Collagen-chondroitin sulfate-based PLLA-SAIB-coated rhBMP-2 delivery system for bone repair

Bone morphogenetic proteins (BMPs) are osteoinductive proteins used intensively in clinical investigations involving various bone-related treatments. Owing to their high potential in new bone formation they require local application at the treatment site. For this purpose various controlled delivery systems with BMPs as the excipients have been prepared in recent years. Focusing on this clinical need a disc-shaped BMP carrier was designed as a local delivery system using soluble collagen and chondroitin sulfate. In situ release studies carried out with a model protein (FITC-labeled Protein A) presented a very high rate of release; with most of the protein content being released within 24 h. This rate could be decreased by providing a poly(L-lactide) (PLLA) and sucrose acetate isobutyrate-based (SAIB-based) coat around the release system, applied after BMP loading. In this way, it was possible to extend the release period from 24 h to about 12 days. In situ release of BMP from the same carriers, as quantitated using an ELISA kit, was even slower, with 50% of the protein being released in 15 days. In order to be able to secure the BMP delivery system at the bone defect site and to provide support a mesh knitted using Vicryl sutures and bonded with poly(L-lactide-co-glycolide) (PLGA) was tested in in vivo. Two time periods, 1 and 3 weeks, were used to evaluate the healing process. Osteoinduction by the BMP carrier system was assessed by histology-based bone scoring and X-ray examinations. PLLA-SAIB-coated collagen discs containing BMP presented good biocompatibility and optimum osteogenic stimulation. Structural changes in histological micrographs at week 1 indicated dose-dependent periosteal ossification. At the end of week 3 histological findings with both BMP (1 and 2 microg) doses were almost the same.     

Lipoxygenase-3 (ALOXE3) and 12(R)-lipoxygenase (ALOX12B) are mutated in non-bullous congenital ichthyosiform erythroderma (NCIE) linked to chromosome 17p13.1.

We report the identification of mutations in lipoxygenase-3 (ALOXE3) and 12(R)-lipoxygenase (ALOX12B) genes in non-bullous congenital ichthyosiform erythroderma (NCIE) linked to chromosome 17. Linkage disequilibrium analysis of six families affected by NCIE permitted us to reduce a recently reported interval of 8.4 cM on chromosome 17p13.1 to a 600 kb region around the marker D17S1796, which contains LOX genes. LOX products have long been implicated in skin disorders. Two point mutations and one deletion were found in ALOXE3 and three point mutations were found in ALOX12B in these consanguineous families from the Mediterranean basin. ALOXE3 and ALOX12B are two genes which are physically linked and functionally related. They are separated by 38 kb, have one more exon than the other LOX genes and are mainly expressed in epithelial cells including keratinocytes. Although the main substrate(s) of the two enzymes is (are) still unknown, the products of ALOX12B obtained in experimental systems have been demonstrated to be of R-chirality. It seems likely that the product of one of these enzymes may be the substrate of the other, and that they belong to the same metabolic pathway.     

The effects of antioxidants on exercise-induced lipid peroxidation in patients with COPD

OBJEctive: The oxidant-antioxidant balance plays an important role in the pathogenesis of COPD. The aim of the present study was to evaluate the effects of exercise, as an oxidative stress factor on the oxidant-antioxidant balance and to investigate whether short-term antioxidant treatment affects lipid peroxidation products. METHODOLOGY: Twenty-one stable COPD patients and 10 control subjects were included in the study. Symptom-limited exercise tests were performed by all subjects. Blood was collected before and 1 h after exercise in control subjects and before, 1 and 3 h after exercise in COPD patients, for analysis of malondialdehyde (MDA), reduced glutathione (GSH) and vitamin E (VE) levels. VE and vitamin C treatments were added to the regular bronchodilator therapy in 10 COPD patients for 1 month. After the treatment period, an exercise test was performed and blood was collected again for MDA, GSH and VE levels. RESULTS: Baseline GSH and VE levels were significantly lower in the COPD group when compared with the control subjects. There was no statistically significant difference in MDA levels between the two groups. In the COPD group, MDA levels 3 h after exercise were significantly higher than at baseline. In contrast there were no significant differences in MDA, VE and GSH levels in the control group after exercise. VE and MDA levels increased significantly after exercise in COPD patients but there was no difference in GSH levels. Baseline exercise time was significantly lower in the COPD group than in the controls. In 10 COPD patients who were given antioxidant therapy, their exercise time increased significantly and there was no increase in MDA and VE levels after the repeated exercise test. CONCLUSIONS: Antioxidant levels were significantly lower in COPD patients than in control subjects. In these patients, exercise results in more significant oxidative stress and lipid peroxidation than in control subjects and antioxidant therapy may decrease lipid peroxidation following exercise and improve exercise capacity.     

Early stage epithelial ovarian cancers: A study of morphologic prognostic factors

We intended to reevaluate the morphologic prognostic factors for early-stage ovarian carcinomas. We reviewed 111 patients diagnosed with early-stage ovarian cancer who had undergone primary surgery at Hacettepe Hospital between 1984 and 2001, using diagnostic criteria from the WHO-2003 classification. We applied the Universal grading system suggested by Shimizu/Silverberg and noted FIGO-stage, histotype, tumor size, bilaterality, and endometriosis. These features were compared with each other and survival. The survival analysis was carried out by Kaplan–Meier curves. Of the cases, 52 were reclassified as ‘borderline tumor’ or ‘cystadenoma with borderline foci’ and 59 as ‘invasive carcinoma’. FIGO-stage and mitotic count were significant for survivals of 59 patients with cancer. Mitotic index was also significant for the probability of metastasis. The patients with stage-II cancer had 5.65 times more risk of recurrence than stage-I cancer. The 5-year overall and disease-free survivals rates were 90.6% and 87.5% for stage-I, 54.7% and 39.3% for stage-II, respectively. Universal grade did not reach statistical significance for survivals but it was related to FIGO-stage significantly. In conclusion, FIGO-stage is the most reliable prognosticator. Although prognostic value of universal grade is not significant, mitotic count may provide important prognostic information for early-stage ovarian carcinomas.     

Higher expression of the novel gene upregulated gene 4 in two acute lymphoblastic leukemia patients with poor prednisolone response

Elucidation of the molecular mechanisms of leukemogenesis is important for a better understanding of the prognosis of acute lymphoblastic leukemia (ALL). Studies have shown that the expression of upregulated gene 4 (URG4), which promotes cell growth and survival, is increased in different types of carcinomas including hepatocellular carcinoma, gastric cancer and osteosarcoma. Similarly, higher expression of URG4 and cyclin D1 gene might promote proliferation of the blast cells by causing escape from the G1 checkpoint and entry into the S phase. This study reports the high expression level of URG4 in 2 high-risk ALL patients for the first time in the literature. In conclusion, the higher expression of URG4 in our 2 patients suggests that URG4 might be involved in leukemogenesis. Future studies with a large number of high-risk ALL patients and cell culture studies are needed to demonstrate the exact role of URG4 in leukemogenesis.     

Effect of Acticoat® and Cutinova Hydro® on wound healing

In this study, the effects of the wound‐covering materials, Acticoat^® and Cutinova Hydro^®, on wound healing have been studied in rabbit models with open and tissue‐lost wounds with full‐thickness flank excisions. Rabbits were used as subjects with three groups of four rabbits each, and trial periods of 7, 14 and 21{\uns}days. Four circular wounds, of 1.5 cm diameter were made two on the right (one of them control) and two on the left (one of them control) of the dorsal sides of the abdomen. Acticoat^® and Cutinova Hydro^® were applied on the wounds with suture for a period of 21 days and one each placed on the right and left sides as control with gauze. Biopsy specimens were taken from the animals at the end of the research period to check the length of the epithelium, epithelial thickness, size of wounds, wound granulation tissue formation and histopathological evaluation for clarity. The Acticoat^® group showed better healing and scar formation compared to the Cutinova Hydro^® group by macroscopic examination. Epithelial wound length and clarity in terms of statistical difference occurred on day 21 (P <0.05); while the length of the wound epithelium decreased patency, epithelial thickness on days~7, 14 and 21, showed no statistical differences (P >0.05). As a result, the Acticoat^® wound dressing was determined as a more reliable for the early wound healing. This study has shown the short‐term clinical benefits of hydroactive, polyurethane dressings in the management of acute wounds. However, longer periods of wound healing procedure should be planned for reliable and safe results of wound dressing. It has also been concluded that microbiological analyses should be included for more robust and reliable comparisons.     

Right Atrial Appendage Function in Different Etiologies of Permanent Atrial Fibrillation: A Transesophageal Echocardiography and Tissue Doppler Imaging Study

Objectives: Several studies exist on the left atrial appendage function (LAA) in permanent atrial fibrillation (AF). However, knowledge about the right atrial appendage (RAA) function is limited. We investigated RAA function with TEE and tissue Doppler imaging (TDI) in permanent AF patients with different etiologies and evaluated predictive parameters of right atrial spontaneous echo contrast (SEC) and thrombi. Methods: Patients with permanent AF developed due to three different etiologies (20 mitral stenosis, 44 hypertension, 20 hyperthyroidism) and 23 subjects with sinus rhythm were included into the study. RAA was examined with TEE and pulsed‐wave and TDI velocities of RAA were measured. Results: Both PW‐Doppler and TDI velocities were significantly impaired in all AF groups compared to controls. The lowest velocities were recorded in mitral stenosis patients. Right atrial moderate–severe SEC was observed in 75% of the mitral stenosis patients, in 25% of hypertensive patients, and in 30% of hyperthyroidism patients. Right atrial thrombus was observed in 25% of mitral stenosis, 4.5% of hypertension, and in none of the hyperthyroidism patients. In the multivariate analysis, the most important parameter associated with the severity of RAA SEC was the percent change in RAA area (B =−0.034, P = 0.03). Conclusion: In patients with permanent AF, impairment of RAA function and development of right atrial SEC‐thrombus are closely related to the underlying etiology. These results suggested that evaluation of RAA functions may have an incremental value over the assessment of the LAA for determining thromboembolic risk. (Echocardiography 2010;27:384‐393)     

Epitope mapping of neutralizing TSST-1 specific antibodies induced by immunization with toxin or toxoids

Toxic shock syndrome toxin-1 (TSST-1), a superantigen produced by Staphylococcus aureus, is a potent stimulator of the immune system. T-cells are activated by crosslinking of MHC class II molecules on antigen presenting cells with T-cell receptors (TCR). TSST-1 is associated with the majority of the cases of menstrual staphylococcal toxic shock, a severe and life-threatening multisystem disorder. Even though antibody mediated protection has been studied, information on antibody specificity directed to individual antigenic determinants of the protein is incomplete.To obtain immunogens with low toxicity, we generated a double-site mutant (dmTSST-1), modified at solvent-exposed residues predicted to be important for both MHC class II and TCR binding, and detoxified recombinantly expressed TSST-1 (rTSST-1) as well as native TSST-1 (nTSST-1) isolated from Staphylococcus aureus by treatment with formaldehyde. Rabbits were immunized with rTSST-1, nTSST-1, dmTSST-1, and formaldehyde inactivated toxoids. The sera obtained were used to map the antigen-reactive regions of the molecule and to identify specificities of antibodies induced by immunization with the different antigens. To detect linear antigenic epitopes of TSST-1 the reactivity of the sera with 11-meric peptides having an overhang of four residues, covering the entire molecule of TSST-1, have been studied. We found that sera of TSST-1 immunized rabbits predominantly reacted with N-terminal residues 1-15, while sera generated with formaldehyde inactivated toxoid recognized a total of 7 regions located at the N- and C-terminus and internal sites of TSST-1. Despite different specificities all sera were able to inhibit TSST-1 induced proliferation of human mononuclear cells.