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Biomedical subjects

M Durand

Publications and source records attributed to M Durand.

At least 91 records · Page 5Linked to original sources

Administration of transgalacto-oligosaccharides increases fecal bifidobacteria and modifies colonic fermentation metabolism in healthy humans.

Transgalacto-oligosaccharides are a mixture of oligosaccharides consisting of glucose and galactose; they are not digested in the human small intestine. In vitro, they specifically stimulate the growth of bifidobacteria. The aim of the present work was to assess tolerance of transgalacto-oligosaccharides and the effects of their prolonged administration on bifidobacteria and fermentative activity of colonic flora. Eight healthy subjects were given 10 g of transgalacto-oligosaccharides per day for 21 d in two daily doses. A breath test and stool sample collection were carried out on d 1, 7, 14 and 21 of transgalacto-oligosaccharides ingestion. The stools of three subjects were collected and mixed before the study, and then inoculated in vitro into a fermentor to which 10 g transgalacto-oligosaccharides was added daily for 14 d. In the eight volunteers, administration of transgalacto-oligosaccharides led to a significant decrease in breath hydrogen excretion (P < 0.01) and a significant increase in fecal concentrations of bifidobacteria from (means +/- SEM) 8.6 +/- 0.6 to 9.7 +/- 0.5, 9.7 +/- 0.6 and 9.5 +/- 0.6 log colony-forming units (CFU)/g on d 1, 7, 14 and 21, respectively (P < 0.05). Fecal concentrations of enterobacteria, as well as stool weight, fecal water and pH did not change during the study. In vitro, transgalacto-oligosaccharides fermentation became more efficient and faster with time. In addition, metabolic alterations such as a rise in acetate proportion and lactate formation after 7 d of fermentation were observed, indicating the transformation of the inoculated fecal flora into an acid-resistant lactic flora. Prolonged administration of transgalacto-oligosaccharides, at a dose which does not induce digestive symptoms, increases the number of bifidobacteria and alters the fermentative activity of colonic flora in humans.

Adult↗

Pulmonary effect of inhaled furosemide in ventilated infants with severe bronchopulmonary dysplasia.

BACKGROUND: When administered parenterally, furosemide, a loop diuretic, results in improved lung compliance and decreased airway resistance in infants with bronchopulmonary dysplasia (BPD). However, furosemide-induced diuresis results in hypokalemia, chloride deficiency, hypercalciuria, nephrocalcinosis, and rickets. In patients with asthma, inhaled furosemide has recently been demonstrated to inhibit the bronchoconstrictive effects of exercise, cold air hyperventilation, and antigen challenge. We hypothesized that inhaled furosemide will result in improved pulmonary mechanics in ventilated infants with BPD and will prevent the systemic complications of parenteral furosemide. OBJECTIVE: To determine the efficacy and safety of a single dose of inhaled furosemide on pulmonary mechanics in infants with severe BPD who are ventilator dependent at 21 days of age. DESIGN AND METHODS: A randomized, double-blind, crossover study was performed on 9 infants with BPD, each serving as his own control. Each patient was randomized to receive an aerosol dose of furosemide (1 mg/kg in 2 mL of saline) or placebo (2 mL of saline) on the first day of the study and the other agent the following day of the study. Pulmonary mechanics were measured before and 1 and 2 hours after the inhalation using the Pulmonary Evaluation and Diagnostics System. RESULTS: Gestational age (mean +/- SEM) was 29 +/- 1 weeks; birth weight was 1.1 +/- 0.1 kg; age at study was 47 +/- 6 days; and weight at study was 1.8 +/- 0.2 kg. There was no significant change in the pulmonary function measurements before treatment and 1 or 2 hours after treatment with either placebo or furosemide. Baseline and 2-hour values were: dynamic compliance (mL/ cm H2O per kilogram): 0.46 +/- .03 to 0.50 +/- .03 (placebo) and 0.50 +/- 0.02 to 0.51 +/- 0.02 (furosemide); dynamic resistance (cm H2O/L per second): 118 +/- 9 to 106 +/- 7 (placebo) and 111 +/- 8 to 105 +/- 7 (furosemide); and tidal volume (mL/kg): 8.6 +/- 0.5 to 8.9 +/- 0.5 (placebo) and 8.9 +/- 0.2 to 9.4 +/- 0.3 (furosemide). CONCLUSION: We conclude that, under the conditions of our study, a single dose of 1 mg/kg inhaled furosemide does not improve the pulmonary mechanics in ventilator-dependent infants with severe BPD.

Administration, Inhalation↗

[Fatal asthma. Description and study of risk factors, in the heart of an asthmatic population followed by the College of Pneumonology of the Southwest].

OBJECTIVES: To describe asthma deaths and to identify the principal short term risk factors in a population followed by twelve thoracic physicians in the South West of France between 1989 and 1995. METHODS: A multicentre clinical study in 312 pure asthmatics recruited freely and reviewed on average 37.4 months later by the same specialist. The attribution of deaths due to asthma was discussed case by case. Predicted risk factors for survival have been researched from variables on the identify card (T0) and analyses using Cox's model. RESULTS: Twenty one subjects died, 16 were due to asthma. This was an annual mortality due to asthma of 1.6%. Seven deaths occurred at home (an acute crisis was the most common) and nine in hospital (respiratory prolonged distress). The principal variables linked to poor survival were: advanced years, asthma with continuous dyspnoea, previous stay in intensive care unit, taking inhaled beta 2 mimetics continuously after inclusion, decreasing FEV1 (P < 0.001). Other variables had a weaker link: duration of asthma, exacerbation of asthma at T0 (P = 0.01), social and psychological problems (P = 0.05), severity of disease at T0 (1992 consensus) were linked to asthma mortality: 75% of the deaths concerned severe asthmatics but 25% occurred in an unforeseen fashion in moderate asthmatics. The presence of personal allergy and of rhinitis was linked to better survival independent of age and severity of asthma. CONCLUSION: This study has shown that it was possible to determine predicted risk factors for asthma deaths in the short term at the time of consultation with an asthmatic and so, to identify the most threatened subjects. The institution of assistance programs could be beneficial as a result of the knowledge of these risk factors.

Adolescent↗

[Lymphocytic alveolitis, chronic viral hepatitis C, lipoproteinosis and cryoglobulinemia in a patient].

Chronic hepatitis C virus (HCV) infection, lipoproteinosis and cryoglobulinemia may all be associated with lymphocyte alveolitis. The pathogenic mechanisms involved would suggest a compromised immune system. We report the first observation of a patient with lipoproteinosis, cryoglobulinemia and hepatitis C virus infection who developed lymphocyte alveolitis. Taken individually, each of these three disease states could explain cellular modifications observed in the lung, but their association aggravated the clinical course.

Cryoglobulinemia↗

[Adenoid cystic carcinomas of the maxillary sinus with intracranial invasion. Review of the literature, apropos of a case].

We report a case of adenocystic carcinoma (cylindroma) of the maxillary sinus with intracranial extension in a 35-year-old man with no previous clinical history. The patient underwent primary neurological and maxillofacial surgery. He then developed two successive recurrences of the tumor in the temporo-parietal area of the brain treated by surgery and radiotherapy for the first one and surgery alone for the second. The patient finally died 4 years and 2 months after the diagnosis. Adenoid cystic carcinomas are malignant epithelial neoplasms that arise mainly from salivary glands (14% of the salivary tumors), and less frequently from other structures. Their histological pattern can be either tubular, cribriform or solid, with different prognosis. They invade local areas (perineural spaces) and also metastasize to the lung, liver, bone, regional lymph nodes. Treatment mainly consists in combined surgery and radiation therapy. Chemotherapy might be also used.

Adult↗

Distamycin A complexation with a nucleic acid triple helix.

The interaction of the minor groove binding drug distamycin with the T-A-T triple helix and the A-T double helix was studied using circular dichroism spectroscopy and thermal denaturation. The triple helix was made by the oligonucleotide (dA)12-x-(dT)12-x-(dT)12, where x is a hexaethylene glycol chain bridged between the 3'-phosphate of one strand and the 5'-phosphate of the following strand. This oligonucleotide is able to fold back on itself to form a very stable triplex. Changing the conditions allows the same oligonucleotide to be in a duplex form with a dangling arm. Circular dichroism spectroscopy demonstrates that the distamycin A molecule can bind to the triple-stranded form of this oligonucleotide. Spectral analysis shows that the bound distamycin exhibits a conformation and an environment slightly different from those which are observed when the drug is bound to the corresponding double-stranded structure. Furthermore, a second type of complex which is observed in the double-strand binding (two stacked distamycins in the minor groove) is not observed with the triple-stranded host. When distamycin is added to the triplex made of unbridged chains (dA)12 + 2(dT)12, the triplex dissociates to give a double-stranded structure. Thermal denaturation experiments demonstrate that distamycin binding destabilizes the triplex whereas it stabilizes the duplex. These results are compared with those obtained by the same experimental approaches on other minor groove binding drugs.

Antiviral Agents↗

Short chain fatty acid and glucose metabolism in isolated pig colonocytes: modulation by NH4+.

Short chain fatty acids (SCFA) from bacterial origin, as well as glucose from vascular origin, are among fuel substrates available to the colonic mucosa. The present work investigated the possible modulation by another bacterial metabolite, i.e. ammonia, of the capacities of colonic epithelial cells to metabolize these substrates. Viable colonocytes were isolated from the proximal colon of 40-50 kg pigs fed a standard diet and were incubated (30 min, 37 degrees C) in the presence of a concentration range of 14C-labeled n-butyrate or acetate, or 14C-labeled glucose (5 mM), with or without NH4Cl (10 mM) addition. 14CO2 and metabolites generated were measured. Butyrate utilization resulted in a high generation of ketone bodies (acetoacetate and beta-OH-butyrate), in addition to 14CO2 production. However, the net ketone body generation was significantly decreased for butyrate concentrations higher than 10 mM. In contrast to n-butyrate, acetate when given as the sole substrate got preferentially metabolized in the oxidation pathway. Acetate metabolism was not affected by NH4Cl, thus indicating that the tricarboxylic acid cycle was unchanged. Conversely, 14CO2 and ketone body production from butyrate were decreased by 30% in the presence of NH4Cl, suggesting that butyrate activation or beta-oxidation was diminished. Glucose utilization rate was increased by 20%, due to an increased glycolytic capacity in the presence of NH4Cl. A dose-dependent stimulation of phosphofructokinase activity by NH4+ could account for this effect. It is concluded that ammonia, whose physiological concentration is high in the colonic lumen, can modulate the metabolism of two major substrates, n-butyrate and glucose, in colonic epithelial cells.

Animals↗

Conservation treatment in subareolar breast cancers.

The results of centromammary conservation in 37 patients with 20 mm-median-size breast cancer, located in the subareolar area (SAA), with an infiltration of the nipple-areolar-complex (NAC) in 12 patients and a retraction in 24, are reported. Breast conservative surgery was initially performed in 30 patients; five patients were first treated with chemotherapy; two patients received initial tamoxifen. Surgery comprised tumorectomy plus axillary dissection, with complete resection of the NAC (20 patients), or partial resection (nine patients), or without resection (eight patients). Post-operatively, all patients received 50 Gy external radiotherapy, with an additional external electron boost in 13 patients; 14 patients received adjuvant tamoxifen and two patients adjuvant chemotherapy. With a median follow-up of 49 months, one patient experienced a local failure and four a metastatic failure; 5-year overall actuarial survival and disease-free survival rates were 97%, and 75%. Cosmetic results were excellent in three patients, good in 25, and poor in seven. Breast conservation appears a satisfying treatment in small breast cancer located in SAA.

Adult↗

Variation of hormonal receptor, pS2, c-erbB-2 and GSTpi contents in breast carcinomas under tamoxifen: a study of 74 cases.

Seventy-four post menopausal patients with primary non-metastatic invasive ductal carcinomas of the breast were first treated with tamoxifen alone (30 mg p.o. daily) for 5 months. To study changes induced by tamoxifen, core biopsies before treatment and surgical specimens after hormonal therapy were assayed by immunohistochemistry for oestrogen (ER) and progesterone receptors (PR), pS2, GSTpi and c-erbB2. After tamoxifen, ER and PR significantly decreased in 60 and 44 cases respectively, whereas 11 and 19 cases showed no variation and 2 and 11 cases showed an increase (P<10(-4)). GSTpi and pS2 showed a significant increase in 43 and 41 cases, a decrease in 2 and 21 cases and no variation in 29 and 12 cases (P<10(-4) and P=0.04 respectively). c-erbB-2 showed no significant variation under tamoxifen, increased in only three cases and decreased in 13 cases. No relation was found between these variations and efficiency of hormone therapy. Our results allow a better knowledge of protein expression modifications occurring in breast cancer cells under tamoxifen therapy. They are also more consistent with clone selection rather than with phenotype modification.

Aged↗

pS2 protein: a marker improving prediction of response to neoadjuvant tamoxifen in post-menopausal breast cancer patients.

Tamoxifen as sole initial therapy is gaining importance in the management of post-menopausal breast cancer patients. Age oestrogen (ER) and progesterone (PR) receptor status are accurately considered to select patients for hormonal treatment. However, additional markers are needed. By immunohistochemistry (IHC), we studied tumour expression of ER, PR, pS2, c-erbB-2 and glutathione S-transferase pi (GST pi) on initial core biopsies of 208 post-menopausal patients with a non-metastatic invasive ductal carcinoma, treated by neoadjuvant tamoxifen therapy. A good response to tamoxifen was defined as tumoral regression > or = 50% (110 patients). Relationship between response and age, tumour size, T, N, histological grade, ER and PR contents evaluated by radioimmunoassay, ER, PR, pS2, c-erbB-2 and GST pi expression evaluated by IHC were studied. Univariate and multivariate analysis showed that tumoral regression was linked only to pS2 (P = 0.004) and ER (P = 0.018) IHC expression. According to the immunohistochemical profile, three groups could be defined: pS2- and ER-positive tumours, pS2- or ER-positive tumours and pS2- and ER-negative tumours with response rates of 60%, 45% and 8% respectively. Although prospective studies are needed to confirm these results, we conclude that pS2 and ER immunohistochemical status are useful tools for predicting tumour regression with neoadjuvant tamoxifen in post-menopausal breast carcinoma patients.

Aged↗

Primary chemotherapy in breast invasive carcinoma: predictive value of the immunohistochemical detection of hormonal receptors, p53, c-erbB-2, MiB1, pS2 and GST pi.

Primary chemotherapy in operable breast invasive carcinoma enables tumour reduction and conservative surgery. In order to search for one or more biological factors capable of predicting tumour behaviour under primary chemotherapy, and subsequent patient survival, an immunohistochemical study was performed with specific antibodies to p53, c-erbB-2 (Her-2/neu), Mib1 (antiKi-67), pS2, GST pi, oestrogen receptors (ERs) and progesterone receptors (PRs). Core biopsies, obtained before primary chemotherapy, were available from a series of 128 breast invasive carcinomas treated between January 1985 and April 1989, with a median follow-up of 93.3 months. Univariate statistical analysis showed that negative ER detection by immunohistochemistry (IHC) was highly correlated with chemosensitivity (P = 0.001). A high percentage of Mib1-positive tumour cells (> 40%), as well as initial tumour size less than 4 cm, were also correlated with tumour responsiveness to chemotherapy (P = 0.009 and P = 0.03). By multivariate analysis IHC-ER, Mib1 and initial tumour size were independent predictors, the last parameter being the most important. Concerning subsequent patient survival, c-erbB-2 overexpression, as detected by IHC, was significant with respect to overall survival (OS) (P = 0.0006), disease-free interval (DFI) (P = 0.03) and metastasis-free interval (MFI) (P = 0.008) by univariate analysis. Furthermore, c-erbB-2 was the major independent prognostic factor for OS and MFI by multivariate analysis.

Adult↗

Molecular modelling study of the netropsin complexation with a nucleic acid triple helix.

A detailed molecular mechanical study has been made on the complexes of netropsin with the double stranded oligonucleotide (dA)12.(dT)12 and with the triple helix (dA)12.(dT)12.(dT)12. The complexes were built using computer graphics and energy refined using JUMNA program. In agreement with circular dichroism experiments we have shown that 3 netropsins can bind the minor grooves of the triple helix and of the double helix. The groove geometry in the duplex and in the triplex is very similar. However a detailed analysis of the energetic terms shows, in agreement with thermal denaturation studies, that the affinity of netropsin toward the double helices is larger than towards triple helices.

DNA↗

False aneurysm of the pulmonary artery induced by a Swan-Ganz catheter: clinical presentation and radiologic management.

OBJECTIVE: This study evaluates retrospectively the clinical presentation, radiographic findings, and angiographic management of false aneurysm of the pulmonary artery resulting from Swan-Ganz catheter placement. MATERIALS AND METHODS: Over a 4-year period, seven false aneurysms of the pulmonary artery were diagnosed in five patients (four women, one man) who were 67-81 years old. All five patients underwent Swan-Ganz catheter placement to monitor cardiac surgery--coronary artery bypass grafting in four and mitral valve replacement in one. All patients were anticoagulated. For five patients, we reviewed the medical records and the results of chest radiography, digital subtraction pulmonary angiography, and pulmonary artery embolization. For two patients, we reviewed the results of CT scanning. RESULTS: Non-life-threatening hemoptysis was noted in all cases and occurred in three patients after the Swan-Ganz catheter had been removed (elapsed time of 1-19 days). Chest radiographs revealed a pulmonary infiltrate in one patient and a pulmonary mass in two patients. The results were unremarkable in the other two patients. CT depicted two false aneurysms of the pulmonary artery as round masses with eccentrically enhanced lumina circumscribed by thrombosis. Pulmonary angiography revealed a single false aneurysm in three patients and two false aneurysms in two patients. All false aneurysms were localized in segmental or subsegmental branches of the right middle pulmonary artery (n = 4) or the right lower pulmonary artery (n = 3). All patients were successfully treated with transcatheter steel-coil embolization. CONCLUSION: Even when the chest radiograph appears unremarkable, patients clinically suspected of developing a false aneurysm of the pulmonary artery after Swan-Ganz catheter placement require enhanced CT or pulmonary angiography to establish the diagnosis. False aneurysms of the pulmonary artery can be treated at the time of pulmonary angiography by steel-coil embolization.

Aged↗

Running economy, preferred step length correlated to body dimensions in elite middle distance runners.

The purpose of this research was to study the relationship between running economy, step length, and body dimensions. Elite middle distance runners were tested for one high submaximal volocity very close to usual training speeds, near the anaerobic threshold (15 km.h-1) and one low submaximal velocity very different to usual training speeds, near the speed transition between walking and running (9 km.h-1). All the subjects were selected after a maximal protocol to be homogeneous on VO2max (65.7 +/- 2.3 ml.kg-1.min-1). Then they were monitored during two submaximal tread-mill tests at 54.4 +/- 2.2% (9 km.h-1) and 78.5 +/- 3.9% VO2max (15 km.h-1). Body weight, body fat, height, sitting height, low extremity length (height - sitting height), relative low extremity length, leg length, thigh length, foot length were determined. The results indicate an effect of the running speed on the relationship between body dimensions, step length and VO2. The relation was inverse between running economy, body dimensions at 9 and 15 km.h-1 and no significant correlation was found for running economy between these two speeds. Furthermore, the mode of expressing VO2 in ml.kg-0.75.min-1 affects these relations. Thus, this result allows us to make the assumption that mechanisms of adaptation can be different according to the running speed, and the specific constraints that it represents for each subject.

Adipose Tissue↗