Levodopa dose-related fluctuations in presumed olivopontocerebellar atrophy

The parkinsonism that occurs in some patients with olivopontocerebellar atrophy (OPCA) can cause diagnostic confusion with idiopathic Parkinson's disease (IPD). The response to levodopa is usually a distinguishing feature, the OPCAs either failing to benefit or losing efficacy relatively quickly. A fluctuating response to levodopa in those OPCA patients who do benefit has not been emphasized in the literature previously. Reported here are three patients with presumed OPCA, dominated by parkinsonian features, who eventually developed typical fluctuations with morning akinesia, wearing off, and periodic lack of response related to meals. These fluctuations were a major source of disability and an important reason for diagnostic confusion with IPD. The possible mechanisms of these fluctuations are discussed.     

Distribution and excretion of 2,3,7,8-tetrachlorodibenzo-p-dioxin in congenic strains of mice which differ at the Ah locus

The effect of the genetic background on the distribution and excretion of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was examined in two sets of congenic mouse strains in which the congenic pairs differed only at the Ah locus. Male C57BL/6J mice which were either Ahb/Ahd or Ahd/Ahd and female DBA/2J mice which were also Ahb/Ahd or Ahd/Ahd were treated with 500 ng/kg 3H-TCDD and held from 1 to 42 days in individual metabolism cages. Daily excretion and tissue distribution at eight time points were determined. The Ah locus had no effect on the distribution of TCDD-derived radioactivity to the major tissue depots of adipose tissue, skin, kidney, carcass, and blood but seemed to cause elevated levels in the liver. The Ah locus also played no role in either the rate or the extent of urinary and/or fecal excretion. However, the route and rates of excretion did vary between the congenic sets with the male C57BL/6J mice excreting greater amounts of radioactivity in the urine and less in the feces than the female DBA/2J mice. The Ah locus also had no effect on the liver weight or adipose tissue volume in either congenic set. Thus, at the dose level studied, the distribution and excretion of TCDD were primarily governed by the total genetic background rather than the allele present at the Ah locus.     

Untersuchungen zur Regulation der Ammoniumassimilation von Candida maltosa

Activities of ammonia-metabolizing enzymes from Candida maltosa were measured. The synthesis of glutamate and glutamine involves three primary enzymes: glutamate dehydrogenase (GDH), glutamine synthetase (GS), and glutamate synthase (GOGAT). This yeast has two distinct GDH, the first responsible for glutamate catabolism, and the second solely biosynthetic. The GS is derepressed during growth on low ammonia or on a variety of alternative nitrogen sources, whereas the catabolic GDH (NAD) is repressed under this conditions. Ammonia limitation did not significantly affect GOGAT as well as biosynthetic GDH (NADP) levels. The relatively low K_m-value for ammonia suggest that the GS is catalytically active during cell growth on low concentrations of ammonia. It seems that under N-limitation ammonia assimilation is achieved via GS/GOGAT and under N-excess via GDH/GS.     

Housing and house-dust mites

Because the mite-allergen content in homes is highly variable even in the same geographic area, we tried to determine which variables influence mite infestation. We evaluated mite-allergen content in bedding relative to housing conditions and living habits. This cross-sectional study included 108 homes. Housing conditions were assessed by an architect and living habits by a researcher specialized in social and family economics. Group I allergen level was measured on the mattress dust with monoclonal antibodies, and relative humidity (RH) was monitored in the bedroom during a 2-week period. Homes with low RH did have low mite-allergen content. In contrast, homes with intermediate RH levels had very variable mite-allergen content. Using analysis of variance and a logistic regression analysis, we were unable to identify any variable predictive of mite-allergen content. Thus, factors other than relative humidity seem to influence mite infestation. Moreover, the absence of association between mite infestation and ventilation rate might be accounted for by the gentle climate in our area with notable outdoor RH.     

Aboriginal status is a prognostic factor for mortality among antiretroviral naïve HIV-positive individuals first initiating HAART

Background  

Although the impact of Aboriginal status on HIV incidence, HIV disease progression, and access to treatment has been investigated previously, little is known about the relationship between Aboriginal ethnicity and outcomes associated with highly active antiretroviral therapy (HAART). We undertook the present analysis to determine if Aboriginal and non-Aboriginal persons respond differently to HAART by measuring HIV plasma viral load response, CD4 cell response and time to all-cause mortality.     

Association of haplotypes in the beta-chemokine locus with multiple sclerosis

Linkage studies in multiple sclerosis (MS) identified several susceptibility loci. One of these regions includes chromosome 17q11 where a meta-analysis of data from three genome scans suggested linkage. This region encodes a cluster of genes for beta-chemokines or CC chemokine ligands (CCLs), which may be involved in the development of MS lesions. Here we aimed to test if CCL alleles and haplotypes are associated with MS. Using methods of linkage and association, we observed deviations from the expected 50% transmission of haplotypes from unaffected parents to their affected children at CCL2, CCL11-CCL8-CCL13 and CCL3 within the investigated 1.85 MB chromosomal segment. Analyses of the linkage disequilibrium map support that variants with possible relevance to MS can be located within these subregions. Identification of MS associated CCL variants may have direct clinical significance, as it can lead to the design of small competitive antagonists of these molecules with beneficial effects in the treatment of patients with early and active disease.