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This study aims to evaluate the effect of autologous adipose-derived mesenchymal stem cells (AAD-MSC), with and without synthetic absorbable hydroxyapatite (HAP-91), on the bone regeneration in rabbits. Thirty-four female white New Zealand rabbits were submitted to a 10 mm distal diaphyseal radius ostectomy, divided into 3 experimental groups according to the treatment established. The bone gap was filled with 0.15 ml of a 0.9% saline solution containing two million AAD-MSC (G1), or AAD-MSC associated with HAP-91 (G2). The control group (CG) received only 0.15 ml of the 0.9% saline solution. Radiographs were made post-operatively, and after 15, 30, 45 and 90 days. Fifty percent of the samples were submitted to a histological examination at 45 days and the remaining ones at 90 days post-operatively. Radiographically, the periosteal reaction, bone callus volume and bone bridge quality were superior in G2 (P < 0.05). Histologically, the bone repair was faster and more efficient in G1 at 45 days (P < 0.05). In conclusion, AAD-MSC improved the regeneration on the experimentally induced bone defects in rabbits; however, the use of hydroxyapatite requires caution given the granulomatous reaction produced in the species.

The presence of Plasmodium ovale has never been previously reported in Myanmar. Using blood samples obtained in many villages across the country between 1996 and 2000, molecular diagnosis of Plasmodium species was made with semi- or full-nested polymerase chain reaction (PCR) with species-specific primers, followed by agarose gel electrophoresis to detect amplification products. The presence of P. ovale was also confirmed with the another PCR-based diagnosis, the microtiterplate hybridization (MPH) method using species-specific probes. Both methods target the A type of the small subunit ribosomal RNA gene of the four human malaria parasites. Plasmodium ovale DNA was amplified in samples from 65 (4.9%) of 1323 PCR-positive patients, with perfect agreement between results obtained by nested PCR and MPH. Only four P. ovale-infected patients had single-species infection; all others were coinfected with P. falciparum, P. vivax and/or P. malariae. Quadruple infections were observed in six subjects. Parasites with typical P. ovale morphology were found in only 19 patients by conventional microscopy of Giemsa-stained thin smears or fluorescence microscopy of acridine orange-stained thin smears. Plasmodium ovale infections were found in villages situated in the southern, central and western regions of Myanmar, suggesting that P. ovale may be widely distributed in this country. [ABSTRACT FROM AUTHOR]

We performed a field evaluation of polymerase chain reaction (PCR)-based enzyme-linked immuno-sorbent assays (ELISA) for the diagnosis of malaria. A commercially available PCR-ELISA microplate hybridization (MPH) assay was used. Blood specimens were collected from 300 volunteers seeking care at malaria clinics in Thailand. Examination of 200 high power fields by Giemsa-stained thick and thin smear (GTTS) revealed 51 P. falciparum (Pf), 45 P. vivax (Pv), seven mixed Pf-Pv infections. These plus a random sample of 48 GTTS-negative specimens were selected for this study. All 151 specimens were processed for parasite DNA extraction and assayed by PCR-MPH. The target DNA sequence of the 18S small subunit ribosomal RNA (SSUrRNA) gene was amplified by PCR and hybridized with species-specific probes for Pf, Pv, P. malariae (Pm) and P. ovale (Po) immobilized in the wells of the microtiter plate and detected by colorimetric assay. Colour development was assessed at an optical density (OD) of 405 nm. An absorbance reading of > or = 0.1 was used as a positive cut-off. In comparison with GTTS results, PCR-MPH sensitivity was 91.4% (53/58, 95% CI 84.2-98.6) for Pf, 94.2% (49/52, 87.9-100) for Pv and specificity was 95.8% (46/48, 95% CI 90.2-100). There was statistically significant positive correlation between parasite densities < or = 7000/microl blood and absorbance reading, suggestive of PCR-MPH being semiquantitative. PCR-MPH also detected additional Pf and Pv cases as well as Pm and Po. [ABSTRACT FROM AUTHOR]

A rapid single-step screening method for detection of glucose-6-phosphate dehydrogenase (G6 PD) deficiency was evaluated on Halmahera Island, Maluku Province, Indonesia, and in Shan and Mon States, Myanmar, in combination with a rapid diagnosis of malaria by an acridine orange staining method. Severe deficiency was detected by the rapid test in 45 of 1126 volunteers in Indonesia and 54 of 1079 in Myanmar, but it was difficult to distinguish blood samples with mild deficiency from those with normal activity. 89 of 99 severely deficient cases were later confirmed by formazan ring method in the laboratory, but 5 with mild and 5 with no deficiency were misdiagnosed as severe. Of the samples diagnosed as mild and no deficiency on-site, none was found to be severely deficient by the formazan method. Malaria patients were simultaenously++ detected on-site in 273 samples on Halmahera island and 277 samples from Shan and Mon States. In Mon State, primaquine was prescribed safely to G6 PD-normal malaria patients infected with Plasmodium vivax and/or gametocytes of P. falciparum. The new rapid test for G6 PD deficiency may be useful for detecting severe cases under field conditions, and both rapid tests combined are can be useful in malaria-endemic areas, facilitating early diagnosis, prompt and radical treatment of malaria and suppression of malaria transmission. [ABSTRACT FROM AUTHOR]

Describes a new interference filter, designed for use with AO in a standard light microscope, and how it can be applied to rapid diagnosis of malaria. Materials and methods; Results; Discussion.

Abstract Background The ideal malaria parasite populations for initial mapping of genomic regions contributing to phenotypes such as drug resistance and virulence, through genome-wide association studies, are those with high genetic diversity, allowing for numerous informative markers, and rare meiotic recombination, allowing for strong linkage disequilibrium (LD) between markers and phenotype-determining loci. However, levels of genetic diversity and LD in field populations of the major human malaria parasite P. vivax remain little characterized. Results We examined single-nucleotide polymorphisms (SNPs) and LD patterns across a 100-kb chromosome segment of P. vivax in 238 field isolates from areas of low to moderate malaria endemicity in South America and Asia, where LD tends to be more extensive than in holoendemic populations, and in two monkey-adapted strains (Salvador-I, from El Salvador, and Belem, from Brazil). We found varying levels of SNP diversity and LD across populations, with the highest diversity and strongest LD in the area of lowest malaria transmission. We found several clusters of contiguous markers with rare meiotic recombination and characterized a relatively conserved haplotype structure among populations, suggesting the existence of recombination hotspots in the genome region analyzed. Both silent and nonsynonymous SNPs revealed substantial between-population differentiation, which accounted for ~40% of the overall genetic diversity observed. Although parasites clustered according to their continental origin, we found evidence for substructure within the Brazilian population of P. vivax. We also explored between-population differentiation patterns revealed by loci putatively affected by natural selection and found marked geographic variation in frequencies of nucleotide substitutions at the pvmdr-1 locus, putatively associated with drug resistance. Conclusion These findings support the feasibility of genome-wide association studies in carefully selected populations of P. vivax, using relatively low densities of markers, but underscore the risk of false positives caused by population structure at both local and regional levels. See commentary: http://www.biomedcentral.com/1741-7007/8/90

The polymorphic merozoite surface protein-2 (MSP-2) of Plasmodium falciparum is a major malaria-vaccine candidate. In the present study, PCR and hybridization with allelic-specific probes were used to type the Msp-2 gene from isolates from hypo-endemic Brazil (N = 113), meso-endemic Vietnam (N = 208) and holo-endemic Tanzania (N = 67). The typing methods were designed to group isolates into the dimorphic allelic families FC27 and IC1 and to detect possible between-family recombination events. The analysis was complemented by a comparison of 156 Msp-2 sequences from the GenBank database with 12 additional sequences obtained during the present study. Statistically significant differences were detected in pair-wise comparisons of the distribution of Msp-2 allelic types in Brazil and Vietnam, and in Brazil and Tanzania, but not in Vietnam and Tanzania. The extent of allelic diversity in the Msp-2 gene, as estimated by the total number of different alleles found in a given parasite population and the mean multiplicity of infections, clearly paralleled the levels of malaria endemicity in the study areas. However, no correlation between age and multiplicity of infections was found in the subjects. The patterns of Msp-2 diversity in Brazil appeared to be temporally stable, since no significant difference was observed in the distribution of Msp-2 allelic types among isolates collected, 10-13 years apart, in the same area of Rondônia. Despite the extensive sequence diversity found in Msp-2 alleles, especially in the central repetitive region of the molecule, several instances of identical or nearly identical alleles were found among isolates from different countries and regions, possibly as a result of extensive homoplasy. No recombinant allele was detected by molecular typing in any of the study sites, and the GenBank database included only 12 recombinant sequences (representing 7% of all reported Msp-2 sequences), all of them with an IC1-type 5' end and an FC27-type 3' end. A single, putative, crossover site was characterised for all recombinant alleles. Most of the allelic diversity observed was therefore attributable to variation in the repetitive region of the gene, instead of recombination between alleles of dimorphic families (as commonly found, for example, in the Msp-1 gene). The implications of these findings for studies on the genetic and antigenic diversity of malarial parasites are discussed. [ABSTRACT FROM AUTHOR]