Quantification of viable biomass in biofilm reactors by extractable lipid phosphate

 Lipid phosphate, which is a measure of viable biomass, was determined using biofilm samples from three different laboratory-scale reactors. The analysis procedure proposed in the literature was modified and tested for suitability in experiments with biofilm reactors. The microbial contents of the biofilms studied are compared in three types of reactor. Received: 2 November 1994/Accepted: 23 January 1995     

Requirement for proliferating cell nuclear antigen expression during stages of the Chinese hamster ovary cell cycle

Proliferating cell nuclear antigen (PCNA/cyclin) is a nuclear protein that can stimulate purified DNA polymerase delta in vitro, and its synthesis correlates with the proliferation rate of cells. We have attempted to determine whether synthesis of PCNA/cyclin in Chinese hamster ovary cells is necessary to regulate entry into S phase. We have measured cellular PCNA/cyclin concentration of the mRNA or protein throughout the cell cycle. Cells were separated by centrifugal elutriation into populations enriched for G-1, S, and G-2/M phases. Quantitative Northern hybridization analysis was performed on RNA isolated from each cell population by using a cDNA clone of PCNA/cyclin as a probe. Results demonstrated that although intact PCNA/cyclin mRNA is present during all phases of the cell cycle, an induction of about 3-fold occurs during S phase. Two-parameter staining for PCNA/cyclin and DNA, and analysis by flow cytometry, confirmed that the quantity of PCNA/cyclin protein in the cells increases severalfold in G-1 or early S phase but generally is invariant in S and G-2/M phases. This cell cycle dependence of PCNA/cyclin expression suggests that the observed synthesis is a prerequisite for initiation of DNA replication. Introduction of an antisense oligonucleotide complementary to the PCNA/cyclin mRNA to inhibit PCNA/cyclin synthesis effectively prevented entry of G-1 phase cells into S phase. A complementary sense oligonucleotide used as a control did not have an inhibitory effect. This result suggests that a threshold concentration of PCNA/cyclin is necessary for entry into S phase.     

眼小叶蝉属和东半球眼小叶蝉族评述：（头喙亚目,叶蝉科,小叶蝉亚科）

本文首先根据眼小叶蝉族Alebrini讨论翅的命名,接着是眼小叶蝉属Alebra Fieb.和东半球眼小叶蝉族各属的评论。Homa elongata Kato移入属AsialebraDwor.,Shaddai distanti Dwor.是S.typicus Dist.的异名。描述了6个新种,即Sobralacapreola,S.clara,Orientalebra drawidana,Afralebra melichari,A.youngi,A.paolii. 本文引言部分讨论小叶蝉亚科Typhlocybinae翅的形态学,正文为分类部分。 在描述内部构造以及端节、头、和胸部背面时,使用习惯术语。 新种模式标本系列保存于下列博物馆中;正模的保管者在有关描述中最先提到: SMTD——德国得累斯顿,国家动物学博物馆。 BMNH——英国伦敦,英国自然历史博物馆。 USNM——美国华盛顿,美国国家博物馆。 MM——捷克斯洛伐克Brno,Moravian博物馆。     

Age, growth, mortality and sex ratio of sand smelt, Atherina boyeri Risso, 1810 (Pisces: Atherinidae) in the estuary of the Mala Neretva River (middle-eastern Adriatic, Croatia)

The present study investigated the age, growth, mortality and morphometry of the sand smelt, Atherina boyeri, in the Mala Neretva River estuary (mid‐eastern Adriatic Sea). The study of scale annuli showed that the population is up to 4 years of age. However, most sand smelt are in their first and second year; the numbers of older individuals are very low because they migrate upstream and are heavily fished. The von Bertalanffy parameters for the total sample of sand smelt were found to be L_∞ = 13.5 cm, K = 0.37 year^?1 and t₀ = ?0.97. Overall total mortality was estimated at 1.81 year^?1, natural mortality was 0.90 year^?1 and fishing mortality was 0.91 year^?1.     

Effect of taurine on wound healing

Summary Taurine which has antioxidant effects is also known to have effects on cell proliferation, inflammation and collagenogenesis. The aim of this study was to investigate the effect of taurine on incisional skin wounds.The mice incised on the dorsal area were divided into control and experimental groups. Saline was injected intraperitoneally to half of the animals in the control group and locally applied to the other half. Fifty mM taurine solution was given intraperitoneally to the first half of the experimental animals and locally to the second half of the experimental group.After four days of treatment, malondialdehyde (MDA) and histamine levels as well as the tensile strength of the wound tissue were measured. Structural alterations in epidermis and dermis were histologically evaluated.The locally administreated taurine significantly increased wound tensile strength by decreasing the MDA and histamine levels and prevented the degranulation of the mast cells. These observations suggest that taurine may be useful on wound healing.     

Interaction of endothelial cells with a laminin A chain peptide (SIKVAV) in vitro and induction of angiogenic behavior in vivo.

Endothelial cells are known to bind to laminin, and two peptides derived from the laminin A (CTFALRGDNP) and B1 (CDPGYIGSR) chains block the capillary-like tube formation on a laminin-rich basement membrane matrix, Matrigel. In the present study, we have used various in vitro and in vivo assays to investigate the angiogenic-biologic effects of a third active site in the laminin A chain, CSRARKQAASIKVAVSADR (designated PA22-2) on endothelial cells. The SIKVAV-containing peptide was as active as the YIGSR-containing peptide for endothelial cell attachment but was less active than either the RGD-containing peptide or intact laminin. Endothelial cells seeded on this peptide appeared fibroblastic with many extended processes, unlike the normal cobblestone morphology observed on tissue culture plastic. In addition, in contrast to normal tube formation on Matrigel, short irregular structures formed, some of which penetrated the matrix and sprouting was more apparent. Analysis of endothelial cell conditioned media of cells cultured in the presence of this peptide indicated degradation of the Matrigel and zymograms demonstrated active collagenase IV (gelatinase) at 68 and 62 Kd. A murine in vivo angiogenesis assay and the chick yolk sac/chorioallantoic membrane assays with the peptide demonstrated increased endothelial cell mobilization, capillary branching, and vessel formation. These data suggest that the -SIKVAV-site may play an important role in initiating branching and formation of new capillaries from the parent vessels, a behavior that is observed in vivo in response to tumor growth or in the normal vascular response to injury.