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Biomedical subjects

J Jamart

Publications and source records attributed to J Jamart.

At least 73 records · Page 4Linked to original sources
PubMed1999

Use of injectable autologous collagen for correcting glottic gaps: initial results.

We report our results pertaining to the use of injectable autologous collagen for the correction of dysphonia resulting from a glottic gap. To date 20 cases have been treated, 13 of which were for unilateral vocal fold immobility and 7 for sulcus vergeture and/or scar. Collagen is extracted from the skin. Approximately 5 cm2 is necessary to yield 2 ml. Injection must take place in the deep layer of Reinke's space. No patient suffered from any local or general intolerance. The phonatory glottic gap was totally or partially closed. In the paralysis group, the improvements were the following: the median maximum phonation time improved from 5.8 seconds to 11 seconds, the median mean flow rate from 0.13 ml/s to 0.09 ml/s, the median glottic gap from 8.4 to 4.5 ml/dB per s, the median intensity range from 21 to 29 dB, and the median frequency range from 141 to 195 Hz. The spectral analysis layout classification improved from 2 to 3.

Adult↗
PubMed1999

Doppler-derived left ventricular rate of pressure rise determination in presence of severe acute mitral regurgitation in pigs.

Doppler-derived left ventricular (LV) rate of pressure rise (Dop LV DeltaP/Deltat) is described as an index of LV performance in the presence of mitral regurgitation (MR). This study was designed to define more accurately the accuracy of the method in the presence of severe MR. Ten pigs were anesthetized and monitored. MR was gradually created. At each grade of MR, preload was manipulated with the intent of modifying LV end-diastolic area value within a range of +/-20%. Concurrently, the mean left atrial pressure (LAP) was recorded, MR was quantified by the mitral to aortic velocity-time integral ratio (mitroaortic VTI ratio), Dop LV DeltaP/Deltat was calculated, and peak LV dP/dt was derived from LV catheterism data. During the procedure Dop LV DeltaP/Deltat gradually underestimated peak LV dP/dt. This difference was correlated to the mean LAP (P < 10(-5)) and mitroaortic VTI ratio (P < 10(-5)) and became clinically significant when the mean LAP was superior to 21 mm Hg.

Animals↗
PubMed1999

Pulmonary effects of short-term exposure to low levels of toluene diisocyanate in asymptomatic subjects.

Isocyanates may be involved in the development of chronic obstructive airway disease among exposed workers. A short-term exposure to toluene diisocyanate (TDI) at concentrations near the permissible levels was investigated to examine whether there was an association with changes in pulmonary function tests and in potential markers of airway injury and inflammation in bronchial lavage (BL) and bronchoalveolar lavage (BAL). Seventeen subjects without respiratory symptoms (eight smokers and nine nonsmokers) were exposed once to ambient air and once to TDI (5 parts per billion (ppb) for 6 h followed by 20 ppb for 20 min) in a randomized, single-blind sequence. Pulmonary function tests were repeatedly assessed during exposure and BAL was performed 1 h after each exposure. Biochemical studies on lavage fluids included albumin, immunoglobulins, antiproteases (alpha2-macroglobulin and alpha1-proteinase inhibitor), potential indicators of epithelial cell function (secretory component and Clara cell protein), and cytokines (tumour necrosis factor-alpha, interleukin (IL)-4, IL-5, IL-6, and IL-8). Exposure to TDI caused a modest decrease in specific airway conductance (sGaw) (p=0.053) and in maximal expiratory flow at 25% of forced vital capacity (MEF25%) (p=0.015) when compared with ambient air. Exposure to TDI resulted in a slight increase in BAL albumin level (TDI: 26.4+/-12.5 versus air: 21.8+/-8.6 microg x mL(-1), p=0.044) and in BL alpha2-macroglobulin concentration (TDI: 0.07+/-0.061 versus air: 0.05+/-0.04 microg x mL(-1), p=0.021). This study suggests that exposure to low toluene disocyanate concentrations is associated with minimal but detectable changes in airway calibre and in epithelial barrier permeability. The pulmonary effects of long-term exposure to low levels of isocyanates require further investigation.

Adult↗
PubMed1999

A new technique for laser-assisted uvulopalatoplasty: decision-tree analysis and results.

OBJECTIVE: Report a new technique of laser-assisted uvulopalatoplasty (LAUP) for snoring performed as a one-stage procedure. STUDY DESIGN: A decision-tree was used in a prospective study of 89 patients from April 1994 to May 1997. It included a fiberscopy and Muller's maneuver, rhinomanometry, pH monitoring, computed tomography scan to measure the pharyngeal lumen, pulse oximetry, and polysomnography in case of sleep apnea syndrome was suspected. METHODS: The authors performed their LAUP technique on 43 patients (48.5%) whose snoring was mainly caused by the velum. This technique consists of scarifying the velum by vaporizing the mucosa and the submucosa along a rectangle extending from the palatal dimple to the uvula and having a width of 1.5 to 2 cm. Vaporization of the palatal arches follows without exceeding the junction of the anterior and posterior pillars in height. The uvula is cut if necessary, preserving a length of at least 0.5 cm. The other patients underwent different procedures according to the cause of snoring. RESULTS: There was no significant difference between LAUP and uvulopalatoplasty (UPPP) regarding pain. No permanent phonatory disorders and no regurgitation occurred. Satisfaction evaluated on a scale ranging from 0 to 10 was equivalent for the two techniques: mean value = 7.68 (+/-2.18) for LAUP and 8.60 (+/-2.27) for UPPP. The mean follow-up was 17 months (range, 1-37 mo). Satisfaction was also identical for all techniques. CONCLUSION: Our LAUP technique combined with other procedures according to a decision-tree is efficient and safe.

Adult↗
PubMed1999

Idiopathic bone marrow edema lesions of the femoral head: predictive value of MR imaging findings.

PURPOSE: To determine the frequency of several subchondral magnetic resonance (MR) imaging features observed in bone marrow edema lesions of the femoral head and to determine their value for differentiation of irreversible from transient lesions. MATERIALS AND METHODS: The authors reviewed MR images of 72 femoral head lesions in 42 men and 25 women (median age, 48 years) with equivocal radiographic findings and bone marrow edema seen at MR imaging (T1- and T2-weighted images in all patients and contrast material-enhanced T1-weighted images in 39 patients). Follow-up MR images showed 57 lesions to be transient and 15 to be irreversible. The presence and size of subtle subchondral features observed on initial MR images were compared for both types of lesion. RESULTS: Lack of any additional subchondral change on T2-weighted or contrast-enhanced T1-weighted images had 100% positive predictive value for transient lesions. For irreversible lesions, presence of a subchondral area of low signal intensity at least 4 mm thick or 12.5 mm long had positive predictive values of 85% and 73%, respectively, on T2-weighted images and 87% and 86%, respectively, on contrast-enhanced T1-weighted images. CONCLUSION: Careful assessment of subchondral changes enables confident differentiation between early irreversible lesions and transient bone marrow edema lesions.

Bone Marrow Diseases↗
PubMed1999

Correcting vocal fold immobility by autologous collagen injection for voice rehabilitation. A short-term study.

We report on a short-term clinical study of injectable autologous collagen (Vocalogen) used to correct dysphonias arising from vocal fold immobility. The collagen is extracted from skin taken from the lower abdominal quadrant area or from just above the bikini line. About 30 cm2 of skin are required to provide 2 mL of injectable collagen. The histologic examination of the preparation before injection disclosed the presence of elastin fibers and some clusters of epithelial cells, beside the collagen fibers. The collagen is naturally reticulated, and the molecule is preserved in its entirety. The technique is exactly the same as that reported for bovine collagen: injection into Reinke's space, under general anesthesia, monitored by direct microlaryngoscopy. The amount injected is also similar: 1.5 mL for correction of glottic insufficiency in which the immobile vocal fold is in the intermediate position. Eight patients were injected, and the average follow-up was 4.5 months. Voice assessments made before and after the treatment included stroboscopy, subjective and perceptual judgments, and aerodynamic and acoustic measurements. The functional results were similar to those obtained with bovine collagen. No complications arose. The probability of any hypersensitivity reaction, always a possibility to be feared with bovine collagen, is negligible with the autologous collagen. Long-term results are as yet unknown, but from the fact that the collagen molecular structure is intact and there is little risk of foreign body response, it would be expected that autologous preparations would be more stable than bovine collagen; this appears to be the case in cosmetic applications. Autologous collagen could be employed for the same indications as bovine collagen, provided that a delay of 45 days (the time required to prepare the injectable collagen) is acceptable. The amount of collagen required is also a limiting factor, since the patient's own skin is the starting donor material.

Aged↗
PubMed1999

Palliative treatment for tracheal stenoses using carbon dioxide laser and the Gianturco stent. Long-term results.

Between September 1992 and March 1998, the self-expandable Gianturco prosthesis was inserted in 23 patients suffering from tracheal stenosis. After radial incision and dilation of the stenosis as described by Shapshay, the positioning of the stent was performed during an endoscopic procedure under optical control. The prosthesis used was a double-ring stent 50 mm long and 20 mm in diameter. The follow-up period ranged between 0.5 and 67 months with an average of 31 +/- 18 months. Pulmonary function tests showed an average improvement of the peak expiratory flow (50%) from preoperative results of 1.06 +/- 0.60 L/s to short-term postoperative results of 2.08 +/- 0.78 L/s and long-term postoperative results of 2.11 +/- 0.78 L/s. The mean peak inspiratory flow (50%) improved from 1.43 +/- 0.85 L/s to 2.40 +/- 1.29 L/s at short term and to 2.56 +/- 1.20 L/s at long term. Eight patients out of the 23 had to undergo a second endoscopic procedure: 3 patients for granuloma vaporization; 1 patient to change a malpositioned stent; 2 patients to add a second stent because of insufficient tracheal enlargement; and 2 patients to resect mucosal membranes between the 2 stent rings and to place a second stent. Optical control of the accurate positioning and use of this model of Gianturco prosthesis helped to avoid the severe complications described in the literature (migration, extrusion, fracture, wall erosion. and hemorrhage). The follow-up must particularly target the prevention of granulomas. The self-expandable Gianturco prosthesis can be advocated for long-term palliative treatment of tracheal stenoses that are inoperable by an external surgical approach.

Aged↗
PubMed1999

A study of vibrato: assessment by panel of judges compared to spectral voice analysis.

Experts in voice singing and voice training were asked to judge the vibrato of 30 singers (4 samples per singer: a sung [a] held without vibrato; a sung a[ held with vibrato; a self-selected passage and an imposed passage. In the first part, they ticked the type of oscillations (vibrato, straight tone, tremolo, quivering...). In the second part, they appraised various criteria. Intra-judge and inter-judge consistencies were determined. The subjective parameters were thereafter correlated with the measurements of six parameters of the MDVP (MultiDimentional Voice Program). The measurements were carried out on each task. Intra-judge consistency was good for only one judge (67-87% consistency). Since judge 2 and 3 were hardly reproducible (45-73%; 28-57%) measurement of the inter-judge consistency was pointless. The results of judge 1 were correlated with the Fundamental Tremor Frequency Index, the jitter and the shimmer.

Adult↗
PubMed1998

Early hepatocyte, endothelial, and bile duct cell injury after pediatric liver transplantation from cadaveric or living-related donors.

BACKGROUND: When compared with cadaveric grafts (Cad), the potential advantages of pediatric orthotopic liver transplantation (OLT) from living-related (LR) donors may include better graft quality, shorter ischemic time, appropriate preparation of the recipient, and better immunologic compatibility. METHODS: The aim of this study was to analyze early hepatocyte, endothelial, and bile duct cell injury following pediatric OLT using LR (n=15) or uncomplicated Cad reduced-size (n=10) grafts. Median (range) total ischemic times were 190 min (105-261) versus 760 min (418-948) in LR and Cad groups, respectively (P<0.001). RESULTS: The post-OLT cytolytic profile, assessed daily during the first 7 days using both plasma glutamate-pyruvate transaminase and serum alpha-glutathione S-transferase, showed significantly higher levels of both parameters for the 10 uncomplicated Cad cases when compared with the 15 LR grafts (P<0.001). The evaluation of hepatic endothelial cell function during the first week after OLT, using serum hyaluronic acid levels, suggested lower endothelial injury in the LR grafts, when compared with the Cad grafts (P=0.059). Bile duct cell injury, as assessed using plasma gamma-glutamyl transferase levels, was similar in both groups, with a progressive increase at the end of the first week after OLT, which was correlated with a similar incidence of early acute rejection in both groups (80% in the LR group vs. 62% in the Cad group, NS). CONCLUSION: (1) The hepatocellular and endothelial cell damage was reduced after OLT with LR grafts, which may be related to shorter ischemic time when compared with Cad grafts; (2) the putative immunologic advantage for LR grafts was not confirmed in terms of incidence of acute rejection.

Adult↗
PubMed1998

The influence of skin temperature on latency and amplitude of the sympathetic skin response in normal subjects.

The influence of skin temperature on latency and amplitude of the sympathetic skin response (SSR) was studied in 10 normal subjects. SSRs were elicited in all four limbs of each subject by electrical stimulation after cooling of the right arm and after cooling of the right hand only. At low skin temperature, the latency was prolonged and the amplitude decreased. Latency and amplitude were linearly correlated with skin temperature of the right arm. There were no changes in the left arm and the legs, which basically excludes involvement of central pathways in these response parameters. With regard to the skin temperature of the arm, a temperature correction factor of 0.088 s/degrees C was calculated for latency. With regard to the skin temperature of the hand, latency prolongation was significantly greater after cooling of the whole arm. This suggests that not only the neuroglandular junction, but also the postganglionic sympathetic C fibers were responsible for latency modifications. In contrast, amplitude was reduced similarly after cooling of the whole arm and the hand only, suggesting that mainly the neuroglandular junction is responsible for amplitude modifications. We conclude that skin temperature is a mandatory measurement in the study of the SSR.

Adult↗
PubMed1998

Pulsed Doppler intraoperative flow assessment and midterm coronary graft patency.

BACKGROUND: This study was designed to assess the value of hemodynamic measurements taken intraoperatively in predicting midterm patency of coronary bypass grafts. METHODS: A pulsed Doppler flowmeter was routinely used during operation to determine the hemodynamic parameters of coronary bypass grafts. During a 7-year period, 85 patients underwent angiographic evaluation. As a result, a thorough hemodynamic assessment of 214 grafts (89 arterial and 125 venous) at initial operation was available for analysis. RESULTS: The overall patency rate was 88.3%. The mean flow measured intraoperatively in 168 intact grafts was 60+/-3 mL/min (range, 9 to 230 mL/min), and the resistance was 1.8+/-0.1 peripheral resistance units (range, 0.3 to 9.0 peripheral resistance units). The mean flow was 36+/-5 mL/min (range, 2 to 107 mL/min), and the resistance was 5.9+/-2.0 peripheral resistance units (range, 0.6 to 46.0 peripheral resistance units) in 25 grafts found occluded at angiographic evaluation. Multivariate analysis identified three independent variables associated with a reduced patency rate: increased resistance as measured in the graft (p = 0.012), increasing interval of control angiography (p = 0.006), and preoperative cardiogenic shock (p = 0.040). CONCLUSIONS: The prognosis for midterm patency of aortocoronary bypass grafts depends on the intraoperative hemodynamic status.

Blood Flow Velocity↗
PubMed1998

Long-term survival after aortic valve replacement for native active infective endocarditis.

BACKGROUND: The objective of this study was to analyse the impact of acute surgery for native aortic valve endocarditis and its influence on the long-term prognosis after surgery. METHODS: A total of 161 patients underwent aortic valve replacement for native active aortic valve endocarditis (NAAVE) during a 29-year period, from 1967 to 1995 (age range: 10 to 72 years; mean 48 +/- 12). The main indication for surgery was progressive congestive heart failure (76%). Other indications were untreatable sepsis (27%), peripheral or central emboli (12%) and, from 1978, echocardiographic evidence of friable, pedunculated vegetations (3%). Streptococcal and staphylococcal infections predominated. Concomitant procedures were performed in 27% of the patients, including mitral and tricuspid valve surgery and coronary bypass procedures. RESULTS: Operative mortality was 8% in the majority of cases caused by heart failure or multi-organ failure. Multivariate logistic regression analysis identified NYHA class IV to be an independent predictor for postoperative death. Long-term survival for discharged patients was 75% at 10 years and 58% at 15 years, with a mortality rate of 3.6%/patient/year. Cox regression analysis identified the year of operation, trivalvular endocarditis and staphylococcal infection as independent predictors of survival. At 10 and 15 years after aortic valve replacement, 91% and 84% of the patients, respectively, were free of recurrent endocarditis. The presence of an abscess cavity at first operation was found to be predictive of recurrent endocarditis. CONCLUSIONS: Valve replacement for NAAVE offers a good chance for a cure and satisfactory long-term survival. Improvements in pre- and per-operative management of the very ill patient, and the use of allograft valves are likely to further improve long-term results. Finally, the presence of staphylococcal endocarditis requires long-term postoperative antibiotic therapy.

Adolescent↗
PubMed1998

Doppler-derived left ventricular rate of pressure rise and inotropic requirements during mitral valve surgery.

BACKGROUND: The estimation of left ventricular (LV) contractility is difficult in the presence of significant mitral regurgitation (MR). Prediction of LV performance after MR repair is even more problematic. The intraoperative Doppler-derived LV rate of pressure rise (LV delta P/delta t) analyzed before cardiopulmonary bypass (CPB) was presumed to be a useful predictive parameter for LV performance. Therefore, its relation to perioperative inotropic requirements (PIR) necessary for separation from CPB after surgical MR repair was investigated. METHODS: Twenty-eight patients scheduled for surgical MR repair fulfilled the selection criteria. Pre-CPB LV delta P/delta t, pre-CPB echocardiographic LV fractional area change (LV FAC), and pre-CPB thermodilution-derived cardiac index (CI) were recorded. After MR repair, separation from CPB was performed with regard to standardized guidelines. PIR during the first 60 minutes following separation were recorded. RESULTS: Pre-CPB LV delta P/delta t could be assessed in 22 patients. Pre-CPB LV delta P/delta t was 882 +/- 450 mmHg/sec, pre-CPB LV FAC was 49% +/- 9%, and pre-CPB CI was 2.0 +/- 0.2 L/kg/min. Pre-CPB LV delta P/delta t was significantly correlated with pre-CPB LV FAC (r = 0.56), and with pre-CPB CI (r = 0.72). Inotropic support was necessary in 16 patients (73%), and was best predicted by the pre-CPB LV delta P/delta t, by means of logistic regression (p = 0.026). CONCLUSIONS: Doppler-derived LV delta P/delta t was assessable in most patients with severe chronic MR, and was the best intraoperative predictive parameter of post-CPB inotropic requirements after surgical MR repair.

Aged↗
PubMed1998

Stage III multiple myeloma: clinical and prognostic value of spinal bone marrow MR imaging.

PURPOSE: To determine the clinical and prognostic value of spinal bone marrow magnetic resonance (MR) imaging in stage III multiple myeloma. MATERIALS AND METHODS: In 80 patients with untreated, newly diagnosed stage III multiple myeloma, initial MR imaging patterns of spinal bone marrow involvement were correlated with hematologic parameters and response to induction chemotherapy. The influence of these patterns on survival was studied in 57 patients who did not undergo cytotoxic therapy with stem cell transplantation. RESULTS: MR imaging patterns of marrow involvement were normal in 19 (24%) patients, focal in 35 (44%), and diffuse in 26 (32%). Patients with the diffuse pattern had higher marrow plasmacytosis (P < or = .003) and cellularity (P < or = .001), higher serum calcium (P < or = .005) and beta 2-microglobulin (P < or = .008) levels, and lower hemoglobin values (P < or = .001) than did those with the normal or focal patterns. Patients with the normal pattern responded better to therapy (P = .007) and survived longer than patients with an abnormal pattern (P = .026). MR imaging findings and C-reactive protein level were the best independent prognostic indicators of survival. CONCLUSION: MR imaging patterns of spinal bone marrow involvement are correlated with several clinical parameters of disease severity and have prognostic value in stage III multiple myeloma.

Adult↗
PubMed1998

Early irreversible osteonecrosis versus transient lesions of the femoral condyles: prognostic value of subchondral bone and marrow changes on MR imaging.

OBJECTIVE: The purpose of this study was to determine the MR imaging features that enable differentiation between early irreversible osteonecrosis and transient lesions in nontraumatic lesions of the femoral condyle having the "bone marrow edema" pattern on MR imaging. MATERIALS AND METHODS: We reviewed 23 nontraumatic painful lesions of the femoral condyle in 23 patients (12 men and 11 women; mean age, 62 years). All patients had undergone radiography of the knee with findings that were normal or inconclusive. Also, all patients underwent MR imaging that revealed the bone marrow edema pattern in a condyle. Lesions observed after trauma, surgery, or glucocorticoid medication, or with epiphyseal collapse or degenerative joint disease on initial plain radiographs, were excluded from this study. Of the 23 lesions, 14 showed complete resolution (and were designated as transient epiphyseal lesions). The remaining nine lesions were irreversible and, on follow-up radiographic and MR imaging studies, evolved to collapsed osteonecrosis (and were designated as early osteonecrosis). The presence and size of the subchondral features observed by two radiologists on initial MR studies were compared for both irreversible and transient epiphyseal lesions. RESULTS: Initial MR imaging characteristics indicative of an early irreversible osteonecrosis included a subchondral area of low signal intensity on T2-weighted images with a thickness of more than 4 mm (sensitivity, 100% and 100%; specificity, 82% and 74% for the two observers) or a length of more than 14 mm (sensitivity, 89% and 88%; specificity, 93% and 87% for the two observers), focal epiphyseal contour depressions, and lines of low signal intensity located deep in the affected condyle. The extent of edema was similar for both transient epiphyseal lesions and early osteonecrosis. CONCLUSION: Careful assessment of MR imaging changes occurring in the subchondral area can enable confident differentiation between transient epiphyseal lesions and early irreversible osteonecrosis of the femoral condyle.

Bone Marrow↗
PubMed1998

[Lasers used by a young surgeon for stapes surgery].

We report the results of the first 38 stapes operations performed by a young surgeon. He achieved a perfect closure of the air-one gap (within 10 dB) in 89% of the patients operated on with the laser, compared with 65% of the patients operated on without laser. We discuss the significance of this difference, taking into account the multiple factors influencing the results. In our opinion, the laser helps a young surgeon to accelerate his learning curve in stapes surgery.

Adolescent↗
PubMed1997

Particle counting assay for anti-toxoplasma IgG antibodies. Comparison with four automated commercial enzyme-linked immunoassays.

An assay for anti-toxoplasma IgG antibodies based on agglutination of latex particles was set up and compared with commercial immunoassays. The reaction was measured by instrumental counting of particles remaining unagglutinated. The running time was 45 min. This test (PaC) was compared using 243 serum samples with four automated commercial immunoassays: the Enzymum test Toxo IgG (ES300, Boehringer), the Vidas Toxo IgG (Biomérieux), the IMX Toxo IgG (Abbott), the Magia Toxoplasma gondii IgG (Merck). The mean values (+/- SD) obtained by IMX (25 IU +/- 68) and ES300 (45 IU +/- 142) were significantly lower than the values obtained by Vidas (73 IU +/- 237, p < 10(-4) and p = 0.006, respectively), by Magia (80 IU +/- 300, p < 10(-4) and p = 0.0005) and by PaC (70 IU +/- 260, p < 10(-4) and p = 0.0126). The correlations between PaC and Toxo IgG Boehringer, Biomérieux, Abbott, Merck were r = 0.97, r = 0.98, r = 0.94, r = 0.98, respectively. The correlation coefficients between the enzyme-immunoassays ranged from 0.96 to 0.99. All positive samples by PaC were found to be positive by enzyme-immunoassays except for eight sera which were doubtful positives by the Enzymum test ToxoIgG from Boehringer. No negative sample by PaC was found positive by any of the enzyme-immunoassays. In PaC, when two latex preparations coated with different antigen were compared, the correlation was rather weak (r = 0.93) suggesting that the selection of the antigen can be critical. In conclusion, the four automated commercial immunoassays now available gave similar results. However, the discrepancies observed in this study underlined the importance of clinical and biological follow-up of the patients and the necessity to confirm the result. The introduction of a new technique such as PaC, which is now available for a large variety of assays in Clinical Chemistry and Microbiology, is justified by its intrinsic advantage of homogeneity. Therefore, automation is easy as well as the control of possible interference.

Animals↗