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A Sarr

Publications and source records attributed to A Sarr.

At least 19 recordsLinked to original sources
PubMed2006

Genetic diversity and gene flow among pearl millet crop/weed complex: a case study.

Weedy plants with intermediate (domesticated x wild) phenotypes occur in most pearl millet fields in West Africa, even in the absence of wild populations. They are usually found, in high numbers, both inside and outside of drills. Questions pertaining to the evolutionary dynamics of diversity within the pearl millet complex (domesticated-weedy-wild forms) were addressed in this study. The diversity of the different components of this complex sampled in two pearl millet fields in two villages of southwestern Niger was assessed at both molecular (AFLP) and morphological levels. Results show that, in both fields, weedy plants found outside of drills are morphologically distinct from weedy plants found inside drills, despite their close similarity at AFLP markers. The data suggest some introgression from the wild to the weedy population but nevertheless that the gene flow between the parapatric wild and domesticated populations is very low. This challenges the traditional view that regular hybridization between domesticated and wild pearl millets explains the abundance of these weedy plants despite farmers' seed selection. The level of genetic differentiation between fields from the two villages was low when considering domesticated and weedy plants. This could be explained by high gene flow resulting from substantial seed exchanges between farmers. The fact that it is very difficult for farmers to keep their own selected seeds, and the consequent substantial seed exchanges between them, is probably the main factor accounting for the maintenance and dispersal of weedy pearl millets in the region, even in areas where no wild forms have been observed.

Evolution, Molecular↗
PubMed2003

[Management of the bank of biological material in the hospital-based SEROCO and HEMOCO cohorts of HIV-infected patients].

The French SEROCO and HEMOCO hospital-based cohorts have enrolled and followed HIV-infected patients, before and after the highly active antiretroviral therapy era. Among the objectives in 1988, was explicitly mentioned the constitution of a centralised bank of biological material (serums at enrollment and every 6 months, PBMC at enrollment and every 18 months). This paper details the organisation of the bank and the numerous studies performed from this bank, and presents a few simple decision rules which have been developed with the growing acquired experience.

Antiretroviral Therapy, Highly Active↗
PubMed2003

[Frequency of microalbuminuria during diabetes in Dakar, Senegal].

Nephropathy is one of the complications occuring during diabetes and it is diagnosed via microalbuminuria. From 1992 to 1999, five hundred and eighty seven (587) diabetic patients were recruited and distributed into two groups, A (n = 270) and B (n = 317). Microalbuminuria was determined by immunonephelemetry for group A and immunoturbidimetry for group B. The results showed respectively 15.5% and 20.19% pathological cases in the two groups (NS). Considering the distribution of patients with microalbuminuria according to the type of diabetes, there were 16.12% type 1 and 15.07% type 2 in group A against 22.60% and 18.13% in group B; no statistically significant differences were observed either in the same group or from one group to another. These frequencies might reflect the situation in the nineties; they are lower than those encountered in other populations. Nevertheless monitoring is needed through a regular schedule to prevent nephropathy.

Adolescent↗
PubMed2002

Characterization of transposable elements in the genome of rice (Oryza sativa L.) using Representational Difference Analysis (RDA).

Representational Difference Analysis was applied to characterize genomic differentiations between rice ( Oryza sativa) and foxtail millet ( Setaria italica) and subsequently to identify rice transposable elements. Rice was used as the tester and millet as the driver. A total of eleven, non-redundant, positive clones were isolated from the library. Their analysis revealed that they all represent dispersed repetitive DNA sequences. In addition, homology searches using the BLAST procedure showed that they correspond to seven distinct rice transposable elements. Three had been previously identified as gypsy-like retroelements ( Retrosat1, RIRE3 and RIRE8). The remaining four are novel: we named them hipa (a CACTA-like transposon), houba (a copia-like retroelement), hopi and dagul (two gypsy-like retroelements). The RDA clones were used as probes in Southern hybridization experiments with genomic DNAs of several species from the family Poaceae. The results suggest that the genomic differentiations associated with the activity of these transposable elements are of relatively recent origin. In addition, comparison of the hybridization patterns obtained for several Oryza species suggests that several independent amplifications of these transposable elements might have occurred within the genus.

Base Sequence↗
PubMed2002

[Frequency of micoalbuminuria during diabetes in Dakar (Senegal)].

Nephropathy is one of the complications occuring during diabetes diagnosed via microalbuminuria. From 1992 to 1999, five hundred and eighty seven (587) diabetic patients were recruited in groups A (n = 270) and B (n=317). Microalbuminuria was determined by immunonepheletry for A and immunoturbidimetry for B. The results pointed out respectively 15.5% and 20.19% pathological cases (NS). Considering the distribution of patients with microalbuminuria according to the type of diabetes there were 16.12% type 1 and 15.07% type 2 in group A against 22.60% and 18.13% in group B ; no stastically significant differences were observed either in the same group or from one group to another. These frequencies would reflect the situation in the nineties; they are lower than those encountered in other populations. Nevertheless monitoring is needed through a regular schedule to prevent nephropathy.

Adult↗
PubMed2001

Representational difference analysis reveals genomic differences between Q. robur and Q. suber: implications for the study of genome evolution in the genus Quercus.

Very similar genome sizes, similar karyotypes and heterochromatin organisation, and identical number/position of ribosomal loci characterise the common oak (Q. robur) and the cork oak (Q. suber), two distantly related oak species. Representational Difference Analysis (RDA) was used to subtract the genome of Q. suber from the genome of Q. robur in order to search for genome differentiation. A library of 400 clones (bearing RDA fragments) representing genome differences between the two species was obtained. Seven Q. robur-specific DNA sequences were analysed with respect to their molecular and chromosome organisation. All belong to the dispersed repetitive component of the genome, as revealed by Southern hybridisation and in situ hybridisation. They are present in the Q. robur genome in between 100 and 700 copies, and are distributed along the length of almost all chromosomes. A search for homologies between RDA fragments and sequences in Genbank revealed similarities of all RDA fragments with known retrotransposons. The RDA fragments were also tested for their presence/absence in the genomes of six additional oak species belonging to different phylogenetic groups, in order to examine the evolutionary dynamics of these DNA sequences.

Base Sequence↗
PubMed2000

Sexual behavior changes and protease inhibitor therapy. SEROCO Study Group.

OBJECTIVE: To examine changes in sexual activity and unprotected sexual intercourse among HIV-infected patients before and after the initiation of protease inhibitor therapy. DESIGN: An analysis of data from the SEROCO Study, a French prospective cohort. METHODS: All 191 patients who initiated protease inhibitor therapy after 1 January 1996, who were interviewed within one year before the initiation of therapy (Time 1), and who had at least 6 months of follow-up after therapy initiation (Time 2) were included. Patients provided information about sex partner characteristics and unprotected sexual intercourse. RESULTS: Eighty-one (42%) were gay or bisexual men, 46 (24%) were heterosexual men, and 64 (34%) were women. No significant increases were found in either the number of patients reporting anal or vaginal sex or the number reporting unprotected sexual intercourse after protease inhibitor initiation. However, in matched pair analysis, gay or bisexual men were three times more likely to report having had unprotected sexual intercourse with partners who were of HIV-negative or unknown serostatus after protease inhibitor initiation [relative risk (RR) = 3.0, 95% confidence interval (CI) = 1.2-7.6]. Non-significant decreases in unprotected sexual intercourse among both heterosexual men and women were also observed. No relationship between plasma viral load after protease inhibitor initiation and unprotected sexual intercourse was found in these data. CONCLUSIONS: A relapse in sex risk practices among some HIV-infected gay or bisexual men cannot be ruled out and requires both continued monitoring and immediate secondary preventative intervention.

Adult↗
PubMed1997

Allozyme variation in Ulmus species from France: analysis of differentiation.

In the present paper, the geographical structure of genetic variation in three French elm taxa is described using electrophoretic data. For three species, Ulmus laevis, U. glabra and U. minor, two kinds of analyses were performed. First, the genetic parameters (genetic diversity indices) of individuals sampled from naturally regenerating forest were compared to samples of cultivated ornamental trees. Secondly, when sample sizes were sufficient, the genetic parameters of trees sampled from different regions of France were compared to detect geographical differentiation. From these analyses, the ultimate aim was to offer recommendations concerning the conservation policies of the genetic resources of French elms. The heterozygosity of Ulmusxhollandica (the presumed hybrid between U. minor and U. glabra) was compared to its putative parent taxa to determine whether the hybrid harbours great levels of genetic variation. In spite of the ravaging effects of Dutch Elm disease in the past, all three species exhibit high levels of electrophoretic variation. The three species surveyed displayed similar levels of genetic diversity, proportions of polymorphic loci and levels of allelic diversity in trees harvested from naturally regenerated forests relative to cultivated ornamental trees. High levels of genetic diversity in U. minor within geographical regions of France were detected, with only moderate levels of genetic differentiation detected between regions. Ulmusxhollandica is not more heterozygous than either of its parent species, suggesting that extant representatives of this taxon are the result of past and ongoing backcrosses with the parental taxa. Ongoing efforts to preserve the genetic variation still present in French elms should take advantage of their high levels of electrophoretic variation and target genetically distinct, vegetatively reproducing genotypes in their natural environment.

Journal Article↗
PubMed1994

[Diabetic pregnancy in Senegal (years 1980 to 1989)].

INTRODUCTION AND OBJECTIVES: Diabetic Pregnancy Prognosis in Seventies is it better in Eighties because of Patient Education? METHODOLOGY: Retrospectively, since 1980 to 1989, in Women in status to breed, Diabetic Pregnancy was screened in our Department. W.H.O.'s (1980) Diabetes Mellitus Criterias, PEDERSEN's Criterias, White's Classification were used. Studied Parameters were etiologic factors (age, type, Diabetes oldness and control), former and present Evolution of Pregnancies (term and pregnancy's product). RESULTS: A--In Global Study, 15.07% Diabetic Pregnancies were observed: 22 (37%) Insulin Dependent and 38 (63%) Non Insulin Dependent. The global mean of age was 31 years; Diabetic Mellitus was less than 10 years old in 90% cases whatever the type. Their control was not good (Glycemic Control < 1.4 g/l in less than 50%). Diabetes complications were nephropathy (13.6% and 8%), retinopathy (13.6% and 18.5%), arterial hypertension (0% and 26.32%), cetoacidosis (31.42% and 0%), urinary tract infection (18% and 0%) respectively in Insulin Dependent and Non Insulin Dependent Pregnancies. Near a third (31.6%) of Insulin Dependent and a third (33.41%) for Non Insulin Dependent were of D, F, H White's Class. Multipares were often Non Insulin Dependent and inversely Insulin Dependent frequently paucipare. Former Pregnancies had near 25.5% interrupted term in Insulin Dependents. Present Pregnancies have given 28.5% and 32% of Normal Children: 14.25 and 12% of Abortions and 14.25% and 6% of Spontaneous Premature Parturitions respectively in Insulin Dependents and Non Insulin Dependents. B--In Analytic Study of Foetopathies, bad Prognosis Factors were high Maternal Age, Multiparity, bad Glycemic Control whatever Diabetes type. For Insulin Dependent, Negligency was added and for Non Insulin Dependent, Obesity, Arterial Hypertension and all PBSP. DISCUSSION AND CONCLUSION: A relatively mild Diabetic Pregnancy Prognosis in our areas with limited means has been observed despite of Patients Education.

Adult↗