Biological monitoring of early genotoxic effects in urothelial cells using the urinary micronucleus (MNu) assay is promising for early detection of cancer, such as bladder carcinoma. But many problems are encountered, the major being the poorly differential staining of cells, particularly in women having an important amount of squamous cells. We have optimized the protocol and obtained a differential staining of the cell types present in urine on 10 subjects. Following Carnoy I fixation and Papanicolaou staining, urothelial cells were blue while most squamous cells were pink. This differential staining allowed for optimization of the MNu assay on a single urine void, for both females and males. Even if our MNu means were comparable to the literature, the great variation in reported MNu results could reside in the ability of scorers to distinguish correctly between urothelial and squamous cells. When monitoring exposed populations, this erroneous distinction could largely influence the results, even more in women's urine samples. Given a situation where exposure would not increase micronuclei frequency in vaginal squamous cells, their erroneous analysis in the MNu assay could mask an early genotoxic effect. Therefore, as transitional cell carcinoma of the bladder originates from transformed urothelial cells, restricting micronuclei analysis to urothelial cells could yield a more precise estimate of cancer risk in exposed populations. Moreover, it is hoped that the improvements proposed in this paper will allow for an easier implementation of the MNu assay in various set-ups and enhance its specificity, since MNu are considered a suitable biomarker.

Because ring Y chromosomes are unstable during cell division most reported patients are mosaics, usually including a 45.X cell line. The phenotype varies from normal males or females with streak gonads to sexual ambiguities. We present here the case of a 23-year-old man who was referred at 11 years for growth delay. The GTG-banded karyotypes of lymphocytes revealed two cell lines: 46,X,dic r(Y) seen in 76% of the metaphases analyzed and 45,X (24%). Karyotypes and FISH were performed eight years later with the following probes: DYZ3 (Y centromere), SRY (sex-region of the Y), DYZ1 (Yq heterochromatin), CEPX/Y (X centromere and Yq heterochromatin), TelVysion Xp/Yp, Xq/Yq (X and Y subtelomeres), pan-telomeric, cosmidclones LLycos130G04 and LLycos37C09 (PARII), and BAC clone RP11-5C5 (Yq11.223). The results showed an increase in the 45,X cell line (60%) and a reduction in the 46,X,dic r(Y) cell line (36.4%). The use of Yq probes showed that the ring Y chromosome was dicentric. In addition, other ring Y structures were observed. The breakpoints occurred in proximal Yp11.32 or in Yp11.31 distal to SRY and in Yq12 distal to the PARII region. Therefore, most of the Y remained intact and all genes, with the exception of those in PARI, are present in double dosage in the dic r(Y). The level of mosaicism was important in defining the phenotype.

Isodicentric chromosomes are the most commonly reported aberrations of the human Y chromosome. As they are unstable during cell division and can generate various types of cell lines, most reported patients are chromosomal mosaics, generally including a 45,X cell line. Phenotypes depend on the location of the breakpoints as well as on the proportion of each cell line and vary from male to abnormal female or individual with ambiguous genitalia. Although phenotypic variability is known to also depend on the degree of mosaicism in the various tissues, gonads are rarely studied. We report nine cases of isodicentric Y chromosomes studied by conventional and molecular cytogenetic: three males, five females, and one individual with sexual ambiguity. Two males had a non‐mosaic karyotype, while the third male was a mosaic with a predominant 46,XY cell line. Three of the females had a major 45,X cell line, while the last two females and the patient with ambiguous genitalia had a major 46,X,idic(Y) cell line. Analyses of gonadal tissues from the individual with sexual ambiguity and of three of the five female patients gave results concordant with their phenotype, allowing us to better understand the sexual differentiation of these patients.

Two cases of pulmonary plasma cell granuloma in children are reported. The main features of this rare entity are described.

From 1979 to 1983, EMG and/or muscle biopsy studies were done in twenty-one of twenty-two patients seen in our institution for the first time for arthrogryposis multiplex congenita (AMC). Most of the muscle biopsies were done with a needle. As expected, the final diagnosis in these patients was very heterogeneous since it is well recognized that AMC can be due to any factor that interferes with fetal mobility. We found however a surprisingly high number of patients (9/22) affected by a myopathic disease. Based on these results, we feel that needle muscle biopsy should be included as a routine procedure in infants affected by AMC since by clarifying the diagnosis it helps in improving genetic counselling and prognosis in these patients. It is now widely accepted that arthrogryposis multiplex congenita (AMC) is not in itself a disease but is secondary to any factor that interferes with fetal movements. The joint deformities seen in these children can be due to mechanical factors (oligohydramnios for example), central or peripheral nervous system disorders, muscle diseases... (Dubowitz 1978, Hageman and Willemse 1983, Hall 1981, Swinyard 1982). However, the relative frequency of each etiologic factor remains unclear since in spite of the abundant literature on the subject, we found only three reports describing the findings of electromyographic (EMG) and muscle biopsy studies done systematically in unselected groups of children affected by AMC (Amick et al 1967, Bharucha et al 1972, Dastur et al 1972, Kullmann and Szijj 1973). Furthermore, each article reached different conclusions in regard to the occurrence of these various etiologies in their respective patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Several authors have recently reported a neurological disorder associated with chronic vitamin E deficiency in man. Except in one patient, this deficiency has always been secondary to an underlying disease resulting in lipid malabsorption. We report a second case of such a neurological syndrome in a patient in whom vitamin E deficiency was an isolated finding. The clinical picture in our patient was characterized by a diffuse muscle weakness most prominent distally and in the lower limbs, generalized areflexia, a decrease in proprioception and vibration sense and slight limb and gait ataxia. His condition improved on alpha tocopherol therapy so that it is very likely that vitamin E deficiency is responsible for his neurological deficit. Since in our patient as well as in several other reported cases this condition has been treatable, it is important that this syndrome be recognized in children presenting a suggestive clinical picture even if they do not have lipid malabsorption.

✓ This is the first case report of an intraspinal cystic teratoma that manifested itself in recurrent episodes of chemical meningitis, with no sign of a space-occupying lesion.

We present the 8th case so far published of generalized giant axonal neuropathy. Many features of the neurological picture of this 8 year 8 month old boy were suggestive of progressive bulbar paralysis of childhood. Muscle and sural nerve biopsies disclosed typical nodular axonal swellings measuring between 10--29 nm. Ultrastructure of the inflated portions of the axon consisted almost exclusively of 10 nm filaments. Normally appearing constituents were found in the non-dilated portions of the axons with this particularity that glycogen and mitochondria were aggregated. Previous clinical and pathological evidence indicates that this rare disorder not only affects the peripheral nerves but also the whole CNS. Our case differs from the others reported in literature by its rapidly deteriorating course and by the prominent involvement of some brain-stem motor functions; we offer the theory that a link might be implicated between this entity and Fazio-Londe disease.

The first Canadian child with complete absence of alpha L-fucosidase is described. The neurological course was characterised by rapid deterioration and he died at the earliest age recorded so far. There are only two published reports of autopsies in this condition to which we add another, together with the ultrastructural findings of a liver biopsy.