Species relations among wild Arachis species with the A genome as revealed by FISH mapping of rDNA loci and heterochromatin detection.

Section Arachis of the homonymous genus includes 29 wild diploid species and two allotetraploids (A. monticola and the domesticated peanut, A. hypogaea L.). Although, three different genomes (A, B and D) have been proposed for diploid species with x = 10, they are still not well characterized. Moreover, neither the relationships among species within each genome group nor between diploids and tetraploids (AABB) are completely resolved. To tackle these issues, particularly within the A genome, in this study the rRNA genes (5S and 18S-26S) and heterochromatic bands were physically mapped using fluorescent in situ hybridization (FISH) in 13 species of Arachis. These molecular cytogenetic landmarks have allowed individual identification of a set of chromosomes and were used to construct detailed FISH-based karyotypes for each species. The bulk of the chromosome markers mapped revealed that, although the A genome species have a common karyotype structure, the species can be arranged in three groups (La Plata River Basin, Chiquitano, and Pantanal) on the basis of the variability observed in the heterochromatin and 18S-26S rRNA loci. Notably, these groups are consistent with the geographical co-distribution of the species. This coincidence is discussed on the basis of the particular reproductive traits of the species such as autogamy and geocarpy. Combined with geographic distribution of the taxa, the cytogenetic data provide evidence that A. duranensis is the most probable A genome ancestor of tetraploid species. It is expected that the groups of diploid species established, and their relation with the cultigen, may aid to rationally select wild species with agronomic traits desirable for peanut breeding programs.

[The effectiveness of recombinant growth hormone in height deficiency due to intrauterine growth retardation]. / Efectividad de la hormona de crecimiento recombinante en el déficit de talla debido a retraso de crecimiento intrauterino.

BACKGROUND: Intrauterine growth retardation (IUGR) is considered to be responsible for approximately 20% of short stature in adulthood. Although GH secretion is normal in the majority of cases, excellent results have been published by some authors using GH to treat children with height deficiency due to IUGR. PATIENTS AND METHODS: Thirty children with a history of IUGR with chronological ages between 2 and 7 years and height less than 2 SD were randomized in two groups for one year: a) control group, no treatment, 14 cases, and b) treatment group, 1 U/kg/week of recombinant GH, 16 cases. Growth and maturation were analysed periodically in both groups. In addition, serum levels of GH, IGF-I, IGFBP3 and GHBP were measured before and under treatment and adverse events were assessed in treatment group. RESULTS: In the treated group significant increments in growth rate, cm/year (median = 6.91 vs 9.94), improvement in height SDS (median = -2.19 vs -1.63) and positivation of growth rate (median = -0.13 vs 3.17) were observed compared with the control group. Bone age evolved parallelly to chronological age and the height age/bone age ratio increased throughout the study under GH therapy. Hormonal findings in the treated group showed a significant increase in IGF-I and IGFBP3 values. Glycaemia levels increased without exceeding upper normal levels in the treated group. CONCLUSION: GH was effective in promoting growth in this short-term study in children with height deficiency due to IUGR. Close follow-up is required to detect any adverse event, particularly those related to carbohydrate metabolism.

Distribution of Defense-Related Enzymatic Activities in the Quiescent Organs of Phaseolus vulgaris L. Seeds.

Analysis of quiescent seed extracts of Phaseolus vulgaris cultivars found high activities of chitinase, N,N'-diacetylchitobiase and ß-N-acetylhexosaminidase in whole seeds and their dissected organs (cotyledons, axis, and seed coat). Activities of these enzymes were compared in seeds of two cultivars phenotypically distinguishable by soft white (cv. Surattowonder) and hard brown (cv. Maisugata) seed coats. In both cultivars, chitinase activity was found high in all organs, chitobiase in the seed coat, and ß-N-acetylhexosaminidase mainly in the axis. In terms of specific activity, all three enzymes were extraordinarily higher in extracts of seed coat than the others, specially referring to the cultivar Surattowonder. Although the cultivars showed in general similar distribution patterns of activities among their seed organs, the discrepancies found between them seem to be expressing intrinsic attributes of their seed coats. The relationship between the two cultivars, the enzyme activities measured and defense mechanisms are discussed.

Immunoprophylaxis of perinatal transmission of the hepatitis B virus: efficacy of hepatitis B immune globulin and hepatitis B vaccine in a low-prevalence area.

One hundred eleven newborn infants born of Spanish hepatitis B surface antigen (HBsAg) carrier mothers were consecutively assigned to one of three treatment groups. Group A was treated with three or four doses of hepatitis B immune globulin (HBIG) in one of three different schedules. Group B received one dose of hepatitis B vaccine (Hevac-B, Pasteur) at birth and at 1, 2 and 12 months. Group C was treated with the same vaccination schedule as group B and in addition received a single dose of HBIG at birth. Comparisons were made in the 85 babies who had strictly completed the immunization schedule and had been followed for at least 12 months. The three immunization protocols were equally effective, since none of the children became a chronic HBsAg carrier or developed acute symptomatic infection. There were five transient and subclinical infections among children who received only HBIG (group A), one transient infection in group B, and one in group C. There seems to be some correlation between anti-HBs levels and degree of protection, since all transient infections in group A occurred in the subgroups who did not maintain protective antibodies during the first 6 months. Although the percentage of responders in the two vaccinated groups did not differ significantly, children who received only vaccine reached higher antibody levels than those who also received HBIG. Our results suggest that any immunization schedule able to maintain anti-HBs levels during the first 6 months of life would be useful to prevent mother-to-infant transmission of the hepatitis B virus in areas where most of the carrier women are expected to be anti-HBe positive and hence relatively less infectious.

Organic acids in urine from preterm infants.

The organic acid excretion was studied in urine samples from 26 preterm infants on the 1st and 5th days of life and the results compared to those obtained in 5 samples from full-term neonates. Gas-chromatography-mass spectrometry with a computer system was the method used in this work. The acids tabulated were those more closely related to lactic acidosis and the Krebs cycle. Great variations were found in the excretion of these acids in preterm infants in contrast to the very homogeneous pattern obtained in full-term neonates.