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Biomedical subjects

J Robert

Publications and source records attributed to J Robert.

At least 73 records · Page 4Linked to original sources
PubMed2001

Efficacies of clarithromycin regimens against Mycobacterium xenopi in mice.

Mice were infected intravenously with 3.5 x 10(7) CFU of Mycobacterium xenopi and treated with various clarithromycin-containing regimens or left untreated for 4 weeks. All nine of the clarithromycin-containing regimens reduced the CFU counts to the levels below the pretreatment values, indicating that these regimens had a bactericidal effect on M. xenopi in mice. The rifampin-isoniazid-ethambutol regimen was significantly less bactericidal than clarithromycin alone or clarithromycin-containing combined regimens.

Animals↗
PubMed2001

[Acute iron poisoning. A case report].

The ingestion of iron-containing products is a potential toxicological emergency. It is a leading cause of pediatric unintentional ingestion fatalities because some iron-containing compounds are readily available (vitamin mixtures, iron pills). Among adults, it has been described as accidental overdoses (mainly in pregnancy) and as suicidal attempts. We report a 42 years old woman, admitted due to the intentional ingestion of iron pills with suicidal purposes. A plain abdominal X ray showed at least 20 pills in the gastric fundus and antrum. She was successfully treated with intravenous desferroxamine chelation. Plain abdominal X ray examination can be very useful in the diagnosis of acute iron poisoning.

Adult↗
PubMed2000

Down-regulation of bcr-abl and bcl-x(L) expression in a leukemia cell line and its doxorubicin-resistant variant by topoisomerase II inhibitors.

K562 cells are usually resistant to apoptosis induction, probably because of the expression of bcr-abl, the hybrid gene characteristic of the Philadelphia chromosome (t 9;22). However, we have previously shown that amsacrine and, to a lesser extent, doxorubicin, could induce apoptosis in the doxorubicin-resistant variant of this cell line. In order to elucidate the role of bcr-abl in triggering apoptosis, we investigated the effect of the topoisomerase II inhibitors doxorubicin, amsacrine, and etoposide on the expression of several genes that may be related to apoptosis induction in both cell lines. This was done using a technique of reverse transcription-polymerase chain reaction coupled with HPLC of the amplified fragments to obtain semiquantitative evaluations. We showed that amsacrine, at pharmacologically relevant concentrations, was able to decrease the expression of bcr-abl down to 20% of the basal value in the doxorubicin-resistant variant only, whereas doxorubicin and etoposide were unable to do so. No effect of these drugs was seen on the expression of the normal abl gene. In addition, there was an effect of amsacrine on the expression of bcl-x(L) in the resistant cell line only, but at concentrations higher than the IC(50) of this drug. Our results emphasize the role of bcr-abl in protecting cells from apoptosis and the possible involvement of specific topoisomerase II inhibitors in overcoming resistance to apoptosis.

Amsacrine↗
PubMed2000

Microrheology of biopolymer-membrane complexes.

We create tailored microstructures, consisting of complexes of lipid membranes with self-assembled biopolymer shells, to study the fundamental properties and interactions of these basic components of living cells. We measure the mechanical response of these artificial structures at the micrometer scale, using optical tweezers and single-particle tracking. These systems exhibit rich dynamics that illustrate the viscoelastic character of the quasi-two-dimensional biopolymer network. We present a theoretical model relating the rheological properties of these membranes to the observed dynamics.

Actins↗
PubMed2000

Preclinical evaluation of the cardiotoxicity of taxane-anthracycline combinations using the model of isolated perfused rat heart.

Paclitaxel strongly potentiates the cardiotoxicity of doxorubicin in the clinical setting. In this study, we aimed (1) to determine whether this potentiation could be reproduced in an ex vivo model and, if so, (2) to select drugs and protocols that did not cause this potentiation. The effect of paclitaxel and docetaxel on the cardiotoxicity induced by doxorubicin and epirubicin was studied using the model of isolated perfused rat heart. Cardiac performances were evaluated after several combination protocols administered every 2 days over a period of 12 days, and anthracycline concentrations in the heart and liver were determined on Day 12. When administered simultaneously, paclitaxel strongly potentiated the cardiotoxicity of doxorubicin ex vivo, and this effect was not due to Cremophor EL, the solvent used in the formulation of paclitaxel. The potentiation of anthracycline cardiotoxicity could be avoided by the replacement of doxorubicin by epirubicin, and/or of paclitaxel by docetaxel. Cardiotoxic potentiation was also avoided by the introduction of a 24-h lag time between the repetitive injections of doxorubicin and docetaxel. The concentration of doxorubicin and its cardiotoxic metabolite, doxorubicinol, in the heart and liver was not significantly altered by the taxanes, but that of epirubicin was increased twofold both in the heart and the liver. These results show that the potentiation of doxorubicin-induced cardiotoxicity by paclitaxel can be reproduced with an ex vivo model, and that it is not related to an increase in tissue concentration of the drug or active metabolite. Our model, therefore, may be useful for the selection of anthracycline-containing protocols with no increased risk of cardiotoxicity for the patients.

Animals↗
PubMed2000

Clinical pharmacokinetics of the irinotecan metabolite 4-piperidinopiperidine and its possible clinical importance.

PURPOSE: To investigate the clinical relevance of 4-piperidinopiperidine (4PP) in the activity of irinotecan (CPT-11), a high-performance liquid chromatography-turboionspray-tandem mass spectrometry assay for plasma 4PP was developed. METHODS: Plasma samples were prepared for analysis following C18 solid-phase extraction. Chromatography was performed on a Waters Nova-Pak Phenyl column. Selected reaction monitoring with the mass transitions m/z 169.2 --> 84.2 and 139.2 --> 98.1 was used for the detection of 4PP and the internal standard (IS), 1-piperidineproprionitrile, respectively. RESULTS: The assay was linear from 14.8 to 591.0 nM with absolute recoveries of 4PP (59.1 nM) and IS (143.7 nM) of 85.7% (n = 10) and 86.7% (n = 10), respectively. The accuracy and imprecision of the method (total) was > or = 96.8% and < or = 8.5% over the concentration range studied, respectively. 4PP was detectable in plasma following the administration of 125, 350, 500 mg/m2 and 600 mg/m2 CPT-11 to patients, with AUC(4PP) correlated with the dose (r2 = 0.66). Plasma concentrations of 4PP declined slowly with a long terminal half-life (33.4 +/- 17.1 h). CONCLUSIONS: Overall, the concentrations of 4PP in plasma were in the sub-micromolar range (< 206.9 nM) and substantially lower than those capable of inducing apoptosis of cancer cells.

Antineoplastic Agents, Phytogenic↗
PubMed2000

Sex differences in presentation, management, and prognosis of patients with non-small cell lung carcinoma.

OBJECTIVE AND METHODS: To characterize gender differences in lung cancer, we conducted a retrospective analysis including all patients undergoing surgery for non-small cell lung carcinoma in a single institution over a 20-year period. RESULTS: Compared with men (n = 839), women (n = 198) were more likely to be asymptomatic (32% vs 20%, P =.006), nonsmokers (27% vs 2%, P <.001), or light smokers (31 pack-years vs 52 pack-years; P <.001). Squamous cell carcinoma predominated in men (65%), and adenocarcinoma predominated in women (54%). Preoperative bronchoscopy contributed more frequently to a histologic diagnosis in men (69% vs 49% in women, P <.001), and fewer pneumonectomies were performed in women (22% vs 32% in men, P =.01). After multivariate Cox regression analysis, women survived longer than men (hazard ratio, 0.72; 95% confidence interval, 0.56-0. 92; P =.009) independently of age, presence of symptoms, smoking habits, type of operation, histologic characteristics, and stage of disease. The protective effect linked to female sex was present in early-stage carcinoma (stage I and II) and absent in more advanced-stage carcinoma (stage III and IV). CONCLUSIONS: This study emphasizes strong sex differences in presentation, management, and prognosis of patients with non-small cell lung cancer.

Adult↗
PubMed2000

Spontaneous hemopneumothorax--results of conservative treatment.

Spontaneous hemopneumothorax is a serious condition complicating spontaneous pneumothorax. Early stage thoracotomy has been advocated to stop the bleeding and evacuate the coagulated blood from the pleural cavity. The present review was undertaken to emphasize the potential life-threatening condition of spontaneous hemopneumothorax and reassess the benefit of conservative treatment with chest tube drainage. Out of six patients, five patients were treated conservatively and one required an emergency thoracotomy because of cardiovascular collapse. Although three patients still had minimal residual hemopneumothorax on discharge, none of them developed empyema or trapped lung. In conclusion, conservative treatment is efficient and should be performed if bleeding persists for less than 24 hours after chest tube placement.

Adult↗
PubMed2000

Primary malignant melanoma of the esophagus.

A case of primary malignant melanoma of the esophagus is reported, followed by a review of the literature. The clinical presentation of this uncommon tumor is similar to esophageal carcinoma and the preoperative diagnosis may be difficult. A total esophagectomy is the treatment of choice. The prognosis remains poor despite aggressive treatment.

Aged↗
PubMed2000

Thirty-year experience of surgery for breast carcinoma in men.

OBJECTIVE: To present the long-term outcome after surgery for breast carcinoma in men. DESIGN: Retrospective study. SETTING: University Hospital, Switzerland. SUBJECTS: 37 consecutive men who were operated on for breast carcinoma between 1968 and 1998. RESULTS: The mean age was 67 years (range 41-89). The delay between the first clinical presentation and operation ranged from 1 month to 3 years (median 3.5 months). Operations included modified radical mastectomy (n = 19), radical mastectomy (n = 12), simple mastectomy (n = 3), Halsted procedure (n = 1), and conservative resection (n = 1). One patient had only a biopsy and was excluded from survival analysis. There were 30 infiltrating ductal carcinomas, 4 in situ ductal carcinomas, 2 papillary carcinomas, and 1 adenoid cystic carcinoma. Most tumors (n = 25, 68%) were in the subareolar region. The overall survival at 10 years was 44%, but it was significantly influenced by the stage of disease, ranging from 57% in stage I (n = 12), to 26% in stage II (n = 15), and 0 in stage III (n = 8). CONCLUSION: Although the long term survival in stage I and II is similar in men and women, the rarity of breast carcinoma in men and its location in the subareolar region may delay diagnosis and treatment.

Adult↗
PubMed2000

The influence of the composition of the nursing staff on primary bloodstream infection rates in a surgical intensive care unit.

OBJECTIVES: To determine the risk factors for acquisition of nosocomial primary bloodstream infections (BSIs), including the effect of nursing-staff levels, in surgical intensive care unit (SICU) patients. DESIGN: A nested case-control study. SETTING: A 20-bed SICU in a 1,000-bed inner-city public hospital. PATIENTS: 28 patients with BSI (case-patients) were compared to 99 randomly selected patients (controls) hospitalized > or =3 days in the same unit. RESULTS: Case- and control-patients were similar in age, severity of illness, and type of central venous catheter (CVC) used. Case-patients were significantly more likely than controls to be hospitalized during a 5-month period that had lower regular-nurse-to-patient and higher pool-nurse-to-patient ratios than during an 8-month reference period; to be in the SICU for a longer period of time; to be mechanically ventilated longer; to receive more antimicrobials and total parenteral nutrition; to have more CVC days; or to die. Case-patients had significantly lower regular-nurse-to-patient and higher pool-nurse-to-patient ratios for the 3 days before BSI than controls. In multivariate analyses, admission during a period of higher pool-nurse-to-patient ratio (odds ratio [OR]=3.8), total parenteral nutrition (OR=1.3), and CVC days (OR=1.1) remained independent BSI risk factors. CONCLUSIONS: Our data suggest that, in addition to other factors, nurse staffing composition (ie, pool-nurse-to-patient ratio) may be related to primary BSI risk. Patterns in intensive care unit nurse staffing should be monitored to assess their impact on nosocomial infection rates. This may be particularly important in an era of cost containment and healthcare reform.

Case-Control Studies↗
PubMed2000

Low-dose ethanol consumption allows strength recovery in chronic alcoholic myopathy.

Chronic skeletal myopathy may affect one third of chronic alcohol misusers. It is generally accepted that abstinence allows partial recovery, and that continued high-dose ethanol consumption progressively deteriorates muscle function. However, the effect of low-dose ethanol consumption in alcoholic myopathy has not been studied. We studied 58 chronic alcoholic male patients with biopsy-proven chronic alcoholic myopathy over 5 years. We evaluated ethanol intake, biochemical and nutritional parameters, and assessed muscle strength. Eighteen patients who remained abstinent showed marked improvement in muscle strength. As expected, the 19 patients who persisted in high-dose ethanol consumption further diminished in their muscle strength. In the 11 patients who maintained low-dose (</=60 g ethanol/day) 'controlled' drinking, muscle strength improved (p=0.003), despite no change in nutritional and exercise status. There is a dose-dependent recovery in muscle strength according to the degree of ethanol consumption, and moderate controlled drinking of up to 60 g ethanol/day still allows improvement in muscle strength.

Adult↗