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Biomedical subjects

P Joubert

Publications and source records attributed to P Joubert.

At least 19 recordsLinked to original sources
PubMed2000

Evaluation of incidence, clinical significance, and prognostic value of circulating cardiac troponin I and T elevation in hemodynamically stable patients with suspected myocardial contusion after blunt chest trauma.

BACKGROUND: The frequency and prognostic influence of myocardial injury in patients with blunt chest trauma is controversial. We investigated the value of cardiac troponin I (cTn-I) and cardiac troponin T (cTn-T), highly specific markers of myocardial injury, to determine whether their measurement would improve the ability to detect myocardial contusion in stable patients with blunt chest trauma in comparison with conventional markers and whether they were associated with significantly worse late clinical outcome. METHODS AND RESULTS: Over an 18-month period, myocardial contusion was diagnosed in 26 of 94 patients (27.6%) with acute blunt chest trauma (motor vehicle crash; 81%), because of echocardiographic abnormalities (n = 12), electrocardiographic abnormalities (n = 29), or both. Patients with myocardial contusion had a significantly higher Injury Severity Score at the time of admission (p = 0.001) and a significantly longer hospital stay (p = 0.0008). All patients survived admission to hospital and were hemodynamically stable. None of the patients died or had severe in-hospital cardiac complications. The percentage of patients with elevated CK, (CK-MB/total CK) ratio, or CK-MB mass concentration was not significantly different between patients with or without myocardial contusion. However, there were significant differences between the two groups when we applied the commonly used threshold levels of CK-MB activity and myoglobin. The percentage of patients with elevated circulating cTn-I and cTn-T (> or = 0.1 microg/L) was significantly higher in patients with myocardial contusion (23% vs. 3%; p = 0.01 and 12% vs. 0%; p = 0.03, respectively). Complete changes in cTn-I and cTn-T correlated well (r = 0.91, p = 0.0001). Sensitivity, specificity, and negative and positive predictive values of cTn-I and cTn-T in predicting a myocardial contusion in blunt trauma patients were 23%, 97%, and 77%, 75%, and 12%, 100%, and 74%, 100%, respectively. Clinical follow-up was available in 83 patients (88%) (mean, 16 +/- 7.5 months). There were no deaths in either group directly attributed to cardiac complications. None of the patients had any long-term cardiac complications or myocardial failure related to blunt chest trauma. CONCLUSION: Although improved specificity of cTn-I and cTn-T compared with conventional markers, it should be emphasized that the main problem with cTn-I and cTn-T is low sensitivity as well as low predictive values in diagnosing myocardial contusion. cTn-I and cTn-T measurement is currently not an improved method in diagnosing blunt cardiac injury in hemodynamically stable patients. Moreover, there was no association of postmyocardial contusion cell injury and late outcome in these patients when cTn-I and cTn-T and other conventional markers were considered.

Abbreviated Injury Scale↗
PubMed2000

Identification of a new cleavage site of the 3C-like protease of rabbit haemorrhagic disease virus.

The calicivirus rabbit haemorrhagic disease virus (RHDV) possesses a 3C-like protease which processes the RHDV polyprotein. In order to monitor the proteolytic activity of the RHDV 3C-like protease on its putative target sequences, i.e. the 10 EG dipeptide bonds distributed along the large polyprotein, a new approach was carried out. Preliminary experiments showed that the luciferase gene when fused in-frame with a long gene yielded a fusion protein almost devoid of luciferase activity. This reporter system was used to test which EG dipeptide bonds were cleaved by the RHDV protease when the coding sequences of the dipeptides and their flanking sequences were inserted at the junction between the protease and luciferase genes. The coding sequences of the fusion proteins were cloned downstream of the T7 promoter and the proteolytic activity was evaluated by measuring the luciferase activity in both in vitro and 'in vivo' systems. The EG dipeptide bonds at positions 718-719, 1108-1109 and 1767-1768 were confirmed as cleavage sites and a new cleavage site EG (143-144) was identified.

Amino Acid Sequence↗
PubMed1998

Temperature-Dependent Line Shift and Broadening of CO Infrared Transitions.

The temperature dependence of lineshift and broadening of the rovibrational transitions R(18) and R(20) of the CO fundamental band, perturbed by Ar, N2, O2, and H2, have been measured with high frequency accuracy and at temperatures between 160 and 270 K in steps of 20 K. A wavelength stabilized tunable diode laser spectrometer has been combined with a low temperature long path cell of 134 m absorption length and 1 m basis length. For all measurements the CO pressure was below 0.1 mbar to avoid self-shift and self-broadening. In case of line broadening the temperature dependence is quite well reproduced by an exponential relation, b(T) = b(T0)(T/T0)-n. For all foreign gases, the exponent n has been obtained (0.53 </= n </= 0.71) and a value for air has been calculated from the weighted mean values of N2 and O2. Within the error limits the magnitudes of all shifts decrease with increasing temperatures, but there is no exponential behavior of the shift versus temperature. The line broadening and shift for CO with Ar and the broadening of CO by N2 and O2 have been compared to calculations from the semi-classical theory of Robert and Bonamy. Sufficient agreement has been achieved for the line broadening, while the calculated shifts are for all temperatures larger than the measured values. Copyright 1998 Academic Press.

Journal Article↗
PubMed1996

Population pharmacokinetics of amikacin in critically ill patients.

The pharmacokinetic parameters of amikacin were determined in a population of 20 adults and 36 pediatric patients admitted into an intensive care unit. Amikacin was administered by repeated intravenous infusion over 0.5 h (600 to 1,350 mg for adults; 70 to 1,500 mg for children). The number of administrations ranged from 2 to 17, and the number of samples collected from each patient ranged from 2 to 70. The population enrolled in the study had large variabilities in age (0.5 to 85 years), weight (6 to 95 kg), height (72 to 187 cm), creatinine clearance rate (18 to 110 ml/min), blood urea nitrogen concentration (1.5 to 15 mmol/liter), and total protein concentration (30 to 91 g/liter). The mean population parameters and their interindividual variabilities were obtained for an initial group of 44 patients (16 adults and 28 children). A two-compartment model was fitted to the population data by using the computer program P-PHARM. Model selection was guided by evaluation of the minimum objective function and the weighted residuals. The population analysis has been performed with the complete set of the collected data, including the individual serum amikacin concentration together with the individual estimate of the creatinine clearance values. The potential sources of variability in the population parameters were investigated by using patients' age, height, weight, creatinine clearance, blood urea nitrogen concentration, and total protein concentration as covariables. A test group of 12 additional patients (4 adults and 8 children) was used to evaluate the predictive performances of the population parameters. The individual pharmacokinetic parameters were computed by a Bayesian fitting procedure. From the resulting individualized values of the parameters, the concentrations of amikacin in the serum of the patients were calculated. To evaluate the performance of the Bayesian estimation, the experimental concentrations were compared with the predicted ones. The Bayesian approached developed in the study accurately predicts amikacin concentrations in serum and allows for the estimation of amikacin pharmacokinetics parameters, minimizing the risk of bias in the prediction. This was demonstrated in patients with both stable and unstable renal functions.

Adolescent↗
PubMed1995

Comparative pharmacodynamics of Ro 41-3696, a new hypnotic, and zolpidem after night-time administration to healthy subjects.

In a double-blind, six-way crossover study the effects on psychomotor performance and memory of single doses of Ro 41-3696 (1, 3, 5 and 10 mg), a novel non-benzodiazepine partial agonist at the benzodiazepine receptor, zolpidem (10 mg) and placebo were compared after night-time administration to 12 healthy young male subjects. Psychomotor performance tests (tracking and attention as part of a standardized task battery) were conducted just before and at 1.5 and 8 h after drug intake. The memory test consisted of the recall of a list of 15 words at 8 h after drug intake which had been learned at 1.5 h after intake. At 1.5 h after drug intake 10 mg zolpidem induced markedly larger psychomotor effects than any dose of Ro 41-3696. The effects of 5 and 10 mg Ro 41-3696 and zolpidem were significantly greater than those of placebo (P < 0.05). The following morning, 8 h after drug intake, the slight residual effects of 5 and 10 mg Ro 41-3696 were statistically significantly greater than placebo, whereas zolpidem effects did not differ from placebo. The results of the memory test showed that learning as well as recall were most clearly impaired by zolpidem. An influence of Ro 41-3696 on these variables was not observed for doses up to 5 mg. In conclusion, Ro 41-3696 at all doses tested induced less effects on psychomotor performance and memory than 10 mg zolpidem at 1.5 h after intake. However, the effects of Ro 41-3696 appeared to be of longer duration.

Adult↗
PubMed1995

[Traumatic tricuspid insufficiency. Apropos of 2 cases].

The authors report two cases of tricuspid regurgitation by a ruptured anterior papillary muscle secondary to non-penetrating thoracic trauma. In the presence of suggestive clinical and electrocardiographic abnormalities (systolic murmur, right heart failure, right bundle branch block), echocardiography confirmed the tricuspid regurgitation, showed its mechanism and excluded any other intracardiac lesions. Tricuspid annuloplasty was performed in both cases because of the persistence of failure or degradation of the patient's clinical condition. Peroperative echocardiography was used to judge the quality of the surgical repair in both cases. Traumatic tricuspid regurgitation is a rare condition and the diagnosis is often delayed. Echocardiography is the investigation of choice and guides treatment which is essentially valvular repair in symptomatic patients.

Adult↗
PubMed1994

[Diagnosis and evaluation of spread of prostate cancer].

In more than 50% of the cases, the diagnosis of prostate cancer is made at the time of extra-prostatic or distant disease involving poor prognosis for cure. Small tumours for which curative treatment is possible are asymptomatic. Thus, useful early diagnosis of prostatic cancer is based on digital rectal examination and PSA concentration. PSA levels are also indicative of tumour volume. Thus, determining dissemination becomes significant only in the case of elevated PSA, indicating a large tumour.

Biopsy, Needle↗
PubMed1993

Thermoregulation during transurethral microwave thermotherapy: experimental and clinical fundamentals.

Transurethral microwave thermotherapy of 340 patients treated at our center for benign prostatic hypertrophy shows the importance of the role played by two thermoregulation processes during the procedure. The first one is artificial and automatically driven by the machine (the power output and cooling rate are adjusted to the urethral and rectal temperature safety thresholds). The second one is natural thermoregulation; the latter is species specific, organ specific, zone specific and even cell specific. Thermoregulation variability is linked to the geometry of the gland, vessel distribution, histology and tissue conductivity. This variability has been demonstrated by interstitial thermometry and histological study. Interstitial thermometry was performed during treatment in 30 dogs and 35 patients; a histological study of prostate specimens was performed 1-12 weeks after treatment in 30 dogs and 15 patients. The human prostate is more resistant to heat than the dog prostate of a comparable volume and treated with the same thermal dose. The prostate of a young patient requires a higher thermal dose than that of an old patient with the same prostate volume in order to achieve a comparable intraprostatic temperature, probably due to a more viable blood supply. The transition zone is more sensitive to heat than the peripheral zone, as demonstrated by temperatures recorded at the same distance from the antenna of up to 60 versus 42 degrees C, respectively. Acinar cells seem to be more resistant to heat than smooth muscle cells when exposed to the same temperature level, as demonstrated by microscopic examination at the periphery of the treated area.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Multiple-dose pharmacokinetics of pefloxacin in patients with hepatocellular deficiency.

Multiple-dose pharmacokinetics of pefloxacin were evaluated in 25 patients with hepatocellular insufficiency. The severity of liver disease was graded A, B or C according to the Child-Pugh classification. Pharmacokinetic parameters evaluated in patients on day 1 of treatment were compared with those computed in 11 healthy volunteers (the control group) after a single dose. Blood samples were taken at frequent intervals after drug administration and assayed by high performance liquid chromatography. The mean age of patients with liver impairment was slightly greater (59.5 years, range 33 to 81 years) than that of the control group (46.7 years, range 42 to 51 years). In the patients with liver disease, the mean (+/- SD) half-life of elimination, although highly variable, was significantly longer (46.3 +/- 42.5 hours) than in the control group (11.3 +/- 3.5 hours, p < 0.001). The total clearance was significantly decreased (1.76 +/- 1.31 L/h vs 6.03 +/- 2.99 L/h in the control group). In groups B and C of the Child-Pugh classification, total body clearance was about 30% of normal values. Elimination half-life increased by 200% in group B and 373% in group C compared with values in healthy volunteers. Intergroup differences (group B vs group C of the Child-Pugh classification) were not statistically significant. The minimum concentrations inhibiting 90% of Gram-negative strains (MIC90) were exceeded by plasma pefloxacin concentrations throughout treatment. For most patients, trough plasma concentrations were above 2 mg/L and peak plasma concentrations averaged 8.5 mg/L. Large inter- and intraindividual variations in the elimination half-life, total clearance and volume of distribution were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Fibrinolytic activity in traumatic hemothorax fluids].

Twenty-nine patients, 15 to 85-year-old (mean: 50 years) who presented with a pleural effusion after trauma were studied. The blood content of pleural fluid was confirmed by thoracocentesis. None of the patients had been taking anticoagulant drugs during the fortnight preceding the trauma. Thoracocentesis was always carried out less than 90 min after the trauma. The following parameters were measured in the haemothorax liquid samples: clotting fibrinogen fraction (Fg C), fibrin degradation D-dimers, functional plasminogen, alpha 2-antiplasmin, alpha 2-macroglobulin, plasminogen tissue activator (tPA Ag), type 1 tPA plasma inhibitor (PAI), and haematocrit. Haemothorax liquid haematocrit values ranged from 13 to 35% (25 +/- 7%, with a mean peripheral venous haematocrit of 34 +/- 6%). Only three patients had some Fg C (0.05-0.13 g.l-1). The D-dimer level was very high (0.23 +/- 0.22 g.l-1). The other factors involved in fibrinolysis were also present. Moreover, there was a statistically significant inverse correlation between D-dimer and alpha 2-macroglobulin levels (r = -0.64, p less than 0.0025). These data suggest two possible mechanisms to explain the fibrinogen levels: coagulation is activated, followed by an important fibrinolytic reaction elicited by the large amounts of plasminogen and tPA present in the haemothorax liquid.

Adolescent↗
PubMed1991

Altered tobramycin pharmacokinetics during chemoprophylaxis in bladder surgery.

The effect of bladder surgery on the pharmacokinetics of tobramycin in hospitalized patients was studied. Fourteen patients with vesical neoplasia undergoing urinary tract surgery were given tobramycin in a dose of 2 mg/kg of body weight. Each patient received the dose at the induction of anesthesia, about 1 h before surgical incision. For seven patients, the drug was also administered 3 weeks later when nutritional conditions were normal. The pharmacokinetic parameters were determined by a two-compartment open model. Except for renal clearance, no significant difference appeared between pharmacokinetic parameters determined from serum data during peri- and postoperative periods. During this work, tobramycin excretion in urine was studied. Twenty-four hours after drug administration, the mean urine tobramycin levels were 25.5 +/- 9.06 and 41.6 +/- 21.5 micrograms/ml after peri- and postoperative administration, respectively; these values were higher than the MICs for most urinary tract pathogens. Seventy-two hours after perioperative administration, the mean value was still elevated (3.54 micrograms/ml), but 72 h after postoperative administration, the urinary tobramycin concentration was not detectable. The percentages of tobramycin recovered unchanged in urine were 54 and 79% after peri- and postoperative administration, respectively. When tobramycin was administered during surgery, a long terminal log-linear phase, with a mean half-life of 25.6 h, was detected. The ratio of renal clearance to total body clearance was 0.52 and 0.79 after peri- and postoperative administration, respectively.

Aged↗
PubMed1990

Urethral lengthening for neurogenic urinary incontinence (Kropp's procedure): results of 16 cases.

Kropp and Angwafo described a urethral lengthening reimplantation operation for the correction of urinary incontinence. We used this technique in 16 girls with neurogenic incontinence with successful results in 13. We describe the problems encountered during the operation, especially with ureters but also with the tube. Sometimes we resected half to all of the muscular layer to obtain a thin and pliable tube. The procedure was used only in girls.

Adolescent↗
PubMed1990

[Uretero-calicostomy for hydronephrosis caused by junction disease in children and adolescents. Apropos of 35 cases].

35 children and adolescents were submitted to ureterocalicostomy for PUJ obstruction. The surgical procedure is explained and specially the importance of performing a regular, muco-mucosal anastomosis to avoid its secondary stenosis. 9 patients have an excellent result with absence of clinical symptoms, sterile urinalysis and normal IVP. 20 patients have a good result with absence of clinical symptoms, sterile urinalysis and improvement of the dilatation of the cavities. 2 secondary nephrectomies have had to be performed because of a dysplastic kidney (1 patient) or of a parenchymal infection (1 patient). 2 patients have no clinical symptoms but have no improvement of their IVP. 3 kinds of indications have been distinguished: failures of previous surgery of the PUJ (5 patients); PUJ obstruction associated with congenital kidney abnormalities as horseshoe kidney (15 patients) and malrotation (3 patients); severe PUJ obstructions with a very thin parenchyma (12 patients). Ureterocalicostomy appears to be a helpful procedure in some defined situations where a declive drainage of the urine essential. No late deteriorations have been recorded in this series.

Adolescent↗
PubMed1989

[Duodenopancreatic contusions. Diagnostic difficulties in children].

The authors describe a case of duodenopancreatic injury in a 6-year-old girl, with the clinical presentation of appendicitis. The findings point to the importance of a precise anamnesis, as in its mild form the traumatism is often poorly recognized, and may be incorrectly diagnosed. It is therefore recommended that a thorough clinical examination be carried out, with abdominal ultrasonography, X-ray barium and tomodensitometry if necessary. Frequently, as is the case with other abdominal, injuries, surgery may be avoided if the patient's condition is carefully followed.

Child↗