Genetic differentiation and detection of cryptic species in the genus Lepismachilis (Insecta: Microcoryphia) from the Western Mediterranean region

Different species of the bristletail genus Lepismachilis were collected in 14 localities in Italy and Spain and an allozyme electrophoretic survey was carried out to estimate the degree of genetic variability and differentiation at intra- and interspecific levels. Four morphological species were initially identified (L osellai, L. y-signata, L. affinis, L. targionii), but the electrophoretic analysis demonstrated the presence of two additional species among the individuals of L. targionii (Lepismachilis spl and sp2). The validity of these species and their differentiation from L targionii were demonstrated by the fixation of alternative allelic patterns at several loci (7 in Lepismachilis spl and 8 in Lepismachilis sp2), coupled with fixed, previously undetected, morphological differences. In addition, Lepismachilis sp2 was sympatric with L. targionii in three collecting sites, where the fixation of alternative allelic patterns unequivocally demonstrated reproductive isolation. Genetic variability did not seem to be correlated with local ecological factors, and differences between species should rather be explained by different historical factors. Low levels of gene flow, estimated with two different indirect methods, were observed in L. targionii and L. y-signata, and were due to high levels of structuring among populations. Genetic differentiation among conspecific populations was not correlated to their geographical arrangement and the presence of loci fixed for different alleles among them suggested that stochastic factors (such as genetic drift) may have played a role in determining genetic differentiation of geographically isolated populations. Genetic divergence values indicated that the six species are well differentiated and allozyme profiles were diagnostic for all of them. On the other hand, allozyme data did not provide adequate information to resolve evolutionary relationships among the species, nor did they confirm the validity of the two subgenera (Lepismachilis and Berlesilis) in which the genus Lepismachilis is traditionally divided.     

Oxalic acid production and its role in pathogenesis of Sclerotinia sclerotiorum

Abstract Sunflower plants were inoculated with a virulent isolate of Sclerotinia sclerotiorum and with the same isolate nutritionally conditioned to produce small amounts of oxalic acid. The preconditioned isolate behaved as hypovirulent. Tomato plants were inoculated with four S. sclerotiorum isolates of increasing virulence. A close correlation among disease severity, accumulation of oxalic acid, decrease in pH and inhibition of polyphenoloxidase in both infected host tissues was demonstrated. Oxalic acid production as an important factor of virulence in S. sclerotiorum is emphasized and its effect on the phenolic metabolism of the host via inhibition of polyphenoloxidase is suggested.     

Intralymphatic administration of BCG in melanoma patients

Summary From November 1973 to December 1974, 20 patients with advanced malignant melanoma were treated with BCG given by intralymphatic route at the Cancer Institute of Milan. The lyophilized Pasteur BCG was used. Patients were treated with a single dose ranging from 0.2–80 mg. Patients' performance status was never severely impaired.The most frequent side effects were fever, lymphangitis, and lymph node enlargement.Variations were observed in white cell count, ERS and immunoglobulins; in no case did we find evidence of liver toxicity or tumor growth enhancement. It is concluded that the intralymphatic route is a safe way of administrating BCG.     

Epicuticular waxes of two sorghum varieties

The epicuticular waxes of the two sorghum varieties Alliance A and SD 102 have been analyzed, after separation of the leaf blades from the sheaths. The major constituents were found to be free fatty acids but small amounts of esters, aldehydes, alcohols, n-alkanes and sterols were also detected. The typical chain lengths of aldehydes, free alcohols and free fatty acids were C₂₈ and C₃₀.     

Effect of Kainic Acid, Glutamate, and Aspartate on CO2 Production by Goldfish Tectal Slices

For a study of the excitatory effect of kainate, glutamate, and aspartate in the goldfish optic tectum, these substances were tested on the production of CO2 from radioactive glucose in tectal slices incubated in Krebs-Ringer medium for fish. Kainate increased the rate of CO2 production for up to 30 min in a dose-related manner, the effect being maximum at 0.1 mM concentration and decreasing at higher doses. The effect was blocked by ouabain (1 mM) as well as by the substitution of choline for Na+ in the incubation medium. Glutamate and aspartate exerted a less pronounced excitatory effect on CO2 production at higher concentration than kainate. This effect was also abolished by ouabain. Glutamate, added to the medium at a concentration at least 100-fold higher than kainate, partially reversed the increase in CO2 production induced by kainic acid. No similar effect was noticed for aspartate. The supposed glutamate antagonists glutamic acid diethylester (1 mM) and proline (5 mM) did not affect the excitatory action of kainic acid or exert an antagonistic effect towards glutamate. At higher concentration (10 mM) glutamic acid diethylester increased CO2 production, an effect that was, however, ouabain insensitive. Methyltetrahydrofolic acid (1 mM), a substance reported to compete for the kainate receptor, did not inhibit the effect of kainic acid or increase CO2 production.     

Amino acid transport in pig lymphocytes Enhanced activity of transport system asc following mitogenic stimulation

Changes in neutral amino acid transport activity caused by addition of phytohaemagglutinin-P to quiescent peripheral pig lymphocytes have been evaluated by measurements of ¹⁴C-labelled neutral and analogue amino acids under conditions approaching initial entry rates. Utilizing methylaminoisobutyric acid, the best model substrate of System A, we confirmed our previous report (Borghetti, A.F., Kay, J.E. and Wheeler, K.P. (1979) Biochem. J. 182, 27–32) on the absence of this transport system in quiescent cells and its emergence following stimulation. Furthermore, we demonstrated the presence in quiescent cells of an Na⁺-dependent transport system for neutral amino acids that has been characterized as System ASC by several criteria including intolerance to methylaminoisobutyric acid, strict Na⁺-dependence, the property of transtimulation and specificity for pertinent substrates such as alanine, serine, cysteine and threonine. Analysis of the relationship between influx and substrate concentration revealed that two independent saturable components contribute to entry of alanine in quiescent cells: a low affinity ($\text{K}{}_{\mathrm{<mtext>m</mtext>}}\text{= ≈4}\text{mM}$) and a high affinity ($\text{K}{}_{\mathrm{<mtext>m</mtext>}}\text{= ≈0.2}\text{mM}$) component. The high affinity component could be inhibited in a competitive way by serine, cysteine and threonine, but methylaminoisobutyric acid did not change appreciably its constants. The enhanced activity of alanine transport through the ASC system observed in activated cells resulted from a large increase in the capacity ($\text{V}$) of the high affinity component without any substantial change in the apparent affinity constant ($\text{K}{}_{\mathrm{<mtext>m</mtext>}}$).