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M Benchimol

Publications and source records attributed to M Benchimol.

At least 19 recordsLinked to original sources
PubMed2006

[Comparison of two routine screening strategies for gestational diabetes mellitus: the experience of Jean-Verdier Hospital].

OBJECTIVE: Screening strategies for gestational diabetes mellitus are controversial. Thus, we sought to determine the benefits of universal screening. PATIENTS AND METHODS: Prospective study with 2121 women involved but 1610 really screened (75.9%). According to WHO's recommendations, the strategy implemented was one-step, universal screening with a 75g oral glucose tolerance test. Screening was performed between 24 and 28 weeks of gestation or earlier if risk factors were identified. Results were compared to previous year (2001) then only a selective screening was done. RESULTS: Application of universal screening increased the prevalence of gestational diabetes mellitus (8.39% to 15.65%). Out of the 252 patients with gestational diabetes, 66 did not display any identified risk factor (26.19%). Some new risk factors have been identified: age>30, Asian, Indian or Pakistan ethnies. If these new risk factors were applied, this super selective screening would have a sensibility of 96%. DISCUSSION AND CONCLUSION: Universal screening seems to be the most appropriate routine screening strategy because it is difficult to know exactly the specific risk factors of a population to do a super selective screening.

Adult↗
PubMed2006

Universal rather than selective screening for gestational diabetes mellitus may improve fetal outcomes.

AIM: The benefit of treating gestational diabetes mellitus (GDM) has recently been shown. The aim of this study was to compare offspring and maternal health benefits from selective or universal screening for GDM. METHODS: The incidence of outcomes was compared in three series of pregnant women: 1) the 159 consecutive women with GDM out of the 1909 women who delivered between October 2000 and September 2001: during this period screening for GDM was based on risk factors (risk factor-GDM); 2) the 265 consecutive women with GDM out of the 2111 women who delivered during the year 2002: during this period screening for GDM was universal (universal-GDM); 3) 1255 women with no GDM during year 2002 (controls). RESULTS: After adjustment for age, pregravid body mass index, parity, and ethnicity, the risk of large for gestational age (Odds ratio 2.19[95% confidence interval 1.36-3.54], P < 10(-3)), delivery before 37 weeks of gestation (OR 2.44 [95CI 1.32-4.51], P = 0.004), jaundice (OR 3.31[95CI 1.58-6.93], P = 0.002), hospitalization in the department of pediatrics (OR 2.35 [95CI 1.53-3.61], P < 10(-3)) was higher in the GDM-risk factor group than in the control group, whereas it was similar in the universal-GDM group and the control group. Compared with the control group, the risk of anticipated delivery and hospital stay > 4 days after delivery was increased in the GDM-risk factor group (OR 2.69[1.88-3.84], P < 10(-3); and OR 2.6 [1.82-3.71], P < 10(-3) respectively) and the universal-GDM group (OR 1.54 [1.15-2.07] P = 0.004; and OR 1.49 [1.13-1.97], P = 0.005 respectively). CONCLUSION: This observational study suggests that universal rather than selective screening for GDM may improve outcomes. Universal screening might reduce delay of diagnosis and care.

Adult↗
PubMed2005

Trichomonas vaginalis polyamine metabolism is linked to host cell adherence and cytotoxicity.

Trichomonas vaginalis secretes putrescine that is readily detected in vaginal secretions. We wanted to examine the effect of decreased putrescine synthesis by inhibition of ornithine decarboxylase (ODC) on T. vaginalis. One reason is because inhibition of Tritrichomonas foetus ODC results in growth arrest, destruction of hydrogenosomes, and decreased amounts of hydrogenosomal enzymes. Treatment of T. vaginalis T016 with >/=20 mM 1,4-diamino-2-butanone (DAB) to inhibit ODC resulted in growth arrest, which was reversed by addition of exogenous putrescine. No similar reversal of growth arrest was achieved with the polyamines spermine or spermidine or with iron. Electron microscopic examination of control versus DAB-treated trichomonads did not reveal any adverse effects on the number and integrity of hydrogenosomes. Further, the adhesins AP65, AP51, and AP33 mediating binding to immortalized vaginal epithelial cells (VECs) share identity to enzymes of the hydrogenosome organelle, and there was no difference in amounts of adhesins between control versus DAB-treated T. vaginalis parasites. Likewise, similar patterns and extent of fluorescence were evident for the prominent AP65 adhesin. Surprisingly, DAB treatment increased by 4- to 20-fold above untreated trichomonads handled identically the level of adherence mediated by adhesins. Interestingly, the enhanced attachment to VECs was reversed by exogenous putrescine added to DAB-treated trichomonads. Equally noteworthy was that DAB-treated T. vaginalis with enhanced adherence did not possess the previously reported ability to kill host cells in a contact-dependent fashion mediated by cysteine proteinases, and total cysteine proteinase activity patterns were identical between control and DAB-treated trichomonads. Overall, these data suggest that polyamine metabolism and secreted putrescine are linked to host cell adherence and cytotoxicity.

Animals↗
PubMed2004

Increase of melanogenesis by retinoic acid: an ultrastructural and morphometric study.

Melanin is a dark pigment protecting the skin against UV radiation in some organisms. Studies on invasion and metastasis using retinoic acid as inhibitor agent are well known, but its role in melanin production (melanogenesis), especially at ultrastructural level and using morphometry were not well studied. In the present study, we analyzed the effects of retinoic acid on the melanosomes in B16F10 melanoma cells. These organelles were identified and quantified using routine electron microscopy and the specific HMB45 antibody. Other approaches such as immunofluorescence, and flow cytometry were also used. Our results indicated that retinoic acid increased the melanogenesis process in B16F10 melanoma cells. Furthermore, this work also provided evidence that this substance interferes at the subcellular level altering the numerical density of melanosomes, as well as the relative volume of the nucleus and nucleolus. In addition, the cells displayed altered morphology and an increase in the percentage of the relative volume of melanosomes, mainly the stages II-III and IV, leading to melanin formation. Furthermore, a decrease in the cells number after retinoic acid treatment was also observed.

Animals↗
PubMed2003

[Endometrial ossification: about one case].

The ossification of the endometrium is a rare disease. The common feature in most reported cases is previous history of abortion with retention of foetal bones. However, the physiopathology is unknown. Clinical presentation may include secondary infertility as well as chronic inflammation of endometrium. About one recent observation and with help of publications, we will discuss physiopathology, symptomatology and therapeutics of this disease.

Abortion, Induced↗
PubMed2002

Visualization of new virus-like-particles in Trichomonas vaginalis.

In the present work, we demonstrate virus-like particles (VLPs) with various morphological variations in Trichomonas vaginalis. The VLPs were distinct based on size, shape and electron density, with VLPs being either electron-dense or electron-lucent. We used electron microscopy thin sections of several T. vaginalis strains virus-infected, and also negative staining of fractions obtained after purification by CsCl buoyant density gradient centrifugation. The particles observed in fractions are identical to those previously described, but by thin sections, we found new forms. The shapes found were icosahedral, spherical and oblong, and the sizes varied from 33 to 120nm in diameter with the most common VLP being spherical and having a size range from 83 to 104nm. The VLPs were found in the cytoplasm closely associated with the Golgi complex, with some VLPs budding from the Golgi, and other VLPs were detected adjacent to the plasma membrane. Unidentified cytoplasmic inclusions were observed in the region close to the VLPs and Golgi. Clusters of the already described icosahedral virus were also observed in the cytoplasm, although less frequently. These results indicate that T. vaginalis organisms may be infected with different dsRNA viruses simultaneously.

Animals↗
PubMed2002

The complex fibronectin--Trichomonas vaginalis interactions and Trichomonosis.

Trichomonosis is the vaginitis caused by Trichomonas vaginalis. This sexually transmitted agent achieves successful host parasitism through various means including: (1). acquisition of nutrients through specific receptors; (2). recognition and binding to mucin followed by cytoadherence mediated by adhesins that resemble metabolic enzymes; (3). evasion of immune responses through (i). masking of organisms by host proteins, (ii). shedding of trichomonad proteins into the secretions and (iii). secretions of cysteine proteinases that degrade all immunoglobulin subclasses and complement; (4). alternating surface expression of at least two antigen repertoires; and (5) alternate and coordinate expression of virulence genes in response to host environmental factors. The fact that the parasite survives long term in the varying and adverse environment of the vagina attests to the highly evolved nature of this protist. An understanding of the non-self-limiting nature of this infection may come from recent findings illustrating the complexity of Trichomonas vaginalis-fibronectin (FN) interactions. The parasite readily attaches to surfaces with immobilized FN and binds to FN in a highly specific receptor-mediated fashion. The amount and affinity of bound FN by live organisms is influenced by concentrations in medium of both iron and calcium. De novo protein synthesis is required for optimal FN acquisition in the presence of calcium. Furthermore, the parasites bind with differing affinities to the N-terminal domain (NTD), the cell-binding domain (CBD) and the gelatin-binding domain (GBD) of FN. Iron modulates binding of NTD similar to that of FN. This minireview summarizes recent findings on the T. vaginalis-FN associations.

Animals↗
PubMed2001

Contribution of cryofixation and freeze-substitution to analytical microscopy: a study of Tritrichomonas foetus hydrogenosomes.

The hydrogenosome, an organelle that produces molecular hydrogen and ATP from the oxidation of pyruvate or malate under anaerobic conditions, presents some characteristics common to mitochondria. It is found in several trichomonad species, protists living in oxygen-poor environments, as well as certain free-living ciliates, rumen ciliates, and some fungi. We performed a comparative microanalytical study (energy dispersive X-ray analysis and electron spectroscopic imaging) of different fixation methods for electron microscopy analyzing hydrogenosomes of the bovine parasite Tritrichomonas foetus. The study included the elemental composition and the mapping of calcium, phosphorus, and oxygen. A preparation of T. foetus cells, based on cryoimmobilization by high-pressure freezing and freeze-substitution, was compared to a second preparation based on chemical fixation followed by dehydration and routine processing. The ultrastructural preservation achieved by the cryotechnique was far superior to the chemical fixation, since it allowed the successful cryoimmobilization of intracellular ion contents. The detection of several cations (Al, Mg, Co, Ca, Fe) by X-ray microanalysis inside the peripheral vesicle of the hydrogenosome was only possible in cryofixed cells. The presence of aluminum and cobalt ion in the hydrogenosomal vesicle was established for the first time. Electron-spectroscopic images of calcium showed that this element, in addition to the vesicle compartment, is present in the hydrogenosome's membrane in varying concentrations, which might reflect changes in the physiology of this organelle.

Animals↗
PubMed2001

Binding of fibronectin by Trichomonas vaginalis is influenced by iron and calcium.

We have reported that Trichomonas vaginalis, the causative agent of the most common, non-viral sexually transmitted disease, bound to cover slips coated with fibronectin (FN) (Crouch & Alderete, Microbiol 1999 145: 2835-43). In this study, we extend that observation by showing that FN binding is specific, and we present data on the requirements of FN binding by T. vaginalis. Immunofluorescence and immuno-gold labelling readily detected FN throughout the trichomonal surface. Parasites bound to(125)I-labelled FN in a time- and concentration-dependent fashion. In the absence of protease inhibitor, iodinated FN was released from the trichomonad surface. Unlabelled FN specifically competed for binding in a concentration-dependent fashion with the(125)I-labelled FN. Interestingly, the amount of FN bound by T. vaginalis organisms was dependent on iron. High-iron-grown trichomonads acquired lower numbers of molecules but with 10-fold higher affinity than low-iron-grown organisms. Further, we show that for iron-replete organisms, calcium (Ca(2+)) at physiological levels increased amounts of bound FN. The increase in binding was rapid, occurring within 5 min of Ca(2+)addition, and required de novo protein synthesis. Co-incubation of live parasites with Ca(2+)in the presence of FN was necessary to increase the amount of FN bound. Treatment of trichomonads with okadaic acid, but not other phosphatase inhibitors, resulted in a 50% decrease in binding of FN, regardless of the presence of Ca(2+), suggesting a role for phosphatase in FN association. These results indicate that depending on the iron status of T. vaginalis organisms in vivo, Ca(2+)may influence trichomonad recognition and binding to FN during host parasitism.

Animals↗
PubMed2001

Immunolocalization of tubulin isoforms and post-translational modifications in the protists Tritrichomonas foetus and Trichomonas vaginalis.

In the present report we show the distribution of multiple tubulin isoforms in Trichomonas vaginalis and Tritrichomonas foetus, flagellated parasitic protists of the urogenital tracts of human and cattle, respectively, using immunofluorescence and immunoelectron microscopy. We used several monoclonal and polyclonal anti-tubulin antibodies from different sources and recognizing variant tubulin isoforms. Our results demonstrate that: (1) there is a heterogeneous distribution of the different tubulin isoforms in the main microtubular cell structures, such as axostyle, flagella, basal bodies, and mitotic spindle, (2) the axostyle-pelta junction is a structure with high affinity for glutamylated tubulin antibodies in T. foetus, (3) the spindle labeling is positive to anti-glutamylated tubulin and anti-alpha-tubulin (TAT1 and purchased from Amersham) antibodies in T. vaginalis but it is negative in T. foetus, (4) the nuclear matrix and the cytosol presented positive reaction using glutamylated and TAT1 (anti-alpha-tubulin) antibodies only in T. vaginalis, and (5) the Golgi complex exhibited staining using the glutamylated tubulin antibody. The present data corroborate with the idea of the existence of a heterogeneous population of microtubules in these protists and of a subset of intracytoplasmic microtubules. Microtubule diversity may reflect distinct tubulins, diverse microtubule-associated proteins, or a combination of both.

Animals↗
PubMed2001

Hydrogenosome morphological variation induced by fibronectin and other drugs in Trichomonas vaginalis and Tritrichomonas foetus.

The hydrogenosome is a spherical organelle, found in some anaerobic protozoa, which participates in ATP and molecular hydrogen formation. The morphological alterations in hydrogenosomes induced by fibronectin, hydroxyurea and cytochalasin B in Trichomonas vaginalis and Tritrichomonas foetus are presented. We demonstrate that, under experimental conditions, the hydrogenosome presents a high diversity in size and shape, suggesting a mechanism that seems to compensate for the stress provoked by drugs. The following experimental procedures were used: (1) fibronectin-mediated endocytic activity, (2) 4 mM hydroxyurea for 15 h, and (3) 10 microg cytochalasin B/ml in the culture medium. The main alterations observed in hydrogenosomes were: (1) formation of giant hydrogenosomes, (2) presence of internal membranes, (3) increased diversity of non-spherical forms, some of them bizarre, (4) presence of sub-compartments in the matrix, as vesicles, (5) presence of ribosome-like particles on the outer hydrogenosomal membrane, (6) enlargement of the peripheral vesicle, and (7) continuity with membrane profiles.

Animals↗
PubMed2001

Structure and division of the Golgi complex in Trichomonas vaginalis and Tritrichomonas foetus.

We present observations on the fine structure and the division process of the Golgi complex in the protists Trichomonas vaginalis and Tritrichomonas foetus, parasites of the urogenital tract of humans and cattle, respectively. The Golgi in trichomonads is a prominent structure, associated with striated parabasal filaments to which this organelle seems to be connected. We followed by immunofluorescence and electron microscopy the Golgi in interphasic and mitotic cells. Ultrastructural studies were performed using fast-freezing fixation, immunocytochemistry using antisera to the known adhesins AP65 and AP51, cytochemistry (acid phosphatase, Ca++-ATPase, zinc iodide-osmium tetroxide technique (ZIO), for analysis of distribution of the endoplasmic reticulum and Golgi complex, and Thiéry's techniques), routine and serial thin-sections. Three-dimensional reconstruction, NBD-ceramide, fluorescent lectin (WGA) and nocodazole treatments were also used. We demonstrate that: (1) the Golgi in trichomonads is a single-copy organelle; (2) presents a fenestrated structure; (3) is formed by 8-12 saccules; (4) is connected to the parabasal filaments by thin filamentous bridges; (5) by cytochemistry, presents a positive reaction for the lectin WGA, Ca++-ATPase, acid phosphatase, ZIO and Thiéry's techniques; (6) does not appear to break down at any point of the cell cycle; (7) elongates during the cell cycle by lateral growth; (8) is labeled by anti-glutamylated tubulin antibodies, but it is not fragmented by nocodazole treatment; (9) before mitosis, the already elongated Golgi ribbon undergoes progressive medial fission, cisternae by cisternae, starting at the cisternae adjacent to the cell surface and ending with the cis-most cisternae; (10) the Golgikinesis originates two small Golgi ribbons; (11) the Golgi is intensely labeled with the antisera to the AP65 and AP51 adhesins in T. vaginalis, thus seeming to be a key station in the production of adhesins.

Acid Phosphatase↗
PubMed2001

Congestive heart failure. Correlation between functional class and systolic and diastolic functions assessed by Doppler echocardiography.

OBJECTIVE: To evaluate the influence of systolic or diastolic dysfunction, or both on congestive heart failure functional class. METHODS: Thirty-six consecutive patients with a clinical diagnosis of congestive heart failure with sinus rhythm, who were seen between September and November of 1998 answered an adapted questionnaire about tolerance to physical activity for the determination of NYHA functional class. The patients were studied with transthoracic Doppler echocardiography. Two groups were compared: group 1 (19 patients in functional classes I and II) and group 2 (17 patients in functional classes III and IV). RESULTS: The average ejection fraction was significantly higher in group 1 (44.84 % +/- 8.04 % vs. 32.59 % +/- 11.48 % with p = 0.0007). The mean ratio of the initial/final maximum diastolic filling velocity (E/A) of the left ventricle was significantly smaller in group 1 (1.07 +/- 0.72 vs. 1.98 +/- 1.49 with p = 0.03). The average maximum systolic pulmonary venous velocity (S) was significantly higher in group 1 (53.53 cm/s +/- 12.02 cm/s vs. 43.41 cm/s +/- 13.55 cm/s with p = 0.02). The mean ratio of maximum systolic/diastolic pulmonary venous velocity was significantly higher in group 1 (1.52 +/- 0.48 vs. 1.08 +/- 0.48 with p = 0.01). A predominance of pseudo-normal and restrictive diastolic patterns existed in group 2 (58.83 % in group 2 vs. 21.06 % in group 1 with p = 0.03). CONCLUSION: Both the systolic dysfunction index and the patterns of diastolic dysfunction evaluated by Doppler echocardiography worsened with the evolution of congestive heart failure.

Diastole↗
PubMed2001

[Removal or conservation of ovaries during hysterectomy for benign lesions].

At the time of hysterectomy, the aging ovary presents a dilemma. We conducted a prospective study to assess the feasibility of systematic oophorectomy in women 50 years or older and a retrospective study of hysterectomy history in patients who developed cancer of the ovary. Our finding and data in the literature point out the requirement for careful assessment of two aspects of the problem, one technical (feasibility of adnexectomy) and the other functional (ovary function and risk of cancer on the retained ovary).

Age Factors↗
PubMed2001

[Role of misoprostol in the delivery outcome].

OBJECTIVES: Delivery-induced hemorrhage is defined as a blood loss greater than 500 ml within the first 24 hours after delivery. Loss of more than 1000 ml is a sign of gravity. For certain authors, 40% of these hemorrhages could be avoided with systematic preventive measures using uterotonic agents to control the third phase of labor. The aim of our work was to assess the preventive efficacy of active management measures during the third phase of labor and to determine which agents are most effective. PATIENTS AND METHODS: We compared two protocols for controlled deliver: a conventional method using ocytocin (2.5 IU i.v. bolus), and a more recent method using a prostaglandin E1 analog: misoprostol (Cytotec, 3 tablets per os). We compared the two methods with a control group where no preventive measures were used, the standard procedure in our maternity unit. RESULTS: Six hundred two women participated in the study. They were divided into 3 homogeneous groups (ocytocin group misoprostol group, control group). There was a 46% reduction in delivery-induced hemorrhage in the ocytocin group but only a minimal preventive effect against severe hemorrhage. Misoprostol did not demonstrate any efficacy in our study. DISCUSSION: It would appear appropriate to take preventive measures against delivery-induced hemorrhage for all deliveries. A bolus intravenous injection of ocytocin immediately after delivery should bed used. The dose should be greater than that used in this study in order to prevent the development of severe hemorrhage. The most satisfactory results can be obtained with 5 IU (1 ampoule of Syntocinon). It is important to obtain a precise quantification of excessive blood loss in order to institute appropriate care rapidly. Misoprostol should be assessed with other prospective studies because of its easy administration, its low cost and easy storage, important advantages in countries with limited resources.

Adult↗
PubMed2000

Vacuolar proton pyrophosphatase activity and pyrophosphate (PPi) in Toxoplasma gondii as possible chemotherapeutic targets.

The addition of PP(i) promoted the acidification of a subcellular compartment in cell homogenates of Toxoplasma gondii tachyzoites, implying the presence of a proton-translocating pyrophosphatase. The proton gradient was collapsed by addition of the K(+)/H(+) antiporter nigericin, and was also inhibited by addition of the PP(i) analogue aminomethylenediphosphonate (AMDP). Both proton transport and PP(i) hydrolysis were dependent upon K(+), but Na(+) caused partial inhibition of these activities. PP(i) hydrolysis was sensitive in a dose-dependent manner to AMDP, imidodiphosphate, NaF and to the thiol reagent N-ethylmaleimide. This activity was unaffected by common inhibitors of phosphohydrolases, except that NaO(3)V (sodium orthovanadate) stimulated the activity by 87%. Immunofluorescence microscopy, using antisera raised against conserved peptide sequences of a plant vacuolar pyrophosphatase, suggested that the pyrophosphatase in T. gondii tachyzoites was located in the plasma membrane and intracellular vacuoles of the parasite. High-field (31)P-NMR spectroscopy showed that PP(i )was more abundant than ATP in tachyzoites. Bisphosphonates (PP(i) analogues), drugs that are used in the treatment of bone diseases, inhibited proton transport and PP(i) hydrolysis in tachyzoite homogenates, and also inhibited intracellular proliferation of tachyzoites in tissue culture cells.

Animals↗
PubMed2000

Transient invagination of flagella by Tritrichomonas foetus.

We describe an experimental system for the study of rapid and reversible formation of pseudocysts, which are spherical forms that lack a true cyst wall, by Tritrichomonas foetus, a trichomonad parasite of the bovine genitourinary tract. It highlights the dynamics of the plasma membrane and cytoskeleton of this parasite, which is perpetually devoid of any sort of protective cell wall, and can reflect a responsive survival mechanism. We have found that cooling of axenic cultures of T. foetus from their normal 37 degrees C to below about 16 degrees C can trigger pseudocyst formation. The three anterior flagella and the single recurrent flagellum can be fully internalized within 1 3 min at 37 degrees C, with the axonemes and flagellar membranes remaining intact within the cell body. Electron microscopy confirms that the internalized flagella are surrounded by a separate membrane. At 37 degrees C the internalized flagella can resume beating movements and become externalized as quickly as within 10 min. We have begun to elucidate the mechanisms of this unusual phenomenon, characterizing its temperature dependence and exploring the effects of agents that interfere with various aspects of the cytoskeleton, phagocytosis, endocytosis, and exocytosis.

Animals↗