单胞锈菌属一新记录种

A species of the genus Uromyces was found to be unrecorded from China.Uromyces onobrychidis (Desm.) Lév., Ann. Sc. Nat. 3. Sér. 8: 371, 1847.Spermagonia and aecia unknown. Uredinia ramicolous or amphigenous, scattered, rounded or elliptic, orange yellow, 0.3～0.5mm in diam., urediniospores ellipsoid or obovoid, 21.5～34.7 × 13.5～ 19.5μm, wall 1～ 1.7μm thich, pale yellowish, echinulate with spines spaced 2～ 2.6μm, pores 2～ 4, equatorial; telia ramicolous or amphigenous, sparsed or loosely grouped, rounded or elliptic, 0.4～0.8mm in diam., chocolate-brown, pulverulent; teliospores obovoid, ellipsoid or globose, 17.5～24.8 × 13.2～ 16.5μm, rounded at the apex, with a subhyaline papilla about 1～ 1.7μmhigh; wall 0.7～ 1.31μm thick, pale-brown, indistinctly verrucose, pedicels hyaline, short, deciduous. Supported by the National natural sciences foundation (NO. 39360069)     

Sperm dimorphism and spermatozeugmata in the commensal bivalve Pseudopythina macrophthalmensis (Galeommatoidea, Kelliidae)

The bivalve Pseudopythina macrophthalmensis (Galeommatoidea) is a commensal with the crab Macrophthalmus convexus (Ocypodidae) in Okinawa Prefecture, Japan. It is a protandric hermaphrodite which incubates the 65-μm large ova in the suprabranchial cavity. The species produces two types of sperm, which were studied with the electron microscope. The euspermatozoon has an elongate 2.8-μm-long, pointed acrosome, a slender 12- to 13-μm-long nucleus and a middlepiece containing several closely packed mitochondria arranged as a 5.5- to 6.0-μm-long sheath around the basis of the flagellum. The paraspermato- zoon is vermiform, 220-μm-long and up to 5-μm-broad. Anteriorly there is a ca 7-μm-long bullet-shaped acrosome followed by a subcylindrical 3.0- to 4.7-μm-long nucleus. Adjacent to the nucleus occurs a bundle of 26–42 40-μm-long flagella. The cytoplasm is packed with spherical lipid droplets and ovoid granules of unknown composition. Sperm of both types aggregate to form spermatozeugmata, which were found in the posterior mantle cavity or in paired seminal receptacles. Within the receptacles the euspermatozoa dissociate themselves from the spermatozeugma and become attached to the epithelial lining of the receptacle whereas the paraspermatozoa presumably disintegrate. The possible significance of the two types of sperm is discussed in the light of their presumed functions in gastropods. Accepted: 9 November 2000     

Morphological changes in Schlemm's canal in treated and newly diagnosed untreated glaucomatous eyes

A custom built 1310 nm center wavelength swept source optical coherence tomography instrument was used to measure morphological changes in treated and newly diagnosed untreated glaucomatous human Schlemm’s canal(SC).Thirty-seven primary open-angle glaucoma patients were divided into two groups depending on the patients having been treated or not.The statistical results showed that there were significant differences between the treated and untreated groups’SC areas(treated,7935.6875±680.003μm2;untreated,3890.71875±871.49844μm2;P0.001),the circumferences(treated,580.37891±44.96529μm;untreated,381.9026±41.22123μm;P0.001),and the long diameters(treated,272.87806±25.7254μm;untreated,185.24047±19.72786μm;P0.001).We hypothesize that,after drug treatment,the SC will expand and the morphometric values especially the areas will become larger,thus helping to reduce intraocular pressure.     

芸香科山小橘属一新种——长瓣山小橘

Glycosmis longipetala F. J. Mou ＆ D. X. Zhang is described from Guangxi and Yunnan provinces in southwestern China. The new species is similar to G. cochinchinensis （Lour.） Pierre ex Engl. by its simple leaves, but distinguishable in having long-elliptic or oblanceolate （vs. ovate） leaves, long-ovoid to ellipsoid （vs. ovoid） floral buds, ovaries with many tubercles （vs. smooth） and glabrous （vs. pubescent） stamens. The pollen grains of the new species are 23.9±3.09 （20.8-27.0）×22.0±1.80 （20.4-24.4）μm in size with reticulate exine ornamentation in equatorial area and foveolate in polar area. The chromosome number of the new species is 2n=72.     

中国丛枝菌根真菌一新记录种

疣壁盾巨孢囊霉图1-5 Scutellospora verrucosa (Koske & Walker) Walker & Sanders, Mycologia, 77(5): 702, 1985. Fig.1-5 孢子单生于土壤中,球形至近球形,桔黄至桔棕色,212-325×212-325μm.孢子壁三层(W1-W3).W1易碎,透明至桔黄色,0.7-1.8μm厚,饰有密集、矮小的圆形疣突,疣突基部0.5-1.0×0.5-1.0μm,高0.5-1.2μm.W2紧贴W1,层状壁,桔黄至桔棕色,半透明,6.2-7.5μm厚,在Melzer's试剂中呈红棕色反应.W3为萌发壁(gerninal walls,GW),包括两层透明薄壁(L1和L2),L1厚度不超过0.5μm,L2 0.6-1.2μm厚,两层壁常紧贴在一起,均无Melzer's试剂反应.在成熟孢子中,由W3折叠形成一个卵圆形、结构复杂的发芽盾室(germination shield),80-90×130-150μm,芽管由发芽盾室上萌发.球茎状细胞(suspensor-like cell)黄棕色,比孢子颜色稍深,40-60×35-60μm,壁厚2-3μm,近孢子处加厚至7μm左右.连孢菌丝壁薄,有隔,直径3-4μm.土生辅助细胞(auxiliary cell)未见.     

Enhanced in vitro hair growth at the air-liquid interface: minoxidil preserves the root sheath in cultured whisker follicles

Summary Inasmuch as hair follicles are difficult to maintain in culture, the study of hair biology using cultured hair follicles has met with only limited success. In our attempts to solve the problem of follicle degeneration, we cultured follicles at the air-surface interface on a modified collagen matrix (Gelfoam). In follicles cultured at the air-surface or submerged, we examined follicular morphology, hair shaft growth, sulfotransferase levels, cysteine incorporation, an expression of a tissue inhibitor of metalloproteinase (TIMP), and ultra-high sulfur keratin (UHSK). Follicles cultured at the air-liquid interface produced a 2.7-fold increase in hair growth and maintained an anagen-like morphology. Substrates such as nylon mesh seeded with fibroblasts, Full Thickness Skin?, or 5-μm polycarbonate filter also supported hair growth, whereas Gelfilm, GF-A glass filter, filter paper, or 1-μm polycarbonate filter did not. The UHSK expression was significantly higher in the air-liquid interface cultures compared to the submerged culture. Several potassium channel openers, including minoxidil, a minoxidil analog, and the pinacidil analog (P-1075), all stimulated significant cysteine incorporation in follicles. Minoxidil and its analog specifically preserved the follicular root sheath, in contrast to P-1075 which did not, indicating a difference in the two drug types. The preservation of the root sheath was measured by increased TIMP expression and sulfotransferase activity and indicates that the root sheath is a target tissue for minoxidil. Our results show that follicles cultured at the air-liquid interface maintain a better morphology and produced greater hair growth than follicles cultured on tissue culture plastic.     

Effect of 2,4-dichlorophenoxyacetic acid concentration on somatic embryogenesis and heritable variation in soybean [Glycine max (L) merr.]

Summary The frequency and quality of embryogenic response from cotyledons of immature zygotic soybean embryos varied with 2,4-dichlorophenoxyacetic acid (2,4-D) concentration in the culture medium. The frequency of variants among progeny of regenerated plants decreased with an increase of 2,4-D concentration. Teratogenic effects on embryo morphology and development were greatest at 22.5μM 2,4-D and decreased with increasing 2,4-D. At the lowest 2,4-D concentration tested, 22.5μM, morphologically abnormal, cotyledonary-stage somatic embryos were produced. Ten percent or less of these embryos converted to plants. Over the nine genotypes tested, 40% of the families derived from plants regenerated under a low 2,4-D concentration manifested heritable variation. In contrast, embryogeny was suppressed at the globular stage by the highest 2,4-D concentration tested, 200μM. Eighty to one-hundred percent of the embryos organized under this latter 2,4-D level converted to plants. Only 3% of the families from the progeny of plants regenerated under a high 2,4-D concentration exhibited heritable variation. This is Journal Paper No. J-14217 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa. Project No. 2974. The mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the United States Department of Agriculture or Iowa State University and does not imply its approval to the exclusion of other products that may be suitable. This work was supported, in part, by American Soybean Association grant no. 400-46-73-15-2763.     

An in vitro model for cell-cell interactions

Summary Heterotypic cell-cell interactions appear to be involved in the control of development and function in a wide variety of tissues. In the vasculature, endothelial cells and mural cells (smooth muscle cells or pericytes) make frequent contacts, suggesting a role for intercellular interactions in the regulation of vascular growth and function. We have previously grown endothelial cells and mural cells together in mixed cultures and found that heterocellular contact led to endothelial growth inhibition. However, this mixed culture system does not lend itself to the examination of the effects of contact on the phenotype of the individual cell types. We have therefore developed a co-culture system in which cells can be co-cultured across a porous membrane, permitting intercellular contact while maintaining pure cell populations. Co-culture of endothelial cells and smooth muscle cells across membranes with pore sizes of 0.02, 0.4, 0.6, and 0.8μm maintained the two cell types as homogeneous populations, whereas smooth muscle cells migrated across the membrane through pores of 2.0μm. Vascular cell co-culture across membranes with 0.8-μm pores resulted the inhibition of endothelial cell proliferation and the generation of conditioned media which inhibited endothelial cell growth. The arrangement of the cells in this co-culture system mimics thein vivo orientation of vascular cells in which mural cells are separated from the abluminal surface of the endothelium by a fenestrated internal elastic lamina or basement membrane. Because this co-culture system maintains separable populations of cells in contact or close proximity allowing for biochemical and molecular analyses of pure populations, it should prove useful for the study of cell-cell interactions in a variety of systems.