High redox potential laccases from the ligninolytic fungi Pycnoporus coccineus and Pycnoporus sanguineus suitable for white biotechnology: from gene cloning to enzyme characterization and applications.

AIMS: Exploitation of natural biodiversity in species Pycnoporus coccineus and Pycnoporus sanguineus to screen for a new generation of laccases with properties suitable for the lignin-processing sector. METHODS AND RESULTS: Thirty strains originating from subtropical and tropical environments, mainly isolated from fresh specimens collected in situ, were screened for laccase activity. On the basis of levels of enzyme activity and percentage of similarity between protein sequences, the laccases from strains BRFM 938, BRFM 66 and BRFM 902 were selected for purification and characterization. Each BRFM 938, BRFM 66 and BRFM 902 laccase gene encoded a predicted protein of 518 amino acids; the three deduced proteins showed 68.7-97.5% similarity with other Polyporale laccases. The three laccases (59.5-62.9 kDa with 7-10% carbohydrate content) had high redox potentials (0.72-0.75 V vs normal hydrogen electrode at pH 6), remained highly stable up to 75-78 degrees C and at pH 5-7 mixtures, and were resistant to methyl and ethyl alcohols, acetonitrile and dimethylsulfoxide at concentrations as high as 50% (v/v). The best laccase-1-hydroxybenzotriazole systems permitted almost 100% of various polyphenolic dye decolourization and oxidation of adlerol and veratryl alcohol. CONCLUSIONS: The three laccases showed complementary biochemical features. BRFM 938 laccase had the highest thermo- and pH stability, catalytic efficiency towards 2,2'-azino-bis-[3-ethylthiazoline-6-sulfonate] and resistance to alcoholic solvents. BRFM 66 laccase had the highest rates of dye decolourization and oxidation of nonphenolic compounds. SIGNIFICANCE AND IMPACT OF THE STUDY: This study identified P. coccineus and P. sanguineus as outstanding producers of high redox potential laccases, easy to purify and scale-up for industrial production. Three new laccases proved to be suitable models for white biotechnology processes and for further molecular breeding to create a new generation of tailor-made enzymes.

[Trans-ureteral pyelostomy: 5 cases]. / Trans-urétéro-pyélostomie: 5 observations.

The authors report 5 cases of extensive loss of substance of the distal ureter due to radiation fibrosis, operative trauma or tumour invasion; these lesions occurred during the course of a genital tumour in 4 cases and rectal prolapse in one case. The lesion was bilateral and radiation-induced in 2 cases and unilateral in 3 cases. The patients presented with renal colic in 2 cases, renal failure in 1 case and infection in 2 cases (pyelonephritis, septic shock). All patients presented with secondary hydronephrosis. The extent of the lesions made vesical anastomosis impossible, especially as the bladder was irradiated and/or absent in 3 cases. Anastomosis of the proximal ureteric stump onto the contralateral ureter was impossible in the presence of bilateral lesions requiring diversion of the contralateral ureter or due to the short donor ureter, or because of the discordant diameter of the two ureters. Transureteropyelostomy was therefore performed in these 5 cases. The postoperative course was uneventful 4 cases, with a transient anastomotic fistula in only one case. Four of the 5 patients achieved long-term survival with an excellent clinical and radiological result.

[Prostatic ultrasonography in routine radiological practice: a survey of 122 radiologists]. / Echographie prostatique en pratique radiologique quotidienne: enquête auprès de 122 radiologues.

OBJECTIVE: To evaluate the indications and practical modalities of prostatic ultrasonography in routine radiological practice. METHODS: An anonymous questionnaire composed of 18 multiple choice questions was sent to 122 radiologists. RESULTS: Among the 76 responses, 90% were men, 90% were in private practice and 94% regularly performed prostatic ultrasonography without clinical information (81%). The prostatic examination was performed by transrectal ultrasonography (60%) combined with vesical and renal ultrasonography. The indications were: urinary functional disorders (56%) and abnormal PSA (40%). Prostatic ultrasonography was considered to be useful to calculate prostatic volumes by 59% of radiologists and in the staging of prostatic cancer (81%). 80% of radiologists did not start by performing digital rectal examination. 59% of patients were informed. CONCLUSION: The observed indications did not correspond to urological consensus recommendations, but ultrasonography was performed according to classical recommendations. This study could justify a more precise definition of the role of ultrasonography in prostatic disease.

[Acucise endoureterotomy for distal ureteral stenosis in a renal transplant patient]. / Endourétérotomie Acucise pour sténose de l'uretère distal chez un transplanté rénal.

The treatment of ureteric strictures in renal transplantation used to be surgical, but has recently benefited from progress in endourology. The authors report the case of a renal transplant recipient who developed late stricture of the ureterovesical reimplantation of the transplant. After percutaneous nephrostomy, which restored good renal function, retrograde endoureterotomy was performed using an Acucise ureterotome balloon, followed by ureteric modelling on a 7F double J stent for 2 months. With a follow-up of 18 months, renal function was normal and ultrasonography showed residual hypotonia of the transplant cavities and no vesicorenal reflux was detected by retrograde voiding cystourethrography. Acucise retrograde endoureterotomy can constitute a simple endourological treatment for late ureteric strictures in renal transplantation.

[Necrotizing hepatic granuloma of brucellosis origin. Apropos of a case]. / Granulome nécrosant hépatique d'origine brucellienne. A propos d'un cas.

The authors report on a case of febrile necrotizing brucellosis hepatic granulomatosis in a patient living in brucellosis endemia areas. This hepatic localization of brucellosis is rare: to our knowledge only 28 cases have been described in the literature. The bacteriological diagnosis was not established by blood or abscess pus cultures, but by Brucella serology only. Surgery completed by biantibiotherapy have permitted a complete recovery.

Hepatic artery thrombosis after liver transplantation: diagnosis with spiral CT.

OBJECTIVE: The purpose of this study was to prospectively evaluate spiral CT with maximum-intensity projection in the diagnosis of hepatic artery thrombosis in patients with liver transplants. SUBJECTS AND METHODS: Thirty liver transplant recipients (19 men, 11 women; mean age, 49 years) underwent Doppler sonography and spiral CT with maximum-intensity projection to evaluate both hepatic parenchyma and hepatic vessels. In five cases, these examinations were followed by angiography for suspected hepatic artery thrombosis. RESULTS: Among the 30 patients, results of both Doppler sonography and spiral CT were abnormal in five patients. In all five patients, Doppler sonography revealed an absence of intrahepatic arterial signal (sensitivity, 100%). Spiral CT showed the hepatic artery to be patent from its origin to the anastomosis and then occluded distally in four patients and showed occlusion of the entire hepatic artery in one patient (sensitivity, 100%). Aortography and/or selective arteriography of the celiac axis confirmed the diagnosis of hepatic artery thrombosis in all five cases. The other 25 patients had a normal clinical outcome, 24 with normal findings on Doppler sonograms (specificity, 96%), and 23 with normal findings on spiral CT. Two patients had false-positive CT studies because of technical failures (specificity, 92%). CONCLUSION: Spiral CT with maximum-intensity projection is highly accurate in identifying hepatic artery thrombosis after liver transplantation.

[Value of radiologic examinations in the diagnosis and staging of upper urinary tract tumors]. / Valeur des examens radiologiques dans le diagnostic et la stadification des tumeurs de la voie excrétric urinaire supérieure.

From 1980 to 1991, 109 patients were treated for a tumour of the upper urinary tract. All patients were examined by intravenous urography (IVU) which had a sensitivity of 61%. The combination of IVU + RUP established the diagnosis in 72% of cases. Renal ultrasonography and abdominal computed tomography (CT) were performed in 41 and 67 cases, respectively. The sensitivity of ultrasonography was 40% and that of CT was 72%. CT was more sensitive for tumours of the renal pelvis (78%) than for ureteric tumours (53%) (p < 0.02) and when the tumour diameter exceeded 2 cm (70% vs 45%: p < 0.01). The sensitivity of CT for lymph node extension was 47% with an accuracy of 88%. Preoperative CT staging was compared to pathological staging: CT staging had an accuracy of 56%; in 31% of cases, CT underestimated the parietal extension of the tumour. The sensitivity of CT to assess invasion of the renal parenchyma and of the perirenal fat was 52% and 74%, respectively (p < 0.01). Morphological examinations are able to diagnose a tumour of the upper urinary tract in 3 out of 4 cases. Correct preoperative staging can only be achieved on one half of cases, which constitutes a drawback to the development of conservative treatment techniques.

MR imaging and CT of surgical materials currently used in ophthalmology: in vitro and in vivo studies.

PURPOSE: To assess methods of imaging postoperative changes in the eyeball by performing in vitro and in vivo studies of the main solid and fluid materials used in the treatment of cataract and retinal detachment. MATERIALS AND METHODS: The samples were analyzed in vitro with computed tomography (CT) and magnetic resonance (MR) imaging performed at 0.5 T. In vivo studies were performed in seven patients who underwent lens implantation (n = 1), scleral buckling with hydrogel or silicone (n = 6), and retinopexy with gas or silicone oil (n = 6). The attenuation and signal intensity of the materials were compared with values for anatomic structures. RESULTS: Lens implants were difficult to visualize. Each scleral buckling and retinopexy material was easily differentiated from the others and from anatomic structures at both CT and MR imaging. CONCLUSION: Postoperative CT or MR imaging may be useful after retinal detachment surgery, particularly when ultrasound is not reliable after intravitreous gas-fluid interchange.

[Preoperative assessment of liver transplantation. Contribution of imaging]. / Bilan pré-transplantation hépatique. Apport de l'imagerie.

Medical imaging plays an essential role in the preoperative assessment of liver transplant patients to detect any lesions contraindicating the operation or to detect any anatomical variants in the recipient likely to lower the chances of success of the transplantation. At the present time, the imaging techniques useful in the preoperative assessment are colour Doppler ultrasound, abdominal CT scan and coeliac and superior mesenteric arteriography. The calibre and patency of the portal trunk and its branches, the hepatic artery at the porta hepatis, the hepatic veins and their distribution and the inferior vena cava are systematically evaluated. Systematic identification of the various portosystemic shunts in the context of portal hypertension helps to define a veritable preoperative map.

[Prognostic value of x-ray computed tomography in acute pancreatitis. Value of a new classification]. / Valeur pronostique de la tomodensitométrie dans les pancréatites aiguës (PA). Intérêt d'une nouvelle classification.

CT plays an important role in the screening of complications of acute hemorrhagic pancreatitis. There are three classifications at present, one based on a bioclinical score (Ranson) and the other two consisting of gradual stages of severity and resorting to CT imaging (Balthazar and Hill). The authors report about a study on 34 cases of acute pancreatitis, including 10 that became complicated, to which they applied a new classification including the existence of glandular necrosis, the number of extrapancreatic streaks, related to Ranson's bioclinical score. This classification makes it possible to classify acute pancreatitis into three stages: a mild stage with a favorable outcome, a medium stage requiring close surveillance, and stage 3 involving a high (75%) risk of severe complications.

Obstruction of the iliac vein by mucoid cyst: successful result of surgical excision.

The third case, if the literature's survey has been exhaustive, of mucoid cyst of the venous wall is reported. Venous obstruction with palpable tumour in the iliac fossa is not always of poor prognosis.