DYT1 mutations amongst adult primary dystonia patients in Singapore with review of literature comparing East and West

BACKGROUND: Dystonia is a heterogenous group of movement disorders whose clinical spectrum is very wide. At least 13 different genes and gene loci have been reported. While a 3-bp deletion in the DYT1 gene is the most frequent cause of early limb-onset, generalized dystonia, it has also been found in non-generalized forms of sporadic dystonia. An 18-bp deletion in the DYT1 gene has also been reported. OBJECTIVES: We screened for the 3-bp and 18-bp deletions in the DYT1 gene among our sporadic, adult-onset primary dystonia patients in Singapore. We reviewed the literature to compare the frequency of DYT1 mutation between the East and the West. METHODS: We screened 54 patients with primary dystonia (focal: n=41; segmental: n=11; multifocal: n=1; generalized: n=1) for the deletions in the DYT1 gene. A careful review of all published literature on DYT1 screening among sporadic, non-familial, non-Ashkenazi Jewish patients was done. RESULTS: We did not detect any mutations in the exon 5 of the DYT1 gene in any of our patients. The frequency of DYT1 mutation amongst Asians (1.0%) was comparable to the West (1.56%) (p=NS). CONCLUSIONS: DYT1 mutations are uncommon amongst adult primary dystonia patients in Singapore.

CD41 T cell recovery during suppression of HIV replication: an international comparison of the immunological efficacy of antiretroviral therapy in North America, Asia and Africa.

BACKGROUND Even among HIV-infected patients who fully suppress plasma HIV RNA replication on antiretroviral therapy, genetic (e.g. CCL3L1 copy number), viral (e.g. tropism) and environmental (e.g. chronic exposure to microbial antigens) factors influence CD4 recovery. These factors differ markedly around the world and therefore the expected CD4 recovery during HIV RNA suppression may differ globally. METHODS We evaluated HIV-infected adults from North America, West Africa, East Africa, Southern Africa and Asia starting non-nucleoside reverse transcriptase inhibitorbased regimens containing efavirenz or nevirapine, who achieved at least one HIV RNA level <500/ml in the first year of therapy and observed CD4 changes during HIV RNA suppression. We used a piecewise linear regression to estimate the influence of region of residence on CD4 recovery, adjusting for socio-demographic and clinical characteristics. We observed 28 217 patients from 105 cohorts over 37 825 person-years. RESULTS After adjustment, patients from East Africa showed diminished CD4 recovery as compared with other regions. Three years after antiretroviral therapy initiation, the mean CD4 count for a prototypical patient with a pre-therapy CD4 count of 150/ml was 529/ml [95% confidence interval (CI): 517–541] in North America, 494/ml (95% CI: 429–559) in West Africa, 515/ml (95% CI: 508–522) in Southern Africa, 503/ml (95% CI: 478–528) in Asia and 437/ml (95% CI: 425–449) in East Africa. CONCLUSIONS CD4 recovery during HIV RNA suppression is diminished in East Africa as compared with other regions of the world, and observed differences are large enough to potentially influence clinical outcomes. Epidemiological analyses on a global scale can identify macroscopic effects unobservable at the clinical, national or individual regional level.

Report by A.Berson about the aerological expedition of the Royal Aeronautic Observatory to East Africa in 1908

This paper is the edited translation of the paper “A. Berson's Bericht über die aerologische Expedition des königlichen aeronautischen Observatoriums nach Ostafrika im Jahre 1908” (Report by A. Berson about the aerological expedition of the Royal Aeronautic Observatory to East Africa in 1908) that was published 1910 in the Meteorologische Zeitschrift 27, 536–542. The paper, provided by R. Süring, co-editor of the journal, is a summary of a more extensive report published in the same year.

Beyond biofuels: jatropha’s multiple uses for farmers in East Africa

The jatropha plant produces seeds containing 25–40% oil by weight. This oil can be made into biodiesel. During the recent global fuel crisis, the price of crude oil peaked at over USD 130 per barrel. Jatropha attracted huge interest – it was touted as a wonder crop that could generate biodiesel oil on “marginal lands” in semi-arid areas. Its promise appeared especially great in East Africa. Today, however, jatropha’s value in East Africa appears to lie primarily in its multipurpose use by small-scale farmers, not in large-scale biofuel production.

Contrasting long-term records of biomass burning in wet and dry savannas of equatorial East Africa

Rainfall controls fire in tropical savanna ecosystems through impacting both the amount and flammability of plant biomass, and consequently, predicted changes in tropical precipitation over the next century are likely to have contrasting effects on the fire regimes of wet and dry savannas. We reconstructed the long-term dynamics of biomass burning in equatorial East Africa, using fossil charcoal particles from two well-dated lake-sediment records in western Uganda and central Kenya. We compared these high-resolution (5 years/sample) time series of biomass burning, spanning the last 3800 and 1200 years, with independent data on past hydroclimatic variability and vegetation dynamics. In western Uganda, a rapid (<100 years) and permanent increase in burning occurred around 2170 years ago, when climatic drying replaced semideciduous forest by wooded grassland. At the century time scale, biomass burning was inversely related to moisture balance for much of the next two millennia until ca. 1750 ad, when burning increased strongly despite regional climate becoming wetter. A sustained decrease in burning since the mid20th century reflects the intensified modern-day landscape conversion into cropland and plantations. In contrast, in semiarid central Kenya, biomass burning peaked at intermediate moisture-balance levels, whereas it was lower both during the wettest and driest multidecadal periods of the last 1200 years. Here, burning steadily increased since the mid20th century, presumably due to more frequent deliberate ignitions for bush clearing and cattle ranching. Both the observed historical trends and regional contrasts in biomass burning are consistent with spatial variability in fire regimes across the African savanna biome today. They demonstrate the strong dependence of East African fire regimes on both climatic moisture balance and vegetation, and the extent to which this dependence is now being overridden by anthropogenic activity.