Risk factors for carcinoma of the pelvic ileal pouch/anal canal in ulcerative colitis

Patients with ulcerative colitis who undergo proctocolectomy and an ileal anal anastomosis (IPAA) require surveillance; dysplasia and carcinoma occur in both the small intestinal mucosa of the ileal pouch and the retained rectal mucosa as early as 2 yr after ileostomy closure. This study evaluated risk factors for carcinoma (eg, dysplasia, p53 overexpression, labeling index, and aneuploidy) in the small intestinal and rectal mucosa. Thirty patients (age 14-64 yr) with ulcerative colitis and IPAA were studied. The mean duration of ulcerative colitis prior to IPAA was 3 yr (range 6 mo-21 yr). Patients were followed by annual endoscopy and biopsies of the ileal pouch and rectal mucosa. Sections of small intestine and rectal mucosa were evaluated for inflammation and dysplasia, and by immunohistochemical stains Ki-67 (MIB-1) for a labeling index and for p53. Ploidy determination was performed by flow cytometry. Active inflammation of the small intestinal mucosa and the rectal mucosa was frequent and the labeling index of both the pouch and rectal mucosa was abnormal. Two patients had changes indefinite for dysplasia, one involving the small bowel mucosa of the pouch and the other the retained rectal mucosa. Fifteen of the 30 patients had overexpression of p53, 9 from the pouch, and 6 from the rectal mucosa. Overexpression of p53 was seen in both of the patients with indefinite dysplasia. Aneuploidy was noted in 3 patients: two from the pouch and one from the rectal mucosa. All aneuploidic specimens were p53-positive, but negative for dysplasia. In conclusion, most biopsies of the ileal pouch and rectal mucosa were inflamed. The labeling indexes of the small bowel and rectal mucosa were higher than normal. The risk factors for carcinoma (dysplasia, overexpression of p53, and aneuploidy) occurred in the small intestinal and the rectal mucosa. Overexpression of p53 was noted in 16 patients, dysplasia only in 2. Therefore, p53 overexpression and aneuploidy should be considered in the evaluation of surveillance biopsies of patients with ulcerative colitis with IPAA, whereas dysplasia is an insensitive marker.     

Microbiologic assessment of tissue biopsy samples from ileal pouch patients.

Tissue biopsy samples from patients with and without ileal pouches were examined by electron microscopic and microbiologic culture techniques to determine the numbers and types of microorganisms closely associated with or within the tissue biopsy samples. The disease status of each patient was determined by endoscopic and histopathologic methods. Of the 78 biopsy samples included in this study, 64 (82%) yielded obligately anaerobic and/or facultative bacteria when they were cultured. Fourteen of the 78 samples (17.9%) were negative by culture. Of the positive samples, 54 contained facultatively anaerobic bacterial species and 50 yielded obligately anaerobic species. The total counts for facultatively anaerobic bacteria for samples from patients with pouchitis were significantly greater than for samples from patients in control groups. In addition, the number of samples from patients with normal pouches that did not contain obligate anaerobes was significantly less than that from patients with pouchitis; 4 of 23 and 6 of 12 samples, respectively (P less than 0.043). For samples in which organisms were detected, there was agreement with electron microscopic detection of bacteria in 23 of 27 samples, for an overall sensitivity of electron microscopy compared with that of culture of 85%. The qualitative studies resulted in the characterization of 273 isolates comprising 77 different phenotypes. The specificity of these findings in patients with ileal pouchitis is discussed.     

Histoarchitecture of the ileal pouch after total colectomy

Total colectomy and the construction of an ileal pouch reservoir that preserves the patient's continence has become a surgical option for the treatment of patients who undergo total colectomy. By using histologic, electron microscopic, and morphometric methods, the histoarchitecture of the terminal ileal pouch, now functioning as a neorectum, was compared with preoperative biopsies from the normal terminal ileum, transverse colon, and rectum from patients undergoing the construction of a pouch as well as controls. Twelve patients, each of which had undergone a total colectomy with an ileal J-pouch anal anastomosis in our hospital between 1984 and 1987, were included in the study. Over a three year period a progressive transformation to a colonic type mucosa was observed in the ileal pouch. While total mucosal thickness remained unchanged, the number and size of the crypts increased dramatically, making some specimens indistinguishable from normal colonic mucosa on histologic examination. The number of mucus producing goblet cells and Paneth cells increased, whereas the endocrine cell population demonstrated no change. The possible metabolic and physiologic consequences of this mucosal transformation are discussed.     

Appendiceal inflammation in colectomy is independently correlated with early pouchitis following ileal pouch anal anastomosis in ulcerative colitis and indeterminate colitis

BackgroundAppendiceal inflammation in colectomy is one of the histologic predictors of pouchitis in ulcerative colitis (UC) following ileal pouch anal anastomosis (IPAA). Fecal calprotectin level has been shown to increase 2 months prior to the onset of pouchitis. We evaluated whether inflammation and calprotectin expression in appendiceal specimens correlate with early-onset pouchitis in UC and indeterminate colitis (IC).Materials and methodsIPAA (2000-2018) cases with appendix blocks available in colectomy specimens were identified (n = 93, 90 UC, 3 IC). Histologic features thought to predict pouchitis were evaluated. The degree of appendiceal inflammation was scored. Calprotectin immunostain was performed on the appendix blocks and the extent of mucosal staining was quantified. Electronic medical records were reviewed for demographics, smoking history, clinical pouchitis, time of onset of pouchitis, and clinical and endoscopic components of the Pouchitis Disease Activity Index (PDAI) score. Follow-up pouch biopsies were reviewed and scored to generate histologic PDAI score, when available.ResultsAmong the patients with clinical pouchitis (n = 73), moderate to severe appendiceal inflammation independently correlated with earlier pouchitis compared to no/mild inflammation (median time to pouchitis 12.0 vs. 23.8, log rank p = 0.016). Calprotectin staining correlated with inflammatory scores of the appendix (Spearman's rho, r = 0.630, p < 0.001) but not with early pouchitis (p > 0.05).ConclusionsThe presence of moderate to severe appendiceal inflammation at the time of colectomy was associated with a shorter time to pouchitis following IPAA. Calprotectin immunostain may be used to demonstrate the presence of inflammation in the appendix but its role in predicting early pouchitis remains limited.     

Increased epithelial cell proliferation in the ileal pouch mucosa of patients with familial adenomatous polyposis

To eliminate the risk of colorectal cancer in patients with familial adenomatous polyposis (FAP), reconstructive proctocolectomy is performed. Although most colonic mucosa is resected during the ileal pouch anal anastomosis, adenomas and carcinomas may develop in the pouch. This may be caused by altered cell kinetics due to intraluminal changes in the pouch. In 32 patients with FAP, biopsy specimens from the mucosa of the pouch and also of the afferent ileal loop were taken. Tissue sections were immunohistochemically processed with the monoclonal antibodies M30 and MIB-1 to assess apoptotic and proliferative indices, respectively. Cell proliferation was also assessed by a modified sign test. There were no significant differences in apoptotic rates between the mucosa of the pouch and the mucosa of the afferent ileal loop. However, cell proliferation was significantly higher in the mucosa of the pouch vs afferent ileal loop, both by using the quantitative (68.3% vs 61.6%, p = 0.001) and semiquantitative methods (p < 0.05). Our newly developed semiquantitative approach outperformed previously described methods. The higher cell proliferation in the pouch as compared to the afferent ileal loop may contribute to the increased risk for adenomas and carcinomas in the pouch of patients with FAP and emphasizes the need for regular endoscopic surveillance. The experiments performed for this study comply with the current laws of The Netherlands.     

Expression of colonic antigens by goblet and columnar epithelial cells in ileal pouch mucosa: their association with inflammatory change and faecal stasis.

AIMS--To investigate colonic metaplasia of goblet and columnar epithelial cells in ileal pouch mucosa; to correlate this with the degree of morphological and inflammatory change; and to assess whether such changes are related to the presence of faecal stasis. METHODS--Biopsy specimens of ileal pouch mucosa were taken from 31 patients (30 with ulcerative colitis, one with familial adenomatous polyposis) either before (eight patients) or after (23 patients) ileostomy closure. A simple morphological technique was used to assess changes in villous height. Inflammatory change was estimated using an established scoring system for pouchitis, and acquisition of colonic antigens was determined by immunohistochemistry using three monoclonal antibodies which recognise components of the two major epithelial cell types in the colorectum. The degree of staining with the monoclonal antibodies was graded and the grades correlated with an index of villous atrophy and with the inflammatory scores. RESULTS--Five of eight (63%) pre-closure and 15 of 23 (65%) post-closure biopsy specimens showed increased staining with an antibody against components of columnar epithelial cells. One of eight (12%) pre-closure and 15 of 23 (65%) post-closure biopsy specimens stained with an antibody for colonic mucin. Although both types of staining showed a positive correlation with the pouchitis score, they also occurred in the absence of inflammation. CONCLUSIONS--Both goblet and columnar cells acquire colonic characteristics which are incomplete, but may represent a true adaptive response as they can develop in the absence of inflammation. As the change in goblet cells occurs after ileostomy closure, faecal stasis is likely to be a major contributory factor. Changes in columnar cells may occur before ileostomy closure in the absence of faecal stasis.     

Magnesium dietary manipulation and recovery of function following controlled cortical damage in the rat.

Previous research has shown that dietary magnesium (Mg2+) deficiency prior to injury worsens recovery of function and that systemic administration of Mg2+ pre or post-injury significantly improves functional recovery. The purpose of the present study was to determine if manipulations in dietary Mg2+ would alter functional recovery following unilateral cortical injuries. Two weeks prior to injury, rats were placed on a customized diet enriched with Mg2+, deficient in Mg2+, or on a standard Mg2+ diet. Rats were then prepared with unilateral cortical contusion injuries (CCI) of the sensorimotor cortex. Two days following CCI, rats were tested on a battery of sensorimotor (vibrissae-forelimb placing and bilateral tactile adhesive removal tests), as well as the acquisition of reference memory in the Morris water maze. Serum analysis for Mg2+ prior to injury showed a diet-dependent modulation in levels. The Mg(2+)-enriched diet showed significantly higher levels of serum Mg2+ compared to the normal diet and the Mg(2+)-deficient diet showed significantly lower levels compared to the Mg(2+)-normal diet. On the placing and tactile removal tests Mg2+ deficiency significantly worsened recovery compared to the Mg(2+)-enriched and Mg(2+-)normal diet conditions. There were no statistically significant differences between the Mg(2+)-normal and Mg(2+)-enriched diets on the sensorimotor tests. On the acquisition of reference memory there were no significant difference between diet conditions; however, the Mg(2+)-deficient diet showed a trend toward impaired performance compared to the other diet conditions. The Mg(2+)-deficient diet resulted in a larger lesion cavity compared to the other diet conditions. These findings suggest that dietary Mg2+ modulates recovery of function.     

Impact of cell death manipulation on the efficacy of photodynamic therapy-generated cancer vaccines

The main task of cancer vaccines is to deliver tumor-specific antigens to antigen-presenting cells for immune recognition that can lead to potent and durable immune response against treated tumor. Using photodynamic therapy (PDT)-generated vaccines as an example of autologous whole-cell cancer vaccines, the importance is discussed of the expression of death-associated molecules on cancer vaccine cells. This aspect appears critical for the optimal capture of vaccine cells by host’s sentinel phagocytes in order that the tumor antigenic material is processed and presented for immune recognition and elimination of targeted malignancy. It is shown that changing death pattern of vaccine cells by agents modulating apoptosis, autophagy or necrosis can significantly alter the therapeutic impact of PDT-generated vaccines. Improved therapeutic effect was observed with inhibitors of necrosis/necroptosis using IM-54, necrostatin-1 or necrostatin-7, as well as with lethal autophagy inducer STF62247. In contrast, reduced vaccine potency was found in case of treating vaccine cells with apoptosis inhibitors or lethal autophagy inhibitor spautin-1. Therefore, PDT-generated cancer vaccine cells undergoing apoptosis or lethal autophagy are much more likely to produce therapeutic benefit than vaccine cells that are necrotic. These findings warrant further detailed examination of the strategy using cell death modulating agents for the enhancement of the efficacy of cancer vaccines.     

Studies on carrageenin air pouch inflammation in the rat.

Inflammation was induced in the 6-day subcutaneous air pouch of the rat by injection of carrageenin. The model was characterized in terms of exudate volume, leucocyte accumulation, granuloma, vascular permeability and protein clearance up to 7 days after injection of carrageenin. From days 2-3 rapid and reproducible changes in these responses were observed which indicated a change from polymorphonuclear (PMN) leucocyte-dominated to mononuclear (MN) leucocyte-dominated inflammation. A second injection of carrageenin on day 3 gave increases in exudate formation and PMN accumulation on day 4. Administration of carrageenin mixed with 3 day inflammatory exudate gave an increased exudate volume and decreased leucocyte accumulation at 6 h. Reduction of 6-h cellular accumulation by use of a lower dose of carrageenin or a I-day air pouch gave complete inhibition of exudate formation on day 3. In contrast, inhibition of the 6-h cell response with prednisolone had no effect on the 3-day response. Daily treatment with indomethacin gave increased PMN accumulation on day 3. Similar treatment with prednisolone additionally reduced exudate volume. Treatment on day 2 with prednisolone gave similar effects whereas indomethacin, BW755C and protease inhibitors had no effect. Administration of colchicine at this time gave inhibition of exudate volume on day 3 whereas complement depletion gave increases in volume and PMNs.     

Transmissible ileal hyperplasia of hamsters. I. Histogenesis and immunocytochemistry.

Transmissible ileal hyperplasia (TIH) was experimentally induced in weanling hamsters, and the development of lesions was characterized. Ileal lesions developed in two phases: a hyperplastic phase which was detected by Day 10 and an inflammatory phase which began by Day 20. Hyperplasia began as focal lengthening of villi with expansion of crypt-type epithelium onto villus walls. Diffuse hyperplasia of distal ileum developed; dilated, tortuous crypts penetrated subjacent supporting tissues; but metastases were not seen. Inflammation began in association with focal or segmental necrosis of crypt epithelium, and crypt abscesses developed. Severe pyogranulomatous inflammation of the ileal wall, focal peritonitis, mesenteric lymphadenitis, and portal hepatitis were common in advanced lesions. Development of ileal lesions was closely correlated with accumulation of particulate antigen, detectable by immunofluorescence, in the cytoplasm of mucosal epithelial cells. Antigen was also detected in ileal granulomas, mesenteric lymph nodes, and liver. There was simultaneous development of serum antibody specific for intracytoplasmic antigen. These studies comfirm that mucosal hyperplasia is the primary lesion in TIH.     

Adenocarcinoma of the anal glands.

Adenocarcinoma of the anal glands is very rare but it is an important lesion to recognise as with early diagnosis, it has an excellent prognosis. Because it involves the submucosa widely and penetrates the mucosa late, it can be mistaken for metastatic gastrointestinal carcinoma, or tumour arising in sinuses and fistulae. Two cases, in a 44 year old man and a 73 year old woman, which illustrate the typical features are reported, in one of which the diagnosis was missed originally. In situ neoplastic change of the associated anal glands and secretion of mucin lacking O-acetyl groups are useful pointers.     

Impact of augmenting dialysis frequency and duration on cardiovascular function

Conventional hemodialysis (CHD) only delivers 10% to 15% of renal function in a nonphysiological intermittent mode. Because it occurs nightly and is sustained over a longer dialysis time, the uremic clearance provided by nocturnal hemodialysis (NHD) far exceeds that of CHD. Increasing the dose and frequency of dialysis by NHD has been demonstrated, in both short- and long-term studies, to reverse several important risk factors for adverse cardiovascular events in patients with end-stage renal disease such as hypertension, left ventricular hypertrophy, systolic dysfunction, conduit artery stiffness, attenuated baroreflex regulation of heart rate, disturbed heart rate variability, sleep apnea, and endothelium-dependent vasodilation. In addition, the Toronto NHD experience has reported an emerging body of evidence demonstrating the benefits of NHD on anemia management, inflammation, and endothelial progenitor cell biology. The mechanism(s) by which nocturnal hemodialysis improves cardiovascular outcomes are under active investigation by our group. It is tempting to speculate that NHD has the potential to decrease endothelial/myocardial injury and restore simultaneously endothelial repair, thereby improving cardiovascular function in patients with end-stage renal disease. The objectives of the present document are (1) to review the mechanisms underlying dialysis-associated cardiovascular morbidity and (2) to describe the restorative potential of NHD on the cardiovascular system.     

The anal transitional zone. Location and extent.

The location and extent of the anal transitional zone (ATZ) were investigated in the age group typical for anal canal carcinomas. The methods used were macroscopic determination after whole-mount staining with Alcian-dyes as well as conventional histological technique. The results show that the epithelial variants may be found over a larger area than previously reported, namely from 6 mm below to 20 mm above the dentate line. Variations in location and extent of the ATZ are described, as well as the frequent finding of mature squamous epithelium high in the anal canal. The significance of the findings in relation to the special types of anal canal carcinomas is discussed, and on the basis of the macroscopic definition of the canal, as well as the histological observations in this study, it is proposed that anal canal carcinomas should be defined as tumours partly or totally located within a distance of 2 cm above the dentate line.     

Histo-physiology of the scent-marking glands of the penile pad, anal pouch, and the forefoot in the aardwolf (Proteles cristatus)

The scentmarking glands of the anal pouch, penile pad, and the forefoot of the aardwolf (Proteles cristatus) were studied by histological, histochemical, immunohistochemical methods, and by electron microscopy. The morphological observations are correlated with eco-ethological aspects of this nocturnal animal. In all studied regions there was a superficial layer of holocrine sebaceous glands and a deeper layer of apocrine scent glands; these two types of glands apparently function in concert. Only in the forefoot were additional tubular glands, resembling eccrine sweat glands found, which may improve the frictional capacities of the paw, while apocrine and holocrine glands serve scent-marking functions of the forefoot. Penile pad and anal pouch are exclusively scent marking organs. The secretion modus of the apocrine glands is both via exocytosis and apocrine mechanism. Homogeneous apical, secretory granules, which contain glycoproteinaceous material, represent evidence for exocytosis. In the anal pouch, additional variably sized granules contain endogenous pigments which are probably responsible for the brownish coloration of the secretory product of the male animals. Variable heights of the glandular cells, frequent apical tall protrusions as well as pinched-off pieces of cytoplasm in the glandular tubules support the concept of an apocrine secretion in the scent glands. The immunohistochemical staining pattern of actin points to the involvement of actin filaments in the pinching-off process of the apical cell protrusion, which does not contain any cell organelles. The variable actin staining patterns suggest a dynamic process during which actin filaments form a ring or sheet at the basis of the pinching-off bleb. Proliferative and apoptotic phenomena show no preference for active and inactive glandular cells suggesting that replacement of cells occurs independently of the functional status of the glands.