Stem cell regenerative potential for plastic and reconstructive surgery

Stem cells represent heterogeneous population of undifferentiated cells with unique characteristics of long term self renewal and plasticity. Moreover, they are capable of active migration to diseased tissues, secretion of different bioactive molecules, and they have immunosuppressive potential as well. They occur in all tissues through life and are involved in process of embryogenesis and regeneration. During last decades stem cells attracted significant attention in each field of medicine, including plastic and reconstructive surgery. The main goal of the present review article is to present and discuss the potential of stem cells and to provide information about their safe utilization in chronic wounds and fistulae healing, scar management, breast reconstruction, as well as in bone, tendon and peripheral nerve regeneration.     

Multilevel examination of minor salivary gland biopsy for Sjögren's syndrome significantly improves diagnostic performance of AECG classification criteria

The recently observed low reproducibility of focus score (FS) assessment at different section depths in a series of single minor salivary gland biopsies highlighted the need for a standardized protocol of extensive histopathological examination of such biopsies in Sjögren's syndrome. For this purpose, a cumulative focus score (cFS) was evaluated on three slides cut at 200-μm intervals from each of a series of 120 salivary biopsies. The cFS was substituted for the baseline FS in the American–European Consensus Group (AECG) criteria set for Sjögren's syndrome classification, and then test specificity and sensitivity were assessed against clinical patient re-evaluation. Test performances of the AECG classification with the original FS and the score obtained after multilevel examination were statistically compared using receiver operating characteristic (ROC) curve analysis. The diagnostic performance of AECG classification significantly improved when the cFS was entered in the AECG classification; the improvement was mostly due to increased specificity in biopsies with a baseline FS ≥ 1 but <2. The assessment of a cFS obtained at three different section levels on minor salivary gland biopsies can be useful especially in biopsies with baseline FSs between 1 and 2.     

Eukaryotic initiation factors and protein synthesis after resistance exercise in rats.

Translational control of protein synthesis depends on numerous eukaryotic initiation factors (eIFs) and we have previously shown (Am. J. Physiol. Endocrinol. Metab. 276: E721-E727, 1999) that increases in one factor, eIF2B, are associated with increases in rates of protein synthesis after resistance exercise in rats. In the present study we investigated whether the eIF4E family of initiation factors is also involved with an anabolic response to exercise. Male Sprague-Dawley rats either remained sedentary (n = 6) or performed acute resistance exercise (n = 6), and rates of protein synthesis were assessed in vivo 16 h after the last session of resistance exercise. eIF4E complexed to eIF4G (eIF4E x eIF4G), eIF4E binding protein 1 (4E-BP1) complexed to eIF4E, and phosphorylation state of eIF4E and 4E-BP1 (gamma-form) were assessed in gastrocnemius. Rates of protein synthesis were higher in exercised rats compared with sedentary rats [205 +/- 8 (SE) vs. 164 +/- 5.5 nmol phenylalanine incorporated x g muscle(-1) x h(-1), respectively; P < 0.05]. Arterial plasma insulin concentrations were not different between the two groups. A trend (P = 0.09) for an increase in eIF4E x eIF4G with exercise was noted; however, no statistically significant differences were observed in any of the components of the eIF4E family in response to resistance exercise. These new data, along with our previous report on eIF2B, suggest that the regulation of peptide chain initiation after exercise is more dependent on eIF2B than on the eIF4E system.     

Effect of Foliar Applications of Carbofuran and a Related Compound on Plant-parasitic Nematodes under Microplot and Field Conditions

Studies were conducted to investigate the basipetal translocation of nematicidal activity from foliar treatments of carbofuran and its analog, 2,3-dihydro-2,2-dimethyl-7-benzofuranyl ([dibutylamino]thio)methyl carbamate, on corn in microplot studies and on tobacco and potato in field trials. Two and three foliar applications of either product at 2,400 μg/ml (9-20 Kg ai/Ha) significantly reduced populations of Pratylenchus penetrans in roots and populations of Tylenchorhynchus claytoni, Xiphinema americanum, and Hoplolaimus sp. in soil. In most cases there was no difference in control between two or three chemical applications. Foliar treatments with carbofuran were equivalent to, or better than, soil treatment, although rates of applications were different.     

Boning up on autophagy: The role of autophagy in skeletal biology

From an evolutionary perspective, the major function of bone is to provide stable sites for muscle attachment and affording protection of vital organs, especially the heart and lungs (ribs) and spinal cord (vertebrae and intervertebral discs). However, bone has a considerable number of other functions: serving as a store for mineral ions, providing a site for blood cell synthesis and participating in a complex system-wide endocrine system. Not surprisingly, bone and cartilage cell homeostasis is tightly controlled, as is the maintenance of tissue structure and mass. While a great deal of new information is accruing concerning skeletal cell homeostasis, one relatively new observation is that the cells of bone (osteoclasts osteoblasts and osteocytes) and cartilage (chondrocytes) exhibit autophagy. The focus of this review is to examine the significance of this process in terms of the functional demands of the skeleton in health and during growth and to provide evidence that dysregulation of the autophagic response is involved in the pathogenesis of diseases of bone (Paget disease of bone) and cartilage (osteoarthritis and the mucopolysaccharidoses). Delineation of molecular changes in the autophagic process is uncovering new approaches for the treatment of diseases that affect the axial and appendicular skeleton.     

New Passalora species on Peixotoa (Malpighiaceae) from the Brazilian Cerrado

Four new Passalora species were found on leaves of Cerrado native plants of the genus Peixotoa (Malpighiaceae). Two of the new Passalora species (P. peixotae-reticulatae and P. cerradensis) belong in Section Mycovellosiella, while P. peixotoae-goianae and P.brasilianensis belong in Section Phaeoramularia.     

Cercosporoid hyphomycetes on malpighiaceous hosts from the Brazilian Cerrado: species of Pseudocercospora on hosts belonging to Byrsonima

Eleven new species of the genus Pseudocercospora were found on Byrsonima spp. from the Cerrado in Brazil: Pseudocercospora annellidica, P. byrsonimae-basilobae, P. byrsonimae-coccolobifoliae, P. byrsonimicola, P. byrsonimigena, P. campograndensis, P. grajauensis, P. mutabiliconidiophorum, P. pediformiconidiorum, P. planaltinensis, and P. subhyalina. The new species are described, illustrated and compared with hitherto described Pseudocercospora spp. on various hosts belonging to the Malpighiaceae, and all species concerned are keyed out.     

Function and ribosomal localization of aIF6, a translational regulator shared by archaea and eukarya

The translation factor IF6 is shared by the Archaea and the Eukarya, but is not found in Bacteria. The properties of eukaryal IF6 (eIF6) have been extensively studied, but remain somewhat elusive. eIF6 behaves as a ribosome-anti-association factor and is involved in miRNA-mediated gene silencing; however, it also seems to participate in ribosome synthesis and export. Here we have determined the function and ribosomal localization of the archaeal (Sulfolobus solfataricus) IF6 homologue (aIF6). We find that aIF6 binds specifically to the 50S ribosomal subunits, hindering the formation of 70S ribosomes and strongly inhibiting translation. aIF6 is uniformly expressed along the cell cycle, but it is upregulated following both cold- and heat shock. The aIF6 ribosomal binding site lies in the middle of the 30-S interacting surface of the 50S subunit, including a number of critical RNA and protein determinants involved in subunit association. The data suggest that the IF6 protein evolved in the archaeal–eukaryal lineage to modulate translational efficiency under unfavourable environmental conditions, perhaps acquiring additional functions during eukaryotic evolution.     

Different Fecal Microbiotas and Volatile Organic Compounds in Treated and Untreated Children with Celiac Disease

This study aimed at investigating the fecal microbiotas of children with celiac disease (CD) before (U-CD) and after (T-CD) they were fed a gluten-free diet and of healthy children (HC). Brothers or sisters of T-CD were enrolled as HC. Each group consisted of seven children. PCR-denaturing gradient gel electrophoresis (DGGE) analysis with V3 universal primers revealed a unique profile for each fecal sample. PCR-DGGE analysis with group- or genus-specific 16S rRNA gene primers showed that the Lactobacillus community of U-CD changed significantly, while the diversity of the Lactobacillus community of T-CD was quite comparable to that of HC. Compared to HC, the ratio of cultivable lactic acid bacteria and Bifidobacterium to Bacteroides and enterobacteria was lower in T-CD and even lower in U-CD. The percentages of strains identified as lactobacilli differed as follows: HC (ca. 38%) > T-CD (ca. 17%) > U-CD (ca. 10%). Lactobacillus brevis, Lactobacillus rossiae, and Lactobacillus pentosus were identified only in fecal samples from T-CD and HC. Lactobacillus fermentum, Lactobacillus delbrueckii subsp. bulgaricus, and Lactobacillus gasseri were identified only in several fecal samples from HC. Compared to HC, the composition of Bifidobacterium species of T-CD varied, and it varied even more for U-CD. Forty-seven volatile organic compounds (VOCs) belonging to different chemical classes were identified using gas-chromatography mass spectrometry-solid-phase microextraction analysis. The median concentrations varied markedly for HC, T-CD, and U-CD. Overall, the r² values for VOC data for brothers and sisters were equal to or lower than those for unrelated HC and T-CD. This study shows the effect of CD pathology on the fecal microbiotas of children.The human gastrointestinal (GI) tract is a complex ecosystem containing up to 10¹⁴ total bacteria. These microorganisms belong to more than 500 different bacterial species, even though 99% of the total community consists of only 30 to 40 species. The GI microbiota plays a key role in health and disease (11, 23). The health effects are direct, due to a stable microbiota resistant to incoming potential pathogenic microbes, and/or indirect, due to cross talk with the gut-associated lymphoid tissue (1). The GI microbiota metabolizes nutrients and activates both innate and adaptive immunity (27). Specific strains of the GI microbiota and/or supplied probiotics decrease intestinal inflammation and normalize dysfunction of the GI mucosa (39). The GI microbiota is also involved in the pathogenesis of chronic inflammatory bowel diseases (IBD) and other immunity-related disorders (42). Overall, IBD patients have altered densities of mucosa-associated bacteria compared to healthy subjects. In particular, the numbers of protective Bifidobacterium and Lactobacillus cells are lower, while the numbers of harmful Bacteroides and Escherichia coli cells are higher (42). Recently, microbial infections and especially imbalances in the composition of the GI microbiota were associated with the presentation of celiac disease (CD) (3, 41).CD is an inflammatory disorder of the small intestine that affects genetically predisposed individuals when they ingest gluten from any Triticum species and similar proteins of barley and rye and their crossbred varieties. CD is associated with maldigestion and malabsorption of nutrients, vitamins, and minerals. Epidemiological studies in Europe and the United States have indicated that the incidence of CD is increasing and that CD affects approximately 1% of the general population (31). The pathogenesis of CD involves interactions between genetic, immunological, and environmental factors. HLA-DQ2/DQ8 molecules of antigen-presenting cells bind and present gluten peptides to the lamina propria of CD4⁺ T cells, triggering a T helper 1-based immune response, along with the synthesis of gamma interferon. Frequently, gamma interferon enhances the synthesis of tumor necrosis factor alpha and plays a crucial role in damaging the intestinal mucosa (3, 29). Events leading to CD also involve activation of the innate immunity mediated by interleukin-15 and are characterized by expansion of intraepithelial T-cell receptor γ/δ⁺ and CD8⁺ T-cell receptor α/β⁺ lymphocytes. These lymphocytes are cytotoxic and also contribute to tissue damage (10). Currently, the only treatment for CD consists of a life-long gluten-free diet. Complete removal of gluten from the diet of CD patients results in symptomatic, serological, and histological remission in the majority of cases (32). With strict dietary control, antibody levels may revert to normal levels within 6 to 12 months, while complete histological resolution may take up to 2 years (31). Nevertheless, in some pathological conditions, such as lactose malabsorption and refractory sprue, symptoms may persist. Such pathological conditions are also characterized by small intestine bacterial overgrowth (44).The role of bacteria during development and treatment of CD should be elucidated (29, 38). The inflammatory milieu caused by gluten antigens could lead to imbalances in the GI microbiota of CD patients. Compared to healthy individuals, CD patients seem to be characterized by higher numbers of gram-negative bacteria and lower numbers gram-positive bacteria (3). Overall, gram-negative bacteria could activate proinflammatory pathways, while gram-positive bacteria, such as lactic acid bacteria and bifidobacteria, could inhibit toxic effects induced by other GI species (26) or gluten antigens (5, 19).This study aimed at investigating the differences in the fecal microbiota between treated children with CD (T-CD), untreated children with CD (U-CD), and healthy children (HC). HC belonging to the same family unit as T-CD were enrolled to avoid interference due to genetic factors and dietary components. The fecal microbiota was characterized by using an integrate approach involving culture-independent and culture-dependent methods and analysis of the fecal volatile organic compounds (VOCs).