PubMed Health⌕ Search

Biomedical subjects

M Leroy

Publications and source records attributed to M Leroy.

At least 19 recordsLinked to original sources
PubMed1992

Vitamin B12 among parturients and their newborns and its relationship with birthweight.

Vitamin B12 (Cobalamin) is an essential nutrient in the diet of humans, particularly during pregnancy, nevertheless very few epidemiological studies have been reported, particularly concerning variation factors. The purpose of this study is to assess the role of vitamin B12 on birthweight after taking into account potential confounders, such as obstetrical, socioeconomic, and biological factors which will be identified. This study was conducted on 188 single births occurring during a 5-month period in an obstetrical care unit in Paris. Vitamin B12 plasma levels and folate plasma levels of mothers and cords along with haematological parameters were measured. Social and obstetrical features of the mothers as well as their tobacco exposure and alcohol consumption were recorded. Cord blood vitamin B12 levels were highly correlated with maternal levels (r = 0.63, P less than 0.001) and were 2-3-fold higher. Three variation factors of vitamin B12 were identified: maternal age, ethnicity and tobacco exposure. Negative correlations between birthweight and vitamin B12 levels were observed only among the smoker group (r mothers = -0.46, P less than 0.05 and r cords = -0.42, P less than 0.05). After adjustment for ethnicity and parity, birthweight remained negatively linked to vitamin B12 in smokers. This relationship could suggest that the availability of vitamin B12 for fetal development depends on certain biological factors present only in mothers who smoked. We hypothesized this relationship could be explained, in part, by lipid metabolism, particular to smokers.

Adult↗
PubMed1992

Bilateral single lung transplantation. Complications and results in 14 patients.

Between November 1989 and April 1991, 14 bilateral single lung transplantations (BSLT) were performed at our institution using the technique we have described without omentoplasty and rarely cardiopulmonary bypass. The indications included emphysema (8), cystic fibrosis (3), infected fibrosis (1), alveolar microlithiasis (1) and lymphocytic interstitial pneumonitis (1). Maximum mean pulmonary artery pressure was 53 mmHg and minimal right ventricular ejection fraction was 15%. Two patients experienced bronchial complications: 1 complete left bronchial dehiscence, 1 late partial stenosis which required a temporary insertion of a stent. One patient had a posterior dehiscence which healed spontaneously. Five patients died postoperatively (3 of infection, 1 after a volume mismatch and 1 after a circulating anticoagulant). BSLT is the technique of choice for double lung transplantation in adults and heart lung transplantation has very few indications in infected end-stage pulmonary disease. We hope that modification of our immunosuppressive regimen will decrease postoperative mortality.

Adult↗
PubMed1992

Bronchial provocation tests in small animals: a quantified and automated procedure.

Bronchial provocation tests using aerosols in laboratory animals are difficult to standardize and quantify, because the amount of drug actually reaching the airways is unknown. To improve the quantification of aerosolized inhaled stimuli, we designed an apparatus that allows, in anesthetized intubated ventilated animals, control of temperature and hygrometry of inspired air, computerized measurement of pulmonary resistance, and fully automated delivery of a known amount of aerosolized drug directly into the trachea. Calibration of the aerosol delivery involved direct measurement of liquid delivered at the tip of the tracheal cannula. Despite all our efforts at standardization and full automation of all steps, reproducibility of aerosol delivery was poor, with stroke-by-stroke differences of 26 or 42%, according to whether an air-jet or an ultrasonic nebulizer was used. Histamine dose-response curves performed in 15 guinea pigs with this device confirmed marked differences among animals and also disclosed large intraindividual changes in bronchial responsiveness.

Aerosols↗
PubMed1992

[Donor-recipient lung volume matching in double lung transplantation. Value of left lower lobe graft].

For double lung transplantation, lung volume matching is easier comparing the predicted total lung capacities of the donor and recipient and the recipient's true TLC. The major concern in the inability to close the chest when the donor lungs are too large. The technique reported of left lower lobe implantation during bilateral single lung transplantation might be of great value in patients with small lung volume.

Adult↗
PubMed1992

[Obstructive sleep apnea syndrome in adults and cardiovascular risk].

Sleep obstructive apnea syndrome (SOAS) is a common condition with a strong male predominance. Its incidence is more than 1 percent in the population as a whole. It exists in snorers. Both snoring and SOAS are linked to the presence of abnormalities (congenital or acquired) of the upper respiratory tract. The nocturnal cardiovascular consequences of SOAS are directly linked to apnea. Bradycardia occurs during apnea and tachycardia when ventilation restarts. Paroxysmal nocturnal hypertension is a constant feature. Even in individuals who are normotensive during the day, each restarting of ventilation is accompanied by peaking of blood pressure. The pulmonary artery pressure curve follows that of systemic blood pressure. Complications begin when SOAS has been present for several years: 1) Chronic: permanent systemic hypertension is common (56 percent of SOAS). It is often refractory to antihypertensive treatment. 2) Acute: the onset of myocardial infarction and of cerebrovascular accidents explains the heavy mortality of SOAS (37 percent at 8 years in untreated individuals with a number of episodes of apnea exceeding 20 per hour of sleep). Other acute complications are less common: acute pulmonary edema, nocturnal sudden death. These events may be prevented by treatment suppressing apnea: actuarial survival curves are then superimposable upon those of the population as a whole. Thus SOAS is a cardiovascular risk factor which is remarkably reversible by specific treatment, though which most often passes unrecognized.

Cardiovascular Diseases↗
PubMed1992

Tracheal sleeve resection for iatrogenic stenoses (subglottic laryngeal and tracheal).

Since 1975 200 tracheal sleeve resections for iatrogenic tracheal and subglottic laryngeal stenoses have been performed in our institution. Preoperative Nd:YAG laser is of paramount help in opening the stenoses. Tracheography is usually performed to specify the length of the stenosis and the distance from the vocal cords. Operative procedures are described. One hundred seventy five (87.5%) patients are definitely cured, but in this group 16 patients required a Montgomery tube for 6 months to 1 year to recover a normal tracheal diameter. Two patients needed a second tracheal sleeve resection. Nine (4.5%) patients died, and 16 (8%) had recurrent stenoses. Stenoses in these patients were treated with use of a tracheostomy tube, a permanent Montgomery tube, or an endotracheal stent. Partial anterior cricoid resections performed in 21 patients have had the same results as those of the whole series. Twenty one laryngeal releases were performed and proved to be efficient and safe. In our experience complications can be avoided by good selection and preparation of the patients, accurate identification of the level and length of the stenosis, and meticulous technique.

Follow-Up Studies↗
PubMed1992

[Single lung transplantation].

Thirteen single lung transplantations have been performed in our department for non-infected end-stage lung diseases. Two patients died after surgery; a female patient died of uterine carcinoma one year and six months after the operation. The remaining ten patients are alive; they have resumed an active life and often working. The number of single lung transplantation is rapidly growing in the world, whereas heart-lung transplantation is regressing considerably.

Adult↗
PubMed1991

[Double lung transplantation. The "bilateral single" graft].

We present 10 cases of a new double lung transplantation technique: following, then the other, without requiring cardiopulmonary bypass. This "bilateral single" lung transplantation procures all the advantages of single lung transplantation.

Adult↗
PubMed1991

Lung and blood superoxide dismutase activity in mercury vapor exposed rats: effect of N-acetylcysteine treatment.

Rats were exposed to mercury vapors (30 mg/m3) for either 1 or 2 h. Histological lesions like alveolar oedema, hyaline membranes and sometimes fibrosis were observed. The lesions were more significant after 2 h of exposure, with about 50% of the animals dying within 2 weeks. The mercury level and the superoxide dismutase activity in the blood and the lungs demonstrated differences according to the time of exposure. In the animals exposed for 2 h to mercury vapors, N-acetylcysteine treatment increased survival time and the percentage of living animals. The lung superoxide dismutase was lower than in the non-treated animals indicating an antioxidant effect. Mercury levels were decreased in blood and lung, suggesting some chelating effect of N-acetylcysteine. The exact mechanism of its action must be further elucidated.

Acetylcysteine↗
PubMed1991

Histological and urinary reactivity of monoclonal antibody 1BE12 in bladder carcinoma. Purification of the antigen from urine.

We have previously reported the production of monoclonal antibody (MAb) 1BE12, which recognizes a glycoprotein in breast-cancer cells. In the present work, 1BE12 reactivity was tested by immunohistochemistry in bladder carcinoma (92 cases) and in non-tumoral bladder samples (15 cases). In 71% of bladder tumors, more than 30% of cells were intensely stained by 1BE12. The percentage of reactive cells was higher in cancers invading the muscle than in more superficial tumors (p = 0.039). In non-tumoral bladder, immuno-staining, when present, was usually confined to the superficial layers with a low number of cells stained (less than 30%) in 13/15 cases. Slot blots, performed on urine samples from 43 bladder-cancer patients and 21 healthy controls, were quantified by densitometry scanning. We found higher optical density (OD) values in urine from muscle-invasive-cancer patients than in urine from more superficial tumors and healthy controls, with a significantly different distribution (p = 0.005). The urinary antigen was detected by immunoblotting with 1BE12 as high-molecular-weight species (greater than 150 kDa). The reactive glycoprotein could thus be purified by immunoaffinity and FPLC filtration from the perchloric-acid-soluble fraction of urine from patients with invasive bladder carcinoma. The availability of purified antigen will allow us to quantitate our assay, in order to evaluate its potential use as a prognostic indicator in bladder-cancer patients.

Antibodies, Monoclonal↗
PubMed1990

Laser in bronchology: methods of application.

The method of application for the endoscopic resection by Nd-YAG-Laser closely depends on the choice of indications. The use of rigid bronchoscope is compulsory in the field of Laser, because of tracheobronchial obstruction in patients which are more or less on the verge of asphyxia. The resection is achieved under general anesthesia. A Nd-YAG-Laser (1.06 wavelength) with 100 watts maximum power is satisfying. The new 200 microns fibers are nearly perfectly flexible and increase the range of endobronchial laser-application. For some time we used a superpulsed mode of laser emission which obtains a real evaporation of tissues instead of carbonization. Cryotherapy may be useful before some resections to minimize bleeding. Endoprotheses can prolong the therapeutic effect of recanalization achieved by laser in end stage carcinomas.

Airway Obstruction↗
PubMed1990

[Detection of cancer of the prostate. A study of 600 cases].

A free screening consultation for carcinoma of the prostate was proposed to men over the age of 50 years working in different companies in the areas of Paris. This consultation included a digital rectal examination, a blood test for determination of serum acid phosphatase and prostatic specific antigen, and two dimensional trans-rectal ultrasonography of the prostate. 600 patients were seen. 575 were evaluable. Prostate biopsy was recommended in 152 men. Ninety-three prostate biopsies were performed. Eighteen prostatic cancers and 1 urothelial cancer invading the prostate were detected with an overall incidence of prostate cancer of 3.1%. Radical prostatectomies were performed in 10 of the 18 patients with a prostate cancer. Sensitivity of digital rectal examination ultrasonography and PSA were respectively 42.8%, 47.3% and 68.4% with an abnormal serum PSA level defined as being greater than 5 ng/ml. The predictive value of a positive ultrasonography (18.7%) contrasts with the predictive value of a positive digital rectal examination (30.7%) and serum PSA (30%). Digital rectal examination and determination of serum prostatic specific antigen seem to be the most useful tests for mass screening of prostate cancer. Transrectal ultrasonography is very useful for guided prostatic biopsy and for a better topographic evaluation of the tumor.

Aged↗
PubMed1989

Radioimmunodetection of lymph node invasion in prostatic cancer. The use of iodine 123 (123I)-labeled monoclonal anti-prostatic acid phosphatase (PAP) 227 A F(ab')2 antibody fragments in vivo.

The therapeutic indications in prostatic cancer depend on the regional and distant extension of the cancer and are difficult to assess before lymphadenectomy. Radioimmunodetection of lymph node involvement with monoclonal anti-prostatic acid phosphatase (PAP) antibodies can be proposed as a noninvasive alternative to lymphadenectomy. Fifteen patients with various stages of histologically proven prostatic cancer were examined by immunolymphoscintigraphy (ILS) before treatment to detect lymph node metastases. These patients had Stage A (n = 7), Stage B (n = 3), Stage C (n = 2), and Stage D (n = 3) tumors. They received between 100 and 400 micrograms of monoclonal antibody 227 A in the form of F(ab')2 fragments labeled with iodine 123 (123I). The antibody was injected directly into the periprostatic area. ILS images were obtained after 1, 3, 6, and 24 hours. Three days later, each patient underwent a lymphadenectomy for histologic examination. The results of the histologic examination and ILS were compared. In ten patients, the examination did not show any images capable of being interpreted as lymphadenopathy and histologic examination confirmed the integrity of the nodes examined. In five cases, scintigraphy suggested the presence of lymph node invasion by prostatic cancer and this was confirmed by histologic examination in three of the five cases. Overall, in terms of lymphadenopathy, this examination had a sensitivity of 100% and a specificity of 83%. Therefore, ILS appears to be capable of detecting lymph node metastases in prostatic cancer.

Acid Phosphatase↗
PubMed1989

[Critical analysis of 1000 systematic assays of serum levels of vitamin B12 and folates].

Between January 15 and April 30, 1988, one thousand assays of serum vitamin B12 and folates were performed, and the reasons why they were requested as well as their clinical usefulness are discussed. In 50 cases these assays were requested for a suspected myeloproliferative syndrome; in some of the patients with polycythaemia vera an excess of B12 was observed without hyperleukocytosis, an argument for keeping the B12 assay as an element of initial evaluation. In numerous cases the assays were performed for aetiological evaluation of a macrocytosis of suspected alcoholic origin in most patients; more than 50 per cent of the patient had folate deficiency and only a few had low B12 values. Folate levels were frequently low and B12 levels generally normal in patients with gastrointestinal disease, but many of them had been supplemented with folate and/or B12 prior to the assay. More than 20 per cent of the 1,000 assays were performed in patients aged 80 years or more, and more than 50 per cent of them had a low folate level; this has no consequences for individual subjects, but it may be of epidemiological or sociological interest. It must be mentioned that too many blood samples (more than 40 per cent) were sent to the laboratory without adequate information and after supplementation in 20 per cent of the cases. Very few patients with very low B12 levels were subjected to Schilling's test, so that the clinical usefulness of this assay, as currently utilized, is questionable in a large number of cases.

Adolescent↗
PubMed1989

Comparison of aminoglycoside concentrations measured in plasma versus serum.

The terms "serum concentration" and "plasma concentration" are often used interchangeably in therapeutic drug monitoring, but few studies have addressed the comparability of serum and plasma drug concentrations. Before implementing a change in the procedure for measuring aminoglycoside concentrations in our institution, we prospectively compared values for tobramycin and gentamicin concentrations measured in serum and plasma. For the 208 samples that were tested, plasma aminoglycoside concentrations were significantly lower than those in serum. This relationship was similar for tobramycin and gentamicin, and was unaffected by the presence of concurrent therapy with ticarcillin. This difference, while statistically significant, was not, in our estimation, of sufficient magnitude to be of clinical importance. Plasma aminoglycoside concentrations may be considered equivalent to serum concentrations and, owing to the shorter processing time involved, appear to be the preferred medium for measuring these values.

Aminoglycosides↗
PubMed1989

[Pulmonary papillomatosis].

The authors report a case of a 30 year old woman with juvenile laryngeal papillomatosis (JLP) who subsequently developed intra-alveolar papillomas. These papillomas demonstrated a marked pseudo-neoplastic loco-regional invasive activity, but did not possess the histological criteria of malignancy and were treated by pneumonectomy and lobectomy.

Adult↗