Importance of some factors on the dimorphism of Candida albicans

The passage between the yeast and mycelial forms of Candida albicans B 311-10 was studied by using the minimal syntehtic medium of Shepherd et al. [19] modified without biotin and with low glucose concentrations. It was observed that biotin, aminoacids and particularly pH are not important factors in the dimorphism of C. albicans. The only factor of notable importance in the passage of yeast form to mycelial form in C. albicans was glucose concentration.     

Ribonucleic acid transfer from nucleus to cytoplasm during interphase and mitosis in mouse somatic cells cultured in vitro

Summary Kidney cells from primary cultures of 15-day old mouse embryos were incubated for 2, 5 or 10 min with H³-uridine, then either fixed immediately or incubated again for various periods in a chase medium containing an excess of unlabeled uridine and cytidine. The number of grains over the non-nucleolar part of the nucleus (chromatin), the nucleolus and the cytoplasm were counted on the autoradiograms.The grain count showed that both chromatin and nucleolus incorporate very rapidly H³-uridine from the medium, whereas a time lag elapses before any H³-radioactivity above background is detected in the cytoplasm. Incorporation of H³-uridine into the RNA of the nucleus and the nucleolus is not immediately blocked after chase, suggesting that the labeled precursor pool is not completely washed out from the living cell, or diluted by the excess of unlabeled uridine present in the medium. The grain count over the nucleus and the nucleolus rises for a certain time after chase and then gradually declines; H³-radioactivity appears in the cytoplasm 10 min after chase and keeps rising through a 110-min interval. The experiment, then — even though it suggests that the bulk of cellular RNA is synthesized in the chromatin and the nucleolus and then continuously released into the cytoplasm — does not rule out the possibility that some RNA fraction, characterized by a low turnover rate, is synthesized independently in the cytoplasm.Synthesis of RNA is a continuous process throughout the cell cycle, except during metaphase and anaphase. It ceases at prometaphase after the disappearance of the nucleolus and disintegration of the nuclear membrane, and resumes in early telophase. Part of the chromosomal RNA does not remain associated with the chromosomes through division, but is suddenly released into the cytoplasm when the cell enters metaphase.     

Dopaminergic Inhibition of Prolactin Release and Calcium Influx Induced by Neurotensin in Anterior Pituitary Is Independent of Cyclic AMP System

The present study demonstrates that 3,4-dihydroxyphenylethylamine (DA, dopamine) prevents neurotensin (NT) stimulation of both prolactin (PRL) release and calcium influx by interacting with specific receptors that are functionally linked to calcium channels. As shown by the studies with dispersed cells from rat anterior pituitary, the pharmacology of the control of PRL release and calcium influx, both induced by NT, was found to be typical of a DAergic process. This was demonstrated by the order of potency of agonists in inhibiting PRL release and calcium influx (DA greater than epinephrine greater than norepinephrine much greater than isoproterenol); by the high affinity of antagonists such as haloperidol and fluphenazine for this process; and by the high degree of stereoselectivity of sulpiride. Specific D2 receptor agonists, such as bromocriptine and lisuride, and the specific D2 receptor antagonist (-)-sulpiride were found to be highly potent on the DA receptors negatively coupled with calcium channels and PRL release. DA was found to lack the capacity to change the influx of calcium induced by either the sodium channel activator veratridine or high extracellular potassium levels, thus indicating a specific action of this amine on calcium channels sensitive to NT. In a range of concentrations that are effective in inhibiting either the calcium influx or the PRL release, both induced by NT, DA did not alter the cyclic AMP generating system. DA (from 1.0 nM to 50 nM) did not affect adenylate cyclase activity in rat pituitary gland homogenates and did not modify intracellular cyclic AMP levels in pituitary cells.(ABSTRACT TRUNCATED AT 250 WORDS)     

Molecular Characterization of Microbial Population Dynamics during Sildenafil Citrate Degradation

Little is known about pharmaceutical and personal care products pollutants (PPCPs), but there is a growing interest in how they might impact the environment and microbial communities. The widespread use of Viagra (sildenafil citrate) has attracted great attention because of the high usage rate, the unpredictable disposal and the unknown potential effects on wildlife and the environment. Until now information regarding the impact of Viagra on microbial community in water environment has not been reported. In this research, for the first time, the genetic profile of the microbial community, developing in a Viagra polluted water environment, was evaluated by means of the 16S and 18S rRNA genes, for bacteria and fungi, respectively, amplified by polymerase chain reaction (PCR) and separated using the denaturing gradient gel electrophoresis (DGGE) technique. The DGGE results revealed a complex microbial community structure with most of the population persisting throughout the experimental period. DNA sequences from bands observed in the different denaturing gradient gel electrophoresis profiles exhibited the highest degree of identity to uncultured bacteria and fungi found previously mainly in polluted environmental and treating bioreactors. Biotransformation ability of sildenafil citrate by the microbial pool was studied and the capability of these microorganisms to detoxify a polluted water ecosystem was assessed. The bacterial and fungal population was able to degrade sildenafil citrate entirely. Additionally, assays conducted on Daphnia magna, algal growth inhibition assay and cell viability determination on HepG2 human cells showed that biotransformation products obtained from the bacterial growth was not toxic. The higher removal efficiency for sildenafil citrate and the lack of toxicity by the biotransformation products obtained showed that the microbial community identified here represented a composite population that might have biotechnological relevance to retrieve sildenafil citrate contaminated sites.     

Glucose Accelerates Copper- and Ceruloplasmin-induced Oxidation of Low-density Lipoprotein and Whole Serum

Glucose at pathophysiological concentrations was able to accelerate copper-induced oxidation of isolated low-density lipoprotein (LDL) and whole serum. The efficiency of glucose was favored under the following circumstances: (a) when LDL oxidation was induced by low copper concentration, (b) when LDL was partly oxidized, i.e. enriched with lipid peroxides. The glucose derivative methyl- &#102 - d -glucoside was ineffective on Cu 2+ -induced LDL oxidation, pointing out the essential role of the reactivity of the aldehydic carbon for the pro-oxidative effect. When LDL oxidation was induced by a peroxyl radical generator, as a model of transition metal independent oxidation, glucose was ineffective. Glucose was found to stimulate oxidation of LDL induced by ceruloplasmin, the major copper-containing protein of human plasma. Thus, glucose accelerated oxidation of LDL induced by both free and protein bound copper. Considering the requirement for catalytically active copper and for the aldehydic carbon, the pro-oxidative effect of glucose is likely to depend on the increased availability of Cu + ; this is more efficient in decomposing lipid peroxide than Cu 2+ , accounting for acceleration of LDL oxidation. The possible biological relevance of our work is supported by the finding that glucose was able to accelerate oxidation of whole serum, which was assessed by monitoring low-level chemiluminescence associated with lipid peroxidation.     

Systematics of Old World Odontacolus Kieffer s.l. (Hymenoptera,Platygastridae s.l.): parasitoids?of?spider?eggs

The genera Odontacolus Kieffer and Cyphacolus Priesner are among the most distinctive platygastroid wasps because of their laterally compressed metasomal horn; however, their generic status has remained unclear. We present a morphological phylogenetic analysis comprising all 38 Old World and four Neotropical Odontacolus species and 13 Cyphacolus species, which demonstrates that the latter is monophyletic but nested within a somewhat poorly resolved Odontacolus. Based on these results Cyphacolus syn. n. is placed as a junior synonym of Odontacolus which is here redefined. The taxonomy of Old World Odontacolus s.str. is revised; the previously known species Odontacolus longiceps Kieffer (Seychelles), Odontacolus markadicus Veenakumari (India), Odontacolus spinosus (Dodd) (Australia) and Odontacolus hackeri (Dodd) (Australia) are re-described, and 32 new species are described: Odontacolus africanus Valerio & Austin sp. n. (Congo, Guinea, Kenya, Madagascar, Mozambique, South Africa, Uganda, Zimbabwe), Odontacolus aldrovandii Valerio & Austin sp. n. (Nepal), Odontacolus anningae Valerio & Austin sp. n. (Cameroon), Odontacolus australiensis Valerio & Austin sp. n. (Australia), Odontacolus baeri Valerio & Austin sp. n. (Australia), Odontacolus berryae Valerio & Austin sp. n. (Australia, New Zealand, Norfolk Island), Odontacolus bosei Valerio & Austin sp. n. (India, Malaysia, Sri Lanka), Odontacolus cardaleae Valerio & Austin sp. n. (Australia), Odontacolus darwini Valerio & Austin sp. n. (Thailand), Odontacolus dayi Valerio & Austin sp. n. (Indonesia), Odontacolus gallowayi Valerio & Austin sp. n. (Australia), Odontacolus gentingensis Valerio & Austin sp. n. (Malaysia), Odontacolus guineensis Valerio & Austin sp. n. (Guinea), Odontacolus harveyi Valerio & Austin sp. n. (Australia), Odontacolus heratyi Valerio & Austin sp. n. (Fiji), Odontacolus heydoni Valerio & Austin sp. n. (Malaysia, Thailand), Odontacolus irwini Valerio & Austin sp. n. (Fiji), Odontacolus jacksonae Valerio & Austin sp. n. (Cameroon, Guinea, Madagascar), Odontacolus kiau Valerio & Austin sp. n. (Papua New Guinea), Odontacolus lamarcki Valerio & Austin sp. n. (Thailand), Odontacolus madagascarensis Valerio & Austin sp. n. (Madagascar), Odontacolus mayri Valerio & Austin sp. n. (Indonesia, Thailand), Odontacolus mot Valerio & Austin sp. n. (India), Odontacolus noyesi Valerio & Austin sp. n. (India, Indonesia), Odontacolus pintoi Valerio & Austin sp. n. (Australia, New Zealand, Norfolk Island), Odontacolus schlingeri Valerio & Austin sp. n. (Fiji), Odontacolus sharkeyi Valerio & Austin sp. n. (Thailand), Odontacolus veroae Valerio & Austin sp. n. (Fiji), Odontacolus wallacei Valerio & Austin sp. n. (Australia, Indonesia, Malawi, Papua New Guinea), Odontacolus whitfieldi Valerio & Austin sp. n. (China, India, Indonesia, Sulawesi, Malaysia, Thailand, Vietnam), Odontacolus zborowskii Valerio & Austin sp. n. (Australia), and Odontacolus zimi Valerio & Austin sp. n. (Madagascar). In addition, all species of Cyphacolus are here transferred to Odontacolus: Odontacolus asheri (Valerio, Masner & Austin) comb. n. (Sri Lanka), Odontacolus axfordi (Valerio, Masner & Austin) comb. n. (Australia), Odontacolus bhowaliensis (Mani & Mukerjee) comb. n. (India), Odontacolus bouceki (Austin & Iqbal) comb. n. (Australia), Odontacolus copelandi (Valerio, Masner & Austin) comb. n. (Kenya, Nigeria, Zimbabwe, Thailand), Odontacolus diazae (Valerio, Masner & Austin) comb. n. (Kenya), Odontacolus harteni (Valerio, Masner & Austin) comb. n. (Yemen, Ivory Coast, Paskistan), Odontacolus jenningsi (Valerio, Masner & Austin) comb. n. (Australia), Odontacolus leblanci (Valerio, Masner & Austin) comb. n. (Guinea), Odontacolus lucianae (Valerio, Masner & Austin) comb. n. (Ivory Coast, Madagascar, South Africa, Swaziland, Zimbabwe), Odontacolus normani (Valerio, Masner & Austin) comb. n. (India, United Arab Emirates), Odontacolus sallyae (Valerio, Masner & Austin) comb. n. (Australia), Odontacolus tessae (Valerio, Masner & Austin) comb. n. (Australia), Odontacolus tullyae (Valerio, Masner & Austin) comb. n. (Australia), Odontacolus veniprivus (Priesner) comb. n. (Egypt), and Odontacolus watshami (Valerio, Masner & Austin) comb. n. (Africa, Madagascar). Two species of Odontacolus are transferred to the genus Idris Förster: Idris longispinosus (Girault) comb. n. and Idris amoenus (Kononova) comb. n., and Odontacolus doddi Austin syn. n. is placed as a junior synonym of Odontacolus spinosus (Dodd). Odontacolus markadicus, previously only known from India, is here recorded from Brunei, Malaysia, Sri Lanka, Thailand and Vietnam. The relationships, distribution and biology of Odontacolus are discussed, and a key is provided to identify all species.     

Fully Plastic Dye Solar Cell Devices by Low‐Temperature UV‐Irradiation of both the Mesoporous TiO2 Photo‐ and Platinized Counter‐Electrodes

The application of UV irradiation processes are successfully proposed for the first time in the fabrication of both of the two plastic electrodes in flexible dye solar cells (DSCs) and modules. For the realization of the photo‐electrode, a customized TiO₂ paste formulation and UV processing method was developed which yields 134% (48%) performance enhancement with respect to the same (binder‐free) paste treated at 120 °C. UV treatment induces both complete removal of organic media and more efficient charge collection. Significantly, highly catalytic platinized flexible counter‐electrodes are also obtained via UV photo‐induced reduction of screen‐printed platinum precursor pastes based on hexachloroplatinic acid. Using both UV‐processed electrodes, a fully plastic DSC is fabricated with a conversion efficiency of 4.3% under 1 Sun (semitransparent) and 5.3% under 0.2 Sun (opaque). Performance is within 10% of the efficiency of a glass‐based DSC prepared with the same materials but with conventional high temperature processes. The material formulations and processes are simple, and easily up‐scaled over large areas, even directly and simultaneously applicable to the preparation of both the photo‐and counter‐electrode on the same substrate which enabled us to demonstrate the first module on plastic realized with a W series interconnection.