Bacterial cellulose an effective material in the treatment of chronic venous ulcers of the lower limbs.

Chronic venous ulcers (CVU) of the lower limbs (LL) are common and cause psychological changes and significant social impact, as they make the patient susceptible to pain, absence from work and social bonds. Some materials are suggested as dressings for the treatment of CVU, but they are expensive and are generally not available for use in public health services. To evaluate the efficacy of the treatment for lower limbs (LL) chronic venous ulcer (CVU) using bacterial cellulose (BC), gel and multi-perforated film associated. A randomized controlled clinical-intervention study was performed among participants with LL CVU, divided into two groups: experimental (EG), treated with BC wound dressing and control (CG), treated with a cellulose acetate mesh impregnated with essential fatty acids (Rayon®). The participants were followed for 180 days, evaluated according to the MEASURE methodology. Thirty-nine patients were treated, 20 from the EG and 19 from the CG. In both groups, the wound area decreased significantly (p < 0.001), the healing rate was similar to the CG. The mean number of dressing changes in the SG was 18.33 ± 11.78, while in the CG it was 55.24 ± 25.81, p < 0.001. The healing dressing of bacterial cellulose, gel and associated film, when stimulating the epithelization of the lesions, showed a significant reduction in the initial area, with a percentage of cure similar to the Rayon® coverage. In addition to requiring less direct manipulation of ulcers.

Use of bacterial cellulose film for repair of bile duct injury in pigs.

BACKGROUND/OBJECTIVE: The aim was to evaluate the use of bacterial cellulose film and bile duct autograft in repairing critical common bile duct injury in pigs. METHODS: A prospective experimental analytical study was carried out on 20 Sus Domesticus, Piau suidae swine, divided into a control group (n = 10) and an experimental group (n = 10) divided into two subgroups: bacterial cellulose film E1 and bacterial cellulose film E2 to which bacterial cellulose film was randomly allocated. The control group underwent two complete critical common bile duct sections 10 mm apart, while the experimental group with a single critical common bile duct defect underwent a 10 mm section of the longitudinal shaft with edge resection. The defects in the control group were treated with end-to-end conventional anastomosis using polyglycolic 6-0 surgical thread and the experimental group with bacterial cellulose film by continuous suture using the same material. The animals were clinically evaluated throughout the experiment on days D150 (bacterial cellulose film E1), D225 (control group), and D330 (bacterial cellulose film E2) and by intraoperative ultrasound examination related to histopathological and biochemical findings. RESULTS: The intraoperative ultrasonography detected the changes resulting from the common bile duct anastomosis in the control group that produced a considerable incidence of ductal narrowing and obstruction to the biliary flow. In the bacterial cellulose film E2 group, there was an increase in inflammation intensity, granulomatous reaction, fibrosis, and vessels density, without producing bile duct dilation in the ultrasonography assessment. Biochemical analysis of liver enzymes yielded results in the normal range confirming preservation of liver function at the different post-surgery time points. CONCLUSION: Bacterial cellulose film, when used as a graft for bile duct repair, proved to be a biocompatible material that produced a complete healing process and biliary flow continuity.

A new approach for optimal morphological identification and immunolabeling of spermatogonial cells.

High quality fixation often inactivates epitopes and gentler fixation can fail to preserve biological structure at the required resolution. For studies of male reproduction, immunofluorescence techniques using paraformaldehyde fixation associated with paraffin as an embedding medium gives good epitope preservation, although the cell becomes morphologically compromised. On the other hand, glutaraldehyde associated with a plastic resin has been used with success to recognize and distinguish each spermatogonial cell subtype, but the antigenic sites become inaccessible to antibodies. Here we describe a new method that provides excellent morphological details of testicular cells while preserving the binding capacity of epitopes. Using a combination of glutaraldehyde and paraformaldehyde as a fixative and LR White resin for embedding, we show that it is possible to clearly recognize spermatogonial subtypes (Aund, A-A4, In and B spermatogonia) on 1-µm thick-sections and to label epitopes such as bromodeoxyuridine, a marker used for cellular cycle studies in the testis. The information gained from this procedure can be critical for understanding spermatogonial process of self-renewal and differentiation.

Spermatogonial behavior in rats during radiation-induced arrest and recovery after hormone suppression.

Ionizing radiation has been shown to arrest spermatogenesis despite the presence of surviving stem spermatogonia, by blocking their differentiation. This block is a result of damage to the somatic environment and is reversed when gonadotropins and testosterone are suppressed, but the mechanisms are still unknown. We examined spermatogonial differentiation and Sertoli cell factors that regulate spermatogonia after irradiation, during hormone suppression, and after hormone suppression combined with Leydig cell elimination with ethane dimethane sulfonate. These results showed that the numbers and cytoplasmic structure of Sertoli cells are unaffected by irradiation, only a few type A undifferentiated (Aund) spermatogonia and even fewer type A1 spermatogonia remained, and immunohistochemical analysis showed that Sertoli cells still produced KIT ligand (KITLG) and glial cell line-derived neurotrophic factor (GDNF). Some of these cells expressed KIT receptor, demonstrating that the failure of differentiation was not a result of the absence of the KIT system. Hormone suppression resulted in an increase in Aund spermatogonia within 3 days, a gradual increase in KIT-positive spermatogonia, and differentiation mainly to A3 spermatogonia after 2 weeks. KITL (KITLG) protein expression did not change after hormone suppression, indicating that it is not a factor in the stimulation. However, GDNF increased steadily after hormone suppression, which was unexpected since GDNF is supposed to promote stem spermatogonial self-renewal and not differentiation. We conclude that the primary cause of the block in spermatogonial development is not due to Sertoli cell factors such (KITL\GDNF) or the KIT receptor. As elimination of Leydig cells in addition to hormone suppression resulted in differentiation to the A3 stage within 1 week, Leydig cell factors were not necessary for spermatogonial differentiation.