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Gelatinous Matrix (gelatinous + matrix)
Selected AbstractsThe association between non-biting midges and Vibrio choleraeENVIRONMENTAL MICROBIOLOGY, Issue 12 2008Meir Broza Summary Vibrio cholerae is a natural inhabitant of aquatic ecosystems, yet its interactions within this habitat are poorly understood. Here we describe the current knowledge on the interaction of V. cholerae with one group of co-inhabitants, the chironomids. Chironomids, non-biting midges (Chironomidae, Diptera), are an abundant macroinvertebrate group encountered in freshwater aquatic habitats. As holometabolous insects, chironomids start life when their larvae hatch from eggs laid at the water/air interface; through various feeding strategies, the larvae grow and pupate to become short-lived, non-feeding, adult flying insects. The discovery of the connection between V. cholerae and chironomids was accidental. While working with Chironomus transavaalensis, we observed the disintegration of its egg masses and searched for a possible microbial agent. We identified V. cholerae as the primary cause of this phenomenon. Haemagglutinin/protease, a secreted extracellular enzyme, degraded the gelatinous matrix surrounding the eggs, enabling bacterial growth. Observation of chironomids in relation to V. cholerae continuously for 7 years in various types of water bodies in Israel, India, and Africa revealed that environmental V. cholerae adhere to egg-mass surfaces of various Chironomini (,bloodworms'). The flying adults' potential to serve as mechanical vectors of V. cholerae from one water body to another was established. This, in turn, suggested that these insects play a role in the ecology of V. cholerae and possibly take part in the dissemination of the pathogenic serogroups during, and especially between, epidemics. [source] Faster and stronger vascular "Biotube" graft fabrication in vivo using a novel nicotine-containing moldJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2009Osamu Sakai Abstract To accelerate the fabrication of in vivo -tissue engineered autologous vascular prosthetic tissues, the "Biotube," a novel drug-coating mold was designed. The mold was prepared by impregnating nicotine as a model drug into a gelatinous matrix coated on acrylate rods (diameter, 2 mm; length, 20 mm). Upon embedding the molds into dorsal subcutaneous pouches of rats, completely encapsulated Biotubes with significant tissue migration accompanied by rich angiogenesis and having 3.8 times as many neovessels as the uncoated controls, were formed at only 2 weeks. The wall thickness and burst strength of the Biotubes were 399.9 ± 135.2 ,m and 2682.6 ± 722.6 mmHg, respectively. These values were, respectively, more than 9.6 and 3.2 times greater than the corresponding controls. Therefore, it is confidently expected that the mechanical properties of Biotubes obtained by nicotine coating make them suitable for application as vascular grafts. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009 [source] The ovarian morphology of Scorpaena notata shows a specialized mode of oviparityJOURNAL OF FISH BIOLOGY, Issue 4 2002M. Muñoz Scorpaena notata is an oviparous species with external fertilization that deposits its eggs in a gelatinous matrix. The internal epithelium of the ovarian wall is chiefly responsible for the production of this matrix, which is particularly abundant and viscous during the spawning period. The oocytes lack lipid droplets, so flotation and transport of the eggs is probably accomplished by means of the matrix that surrounds them. The ovarian stroma is situated along the centre of the gonad and the developing oocytes are connected to it by peduncles. The paucity and small size of the cortical alveoli of the oocytes are notable, as is the thinness of the zona radiata. These are characteristics that would be typical of viviparous species. The histological and ultrastructural observations lead to the conclusion that this species presents a type of oviparity more highly specialized than that of the majority of teleosts. [source] New records of Peyssonnelia armorica and Peyssonnelia harveyana (Rhodophyta, Gigartinales) from JapanPHYCOLOGICAL RESEARCH, Issue 4 2005Aki Kato SUMMARY Two species of the crustose red algal genus Peyssonnelia (Gigartinales, Peyssonneliaceae) are reported from Japanese waters for the first time. These species share the following combination of vegetative and reproductive features: thalli with appressed margins, perithallial filaments arising from the whole upper surface of each hypothallial cell (the Peyssonnelia rubra -type anatomy), unicellular rhizoids, hypobasal calcification and spermatangia that are produced in double chains (the Peyssonnelia harveyana -type spermatangial filament). However, they differ obviously from each other in the hypothallus orientation as seen from below, the perithallus structure in relation to the consistency of the crust, the origin of gonimoblasts and the elevation of the nemathecia. Peyssonnelia armorica is characterized by: (i) hypothallial filaments comprising a polyflabellate layer; (ii) easily separable perithallial filaments in a gelatinous matrix; (iii) gonimoblasts originating exclusively from the auxiliary cell; and (iv) semi-immersed (slightly elevated) nemathecia. Peyssonnelia harveyana is characterized by: (i) hypothallial filaments arranged in parallel rows; (ii) closely packed perithallial filaments in a firm matrix; (iii) gonimoblsts originating from both the auxiliary cell and the connecting filament; and (iv) conspicuously elevated nemathecia. [source] | ||||||||||