In vivo inhibition of megakaryocyte and platelet production by platelet factor 4 in mice.

The in vivo effect of human platelet factor 4 (PF4) on murine megakaryocytopoiesis and thrombopoiesis was studied. Administration of PF4 induced a dose-dependent decrease in the numbers of megakaryocytes and their progenitor cells (CFU-MK), continuing for 1 week after the injection. However, the size of megakaryocytes and their colonies was not changed following PF4 injection. Platelet levels were significantly decreased at days 3-4. The number of CFU-GM was decreased at days 1-2. White blood cells and hemoglobin were unaffected by PF4. These data indicate that PF4 inhibits megakaryocyte and platelet production in vivo by acting on the early stage of megakaryocyte development.     

Optimal nonsingular control of fed-batch fermentation

Presented is a new simple method for multidimensional optimization of fed-batch fermentations based on the use of the orthogonal collocation technique. Considered is the problem of determination of optimal programs for fermentor temperature, substrate concentration in feed, feeding profile, and process duration. By reformulation of the state and control variables is obtained a nonsingular form of the optimization problem which has considerable advantage over the singular case since a complicated procedure for determination of switching times for feeding is avoided. The approximation of the state variables by Lagrange polynomials enables simple incorporation of split boundary conditions in the approximation, and the use of orthogonal collocations provides stability for integration of state and costate variables. The interpolation points are selected to obtain highest accuracy for approximation of the objective functional by the Radau-Lobatto formula. The control variables are determined by optimization of the Hamiltonian at the collocation points with the DFP method. Constraints are imposed on state and control variables.The method is applied for a homogeneous model of fermentation with volume, substrate, biomass, and product concentrations as the state variables. Computer study shows considerable simplicity of the method, its high accuracy for low order of approximation, and efficient convergence.     

Assembly of the mammalian muscle acetylcholine receptor in transfected COS cells

We have investigated the mechanisms of assembly and transport to the cell surface of the mouse muscle nicotinic acetylcholine receptor (AChR) in transiently transfected COS cells. In cells transfected with all four subunit cDNAs, AChR was expressed on the surface with properties resembling those seen in mouse muscle cells (Gu, Y., A. F. Franco, Jr., P.D. Gardner, J. B. Lansman, J. R. Forsayeth, and Z. W. Hall. 1990. Neuron. 5:147-157). When incomplete combinations of AChR subunits were expressed, surface binding of 125I-alpha-bungarotoxin was not detected except in the case of alpha beta gamma which expressed less than 15% of that seen with all four subunits. Immunoprecipitation and sucrose gradient sedimentation experiments showed that in cells expressing pairs of subunits, alpha delta and alpha gamma heterodimers were formed, but alpha beta was not. When three subunits were expressed, alpha delta beta and alpha gamma beta complexes were formed. Variation of the ratios of the four subunit cDNAs used in the transfection mixture showed that surface AChR expression was decreased by high concentrations of delta or gamma cDNAs in a mutually competitive manner. High expression of delta or gamma subunits also each inhibited formation of a heterodimer with alpha and the other subunit. These results are consistent with a defined pathway for AChR assembly in which alpha delta and alpha gamma heterodimers are formed first, followed by association with the beta subunit and with each other to form the complete AChR.     

Cold spray metal embedment: an innovative antifouling technology

The study demonstrates that embedment of copper particles into thermoplastic polymers (polymers) using cold spray technology is an effective deterrent against fouling organisms. Two polymers, high-density polyethylene (HDPE) and nylon were metallised with copper powder using cold spray technology. After 250 days in the field, Cu-embedded HDPE and copper plate controls were completely free of hard foulers compared to Cu-embedded nylon and polymer controls which were heavily fouled with both soft and hard fouling. Antifouling (AF) success is related to the interaction between the properties of the polymers (elastic modulus and hardness) and the cold spray process which affect particle embedment depth, and subsequently, the release of copper ions as determined by analytical techniques. Embedding metal using cold spray equipment is shown to be an effective AF technology for polymers, in particular those that are difficult to treat with standard AF coatings, with efficacy being a function of the interaction between the cold spray metal and the polymer recipient.     

Anti-cancer activities of tea epigallocatechin-3-gallate in breast cancer patients under radiotherapy

The purpose of this study was to test the hypothesis that administration of epigallocatechin-3-gallate (EGCG), a polyphenol present in abundance in widely consumed tea, inhibits cell proliferation, invasion, and angiogenesis in breast cancer patients. EGCG in 400 mg capsules was orally administered three times daily to breast cancer patients undergoing treatment with radiotherapy. Parameters related to cell proliferation, invasion, and angiogenesis were analyzed while blood samples were collected at different time points to determine efficacy of the EGCG treatment. Compared to patients who received radiotherapy alone, those given radiotherapy plus EGCG for an extended time period (two to eight weeks) showed significantly lower serum levels of vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), and reduced activation of metalloproteinase-9 and metalloproteinase-2 (MMP9/MMP2). Addition of sera obtained from patients treated with combination of radiotherapy and EGCG feeding for 2-8 weeks to in vitro cultures of highly-metastatic human MDA-MB-231 breast cancer cells resulted in the following significant changes: (1) suppression of cell proliferation and invasion; (2) arrest of cell cycles at the G0/G1 phase; (3) reduction of activation of MMP9/MMP2, expressions of Bcl-2/Bax, c-Met receptor, NF-κB, and the phosphorylation of Akt. MDA-MB-231 cells exposed to 5-10 μM EGCG also showed significant augmentation of the apoptosis inducing effects of γ-radiation, concomitant with reduced NF-κB protein level and AKT phosphorylation. These results provide hitherto unreported evidence that EGCG potentiated efficacy of radiotherapy in breast cancer patients, and raise the possibility that this tea polyphenol has potential to be a therapeutic adjuvant against human metastatic breast cancer.     

Evolution of the tetraploid Anemone multifida (2n = 32) and hexaploid A. baldensis (2n = 48) (Ranunculaceae) was accompanied by rDNA loci loss and intergenomic translocation: evidence for their common genome origin

Background and Aims

In the genus Anemone two small groups of taxa occur with the highest ploidy levels 2n = 6x = 48, belonging to the closely related clades: the montane/alpine Baldensis clade and the more temperate Multifida clade. To understand the formation of polyploids within these groups, the evolution of allohexaploid A. baldensis (AABBDD, 2n = 6x = 48) from Europe and allotetraploid Anemone multifida (BBDD, 2n = 4x = 32) from America was analysed.

Methods

Internal transcribed spacer and non-transcribed spacer sequences were used as molecular markers for phylogenetic analyses. Cytogenetic studies, including genomic in situ hybridization with genomic DNA of potential parental species as probe, fluorescence in situ hybridization with 5S and 18S rDNA as probes and 18S rDNA restriction analyses, were used to identify the parental origin of chromosomes and to study genomic changes following polyploidization.

Key Results

This study shows that A. multifida (BBDD, 2n= 4x = 32) and A. baldensis (AABBDD, 2n = 6x = 48) are allopolyploids originating from the crosses of diploid members of the Multifida (donor of the A and B subgenomes) and Baldensis groups (donor of the D subgenome). The A and B subgenomes are closely related to the genomes of A. sylvestris, A. virginiana and A. cylindrica, indicating that these species or their progeny might be the ancestral donors of the B subgenome of A. multifida and A and B subgenomes of A. baldensis. Both polyploids have undergone genomic changes such as interchromosomal translocation affecting B and D subgenomes and changes at rDNA sites. Anemone multifida has lost the 35S rDNA loci characteristic of the maternal donor (B subgenome) and maintained only the rDNA loci of the paternal donor (D subgenome).

Conclusions

It is proposed that A. multifida and A. baldensis probably had a common ancestor and their evolution was facilitated by vegetation changes during the Quaternary, resulting in their present disjunctive distribution.     

Characterization of a xylanase from the newly isolated thermophilic Thermomyces lanuginosus CAU44 and its application in bread making

AIMS: A xylanase from the newly isolated thermophilic fungus, Thermomyces lanuginosus CAU44, was characterized and evaluated for its suitability in bread making. METHODS AND RESULTS: Xylanase was purified 3.5-fold to homogeneity with a recovery yield of 32.8%. It appeared as a single protein band on SDS-PAGE gel with a molecular mass of c. 25.6 kDa. The purified xylanase had an optimum pH of 6.2, and it was stable over pH 5.6-10.3. The optimal temperature of xylanase was 75 degrees C and it was stable up to 65 degrees C at pH 6.2. Study was further carried out to investigate the effect of the purified xylanase on the properties of wheat bread and its staling during storage. CONCLUSIONS: The purified xylanase from T. lanuginosus CAU44 was stable up to 65 degrees C and had a broad pH range. The presence of thermostable xylanase during bread making led to an improvement of the specific bread volume and better crumb texture. Besides, addition of xylanase provided an anti-staling effect. SIGNIFICANCE AND IMPACT OF THE STUDY: The xylanase from the newly isolated Thermomyces lanuginosus CAU44 shows great promise as a processing aid in the bread-making industry.     

Formaldehyde and some fully n-methylated substances in boar seminal fluids. Short communication

On the basis of recent observations it is supposed that seminal fluids may contain--mainly in hydroxymethyl groups--formaldehyde (HCHO) and quaternary ammonium compounds as potential HCHO generators, therefore, preliminary investigations were carried out for the identification of these compounds in pig seminal fluids using OPLC, HPLC and MALDI MS techniques. The fresh pig seminal fluid was frozen in liquid nitrogen, powdered and aliquots (0.25 g) were treated with 0.7 ml ethanolic dimedone solution. The suspension was centrifuged and the clear supernatant was used for analysis by OPLC or after dilution with HPLC or MALDI MS technique. After OPLC separation of formaldemethone the fully N-methylated compounds which are stayed on the start point were separated by OPLC using an other eluent system. It has been established that the HCHO is really a normal component of the pig seminal fluid, as well. It can be isolated and identified in dimedone adduct form. The measurable amount of HCHO depended on the concentration applied of dimedone. According to OPLC and MALDI MS investigations L-carnitine is the main quaternary ammonium compound in pig seminal fluid which can generate a protection of the sperm cells against environmental and other influences. Considerable differences have been found among individuals concerning concentrations of quaternary ammonium compounds in the seminal fluid of pigs.     

KF核及B(o)tzinger复合体内GABA能神经元向膈神经核的投射

实验在６只成年猫上进行。将ＷＧＡ－ＨＲＰ微量注入Ｃ５膈神经核内,通过逆行追踪及ＧＡＢＡ免疫组织化学ＦＩＴＣ荧光双重标记方法,研究了脑干内ＧＡＢＡ能神经元向膈神经核的投射。结果在脑桥ＫＦ核和面神经后核周围区（即Ｂｏｔｚｉｎｇｅｒ复合体）观察到ＧＡＢＡ－ＨＲＰ双标神经元。另外,在中缝大核、旁巨细胞外侧核及前庭神经核也观察到双标神经元。本实验结果表明：发自上述脑干神经核团,特别是ＫＦ核及Ｂｏｔｚｉｎｇｅ