Positive correlation of CTG expansion and pharyngoesophageal alterations in myotonic dystrophy patients

Alteration of the pharyngoesophageal musculature is a common finding in patients with myotonic dystrophy (MD), regardless of the presence of dysphagia. The aim of the present study was to determine whether a specific pattern of swallowing abnormalities could be identified in MD patients, and the possible correlation with the size of CTG repeats. Fifteen MD patients, 8 of whom were asymptomatic for dysphagia, underwent a videofluoroscopic study of swallowing. Alterations of the pharyngoesophageal phase of swallowing were detected in 12 of 15 patients, 6 without clinical evidence of dysphagia. Incomplete relaxation of the upper esophageal sphincter (UES) and esophageal hypotonia were the most common alterations. We found a significant correlation between the number of radiological alterations and the size of CTG repeats. A typical radiological pattern of swallowing has also been identified. The role of videofluoroscopy in evaluation of MD patients is briefly discussed.

Induction of anti-GM1 ganglioside antibodies by Campylobacter jejuni lipopolysaccharides

A frequent association exists between acute motor neuropathy, antecedent Campylobacter jejuni (CJ) and anti-GM ganglioside antibodies. Despite the chemical and immunological similarity between CJ lipopolysaccharides (LPS) and GM1, the mechanism of induction of anti-GM1 antibodies is still unclear. We used CJ LPS to immunize rats, mice and immunodeficient mice lacking in NK, CD8+ or T-cell populations. None of these animals developed significant anti-GM1 titers. However, rats immunized with keyhole limpet hemocyanin which contains the cross-reactive sugar epitope Gal(beta1-3)GalNAc developed high titers of IgM anti-GM1 antibodies. This occurred only after these rats were given an intraperitoneal injection of CJ LPS. These results suggest that a glycoprotein antigenic stimulus can induce B-cells which are autoreactive to ganglioside but which remain anergic. A second stimulus with a cross-reactive LPS can then overcome the anergy to induce autoantibody production. A similar mechanism may explain the occurrence of GM1 antibodies in patients after CJ enteritis.

Oxidative liver DNA damage in rats treated with pesticide mixtures

Oxidative damage was quantified in the liver of rats by measuring the levels of 8-OH-2-deoxyguanosine (8-OH-2DG) relative to 2-deoxyguanosine in DNA after treating rats for 10 days at a total dose of 1 mg/kg/day with a mixture of the 15 pesticides most commonly found in Italian foods (comprised of dithiocarbamate, benomyl, procymidone, methidathion, chlorpyrifos-ethyl, parathion-methyl, chlorpropham, parathion, vinclozolin, chlorfenvinphos, pirimiphos ethyl, thiabendazole, fenarimol, diphenylamine and chlorothalonil). We fractionated this pesticide mixture into subgroups in order to determine which molecules, if any, induced DNA oxidative damage. The administration of diphenylamine (0.09-1.4 mg/kg/day) and chlorothalonil (0.13-1 mg/kg/day) induced a dose-dependent increase in 8-OH-2DG levels in liver DNA. The other 13 pesticides of the mixture on the contrary, did not produce oxidative liver DNA damage. These results indicate that the toxicity of low doses of pesticide mixtures present in food might be further reduced by eliminating diphenylamine and chlorothalonil.

Motor neuron disease in the Padua district of Italy: an epidemiological study

Recent epidemiological surveys indicated that the rate of morbidity and mortality from motor neuron disease (MND) has increased worldwide. We evaluated whether the incidence of the disease has also changed in Padua, Italy, using a retrospective method to study all MND cases hospitalized in the Padua district from 1980 to 1991. As in other regions of the world, we also found an increased incidence of the disease.

Keyhole limpet hemocyanin contains Gal(beta 1-3)-GalNAc determinants that are cross-reactive with the T antigen

Keyhole limpet hemocyanin (KLH) is widely used as a carrier molecule to enhance immune responses to administered antigens, and for immunotherapy of bladder and renal carcinoma. In the present study we show, using lectin and antibody binding studies, that native KLH contains Gal(beta 1-3)GalNAc-bearing oligosaccharides, and that immunization with KLH in Lewis rats induces the production of anti-Gal(beta 1-3) GalNAc antibodies. This might explain the beneficial effect of KLH in bladder cancers that express cross-reactive Gal(beta 1-3)GalNAc determinants or the T antigen.

Dopamine receptor SPET imaging in Parkinson's disease: a [123I]-IBZM and [99mTc]-HM-PAO study

Single photon emission tomography (SPET) with the novel ligand [123I]-IBZM was used to image central dopamine D2 receptors in Parkinson's disease (PD) patients. The aim was to assess basal ganglia (BG) receptor densities in relation to the response to L-dopa therapy. To better characterize the clinical potential of [123I]-IBZM SPET, each patient underwent a second study with the regional perfusion tracer [99mTc]-HM-PAO. Tracer activity ratios were calculated for caudate and putamen with mean activity over the cerebellar hemispheres as internal standard. In PD patients we found a significant decline of mean caudate [123I]-IBZM activity, as compared with age-matched control subjects. However, when patients were grouped according to their therapeutic behavior, the [123I]-IBZM uptake in BG ganglia regions of the PD patient group with a poor and fluctuating response to L-dopa was significantly reduced from mean values of patients with a sustained response to L-dopa therapy. [99mTc]-HM-PAO caudate and putamen uptake indexes in PD were similar to control values, even in patients with deteriorated therapeutic response. Our results indicate that BG D2 receptor alterations in PD may contribute to the altered response to L-dopa.