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Biomedical subjects

J Lang

Publications and source records attributed to J Lang.

At least 343 records · Page 19Linked to original sources
PubMed1988

[The hiatus semiluminaris, the infundibulum and the ostium of the sinus maxillaris, the anterior attached zone of the concha nasalis and its distance to the landmarks of the outer and inner nose].

The authors described the Infundibulum and Ostium of the maxillary sinus, its width and location and course in the Hiatus semilunaris. There were counted and measured also the accessory Ostia, the Processus uncinatus and Bulla ethmoidalis and distances to landmarks between the outer nose and the Limen nasi to these structures.

Ethmoid Bone↗
PubMed1988

Acoustic neuroma surgery in Northern Ireland 1976-1986.

Forty acoustic neuromas have been removed surgically between 1976 and 1986. The condition was unilateral in 32 and bilateral in four. There were 31 large, four medium and five small tumours. Excision was complete in 16 and incomplete in 24. Of the incomplete removals 14 were subtotal leaving microscopic remnants, eight were partial capsular and two were intracapsular. Follow-up ranged from two months to ten years (median 3.5 years).There was one early death in an 83-year-old. The overall incidence of post-operative complete facial paralysis was 20% but reached 55% for large tumours when excision was complete. Twenty-eight patients had hearing before operation and in eleven patients some preservation of hearing was possible (39%). In these, the excision was complete in three, subtotal in four, partial capsular in three and intracapsular in one.Of the unilateral tumours, there have been three recurrences requiring repeat surgery. All were initially incompletely excised. Two were of an invasive nature causing considerable erosion of the petrous temporal bone making complete excision impossible. For the bilateral tumours a deliberate incomplete excision was first performed on one side to ensure preservation of hearing. Further excision on this side was then left until such time as hearing was lost. Complications included CSF otorhinorrhoea (5%), persistent but temporary nausea and vomiting (10%), meningitis (5%), facial numbness (5%) and hoarseness and dysphagia (3%).

Adolescent↗
PubMed1988

[Veins in the area of the mesencephalon].

The veins on the surface of the mesencephalon were measured on 100 brain halves. The results of this measurements are discussed with issues of earlier authors.

Cerebral Veins↗
PubMed1987

Characterization of two D-glyceraldehyde-3-phosphate dehydrogenases from the extremely thermophilic archaebacterium Thermoproteus tenax.

Thermoproteus tenax possesses two different glyceraldehyde-3-phosphate dehydrogenases, one specific for NADP+ and the other for NAD+. NADP(H) inhibits the NAD+-specific enzyme competetively with respect to NAD+ whereas NAD(H) virtually does not interact with the NADP+-specific enzyme. Both enzymes represent homomeric tetramers with subunit molecular masses of 39 kDa (NADP+-specific enzyme) and 49 kDa (NAD+-specific enzyme), respectively. The NADP+-specific enzyme shows significant homology to the known glyceraldehyde-3-phosphate dehydrogenases from eubacteria and eukaryotes as indicated by partial sequencing. The enzymes are thermostable, the NADP+-specific enzyme with a half-life of 35 min at 100 degrees C, the NAD+-specific enzyme with a half-line of greater than or equal to 20 min at 100 degrees C, depending on the protein concentration. Both enzymes show conformational and functional changes at 60-70 degrees C.

Amino Acid Sequence↗
PubMed1987

Pertussis toxin abolishes the antinociception mediated by opioid receptors in rat spinal cord.

Intrathecal injection of pertussis toxin (1 microgram) in rats produced a marked decrease in the antinociceptive effect of the intrathecally administered opioid agonists [D-Ala2,D-Leu5]enkephalin, [D-Ala2,N-Me-Phe4,Gly5-ol]enkephalin and bremazocine. The effect of the toxin was time-dependent, since it was more pronounced at 6 than at 2 days after its injection. The pertussis toxin-catalyzed ADP ribosylation of a 40 KDa substrate in membranes prepared from the spinal cord of toxin-injected rats was strongly reduced as compared to controls. The data indicate that the antinociceptive effect produced by opioid agonists with different receptor preference is initiated at receptor sites which interact with G-protein substrates of pertussis toxin.

Adenosine Diphosphate↗
PubMed1987

Antisera against the 3-17 sequence of rat G alpha i recognize only a 40 kDa G-protein in brain.

To obtain antisera specific for the GTP-binding protein Gi alpha we immunized rabbits against a synthetic peptide derived from the N-terminal (3-17) sequence predicted from the rat Gi alpha cDNA clone published by Itoh et al. (1986) (Proc. Natl. Acad. Sci. USA 83, 3776-3780). Western-blot analysis of bovine brain G-proteins purified and resolved by hydrophobic chromatography and of rat striatal membranes, indicate that this antiserum does not recognize 41 kDa alpha i or 39 kDa alpha o. However, it reacts with a 40 kDa alpha-subunit. The data suggest that the sequence deduced from the rat G alpha i cDNA corresponds to a G40 alpha protein and that N-terminus directed antisera are useful tools to discriminate between two different G alpha i-like types of G-proteins present in mammalian brain.

Amino Acid Sequence↗
PubMed1987

Potentiation by acetylcholine of the effects of a calcium channel activator, Bay k 8644, on dog atria in situ.

The effects of Bay k 8644 were studied in the canine in situ heart under vagal influence and out of this influence on sinus rate and sinus recovery time, conduction time and effective refractory period (ERP) in the atrioventricular (AV) node and ERP of the atrial muscle. Bay k 8644, intravenously infused at the 2 micrograms X kg-1 X min-1 rate for 30 min, enhanced the inhibition of the atrial specialized tissue as well as the shortening of the atrial muscle ERP during vagal activity, elicited by the injection of dextromoramide into the cisterna magna. It did not develop any atrial action in the absence of vagal activity, suppressed by atropine. The reflex increase of vagal tone, in response to a small increase in blood pressure produced by Bay k 8644, is not the only cause of the phenomena observed in the former case. The observations can be explained primarily in terms of an interaction between Bay k 8644 and acetylcholine (ACh):ACh intraaortically injected near the coronary ostia, in a dose just sufficient to slow down sinus rate before Bay k 8644, reduced the rate by 50% at the end of a 60 min infusion of Bay k 8644 and the ACh threshold dose necessary to elicit a short third degree AV block before Bay k 8644 was reduced by 50% at the end of a 30 min infusion of Bay k 8644. Therefore, ACh appeared to be capable of enhancing the effects of a calcium channel activator as well as the effects of hypercalcaemia, as earlier reported.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1987

Effects of the lipid peroxidation product 4-hydroxynonenal on the aggregation of human platelets.

The stimulation by ADP or arachidonic acid of the aggregation of human platelets in plasma was inhibited by 4-hydroxynonenal (HNE). This reduction of aggregation was time related, and was increased by prolonged preincubation of the platelets with the aldehyde. HNE was more potent than its homologue 4-hydroxypentenal (HPE). HNE was less active in decreasing the aggregation induced by calcium ionophore A23187 or collagen in comparison with ADP. HNE was inactive against aggregation of platelet-rich plasma (PRP) stimulated by thrombin whereas it potently inhibited the aggregation of washed platelets in response to both thrombin and collagen. Platelets were found to degrade HNE, and mechanisms additional to covalent binding to glutathione are indicated by the results obtained. The aldehydes, including HNE, generated by platelets originated principally from arachidonic acid metabolism.

Adenosine Diphosphate↗
PubMed1987

Role of calcium in the rate-dependent depression of atrioventricular nodal conduction in the dog heart under vagal influence.

Increase in heart rate may be detrimental to atrioventricular conduction. The effects of such an increase were investigated in the paced intact dog heart, by measuring the conduction time in the atrioventricular node (obtained from the His bundle potential recording) and the effective refractory period in this node as determined by the extrastimulus method. Investigations on atrioventricular nodal conduction were performed with and without vagal influence. After central restoration of vagal tone by dextromoramide in anesthetized animals, both parameters appeared to lengthen as the heart rate rose. This lengthening became considerable at the highest rates. After blockade of cholinergic receptors by atropine, no significant change occurred when the heart rate was raised. The prolongation observed under vagal tone was enhanced by the rise in the plasma calcium concentration to 3.10 mmol X l-1 and reduced by a calcium influx inhibitor, verapamil, in 0.2 mg X kg-1 dose. These effects are related to the calcium intracellular concentration, since the rise in this concentration beyond an optimum has been demonstrated to inhibit the calcium and potassium channel.

Animals↗
PubMed1987

[Further findings on the mesencephalic veins].

On 50 human brains the width and course of the veins on the surface of the mesencephalon were determined. The basal vein, for example, has an inside diameter of 1.70 (0.91-2.88) mm. A lateral mesencephalic vein could be demonstrated in 70% of the cases, the width being 0.81 (0.29-1.78) mm. A posterior mesencephalic vein was found in 51%, measuring 0.57 (0.24-1.01) mm in diameter. The ponto-mesencephalic vein and the intercollicular vein were also included in this examination.

Cerebral Veins↗
PubMed1987

[Further findings on the diencephalic artery branches].

Following earlier examinations, we determined the number, extracerebral length and pattern of branching of the diencephalic branches in 50 human brains. These small arteries have their origin in the anterior cerebral artery, the anterior communicating artery, the posterior communicating artery, the anterior choroidal artery, the posterior cerebral artery, the basilar artery and the superior cerebellar artery. With regard to the number and width of these vessels, we found some minor differences compared with specimens examined earlier. The extracerebral length and branching inside the skull have not so far been examined by us.

Arteries↗
PubMed1987

Effect of exercise training on tissue vitamin E and ubiquinone content.

Endurance exercise training led to an adaptive increase in the ubiquinone content and cytochrome c reductase activity of red quadriceps and soleus muscles and adipose tissues, but not of cardiac or white quadriceps muscle. These findings are consistent with the well-known positive adaptation of skeletal muscle mitochondria to endurance training. However, there was no concomitant increase in the vitamin E content of tissues, which showed an increase in mitochondrial content. Since ubiquinone is located in the mitochondrial inner membrane and the major pool of vitamin E is also associated with mitochondrial membranes, the results suggest that training causes a substantial decrease in vitamin E concentration in the proliferating muscle mitochondrial membranes, thus depleting muscle mitochondria of their major lipid antioxidant. Since vitamin E is the major cellular, lipid-soluble, chain-breaking antioxidant, these findings indicate increased free radical reactions in the tissues of exercising animals.

Adipose Tissue, Brown↗