Potentiation of cadmium nephrotoxicity by acetaminophen

The possible interactions between acetaminophen and cadmium (Cd) on the kidney were investigated in female Sprague-Dawley rats. Acetaminophen was administered in the food at an average dose of 900 mg/kg and Cd in drinking water at the concentration of 200 ppm. The treatment with acetaminophen and Cd lasted 2 and 10 months, respectively. No interaction between Cd and acetaminophen was observed during the period of their concomitant administration: the increase in albuminuria caused by Cd and acetaminophen was additive, while the tubular impairment caused by acetaminophen (increased ₂-microglobulinuria and decreased kidney concentrating ability) was not exacerbated by Cd. None of these treatments affected the glomerular filtration rate. Four months after the end of acetaminophen treatment, the renal changes had almost completely disappeared in the rats which had received the analgesic alone. Those continously exposed to Cd had developed slight tubular damage, as evidenced by an increased urinary excretion of ₂-microglobulin and -N-acetylglucosaminidase. By contrast, rats pretreated with acetaminophen for 2 months and exposed to Cd showed a marked increase in urinary excretion of albumin and ₂-microglobulin, suggesting an interaction between both treatments. At the end of the study, only the interaction with ₂-microglobulin excretion was still evident; that with the urinary excretion of -N-acetylglucosaminidase and albumin having been masked by the chronic progessive nephrosis affecting most animals at that stage. As acetaminophen had no effect on the renal accumulation of Cd, it may be concluded that pretreatment with this analgesic at a dose causing slight tubular dysfunction renders rat kidney more sensitive to the nephrotoxic action of Cd. This observation may be of clinical relevance for population groups occupationally or environmentally exposed to Cd.     

New variant of familial cerebellar ataxia with hypergonadotropic hypogonadism and sensorineural deafness

Cerebellar ataxia and hypergonadotropic hypogonadism comprise a rare and presumably heterogeneous association. Inheritance in most cases appears to be autosomal recessive, and associated features include deafness, intellectual impairment, and neuropathy. Typically, onset of ataxia is in the first decade and hypogonadism results in primary amenorrhoea in females. We describe two sisters with a previously undescribed pattern of adult onset progressive cerebellar ataxia and secondary amenorrhoea due to hypergonadotropic hypogonadism. Sensorineural deafness with vestibular hypofunction and peripheral sensory impairment were also present, and intellect was normal. Onset of neurological symptoms was in the third decade, with secondary amenorrhoea occurring at the ages of 16 and 32 years, respectively. The association of ataxia and hypergonadotropic hypergonadism has been classified both as a variant of Holmes type ataxia and as a variant of Perrault syndrome, but we suggest the use of a separate category of ataxia with hypergonadotropic hypogonadism. Copyright Wiley-Liss. Inc.     

The effect of cycloleucine on SFV A7(74) infection in mice

Cycloleucine (CL), a non-metabolizable amino acid analogue, was found to reduce thymus and spleen weights in Semliki Forest virus (SFV) strain A7(74) infected and control mice. The maximum effects were seen when three daily doses of CL were given to mice 24 h after an SFV A7(74) infection. In these mice thymus atrophy led to abolition of thymus dependent immune responses and changes in the pathological features of the viral infection--the most striking feature being prevention of demyelination. In addition virus titres in the brains of CL treated infected mice were increased and prolonged. These results show that demyelination following an SFV A7(74) infection is not a result of direct virus action, but of a T-cell mediated mechanism.     

The effect of cycloleucine on SFV A7(74) infection in mice.

Cycloleucine (CL), a non-metabolizable amino acid analogue, was found to reduce thymus and spleen weights in Semliki Forest virus (SFV) strain A7(74) infected and control mice. The maximum effects were seen when three daily doses of CL were given to mice 24 h after an SFV A7(74) infection. In these mice thymus atrophy led to abolition of thymus dependent immune responses and changes in the pathological features of the viral infection--the most striking feature being prevention of demyelination. In addition virus titres in the brains of CL treated infected mice were increased and prolonged. These results show that demyelination following an SFV A7(74) infection is not a result of direct virus action, but of a T-cell mediated mechanism.     

The induction of human antinuclear antibodies by D-penicillamine: activation of inducer helper T cells in the absence of irradiation sensitive suppressor T cells.

The capacity of D-Penicillamine (DP) to induce or to potentiate the production of antinuclear antibodies (ANA), detected by immunofluorescence (IF), was investigated in vitro, using peripheral blood mononuclear cells (PBMC) from patients with systemic lupus erythematosus (SLE) and normal individuals. Except in one patient with SLE, DP did not enhance ANA synthesis when using unseparated PBMC. In contrast, when B cells were cocultured with irradiated T cells or irradiated enriched T4+ subset, DP induced or potentiated the production of ANA. These results indicate that DP acts by stimulating T4+ helper cells to promote ANA synthesis in the absence of radio-sensitive suppressor T cell function contained within the T4+ population.     

Epidural haematoma of the posterior fossa with delayed operation

Summary A case of chronic epidural haematoma of the posterior fossa is reported. The lesion was studied with cerebral angiography and computed tomography. The patient was under observation for two weeks before the extradural clot was. removed. The membrane surrounding the haematoma was examined histologically. The importance of computed tomography in the diagnosis of traumatic lesions of the posterior fossa is emphasized.     

Langerhans cell histiocytois of the thyroid: a rare disease not to be ignored

Thyroid involvement by Langerhans cell histiocytosis is rare. We report the case of a ten-year old boy who presented with a 5 cm goitre. He was treated for diabetes insipidus 14 months before. Thyroid isotopic scan showed hypoactivity of right lobe and revealed a cold left nodule. The patient was treated by right lobo-isthmectomy with adjuvant corticotherapy and chemotherapy (vinblastine). He is well with 12 months follow-up. Microscopic analysis demonstrated a diffuse infiltrate of thyroid parenchyma by sheets of CD1a positive Langerhans cells associated with lymphocyte foci. This case is remarkable by the abundance of Langerhans cells and scarcity of eosinophils. The diagnosis of thyroid langerhans cell histiocytosis should not be ignored in both children and adult patients.     

Cloning and expression of rfb genes from Vibrio anguillarum serotype O2 in Escherichia coli: evidence for cross-reactive epitopes.

Vibrio ordalii and Vibrio anguillarum O2 express lipopolysaccharide (LPS) O antigens containing both specific and cross-reactive epitopes. The localization of these epitopes on the O antigen is not known. We have cloned and expressed the rfb gene cluster for O-antigen synthesis from V. anguillarum O2 (rfbVaO2) in Escherichia coli. E. coli DH5 alpha containing the recombinant plasmid pAM86 expressed O antigens which reacted with polyclonal antisera to V. ordalii and to V. anguillarum O2 LPS and with monoclonal antibody (MAb) 7B4, which is specific for V. anguillarum O2 O antigens. The recombinant strains were also protected from bactericidal killing by normal fish serum. Surprisingly, the LPS expressed from the cloned rfbVaO2 genes also reacted with MAb A16, which is specific for V. ordalii O antigens. Western immunoblot analysis revealed that MAb 7B4 reacted with recombinant LPS bearing shorter O-antigen repeat units, while MAb A16 reacted with the longer O antigens. Similar results were obtained when pAM86 was transformed into E. coli CLM4, which has a deletion spanning the sbcB-rfb region, indicating that the changes in antigenic profiles of O antigens from the recombinant strains were not due to genes within the E. coli rfb cluster. These data suggest that the epitope recognized by the MAb A16 is expressed by V. anguillarum O2 strains but it is apparently not accessible to the antibody in the native O polysaccharide. Cloning of the rfbVaO2 gene cluster resulted in expression of a novel O antigen. The modification(s) which leads to the alterations in antigenic profile of these recombinant LPS remains to be determined.     

Parental mosaicism of JAG1 mutations in families with Alagille syndrome

The Alagille syndrome (AGS), a congenital disorder affecting liver, heart, skeleton and eye in association with a typical face, is an autosomal dominant disease with nearly complete penetrance and variable expression. AGS is caused by mutations in the developmentally important JAG1 gene. In our mutation screening, where 61 mutations in JAG1 were detected, we identified five cases where mosaicism is present. Our results point to a significant frequency of mosaicism for JAG1 mutations in AGS of more than 8.2%. Because mosaicism may be associated with a very mild phenotype, the appropriate diagnosis of AGS and consequently the determination of the recurrence risk can be complicated.