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Biomedical subjects

J Jamart

Publications and source records attributed to J Jamart.

At least 109 records · Page 6Linked to original sources

Reperfused ischemia of the rat intestine: detection by MR imaging with polylysine-Gd-DTPA enhancement.

To detect reperfused ischemia of the rat intestine, T2-weighted spin-echo images were acquired, followed by T1-weighted images before and after administration of polylysine-Gd-DTPA or Gd-DTPA. Before administration of the contrast agent, the reperfused intestine was hyperintense on T2-weighted images, and to a lesser extent on T1-weighted images. After administration of polylysine-Gd-DTPA, the reperfused intestine enhanced more than the normal one, giving a significantly better contrast-to-noise (CNR) ratio than on unenhanced images. Gd-DTPA induced the same enhancement of the reperfused and the normal intestine and the CNR was lower than on unenhanced T2-weighted images. Reperfused intestinal ischemia could thus be better detected on polylysine-Gd-DTPA-enhanced MR images than on unenhanced images or on Gd-DTPA-enhanced images.

Animals↗

MRI of the anal canal: correlation with histologic examination.

The purpose of this study was to correlate the MRI features of the anal canal with histologic findings. T1- and T2-weighted MR images of nine anal canals were obtained after fixation in 10% formalin. In three specimens, imaging was repeated after removal of histologic layers with a dissecting microscope. Corresponding histologic slices were stained with hematoxylin-eosin, Masson trichrome, and periodic acid-Schiff. Four layers were visualized on T2-weighted images. An inner layer of high signal intensity and a second layer of low signal intensity corresponded to the mucosa as well as mucous secretions and to the submucosa. The high signal intensity layer vanished at the distal part of the anal canal in accordance with the lack of mucus-secreting epithelium below the level of the dentate line. A third layer of intermediate signal intensity corresponded to the internal sphincter. A fourth layer of low signal intensity corresponded to the longitudinal muscle and external sphincter. T2-weighted MRI is capable of showing the internal architecture of the wall of the anal canal. In particular, the internal sphincter can be differentiated from the external sphincter and longitudinal muscle.

Anal Canal↗

Flow-mediated vasodilation during pacing of the free epigastric artery bypass graft early and late postoperatively.

OBJECTIVES: The free epigastric artery bypass graft is proposed as an alternative conduit to the saphenous vein graft, known for its high rate of attrition. The aim of our study was to assess its endothelial function in vivo. BACKGROUND: The endothelium of arterial bypass grafts plays a role in both the performance and the patency of such grafts. METHODS: We studied 73 epigastric grafts early (mean +/- SD 10 +/- 3 days) and 36 late (12 +/- 5 months) after coronary bypass surgery with quantitative angiography at rest, after 2 min of atrial pacing (130 beats/min) and after injection of isosorbide dinitrate (1 to 2 mg) into the graft. RESULTS: At rest, mean epigastric graft diameter was lower in the late than in the early postoperative period (2.26 +/- 0.39 vs. 2.61 +/- 0.49 mm, p < 0.001). Early after operation, epigastric grafts with a small or an intermediate runoff, but not those with a large runoff, were capable of vasodilation with nitrates (+0.09 +/- 0.10 mm). Late after operation, vasodilation after administration of isosorbide dinitrate was similar in epigastric grafts with a large runoff and in those with a small or intermediate runoff (+ 0.23 +/- 0.09 vs. +0.23 +/- 0.18 mm). Significant vasodilation during pacing was observed late (+4 +/- 9%, p < 0.01) but not early postoperatively, except in a subset of patients with grafts capable of vasodilation after nitrates. A correlation between the response to nitrates and the response during pacing was observed early (r = 0.579, p < 0.001) and late postoperatively (r = 0.530, p = 0.02). CONCLUSIONS: Flow-mediated vasodilation during pacing was observed in most epigastric grafts late, but not early, after operation. This endothelium-dependent dilation was correlated with the importance of the vasodilation observed with nitrates (endothelium-independent), which was related to the importance of the runoff only in the early postoperative period. The ability of epigastric grafts late postoperatively to dynamically adapt their dimensions to an acute increase in demand could contribute to the good functional results of this new alternative arterial graft.

Cardiac Catheterization↗

Myocardial revascularization for severe left ventricular dysfunction. Factors influencing early and late survival.

The results of coronary bypass surgery have been assessed in 102 patients with severe left ventricular dysfunction who had a preoperative left ventricular ejection fraction of < or = 0.35 (mean (s.e.m.) 0.29 (0.01)). Independent risk factors influencing operative mortality were obesity (P = 0.0290) and the need for preoperative intra-aortic balloon counterpulsation (P = 0.0010). Cox regression analysis using as its end-point 'cardiac-related death' demonstrated three variables; the need for preoperative intra-aortic balloon counterpulsation (P < 0.001), advanced age (P = 0.011), and obesity (P = 0.36). In a subset of 43 patients who did not have these risk factors, the 4-year cardiac-related death rate was 95.1 (3.4)%. The operative mortality and long-term survival can be expected to be satisfactory in patients with severe left ventricular dysfunction, provided they have a viable myocardium rather than myocardial fibrosis.

Aged↗

Posterior cordectomy and subtotal arytenoidectomy for the treatment of bilateral vocal fold immobility: functional results.

We report vocal and respiratory results following endoscopic CO2 laser therapy for bilateral vocal fold immobility in adduction. Two techniques were used: posterior cordectomy (PC) and subtotal arytenoidectomy (SA). Respiratory improvement was demonstrated by the peak expiratory flow/peak inspiratory flow ratio (PEF/PIF, normal = 1), which was less than 2 for 83% of patients following PC and for 81% following SA. As for vocal results, there were no significant quantitative differences between the two techniques. Mean maximum phonation time (/a/) was 6.8 +/- 2.6 s after SA and 7.8 +/- 1.6 s following PC. The phonation quotient was 288 +/- 116 ml/s after SA and 304 +/- 92 ml/s after PC. Mean vocal intensity was 62 +/- 4 dB after SA and 59 +/- 3 dB after PC. Vocal quality was measured by high-resolution vocal frequency analysis, as represented by a histogram. Peaks corresponding to fundamental frequency and first harmonics were preserved in more than 60% of patients in the two groups. Vocal preservation is better when the paralyzed folds are in the paramedian position, with the possibility of adduction (Gerhardt syndrome). SA is performed in our procedure, though it is longer and more difficult to perform than PC. PC often requires two procedures to achieve satisfactory results.

Adolescent↗

Propofol-alfentanil versus fentanyl-midazolam in coronary artery surgery.

OBJECTIVE: To compare intraoperative hemodynamics profiles and recovery characteristics of propofol-alfentanil with fentanyl-midazolam anesthesia in elective coronary artery surgery. DESIGN: Prospective, randomized study. SETTING: University hospital. PARTICIPANTS: Fifty patients with impaired or good left ventricular function. INTERVENTIONS: In group 1, (n = 25) anesthesia was induced with an infusion of propofol, 3 to 4 mg/kg/h, alfentanil, 500 micrograms, and pancuronium 0.1 mg/kg, and maintained with propofol, 3 to 6 mg/kg/h (variable rate), and alfentanil infusions, 30 micrograms/kg/h (fixed rate). Additional boluses of alfentanil, 1 mg, were administered before noxious stimuli; group 2 (n = 25) received a loading dose of fentanyl, 25 micrograms/kg, midazolam, 1.5 to 3 mg, and pancuronium, 0.1 mg/kg for induction, followed by an infusion of fentanyl, 7 micrograms/kg/h, for maintenance. Additional boluses of midazolam (1.5 to 3 mg) and fentanyl (250 micrograms) were administered before noxious stimuli. MEASUREMENTS AND MAIN RESULTS. Cardiovascular parameters at eight intraoperative time points as well as time to extubation, morphine consumption, and pain scores were recorded. Induction of anesthesia was associated in both groups with a small but significant decrease in mean arterial pressure (1: 15 mmHg (15%); 2: 8 mmHg (8%) with significant decreases in cardiac index (1: 8%; 2: 8%) and left ventricular stroke work index (1: 24%; 2: 21%). Throughout surgery, hemodynamic profiles were comparable between groups except after intubation when the MAP was significantly lower in group 1 (75 +/- 12 mmHg) than in group 2 (89 +/- 17 mmHg). Group 1 required less inotropic support. Extubation was performed faster in group 1 (7.6 h) than in group 2 (18.0 h). Morphine requirements and pain scores were comparable between groups. CONCLUSIONS: Propofol-alfentanil anesthesia provides good intraoperative hemodynamics and allows early extubation after coronary artery surgery.

Aged↗

Endoscopic treatment of tracheal stenosis using the carbon dioxide laser and the Gianturco stent: indications and results.

The self-expandable Gianturco stent was used in 11 patients with tracheal stenosis who where treated from September 1992 through July 1994. Under optical control, the stent was placed through a bronchoscope with an outside diameter of 9 mm after cross-section and dilation of the stenosis were performed with the carbon dioxide laser according to the Shapshay technique. The follow-up period varied from 3 to 22 months, with a mean of 12 +/- 6 months. Pulmonary function tests showed a mean improvement of the peak expiratory flow (50%), from 0.95+/-0.45 L/sec before the operation to 2.13+/-0.86 L/sec after the procedure. Radiologic and fibroscopic controls showed prosthesis stability. Three patients needed a second endoscopic procedure because of malposition of the stent, the formation of granuloma at the superior end of the prosthesis, and the development of a mucous membrane webbing between the two loops of a stent. Due to the lack of long-term follow-up, this technique is reserved for the treatment of severe tracheal stenosis with cartilage impairment in patients who have contraindications for external reconstructive surgery.

Aged↗

Long-term stability of cefuroxime and cefazolin sodium in intravenous infusions.

Cefazolin and cefuroxime sodium are often used as antibiotic infusions for hospitalized patients. Because advance preparation of these intravenous solutions is efficient, the stability of both antibiotics stored at 4 degrees C in polyvinyl chloride (PVC) bags was studied. Five bags of solutions containing either 1 g of cefazolin sodium or 1.5 g of cefuroxime sodium per 100 ml of 5% dextrose were studied for 1 month by high-performance liquid chromatography (HPLC), visual inspection and pH measurement. No colour change or precipitation was observed. The pH values of both drugs increased significantly over the period of study. Based on a shelf-life of 90% residual potency, the cefuroxime sodium concentration was stable for 13 days when stored at 4 degrees C, and the cefazolin sodium concentration was stable for at least 30 days at 4 degrees C. Within these limits, both antibiotics may be prepared in advance by a centralized intravenous admixture service.

Cefazolin↗

Increase in non-specific bronchial hyperresponsiveness as an early marker of bronchial response to occupational agents during specific inhalation challenges.

BACKGROUND: Specific bronchial reactivity to occupational agents may decline after exposure in the workplace ceases leading to falsely negative specific inhalation challenges. A study was carried out to assess prospectively whether increases in nonspecific bronchial hyperresponsiveness could be useful in detecting the bronchial response to occupational agents during specific inhalation challenges. METHODS: Specific inhalation challenges were performed in 66 subjects with possible occupational asthma due to various agents. After a control day the subjects were challenged with the suspected agent for up to two hours on the first test day. Those subjects who did not show an asthmatic reaction were rechallenged on the next day for 2-3 hours. The provocative concentration of histamine causing a 20% fall (PC20) in the forced expiratory volume in one second (FEV1) was assessed at the end of the control day as well as six hours after each challenge that did not cause a > or = 20% fall in FEV1. The subjects who had a significant (> or = 3.1-fold) reduction in PC20 value at the end of the second challenge day were requested to perform additional specific inhalation challenges. RESULTS: The first test day elicited an asthmatic reaction in 25 subjects. Of the other 41 subjects five (12%, 95% confidence interval (CI) 4% to 26%) exhibited a > or = 3.1-fold fall in the PC20 value after the inhalation challenge and developed an asthmatic reaction during the second (n = 3) or third (n = 2) challenge exposure. The offending agents included persulphate (n = 1), wood dust (n = 2), isocyanate (n = 1), or amoxycillin (n = 1). These five subjects had left their workplace for a longer period (mean (SD) 21 (14) months) than those who reacted after the first specific inhalation challenge (8 (11) months). CONCLUSIONS: The increase in non-specific bronchial hyperresponsiveness after a specific inhalation challenge can be an early and sensitive marker of bronchial response to occupational agents, especially in subjects removed from workplace exposure for a long time. Non-specific bronchial hyperresponsiveness should be systematically assessed after specific inhalation challenges in the absence of changes in airway calibre.

Adult↗

Stage I multiple myeloma: value of MR imaging of the bone marrow in the determination of prognosis.

PURPOSE: To determine the prognostic value of bone marrow findings at magnetic resonance (MR) imaging in patients with stage I multiple myeloma. MATERIALS AND METHODS: In 24 patients with stage I multiple myeloma, findings from MR imaging of the vertebral, pelvic, and femoral bone marrow were analyzed and correlated to spontaneous outcome. Progressive multiple myeloma was observed in 12 patients and stable stage I multiple myeloma was observed in 12 after a follow-up period of 4-67 months (median, 27 months). RESULTS: In 17 patients, MR imaging findings were normal, and in seven patients, bone marrow abnormalities were depicted on MR images. Of the 12 patients with progressive multiple myeloma, six had bone marrow abnormalities that were depicted at MR imaging. In the group of patients with progressive multiple myeloma, the six patients with abnormal MR imaging findings showed earlier disease progression (median, 10 months) than the six patients in whom MR imaging findings were normal (median, 32 months) (P < .0001). Multivariate analysis of clinical and MR imaging findings showed that MR imaging (P = .006) were two independent factors in the prediction of disease progression. CONCLUSION: MR imaging of the bone marrow in patients with stage I multiple myeloma is an independent factor in the prediction of disease progression.

Bone Marrow↗

Persisting perfusion defect in transient ischemic attacks: a new clinically useful subgroup?

BACKGROUND AND PURPOSE: Cerebral infarction and prolonged regional hypoperfusion have been described in patients with transient ischemic attacks (TIAs). The aim of this study was to compare the sensitivity of single-photon emission CT (SPECT) with that of brain CT and to evaluate the clinical significance of differentiation of TIA patients with or without focal hypoperfusion. METHODS: From a hospital-based population, we studied the SPECT and CT findings in 76 consecutive patients, without a stroke history, who presented with TIA in the carotid artery territory. The recorded variables were the time of SPECT, imaging (<36 or > or = 36 hours), clinical presentation, history of previous TIA(s), duration of the presenting attack (<2 or > or = 2 hours), vascular risk factors, and etiology. We used both visual and semiquantitative analyses for the SPECT evaluation. Acetazolamide challenge was not performed. RESULTS: The overall SPECT sensitivity was 36% (27/76). When brain CT and SPECT were performed in the same patients, the SPECT sensitivity was significantly higher than that of CT (19/59 [32%] versus 8/59 [14%]; P=.007). The SPECT sensitivity was not dependent on the time of investigation, duration of attacks, history of TIA(s), or the clinical presentation. The vascular risk and etiologic factors were not significantly different between the patients with or without prolonged focal hypoperfusion. Logistic regression did not identify any variable to discriminate the two groups. CONCLUSIONS: Despite its better sensitivity compared with CT, SPECT performed without the acetazolamide test provides no additional clinically useful information on the vascular risk factors and etiology in TIA patients.

Acetazolamide↗

Subtotal carbon dioxide laser arytenoidectomy by endoscopic approach for treatment of bilateral cord immobility in adduction.

Subtotal carbon dioxide (CO2) laser arytenoidectomy for endoscopic treatment of bilateral immobility of the vocal folds in adduction is a variant of total arytenoidectomy. The principal modification involves preservation of a thin posterior shell providing good postoperative fixation of the arytenoid region. The risk of aspiration is thus averted and collapse of arytenoid mucosa into the larynx during inspiration is prevented. The risk of synechia with the posterior commissure is avoided. The CO2 laser is operated at a working distance of 400 mm with a continuous 7-W beam in superpulse mode. Operation time is thus reduced to approximately half an hour and the risk of postoperative edema is reduced. Tracheotomy is not necessary. Forty-one patients, including 16 men and 25 women, were treated by this technique between 1985 and 1994. Their mean age was 55 +/- 17 years, ranging from 11 to 83 years. Follow-up ranged from 1 month to 111 months (9 years 3 months), with a mean of 56 +/- 29 months (4 years 8 months). The mean peak forced expiratory flow-peak inspiratory flow ratio (normal = 1), which permits a measurement of respiratory quality, is improved from 3.7 +/- 1.4 preoperatively to 1.6 +/- 0.5 postoperatively (p<.001). Postoperative voice measurements show a mean vocal intensity of 61 +/- 3 dB hearing level, a mean maximum phonation time of 8 +/- 4 seconds, and a mean phonation quotient of 397 +/- 150 mL/s. As for vocal quality, 38% of the patients now have a near-normal voice according to our high-resolution frequency analysis, and all of the patients retained satisfactory voice quality.

Adult↗

MR imaging of the acetabular labrum: variations in 200 asymptomatic hips.

OBJECTIVE: The purpose of this study was to describe the MR appearance of the acetabular labrum in asymptomatic subjects and correlate the MR appearance with age and sex. MATERIALS AND METHODS: We evaluated high-resolution T1-weighted spin-echo coronal MR images of one hip in each of 200 asymptomatic individuals (84 men, 116 women; mean age, 44 years old; range, 15-82 years old). The labral shapes (triangular, round, flat, or absent), the intralabral signal intensity changes, and the possible extension of the intralabral signal intensity changes to the labral surface were assessed on two sections for each subject and correlated with age and sex. RESULTS: Triangle was the dominant shape seen on MR imaging (66%). However, its frequency decreased significantly with age. Absence of labrum was the second most frequent pattern (14%) and increased significantly with age. Round and flat labra were found in 11% and 9% of subjects, respectively, with no significant age correlation. The frequency of homogeneous labra with low signal intensity decreased with age. Intralabral areas of high signal intensity communicating with the free surface increased with age. CONCLUSION: The large variability of the MR appearance of the labrum in asymptomatic hips must be considered when interpreting MR examinations of patients in whom labral lesions are suspected.

Acetabulum↗

Comparison of colour Doppler imaging with conventional duplex scanning in the evaluation of extracranial carotid stenosis.

OBJECTIVE: To assess the concordance between conventional duplex scanning and colour Doppler imaging in the grading of extracranial carotid artery stenosis. PATIENTS AND METHOD: A total of 67 carotid bifurcations in 48 patients were studied independently by two observers. First, each observer obtained a conventional duplex scan and recorded peak systolic and diastolic velocities. Then, each observer performed a colour Doppler study in which only the point of maximal colour shift was sampled. The stenosis in each case was subsequently classified, first as one of four classes (mild, moderate, severe or critical) on the basis of percent stenosis and peak systolic and diastolic velocities, and then as one of two groups (less than 70% or 70% or greater, with a peak systolic velocity of 2.3 m/second as the cut-off point). RESULTS: For the first observer, the two methods disagreed in 10 (15%) of the 67 cases. In five of these cases, colour Doppler imaging indicated a higher class of stenosis, and in the other five cases conventional duplex scanning indicated a higher class of stenosis. For this observer, the mean of the difference between conventional duplex and colour Doppler scanning for peak systolic and diastolic values was not statistically different from 0 (three-way analysis of variance). With colour Doppler imaging observer 1 detected all of the 14 cases of stenosis of 70% or greater that were detected by conventional duplex scanning. For observer 2, the results of the two methods differed in 12 (18%) of the 67 cases. For all 12 cases, conventional duplex scanning indicated a higher class of stenosis. The mean of the difference between the two methods was -23.8 cm/second (standard deviation 46.0) for peak systolic velocity and -10.7 cm/second (standard deviation 24.7) for peak diastolic velocity (both significantly different from 0). With colour Doppler imaging observer 2 did not identify 3 of the 16 cases of stenosis of 70% or greater that were detected by conventional duplex scanning. CONCLUSION: Discrepancies may exist between conventional duplex scanning and colour Doppler imaging in assessing extracranial carotid artery stenosis.

Adult↗

Cetirizine and pseudoephedrine retard alone and in combination in the treatment of perennial allergic rhinitis: a double-blind multicentre study.

We compared the efficacy and safety of 5 mg cetirizine (CTZ), 120 mg pseudoephedrine retard (PER) and their combination (COM), given twice daily for three weeks, for the treatment of perennial allergic rhinitis. Two hundred and ten evaluable patients (97 males and 113 females) were included in the study and randomly allocated to one of three treatment groups, each of 70 patients. Nasal obstruction, sneezing, rhinorrhoea, nasal and ocular pruritus were scored each day throughout the study by patients using a symptom scale ranging from 0 (no symptom) to 3 (severe). The mean proportion of days without symptoms was higher in the COM group (11.8%) than in the CTZ (6.8%) and PER (5.1%) groups, but the differences were not statistically significant. The mean percentage of days when symptoms were absent or at most mild was significantly higher in the COM group (64.8%) than in either CTZ (45.5%; p = 0.003) or PER groups (40.6%; p = 0.0001). In addition, evaluation of symptoms by investigators and their global evaluation at the end of treatment showed statistically significant differences in favour of COM compared, to both CTZ and PER. The most frequent adverse events were somnolence in the CTZ and COM groups (8.6% and 12.9%, respectively) while insomnia was most frequent in the PER group. No clinically significant abnormalities were found in haematological or biochemical tests. These results indicate that the combined treatment was more effective than and as well tolerated as treatment with each individual agent.

Adult↗

Comparison of urinary excretion of albumin, alpha 1-microglobulin and retinol-binding protein in diabetic patients.

Small amounts of urinary proteins observed at early stages of diabetic nephropathy may result from both glomerular and proximal tubular dysfunction. However, the relative contribution of the two mechanisms remains controversial. We compared the urinary excretion of three low-molecular-weight proteins (albumin, alpha 1-microglobulin and retinal-binding protein) in 104 diabetic patients and 104 control subjects who had a plasma creatinine concentration of less than 130 mumol/l. Excretion of low-molecular-weight proteins was expressed as the ratio of protein to creatinine concentration. There were significant correlation (p < 0.01) between excretion of the three low-molecular-weight proteins measured in urine sample and 24-h urine collections in diabetic and control subjects. The concentrations of these proteins in single voided urinary samples and 24-h urine collections in diabetic patients were highly correlated. Excretion of retinal-binding protein, alpha 1-microglobulin and glucose in 24-h urine collections and of RBP and glucose in urinary samples was higher in diabetic than non-diabetic patients regardless of the type of diabetes and insulin-dependence. alpha 1-microglobulin and albumin excretions in urinary samples were significantly influenced by blood glucose control, as attested by the glycosylated haemoglobin level. Increased urinary excretion of alpha 1-microglobulin and retinol-binding protein reflected proximal tubular dysfunction in diabetic patients. However, only alpha 1-microglobulin correlated with the glycaemic control. It remains to be determined whether this protein could serve as an additional early marker of diabetic nephropathy.

Albuminuria↗

Operation for unstable angina pectoris: factors influencing adverse in-hospital outcome.

Coronary artery bypass grafting for the treatment of unstable angina is still associated with increased operative risk and postoperative morbidity. The impact of the extended use of arterial grafts on early results is incompletely defined. In a 7-year period (1986 to 1993), 474 patients (average age, 65 years; range, 34 to 85 years) underwent coronary artery bypass grafting for the treatment of unstable angina. Sixty-eight patients were operated on emergently and 406 urgently. They received an average of 3.0 distal anastomoses (range, 1 to 6). Seventy-nine patients had exclusively venous grafts, 316 had one internal thoracic artery graft, 79 had bilateral internal thoracic artery grafts, and 20 had inferior epigastric artery grafts. Sequential internal thoracic artery grafting was performed in 70 patients. Redo operations were performed in 26 patients. Thirty-four patients (7.2%) experienced a new myocardial infarction. Eighty-nine patients (18.8%) had an intraaortic balloon pump inserted preoperatively, intraoperatively, or postoperatively. Eight patients (1.7%) died intraoperatively and 24 patients (5.1%) died postoperatively. Seventy-seven patients (16.2%) had an adverse outcome, as shown by the need for an intraaortic balloon pump (intraoperatively or postoperatively) or hospital death, or by both. Forty variables were examined by multivariate analysis for their influence on the occurrence of an adverse outcome. Aortic cross-clamp time (p = 0.0004), transfer from the intensive care unit (p = 0.0023), female sex (p = 0.0023), operation performed in early years (p = 0.0041), left ventricular aneurysm (p = 0.0068), the number of diseased coronary vessels (p = 0.0312), and reoperation (p = 0.0318) were all found to be significant independent predictors of increased risk.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗