Experimental evaluation of PCXMC and prepare codes used in conventional radiology.

The objective of this study is to evaluate the precision of dose-calculation computer codes used in our laboratory (PCXMC and PREPARE) for organ dose evaluation. Measurements of entrance and organ dose were performed using ionisation chamber and thermoluminescence dosimetry. To obtain a mean dose of organ, we have used the Rando-Alderson phantom. The results showed that computed and measured doses correlate well (within 28%) in 60% of the samples. The percentage shows that the computed doses correlate with the experimental doses rather well for PCXMC software than PREPARE. Although the two programs are based on the Monte-Carlo method, their calculations differ. PCXMC carries out a simulation of the trajectory of the photon, whereas PREPARE provides interpolated values. Our experimental results are close to the values given by the PCXMC, a program which takes into account the weight, the height of the patient and field dimensions.

[Cecal volvulus: anatomical bases and physiopathology]. / Volvulus du caecum: bases anatomiques et physiopathologie.

UNLABELLED: The aim of this study was to report on 7 cases of cecal volvulus and to evaluate anatomical variations allowing this pathology. METHODS: 7 consecutive patients (4 women) treated for cecal volvulus were included. The clinical and paraclinical parameters, the management of patients, were studied through an analysis of medical histories. Contributing factors for cecal volvulus were analysed by an anatomical study and literature analysis. RESULTS: all patients complained about abdominal pain associating or not to acute intestinal obstruction. The diagnosis was radiographically carried out for 3 patients. All patients were treated by surgical procedures (right colectomy: n = 6, cecopexy: n = 1). The mortality and morbidity rates were 0 percent and 28 percent. Fifteen anatomical subjects had complete dorsal fixation (75 percent). Seven out of them had retrocecal recessus. Five subjects (25%) had a non fixed cecum, according to the literature relating a non-fixation of ascending colon to parietal peritoneum in 11 to 25 percent of the cases. The main factor of risk is the female gender. CONCLUSION: cecal volvulus can be advocated for patients having abdominal pain. The diagnosis is rarely based on an only clinical examination or abdominal radiographs alone. Tomodensitometry is most performing examination for diagnosis. An early and appropriate management of patients is necessary to avoid significant morbidity and mortality rates.

Assessment of radiation protection of patients and staff in interventional procedures in four Algerian hospitals.

This study was aimed to assess patient dosimetry in interventional cardiology (IC) and radiology (IR) and radiation safety of the medical operating staff. For this purpose, four major Algerian hospitals were investigated. The data collected cover radiation protection tools assigned to the operating staff and measured radiation doses to some selected patient populations. The analysis revealed that lead aprons are systematically worn by the staff but not lead eye glasses, and only a single personal monitoring badge is assigned to the operating staff. Measured doses to patients exhibited large variations in the maximum skin dose (MSD) and in the dose area product (DAP). The mean MSD registered values are as follows: 0.20, 0.14 and 1.28 Gy in endoscopic retrograde cholangiopancreatography (ERCP), coronary angiography (CA) and percutaneous transluminal coronary angioplasty (PTCA) procedures, respectively. In PTCA, doses to 3 out of 22 patients (13.6 %) had even reached the threshold value of 2 Gy. The mean DAP recorded values are as follows: 21.6, 60.1 and 126 Gy cm(2) in ERCP, CA and PTCA procedures, respectively. Mean fluoroscopic times are 2.5, 5 and 15 min in ERCP, CA and PTCA procedures, respectively. The correlation between DAP and MSD is fair in CA (r = 0.62) and poor in PTCA (r = 0.28). Fluoroscopic time was moderately correlated with DAP in CA (r = 0.55) and PTCA (r = 0.61) procedures. Local diagnostic reference levels (DRLs) in CA and PTCA procedures have been proposed. In conclusion, this study stresses the need for a continuous patient dose monitoring in interventional procedures with a special emphasis in IC procedures. Common strategies must be undertaken to substantially reduce radiation doses to both patients and medical staff.

[Detection of trypanosomes in blood by the Quantitative Buffy Coat (QBC) technique: experimental evaluation]. / Détection des trypanosomes dans le sang par la technique du Quantitative Buffy Coat (QBC): évaluation expérimentale.

Microhematocrit centrifugation (Woo test) and miniature anion exchange are the most widely used techniques for routine detection of Trypanosoma brucei gambiense in endemic areas. The QBC technique developed for diagnosis of malaria has been successfully used for detection of trypanosoma in blood. The purpose of this laboratory study was to evaluate the end-point sensitivity of the QBC test in comparison with the Woo test. Decreasing concentrations from 15 x 10(5) to 15 trypanosomes/ml of human blood were tested using the two techniques. Sensitivity was calculated in function of reading time at each concentration. Results showed that the sensitivity of the QBC test was 95% down to a concentration of 450 trypanosomes/ml. In comparison 95% sensitivity of the Woo test was observed only down to 7500 trypanosomes/ml and reading time was twofold longer. These findings were reproducible for two hours after sample preparation but deterioration was rapid thereafter. Given its simplicity and sensitivity, QBC test would appear to be a suitable technique for in-field screening programs for human African trypanosomiasis.

[Pre-reduced TGY-V medium]. / Milieu pré-réduit TGY-V.

Anaerobic bacteria need, for its multiplication, a reduce middle devoid of oxygen, who contains growth factors. We have prepared the prereduce middle TGY-V according to the recommendations of M. SEBALD [1]. This middle has been tested for its ability to permit the growth of the most exigent anaerobic bacteria. It could be used as a middle of transport and culture for any monomicrobial sampling that can contain anaerobic bacteria.

[Efficiency of inhibitors (phenylethanol, nalidixic acid, sodium azide)in the isolation of strictly anaerobic bacteria from a polymicrobial specimen]. / Efficacité des inhibiteurs (P.E.A, Ac Nal, Az de Na) dans l'isolement des bactéries anaérobies strictes, à partir d'un prélèvement polymicrobien.

The efficacy of inhibitors (PEA, Ac Nal, Az de Na) in the isolation of strict anaerobes in polymicrobial sample. The efficacy of three inhibitors to select strict anaerobic bacteria in the polymicrobial sample had been studied. First step: The most frequent anaerobes encountered in the infections are isolated in the agar Columbia containing the different inhibitors. This step allowed us to check the inhibition of the germ we have to isolate. Next step: polymicrobial mixtures were made. The composition of which is very similar to the samples we receive in the laboratory. The swarming Proteus is the facultative anaerobic germ which gives us difficulties when isolating strict anaerobic bacteria. Then, the different mixtures were isolated separately in the agar in which the inhibitors were added. The plates containing Azide of Na and PEA gave us the best results.

[Antibiotic sensitivity of Bacteroides fragilis group in Algeria]. / La sensibilité aux antibiotiques des Bacteroïdes du groupe fragilis en Algérie.

The antimicrobial resistance evolution of the Bacteroïdes fragilis group is the subject of international survey. Eighty-six clinical isolates collected in anaerobic service of I.P. A were tested for susceptibility to twelve antimicrobial agents. Chloramphenicol, metronidazole and imipenem proved to be the most active agents. After these agents, amoxicillin-clavulanic acid, carbenicillin and piperacillin were the most effective agents tested with respectively 15%, 17% and 17% of resistant isolates. Clindamicin and cefotaxin were active from only 70% and 65% of clinical isolates, and 71% of them were found resistant to cefotaxin with minimal inhibitory concentration above 32 ug/ml. beta Lactamasic profile determination according to Rolfe and Finegold modified method allowed to show five different beta lactamase types. The isoelectric points (pI) vary between 4.3 and 7.5 according to the enzymatic extracts of the clinical isolates. No transfer and no plasmid were observed with respectively imipenem and metronidazole resistant isolates. But, transconjugants were obtained with TRCcR isolate.