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Biomedical subjects

A Appel

Publications and source records attributed to A Appel.

13 recordsLinked to original sources
PubMed1986

Change in the synthesis of glycosaminoglycans by fibrotic vitreous induced by erythrocytes.

Vitreous fibrosis was induced in rabbit eyes by intravitreal injection of erythrocytes. The fibrotic vitreous removed from experimental animals were then incubated with [3H]glucosamine at 37 degrees C for 24 h. The newly synthesized 3H-labeled glycosaminoglycans were isolated by 4 M guanidium hydrochloride extraction followed by pronase digestion. The 3H-labeled glycosaminoglycans were then characterized by gel filtration column chromatography and by specific enzymatic degradation, i.e., hyaluronidase, chondroitinase AC, and/or chondroitinase ABC. The disaccharides derived from chondroitinase ABC degradation were identified by thin-layer chromatography. We previously demonstrated that 91% of the total glycosaminoglycan synthesized by normal vitreous was hyaluronic acid. Our present results indicate that in the fibrotic vitreous, the synthesis of hyaluronic acid was decreased to 26%, whereas the synthesis of chondroitin sulfate increased to 59% of the total newly synthesized glycosaminoglycans. These results suggest that cells present in fibrotic vitreous resemble fibroblasts with respect to their activities in glycosaminoglycans synthesis.

Animals↗
PubMed1979

Cell-free synthesis of hyaluronic acid in Marfan syndrome.

The cell-free synthesis of hyaluronic acid has been demonstrated in extracts of cultured human fibroblasts. Preparations from fibroblasts of normal individuals as well as those from patients with Marfan syndrome incorporate glucuronic acid and N-acetylglucosamine from their UDP derivatives into hyaluronic acid. Extracts from Marfan fibroblasts demonstrate 3 to 10 times more total and specific hyaluronic acid synthetase activity than do preparations from normal fibroblasts. All synthetic activity was found in particulate fractions with the bulk of activity localized in material sedimenting as large membrane fragments. Marfan and normal preparations exhibited similar properties with respect to substrate, cofactor, pH requirements, and heat stability. Neither the Marfan nor normal enzyme systems could be stimulated by exogenous acceptors, nor did either preparation contain a soluble factor which stimulated or inhibited the enzymic activity of the other. The genetic defect in Marfan syndrome appears to result in increased activity of hyaluronic acid synthetase without demonstrable changes in properties of the particulate enzymes involved.

Cell-Free System↗
PubMed1979

[Biopsy of para-aortic lymphnodes in patients with malignant lymphomas (author's transl)].

In treatment of malignant lymphomas exploratory laparotomy with splenectomy, liver and lymphnodes biopsy is necessary in order to individualize appropriate management. The surgeon must make maximal effort to obtain lymphnodes for histological examination. The surgical anatomy of the retroperitoneum in space of abdominal aorta and the biopsy procedure of paraaortic lymphnodes were described. The literature was reviewed.

Biopsy↗
PubMed1979

[Nontraumatic perforations of the small intestine].

From 1970 to 1978, 14 patients with nontraumatic perforations of the small intestine were treated in the Department of General and Abdominal Surgery of the University Frankfurt am Main. In eight cases suture and bypass and/or interval operation with enterostomy was performed. Seven patients survived, one died. In the six other patients resection with primary anastomosis or suture were performed. One patient survived and five patients died following peritonitis due to insufficiency of the anastomosis. The problem of nontraumatic perforation of the small intestine is discussed and the literature reviewed. It is suggested that the operation of choice is suture of the perforation with bypass or the two-stage operation with enterostomy.

Adolescent↗
PubMed1976

[Animal experiment studies on the damage caused by barium sulfate].

An experimental study is reported on different injections of barium sulfate into peritoneal cavity of 10 dogs and intravasal. All experimental animals died. The experiments show that barium sulfate causes not only local reaction but the most important is it's general deleterious effect. There results macro- and microembolies yet another adverse effect which is not widely appreciated. Barium sulfate medium only may be considered non toxic as long as staying in the gastrointestinal tract.

Animals↗
PubMed1975

[Injuries of the rectum in barium contrast enema].

Perforation of the rectum during a barium enema can be catastrophic. Most reports and in our experience too, the lethality in these patients is more than 50%. This effect of barium is not widely appreciated. Injections of barium sulfate with faeces, of commercial barium both sterile and unsterile into the peritoneal cavity and barium perforation were fatal in 20--48 hours in the dog without further treatment. This study shows that the repair of a barium perforation should be considered as one of the most important emergency procedures. Operative methods and problems are described.

Animals↗
PubMedDate not supplied

Convergence insufficiency in brain-injured patients.

Disorders of eye movements are relatively common in brain-injured patients. Some of these disturbances are caused by direct trauma to the orbital content, cranial nerves and other brain areas. Convergence, which is a part of the near-vision complex and depends on the integrative function of the cortical and subcortical areas, is commonly affected by traumatic brain injury. Intact vergence needs the integrative function of brain structures associated with acquisition of information on one side and intact mesencephalic function, including function of a vergence integrator, and their interconnections. Clinical investigation of vergence function in 26 traumatically brain-injured patients examined as early as possible after trauma revealed disturbances in over a third of the examinees. A follow-up of 72 patients some 3 years after injury revealed vergence insufficiency in 42%. Convergence insufficiency was associated with longer periods of coma (p less than 0.001), presence of cognitive disturbances (p less than 0.005) and patients' failing to find work in the open market (p less than 0.01). It is suggested that the presence of disturbed vergence several years after trauma, and its close association with prolonged coma and cognitive disturbances, is an expression of permanent damage to mesencephalic and cortical brain structures and can serve as an important aid in evaluation of these patients. This paper describes the close relationship between vergence state and over-all rehabilitation outcome as evaluated by patients' occupational status.

Adult↗