Anthranilic Acid,as a Fruiting Body Inducing Substance in Favolus arcularius,from a Strain TA 7 of Actinomycetes

The stereochemical inversion of (R)-5-hydroxymethyl-3-tert-butyl-2-oxazolidinone (la) or (R)-5-hydroxymethyl-3-isopropyl-2-oxazolidinone (lb) to the corresponding (S)-isomer was accomplished via a key intermediate, (R)-3-N-ethoxycarbonyl-N-tert-butylamino-l,2-epoxypropane (5a) or (R)-3-N-ethoxycarbonyl-N-isopropylamino-l,2-epoxypropane (5b), in a high enantiomeric excess. (S)-la (99%e.e.) or (S)-lb (91%e.e.) was thus obtained from the respective (R)-isomer (la; 99%e.e., lb; 95%e.e.).     

Sydonol,a New Fungal Morphogenic Substance Produced by an Unidentified Aspergillus sp.

The “intrinsic” thermal conductivity values of unfrozen wet egg-albumin, wheat gluten and milk casein were determined on the basis of the series heat conduction model to be 0.238, 0.219 and 0.200 [W/m·°C], respectively. The corresponding values for frozen samples were 0.403, 0.315 and 0.273 [W/m·°C], respectively. The “intrinsic” thermal conductivity values of wet proteins determined in the previous and present studies were between the thermal conductivity values of water (or ice) and oils (or fats), in the reverse order of the average hydrophobicity values of proteins.     

The Occurrence and Some Properties of a Spawning Inducing Substance in the Testis of the Hydromedusan Spirocodon saltatrix

Gas chromatographic methods were developed for the determination of optical isomers of 2-(4-chlorophenyl)isovaleric acid (CPIA) which constituted the acid moiety of the insecticide Fenvalerate molecule. The enantiomers of CPIA were derivatized into diastereoisomeric l-menthyl esters quantitatively via their acid chlorides and separated from each other on a column of 10% silicone DC QF-1 (3 mm i.d. × 2.25m). They were also derivatized into isopropylamides in the presence of N,N′-dicyclohexylcarbodiimide and were resolved on an open tubular glass capillary column (0.25 mm i.d. × 40 m) coated with optically active N,N′-[2,4-(6-ethoxy-1,3,5-triazine)diyl] bis(l-valyl-l-valyl-l-valine isopropyl ester) (OA-300). The ratios of optical isomers were determined from their separated peak areas and analytical values obtained by two methods were in good agreement with each other.

The chemical purity of CPIA was also determined by gas chromatography after derivatization to its methyl ester on a column of 2% DEGS (3 mm i.d. × 3 m) using m-nitroanisole as an internal standard.     

齐墩果酸诱导多种小鼠胚胎干细胞向生殖细胞方向分化研究

目的：寻找一种能诱导多种胚胎干细胞向生殖细胞方向分化的化合物,并以常用的诱导物维甲酸（Retinoic Acid, RA）作为阳性参照物。方法：分别培养小鼠胚胎干细胞1 B10、D3、R1／E,诱导它们形成拟胚体,让拟胚体贴壁生长,加入特定化合物诱导贴壁细胞分化,诱导72 h后,提取被诱导细胞的RNA,再合成cDNA,最后利用实时荧光定量PCR检测各被诱导细胞中与生殖分化相关的基因的表达水平的变化。结果：发现齐墩果酸（Oleanolic Acid,OA）显著上调了所有被研究的小鼠胚胎干细胞的生殖分化关键基因的表达水平,同时发现阳性参照物RA仅能诱导1 B10、R1／E ,而不能诱导D3向生殖细胞方向分化。结论：OA能诱导多种胚胎干细胞向生殖细胞方向分化,诱导能力方面具有比常用诱导物维甲酸更广泛的普遍性。     

In-vitro Production of Meiosis Inducing Substance (MIS) by Isolated Amphibian (Rana pipiens) Follicle Cells*

Previous studies indicated that pituitary hormone induced oocyte maturation in preovulatory amphibian ovarian follicles is mediated by somatic elements of the follicle. In this study procedures were developed for isolating and culturing follicle cells and their ability to produce meiosis inducing substance (MIS) was assessed. Defolliculated oocytes surrounded by a single layer of follicle cells but not denuded oocytes matured in response to frog pituitary hormone (FPH) stimulation. Cultured follicle cells secreted MIS following stimulation with FPH. The amount of MIS activity produced was related to the number of follicle cells cultured and the dose of FPH utilized. Radioimmunoassay (RIA) analysis of medium from follicle cell cultures demonstrated that FPH stimulated steroid (progesterone) secretion from these cells. Addition of cAMP to follicle cell cultures enhanced FPH stimulated steroid production. The results indicate that follicle cells retain FPH responsiveness when uncoupled from the immature oocyte and exhibit both MIS and steroid secretory functions.     

A Fatty Acid Messenger Is Responsible for Inducing Dispersion in Microbial Biofilms

It is well established that in nature, bacteria are found primarily as residents of surface-associated communities called biofilms. These structures form in a sequential process initiated by attachment of cells to a surface, followed by the formation of matrix-enmeshed microcolonies, and culminating in dispersion of the bacteria from the mature biofilm. In the present study, we have demonstrated that, during growth, Pseudomonas aeruginosa produces an organic compound we have identified as cis-2-decenoic acid, which is capable of inducing the dispersion of established biofilms and of inhibiting biofilm development. When added exogenously to P. aeruginosa PAO1 biofilms at a native concentration of 2.5 nM, cis-2-decenoic acid was shown to induce the dispersion of biofilm microcolonies. This molecule was also shown to induce dispersion of biofilms, formed by Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Streptococcus pyogenes, Bacillus subtilis, Staphylococcus aureus, and the yeast Candida albicans. Active at nanomolar concentrations, cis-2-decenoic acid appears to be functionally and structurally related to the class of short-chain fatty acid signaling molecules such as diffusible signal factor, which act as cell-to-cell communication molecules in bacteria and fungi.Biofilms are comprised of microorganisms enmeshed in a hydrated polymer matrix attached to a solid surface. Biofilm growth is a leading cause of materials damage, product quality degradation, and risk to public health. Bacterial biofilms are an important cause of chronic inflammatory and infectious diseases in plants and animals. In humans, biofilms have been implicated in chronic otitis media, native valve endocarditis, gastrointestinal ulcers, urinary tract and middle ear infections, and chronic lung infections in patients with cystic fibrosis (8, 11, 13, 15, 16, 29). Unfortunately, the control of biofilm growth and persistence has been problematic due to the enhanced resistance of biofilms to treatment with microbicides and antibiotics when compared to planktonic cells (30).Biofilm formation has been most intensively studied in the bacterium Pseudomonas aeruginosa, which has been shown to progress through multiple developmental stages, beginning with reversible attachment to a surface, followed by irreversible attachment and the development of microcolonies, which continue to grow to the final stage of development when dispersion occurs, releasing cells into the bulk liquid (27, 32). Bacteria have been shown to display unique phenotypes at each stage of biofilm development and possess properties that are markedly different from planktonic cells of the same species (27, 28, 32, 33, 36, 38). As a behavioral characteristic of bacteria, biofilm dispersion is of major significance because of its promise to provide a mechanism for the control of the growth and persistence of biofilms, particularly in household, medical, and industrial settings.The search for an extracellular signal responsible for biofilm dispersion has uncovered a range of factors that have been shown to stimulate biofilm disruption. In 2000, Chen and Stewart (6) reported that reactive chemicals (e.g., NaCl, CaCl₂, hypochlorite, monochloramine, and concentrated urea), chelating agents, surfactants (e.g., sodium dodecyl sulfate, Tween 20, and Triton X-100), and lysozyme, as well as a number of antimicrobial agents, when added to mixed biofilms of P. aeruginosa and Klebsiella pneumoniae, resulted in the removal of more than 25% of protein from the surface, indicating cell release from the biofilms. Sauer et al. (27) have shown that a sudden increase in the concentration of organic carbon causes bacteria to disaggregate from a biofilm. Thormann et al. (33) reported that a rapid reduction in oxygen could induce biofilm dispersion after cessation of flow in an oxygen-limited growth medium. Other studies have shown that starvation may be a trigger for dispersion (14), that a prophage in P. aeruginosa may mediate cell death and provide a vehicle for cell cluster disaggregation (37), and that nitric oxide may play a role in the biofilm dispersion process (3). Finally, the chelator EDTA has been shown to induce killing and dispersion in P. aeruginosa biofilms (1). Although the mechanism of dispersion induction is unknown in these cases, a common thread throughout these studies is that they induce major perturbations of cellular metabolism and likely also activate stress regulons, which may be involved in biofilm dispersion.The identification of a cell-to-cell communication molecule responsible for biofilm dispersion has been the focus of a number of researchers over the past decade. Recently, indole has been shown to act as an intercellular messenger, inhibiting biofilm formation in Escherichia coli but enhancing biofilm formation in P. aeruginosa (19, 20). To date, however, indole has not been shown to activate a dispersion response in existing biofilms. Rice et al. (23) described a limited role for N-butanoyl-l-homoserine lactone in modulating detachment, or sloughing, of Serratia marcescens; however, the role of quorum-sensing molecules in biofilm dispersion remains controversial. Dow et al. (10) have characterized a substituted fatty acid messenger, cis-11-methyl-2-dodecenoic acid, called diffusible signal factor (DSF), recovered from Xanthomonas campestris and shown it to be responsible for virulence, as well as induction of the release of endo-β-1,4-mannanase. Intriguingly, DSF was shown to be able to disaggregate cell flocs formed in broth culture by X. campestris, although no activity against extracellular xanthan was detected (10).In the present study we demonstrate that an unsaturated fatty acid, cis-2-decenoic acid, produced by P. aeruginosa both in batch and biofilm cultures is responsible for inducing a dispersion response in biofilms formed by a range of gram-negative bacteria, including P. aeruginosa, and by gram-positive bacteria. Furthermore, cis-2-decenoic acid was also capable of inducing dispersion in biofilms of Candida albicans, indicating that this molecule has cross-kingdom functional activity.     

Morphogenic effects of ramihyphin A in filamentous fungi

Ramihyphin A at subfungistatio concentrations stimulates ramification of hyphae of filamentous fungi. Stimulation of terminal ramification of hyphae that can be observed particularly in phytopathogenic fungi is most frequent. Hyphae ofMicrosporon canis, Trichophyton mentagrophytes, Blastomyces dermatitidis, Coccidioides immitis andHistoplasma capsulatum ramify intensively laterally. Stimulation of the lateral ramification was observed inMonilia fructigena, Penicillium marneffei andPenicillium chrysogenum. The antibiotic induces also formation of vesicular structures in phytopathogens. Due to the substantial ramification of hyphae, both terminal and lateral, the growth of colonies is interrupted. The addition of the antibiotic to a growing colony ofBotrytis cinerea induces dichotomic ramification of terminal hyphae after 3 h of growth. Lateral hyphae begin to grow later and further ramify dichotomically. Dense bundles of ramified hyphae are formed after 24 h due to the unbalanced ramification and the colony no longer increases its size.     

Nodal Signaling Regulates the Bone Morphogenic Protein Pluripotency Pathway in Mouse Embryonic Stem Cells

Members of the transforming growth factor-β superfamily play essential roles in both the pluripotency and differentiation of embryonic stem (ES) cells. Although bone morphogenic proteins (BMPs) maintain pluripotency of undifferentiated mouse ES cells, the role of autocrine Nodal signaling is less clear. Pharmacological, molecular, and genetic methods were used to further understand the roles and potential interactions of these pathways. Treatment of undifferentiated ES cells with SB431542, a pharmacological inhibitor of Smad2 signaling, resulted in a rapid reduction of phosphorylated Smad2 and altered the expression of several putative downstream targets. Unexpectedly, inhibition of the Nodal signaling pathway resulted in enhanced BMP signaling, as assessed by Smad1/5 phosphorylation. SB431542-treated cells also demonstrated significant induction of the Id genes, which are known direct targets of BMP signaling and important factors in ES cell pluripotency. Inhibition of BMP signaling decreased the SB431542-mediated phosphorylation of Smad1/5 and induction of Id genes, suggesting that BMP signaling is necessary for some Smad2-mediated activity. Because Smad7, a known inhibitory factor to both Nodal and BMP signaling, was down-regulated following inhibition of Nodal-Smad2 signaling, the contribution of Smad7 to the cross-talk between the transforming growth factor-β pathways in ES cells was examined. Biochemical manipulation of Smad7 expression, through shRNA knockdown or inducible gene expression, significantly reduced the SB431542-mediated phosphorylation of Smad1/5 and induction of the Id genes. We conclude that autocrine Nodal signaling in undifferentiated mouse ES cells modulates the vital pluripotency pathway of BMP signaling.     

A Role for a Protease in Morphogenic Responses during Yeast Cell Fusion

Cell fusion during yeast mating provides a model for signaling-controlled changes at the cell surface. We identified the AXL1 gene in a screen for genes required for cell fusion in both mating types during mating. AXL1 is a pheromone-inducible gene required for axial bud site selection in haploid yeast and for proteolytic maturation of a-factor. Two other bud site selection genes, RSR1, encoding a small GTPase, and BUD3, were also required for efficient cell fusion. Based on double mutant analysis, AXL1 in a MATα strain acted genetically in the same pathway with FUS2, a fusion-dedicated gene. Electron microscopy of axl1, rsr1, and fus2 prezygotes revealed similar defects in nuclear migration, vesicle accumulation, cell wall degradation, and membrane fusion during cell fusion. The axl1 and rsr1 mutants exhibited defects in pheromone-induced morphogenesis. AXL1 protease function was required in MATα strains for fusion during mating. The ability of the Rsr1p GTPase to cycle was required for efficient cell fusion, as it is for bud site selection. During conjugation, vegetative functions may be redeployed under the control of pheromone signaling for mating purposes. Since Rsr1p has been reported to physically associate with Cdc24p and Bem1p components of the pheromone response pathway, we suggest that the bud site selection genes Rsr1p and Axl1p may act to mediate pheromone control of Fus2p-based fusion events during mating.     

重组人凋亡诱导因子基因的构建、表达及其对HeLa细胞的促凋亡作用

凋亡诱导因子（apoptosis-inducing factor, AIF）定位于细胞的线粒体膜间隙.当凋亡信号刺激时,AIF分子从线粒体释放到胞浆,然后转位到细胞核内,引起染色体核周边凝集和DNA呈大片段断裂（～50 kb）.用RT-PCR法分段克隆得到人全长AIF基因,经改造截去其N端线粒体定位信号编码序列,代之以不同长度的绿脓杆菌外毒素(PE)转膜结构域序列.把这些重组基因克隆入pIRES2-EGFP真核表达载体,脂质体法转染HeLa细胞,通过荧光显微镜观察、共聚焦显微镜观察、电镜观察等方法检测了多种重组人AIF基因的表达及其对细胞生长的影响.证明了重组人AIF基因的表达可引起HeLa细胞死亡,为肿瘤的杀伤提供了新的策略.     

Chlamydospore-like cells of Candida albicans in the gastrointestinal tract of infected, immunocompromised mice

We have demonstrated in a previously described murine model of gastrointestinal (GI) and systemic candidiasis that the antifungal angent cilofungin was efficacious in clearing infection of body organs when administered subcutaneously by infusion, but permitted large numbers of Candida albicans in the GI tract to persist. Yeast and hyphae in these animals were associated primarily with the stratified squamous epithelium of the stomach. Administration of immunocompromising drugs (cyclophosphamide plus cortisone acetate) to animals with persistent GI infection resulted in relapse of systemic candidiasis. Histological examination of the gastric mucosa revealed invasive hyphal elements and yeast as well as multiple chlamydospore-like cells. Comparative histochemical and electron-microscopic examinations of these latter cells produced in host tissue and chlamydospores formed in vitro were conducted. The results suggested that similarities in wall and cytoplasmic composition and ultrastructure exist between these in vivo and in vitro produced C. albicans cells. Exposure of C. albicans to cyclophosphamide during in vitro growth resulted in stimulation of chlamydospore production. No significant effect of cortisone acetate on C. albicans morphogenesis was detected. The murine model used in this study permits investigation of the formation of chlamydospore-like cells of C. albicans during early stages of fungal invasion of cyclophosphamide-treated mice, and of the possible influence of these cells on immunological response of the host to persistent candidiasis of the GI tract.     

Airborne Fungi Survey of Some Residences in Durham,North Carolina,USA

Gravity settling culture (GSC) plate collections of endogenous fungi were made at four homes in Durham, North Carolina. During frost-free periods (May-August), the most frequently isolated genera included Mucor, Cladosporium (Hormodendrum), Aspergillus, Penicillium, Rhizopus, Alternaria, Cunninghamella, Aureobasidium, Fusarium, Heterosporium, Amblyosporium, and other (unidentified) fungi. Higher numbers of mold isolates were associated with high shade and high levels of organic debris near the home and poor landscaping and landscape maintenance. Lower concentrations of mold isolates were associated with the presence of a central electrostatic filtration system and good compliance with dust controls. The viable mold spore levels were lower in homes where the electrostatic filtration unit was operated continuously rather than intermittently. These findings reflect the ease with which outdoor spore clouds may penetrate structures and obscure evidence of internal fungus source. The data also imply that because of size-related undersampling, open plates can exclude abundant types of recovery. No statistically significant correlations could be made between indoor mold isolates and any of the following: number and age of the occupants, age and size of home, month of survey or the presence of plants. Attempts have been made to facilitate the diagnosis of fungal allergy by gathering together examples of places and materials which are most likely to be a risk for mold sensitive patients.     

Basic Fuchsin-Tannic Acid; A One-Solution Stain for Spore Walls in Fungi

Spore walls in fungi are stained with the supernatant obtained by centrifuging at 2000 rev/min for 15 min, equal parts by volume of 10% aqueous tannic acid and 1% aqueous basic fuchsin. Advantages of this technique are: (1) the spore walls show up better than when stained with any other dye; (2) in photomicrographs, the spore walls contrast very well with the cytoplasm; (3) it is performed quickly and easily. A comprehensive review of work done to date by other workers reveals that all of the cell wall stains found in the literature stain the spore walls faintly, or both walls and cytoplasm heavily, or only the cytoplasm.     

2-Amino-5-phosphono-3-pentenoic Acid,a New Amino Acid from N-1409 Substance,an Antagonist of Threonine

Discrimination of soy sauce samples consist of different 8 brands on the basis of principal components extracted from GC profiles of aroma concentrates was performed by stepwise discriminant analysis. Considering the results from sensory evaluation, classification of samples into 8, 3, and 2 groups was examined. Statistically significant difference was found among the 8 brands on the basis of principal components. The three groups consist of good, common, and inferior samples also classified correctly. Completely correct two way discrimination, good and bad, was accomplished in the same manner. These clear classifications suggested that evaluation and discrimination in sensory tests were performed by comparing the profiles of aroma substances.     

Violent Spore Release in Some Fungi Imperfecti

Violent spore discharge in the Hyphomycetes Alternaria tenuis,Memnoniella supsimplex, Curvularia lunata, C. geniculata, Corynesporacassiicola, and Zygophiala jamaicensis occurs after transferfrom a humid to a dry atmosphere. Mechanisms of discharge aresuggested.     

Skin Filling and Firming Activity of a Hyaluronic Acid Inducing Synthetic Tripeptide

International Journal of Peptide Research and Therapeutics - Aging of skin manifests in loss of volume and firming due to degradation of extracellular matrix components such as collagen and...     

A New Differentiation Inducer of Friend Leukemia Cells,Trichostatic Acid

FL-657B, which induced differentiation of Friend leukemia cells, was isolated from the culture fluid of Streptomyces sioyaensis and identified with trichostatic acid, a hydrolysis product of trichostatin A and C. FL-657B induced hemoglobin biosynthesis of both dimethyl sulfoxide-sensitive and -resistant Friend leukemia cells. FL-657B caused approximately 90% of the cells to be benzidine positive and reduced the growth to approximately 30~70% of the control at 2.42 μ/ml. Hemoglobin newly biosynthesized by the induction of FL-657B showed a UV absorption pattern similar to that from the normal mouse.