Identification and genetic diversity of Meloidogyne spp. (Tylenchida: Meloidogynidae) on coffee from Brazil, Central America and Hawaii

The present study was based on 18 populations of Meloidogyne spp. originating from different coffee fields in Brazil, Central America and the USA (Hawaii). The identification of the main species and an outline of the diversity of root-knot nematodes parasitising coffee in these countries with respect to esterase phenotypes, morphology and molecular polymorphism, are provided. With the present electrophoretic procedure, esterase phenotypes were demonstrated to be species-specific and constitute a good tool for identifying root-knot species from coffee, viz., M. incognita (Est I1, I2), M. paranaensis (Est P1, P2), M. arenaria (Est A2), M. arabicida (Est AR2), M. exigua (Est E1), M. mayaguensis (Est M2) and two unknown populations that probably represent new species (Est SA2, SA4). The perineal pattern is often an unreliable character when used alone for making diagnostic conclusions but, when used as a complementary tool together with enzyme characterisation, is essential for checking the morphological consistency of the identification. Male characters are important for confirming the diagnosis of some species, such as M. paranaensis, M. konaensis and M. incognita. The results showed that the RAPD markers produced are consistent with other approaches (esterase phenotypes and morphological features) for confirming species identification and for estimating genetic relationships among species and isolates. Phylogenetic analyses showed that M. mayaguensis and M. exigua are more closely related to one another than they are to the other species. This was also true for M. javanica, M. arenaria and Meloidogyne spp. Low levels of intraspecific polymorphism were detected in M. exigua (8.6%), M. incognita (11.2%) and M. paranaensis (20.3%). Conversely, M. arenaria and the two unknown Meloidogyne spp. exhibited higher levels of intra- or interspecific variability (34.9 and 29.9%, respectively).

Direct comparison of performance characteristics of two immunoassays for bone isoform of alkaline phosphatase in serum

A clinical need exists for a sensitive and specific assay for the quantitation of the bone isoform of alkaline phosphatase in serum. The majority of methods do not meet this requirement; however, the recent development of immunoassays for this isoform may provide a solution. In a detailed evaluation of two immunoassays, we found a degree of imprecision that enables the discrimination of changes within the reference range. The cross-reactivity of the liver isoform was found to be between 7.1% and 12.7% when two different methods of assessment were used. The comparison of results with an electrophoretic procedure showed that the immunocapture method recovered less of the bone isoform in samples from children than in samples from patients with Paget disease; no such difference was found with the immunometric method. This suggests that the immunocapture antibody may discriminate between different bone isoforms in children whereas the immunometric assay does not.

Improved procedure for measuring gamma-glutamyltransferase isoenzymes in serum.

In this electrophoretic procedure for measuring isoenzymes of gamma-glutamyltransferase, patterns obtained are highly reproducible and the analytical imprecision (CV) ranges from 1.10% to 6.17%. A cellulose acetate support is used, at 220 V for 40 min. Sharply resolved isoenzyme bands were made visible by fluorescence scattered light, formed by use of a coumarin derivative as donor substrate. Two bands were observed for sera from normal subjects; four bands were variably present in sera from patients with different hepatobiliary diseases. Detection of the latter was satisfactory, down to a total activity in serum of 8-10 U/L. Three of the pathological bands were associated with low- and (or) very-low-density lipoproteins, whereas a major fraction of one of the normal bands in cirrhotic sera precipitated with high-density lipoprotein. The bands in normal sera, and one of the abnormal bands, did not.

The gamma-glutamyltransferase isoenzyme pattern in serum as a signal discriminating between hepatobiliary diseases, including neoplasias.

We have used the gamma-glutamyltransferase (GGT) isoenzyme pattern in serum as a means for discriminating between hepatobiliary diseases, including neoplasias. The reference pattern, determined in 142 normal subjects with a simplified conventional cellulose acetate electrophoretic procedure, contained two GGT bands, alpha 1-GGT and alpha 2-GGT, in proportions of 60-80% and 20-40%, respectively. Sera from 95 hepatobiliary patients showed typical isoenzyme features: (a) a beta-migrating GGT form that was less than 10% of the total GGT in chronic hepatitis and cirrhosis, and less than or equal to 30% of the total GGT in cirrhosis with intrahepatic cholestasis and in cases of extra- and intrahepatic obstructive jaundice, including liver neoplasias; (b) a gamma-migrating GGT band and (or) a "dep-GGT" (nonmigrating) band in cases of extrahepatic jaundice; and (c) an albumin-migrating GGT band that had a diagnostic sensitivity of 75% for hepatic tumors. The diagnostic specificity of this last band is 92% toward other hepatic disorders and 91% toward nonhepatic neoplasias; we consider it a potential specific marker for primary or metastatic liver neoplasias.

IDENTIFICATION OF CULTIVARS OF FORAGE LEGUME (Desmodium ovalifolium GUILL ET PERR.) BY THEIR ELECTROPHORETIC PATTERNS

An electrophoretic procedure was developed for discriminating cultivars of Desmodium ovalifolium on the basis of patterns of partially purified seed proteins. Electrophoresis was done on uniform 15% polycrylamide gels in basic (8.9) pH. The method produced satisfactory discrimination of eight cultivars used in its initial evaluation.Key words: Forage legume, Desmodium ovalifolium Guill et Perr., cultivar identification, polyacrylamide gel electrophoresis