Oxidative toxicity in diabetes and Alzheimer’s disease: mechanisms behind ROS/ RNS generation

Reactive oxidative species (ROS) toxicity remains an undisputed cause and link between Alzheimer’s disease (AD) and Type-2 Diabetes Mellitus (T2DM). Patients with both AD and T2DM have damaged, oxidized DNA, RNA, protein and lipid products that can be used as possible disease progression markers. Although the oxidative stress has been anticipated as a main cause in promoting both AD and T2DM, multiple pathways could be involved in ROS production. The focus of this review is to summarize the mechanisms involved in ROS production and their possible association with AD and T2DM pathogenesis and progression. We have also highlighted the role of current treatments that can be linked with reduced oxidative stress and damage in AD and T2DM.     

Role of cell-mediated immunity in the resistance to experimental sporotrichosis in mice

The in vitro activity of several new imidazoles, cloconazole, sulconazole, butoconazole, isoconazole and fenticonazole, were compared with those of amphothericin B, flucytosine, and three azoles: econazole, miconazole and ketoconazole against isolates of pathogenic Candida. A total of 186 clinical isolates of 10 species of the genus Candida and two culture collection strains were tested by an agar-dilution technique. Isoconazole was the most active azole, followed by butoconazole and sulconazole. Differences between some of the species in their susceptibility to the antifungal agents were noted. Sulconazole and cloconazole had the highest activity in vitro against 106 isolates of C. albicans. Butoconazole and isoconazole were also very active against isolates of C. albicans, and were the most active azole compounds against 80 isolates of Candida spp.     

DETERMINATION OF GUSTATORY SUCROSE THRESHOLD IN WATER BY USE OF A LINEAR SUCROSE GRADIENT

A novel experimental method was developed which allows the determination of the threshold concentration of sucrose by use of a linear sucrose gradient in water. With this method a continuous tasting of the test-liquid is possible. A panel of 15 persons experienced in taste-testing was used. Three gradients of different steepness were applied: 0 to 1.5% (w/w) sucrose in 2 min (I), 3 min (II) and 4 min (III). The results of the new method were compared with those of the standard method (DIN). With gradients I and II we found values which were significantly higher than those of the standard method (I: 0.49% (w/w); II: 0.46% (w/w); DIN: 0.31% (w/w)), whereas with gradient III the same threshold value was found as with the DIN-Method (III: 0.32% (w/w)).     

Development of in vitro matured and fertilized bovine oocytes co-cultured with Buffalo Rat Liver cells

This study was designed to evaluate the efficacy of Buffalo Rat Liver cells (BRLC) monolayers in supporting the development of in vitro matured and fertilized (IVM/IVF) bovine oocytes through to the hatched blastocyst stage compared to the commonly used co-culture system of bovine oviduct epithelial cells (BOEC). Cumulus oocyte complexes (COCs) obtained from 2- to 6-mm ovarian follicles at slaughter were matured for 24 h in TCM-199 supplemented with FBS and hormones (FSH, LH and estradiol 17-beta). In vitro fertilization (IVF) was performed using 1 x 10(6) percoll separated frozen-thawed spermatozoa in 1 ml of IVF-TL medium containing 18 to 20 matured oocytes. After 20 to 22 h of sperm exposure, 584 presumptive zygotes in 2 separate trials were randomly assigned to 3 treatment groups (BRLC co-culture, BOEC co-culture and control, consisting of medium alone). Zygotes were cultured in CZB media, a simple semi-defined medium, without glucose for the first 2 d, transferred to M199/FBS (TCM-199-HEPES supplemented with 20% HTFBS, 1 mM Sodium pyruvate), and cultured for an additional 8 days. Cleavage and development to morula and various blastocyst stages were recorded between d 3 and 11 after the start of IVF. Overall average cleavage rate was 75% (440 584 ) and did not vary across the treatments or trials. The proportion of embryos that reached the morula stage in both co-culture systems did not differ (P > 0.05) and was significantly higher (P > 0.05) compared to the control group. However, the percentage of the number of blastocysts, expanded blastocysts and hatched blastocysts varied across the treatment groups (P < 0.05), with the highest results obtained in the BRLC co-culture system. The production of blastocysts in BOEC co-culture was inconsistent between the 2 trials where a significant difference (40.6 vs 53.0%; P > 0.05) was observed. Rate of development to the blastocyst stage was similar between the 2 co-culture systems, with most of the embryos reaching the blastocyst stage by d 8 post insemination. The results of this study show that BRLC from a commercially available established cell line offer a more reliable alternative to a BOEC co-culture system for in vitro maturation, fertilization and culture of bovine embryos.     

Development of IVM-IVF produced 8-cell bovine embryos in simple,serum-free media after conditioning or Co-culture with buffalo rat liver cells

Development of 8-cell bovine embryos derived from in vitro matured/in vitro fertilized (IVM/IVF) oocytes was evaluated in two simple, serum-free media (CZB and SOM) with buffalo rat liver cells co-culture (BRLC) or after conditioning compared to a commonly used, serum-supplemented complex medium TCM-199. In a 3 x 4 factorial design, 578 eight-cell embryos were randomly assigned to 12 treatment groups. The factors were: first, type of culture medium (M199/FBS, CZBg and SOM), and second, the use of BRLC (as co-culture or to condition media for 24 hr and 48 hr) and unconditioned media. Development to morula was not affected by the type of medium, but co-culture and 48 hr conditioning within media type resulted in better development when compared to the 24-hr conditioned or unconditioned groups. Blastocyst development in SOM (38.9%) was different (P < 0.05) than in CZBg (46.6%) and M199/FBS (48.7%) and was lowest in the unconditioned group (27.8%) followed by 24 hr conditioned (33.3%), 48 hr (56.3%), and co-culture (59.6%). No blastocyst expansion was observed with unconditioned media and 24 hr conditioned SOM. Significant differences (P < 0.05) were found among all treatment groups except the co-culture and 48-hr conditioned groups. Hatching occurred only with co-culture and 48-hr conditioned groups of M199/FBS and CZBg media. These data show that CZB with glucose conditioned by BRLC monolayers for 48 hr can support the development of IVM/IVF produced bovine embryos to blastocyst compared to culture in TCM-199 with serum. © 1994 Wiley-Liss, Inc.     

应用气-质联用仪测定三种螺旋藻中的甾醇成分

应用GLC/MS联用仪对室内培养的钝顶螺旋藻(Spirulina platensis (Nordstedt) Geitler)、极大螺旋藻(S.maxima (Stechell & Gardiner) Geitler)和盐泽螺旋藻(S.subsalsa Oerst)的甾醇成分进行了测定。从钝顶螺旋藻和盐泽螺旋藻中共分出11个相同的甾醇组分:胆甾醇、胆甾烷醇、芸苔甾醇、麦角甾醇、海绵甾醇、菜子甾醇、豆甾醇、24-乙基-Δ~(5,7,22)-胆甾醇、β-谷甾醇、异岩藻甾醇和4α,23,24-三甲基Δ~(5,22)-胆甾醇;从极大螺旋藻中只分离出8个甾醇组分。其中胆甾醇含量最高。4α,23,24-三甲基-Δ~(5,22)-胆甾醇为蓝藻中首次报导。     

Cytoplasmic filaments and cellular wound healing in amoeba proteus

The flexibility and self-healing properties of animal cell surface membranes are well known. These properties have been best exploited in various micrurgical studies on living cells (2, 3), especially in amoebae (7, 20). During nuclear transplantation in amoebae, the hole in the membrane through which a nucleus passes can have a diameter of 20-30 μm, and yet such holes are quickly sealed, although some cytoplasm usually escapes during the transfer. While enucleating amoebae in previous studies, we found that if a very small portion of a nucleus was pushed through the membrane and exposed to the external medium, the amoeba expelled such a nucleus on its own accord. When this happened, a new membrane appeared to form around the embedded portion of the nucleus and no visible loss of cytoplasm occurred during nuclear extrusion. In the present study, we examined amoebae that were at different stages of expelling partially exposed nuclei, to follow the sequence of events during the apparent new membrane formation. Unexpectedly, we found that a new membrane is not formed around the nucleus from inside but a hole is sealed primarily by a constriction of the existing membrane, and that cytoplasmic filaments are responsible for the prevention of the loss of cytoplasm.     

Effects of prolonged poisoning by Russell's viper venom on blood coagulation, platelets and fibrinolysis

The effects of Russell's viper venom on blood coagulation, platelets and the fibrinolytic enzyme system were studied in rabbits after injecting repeated doses of 0.05 MLD of the venom. Thrombocytopenia was the earliest change to appear. It was followed by rise in serum fibrinogen degradation products and prolongation of prothrombin time, activated partial thromboplastin time and thrombin time indicating a progressive consumption coagulopathy and activation of fibrinolysis. Red blood cell morphology was unchanged during the first three weeks; whereas the fragmentation appeared after the fourth week and it increased in severity with further envenomations, i.e. when chronic DIC was established.