Correlation of oral health home-care practices, snacking habits and dental caries experience among HIV-positive children in Nairobi, Kenya

Objective: To determine the correlation of oral health home-care practices, snacking habits and dental caries experience among 3-15 year-old- HIV-positive children attending out-patient clinic at the Kenyatta National Hospital, Kenya.Design: Cross-sectional descriptive study.Setting: Kenyatta National Hospital comprehensive care centre out-patient clinic.Subjects:Two hundred and twenty participants were selected by consecutive sampling. The children’s socio-demographic characteristics and oral health home-care practices were obtained from parent or guardian interviews. Oral examination of the children was carried out to determine the presence of dental caries.Results: Of the 220 children in the study, 126 (57.3%) brushed their teeth at least once a day. Forty one (18.6%) children regularly consumed sweetened snacks daily. Almost all children (75.5%) were taking medication in the form of tablets and capsules. One hundred and seventy nine (81.4%) children had never had a dental visit. The prevalence of dental caries was 65% while the mean dmft and DMFT scores were 1.75 and 1.08 respectively. Caries experience was significantly higher for those children who frequently consumed sweetened snacks and those who took their medication in the form of sweetened syrups while it was lowest in those who brushed their teeth at least twice a day.Conclusion: Dental caries experience was significantly higher among HIV-infected children who had increased frequency of consumption of sweetened snacks and those who used syrupy medication. There was poor attendance for dental treatment among the children

External root morphology of maxillary first premolars in Kenyan Africans

Objective: To determine the external root morphology of the maxillary first premolars in Kenyan Africans.Design: In vitro descriptive cross-sectional study.Setting: School of Dental Sciences, University of Nairobi.Subjects: One hundred and fifty five extracted maxillary first premolar teeth obtained from patients aged between 13-30 years attending dental clinics within Nairobi.Main outcome measures: Number of roots, direction of root curvature and tooth length.Results: A total of 155 maxillary first premolars were studied, 77 from males and 78 from females. Overall, there were 83.2% two-rooted teeth (mean tooth length: buccal root 22.3 mm; lingual root 21.2 mm), 10.3% one-rooted (mean tooth length-22.6 mm) and 6.5% three-rooted. Three roots occurred more commonly in males than females and this was a statistically significant gender difference (P0.05).Conclusions: Maxillary first premolars were mostly two-rooted with straight roots. Males presented with two or three roots more often than females and had significantly larger mean tooth lengths

Internal root morphology of the maxillary first premolars in Kenyans of African descent

Objective: To determine the internal root morphology of the maxillary first premolar in Kenyans of African descent.Design: In vitro descriptive cross-sectional study.Setting: School of Dental Sciences, University of Nairobi.Subjects: One hundred and fifty five extracted maxillary first premolars obtained from patients aged between 13-30 years attending dental clinics within Nairobi.Results: There were 77 premolars from males and 78 from females. Majority (87.1%) of the teeth had two canals. Males presented with three canals more commonly than females. This difference was statistically significant. According to Vertucci’s classification, male specimens demonstrated five of the canals types while female specimens demonstrated all the eight canal types. These differences were not statistically significant.Conclusions: Kenyan maxillary first premolar was mostly found to have two canals. There were eight canal types, with type IV being the commonest

Discovery of mating in the major African livestock pathogen Trypanosoma congolense

The protozoan parasite, Trypanosoma congolense, is one of the most economically important pathogens of livestock in Africa and, through its impact on cattle health and productivity, has a significant effect on human health and well being. Despite the importance of this parasite our knowledge of some of the fundamental biological processes is limited. For example, it is unknown whether mating takes place. In this paper we have taken a population genetics based approach to address this question. The availability of genome sequence of the parasite allowed us to identify polymorphic microsatellite markers, which were used to genotype T. congolense isolates from livestock in a discrete geographical area of The Gambia. The data showed a high level of diversity with a large number of distinct genotypes, but a deficit in heterozygotes. Further analysis identified cryptic genetic subdivision into four sub-populations. In one of these, parasite genotypic diversity could only be explained by the occurrence of frequent mating in T. congolense. These data are completely inconsistent with previous suggestions that the parasite expands asexually in the absence of mating. The discovery of mating in this species of trypanosome has significant consequences for the spread of critical traits, such as drug resistance, as well as for fundamental aspects of the biology and epidemiology of this neglected but economically important pathogen

Duck (Anas platyrhynchos) linkage mapping by AFLP fingerprinting

Amplified fragment length polymorphism (AFLP) with multicolored fluorescent molecular markers was used to analyze duck (Anas platyrhynchos) genomic DNA and to construct the first AFLP genetic linkage map. These markers were developed and genotyped in 766 F2 individuals from six families from a cross between two different selected duck lines, brown Tsaiya and Pekin. Two hundred and ninety-six polymorphic bands (64% of all bands) were detected using 18 pairs of fluorescent TaqI/EcoRI primer combinations. Each primer set produced a range of 7 to 29 fragments in the reactions, and generated on average 16.4 polymorphic bands. The AFLP linkage map included 260 co-dominant markers distributed in 32 linkage groups. Twenty-one co-dominant markers were not linked with any other marker. Each linkage group contained three to 63 molecular markers and their size ranged between 19.0 cM and 171.9 cM. This AFLP linkage map provides important information for establishing a duck chromosome map, for mapping quantitative trait loci (QTL mapping) and for breeding applications

Molecular characterization and evolution of a gene family encoding male-specific reproductive proteins in the African malaria vector Anopheles gambiae

<p>Abstract</p> <p>Background</p> <p>During copulation, the major Afro-tropical malaria vector <it>Anopheles gambiae </it>s.s. transfers male accessory gland (MAG) proteins to females as a solid mass (i.e. the "mating plug"). These proteins are postulated to function as important modulators of female post-mating responses. To understand the role of selective forces underlying the evolution of these proteins in the <it>A. gambiae </it>complex, we carried out an evolutionary analysis of gene sequence and expression divergence on a pair of paralog genes called <it>AgAcp34A-1 </it>and <it>AgAcp34A-2</it>. These encode MAG-specific proteins which, based on homology with <it>Drosophila</it>, have been hypothesized to play a role in sperm viability and function.</p> <p>Results</p> <p>Genetic analysis of 6 species of the <it>A. gambiae </it>complex revealed the existence of a third paralog (68-78% of identity), that we named <it>AgAcp34A-3</it>. FISH assays showed that this gene maps in the same division (34A) of chromosome-3R as the other two paralogs. In particular, immuno-fluorescence assays targeting the C-terminals of <it>AgAcp34A-2 </it>and <it>AgAcp34A-3 </it>revealed that these two proteins are localized in the posterior part of the MAG and concentrated at the apical portion of the mating plug. When transferred to females, this part of the plug lies in proximity to the duct connecting the spermatheca to the uterus, suggesting a potential role for these proteins in regulating sperm motility. <it>AgAcp34A-3 </it>is more polymorphic than the other two paralogs, possibly because of relaxation of purifying selection. Since both unequal crossing-over and gene conversion likely homogenized the members of this gene family, the interpretation of the evolutionary patterns is not straightforward. Although several haplotypes of the three paralogs are shared by most <it>A. gambiae </it>s.l. species, some fixed species-specific replacements (mainly placed in the N- and C-terminal portions of the secreted peptides) were also observed, suggesting some lineage-specific adaptation.</p> <p>Conclusions</p> <p>Progress in understanding the signaling cascade in the <it>A. gambiae </it>reproductive pathway will elucidate the interaction of this MAG-specific protein family with their female counterparts. This knowledge will allow a better evaluation of the relative importance of genes involved in the reproductive isolation and fertility of <it>A. gambiae </it>species and could help the interpretation of the observed evolutionary patterns.</p

The origins of the trypanosome genome strains Trypanosoma brucei brucei TREU 927, T. b. gambiense DAL 972, T. vivax Y486 and T. congolense IL3000

The genomes of several tsetse-transmitted African trypanosomes (Trypanosoma brucei brucei, T. b. gambiense, T. vivax, T. congolense) have been sequenced and are available to search online. The trypanosome strains chosen for the genome sequencing projects were selected because they had been well characterised in the laboratory, but all were isolated several decades ago. The purpose of this short review is to provide some background information on the origins and biological characterisation of these strains as a source of reference for future users of the genome data. With high throughput sequencing of many more trypanosome genomes in prospect, it is important to understand the phylogenetic relationships of the genome strains

Socio-demographic characteristics and clinical features among patient attending a private paediatric dental clinic in Nairobi, Kenya

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