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Biomedical subjects

J Acar

Publications and source records attributed to J Acar.

At least 19 recordsLinked to original sources
PubMed1998

Incidence of patulin in apple juice concentrates produced in Turkey.

A total of 215 apple juice concentrate samples from three different producers in Turkey were analyzed for patulin using reversed-phase high-performance liquid chromatography. The detection limit of patulin in single strength apple juice at a sugar content of 11.2 degrees Brix was lower than 5 micrograms/l. Patulin was detected in all of the samples analyzed, at concentrations ranging from 7 to 375 micrograms/l. Of the samples, 43.5% were found to exceed a patulin contamination level of 50 microgram/l.

Beverages↗
PubMed1998

Liquid chromatographic determination of beta-naphthoxyacetic acid in tomatoes.

An alternative high-performance liquid chromatographic method for the determination of beta-naphthoxyacetic acid (BNOA) in tomatoes is described. BNOA was extracted from tomatoes with acetone-dichloromethane (2:1). The extract was cleaned up by Bio-Beads S-X3 gel-permeation chromatography and by partitioning. A reversed-phase C18 column was used for HPLC analysis. The mobile phase was acetonitrile-2% acetic acid in water (50:50, v/v) pumped at a flow-rate of 1.0 ml/min. Retention time of BNOA was ca. 7 min with a percentage coefficient of variation of 0.71. Resolution of BNOA was good on the column. Percentage recoveries of BNOA were 79.5 +/- 6.82, 94.8 +/- 2.70 and 86.4 +/- 16.43 for the corresponding spiking levels of 0.5, 1.0 and 2.0 micrograms per g tomato, respectively. Analysis of 10 greenhouse tomato samples from local markets in Ankara showed no BNOA residue.

Acetone↗
PubMed1998

Antibiotic resistance problems in the critical care unit.

The increased resistance of bacteria to antimicrobial agents poses major therapeutic problems for the treatment of patients hospitalized in critical care units. This article discusses the mechanisms of resistance and the basic rationale for the treatment of infected patients. The authors also discuss methods used to control the dissemination of resistant bacteria from patient to patient, the complex problems of colonization, and the strategies used to delay the emergence of resistance to new antibiotics.

Aminoglycosides↗
PubMed1997

Haemophilus endocarditis: report of 42 cases in adults and review. Haemophilus Endocarditis Study Group.

To define the clinical, microbiological, and therapeutic characteristics of haemophilus endocarditis, we reviewed the charts of 42 adults with haemophilus endocarditis (native valve disease, 37; prosthetic valve disease, five) who were followed up between 1983 and 1995 in France. The mean duration of symptoms before diagnosis was 34 days. The causative Haemophilus species were as follows: H. parainfluenzae (26 adults), H. aphrophilus (9), H. paraphrophilus (4), and H. influenzae (3). According to the Duke criteria, 38 cases of endocarditis were definitive and four were possible. Thirty-nine patients received combination antibacterial therapy and three received therapy with a beta-lactam agent alone (mean duration, 46 days). Arterial embolism occurred in 15 patients. Cardiac surgery was indicated for 18 patients; 16 of these surgeries were performed within 3 months. Two patients died of heart failure. In conclusion, haemophilus endocarditis is rare and is mainly due to H. parainfluenzae. Although surgery is often necessary, haemophilus endocarditis has a favorable prognosis.

Adolescent↗
PubMed1997

[Statistical study of the SIRSCAN computerised camera].

The antibiograms of 1162 bacterial strains, including references, have been performed within four centres. They have been read manually and by the SIRSCAN camera, which yields to 30936 couples of diameters values. A non-concordance, at a 3 mm level, was observed fot 11.14% of the diameters. The mean of difference is 0.82 mm and the standard deviation 3.34 mm. Round Petri dishes gave results less reliable than those obtained with square dishes. A deviation in function of the centres is obtained for wild-strains as for the references. For the whole population a S/R discordance (sensible/résistant confusion) is obtained for 1.76% of the diameters. This value drops to 0.93% for enterobacteriaceae, P. aeruginosa and S. aureus (968 strains).

Anti-Bacterial Agents↗
PubMed1996

AREVA: multicenter randomized comparison of low-dose versus standard-dose anticoagulation in patients with mechanical prosthetic heart valves.

BACKGROUND: Moderate anticoagulation may be proposed to reduce the risk of hemorrhage for certain patients with a mechanical prosthesis, but the consequences for risk of thromboembolism are debated. METHODS AND RESULTS: The purpose of the AREVA trial was to compare moderate oral anticoagulation (international normalized ratio [INR] of 2.0 to 3.0) with the usual regimen (INR of 3.0 to 4.5) after a single-valve replacement with a mechanical prosthesis, either Omnicarbon or St Jude. Patients included were between 18 and 75 years old, in sinus rhythm, and with a left atrial diameter < or = 50 mm on the time-motion echocardiogram. Patients were randomized for INR after surgery. From 1991 to 1994, 433 patients underwent valve replacement (aortic, 414; mitral, 19) with 353 St Jude and 80 Omnicarbon prostheses; 380 patients were randomized for INR: 188 for INR 2.0 to 3.0 and 192 for INR 3.0 to 4.5. Mean follow-up was 2.2 years (1 to 4 years). Analysis of 18001 INR samples showed that the mean of the median of INR was 2.74 +/- 0.35 in the 2.0 to 3.0 group and 3.21 +/- 0.33 in the 3.0 to 4.5 group (P < .0001). Thromboembolic events, as assessed from clinical data and CT brain scans, occurred in 10 patients in the 2.0 to 3.0 INR group and 9 patients in the 3.0 to 4.5 INR group (P = .78). Hemorrhagic events occurred in 34 patients in the 2.0 to 3.0 INR group and 56 patients in the 3.0 to 4.5 INR group (P < .01), with 13 and 19 major hemorrhagic events, respectively (P = .29). CONCLUSIONS: In selected patients with mechanical prostheses, moderate anticoagulation prevents thromboembolic events as effectively as conventional anticoagulation and reduces the incidence of hemorrhagic events.

Administration, Oral↗
PubMed1996

Immediate results of percutaneous mitral commissurotomy. A predictive model on a series of 1514 patients.

BACKGROUND: The wide use of percutaneous mitral commissurotomy (PMC) underlines the need to identify the predictive factors of the results. Using a large series allowed us to develop a multivariate model that can be applied to improve patient selection. METHODS AND RESULTS: Between 1986 and 1995. PMC was undertaken in 1514 patients. Mean age was 45 +/- 15 years. Echocardiography showed that 245 patients (16%) had pliable valves and mild chordal thickening (group 1), 886 (59%) had extensive subvalvular disease (group 2), and 383 (25%) had calcified valves (group 3). PMC failed in 22 patients; it was performed with a single balloon in 30 patients, a double balloon in 586, and the Inoue balloon in 876. Good immediate results were defined as a valve area > or = 1.5 cm2 with mitral regurgitation Sellers' grade < or = 2 and were obtained in 1348 patients (89%). A logistic model developed from the first 1088 cases identified the following predictors of immediate results: age (P = .004), echocardiographic group (P < .0001), valve area (P < .0001), and effective balloon dilating area (EBDA) (P = .03). Two interactions were significant: age at previous commissurotomy (P = .013) and EBDA by initial mitral regurgitation (P = .034). The type of balloon was of borderline significance (P = .09). The model was validated on an independent sample comprising the subsequent 426 procedures. For a threshold of probability of good results of .75, sensitivity was 92%, specificity 25%, and predictive accuracy 87%. CONCLUSIONS: Prediction of the immediate results of PMC is multifactorial. The predictive model developed and validated can be contributive in decision making for individual patients.

Adolescent↗
PubMed1996

Rapid reversed-phase liquid chromatographic determination of patulin in apple juice.

A rapid, simple and economical method using a limited amount of organic solvent is described for the determination of patulin in apple juice. The sample was extracted with ethyl acetate and the extract was cleaned up by extraction with sodium carbonate solution. Patulin was then determined by reversed-phase liquid chromatography using a MicroPack C18 column and a variable-wavelength UV-Vis detector set at 276 nm. Patulin and 5-hydroxymethylfurfural were completely resolved by using water-acetonitrile (99:1, v/v) as the mobile phase at a flow-rate of 1.0 ml/min. The detection limit was < 5 micrograms/l and the recovery was 98%.

Beverages↗
PubMed1996

Early assessment by transesophageal echocardiography of left atrial appendage function after percutaneous mitral commissurotomy.

Thirty-seven consecutively admitted patients with severe mitral stenosis underwent percutaneous mitral commissurotomy with a transthoracic and biplane or multiplane transesophageal echocardiographic examination before and between 24 and 48 hours after percutaneous mitral commissurotomy. Thirty patients (81%) were in sinus rhythm and 7 were in atrial fibrillation. Left atrial appendage (LAA) function was evaluated in both the transverse and the longitudinal planes by planimetry and pulsed Doppler echocardiographic interrogation at the LAA outlet. Percutaneous mitral commissurotomy resulted in a twofold increase in mitral valve area, and no severe mitral regurgitation occurred. With use of the planimetry method, there was no significant improvement in LAA ejection fraction, except in the transverse plane for patients in sinus rhythm (p = 0.03). With use of Doppler method, 3 distinct flow patterns were observed before the procedure: a "sinus pattern" in patients in sinus rhythm, and a "fibrillatory pattern" (n = 3) or a "no-flow pattern" (n = 4) in patients in atrial fibrillation. After commissurotomy, there was a marked increase in LAA peak Doppler velocity (+62%) and in LAA velocity time integral (+31%). Of the 4 patients in atrial fibrillation with a no-flow pattern, 2 had recovery of a typical effective fibrillatory flow pattern after the procedure. The increase in peak Doppler velocity after commissurotomy was related to the decrease or regression in left atrial spontaneous echo contrast, and correlated with the increase in mitral valve area, the decrease in tranmitral pressure gradient, and the increase in cardiac index; improvement in valve function after successful percutaneous mitral commissurotomy is associated with early improvement in LAA function.

Adult↗
PubMed1996

Functional results 5 years after successful percutaneous mitral commissurotomy in a series of 528 patients and analysis of predictive factors.

OBJECTIVES: This study sought to assess late functional results after successful percutaneous mitral commissurotomy and to determine their predictors. BACKGROUND: Few studies have reported late results of percutaneous mitral commissurotomy or have analyzed their late results regardless of immediate results, despite the fact that late deterioration may well be related either to a decrease in valve area or to poor initial results. METHODS: Between 1986 and 1992, 528 patients underwent successful percutaneous mitral commissurotomy (mean [+/- SD] age 46 +/- 18 years; mean follow-up 32 +/- 18 months). A successful procedure was defined by a mitral valve area > or = 1.5 cm2 and no regurgitation > 2/4. Dilation was performed using a single balloon in 13 patients, a double balloon in 349 and the Inoue balloon in 166. Multivariate analysis was performed with a Cox model. RESULTS: The survival rate for patients in New York Heart Association functional class I or II, with no cardiac-related deaths or need for mitral surgery or repeat dilation, was 76 +/- 6% at 5 years. By multivariate analysis, the independent predictors of good functional results were echocardiographic group (p = 0.01), functional class (p = 0.02) and cardiothoracic index (p = 0.005) before the procedure and valve area after the procedure (p = 0.007). The predictive model derived allowed estimation of the probability of good functional results according to the value of these four predictors for any given patient. CONCLUSIONS: Good functional results were observed 5 years after successful percutaneous mitral commissurotomy in a large series of varied patients. The analysis of predictive factors may provide useful indications for follow-up results in patients undergoing this technique.

Catheterization↗
PubMed1996

How to manage patients with severe left ventricular dysfunction and valvular regurgitation.

BACKGROUND AND AIMS OF THE STUDY: The purpose of this study is to analyze treatment options for valvular regurgitation with severe left ventricular dysfunction. MATERIAL AND METHODS: Results of valvular surgery in 98 patients with mitral or aortic regurgitation and severe systolic left ventricular dysfunction (LVD) were analyzed. Selection criteria were the absence of significant coronary heart disease and a resting ejection fraction (EF) < 40% for aortic and < 50% for mitral regurgitation. RESULTS: In patients with aortic regurgitation (n = 46) operative mortality was higher but not significantly so than in a control group of 238 cases (6.5% vs. 3.4%). The actuarial survival rates at five and 10 years were 84% and 55% vs. 84% and 67%, respectively. Independent preoperative predictors of severe postoperative LVD were rheumatic etiology and increased left ventricular end-systolic diameter. In patients with mitral regurgitation (n = 52), operative mortality was not significantly different from that of a control group of 273 cases (3.8% vs. 2.6%), whether the surgical procedure was valve replacement or valve repair. Perioperative morbidity was frequent (30% of cases), mainly low cardiac output, after valve replacement. The actuarial survival rates at eight years were respectively for the groups with and without LVD: 81% and 89% after valve repair, 60% and 75% after valve replacement. Independent predictors of severe postoperative LVD were increased left ventricular end-systolic volume and the type of surgery. Better results were observed after valve repair. CONCLUSIONS: It is concluded that a low EF is not a predictive factor of operative mortality but it influences late survival as do the degree of left ventricular dilatation, etiology in aortic and type of surgery in mitral regurgitation. Alternatives to valvular surgery have been envisaged but information on vasodilators in these patients is scant and results of heart transplantation are known only from a few small series.

Adult↗
PubMed1996

Apolipoprotein E5 (Glu212-->Lys): increased binding to cell surface proteoglycans but decreased uptake and lysosomal degradation in cultured fibroblasts.

A new apolipoprotein (apo) E variant, apoE5 (Glu212-->Lys) was identified in a Turkish family. The variant was due to a point mutation (CAG-->AAG) at the first nucleotide position of the codon encoding amino acid residue 212 of the mature apoE. The 23-year-old index patient was heterozygous for the mutation. Examination of the proband's kindred revealed six heterozygous and two homozygous mutation carriers. Compared to non-carriers, carriers of the mutation had slightly higher triglycerides (1.25 versus 1.11 g/l) and lower HDL cholesterol (0.36 versus 0.41 g/l). Very low density lipoproteins (VLDL) from an apoE5 (Glu212-->Lys) homozygote displayed enhanced binding (+17%, P < 0.05), but decreased uptake (-35%, P < 0.0001) and degradation (-51%, P < 0.0001) in cultured fibroblasts, compared to E3/3-VLDL. The region of the apoE molecule surrounding residue 212 contains a heparin binding domain. Consistently, the enhanced cell surface binding of E5/5-VLDL was observed in "wild-type" Chinese hamster ovary cells (+19%, P < 0.05), but not in proteoglycan-deficient cells. The binding of E5/5-VLDL to heparin was increased (+22%, P < 0.05). As the endocytosis of apoE-containing particles involves the transfer of proteoglycan-bound ligands to lipoprotein receptors, the stronger binding of apoE5 (Glu212-->Lys) to proteoglycans could reduce the rate at which the mutant is finally delivered to endocytotic pathways. These data may provide evidence for a functionally important heparin binding site around amino acid residue 212 of the apoE molecule in vivo.

Adolescent↗
PubMed1995

Bartonella (Rochalimaea) quintana endocarditis in three homeless men.

BACKGROUND: Bartonella (Rochalimaea) quintana is the agent of trench fever and is transmitted by the body louse. We searched for this organism in three alcoholic homeless men with endocarditis. METHODS: Blood samples were cultured on a human endothelial cell line and on blood agar. Bacteria were identified by sequencing the amplified 16S ribosomal RNA gene. The presence of bartonella in tissue was assessed by Gram's staining, immunostaining, and polymerase-chain-reaction amplification. Serologic studies for antibodies to bartonella species were performed by indirect immunofluorescence and Western immunoblotting. RESULTS: B. quintana was isolated from one patient in the blood-agar culture and from the other two patients in the endothelial-cell culture. The organism was also identified by both immunostaining and molecular techniques in the valvular vegetations from the three patients and in a cervical lymph node from one patient. The 16S ribosomal RNA gene sequences of the three isolates were almost identical to that of the prototype strain of B. quintana. High titers of antibodies to B. quintana were detected in all three patients, but so were cross-reacting antibodies to chlamydia species. In all three patients studies were repeatedly negative for antibodies to the human immunodeficiency virus. CONCLUSIONS: B. quintana is a cause of endocarditis in homeless patients and may be serologically misdiagnosed as a chlamydial infection.

Adult↗
PubMed1995

[Indications for percutaneous mitral commissurotomy].

Percutaneous mitral dilatation is now recognized as a valid alternative to open heart surgery. Indications have been clearly established for symptomatic patients with major stenosis (1.5 cm2, or 1 cm2/m2 body surface area). In other cases, the level of functional impairment, the anatomic state of the valve and the patient's past history must all be taken into consideration. In Western countries, there is a relatively large number of elderly patients with a moderately or severely damaged mitral valve. A critical evaluation of immediate and long-term outcome is required to determine the precise indications for dilatation and for surgery. Finally, these two methods should not be considered as contradictory but rather as complementary tools to control the natural history of the disease.

Catheterization↗
PubMed1995

Nosocomial acquisition of multiresistant Acinetobacter baumannii: risk factors and prognosis.

To identify risk factors for and prognostic indicators of the nosocomial acquisition of multiresistant Acinetobacter baumannii in an intensive care unit, we prospectively studied 40 patients: 13 who were infected with this organism and 27 who were colonized. Isolates were identified by pulsed-field gel electrophoresis; the infected/colonized patients were compared with 348 noninfected, noncolonized patients by logistic regression analysis and with matched historical controls in a cohort study. The severity of illness (evaluated by the APACHE II score; P < .05) and previous infection (P < .001) were retained as independent risk factors for acquiring A. baumannii. Logistic regression analysis selected a high APACHE II score (P < .01) and the acquisition of A. baumannii (P < .01) as factors independently associated with death. The acquisition of A. baumannii was associated not only with high mortality but also with a length of stay on the intensive care unit in excess of that due to the underlying disease alone; specifically, the attributable mortality was 25%, with a risk ratio for death of 2.0 (95% confidence interval, 1.11-3.62), and the duration of stay for infected/colonized patients was 10.3 days longer than that for controls (P < .001).

APACHE↗