Mucosal cell proliferation of the rectal stump in ulcerative colitis patients after ileorectal anastomosis

The proliferative activity and polyamine levels of the rectal epithelium in unoperated ulcerative colitis patients and in ulcerative colitis patients after total colectomy and ileorectal anastomosis were determined and compared with control subjects. Cell proliferation was evaluated in rectal biopsies by in vitro 3H thymidine incorporation by measuring the labeling index and the position of labeled cells along the crypt; polyamines were determined with a chromatographic method. In ulcerative colitis patients the labeling index was significantly increased, and labeled cells were shifted toward the upper part of the crypt when compared with controls. Ileorectal anastomosis patients showed a normalization of the labeling index and a distribution of labeled cells similar to controls. Polyamine levels were also increased in ulcerative colitis patients; in ileorectal anastomosis patients, the level of polyamines was decreased in respect to unoperated patients and return to normal values except for spermine. Because the increased proliferation and higher polyamine levels are related to increased colon cancer risk, our results confirm that ulcerative colitis is a risk factor for the development of carcinoma. Ileorectal anastomosis may reduce this risk through a normalization of mucosal cell proliferative activity and of some polyamine levels.

What affects continence after anterior resection of the rectum?

Functional results after anterior rectal resections are commonly considered satisfactory but variable percentages of postoperative incontinence are often reported. Continence was evaluated after 20 low anterior resections (LAR) and 13 high anterior resections (HAR) by means of clinical assessment, anorectal manometry, and evacuation proctography. Whereas all HAR patients had perfect continence, 10 patients (50 percent of the LAR group had occasional episodes of soiling from liquid feces, 5 patients (25 percent had frequent soiling or occasional incontinence for solid feces, and 1 patient (5 percent had frequent solid stool loss requiring surgical treatment. Anal canal resting pressure at 3 and 4 cm from the anal verge was significantly lower in the LAR group (P less than 0.02 and P less than 0.05, respectively) than in the HAR group. However, the maximum voluntary contraction did not differ between the two groups. Rectoanal inhibitory reflex was found to be present in 17 of the 20 patients with LAR and in all patients with HAR. The volume at which the anal sphincter is continuously inhibited was significantly reduced in the LAR group (P less than 0.001). Also, the conscious rectal sensibility volumes were found to be significantly reduced for threshold, constant, and maximum tolerated volume. Threshold volume for internal sphincter relaxation was lower than the threshold volume for rectal sensation in some patients with LAR. This could allow postoperative fecal soiling. Rectal compliance was decreased (P less than 0.001) in the LAR group. Evacuation proctography, performed in six LAR patients affected by major soiling or solid stool loss, revealed an abnormal obtuse anorectal angle and pathologic lowering of the perineum at rest and during defecation. The concomitance of internal and sphincter impairment, reduction in rectal compliance, and previous pelvis floor muscle damage are postulated as cause affecting continence in patients who underwent LAR.

Pathological features of Crohn's disease determining perforation

Even if Crohn's disease (CD) stenoses are related to perforating complications, such as abscess or fistula, it remains unclear why only some stenoses lead to such complications. We have studied the surgical specimens in 94 cases of CD to characterize the anatomical features of stenosis. We found no differences between group A (patients with perforation) and group B (noncomplicated patients) as far as extent of lesion, number of stenoses, and the caliber of the stenotic bowel. In CD of the ileum, the wall thickness of the stenoses was significantly different: 12.0 +/- 3.4 mm in group A and 7.6 +/- 3.1 mm in group B (p less than 0.001). In colonic CD, the length of stenosis was significantly greater in patients with perforation. Duration of symptoms, age at surgery, and sex did not correlate with the increased thickness or with perforating complications. These observations suggest that the fibrotic gastrointestinal tract, poorly distensible, may increase the intraluminal pressure above the stenosis and in this way squeeze bowel content through mucosal fissures of the inflamed bowel. Evaluation and monitoring of wall thickness may help in prompting surgery before the disease is complicated by perforation.

[Preoperative staging of rectal carcinoma by transrectal echography combined with pelvic computerized tomography]

The accurate staging of rectal carcinoma is very important for treatment planning. The histological data obtained from the surgical specimens of 22 patients with rectal carcinoma were compared with pre- and postoperative endorectal US findings and with preoperative CT results. According to an adapted version of the Astler and Coller classification, the different degrees of tumor spread into the rectal wall were represented as follows: stage A: 1 patient; stage B1: 5 patients; stage B2: 6 patients; stage C1: 1 patient; stage C2: 8 patients and stage D: 1 patient. Preoperative staging, based on the overall results of CT and US, was in agreement with histology in 19 of 22 cases. Individual analysis of US and CT results, in comparison with histological data, showed US staging accuracy to be 77.3% (17/22 patients). US accuracy in demonstrating tumor spread into the rectal wall (stages A, B1, C1) was 100% (7/7 patients); US was 70% accurate in lymph node detection (7/10 patients) and 93.3% accurate in demonstrating perirectal infiltration (14/15 patients). CT diagnostic accuracy was 66.7% (10/15 patients) in the evaluation of perirectal lymph nodes, but tumor spread into the rectal wall (stages A and B1) could not be evaluated. While admitting the primary role of US in the staging of rectal carcinoma, according to our results a combination of US and CT yields a more accurate preoperative diagnostic picture.

Tissue distribution of cefotetan in patients with Crohn's disease

Concentrations of cefotetan in the intestinal wall of patients with Crohn's disease were investigated with the method of tissue homogenates with the aim to evaluate the effects of inflammation on tissue distribution. Twenty-four patients who underwent surgery were treated with a 2-gram single dose of cefotetan intravenously before the operation. The mean tissue levels in inflamed intestinal wall were constantly higher than in normal wall, but the difference was statistically significant only in samples taken more than 2 h after cefotetan administration (31.0 +/- 17.8 vs 14.7 +/- 11.4 mg/kg; p less than 0.05). The mean residence time was 284.3 min for inflamed tissue and 123.9 min for normal. The areas under the curve were significantly higher in inflamed wall than in normal, with mean values of 4,789 and 3,020.2 mg/l.h, respectively (p less than 0.05). Inflammation seems to facilitate the penetration of cefotetan into the intestinal wall of patients with Crohn's disease but above all, it increases the mean residence time in inflamed tissue.

Glucose transport during ageing by human intestinal brush-border membrane vesicles

Glucose absorption by the small intestine is a complex phenomenon, that can be successfully studied by means of isolated brush-border and basolateral membrane vesicles of the enterocytes. We have carried out transport experiments on isolated brush-border membrane vesicles from the human small intestine, taking into account the age of the subjects. Our studies demonstrated that Na+-glucose cotransporter activity decreased as age increased with the "overshoot" phenomenon disappearing altogether in the oldest subjects. This effect was compared to that observed in intestinal membrane vesicles of young patients suffering from Crohn's disease; in this case there was a marked decrease in the Na+-dependent D-glucose uptake, but the "overshoot", even though low, was present. K+-dependent D-glucose transport, diffusion of L-glucose and the levels of some enzyme markers for intestinal brush-border membranes were also studied.

[Intramuscular hemangioma: problems of differential diagnosis from angiosarcoma]

Despite recent technical advances in diagnostic imaging (computerised tomography, magnetic resonance), intramuscular haemangiomas are relatively uncommon and often difficult to diagnose. Angiosarcomas are probably the most important tumour to be differentiated from hemangiomas, in order to define the optimal therapeutic approach. Only biopsy allows a proper preoperative diagnosis, although this diagnostic technique involves some risks. Total excision is the treatment of choice. Radiotherapy has been employed without substantial results. A review of the literature and a case report are presented here.

Single-dose cefotetan vs. multiple-dose cefoxitin--antimicrobial prophylaxis in colorectal surgery. Results of a prospective, multicenter, randomized study

This multicenter, prospective, randomized trial of short-term antimicrobial prophylaxis in colorectal surgery was designed to compare the efficacy of a single dose of cefotetan vs. multiple doses of cefoxitin. Of the 403 evaluable patients, 206 received cefoxitin (1 gm intravenously at the beginning of surgery and after 3, 6, and 12 hours, group A) and 197 cefotetan (2 gm intravenously at the beginning of surgery, group B). The two groups of patients were similar in respect to age, sex, obesity, preoperative weight loss, diabetes, type of disease, type, and mean duration of surgery. The abdominal wound infection rate was 11.2 percent in group A and 9.1 percent in group B (difference not significant). The number of patients with infections at nonsurgical sites (respiratory and urinary tract, phlebitis, and septicemia) was significantly greater in group A than in group B (17 vs. 9.1 percent, P less than .05). The mean postoperative hospital stay was similar in both the cefoxitin and cefotetan groups (15.1 vs. 15.9 days). Both regimens were inadequate in preventing infections in the presence of severe contamination of the operative field.

Antimicrobial chemoprophylaxis in colorectal surgery

Infective complications are often seen in colorectal surgery. These even occur in cases of elective surgery and in patients where adequate bowel preparation has been performed and is due to the very high numbers of bacteria colonising the bowel. Several controlled clinical studies showed that antimicrobial prophylaxis is effective in preventing infective complications and the lack of prophylaxis is no longer justified. Antimicrobial prophylaxis can be oral (poorly absorbed antibiotics aimed to reduce the number of bacteria in the bowel) or systemic (aimed to reach a high tissue concentration when bacterial contamination occurs, in order to prevent colonisation) or a combination of the two. Which is to be preferred is still controversial. Systemic prophylaxis should have the following features: 1) use of a single agent with a broad spectrum of action, effective both on aerobes and anaerobes; 2) rapid I.V. administration, at the beginning of surgery; 3) good tissue penetration; 4) long half-life, in order to assure that the single dose will cover the whole duration of surgery; 5) good therapeutic ratio. The use of long half-life cephalosporins, particularly cefotetan, was shown to be highly beneficial. Prophylaxis can fail if contamination during surgery is severe, with a particularly high bacterial count. The degree of contamination of the operating field can be evaluated both by surgeon's judgment, and by tissue or peritoneal cavity lavage fluid sampling and culture. In case of severe contamination (bacterial number greater than 10(5) CFU/ml of fluid or mg of tissue) prolonging of antibiotic therapy for some days is justified. Otherwise, no evidence supports its prolongation beyond surgery.

EDTA affects cytochrome P450-dependent biotransformation reactions during incubations for the liver microsomal assay

In order to optimize the condition of the liver microsomal assay (LMA), studies were carried out to determine the effects of EDTA on mixed-function oxidase activity and its stability under the exact incubation conditions for the LMA. Aminopyrine N-demethylase (APD) and p-nitroanisole O-demethylase (p-NAD) activities as well as lipid peroxidation development (LP) in S9 liver fractions from beta-naphthoflavone and sodium phenobarbital (beta-NF + PB)- or Aroclor 1254 (AC)-treated mice were examined during a period of preincubation with EDTA ranging from 1 to 40 mM. At 5 mM EDTA, we obtained a strong inhibition of the microsomal LP as well as the greatest value of the mean specific activity (Asp) for both APD and pNAD activities. In agreement with the biochemical data, the presence of 5 mM EDTA in the incubation mixtures for the LMA significantly increased the mitotic gene conversion, mitotic crossing-over and point-reverse mutation of the well-known premutagen cyclophosphamide (30 mM) on the diploid D7 strain of Saccharomyces cerevisiae as the outcome of a greater metabolic activity. We concluded that the systematic use of 5 mM EDTA in LMA mixtures could improve the reliability and sensitivity of such a test.

Stability of drug metabolizing enzymes during the incubation conditions of the liver microsomal assay with non-induced and induced mouse liver S-9 fractions

The purpose of this work was to study the relative activities and stabilities of phase-I and phase-II drug metabolizing enzymes in incubation mixtures used in vitro genotoxicity testing in order to optimize the conditions of the assay, increase sensitivity and eliminate false negative results. Cytochrome P-450, NADPH-cytochrome P-450 (cytochrome c) reductase activity and various phase-I and phase-II enzyme activities of the drug-metabolizing system were determined in incubation mixtures used in liver microsomal assays. The behaviour of aminopyrine N-demethylase and p-nitroanisole O-demethylase activities as phase-I markers have been reported previously. Other activities measured were glutathione S-transferase, glutathione S-epoxide transferase and epoxide hydrase, and lipid peroxidation (LP) was determined. The experiments were carried out on liver S9 fractions derived from non-induced mice or mice induced with sodium phenobarbital (PB), and/or beta-naphthoflavone (beta-NF). The phase-II enzymes were much more stable (70-90% residual activity) than phase-I enzyme activities (35-60%) in all conditions tested. The residual cytochrome P-450 was approximately 70% stable and the remaining activity of NADPH-cytochrome c-reductase about 80%, indicating that this latter enzyme does not limit the rate of the monoxygenase system in these conditions. Phase-II enzymes were induced to a smaller extent (about 2 times) than in phase-I enzymes (5-6 times) by beta-NF + PB. NADPH-cytochrome c-reductase behaved as phase-II enzymes in this respect as well as for stability. LP was appreciably higher in non-induced than in induced animals. Treatment with the beta-NF + PB mixture, however, showed that induced enzymes were more stable than those obtained by simple induction with either beta-NF or PB alone. These results lead to the conclusion that prolonged incubation times in mutagenicity assays are unnecessary when considering the relative stabilities of the various phase-I and phase-II enzyme activities in the drug-metabolizing system.

Histochemistry of small intestinal dysplasia in familial polyposis coli

Biopsies of duodenal and ileal mucosa from patients with familial polyposis coli were studied. Areas of atypia were identified in the duodenum of six patients and in the ileum of three patients. Grade I atypia was characterized by crowding and elongation of cells and nuclei, a slight reduction in the number of goblet cells and the presence of a brush border; grade II atypia was further characterized by pseudo- or pluristratification of cells, a marked reduction in the number of goblet cells and the absence of a brush border. In areas of atypia, columnar cells often contained PAS-positive apical granules, which were diastase-resistant and unstained by alcian blue at any pH; the brush border, even where recognizable in haematoxylin-eosin and PAS-stained sections, was unreactive histochemically for alkaline phosphatase. Goblet cells were few in areas of atypia, but those present were regularly stained by PAS and alcian blue pH 2.6. Apical granules, similar in their histochemical characteristics to those observed in columnar cells in areas of atypia, were also found in otherwise normal mucosal areas, even in some patients with no overt areas of atypia in the biopsies studied. These granules have been interpreted as an abnormality, possibly preceding the onset of atypia. Hyperplasia of goblet cells, secreting mucins with the same staining pattern as in normal intestine, was found in some patients, either adjacent to areas of atypia or independent of them. Intervening columnar cells had a normal morphology, alkaline phosphatase-reactive brush borders and no sign of mucus secretion. This goblet cell hyperplasia has been interpreted as a reactive, nonspecific alteration of the mucosa.

Extracolonic polyps in familial polyposis coli and Gardner's syndrome

Endoscopy and biopsy of the upper gastrointestinal tract and terminal ileum were performed in 24 patients with familial polyposis or Gardner's syndrome in order to further define the incidence of extracolonic adenomatous polyps. Polyps, usually multiple and small in size, were detected in the gastric fundus (12.5 percent), antrum (29.1 percent), duodenum (66.6 percent), and terminal ileum (41.7 percent). Histology showed hyperplasia of the fundic glands and cystic dilatation in the polyps of gastric fundus, and adenomas in several cases of antral (three patients) or duodenal polyps (14 patients). Polyps of the terminal ileum were either adenomas (five patients) or lymphoid aggregates. Patients with stigmata of Gardner's syndrome, desmoids or mesenteric fibromatosis presented a major incidence of adenomas in the duodenum, but not in other parts of the digestive tract investigated. Subsequent checkup after an average of 33 months in ten patients revealed an increase of lesions only in the duodenum in two patients. These findings confirm that adenomatous polyps are not limited to the colon and rectum, as previously believed, but can affect the whole gastrointestinal tract. Periodic surveillance of mucosa seems to be indicated, especially for the duodenum, since degeneration of adenomas into carcinoma is possible.

Effect of repeated ether anesthesias on the mono-oxygenase system of rat liver S-9 fraction

This study was designed to investigate the effect of ether anesthesia in rats, before i.p. injections to induce the mono-oxygenase enzyme system, on biochemical properties of liver S9 fractions. Aminopyrine N-demethylase and rho-nitroanisole O-demethylase activity levels, their stability, and lipid peroxidation were determined in S9 fractions after etherization (about 1 min in ether vapor chamber daily for 3 consecutive days, before i.p. injections of Na-phenobarbital and beta-naphthoflavone) and compared with controls receiving the same injections without etherization. The activities were slightly (but not significatively) enhanced after this treatment, but stability was markedly and significatively greater after 1 h of incubation in the conditions of the liver microsomal assay (+ 14.8% and + 74.7%, respectively); lipid peroxidation was strongly and significatively depressed (-76.0%). Etherization sufficient to kill the animals on the 4th day resulted in equally active but less stable S9 fraction enzymes. Dimethylnitrosamine (as a standard premutagen) was assayed with the D7 strain of Saccharomyces cerevisiae using S9 fractions obtained from both anesthetized and nonanesthetized rats. According to biochemical data, results obtained with S9 from partially anesthetized rats were comparable with the conventional ones (S9 from nonanesthetized rats). On the contrary, the use of more prolonged ether anesthesia, including one on the day the animals are killed, gives S9 fraction significantly less effective. We conclude that if brief etherizations are used, for i.p. injections only, the S9 fractions obtained are entirely satisfactory and the procedures involved in production are simplified; the additional animal treatment (etherization) must be specified.

Cholinergic innervation of the human pulmonary circulation

The cholinergic innervation of the pulmonary circulation was studied in man. Both extra- and intrapulmonary branches of the pulmonary artery and vein are provided with a cholinergic of the vein. In the main branches of the pulmonary vessels, the existence of two nerve plexuses, a superficial and a deep one, was observed. The superficial plexus is localized in the outer adventitial layer while the deeper plexus is localized in the adventitial-medial transitional zone. In smaller arteries and veins, the existence of a single plexus (adventitial-medial) was observed. In some specimens, the presence of diffuse masses of acetylcholinesterase (AChE)-positive material or elbow-shaped AChE-positive formations was observed. The nature of these formations as well as the possible functional role of a cholinergic system in the pulmonary circulation are discussed.

The cholinergic innervation of human pancreatic islets

The cholinergic innervation of pancreatic islets was investigated in the human using operatory samples. In order to analyze the nature of stained cholinergic nerve fibers some specimens were incubated in a solution containing 6-hydroxydopamine (6-HDA) to obtain a selective degeneration of adrenergic nerves. Cholinergic nerve fibers are present in human pancreatic islets, and appear to be organized in an external peri-insular plexus. Some nerve fibers from the peri-insular plexus enter the islets and seem to innervate directly various types of endocrine insular elements. The 6-HDA treatment does not alter the distribution pattern of cholinergic nerve fibers within pancreatic islets.

Plasma levels of glucagon-like polypeptides in gastrectomized patients transformed from Billroth II into Billroth I

An oral glucose tolerance test (OGTT) has been performed in a group of patients with partial gastrectomy before and after transforming the anastomosis from Billroth type II (B II) into Billroth type I (B I). Glucose tolerance was normal in both groups. The statistically significant differences in blood glucose (BG) values observed at 30 min between B I and normals and at 30, 60 and 90 min between B II and normals occur without concomitant changes in insulin (IRI) plasma levels. In the course of the test a marked rise (statistically significant from 30 to 180 min) in glucagon-like immunoreactants (GLI) plasma levels was noted in B II patients and has been attributed to the rapid intestinal transit. Otherwise, the restoration of duodenal passage induced a clear decrease of GLI levels which returned to normal values. Increased immunoreactive glucagon (IRG) plasma levels in B II group do not seem to be due to cross-reactivity with GLI. The raised BG levels occurring in B II cannot be attributed either to a reduced insulin secretion or to an increase in biologically active components of glucagon.

Cephalothin, cefoxitin, or metronidazole in elective colonic surgery? A single-blind randomized trial

A randomized controlled trial aimed at comparing the individual efficacy of cephalothin, cefoxitin, and metronidazole in the prevention of postoperative wound infection was performed among 74 colorectal surgical patients. Of 28 patients on cephalothin, seven (25 per cent) developed a postoperative infection, but among 23 patients in each of the other two groups, only one (4 per cent) in each group became infected. These results confirm the primary importance of anaerobes in the causation of postoperative sepsis after colorectal surgery.

Plasma levels of glucagon-like polypeptides in patients with esophagoplasty

Seven patients with interposition of a jejunal tract between the esophagus and stomach or duodenum (EP group) and ten healthy normal volunteers have been submitted to an oral glucose load (OGTT) to clarify the significance of glucagon-like polypeptides (GLI) induced by glucose in carbohydrate metabolism. Blood glucose (BG) and GLI plasma levels were significantly higher in the EP group than in the normal one (p less than 0.01), respectively 30, 60, 90 min for BG and during all the test for GLI. The fasting immunoreactive glucagon (IRG) plasma levels were significantly lower in patients than in normals (p less than 0.05) whereas a marked and significant increase was observed in the EP group (p less than 0.01) from 90 to 240 min. The precocious stimulation of jejunal mucosa and the rapid intestinal transit which occur in these patients may explain the elevated GLI (probably glicentin) plasma levels. The rise in IRG plasma levels might be due to the enzymatic transformation of glicentin. The role of these types of glucagon on carbohydrate metabolism is still to be fully clarified.

Cholinergic nerves in the human liver

The cholinergic innervation of the human liver was studied. Slices (150--200 micrometer thick) of human liver and of the greater hepatic blood vessels (hepatic artery and vein, portal vein) were incubated in a solution of 6-hydroxydopamine (6-HDA) in order to obtain a selective degeneration of adrenergic nerves. Controls were prepared from samples incubated with buffer alone. The slices were cut on a cryostat into 15-20 micrometer thick sections and processed for the histochemical detection of cholinesterases. Cholinergic nerve fibres innervate the extra hepatic and the intrahepatic branches of the hepatic artery, the portal vein as well as the hepatic vein. Fewer cholinergic fibres innervate the hepatocytes and the hepatic sinusoids. The 6-HDA treatment does not seem to alter the pattern of the cholinergic innervation of the liver. The findings indicate the presence of a cholinergic parasympathetic innervation in the human liver.