Biomedical subjects

Jacques Jamart

Publications and source records attributed to Jacques Jamart.

30 records · Page 2Linked to original sources

PubMed2003

Progressive experience in tracheal stenting with self-expandable stents.

We experienced an unacceptably high 21% complication rate with the stainless steel Gianturco stent: a 68-month mean follow-up (range: 37-96 months) of 23 patients revealed three stent fractures and two migrations. Consequently, we began using nitinol mesh stents (Ultraflex) for fibrous stenoses and silicone-covered prostheses (Rush) for proliferative tracheal tumors. The extractable nitinol stent, made from alloy with thermal memory, was palliatively used in 15 patients with fibrous tracheal stenosis; the mean follow-up currently covers 21 months (range: 1-60 months). The silicone-covered prosthesis was used for two patients with inoperable tracheal tumor; follow-up covers 4 months and 2 months, respectively. The prostheses were positioned under visual guidance via the endoscopic approach. The median forced inspiratory volume in 1 s (FIV1) improved from 2.1 l/s (IQR: 0.7-2.4) to 3.2 l/s (IQR: 0.9-3.4) (P=0.018, Wilcoxon signed rank test). The median ratio of peak inspiratory flow (PIF 50%) to peak expiratory flow (PEF 50%) was 1.0 preoperatively (IQR: 0.8-1.5) and 1.8 postoperatively (IQR: 0.6-6.3). Between months 1 and 12, six granulomas developed. Five were treated with antibiotics and steroid aerosol inhalation therapy and one required CO2 laser vaporization. On day 10, one stent migration was observed. The migrated stent was substituted. To date, no stent fracture has been observed. Nitinol and silicone-covered prostheses can be proposed for the palliative treatment of fibrous tracheal stenoses and tracheal tumors, respectively.

Adult↗

PubMed2003

Predictive value of the fraction of cancer cells immunolabeled for proliferating cell nuclear antigen or Ki67 in biopsies of head and neck carcinomas to identify lymph node metastasis: comparison with clinical and radiologic examinations.

BACKGROUND: Neck metastasis is a major prognostic factor of head and neck carcinoma, but its preoperative detection is currently unreliable. Molecular markers of the metastatic potential of a carcinoma would help to avoid unnecessary neck dissection in patients with nonmetastatic cancer. METHODS: The fractions of cancer cells immunostained for proliferating cell nuclear antigen (PCNA) and Ki67 were determined in 80 preoperative biopsy specimens of head and neck carcinomas. The value of both indexes to detect metastasis in the subsequent neck dissection was compared with that of the clinical and radiologic examinations. RESULTS: PCNA and Ki67 indexes correlated with neck metastasis. Cutoff points were determined for both indexes to discriminate metastatic from nonmetastatic carcinomas. By multivariate logistic regression, these indexes were significant predictors of metastases, together with clinical T stage and neck palpation. CONCLUSION: The fraction of cancer cells immunolabeled for PCNA or Ki67 in preoperative biopsy specimens is helpful to predict neck metastasis.

Adult↗

PubMed2003

Capillarization of the sinusoids in liver fibrosis: noninvasive assessment with contrast-enhanced MRI in the rabbit.

Sinusoidal capillarization induces microcirculatory changes in liver cirrhosis and fibrosis. The purpose of this study was to assess whether contrast-enhanced MRI can be used to demonstrate the effects of sinusoidal capillarization in liver fibrosis. Dynamic MRI after injection of a low-molecular-weight contrast agent of 0.56 kDa (Gd-DOTA), and two high-molecular-weight contrast agents of 6.47 kDa and 52 kDa (P792 and P717) was performed in rabbits with liver fibrosis induced by cholesterol and diethylstilbestrol. The hepatic distribution volume accessible to the high-molecular-weight agents decreased in the rabbits with liver fibrosis (P792: 7.8% +/- 1.7% vs. 10.1% +/- 1.8% in normal rabbits, P =.038; P717: 6.2% +/- 2.1% vs. 9.7% +/- 1.6% in normal rabbits, P =.007), whereas the hepatic mean transit time (MTT) of the low-molecular-weight agent was increased (15.9 +/- 8.0 s vs. 8.8 +/- 2.6 s in normal rabbits, P =.015). In rabbits with liver fibrosis, the clearance of indocyanine green (ICG) was correlated with the volume accessible to the high-molecular-weight agents (P792: r = 0.810, P =.015; P717: r = 0.857, P =.007). The collagen content of the liver was inversely correlated with the distribution volume of P717 (r = -.833, P =.010) and with the ICG clearance (r = -.810, P =.015). It was concluded that the microcirculatory changes induced by sinusoidal capillarization in liver fibrosis can be demonstrated noninvasively with MRI.

Animals↗

PubMed2003

Adjuvant indocyanine green in transpupillary thermotherapy for choroidal melanoma.

OBJECTIVE: To determine the effect of indocyanine green (ICG) injection on the regression pattern of choroidal melanomas treated with transpupillary thermotherapy (TTT). DESIGN: Prospective, randomized, controlled study. PARTICIPANTS: Of the 60 patients with posterior pole choroidal melanoma, 30 were managed with TTT alone (control group), and 30 received adjuvant ICG before TTT. METHODS: Subjects with selected choroidal melanoma were treated with TTT by using infrared radiation delivered from the diode laser. For those patients randomized to ICG administration, the start of TTT was based on the onset of fluorescence documented on ICG angiography. MAIN OUTCOME MEASURES: Final tumor thickness (1.5 mm) and temporal tumor thickness regression. RESULTS: The mean initial tumor basal diameter was 7.7 mm, and tumor thickness was 2.9 mm in the TTT treatment group. Tumor dimensions were initially 7.8 mm in the base and 3.1 mm in thickness in the TTT + ICG treatment group. During a median follow-up of 30 months (range, 6-49 months), the mean tumor thickness gradually decreased to 2.3 mm at month 3 and to 1.9 mm at month 6 after the initial session in the TTT treatment group and to 2.5 mm at month 3 and 2.2 mm at month 6 in the TTT + ICG treatment group. In the TTT treatment group, the reduction of tumor thickness was 19% at month 3 and 30% at month 6. In the TTT + ICG treatment group, the reduction of tumor thickness was 22% at month 3 and 31% at month 6. There were 12 tumors (40%) in the TTT treatment group and 15 (50%) in the TTT + ICG treatment group that measured 1.5 mm in thickness, with a flat ophthalmoscopic appearance. Tumor control was achieved in 55 tumors (92%). Two patients developed tumor recurrence in the TTT treatment group, and three developed recurrence in the TTT + ICG treatment group. A smaller initial tumor thickness, more TTT sessions, and a tumor location other than temporal were statistically predictive of a final tumor thickness of 1.5 mm. There was no apparent effect of ICG administration before TTT on the final tumor thickness and temporal tumor thickness regression. CONCLUSIONS: Despite the efficacy of TTT in the management of selected choroidal melanomas, adjuvant ICG administration before each TTT session does not seem to be beneficial in their regression pattern. Further research in vivo with a larger sample of patients and longer follow-up will be necessary to determine the role of ICG in TTT for choroidal melanomas.

Adult↗

PubMed2002

Prognostic value of cell proliferation markers, tumour suppressor proteins and cell adhesion molecules in primary squamous cell carcinoma of the larynx and hypopharynx.

In an attempt to identify molecular prognostic markers, a series of laryngeal and hypopharyngeal carcinomas was examined for PCNA, Ki67, p27(Kip1), p53, E-cadherin and CD44 by immunohistochemistry and for DNA content by flow cytometry. No correlation was found between E-cadherin, CD44, p53 or DNA ploidy and the clinicopathological data. The fraction of cancer cells immunolabelled for p27(Kip1) correlated with tumour differentiation, but not with lymph node metastasis. In contrast, the PCNA, Ki67 and S-phase fractions of cancer cells were significantly higher in tumours with lymph node metastasis than in those without lymph node metastasis and were correlated with pathological T-stages and with tumour dedifferentiation. In univariate analysis, advanced pathological T-stage, lymph node metastasis and high fractions of cancer cells immunolabelled for PCNA or Ki67 inversely correlated with overall and disease-free survival. In multivariate analysis, lymph node metastasis was the only factor significantly associated with poor survival. The data suggest that immunohistochemical investigation of PCNA and Ki67 and flow cytometric analysis of S-phase fractions may be useful predictive markers of biological aggressiveness in laryngeal carcinomas.

Aged↗

PubMed2002

Off-pump coronary artery bypass grafting: a case-matched comparison of hemodynamic outcome.

OBJECTIVE: The objective of this study was to assess improved myocardial protection by performing coronary artery bypass grafting (CABG) on the beating heart. A case-matched study was conducted among patients who underwent CABG either on-pump (group 1), or off-pump (group 2). METHODS: Forty-five pairs of patients, having a similar clinical profile, were selected on the basis of five variables: age, gender, body surface area, ejection fraction, extent of coronary disease. Operative risk predicted by the The Society of Thoracic Surgeons national database was 1.80+/-0.35% in group 1, and 1.89+/-0.37% in group 2 (NS). Cold blood cardioplegia and 28 degrees C cardiopulmonary bypass were used in group 1. In group 2, beating heart coronary grafting was achieved with the Octopus 1 and 2 stabilizers. The average number of distal anastomoses was 2.8+/-0.1 in group 1 and 2.3+/-0.1 in group 2 (P=0.015). RESULTS: There was no significant difference among the groups regarding the trend in cardiac index, left and right ventricular stroke work indexes, and systemic and pulmonary vascular resistance indexes. However, heart rate trend was slower in group 2 (P=0.05). Pharmacological support was required in 65% of the patients in group 1, and in 33% in group 2 (P<0.001). The total amount of Dobutamine and/or Dopamine administered during the first 48 h was 3914+/-1306 gamma/kg in group 1 and 1645+/-697 gamma/kg in group 2 (P=0.049). Release of creatine kinase MB mass isoenzyme (CK-MB mass) was markedly reduced in group 2 (P<10(-4)). CONCLUSIONS: Hemodynamic outcome following off-pump CABG is similar to on-pump CABG but the need for inotropic support is significantly reduced and CPK-MB mass release is markedly lower.

Aged↗

PubMed2002

Occupational asthma caused by natural rubber latex: outcome according to cessation or reduction of exposure.

BACKGROUND: The long-term effects of reducing exposure to latex in subjects with latex-induced asthma remain unknown. OBJECTIVE: The purpose of this study was to compare the health and socioeconomic outcomes of subjects with latex-induced asthma before and after reduction or cessation of exposure to latex. METHODS: Thirty-six subjects with latex-induced asthma as ascertained by specific inhalation challenges were investigated after a median follow-up of 56 months (range, 12 to 92 months). Initial and follow-up visits included use of a detailed questionnaire and measurement of the concentration of histamine causing a 20% fall in FEV(1) (PC(20)). At follow-up, information on employment, financial status, and quality of life was collected. RESULTS: At follow-up, 16 subjects were no longer exposed to latex, whereas 20 subjects had reduced exposure. In the subjects who avoided exposure, asthma severity decreased from a median score of 8.5 to 3.5 (P =.001) and the median histamine PC(20) value increased from 0.4 mg/mL to 2.3 mg/mL (P =.002). In the subjects who reduced their exposure, asthma-severity score improved from 6.5 to 2.5 (P <.001) and PC(20) values rose from 0.5 mg/mL to 2.4 mg/mL (P <.001). Cessation of exposure to latex was associated with asthma-related work disability (69%) and loss of income (62%) more frequently than was reduction of exposure (35% and 30%, respectively). CONCLUSION: Reduction of exposure to latex should be considered a reasonably safe alternative that is associated with fewer socioeconomic consequences than removal from exposure.

Adult↗

PubMed2002

Prognosis of hematologic malignancies does not predict intensive care unit mortality.

OBJECTIVE: To evaluate the correlation between specific prognosis of hematologic malignancies on the one hand and intensive care unit and hospital mortality in critically ill patients with hematologic malignancies on the other hand. DESIGN: Observational study during a 10-yr period. SETTING: A 22-bed medical-surgical intensive care unit. PATIENTS: A total of 84 consecutive patients with nonterminal hematologic malignancies with medical complications requiring intensive care. INTERVENTIONS: None. MEASUREMENTS: Demographic factors, acute physiology and organ dysfunction scores, microbiology, therapeutic support, and hematologic factors data on admission and during the intensive care unit stay were collected, together with mortality follow-up. Based on specific-disease prognostic factors and related published survival curves, the prognosis of hematologic malignancies was assessed and defined as good, intermediate, or poor according to a 3-yr survival probability of >50%, 20-50%, or <20%, respectively. MAIN RESULTS: Prognosis of hematologic malignancies does not predict intensive care unit or hospital mortality and almost reaches significance for 6-mo mortality (53%, 71%, and 84% rate for patients with good, intermediate, and poor prognosis, respectively, p =.058), but it determines long-term survival (p =.008). Intensive care unit, hospital, and 6-mo overall mortality rates were 38%, 61%, and 75%, respectively. Using multivariate analysis, intensive care unit mortality was best predicted on admission by respiratory failure and fungal infection, whereas hospital mortality was predicted by the number of organ failures, the bone marrow transplant status, and the presence of fungal infection. The Acute Physiology and Chronic Health Evaluation II and the Simplified Acute Physiology Score II had no prognostic value, whereas the difference of the Multiple Organ Dysfunction Score between at the time of admission and at day 5 allowed quick prediction of hospital mortality. Diseases with the poorest 6-mo prognosis were acute myeloid leukemia and non-Hodgkin lymphoma. CONCLUSION The severity of the underlying hematologic malignancies does not influence intensive care unit or hospital mortality. Short-term prognosis is exclusively predicted by acute organ dysfunctions and by a pathogen's aggressiveness. Therefore, reluctance to admit patients with nonterminal hematologic malignancies to the intensive care unit based only on the prognosis of their underlying hematologic malignancy does not seem justified.

APACHE↗

PubMed2002

Assessment of knee cartilage in cadavers with dual-detector spiral CT arthrography and MR imaging.

PURPOSE: To assess dual-detector spiral CT arthrography in the evaluation of the entire knee cartilage obtained from cadavers. MATERIALS AND METHODS: Two independent observers characterized articular cartilage in 12 cadaver knees in which MR imaging and dual-detector spiral CT arthrography were performed and compared their findings to those found during macroscopic assessment. The sensitivity and specificity of MR imaging and spiral CT arthrography for detecting grade 2A or higher and grade 2B or higher cartilage lesions, the Spearman correlation coefficient between arthrographic and macroscopic grading, and kappa statistics for assessing interobserver reproducibility were determined. RESULTS: At spiral CT arthrography, sensitivities and specificities ranged between 80% and 88% for the detection of grade 2A or higher cartilage lesions and ranged between 85% and 94% for the detection of grade 2B or higher cartilage lesions. At MR imaging, sensitivities and specificities ranged between 78% and 86% and between 76% and 91% for the detection of grade 2A or higher and grade 2B or higher cartilage lesions, respectively. Spearman correlation coefficients between spiral CT arthrography or MR imaging and macroscopic grading of articular surfaces were 0.797 and 0.702, respectively. CONCLUSION: Dual-detector spiral CT arthrography of the knee is a valuable method for the assessment of open cartilage lesions of the entire knee.

Aged↗

PubMed2002

Influence of respiratory behavior on ventilation, respiratory work and intrinsic PEEP during noninvasive nasal pressure support ventilation in normal subjects.

BACKGROUND: In clinical practice, patients have different inspiratory behaviors during noninvasive pressure support ventilation (PSV): some breathe quietly, others actively help PSV by an additional effort, and others even resist the inspiratory pressure of PSV. OBJECTIVE: What is the influence of patient collaboration (inspiratory behavior) on the efficiency of PSV? METHODS: We ventilated 10 normal subjects with nasal PSV (inspiratory/expiratory: 10/0 and 15/5 cm H(2)O) and measured their flow and volume with a pneumotachograph and their esophageal and gastric pressures during three different respiratory voluntary behaviors: relaxed inspiration, active inspiratory work and resisted inspiration. RESULTS: When compared with relaxed inspiration with 10/0 cm H(2)O PSV: (1) an active inspiratory effort increased tidal volume (from 789 +/- 356 to 1,046 +/- 586 ml; p = 0.006), minute ventilation (from 10.40 +/- 4.45 to 15.77 +/- 7.69 liters/min; p < 0.001), transdiaphragmatic work per cycle (from 0.55 +/- 0.33 to 1.72 +/- 1.40 J/cycle; p = 0.002) and inspiratory work per cycle (from 0.14 +/- 0.20 to 1.26 +/- 1.01 J/cycle; p = 0.003); intrinsic positive end-expiratory pressure (PEEP(i)) increased from 1.23 +/- 1.02 to 3.17 +/- 2.30 cm H(2)O; p = 0.002); (2) a resisted inspiration decreased tidal volume (to 457 +/- 230 ml; p = 0.007), minute ventilation (to 6.93 +/- 3.04 liters/min; p = 0.028) along with a decrease in transdiaphragmatic work but no change in PEEP(i). Data obtained during a bilevel PSV of 15/5 cm H(2)O were similar to those obtained with the 10/0 cm H(2)O settings. CONCLUSIONS: Active inspiratory effort increases ventilation during PSV at the expense of an increased breathing work and PEEP(i). Resisted inspiration inversely decreases inspiratory work and ventilation with no air trapping. These differences between inspiratory behaviors could affect the expected beneficial effects of PSV in acutely ill patients.

Adult↗

PubMed2002

Effects of nasal pressure support on ventilation and inspiratory work in normocapnic and hypercapnic patients with stable COPD.

OBJECTIVES: To assess and compare the effect of nasal continuous positive airway pressure (nCPAP), inspiratory pressure support (PSV), and bilevel positive airway pressure (biPAP) on ventilatory parameters and inspiratory work (WOB) in normocapnic and hypercapnic patients with stable COPD. METHODS: While administering nasal pressure support to 10 normocapnic and 10 hypercapnic patients with COPD, we measured airflow and volume with a pneumotachograph as well as esophageal and gastric pressures under nCPAP, PSV, and biPAP conditions. RESULTS: nCPAP had no influence on ventilatory parameters but decreased WOB and transdiaphragmatic work (Wdi) at 10 cm H(2)O of pressure in both groups. With PSV and biPAP, ventilatory parameters increased proportionally to the inspiratory applied pressure. WOB and Wdi decreased significantly in both groups while increasing the pressure support. A similar decrease was observed during biPAP proportionally to the level of pressure support. The diaphragmatic pressure-time product decreased similarly in both groups during PSV and biPAP. CONCLUSION: The ventilatory response under nCPAP, PSV, and biPAP conditions is similar in hypercapnic and normocapnic patients with stable COPD; PSV and biPAP increase ventilatory parameters and improve Wdi. On the contrary, nCPAP improves WOB but does not increase ventilatory parameters.

Blood Gas Analysis↗

PubMed2002

Hearing outcome following laser-assisted stapes surgery.

This article reports the postoperative results of 76 operations addressing otosclerosis. All procedures were performed by the same surgeon and took place within a 4-year period. We compared the postoperative audiometric results of 54 laser-assisted procedures with those of 22 nonlaser operations. Our findings revealed a statistically significant improvement in the air-bone gap closure of the laser-operated patients: the air-bone gap was narrowed to within 10 dB in 72% of laser-operated cases versus 54% in nonlaser cases. Furthermore, laser use does not induce high-frequency sensorineural hearing loss. We believe that a laser entails less risk of inner ear microtrauma and improves the accuracy and reliability of stapedotomy.

Adolescent↗