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Cent quatre vingt-deux Glossina tachinoidesont été infectées avec Trypanosoma congolensetype « savane ». Les taux d'infection ont été évolués par examen microscopique et par PCR. L'émission des trypanosomes par salivation provoquée a été étudiée selon différentes techniques de détection des parasites qui ont été comparées. Les résultats des dissections ont révélé un fort pourcentage d'infections immatures. La technique PCR appliquée sur les proboscis a confirmé les résultats parasitologiques. Les expériences de salivation ont montré une grande variabilité, inter et intra-individuelle, dans l'émission des trypanosomes lors des sondages. La technique PCR a été équivalente à l'examen microscopique pour détecter les trypanosomes dans les salivats. La méthode de xénodiagnostic inverse s'est révélée la moins performante des trois pour détecter les glossines infectantes. L'ensemble de ces résultats a permis de préciser la capacité vectorielle de G. tachinoidesvis-à-vis de T. congolensetype « savane » au laboratoire, et de donner des éléments supplémentaires de compréhension au rôle de cette glossine dans Tépidémiologie de la maladie.

In order to better understand the epidemiology of Human and Animal trypanosomiasis that occur together in sleeping sickness foci, a study of prevalences of animal parasites (Trypanosoma vivax, T. congolense“forest type”, and T. simiae) infections was conducted on domestic animals to complete the previous work carried on T. brucei gambienseprevalence using the same animal sample. 875 domestic animals, including 307 pigs, 264 goats, 267 sheep and 37 dogs were sampled in the sleeping sickness foci of Bipindi, Campo, Doumé and Fontem in Cameroon. The polymerase chain reaction (PCR) based method was used to identify these trypanosome species. A total of 237 (27.08%) domestic animals were infected by at least one trypanosome species. The prevalence of T. vivax, T. congolense“forest type” and T. simiaewere 20.91%, 11.42% and 0.34% respectively. The prevalences of T. vivaxand T. congolense“forest type” differed significantly between the animal species and between the foci (p < 0.0001); however, these two trypanosomes were found in all animal species as well as in all the foci subjected to the study. The high prevalences of T. vivaxand T. congolense“forest type” in Bipindi and Fontem-Center indicate their intense transmission in these foci.

The present study was carried out in order to investigate if there was really a failure of PCR in identifying parasitologically positive tsetse flies in the field. Tsetse flies (Glossina palpalis gambiensisand Glossina morsitans morsitans) were therefore experimentally infected with two different species of Trypanosoma (Trypanosoma brucei gambienseor Trypanosoma congolense). A total of 152 tsetse flies were dissected, and organs of each fly (midgut, proboscis or salivary glands) were examined. The positive organs were then analysed using PCR. Results showed that, regardless of the trypanosome species, PCR failed to amplify 40 % of the parasitologically positive midguts. This failure, which does not occur with diluted samples, is likely to be caused by an inhibition of the amplification reaction. This finding has important implications for the detection and the identification of trypanosome species in wild tsetse flies.

An explanation of the endemic nature and/or the resurgence of Human African Trypanosomiasis (HAT) in the historic foci in West and Central Africa may be the existence of an animal reservoir. In some HAT foci, pigs were found infected by Trypanosoma brucei gambiensebut the implication of the other domestic animals was not quite evaluated. This study aims to determine the prevalence of T. b. gambiensein domestic animal species (goat, sheep, pig and dog) commonly found in the four active HAT foci in Cameroon (Bipindi, Fontem, Campo and Doumé). Blood samples were collected from 307 pigs, 264 goats, 267 sheep and 37 dogs and used for parasitological (QBC), immunological (LiTat 1.3 CATT) and molecular (PCR) analyses. QBC detected trypanosomes in 3.88 % domestic animals while 22.7 % were sero-positive with LiTat 1.3 CATT tests. Of the 875 animals analysed, 174 (19.88 %) harboured T. bruceis.l. DNA, found in each of the four types of animal and in the four localities. The infection rate significantly differed among the animal species (p < 0.0001) and localities (p < 0.0001). The PCR also revealed T. b. gambiensegroup 1 DNA in 27 (3.08 %) domestic animals. The specific infection rates were as follows: sheep (6.74 %), goats (3.08 %), pigs (0.32 %) and dogs (0 %). T. b. gambiensewas found in 8 (3.92 %) animals from Bipindi, 15 (4.83 %) from Campo, 4 (2.59 %) from Fontem-Center and none from Doumé. The infection rates significantly differed between the localities, and correlated with the intensity of HAT transmission in the foci.

Following confirmed cases of trypanosomosis in military working dogs, a cross-sectional study was undertaken to evaluate the source of infection and determine the prevalence of canine infection with Trypanosoma congolensein the urban focus of Abidjan, Ivory Coast. Blood from 123 dogs were collected and subjected to PCR using specific primers for Trypanosoma congolense“forest type”. In addition, an entomological study was conducted in an urban area near the forest surronding the military camp. The observed prevalence was 30.1% and PCR positivity to Trypanosoma congolensewas not significantly associated with sex or age of animals. This study demonstrates the high contamination rate of dogs in enzootic zones, the potential risk of introduction of the disease in free animal populations and the ability of Glossina palpalisto adapt to urban areas and to transmit trypanosomosis in such areas. The factors leading to a possible emergence of canine trypanosomiasis in enzootic zones need further investigations.

Kinases, which number > 500 in humans, are a class of enzymes that participate in an array of important functions within normal cellular physiology and during various pathological conditions. Due to the key role of kinases in the regulation of all aspects of cellular signaling and the well established contribution of kinase dysregulation to the etiology of many human pathologies, the development of kinase inhibitors has emerged as a therapeutic strategy for the treatment of human disease, including most notably oncology. Difficulties generating selective inhibitors have hampered their use in other therapeutic areas with less tolerance for off-target effects. However, with an increasing understanding of kinase structures and with the advent of newer inhibitor design strategies more highly selective inhibitors are beginning to emerge. This has prompted interest in utilizing kinase inhibitors in therapeutic areas beyond oncology, including acute and chronic neurodegenerative conditions for which disease modify therapies are lacking. This review provides a background in acute (i.e. brain ischemia and traumatic brain injury) and chronic (i.e. Alzheimers, Parkinsons, Huntingtons disease, amyotrophic lateral sclerosis and multiple sclerosis) neurodegenerative conditions. Then, the role of several kinase (i.e. JNK3, p38 MAPK, ERK, PKC, ROCKII, GSK3, Cdk5, MLK, EphB3 kinase, RIP1 kinase, LRRK2, TTBK1, ASK1, CK, DAPK, and PKN1) that could serve as potential therapeutic targets for these maladies are reviewed.

In a sleeping sickness focus of Côte d'Ivoire, trypanosomes were characterized in humans, pigs and tsetse using various techniques. Out of 74 patients, all the 43 stocks isolated by KIVI (Kit for In Vitro Isolation) appeared to belong to only one zymodeme of Trypanosoma brucei gambiense group 1 (the major zymodeme Z3). The only stock isolated on rodents belonged to a different, new, zymodeme (Z50), of T. b. gambiense group 1. From 18 pigs sampled in the same locations as the patients, PCR showed a high proportion of mixed infections of T. brucei s. l. and T. congolense riverine-forest. Zymodemes of T. brucei s. l. from these pigs were different from those found in humans. From a total of 16260 captured tsetse (Glossina palpalis palpalis), 1701 were dissected and 28% were found to be infected by trypanosomes. The most prevalent trypanosome was T. congolense riverine-forest type, followed by T. vivax, T. brucei s. l. and T. congolense savannah type, this latter being associated to the forest type of T. congolense in most cases. Mixed infections by 2 or 3 of these trypanosomes were also found. Use of a microsatellite marker allowed us to distinguish T. b. gambiense group 1 in some of the mature infections in tsetse. Differences in infection rates and in trypanosome genotypes according to the host might indicate that the pig may not be an active animal reservoir for humans in this focus.

Un nouveau gisement d'âge triasique supérieur a été découvert à Syren (G.-D. Luxembourg). Son analyse palynologique révèle la présence de toutes les espèces typiques de l'Assemblage à Rhaetipollis germanicus, permettant d'attribuer un âge Rhétien au niveau étudié. La faune de vertébrés est dominée par des formes marines typiques du faciès rhétien. L'étude de l'ultrastructure de l'émail montre qu' "Hybodus" minor est un Neoselachii et que les dents attribuées dans le passé à cette espèce pourraient en fait appartenir à Nemacanthus monilifer. La composante terrestre de la faune est très diversifiée, incluant des dents de Phytosauria, Pterosauria, ?Ornithischia, Cynodontia et Mammalia (Haramiyidae, Morganucodontidae et Kuehneotheriidae). Contrairement à la composante marine, la faune terrestre montre très peu de variations au cours de la trangression rhétienne.

We have adapted a simple and efficient technique to detect trypanosomes in human blood, without DNA purification, and increased the sensitivity threshold to 1 parasite in 1 ml. We have then applied it for detection of parasites in midguts of tsetse flies, negative by microscopy. This technique has been developed for field conditions and could greatly facilitate epidemiological studies.

Newly developed techniques (RADP: Random Amplified Polymorphic DNA and microsatellite DNA sequences) were used to study genetic variation in Onchocerca volvulus. RAPD technique, derived from the Polymerase Chain Reaction (PCR), allow clear distinction between the different species of the genus Onchocerca.

The polymerase chain reaction (PCR) method was used to characterize trypanosome infections in tsetse flies from 3 sleeping sickness foci in Cameroon. The predominant tsetse species found was Glossina palpalis palpalis. An average infection rate of 12·1% was revealed by microscopical examination of 888 non-teneral tsetse flies. PCR amplification analyses for trypanosome identification were carried out on 467 flies, with primer sets specific for Trypanosoma (Trypanozoon) brucei s.l., T. (Duttonella) vivax, T. (Nannomonas) simiae and forest type T. (Nannomonas) congolense. Of 467 flies 93 were positive by microscopical analysis while PCR succeeded in identifying 89 positive flies. Of the PCR-positive flies 34 (38·2%) were negative by microscopical examination. PCR amplification, when compared to the parasitological technique, gave a higher estimate of infection rate of trypanosomes in natural tsetse populations. The PCR technique did, however, fail to identify 40·9% (38/93) of the parasitologically positive flies. The reasons for this failure are discussed. The overall prevalence of mixed infections, assessed by PCR, was 37·1%; the majority (72·7%) involved T. brucei and forest type T. congolense.

High simian immunodeficiency virus (SIV) seroprevalence rates have been reported in the different African green monkey (AGM) subspecies. Genetic diversity of these viruses far exceeds the diversity observed in the other lentivirus-infected human and nonhuman primates and is thought to reflect ancient introduction of SIV in the AGM population. We investigate here genetic diversity of SIVagm in wild-living AGM populations from the same geographical locale (i.e., sympatric population) in Senegal. For 11 new strains, we PCR amplified and sequenced two regions of the genome spanning the first tat exon and part of the transmembrane glycoprotein. Phylogenetic analysis of these sequences shows that viruses found in sympatric populations cluster into distinct lineages, with at least two distinct genotypes in each troop. These data strongly suggest an ancient introduction of these divergent viruses in the AGM population.

The high seroprevalence of simian immunodeficiency viruses (SIVs) in African green monkeys (AGMs) without immunological defects in their natural hosts has prompted consideration of SIV-infected AGMs as a model of apathogenic SIV infection. Study of the molecular mechanisms of SIVagm asymptomatic infection could thus provide clues for understanding the pathogenesis of human immunodeficiency viruses. Regulatory genes could be candidates for genetic control of SIVagm apathogenicity. We have characterized Vpr, Tat, Rev, and Nef genes of two SIVagm strains isolated from naturally infected sabaeus monkeys captured in Senegal. The results provide further evidence that SIVagm from West African green monkeys is the most divergent class of AGM viruses, with structural features in long terminal repeat sequences and Vpr and Tat genes that distinguish them from viruses isolated from other AGM species (vervet, grivet, and tantalus monkeys).

Little is known about intraspecific variability in tsetse flies and its consequences for vectorial capacity. Microsatellite markers have been developed for Glossina palpalis gambiensis. Three loci have been identified and showed size polymorphisms for insectarium samples. G. palpalis gambiensisfrom Burkina Faso were also subjected to PCR to investigate their genetic variability. Amplifications were observed in different species belonging to the palpalisgroup. These molecular markers will be useful to estimate gene flow within G. palpalis gambiensispopulations and analysis could be extended to related species.

Full-length L1 elements have been shown to possess, at their 5' end, tandem repeats called "A" or "F" types. By sequencing the 5' region of two large L1 copies that did not hybridize to A or F probes, we have identified a new sequence that is found at the 5' end of many L1 elements and that we call "V." The element characterized has no 200-bp tandem repetitive structure, and the new 5' sequence is not similar to the A or F sequences. The study of the relationships between the V and L1 sequences has shown that only half of the V (i.e., V-specific 5') sequences in the genome are linked to the 5' end of L1 copies. In related rodent species, a comparative study by Southern blot and PCR analysis of the V sequence suggests that this L1 subfamily has an ancient origin and that V sequence isolated from the remainder of the L1 element has been amplified during the evolution of the mouse genome.

AbstractTeneral Glossina morsitans mositans, G.m.submorsitans, G.palpalis gambiensisand G.tachinoideswere allowed to feed on rabbits infected with Trypanosoma congolensesavannah type or on mice infected with T.congolenseriverine‐forest type. The four tsetse species and subspecies were also infected simultaneously in vitroon the blood of mice infected with the two clones of T.congolensevia a silicone membrane. The infected tsetse were maintained on rabbits and from the day 25 after the infective feed, the surviving tsetse were dissected in order to determine the infection rates.

DNA preparations from circulating leukocytes, lymph node tumors, and spleens of three bovine leukemia virus-infected cattle were fractionated by Cs2SO4/3,6-bis(acetatomercurimethyl)dioxane density gradient centrifugation. Bovine leukemia virus proviral sequences were found in large GC-rich fragments having a buoyant density in CsCl close to 1.708 g/cm3. Provirus integration, therefore, does not take place at random locations in the host genome, but in a specific class of DNA segments. Hybridization of cDNA synthesized on viral RNA to EcoRI and Xba I restriction fragments of the DNA from infected cells showed that: (i) only one copy of proviral DNA is integrated per haploid genome; (ii) different restriction patterns were found in the proviral DNAs present in the genomes of different animals, providing evidence for the existence of several strains or mutants; and (iii) different integration sites for the proviral DNA were found in the genome of different animals and of different infected cells in the same animal. The latter finding strongly suggests a polyclonal origin of bovine leukemia virus-infected cells.

Bulinus globosus, one of the intermediate hosts for Schistosoma, is a hermaphrodite freshwater snail. Multilocus DNA fingerprinting was applied in order to investigate the mating system of this facultatively self-fertilizing species. By analysing DNA fingerprints of eight broods, we have shown that selfed and outcrossed individuals could be unambiguously distinguished by comparison with their parent fingerprints. First, selfed offspring patterns shared a higher number of bands with their mother than did outcrossed ones. Secondly, at least three paternal bands could be detected per out-crossed offspring pattern.Heredity (1992) 68, 141–146; doi:10.1038/hdy.1992.22

We have investigated that organization and the distribution of a family of interspersed DNA repeats in the mouse genome. The repeats are at least 5600 base pairs (bp) in size and contain two contiguous BamHI endonuclease fragments, 4000 and 540 bp in size, the larger of which includes a 1350-bp EcoRI fragment studied by previous authors. The repeats are polymorphic in their restriction maps, and represent the major family of interspersed repeats in the mouse genome. The repeats are present almost exclusively in the two light major components of mouse DNA, and the base composition of their large BamHI fragments matches that of those components. The genomic distribution of the repeats is different from that of structural genes, which are present not only in the two light components but also in the two heavy components of mouse DNA. This distribution indicates that the repeats are not involved, at least in any simple way, in the regulation of gene expression.

Summary: Sodium fluoride (NaF) is used in the treatment of axial osteoporosis and so is mostly given to old patients. Since its pharmacokinetics has not been studied in the elderly, the pharmacokinetics of an enteric-coated tablet containing 50 mg NaF has been investigated in 15 aged inpatients (aged 65 to 75 y) and 12 young healthy volunteers (aged 21 to 26 y). The serum AUC of fluoride was 1.7-time higher in older than in younger subjects. There was a strong inverse correlation between the AUC and either body surface area (BSA) or glomerular filtration rate (GFR), both of which were very much lower in the elderly. This concluded that if efficacy or safety are related to the bioavailability of fluoride, it maybe valuable to adjust the dosage of fluoride accordingly to the GFR and BSA.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.