Choroideremia, sensorineural deafness, and primary ovarian failure in a woman with a balanced X-4 translocation.

We present clinical and cytogenetic studies of a female patient affected with choroideremia, mild sensorineural deafness, and primary amenorrhea showing a balanced translocation between chromosomes X and 4. The breakpoint was precisely defined applying FISH techniques: 46,X,t(X;4)(q21.2;p16.3).ish t(X;4)(D4S96+, D4F26+; wcpX+). The X-chromosomal breakpoint was located within a region where both the choroideremia locus and a deafness locus (DFN3/POU3F4) have been mapped. The presence of X-linked disorders in this balanced carrier of X-autosomal translocations (XAT) can be explained either by the disruption of the structural coding or regulatory sequences of the gene(s) or by the submicroscopic deletion of this region leading to a contiguous gene deletion syndrome. The primary ovarian failure (POF) found in the present case has been already observed in XAT when the breakpoint is within a previously defined critical region (Xq13-26). A position effect is postulated as a possible explanation.

A single nucleotide change in the E protein gene of dengue virus 2 Mexican strain affects neurovirulence in mice.

Eleven clones of dengue virus 2 Mexican strain were selected by the size of their lytic plaques. Nucleotide sequences of the clones producing large plaques (D2ML2, D2ML3 and D2ML4) revealed 11 mutations, 10 of which were silent. The substitution at nucleotide 1168 (G-->C) generates one amino acid difference at residue 390 (Asp-->His) of the envelope protein (E). These clones showed high virulence in suckling mice when inoculated intracerebrally (> or = 70% mortality). However, the clones which showed small lytic plaques (D2MS1, D2MS2 and D2MS4) displayed a substitution from Asp-->Asn at the same position and had attenuated virulence. Based on these data, we suggest that substitution of Asp-->His at residue 390 perhaps affects a functionally important structural element that could be a determinant of dengue neurovirulence. This substitution falls in domain III of the E protein, which plays an important role in viral binding; therefore, we propose that the substitution affects virulence and cellular tropism.

Orbital inflammatory syndrome and systemic lupus erythematosus.

Orbital inflammatory syndrome (OIS) is a rare condition characterized by inflammation of orbital structures in the absence of underlying infection, neoplasm or endocrinopathy. The pathogenesis of OIS has not been fully described, but histopathology reveals diffuse lymphocytic infiltration of the involved structures. This disorder presents clinically as acute pain and swelling in the orbit and usually responds rapidly to high dose corticosteroids. This entity has been reported previously in seven patients with systemic lupus erythematosus (SLE). Herein, we describe a patient with SLE who developed OIS, review the previously reported cases that have occurred in association with SLE, and describe the diagnostic evaluation and therapy for OIS. This rare entity can pose both a diagnostic and therapeutic dilemma in SLE patients given immunoppressive therapy.

[Study of leukemic colony-forming units (CFU-L) in non-lymphoblastic malignant hemopathies]. / Estudio de la unidad formadora de colonias leucémicas (CFU-L) en hemopatías malignas no linfoblásticas.

CFU-L is considered as the clonogenic cell of acute non-lymphoblastic leukaemias (ANLL). Twenty-five malignant myelogenous hemopathies (5 blast crisis and 20 "de novo" ANLL) were studied in order to assess the proliferative capability of these cells and its relationship to FAB types and the achievement or not of complete remission (CR). The proliferative capability was assessed by culture on methylcellulose using conditioned leucocyte medium stimulated with phytohaemagglutinin as stimulating agent. Cell proliferation was observed in 21 cases, reaching 100% of the blast crisis and 80% (i.e., 16 cases) of the "de novo" ANLL. As regards the FAB types, it was found that the leukaemias with monocytic cells showed higher cell-growth than those of granulocytic lineage (90%, vs 60%). Of the patients not achieving CR (12 cases) colonies were formed in 66.6% (8 cases), while of the 8 patients who attained CR only in 3 (37.5%) were colonies observed. It was concluded that the FAB types of ANLL show different proliferative capability, which might influence the prognosis of the disease.