Incidence of Heat-Resistant Molds in Eastern Orchards and Vineyards

Over 70% of the samples of fruit, vegetation, and soil obtained in surveys of New York orchards and vineyards were contaminated with heat-resistant molds. The counts generally were low, under one per gram. Byssochlamys fulva was the most common isolate. Other isolates were identified as B. nivea, Paecilomyces varioti, Aspergillus fischeri, A. fischeri var. spinosus, A. fumigatus, Penicillium vermiculatum, and P. ochro-chloron.     

Interstitial cells from the atrial and ventricular sides of the bovine mitral valve respond differently to denuding endocardial injury

Summary The mitral valve has atrial and ventricular sides, each lined by endocardial cells. The valve stroma contains α smooth muscle actin positive interstitial cells, collagen, glycosaminoglycans, and elastic tissue. To eliminate the effect of endocardium on wound repair in bovine mitral valve organ culture, the endocardium was removed from both sides of the valve. At 6 days, organ cultures of these preparations revealed surface cells on the ventricular side but not on the atrial side. Ventricular surface cells were negative for Factor VIII-related antigen, and positive for α smooth muscle actin. Immuno-peroxidase staining for proliferating cell nuclear antigen/cyclin, a marker for cell proliferation, revealed a positive labeling index of (mean ± standard deviation) 0.08 ± 0.16% for interstitial cells from the atrial side and 0.14 ± 0.19% for ventricular side interstitial cells in uncultured preparations (not significant), and 0.44 ± 0.69% for atrial side interstitial cells and 2.25 ± 1.64% for ventricular side interstitial cells in the cultured preparations (significant,P<0.0006). The results suggest that in organ culture, interstitial cells from the ventricular side of the mitral valve respond to a denuding endocardial injury by proliferating and migrating onto the adjacent surface whereas interstitial cells from the atrial side do not. This difference in the response to injury of interstitial cells from the atrial and ventricular sides of the valve may reflect differences in phenotype or may be due to effects of extracellular matrix on interstitial cell behavior. The latter is possible because of differences in the extracellular matrix of the atrial and ventricular sides of the valve.     

Benzolactam growth hormone secretagogues: Replacement of the C-3 amide bond in L-692,429

The synthesis and structure-activity relationships of various C-3 amide bond modifications in the novel nonpeptidyl growth hormone secretagogue L-692,429 are described. Several C-3 amide surrogates were prepared and the urea moiety was found to exhibit growth hormone releasing activity similar to that observed with L-692,429.     

Toxoplasma gondii infection: analysis of serological response by 2-DE immunoblotting

The potency testing of Clostridium perfringens mono- and multicomponent veterinary vaccines is currently performed with the mouse neutralisation test (MNT) to estimate levels of C. perfringens beta- and epsilon-antitoxin levels in the sera of rabbits immunised with the vaccine. Two in vitro methods based on monoclonal antibodies (mAb) have been developed for the determination of specific antibodies against C. perfringens beta-toxin (capture ELISA) and epsilon-toxin (competitive ELISA) in these sera. Both test systems show high specificity and good reproducibility. These ELISA procedures were used in addition to the routine batch potency test in mice (MNT) to determine beta- and epsilon-antitoxin levels in 523 samples of rabbit serum. There was good agreement between the rank order of sera determined in vivo and the rank order determined in vitro. Linear regression analysis gave correlation coefficients of 0.88 for the capture ELISA and 0.41 for the competitive ELISA, with a significance level of P < 0.01 in both cases. Furthermore, a prevalidation study was carried out in four laboratories to evaluate the transferability of the ELISA procedures and the interlaboratory reproducibility of the results. Three coded serum samples were tested several times. The results indicated that both ELISA systems are suitable candidates to replace the MNT used for the potency testing of beta- and epsilon-toxoid in mono- and multicomponent veterinary vaccines. However, these assays still need to be validated in an international collaborative study.     

Allocation of reproductive effort in female Arrenurus spp. water mites (Acari: Hydrachnidia; Arrenuridae)

Summary Twenty-seven species of water mites of the genus Arrenurus were compared with respect to allocation of reproductive effort. Clutch volume was positively correlated to female volume, female volume was positively correlated with clutch size and with larval volume, while clutch size and larval volume were negatively correlated. In threespace, corresponding to female volume, clutch size and larval volume, species were arranged along two trajectories representing separate reproductive strategies. The strategy characterized by small larvae, large clutches and large females corresponded to species of the subgenus Arrenurus, known to be larval parasites of adult Odonata. Members of three subgenera, known to be larval parasites of adult Diptera, followed the second strategy of small clutch size and alrge larvae. Of nine species of mites tested for intraspecific relationships, only one significant relationship was found, between female volume and clutch size for A. (Megaluracarus) bartonensis.     

Effects of bivalent cations on the initiation of Na-induced pinocytosis inAmoeba proteus

Summary EGTA in moderate concentrations, sufficient to remove all Ca²⁺ from the cell surface, blocks pinocytosis. But in higher concentrations of EGTA, which chelate also Mg²⁺, the pinocytosis reappears and is strongly enhanced. Simultaneous removal of both Ca and Mg ions by EDTA brings about only potentiating effect. Reintroduction of either Ca or Mg separately, demonstrates that Mg²⁺ is a powerful inhibitor of pinocytosis. The influence of chelators on the pinocytosis is attributed respectively to their selective or unspecific influence on both bivalent ions at the cell surface, without affecting the intracellular contraction mechanism.Study supported by the Research Project II. 1 of the Polish Academy of Science.     

Epiphytic microflora of poplar clones susceptible and resistant to infection by Dothichiza populea

One-year-old poplar shoots (nodes, internodes and lenticels) of clones susceptible to infection by the pathogenic fungus Dothichiza populea, viz. Populus nigra Italica and P. Robusta, resistant ones, viz. P. Grandis and P. Hybrida 275, as well as a hybrid of a susceptible and a resistant clone, viz. P. maximowiczii x P. nigra (P. Kórnik 42), were used. The plate method was employed to determine: 1. the abundance of the epiphytic microflora on a mineral medium with glucose; 2. the quantitative composition of epiphytic communities by determining the numbers of typical bacteria (including rod-shaped, spherical and sporulating forms), actinomycetes and yeasts in microscopic preparations from epiphyte colonies; 3. the abundance and level of activity of epiphytes antagonistic towards Dothichiza populea. In all poplar clones the epiphytic microflora was most abundant on nodes and least abundant on lenticels. In the resistant clones epiphytes were 7 (P. Grandis) to as many as 84 times (P. Hybrida 275) less numerous than in the susceptible ones. In the microflora communities of the susceptible poplars, rod-shaped bacteria were the most abundant, and in the resistant ones and the hybrid, yeasts, which made up from 60% to 70% of the strains tested. Spherical and sporulating bacteria as well as actinomycetes were found in numbers not exceeding 4% of the total number of epiphytes. The proportion of antagonistic microflora in whole epiphytic communities was higher in the resistant clones and the hybrid than in the susceptible clones, with the microflora having a more restrictive effect on the development of the pathogen.