一氧化氮与哺乳动物卵泡发育

一氧化氮作为一种分子物质参与哺乳动物生殖活动,参与卵泡发育周期的各个阶段,如原始卵泡、腔前卵泡、有腔卵泡,排卵和黄体阶段。文章主要围绕卵泡发育的各个阶段,一氧化氮合成酶在卵泡中不同细胞中的定位,一氧化氮与卵母细胞的成熟、排卵及卵泡闭锁方面进行综述。     

牛卵巢内卵泡及卵母细胞生长发育的组织学研究

随机摘取牛离体卵巢18枚,常规石蜡切片,光镜下共观察卵泡5 818个,并测得卵泡、卵母细胞直径和透明带厚度（平均值）。结果:在整个卵泡发育过程中,卵泡与卵母细胞发育是完全显著正相关（P<0.01,R=0.9906）,其中腔前期P<0.01,R=0.9917,有腔期P<0.01,R=0.9951。腔前卵泡时期,卵泡和其卵母细胞直径增长幅度大体相等,而从有腔卵泡始,卵泡生长速度远远大于其卵母细胞。透明带与卵母细胞发育呈不显著正相关（P>0.05,R=0.9521）。     

Expression of Vascular Endothelial Growth Factor Receptors in Bovine Cystic Follicles

Cystic follicles have excess fluid derived from blood flow in the theca interna of the follicle; therefore, the vasculature network is related to cystic follicle formation. Vascular endothelial growth factor (VEGF) is a potent stimulator of blood vessel permeability and angiogenesis. The aim of this study was to examine the expression of VEGF receptors proteins and mRNA in cystic follicles to elucidate the VEGF system in cystic follicles. The expression of protein for VEGF receptors; fms‐like‐tyrosine kinase‐1 (Flt‐1) and foetal liver kinase‐1 (Flk‐1) was detected by the immunohistochemical method. The mRNA expression of Flt‐1 and Flk‐1 in cystic follicles was determined by RT‐PCR. Concentration of oestradiol‐17β and progesterone in the follicular fluid of cystic follicles was determined using ELISA. Flt‐1‐ and Flk‐1 proteins were localized in granulosa and theca interna cells and endothelial cells of theca layers. The intensity of Flt‐1 and Flk‐1 immunoreaction was similar among cystic follicles with various ratios of oestradiol‐17β/progesterone concentrations. The expression of Flt‐1 and Flk‐1 mRNA was similar, regardless of the ratio of oestradiol‐17β to progesterone in follicular fluid. These results demonstrate that cystic follicles have both VEGF receptors in the granulosa and theca interna layers, which may be responsible for the increased permeability of microvessels, causing the accumulation of follicular fluid in cystic follicles.     

Foetal Growth Curves and Seasonal Breeding in the Natal Clinging Bat Miniopterus Schreibersi Natalensis

Growth of the foetus of Miniopterus schreibersi natalensis is described. The gestation period in this subspecies is 240 days of which 120 days is the period of delayed implantation. Birth mass is taken as 2,7 g from measurements of near-term foetuses. Foetal growth follows a typical J-shaped curve during the last half of the gestation period. Young of M. s. natalensis are proportionately lighter at birth than many other mammals.     

Allometric Study on the Relationship between the Growth of Ovarian Follicles and Oocytes in Domestic Cats

The relationship between the growth of preantral and antral follicles and that of their oocytes in ovaries of domestic cats (Felis catus) was analyzed. Eight hundred and five pairs of follicles and oocytes from the ovaries of 51 female cats were collected, and only healthy and fresh follicles and oocytes with or without zona pellucida were used in this study. Immediately after collection, the diameters of follicles and their oocytes were measured. The relationship of the follicle diameter to the oocyte diameter was applied to four regression models and statistically analyzed. The best fitting model was found to be a hyperbolic regression (the coefficient of determination was 0.976 between the follicles and their oocytes with a zona pellucida, y=184x/(x+0.0738); the coefficient of determination was 0.983 between the follicles and their oocytes without a zona pellucida, y=122x/(x+0.0301)). The differentiated equations for the hyperbolic curves in the oocytes with or without a zona pellucida and the follicles were found to be y'=13.6/(x+0.0738)(2) and y'=3.67/(x+0.0301)(2), where y and x were the diameters of the oocytes (μm) and follicles (mm), respectively. When follicles grew to a size larger than 0.4 mm in diameter, the growth rates of their oocytes calculated by the differentiation equations showed an asymptotic depression around zero. Thus, it was suggested that when the follicles grew to a size larger than 0.4 mm in diameter, their oocytes reached full size and ceased to grow and that the zona pellucida stopped growing when the diameter of the follicles reached 0.3 mm in domestic cats.     

成纤维细胞生长因子FGF11、13、18对小鼠毛囊第一生长周期作用的研究

为了探究成纤维生长因子家族(Fibroblast growth factor families,FGFs)中,FGF11、13、18对毛囊的生长发育的作用,本研究以3/5/8/13/16/18/20/23日龄小鼠背部皮肤为试验样本,利用免疫组织化学技术、实时荧光定量PCR和蛋白免疫印迹技术检测FGF11、FGF13、FGF18基因及蛋白在小鼠背部皮肤的分布和表达情况。定位结果显示:FGF11、FGF13、FGF18在皮肤真皮乳头、毛基质、内根鞘、外根鞘和皮脂腺表达,而FGF13在膨大部、基底层和表皮也表达,FGF18也表达在膨大部和表皮。定量结果均显示:FGF11的表达没有一定的规律;FGF13在13日龄表达量最低,从16日龄开始上升;FGF18从3日龄表达量开始降低,16日龄降到最低,18日龄开始上升。提示:FGF11对小鼠毛囊第一生长周期可能没有明显和特定的调节作用;FGF13可能对毛囊的自我更新有一定的作用,诱导毛囊从静止期向再生长期过渡,促进毛囊生长;而FGF18在毛囊生长周期中从静止期向生长期过度有一定的作用,可促使毛囊从静止期进入再生长期。     

一氧化氮对猪腔前卵泡生长发育的影响

旨在研究在培养液中添加不同浓度（0、0.001、0.01、0.1和1 mmol.L^-1）的一氧化氮供体硝普钠（Sodium Nitroprusside,SNP）对猪腔前卵泡体外生长发育的影响。结果显示,体外培养后,各处理组卵泡直径均增加,但未达显著水平（P〉0.05）;第6天1 mmol.L^-1SNP处理组卵泡存活率要显著低于1μmol.L^-1SNP（61.61%vs81.52%,P〈0.05）,与其它各组间差异不显著（P〉0.05）;卵泡成腔率在第4天以1μmol.L^-1SNP组最高,达到50%;第6天,1μmol.L^-1SNP组的卵泡成腔率显著高于0.1和1 mmol.L^-1SNP组（73.07%vs50%,47.62%,P〈0.05）,也高于对照组和0.01 mmol.L^-1SNP组,但差异不显著（P〉0.05）。培养结束（6 d）后,除1mmol.L^-1SNP组卵母细胞正常率显著低于1μmol.L^-1SNP组（71.21%vs 48.18%,P〈0.05）外,其余各组间差异不显著（P〉0.05）,其中0.001 mmol.L^-1SNP组卵母细胞正常率最高,为71.21%;0.001 mmol.L^-1SNP组COC回收率要显著高于其余各组（37.27%vs 22.88%、25.59%、20.74%和19.39%,P〈0.05）。结果表明,NO对猪腔前卵泡的存活、发育成腔及卵母细胞发育都有促进作用,但高浓度会产生毒性作用。     

Effects of Nitric Oxide on the Growth and Development of Porcine Preantral Follicles Cultured in Vitro

<正>In order to investigate the effects of nitric oxide(NO) on the growth and development of porcine preantral follicles,we treated the follicles with different concentrations of sodium nitroprusside(SNP,0, 0.001,0.01,0.1 and 1 mmol/L),a NO donor.The results showed that the follicle diameter increased during in vitro culture,but there were no significant differences between the treatments(P0.05);the survival rate in the 1 mmol/L SNP group was significantly lower than that in the 1μmol/L SNP group(61.61% vs 81.52%,P0.05),but no significant differences were found between other treatments(P0.05);the rate of antrum formation in the 1μmol/L SNP group peaked at 50%on day 4,and the rate in the 1μmol/L SNP group on day 6 was higher than that in the 0.01 mmol/L SNP group;in addition,the rate of antrum formation in the 1μmol/L SNP group was significantly higher than that in the 0.1 and 1 mmol/L SNP groups (Day 6:73.07%vs 50%,47.62%,P0.05).After 6 days of culture,the proportion of normal oocytes in the1 mmol/L SNP group was significantly lower than that in the 1μmol/L SNP group(71.21%vs 48.18%, P0.05),with no significant differences between other treatments(P0.05).The recovery rate of cumulus cells oocyte complexes(COCs) in the 1μmol/L SNP group was significantly higher than that in the controls and all other treatments(37.27%vs 22.88%,25.59%,20.74%and 19.39%,P0.05).The results indicate that during the in vitro culture of porcine preantral follicles,low concentration of NO released from SNP improves growth and development of oocytes and follicular antrum formation while high levels of NO are toxic to follicular survival.     

牛次级卵泡和三级卵泡前期生长发育的组织学研究

通过对牛次级卵泡和三级卵泡前期生长发育的组织学研究 ,探讨了次级卵泡和三级卵泡前期的生长发育规律。结果表明 :在卵泡生长发育过程中 ,卵泡颗粒细胞层数达 5～ 6层时 ,开始出现不连续卵泡腔 ;其层数在 8层以上则以连续腔为主 (占 94 .74 % ) ,连续腔出现最多的层数为 8～ 16层 (占 84 .2 1% )。次级卵泡在颗粒细胞层数达到 3～ 4层时 ,已形成完整的透明带 ,颗粒细胞层数达到 5层时 ,透明带增厚。随着颗粒细胞层数的增多 ,卵泡直径和卵母细胞直径均增大。次级卵泡卵母细胞直径的增长和卵泡直径增长速度基本接近 ;而进入有腔卵泡阶段 ,卵母细胞直径的增长速度相对于其卵泡直径的增长缓慢。次级卵泡颗粒细胞层数在 2～ 5层 ;颗粒细胞层数达 5层之后进入三级卵泡初期阶段     

Pasture research in Natal

Uittreksel

Die benutting van gespaarde suurveld skep praktiese probleme. As gevolg van die ontwikkeling van hoë proteien‐ en stikstoflekke is dit nou moontlik om gespaarde veld af te wei. Verslag word gedoen van proewe oor drie winters vvaar gespaarde suurveld, òf deur skape, òf deur beeste afgewei is. Hergroei op hierdie veld die daaropvolgende somer is vergelyk met die hergroei van veld wat in die winter lig bewei of gladnie bewei is nie en dan in die lente skoongebrand of skoongesny is. Waar bevveiding nie te straf was nie, is daar geen aanduiding dat skoonwei nadeliger was as enige behandeling wat lentebrand ingesluit het. Temperatuurlesings is geneem en grondvogbebepalings is gedoen op beweide en onbeweide veld. Dit is opgemerk dat veld wat vroeg in die winter afgewei is, vroeg die daaropvolgende lente bot.     

Expression Pattern of Vascular Endothelial Growth Factor in Canine Folliculogenesis and its Effect on the Growth and Development of Follicles after Ovarian Organ Culture

In this study, the expressions of VEGF in dog follicles were detected by immunohistochemistry and the effects of VEGF treatment on the primordial to primary follicle transition and on subsequent follicle progression were examined using a dog ovary organ culture system. The frozen‐thawed canine ovarian follicles within slices of ovarian cortical tissue were cultured for 7 and 14 days in presence or absence of VEGF. After culture, the ovaries were fixed, sectioned, stained and counted for morphologic analysis. The results showed that VEGF was expressed in the theca cells of antral follicles and in the granulosa cells nearest the oocyte in preantral follicle but not in granulosa cells of primordial and primary follicles; however, the VEGF protein was expressed in CL. After in vitro culture, VEGF caused a decrease in the number of primordial follicles and concomitant increase in the number of primary follicles that showed growth initiation and reached the secondary and preantral stages of development after 7 and 14 days. Follicular viability was also improved in the presence of VEGF after 7 and 14 days in culture. In conclusion, treatment with VEGF was found to promote the activation of primordial follicle development that could provide an alternative approach to stimulate early follicle development in dogs.     

Effects of Growth Hormone on In Situ Culture of Bovine Preantral Follicles are Dose Dependent

The objective of this study was to evaluate different concentrations of growth hormone (GH) on the development of bovine preantral follicles cultured included in the ovarian tissue (in situ) on the rates of morphologically normal, viable, primordial and developing follicles, as well as the oocyte and follicle diameter and ultrastructural analysis. Ovarian fragments collected from cows with no cross‐breeds defined were cultured in situ for 1 and 7 days in minimal essential medium (α‐MEM+) supplemented with different concentrations of recombinant human GH (0, 10, 25, 50 ng/ml). The ovarian fragments non‐cultured (control) and cultured were processed for classic histology, mechanical isolation and electron transmission microscopy (MET). The parameters underwent anova (Tukey′s and Dunnett′s tests) and chi‐square test (χ²). After 7 days of culture, the treatment with 50 ng/ml GH showed no differences with fresh control (p > 0.05) and had greater effectiveness than in the 0, 10 and 25 ng/ml GH concentrations of the morphologically normal follicles. Regarding the primordial follicles, a reduction was observed in the 50 ng/ml GH concentration concomitant with the significant increase in developing follicles, differing from both the fresh control and the other GH concentrations tested. In addition, 50 ng/ml GH showed a larger follicle and oocyte diameter when compared to the other treatments cultured. Similar structures were ultrastructurally observed in the control group, 50 ng/ml GH. Follicles cultured in 10 ng/ml GH showed nuclear invagination, vacuoles and lesioned basal membrane. Hence, it is concluded that 50 ng/ml GH is the most effective concentration for the development of preantral follicles cultured in situ.     

The Insulin‐like Growth Factor System: a Key Determinant Role in the Growth and Selection of Ovarian Follicles? A Comparative Species Study

The aim of the present paper is to make a comparative study of the expression of the elements of the insulin‐like growth factor (IGF) system in different mammalian species and thus illuminate their potential role in the process of ovarian folliculogenesis in mammals. In most mammalian species, IGFs and IGFBPs (in particular IGFBP‐2 and IGFBP‐4) are considered, respectively, as stimulators and inhibitors of follicular growth and maturation. In mammalian species, IGFs might play a key role in sensitizing ovarian granulosa cells to FSH action during terminal follicular growth. Concentrations of IGFBP‐2 and IGFBP‐4 in follicular fluid strongly decrease and increase during follicular growth and atresia, respectively, leading to an increase and a decrease in IGF bioavailability, respectively. The decrease in these IGFBPs is because of a decrease in mRNA expression (IGFBP‐2) and an increase in proteolytic degradation by PAPP‐A in follicular fluid (IGFBP‐2, IGFBP‐4 and IGFBP‐5), and likely participates in the selection of dominant follicles. In contrast, levels and/or sites of expression of IGF‐I, IGF‐II, IGFBP‐4, IGFBP‐5 and type II receptor in follicular cells strongly differ between mammalian species, suggesting that these phenomena might play species‐specific or secondary roles in ovarian folliculogenesis.     

The ecology of sandy beaches in Natal

Data from an ecological survey of four sandy beaches on the Natal coast of South Africa are presented. Physical parameters such as beach profile, particle size, moisture, Eh and carbonate content, as well as abundance, composition, biomass and distribution of both macrofauna and meiofauna were Investigated. A survey of the surf and swash zone mysids was also made. Natal beaches may be divided into two general types: (i) moderately exposed beaches of medium sand north of Blythdale with diverse meiofauna and typical sand beach macrofauna communities, and (ii) very exposed beaches of coarse sand south of Blythdale with true intertidal macrofauna often absent and a meiofauna dominated by large archiannelids.     

Cryopreservation of Sheep Primordial Follicles

The aim of this study was to evaluate the efficiency of 1 M dimethylsulphoxide (DMSO), ethylene glycol (EG), propylene glycol (PROH) and glycerol (GLY) to cryopreserve primordial follicles. The first evaluation was performed soon after cryopreservation and the second evaluation after 4 days of in vitro culture, using the cryoprotectants that allowed the higher results (higher follicular survival rate) after cryopreservation. The results after follicular isolation (control) and cryopreservation using 1 M DMSO, EG, PROH and GLY showed that the mean number (+/- SEM) of live follicles per millilitre was 3204 (100%) +/- 319.27, 2798 (87%) +/- 239.14, 2492 (78%) +/- 345.8, 448 (14%) +/- 46.3 and 208 (7%) +/- 75.26, respectively. Higher follicular survival was reported when DMSO and EG were used. Control follicles and follicles cryopreserved with these two cryoprotectants were cultured and the percentage of follicular survival was 55% (control), 42% (EG) and 34% (DMSO). Similar results were found between control and follicles cryopreserved with EG. In conclusion, 1 M EG is the most effective cryoprotectant to preserve primordial follicles isolated from ovaries of sheep.     

Natal patterns among registered dogs in the United States

Breed, geographic, and seasonal distributions of canine births registered with the American Kennel Club for the years 1971 to 1973, accompanied by litter size and sex ratio data, were studied. A few breeds accounted for a large portion of the births. The breed distribution of births changed as popularity of various canine types waxed and waned. The geographic distribution of births generally paralleled the pattern of human population and was relatively stable. A distinct, repetitive seasonal distribution of births was evident. Human intervention probably molded much of this pattern, but genetic factors and environmental conditions also were involved. Litter size and sex ratio varied primarily with breed rather than with region or season and hence appeared genetically based.     

Evidence of Australian bat lyssavirus infection in diverse Australian bat taxa

Historically, Australia was considered free of rabies and rabieslike viruses. Thus, the identification of Australian bat lyssavirus (ABLV) in 1996 in a debilitated bat found by a member of the public precipitated both public health consternation and a revision of lyssavirus taxonomy. Subsequent observational studies sought to elaborate the occurrence and frequency of ABLV infection in Australian bats. This paper describes the taxonomic diversity of bat species showing evidence of ABLV infection to better inform public health considerations. Blood and/or brain samples were collected from two cohorts of bats (wild‐caught and diagnostic submissions) from four Australian states or territories between April 1996 and October 2002. Fresh brain impression smears were tested for ABLV antigen using fluorescein‐labelled anti‐rabies monoclonal globulin (CENTOCOR) in a direct fluorescent antibody test; sera were tested for the presence of neutralising antibodies using a rapid fluorescent focus inhibition test. A total of 3,217 samples from 2,633 bats were collected and screened: brain samples from 1,461 wild‐caught bats and 1,086 submitted bats from at least 16 genera and seven families, and blood samples from 656 wild‐caught bats and 14 submitted bats from 14 genera and seven families. Evidence of ABLV infection was found in five of the six families of bats occurring in Australia, and in three of the four Australian states/territories surveyed, supporting the historic presence of the virus in Australia. While the infection prevalence in the wild‐caught cohort is evidently low, the significantly higher infection prevalence in rescued bats in urban settings represents a clear and present public health significance because of the higher risk of human exposure.