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Biomedical subjects

M Lévy

Publications and source records attributed to M Lévy.

At least 19 recordsLinked to original sources
PubMed2004

[Clinical case: beliefs, Ramadan and diabetes mellitus].

From the clinical case of a 52-Year old, type 2 diabetic obese woman, muslim algerian native, an endocrinologist and a religious representative discuss the influences of religion, beliefs and environment, on compliance to the diabetes diet and therapeutic management, with a particular emphasis on the Ramadan period. Inadequate behaviours, result in a worsening in glucose control. This, should be avoided through an appropriate patient's education, all along the Year, not only through the healthcare team, but involving patient's family and friends too, as well as the community and religious Authorities.

Blood Glucose↗
PubMed2004

[Endothelial vasoactive factors: predictive markers of the results of the Fontan intervention?].

UNLABELLED: We retrospectively analyzed the pulmonary biopsies of a Fontan intervention in order to identify predictive markers of its result. The pulmonary biopsies of 17 patients who benefited from the Fontan intervention and 6 controls were studied. The histomorphometric measurements and endothelial expression of vasoactive factors (NO synthase, endothelin-1) and angiogenic factors (VEGF) were analyzed with immunohistochemistry at the level of intra-acini pulmonary arterioles. Eight patients presented a good surgical result (group 1). Distal arterioles presented a thin and regular wall: the NO synthase, endothelin and VEGF expression was low. Nine patients presented a failure of the Fontan operation (group 2). The distal arterioles were slightly musculated (p<0.01 vs. group 1 and group control). The endothelin-1 expression was comparable to that observed in group 1. Conversely, the NO synthase and VEGF expressions were significantly increased in that group (<0.001 vs. group 1 and group control). CONCLUSION: In case of Fontan operation failure, the histological modifications are subtle with a muscular extension of the distal pulmonary arterioles wall. Conversely, a marked increase of NO synthase and VEGF expression is observed which can witness of an endothelial dysfunction. This study could be able to define predictive factors of the evolution and refine the selection of patients candidate for a Fontan operation.

Adolescent↗
PubMed2003

[Childhood-onset systemic lupus erythematosus].

Systemic Lupus Erythematosus (SLE) remains a challenging autoimmune disease in term of etiology, pathogenesis and treatment. It is estimated that 10-17% of lupus patients present before the age of 16. SLE in children appears to have more severe organ involvement than in adults. The outcome of childhood SLE has improved during the last decade, but the morbidity remains high.

Adolescent↗
PubMed2001

Molecular characterization of a monoclonal murine anti-blood group A antibody.

A mouse monoclonal anti-human blood group A antigen (AC12, mu, kappa) has been generated and sequenced in order to analyze the immunoglobulin genes used to generate antibodies with anti-human blood group A specificity. Mice were immunized with human type A RBC. Anti-A producing hybridomas were detected by agglutination against human type A RBC. Total cellular RNA was extracted from hybridomas cells. PCR amplification and sequencing of anti-A heavy and light chain cDNAs were performed. The VH and VK sequences of antibody AC12 were shown to be very homologous to that used by other antibodies recognizing carbohydrates as well as glycoproteins, peptides or haptens constituting self antigens as well as nonself antigens. The VH sequence of antibody AC12 presented important homology with a previously reported monoclonal anti-blood group B antibody. The antibody AC12 also presented homology with the VH and VK sequences of a previously reported human anti-blood group A antibody which contributes additional evidence in favor of a restricted usage of V segments by antibodies directed against red blood antigens.

ABO Blood-Group System↗
PubMed2001

Detection of Y chromosome DNA as evidence of semen in cervicovaginal secretions of sexually active women.

The detection of traces of semen in cervicovaginal secretions (CVS) from sexually active women practicing unprotected sex is a prerequisite for the accurate study of cervicovaginal immunity. Two semen markers, the prostatic-specific antigen (PSA) and the Y chromosome, were detected in parallel in CVS obtained by a standardized vaginal washing of consecutive women attending the principal medical center for sexually transmitted diseases of Bangui, Central African Republic. PSA was detected by immunoenzymatic capture assay in the cell-free fraction of CVS, and the Y chromosome was detected by a single PCR assay of DNA extracted by silica from the cell fraction (Y PCR). Fifty (19%) cell-free fractions of the 264 beta-globin-positive CVS samples were positive for PSA, and 100 (38%) cell fractions of the CVS samples were positive for the Y chromosome. All the 50 (19%) PSA-containing CVS samples were also positive for the Y chromosome. Fifty (19%) CVS samples were positive only for the Y chromosome, with no detectable PSA. The remaining 164 (62%) CVS samples were both PSA and Y chromosome negative. These findings demonstrate that CVS from sexually active women may contain cell-associated semen residues unrecognized by conventional immunoenzymatic assays used to detect semen components. The detection of cell-associated male DNA with a highly sensitive and specific procedure such as Y PCR constitutes a method of choice to detect semen traces in female genital secretions.

Adolescent↗
PubMed2000

Secretory anti-human immunodeficiency virus (HIV) antibodies in colostrum and breast milk are not a major determinant of the protection of early postnatal transmission of HIV.

The immune response to human immunodeficiency virus (HIV) type 1 was evaluated in breast milk from HIV-infected African mothers who had transmitted and those who had not transmitted HIV to their children through breast-feeding. The levels, specific activities against gp160 and 2 HIV-derived peptides from gp41 and gp120 (V3 loop), and inhibitory activity toward viral transcytosis in vitro of secretory IgA (S-IgA) and IgG purified from breast milk were investigated in 8 transmitting mothers and 18 nontransmitting mothers. S-IgA and IgG antibodies to gp160 and to peptides were found in all breast milk samples. The specific activities of S-IgA and IgG to gp160 and peptides were similar between transmitting and nontransmitting mothers. No difference of the capacity of S-IgA and IgG to block HIV transcytosis in vitro was found between the 2 groups. These results suggest that humoral mucosal immunity to HIV does not appear as a predominant factor for protection against viral transmission through breast milk.

Adult↗
PubMed2000

Duodenal mucosa-associated lymphoid tissue lymphoma: treatment with oral cyclophosphamide.

Small cell mucosa-associated lymphoid tissue (MALT) lymphomas rarely affect the duodenum, and optimal treatment has not been defined. The aim of this case series was to determine the clinical features and outcome of duodenal MALT lymphoma in four patients (three men, one woman; median age 52 yr) treated with cyclophosphamide p.o. Initial manifestations were abdominal pain (n = 4), vomiting (n = 2), and an obstructive syndrome (n = 1). MALT lymphoma was diagnosed on the basis of endoscopic biopsies. It was localized in the duodenum in three cases and involved the entire small bowel in one case. Tumor infiltration was limited to the duodenal wall in one case and was associated with locoregional lymphadenopathy in three cases. The patients were graded EI (n = 1) and EII1 (n = 3), respectively, according to the Ann Arbor classification revised by Musshof. Cyclophosphamide, 100 mg daily, was administered p.o. for 18 months. Gastroscopy with biopsies, radiography of the small intestine and abdominal CT (CT) were performed every 6 months. Complete remission was defined by morphological and histological normalization, and partial remission as morphological normalization only. Follow-up lasted from 9 to 65 months. Three patients were in complete remission at 18 months: two relapsed after 2 yr and one was still in complete remission at 65 months. The patient with 9 months of follow-up was in complete remission at 6 months. The two patients who relapsed did not complain of symptoms, and no morphological abnormalities were seen. Relapse was diagnosed on histological grounds. Cyclophosphamide monotherapy p.o. thus seems well adapted to this slowly progressive disease, but it is unclear whether it should be resumed in the case of histological relapse or only in the case of symptomatic relapse. (Am J Gastroenterol 2000;95:536-539. (O 2000 by Am. Coll. of Gastroenterology)

Administration, Oral↗
PubMed2000

Maturational changes of endothelial vasoactive factors and pulmonary vascular tone at birth.

The aim of this study was to determine which endothelial factors were involved in the decrease of pulmonary vascular resistance at birth, and how they changed with maturation. Response of intrapulmonary artery rings precontracted with prostaglandin F2alpha were studied from piglets aged <2 h, 2-3 day, 10 day and adult pigs for pharmacological responses to acetylcholine (ACh) and cromakalim (CMK) in the presence and the absence of the nitric oxide synthase (NOS) inhibitor, N(omega)-nitro-L-arginine (L-NA), the adenosine triphosphate sensitive potassium (K(ATP)) channel blocker, glibenclamide and the endothelin (ET)-A receptor antagonist, BQ123. In situ hybridization and immunochemistry studies were performed in lung tissues of the same animals in order to determine the expression of NOS and ET. There was a small contractile effect of ACh in the newborn. Relaxation to ACh, which was blocked by L-NA and reduced by glibenclamide, only appeared from the age of 3 days. The significantly greater relaxation to CMK in rings without endothelium (p<0.05) was abolished by BQ123 in the newborn, and then disappeared by 2 days of age. Glibenclamide had a greater inhibitory effect on relaxation induced by CMK at 10 days than in the newborn and 2 days old piglets. NOS expression was low in pulmonary arteries of the newborn and increased by 2 days of age whereas the converse was seen with ET expression. It is concluded that: 1) relaxant response to acetylcholine was absent at birth and appeared at 2 days; 2) the reduced relaxant response to cromakalin in rings with endothelium at birth could be blocked by BQ123; and 3) the expression of endothelin decreased whereas the expression of nitric oxide synthase increased from birth to 2 days of age.

Age Factors↗
PubMed1999

Decreasing occupational risk related to blood-borne viruses in cardiovascular surgery in Paris, France.

BACKGROUND: Surgeons face the risk of patient-to-physician transmission of blood-borne viruses. This risk is related to the seroprevalence of the viruses in the patient population. METHODS: The seroprevalence of the human immunodeficiency virus, hepatitis B virus, and hepatitis C virus were determined in cardiovascular patients at Hôpital Broussais in Paris, France, over a 5-year period (1994 to 1998). RESULTS: Hepatitis C virus is the most prevalent virus in the patient population, whereas human immunodeficiency virus is the least frequent. The seroprevalence of hepatitis C virus and human immunodeficiency virus has decreased over time, whereas hepatitis B virus has remained constant. We apply the seroprevalence data to a mathematical model to estimate the occupational risk of seroconversion faced by surgeons over the length of their career. Our results show that the principal risk faced by the surgeon arises from hepatitis B virus and hepatitis C virus. The decreasing seroprevalence of the hepatitis C virus has resulted in a decrease in the occupational risk. CONCLUSIONS: The probability of becoming infected with a blood-borne virus over the career of the surgeon is notable. The greatest occupational risk to the surgeon is from the hepatitis viruses and not HIV.

Adolescent↗
PubMed1999

Bi-directional cavopulmonary shunt: is accessory pulsatile flow, good or bad?

OBJECTIVE: Evaluation of the effect and long-term outcome of accessory pulsatile blood flow versus classical bi-directional cavopulmonary connection (BCPC). METHODS: Retrospective review of the medical and surgical records. RESULTS: Two-hundred and five patients (119 boys, 86 girls) underwent BCPC from 1990 to 1996. Accessory pulsatile flow was present in 68%, flow being maintained through the pulmonary trunc in 46%, systemic-to-pulmonary artery shunt in 13% and mixed in 7%, or patent ductus arteriosus in 2%. Patients with accessory pulsatile flow had lower hospital mortality (3% versus 5%), while mean pulmonary artery pressure (14.1 versus 12.6 mmHg P = 0.050) and increase of oxygen saturation (12.4 versus 8.7, P = 0.034) were significantly higher. The period of artificial ventilation (1.9 day) and ICU stay (6 days) did not differ for both groups. Late mortality was higher following accessory pulsatile flow (6% versus 1%). At late follow-up patients with accessory pulsatile flow had significantly higher oxygen saturation (mean 85 +/- 4%, versus 79 +/- 4%; P < or = 0.005). If subsequent completion of Fontan is considered the optimal palliation and subsequent systemic to pulmonary artery shunt, arteriovenous fistula and transplantation is considered a failure, patients with accessory pulsatile flow had significantly more and earlier completion of the Fontan procedure (mean 1.7 +/- 2.4 years, versus 2.7 +/- 4.4 years; P = 0.008). Survival is not influenced by age at bi-directional cavopulmonary shunt surgery, left or right functional ventricular anatomy or previous palliative surgery. One patient with accessory pulsatile flow developed systemic-to-pulmonary collateral's eventually requiring lobectomy. CONCLUSION: Despite two different initial palliative techniques the outcome was not significantly different. Accessory pulsatile blood flow appeared not to be a contra-indication for a completion Fontan procedure. Moreover, the data suggest that after accessory pulsatile flow can safely be performed, at late follow-up oxygen saturation is higher, while, significantly more and earlier completion of Fontan occurred. Age at bi-directional cavopulmonary shunt, basic left or right ventricular anatomy or previous palliative surgery did not influence survival.

Adolescent↗
PubMed1998

[Comparative study of the global left ventricular ejection fraction obtained by ECG gated perfusion MIBI and thallium scintigraphy].

The isotopic LVEF was measured by a planar method with injection of a product visualising the ventricular cavity. Perfusion was assessed by Thallium and sesta MIBI. The investigation of ischaemia and assessment of wall motion in the coronary patient, therefore, requires two isotopic methods. The Cedars Sinai group have developed a programme allowing acquisition of a perfusion tomoscintigraphy in the cardiac cycle after injection of MIBI. This programme automatically detects the endocardial borders and calculates the LVEF. This provides a study of function and perfusion in a single investigation. However, MIBI is not considered by all as a good marker of viability, contrary to Thallium. And the acquisition of Thallium tomography with ECG gating may pose problems because of the low counting statistic. Several authors have therefore studied the possibility of using it for assessing left ventricular function. The authors have then compared LVEF with MIBI and with Thallium in 72 patients. The Thallium LVEF was 33.62% +/- 15.79%; that of MIBI was 32.51% +/- 14.73%. ThalEF = MIBI EF x 1.02 + 0.34 (r = 0.955). The mean of the standard deviation was 1.09. In conclusion, the EF measured by Thallium tomography with ECG gating was closely correlated to that obtained with MIBI. These results suggest that myocardial viability, ischaemia and function may be studied in routine daily practice with a single injection, so improving patient comfort and reducing the costs of the procedures.

Adult↗
PubMed1997

Endoscopic ultrasonography for the initial staging and follow-up in patients with low-grade gastric lymphoma of mucosa-associated lymphoid tissue treated medically.

BACKGROUND: Endoscopic ultrasonography is an appropriate procedure to assess the depth of tumoral infiltration in primary gastric lymphoma. The aims of the present study were to characterize the endoscopic ultrasonographic aspects of low-grade gastric lymphoma of mucosa-associated lymphoid tissue and to determine the value of this procedure in medical treatment assessment. METHODS: Between 1991 and 1996, 15 patients with low-grade gastric lymphoma of mucosa-associated lymphoid tissue were treated with oral cyclophosphamide and/or anti-Helicobacter pylori treatment. Endoscopic ultrasonography was carried out at the time of the diagnosis in all patients, 8 of whom (4 in complete remission and 4 with a stable or progressive disease) had at least one endoscopic ultrasonography examination within the treatment period (median follow-up 17 months). RESULTS: The initial procedure showed an increased gastric wall thickness from 6 to 12 mm in 8 patients, equal to 5 mm in 5 patients, and normal in 2 patients. The thickening was predominantly of the mucosa alone and/or the submucosa but never extended beyond the muscularis propria. No lymph node was found. Gastric wall thickness returned to normal in the 4 patients in complete remission and remained thick in 3 of the 4 patients with a stable or progressive disease. Of these 3 patients, at least one set of biopsy samples, carried out during follow-up, showed the absence of lymphoma, but histology performed subsequently found evidence of disease. CONCLUSIONS: Endoscopic ultrasonography differentiates superficial from infiltrative types of gastric lymphoma of mucosa-associated lymphoid tissue, which may have a prognostic significance and confirms remission or persistence of the disease with medical treatment during follow-up. When the gastric wall remains thick, even if histology is negative, repeated biopsies should be performed to detect evolving disease or relapse.

Adult↗
PubMed1997

[Roles of vasoactive factors synthetized by endothelium in pulmonary arterial hypertension].

Pulmonary vascular endothelium synthesizes and releases two groups of vasoactive substances, namely the endothelium-derived relaxing and contracting factors. Among the former, the effects of nitric oxide (NO), formerly known as endothelium-derived relaxing factor (EDRF), and those of the so-called endothelium-derived hyperpolarizing factor (EDHF) have been extensively investigated. Among the latter, endothelin is probably one of the most potent endogenous vasoconstrictors. NO is a free radical which can be readly inactivated by hemoglobin. NO has all the characteristics of a gas, whereas its pharmacological properties are consistent with those of an endogenous nitrovasodilator. Therefore, inhalation of the gas NO is now considered as one of the most promising means to treat persistent pulmonary hypertension of the newborn. EDHF relaxes vascular smooth muscle through activation of ATP-dependent potassium channels. Both the chemical nature and the physiological role of EDHF are still unclear. The pharmacological properties of endothelin are far from being unequivocal. It is a potent vasoconstrictor, when it directly acts on vascular smooth muscle. However, it can also induce the release of NO and EDHF, hence causing vasorelaxation. These effects of endothelin are mediated by various transduction pathways. Activations of ET-B receptors located on endothelium on the one hand, and ET-A receptors located on smooth muscle on the other hand, are responsible for relaxation and constriction of vascular smooth muscle, respectively. Such highly complex cellular mechanisms highlight the need for further insight into the physiology of the cell related to the pulmonary circulation. This, in turn, will help to better define the target upon which one can try to correct the abnormal function of the cell underlying the pathophysiological processes.

Biological Factors↗
PubMed1997

In vivo semen-associated pH neutralization of cervicovaginal secretions.

Physiological cervicovaginal acidity can partly inactivate human immunodeficiency virus (HIV). Basic semen components should be able to partially neutralize in vivo cervicovaginal pH. The goals of the study were to evaluate the relationship between cervicovaginal pH and presence of semen components in sexually active African women and to assess whether vaginal douching with water performed just after sexual intercourse could significantly reduce semen components and restore physiological cervicovaginal pH. Cervicovaginal secretion (CVS) from 56 heterosexual African women (19 to 45 years old), living in Bangui, Central African Republic, were evaluated for pH, semen components (prostatic acid phosphatase [PAP] and prostatic specific antigen [PSA]), cellularity, and hemoglobin at inclusion and after vaginal douching with 100 ml of water by using a bock. Before douching, semen components were found in 46 of 56 CVS (82%). The mean vaginal pH was 5.2 (range, 3.6 to 7.7), and concentrations of both PAP and PSA correlated positively and strongly with cervicovaginal pH (P < 0.001). After douching, semen components were found in 35 of 56 CVS (62%) (P = 0.03). Cervicovaginal PAP and PSA levels were significantly decreased (respectively, P < 0.0001 and P < 0.01; PAP, -72%; PSA, -87%), as was the total cell count (-60%; P < 0.0001). Furthermore, in CVS previously positive for both PAP and PSA, the mean vaginal pH was significantly decreased (6.5 versus 5.3, P < 0.01); no genital bleeding was observed. Frequent persistence of semen in CVS from heterosexually active African women leads to a shift from acidity to neutrality that could favor male to female HIV transmission. Vaginal douching provides significant elimination of semen after sexual intercourse; it should be considered for study as a supplementary means for the prevention of heterosexual HIV transmission.

Acid Phosphatase↗
PubMed1997

[Isolated left ventricular muscular diverticulum in an adult. Value of non-invasive examinations].

The authors report a case of ventriculum in a 45 year old women investigated for chest pain. This was a congenital muscular left ventricular diverticulum confirmed by a complete imaging series including echocardiography, magnetic resonance imaging, angio-scintigraphy and conventional angiography. This diverticulum was unusual due to the fact that there was no associated congenital disease and that it was discovered in an adult. The authors review the literature and discuss the value of non-invasive imaging procedures.

Angiocardiography↗
PubMed1995

Dilution assessment of cervicovaginal secretions obtained by vaginal washing for immunological assays.

Local immunological defense mechanisms in the cervicovaginal mucosa currently remain incompletely defined, especially from a quantitative point of view. Addition of an inert substance, lithium chloride (LiCl), into the washing buffer used to carry out the vaginal washing for collecting cervicovaginal secretions and measurement of its concentration with a flame absorption spectrophotometer, before and after the specimen is sampled, permits the quantification of the volume of cervicovaginal secretions collected and the approximation of the dilution factor of a soluble component introduced by the washing. Lithium, at a concentration of 10 mM, gives the best precision of measurement and has no effect on the results of the immunoassays. In a population of 27 nonpregnant women (age range, 18 to 45 years), the volume of cervicovaginal secretions collected by vaginal washing with 3 ml of LiCl-phosphate-buffered saline was 12% +/- 3.2% (mean +/- standard deviation) of the total volume and showed large interindividual variations (range, 5.6 to 18.8%); the mean dilution factor of a soluble component from the vaginal secretions was 9.9% +/- 2.8% (range, 6.3 to 18.8%). According to the date of the menstrual cycle, the mean volume of collected cervicovaginal secretions was significantly increased in the luteal phase in comparison with the follicular phase; conversely, the mean dilution factor of a soluble component was more important in the follicular than in the luteal phase. These features strengthen the need to quantify accurately the dilution factor introduced by vaginal washing when studying cervicovaginal immunity.

Adolescent↗