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Biomedical subjects

S Ben Ayed

Publications and source records attributed to S Ben Ayed.

8 recordsLinked to original sources
PubMed2006

Prevalence of agr specificity groups among methicilin resistant Staphylococcus aureus circulating at Charles Nicolle hospital of Tunis.

Methicillin resistant Staphylococcus aureus (MRSA) is a major human pathogen with many clinical aspects. In S. aureus, the accessory gene regulator (agr) globally controls the production of virulence factors. There are four agr groups. Our study was done to define the agr specificity of MRSA circulating at Charles Nicolle hospital and to investigate a possible relationship between agr groups and human disease types. From January 2004 to June 2005, a total of 57 MRSA isolated from individual hospitalized patients were collected, representing 12% of the total S. aureus isolates. The isolates were identified by conventional methods. Methicillin resistance was detected by oxacillin and cefoxitin disks and confirmed by the amplification of mecA gene by PCR. The agr groups were identified by multiplex PCR. All the strains were recovered from different wards: medicine (57.8%) especially from dermatology (56.2%), surgery (28%) and pediatrics (7%). Cutaneous pus (36.84%) and blood culture (35.08%) represented the main specimens. The agr groups were distributed as follow nine (15.7%) belonged to group I, two (3.5%) belonged to group II and 23 (40.3%) belonged to group III. For 23 strains, the agr group was not identified. A relationship between agr group and type of disease was observed: agr group III strains were associated with non invasive infections (P=0.02) and agr group I strains with invasive infections especially bacteremia (P=0.002).

DNA, Bacterial↗
PubMed2002

Usefulness of procalcitonin as a marker of systemic infection in emergency department patients: a prospective study.

We prospectively evaluated serum procalcitonin concentrations in patients who presented to an emergency department (ED) with suspected infectious or inflammatory disease. Of 195 study patients, 68 had final diagnosis of systemic infection, and 24 of those 68 had elevated serum procalcitonin levels (>0.5 ng/mL). The procalcitonin level had a sensitivity of 0.35 and specificity of 0.99 for the diagnosis of systemic infection. In multivariate analysis, the procalcitonin level was the only independent variable associated with this diagnosis; in contrast, the C-reactive protein level was not. All patients with systemic infections who ultimately died had procalcitonin levels of >0.5 ng/mL at admission. Procalcitonin levels were significantly higher in patients who ultimately died of systemic infection than in patients who survived. The optimal procalcitonin threshold for the ED population may be lower than that proposed for critically ill patients. Determination of the procalcitonin level may be useful for screening and prognosis of more-severely ill ED patients.

Adolescent↗
PubMed2000

Cardiac troponin I is reliable with immediate but not medium-term cardiac complications after abdominal aortic repair.

BACKGROUND: The diagnosis of cardiac complications is particularly challenging in the postoperative course of non-cardiac surgery. Follow-up of patients suggests that silent or symptomatic postoperative myocardial infarction have similar short-term outcomes. Cardiac troponin I (cTnI) has been reported as being a sensitive and specific marker of these complications. METHODS: We conducted a prospective study to determine the cut-off values of cTnI which may predict cardiac complications, i: in the postoperative period until discharge, and ii: during a 1-year period after aortic surgery. Three hundred and twenty-nine consecutive patients undergoing infrarenal aortic surgery were included over a 2-year period in a single center. cTnI was measured at recovery and on the 1st, 2nd and 3rd postoperative days. The presence or absence of cardiac complications was classified by reviewers who had no knowledge of cTnI. For evaluation of the ideal discrimination value of cTnI between the complicated and uncomplicated patient groups, we calculated receiver-operator characteristics for the mean values of the peak of cTnI. RESULTS: Thirteen patients (4%) developed 19 postoperative cardiac complications. Thirteen patients (4%) died in the postoperative period. Nine patients (3%) developed 10 cardiac complications during the 1-year follow-up in 316 patients. In 280 patients, cTnI was below 0.5 ng/ml, in 22 patients between 0.5 and 1.5 ng/ml and the 27 remaining patients had a cTnI higher than 1.5 ng/ml. The area under the curve for postoperative cardiac complications was 0.84 (SD=0.21). A limit value of 0.54 ng/ml yielded a sensitivity of 75% and a specificity of 89%. The area under the curve for late cardiac complications was 0.45 (SD= 0.13). CONCLUSION: A cTnI level greater than 0.54 ng/ml appears to be correlated with the occurrence of cardiac complications in the period until discharge, but no value of cTnI is predictive of late cardiac complications occurring in the 1st year after aortic surgery.

Aged↗
PubMed1999

Cardiac troponin I cutoff values to predict postoperative cardiac complications after circulatory arrest and profound hypothermia.

OBJECTIVE: Cardiac failure and myocardial infarction are complications of thoracic aorta, thoracoabdominal aorta, or aortic arch surgery, especially when surgery is performed using profound hypothermia and circulatory arrest (PHCA). Moreover, the diagnosis of non-Q-wave postoperative myocardial infarction (PMI) is challenging because there is no gold standard. The aims of this study were to determine values for cardiac troponin I (cTnl) in patients undergoing aortic arch or thoracoabdominal aortic surgery with PHCA who were free of cardiac complications in the postoperative period, and to test the validity of cutoff values of cTnl to predict postoperative cardiac complications in such patients. DESIGN: Prospective, nonrandomized study. SETTING: Single university hospital; Departments of Anesthesiology, Biochemistry and Vascular Surgery. PARTICIPANTS: Fifty-two consecutive patients were studied over a 2-year period. None was excluded, even patients who underwent emergency surgery. INTERVENTIONS: Patients undergoing aortic arch or thoracoabdominal aortic surgery with PHCA were studied. Thirty patients undergoing coronary artery bypass grafting (CABG) in the same period constituted a control group. MEASUREMENTS AND MAIN RESULTS: The cTnl concentrations were determined using an immunoenzymofluorometric assay on a Stratus analyzer (Dade, Massy, France) on blood samples obtained at recovery and on day 1 (D1) and D2. Seventeen patients developed a cardiac complication, which was lethal in 10 patients. In patients without cardiac complication, the peak level for cTnl was observed on D1. Cutoff values of cTnl were identical in both the CABG control group (11 .6 microg/mL) and the sternotomy group (12.2 microg/mL), but were significantly greater (20.5 microg/mL) in patients with a thoracotomy approach. Sensitivity and specificity of these cutoff values were high in both groups (control group, sensitivity = 100%, specificity = 100%; sternotomy group, sensitivity = 78%, specificity = 100%; thoracotomy group, sensitivity = 100%, specificity = 94%). CONCLUSION: In patients who underwent surgery using PHCA for aortic arch or descending aorta repair, myocardial damage related to cardiac arrest, vents or fibrillation explains the increased cutoff value (12.2 microg/mL). This value is similar to patients undergoing CABG surgery through a sternotomy approach with cardioplegia administration. In contrast, and probably related to the absence of cardioplegia, patients undergoing surgery through a left thoracotomy approach had a greater cutoff value (20.5 microg/mL). Values of cTnl greater than these respective cutoff values were closely related to cardiac complications during the postoperative period.

Adult↗
PubMed1995

Does the enhancement of cholinergic neurotransmission influence brain glucose kinetics and clinical symptomatology in progressive supranuclear palsy?

Cholinergic systems are markedly affected both in cortical and subcortical cerebral areas of patients with progressive supranuclear palsy (PSP). To determine whether it is possible to modify the clinical picture of PSP through the enhancement of brain cholinergic neurotransmission, we studied the effects of physostigmine, an anticholinesterase reference drug, on symptoms and brain glucose metabolism using [18F]fluorodeoxyglucose (FDG) and PET. Patients were evaluated blind in a randomized order with both placebo and physostigmine infusions after an individual determination of maximal tolerated dose. Under steady-state physostigmine infusions, although glucose consumption was not significantly modified, the entry of glucose from blood to brain was regionally increased from 8 to 32% of placebo values suggesting an increase in cerebral blood flow (CBF) or an increase in the activity of brain glucose transporter. Following physostigmine administration in the same patients: the errors in antisaccades during ocular movement testing were significantly reduced, a significant reduction in errors or performance was found in four out of seven neuropsychological tests, and motor disability was not significantly altered. Although the precise pathophysiology of these physostigmine-induced effects needs further investigations, our study suggests that part of the clinical symptomatology in PSP could be relieved by the enhancement of brain cholinergic neurotransmission.

Aged↗
PubMedDate not supplied

On some glycosidases (beta-D-mannosidase, alpha-L-fucosidase, N-acetyl-beta-D-glucosaminidase) of human seminal plasma.

The glycosidase activities (beta-D-mannosidase, alpha-L-fucosidase and N-acetyl-beta-D-glucosaminidase) have been compared in whole and split ejaculate samples from men whose couple suffers from infertility. The site of secretion of enzymatic activities is either prostatic or epididymal. The three enzymatic activities have possibly different origin and should constitute new biochemical markers of male genital tract.

Acetylglucosaminidase↗