Neural contractions in colonic strips from patients with diverticular disease: role of endocannabinoids and substance P.

BACKGROUND AND AIMS: Diverticulosis is a common disease of not completely defined pathogenesis. Motor abnormalities of the intestinal wall have been frequently described but very little is known about their mechanisms. We investigated in vitro the neural response of colonic longitudinal muscle strips from patients undergoing surgery for complicated diverticular disease (diverticulitis). METHODS: The neural contractile response to electrical field stimulation of longitudinal muscle strips from the colon of patients undergoing surgery for colonic cancer or diverticulitis was challenged by different receptor agonists and antagonists. RESULTS: Contractions of colonic strips from healthy controls and diverticulitis specimens were abolished by atropine. The beta adrenergic agonist (-) isoprenaline and the tachykinin NK1 receptor antagonist SR140333 had similar potency in reducing the electrical twitch response in controls and diseased tissues, while the cannabinoid receptor agonist (+)WIN 55,212-2 was 100 times more potent in inhibiting contractions in controls (IC50 42 nmol/l) than in diverticulitis strips. SR141716, a selective antagonist of the cannabinoid CB1 receptor, had no intrinsic activity in control preparations but potentiated the neural twitch in diseased tissues by up to 196% in a concentration dependent manner. SR141716 inhibited (+)WIN 55,212-2 induced relaxation in control strips but had no efficacy on (+)WIN 55,212-2 responses in strips from diverticular disease patients. Colonic levels of the endogenous ligand of cannabinoid and vanilloid TRPV1 receptors anandamide were more than twice those of control tissues (54 v 27 pmol/g tissue). The axonal conduction blocker tetrodotoxin had opposite effects in the two preparations, completely inhibiting the contractions of control strips but potentiating those in diverticular preparations, an effect selectively inhibited by SR140333. CONCLUSIONS: Neural control of colon motility is profoundly altered in patients with diverticulitis. Their raised levels of anandamide, apparent desensitisation of the presynaptic neural cannabinoid CB1 receptor, and the SR141716 induced intrinsic response, suggest that endocannabinoids may be involved in the pathophysiology of complications of colonic diverticular disease.

Functional assessment of neuronal cannabinoid receptors in the muscular layers of human ileum and colon.

BACKGROUND & AIMS: The notion that specific receptors account for the ability of natural and synthetic cannabinoids to alter physiological functions, prompted this study aimed at assessing their functional presence in the human gut. METHODS: The effects have been studied of cannabinoids and selective antagonists of their receptors on chemically or electrically evoked contractions in preparations of human intestinal smooth muscle in vitro. RESULTS: Atropine prevented the contractions of longitudinal and circular muscle strips of ileum and colon induced by carbachol or electrical field stimulation; tetrodotoxin abolished only the latter which suggests they do involve activation of cholinergic neurons. The synthetic cannabinoid (+)WIN 55,212-2 had no effect on carbachol contractions, but in a concentration-dependent fashion prevented those elicited by electrical field stimulation - which were insensitive to the putative endogenous cannabinoid anandamide - more potently in longitudinal than in circular strips. The selective CB1 receptor antagonist SR141716, which had no effect in the absence of (+)WIN 55,212-2, competitively antagonised its inhibition of electrical field stimulation contractions, unlike the selective CB2 antagonist SR144528. CONCLUSIONS: Cannabinoid CB1 receptors are functionally present in the human ileum and colon; their pharmacological activation apparently results in inhibition of excitatory cholinergic pathways subserving smooth muscle contraction.

Role of hepatic resection in the treatment of hepatolithiasis.

BACKGROUND: The aim of the present study was to evaluate the safety and the efficacy of hepatic resection in the treatment of hepatolithiasis with intrahepatic biliary strictures. EXPERIMENTAL DESIGN: retrospective study. SETTING: University hospital, Italy. PATIENTS: 6 consecutive patients with single lobe hepatolithiasis operated on during the 4-year period 1994-98 inclusive. INTERVENTIONS: major hepatic resections (3 left hepatectomies, 2 left lobectomies, 1 right hepatectomy). MAIN OUTCOME MEASURES: type and duration of the surgical procedure, intra/postoperative blood losses, intra/postoperative course and complications, pathology, and hepatolithiasis recurrence. RESULTS: Mean operative time was 3.34+/-0.02 hrs (range 3.0-4.3 hrs). Mean blood loss was 233+/-150 ml (range 100-500 ml). No patient required intra/postoperative blood transfusions. No intraoperative complication was recorded. Mean postoperative hospitalization was 17+/-7 days (range 6-28 days). Postoperative course was uneventful in 4 (66%) cases. No postoperative mortality was recorded. One pancreatitis and 1 biliary fistula occurred, for an overall postoperative morbidity of 33%. Pathology showed cholangiocarcinoma in 2 cases (33%). During the follow-up period (range 3-48 months, mean 19.1+/-16.4 months), 1 patient had recurrent cholangitis due to right lobe lithiasis and 1 patient died for cholangiocarcinoma. CONCLUSIONS: Hepatic resection is the treatment of choice in patients with single lobe hepatolithiasis and unreversible biliary strictures or possible presence of cholangiocarcinoma. An early indication for surgery may reduce the mortality/morbidity rates of hepatic resection for hepatolithiasis.

[Advanced age as risk factor in liver resection surgery]. / L'età avanzata come fattore di rischio nella chirurgia resettiva epatica.

To evaluate the influence of age on the outcome of liver resections, 105 consecutive patients undergoing hepatic resection were divided into two groups: age > or = 65 years [Old Group (O-Group)] and age < 65 years [Young Group (Y-Group)]. O-Group and Y-Group patients were analyzed comparatively in terms of primary diagnosis, concomitant diseases, previous surgery, type of operation (major or minor resection), associated procedures, presence and length of portal clamping, intraoperative blood losses and transfusions, and length of operation. The end points of the study were postoperative mortality, morbidity, transfusions, and length of post-operative hospitalization. The Y-Group included 61 resections in 60 patients, with a mean age of 52 +/- 10 years (mean +/- SD), range 23-64 years, and the O-Group 44 resections in 43 patients, with a mean age of 71 +/- 4 years, range 65-82 years. The O-Group included more cases of hepatoma (45.4% vs 18%, p = 0.002) and cirrhosis (40.9% vs 18.7%, p = 0.017). Median length of operation was slightly higher in the Y-Group (330 vs 270 minutes, p = 0.003). The O- and Y-Groups were comparable (p = n.s.) when evaluated for all other variables listed. As regards the end points of the study, length of post-operative hospitalization was identical in both groups (median 9 days, range 5-60 days) and neither PRBC transfusions (O-Group vs Y-Group: 16% vs 25%) nor FFP transfusions (O-Group vs Y-Group: 13.6% vs 6.5%) showed any statistically significant difference. Postoperative mortality consisted in 1 death among the younger patients while no deaths were recorded among the older patients. Postoperative morbidity was higher in the Y-Group than in the O-Group (31.1% vs 20.5%, p = 0.59). Advanced age does not negatively affect the outcome of liver resections.

Right hepatic artery indwelling catheter for adjuvant chemotherapy after right hepatectomy.

Intraarterial hepatic adjuvant chemotherapy after radical hepatic resection for liver metastases from colorectal carcinoma lowers the rate of liver disease relapse. The technique for catheter implantation in the right hepatic artery for subsequent intraarterial hepatic adjuvant chemotherapy after right hepatectomy is herein described and recommended as an effective alternative approach to the standard catheter implantation in the gastroduodenal artery in cases of hepatectomies for liver metastases from colorectal cancer.

Functional assessment of beta adrenoceptor subtypes in human colonic circular and longitudinal (taenia coli) smooth muscle.

BACKGROUND AND AIMS: The subtype and species related heterogeneity of beta adrenoceptors prompted a functional reappraisal of these molecular targets of motility inhibition in the human colon. METHODS: Relaxation of muscle strips was measured in vitro. RESULTS: The following agonists had decreasing relaxing potency (effective concentration range 10(-8)-10(-4) mol/l): (-)isoprenaline (non-selective), terbutaline (beta(2) selective), CGP 12177 (beta(3) selective, also beta(1), beta(2) antagonist), and SR 58611A (beta(3) selective). Isoprenaline and terbutaline were more potent on circular than taenia strips; CGP 12177 and SR 58611A weakly and partially relaxed taenia but had little effect on circular strips. The potency of isoprenaline on circular strips was greatly reduced by the beta(1) selective antagonist CGP 20712 (10(-7) mol/l), and less so by ICI 118551 (10(-7) mol/l, beta(2) selective). CGP 20712 and ICI 118551 together (both 3 x 10(-6) mol/l) had no effect on taenia relaxation by SR 58611A and rendered isoprenaline and terbutaline virtually inactive on circular strips, although not on taenia, which was relaxed at higher than control concentrations and maximally by isoprenaline. Propranolol, a beta(1), beta(2) non-selective antagonist, at high concentrations (10(-5) mol/l) prevented taenia relaxation by CGP 12177 and SR 58611A; its quantitative antagonism of isoprenaline (in common with that of CGP 12177 used as an antagonist) was competitive in circular strips but not on taenia. CONCLUSIONS: beta(1), beta(2), and beta(3) adrenoceptors are functionally detectable in the human colon; agonist stimulation of any one type relaxed taenia but only isoprenaline was fully effective at the beta(3) subtype.

In vitro functional evidence of different neurotensin-receptors modulating the motor response of human colonic muscle strips.

1. The newly developed non-peptide neurotensin (NT)-receptor antagonists SR 48692 and SR 142948 were used to challenge NT responses of human colonic circular smooth muscle strips in vitro. The presence of NT1 and NT2 receptor transcripts in this tissue was tested by reverse transcriptase polymerase chain reaction (RT - PCR) analysis. 2. NT potently and dose-dependently contracted muscle strips, with significant regional differences in potency and efficacy between the transverse and distal colon: EC50, 3.6 and 7.5 nM; the maximal effect was 70 and 55% of 0.1 mM carbachol. Colonic responses to NT in both segments were virtually the same in the presence of atropine (1 microm), levocabastine (10 microM) or tetrodotoxin (1 microM). 3. SR 142948 (10 nM - 1 microM) competitively antagonized NT responses in the transverse and distal colon with similar affinities: pA2 values 8.71 and 8.45, slopes 0.98 and 0.99. SR 48692 (10 nM - 10 microM) antagonized the NT response competitively in the distal colon (pA2 6.55, slope 0.79) and non-competitively in the transverse colon (pA2 8.0, slope 0.51). Neither compound had any agonist effect. 4. The fact that the specific antagonists prevented NT-evoked atropine- and tetrodotoxin-insensitive mechanical responses of colonic muscle strips is highly consistent with the presence in these tissues of non-neuronal NT receptors, whose heterogeneity in the transverse segment is supported by the non-competitive antagonism of SR 48692. The finding of NT1 receptor transcript in both transverse and distal colon suggests its identity with the lower affinity site disclosed functionally by SR 48692 in these segments.

In vitro characterization of tachykinin NK2-receptors modulating motor responses of human colonic muscle strips.

1. Human in vitro preparations of transverse or distal colonic circular smooth muscle were potently and dose-dependently contracted by neurokinin A (EC50, 4.9 nM), the tachykinin NK2-receptor selective agonist [beta-Ala8]neurokinin A (4-10) ([beta-Ala8]NKA (4-10)) (EC50, 5.0 nM), neurokinin B (EC50, 5.3 nM) and substance P (EC50, 160 nM), but not by the tachykinin NK1-receptor selective agonist [Sar9Met(O2)11] substance P, or the NK3-receptor selective agonists, senktide and [MePhe7] neurokinin B. No regional differences between transverse and distal colon were observed in response to [beta-Ala8]NKA (4-10). 2. Atropine (1 microM) and tetrodotoxin (1 microM) did not significantly inhibit responses to [beta-Ala8]NKA (4-10), neurokinin A, substance P or neurokinin B. 3. The newly developed non-peptide antagonists for tachykinin NK2-receptors SR 48968, SR 144190 and its N-demethyl (SR 144743) and N,N-demethyl (SR 144782) metabolites, were used to challenge agonist responses, as appropriate. SR 144190 and the metabolites all potently and competitively antagonized the response to [beta-Ala8]NKA (4-10), with similar potency (Schild plot pA2 values 9.4, 9.4 and 9.3, slope = 1). SR 48968 antagonism was not competitive: the Schild plot slope was biphasic with a high (X intercept approximately 9.3) and a low (X intercept 8.4, slope 1.6) affinity site. Co-incubation of SR 48968 (10, 100 nM) and SR 144782 (10 nM) produced additive effects; in this experimental condition, SR 48968 apparent affinity (pKB) was 8.2. In addition, SR 144782 (0.1 microM) antagonized responses to neurokinin A, substance P and neurokinin B, with pKB consistent with its affinity for tachykinin NK2-receptors. The potent and selective NK1 and NK3-receptor antagonists, SR 140333 and SR 142801 (both 0.1 microM), failed to inhibit contractions induced by SP or NKB. 4. In conclusion, the in vitro mechanical responses of circular smooth muscle preparations from human colon are strongly consistent with the presence of non-neuronal tachykinin NK2-receptors, but not tachykinin NK1- or NK3-receptors. Our findings with SR 48968 suggest the existence of two tachykinin NK2-receptor subtypes, that it seems to distinguish, unlike SR 144190 and its metabolites. However, the precise nature of SR 48968 allotopic antagonism remains to be elucidated, since allosteric effects at the tachykinin NK2-receptor might well account for the complexity of the observed interaction.

In vitro functional evidence of neuronal cannabinoid CB1 receptors in human ileum.

We investigated the effect of the cannabinoid agonist (+)WIN-55212-2 on human ileum longitudinal smooth muscle preparations, either electrically stimulated or contracted by carbachol. Electrical field stimulation mostly activated cholinergic neurons, since atropine and tetrodotoxin (TTX), alone or coincubated, reduced twitch responses to a similar degree (85%). (+)WIN-55212-2 concentration-dependently inhibited twitch responses (IC50 73 nM), but had no additive effect with atropine or TTX. The cannabinoid CB1 receptor antagonist SR 141716 (pA2 8.2), but not the CB2 receptor antagonist, SR 144528, competitively antagonized twitch inhibition by (+)WIN-55212-2. Atropine but not (+)WIN-55212-2 or TTX prevented carbachol-induced tonic contraction. These results provide functional evidence of the existence of prejunctional cannabinoid CB1-receptors in the human ileum longitudinal smooth muscle. Agonist activation of these receptors prevents responses to electrical field stimulation, presumably by inhibiting acetylcholine release. SR 141716 is a potent and competitive antagonist of cannabinoid CB1 receptors naturally expressed in the human gut.

Distribution of diaphragmatic lymphatic lacunae.

The morphology of the submesothelial lymphatic lacunae on the pleural and peritoneal surface over the tendinous and muscular portion of the diaphragm was studied in 10 anesthetized rabbits. The lymphatic network was evidenced by injecting 1 ml of colloidal carbon solution in the pleural (n = 5) or the peritoneal (n = 5) space. After 1 h of spontaneous breathing, the animal was killed and the diaphragm was fixed in situ by injection of approximately 5 ml of fixative in pleural and peritoneal spaces. Then both cavities were opened and the diaphragm was excised and pinned to a support. According to which cavity had received the injection, the peritoneal or the pleural side of the diaphragm was scanned by sequential imaging of the whole surface by use of a video camera connected to a stereomicroscope and to a video monitor. The anatomic design appeared as a network of lacunae running either parallel or perpendicular to the major axis of the tendinous or muscular fibers. The lacunae were more densely distributed on the tendinous peritoneal area than on the pleural one. Scanty lacunae were seen on the muscular regions of both diaphragmatic sides, characterized by large areas without lacunae. The average density of lacunae on tendinous and muscular regions was 6 and 1.7/cm2 for the pleural side and 25 and 3.4/cm2 for the peritoneal side, respectively. The average width of lacunae was 137.9 +/- 1.6 and 108.8 +/- 1.7 microns on the tendinous pleural and the peritoneal side, respectively, and 163 +/- 1.8 microns on the muscular portion of the pleural and peritoneal surfaces.

[Pyeloureteral junction syndrome caused by "anomalous vessel"]. / Sindrome del giunto pieloureterale da "vaso anomalo".

In presenting and describing the pathogenesis of the pyeloureteral junction syndrome, the Authors report their recent experience with four cases due to an "abnormal vessel". Symptoms, diagnosis, and surgical techniques are discussed.

Distribution of diaphragmatic lymphatic stomata.

In seven anesthetized rabbits we measured the size, shape, and density of lymphatic stomata on the peritoneal and pleural sides of the diaphragm. The diaphragm was fixed in situ and processed for scanning electron microscopy. Results are from 2,902 peritoneal and 3,086 pleural fields (each 1,620 microns 2) randomly chosen from the various specimens. Stomata were seen in 9% of the fields examined, and in 30% of the cases they appeared grouped in clusters with 2-14 stomata/field. Stoma density was 250 +/- 242 and 72 +/- 57 (SD) stomata/mm2 on peritoneal and pleural sides, respectively, and it was similar over the muscular and tendinous portion of the two surfaces. The maximum diameter ranged from less than 1 to approximately 30 microns, with an average value of 1.2 +/- 3.1 micron. The ratio of the maximum to the minimum diameter and the surface area averaged 2 +/- 1.4 and 0.7 +/- 2.4 micron 2, respectively. The maximum and minimum diameter and surface area values followed a lognormal frequency distribution, suggesting that stomata geometry is affected by diaphragmatic tension.

[Anatomical and surgical considerations on the internal spermatic venous system]. / Considerazioni anatomiche e chirurgiche sul sistema venoso spermatico interno.

The surgical anatomy of the spermatic venous system is described. Thereafter an experimental evaluation performed on cadavers by the vascular mould technique using plastic materials is reported. The resulting data point out the complex variability of the spermatic venous circulation, stressing the value of preoperative phlebography in the surgical approach to varicocele.

Liquid drainage through the peritoneal diaphragmatic surface.

In 14 spontaneously breathing anesthetized rabbits, we used cyanoacrylate to glue a hollow capsule, at end expiration or at end inspiration, to the peritoneal surface of the tendinous portion of the diaphragm. The capsule was connected to a pressure transducer and a pipette calibrated in microliters. We filled the system with fluid and measured flow into the diaphragmatic surface facing the capsule (Fcap, microliter/cm2), from liquid displacement in the pipette at different hydraulic pressures in the system (Pcap). Pleural liquid pressure was simultaneously measured in the supraphrenic region (Psup). Fcap was positively correlated to transdiaphragmatic pressure gradient (Psup-Pcap) and breathing frequency but was unaffected by protein concentration of capsular fluid. For a breathing frequency of 30 cycles/min and a Psup - Pcap = -2 cmH2O, Fcap was 0.54 microliter.min-1.cm-2 for capsules applied at end expiration and 10-fold greater for capsules applied at end inspiration. Data indicate that the diaphragmatic tendinous portion in rabbits is a draining site for peritoneal fluid and that the conductance of the draining pathways (lymphatic stomata) is related to diaphragmatic tension. In the intact rabbit the average peritoneal fluid drainage through the tendinous portion of the diaphragm (approximately 16 cm2) was estimated at 43 microliters/min.

Differential diagnosis of Crohn's disease of the colon from ulcerative colitis: ultrastructure study with the scanning electron microscope.

Mucosal biopsies from patients with Crohn's disease and with ulcerative colitis were studied by scanning electron microscopy. Important abnormalities of the mucosal surface were found in both diseases. For Crohn's disease, the characteristic abnormality was loss of the regularity of the polygonal units, but with preservation of the mucosal integrity and of the normal mucosal design. For ulcerative colitis, the abnormalities were disorganization of the cells, signs of sloughing, and superficial erosions. Patients with Crohn's disease always had a significantly increased number of muciparous cells, while those with ulcerative colitis had obvious signs of decreased mucus production. The lesions of ulcerative colitis could be seen under the scanning electron microscope in mucosal areas that appeared normal endoscopically. We feel therefore that scanning electron microscopy of biopsy specimens from patients with inflammatory bowel diseases can be of great help in differential diagnosis.

Electromicroscopic observations on small vessels in animals treated with sulfinpyrazone and placebo following vascular microsurgery.

To evaluate the antithrombotic effect of sulfinpyrazone on blood vessels (1-2 mm diameter) injured by microsurgical procedures, twenty male rabbits were chosen at random to receive sulfinpyrazone (10 mg/kg/die) or placebo three days prior to and on the morning of vascular microsurgery, which consisted of a complete transverse section, or a longitudinal section 1 cm long, of the femoral artery and vein, followed by interrupted suture. Scanning electron microscopy revealed consistently less fibrin and blood cell adhesion to the endothelial areas adjacent to the surgical trauma in the animals treated with sulfinpyrazone than in those treated with placebo. Our results agree with those reported in the literature, demonstrating the antithrombotic effects of sulfinpyrazone at the level of the vascular endothelium injured by various kinds of trauma and are sufficiently encouraging to justify testing this drug in the prevention of vascular thrombosis following microsurgical procedures in man.