Characterization of 13 newly isolated strains of anaerobic, cellulolytic, thermophilic bacteria

Characteristics of 13 newly isolated thermophilic, anaerobic, and cellulolytic strains were compared with previously described strains of Clostridium thermocellum: ATCC 27405 and JW20 (ATCC 31549). Colony morphology, antibiotic sensitivity, fermentation end-products, and cellulose degradation were documented. All 13 strains were sensitive to erythromycin (5 μg/ml) and chloramphenicol (25 μg/ml), and all strains but one were sensitive to kanamycin (20 μg/ml). Polymerase chain reaction (PCR) amplification using primers based on gene sequences from C. thermocellum ATCC 27405 was successful for all 13 strains in the case of the hydrogenase gene and 11 strains in the case of phosphotransacetylase/acetate kinase genes. Ten strains amplified a product of the expected size with primers developed to be specific for C. thermocellum 16SrRNA primers. Two of the 13 strains did not amplify any product with the PCR primers designed for the phosphotransacetylase/acetate kinase and 16SrRNA primers. A MboI-like GATC- recognizing restriction activity was present in all of the five strains examined. The results of this study have several positive implications with respect to future development of a transformation system for cellulolytic thermophiles. Journal of Industrial Microbiology & Biotechnology (2001) 27, 275–280. Received 12 September 2000/ Accepted in revised form 20 November 2000     

Interaction between Reelin and Notch signaling regulates neuronal migration in the cerebral cortex

Neuronal migration is a fundamental component of brain development whose failure is associated with various neurological and psychiatric disorders. Reelin is essential for the stereotypical inside-out sequential lamination of the neocortex, but the molecular mechanisms of its action still remain unclear. Here we show that regulation of Notch activity plays an important part in Reelin-signal-dependent neuronal migration. We found that Reelin-deficient mice have reduced levels of the cleaved form of Notch intracellular domain (Notch ICD) and that loss of Notch signaling in migrating neurons results in migration and morphology defects. Further, overexpression of Notch ICD mitigates the laminar and morphological abnormalities of migrating neurons in Reeler. Finally, our in vitro biochemical studies show that Reelin signaling inhibits Notch ICD degradation via Dab1. Together, our results indicate that neuronal migration in the developing cerebral cortex requires a Reelin-Notch interaction.     

Development of the human cerebral cortex: Boulder Committee revisited

In 1970 the Boulder Committee described the basic principles of the development of the CNS, derived from observations on the human embryonic cerebrum. Since then, numerous studies have significantly advanced our knowledge of the timing, sequence and complexity of developmental events, and revealed important inter-species differences. We review current data on the development of the human cerebral cortex and update the classical model of how the structure that makes us human is formed.     

Semiquantitative cytochemistry in evaluation of apoptotic capacity in bronchoalveolar lavage of smokers and patients with non-small-cell lung cancer

Apoptotic capacity of pulmonary tissue to produce or remove apoptotic cells by alveolar macrophages (ALMs) was investigated in three groups: healthy volunteers, smokers and patients with non-small-cell lung cancer (NSCLC). Differential cell counting of bronchoalveolar lavage (BAL) specimens revealed significantly higher percentages of neutrophils and eosinophils and decreased percentage of macrophages in BAL of patients with NSCLC in comparison with nonsmokers and smokers. Proportion of lymphocytes was significantly higher in patients with NSCLC than in smokers. These changes in the BAL cell profile may reflect immunology of the lung in pulmonary malignancies. BAL eosinophils were significantly lower and AMs increased in smokers in comparison with nonsmokers. This result might be understood as a consequence of changed tissue architecture of pulmonary tissue in situ, influenced by smoking. Apoptotic detection in cytocentrifuge preparations of BAL cell suspensions was evaluated by TUNEL method. Subsequent steps, adsorption, internalization and digestion of apoptotic cells by alveolar macrophages (AMs) were estimated by semiquantitative cytochemical scoring and indexing method and correlated with percent of free apoptotic cells. Significant increase of apoptotic capacity of pulmonary tissue in control smokers (289.55+/-50.77) in comparison with that of non-smokers (218.29+/-56.24) could be a consequence of stimulated digestion inside the AMs; decreased apoptotic capacity of pulmonary tissue in NSCLC (150.30+/-40.61; p<0.05), in comparison with non-smokers and smokers is in relation to a reduced phagocytosis of the apoptotic remnants, which might be either the cause or the consequence of the oncogenic process.     

Interactions of Photobleaching and Inorganic Nutrients in Determining Bacterial Growth on Colored Dissolved Organic Carbon

Abstract Bacteria are key organisms in the processing of dissolved organic carbon (DOC) in aquatic ecosystems. Their growth depends on both organic substrates and inorganic nutrients. The importance of allochthonous DOC, usually highly colored, as bacterial substrate can be modified by photobleaching. In this study, we examined how colored DOC (CDOC) photobleaching, and phosphorus (P) and nitrogen (N) availability, affect bacterial growth. Five experiments were conducted, manipulating nutrients (P and N) and sunlight exposure. In almost every case, nutrient additions had a significant, positive effect on bacterial abundance, production, and growth efficiency. Sunlight exposure (CDOC photobleaching) had a significant, positive effect on bacterial abundance and growth efficiency. We also found a significant, positive interaction between these two factors. Thus, bacterial use of CDOC was accelerated under sunlight exposure and enhanced P and N concentrations. In addition, the accumulation of cells in sunlight treatments was dependent on nutrient availability. More photobleached substrate was converted into bacterial cells in P- and N-enriched treatments. These results suggest nutrient availability may affect the biologically-mediated fate (new biomass vs respiration) of CDOC.     

Cerebellar neurones: Differentiation and modulation of sensitivity to excitotoxic treatment

The neurite outgrowth and adhesion complex (NOAC), isolated from rabbit sera has been dissociated in its major components by reverse-phase chromatography in HPLC by using a C₁₈ column. SDS-PAGE analisys of the active fractions revealed the presence of three major bands of approximately 100, 70 and 50 kDa. Studies on the biological activity of NOAC were carried out on rat cerebellar granule cells. NOAC-cultured cells exhibit a marked resistance to excitotoxic stimuli carried by glutamate.     

Distribution of the molossinus allele of Sry, the testis-determining gene, in wild mice

When the Y chromosome of the laboratory inbred mouse strain C57BL/6 (B6) is replaced by the Y of certain strains of Mus musculus domesticus, testis determination fails and all XY fetuses develop either as hermaphrodites or XY females (XY sex reversal). This suggests the presence of at least two alleles of Sry, the male-determining gene on the Y:M. m. domesticus and B6. The B6 Y chromosome is derived from the Japanese house mouse, M. m. molossinus and therefore carries a molossinus Sry allele. As a first step to determine how the molossinus Sry allele evolved, its distribution pattern was determined in wild mice. The cumulative data of 96 M. musculus samples obtained from 58 geographical locations in Europe, North Africa, and Asia show the molossinus Sry allele is restricted to Japan and the neighboring Asian mainland and confirm that Japanese M. m. molossinus mice were derived in part from a race of M. m. musculus from Korea or Manchuria. Sry polymorphisms, as illustrated by the molossinus Sry allele, can serve as molecular markers for studies on the evolution of wild M. musculus populations and can help determine the role sex determination plays in speciation.      

Chromatin,gene silencing and HIV latency

One of the cellular defenses against virus infection is the silencing of viral gene expression. There is evidence that at least two gene-silencing mechanisms are used against the human immuno-deficiency virus (HIV). Paradoxically, this cellular defense mechanism contributes to viral latency and persistence, and we review here the relationship of viral latency to gene-silencing mechanisms.     

Anti-angiogenic therapy of exudative age-related macular degeneration: current progress and emerging concepts

Age-related macular degeneration (AMD) is the leading cause of blindness in elderly patients. The more aggressive exudative form is characterized by abnormal blood-vessel development that occurs beneath the retina as a result of choroidal neovascularization (CNV). Vascular endothelial growth factor (VEGF) has emerged as the key mediator of CNV formation; this has led to intensive research on VEGF and the recent approval of anti-VEGF compounds by the US Food and Drug Administration. Despite this successful introduction of anti-angiogenic therapies into the clinical setting, there is still a lack of treatments that definitively reverse damaged vision. Here, we consider the importance of putative molecular targets other than VEGF that might have been underestimated. Emerging cellular mechanisms offer additional opportunities for innovative therapeutic approaches.