[Association between oral conditions and colorectal cancer: A literature review and synthesis]. / Association entre les affections buccodentaires et le cancer colorectal: une revue et synthèse de la littérature.

BACKGROUND: Chronic periodontitis and tooth loss are chronic oral conditions that, in recent decades, have been implicated in the occurrence of certain types of cancer. In this review, we address the question of whether colorectal cancer is associated with these oral conditions. RESULTS: Epidemiological studies evaluating a potential association between periodontitis, tooth loss and colorectal cancer are scarce. However, several mechanisms argue in favor of this association, notably inflammation, nutrition and possibly infection by specific bacteria, as suggested by this literature review.

Laparoscopic vs. open abdominoperineal resection for cancer.

PURPOSE: The aim of this study was to compare the safety and efficacy of laparoscopic abdominoperineal resection and open abdominoperineal resection for cancer. METHODS: Records of 194 patients who underwent laparoscopic abdominoperineal resection (42 patients) or open abdominoperineal resection (152 patients) at three institutions between 1991 and 1997 were reviewed. Follow-up was through office charts, American College of Surgeons cancer registry, or telephone contact. Tumors included (laparoscopic abdominoperineal resection and open abdominoperineal resection, respectively) adenocarcinoma (86 and 92 percent), squamous (12 and 7 percent), and gastrointestinal stromal (2 and 1.4 percent) types; Stages I (17 and 26 percent), II (24 and 33 percent), III (43 and 32 percent), and IV (14 and 9 percent); and those with invasion of pelvic structures (14 and 16 percent). RESULTS: Laparoscopic abdominoperineal resection was converted to open abdominoperineal resection in 21 percent because of vessel injury (33 percent), poor exposure (22 percent), adhesions (22 percent), inguinal hernia (11 percent), or radiation fibrosis (11 percent). Perineal infections occurred more often in the laparoscopic abdominoperineal resection group (24 vs. 8 percent; P=0.02). Late stoma complications were similar. Mean hospital stay was shorter after laparoscopic abdominoperineal resection (7 vs. 12 days). Radial margins were positive in 12 percent of laparoscopic abdominoperineal resection and 12.5 percent of open abdominoperineal resection specimens. Tumor recurrence was similar for both local (19 and 14 percent) and distant (38 and 26 percent) recurrence. Survival rates were similar by Kaplan-Meier curves, with median follow-up of 19 and 24 months, respectively (P=0.22; log rank). CONCLUSION: Laparoscopic abdominoperineal resection can be performed safely and results in a shorter hospital stay. A randomized, prospective trial is needed to determine the long-term outcome of cancer treatment.

Long-term functional evaluation of straight coloanal anastomosis and colonic J-pouch: is the functional superiority of colonic J-pouch sustained?

AIM: This study was designed to analyze the functional and clinical outcomes of straight coloanal anastomosis compared with colonic J-pouch performed after low anterior resection. MATERIALS AND METHODS: Between September 1989 and June 1996, all patients who underwent low anterior resection with anastomosis less than 4 cm from the dentate line were classified into two groups based on the restoration of intestinal continuity: "straight" coloanal anastomosis (n = 39) or colonic J-pouch (n = 44). Both groups were assessed according to the level of anastomosis, anastomotic complications (stricture, leak, pelvic abscess), age, and gender. For comparison of functional outcome, daily bowel movements, tenesmus, urgency, incontinence score (range, 0-20), and anorectal manometric findings were evaluated preoperatively and at six months, and one and two years after surgery. RESULTS: There were no significant differences between the groups relative to age: (coloanal anastomosis, 66.3 +/- 10.1 (range, 46-86), vs. colonic J-pouch, 64.9 +/- 13.2 (range, 39-88) years); gender (females): (coloanal anastomosis, 46.2 percent vs. colonic J-pouch; 38.6 percent); diagnosis: (rectal carcinoma: coloanal anastomosis, 84.6 percent, vs. colonic J-pouch, 77.3 percent); preoperative incontinence score (coloanal anastomosis, 1.5 +/- 4.6, vs. colonic J-pouch, 1.1 +/- 4); bowel movements: (coloanal anastomosis, 2.1 +/- 2.3, vs. colonic J-pouch, 2.1 +/- 1.9/day); level of anastomosis: (coloanal anastomosis, 1.8 +/- 1.3, vs. colonic J-pouch, 1.5 +/- 1.3 cm from the dentate line); history of perioperative radiation therapy: (coloanal anastomosis, 15.4 percent, vs. colonic J-pouch, 20.5 percent); or manometric findings. There was also no significant difference in postoperative mortality: (coloanal anastomosis, 5.1 percent, vs. colonic J-pouch, 2.3 percent); or anastomotic complications: (coloanal anastomosis, 7/39 (17.9 percent), vs. colonic J-pouch, 2/44 (4.5 percent) P = 0.08); strictures: (10.3 vs. 0 percent); leaks: (5.1 vs. 2.3 percent); bleeding: (2.6 vs. 0 percent); rectovaginal fistula: (0 vs. 2.3 percent). Also, in the colonic J-pouch group, two patients developed pouchitis, and one patient experienced difficult evacuation one year after surgery. There was a statistically significant better function judged by less frequent bowel movements (4 +/- 2 vs. 2.4 +/- 1.3/day; P < 0.005) and urgency (36.7 vs. 7.7 percent; P < 0.05), incontinence score (2.2 +/- 3.7 vs. 0.8 +/- 1.6; P < 0.05) up to one year after surgery. At two years, the coloanal anastomosis group did not show statistical improvement in functional results compared with one year postoperatively. Rectal compliance in manometric findings was significantly increased in the coloanal anastomosis group at one year after surgery (12.4 +/- 12.6 vs. 4.2 +/- 1.5 ml/mmHg; P < 0.05). However, these differences were less profound after two years. CONCLUSION: The functional superiority of the colonic J-pouch was greatest at one year after surgery. By two years, adaptation of the "straight" coloanal anastomosis yielded similar functional results. However, the almost fourfold reduction in anastomotic complications in the colonic J-pouch group reveals a second potential advantage of this technique.

Laparoscopic colorectal surgery and cancer.

Review article of the actual level of knowledge about laparoscopic colorectal surgery and laparoscopic-assisted procedures. At present time laparoscopy for the cure of colorectal neoplasia should only be performed within prospective randomized trials. In the meantime it is perfectly appropriate to perform laparoscopy for palliation of metastatic disease. Patients with benign colorectal neoplasms can achieve better outcome if treated by laparoscopy rather than laparotomy. Other areas in which laparoscopy may be useful include enterolysis and possibly, treatment of rectal prolapse. Laparoscopy can be appropriately applied for the treatment of terminal ileal Crohn's disease, sigmoid diverticulitis, reversal of Hartmann's pouches and the construction of stomas.

[Effect of the ventricular preload on the basal and stimulated coronary circulation of the isolated rat heart]. / Influence de la précharge ventriculaire sur la circulation coronarienne basale et stimulée du coeur de rat isolé.

Langendorff perfused isolated rat heart is a common model for coronary blood flow study. Left ventricular preload can both increase coronary blood flow by direct inotropic effect or decrease it by rising transmural tension. Experiments were designed to determine optimal preload conditions for observation of basal (CBF) and 5-hydroxytryptamine (5-HT) stimulated coronary blood flow (SCBF) in the isolated rat heart model. Rat hearts (n = 6) were harvested and stabilized in the Langendorff apparatus and a left ventricular balloon was inserted and inflated at different volumes (0.05 to 0.4 ml) to stimulate preload. Left ventricular systolic (LVSP), diastolic (LVDP), myocardial oxygen consumption (MVO2) and extraction (MEO2) were also measured. Under basal conditions, optimal LVSP was obtained at 0.2 ml (111 +/- 15 mmHg). MVO2 was optimal at 0.2 ml of preload and decreased thereafter while MEO2 remained stable. Optimal CBF was reached at 0.2 ml of preload. Under 5-HT stimulation, CBF increased significantly (CBF: 8.2 +/- 0.6 ml/min vs SCBF: 16.4 +/- 1.0 ml/min, p < 0.01) while left ventricular hemodynamics did not differ from basal observations. At preload volume > 0.2 ml a significant drop in SCBF was observed (0 ml: 16.4 +/- 1 ml/min vs 0.4 ml: 11 +/- 1 ml/min, p < 0.01). MVO2 and MEO2 followed the same pattern observed under basal conditions. In basal and stimulated conditions, a hyperemic flow was also seen after deflation of the balloon with preload > = 0.2 ml in both CBF and SCBF suggesting myocardial oxygen debt. We conclude that in the Langendorff model preload affects coronary flow under both basal and 5-HT stimulation. A volume > 0.2 ml for rats of 350-400 g can impede CBF and generate myocardial oxygen debt as suggested by a decreased MVO2 and a post-deflation hyperemic flow. Left ventricular preload should be maintained under 0.2 ml for optimal coronary blood flow study in the Langendorff perfused rat heart model.

Orotracheal intubation of rats by transillumination.

We described a new technique of orotracheal intubation in the rat. This technique is performed under direct vision by transillumination to obtain a better view of the rat's small and distant vocal cords. We also emphasize overextension of the neck to allow for a more direct path to the animal's trachea. This technique is easily learned, is atraumatic, and does not depend on expensive equipment.

[Effect of pentoxifylline on the vascular toxicity secondary to cyclosporine in rats]. / Influence de la pentoxifylline sur la toxicité vasculaire secondaire à la cyclosporine chez le rat.

Chronic administration of cyclosporine (CyA) has been shown to affect local vascular tone. Pentoxifylline (PTX), a xanthine-derived vasoactive agent, has been reported to prevent CyA toxicity but its effect on CyA-related increased vascular tone remains uncertain. In vitro experiments were designed to study the effects of PTX on endothelium-dependent and independent vasorelaxation of the rat thoracic aorta. Three groups of rats (n = 10) were respectively treated for 4 weeks with CyA (30 mg/kg/day), CyA and PTX (40 mg/kg/day), and CyA and PTX (80 mg/kg/day). At the end of the period, rings (4-5 mm) of aorta were harvested and suspended in organ chambers containing Krebs Ringer solution (37 degrees C, 95% O2, 5% CO2) for assessment of endothelial and smooth muscle reactivity. Endothelium-dependent relaxation to acetylcholine was significantly enhanced in animals treated with CyA and PTX (40 mg/kg/day) compared to those exposed to CyA alone (p < 0.05). Response to histamine and adenosine diphosphate was not affected. However, the use of PTX (80 mg/kg/day) significantly deteriorated the endothelial response to the same drugs (p < 0.05) suggesting a detrimental effect of PTX at this concentration. Endothelial-independent relaxation to sodium nitroprusside was comparable in all groups. The results suggest the clinical benefit reported with the use of PTX on patients chronically exposed to CyA may partly be due to an improvement of the vascular endothelial function. However, the toxicity encountered at high dose should cautioned its use in clinical setup.

[Effect of solutions of preservation on the vascular reactivity of human saphenous veins]. / Influence des solutions de préservation sur la réactivité vasculaire des veines saphènes humaines.

It is mandatory to preserve the vascular tone regulation of the saphenous vein in order to optimize its performance as a vascular conduit. To determine the optimal preservation solution, human saphenous vein segments (3-4 cm) were harvested, stored for 60 minutes in different preservation solutions and studied in organ chambers for endothelial and smooth muscle assessment. A 1st group (n = 10) was stored in the heparinized blood of the patient (SH), a 2nd group (n = 10) in physiologic saline solution (NaCl) and a 3rd group (n = 10) in Krebs Ringer (KR) solution. All solutions were maintained at room temperature (21 degrees C). Each preserved segment was paired to a control segment, harvested in the same patient, and studied before storage. Following 60 minutes of preservation decreased endothelial-dependent relaxation to acetylcholine and histamine was observed among the group stored in KR (p = 0.06 and p < 0.02 respectively) compared to the other groups. Endothelium-independent relaxation to sodium nitroprusside was not affected regardless of the solution used. However, veins stored in SH disclosed an increased contractility to norepinephrine (p < 0.04). When intergroup variability was considered (by variance analysis), no significant difference was seen between each group. This study suggests that KR and SH were not as efficient as NaCl in preserving saphenous endothelial function. Furthermore, storage in SH increased smooth muscle response to catecholamine. In this experimental setup, 0.9% NaCl solution is an acceptable preservation solution of the saphenous vein.

Effect of ethosuximide on rest tremor in the MPTP monkey model.

Based on the hypothesis that low-threshold calcium conductance in the thalamus might be involved in the pathophysiology of parkinsonian tremor, ethosuximide was given chronically to a monkey previously treated with MPTP and displaying exceptionally a typical rest tremor. After 5 days of daily treatment, the tremor was reduced by 60%. Diltiazem and verapamil which act on different calcium channels had no such effect. Ethosuximide also potentiated the anti-tremor effect of the dopamine D2 agonist LY-171555.