Molecular genetic and physiological differentiation of <Emphasis Type="Italic">Kluyveromyces lactis</Emphasis> and <Emphasis Type="Italic">Kluyveromyces marxianus</Emphasis>: Analysis of strains from the all-Russian collection of microorganisms (VKM)

Molecular genetic identification of 52 Kluyveromyces strains from VKM, mainly of dairy origin, was carried out. Restriction analysis of 5.8S-ITS rDNA fragments was used to differentiate between Kl. lactis var. lactis, Kl. lactis var. drosophilarum (European population of “krassilnikovii”), and Kl. marxianus. Kl. lactis was shown to differ from Kl. marxianus in its ability to assimilate α-glucosides: maltose, melezitose, and α-methyl-glucoside.     

Ropren(?) is a polyprenol preparation from coniferous plants that ameliorates cognitive deficiency in a rat model of beta-amyloid peptide-(25-35)-induced amnesia

This study assesses the efficacy of a fixed dose of Ropren(?) (a plant preparation isolated from the neutral fraction of an extract of spruce needles) on cognitive impairment in rats with β-amyloid peptide-(25-35)-induced amnesia. Ropren(?) was administered at a dose of 8.6mg/kg for 28 days, per os, to rats with β-amyloid peptide-(25-35)-induced amnesia. Cognitive performance was assessed using the passive avoidance paradigm and the Morris water maze and behavior was assessed using the open field test. After four weeks, Ropren(?) treatment significantly improved non-spatial and spatial learning in rats with β-amyloid peptide-(25-35)-induced amnesia. The results of the present study suggest that Ropren(?), a novel plant preparation, ameliorates cognitive deficiencies in an animal model relevant to Alzheimer's disease.     

Collagenolytic activity in several species of deuteromycetes under various storage conditions

The ability of deuteromycetes of the genera Penicillium, Aspergillus, and Botrytis to retain collagenolytic activity was studied after both 2 and 10 years of storage on a Czapek medium under a layer of mineral oil at 4°C, as well as in silica gel granules at 20 and ?60°C. The enzymatic activity of several species, including Botrytis terrestris, Penicillium janthinellum, Penicillium chrysogenum, and Penicillium citrinum, was retained under both conditions of storage. Aspergillus repens retained enzymatic activity only if stored under a layer of mineral oil. The viability of conidia and the collagenolytic activity of Botrytis terrestris, P. janthinellum, P. chrysogenum, and Penicillium citrinum, maintained on silica gel for 10 years, depended on the storage temperature. The viability of the test strains improved after storage on a silica gel at ?60°C. A strain of Aspergillus repens lost its ability to dissolve collagen at various storage tempeatures on the silica gel. The index of lysis for three strains of Penicillium deuteromycetes (Penicillium janthinellum, Penicillium chrysogenum, and Penicillium citrinum) increased after a 10-year storage on silica gel at ?60°C.     

Calcium sensitivity of vasospastic basilar artery after experimental subarachnoid hemorrhage

Arteries that develop vasospasm after subarachnoid hemorrhage (SAH) may have altered contractility and compliance. Whether these changes are due to alterations in the smooth muscle cells or the arterial wall extracellular matrix is unknown. This study elucidated the location of such changes and determined the calcium sensitivity of vasospastic arteries. Dogs were placed under general anesthesia and underwent creation of SAH using the double-hemorrhage model. Vasospasm was assessed by angiography performed before and 4, 7, or 21 days after SAH. Basilar arteries were excised from SAH or control dogs (n = 8-52 arterial rings from 2-9 dogs per measurement) and studied under isometric tension in vitro before and after permeabilization of smooth muscle with alpha-toxin. Endothelium was removed from all arteries. Vasospastic arteries demonstrated significantly reduced contractility to KCl with a shift in the EC(50) toward reduced sensitivity to KCl 4 and 7 days after SAH (P < 0.05, ANOVA). There was reduced compliance that persisted after permeabilization (P < 0.05, ANOVA). Calcium sensitivity was decreased during vasospasm 4 and 7 days after SAH, as assessed in permeabilized arteries and in those contracted with BAY K 8644 in the presence of different concentrations of extracellular calcium (P < 0.05, ANOVA). Depolymerization of actin with cytochalasin D abolished contractions to KCl but failed to alter arterial compliance. In conclusion, it is shown for the first time that calcium sensitivity is decreased during vasospasm after SAH in dogs, suggesting that other mechanisms are involved in maintaining the contraction. Reduced compliance seems to be due to an alteration in the arterial wall extracellullar matrix rather than the smooth muscle cells themselves because it cannot be alleviated by depolymerization of smooth muscle actin.     

Gene regulatory networks that control the specification of neural-crest cells in the lamprey

The lamprey is the only basal vertebrate in which large-scale gene perturbation analyses are feasible at present. Studies on this unique animal model promise to contribute both to the understanding of the basic neural-crest gene regulatory network architecture, and evolution of the neural crest. In this review, we summarize the currently known regulatory relationships underlying formation of the vertebrate neural crest, and discuss new ways of addressing the many remaining questions using lamprey as an experimental model.     

Activities of digestive enzymes in rats kept on standard or excessive breast feeding and on low-protein diet at once after weaning

Activities of digestive enzymes (maltase, alkaline phosphatase, aminopeptidase M, and glycyl-L-leucine dipeptidase) in small and large intestine, liver, and kidney were studied in rats of different ages kept at the period of lactation under conditions of the standard (8 individuals per litter) and low (3 individuals) number of pups per litter. The low-protein diet for 10 days at once after weaning was found to change the mass of organs and their digestive enzyme activities in all studied rat groups. The revealed changes were more prominent in rats kept under conditions of excessive breast feeding. In adult animals of this group, distribution of the alkaline phosphatase activity along the small intestine differed from that in control rats. The obtained results seem to confirm that any disturbance of the nutrition quality in early ontogenesis leads to disturbance of the «metabolic programming of enzyme systems» of digestive organs.     

Nuclear factor-kappa B localization and function within intrauterine tissues from term and preterm labor and cultured fetal membranes

Background  

The objective of this study was to quantify the nuclear localization and DNA binding activity of p65, the major transactivating nuclear factor-kappa B (NF-kappaB) subunit, in full-thickness fetal membranes (FM) and myometrium in the absence or presence of term or preterm labor.     

Novel Photosensitizers Trigger Rapid Death of Malignant Human Cells and Rodent Tumor Transplants via Lipid Photodamage and Membrane Permeabilization

Background

Apoptotic cascades may frequently be impaired in tumor cells; therefore, the approaches to circumvent these obstacles emerge as important therapeutic modalities.

Methodology/Principal Findings

Our novel derivatives of chlorin e₆, that is, its amide (compound 2) and boronated amide (compound 5) evoked no dark toxicity and demonstrated a significantly higher photosensitizing efficacy than chlorin e₆ against transplanted aggressive tumors such as B16 melanoma and M-1 sarcoma. Compound 5 showed superior therapeutic potency. Illumination with red light of mammalian tumor cells loaded with 0.1 µM of 5 caused rapid (within the initial minutes) necrosis as determined by propidium iodide staining. The laser confocal microscopy-assisted analysis of cell death revealed the following order of events: prior to illumination, 5 accumulated in Golgi cysternae, endoplasmic reticulum and in some (but not all) lysosomes. In response to light, the reactive oxygen species burst was concomitant with the drop of mitochondrial transmembrane electric potential, the dramatic changes of mitochondrial shape and the loss of integrity of mitochondria and lysosomes. Within 3–4 min post illumination, the plasma membrane became permeable for propidium iodide. Compounds 2 and 5 were one order of magnitude more potent than chlorin e₆ in photodamage of artificial liposomes monitored in a dye release assay. The latter effect depended on the content of non-saturated lipids; in liposomes consisting of saturated lipids no photodamage was detectable. The increased therapeutic efficacy of 5 compared with 2 was attributed to a striking difference in the ability of these photosensitizers to permeate through hydrophobic membrane interior as evidenced by measurements of voltage jump-induced relaxation of transmembrane current on planar lipid bilayers.

Conclusions/Significance

The multimembrane photodestruction and cell necrosis induced by photoactivation of 2 and 5 are directly associated with membrane permeabilization caused by lipid photodamage.     

Effect of protein deficiency in the female rat diet during pregnancy and lactation on the activity of the membrane and soluble forms of digestive enzymes in the offspring small intestine

Protein deficiency in female rats diet during pregnancy and lactation resulted in deceleration of induction of sucrase both forms in the jejunum and ileum; in acceleration of induction of the maltase membrane from in the jejunum; and in suppression of the lactase membrane form in the ileum; in earlier forming of the adult-type distribution of activity of the membrane form of intestinal alkaline phosphatase and in a decrease in activity of the enzyme soluble form. The findings are corroborated by a suppression of activities of the membrane and soluble forms of the small intestine digestive enzymes in 30-day old rat pups fed with a control (adequate) ration starting 21 days after the birth.