Short report: Lack of sex effect on the pharmacokinetics of primaquine

The pharmacokinetics of primaquine have been well defined in male volunteers, but there is little data on the disposition of the drug in women. We compared the kinetics of primaquine in nine male and nine female healthy Australian volunteers after the administration of a single oral dose (30 mg base) of primaquine. No statistical differences were observed in the following kinetic parameters of primaquine between men and women, respectively: maximum plasma concentration (93 +/- 26 and 115 +/- 38 ng/mL; 95% confidence interval [CI] of the mean difference: -55 to 10 ng/mL; P = 0.16), area under the curve (1.1 +/- 0.5 and 1.2 +/- 0.4 mu g.h/mL; 95% CI: -0.6 to 0.3 mu g.h/mL; P = 0.54), and clearance (0.34 +/- 0.12 and 0.39 +/- 0.14 L/h/kg; 95% CI: -0.17 to 0.08 L/h/kg; P = 0.46). The clinical relevance of such findings would suggest that sex does not have to be taken into account as a factor when prescribing primaquine for radical cure or terminal prophylaxis of Plasmodium vivax malaria.

Global processing speed as a mediator of developmental changes in children's auditory memory span

This study examined the role of global processing speed in mediating age increases in auditory memory span in 5- to 13-year-olds. Children were tested on measures of memory span, processing speed, single-word speech rate, phonological sensitivity, and vocabulary. Structural equation modeling supported a model in which age-associated increases in processing speed predicted the availability of long-term memory phonological representations for redintegration processes. The availability of long-term phonological representations, in turn, explained variance in memory span. Maximum speech rate did not predict independent variance in memory span. (c) 2005 Elsevier Inc. All rights reserved.

Genetic uniformity of international isolates of Leifsonia xyli subsp xyli, causal agent of ratoon stunting disease of sugarcane

An international collection of the sugarcane ratoon stunting disease pathogen, Leifsonia xyli subsp. xyli, was analysed to assess genetic diversity. DNA fingerprinting using BOX primers was performed on 105 isolates, comprising 65 Australian isolates and an additional 40 isolates from Indonesia (n = 8), Japan (n = 1), USA (n = 3), Brazil (n = 2), Mali (n = 2), Zimbabwe (n = 13), South Africa (n = 9) and Reunion (n = 2). Sixty-two of these isolates were also screened using ERIC primers. No variation was found among any of the isolates. The intergenic spacer (IGS) region of the ribosomal RNA genes from 54 isolates was screened for sequence variation using single-stranded conformational polymorphism (SSCP), but none was observed. Direct sequencing of the IGS from a subset of nine isolates, representing all of the countries sampled in this study, confirmed the results of the SSCP analysis. Likewise, no sequence variation was found in the 16S ribosomal RNA genes of the same subset. Four Colombian isolates from sugarcane, morphologically similar to L. xyli subsp. xyli, were putatively shown to be an undescribed Agrococcus species of unknown pathogenicity. The lack of genetic variation among L. xyli subsp. xyli isolates, independent of time of sampling, cultivar of isolation, or country of origin, suggests the worldwide spread of a single pathogenic clone, and further suggests that sugarcane cultivars resistant to ratoon stunting disease in one area should retain this property in other regions.

A design pattern for efficient retrieval of large data sets from remote data sources

Retrieving large amounts of information over wide area networks, including the Internet, is problematic due to issues arising from latency of response, lack of direct memory access to data serving resources, and fault tolerance. This paper describes a design pattern for solving the issues of handling results from queries that return large amounts of data. Typically these queries would be made by a client process across a wide area network (or Internet), with one or more middle-tiers, to a relational database residing on a remote server. The solution involves implementing a combination of data retrieval strategies, including the use of iterators for traversing data sets and providing an appropriate level of abstraction to the client, double-buffering of data subsets, multi-threaded data retrieval, and query slicing. This design has recently been implemented and incorporated into the framework of a commercial software product developed at Oracle Corporation.

Progressive loss of expressive language in a journalist: What news for dementia?

A 77-year-old man with 8 year progressive language deterioration in the face of grossly intact memory was followed. No acute or chronic physiological or psychological event was associated with symptom onset. CT revealed small left basal ganglia infarct. Mild atrophy, no lacunar infarcts, mild diffuse periventricular changes registered on MRI. Gait normal but slow. Speech hesitant and sparse. Affect euthymic; neurobehavioral disturbance absent. MMSE 26/30; clock incorrect, concrete. Neuropsychological testing revealed simple attention intact; complex attention, processing speed impaired. Visuospatial copying and delayed recall of copy average with some perseveration. Apraxia absent. Recall mildly impaired. Mild deficits in planning, organization apparent. Patient severely aphasic, dysarthric without paraphasias. Repetition of automatic speech, recitation moderately impaired; prosody intact. Understanding of written language, nonverbal communication abilities, intact. Frontal release signs developed over last 12 months. Repeated cognitive testing revealed mild deterioration across all domains with significant further decrease in expressive, receptive language. Neurobehavioral changes remain absent to date; he remains interested, engaged and independent in basic ADLs. Speech completely deteriorated; gait and movements appreciably slowed. Although signs of frontal/executive dysfunction present, lack of behavioral abnormalities, psychiatric disturbance, personality change argue against focal or progressive frontal impairment or dementia. Relative intactness of memory and comprehension argue against Alzheimer’s disease. Lack of findings on neuroimaging argue against CVA or tumor. It is possible that the small basal ganglia infarct has resulted in a mild lateral prefrontal syndrome. However, the absence of depression as well as the relatively circumscribed language problem suggests otherwise. The progressive, severe nature of language impairments, with relatively minor impairments in attention and memory, argues for a possible diagnosis of primary progressive aphasia.