Influence Of Micro-Impurity On Protein Crystal Growth Studied By The Etch Figure Method

The investigation of the effect of micro impurity on crystal growth by optical microscopy has been validated. The results showed that the growth rate of a lysozyme crystal was affected even if the concentration of impurity of fluorescent-labeled lysozyme (abbreviation, F-lysozyme) was very small. Different concentrations of F-lysozyme had different effects on crystal growth rate. The growth rate decreased much more as F-lysozyme concentration increased. The density of incorporated F-lysozyme on different grown layers of a lysozyme crystal during crystal growth was obtained from the results of flat-bottomed etch pits density. (C) 2008 Elsevier B.V. All rights reserved.

Gain and noise figure of a double-pass waveguide amplifier based on Er/Yb-doped phosphate glass

A waveguide amplifier is fabricated by Ag+-Na+ two-step ion exchange on Er/Yb-doped phosphate glass. The spectroscopic performance of glass and the properties of channel waveguide are characterized. A double-pass configuration is adopted to measure the gain and noise figure (NF) of the waveguide amplifier, and the comparison of gain and NF for the single and double-pass configuration of the waveguide amplifier is presented. The results show that the double-pass configuration can make the gain increase from 8.8dB (net gain 2.2dB/cm) of the single-pass one to 14.6 dB (net gain 3.65 dB/cm) for small input power at 1534 nm, and the NF are all lower than 5.5dB for both the configurations.

Mitochondrial DNA variation, effective female population size and population history of the endangered Chinese sturgeon, Acipenser sinensis

The anadromous Chinese sturgeon (Acipenser sinensis), mainly endemic to the Yangtze River in China, is an endangered fish species. The natural population has declined since the Gezhouba Dam blocked its migratory route to the spawning grounds in 1981. In the near future, the completion of the Three Gorges Dam, the world's largest hydroelectric project, may further impact this species by altering the water flow of the Yangtze River. Little is currently known about the population genetic structure of the Chinese sturgeon. In this study, DNA sequence data were determined from the control region (D-loop) of the mitochondrial genome of adult sturgeons (n = 106) that were collected between 1995-2000. The molecular data were used to investigate genetic variation, effective female population size and population history of the Chinese sturgeon in the Yangtze River. Our results indicate that the reduction in abundance did not change genetic variation of the Chinese sturgeon, and that the population underwent an expansion in the past. AMOVA analysis indicated that 98.7% of the genetic variability occurred within each year's spawning populations, the year of collection had little influence on the diversity of annual temporary samples. The relative large effective female population size (N-ef) indicates that good potential exists for the recovery of this species in the future. Strikingly, the ratio of N-ef to the census female population size (N-f) is unusually high (0.77-0.93). This may be the result of a current bottleneck in the population of the Chinese sturgeon that is likely caused by human intervention.

Transport of anti-sperm monoclonal IGA and IGC into murine male and female genital tracts from blood - Effect of sex hormones

Ab levels in the genital tract may be important in fertility and in preventing sexually transmitted diseases, In this study, I-125-labeled polymer or monomer mAb IgA (C4pIgA or C4mIgA) and IgC2b (C4IgC) to murine lactate dehydrogenase C4 and a polymer mAb IgA (npIgA) not cross-reacting with mouse sperm were intravenously injected into BALB/c mice, and the relative distribution of these Abs was determined. Polymer IgA was transported much more efficiently into the genital tract, trachea, and duodenum of both sexes than C4IgG and C4 mIgA (p < 0.01), The transport of polymer IgA (C4pIgA and npIgA) into the male genital tract greatly increased following orchiectomy (p < 0.01); this change was not affected by testosterone, suggesting that the unknown regulatory factor(s) from the testis may suppress polymer IgA transport, However, the transport of polymer IgA into female genital tissues was significantly decreased by ovariectomy (p < 0.01); this decline can be rectified by P-estradiol but not progesterone treatment, suggesting that estradiol may stimulate polymer IgA transport, Furthermore, the transport of C4IgG into tissues of the Fallopian tubes and the uterus was significantly decreased by treatment with progesterone (p < 0.01). Together, these findings indicate that serum polymer IgA can be transported selectively into the genital tracts of both sexes, that this transport is strongly under the control of gonads, and that transport of Ige into the Fallopian tubes and uterus is downregulated by progesterone.

Circulating immunoglobulin A- and immunoglobulin G-secreting hybridoma cells in peripheral blood preferably migrate to female genital tracts. The role of sex hormones

Antigen-specific circulating immunoglobulin-secreting cells (ISC) migrate to various secondary and tertiary lymphoid tissues. To understand the migration of the cells into the genital tract and its regulation by sex hormones, spleen-derived SG2 hybridoma cells secreting immunoglobulin G2b (IgG2b) and Peyer's patch-derived PA4 hybridoma cells secreting polymer IgA were labelled with (3) H-TdR, and intravenously injected into syngeneic mice of both sexes. Using flow cytometry, surface molecular markers of plasma cells, CD38 and CD138, and adhesion molecules, CD49d, CD162, and CD11a were found to be positive in SG2 and PA4 cells, but CD62L, alpha4beta7 and CD44 were not expressed on these cells. The relative distribution indexes (RDIs) of the cells in genital tract and other tissues were measured. The means of RDIs of SG2 and PA4 cells in female genital tissues were 6.5 and 4.5 times as many as the means in male genital tissues, respectively. The treatment of ovariectomized mice with beta-oestradiol significantly increased the RDIs of PA4 cells in cervix and vagina, but decreased the RDIs of SG2 cells in vagina, horn of uterus, uterus and rectum (P <0.05). Progesterone treatment increased the RDIs of PA4 cells in vagina and rectum (P <0.05). The treatment with testosterone significantly increased the RDIs of SG2 and PA4 cells in epididymis and accessory sex glands (P <0.05). These results demonstrate that the female genital tract is the preferable site for the migration of circulating hybridoma cells to the male genital tract, and sex hormones play an important role in regulation of the migration of circulating ISC to genital tracts.

Deceptive female oviposition behaviour elicits male ejaculation in the European bitterling

In European bitterling Rhodeus amarus, fish that lay their eggs in the gill chambers of living freshwater mussels, females perform conspicuous behaviours associated with spawning that increases the probability of males performing ejaculatory behaviour and participating in a spawning. A significant positive association was detected between behaviour in which a female performs a spawning action but without releasing eggs, here termed 'deceptive female oviposition', and ejaculatory behaviour by courting males.

First description of the male and redescription of the female of Philometra clavaeceps Dogiel and Akhmerov, 1959 (Nematoda : Philometridae), a parasite of east Asian cyprinid fish

The first description of the male and a redescription of the female of the nematode Philometra clavaeceps Dogiel and Akhmerov, 1959, a parasite of east Asian cyprinids, are presented on the basis of specimens collected from Culter erythropterus Basilewsky and Culler dabryi Bleeker from Liangzi Lake (the Yangtze River basin), Hubei Province, central China. Gravid females from the fish abdominal cavity, penetrating often into ovaries, occurred in May-June, whereas conspecific males and young mature females on the swimbladder were recorded in January. Philometra clavaeceps seems to have a pronounced annual maturation cycle in the locality. The finding of P. clavaeceps in C. dabryi represents a new host record.

Estradiol stimulates growth hormone production in female goldfish

The effects of estradiol (E(2)) on growth hormone (GH) production was investigated in gonad-intact female goldfish. It was first necessary to generate a specific antibody for use in immunocytochemistry, Western, and dot-blot analyses of GH production. To accomplish this, grass carp GH (gcGH) cDNA was cloned by the reverse transcription polymerase chain reaction (RT-PCR) and expressed in Echerichia coli and a specific polyclonal antibody to recombinant gcGH was generated in the rabbit. In Western blot, the anti-gcGH antibody specifically immunoreacted with recombinant gcGH, purified natural common carp GH, and with a single 21.5-kDa GH form from pituitary extracts of grass carp, common carp, goldfish, and zebrafish but not salmon, trout, or tilapia. Intraperitoneal injection of the recombinant gcGH enhanced the growth rates of juvenile common carp demonstrating biological activity of this GH preparation. Electron microscopic studies showed that the anti-gcGH-I antibody specifically reacted with GH localized in the secretory granules of the goldfish somatotroph. Using anti-gcGH-I in a dot-blot assay, it was found that in vivo implantation of solid silastic pellets containing E(2) (100 mu g/g body weight for 5 days) increased pituitary GH content by 150% in female goldfish. In a second, independent study employing a previously characterized anticommon carp GH antibody for radioimmunoassay, it was found that E(2) increased pituitary GH content by 170% and serum GH levels by approximately 350%. The E(2)-induced hypersecretion of GH and increase in pituitary GH levels was not associated with changes in steady-state pituitary GH mRNA levels, suggesting that this sex steroid may enhance GH synthesis at the posttranscriptional or translational level. Previous observations indicate that GH can stimulate ovarian E(2) production. The present results show that E(2) can in turn stimulate GH production, indicating the existence of a novel pituitary GH-ovarian feedback system in goldfish. (C) 1997 Academic Press.