Augmentation cystoplasty using decellularized vermiform appendix in rabbit model

Purpose

The aim of this study was to produce a decellularized rabbit vermiform appendix (sacculus rotundus) and investigate its feasibility in bladder augmentation or appendicovesicostomy. The superiority of sacculus rotundus over other tissues is its unique mechanical properties as well as its abundant collagen content.

Materials and methods

The acellular matrix of vermiform appendix underwent different laboratory investigations prior to transplantation. We divided 12 rabbits into 3 groups: group I underwent bladder augmentation cystoplasty by detubularized acellular matrix. Group II underwent implantation of the tapered (tubularized) acellular matrix just beneath the seromuscular part of the bladder without connection to the bladder urothelium. Group III underwent the same procedure as group II plus reimplantation of tapered and tubularized acellular matrix (simulating an appendicovesicostomy). The distal end of the transplanted graft was connected to the bladder mucosal opening and was intubated by a 5 Fr double blind ended feeding tube catheter. Biopsies were taken 3, 12, and 36 months post-operatively for further histological and immunohistochemical analyses.

Results

The results of the examinations performed prior to transplantation, revealed a decellularized structure resembling the native tissue with intact extracellular matrix, normal pits and appropriate gaps that will be suitable for further cell seeding. Histopathology examination of the biopsies after transplantations confirmed successful cell seeding with urothelial lining in groups I and III, while the inner lumen in group II showed no urothelial lining.

Conclusion

The results suggest that we can prospect to perform bladder reconstruction by the application of this method without complications of previously reported augmentation cystoplasty. In the current study we used the bladder as a natural bioreactor for autologous recellularization which may pave the road for clinical application in acellular matrix augmentation cystoplasty.     

Electrospun acellular scaffolds for mimicking the natural anisotropy of the extracellular matrix

In tissue engineering, the use of scaffolds helps establish a synergistic relationship between the scaffolds and the tissues by improving cell–scaffold interaction. This interaction is enhanced when physiologically relevant biophysical cues are replicated in the artificial scaffolds. Here, we present a novel scaffold that mimics the natural anisotropy of the native extracellular matrix of tissues, fabricated by electrospinning a combination of three polymers: polycaprolactone (PCL), polyvinylidene fluoride (PVDF) and polyaniline (PANI). The scaffolds were characterized for their morphology, surface and mechanical properties. Rat cardiomyoblast (H9c2) cells, cultured on the PCL–PANI–PVDF scaffold, demonstrated cell alignment, penetration and proliferation across the entire surface area of the scaffold without any external chemical or physical stimuli. The PCL–PANI–PVDF scaffold, unlike other scaffolds, does not require post-processing or specific temperature conditions of storage, prior to use. These acellular scaffolds fabricated through polymer blending, open new avenues for research on functional acellular scaffolds for tissue engineering, based on synthetic materials.

Co-axial electrospinning of three immiscible polymers by sequentially blending in solvents of different boiling points to obtain biomimetic scaffolds.     

An approach to the design of a particulate system for oral protein delivery. I. In vitro stability of various poly (α-hydroxy acids)-microspheres in simulated gastrointestinal fluids

The stability of various biodegradable polyester polymers with different molecular weights and lactic/glycolic acids ratios were evaluated in simulated gastrointestinal fluids as an approach to apply microparticles for oral protein delivery on the basis of particle uptake mechanism. A common w/o/w emulsion solvent evaporation technique using dichloromethane for dissolving the polymer and polyvinyl alcohol as the stabilizer was used for encapsulation. Microspheres were incubated at 37°C in USP simulated fluids with a concentration of 20 mg mL^?1 and also in the literature, which suggested fed or fasted simulated intestinal fluids for different times up to 24 h, while shaking at 75 rpm. The stability assessment was done by detecting pH alterations of the media, enzymatic assay of L-lactic acid, performing differential scanning calorimetric studies and observing the size and morphology of particles. Results showed that the three polymers, namely Resomers® R207, RG756 and RG505, could be suitable for the preparation of protein-loaded microspheres.     

The impact of autologous platelet concentrates on endodontic healing: a systematic review

The current literature was reviewed to determine the impact of autologous platelet concentrates (APCs) on endodontic healing. All types of clinical study designs concerning any kind of endodontic treatment involving the application of APCs were included. Two independent reviewers searched three databases (PubMed, Embase, and Cochrane Library) for studies, complemented by hand search, until 16/1/2016. From the 423 identified records, 48 articles met the inclusion criteria. Selected randomized controlled clinical trials (RCTs) underwent Cochrane Collaboration’s risk-of-bias assessment and data extraction. Only two RCTs showed low risk of bias. There was considerable heterogeneity between the RCTs with regard to the type of therapy, type of APCs, assessment method, and study quality, and therefore the data could not be analyzed quantitatively. The included case reports/series and non-randomized comparative studies underwent qualitative analysis with the revised Methodological Index for Non-Randomized Studies (MINORS) and data extraction. The two comparative non-randomized studies scored qualitatively high, though the MINORS-scores of the case series and reports were dispersed. APCs were involved in five endodontic treatment modalities, namely apexification, regenerative endodontic procedures, pulpotomy, apical surgery, and treatment of endo-perio/perio-endo lesions. APCs seem to accelerate postoperative bone healing, augment the patients’ postoperative quality of life, aid further root development, and support maintenance/regaining of pulp vitality. No adverse events were reported. APCs in endodontic treatments seem to contribute to the healing of soft and hard tissues, though there is a lack of long-term high quality clinical trials and standardized treatment protocols.     

Efficacy and safety of oral silymarin in comparison with oral doxycycline and their combination therapy in the treatment of acne vulgaris

Two factors of oxidative stress and inflammatory processes are implicated in pathogenesis of acne vulgaris. Silymarin has antioxidant and anti‐inflammatory activities. This study was done to evaluate the effect of oral silymarin in the treatment of acne vulgaris compared to doxycycline and also their combination therapy. This randomized controlled trial was performed on 60 patients with acne vulgaris were divided into three groups of 20 patients, including: Silymarin (Group 1), Doxycycline (Group 2), and both compounds (Group 3). The patients' response was monitored every month and the lesions were evaluated using photography and two methods of Global Acne Grading system (GAGS) and Acne Severity Index (ASI). According to the results, the response to silymarin was not significantly different with doxycycline in the GAGS index (p = .260), but was lower in the ASI (p = .021). In this study, the synergistic effects of silymarin and doxycycline combination have been investigated in comparison with doxycycline. Although the improvement was more favorable in combination group, there was no statistically significant difference (p = .9 in ASI and p = .5 in GAGS). The results of our study suggest that although the silymarin monotherapy is not as effective as doxycycline for the treatment of acne vulgaris, it can be a therapeutic option.     

Halothane-induced hepatitis: A forgotten issue in developing countries: Halothane-induced hepatitis

Halothane was introduced as an anesthetic in the 1950s and was considered a revolutionary agent in the field of anesthesia. Soon after, halothane-induced hepatitis became a concern, leading to the development of less toxic gases that induced a lower incidence of side effects. Two types of halothane-related hepatotoxicity have been described: type 1, or mild hepatitis, is associated with elevated transaminase levels and self-limiting symptoms, and type 2, or severe hepatotoxicity, is associated with acute fatal liver failure and is fatal in most cases. Hepatotoxicity is most likely to be immune-related, based on much evidence. Free radicals that are produced by the metabolism of halothane in the liver can modify cellular proteins and introduce neo-antigens to the immune system. Sensitization to these neo-antigens induces a more severe response after multiple exposures; most cases of type 2 hepatitis occur after repeated contact. New halogenated anesthetics such as enflurane, sevoflurane, and desflurane, are not metabolized in the liver, causing few cases of sensitization. Compared with halothane, these anesthetics are expensive. As a result, replacement of halothane with new halogenated anesthetics requires a precise cost-benefit analysis, especially in developing countries that have low health care budgets.     

Prevalence of hepatitis C virus infection and its related risk factors in drug abuser prisoners in Hamedan--Iran

AIM: Recent studies in Iran has shown that prevalence of hepatitis C virus (HCV) infection among Iranian prisoners is high, in spite of low HCV seroprevalence in general population. METHODS: This study was carried out in the central prison of Hamedan - Iran, in year 2002. Inmates were interviewed using a standard questionnaire including demographic, imprisonment history and HCV-related risk behaviors items. Thereafter, the sera drawn from the participants were tested for anti-HIV and anti-HCV antibodies. RESULTS: A total number of 427 drug abuser inmates participated in our study. Three hundred and ninety-seven (93%) were men and 30 (7%) were women. Total number of IV drug abusers (IDA) and non-IV drug abusers (NIDA) was 149 (34.9%) and 278 (65.1%), respectively. The overall rate of antibody positivity among inmates was 0.9% for HIV and 30% for HCV. Of all IDAs, 31.5% and of NIDAs, 29.1% had serological evidence of HCV infection. CONCLUSION: The seroprevalence of HCV infection among drug abuser prisoners in comparison with the general population in Iran, is very high (30% vs in italics 0.2%). Our results indicate the importance of policies to prevent transmission of HCV infection during and following incarceration.