PubMed Health⌕ Search

Biomedical subjects

P Michaud

Publications and source records attributed to P Michaud.

At least 19 recordsLinked to original sources
PubMed2000

Late results of percutaneous mitral commissurotomy for calcific mitral stenosis.

The aim of this study was to assess late results of percutaneous mitral commissurotomy (PMC) in calcific mitral stenosis and to identify predictors to improve patient selection. We analyzed 422 patients who underwent PMC for calcific mitral stenosis. The extent of calcium was graded from 1 to 4 by fluoroscopy: 227 patients (53%) were graded 1, 125 (30%) graded 2, 55 graded 3 (13%), and 15 graded 4 (4%). The procedure failed in 15 patients, used a single balloon in 11, a double balloon in 126, and the Inoue balloon in 270. In-hospital mortality was 1.2%. Good immediate results (valve area >/=1.5 cm(2) without mitral regurgitation >2/4), were obtained in 321 patients (76%). Multivariate analysis identified 5 predictors of good immediate results: a younger age (p = 0.0004), a lesser degree of stenosis (p = 0.0005), a smaller extent of calcium (p = 0.04), the use of the Inoue balloon (p = 0.015), and a larger effective balloon dilating area (p = 0.006). Good functional results, defined as survival with no further intervention and in New York Heart Association class I or II, were 36 +/- 4% at 8 years. The predictors of good functional results after good immediate results were a younger age (p = 0.04), a lower pre-PMC New York Heart Association class (p <0.0001), sinus rhythm (p = 0.0006), a smaller extent of calcium (p = 0.02), and a lower gradient after PMC (p <0.0001). Despite a frequent deterioration on follow-up after PMC for calcific mitral stenosis, the predictive analysis suggests that PMC may be useful in deferring surgery in selected patients with mild to moderate calcific deposits, who have otherwise favorable characteristics.

Aged↗
PubMed2000

Percutaneous mitral commissurotomy for restenosis after surgical commissurotomy: late efficacy and implications for patient selection.

OBJECTIVES: The results of percutaneous mitral commissurotomy were assessed in patients with restenosis after surgical commissurotomy. BACKGROUND: Balloon dilation is feasible in patients with restenosis after surgical commissurotomy, but little is known about its late efficacy. METHODS: We studied 232 patients who had undergone percutaneous mitral commissurotomy a mean of 16 +/- 8 years after surgical commissurotomy. Mean age was 47 +/- 14 years; 81 patients (35%) had valve calcification. All patients had restenosis with bilateral commissural fusion as assessed by echocardiography. Technical failure occurred in 9 patients and the procedure used a single balloon in 7 patients, a double balloon in 95, and the Inoue balloon in 121. RESULTS: Complications were death in 1 patient (0.4%) and mitral regurgitation >2/4 in 10 (4%); 191 patients (82%) had good immediate results (valve area > or =1.5 cm2 without regurgitation >2/4). Predictors of poor immediate results in multivariate analysis were older age (p < 0.001), lower initial valve area (p = 0.01) and the use of the double-balloon technique (p = 0.015). In the 175 patients who underwent follow-up, 8-year survival without operation and in New York Heart Association class I or II was 48 +/- 5%, and 58 +/- 6% after good immediate results. In this latter group, poor late functional results were predicted by higher cardiothoracic index (p < 0.0001), previous open-heart commissurotomy (p = 0.05) and lower final valve area (p < 0.0001) in a multivariate Cox model. CONCLUSIONS: Percutaneous mitral commissurotomy is safe and provides good immediate results in selected patients with restenosis after surgical commissurotomy. After good immediate results, the conditions of more than half of the patients remained improved at 8 years, enabling reoperation to be deferred.

Adult↗
PubMed2000

Protective correlates of stages in adolescent substance use: a Swiss National Study.

OBJECTIVE: To identify factors potentially protective against involvement with additional illicit drugs among adolescent users of marijuana. DESIGN AND METHODS: A cross-sectional, secondary analysis of a national data set of Swiss adolescents was performed. The original survey was conducted in 1992-1993 (N= 9268). Stages of substance use were conceptualized as lifetime use of marijuana of three or more times and as use of marijuana and other illicit drugs (opiates, inhalants, cocaine, hallucinogens, or stimulants) more than twice in the past month. Behavioral characteristics associated with level of drug use were examined. Based on the resilience literature, factors potentially protective against progression of drug use were examined in their bivariate relationships and analyzed in a multiple regression model. RESULTS: Almost one quarter of the surveyed adolescents were classified as past or current marijuana users. One in 20 of these adolescents also used other illicit drugs. Prevalence of risk-related behaviors (e.g., antisocial behavior, accidents, suicide attempts) was elevated for marijuana users compared to nonusers and even more elevated for users of marijuana with other illicit drugs. In a multivariate logistic regression model, communicating well with a parent was significantly associated with not having progressed to use of illicit drugs other than marijuana [for males, odds ratio (OR) = 0.72, confidence interval (CI) = 0.55, 0.92; for females, OR = 0.60, CI = 0.39, 0.93]. Other significant protective correlates for boys were academic achievement (OR = 0.66, CI = 0.47, 0.92), type of education: school versus apprenticeship (OR = 0.42, CI = 0.21, 0.87), confiding in a family member (OR = 0.49, CI = 0.28, 0.85), and regular participation in a sports club (OR = 0.39, CI = 0.22, 0.77). CONCLUSION: Within this national sample of Swiss adolescents, a cross-sectional analysis identified the quality of relationships within the family and factors related to school associated with lack of progression of illicit substance use. However, longitudinal studies will be necessary to confirm these associations and to allow for designing interventions targeting the enhancement of protective factors among young people already at risk for serious substance use.

Adolescent↗
PubMed2000

Does perchlorate in drinking water affect thyroid function in newborns or school-age children?

Perchlorate is known to suppress thyroid function by inhibiting uptake of iodide by the human thyroid at doses of 200 mg/day or greater. A study was conducted to investigate the potential effects of perchlorate in drinking water on thyroid function in newborns and school-age children. A total of 162 school-age children and 9784 newborns were studied in three proximate cities in northern Chile that have different concentrations of perchlorate in drinking water: Taltal (100 to 120 micrograms/L), Chañaral (5 to 7 micrograms/L), and Antofagasta (non-detectable: < 4 micrograms/L). Among schoolchildren, no difference was found in thyroid-stimulating hormone levels or goiter prevalence among lifelong residents of Taltal or Chañaral compared with those of Antofagasta, after adjusting for age, sex, and urinary iodine. No presumptive cases of congenital hypothyroidism were detected in Taltal or Chañaral; seven cases were detected in Antofagasta. Neonatal thyroid-stimulating hormone levels were significantly lower in Taltal compared with Antofagasta; this is opposite to the known pharmacological effect of perchlorate, and the magnitude of difference did not seem to be clinically significant. These findings do not support the hypothesis that perchlorate in drinking water at concentrations as high as 100 to 120 micrograms/L suppresses thyroid function in newborns or school-age children.

Age Distribution↗
PubMed1999

Frequency and prognostic value of cardiac troponin I elevation after coronary stenting.

Mild myocardial injuries after coronary angioplasty are associated with adverse late outcomes. The incidence and prognostic value of this phenomenon when using cardiac troponin I (cTnI) after stent implantation is unknown. We studied cTnI and creatine kinase (CK) release in 109 patients after stenting. Clinical success was achieved in 103 patients (94%). In-hospital major adverse coronary events were: death in 1 patient, Q-wave myocardial infarction in 1 patient, and non-Q-wave myocardial infarction in 2 patients. Twenty-nine patients (27%) had postprocedural cTnI increase, 16 (15%) had CK elevation. No preprocedural variables predicted marker elevation. Marker release was related to the occurrence of in-lab complications (59% vs 29% [p = 0.004 for cTnI] and 69% vs 32% [p = 0.011 for CK]). In 34% no explanation was found for cTnI increase. Success was more frequent in patients without cTnI elevation (100% vs 86%, p <0.001). The negative predictive value of cTnI increase was 100% for in-hospital major adverse coronary events (MACE), whereas its positive predictive value was 14%. cTnI and CK concordant elevation was associated with more intra- and postprocedural adverse events. During a mean follow-up of 8+/-3 months, major adverse coronary events were: death in 2 patients, myocardial infarction in 2 patients, and repeat PTCA in 8 patients. cTnI elevation was not predictive of these late MACE. cTnI elevation is common after stenting, and is related to the occurrence of in-lab complications. Its isolated elevation is not a good predictor of MACE. Patients with concordant cTnI and CK elevation seem to be at higher risk of in-hospital MACE.

Adult↗
PubMed1999

Late results of percutaneous mitral commissurotomy in a series of 1024 patients. Analysis of late clinical deterioration: frequency, anatomic findings, and predictive factors.

BACKGROUND: The optimal use of percutaneous mitral commissurotomy (PMC) in a wide range of patients requires accurate evaluation of late results and identification of their predictors. METHODS AND RESULTS: Late results of PMC were assessed in 1024 patients whose mean age was 49+/-14 years. Echocardiography showed that 141 patients (14%) had pliable valves and mild subvalvular disease, 569 (55%) had extensive subvalvular disease, and 314 (31%) had calcified valves. A single balloon was used in 26 patients, a double balloon in 390, and the Inoue Balloon in 608. Good immediate results were defined as valve area >/=1.5 cm2 without regurgitation >2/4 (Sellers' grade) and were obtained in 912 patients. Median duration of follow-up was 49 months. The 10-year actuarial rate of good functional results (survival with no cardiovascular death and no need for surgery or repeat dilatation and in New York Heart Association [NYHA] class I or II) was 56+/-4% in the entire population. Follow-up echocardiography was available in 90% of the patients who experienced poor functional results after good immediate results and showed restenosis in 97% of these. In multivariate analysis, the predictors of poor functional results were old age (P=0.0008), unfavorable valve anatomy (P=0.003), high NYHA class (P<0.0001), atrial fibrillation (P<0.0001), low valve area after PMC (P=0.001), high gradient after PMC (P<0.0001), and grade 2 mitral regurgitation after PMC (P=0.04). CONCLUSIONS: PMC can be performed with good late results in a variety of patient subsets. Prediction of late events is multifactorial. Knowledge of these predictors can improve patient selection and follow-up.

Adult↗
PubMed1999

Assessment of adolescent food habits in Switzerland.

Several physical, psychological and behavioural changes may affect food habits during adolescence and have long-term consequences on adult health status. Also, as food habits are related to lifestyle and physical activity, all should be assessed together. This paper describes a self-administered food frequency questionnaire (FFQ) designed to assess semi-quantitatively food habits of adolescents, and evaluates its use in a study of lifestyle and physical activity. A FFQ was developed, tested in 20 adolescents and compared with a modified version of the diet history method (a combination of a 3-day dietary record and an interview with a dietitian). This validated semi-quantitative questionnaire was later included in a larger questionnaire on lifestyle and physical activity in a study of 3540 adolescents aged 9-19 years. In the validation study with 20 adolescents, the FFQ showed a good agreement with the modified version of the diet history. During the survey several consumption frequencies were found to be low. In the group of adolescents aged 14-19 years old, dairy products were consumed daily by less than 50% of the sample. About 53% girls but only 33% boys consumed one fruit daily. For one vegetable portion, these proportions were 17 and 8%, respectively. The self-administered food frequency questionnaire correctly describes food consumption in adolescents. Moreover, it was well accepted by the target group, easily understood and completed with very few problems. The results show that a significant proportion of adolescents didn>>t consume milk, fruit and vegetable on a daily basis.

Adolescent↗
PubMed1999

Results of IIb/IIIa receptor blockade in patients with unstable angina.

The efficacy of GPIIb/IIIa inhibitors has now been evaluated in over 20 000 patients with unstable angina and non-Q MI. These agents have shown great efficacy in patients undergoing percutaneous coronary intervention. They are also effective, even if to a lesser degree, as an addition to medical treatment. The safety profile is satisfactory. Several issues have to be investigated in the future: comparison of agents, use of oral inhibitors, associations with Heparin, consequences on management, and cost efficacy. As of now, it is clear that GPIIb/IIIa inhibitors represent a significant progress in the treatment of patients with acute coronary syndromes.

Angina, Unstable↗
PubMed1999

Effects of cigarette smoking on short-term variability of blood pressure in smoking and non smoking healthy volunteers.

The present trial was planned to study the effects of smoking on short-term variability of blood pressure and on haemodynamic parameters after an overnight cessation and after one day of repeated smoking in healthy cigarette smoking volunteers, compared to a control group of non-smokers who were not asked to smoke. 40 healthy male volunteers, 20 smokers and 20 non-smokers, participated in an open study with two period of measurements over a single day (morning and afternoon). Blood pressure and heart rate were measured using standard and finger recordings over 6 min before and 10 min after smoking one cigarette (in smokers only). During the two periods, smokers were asked to smoke 4 cm of a cigarette containing 1 mg of nicotine in 2 min, and a blood sample was taken for a plasma nicotine assay. In the smoking group, smoking the first cigarette of the day caused a significant increase of systolic blood pressure (+7%), diastolic blood pressure (+10%) and heart rate (+25%). The blood pressure variability in the frequency range of the Mayer waves (66-129 mHz) was increased after an overnight cessation of smoking in the smoking group in comparison to the non-smokers, and decreased significantly after the first cigarette of the day (7.1 +/- 4.0 to 3.2 +/- 1.8 mmHg2; P < 0.01). The changes observed in the afternoon after continuous smoking were significantly less important (3.8 +/- 1.9 to 3.2 +/- 1.9 mmHg2; NS). In the non-smoking group, the different parameters remained stable between the different measurements. These results suggest that an overnight cessation of smoking in smoking subjects is associated with a increase in sympathetic activity to the vascular system in the morning, which is released by smoking the first cigarette. This effect of smoking is reduced in the afternoon after a continuous nicotinic impregnation.

Adult↗
PubMed1998

[Thyroid function in a population with an extra iodine intake].

BACKGROUND: After 20 years of iodine salt fortification, the prevalence of goiter has decreased significantly in the rural area of Pirque, central Chile. In this location, equipment has been installed that efficiently and economically adds 0.5 mg of elemental iodine per liter of water to render it potable. AIM: To study thyroid function and urinary iodine excretion in school age children of this zone, after two years of extra iodine intake. MATERIAL AND METHODS: One hundred thirty four children aged 6 to 12 years old were examined. In 56 randomly chosen children a morning urine sample was obtained to measure iodine excretion. In 45 children without goiter, a blood sample was drawn to measure TSH and thyroxin. RESULTS: In nine children (7%) a diffuse goiter was found. Median urinary iodine excretion was 158 micrograms/dl. Thyroxin and TSH levels were within normal limits (8.4 +/- 1.1 micrograms/dl and 2.2 +/- 1.5 microU/ml respectively). During the period of iodine water supplementation there were 47 births in the zone. All newborns had normal TSH values and none had goiter. CONCLUSIONS: When present results are compared with the period before water iodination (when the prevalence of goiter was 9.6% and mean urinary iodine excretion was 57.6 micrograms/dl), it can be concluded that extra iodine intake in this rural population has not caused additional thyroid problems.

Child↗
PubMed1998

[Diffuse sclerosing papillary thyroid carcinoma. Report of two cases].

Unlike classical papillary carcinoma, diffuse sclerosing papillary thyroid carcinoma presents as a diffuse goiter with a discretely irregular surface, associated to hypo or hyperthyroidism, specially in young women. We report two women aged 41 and 23 years old with this disease, one with normal thyroid function and the other with hyperthyroidism. It is concluded that diffuse sclerosing papillary thyroid carcinoma must be suspected in patients with rapidly growing goiter with irregular surface or diffuse minute calcifications, specially in the presence of hypo or hyperthyroidism. Fine needle aspiration is a good diagnostic procedure.

Adult↗
PubMed1998

[Consensus proposal on the use of 131I in the treatment of thyrotoxicosis and thyroid cancer].

A consensus meeting held by the Chilean Endocrinological Society reached to 22 consensus proposals on the use of iodine-131 in hyperthyroidism and thyroid cancer, that are reported in this paper. Some of these propositions are: 1) Hyperthyroidism: A previous 131I uptake test must be performed. A calculated or an ablative dose should be administered. Hypothyroidism must be considered an objective rather than a complication. In patients with cardiovascular risk, normal thyroid function must be attained with prophythioturacil. In cases of treatment failure, the dose should not be repeated before six months. It must be used with used with caution in children and teenagers. 2) Thyroid cancer: A iodine free diet is recommended prior to the therapeutic dose. A 100 mCi complementary ablative dose should be given after surgery, with a posterior exploration. This examination must not be done routinely, and if required, a 5 mCi dose should be used. For the treatment of metastases, a dose of 150 to 200 mCi is recommended. There is no radiation risk in hyperthyroidism or thyroid cancer. The only absolute contraindication is pregnancy. Recommendations for radiological protection are formulated. Hospitalization is suggested to protect other people from radiation exposure.

Humans↗
PubMed1997

Falsified or forged medical prescriptions as an indicator of pharmacodependence: a pilot study. Community pharmacists of the Midi-Pyrénées.

OBJECTIVE: While data on drug abuse liability have been determined for selected drugs in experimental studies, there is limited information available about drug abuse in real life. This study presents the results of a simple experimental epidemiologic survey of prescription forgeries in community pharmacies in the Midi-Pyrénées area (southwest France). During four periods (September-October 1991, January-June 1992, September-October 1992 and January-June 1993), resident pharmacy students in several volunteer pharmacies were asked to complete a specific report form for each suspect prescription request. The main criteria used to identify forgeries were: inadequate dosage, multiple use of the prescription form, drafting not in accordance with the rules of prescription or false prescription forms (stolen prescription forms, photocopies). RESULTS: A total of 165 falsified prescriptions were collected. The 305 drugs involved in these forged prescriptions were opiate analgesics, benzodiazepines, amphetamines and minor opiate analgesics. Medications were essentially buprenorphine, flunitrazepam (in 2 mg dosage), phenobarbitone+amphetamine and chlorazepate. CONCLUSION: These results suggest that forged prescriptions can be used as an indicator of potential abuse liability of marketed psychoactive drugs. Although this survey cannot describe the real prevalence of the misuse or abuse of drugs, it constitutes a useful warning epidemiologic system to elicit early observations regarding new misuses of drugs as they are requested at the pharmacy.

Drug Prescriptions↗
PubMed1997

Identification of glucuronan lyase from a mutant strain of Rhizobium meliloti.

The Rhizobium meliloti M5N1CS (NCIMB 40472) mutant strain wich induces nodule formation on alfalfa roots, produces a (1 --> 4)-beta-D-glucuronan partially acetylated. During fermentation under specific conditions, the molecular weight of the polymer decrease, the presence of polysaccharide degrading enzyme was suspected. A glucuronan lyase was identified, this new bacterial lyase produces d.p. 4 oligoglucuronans, substituents (acetates) present on the substrate reduced the enzyme activity.

Acetylation↗
PubMed1996

[Prevalence of goiter in school-age children in the Pirque Zone. Effects of salt iodination].

BACKGROUND: Twenty years ago, Pirque was a zone with a goiter prevalence of 39%. AIM: To assess the effects of salt iodination on the prevalence of goiter in school-age children of this zone. SUBJECTS AND METHODS: School age children from four public schools in Pirque were examined, following WHO criteria for the diagnosis of goiter. Urinary iodine excretion was also measured. RESULTS: Five hundred ninety one males and 298 females aged 12.1 +/- 2.5 years were examined. Fifty seven children (9.6%) bad goiter. In 53 the goiter was grade I and in 4, grade II. No sex differences were observed. Minimal and median urinary iodine excretion values were 12.6 and 57.6 micrograms/dl respectively. CONCLUSIONS: Goiter prevalence dropped from 39 to 10%. The fact that iodine intake is over minimal recommendations, underscores the effectiveness of salt iodination.

Adolescent↗
PubMed1996

[Diffuse fatty infiltration of the thyroid gland associated to amyloidosis in a patient with chronic renal failure].

We report a 26 years old male with secondary amyloidosis and chronic renal failure who consulted due to a rapidly growing goiter associated with coarseness and dysphagia. Serum levels of thyroid hormones and TSH were normal and a neck CT scan showed a big mass in the anterior and lateral regions, that compressed neighboring structures. The patient was subjected to a total thyroidectomy and the pathological study revealed a diffuse fatty and amyloid infiltration of the thyroid gland. There was no evidence of malignancy.

Adipose Tissue↗