributed to M Lang.

At least 217 records · Page 12Linked to original sources
PubMed1983

Human cerebral potentials and visuomotor learning.

Cortical potentials during visuomotor learning were investigated in man using two hand tracking tasks: (i) direct tracking (T) and (ii) inverted (mirror) tracking (IT). Negative cerebral potentials were higher during the IT task over several cortical areas but in particular over the supplementary motor area (SMA). The acquisition of motor skill as measured in the IT task, was highly correlated with the enhancement of the negative potential. This correlation only held for the frontolateral and frontomedial cortex including the SMA but not for the other electrodes.

Cerebral Cortex↗
PubMed1983

Adjuvant chemo(immuno-)-therapy of primary breast cancer with adriamycin-cyclophosphamide (and levamisole)--six-year evaluation.

In a phase II-type study 52 patients with no signs of metastases but with a high risk of recurrence were treated with 6 courses of adriamycin-cyclophosphamide as adjuvant systemic therapy following modified radical mastectomy of primary breast cancer. Half of the patients were randomized to receive additional immunotherapy with levamisole for 2 yr. The scheduled dose and time regimen could be achieved in over 90% of patients. A comparison of the actuarial disease-free and overall survival with data reported in the literature indicates a similar positive effect of adjuvant systemic therapy as described in adjuvant studies using polychemotherapy regimens. Immunotherapy with levamisole has no effect on disease-free and overall survival but added to general toxicity. Particular attention was paid to psychological consequences of adjuvant systemic therapy; consistent attention by one specifically trained physician during the whole therapy and follow-up period was effective in coping with the emotional problems. The difficulties in treating recurrences after adjuvant therapy became apparent. A high rate of loco-regional recurrences and of cerebral metastases was noted.

Breast Neoplasms↗
PubMed1983

Frontal hemispheric differences in the Bereitschaftspotential associated with writing and drawing.

Twenty right-handed subjects participated in a study investigating the cerebral potentials related to three complex actions: (1) writing one's own signature, (2) drawing a pentagram, and (3) fast meaningless scribbling. The Bereitschaftspotential (BP, readiness potential) started as early as 3 s prior to writing, 2.5 s prior to drawing, but only 1.5 s prior to scribbling. In all three tasks, the BP had its earliest onset over the supplementary motor area (SMA). BP topography was shifted towards the frontal lobes when compared to encephalographic activity reflecting simple finger movements, and was very weak in retro-rolandic leads. The side of the performing hand, as assessed from scribbling, was reflected in a contralateral preponderance of the precentral BP. The maximum BP (about 6 microV) was, in all three tasks, located in FCz (mid fronto-central) overlying the SMA. This location is different from that for simple finger movements, when the maximum is at the vertex. Hemispheric differences were found over the frontal cortex and were characteristic for the verbal and spatial tasks involved: for writing, the BP was significantly larger left frontally than right (even after considering the effect of the performing hand from scribbling), and the difference was largest prior to the onset of movement; for drawing, the BP was larger over the right than over the left frontal lobe, and the difference was largest during the movement.

Action Potentials↗
PubMed1982

Adjuvant intermittent chemoimmunotherapy for primary breast cancer: a prospective study with immunologic follow-up.

In an interdisciplinary prospective study 50 patients surgically treated for breast cancer were treated with six monthly courses of aggressive adjuvant chemotherapy (adriamycin and cyclophosphamide) and were randomized to receive either immunotherapy with levamisole or no additional therapy. Probability of disease-free survival for the whole group is 54.9% at 42 months. There was no noticeable difference in disease-free survival for either pre- and postmenopausal women or for patients treated with or without levamisole. The addition of levamisole had no effect on the depression of in vitro immunologic functions during chemotherapy.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1982

Short-term and long-term effects of chemoimmunotherapy on granulopoiesis: adjuvant therapy of breast cancer.

The effect of adjuvant chemoimmunotherapy on normal human granulopoiesis has been studied. The short-term pattern of hemopoietic depletion and regeneration confirms that human bone marrow shows reaction to cytotoxic agents similarly to that observed in animal experiments. A regenerative response to the drug-induced depletion of the committed stem cell compartment occurs very early, thus suggesting local CFUC population size control of negative feedback from the early granulocytic compartments. Levamisole in that particular regimen did not influence the reaction pattern of granulopoiesis following cytotoxic drug exposure. A model of quantitative evaluation leads to a description of compartment changes which is compatible with the concepts of hemopoietic reaction to cytotoxic drugs. Of particular importance to the planning of adjuvant therapy is the observation of a long-term defect of granulopoiesis after discontinuation of chemotherapy. Studies like those presented here should be performed on any regimen of adjuvant therapy to select the least toxic regimen when several cytotoxic combinations with similar activities are available.

Bone Marrow↗
PubMed1982

Increased fluidity of a model membrane caused by tetrahydro-beta-carbolines.

Alterations in membrane fluidity caused by alcohols and tetrahydro-beta-carbolines (THBCs) have been studied. Dipalmitoylphosphatidylcholine vesicles were used as a membrane preparation, and changes in the fluidity were revealed by two fluorescent probes: 1-anilinonaphthalene-8-sulfonic acid (1,8-ANS) and N-phenylnaphthylamine (NPN). It was found that THBCs, which are condensation products of tryptamine and formaldehyde or acetaldehyde, were at least 2 orders of magnitude more potent in causing fluidity changes than the comparable alcohols (methanol and ethanol). Both 1,8-ANS (binding close to the polar end of the phospholipid molecules) and NPN (binding to the hydrophobic region of the membrane) were able to reveal changes in membrane fluidity, although there were differences between the behavior of the two probes. The condensation product of acetaldehyde--the primary metabolite of ethanol--and tryptamine were found to be 200-300 times more potent in causing fluidity changes than ethanol itself (as determined with both 1,8-ANS and NPN).

Anilino Naphthalenesulfonates↗
PubMed1981

Role of guanine nucleotides in the stimulation of thyroid adenylate cyclase by prostaglandin E1 and cholera toxin.

Cholera toxin in the presence of GTP increased adenylate cyclase activity in a purified bovine thyroid plasma membrane preparation, whereas, in the presence of guanosine 5'-(beta, gamma-imido)-triphosphate (Gpp(NH)P), cholera toxin had no stimulatory effect. Similarly, prostaglandin E1 enhanced the adenylate cyclase activity induced by GTP but not by Gpp(NH)p. Gpp(NH)p-stimulated adenylate cyclase activity, assayed with hydrolysis-resistant adenosine 5'-(beta, gamma-imido)-[32P]triphosphate as substrate and no ATP-regenerating system was inhibited by GDP in a competitive fashion. Furthermore, prostaglandin E1, but not cholera toxin, influenced the GDP inhibition of Gpp(NH)p-stimulated activity by increasing the concentration of GDP resulting in 50% inhibition approx. 2-fold. Inosyl nucleotides mimicked the effects of guanyl nucleotides on thyroid adenylate cyclase in that ITP could substitute for GTP in enhancing cholera toxin- and prostaglandin #1-induced activities and that inosine 5'(beta, gamma-imido)-triphosphate [Ipp(NH)p] was also a potent stimulator per se. Conclusions. (1) Cholera Toxin and prostaglandin E1 enhance thyroid adenylate cyclase activation by GTP (or ITP), but have no stimulatory effect on the Gpp(NH)p (or Ipp(NH)p) response; (2) the stimulatory effect of prostaglandin E1 on adenylate cyclase may result from decreased affinity for GDP at the guanine nucleotide regulatory site; (3) the date regarding cholera toxin stimulation of thyroid adenylate cyclase are consistent with the hypothesis that cholera toxin exerts its effect by inhibiting an endogenous GTPase.

Adenylyl Cyclases↗
PubMed1981

Structural and biotransformational membrane changes in the liver and intestine during chronic ethanol administration.

The binding of a fluorescent probe 1-anilinonaphthalene-8-sulphonic acid (1,8-ANS) to liver microsomal membranes was markedly increased after chronic ethanol administration while the binding of a non-ionised probe phenylnaphthylamine (PNA) was not altered. The increase in 1,8-ANS binding is in accordance with the simultaneous increase of the ethoxycoumarin O-de-ethylase activity and cytochrome P-450 concentration. Also the intestinal ethyoxycoumarin O-de-ethylase activity and cytochrome P-450 concentration were increased. No changes in the aryl hydrocarbon hydroxylase or UDP-glucuronosyltransferase activities were found. The chronic ehtanol administration increased the phospholipid amount in the liver microsomes and altered the fatty acid composition of microsomal phospholipids by decreasing the amount of oleic acid and increasing linoleic acid proportion. The data suggest that chronic ethanol administration may effect the biotransformation enzyme activities by changing the structural properties of the membranes as well as increasing the cytochrome P-450 concentration.

Animals↗
PubMed1980

A further parallel between selective adaptation and contrast.

It is generally believed that selective adaptation effects in speech perception are due to a reduction in sensitivity of auditory feature detectors. Recent evidence suggest that these effects may derive instead from contrast. In a further test of the contrast hypothesis, we conducted two experiments each involving both adaptation and contrast sessions with matching stimulus sets. During the adaptation sessions of Experiment 1, subjects identified two series of velar stimuli varying in voice onset time, [ga]-[kha] and [gi]-[khi], before and after adaptation with of the following stimuli: [ga], [kha], [gi], and [khi]. In the contrast session, subjects identified either of two ambiguous test items (drawn from near the phonetic boundaries of the [ga]-[kha] and the [gi]-[khi] series) following a single presentation of [ga], [kha], [gi], or [khi]. For both the adaptation and contrast sessions, (a) the [--a] test items were more greatly affected (in a contrast direction) by the [--a] than by the [--i] adaptor/context stimuli, and (b) the [--i] test items were not differentially affected by the [--1] and [--i] adaptor/context stimuli. An analogous design was used in Experiment 2, except that the stimulus sets varied in pitch rather than vowel quality. For both the adaptation and contrast sessions, the test items were not differentially affected by the pitch of the adaptor/context stimulus. These parallel results provide further evidence that adaptation effects are actually a form of contrast.

Habituation, Psychophysiologic↗
PubMed1980

Differences in the response of hepatic and intestinal drug metabolizing enzymes in rats following carbon tetrachloride and/or phenobarbital treatment.

The activities of the microsomal drug metabolizing enzymes in the liver and intestinal mucosa of rats were studied after the intraperitoneal administration of carbon tetrachloride and/or subcutaneous phenobarbital administration. The membrane phospholipid content was decreased after carbon tetrachloride treatment indicating destruction in the membrane structure. Aryl hydrocarbon hydroxylase activity was decreased in the liver and intestinal mucosa after treatment with CCl4 alone and in combination with phenobarbital. The CCl4 treatment increased the intestinal epoxide hydratase activity but decreased the activity in the liver. The hepatic UDPglucuronosyltransferase was slightly induced by phenobarbital and the activity was elevated by the CCl4 treatment. In the intestinal mucosa the enhanced UDPglucuronosyltransferase activity was observed only after phenobarbital pretreatment and the activity was decreased by CCl4. These results support the view that epoxide hydratase and UDPglucuronosyltransferase enzymes occupy different locations in the endosplasmic reticulum of intestinal mucosa than of liver.

Animals↗