A telemedicine instrument for remote evaluation of tremor: design and initial applications in fatigue and patients with Parkinson's Disease

Introduction  

A novel system that combines a compact mobile instrument and Internet communications is presented in this paper for remote evaluation of tremors. The system presents a high potential application in Parkinson's disease and connects to the Internet through a TCP/IP protocol. Tremor transduction is carried out by accelerometers, and the data processing, presentation and storage were obtained by a virtual instrument. The system supplies the peak frequency (fp), the amplitude (Afp) and power in this frequency (Pfp), the total power (Ptot), and the power in low (1-4 Hz) and high (4-7 Hz) frequencies (Plf and Phf, respectively).     

Study of the effect of tegalide and bithionol on biological membranes using fluorescent probes

Fluorescent probes were used to study structural changes in different membranes affected by gamma-radiation, protonophores and radioprotective agents, tegalide and bithionol. The preparations of the defined concentrations decreased the microviscosity of membranes, lowered the peaks and changed the temperature of phase transitions in liposomes from dipalmitoyl lecithin, and induced the output of Ca2+ from mitochondria. The effects depended on the radiation dose, the structure, concentration and lipophilicity of the preparation; protonophores produced a specific effect.     

Molecular characteristics of diverse populations are consistent with the hypothesis of a recent invasion of Drosophila melanogaster by mobile P elements

Approximately 100 strains derived from natural populations of Drosophila melanogaster were tested for the presence or absence of P- element sequences by using two molecular probes derived from internal regions of a full-sized P element. Strains that had been collected from several continents at varying times during the past 60 years were examined. The oldest available strains, representing most major geographical regions of the world, exhibited no detectable hybridization to the P-element probes. In contrast, all recently collected natural populations that were tested carried P-element sequences. The earliest appearance of P elements occurred in collections made during the 1950s and early 1960s in the Americas and during the late 1960s on other continents. The youngest strains that were completely devoid of P elements originated in populations sampled during the mid-1960s in America, but as late as 1974 in populations from the USSR. There are differences in the patterns of hybridization to the two P-element probes between populations from different geographical regions. These differences are consistent with the varying P-M phenotypic properties of these populations. Taken together with the results of phenotypic tests reported in earlier studies, the available evidence is consistent with the hypothesis of a worldwide P-element invasion of D. melanogaster during the past 30 years and suggests that the putative invasion of the Americas possibly preceded by approximately a decade that in Europe, Africa, and the rest of the world.      

Mitochondrial control-region sequences in two shorebird species, the turnstone and the dunlin, and their utility in population genetic studies

We determined the mitochondrial control-region sequences of five turnstones (Arenaria interpres) and three dunlins (Calidris alpina). Comparisons revealed that the central part (part II) is conserved relative to much more variable parts at the beginning (part I) and the end (part III). This pattern of sequence conservation is also found in the control regions of other vertebrates. The average sequence divergence between turnstone and dunlin was 21.8% for part I, 7.5% for part II, and 29.5% for part III. Within-species sequence divergence over the entire control region was much lower, at 0.9% for turnstones and 2.0% for dunlins. In both shorebird species, part III contains a repetitive sequence composed only of A and C nucleotides, which has not been found in the control regions of other birds. A survey of the part I sequences of 25 turnstones and 25 dunlins sampled around the world revealed that these species have very different population genetic structures. Dunlins are not only much more differentiated in their sequences but also have a strongly subdivided population genetic structure. Pleistocene vicariant events combined with strong natal philopatry and high mutation rates of the sequences are likely responsible for this population genetic subdivision. Conversely, part I sequences of turnstones are weakly differentiated and are geographically unstructured. We argue that this is not the result of global gene flow but that, instead turnstones have recently expanded from a refugial population that was bottlenecked.      

Systematic review and meta-analysis: rapid diagnostic tests versus placental histology, microscopy and PCR for malaria in pregnant women

Background

To prepare field sites for malaria vaccine trials, it is important to determine baseline antibody and T cell responses to candidate malaria vaccine antigens. Assessing T cell responses is especially challenging, given genetic restriction, low responses observed in endemic areas, their variability over time, potential suppression by parasitaemia and the intrinsic variability of the assays.

Methods

In Part A of this study, antibody titres were measured in adults from urban and rural communities in Ghana to recombinant Plasmodium falciparum CSP, SSP2/TRAP, LSA1, EXP1, MSP1, MSP3 and EBA175 by ELISA, and to sporozoites and infected erythrocytes by IFA. Positive ELISA responses were determined using two methods. T cell responses to defined CD8 or CD4 T cell epitopes from CSP, SSP2/TRAP, LSA1 and EXP1 were measured by ex vivo IFN-γ ELISpot assays using HLA-matched Class I- and DR-restricted synthetic peptides. In Part B, the reproducibility of the ELISpot assay to CSP and AMA1 was measured by repeating assays of individual samples using peptide pools and low, medium or high stringency criteria for defining positive responses, and by comparing samples collected two weeks apart.

Results

In Part A, positive antibody responses varied widely from 17%-100%, according to the antigen and statistical method, with blood stage antigens showing more frequent and higher magnitude responses. ELISA titres were higher in rural subjects, while IFA titres and the frequencies and magnitudes of ex vivo ELISpot activities were similar in both communities. DR-restricted peptides showed stronger responses than Class I-restricted peptides. In Part B, the most stringent statistical criteria gave the fewest, and the least stringent the most positive responses, with reproducibility slightly higher using the least stringent method when assays were repeated. Results varied significantly between the two-week time-points for many participants.

Conclusions

All participants were positive for at least one malaria protein by ELISA, with results dependent on the criteria for positivity. Likewise, ELISpot responses varied among participants, but were relatively reproducible by the three methods tested, especially the least stringent, when assays were repeated. However, results often differed between samples taken two weeks apart, indicating significant biological variability over short intervals.     

Phylogenetic relationships among prokaryotic and eukaryotic catalases

Seventy-four catalase protein sequences, including 29 bacterial, 8 fungal, 7 animal, and 30 plant sequences, were compiled, and 70 were used for phylogenetic reconstruction. The core of the resulting tree revealed unique, separate groups of plant and animal catalases, two groups of fungal catalases, and three groups of bacterial catalases. The only overlap of kingdoms occurred within one branch and involved fungal and bacterial large-subunit enzymes. The other fungal branch was closely linked to the group of animal enzymes. Group I bacterial catalases were more closely related to the plant enzymes and contained such diverse taxa as the Gram-positive Listeria seeligeri, Deinocococcus radiodurans, and gamma-proteobacteria. Group III bacterial sequences were more closely related to fungal and animal sequences and included enzymes from a broad range of bacteria including high- and low-GC Gram positives, proteobacteria, and a bacteroides species. Group II was composed of large-subunit catalases from diverse sources including Gram positives (low-GC Bacilli and high-GC Mycobacteria), proteobacteria, and species of the filamentous fungus Aspergillus. These data can be interpreted in terms of two gene duplication events that produced a minimum of three catalase gene family members that subsequently evolved in response to environmental demands. Horizontal gene transfer may have been responsible for the group II mixture of bacterial and fungal large-subunit catalases.      

Molecular evolution of P transposable elements in the genus Drosophila. I. The saltans and willistoni species groups

A phylogenetic survey using the polymerase chain reaction (PCR) has identified four major P element subfamilies in the saltans and willistoni species groups of Drosophila. One subfamily, containing about half of the sequences studied, consists of elements that are very similar to the canonical (and active) P element from D. melanogaster. Within this subfamily, nucleotide sequence differentiation among different copies from the same species and among elements from different species is relatively low. This observation suggests that the canonical elements are relatively recent additions to the genome or, less likely, are evolving slowly relative to the other subfamilies. Elements belonging to the three noncanonical lineages are distinct from the canonical elements and from one another. Furthermore, there is considerably more sequence variation, on the average, within the noncanonical subfamilies compared to the canonical elements. Horizontal transfer and the coexistence of multiple, independently evolving element subfamilies in the same genome may explain the distribution of P elements in the saltans and willistoni species groups. Such explanations are not mutually exclusive, and each may be involved to varying degrees in the maintenance of P elements in natural populations of Drosophila.