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Biomedical subjects

M Dufour

Publications and source records attributed to M Dufour.

At least 19 recordsLinked to original sources
PubMed2005

Construction and characterization of a Coffea canephora BAC library to study the organization of sucrose biosynthesis genes.

The first bacterial artificial chromosome (BAC) library of Robusta coffee (Coffea canephora) was constructed, with the aim of developing molecular resources to study the genome structure and evolution of this perennial crop. Clone 126, which is highly productive and confers good technological and organoleptic qualities of beverage, was chosen for development of this library. The BAC library contains 55,296 clones, with an average insert size of 135 Kb per plasmid, therefore representing theoretically nine haploid genome equivalents of C. canephora. Its validation was achieved with a set of 13 genetically anchored single-copy and 4 duplicated RFLP probes and yielded on average 9 BAC clones per probe. Screening of this BAC library was also carried out with partial cDNA probes coding for enzymes of sugar metabolism like invertases and sucrose synthase, with the aim of characterizing the organization and promoter structure of this important class of genes. It was shown that genes for both cell wall and vacuolar forms of invertases were probably unique in the Robusta genome whereas sucrose synthase was encoded by at least two genes. One of them (CcSUS1) was cloned and sequenced, showing that our BAC library is a valuable tool to rapidly identify genes of agronomic interest or linked to cup quality in C. canephora.

Amino Acid Sequence↗
PubMed2003

Development of a method to quantify in vitro the synergistic activity of "natural" antimicrobials.

Despite numerous papers being published on the use of hurdle technology to control food-borne pathogens or spoilage organisms, there is no commonly accepted methodology to quantify the level of synergistic activity. This paper describes a method to quantify in vitro the synergistic activity of antibacterial agents against bacteria. Initially, a microtiter plate growth assay was used to determine the inhibitory concentrations of four "natural" antimicrobials (nisin, lauricidin, totarol, and the lactoperoxidase system (LPS)) against a panel of eight bacteria. Using the same microtiter system, the impact of various combinations of antimicrobials was assessed. The degree of synergy was based on the analysis of three criteria: (1) increase in lag phase, (2) reduction in culture density after 24 h, (3) and residual viability at 24 h. Only the lactoperoxidase system was active against all the Gram-positive and Gram-negative bacteria tested. Nisin, lauricidin, and totarol were only effective against the Gram-positive bacteria. The method successfully identified three combinations (nisin-lauricidin, LPS-nisin, and LPS-lauricidin) previously reported to have synergistic activity and highlighted the synergistic activity of two novel combinations (nisin-totarol and LPS-totarol). The development of a quick and reliable method to identify and quantify synergistic activity is a useful screening tool to establish preservative techniques that could have potential antimicrobial synergy in food-based systems.

Abietanes↗
PubMed2003

AFLP and SSR polymorphism in a Coffea interspecific backcross progeny [( C. heterocalyx x C. canephora) x C. canephora].

An interspecific cross (BC 1) involving a species with one of the largest genomes in the Coffea genus [ Coffea heterocalyx (HET), qDNA = 1.74 pg] and a species with a medium-sized genome [ Coffea canephora (CAN), qDNA = 1.43 pg] was studied using two types of molecular markers, AFLP and SSR. One hundred and eighty eight AFLP bands and 34 SSR primer pairs were suitable for mapping. The total map length was 1,360 cM with 190 loci distributed in 15 linkage groups. The results were compared to those obtained previously on an interspecific BC 1 progeny involving a species with a medium-sized genome ( Coffea liberica var dewevrei, DEW) and a species with one of the smallest genomes ( Coffea pseudozanguebariae, PSE). They are discussed relative to three main points: (1) the relevance of the different marker types, (2) the genomic distribution of AFLP and SSR markers, and (3) the relation between AFLP polymorphism and genome size.

Chromosomes, Plant↗
PubMed2000

The reliability and validity of the inventory to diagnose depression in alcohol-dependent men and women.

PURPOSE: This study examined the reliability and validity of the Inventory to Diagnose Depression (IDD) in alcohol-dependent men and women. The IDD is a self-report instrument that provides a continuous score reflecting depression severity and a DSM-IV major depression diagnosis (MDD). METHODS: Participants (N = 57) were administered the IDD, Beck Depression Inventory (BDI), and the mood module of the Structured Clinical Interview for the DSM (SCID). RESULTS: Internal reliability and item-total correlations were generally good and the IDD severity score correlated highly with the BDI. The diagnostic performance of the IDD using the DSM-IV scoring algorithm was good overall but excellent for currently abstinent participants and fair for participants who had recently consumed alcohol. The IDD cut-off score for identifying cases of depression appears stringent compared to the BDI and SCID. IMPLICATIONS: The present investigation provides some support for the use of the IDD with abstinent alcoholic outpatient samples when a self-report diagnostic instrument is desirable. For a current drinker, a positive IDD does not distinguish between an alcohol-induced depression and MDD.

Adult↗
PubMed1999

Implications of depression on outcome from alcohol dependence: a 3-year prospective follow-up.

The prognostic implications of comorbid depression for outcome from alcohol dependence are unclear. It has been suggested that drinking may represent self-medication of depressive disorders and, alternatively, that the pharmacological properties of alcohol induce episodes of depression. In the present study, these questions were investigated by following 84 alcohol-dependent individuals seeking treatment (34% women) for 3 years in a naturalistic, prospective design. During the follow-up period, depressive and drinking outcomes were significantly related. However, there was no evidence that drinking reliably preceded depressive episodes or that depressive episodes precipitated heavy drinking. Despite their high co-occurrence, this study did not find evidence of a strong, direct causal relationship between these phenomena.

Adolescent↗
PubMed1998

Prevention and Treatment of Hypertension Study (PATHS): effects of an alcohol treatment program on blood pressure.

OBJECTIVE: To determine whether blood pressure is reduced for at least 6 months with an intervention to lower alcohol intake in moderate to heavy drinkers with above optimal to slightly elevated diastolic blood pressure, and whether reduction of alcohol intake can be maintained for 2 years. DESIGN: A randomized controlled trial. METHODS: Six hundred forty-one outpatient veterans with an average intake of 3 or more alcoholic drinks per day in the 6 months before entry into the study and with diastolic blood pressure 80 to 99 mm Hg were randomly assigned to a cognitive-behavioral alcohol reduction intervention program or a control observation group for 15 to 24 months. The goal of the intervention was the lower of 2 or fewer drinks daily or a 50% reduction in intake. A subgroup with hypertension was defined as having a diastolic blood pressure of 90 to 99 mm Hg, or 80 to 99 mm Hg if recently taking medication for hypertension. RESULTS: Reduction in average weekly self-reported alcohol intake was significantly greater (P<.001) at every assessment from 3 to 24 months in the intervention group vs the control group: levels declined from 432 g/wk at baseline by 202 g/wk in the intervention group and from 445 g/wk by 78 g/wk in the control group in the first 6 months, with similar reductions after 24 months. The intervention group had a 1.2/0.7-mm Hg greater reduction in blood pressure than the control group (for each, P = .17 and P = .18) for the 6-month primary end point; for the hypertensive stratum the difference was 0.9/0.7 mm Hg (for each, P = .58 and P = .44). CONCLUSIONS: The 1.3 drinks per day average difference between changes in self-reported alcohol intake observed in this trial produced only small nonsignificant effects on blood pressure. The results from the Prevention and Treatment of Hypertension Study (PATHS) do not provide strong support for reducing alcohol consumption in nondependent moderate drinkers as a sole method for the prevention or treatment of hypertension.

Adult↗
PubMed1998

Steroid production, cell proliferation, and apoptosis in cultured bovine antral and mural granulosa cells: development of an in vitro model to study estradiol production.

This study was undertaken to characterize the relationship between changes in steroid production, cell cycle activity (ie, cell proliferation) and apoptosis in antral and mural bovine granulosa cells cultured in vitro. This was done to select conditions promoting optimal estradiol production by bovine granulosa cells cultured in completely defined conditions. In the first experiment, antral granulosa cells were cultured over the entire 4 days of the culture period in the presence of either 0, 2, or 10 ng/ml of FSH (chronic conditions) or were maintained under minimal FSH support (0.5 ng/ml FSH) for the first 3 days of culture and then were challenged over the fourth day of culture with either 0, 2, or 10 ng/ml FSH (challenged conditions). Compared with cells exposed to constant FSH levels (chronic conditions), the FSH-induced production of estradiol was higher (P < 0.006) and that of progesterone was lower (P < 0.02) over the last 24 h of culture, when antral granulosa cells were maintained under minimal FSH support during the first 3 days of culture (challenged conditions). In the second experiment, dynamics of estradiol and progesterone productions, conversion of [14C]androstenedione into subsequent steroid metabolites, DNA content, cell cycle activity, and apoptosis (as assessed by flow cytometry) of antral and mural granulosa cells over the first 3 days of culture under minimal FSH support and in response to a challenge with FSH during the last 24 h of culture were evaluated. Estradiol production as well as the conversion of androstenedione into testosterone and estradiol were greater (P < 0.01) in antral than in mural granulosa cells cultured under challenged conditions. A higher proportion of mural than antral granulosa cells were in the proliferative state at the end of culture (P < 0.03). This may be related to the decreased ability of mural cells to produce estradiol. FSH suppressed (P < 0.05) the spontaneous onset of apoptosis in both cell types. These results suggest that functional differences between these two cell compartments need to be considered in studying bovine granulosa cells in vitro. Because of their large (400 to 600%) FSH-induced estradiol production, antral granulosa cells cultured under challenged conditions provide a model that can be used to examine substances for their ability to alter estradiol production and apoptosis in bovine granulosa cells.

Animals↗
PubMed1998

Isolation, purification and partial characterization of chloragocytes from the earthworm species Lumbricus terrestris.

Chloragocytes were isolated from the earthworm species Lumbricus terrestris. After mechanical dissociation and sedimentation through Percoll, a highly purified fraction of viable chloragocytes was obtained. The isolated chloragocytes accumulated the vital dye neutral red and reduced the tetrazolium dye MTT, thereby indicating cellular integrity. Time of flight flow cytometric analyses revealed a main population of large and highly granulated cells in the 30-33 microm size range. Hydrolase measurements showed that beta-D-N-acetyl-glucosaminidase and acid phosphatase exhibited the highest activities (146.6 and 24.9 mU/mg of protein, respectively), possibly indicating a major role for these 2 hydrolases in the physiological function of chloragocytes. In contrast, other acid hydrolases such as beta-D-galactosidase and beta-D-glucuronidase had specific activities of respectively 26 and 182 times lower than the glucosaminidase. The specific activity of the membrane-bound alkaline phosphatase was comparable to that of its acid counterpart (18.9 vs. 24.9 mU/mg of protein, respectively) and this level of activity may show an important trans-membrane activity in chloragocytes. The cytoplasmic and mitochondrial enzyme isocitrate dehydrogenase had a level of activity comparable to that of the exclusively cytoplasmic enzyme lactate dehydrogenase (6.6 vs. 8.1 mIU/mg of protein, respectively). When L. terrestris chloragocyte homogenates were separated on Percoll, results showed that hydrolases and dehydrogenases were mainly associated with the lighter materials that remained above the Percoll layer. Nonetheless, the detection of significant proportions (15-25%) of the total recovered activity of acid phosphatase and beta-galactosidase in the enriched chloragosome fraction supports the notion that some chloragosomes may be 'lysosome-like' organelles.

Animals↗
PubMed1998

[Sagittal load-bearing tomography of the forefoot and static metatarsalgia].

We describe the use of weight-bearing foot tomograms. The outline of the food is drawn so as the axes of the metatarsal beyond the toes on the AP plain radiogram and the tomograms are done successively on each metatarsal. This morphological, but also functional, analysis enables exact diagnosis of excessive loading on the metatarsal head. This procedure is used in case of metatarsalgia with normal metatarsal length and in late post-traumatic sequellae of the forefoot. Surgical correction can then be precisely performed.

Arthralgia↗
PubMed1998

[Pigmented villonodular synovitis of the knee. Treatment results in 22 cases].

PURPOSE OF THE STUDY: The authors report their experience about 22 cases of pigmented villonodular synovitis of the knee observed between 1970 and 1997. The authors studied the results of treatments according to localization, evolutionary stage and condition of an early diagnosis. MATERIAL AND METHODS: Among thirty three cases of pigmented villonodular synovitis treated during the same period the knee was involved in twenty two cases. Diagnosis was done or highly suspected in 13 cases because of significant symptoms (iterative hemarthrosis, bony gap in both articular components of the joint) or by MRI. The biopsy performed in each case allowed histological assessment in 22 patients. Surgical treatment was achieved in 19 patients. Three knees were not operated (two patients refused; one had a synoviorthesis) the treatment was a synovectomy alone for fifteen patients; four patients, needed a knee prosthesis, because of important degenerative joint disease. RESULTS: Fourteen patients, with a mean follow-up of five years were reviewed. Four had a recurrence which appeared between three and eight years after subtotal synovectomy for diffuse synovitis. There were no recurrence after arthroplastic treatment and in localized lesions. DISCUSSION: Pigmented villonodular synovitis should be treated as soon as possible but its different clinical features make diagnosis sometimes difficult. Because of an aggressive tendency of the disease which finds expression in extensive lesions in joint and bone, and early diagnosis allowed by MRI could make the prognosis more favourable. CONCLUSION: Surgical synovectomy is the usual treatment. In evolved stages arthroplasties are performed. Localized lesions and recurrences should need arthroscopic treatment.

Adolescent↗
PubMed1997

The relationship of drinking and birth outcome in a US national sample of expectant mothers.

Alcohol consumption by pregnant women and birth outcome were studied in 9953 livebirths, 3309 fetal deaths and 5332 infant deaths from the 1988 National Maternal and Infant Health Survey. In crude analyses, race, age, mother's education, prenatal care, parity, low birthweight, gestational age, smoking and alcohol consumption during pregnancy were significantly related to the occurrence of fetal deaths and infant deaths. Among women having livebirths, race, age, mother's education, prenatal care, prematurity, gestational age, smoking and alcohol consumption during pregnancy were significantly related to having a low birthweight baby (< 2500 g). In this group, women who drank more during pregnancy also smoked more, were younger and less educated than women who drank at lower levels or not at all. The relationship of alcohol consumption during pregnancy and infant birthweight for those women having livebirths was studied using multivariable linear regression. The results indicated that race, mother's education, baby's sex, parity, mother's height, mother's body mass index and smoking, but not alcohol consumption, were significantly related to birthweight. Multivariable logistic regressions were performed for the occurrence of low birthweight, fetal death and infant death. The effect of alcohol was significant in all these analyses. These results indicate that alcohol has an important relationship with birth outcome, but that for the drinking reported in this study, the alcohol effect on mean birthweight is small relative to that of other risk factors, accounting for the non-significant result in the multiple linear regression.

Adult↗
PubMed1997

Extrusion of earthworm coelomocytes: comparison of the cell populations recovered from the species Lumbricus terrestris, Eisenia fetida and Octolasion tyrtaeum.

Coelomocytes were extruded from three earthworm species: Lumbricus terrestris, Eisenia fetida and Octolasion tyrtaeum. Featuring a simple low-vacuum holding device, the proposed methodology allows the recovery of cells with minimum risk of contamination by faecal material. The viability of O. tyrtaeum coelomocytes was highly reproducible (average 93%), with an average yield of 0.92 x 10(6) viable cells per earthworm. Cell viability for L. terrestris and E. fetida averaged approximately 68% but the cell yields were higher (respectively 1.67 x 10(6) and 1.28 x 10(6)). Large inter-individual differences in cell yields were observed with L. terrestris. Flow cytometric analyses indicated species to species differences in cell populations. Coelomocytes from E. fetida were the smallest with approximately 57% of the total viable cells recovered being monitored between 2 and 10 microns. Large granulated cells (> or = 20 microns) were detected in fairly large proportions in L. terrestris and O. tyrtaeum (approximately 52 and approximately 96%, respectively) while they were less abundant in E. fetida (approximately 9%). Using the vital dye neutral red to assess functional integrity, average cellular uptakes were significantly higher for L. terrestris and O. tyrtaeum than for E. fetida (2.94, 2.66 and 0.64 micrograms/2 x 10(5) cells, respectively). In summary, the extrusion methodology herein described is applicable for the recovery of coelomocytes from a wide range of earthworm sizes and species. Moreover, this study strengthens the fact that extruded coelomocytes could be used for the evaluation of cell dysfunction and/or cell death following an in vitro and/or in vivo treatment.

Animals↗
PubMed1997

Microscopic diagnosis of blood parasites following a cytoconcentration technique.

An isotonic fixative (formalin and thimerosal) solution, with a saponin additive to lyse erythrocytes and platelets, has been developed. The formalin and thimerosal ensure good preservation of blood parasites. This fixative has led to the development of a new concentration technique using cytocentrifugation (cytospin) in the search for Plasmodium spp., Leishmania spp., and microfilariae, as well as leukocytes in which parasites or pigment may be present. The concentration of the parasites present in the sediment from 100 microl of blood spread on a 6-mm diameter circle results in good morphology that is well stained using the usual Giemsa or Wright techniques. This new technique has the advantage of a relatively low cost and offers the possibility of isolating and identifying in the same sediment the main blood-stage parasites, with the exception of young trophozoites, of Plasmodium falciparum.

AIDS-Related Opportunistic Infections↗
PubMed1996

Magnetic resonance imaging of the wrist in rheumatoid arthritis: comparison with other inflammatory joint diseases and control subjects.

The aim of this study was to evaluate magnetic resonance images (MRI) of the wrist of rheumatoid arthritis (RA) patients. MRI and plain X-ray of the wrists were performed in 15 patients with RA, 7 patients with another chronic inflammatory joint disease (CIJD), and 10 control subjects. Patients had only minor changes on plain X-ray. Coronal T1 weighted spin echo sequences were performed before and after an intravenous pulse of gadolinium (GD). Contiguous 3 mm thick slices were obtained. Synovitis was frequently objectivized in the two groups of patients. MRI detected far more erosions and central bone geodes than plain X-ray. Geodes were frequent among controls while cortical bone erosions were frequent in patients. Most of the erosions were enhanced after GD injection in the RA patients but not in the 2 other groups. Thus MRI is not only useful in diagnosing inflammatory changes of the wrist but also in distinguishing early stage RA from other CIJD.

Adult↗
PubMed1996

Appearance of low signal intensity lines in MRI of silicone breast implants.

Magnetic resonance (MR) images of five explanted mammary prostheses were obtained with a 1.5 T GE Signa system using a conventional spin-echo pulse sequence, in order to investigate the low-intensity curvilinear lines which may be observed in MR images of silicone gel-filled breast implants under pressure from fibrous capsules. MR images showed ellipsoid prostheses, often containing multiple low-intensity curvilinear lines which in some cases presented an appearance very similar to that of the linguine sign. Upon opening the fibrous capsules, however, all of the prostheses were found to be completely intact demonstrating that the appearance of multiple low signal intensity curvilinear lines in MR images of silicone gel-filled prostheses is not necessarily a sign of prosthesis rupture. The MR image features which are specific to the linguine sign must be more precisely defined.

Breast Implants↗
PubMed1996

Analysis of atresia in bovine follicles using different methods: flow cytometry, enzyme-linked immunosorbent assay, and classic histology.

This study was performed in order to validate flow cytometry as an acceptable method for analyzing follicular atresia in bovine granulosa cells by comparing it to two other techniques, histology and ELISA. Ovaries from 35 nontreated cows, all at different times of their estrous cycle, and 12 superovulated cows were collected. Superovulation treatments began between Days 9 and 12 (Day 0 = estrous), and animals were administered 8 doses of FSH-P (32 or 20 mg) at 12-h intervals over 4 days with or without the addition of 1 mg of prostaglandin s.c. on the third day. Animals were slaughtered after the last FSH-P injection. Granulosa cells from 133 follicles from non-treated cows and 85 follicles from superovulated cows were analyzed. Follicular diameters ranged from 2 to 20 and 2 to 16 mm, respectively. Because of the ample amounts of cells collected, it was possible to perform more than one technique for each follicle. Flow cytometry detected in most follicles a subpopulation of cells that possessed less DNA than normal, viable cells (referred to as -G1 cells). Histological classes used (established in previous work) were nonatretic (< or = 5% picnotic nuclei), slightly atretic (> 5 to < 15% picnotic nuclei), and atretic (> or = 15% picnotic nuclei). A strong linear correlation existed between the percentage of picnotic nuclei and the percentage of -G1 cells (R = 0.86; p < 0.001) with granulosa cells from follicles from nontreated cows. In some cases, flow cytometry detected a certain percentage of cells with reduced DNA content while histology revealed very few picnotic nuclei, indicating a higher sensitivity of flow cytometry. Superovulation decreased considerably the percentage of atretic cells seen with both techniques. The linear correlation was not as strong because follicles from superovulated animals represent a very homogenous population (R = 0.54; p < 0.001). The ELISA technique coincided with flow cytometry as seen in the strong correlation between the two techniques (R = 0.91; p < 0.001). Flow cytometry appeared to be very effective and rapid in evaluating the atretic states of follicles from nontreated and superovulated cows. Strong correlations existed between this method and histology and ELISA.

Animals↗