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Biomedical subjects

W Mohr

Publications and source records attributed to W Mohr.

At least 19 recordsLinked to original sources
PubMed1992

Chemically-induced chronic nerve compression in rabbits--a new experimental model for the carpal tunnel syndrome.

In order to create an experimental model for the carpal tunnel syndrome without the use of the commonly applied foreign bodies (silicone or rubber tubes, tourniquets etc.), the present study tried to induce a chemically provoked compression of the median nerve in rabbits. In 9 female rabbits 1 ml of Aethoxskerol 3% (Hydrox-polyethoxy dodecan) was instilled into the carpal tunnel around the median nerve after visualisation of the nerve. The other foreleg served as the control and was treated with the same amount of saline solution. Electroneurophysiologic parameters were registered preoperatively, 1 month and 6 months post surgery and histomorphologic investigations by light and electron microscopy were performed after 6 months. 6 months after treatment with Aethoxysklerol, a statistically significant lengthening of the distal latency period as well as a significant reduction of the compound potential amplitude could be observed. In accordance with these findings, morphological investigation revealed the presence of extensive granulation tissue around the median nerve together with signs of demyelination. Our results indicate that we were able to produce the development of extensive granulation tissue in the carpal tunnel of rabbits with subsequent compression of the median nerve which was confirmed by histomorphologic investigation as well as by measurement of nerve conductive velocity.

Animals↗
PubMed1992

Fibrosarcoma in association with a total knee joint prosthesis.

A case of fibrosarcoma of the proximal tibia, arising at the site of a cemented Richards total knee joint replacement with cobalt chrome alloy is reported. The patient, an 80-year-old man, received the endoprosthesis because of osteoarthritis of the knee 4 years ago. The literature on malignant tumours occurring in association with endoprostheses is summarized and briefly discussed.

Aged↗
PubMed1992

[Paraganglioma of the glomus caroticum--a frequently misdiagnosed disease picture].

24 carotid body tumors in 21 patients (1970-1990) have been analysed retrospectively. These well vascularized tumors are growing slowly in the carotid bifurcation and often cause failures in diagnostic and therapeutical approach. 66% (14) have been operated on partially 2-3 times with wrong diagnosis (cervical gland, lateral cervical cyst a.o.) in other hospitals. It is important to come to an early diagnosis by the typical trias according to Fontaine and Kocher, by CT-scan and arteriography. The best method of operation is the so-called technique of transsection, which is also applicable in advanced tumor stage (type II-III acc. to Linder). In tumors, which are beyond radical operability, good cosmetic and functional results can be achieved by partial resection.

Adult↗
PubMed1992

[Current concept of mood disorders. Impact on the therapeutic management].

The unipolar-bipolar distinction underlines the recurrence of the disorder (40 to 80% of unipolars and 95% of bipolars) and also the transition from one subtype to the other (10 to 15% of unipolars will become bipolars). Some semiological forms of depressive illness may give clues concerning the required management modalities. Depressions with psychotic features have a good response to ECT or to TCAs+neuroleptics. As other authors, Quitkin et al. find a good response of atypical depression to MAOIs. The comorbidity of mood disorders with personality disorders may be of poor prognosis. Akiskal suggested the presence of a depressive personality, Hudson and Pope suggest the notion of an affective disorders spectrum in which bulimia and OCD have a good response to serotoninergic antidepressants, whereas panic disorders have a good response to clomipramine, imipramine and MAOIs. Patient management should start with taking both the history of the disease and patient's previous treatment with a much precision as possible. Today the focus is on the particular progressive forms of resistant and chronic depressions, among which there are patients who have not received adequate treatment, and of rapid cyclers. The hypothesis of hypothyroïdism in rapid cyclers has been suggested recently. Carbamazepine and Valproate seem to be efficacious in several recent open studies and in controlled for carbamazepine. The initiation of chemotherapy to prevent the recurrences of depression takes into account the unipolar or bipolar aspect of the mood disorder. Lithium has emerged as the prophylactic agent of choice in bipolar disorders, especially if the index episode is manic. Early prophylaxis is justified when the first episode is manic or after two depressive episodes.(ABSTRACT TRUNCATED AT 250 WORDS)

Antidepressive Agents↗
PubMed1991

Deposition of amyloid of unknown origin in articular cartilage.

Articular cartilage, obtained from the large toe during hallux valgus operations in 37 patients, was investigated for the presence of amyloid by using the Congo red staining method. Amyloid deposits were demonstrated, particularly in the superficial layer of the cartilage, in 30 cases. This amyloid did not react immunohistochemically with any of the antibodies against the known five major amyloid types (AA, A lambda, A kappa, AF, AB). From these data it is concluded that hyaline cartilage in older individuals is prone to infiltration by an amyloid of a hitherto unidentified class. From the morphological observations there seems to be no correlation between amyloid deposits and the development of osteoarthrosis.

Aging↗
PubMed1991

Unilateral extended amyloidosis of the renal pelvis and ureter: a case report.

Localized amyloidosis of the genitourinary tract is a rare phenomenon. The differential diagnosis between amyloidosis and malignancy is difficult. We report the case of an 81-year-old man with extensive unilateral localized amyloidosis of the renal pelvis, ureter and ureteral orifice. Diagnosis of amyloidosis was confirmed only postoperatively.

Aged↗
PubMed1991

[Digital roentgen analysis as a tool for kinematic studies of the shoulder--a study of radiation dosage].

The radiation exposure during biomechanical investigation of the shoulder joint done with a digital radiography system (Polytron 1000 VR - Siemens) was measured experimentally. Total radiation dose and surface dose were determined by phantom measurements. The radiation exposure per image is about 1/6 to 1/7 of that of a conventional study. The digital radiography system used is thus suitable for kinesiologic studies of large joints in healthy volunteers.

Humans↗
PubMed1991

[Paragangliomas of the carotid body--clinical problems and therapy].

24 carotid body tumors in 21 patients (1970-1990) have been analysed retrospectively. These well vascularized tumors are growing slowly in the carotid bifurcation and often cause failures in diagnostic and therapeutical approach. 66% (14) have been operated on partially 2-3 times with wrong diagnosis (cervical gland, lateral cervical cyst and others) in other hospitals. It is important to come to an early diagnosis by the typical trias according to Fontaine and Kocher by CT-scan and arteriography. The best method of operation is the so-called technique of transsection, which is also applicable in advanced tumor state (type II-III according to Linder). In tumors, which are beyond radical operability, good cosmetic and functional results can be achieved by partial resection.

Adult↗
PubMed1991

[Changes in the form of perigraft reaction].

Perigraft-reaction is characterized by a late fluid accumulation around a graft. As a rule bacterial contamination is missed. The fluid has the same characteristics as blood serum. An aggressive surgical approach is necessary. The cyst wall must be excized and the prosthesis has to be replaced by a different synthetic material. In these cases a healing can be expected in more than 90%. By using the same material after resection of the cyst wall is followed by a recurrence rate of 79%.

Blood Vessel Prosthesis↗
PubMed1990

[Morphologic changes in the early stages of arthrosis].

"Joint failure" may be the result of different pathological conditions. While in some arthropathies initial changes prior to secondary cartilage destruction may be observed morphologically, the early changes in "mechanically induced" osteoarthrosis are not well known. In the present paper the ultrastructural events, eventually leading to osteoarthrotic cartilage destruction are presented. From the morphological changes it is assumed that the primary lesion leading to cartilage destruction may be seen in the loss of the granular surface microstructures of cartilage that may be followed by an increased hydration and thereafter chondrocytic death with destruction of cartilaginous matrix.

Cartilage, Articular↗
PubMed1990

[ Topography of carpal bone - An experimental model for carpal tunnel syndrome ].

By preparing a new experimental model for the carpal tunnel syndrome, the authors evaluated the differences of the human and rabbit carpal tunnels using a comparative anatomical study. A nearly identical situation-regarding the osseous and connective tissue formations in the carpal channel--was found. Therefore, the carpal tunnel of the rabbit is recommended for a model of chronic nerve compression, which is now planned by the authors.

Animals↗
PubMed1989

New techniques of analyzing the healing process of artificial vascular grafts, transmural vascularization, and endothelialization.

Beside traditional techniques (light, immunofluorescence, transmission electron (TEM)- and scanning electron microscopy (SEM), a new more sensitive method for producing microcorrosion casts using a polyester-based resin has been developed. The SEM analyses of the microcorrosion casts of alloplastic vascular grafts was realized in an absolutely stable stage of polymerization. For the first time, a transprosthetic vascularization could be shown in great three-dimensional detail. The importance of a complete and rapid endothelialization of artificial vascular grafts is discussed.

Animals↗
PubMed1989

New observations on the healing process in prosthetic substitution of large veins by microporous grafts--animal experiments.

Based on the experimental experiences in more than 180 implantations of different materials as venous substitutes segments of the inferior vena cava have been replaced in 34 dogs by Polyurethane (low microporosity) and modified e-PTFE prostheses (increased microporosity of 60 microns and 90 microns fibril length). The 12 months patency rate didn't differ between both tested optimized materials and ranged from 43 to 50%. After a follow-up of 12 months the grafts were taken out and analysed by light, immunofluorescence microscopy, scanning and transmission electron microscopy. In addition a new technique of microcorrosion casts was used for SEM-analyses. As a result a transmural microvessel system in the microporous meshwork of the prostheses with multiple orifices at the inner surface of the grafts could be demonstrated. Complete endothelialization was only observed in e-PTFE prostheses of high microporosity (greater than 60 microns fiber length). There is strong evidence that a full tissue incorporation of microporous artificial grafts mainly depends on a sufficient primary intramural deposit of blood components (fibrin, platelets, leucocytes), which initiates cell invasion from the surrounding tissue, accompanied by a highly developed microvessel network. A multifocal endothelialization takes place from the numerous microvascular orifices on the inner surface of the prostheses. Other sources such as pannus invasion or adhesion of multipotent cells from the blood stream play probably a very limited role.

Animals↗