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Biomedical subjects

H Merk

Publications and source records attributed to H Merk.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Recurrent luxations after arthroscopic refixation of the labrum using suture anchors in traumatic ventral shoulder luxation].

OBJECTIVE: Recurrence rates after arthroscopic labral reconstruction for anterior shoulder instability are still higher than after open procedures. Therefore, proper selection of patients becomes increasingly important. The aim of this study was to investigate factors influencing recurrence rates after arthroscopic labral repair with suture anchors. PATIENTS AND METHODS: We examined 53 patients (43 male, 10 female) with traumatic anterior shoulder dislocations, who were treated with arthroscopic labral repair using Fastak-Suture anchors between 1995 and 1996. The average follow-up time was 18 (12-30) months. The mean age of the patients at the time of operation was 27 (15-44) years. RESULTS: Postoperatively, 11 patients (20.7%) reported on redislocations. Recurrence rates increased significantly in patients with more than 4 preoperative dislocations and in patients with bony Bankart lesions. In patients without redislocations, the mean Rowe score improved from 65.9 (SD +/- 12.3) preoperatively to 88.6 (SD +/- 12.5) at follow-up. Thus, there were 24 excellent, 9 good and 6 fair results, while in 3 patients with persisting signs of shoulder instability results had to be estimated as poor. Deficits in the range of motion of more than 15 degrees were seen in 7 patients with predominant affection of the external rotation. CONCLUSION: Frequent preoperative dislocations and bony Bankart lesions contribute substantially to high recurrence rates after arthroscopic labral repair. Therefore, in these cases open procedures should be preferred.

Adolescent↗
PubMed2001

[Ultrasonography of the Osgood-Schlatter disease].

AIM: The aim of our study was to asses the value of ultrasound in the diagnosis of M. Osgood-Schlatter. The results of the primary ultrasound examination were compared with the use of X-ray. METHOD: 15 patients were included in our study (average age 11 - 17 years, 8 female, 7male). All patients get an X-ray of the knee in two or three images. There was a reference-group of 10 patients with 20 joints (average age 11 - 14 years). RESULTS: We observed typical sonographic images in different stages of M. Osgood-Schlatter. The changes depended on the duration of the disease. In every case we found a thickness of the patellar tendon of more than 1 mm (stage I and II), a bursitis infrapatellaris (stage II) and a fragmentation of the cortical bone of the apophysis (stage II). In cases of stage III disease a thickness of the patellar tendon of less than 1 mm was to be seen. In healthy people the average thickness of the patella tendon was 4.8 mm (3.5 - 5.7 mm). The maximal difference between the left and the right side was 0.4 mm. CONCLUSIONS: With the use ultrasound in cases of M. Osgood-Schlatter a reduced exposure of children to X-ray is possible. Ultrasound examination is a clear and easy way to diagnose the disease correctly and evaluate its course and cure.

Adolescent↗
PubMed2000

Photodynamic therapy in dermatology.

UNLABELLED: The combination of light and chemicals to treat skin diseases is widely practiced in dermatology. Within this broad use of light and drugs, in recent years the concept of photodynamic therapy (PDT) has emerged. PDT is a promising modality for the management of various tumors and nonmalignant diseases, based on the combination of a photosensitizer that is selectively localized in the target tissue and illumination of the lesion with visible light, resulting in photodamage and subsequent cell death. Moreover, the fluorescence of photosensitizing compounds is also utilized as a helpful diagnostic tool for the detection of neoplastic tissue. Intensive basic and clinical research culminated in the worldwide approval of PDT for bladder, esophageal, and lung cancer. The expanding use of this relatively new therapeutic modality in dermatology at many centers around the world has revealed its efficacy for the treatment of cutaneous precancer and cancer, as well as selected benign skin disorders. The following article summarizes the main principles of PDT considering the most recent developments and provides a comprehensive synopsis of the present status of the use of PDT in dermatology. (J Am Acad Dermatol 2000;42:389-413.) LEARNING OBJECTIVE: At the conclusion of this learning activity, participants should be able to describe the basic concepts of PDT, including fundamental knowledge of the most relevant photosensitizers, the light sources, the mechanisms involved in PDT-mediated cell destruction, as well as the indications and limitations of photodynamic treatment of skin diseases.

Dermatology↗
PubMed2000

Multicentre study for the development of an in vivo model to evaluate the influence of topical formulations on irritation.

Although skin protective products to prevent irritant skin reactions are in wide use, neither standardized test models to prove differences in efficacy exist, nor has the quality or the reproducibility of results been evaluated in a multicentre approach. This should be mandatory when developing or testing skin care products. Therefore, we have designed a multicentre study in an approach to find a standardized test procedure for the evaluation of skin protective products. In this irritation study, a repeated short-time occlusive irritation test (ROIT) with a standardized protocol has been evaluated in 2 phases (12 days and 5 days protocol) in 4 (n=20) respectively 6 (n=33) skilled centres. The skin reaction was induced by 2 irritants (0.5% aq. SLS and toluene, 2x a day for 30 min). Its modification by 3 different cream bases with different hydrophilicity was analyzed. The irritation was monitored by bioengineering methods (TEWL measurement, colorimetry) and by clinical scoring. The evaluation showed that significant results could already be achieved with the 5-day protocol. Furthermore, in spite of the expected inter-centre variations due to heterogeneity of the individual threshold of irritation, interpretation of clinical score, and inter-instrumental variability, the ranking of the vehicles regarding reduction of the irritant reaction was consistent in all centres.

Administration, Topical↗
PubMed1999

[Medialization of the tibial tuberosity in habitual dislocation of the kneecap].

Referring to relevant literature, various concepts are discussed in the treatment of habitual dislocation of the kneecap. Between 1987 and 1997, 88 patients have been treated surgically in our clinic by uni- or bilateral medial transfer of the tibial tuberositas. In 21 of the cases lateral release was also performed. In the follow-up, after an average of 4.9 years, 79 patients were examined clinically, radiologically and isokinetically (Kintrex-Dynamometer). Isokinetic measurement of the extension showed an average deficit of 19 nm compared to the contralateral side. Using the Juliusson and Markhede scores, 51 cases had a good, 18 a fair and 10 a poor clinical outcome. In 79 % of the cases, the postoperative sports activity level was the same as preoperatively. Isokinetic measurement with the Kintrex is a useful method of evaluating the development of muscle strength.

Adolescent↗
PubMed1999

[Microsurgical lumbar intervertebral disk operation. Technique and complications].

Lumbar Microdiscetomy requires special instruments and provides a good view with a narrow approach. The microscope is the best surgical aid. Alternatives are a retractorintigrated light or headlamp. A specific complication of lumbar microdiscectomy--the wrong level--can be minimized by an exact preoperative planning. Other complications like dural lesions and exessive bleeding are less frequent with the microscope because of the better view. The most severe complications that can occur with any lumbar disc operation, major vessel or visceral injury, can be avoided by lusing the new rongeur with a depth guard.

Diskectomy↗
PubMed1999

The frequency of phospholipase A2 binding of basophilic granulocytes does not decrease during bee-venom-specific immunotherapy.

BACKGROUND: The major allergenic component of bee venom is phospholipase A2 (PLA2). METHODS: In this study, PLA2 was used to analyze and enrich PLA2-binding cells from peripheral blood by high gradient magnetic cell sorting. RESULTS: In normal donors, the frequency of allergen (PLA2)-binding cells among peripheral blood mononuclear cells (PBMC) as determined by flow cytometry is below 0.1%, whereas in bee-venom-allergic patients, PLA2-binding cells are readily detectable at frequencies of up to 2.3%. In severely bee-venom-allergic patients, many basophilic granulocytes are present, as defined by anti-CD9, CD25, and CD38 mAb, comprising up to 95% of the PLA2-binding cells. From blood of allergic and normal donors, about equal absolute numbers of allergen-binding CD19/21-positive B cells can be enriched. Severe anaphylactic reactions (Mueller grade IV) and failure of or adverse reactions during immunotherapy are associated with high numbers of circulating allergen-binding basophils. Interestingly, in the patients studied, the number of PLA2-binding basophilic granulocytes did not markedly change during rush immunotherapy and up to 6 months of maintenance immunotherapy. CONCLUSIONS: The specific and reproducible enrichment of PLA2-binding cells provides a new tool for the analysis and monitoring of effector cells in bee-venom-allergic patients with immediate-type hypersensitivity.

Adolescent↗
PubMed1999

Inhibition of allergic contact dermatitis to DNCB but not to oxazolone in interleukin-4-deficient mice.

The role of interleukin-4 as a regulator of immune responses in the skin is investigated with regard to the outcome of contact hypersensitivity reaction in interleukin-4-deficient BALB/C mice. In previous studies conflicting results were obtained concerning the role of interleukin-4 in contact hypersensitivity reactions supporting either a proinflammatory or rather an inhibitory function of this cytokine. Interleukin-4 deficient BALB/C mice sensitized to 2,4-dinitrochlorobenzene showed after challenge a significant reduction in magnitude and duration of the contact hypersensitivity response in comparison with wild-type mice. This attenuation was accompanied by a significant reduction of edema and cellular infiltrates in the dermis and a lacking induction of IL-10 mRNA expression in skin. Also, adoptive transfer experiments revealed that BALB/C mice failed to exhibit contact hypersensitivity after injection of lymph node cells obtained from sensitized interleukin-4 deficient mice. To examine further the role of the contact allergen used to induce the contact hypersensitivity response, mice were also sensitized and challenged with Oxazolone. Here a similar magnitude and duration of contact hypersensitivity in both the interleukin-4 deficient mice and BALB/C control mice was observed. This indicates that the contact hypersensitivity response to 2,4-dinitrochlorobenzene and Oxazolone may partly evolve on different pathways being dependent and independent of interleukin-4. Our results clearly show that the complete loss of endogenous interleukin-4 expression in BALB/C mice is associated with an impaired manifestation of contact hypersensitivity response to 2,4-dinitrochlorobenzene, implying an important proinflammatory function of this cytokine.

Animals↗
PubMed1999

[Ultrasonography as a diagnostic tool in cases of quadriceps tendon rupture].

AIM: Determination of the reliability of ultrasonography as a diagnostic tool for rupture of the quadriceps tendon and for follow-up after surgical repair. METHOD: 11 patients (12 tendons) with a clinical suspicion of quadriceps tendon rupture were studied with ultrasonography in two planes. RESULTS: In 9 cases we were able to confirm the results of the clinical examination using ultrasonography. In 2 cases we did not find a rupture of the quadriceps tendons ultrasonographically. Within the postoperative follow-up, the homogeneity and echogeneity normalised after the sixth week. CONCLUSION: Using ultrasonography we are able to clearly diagnose ruptures of the quadriceps tendon and objectively assess the postoperative follow-up.

Adult↗
PubMed1999

[Diagnostic ultrasonography of the sternoclavicular joint].

PURPOSE: To evaluate the value of ultrasonography in the diagnosis of swelling and lesions of the sternoclavicular joint (SCG). MATERIAL AND METHODS: We analysed the sonograms of 20 SCG of 18 patients with pain and swelling of the SCG. Ultrasonography was performed just after the clinical examination, using a 7.5 MHz linear scanner. RESULTS: All examinations of the SCG produced distinct and clear sonographical findings. We showed that luxations of the SCG as well as tumors and local inflammation can be identified. CONCLUSION: Ultrasonographic examination is a noninvasive, time sparing and economical diagnostic tool for clarifying the differential diagnosis of lesions of the SCG and establish may a therapy regimen.

Diagnosis, Differential↗
PubMed1999

[Follow-up control of ultrasonographic neonatal screening of the hip].

1656 newborns were examined by ultrasound for early diagnosis of CDH in a screening program. In 2.5% of the cases, dysplasia or dislocation of the hip was diagnosed and required treatment. In all cases the final outcome after adequate treatment showed a hip joint without any abnormalities. 11.3% of type IIa-hips (using Graf's classification) did not reach an alpha-angle of 60 degrees until the 12th week. They were then therefore classified as type IIb. 97% of all hip joints were judged as normal in the course of the 4th month. This study emphasizes the necessity of a general ultrasound screening program. It also demonstrated that early and adequate treatment leads to a normal development of the joint.

Follow-Up Studies↗
PubMed1999

Cell-free expression of two single-chain monoclonal antibodies against lysozyme: effect of domain arrangement on the expression.

Single-chain antibodies (scFv), which can be produced in Escherichia coli cells, have been shown in numerous cases to be active in antigen binding. In the case of the two anti-lysozyme single-chain antibodies, scFvLH and scFvHL, which have the reversed arrangement of the variable domains of the heavy and light chains of the corresponding monoclonal antibodies, the expression level differs greatly when they are produced in Escherichia coli [Tsumoto et al. (1995) Biochem. Biophys. Res. Commun. 201, 546-551]. Although the expression level of scFvLH is high in vivo, the single chain antibody with the reversed orientation (scFvHL) was synthesized in a very low yield and no active product could be obtained. We report here the synthesis of these two anti-lysozyme single-chain antibodies in high yields and with high biological activities in a cell-free E. coli expression system in the presence of reduced and oxidized glutathione, protein disulfide isomerase (PDI), and chaperones. In immunological blotting assays, the synthesized scFvs with both arrangements exhibit specific binding activity to the corresponding antigens, hen egg-white lysozyme, and in an activity assay both inhibited the action of lysozyme. scFvLH is synthesized mainly as a product with the expected molecular weight, whereas scFvHL is produced with additional shorter fragments, suggesting that the low yield isolation through the expression in vivo is due to mistranslation or ribonucleolytic cleavage of the transcript. In the cell-free expression of scFv a certain amount of the product is precipitated but in the presence of chaperones the amount of soluble protein increased from 25 to 90% (PDI and chaperones). The overall expression level and the specific biological activity, however, were hardly influenced. The system reported here can provide significant amounts of various scFv fragments regardless of the order of variable regions, including those which are hardly expressed in vivo.

Antibodies, Monoclonal↗
PubMed1999

[Experiences with the GSB (Geschwend-Scheier-Bähler) III total endoprosthesis in the elbow joint].

Studies on the results with elbow prostheses published in the seventies reported on marked problems such as high loosening rates and instabilities of the joints. However, enormous progresses in elbow replacements have been made in the meantime. Therefore, we analyzed the results of the GSB III-elbow-prostheses that were implanted in our department for 9 years. Between January 1, 1987 and April 1995 at our department 34 total elbow replacements were performed in 32 patients. In this study, we reviewed 25 patients with elbow replacements both clinically and radiologically. The clinical outcome was rated according to the score of INGLIS and PELLICI. The mean follow-up time was 3.7 years. Our follow up examination revealed a total complication rate of 22%. Septic prosthesis loosening with explantation of the prostheses occurred in 3 patients resulting in a prosthesis survival-rate of 88%. However, clinical assessment revealed 80% excellent or good results. While the range of motion could only be improved to a small degree, a marked reduction of the preoperative pain could be achieved. Patients were satisfied with the outcome of the operation in 97%. Although the results of total elbow arthroplasties cannot be compared with those of hip or knee arthroplasties, in selected patients with rheumatoid arthritis and osteoathrosis the use of elbow replacements proved to be a successful procedure with satisfactory results. The implantation of elbow prostheses should mainly be considered when debilitating pain, strongly limited range of motion and instability of the joint are the main problems.

Arthritis, Rheumatoid↗
PubMed1998

[Long-term outcome of Putti-Platt operation in recurrent traumatic ventral shoulder dislocations].

In the present study, we reviewed 25 patients who had been treated by Putti-Platt procedure for recurrent traumatic anterior shoulder dislocations between 1988 and 1991. The average follow up time was 6.8 years. Redislocations occurred in nine cases (36%), five of these patients had to undergo a second shoulder reconstruction. Clinical examination with exclusion of the reoperated patients revealed signs of instability in further six patients. Six patients showed decreases in external rotation of more than 40 degrees compared with the nonoperated shoulder. According to the Rowe-score, results were judged as excellent or good only in 55% while they had to be estimated as poor in 30%. At follow up, 13 patients still suffered from limitations in their shoulder functions, only six out of 15 patients were able to return to their sporting activities postoperatively. Thus, the Putti-Platt procedure revealed rather disappointing long-term results and cannot be recommended.

Adolescent↗