The art of strain improvement of industrial lactic acid bacteria without the use of recombinant DNA technology

The food industry is constantly striving to develop new products to fulfil the ever changing demands of consumers and the strict requirements of regulatory agencies. For foods based on microbial fermentation, this pushes the boundaries of microbial performance and requires the constant development of new starter cultures with novel properties. Since the use of ingredients in the food industry is tightly regulated and under close scrutiny by consumers, the use of recombinant DNA technology to improve microbial performance is currently not an option. As a result, the focus for improving strains for microbial fermentation is on classical strain improvement methods. Here we review the use of these techniques to improve the functionality of lactic acid bacteria starter cultures for application in industrial-scale food production. Methods will be described for improving the bacteriophage resistance of specific strains, improving their texture forming ability, increasing their tolerance to stress and modulating both the amount and identity of acids produced during fermentation. In addition, approaches to eliminating undesirable properties will be described. Techniques include random mutagenesis, directed evolution and dominant selection schemes.     

Antioxidant effect of carnosine treatment on renal oxidative stress in streptozotocin-induced diabetic rats

Nitric oxide (NO) plays a significant role in the development of diabetic nephropathy. We investigated the effects of an antioxidant, carnosine, on streptozotocin (STZ)-induced renal injury in diabetic rats. We used four groups of eight rats: group 1, control; group 2, carnosine treated; group 3, untreated diabetic; group 4, carnosine treated diabetic. Kidneys were removed and processed, and sections were stained with periodic acid-Schiff (PAS) and subjected to eNOS immunohistochemistry. Examination by light microscopy revealed degenerated glomeruli, thickened basement membrane and glycogen accumulation in the tubules of diabetic kidneys. Carnosine treatment prevented the renal morphological damage caused by diabetes. Moreover, administration of carnosine decreased somewhat the oxidative damage of diabetic nephropathy. Appropriate doses of carnosine might be a useful therapeutic option to reduce oxidative stress and associated renal injury in diabetes mellitus.     

Development of cell surface saccharides on embryonic pancreatic cells

Using a battery of seven lectin-ferritin conjugates as probes for cell surface glycoconjugates, we have studied the pattern of plasmalemmal differentiation of cells in the embryonic rat pancreas from day 15 in utero to the early postpartum stage. Our results indicate that differentiation of plasmalemmal glycoconjugates on acinar, endocrine, and centroacinar cells is temporally correlated with development and is unique for each cell type, as indicated by lectin-ferritin binding. Specifically, (a) expression of adult cell surface saccharide phenotype can be detected on presumptive acinar cells as early as 15 d in utero, as indicated by soybean agglutinin binding, and precedes development of intracellular organelles characteristic of mature acinar cells; (b) maturation of the plasmalemma of acinar cells is reached after intracellular cytodifferentiation is completed, as indicated by appearance of Con A and fucoselectin binding sites only at day 19 of development; conversely, maturation of the endocrine cell plasmalemma is accompanied by "loss" (masking) of ricinus communis II agglutinin receptors; and (c) binding sites for fucose lectins and for soybean agglutinin are absent on endocrine and centroacinar cells at all stages examined. We conclude that acinar, centroacinar, and endocrine cells develop from a common progenitor cell(s) whose plasmalemmal carbohydrate composition resembles most closely that of the adult centroacinar cell. Finally, appearance of acinar lumina beginning at approximately 17 d in utero is accompanied by differenetiation of apical and basolateral plasmalemmal domains of epithelial cells, as indicated by enhanced binding of several lectin-ferritin conjugates to the apical plasmalemmal, a pattern that persists from this stage through adult life.     

B30.2-like domain proteins: update and new insights into a rapidly expanding family of proteins

The B30.2 domain is a conserved region of around 170 amino acids associated with several different protein domains, including the immunoglobulin folds of butyrophilin and the RING finger domain of ret finger protein. We recently reported several novel members of this family as well as previously undescribed protein families possessing the B30.2 domain. Many proteins have subsequently been found to possess this domain, including pyrin/marenostrin and the midline 1 (MID1) protein. Mutations in the B30.2 domain of pyrin/marenostrin are implicated in familial Mediterranean fever, and partial loss of the B30.2 domain of MID1 is responsible for Opitz G/BBB syndrome, characterized by developmental midline defects. In this study, we scrutinized the available sequence data bases for the identification of novel B30.2 domain proteins using highly sensitive database-searching tools. In addition, we discuss the chromosomal localization of genes in the B30.2 family, since the encoded proteins are likely to be involved in other forms of periodic fever, autoimmune, and genetic diseases.      

Placentation in dolphins from the Amazon River Basin: the Boto, Inia geoffrensis, and the Tucuxi, Sotalia fluviatilis

A recent reassessment of the phylogenetic affinities of cetaceans makes it timely to compare their placentation with that of the artiodactyls. We studied the placentae of two sympatric species of dolphin from the Amazon River Basin, representing two distinct families. The umbilical cord branched to supply a bilobed allantoic sac. Small blood vessels and smooth muscle bundles were found within the stroma of the cord. Foci of squamous metaplasia occurred in the allanto-amnion and allantochorion. The interhemal membrane of the placenta was of the epitheliochorial type. Two different types of trophoblastic epithelium were seen. Most was of the simple columnar type and indented by fetal capillaries. However, there were also areolar regions with tall columnar trophoblast and these were more sparsely supplied with capillaries. The endometrium was well vascularised and richly supplied with actively secreting glands. These findings are consistent with the current view that Cetacea are nested within Artiodactyla as sister group to the hippopotamids.     

细胞周期与细胞凋亡

从海洋生物胚胎细胞到哺乳动物的细胞周期,主要是在其细胞周期基因产物周期素及Ｐ３４的调控下启动,运行和脱出周期的;某些原癌基因或抑癌基因的产物如ｐ５３,ｐＲＢ也直接调控着细胞周期。     

Granuloma Due to Oxidized Regenerated Cellulose in an Aged Rhesus Macaque (Macaca mulatta)

Bioabsorbable hemostatic agents such as oxidized regenerated cellulose are widely used to control intraoperative diffuse capillary bleeding. Compared with electrocautery or ligation, oxidized regenerated cellulose has the advantage of controlling bleeding without occluding the vessel lumen or causing thermal injuries to adjacent tissue. Although the manufacturer recommends removal of the material once hemostasis is achieved, oxidized regenerated cellulose is a bioabsorbable hemostatic agent and is often left in the surgical bed to prevent subsequent bleeding after surgical closure. However, noninvasive imaging techniques have revealed granulomatous foreign-body reactions that mimic infection or tumor recurrence. We present a case report of sterile peritonitis and granuloma formation secondary to the presence of oxidized regenerated cellulose after intestinal resection to excise a colonic adenocarcinoma in an aged rhesus macaque.Bioabsorbable hemostatic agents such as oxidized regenerated cellulose (for example, Surgicel) are widely used to control intraoperative diffuse capillary bleeding. Compared with electrocautery or ligation, oxidized regenerated cellulose has the advantage of controlling bleeding without occluding the vessel lumen or causing thermal injuries to adjacent tissue.¹⁶Oxidized regenerated cellulose is formed by dissolving the α-cellulose of decomposed wood pulp in an alkaline solution and subsequently regenerating it as a continuous fiber. This fiber is then woven into a gauze and oxidized.^17,22 Oxidized regenerated cellulose is supplied as a substrate that is flexible, malleable, and trimable.¹⁶The mechanism of hemostasis of oxidized regenerated cellulose is reportedly associated with its caustic activity.² The oxidation of cellulose produces a low-pH organic acid that reacts with blood, thus forming an artificial clot and causing platelet aggregation.¹⁸Although the manufacturer recommends the removal of oxidized regenerated cellulose once hemostasis is achieved,⁸ the product, a bioabsorbable hemostatic agent, is often left in situ within the surgical bed to prevent bleeding after surgical procedures. The biodegradation and elimination of oxidized regenerated cellulose from the tissue occurs in 2 phases.¹⁴ Polyanhydroglucuronic acid, the major functional unit of oxidized regenerated cellulose, is readily soluble. This acid is degraded extracellulary and systematically cleared from the system approximately 18 h after implantation.^13,14 The remaining fibrous residue, however, requires macrophage phagocytosis for clearance and can be observed within macrophages for at least 48 h after implantation.¹³ Unfortunately, these fibrous residues have a prolonged degradation, and their persistence for as long as 7 mo after surgery has been confirmed histologically.⁷Despite the biocompatibility of oxidized regenerated cellulose, granulomatous foreign-body reactions that imitate infection or tumor recurrence have been revealed by using noninvasive imaging techniques.^{1,11,12,15,17,18,22} Here we describe a case of peritonitis and granuloma formation secondary to the presence of oxidized regenerated cellulose after an intestinal resection to excise a colonic adenocarcinoma in an aged rhesus macaque.     

Transitional cell carcinoma of the ovary: A rare case and review of literature

Goblet cell carcinoid of the large intestine is a rare neoplasm, usually located in ascending colon and rectum. A 60-year-old male patient underwent surgery after the diagnosis of acute abdomen. Exploratory laparotomy revealed perforation with a diameter of 1 cm at the site of the previously performed gastroenterostomy and dilatation of the right colic flexure, secondary to a solid obstructive mass located in the mid-portion of transverse colon. Histopathological investigation of the biopsies, taken from the gastroenterostomy site and the tumor, revealed mixed carcinoid-adenocarcinoma with carcinoid component, predominantly composed of goblet cells. Three cycles of FOLFOX-4 protocol was administered. Following respiratory distress secondary to pulmonary metastasis, the patient's condition deteriorated and subsequently died in the fourth postoperative month. Our aim with this paper is to point out that more cases should be reported for more effective diagnosis, histopathological study, clinical investigation, treatment and prognosis of this specific neoplasm.