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Biomedical subjects

E Freund

Publications and source records attributed to E Freund.

At least 37 records · Page 2Linked to original sources
PubMed1988

[Experimental studies in animals of the regeneration of peripheral nerves].

In bridging nerve gaps and studying the process of nerve regeneration the method of "tubulation" becomes of new worldwide importance during the last years. In this technique the both stumps are introduced in a preformed tube without tension, the further healing process is left to the neuron's potency for self-repair. Although until now the experimental results confirm the possibility of this management it is often impossible to compare the findings because of the insufficient quantitative analyses. In this paper the own results of bridging a 4-6 mm defect in rat sciatic nerves with a connective tissue-teflon-tube are presented including an extensive quantitative analysis with methods of computer-based multivariate data analysis. The theoretic advantages of this technique are discussed in relation to the autologous interfascicular nerve transplantation.

Animals↗
PubMed1986

Identification of a nucleoside triphosphate binding site on calf thymus RNA polymerase II.

A nucleoside triphosphate binding site on calf thymus RNA polymerase II was identified by using photoaffinity analogues of adenosine 5'-triphosphate and guanosine 5'-triphosphate. Both radiolabeled 8-azidoadenosine 5'-triphosphate (8-N3ATP) and radiolabeled 8-azidoguanosine 5'-triphosphate (8-N3GTP) bound to a single polypeptide of this enzyme. This polypeptide has a molecular mass of 37 kilodaltons and an isoelectric point of 5.4. Ultraviolet (UV) irradiation was necessary for photolabeling to occur. In addition, no labeling occurred when the probe was prephotolyzed or when the enzyme was inactivated. Furthermore, photolabeling of the enzyme could be decreased by preincubation with natural substrates. To provide evidence that the radiolabeled polypeptide forms a part of the domain of the nucleoside triphosphate binding site, experiments were performed using unlabeled 8-N3ATP. Although this unlabeled analogue was not a substrate for RNA polymerase II, it photoinactivated the enzyme in the presence of UV irradiation, and it inhibited transcription elongation by the enzyme in a competitive manner in the absence of UV irradiation. As in the case with photolabeling, photoinactivation by 8-N3ATP could be decreased by natural substrates; in both cases, purine ribonucleoside triphosphates were more efficient than pyrimidine nucleoside triphosphates. Furthermore, photoinactivation was saturable at about the same concentration as the inhibition constant for 8-N3ATP. Collectively, these results provide evidence that the radiolabeled polypeptide in calf thymus RNA polymerase II is an essential component for activity and suggest that this polypeptide may be part of this enzyme's purine ribonucleoside triphosphate binding site.

Adenosine Triphosphate↗
PubMed1986

Characterization of RNA polymerase type II from human term placenta.

RNA polymerase type II from human term placenta has been isolated and characterized with respect to its template, ammonium sulfate, divalent cation, and buffer preferences. In addition, the apparent Michaelis constants for AMP and UMP incorporation have been determined. The enzyme was also analyzed by native and denaturing polyacrylamide gel electrophoresis, and evidence is presented that a single polypeptide is radiolabeled with azido purine nucleoside triphosphate photoprobes.

Adenosine Triphosphate↗
PubMed1986

[Toe transfer to a mid-hand stump covered with abdominal skin].

Following amputation of all four fingers from the hand, the cover of the amputation site with an abdominal flap gives a hand which is functionally inferior. This paper reports our experiences of three toe transfers to such a hand in two patients, one a 22-year-old man, the other, a 50-year-old woman. In our opinion, the toe transfer will be successful if the vessels, nerves and tendons are harvested to the level of the extensor retinaculum, giving a length in excess of the skeleton of some 12-15 cm. The routing of these structures beneath the abdominal flap is done in such a way as to avoid any ischemia and therefore, infection. In the first case, these latter considerations were not fully observed and in the third postoperative week, arterial thrombosis with loss of the transfer developed, following an infection. The two other transposed digits have survived with a good functional result.

Adult↗
PubMed1985

[Toe transfer].

Today toe-to-hand transfer by micro-anastomoses is one of the most important methods in reconstructing severely injured hands. An experienced surgeon will obtain a survival rate of the transplant in about 94 to 96% of cases. All measures required can be performed by only one operation. The free toe-to-hand transfer guarantees the best functional and aesthetic results so far known.

Amputation, Traumatic↗
PubMed1985

[Cephalic insulin secretion--neuromorphologic findings].

The paper presented deals with the electron microscopy bases of experimental results, which show a cephalic insulin secretion. The B cell-producing insulin--is a highly innervated endocrine cell. Several nerve endings often form synaptic connexions at a single B cell. The synaptic clefts are usually 20-25 nm. The nerve endings cause an evident impression of the cell membrane. The narrow neuro-cellular connexions form a structural bases of the cephalic insulin response. The interruption of this reflex loop caused by vagotomy eliminates cephalic mechanism. However, the innervation of the islets (electron microscopic examination) remains unaffected. Therefore the intramural nervous mechanism seems to be not excluded by vagotomy.

Animals↗
PubMed1984

Microinjection of RNA polymerase II corrects the temperature-sensitive defect of tsAF8 cells.

tsAF8 cells are a temperature-sensitive (ts) mutant of BHK cells that arrest in the G1 phase of the cell cycle at the non-permissive temperature of 40.6 degrees C. Previous reports had suggested that the temperature-sensitivity of these cells was based on a defect in either the synthesis, assembly or turnover of RNA polymerase II. We now show that the direct microinjection of purified RNA polymerase II into nuclei of tsAF8 cells corrects the ts defect and allows these cells to enter the S phase of the cell cycle.

Animals↗
PubMed1984

Varicose veins of the abdominal wall in a child. A case report.

A case of a venous malformation of the abdominal wall in a 13-year-old boy is hereby presented. This malformation, manifesting as varicosities which were present from infancy caused no disturbances other than cosmetic. Clinical, laboratory and radiological examinations revealed no underlying pathology linked with this malformation. Considering the patient's history, we assumed the varicosities to be sequelae of a deep thrombophlebitis of the right leg in infancy, although a congenital etiology was not excluded. The varicose veins were surgically excised with excellent postoperative results. To the best of our knowledge, no such case was previously reported in literature.

Abdominal Muscles↗