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Robert Vincent

Publications and source records attributed to Robert Vincent.

11 recordsLinked to original sources
PubMed2006

Tissue Doppler imaging detects severely abnormal myocardial velocities that identify children with pre-terminal cardiac graft failure after heart transplantation.

BACKGROUND: Children with orthotopic heart transplants (OHT) may die or require retransplantation due to chronic graft failure usually due to severe coronary allograft vasculopathy (CAV). Non-invasive detection of chronic transplant failure has been problematic due to lack of specific echocardiographic findings. Tissue Doppler Imaging (TDI) is a non-invasive ultrasound methodology, which measures myocardial contraction and relaxation velocities. The purposes of this study were to: 1. Determine quantitative changes of longitudinal TDI velocities characteristic to "pre-terminal" patients who subsequently either died or were listed for re-transplantation due to graft failure; 2. to define the time course of these changes, and 3. to show whether RV and LV velocities were equally effected. METHODS: 53 heart transplantation recipients were evaluated. Of these, 45 were "well" patients. They ranged in age at enrollment from 0.5 to 20.1 (mean 10.21) years, age at transplantation from 0.2 to 18 (mean 5.7) years. The time from transplantation to enrollment was 1 day to 14.9 (mean 4.5) years. There were 8 "pre-terminal" (test group) patients who died or were listed for re-transplantation within 9 months after TDI echo. These ranged in age from 2.6 to 17 (mean 11.6) years, age at transplant from 1 month to 15.9 (mean 8.1) years, and time from transplant to enrollment was 0.7 to 9.8 (mean 3.6) years. TDI was performed in the apical four-chamber view. Systolic (S, cm/s) and diastolic early (E, cm/s) and late (A, cm/s) velocity. Mitral and tricuspid annular TDI velocities were measured. Tricuspid regurgitation and LV ejection fraction were also compared. RESULTS: Pre-terminal patient's Left Ventricular Ejection Fraction began diverging from controls at 3 to 6 months prior to endpoint (p < 0.001). Tricuspid TDI S velocities of pre-terminal patients diverged by 2.0 cm/sec from controls (p < 0.002) 6 months prior to, and reduced further by 2.9 cm/sec 3 months prior to endpoint (p < 0.001). Tricuspid TDI E velocities diverged 3 to 6 months before endpoint, by 1.9 cm/sec (p < 0.02) and by 3.7 cm/sec 0-3 months prior to endpoint, (p < 0.001). Mitral S velocities diverged from controls by 1.5 cm/sec at 0 to 3 months before terminal endpoints (p = 0.002). Mitral E velocities were statistically similar at all time intervals (p > or = 0.15). Septal S velocities equaled controls 6 months (p = 0.92) and between 3 to 6 months (p = 0.83) but diverged by 1.6 cm/sec 0 to 3 months before terminal endpoints (p = 0.01). Septal E velocities equaled controls. Mortality Prediction: LVEF, tricuspid annulus systolic and diastolic velocities, and tricuspid regurgitation severity were significant in predicting mortality. Coronary angiography was performed in 26 patients, 5 had severe coronary artery disease and all were pre-terminal. DISCUSSION: The TDI data reported here show 3 to 6 months before the terminal graft failure, tricuspid, but not mitral, S and E TDI velocities, deteriorated to uniquely low levels not seen in other clinically well pediatric transplant recipients. Further RV deterioration occurred during the final 3 months before death and severely reduced left ventricular velocities then occurred. Small decreases in LVEF and progressive increases in the severity of tricuspid regurgitation were also detectable and predicted an increased likelihood of mortality. Seven of the 8 preterminal patients had angiograms 5 of which showed severe CAV. These data suggest that there is a critical "pre-terminal" window of time in which children demonstrate uniquely reduced right and subsequently left sided myocardial velocities at approximately 6 months prior to graft failure. The practice of annual catheterization and coronary angiography may not allow caregivers an opportunity to intervene early in the process of graft dysfunction. Therefore, a strategy of tissue Doppler echocardiography 2 or 3 times each year might be an appropriate regimen to survey for graft impairment.

Adolescent↗
PubMed2006

Surgical findings and long-term hearing results in 3,050 stapedotomies for primary otosclerosis: a prospective study with the otology-neurotology database.

OBJECTIVE: To evaluate with a new otologic database the results of primary stapes surgery for otosclerosis with up to 14 years of follow-up in a consecutive series of 2,525 patients operated on by the same surgeon with the same technique (stapedotomy and vein graft interposition) and to provide online access to the complete data of this study for the reviewers. To study the effect of specific operative findings (obliterative otosclerosis and simultaneous malleus ankylosis) and age at the time of surgery on the long-term outcome. STUDY DESIGN: Prospective clinical study using a new computerized otologic database. SETTING: : Tertiary referral center. PATIENTS: Two thousand five hundred twenty-five patients who underwent 3,050 stapedotomies for otosclerotic stapes fixation were enrolled in this study from January 1991 to December 2004. Separate analyses were made for two unique pathologies (92 cases of obliterative otosclerosis and 19 cases of simultaneous malleus ankylosis) diagnosed during surgery and for patients in two age brackets ( or=65 yr [302 patients]). INTERVENTION: Stapedotomy with vein graft interposition and reconstruction with either a Teflon piston, a bucket handle prosthesis, or a total prosthesis. MAIN OUTCOME MEASURES: Preoperative and postoperative audiometric evaluation using conventional audiometry. Air-bone gap (ABG), bone-conduction thresholds, and air-conduction thresholds were all assessed. Postoperative audiometry was performed at 3, 6, 9, 12, 18, and 24 months and then annually for 14 years. RESULTS: Overall, the postoperative ABG was closed to 10 dB in 94.2% of cases. The mean four-frequency postoperative ABG was 1.7 dB compared with 25.6 dB preoperatively. The mean four-frequency bone-conduction thresholds were unchanged postoperatively. A significant postoperative sensorineural hearing loss (SNHL; >15 dB) was seen in 0.5% of cases in this series. Postoperative ABG was achieved to within 10 dB in 95% of cases of obliterative otosclerosis and in 64.7% of cases of simultaneous malleus ankylosis. A significant postoperative SNHL (>15 dB) was seen in 4.8% of cases of obliterative otosclerosis and was not observed in any cases of simultaneous malleus ankylosis. Postoperative ABG was achieved to within 10 dB in 93.5% of cases in the pediatric series and in 94.5% of cases in the senior series. A significant postoperative SNHL (>15 dB) was seen in 0.7% of cases in the senior group but was not observed in the children. CONCLUSION: Using a new otologic database, our series confirms that stapedotomy with vein graft interposition for otosclerotic stapes fixation is a safe and successful treatment for long-term hearing improvement. The deterioration in hearing with time after stapedotomy did not exceed the rate of hearing loss because of presbyacusis. Therefore, argon laser stapedotomy with vein graft interposition is our preferred surgical technique in the treatment of otosclerosis. Obliterative otosclerosis and simultaneous malleus ankylosis may be encountered during stapedotomy. Our study shows that reasonable success rates can still be expected in these situations. Stapedotomy results in the elderly and in children are comparable to those obtained in patients of other groups of age undergoing surgery for otosclerosis without an increased risk for complications.

Adolescent↗
PubMed2005

Stapedotomy in osteogenesis imperfecta: a prospective study of 23 consecutive cases.

OBJECTIVE: To prospectively evaluate the hearing results in surgically treated cases of stapes fixation in patients with osteogenesis imperfecta. STUDY DESIGN: A prospective study of osteogenesis imperfecta patients with stapes fixation. SETTING: One tertiary referral center. PATIENTS: Eighteen patients (23 ears) who underwent stapes surgery from 1994 to 2004 were prospectively included. INTERVENTION: Stapedotomy with vein graft interposition and reconstruction with a Teflon piston or a bucket handle (cup) prosthesis. MAIN OUTCOME MEASURES: Preoperative and postoperative audiometric evaluation using conventional audiometry. Air-bone gap, bone-conduction thresholds, and air-conduction thresholds were measured. Postoperative audiometry was performed at 6, 9, 12, 18, and 24 months after surgery and at a yearly interval thereafter. RESULTS: Overall, a postoperative air-bone gap closure to within 10 dB was achieved in 85.7% of cases. Postoperative improvement of air-conduction thresholds superior to 20 dB was found in 57% of cases. The postoperative bone-conduction thresholds were unchanged. CONCLUSION: This study shows that safe and successful stapedotomy is possible in cases of stapes fixation in patients with osteogenesis imperfecta.

Adolescent↗
PubMed2005

Ossiculoplasty with intact stapes and absent malleus: the silastic banding technique.

OBJECTIVE: To report an original method of ossicular reconstruction with intact stapes and absent malleus. Ossiculoplasty is performed with a total ossicular replacement prosthesis positioned from the stapes footplate to the under-surface of the tympanic membrane, using a Silastic banding technique to stabilize the prosthesis. STUDY DESIGN: A prospective study of ossicular reconstruction using the Silastic banding technique. A consecutive series of cases with intact stapes superstructure and missing malleus handle (Austin-Kartush Group C) is presented. SETTING: One tertiary referral center. PATIENTS: Ninety-nine patients who underwent total ossicular reconstruction with Silastic banding technique were enrolled in the study from January 2000 to December 2002. INTERVENTIONS: Ossiculoplasty with total ossicular replacement prostheses with Silastic Rubber Band for chronic otitis media and non-inflammatory disease. MAIN OUTCOME MEASURES: Preoperative and postoperative audiometric evaluation using conventional audiometry. Air-bone gap, bone-conduction threshold, and air-conduction threshold were assessed. Postoperative audiometry was performed at the 6th, 9th, 12th, 18th, 24th, and 36th months. RESULTS: Overall, a postoperative air-bone gap closed to within 10 dB was achieved in 61.5% of cases. An air-bone gap smaller than 20 dB was obtained in 77% of cases. Postoperative improvement of air-conduction thresholds by at least 20 dB was found in 51% of cases. There was no case of postoperative sensorineural hearing loss. One case of extrusion of the prosthesis was seen (1%). CONCLUSION: Stabilizing the total ossicular replacement prosthesis with the Silastic banding technique when performing ossicular reconstruction is a safe, effective method when the stapes supra-structure is present and the malleus absent.

Adolescent↗
PubMed2004

Computational BAC clone contig assembly for comprehensive genome analysis.

Comparative genomic hybridization (CGH) has proved to be a powerful tool for the detection of genome copy number changes in human cancers and in other diseases caused by segmental aneusomies. Array versions of CGH allow the definition of these aberrations, with resolution determined by the size and distribution of the array elements. Resolution approaching 100 kb can be achieved by use of arrays comprising bacterial artificial chromosomes (BACs) distributed contiguously across regions of interest. We describe here a computer program that automatically assembles contigs of minimally overlapping BAC clones, using information about BAC end-sequences and the normal genome DNA sequence. We demonstrate the characteristics of contigs assembled and annotated by use of this approach for regions of recurrent abnormality in human ovarian and breast cancers at chromosome bands 3q25-q27 and 8q24 and chromosome arm 20q. We also show illustrative analyses of regions of amplification in these regions in breast and ovarian tumor cell lines by use of array CGH with arrays comprising contiguous BACs.

Breast Neoplasms↗
PubMed2004

Malleus relocation in ossicular reconstruction: managing the anteriorly positioned malleus: results in a series of 268 cases.

OBJECTIVE: The objective of this study was to report an original method of malleus relocation allowing for better placement of both partial and total prostheses in ossicular reconstruction. STUDY DESIGN: We conducted a retrospective review of clinical and audiometric findings. SETTING: A tertiary referral center. MATERIALS AND METHODS: This is a study of 268 patients who underwent ossiculoplasty surgery from October 1997 to October 2000 for chronic otitis media, noninflammatory disease, and otosclerosis revision. Malleus relocation with total and partial ossicular replacement prostheses was used in all cases. Audiometric assessment included pre- and postoperative audiometric evaluation using conventional audiometry. Air-bone gap, bone-conduction thresholds, and air-conduction thresholds were measured. RESULTS: A postoperative air-bone gap closed to within 10 dB was achieved in 56% of cases. An air-bone gap smaller than 20 dB was obtained in 78% of cases. Postoperative improvement of air-conduction thresholds superior to 20 dB was found in 41.5% of cases. The postoperative bone-conduction thresholds were unchanged in 98% of cases. One case of total postoperative sensorineural hearing loss was seen in this series (0.4%). Extrusion of the protheses was not observed in this series. Follow up ranged from 6 to 36 months (mean, 12.4 months). CONCLUSION: This study shows that malleus relocation is a safe and efficient technique for ossicular reconstruction. The ideal position of the relocated malleus allows easier and more stable placement of middle ear prostheses.

Adolescent↗
PubMed2003

Gene structure, chromosomal localization, and mutation screening of the human gene for the inner ear protein otospiralin.

Otospiralin is a novel protein of unknown function that is produced by non-sensory cells (fibrocytes) of the inner ear (cochlea and vestibule). We showed that downregulation of otospiralin in guinea pigs leads to deafness and we therefore hypothesized that genetic defects in the otospiralin gene could also cause deafness in humans. In this study, we cloned and localized OTOSP, the human gene for otospiralin. OTOSP spans 1630 nucleotides, contains four exons and codes for a 567-nucleotide cDNA. By fluorescence in situ hybridization and hybrid panel mapping we localized OTOSP on chromosome 2 at position q37.3. There is currently no deafness family linked to this region. We screened OTOSP for mutations in 410 unrelated patients exhibiting various levels of hearing loss. Beside intronic polymorphisms, a rare variant (Pro7Leu) was found in 4 deafness patients and 3 control individuals, indicating that this change is not involved in this condition and excluding OTOSP as a major gene for genetic deafness.

Amino Acid Substitution↗
PubMed2003

Enalaprilat improves systemic and mesenteric blood flow during resuscitation from hemorrhagic shock in dogs.

We investigated the systemic and mesenteric cardiovascular effects of administering enalaprilat during resuscitation from hemorrhage. Dogs were hemorrhaged (mean arterial pressure [MAP] 40-45 mmHg for 30 min, then 30-35 mmHg for 30 min) and were then resuscitated with intermittent lactated Ringer's solution (200 mL/kg/h during first 40 min, and 60 mL/kg/h during the following 130 min, MAP 75-80 mmHg). A constant-rate infusion of saline with or without enalaprilat (0.02 mg/kg/h) was initiated after 40 min of resuscitation. Blood flows declined with hemorrhage, increased with resuscitation, and then declined during the initial 40 min of resuscitation. Enalaprilat administration resulted in blood flow increases not seen in the controls (ending values for cardiac index: 2.8 +/- 0.4 L/min/m2 vs. 1.6 +/- 0.3 L/min/m2; celiac arterial flow 314 +/- 66 L/min/m2 vs. 139 +/- 13 mL/min/m2; and portal venous flow 596 +/- 172 L/min/m2 vs. 414 +/- 81 mL/min/m2 for enalaprilat versus controls, respectively). The greater flows with enalaprilat appeared to be due to prevention of the increases in afterload noted in the controls (ending arterial elastance values 3.73 +/- 0.97 mmHg/m2/mL vs. 7.74 +/- 1.80 mmHg/m2/mL for enalaprilat versus controls, respectively). We conclude that administration of a constant-rate infusion of enalaprilat during resuscitation can be used to improve systemic and mesenteric blood flow.

Animals↗
PubMed2002

Airflow-based PCO2 monitoring delivers O2 and removes CO2 from the monitored environment.

Previous investigation has suggested that the use of airflow-based gastrointestinal intraluminal PCO2 (GI PiCO2) monitoring systems may affect the local tissue microenvironment, making it not representative of the organ system as a whole. Therefore, we investigated the effects of using an airflow-based PCO2 monitoring system in a sealed environment. A 250-mL Erlenmeyer flask was filled with 10% CO2/90% N2 and was sealed with probes in place. Using a fiber-optic (Neotrend, Diametrix Medical, St. Paul, MN) system, the PCO2 and PO2 were continuously monitored with and without the airflow-based (Tonocap, Tonometrics, Datex-Ingstrom, Helsinki, Finland) system operating. PCO2 and PO2 remained constant when the airflow-based system was not in operation. PCO2 decreased 25.3 mmHg and PO2 increased 30 mmHg from a starting value of 0 mmHg when the airflow-based system was in operation for 12 h. The use of airflow-based methods for determining GI PiCO2 may influence the values obtained. Nonsample removing techniques such as fiber-optic methods for monitoring GI PiCO2 are preferable because they neither deliver O2 to nor remove CO2 from the local microenvironment.

Carbon Dioxide↗
PubMed2002

Stapedotomy for tympanosclerotic stapes fixation: is it safe and efficient? A review of 68 cases.

OBJECTIVE: Performing stapedotomy in cases of tympanosclerotic stapes fixation is controversial. The procedure is traditionally considered to carry a high risk of postoperative sensorineural hearing loss. The aim of this study was to report the hearing results in surgically treated cases of stapes fixation. STUDY DESIGN: A retrospective review of tympanosclerosis of the oval window with stapes fixation. SETTING: The study was performed at the Jean Causse Ear Clinic in Clombiers, France. PATIENTS: Sixty-five patients who underwent surgery for tympanosclerotic stapes fixation between January 1992 and October 1999. INTERVENTION: Stapedotomy with vein graft interposition and reconstruction with a Teflon piston, or a total prosthesis in cases of incudal erosion. MAIN OUTCOME MEASURES: Preoperative and postoperative audiometric evaluation using conventional audiometry. Air-bone gap, bone conduction threshold, air conduction threshold, and Glasgow Benefit Plot were measured. RESULTS: Postoperative air-bone gap closure to within 10 dB was achieved in 39% of cases. An air-bone gap less than 20 dB was obtained in 70% of cases. Significant postoperative improvement of air conduction thresholds, more than 20 dB, was found in 46% of cases. The postoperative bone conduction thresholds were unchanged in 92% of cases. No significant sensorineural hearing loss was seen in this series. CONCLUSION: This series demonstrates that safe and successful stapedotomy is possible if certain rules are respected.

Adolescent↗