Is nitric oxide involved in the tolerance of Calomys callosus as a reservoir host towards Trypanosoma cruzi infection?

Trypanosoma cruzi, the agent of Chagas disease, is known to cause enhanced nitric oxide (NO) production, which might be involved in host resistance. The inducible nitric-oxide-synthase (iNOS) is assumed to be responsible for the NO increase after several infections. We studied the potential role of NO in Calomys callosus, a natural reservoir of this protozoan parasite. The concentration of NO was determined in spleen and liver of animals infected with two different T. cruzi strains, BOL and BOL-SB. Furthermore, the iNOS mRNA expression was quantified in the same cell types. NO production was detectable in both tissues exhibiting only slight differences compared to non-infected controls. All measured NO values were significantly lower than those reported for a number of different mouse strains, which displayed extremely enhanced NO levels after T. cruzi infection. Surprisingly, iNOS mRNA expression was induced in infected C. callosus but without subsequent increase of NO levels, indicating a post-transcriptional regulation mechanism. In summary, our results, indicate that the tolerance of C. callosus to T. cruzi is only accompanied by non-toxic NO intracellular concentrations.

Six Trypanosoma cruzi strains characterized by specific gene expression patterns.

The intracellular parasite Trypanosoma cruzi, the causative agent of Chagas disease, is known to comprise heterogeneous populations. One possibility to explain the obviously distinct phenotypes of different T. cruzi strains is differential expression of particular genes. This could result in environmental adaptations of the parasite within host organs, leading to distinct clinical symptoms. With the aim of identifying differentially expressed genes, we examined different T. cruzi strains by suppression subtractive hybridization analysis. The isolated clones were sequenced and Blasted for sequence-homology with known T. cruzi genes. A stage-specific glycoprotein (82gp), an 85-kDa protein with homology to heat-shock proteins, a beta-tubulin gene, a hexosetransporter, a dehydrogenase/ prostaglandin F2alpha-synthase and a cathepsin B-like protease were identified. The expression of these genes was analyzed by RT-PCR. Diverse expression patterns were detected for different T. cruzi strains, but no specific correlation between the gene expression and the classification of groups could be found. We discuss the presumed importance of these T. cruzi gene expression patterns for future strategies of molecular therapy of Chagas disease. For pathological studies, other parameters such as distinct gene/antigen expression could also be of interest, because they probably likewise correlate with distinct phenotypes.

Molecular genetic characterization of different Trypanosoma cruzi strains and comparison of their development in Mus musculus and Calomys callosus.

Trypanosoma cruzi populations are characterized by diverse morphology, heterogeneous biological behavior, high genetic variability, and distinctly different clinical courses. The first objective of this work was to characterize different strains of T. cruzi with various molecular markers [simple-sequence-repeat PCR, randomly amplified polymorphic DNA (RAPD)-PCR, mini-exon genes]. All examined strains could be divided into two major lineages. Only one strain showed a different banding pattern in RAPD-PCR, which could be a further indication of the existence of a third lineage. The second aim was to examine the biological behavior of the different strains. Two animal models, Calomys callosus and Mus musculus, were infected. The results provide strong evidence that the biological behavior of the strains is not only lineage-specific. It appears that all factors, such as the infecting strain belonging to a certain lineage, the predominant morphological form of the isolate, and the immune response of the respective infected host, play an important role in the course of this infection.

[Cholecystectomy by laparoscopy. Operative technic. Results of the first 100 cases]. / Cholécystectomie par laparoscopie. La technique opératoire. Les résultats des 100 premières observations.

The authors describe their own technique for the treatment of gallbladder stones using a laparoscopic approach. They squeletonsie the cystic artery and duct. Their clamp them by clips. Next they introduce into the gallbladder an ultrasonic lithotriptor which fragments the stones into powder evacuated by aspiration. The empty and clear gallbladder is severed off the liver and extracted out of the abdomen through an 8 mm orifice formerly used for the introduction of the lithotriptor. Among the 104 first cases performed between November 1988 to December 1989 the mortality is zero. On three patients the laparoscopic procedure has had to be stopped and replaced by a traditional open cholecystectomy. 3 complications occurred postoperatively: 1 biliary fistula which cured spontaneously within 7 days and 2 intra abdominal abscess which were treated by a secondary laparoscopic drainage. In the other cases the postoperative time has been uneventful. The patients appreciate mostly the painless postoperative time the absence of skin scar the short hospital stay 4 days and the possibility to go working one week later.

[Laparoscopic surgery of gallstones--report of treatment of 157 patients]. / Laparoskopische Chirurgie der Gallensteine--Behandlungsbericht von 157 Patienten.

From November 1988 to February 1990 157 patients with gallbladder stones haven been treated by a laparoscopic surgical procedure. They are 28 males and 129 females from 13 to 81 years old. 18 have had a cholecystostomy after intracorporeal lithotripsy (Lus Ultrasonic Olympus). They were placed on bue acids during 3 months. The average follow up time is 11 months. The mortality is zero and 2 mild complications occurred medically cured. 3 patients have a recurrent stone 6 months after surgery. 139 patients have had a cholecystectomy 89 after the same lithotripsy procedure seen above, 50 without prior lithotripsy. In 3 cases the laparoscopic procedure was abandoned, twice because of a sever bleeding, one for too compact surrounding adhesions. The mean follow up is 9 months. 123 were drained 1 day 16 had no drain. The mortality is zero. 2 patients without drainage developed a sub hepatic and douglas pouch abscess. They were cured by a lavage drainage laparoscopically made. 1 patient with drainages had a 7 days bile leak, which disappeared spontaneously. The 136 others have had a short stay in the hospital (2-4 days) a painless post operative time. They could go back to work and sport within 1 week. They have minimal scars and no danger of incisional herriae. The magnification of the optical system enables the dissection of the cystic duct and artery easier and safer than it is by mini laparotomy mostly in obese people. At the beginning of our experience only the patients with frequent biliary colics have been selected for the laparoscopic procedure. At that time 13 patients with subacute cholecystitis and 9 patients with stones in the commun bile duct have had a laparoscopic cholecystectomy associated with an endoscopic sphincterotomy in the last cases without complications.

[Cholelithiasis. Laparoscopic treatment with intracorporeal lithotripsy followed by cholecystostomy or cholecystectomy. Personal technique]. / Lithiase vésiculaire. Traitement laparoscopique par lithotritie intra-corporelle (LIC) suivie de cholécystostomie ou cholécystectomie. Technique personnelle.

From November 1988 to February 1990 157 patients with gallbladder stones have been treated by a laparoscopic surgical procedure. They are 28 males and 129 females from 13 to 81 years old, 18 have had a cholecystostomy after intracorporeal lithotripsy (Lus Ultrasonic Olympus). They were placed on bile acids during 3 months. The average follow up time is 11 months. The mortality is zero and 2 mild complications occurred medically cured. 3 patients have a recurrent stone 6 month after surgery. 139 patients have had a cholecystectomy 89 after the same lithotripsy procedure seen above, 50 without prior lithotripsy. In 3 cases the laparoscopic procedure was abandoned, twice because of a sever bleeding, one for too compact surrounding adhesions. The mean follow up is 9 months. 123 were drained 1 day 16 had no drain. The mortality is zero. 2 patients without drainage developed a sub hepatic and douglas pouch abscess. They were cured by a lavage drainage laparoscopically made. 1 patient with drainage had a 7 days bile leak which disappeared spontaneously. The 136 others have had a short stay in the hospital (2-4 days) a painless post operative time. They could go back to work and sport within 1 week. They have minimal scars and no danger of incisional herniae. The magnification of the optical system enables the dissection of the cystic duct and artery easier and safer than it is by mini laparotomy mostly in obese people. At the beginning of our experience only the patients with frequent biliary colics have been selected for the laparoscopic procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

[Easily closed gun-barrel enterostomy. A new technique]. / Entérostomie cutanée en canon de fusil de fermeture simple. Description d'une technique originale.

The availability of continuous low rate enteral and parenteral feeding has enlarged the indications of enterostomy, notably in patients with multiple operations. However, closing an enterostomy, which may be high up in the small bowel, rises technical problems and is not always without risk. In this study a new technique of gun-barrel enterostomy easily closed with automatic sutures and without reopening of the abdominal wall is presented.

[Pelvic-peritoneal recurrences after amputation of the rectum for cancer. Report of 23 cases (author's transl)]. / Les récidives pelvi-périnéales après amputation du rectum pour cancer. A propos de 23 observations.

Of 79 patients surviving after amputation of the rectum for cancer, local and regional recurrences occurred in 23 cases, in 3 out of 4 of these during the 2-year period following operation. Only 3 patients survived. This illustrates the frequency and serious nature of these recurrent lesions. Based on their experience, the authors consider the risk of recurrence to be doubled if one of the following factors is present : patient under 60 years of age, cancer located in the lower rectum, tumour over 4 cm in diameter, stages B or C according to Dukes' classification, an anaplastic or colloid structure. Enzyme assay and computed tomography are unfortunately not determining factors for early diagnosis and effective therapy of pelvic-peritoneal recurrences. the authors suggest, therefore, though it was never employed in their own series, that pre-operative irradiation could be of value, in those patients that have a high risk of developing local or regional recurrences. The general use of this technique is not suggested because its known inconveniences.

[Statistical analysis of results of operative treatment of 223 cases of left colon cancer (author's transl)]. / Réflexions statistiques sur une série de 223 interventions pour cancer du côlon gauche.

Statistical analysis of results of 223 operations for left colon cancer over a period of ten years is presented. The patients (age, condition), and the clinical expression (urgent or cold surgery) are discussed. The authors then give the lesions a sort of identity card of macroscopic findings (topography, local extension, invasion of glands, metastatic spread) to enable interpretation of the long-term survival results as a function of each parameter. Their conclusions are that, apart from left hemicolectomy conducted for oncological reasons or for safety of technique, no element demonstrates the superiority of standard left hemicolectomy over segmentary colectomy. They also adopt the principle of a proximal colostomy in certain cases that are difficult to treat, this procedure being for them a definite factor of security, but also a risk factor. An urgent bypass operation is conducted except when the lesion requires excision. If conditions are suitable for immediate re-establishment of continuity, which rarely happens, they carry out a systematic protective subjacent colostomy.

[Nycthemeral variations of blood and urine urea, creatinine and total proteins in rats]. / Etude des variations nycthémérales du taux sérique et urinaire de l'urée, de la créatinine et des protéines totales chez le rat.

The present study evidences blood and urine urea, creatinine and total proteins circadian variations in 50 male rats. Venous blood is sampled at behind socket sinus once a week at different hours (8, 11, 14, 17, 20, 23, 2 and 5) and urines are collected during 4 consecutive six hours periods in animals living in metabolism cages (8-14, 14-20, 20-2, 2-8). Blood three nitrogen substances circadian variations bring out the decrease at 17 h and increase at 23 or 2 h. Urinary excretion variations curves shows, in all cases, an increase more than 40% during the nightly periods. The influence of feeding rhythms on the blood and urine three derivates circadian rhythms is discussed. Moreover, night diuresis increase and urea and creatinine urinary remarkable constancy suggest water, solutes and macrosolutes transglomerular pathway nightly increase existence. Urea (+ 40%) and creatinine (+ 30%) clearance nightly significative increase confirms glomerular filtration circadian variations and its nightly increase.