SSR markers: a tool for species identification in Psidium (Myrtaceae).

Molecular DNA markers are used for detection of polymorphisms in individuals. As they are independent of developmental stage of the plant and environmental influences, they can be useful tools in taxonomy. The alleles of simple sequence repeat (SSR) markers (or microsatellites) are traditionally used to identify taxonomic units. This application demands the laborious and costly delimitation of exclusive alleles in order to avoid homoplasy. Here, we propose a method for identification of species based on the amplification profile of groups of SSR markers obtained by a transferability study. The approach considers that the SSR are conserved among related species. In this context, using Psidium as a model, 141 SSR markers developed for Psidium guajava were transferred to 13 indigenous species of Psidium from the Atlantic Rainforest. Transferability of the markers was high and 28 SSR were conserved in all species. Four SSR groups were defined and they can help in the identification of all 13 Psidium species studied. A group of 31 SSR was genotyped, with one to six alleles each. The H0 varied from 0.0 to 0.46, and PIC from 0.0 to 0.74. Cluster analysis revealed shared alleles among species. The high percentage of SSR transferability found in Psidium evidences the narrow phylogenetic relationship existing among these species since transferability occurs by the preservation of the microsatellites and anchoring regions. The proposed method was useful for distinguishing the species of Psidium, being useful in taxonomic studies.

The FMR1 CGG repeat and linked microsatellite markers in two Basque valleys.

Fragile X syndrome is associated with an unstable CGG repeat sequence in the 5' untranslated region of the first exon of the FMR1 gene. The present study involved the evaluation of factors implicated in CGG repeat stability in a normal sample from two Basque valleys (Markina and Arratia), to discover whether the Basque population shows allelic diversity and to identify factors involved, by using the data in conjunction with previous findings. The study was based on a sample of 204 and 58 X chromosomes from the Markina and Arratia valleys, respectively. The CGG repeat, the AGG interspersion and two flanking microsatellite markers, FRAXAC1 and DXS548, were examined. In the Markina valley, gray zone alleles (> or =35 CGG repeats) were associated with anchoring AGGs, with the longest 3' pure CGG repeats of the valley (=15), with the 5' instability structure 9+n and with one principal fragile X FRAXAC1-DXS548 haplotype 42-50. In the Arratia valley, gray zone alleles (> or =35 CGG repeats) showed the highest frequency among the Basque samples analyzed, and were associated with anchoring AGGs, with the longest 3' pure repeats (> or =20), with the 5' instability structure 9+n and with one "normal" FRAXAC1-DXS548 haplotype 38-40 (these data from Arratia suggest the existence of a "protective" haplotype). The results showed, on the one hand, differences between Markina and Arratia in factors implicated in CGG repeat instability and, on the other hand, a great similarity between the general Basque sample from Biscay and the Markina valley.

[Mast cell hyperplasia in bone oxalosis]. / Hiperplasia de mastócitos na oxalose óssea.

BACKGROUND: To assess by means of histomorphometry the incidence of bone marrow mast cell hyperplasia in patients with chronic renal failure and oxalosis. MATERIAL AND METHODS: Eighteen individuals were assigned to three groups: 6 (4 males and 2 females, aged 26.31 +/- 2.5 yrs) had chronic renal failure (CRF) and oxalosis of bone; 6 (1 male and 5 females aged 22.1 +/- 3.56 yrs) had CRF and 6 normal (5 males and 1 female aged 23 +/- 2.78 yrs) individuals entered the control group. Quantitative histologic assessments were completed in undecalcified sections of plastic embedded iliac crest bone biopsies stained by the Toluidine Blue method for identification of mast cells. The number of mast cells (cell/mm2 tissue area, x +/- sd) was determined by a semiautomatic image-analyzing system. RESULTS: The number of mast cells was greater in patients with oxalosis of bone, 32.67 +/- 9.59, than in patients with CRF (20.84 +/- 5.04, p < 0.05) and than in the control group (3.26 +/- 1.03, p < 0.001). CONCLUSIONS: Oxalosis of bone is associated with substantial increases in the number of mast cells in the bone marrow. Such a change is not related to chronic renal failure per se and does not appear to represent a non-specific response to bone marrow fibrosis. Mast cell accumulation may contribute to the development of bone marrow fibrosis seen in this disorder.

Hiperplasia de mastócitos na oxalose óssea / Incresead mast cell number in oxalosis of bone

Objetivos. Avaliar através de técnicas de hitomorfometria a incidência de hiperplasia de mastócitos na medula óssea de pacientes portadores de oxalose e insuficiência renal crônica. Material e Métodos. Foram estudados 18 indivíduos em 3 grupos: 6 (4 homens e 2 mulheres com média de idade de 26.31+2.5 anos) portadores de oxalose óssea e insuficiência renal crônica (IRC); 6 (5 mulheres e 1 homem com idade média de 22.1+3.56 anos) portadores de IRC e 6 indivíduos saudáveis (5 homens e 1 mulher com idade média de 23+2.78 anos). A análise do tecido ósseo foi realizada em biópsias de crista ilíaca, incluídas em resina, sem descalcificaçao prévia e coradas pela técnica do Azul de Toluidina. A contagem dos mastócitos foi feita utilizando-se sistema analisador de imagens e os valores (média+DP) foram expressos sob a forma de células por mm2 de tecido. Resultados. O número de mastócitos foi significativamente maior nos portadores de oxalose óssea, 32.67+9.59, ao comparar com os pacientes portadores de IRC sem oxalose (20.84+5.04, p<0.05) e nos indivíduos do grupo controle (3.26+1.03, p<0.001). Conclusoes. A oxalose óssea está associada com um aumento substancial do número de mastócitos na medula óssea. Esta alteraçao nao está relacionada com a IRC per se e nao parece representar uma resposta inespecífica à fibrose medular. O acúmulo anormal de mastócitos deve, de alguma forma, contribuir para o desenvolvimento da fibrose de medula óssea que acompanha esta condiçao.

The spectrum of bone disease in 200 chronic hemodialysis patients: a correlation between clinical, biochemical and histological findings.

INTRODUCTION: Renal osteodystrophy includes the complete range of mineral metabolism disorders that affect the skeleton in patients with chronic renal failure. PATIENTS AND METHODS: 200 patients with end-stage renal disease and on dialysis were investigated regarding the clinical, biochemical and histological findings of bone disease. RESULTS: The spectrum of renal osteodystrophy consisted mainly of high turnover bone lesions (74.5%), including osteitis fibrosa in 57.5%. Patients with mild bone disease were on dialysis for shorter periods of time and were mostly asymptomatic. Patients with aluminum-related bone disease (16.5%) had the greatest aluminum exposure, either orally or parenterally, and together with patients with high turnover mixed disease, were the most symptomatic. Although on a non-regular basis, the vast majority of the patients (82.5%) had been receiving vitamin D. The incidence of adynamic bone disease was high (n = 8) among parathyroidectomized patients (n = 12). Significantly higher serum levels of alkaline phosphatase were observed in osteitis fibrosa. CONCLUSIONS: The use of calcitriol and phosphate-binding agents on a non-regular basis seems to be the reason for the apparent reduced response to the treatment of secondary hyperparathyroidism. Alkaline phosphatase has been shown to be a fair marker for bone turnover in patients with osteitis fibrosa. The severity of the clinical manifestations of bone disease correlates with the histological features of bone lesion and to the time spent on dialysis.