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Biomedical subjects

N Roux

Publications and source records attributed to N Roux.

17 recordsLinked to original sources

The myocardial sleeves of the pulmonary veins: potential implications for atrial fibrillation.

Atrial fibrillation (AF) is the most common abnormal heart rhythm and contributes to cardiac morbidity and mortality. Electrophysiological studies with pacing have shown that AF is initiated by ectopic beats localized in the pulmonary vein (PV) walls. The aim of this work was to look for some anatomical or histological particularities to explain these ectopic beats. Ten autopsied hearts were examined (6 males, 4 females). The myocardium was studied from the left atrium to the PV. Histological sections were made from 39 PVs. Myocardial cells were localized to PV between 9 and 38 mm from the PV-atrial junction. The sleeve was composed of circularly and longitudinally oriented bundles of cardiomyocytes. The peripheral end of the myocardial sleeve was irregular. The longest myocardial sleeves were found in the superior veins and were longitudinally oriented. At the PV-atrial junction, the circular bundles were not often circumferential. PV myocardial architecture confirmed the possibility of initiating AF. This fact is important for therapeutic radiofrequency ablation and explains why PV disconnection is essential.

Atrial Fibrillation↗

Rapid detection of aneuploidy in Musa using flow cytometry.

We report a procedure for the rapid and convenient detection of aneuploidy in triploid Musa using DNA flow cytometry. From a population of plants derived from gamma-irradiated shoot tips, plants were selected based on aberrant morphology and their chromosome numbers were counted. Aneuploids plants with chromosome numbers 2n=31 or 32 were found as well as the expected triploid plants (2n=3x=33). At the same time, the nuclear DNA content of all plants was measured using flow cytometry. The flow cytometric assay involved the use of nuclei isolated from chicken red blood cells (CRBC), which served as an internal reference standard. The relative DNA content of individual plants was expressed as a ratio of DNA content of CRBC and Musa (DNA index). In order to estimate the chromosome number using flow cytometry, the relative DNA content of plants with unknown ploidy was expressed as a percentage of the DNA content of triploid plants. The classification based on flow cytometry fully agreed with the results obtained by chromosome counting. The results indicated that flow cytometry is a convenient and rapid method for the detection of aneuploidy in Musa.

Aneuploidy↗

Different aminoglycoside-resistant phenotypes in a rabbit Staphylococcus aureus endocarditis infection model.

The impact of different types of enzymatic resistance on the in vivo antibacterial activity of aminoglycosides (amikacin, gentamicin, and netilmicin) was studied in the rabbit endocarditis model with four strains of Staphylococcus aureus. Animals were treated in a manner simulating the administration of a single daily human dose. Amikacin had no effect on the three kanamycin-resistant strains despite apparent susceptibility in the disk diffusion test. Gentamicin appears to be the preferable aminoglycoside for treatment of staphylococcal infections.

Aminoglycosides↗

Influence of occupational exposure to latex on the prevalence of sensitization and allergy to latex in a Swiss hospital.

BACKGROUND: Replacement of powdered latex gloves has been recommended in order to prevent the development of latex allergy in health care workers. The conclusion that occupational exposure to latex gloves represents a risk factor for latex allergy is mainly based on studies without exposure controls. Atopy is also thought to be a risk factor for the development of latex allergy. OBJECTIVE: To determine the prevalence of atopy, sensitization to latex, and symptoms following latex exposure in professionally exposed and nonexposed hospital personnel by means of a cross-sectional study. METHODS: Six hundred randomly sampled individuals working in medicine and surgery departments and in surgery theaters and 300 sex- and age-matched individuals classified as administrative personnel were selected from the employee data base of the Geneva University Hospital. A questionnaire about exposure to latex and symptoms following this exposure was sent to all individuals. Skin prick test reactions and serum IgE to latex as well as standard environmental allergens were determined in both groups. RESULTS: Respiratory and skin (local) symptoms but not objective tests of latex sensitization (positive skin prick test and specific IgE to latex) were significantly associated with occupational exposure to latex (p < 0.001). Only among atopics subjects was 15 years or more of occupational exposure associated with a significantly higher prevalence of local symptoms than among those who were exposed from 1 to 9 years (odds ratio: 3.2; 95% confidence interval: 1.6-6.5). Atopy was significantly associated with sensitization to latex (odds ratio: 10.3; 95% confidence interval: 4.0-26.6) but not with local symptoms. Tests of latex sensitization were both frequently positive, less frequently negative, resulting in low kappa values. CONCLUSION: These results support the current preventive health care recommendation to replace powdered latex gloves. In atopics, increasing years of occupational exposure increase the risk of developing latex allergy. In contrast to questionnaires about local symptoms, skin prick tests and specific serum IgE to latex are of limited value in epidemiologic studies of latex allergy.

Adult↗

Fungal contamination of food in hematology units.

The prevalence of thermotolerant fungi on non-heat-sterilizable food was determined. Aspergillus spp. were noted in 100% of pepper and regular tea samples, 12 to 66% of fruits, 27% of herbal teas, and 20% of freeze-dried soup samples. All soft cheese samples were contaminated by Geotrichum and yeast (Candida norvegensis) but Candida albicans was never identified.

Aspergillus↗

[Papillary fibroelastoma. Report of 3 cases].

Papillary fibroelastoma is a rare, benign, primary cardiac tumour. The authors report three cases presenting with transient or full cerebrovascular accidents. The tumours were diagnosed during investigation by echocardiography, especially transoesophageal echocardiography. In view of the severity of symptoms and the high risk of recurrence, the patients were rapidly referred for surgery. In two cases, the tumour was located on the aortic valve at several sites. In one case, the tumour was single and implanted on the mitral valve. Surgery was successful with the pathology reports confirming complete ablation. The patients have not had any recurrence to date. The multiple nature of these tumours raises the questions of local spread, secondary degeneration of valvular nodes? The problem of possible recurrences is discussed.

Adult↗

Ethanol-induced urticaria: elevated tryptase levels after double-blind, placebo-controlled challenge.

We present a 48-year-old patient who complained for 1 year about urticarial reactions which appeared always when he ingested alcoholic beverages. Skin prick tests with ethanol were negative but positive with 10% acetic acid in the patient. Normal controls tested negative with acetic acid. Skin prick tests to common immediate-type allergens were negative. The patient underwent a double-blind, placebo-controlled challenge test. A few minutes after challenge with ethanol but not with placebo, the patient developed erythema and wheals on the chest and the upper arms. The tryptase serum level rose from undetectable (0.1 U/ml) before challenge to 3.8 U/ml after skin lesions had appeared. This case demonstrates that increased tryptase serum levels can help in the diagnosis of ethanol-induced urticaria.

Alcoholic Beverages↗

Usefulness of longitudinal evaluation of Cyfra 21-1 variations in advanced lung cancer monitoring.

To investigate the usefulness of Cyfra 21-1 as an indicator of therapy effectiveness and prognosis in advanced primary lung cancer, sixty-three patients were selected on the basis of a high Cyfra 21-1 serum level (> 3.3 ng/ml) at the time of diagnosis. Serial assays of Cyfra 21-1 were performed during the first three courses of chemotherapy among 63 patients. The serial-values were analysed according to response to treatment and overall survival. After three courses of chemotherapy, a 70% reduction under the initial marker's value or a return to normal was observed for 36 patients. Twenty-two (61%) of these patients presented an objective response to therapy, making Cyfra 21-1 a moderate indicator in terms of positive predictive value (PPV). However, a significant decrease of Cyfra 21-1 was observed in 88% (sensitivity) of the 25 objective responders. Cyfra 21-1 changes after one course of chemotherapy (61 patients) were not sufficient to predict the future response after three courses (sensitivity 52%, specificity 56%, PPV 45%). Among 30 clinical or radiological relapses, a 10% increase or a return upper reference limit in Cyfra 21-1 level was observed in 18 cases (sensitivity 60%, specificity 100%, PPV 100%). Survival data were available for 61 patients. No significant statistical difference (P > 0.05) was found between survival curves depending on a significant decrease of Cyfra 21-1 after the first course of chemotherapy. We can conclude that the only interest of serial Cyfra 21-1 assays may be the detection of relapse, where one observes a significant decrease of the marker correlated with an objective response to first treatment.

Adult↗

Pulmonary function tests and high resolution computed tomography of the lungs in patients with rheumatoid arthritis.

OBJECTIVE: To compare the results of pulmonary function tests (PFTs) and high resolution computed tomography (HRCT) of the lungs in rheumatoid arthritis (RA) patients. METHODS: Sixty eight patients (54 women, 14 men) fulfilling the revised criteria for RA were consecutively included in a transversal prospective study. Their mean age was 58.8 years (range: 35-82) and the mean duration of the disease was 12 years (range: 5-16). Rheumatoid factor was positive in 52 patients (76.5%). Fifty two patients (76.5%) were lifelong non-smokers. Detailed medical and drug histories were obtained. PFTs comprised spirometry and gas transfer measurements. Results for PFTs were expressed as percentage of predicted values for each individual adjusted for age, sex, and height. HRCT was undertaken with a Siemens Somatom Plus. RESULTS: A significant decrease of FEV1/ FVC, FEF25%, FEF50%, FEF75%, FEF25-75%, and TLCO was observed (p < 0.05) and 13.2% of the patients had a small airways involvement defined by a decrease of FEF25-75% below 1.64 SD. The most frequent HRCT findings were: bronchiectasis (30.5%), pulmonary nodules (28%), and air trapping (25%). The patients with small airways involvement had a high frequency of recurrent bronchitis (75% v 34%, p = 0.05) and bronchiectasis (71% v 23%, p = 0.019). The patients with bronchiectasis were characterised by low values of FEV1, FVC, FEF25-75%, and TLCO (p < 0.01), a high prevalence of small airways involvement (29% v 5%, p = 0.019), and a low prevalence of HLA DQA1 *0501 allele (14% v 33%, p < 0.05). CONCLUSION: This study suggests a significant association between small airways involvement on PFTs and bronchiectasis on HRCT in unselected RA patients.

Adult↗

Pneumocystis carinii pneumonia in rheumatoid arthritis patients treated with methotrexate. A report of two cases.

Use of methotrexate to treat rheumatoid arthritis is associated with pulmonary adverse effects in 3% to 5% of cases. In addition to immunoallergic lung disease, bronchitis and pneumonia due to pyogenic organisms, opportunistic lower respiratory tract infections have been reported, including, to our knowledge, 18 cases of Pneumocystis carinii pneumonia. We report two new cases of P. carinii pneumonia in methotrexate-treated rheumatoid arthritis patients. One case occurred in a 62-year-old woman with a nine-year history of seropositive rheumatoid arthritis treated for the last seven months with methotrexate, 15 mg per week, and prednisone, 10 mg/d. The other patient was a 58-year-old woman who had been diagnosed with rheumatoid arthritis 18 months earlier and had been receiving 15 mg per week of methotrexate for eight months in combination with 12.5 mg of prednisone per day. Both patients had negative tests for the human immunodeficiency virus. Symptoms consisted of fever, cough and dyspnea, with interstitial infiltrates on chest films, hypoxia, and lymphopenia (700 and 600/mm3, respectively). The diagnosis was confirmed by bronchoalveolar lavage. Both patients recovered under treatment with trimethoprim-sulfamethoxazole. An analysis of the 20 cases of P. carinii pneumonia reported to date in methotrexate-treated rheumatoid arthritis patients demonstrated a number of characteristics: the rheumatoid arthritis was of recent onset in some cases (a few months in one patient); lymphopenia was present in two thirds of cases; one-third of patients were not receiving corticosteroid therapy; the dosage and duration of methotrexate therapy varied widely, from 5 to 30 mg per week and two to 48 months; and four patients died.

Anti-Infective Agents↗

Prevalence and symptoms at onset of bipolar illness among adolescent inpatients.

The records of 236 adolescents (116 males and 120 females) admitted to an inpatient psychiatric unit over an eight-year period were retrospectively reviewed to determine the characteristics of patients with a discharge diagnosis of bipolar disorder. Forty-two patients had a diagnosis of an affective disorder, including 18 patients (nine males and nine females) with bipolar disorder. Mean age at onset of illness for patients with bipolar disorder was 15.7 years, and their onset of illness was likely to have been associated with psychotic symptoms. On admission, they were more likely to show symptoms of mania than of depression.

Adolescent↗

Family therapy and some personality disorders in adolescence.

To prevent an endless debate between those supporting an intrinsic deficit versus an environmental deficit, the adolescent's problem has been seen here as both an individual problem and the metaphorical expression of a family problem. The intricacy of this two-faceted problem appears vividly with borderline and immature adolescents. Both the adolescent and family have, among other problems, difficulty separating. The approach described here focuses on that particular aspect; each therapeutic step is geared toward the adolescent's separation-individuation. Concerning the course of therapy, restructuring is perceived as the first therapeutic step and a prerequisite to work on such issues as delineating personal and family problems and improving communications. The approach is not, though, a panacea for the treatment of all personality disorders in adolescence and should not preempt the use of other approaches. As reported by Esman (1989) in regard to borderline adolescents, there is enough variation in the syndrome to allow the use of a variety of treatment approaches. Involving the family may not be feasible, and the adolescent sometimes must be removed from a detrimental family situation. The family of the immature or borderline adolescent is often seen as untreatable but what the therapist wants to accomplish and is ready to share often paves the way to effective intervention (Offer and Vanderstoep, 1974). The therapist must be ready to struggle with the family and with himself. The therapist has to be courageous, patient, and optimistic. The intervention is usually done on a middle-term basis with encouragement to the family to consult again if needed. The approach may thus appear obsolete at a time of a "quick-fix" culture. Family therapy can be a powerful tool with very disturbed, personality-disordered adolescents. The family approach must be flexible and based on a psychodynamic understanding of the problems. As so many of these cases fail to respond to the usual treatment and make therapists and institutions feel powerless, looking at the intervention from another angle can be refreshing. The experience can be rewarding for the adolescent, as she is becoming emancipated from the family, and for the parents, who facilitate the process. Working with these families is difficult but can also be rewarding for the clinician. Hours spent with them gives access to the subjective experiential reality that makes the substance of behavior and may allow the exploration of shadowy areas of the human condition. Family therapy becomes, then, a journey full of pain, uncertainties, and wonder for both the family and the clinician.

Acting Out↗

[Pericardium and heart transplantation].

The authors emphasise the role of the pericardium in the post-operative complications of cardiac transplantation: its role is as important as it is underestimated in its frequency, severity and the pathogenic discussions that it induces. This study, based on a retrospective analysis of 191 anatomo-clinical cases (156 autopsies and 35 retransplantations) of patients undergoing cardiac transplantation before the 1/03/1993 including macroscopic and histopathologic analysis of the pericardial lesions, histochemical analysis of the lymphocytic populations, and analysis of associated coronary and myocardial lesions. The results were classified as early or late (after the 75th postoperative day) complications. Early complications included 27 suppurating mediastino-pericarditis (13 aspergillosis and 14 bacterial), 16 autonomous non-infective pericardial complications (6 haemopericardiums, 6 organised compressive haematomas, 4 early constrictive pericarditis) and 9 lymphocytic epicarditis associated with acute myocardial rejection. Late complications included one common constrictive symphysis and 14 reactivated epicarditis associated with transplantation coronary disease (chronic rejection) with associated lymphoplasmocytic nodules and a myocardial vasculitis. These observations suggest two important conclusions: 1) the need for active diagnostic measures to detect pericardial complications in cases of cardiac transplant dysfunction in the early postoperative period with no signs of acute rejection on myocardial biopsy: the presence of epicardial lesions on biopsy should be taken into account and not just assumed to be a postoperative epiphenomenon; 2) the presence of epicarditis due to reactivated epicarditis may cause inextensible hardening of the epicardium which adds to the effects of restrictive cardiomyopathy of chronic rejection.

Adult↗

Phase I pharmacokinetics study of high-dose fotemustine and its metabolite 2-chloroethanol in patients with high-grade gliomas.

The pharmacokinetics of high-dose fotemustine followed by autologous bone-marrow transplantation during a phase I-II clinical trial in 24 patients with glioblastoma or astrocytoma (grade III-IV) was investigated. Plasma levels of fotemustine were determined by high-performance liquid chromatography (HPLC) and UV detection. The metabolite, 2-chloroethanol, was simultaneously followed in six patients by gag liquid chromatography and electron capture detection (GLC-ECD) assay. The drug was given as a 1-h infusion on 2 consecutive days. In all, 40 pharmacokinetic determinations of fotemustine were made at dose levels ranging from 2 x 300 to 2 x 500 mg/m2. Plasma drug elimination was best described by a bi-exponential model, with short distribution and elimination half-lives of 4.15 +/- 2.57 and 28.8 +/- 12.1 min being observed, respectively. No significant difference in half-lives or clearance was seen between the first and the second administration. During dose escalation, the mean area under the concentrationtime curve (AUC) increased from 5.96 +/- 2.89 to 12.22 +/- 3.95 mg l-1 h. Drug clearance was independent of the dose given and equal to 109 +/- 65 l/h, indicating no possible saturation of metabolism and elimination mechanisms at these high-dose levels. The metabolite 2-chloroethanol appeared very early in plasma samples. Its elimination was rapid and rate-limited by the kinetics of the parent compound, giving the same apparent terminal half-life. A close relationship between AUC and C45 values was evidenced (r = 0.890). Associated with the stability of fotemustine kinetic parameters, this could be used in future studies for individual dose adjustment, particularly for high-dose fractionated regimens.

Adult↗

[Late anatomical lesions after cardiac transplantation. Study of 44 autopsies beyond 6-months survival].

The aim of this study was to attempt to determine which anatomical lesions were found late after cardiac transplant and could be fatal. A series of 44 autopsies, beyond a 6 month survival time, revealed the types of cardiac and extra-cardiac lesions encountered. They were viewed in the context of clinical findings. Three lesion patterns accounted for more than 9 cases out of 10: coronary disease affecting the transplant (accelerated atherosclerosis or chronic cardiac rejection: 48% of cases), infectious lesions (29%), more than half of which were due to aspergillosis, and neoplasia (14%), favourised by immune-depression. Three results show that graft coronary disease is currently the essential long term problem in the many patients who survive the early postoperative period of cardiac transplant.

Adult↗

[Anatomoclinical diversity of bronchiolitis obliterans after lung transplantation. Anatomical study of 16 cases among 64 transplantations].

The aim of this study was to define the presence, histological types and extent of bronchiolitis obliterans (BO) after lung transplantation and to discuss the place of bronchiolitis obliterans in the progressive obstructive ventilatory disorder observed in some patients and considered to correspond to "chronic lung rejection". The histological lesions were studied in 16 subjects surviving for more than one month after lung transplantation or heart-lung transplantation: 12 autopsies, 3 surgical biopsies and one lung explanted for retransplantation. Thirteen subjects presented lesions of bronchiolitis obliterans: 5 cases of granulomatous BO, 6 cases of proliferative BO, one acute necrotising BO and one tuberculous granulomatous BO. Three of these patients presented an obstructive ventilatory disorder: one death on the 213rd day (acute necrotising BO), one retransplantation on the 672nd day (granulomatous BO), one death 53 days after surgical biopsy on the 247th day (proliferative BO). Two patients undergoing surgical biopsies with lesions of proliferative BO are still alive (cases 15 and 16) and do not present any signs of obstructive ventilatory disorder. This study suggests the existence of various histological types of BO in transplanted lungs, which is not exclusively of immunopathological origin, that infections and various inhalations also play a role and that alterations of pulmonary structures other than bronchioles are also involved in the pathogenesis of the obstructive ventilatory disorder (functional destruction of the transplant), corresponding to "chronic lung rejection".

Adolescent↗