PubMed Health⌕ Search

Biomedical subjects

J Rosier

Publications and source records attributed to J Rosier.

At least 19 recordsLinked to original sources
PubMed2001

A novel bending point criterion for dissolution profile interpretation.

A novel bending point criterion was developed and compared with a number of existing criteria for the interpretation of certain dissolution profiles; these comparison criteria were the percentage dissolved at a fixed time point, the fitted Weibull parameters, and the area under the dissolution curve (AUC). The statistical bending point model was applied to dissolution curves that showed linear dissolution. The bending point model is based on a general linear model, and its confidence information is obtained using the variance-covariance matrix of the parameter estimates. Practically, three time points in the linear part and two time points on the plateau level are used for a reliable bending point estimation. A comparative study with three batches and three storage conditions of slow-release mucoadhesive buccal tablets was performed. The relative standard deviation (RSD) values of the bending point were typically between 1% and 5% which are considerably lower than the corresponding values of the other criteria (typically between 3% and 15%). The bending point criterion is considered robust and stable for the characterization of certain dissolution profiles. Moreover, the bending point has a particular physical interpretation that is helpful in the framework of the slow-release application of this buccal tablet.

Adhesives↗
PubMed1996

Protection of the spinal cord during surgery of thoraco-abdominal aortic aneurysms.

OBJECTIVE: To assess the risk of ischemic cord injury, we have retrospectively studied the 115 patients who underwent a replacement of the thoracic descending or thoraco-abdominal aorta between January 1980 and December 1994. METHODS: In 72 patients the aortic lesion was located above the diaphragm. The aortic replacement was performed with the aid of extracorporeal circulation in all but 2 patients (97.2%). Only two cases of postoperative paraplegia were observed (2.7%). In 43 patients (10 females and 33 males aged from 26 to 69 years), the occurrence of postoperative paraplegia was considered as a major risk, because of the extension of the aortic lesions (Crawford types I, II and III). Twenty-six patients (60.4%) suffered from chronic dissection and 17 patients had atheromatous aneurysms. Sixteen patients (37.2%) had Marfan syndrome. Twelve patients (27.9%) had already undergone aortic replacement. A preoperative study of the spinal cord vascularization was carried out in 36 patients (83.6%) and the Adamkiewicz artery was visualized in 28 patients (77.8%). In 17 patients (39.5%, group I), the surgical procedure was performed without the aid of extracorporeal circulation. In the remaining 26 patients (60.5%, group II), the surgical procedure was carried out with the aid of cardiopulmonary bypass and profound hypothermic circulatory arrest. Sequential unclamping of the aorta was used in all patients. The cord vascularization was surgically restored in 32 patients (74.4%). When the Adamkiewicz artery was identified, the critical intercostal artery was reimplanted together with the two pairs of adjacent intercostal arteries (25 patients). When the origin of the Adamkiewicz artery remained unknown, the two or three most important patent pairs of intercostal arteries were reimplanted (7 patients). In 8 patients (18.6%) there were no patent intercostal arteries. RESULTS: Hospital mortality accounted for 37.2% (16 patients, including 5 patients with paraplegia). On univariate analysis, extension of the aortic lesions, emergency and redo surgery were the only significant risk factors of mortality (P = 0.05). Cord ischemia was observed in 9 patients (21%): permanent paraplegia in 7 patients (16.2%) and transient medullar disturbance in 2 patients (4.6%). The occurrence of paraplegia was reduced, though not significantly, in group II (16%) vs group I (29%) and in patients with preoperative assessment of the cord vascularization (18% vs 38%). CONCLUSIONS: In our experience: 1) The risk of paraplegia is related to the extension and the type of the aortic lesions. 2) The preoperative study of the medullar vascularization and the use of extracorporeal circulation with deep hypothermia and sequential aortic unclamping, reduce the risk of severe cord ischemia, and 3) Occurrence of postoperative paraplegia depends on several factors and cannot be totally prevented by the surgical technique.

Adult↗
PubMed1988

A screening method for the simultaneous determination of putrescine, cadaverine, histamine, spermidine and spermine in fish by means of high pressure liquid chromatography of their 5-dimethylaminonaphthalene-1-sulphonyl derivatives.

A simple and rapid method is described for the extraction, derivatization and subsequent determination by means of high pressure liquid chromatography of putrescine, cadaverine, histamine, spermidine and spermine as their 5-dimethylaminonaphthalene-1-sulphonyl derivatives. The amines are extracted from the fish material by an aqueous trichloroacetic acid solution and derivatized by means of 5-dimethylaminonaphthalene-1-sulphonylchloride (dansyl chloride). The reaction mixture is then injected on a RP-8 column using gradient elution to separate the amine derivatives. Use of the method results in a considerable saving with respect to both time and costs.

Animals↗
PubMed1987

Experimental human exposure to carbon disulfide. I. Respiratory uptake and elimination of carbon disulfide under rest and physical exercise.

Six human volunteers were exposed to 10 and 20 ppm carbon disulfide at rest and to 3 and 10 ppm carbon disulfide under a 50 W level of physical exercise during four consecutive periods of 50 min. Every 5 min a sample was taken from the mixed exhaled air in which the concentration of carbon disulfide was determined. It was established that only an apparent steady state was reached during this exposure period. The retention values were established as 0.374 (SD = 0.106; n = 239) for exposure to 10 ppm carbon disulfide at rest and as 0.410 (SD = 0.103; n = 239) for exposure to 20 ppm carbon disulfide at rest. During exposure to 10 ppm and 3 ppm carbon disulfide, combined with a 50 W level of physical exercise, the retention values decreased to 0.286 (SD = 0.083; n = 239) and 0.277 (SD = 0.049; n = 239) respectively. Thereby, the measured individual retention values of carbon disulfide show considerable interindividual differences. The respiratory uptake of carbon disulfide (mg CS2) proved significantly influenced by the amount of body fat estimated from skinfold thickness measurements. The respiratory elimination of carbon disulfide in the exhaled air can be described by means of a two-exponential decay.

Adult↗
PubMed1987

Experimental human exposure to carbon disulfide. II. Urinary excretion of 2-thiothiazolidine-4-carboxylic acid (TTCA) during and after exposure.

Six human volunteers were exposed to 10 and 20 ppm carbon disulfide at rest and to 3 and 10 ppm carbon disulfide under a 50 W level of physical exercise during four consecutive periods of 50 min. At the start of the experiments, at the end of the exposure periods and during the post-exposure period, urine was sampled and the concentration of 2-thiothiazolidine-4-carboxylic acid (TTCA) was determined. It was established that only a small percentage, ranging from 0.7 to 2.2% of the absorbed carbon sulfide was transformed into TTCA. The excretion rate of TTCA (mumol TTCA h-1) was found to be the best parameter in evaluating the respiratory uptake of carbon disulfide over a range of 37.9 to 163.3 mg CS2 compared to the urinary concentration of TTCA (mole TTCA ml-1) or the creatinine corrected concentration of TTCA (mmol TTCA mol-1 creatinine). The total amount of TTCA (mumol TTCA) excreted proved to be independent of the urinary flow (ml h-1), the estimates of the individual fatty tissue content and the urinary pH. No correlation was found between the respiratory uptake of carbon disulfide (mg CS2) and the excretion rate of TTCA within each exposure condition of 3, 10 or 20 ppm carbon disulfide, respectively.

Adult↗
PubMed1984

Relation between the iodine azide test and the TTCA test for exposure to carbon disulphide.

Exposure to carbon disulphide (CS2) in a viscose plant was measured by personal monitoring and by application of the iodine azide test and quantification of 2-thio-thiazolidine-4-carboxylic-acid (TTCA) in urine samples. A relation was found between the rise in urinary TTCA concentration during the workshift and the exposure index E1. The correlation (r) between the exposure index and the atmospheric concentrations of CS2 in workroom air below 100 mg CS2/m3 was 0.59 (n = 9). The correlation between the increase in TTCA concentrations during the workshift and the atmospheric CS2 concentrations was found to be higher when urine samples at the end of the workshift with creatinine concentrations below 1 mg/ml and above 3 mg/ml were disregarded (from r = 0.61; n = 20 to r = 0.84; n = 14). A high correlation was found (r = 0.86; n = 13) when the end of workshift urine samples were analysed, provided that their creatinine concentrations are not beyond the limits given above.

Azides↗
PubMed1982

Preliminary evaluation of urinary 2-thio-thiazolidine-4-carboxylic-acid (TTCA) levels as a test for exposure to carbon disulfide.

The exposure to carbon disulfide of workers in charge of different jobs in a Belgian viscose plant was measured by means of personal monitoring of the inhaled air and by quantitative assay of 2-thio-thiazolidine-4-carboxylic acid (TTCA) in urine. It was found that the atmospheric carbon disulfide concentration varied considerably among different jobs, among different individuals doing the same jobs and for the same individuals in the course of the working period. The 2-thio-thiazolidine-4-carboxylic-acid levels increased markedly during the exposure. The correlation between individual personal monitoring results and the increase TTCA levels was found to be statistically significant.

Adult↗
PubMed1981

[Surgical treatment of thoracic and thoraco-abdominal aneurysms involving the Adamkiewicz's artery. Usefulness of deep hypothermia (author's transl)].

The authors present a new surgical technique for the treatment of thoracic and thoraco-abdominal aneurysms involving the artery of the lumbar enlargement (Adamkiewicz's artery) at its point of origin. In two patients the aortic segment giving birth to the artery was accurately located by angiography and re-impaired under deep hypothermia and extracorporeal circulation.

Adult↗