RAMARIA SUBGENERA RAMARIA AND LAETICOLORA IN YUNNAN

Three taxa of Ramaria subgenus Ramaria, and 18 of subg. Laeticolora are reported from Yunnan Province. Of these 13 are considered new to science. Only one taxon (R. formosa) is considered of widespread distribution, the others being known olay from the Indo-Asian subcontinent. Wide distribution patterns, based on phenetic similarity, seem to be at the infraspecific to species complex level, but only rarely contaxie. New taxa are as follows: subg. Ramaria: R. eryuanensis; subg. Laeticolora: R. brunneipes, R. distinctissima, R. ephemeroderma, R. hilaris, R. lacviformosoides, R. linearioides, R. linearis, R. nanispora, R. rubri-attenuipcs, R. sino-conjunctipes, R. rubricarnata var. laeta, R. botrytoides var. microspora, and R. neoformosa var. sinensis. Keys to Yunnan taxa of Ramaria subgenera Ramarla and Laeticolora are furnished.     

A Freeze-Sectioning Method for Preparation of the Detergent-Resistant Cytoskeleton Identifies Stage-Specific Cytoskeleal Proteins and Associated mRNA in Xenopus Oocytes and Embryos

Proteins of the detergent-resistant cytoskeleton fraction and the detergent-soluble fraction from Xenopus oocytes and embryos are examined using a procedure which allows rapid and uniform extraction of tissues and large, single cells. SDS-polyacrylamide gels reveal only a few prominent cytoskeletal proteins in the early embryo, however qualitatively different proteins begin to appear after gastrulation. Incorporation of [³⁵S]-methionine into newly synthesized proteins indicates that there is synthesis and assembly of proteins into the cytoskeleton, but the amount remains low until after gastrulation. The use of nucleic acid probes for alpha-tubulin and actin mRNA indicates that about 80% of these mRNAs in the oocyte and meiotically mature egg are bound to the detergent-resistant cytoskeleton.     

Identification of thetrans-stilbene oxide-active glutathione transferase in human mononuclear leukocytes and in liver as GST1

A glutathione transferase from human mononuclear leukocytes with a high activity towardtrans-stilbene oxide (GT-tSBO) has been studied in liver and blood from fetus and adults and in blood from neonates. Using starch gel electrophoresis, different phenotypes of GST1 have been determined, GST1 0, GST1 1, and GST1 2. As judged from activity measurements and the fact that only those individuals who express the null allele of GST1, the GST1 0, which has a low activity towardtrans-stilbene oxide, it is concluded that the hepatic transferase GST1 is identical to GT-tSBO, as well as to hepatic transferase μ. In addition, it has been shown that the different genotypes of GST1 1 (GST1 1-1, GST1 1-0) and GST1 2 (GST1 2-2, GST1 2-0) can be separated by measuring the GT-tSBO activity in whole blood from the same individual. It is also demonstrated that GT-tSBO activity is much lower in fetal liver, approximately 10 times, compared with adult liver, while this activity seems to be unchanged in the blood from fetus and adults, as well as in neonates.     

Physiological and biomechanical differences between wheelchair-dependent and able-bodied subjects during wheelchair ergometry

The purpose of this study was to compare the physiological and biomechanical responses of wheelchair-dependent persons (WCD) to able-bodied persons (AB) during manual wheelchair ergometry. Five WCD and five AB performed a discontinuous wheelchair ergometer test starting at 12.8 W at 30 rev.min-1 (57 m.min-1) with increments of 7.0 W at 6-min intervals. Biomechanical data were collected 3.5 min into each stage followed by the collection of physiological data. After the fifth stage, peak oxygen consumption was determined by having the subject work against a resistance of 14.7-19.6 N at 30 rev.min-1. The WCD had significantly higher net mechanical efficiency at 26.7, 33.6 and 40.6 W in comparison to the AB. The WCD had significantly greater shoulder extension at the point of initial wheel contact as measured by the shoulder angle, while the AB had significantly greater shoulder range of motion at all work rates in comparison to the WCD. The results demonstrate that a significant physiological difference exists in the manner by which WCD and AB accomplish wheelchair ergometry. The biomechanical differences between AB and WCD were found to be a prominent factor contributing to the higher mechanical efficiency of WCD over AB. It was concluded that basic physiological and biomechanical differences exist between WCD and AB in manual wheelchair locomotion and that these differences are important considerations to the interpretation of data in wheelchair ergometry studies.     

Comparative studies of hepatotoxicity and fumonisin B1 and B2 content of water and chloroform/methanol extracts of Fusarium moniliforme strain MRC 826 culture material

Fusarium moniliforme has been associated with several diseases including equine leukoencephalomalacia, human esophageal cancer and hepatotoxicity/hepatocarcinogenicity in laboratory animals. The potential health risks to animals and humans posed by F. moniliforme contaminated grains cannot be assessed until the toxins are identified and toxicologically evaluated. As part of a systematic approach to identifying the hepatotoxins produced by F. moniliforme, diets containing aqueous and chloroform/methanol (11) extracts of F. moniliforme strain MRC 826 culture material (CM) and/or the extracted CM residues were fed to male Sprague-Dawley rats for four weeks. Serum alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase activities were increased after two and four weeks and microscopic liver lesions were found in those animals fed aqueous CM extract and the CM residue after chloroform/ methanol extraction. Fumonisins B₁ and B₂ were extracted from the CM by water, but not chloroform/ methanol, and were present in the toxic diets at concentrations of 93–139 and 82–147 ppm, respectively. Nontoxic diets contained 22 ppm fumonisin B₁ and 65 ppm fumonisin B₂.Abbreviations CM culture material - ELEM equine leukoencephalomalacia Mention of a trademark, proprietory name or vendor does not imply its approval by the US Department of Agriculture to the exclusion of others that may also be suitable.     

Hydrocortisone regulates arylsulfatase A (cerebroside-3-sulfate-3-sulfohydrolase) by decreasing the quantity of the enzyme in cultures of cells dissociated from embryonic mouse cerebra

Previous work from our laboratory (Biochem. J. 219:689–697 (1984) had shown that hydrocortisone stimulated the net accumulation of the myelin-specific sulfolipid in cultures of cells dissociated from embryonic mouse cerebra. This accumulation caused by hydrocortisone was shown to be due to a decrease of sulfolipid degradation by arylsulfatase A (ASA) and not due to a stimulation of its synthesis by a sulfotransferase. Both ASA activity and the turnover of sulfolipid were decreased by hydrocortisone to 60–62% of untreated cells. In current work the same decrease in enzyme activity was obtained and enzyme linked immunosorbent assays demonstrate that hydrocortisone decreased the number of ASA protein molecules to 61% of untreated cells [(-)hydrocorcortisone 0.31±0.06 ng ASA/g protein; (+)hydrocortisone: 0.18±0.04 ng ASA/g protein]. This decrease in the number of ASA molecules correlates well with the decrease in both the enzyme activity and the sulfolipid turnover, which suggests that the major mode of inhibition of ASA activity by hydrocortisone involves a decrease in the concentration of ASA in the cells rather than some other mechanism of inhibition.The material in this paper has been included in a dissertation submitted by A.J.M. in partial fulfillment of the requirements for the degree of Doctor of Philosophy. Temple University.     

Inhibition of abscisic acid biosynthesis inCercospora rosicola by triarimol

The fungicide triarimol was tested for its effect on abscisic acid (ABA) accumulation in growing culturesof Cercospora rosicola. ABA accumulation was reduced by approximately 50% with 10^–8 M triarimol. Growth ofC. rosicola, as measured by dry weight accumulation, was inhibited by triarimol concentrations at or greater than 10^–7 M. These results are compared with those obtained with clomazone, ancymidol, and paclobutrazol, which inhibit ABA accumulation by 50% at concentrations of 5 × 10^–5, 5 × 10^–6, and 5 × 10^–7 M, respectively. Triarimol, therefore, is among the most potent inhibitors of ABA biosynthesis reported to date. Feeding studies with [¹⁴C]mevalonic acid confirmed the inhibition of ABA biosynthesis by 5 × 10^–8 M triarimol. These results support previous suggestions that one or more of the steps in the ABA biosynthetic pathway from mevalonic acid is catalyzed by cytochrome P-450. Feeding studies with 1-deoxy-[²H]-ABA in resuspended cultures ofC. rosicola show that the conversion of this substrate is not inhibited by triarimol.     

Effects of trypsin on secretion stimulated by micromolar Ca2+ and phorbol ester in digitonin-permeabilized adrenal chromaffin cells

1. Catecholamine secretion from digitonin-treated chromaffin cells is stimulated directly by micromolar Ca2+ in the medium. The permeabilized cells are leaky to proteins. 2. In this study trypsin (30-50 micrograms/ml) added to cells after digitonin treatment completely inhibited subsequent Ca2+-dependent catecholamine secretion. The same concentrations of trypsin did not inhibit secretion from permeabilized cells if trypsin was present only prior to cell permeabilization. 3. The data indicate that trypsin entered digitonin-treated chromaffin cells which were capable of undergoing secretion and that an intracellular, trypsin-sensitive protein is involved in secretion. Chymotrypsin was less potent but had effects similar to those of trypsin. 4. The enhancement of Ca2+-dependent secretion from permeabilized chromaffin cells induced by the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) was inhibited by trypsin added simultaneously with Ca2+ to permeabilized cells at concentrations (3-10 micrograms/ml) which had little or no effect on Ca2+-dependent secretion from cells untreated with TPA. Ca2+-dependent secretion in TPA-treated cells was reduced by trypsin only to the level that would have occurred in cells not treated with TPA. Trypsin reduced the large TPA-induced increment of membrane-bound protein kinase C.     

Binding selectivity ofStreptococcus pyogenes and M-protein to epithelial cells differs from that of lipoteichoic acid

The ability of M-protein-positive (M⁺) and M-protein-negative (M^–) strains (including an M^– mutant lacking the structural gene for M-protein) ofStreptococcus pyogenes to attach to human pharyngeal, buccal, and tongue epithelial cells was compared. We observed that M⁺ strains ofS. pyogenes attached in significantly higher numbers to human pharyngeal epithelial cells than to human buccal or tongue cells. M^– strains did not exhibit high-level binding to any type of epithelial cell. Also, the adhesion of an M⁺ and an M^– strain ofS. pyogenes was low to all types of rat epithelial cells tested. The apparent differences in the surface components between human pharyngeal and buccal epithelial cells were confirmed by studies utilizing radiolabeled lectins.Ulex europaeus lectin with a specificity for fucosyl residues, andTriticum vulgaris lectin with a specificity for N-acetyl glucosamine and N-acetyl neuraminic acid residues, bound in higher amounts to human pharyngeal cells than to buccal cells. Pretreatment of pharyngeal epithelial cells with microgram quantities of highly purified type 6 M-protein or miligram quantities of lipoteichoic acid (LTA) derived fromS. pyogenes decreased the subsequent attachment of the organism. However, the binding specificities of³H-LTA were different from those of intact streptococci;³H-LTA bound comparably to human pharyngeal, buccal, and tongue epithelial cells, and it bound in higher quantities to rat epithelial cells. Also, although the adsorption ofS. pyogenes cells to pharyngeal cells was inhibited by the presence of fucose and galactose, these sugars had little effect on the binding of³H-LTA to epithelial cells. In contrast, the high adhesion of M⁺ strains but not M^– mutants to pharyngeal cells suggested that M-protein may play an important role. This possibility was supported by the observation that³H-labeled purified type 6 M-protein bound in higher concentrations to human pharyngeal epithelial cells than to human buccal cells. Furthermore, human pharyngeal epithelial cells were estimated to contain larger numbers of binding sites for M-protein than buccal cells, whereas the affinity of M-protein was similar to both cell types. These adsorption parameters are similar to those previously established for intact streptococcal cells.     

Dimethyl sulfide metabolism in salt marsh sediments

Abstract Anoxic sediment slurries prepared from Spartina salt marsh soils contained dimethyl sulfide (DMS) at concentrations ranging from 1 to 10 μM. DMS was produced in slurries over the initial 1–24 h incubation. After the initial period of production, DMS decreased to undetectable levels and methane thiol (MSH) was produced. Inhibition of methanogenesis caused a 20% decrease in the rate of DMS consumption, while inhibition of sulfate reduction caused a 80% decrease in DMS consumption. When sulfate reduction and methanogenesis were simultaneously inhibited, DMS did not decrease. DMS contributed about 28% to the methane production rate, while DMS probably contributed only 1% or less to the sulfate reduction rate. Incubation of the sediment slurries under an atmosphere of air resulted in similar DMS consumption compared to anaerobic incubations, but MSH and CH₄ were not evolved.
Sediments from the marsh released significant quantities of DMS when treated with cold alkali, indicating that potentially significant sources of DMS existed in the sediments. Values of base-hydrolyzable DMS as high as 190 μmol per liter of sediment were observed near the sediment surface, and values always decreased with depth in the sediment. Simple flux experiments with small intact sediment cores, showed that DMS was emitted from the marsh surface when cores were injected with glutaraldehyde or molybdate and 2-bromoethanesulfonate (BES), but nit when cores were left uninhibited. These results showed that DMS was readily metabolized by microbes in marsh sediments and that this metabolism may be responsible for reducing the emission of DMS from the marsh surface.