Decreased N-acetyl-aspartate/choline ratio and increased lactate in the frontal lobe of patients with Huntington's disease: a proton magnetic resonance spectroscopy study

BACKGROUND

Both the effect of the mutation and the pathogenesis of Huntington's disease are unknown and a lack of biological markers for the natural history of the disease impedes the evaluation of novel therapeutic approaches.

METHODS

Proton magnetic resonance spectroscopy was carried out on a frontal region of the cortex in 17 patients with clinically overt Huntington's disease and four asymptomatic gene carriers.

RESULTS

Eight of 17 (47%) clinically affected patients with Huntington's disease and each of the asymptomatic carriers had lactate peaks in the frontal cortex which were not present in controls. The N-acetyl-aspartate/choline (NAA/Ch) ratio was significantly reduced in the symptomatic patients indicating the presence of neuronal loss. The reduction was related to the clinical severity of the disease and was absent in the asymptomatic carriers.

CONCLUSION

The finding of lactate peaks supports the hypothesis that disturbed cerebral energy metabolism contributes to the pathogenesis of Huntington's disease.

[New knowledge of the etiology and pathogenesis of Huntington chorea]

Huntington's disease (HD) is a neurodegenerative disorder for which no causal therapy is currently available. It is inherited as an autosomal dominant trait and the responsible gene was localized 10 years ago to chromosome 4. Recently the gene has been identified. This discovery now allows a definitive diagnosis to be made in most cases. Preclinical testing, however, requires careful psychological counselling. So far the structure and function of the gene product are unknown. Using experimental neurotoxicological methods it is possible to mimic several features of the disease process to such an extent that preliminary hypotheses regarding the function of the encoded protein are possible. It will be of great interest to see how the results of molecular genetic studies and of experimental research can be synthesized in the future.

The Kabuki (Niikawa-Kuroki) syndrome: further delineation of the phenotype in 29 non-Japanese patients

The Kabuki (Niikawa-Kuroki) syndrome was reported in 1981 by Niikawa et al. and Kuroki et al. in a total of ten unrelated Japanese children with a characteristic array of multiple congenital anomalies and mental retardation. The syndrome is characterized by a distinct face, mild to moderate mental retardation, postnatal growth retardation, dermatoglyphic and skeletal abnormalities. In Japan, the syndrome appears to have an incidence of about 1:32,000 newborns. Outside of Japan, a growing number of patients have been recognized. Clinical data are presented on 29 Caucasian patients; the patients were diagnosed over a relatively short period of time, indicating that the incidence outside of Japan is probably not lower than in Japan. A literature review of 89 patients (60 Japanese and 29 non-Japanese) is given. In 66% of the non-Japanese patients serious neurological problems were present, most notably hypotonia and feeding problems (which were not only related to the cleft palate); this was not reported in the Japanese patients. Inheritance is not clear. Most patients are isolated, sex-ratio is equal. The syndrome can be recognized in patients with cleft (lip/)palate, with mild to moderate developmental delay and in young children with hypotonia and/or feeding problems. In counselling parents, the designation "Kabuki" syndrome seems to be more appropriate than "Kabuki make-up" syndrome.

[Clinico-genetic diagnosis of ataxia telangiectatica (Louis-Bar syndrome)]

We describe the possible difficulties in getting the diagnosis "ataxia telangiectasia" using the example of a 16 years old girl. If cases of cerebellar ataxia in childhood present without classical symptoms, the diagnosis of ataxia telangiectasia should not be excluded before chromosome analysis. In our case, first signs of cerebellar ataxia were observed from the age of 11 years and we found only mild, atypical located and late onset telangiectasis. Other signs of the syndrome, such as elevated alpha-fetoproteine and deficiency of IgA or IgE could not be detected. Chromosome analysis, however, demonstrated a breakage syndrome with chromosome 14 to 7 translocation and established a firm diagnosis of ataxia telangiectasia. Patients with chromosome breakage syndromes including the Louis-Bar-syndrome have an increased risk for malignomas. Therefore chromosome analysis should be undertaken in cases of children with cerebellar ataxia, and frequent radiological examination avoided.

Picosecond pump and probe spectroscopy utilizing freely propagating terahertz radiation

We demonstrate the feasibility of scaling up a terahertz-pulse generation scheme for use with a 10-Hz amplified femtosecond laser system. Visible pulsed excitation combined with a far-infrared probe should prove to be a powerful picosecond time-resolved technique.

[Alpha 1-fetoprotein--a marker of potential PUVA side-effects in psoriasis?]

Serum concentrations of alpha 1-fetoprotein (AFP) during PUVA treatment have been analyzed in 12 patients suffering from severe psoriasis or psoriatic arthritis. The results have been compared with AFP levels in psoriatics without PUVA treatment (group II), patients with psoriatic arthritis treated with methotrexate (group III), as well as dermatological patients without psoriasis (group IV). All groups revealed AFP levels below 25 ng/ml. Although a slight raise of AFP could be observed during PUVA therapy (p less than 0.005), we assume that AFP detection cannot be regarded as a marker of potential PUVA side-effects in psoriasis.

Direct analysis of lead in fruit juice by anodic stripping voltammetry with no prior sample preparation

A method is presented for determining lead in fruit juice in less than 3 min after instrument calibration. The range examined is 0.01 to 1.3 ppm lead. The method is compared with 3 other methods in general use. Standard error of estimates between the methods compared range from 0.023 to 0.051 ppm for a set of 50 samples and from 0.037 to 0.091 ppm for a set of 9 samples. Regression correlation coefficients between methods range from 0.968 to 0.995. Judged by the comparisons, the direct method is precise and accurate over greater than a 100-fold range of lead concentrations.