Search PubMed⌕ Search

Biomedical subjects

P Cartier

Publications and source records attributed to P Cartier.

At least 37 records · Page 2Linked to original sources
PubMed1998

Different effects of nifedipine and amlodipine on circulating catecholamine levels in essential hypertensive patients.

OBJECTIVE: To compare the acute and chronic effects of nifedipine retard (NPA), nifedipine gastrointestinal therapeutic system (NGITS) and amlodipine at trough and peak plasma concentrations of drug on blood pressure and heart rate, and on plasma norepinephrine and epinephrine levels in patients with mild-to-moderate hypertension (diastolic blood pressure 95-115 mmHg). DESIGN AND METHODS: After 3-4 weeks' placebo treatment, patients of both sexes were randomly allocated to be administered 10 or 20 mg NPA twice a day, 30 or 60 mg NGITS once a day, and 5 or 10 mg amlodipine once a day for 6 weeks. Initially, for the first 2 weeks, the lowest dose of each drug was used, but higher doses were administered after 2 weeks if sitting diastolic blood pressure was > 90 mmHg. Patients were evaluated after administration of the first dose and after 6 weeks' therapy in a hospital setting. Blood samples were taken for high-performance liquid chromatography measurement of catecholamine and drug levels at various intervals for a period covering trough to peak drug level ranges. RESULTS: Administration of all three drugs reduced clinic blood pressure to the same level after 6 weeks' therapy, but heart rate was increased slightly only with amlodipine (P < 0.05). Administration of NPA reduced blood pressure more abruptly whereas administrations of NGITS and amlodipine induced smoother falls after acute and chronic treatments: a significant increase in heart rate was observed with amlodipine after chronic treatment. Both acute and chronic treatments with NPA (n = 19) increased norepinephrine levels (P < 0.01) transiently (2-4 h). In contrast, administration of NGITS (n = 22) did not increase norepinephrine levels and even induced a slight but significant decrease in norepinephrine levels 5-6 h after chronic treatments. Although administration of amlodipine (n = 22) did not increase norepinephrine levels transiently either after acute or after chronic administration, it did induce a sustained rise in basal norepinephrine levels by more than 50% after chronic therapy (P < 0.01). Plasma epinephrine levels were not increased by any of the treatments and even a slight decrease was observed 4 h after administration of a dose following chronic treatments with NGITS and amlodipine (P < 0.05). CONCLUSIONS: The transient increase in norepinephrine levels observed with NPA and the sustained increases in norepinephrine levels observed after chronic treatment with amlodipine suggest that sympathetic activation occurs with those two drugs. The lack of increase in norepinephrine levels after administration of NGITS suggests that this formulation does not activate the sympathetic system. The lowering of epinephrine levels after administrations of NGITS and amlodipine suggests that inhibition of release of epinephrine by the adrenal medulla occurs with longer-acting dihydropyridine formulations.

Adult↗
PubMed1998

Rapidly evolving constrictive tuberculous pericarditis: case presentation and review of the literature.

A 69-year-old male presented with a diagnosis of idiopathic pericarditis, first treated with prednisone for a few weeks with resolution of the symptoms. A few days after stopping the medication, he presented with malaise, cough and signs of pericardial constriction confirmed by echocardiography. He was diagnosed with pulmonary tuberculosis with pericardial involvement and treated accordingly. Pericardiectomy was performed after a few days of treatment because the symptoms related to constriction progressed. The procedure was successful, and the patient was completely asymptomatic after 10 months. The removed pericardium stained positive for acid-fast bacilli.

Aged↗
PubMed1997

Comparison of a fluorescence polarization immunoassay of netilmicin in plasma, peritoneal dialysate, and urine with a high-performance liquid chromatographic method.

The quantitative analysis of netilmicin in plasma, peritoneal dialysate, and urine using the fluorescence polarization immunoassay (FPIA) of the Abbott TDx system is compared with the modified high-performance liquid chromatography (HPLC) method of Peng et al., which was chosen as a reference. Using the least square method, we found that the results of the FPIA (y) correlated well with those obtained with HPLC (x). The three regression equations for the plasma, peritoneal dialysate, and urine samples, respectively, were y = 0.71x + 0.44 with r = 0.88 and n = 45; y = 0.94x + 1.22 with r = 0.93 and n = 95; and y = 0.92x + 0.70 with r = 0.93 and n = 61. The corresponding mean errors (FPIA-HPLC) with their 95% confidence intervals were -0.19 (-0.38 to -0.02), 0.69 (-0.42 to 1.81), and -0.13 (-1.13 to 0.87) microgram/ml. According to results of the Wilcoxon matched-pairs signed-ranks test, these errors did not represent a significant bias. The FPIA is thus suitable for analyzing netilmicin in the three biological fluids studied except when dialysate is contaminated with Amuchina. In this case, HPLC should be used.

Chromatography, High Pressure Liquid↗
PubMed1996

Rapid protein identification using N-terminal "sequence tag" and amino acid analysis.

Proteins can be identified by amino acid analysis and database matching, but it is often desirable to increase the confidence in identity through the use of other techniques. Here we describe a rapid protein identification method that uses Edman degradation to create a 3 or 4 amino acid N-terminal "sequence tag," following which proteins are subjected to amino acid analysis protein identification procedures. Edman degradation methods have been modified to take only 23 min per cycle, and rapid amino acid analysis techniques are used. The Edman degradation and amino acid analysis is done on a single PVDF membrane-bound protein sample. A computer database matching program is also presented which uses both amino acid composition and "sequence tag" data for protein identification. This method represents the most inexpensive, accurate, and rapid means of protein identification, which is ideal for the screening of proteomes separated by 2-D gel electrophoresis. The creation of N-terminal Edman degradation "sequence-tags" prior to peptide mass fingerprinting of samples should also be useful.

Amino Acid Sequence↗
PubMed1996

Postdialysis urea rebound: determinants and influence on dialysis delivery in chronic hemodialysis patients.

We measured postdialysis urea rebound (PDUR) 30 minutes after dialysis in 92 chronic hemodialysis patients. The impact of PDUR on the estimation of dialysis delivery assessed by urea reduction ratio and Kt/V was evaluated. Total recirculation, access plus cardiopulmonary, was measured at the end of dialysis with the two-needle low blood flow method. The mean age of the 92 patients (49 men and 43 women) was 59.6 +/- 1.4 years. Thirty-eight patients had been receiving erythropoietin therapy for more than 3 months. Fifteen patients had central venovenous access and 77 had peripheral arteriovenous access. Sixty-five patients were dialyzed using hemophan membranes and 27 were dialyzed using polyacrylonitrile membranes. The mean blood flow rate was 240 +/- 28 mL/min and the mean length of the hemodialysis sessions was 3.6 +/- 0.1 hours. Kt/V was calculated with Daugirdas' second-generation formula. The mean PDUR was 16.6% +/- 0.8% (range, 2% to 44%) (n = 92), and significantly decreased the mean urea reduction ratio from 61.7% +/- 0.8% to 55.5% +/- 0.9%, the mean Kt/V from 1.14 +/- 0.03 to 0.97 +/- 0.02, and the mean protein catabolic rate from 1.06 +/- 0.04 to 0.98 +/- 0.02 (P = 0.0001). The effective Kt/V at 30 minutes postdialysis was well predicted by using a recently proposed equation: eKt/V30 = Kt/Vsp - (0.6 x Kt/Vsp/t) + 0.03, with a mean value corresponding also to 0.97 +/- 0.02. However, this estimation was less predictive in patients with very high PDUR. Moreover, PDUR showed only a weak negative correlation with dialysis session length (r = -0.28) and predialysis patient weight (r = -0.29), and showed no correlation with predialysis serum urea level or with blood flow rate. However, dialysis efficiency, as assessed by K/V, presented a correlation of 0.54 with both PDUR and the difference in Kt/V when using urea immediately postdialysis and at 30 minutes. The mean total recirculation was 7.4% +/- 0.6% (n = 86). Postdialysis urea rebound, calculated between 30 or 120 seconds and 30 minutes after dialysis to deduce the influence of recirculations, was reduced but remained important with a mean of 11.8% +/- 0.7%. Thus, total recirculation contributed to nearly 30% of PDUR. The 24 patients with PDUR > or = 20% were compared with the 68 patients with PDUR lower than 20%: women and patients with higher K/V and higher total recirculation presented greater PDUR. Because of relatively few predictive factors for PDUR, its potential considerable impact on dialysis delivery estimation, and the influence of recirculations on the total PDUR amount, total recirculation and PDUR should be determined on an individual basis in chronic hemodialysis patients. The equation proposed to estimate effective Kt/V at 30 minutes is accurate in most patients with PDUR lower than 30% and is a simple alternative.

Acrylic Resins↗
PubMed1996

Unicompartmental knee arthroplasty surgery. 10-year minimum follow-up period.

Sixty knees in 54 patients were followed a minimum of 10 years after unicompartmental knee arthroplasty surgery. Follow-up periods ranged from 10 to 18 years (average, 12 years). In all cases, a Marmor prosthesis was used. Two patients required arthroplasty surgery after the 10-year mark. Seven knees required revision prior to 10 years, and the 10- to 12-year survivorship for the entire cohort was 93%. Slight undercorrection of varus alignment and adequate polyethylene thickness of the tibial component appear to be important contributors to a successful outcome.

Adult↗
PubMed1996

Combined endarterectomy of the internal carotid artery and persistent hypoglossal artery: an unusual case of carotid revascularization.

Persistence of the hypoglossal artery is an unusual congenital abnormality of the carotid arterial system, and the simultaneous occurrence of atheromatous disease in the internal carotid artery and persistent hypoglossal artery is even more uncommon. Carotid surgery in this situation is challenging, and the surgeon must be aware of potential inherent pitfalls. A 74-year-old woman with asymptomatic stenosis of both internal carotid and hypoglossal arteries associated with occlusion of the contralateral internal carotid artery underwent successful revascularization. The anatomy of this unusual lesion and the surgical strategies, which included cranial nerve dissection and mandibular subluxation, are reviewed.

Aged↗
PubMed1996

[Peritoneal dialysis: peritonitis and catheter infections].

Infections were reviewed among 118 patients (M = 64, F = 54) undergoing peritoneal dialysis (PD) from 01-86 to 12-91. One hundred and fifty-five catheters were installed during the study period. Twenty-seven (23%) had more than one catheter. Forty-seven patients (39.8%) were diabetics. Mean follow-up was 460 days per catheter and 540 days per patient. Factors were collected and analyzed by multiple logistic regression. Survival curves were drawn according to the Kaplan-Meyer method. One year survival was 73.8%. Respective incidence of the different infections are presented. Fourteen percent of peritonitis, 48% of tunnel infections and 2.1% of exit site infections led to catheter removal. Younger patients had more catheter infections (p < 0.05). The different types of infections were significantly influenced by the system of dialysis employed (p < 0.005). Perioperative antibiotic coverage diminished the incidence of peritonitis during the first three months (p < 0.05). With our data and our literature review, we have attempted to make some recommendations in order to reduce the occurrence of infections under PD.

Adult↗
PubMed1994

Infection with fatal outcome after endovascular metallic stent placement.

The authors describe a case in which infection developed in a patient after placement of a metallic endoprosthesis in the iliac artery. The patient died of respiratory failure secondary to sepsis. Imaging studies did not reveal an abscess, aneurysm, or stent occlusion. Stent cultures and hemocultures grew Staphylococcus aureus. As with any foreign body, infectious complications may occur after insertion of metallic stents and should be recognized as soon as possible to initiate appropriate therapy.

Fatal Outcome↗
PubMed1994

[Pulmonary autograft as aortic valve replacement in children].

The aortic stenosis represents 5% of all congenital cardiac pathology. The conventional treatments often do not give very satisfactory results. Since 1990, as alternative to the traditional aortic valve replacement, we used, in our institution, the Ross procedure (pulmonary autograft). This consists in using the pulmonary valve as an autograft in aortic position to replace the diseased valve. Then, the pulmonary outflow is reconstructed with a cryopreserved homograft. This study includes 15 patients, aged between 16 months and 18 years, treated with this technique since 1990. There has been no mortality. All the patients are alive at the follow-up, and all in NYHA functional class I. No reoperation has been necessary for valvular dysfunction. The post-operative doppler study at aortic level demonstrated those gradients: Mean + SD, 3.8 +/- 8.1 (range 0-23). No regurgitation haemodynamically important has been recorded at aortic level nor in the pulmonary position. Post-operative gradients at pulmonary level were: Mean + SD, 14.6 + 10.6 (range 14-32).

Adolescent↗
PubMed1994

Surgical treatment of left main coronary aneurysm.

Aneurysms of the coronary arteries occur in 0.3% to 4.9% of angiograms. Only 13 cases of left main artery (LMA) aneurysms have been reported. Of these, three were treated by ligation of the aneurysm and coronary revascularization; the others by revascularisation alone. We report the case of a 56 years old man presenting with unstable angina and previous history of myocardial infarction. Coronary angiography confirmed three vessels disease and the presence of an aneurysm of the LMA extending to the proximal part of the left anterior descending artery (LAD). The patient was treated with ligation of the aneurysm and total myocardial revascularization. The clinical and radiological features are reviewed, and the surgical options considered.

Angina, Unstable↗
PubMed1993

Carotid endarterectomy without angiography. The reliability of Doppler ultrasonography and duplex scanning in preoperative assessment.

OBJECTIVE: To validate the use of Doppler ultrasonography and duplex scanning as the only means of preoperative assessment in carotid disease. DESIGN: A retrospective study performed between January 1980 and December 1989. PATIENTS: Of 597 carotid endarterectomies carried out by one author, 130 procedures were performed on 118 patients (47 women, 71 men, ranging in age from 49 to 85 years) without preoperative cerebral angiography. Justifications for proceeding without angiography were risk of angiography (27 patients), iodine allergy (8 patients), renal insufficiency (5 patients), technical problems (4 patients) and surgeon's preference (74 patients). INTERVENTIONS: Doppler ultrasonography and duplex scanning were the only means of preoperative assessment on 130 occasions. The studies were done by fully trained radiologists. Until 1982 carotid stenosis was assessed with a continuous wave bidirectional Doppler flowmeter and gray-scale ultrasonography in equivocal cases. Thereafter, a real-time spectrum analyser connected on-line to a Doppler flowmeter was used. Duplex scanning was introduced in 1985. MAIN OUTCOME MEASURES: Surgical observations confirmed the preoperative assessment on 124 occasions (96%). RESULTS: Six patients had occlusion of the internal carotid artery (ICA); five patients had recent thrombosis that had occurred between the noninvasive assessment and the endarterectomy. Revascularization was successful in all. In one patient, the ICA was chronically occluded. In 63 patients, the mean pressure in the ICA stump and the mean gradient across the stenosis, measured intraoperatively, were 40 +/- 3 mm Hg (95% confidence interval: 34 to 48 mm Hg) and 55 +/- 3 mm Hg (95% confidence interval: 46 to 58 mm Hg), respectively, which confirmed the severity of the stenosis. CONCLUSION: The authors conclude that in their institution, carotid endarterectomy based on Doppler ultrasonography and duplex scanning only is reliable and safe.

Aged↗
PubMed1992

Canadian Hemodialysis Morbidity Study.

The objective of this study was to determine the probabilities of specific morbid events or death among patients with end-stage renal disease (ESRD) treated by hemodialysis. A prospective cohort study was performed between March 1988 and September 1989 in 18 hemodialysis centers in 13 Canadian cities, representing about one third of the hemodialysis population in Canada. The inception cohort consisted of 496 patients entering hemodialysis who had survived 1 month. The few new hemodialysis patients who received erythropoietin (EPO) in the last 3 months of the study were excluded. Survival curves were compared using the Cox proportional hazards regression model. Older age and history of cardiovascular disease were independently associated with a greater probability of death. Age and history of cardiovascular disease were also associated with a greater probability of nonfatal circulatory events (myocardial infarction, angina requiring hospitalization, or stroke), while a serum albumin level less than or equal to 30 g/L (3.0 g dL) was associated with an increased probability of pulmonary edema. The probability of surviving 12 months without receiving a blood transfusion was 47.2% for males and 27.5% for females. The incidence of non-A, non-B hepatitis, as estimated by unexplained elevations in serum aspartate aminotransferase (AST) values, was not different between patients receiving and not receiving blood transfusions. The probability of hospitalization for any cause was greater for patients with grafts for vascular access than for those with fistulae, for those with a history of cardiovascular disease, for those with a serum albumin level less than or equal to 30 g/L, and for those with renal disease due to diabetes or vascular disease. Hospitalization due to circulatory disease was more likely among those with a history of cardiovascular disease and among those with a lower serum albumin level. Hospitalization for infectious disease was more likely among those with a lower serum albumin level and less likely among those with a fistula for vascular access. Among all patients receiving hemodialysis treatment for more than 6 months, there were 14.8 hospital days per year.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1992

[The intermittent "warm" blood cardioplegia].

Even today, a plethora of cardioplegic solutions are in clinical use. In the study presented here, sixty-six consecutive coronary bypass procedures received normothermic (37 degrees C) blood cardioplegia (NBC) intermittently. This group of patients was compared to an historical group of 68 patients having received cold crystalloid cardioplegia (CCC), and a second group of 41 patients having received cold blood (10 degrees C) cardioplegia (CBC). The number of patients, as well as their age, sex, functional class, ejection fraction and urgency of intervention were comparable between the three groups. The preoperative use of inotropic drugs was less prevalent in the normothermic blood cardioplegia group (NBC 24% v. CCC 52% and CBC 51%, p < 0.05), as was the use of a pacemaker (NBC 8% v. CCC 52% and CBC 51%, p < 0.02). Finally, the rates of myocardial infarction and mortality were comparable between the three groups. These results suggest that normothermic blood cardioplegia is efficient in reducing the demand in O2, by inducing the electromechanical arrest of the heart and, that intermittent normothermic blood cardioplegia can be safe and effective.

Aged↗
PubMed1992

A unicompartmental knee replacement is not "half a total knee": five major differences.

Unicompartmental knee replacement surgery has known uneven success. It fell out of favor in the late 1970s as it was gradually replaced by total knee arthroplasty. The failures of unicompartmental replacements were due partly to the implants themselves but largely to incomplete knowledge of the principles and techniques associated with the unicompartmental knee replacement procedure. As newer implants become available, it is easy to focus on the technology at the expense of basic principles. The authors elaborate on five key principles that differentiate unicompartmental knee replacement from total knee arthroplasty.

Arthroplasty↗
PubMed1990

Patellofemoral arthroplasty. 2-12-year follow-up study.

Seventy-two patellofemoral arthroplasties in 65 patients were followed an average of 4 years (range, 2-12 years). In 69 cases concomitant surgery was performed, including soft tissue realignments, tibial tubercle transfers, and unicompartmental femorotibial reconstructions. Twenty-two patients had already had knee procedures, 18 of which addressed their patellofemoral joint. The implant used in all cases features a deep, nonanatomic trochlear component. Using the Mansat scoring system, 85% of the results were good to excellent, with nearly 50% of these excellent. Fourteen complications were noted, seven related to the implant itself and seven associated with extrapatellar pathology. The authors have found patellofemoral arthroplasty to be a viable solution to end-stage patellofemoral arthritis, keeping in mind a nonforgiving surgical technique and the necessity to address all extraarticular pathology.

Adult↗
PubMed1990

Comprehensive approach to patellar pathology.

As investigators continue to report new realignment operations, controversy persists regarding the selection of procedures for patients with intractable patellar pain. This report summarizes an approach to the patella involving well-documented operations used in individualized combinations tailored to each patient. The outline of the decision-making process is reviewed.

Aged↗