Splash seed dispersal by raindrops

Splash seed dispersal by raindrops was investigated for plants in southern Japan. Nine families, 10 genera and 19 species were confirmed as raindrop-dispersed plants. The 10 genera were Gentiana, Gratiola, Chrysosplenium, Mazus, Mitella, Ophiorrhiza, Sagina, Sedum, Trigonotis and Veronica. The method of splash rain dispersal in these species was clarified. Raindrop-dispersed species were all small herbaceous plants with a vertical pedicel and an apically opening fresh capsule when the seeds mature. Open capsules were cup-shaped or boat-shaped and can accommodate raindrops easily. The raindrops splashed the seeds from the capsule. In general, the seeds weighed very little, but they were heavier than powder or dust seeds dispersed by wind. A strong negative correlation was found between seed weight and the number of seeds per capsule. In the case of Trigonotis brevipes (Maxim.) Maxim., raindrops were received into the cup-shaped calyx-tube and dispersed the fruitlets. Some species, such as Gentiana thunbergii (G. Don) Griseb., Gentiana zollingeri Fawcett and Ophiorrhiza japonica Blume, had hydroscopic movement capsules that opened widely only when wet. Raindrop-dispersed plants were found in various habitats. For example, some plants grew together on rocks along the mountain torrents where splash water could easily be caught. The results of the laboratory and field experiments indicated that the dispersal distance of seeds by raindrops was 1m or less. For small herbaceous plants, splash dispersal by rain might be an effective and advantageous method of seed dispersal because dispersal is not affected by plant height.     

Stimulation of voltage-dependent calcium channels during capacitation and by progesterone in human sperm

To fertilize, mammalian sperm must undergo two sequential steps that require activation of calcium entry mechanisms, capacitation and acrosomal exocytosis, induced in the latter case by the egg zona pellucida glycoprotein ZP3 or by progesterone. Voltage-dependent calcium channels (VDCC) could participate in these processes. Since patch clamp recordings are extremely difficult in mature sperm, the activity of VDCC has been alternatively analyzed with optical detectors of membrane potential and intracellular calcium in sperm populations. Using this approach, we previously reported that in human sperm there is a voltage-dependent calcium influx system that strongly indicates that human sperm are endowed with functional VDCC. In this study we developed evidence indicating that calcium influx through VDCC is significantly stimulated during sperm in vitro capacitation and by progesterone action, which is present in the follicular fluid that surrounds the egg. The observed effects of capacitation and progesterone on VDCC may be physiologically significant for sperm-egg interaction.     

Purification and characterization of KpsT,the ATP-binding component of the ABC-capsule exporter of Escherichia coli K1

The K1 capsule, an alpha(2,8)-linked polymer of sialic acid, is an important virulence determinant of invasive Escherichia coli. The 17-kb kps gene cluster of E. coli K1 encodes the information necessary for capsule expression at the cell surface. Two proteins, KpsM and KpsT, play a role in the transport of capsular polysaccharide across the cytoplasmic membrane, utilizing the energy from ATP hydrolysis. They belong to the ATP-binding cassette superfamily of transport proteins. In this study, we purified KpsT in its native form and show that the purified protein is able to bind ATP, undergo an ATP-dependent conformational change and hydrolyze ATP. Protease accessibility studies demonstrate the in vivo interaction between KpsM and KpsT.     

Microbial hydroxylation of progesterone with Acremonium strictum

Microbial hydroxylation of progesterone occurred in the culture of Acremonium strictum PTCC 5282 to produce two hydroxylated pregnene-like steroids. The metabolites were purified and characterized using spectroscopic methods and identified as 15alpha-hydroxyprogesterone and 15alpha-hydroxydeoxycorticosterone.     

Anti-glucocorticoid effects of progesterone in vivo on rat adipose tissue metabolism

Steroid hormones seem to be important for adipose tissue metabolism and accumulation. As progesterone has been suggested to modulate the glucocorticoid effects, the interactions between glucocortioid and progesterone on adipose tissue metabolism were investigated.Forty-eight male Wistar rats were adrenectomized and divided into four groups; controls (treated with vehicle only), dexamethasone treated (10 micro g per rat), progesterone treated (5mg per rat) and the last group received both dexamethasone and progesterone.The dexamethasone-treated group had a significant loss of body weight and smaller intra-abdominal fat depots compared to the control group in addition, dexamethasone increased LPL-activity and increased catecholamine stimulated lipolysis. When progesterone was given concomitantly the dexamethasone effects on adipose tissue mass, LPL-activity and lipolysis were blocked. When given alone progesterone had no influence on body weight, amount of adipose tissue, lipolysis or LPL-activity.These data indicate that progesterone acts as an anti-glucocorticoid in adipose tissue in vivo, thus attenuating the glucocorticoid effect on adipose tissue metabolism.     

DNA slows dissociation of progesterone receptor-steroid ligand complexes

Steroid ligands are known to affect the interactions of their respective receptors with DNA. In the present study, the possibility of DNA interference in progesterone receptor-ligand interactions was investigated. An oligonucleotide containing a hormone response element (HRE) was shown to decrease the dissociation rate of complexes of [3H]progesterone or [3H]16alpha,17alpha-cycloalkanoprogesterones with PRs from rabbit and rat uterine cytosol. The extent to which the oligonucleotide affected the dissociation constant varied from about 4- to 1.5-fold depending on the ligand structure and was ranked in the following order: progesterone>16alpha,17alpha-cyclopropanoprogesterone approximately 16alpha,17alpha-cyclopentanoprogesterone>/=16alpha,17alpha-cyclohex-2'-enoprogesterone approximately 6alpha-methyl-16alpha,17alpha-cyclohexanoprogesterone>/=16alpha,17alpha-cyclohexanoprogesterone. The control oligonucleotide lacking HRE had a weak effect, if any, on the dissociation kinetics. No influence of the HRE-containing oligonucleotide on the equilibrium binding of ligands to PR was observed. The results suggest that the DNA partner affects binding of PR to its ligand.     

Tumour biology of a breast cancer at least partly reflects the biology of the tissue/epithelial cell of origin at the time of initiation - a hypothesis

A hypothesis is presented suggesting that initiation of breast epithelial cell freezes the cell at least partly according to the development/differention of cell at the time of initiation. Tumour biology will mimic the physiology of normal cell development at the time of initiation and this is preserved at least partly onwards. Also preferentially, tumours will develop from the cell type that is proliferating at the time of initiation. This may explain the overrepresentation of different types of histology in breast cancer in relation to age of the woman. The development of each tumour may follow at least partly a distinct pathway of evolution.     

Successful artificial insemination for indoor breeding in the Japanese monkey (Macaca fuscata) and the cynomolgus monkey (Macaca fascicularis)

Methods of artificial insemination (AI) for indoor breeding in the Japanese monkey and the Cynomolgus monkey were investigated. For the Japanese monkey AI was carried out in six females during the winter mating season and in six females during the summer non-mating season. During the mating season, semen was inseminated near ovulation time in natural menstrual cycles. In the mating season study, three females inseminated at the uterine cavity became pregnant. Three inseminated at the cervical canal failed to become pregnant. For the non-mating season study, ovulation was induced artificially by PMSG and hCG and AI was carried out near the induced ovulation time. In the non-mating season, no animals became pregnant. Of four Cynomolgus monkeys used, pregnancy occurred in two animals inseminated near ovulation time in natural menstrual cycles. AI occurred at the uterine cavity in one and cervical canal in the other. In both species ovulation was verified by laparoscopy. Semen was collected by penile electro-stimulation then diluted to 2.5 to 5.0×10⁷/ml with Whitten's medium. Diluted semen of 0.2l was inseminated at the uterine cavity or cervical canal. Our results indicate the usefulness of vaginal AI as a method of artificial indoor breeding.     

薄层扫描法测定保元肠疡胶囊中人参皂苷Rg_1的含量

本文报道了用双波长薄层扫描法测定中成药制剂保元肠疡胶囊中微量人参皂苷Ｒｇ１的含量．方法稳定、检测灵敏度高,变异系数小于５％．可作为该成药制剂的质量控制标准．     

Influences of milk components on biofilm formation of Cronobacter spp. (Enterobacter sakazakii)

Aim:  To determine the critical component(s) of skim milk for biofilm formation of Cronobacter species.
Methods and Results:  Biofilm forming ability of 72 Cronobacter strains in skim milk preparation was assayed by crystal violet staining. The results revealed that whey protein and casein are more important determinants of skim milk for biofilm formation than lactose, although there was a wide variation in biofilm forming ability. Biofilm structure and capsular material of six strains exhibiting different biofilm forming ability was investigated via electron microscopes. Scanning electron microscopy showed visually that while the strong biofilm formers (E27B, FSM 30 and 2·82) resulted in almost complete coagulation of skim milk, the weak biofilm formers (55, FSM 290 and 2·84) caused less coagulation. No capsule was clearly delineated in transmission electron micrographs of either strong or weak biofilm formers.
Conclusion:  These results indicate that, for biofilm formation of Cronobacter species in skim milk, nitrogen source is probably a more important determinant than carbohydrate, and that strong biofilm formers are responsible for substantial coagulation of skim milk.
Significance and Impact of the Study:  This study provides information for better understanding of the underlying mechanisms by which Cronobacter species form biofilm in infant formula milk.