A new structural class of serine protease inhibitors revealed by the structure of the hirustasin–kallikrein complex

AbstractBackground: Hirustasin belongs to a class of serine protease inhibitors characterized by a well conserved pattern of cysteine residues. Unlike the closely related inhibitors, antistasin/ghilanten and guamerin, which are selective for coagulation factor Xa or neutrophil elastase, hirustasin binds specifically to tissue kallikrein. The conservation of the pattern of cysteine residues and the significant sequence homology suggest that these related inhibitors possess a similar three-dimensional structure to hirustasin.Results: The crystal structure of the complex between tissue kallikrein and hirustasin was analyzed at 2.4 Å resolution. Hirustasin folds into a brick-like structure that is dominated by five disulfide bridges and is sparse in secondary structural elements. The cysteine residues are connected in an abab cdecde pattern that causes the polypeptide chain to fold into two similar motifs. As a hydrophobic core is absent from hirustasin the disulfide bridges maintain the tertiary structure and present the primary binding loop to the active site of the protease. The general structural topography and disulfide connectivity of hirustasin has not previously been described.Conclusions: The crystal structure of the kallikrein–hirustasin complex reveals that hirustasin differs from other serine protease inhibitors in its conformation and its disulfide bond connectivity, making it the prototype for a new class of inhibitor. The disulfide pattern shows that the structure consists of two domains, but only the C-terminal domain interacts with the protease. The disulfide pattern of the N-terminal domain is related to the pattern found in other proteins. Kallikrein recognizes hirustasin by the formation of an antiparallel β sheet between the protease and the inhibitor. The P1 arginine binds in a deep negatively charged pocket of the enzyme. An additional pocket at the periphery of the active site accommodates the sidechain of the P4 valine

Long-term functional outcome and quality of life following rotationplasty for treatment of malignant tumors

Background: Malignant bone tumors of the lower extremity are more frequently found in children and adolescents than in adults. Modern treatment regimens led to high limb salvage rates and offer the choice between endoprosthetic replacement and rotationplasty in many cases. Rotationplasty has proven to be an effective, highly functional option in short-and mid-term studies. Aim of this study was to assess long-term results regarding quality of life and functionality after rotationplasty and to compare the obtained results to a representative healthy German sample cohort. Methods: In total 12 patients who underwent rotationplasty between 1991 and 2001 were enrolled in this study. After physical examination, they were evaluated regarding health related quality of life, functional outcome and psychosocial status. While quality of life was mainly assessed using the SF-36 (The Short Form (36) Health Survey v2),functional outcome was measured using the musculoskeletal tumor society score (MSTS) as well as the Tegner activity level scale. Results: Average age at the time of surgery was 19 +/- 10 year. and 32 +/- 11 year. at the time of follow up. Mean follow-up was 14 +/- 9 years. The SF-36 scores accounted for 80.4 +/- 15.7 regarding physical functioning, for 78.1 +/- 24.1 regarding the physical role functioning, for 74.1 +/- 17.6 regarding bodily pain and for 71.8 +/- 26.1 regarding general health. SF-36 score for vitality was 75.0 +/- 12.8, for social functioning 98.9 +/- 3.6, 88.2 +/- 23.9 for emotional role functioning and 89.6 +/- 10.1 for the mental health. Comparison to a representative German sample cohort revealed significantly higher patient's scores for vitality, social functioning and mental health (p < 0.05). The overall MSTS resulted in an average of 64 +/- 12 % and the Tegner activity level scale accounted for 4.1 +/- 0.6 pts. Conclusions: The presented long-term results indicate that rotationplasty provides a high quality of life. Patients are satisfied with a good functional outcome regarding activities of daily life and even sports

Prognostic factors and outcome of Liposarcoma patients: a retrospective evaluation over 15 years

Abstract Background Soft tissue sarcomas are rare entities with over 50 histological subtypes. Liposarcoma (LS) is the most common neoplasm in this group; it is a complex neoplasm that is divided into different histological subtypes. Different therapy options, such as surgical resection, radiation, and chemotherapy, are available. Depending on the subtype, location, status of the resection margins and metastatic status, different therapy options are used. Therefore, the aim of this study was to determine the prognostic factors influencing the survival of patients affected by LS with consideration for the grading, histological subtype, state of the resection margin, size, location, metastases and local recurrence in a retrospective, single-centre analysis over 15 years. Methods We included 133 patients (male/female = 67/66) in this study. We recorded the histologic subtype, grade, TNM classification, localization, biopsy technique, tumour margins, number of operations, complications, radiation and dose, chemotherapy, survival, recrudescence, metastases and follow-up. Survivorship analysis was performed. Results We detected 56 (43%; 95%-CI 34.6–51.6%) atypical LS cases, 21 (16.2%; 95%-CI 9.8–22.5) dedifferentiated LS cases, 40 (30.8%; 95%-CI 22.8–38.7) myxoid LS cases and 12 (9.2%; 95%-CI 4.3–14.2) pleomorphic LS cases. G1 was the most common grade, which was followed by G3. Negative margins (R0) were detected in 67 cases (53.6%; 95%-CI 44.9–62.3) after surgical resection. Local recurrence was detected in 23.6% of cases. The presence of metastases and dedifferentiated LS subtype as well as negative margins, grade and tumour size are significant prognostic factors of the survival rates (p < 0.015). Conclusion Grading, LS subtype, negative margins after surgery, metastases and tumour size are independently associated with disease-specific survival, and patients with local recurrence had lower survival rates. We hope our investigation may facilitate a further prospective study and clinical decision-making in LS

Qualitative evaluation, clinical.

<p>Reduction of artifacts in the VAT&SEMAC group as compared to the conventional group for each pulse sequence. Parameters were “geometric distortion”,”signal changes”, “diagnostic confidence” and “spacial blurring". SEM, standard error of the mean; P-value, P (Wilcoxon-signed rank test) compared to “conventional” for each pulse sequence.</p><p>Qualitative evaluation, clinical.</p

Initial diagnoses of the analyzed patient cohort.

<p>^a Recurrence was diagnosed for one patient with a history of chondrosarcoma and for one patient with a history of plasmacytoma.</p><p>Initial diagnoses of the analyzed patient cohort.</p