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Biomedical subjects

T Somer

Publications and source records attributed to T Somer.

At least 19 recordsLinked to original sources

Detailed anatomy of the antebrachiocarpal joint in dogs.

A comparative study of the anatomy of the antebrachiocarpal (AC) articulation was carried out in 30 adult dogs with 60 joints. Although a considerable degree of similarity was found between the AC joint in dogs and the corresponding wrist joint in humans, a number of differences between these two homologous joints were also noted. The distal end of the ulna in dogs directly articulates with the ulnar carpal and accessory carpal bones forming a specialized antebrachiocarpal arrangement more adapted to running. The accessory carpal bone in dogs is a massive, long bone and is strikingly different from its homologue in humans, the pisiform bone. The joint between the accessory and ulnar carpal bones, which corresponds to the piso-triquetral joint in humans, is always connected with the AC joint, whereas in humans this communication could be found occasionally. The large radial carpal bone in dogs, characteristic for carnivores, corresponds to the fused scaphoid and lunate bones in humans, in whom this type of fusion is very rarely found. The palmar ulnocarpal and radiocarpal ligaments in dogs are distinctly intra-articular, whereas in humans these ligaments are intracapsular. One of the controversies of the AC joint in dogs is a structure located between the distal-most parts of the radius and ulna forming a strong bond between these two bones and a part of the antebrachial articular surface. It is cartilage-like and is composed of typical fibrocartilaginous tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

[Patellar height in patients with chondromalacia].

A radiogrametric assessment of the patellar height performed by three measurement methods, in the lateral views of radiograms of 136 patients with chondromalacia of the patella was aimed at the establishment of certain parameter values in the studied population and the assessment of the influence the altered patellofemoral ratio has upon the onset of the disease. The results of the study verified the remarkable advantages of the method by Insall and Salvati for the measurement of the patellar height and showed a significant involvement of patellofemoral incongruity in the development of chondromalacia, since in 15-16% of the cases the patella was not properly placed.

Adult

Histologic structure of the articular disk of the human distal radioulnar joint.

A histologic study of the structure of the articular disk of the distal radioulnar joint in humans was performed on 57 disks from 37 fresh cadavers that included fetuses and individuals up to age 65 years. The specimens were stained with hematoxylin and eosin, orcein, and Mallory and Mann-Dominici's methods, and studied with the light microscopy. It was found that the disks of adults were basically formed of the so-called fibrocartilagenous tissue composed of an intercellular substance in which there were interwoven wavelike collagen fiber bundles and between them three specific types of cells: (1) rather sparse fibrocytes mostly situated in dorsal and palmar margins, (2) predominant and constant chondroid cells dispersed throughout the disk, and (3) less-frequent real chondocytes distributed mostly in the central parts. This basic tissue is modified according to the age of the subjects and functional requirements. In fetuses and newborns, it is almost completely fibrous and very cellular, while in adults, it is more cartilaginous with significantly reduced cellularity. The structure of various parts of disks is adapted to the functional stresses exerted on them. In central parts exposed to pressure, the tissue is more cartilaginous, while peripheral, massive margins, subjected mostly to traction, are built in a ligamentlike pattern. The ulnar and carpal surfaces are adapted to the gliding movements of the ulna and carpus. It is concluded that the articular disk in humans, which is basically of fibrocartilagineous nature, is a dynamic structure biomechanically, predetermined and changing with aging.

Adolescent

Diagnostic significance of angiographically observed visceral aneurysms with regard to polyarteritis nodosa.

During a 10-year period, intraparenchymal aneurysms were found in 38 of 748 patients at selective abdominal angiography with magnification technique. According to strict criteria, 17 patients were classified as suffering from necrotizing vasculitis of the polyarteritis nodosa group (PAN), 7 from severe arterial hypertension, and 3 from rheumatoid arthritis. The diagnoses of 5 patients remained to be confirmed, and each of the remaining 6 patients suffered from various other diseases. PAN was diagnosed histopathologically in 2 patients without angiographic aneurysms. Based on the 156 patients in whom the indication for angiography was suspicion of arteritis, the angiographic diagnosis of PAN had a sensitivity of 89 percent and a specificity of 90 percent, a positive predictive value of 55 percent and a negative predictive value of 98 percent. The mean number of both renal and hepatic aneurysms was higher in patients with PAN than in the other patients (p less than 0.01 and p less than 0.05, respectively). Five PAN patients had numerous and large aneurysms, whereas the aneurysms of the other 12 PAN patients did not differ from those of patients with other diseases. Patients with PAN had renal infarcts more often than the other patients (p less than 0.05). Our findings suggest that visceral angiography is useful in establishing the diagnosis of PAN, but the angiographic finding of aneurysms is not pathognomonic.

Adult

[Early functional and anatomic results after total condylar knee prosthesis implantation].

The results of total knee replacement in 30 patients have been analyzed. Total knees were implanted during 1990, and the shortest follow-up time after the operations amounted to 6 months. All 30 total condylar prosthesis were of Insall-Burstein posterior stabilized design. The average age of the operated patients was 61 years. Osteoarthritis caused serious knee damage in 21 patients and was the indication for the operation; in 7 patients it was rheumatoid arthritis; in 1 patient synovitis villonodularis; and severe posttraumatic osteoarthrosis in 1 patient. In 18 patients axial knee deformity was noted prior to operation in the sense of valgus or varus. The continuous passive motion machine was used in the postoperative treatment of all patients. Clinically acceptable results were obtained in 90%. Wound healing complications were noted in 2 patients. Full axial deformity correction was achieved in all the patients with a full extension and flexion of over 90 degrees in the operated knees. Preliminary results after the implantation of this type of prosthesis are very encouraging and justify it's further routine use.

Adult

Pigmented villonodular synovitis and plasmacytoid lymphoma in a dog.

A 4-year-old Labrador Retriever was examined because of progressive left hind limb lameness involving the stifle. A villous synovial mass was evacuated by synovectomy. Initially, the macroscopic and histopathologic features suggested a malignant fibrosarcomatous process; however, further histologic studies revealed lesions consistent with pigmented villonodular synovitis. Nine months later, the dog developed a large retroperitoneal tumor, with metastasis to the lungs and liver. The dog was then euthanatized. By histologic and electron microscopic examinations, the tumor was found to be a primitive plasmacytoid lymphoma.

Animals

[Radiographic measurement of the antebrachiocarpal joint in dogs].

Radiographic processing of the antebrachiocarpal joint was conducted in 30 sexually mature dogs of different race, sex and body weight. Anteroposterior and profile radiograms of joints were made in standardized conditions. The aim of this paper was to determine the qualitative radiographic characteristics of the antebrachiocarpal joint in dogs, and the possibilities of applying various radiographic parameters in quantitative radiographic investigations of this region. The observed differences in the morphology of this joint in dogs in relation to the one in humans, are the result of evolutionary racial adaptation. By knowing these differences it is possible to adjust the radiographic measurement parameters which are in clinical practise use, and in that way enable the full use of dogs as experimental models in radiographic and surgical research projects.

Animals

[The size and suitability of blood vessels for transplantation into the knee of the dog].

An investigation of the size and suitability for the transplantation procedures of the knee blood vessels was made in 20 adult dogs with 40 extremities using the technique of injection of the arterial network through the femoral artery with the mixture of the methacrylic resin (SIGMAL R "Galenika", Belgrade) and the red ink. When the polymerisation of injected methacrylic resin was completed the specimens were exposed to either chemical or biological maceration of the tissues. Thirty-five specimens were chemically macerated using either 30% solution of hydrochloride acid or 40% potassium hydroxide. With this method bones were also destroyed and only the methacrylic vascular cast remained unaffected. Five specimens were exposed to the biological maceration using the insects (Dermestes vulpinus). This method proved to be better as the bones elements were not destroyed which allowed more precise study of vessel relations and topography. Calibre of the arteries was measured using the micromethod MEBA (Zagreb) with the accuracy of 0.01 mm. The main arterial vessels of the knee joint on the medial side are aa. saphena, genus descendes (branches of the femoral artery, then a. genus descendens (branches of the femoral artery, then a. genus medialis (branch of the popliteal artery), and on the lateral side are a. caudalis femoris distalis, (branch of the femoral artery), a genus lateralis (branch of the popliteal artery) and recurrent branches of the a. tibialis cranialis. Calibre of the femoral and popliteal arteries was over 2 mm which means that they are suitable for macrosurgical sutures, while the calibre of all other arteries was under 2 mm, and it is concluded that they are suitable only for microsurgical sutures.

Animals

[Transplantation of the meniscus in dogs--preliminary report].

A preliminary investigation of the allogenic transplantation of the meniscus without the vascular bundle was carried out in 4 adult dogs with 8 knees. In one operation session on 2 dogs at 2 operative tables and with two operative teams an identical surgical procedure in general anaesthesia was done. A medial parapatellar incision of the knee was used, the medial capsule and the collateral ligament near its proximal insertion were severed. Explanted medial menisci were exchanged and the meniscus from the other dog was put in position of the explanted one and fixed with 3 tangentially placed sutures (posterior, medial and anterior) which were taken out through the capsule and teid extra-articularly; there was no immobilisation, and after 3 weeks the identical operation was done on the other knee. The animals were sacrificed 4-5 months after the operation, the knees were dissected and observed. In all 8 knees transplanted menisci were completely healed around their periphery, however their appearance was rather changed. They were narrower, thinner, and of different colour and consistency. The transplanted menisci were removed and conserved in 10% (formalin) for the further investigation. It is concluded that the allogenic meniscal transplantation without the vascular bundle is possible and that the further investigation of this problem is justified.

Animals

[Specifics in the reconstruction of individual elements in replantation of the forelimb in dogs].

The experiment was carried out on the four extremities of six, sexually mature dogs of a different race. Gradual reconstruction of the anatomic structures was performed as a single act after the section of the elements. To reach stability of the forearm we employed different osteosynthetic techniques and succeeded to reconstruct blood vessels, nerves, ligaments and the skin, afterwards. Numerous techniques of suturing material were used. The animals were sacrificed six months after being operated and were exposed to microscopic observation and histological analysis. The results obtained suggested the necessity of a firm osteosynthesis of the forearm bones, use of less traumatic suturing material for suturing both blood vessels and fasciculi when preparating nerves.

Animals

[Revascularization of the forelimb in dogs].

Revascularization of the forearm was performed on six mature dogs of a different race. Arteria mediana was cut 2 cm above the fork of the arteria radialis and later sutured with a nonresorptive monofilament thread/Ethilonr/7-0 and 8-0 in diameter. The same process was repeated on the cefalica vein. Arteriographies were performed on the operated extremities, pre-operatively, immediately after operation and while an animal being sacrificed. The subjects were sacrificed six months after the operation. Then microscopic and histological analyses were carried out to assess the quality of the blood vessels at the suturing place. At the place of the blood vessels reconstruction, lumen did not get narrower which indicated that all the vessels were in a perfect functional condition. In a number of dogs a higher collagenic proliferation was noticed, in the vicinity of the blood vessels sutured. In the regenerative process of the arterial wall tunica mediana almost took a predominant position, like in the intact arteria. All the three strata were present with no relevant deviations in structure. In the cefalica vein the regeneration of the connective tissue support of the smooth muscles cells was insufficient. Based on the analysis of the results obtained it might be concluded that after revascularization of the forearm of the dog the regeneration of the blood vessels made the segment functionally capable with the structure not different from the normal one which existed in the blood vessels of the same part of the body.

Angiography

[Histologic changes in fascia lata transplants in the replacement of the anterior cruciate ligament of the knee in dogs].

Lesions of the anterior cruciate ligament of the knee are very frequent misfortune and the results of their suture being insufficient yet, made us to explore the possibility to replace the damaged ligament with the fascia lata as an autologous transplant. Surgical operation was performed on dogs. Instead of the anterior cruciate ligament removed, we used a piece of a rolled fascia lata. Six months after transplantation being performed, samples of the fascia lata were extracted for histological analysis to assess their structure and to evaluate the transplant as a neoligament, on the basis of its similarity with the normal structure of the ligament. After degeneration of a part of transplant because of the insufficient supply of nutrients, the invasion of the synovial blood vessels into the fascia lata was established and the young granulation tissue formed on the account of the nondifferentiated adventitial cells. In the mosaic of the transplant structure there were present parts of a more mature, dense connective tissue with longitudinal orientation of the cells, the fibers and the vascular elements, which partially made structure similar to that in ligaments. In the attachment region fibrocartilage was noticed, gradually passing into the hyaline one, to merge with the hyaline cartilage of the joint surface. After the histological analysis follows the conclusion that fascia lata functionally could replace the anterior cruciate ligament if a role was supplied with sufficient collagenic fibers on the cross-section. Time is of a high importance, too.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Rheology of paraproteinaemias and the plasma hyperviscosity syndrome.

The proper understanding of the causes, pathophysiology, diagnosis and management of the plasma hyperviscosity syndrome is based on good knowledge of malignant paraproteinaemias, properties of immunoglobulins, rheology of blood in the microcirculation, and modern plasma separation techniques. This multifaceted syndrome complicates less than ten per cent of IgA and IgG myelomas, and up to one-third of Waldenström's macroglobulinaemias. A few cases of HVS have also been reported in association with polyclonal hypergammaglobulinaemias. Excessive paraproteinaemia may cause the plasma HVS, especially when paraproteins are extraordinarily large, asymmetrical or cryosensitive, or if they aggregate into hyperviscous macroaggregates. The resultant severe microcirculatory impairment is mainly due to the combined effects of plasma hyperviscosity, significant plasma volume expansion and intense red cell aggregation. The individually variable general symptoms, bleeding tendency, ocular, neurological, cardiovascular, and renal manifestations and laboratory parameters of the HVS are summarized briefly. The majority of patients present hyperviscosity manifestations when the plasma viscosity exceeds 5-6 mPa.s. Plasmapheresis or plasma exchange have established themselves as efficient and safe modes of therapy of hyperviscosity and hypervolaemia. The therapeutic guidelines for the plasma HVS are briefly discussed with regard to recent experience with developing plasma separation techniques. Diagnostic and therapeutic advances combined with increasing haemorheological knowledge have greatly improved the proper management of this potentially lethal complication of paraproteinaemias.

Blood Viscosity