Artroskopicky asistovaná osteosyntéza nitrokloubních zlomenin lopatky ­ první zkusenosti a dvouleté klinické výsledky.

PURPOSE OF THE STUDY Fractures of the scapula are less frequent, with the incidence reported in literature of approximately 1% of all fractures and 3-5% fractures of shoulder. These fractures are predominantly treated non-operatively. Osteosynthesis is indicated in displaced intra-articular fractures and severely displaced extra-articular fractures of the scapular body, its lateral border in particular. Apart from open reposition and osteosynthesis, also minimally invasive osteosynthesis under fluoroscopic and arthroscopic control has recently been used to treat intra-articular fractures of the scapula. The arthroscopy facilitates debridement of the fracture line in the intra-articular region and control over the insertion of the osteosynthesis material in the subchondral bone of the glenoid and it also makes visible the accuracy of reduction of fractures of the glenoid articular surface. MATERIAL AND METHODS In 2013-2017, osteosyntheses of 9 intra-articular fractures of the scapula were performed with the use of both perioperative fluoroscopy and arthroscopy. The group included 7 men and 2 women, with the mean age of 37 years (range 24-52 years). 4.5 mm cannulated screws inserted in the subchondral bone either from the cranial or dorso-caudal part of the glenoid in dependence on the type of the fracture were used as osteosynthesis material. Postoperatively, the extremity was fixed by Desault type shoulder brace for 4 weeks. Rehabilitation using standard procedures for shoulder joint followed. The patients were followed up at regular intervals, namely on 10th day, at 4 weeks, 3, 6, 12 and 24 months postoperatively. The clinical outcomes and radiologic signs of healing were evaluated continuously and two years after the surgery the clinical outcomes were assessed using the Constant score. Arm elevation was assessed separately, as a dominant indicator of shoulder joint function. RESULTS No perioperative complications were reported, the operative times ranged from 45 to 120 minutes. Reduction was always performed in fractures with intra-articular displacement of less than 2 mm, which was measured both arthroscopically and on perioperative and postoperative radiographs. No complications of wound healing were observed. One patient experienced temporary paresthesia in the innervation zone of the sensitive branch of the radial nerve. The mean healing time of fractures was 121 days (range 107-146 days). The mean Constant score at two years after surgery was 83 points (range 78-87 points), the resulting restriction of elevation was 12° on average (range 0-23°). DISCUSSION There are not many papers covering a similar topic in world literature, most of them present the benefits of arthroscopy in some types of osteosyntheses of intra-articular fractures of the scapula. Most frequently mentioned are osteosyntheses of the anterior portion of the glenoid in case of a bony Bankart lesion. These papers highlight the benefits of minimal invasiveness of this procedure. CONCLUSIONS By visualising the fracture line, the arthroscopy facilitates a more accurate reduction of fragments and a minimally invasive osteosynthesis of some intra-articular fractures of the scapula when compared to closed reduction with fluoroscopic intraoperative control only. The use of arthroscopy in these interventions is conditional on perfect mastering of the surgical technique and also the use of special instruments both for arthroscopy and minimally invasive osteosynthesis. If these criteria are observed and the surgical technique mastered, the authors consider this method beneficial in treating the glenoid fractures. Key words: minimally invasive osteosynthesis, glenoid fractures.

Changes in spatio-temporal localization of tripeptidyl peptidase II (TPPII) in murine colon adenocarcinoma cells during aggresome formation: a microscopy study based on a novel fluorescent proteasome inhibitor.

Extralysosomal proteolysis is a multistep process involving the Ubiquitin- Proteasome System (UPS) and supplementary peptidases. Tripeptidyl peptidase II (TPPII) is the most extensively characterized enzyme, supplementing and sometimes substituting for proteasomal functions. In response to proteasome inhibition, polyubiquitinated proteins acting as proteasome substrates aggregate with proteasomes and form aggresomes. Several proteasome inhibitors are used as anti-cancer drugs. Thus, in our study, we used a novel fluorescent-tagged proteasome inhibitor BSc2118 to induce aggresome formation in C26 murine colon adenocarcinoma cells. It allowed us to obtain effective, inhibitor-based, proteasome staining in vivo. This method has been validated by standard post-fixed indirect immunostaining and also allowed co-immunodetection of TPPII and polyubiquitinated proteins under laser scanning confocal microscopy. We found that in the absence of the inhibitor, TPPII is diffusely dispersed within the cytoplasm of C26 cells. The proteasome and ubiquitin-rich perinuclear region failed to display enhanced TPPII staining. However, when proteasome function was impaired by the inhibitor, TPPII associated more closely with both the proteasome and polyubiquitinated proteins via TPPII recruitment to the perinuclear region and subsequently into emerging aggresomal structures. Furthermore, we have demonstrated the dynamic recruitment of TPPII into the developing aggresome: TPPII in the early aggresome was dispersed within the central part but subsequently aggregated on the surface of this structure. In the mature aggresome of C26 cells TPPII formed a spherical mantle, which surrounded the round core containing proteasomes and polyubiquitinated proteins. Our morphological data indicate that TPPII displays spatial localization with proteasomes especially upon proteasome inhibition in aggresomes of C26 cells.

Lack of awareness in both patients and physicians contributes to a high rate of late presentation in a South West German HIV patient cohort.

PURPOSE: To assess rate of late presentation with HIV in Southwestern Germany and to identify patient characteristics correlated with CD4 nadir. METHODS: Patients with primary diagnosis who presented to one of ten participating clinics rated on knowledge and behavior towards HIV testing on a self-developed questionnaire, whereas clinical data was assessed by the physician. RESULTS: 161 patients were included. Risk factors were homosexual (59.5 %) or heterosexual contacts (26.8 %), drug use (2.0 %), migration (3.9 %), or others (7.8 %). 63.5 % had a CD4 T cell count < 350/µl. 52.5, 17.4, and 31.1 % were diagnosed in CDC stadium A, B or C, respectively. 209 disease episodes were reported, from whom 83.7 % had led to the diagnosis of HIV. 75.2 and 68.3 % said to have been well-informed about ways of transmission and testing offerings, respectively, and 20.4 % admitted to have psychologically repressed the possibility of being infected. 48 patients rated their personal behavioral risk as "high" or "very high". Of these, however, only ten had performed at test in the precedent year. Performing a regression analysis, younger age and previous testing were correlated with a higher CD4 T cell nadir (p = 0.005, and 0.018, resp.). CONCLUSION: The rate of late presentation in this region was even higher compared to national or European surveys. Most infected patients perceived to have had only a low risk. Several disease episodes did not lead to the initiation of HIV testing by the physician.

Effects of the combination of a proteasome inhibitor (PSI) and an inhibitor of ubiquitin-ligases (Leu-Ala) on the ultrastructure of human leukemic U937 cells.

We have used the dipeptide Leu-Ala in an attempt to prevent the formation of ubiquitin-protein conjugates in U937 cells by inhibition of cellular E3 enzymes (ubiquitin ligases). Proteasome inhibitors induce the formation of perinuclear aggregates of ubiquitinated proteins and proteasomes (aggresomes) in the area of the proteolytic center of the cell. Leu-Ala did not prevent the forrmation of those aggregates under the action of PSI (peptidyl aldehyde, selective inhibitor of the chymotrypsin-like activity of the proteasome), however it induced an accumulation of lipid droplets in treated cells, suggesting a previously unknown involvement of Leu-Ala in lipid metabolism. We conclude, that either Leu-Ala is not able to completely inhibit the cellular E3 enzymes or some of those enzymes are insensitive to this dipeptide, allowing therefore the build-up of ubiquitin-conjugates in the proteolytic centre of the cell.

Proteasome localization and ultrastructure of spermatozoa from patients with varicocele--immunoelectron microscopic study.

Localization of proteasomes in spermatozoa from patients with varicocele-associated sterility was studied by means of immunolabeling with the MPC21 monoclonal antibody detecting the C3 subunit of the 20S proteasome. The reaction was visualized for electron microscopy using the secondary Nano-Gold-coupled antibody with Gold-Enhancement in pre-embedding technique. We found that semen samples from varicocele patients contained a large amount of abnormal spermatozoa characterized by the presence of dispersed chromatin and large residual bodies (cytoplasmic droplets) as well as spermatids at various stages of spermiogenesis. In normal spermatozoa, the immunolabeling was found in the acrosome, postacrosomal regions, nuclear vacuoles, in the neck and in the middle-piece as well as in the residual bodies, while chromatin remained unlabeled. In varicocele spermatozoa, the immunolabeling was also associated with chromatin and large residual bodies (cytoplasmic droplets). In contrast to normal, mature spermatozoa, the chromatin of the cells at earlier stages of spermiogenesis was strongly immunolabeled. The association of proteasomes with sperm chromatin and large residual bodies can be the sign of abnormality and disturbances in spermatogenesis associated with varicocele.

Localization of a proteasomal antigen in human spermatozoa: immunohistochemical electron microscopic study.

The ultrastructural localization of a proteasomal antigen in human spermatozoa was studied by means of immunolabeling with the MPC21 monoclonal antibody and secondary gold labeled antibody with 1.4 nm gold particles in combination with silver enhancement reaction using pre-embedding technique. The labeling was found in the acrosomal and postacrosomal regions, in the connecting-piece (neck) and, in some cases, in the middle-piece and also in the residual bodies. There was no significant reaction in condensed chromatin. In some abnormal forms of spermatozoa, in which the chromatin was not well condensed, the labeling in nuclei was present. The nuclear vacuoles with looser chromatin were usually strongly labeled. The nuclei of cells representing different stages of spermatogenesis, that were present in semen samples, were also labeled.