Low susceptibility of stress ulcer in diabetic rats: role of cholinergic gastric motility

There is no reference to the cell wall formation during the regeneration process in dermatophyte. Having succeeded in identifying the cell wall formation system of protoplast from Trichophyton mentagrophytes I introduce here the dynamics of the regeneration of this protoplast and the formation of cell wall using ultrahigh resolution low-voltage scanning electron microscopy and transmission electron microscopy (TEM), compare to the formation of yeast cell wall. Protoplasts were formed from mycelia of T. mentagrophytes; they regenerated the cell wall substances and were followed by a network of fibrils after 4-6 hr, which developed into mature mycelia after 21 hr. A network of twisted microfibrils and rope-shaped thick fiber was seen; it was covered with a sheath-shaped structure and was created on the surface of the developing mycelium. Intrafibrillar space and the surface of thick fibers were gradually filled with amorphous particles and a mature cell wall surface was formed. This protoplast regeneration was completely inhibited by the antifungal agent, lanoconazole (2 ng/ml ). The sectioned TEM image revealed that normal mycelium having a thin cell wall developed from the abortive bead-shaped mycelium which was visible in the lose fibrous structure. Based on this result and our previos work on the ultrastructure of the mycelial surface of T. rubrum with lanoconazole, a model of the cell wall composition of Trichophyton is proposed.     

Helminths of six species of Anolis lizards (Polychrotidae) from Hispaniola, West Indies

The gastrointestinal tracts of gekkonid lizards from Guam (Gehyra mutilata [n = 4], Gehyra oceanica [n = 11], Hemidactylus frenatus [n = 43], and Lepidodactylus lugubris [n = 38]) and Rota (Gehyra oceanica [n = 2], Hemidactylus frenatus [n = 13], and Lepidodactylus lugubris [N = 20] were examined for helminths. Found were 2 species of cestodes, Cylindrotaenia allisonae, Oochoristica javaensis, 1 species of trematode, Allopharynx macallisteri, and 5 species of nematodes, Pharyngodon lepidodactylus, Spauligodon gehyrae, Spauligodon hemidactylus, Skrjabinelazia machidai, Oswaldocruzia sp. New host records included Gehyra mutilata for Spauligodon hemidactylus, Gehyra oceanica for Oochoristica javaensis, Hemidactylus frenatus for Skrjabinelazia machidai, and Lepidodactylus lugubris for Cylindrotaenia allisonae and Oswaldocruzia sp. These helminths are known only from Pacific Islands and the Australian biogeographic realm.     

Apoptosis and ageing

Stimulation of T cells from aged individuals leads to different kinds and/or size of responses if compared with the responses of T cells obtained from young individuals. In fact elderly is associated with a progressive decline of immune response besides an increasing incidence of autoimmune phenomena. These differences might be the result of modified cellular mechanisms controlling the immune system in the course of ageing. The apoptotic deletion of activated T cells has been proposed as the key mechanism to maintain T cell homeostasis, and in this respect CD95 (Fas antigen) seems to play a major role in this course of events. In this study we show that just collected lymphocytes from old subjects displayed an increased expression of the apoptosis molecule CD95. The expression of CD95 and the spontaneous apoptosis showed the same trend. In fact the percentage of apoptotic cells in blood collected from old subjects was enhanced too. The lymphocyte subpopulation analysis by flow cytometry did not show significant changes in T subset percentages between old and young subjects. Moreover mononuclear cells obtained from aged individuals underwent apoptosis in culture in response to a single stimulation with mitogen or anti-CD3, more than mononuclear cells from young controls. To gain insight into mechanisms of this increased apoptosis, experiments were performed to evaluate the behaviors of lymphocytes from old and young donors in respect of interleukin-2 (IL-2) rescue from apoptosis. Results show that IL-2 rescued only a little fraction of cells of old donors from apoptosis when activated by anti-CD3 and that this effect was not related to a different expression of CD95. Thus, during the course of ageing the different regulation of T cell homeostasis might be also explained by the modified proneness of lymphocytes to undergo apoptosis. The contemporaneous demonstration of a reduced Ca2+ influx in lymphoid cells of these subjects allows to suppose that multiple defects play a role in the pathogenesis of immunosenescence.     

Maxillary sinus augmentation using different grafting materials and dental implants in monkeys. Part I. Evaluation of anorganic bovine-derived bone matrix

The aim of this study was to evaluate clinically, histologically and histometrically the use of anorganic bovine bone matrix (i.e. Bio-oss) as a grafting material for maxillary sinus augmentation procedures. In 4 adult male rhesus monkeys (i.e. Macaca mulatta) the 1st, 2nd and 3rd maxillary molars on one side of the jaws were extracted. The remaining bone between the alveolar crest and the bottom of the sinus was then reduced to 3-4 mm. After 3 months, maxillary sinus augmentation procedures were performed on one side of the jaws in each monkey and the sinuses were grafted with the bovine bone matrix. At that time, 2 IMZ pure titanium plasma coated implants were immediately placed into the augmented sinuses (i.e. simultaneous implants-loaded group). After 4 months, 2 additional similar implants were placed into these previously augmented sinuses (i.e. delayed implants-loaded group). Four months later, the abutment connection was performed and all 4 implants were loaded with a gold-alloy bridge for 6 months (i.e. until sacrifice of the animals). The contralateral side of each monkey received the same treatment with the exception that the extractions were performed 7 months after those in the opposite side and that the implants in this side were not loaded. Thus, 2 additional study groups (i.e. simultaneous implants-unloaded group and delayed implants-unloaded group) were obtained. Clinically, all loaded implants were stable at the day of sacrifice. Histologically, the grafted sinuses exhibited significant bone formation with integration of the bovine bone matrix particles to the new bone. Direct mineralized bone-to-implant contact was greater for the delayed implant placement groups than for the implants installed simultaneously with the sinus augmentation. Furthermore, the percentage of direct mineralized bone-to-implant contact was greater in the residual bone than in the augmented area. It was concluded that the anorganic bovine bone matrix facilitated bone formation and implant osseointegration in the augmented sinuses and that the delayed implant placement in combination with the sinus augmentation procedure seemed to be preferable.     

Computational and numerical methods for bioelectric field problems

Fundamental problems in electrophysiology can be studied by computationally modeling and simulating the associated microscopic and macroscopic bioelectric fields. To study such fields computationally, researchers have developed a variety of numerical and computational techniques. Advances in computer architectures have allowed researchers to model increasingly complex biophysical systems. Modeling such systems requires a researcher to apply a wide variety of computational and numerical methods to describe the underlying physics and physiology of the associated three-dimensional geometries. Issues naturally arise as to the accuracy and efficiency of such methods. In this paper we review computational and numerical methods of solving bioelectric field problems. The motivating applications represent a class of bioelectric field problems that arise in electrocardiography and electroencephalography.