Biomedical subjects

S Sell

Publications and source records attributed to S Sell.

304 records · Page 17Linked to original sources

PubMedDate not supplied

[Osteogenesis in exposure to ionizing radiation in vitro].

Irradiation is a well established therapeutical concept to prevent heterotopic ossification after joint replacement. The influence of irradiation on proliferation of mature osteoblasts and their potential osteoprogenitors, matrix formation and mineralization are not well known in this setting. We therefore studied the effect of different doses of ionizing irradiation on the several steps of osteogenesis in vitro, using cells isolated from the juvenile rat. A colony forming test, the MTT-viability assay, a cell count, measurement of the cellular protein content and alkaline phosphatase activity, as well as determination of in vitro mineralisation have been applied to calvarian osteoblasts, fibroblasts and stromal bone marrow cells. Irradiation results in a dose-dependent suppression of clonogenic activity in all mitotically active cells, but metabolic activity and matrix synthesis were not impaired. In dense cultures alkaline phosphatase expression and in vitro mineralisation were not significantly affected by irradiation. Our experimental in vitro data suggest that irradiation inhibits the initial phase of in vivo osteogenesis due to the cytostatic effect. Postoperative irradiation after THR must therefore take place as early as possible. The homoeostasis of normal, orthotopic bone does not seem to be severely affected by local low-dose irradiation.

Alkaline Phosphatase↗

PubMedDate not supplied

[Validity and reproducibility of osteodensitometric DEXA-measurements following total hip endoprosthesis].

For the determination of reproducibility of bone densitometric measurements we performed a measurement according to the DEXA- method. 35 patients after implantation of total hip replacement were examined with a Lunar DPX-L. We received a maximum reproduction error of 1.2% according to the GRUEN-analysis. The operated hip of 17 patients showed an increase in bone density between 5 and 18% by the implantation of an arthroplasty compared to the preoperative values. The non-operated prosthesis-corrected hip showed a reproduction error of 3.8% in ROI 1 in 17 patients, otherwise a maximum of 1.3%. Considering an interfemoral difference in bone density of up to 20%, differences in periprosthetic bone density of up to 40% compared to the contralateral side can be within the normal range in a retrospective measurement. Therefore retrospective determination of bone density after cementless hip arthroplasty only is of limited value. Only prospective analysis can provide reliable information about the actual loss of bone density.

Absorptiometry, Photon↗

PubMedDate not supplied

[Proteus syndrome: a case report].

The Proteus-syndrome is a recently described congenital hamartomatosis consisting of numerous clinical features of great variety. Mainly affected are the musculo-skeletal system, primarily by hemihypertrophy, macrodactyly and exostoses, and the skin and the subcutaneous tissue, primarily by pigmented naevi and subcutaneous tumors. The differential diagnosis includes other malformation syndromes, e. g. Klippel-Trenaunay-Weber syndrome and other hamartomatosis. Surgical intervention and treatment is difficult because of a frequency of complications and recurrences. This article describes clinical manifestations of Proteus syndrome, differential diagnosis and therapeutic strategies.

Child↗

PubMedDate not supplied

[Ultrasound imaging of the patellar tendon--an experimental study].

QUESTION: The accuracy of ultrasound in the detection of histological changes is a point of discussion. METHOD: In an experimental study we examined on 58 explanted human patellar tendons the correlation between histological and sonographic changes. RESULTS: Ultrasonographic measurements of length, width, thickness and circumference of the ligaments correlated highly to the explants' macroscopic evaluated dimensions. The sonographic lesions were distinguished in changes in form and echogenicity. Macroscopic visible changes in the explanted ligaments could be detected ultrasonographically. In histological aspect 2 tendons and in ultrasonographical aspect 16 tendons were found to be normal in the whole course of the tendons. 14 ligaments showed histological but not ultrasonographical abnormalities. 42 ligaments were conspicuous in both methods of examination. In the course of the tendons a very high correlation (up to 92%) between sonographical and histological findings was detected. At the insertion are of the patellar ligament the correlation was low. CONCLUSION: The performed study shows that ultrasonographically detected lesions of the patellar ligament point to histological changes but no conclusions to the kind of histological changes can be taken. However ultrasonographically found abnormalities correlate in a high proportion to histologically detectable changes in the ligaments. Ultrasonography is a good method to evaluate degenerative symptoms in the patellar ligament.

Adult↗

PubMedDate not supplied

[Prevention of heterotopic ossification following cementless hip replacement using 5 x 2 Gy fractionated irradiation. A prospective study].

97 patients were treated with cementless custom-made total hip replacement of the Aldinger type for osteoarthritis of the hip. All were prophylactically treated by radiotherapy with 5 x 2 Gy. 10.3% showed heterotopic ossification. 8 patients showed ossification grade I by the Arcq scale and 2 of grade II. Clinical results according to the Merle d'Aubigné score were good or very good in over 90% at one year postoperatively. One patient showed loosening of the femoral stem caused by sinking-in of the custom-made implant. During the revision procedure there were no signs of radiation induced damage to the implant bed. Negative sequelae to the bony implant bed by prophylactic radiotherapy cannot be detected on radiological assessment. Side effects like delayed wound healing or alteration of local immune status with subsequent infection which are commonly discussed, were not seen. Fractionated irradiation is an effective means of prophylaxis of heterotopic ossification.

Adult↗

PubMedDate not supplied

[Suppression of heterotopic ossification: single-dose versus fractionated irradiation--animal study].

Periarticular ossification is one of the main problems of total hip replacement. Irradiation with megavolt photons is known to be a well recognized means of prevention of heterotopic ossification. So far only little scientific basis exists about the most favourable way of radiotherapy for prevention of ectopic ossification. In this study two theoretically equivalent doses are compared. Allogeneic bone matrix was implanted into both thighs of 50 adult male Wistar rats for experimental induction of heterotopic ossification. Immediately after operation the thigh implants were irradiated with a single dose of 7 Gy or a total dose of 10 Gy given in 5 fractions of 2 Gy each. In the model of matrix-induced osteogenesis in rats fractionated irradiation by 5 x 2 Gy leaded to a highly-significant (p = 0.001) better suppression of ectopic ossification compared to irradiation by 1 x 7 Gy. Once-only irradiation with 1 x 7 Gy leads to a reduction of the calcium contents by 27.5%, split irradiation by 5 x 2 Gy obtained a reduction by 66.9% compared to the calcium contents of thigh implants not exposed to radiation. In view of experimentally proven better effects, fractionated irradiation has to be preferred to single dose radiation also considering less side effects in split radiation.

Animals↗

PubMedDate not supplied

[Strength of muscles surrounding the hip joint and gait in patients following implantation of a cementless hip endoprosthesis].

There are only a few studies which could support conclusions concerning the strength of the muscles surrounding the hip joint and especially concerning the strength relationships following implantation of endoprotheses. The aim of this study was to examine the pre- and postoperative course of strength deficits in this musculature compared to clinical parameters and the uninvolved side. Fifty-eight patients between 30 and 67 years of age, in whom individual total hip protheses were implanted were clinically examined prior, 9 weeks and 6 months after surgery. Moreover, the maximum isometric strength of abductors, flexors, and rotator muscles as well as maximum isokinetic strength of the extensors and flexor musculature at 60% and 120%/s were measured. The flexor and extensor musculature already showed a clear increase in maximum strength after 9 weeks and 6 months (90-124%). By contrast, the isometric strengths of the rotators increased only slightly, the abductor strength decreased after 6 weeks to below the preoperative baseline level and attained this level again only after 6 months. The clinical parameters Trendelenburg sign, limping and walking capacity were clearly improved after 6 months, but no correlation to the abductor strength could be demonstrated. It is concluded that limp-free gait can be attained even without maximum strength increase in the abductors, which are important for fluid gait, at least for short distances. The importance of regular training of the rotator and abductor musculature in coxarthrosis is emphasized to delay limitation of movement and decreased strength in the sense of capsule pattern.

Adult↗

PubMedDate not supplied

[Medium-term results using the cement-free individual femur replacement].

Between april 1985 and march 1989 183 individual hip prosthesis of the Aldinger type have been implanted at the university hospital of Tübingen. The time of follow up was 37.3 months. In the average the patients were 55.0 years old. In 39 patients one or several operations had be done at the same hip joint before the implantation of the individual hip. 7 hip prosthesis had to be removed. In two cases 1 respectively 1 1/2 years after the primary operation an infection of the prosthesis mad a replacement necessary. In five cases a aseptic loosening of the prosthesis occurred. 139 patients were painfree. In 13 patients there was an intensive femoral pain; 4 of these patients showed radiological signs of loosening. 159 Patients were satisfied with the result of the operation. In one case a fissure of the femoral shaft occurred; a fracture of the femoral shaft was not found. Our early results with an individual hip prosthesis are promising, but we have to wait for the long-term-results.

Adult↗

PubMedDate not supplied

[Periarticular ossification following cement-free and cement fixed total endoprosthesis implantation in the hip joint].

218 Patients, primary treated with total replacement of the hip joint were examined for ectopic ossifications. Frequency and Arcq-classification are described in relation to the transgluteal approach to the hip joint, age, sex an the technic of implantation. We found 3.5% more paraarticular ossifications in the group of cementfixed endoprotheses compared with the group of cementless CAT-endoprotheses type Heramed. In comparison men were affected more often with heterotopic ossifications than women. In both groups the overall incidence of paraarticular ossifications was 34.0%.

Adult↗

PubMedDate not supplied

Failure to induce hypersensitivity reactions to opaque contrast media analogs in guinea pigs.

In a further exploration of idiosyncratic reactions to injections of contrast media, a systematic study of immediate or delayed hypersensitivity in guinea pigs injected with contrast media analogs was performed. No evidence of immediate or delayed hypersensitivity could be ascertained to either contrast media analogs alone, or analogs bound to protein carriers. This does not represent conclusive evidence against the notion of antibody formation as a factor in the production of some adverse reactions, but makes such a pathogenesis less likely.

Acetrizoic Acid↗

PubMedDate not supplied

T-cell hyperplasia of lymphoid tissues of rabbits infected with Treponema pallidum: evidence for a vigorous immune response.

Specific identifications by immunofluorescence of infecting organisms and lymphoid cells in lymphoid organs and testes of rabbits were compared with the light microscopic appearances of these cells and organs on days 10, 11, 13, and 20 after intratesticular inoculation with Treponema pallidum (Nichols strain). Large numbers of T. pallidum were observed in the interstitial tissues of the testes on days 10 and 11. These numbers had declined markedly by day 13, and by day 20 only rare organisms (estimated as fewer than one to three per cross section) were seen. Organisms were also easily identified in much smaller numbers in the lymph nodes and spleen on days 13 and 20. Disappearance of organisms from the testes were associated with infiltration of large numbers of T cells. Marked follicular and diffuse cortical hyperplasia of the lymph nodes as well as follicular and periarterial hyperplasia of the spleen were observed. Specific immunofluorescence revealed large numbers of T cells in the diffuse cortex of the lymph nodes and the periarteriolar zones of the spleen. There was also a periportal infiltration of T cells in the liver. It is concluded that rabbits infected intratesticularly with T. pallidum mount an intense immune response that effectively eliminates most of the infecting organisms. However, despite this response, surviving T. pallidum may be identified not only at the original site of infection, but also disseminated in lymphoid organs. Normal mechanisms for controlling immune responses apparently shut down the specific response at a time when infecting organisms have not been completely eradicated from the host's tissues.

Animals↗

PubMedDate not supplied

Characterization of the humoral immune response of the rabbit to antigens of Treponema pallidum after experimental infection and therapy.

The development of IgM and IgG antibody responses to antigenic molecules of Treponema pallidum was examined in intratesticularly and intradermally infected rabbits by use of immunofluorescence (IF) and Western blotting techniques. IgM antibody was first detectable on day 6 following intratesticular infection and reached maximal IF titers during the period of clinical orchitis (days 10-17). IgG reached peak IF titers in the resolution period following clearance of most organisms from the testes (after day 17). Initial IgM antibody responses on day 6 were directed against the 46-, 43-, and 37-kdalton molecules, with reactivity to the 14- and 12-kdalton molecules appearing on day 10. IgG antibody, which was first apparent in the Western blot on day 6, was directed against the 37-kdalton molecule. IgG antibody to the 46-kdalton molecule was first apparent on day 13, and the full spectrum of 22 molecules was recognized on day 31. Curative therapy of intradermally infected rabbits one week after infection resulted in lower IgG antibody titers but did not abrogate the development of humoral responses to all of the major antigens.

Animals↗

PubMedDate not supplied

Demonstration of Treponema pallidum in axons of cutaneous nerves in experimental chancres of rabbits.

After cutaneous inoculation of viable Treponema pallidum subsp pallidum into the skin of chancre-immune or previously uninfected rabbits, organisms move from perivascular connective tissue to localize extracellularly in hair follicles, erector pili muscles, and cutaneous nerves. Large numbers of intact organisms can be seen within the perineurium using electron microscopy, and after extensive sampling a few organisms can be detected within the axon cytoplasm. These findings support the concept that T. pallidum may be able to pass along the nerve fibers to the central nervous system.

Animals↗

PubMedDate not supplied

[Potentials of the echographic documentation of hip epiphysiolysis].

The results are presented of a study on patients affected by hip joint epiphyseolysis. The sonographic examination was performed using a unit with a linear 5 MHz probe; oblique scans were obtained, along the axis of the neck of the femur. Typical US findings are described, namely a small step corresponding to a positioning defect of the cartilage between head and neck of the femur and dilatation of the infracapsular space due to the presence of intra-articular fluid.

Adolescent↗

PubMedDate not supplied

[Disorders of proprioception of the arthrotic knee joint].

We measured proprioception of the knee joint by an active and a passive method in 40 subjects under 30 years of age and in 80 subjects older than 50 years with no evidence of knee joint disease. Joint position sense was also determined in an additional 59 patients with osteoarthrosis of the knee. Proprioception was found to decline with increasing age. In the osteoarthritic knee the measured values were significantly higher than in both groups without knee-joint involvement. An elastic bandage had a positive effect. There was a positive correlation between proprioception and clinical parameters. Walking ability and range of motion did not significantly influence the proprioception. Patients receiving physical therapy showed an improved joint position sense.

Adult↗

PubMedDate not supplied

[Ultrasound study of the elbow joint in patients with chronic inflammatory joint diseases--an enrichment of diagnosis?].

After clinical and radiological examination, the elbows of 74 patients with rheumatoid arthritis were examined by ultrasound. Clinical examination gives a good impression of the inflammatory changes of the elbow joint. Sonography was very useful in detecting synovitis and joint effusion and their distribution in the different parts of the joint. It is a good method to document the therapeutic effects; therefore, beside the clinical and radiological findings ultrasound may be helpful in planning further therapeutic measures for the patient.

Arthritis, Psoriatic↗