Bacterial translocation to mesenteric lymph nodes is increased in cirrhotic rats with ascites

BACKGROUND/AIMS

Cirrhotic patients are predisposed to develop spontaneous bacteremias and/or peritonitis, mainly caused by enteric bacteria. The aim of this study was to investigate if bacterial translocation, which is the passage of bacteria from the intestinal lumen to regional lymph nodes and/or the systemic circulation, is increased in a rat model of cirrhosis.

METHODS

Rats were studied after 12-16 weeks of CCl4 inhalation, when samples of mesenteric lymph nodes, blood, liver, and spleen for standard bacteriologic cultures and a fragment of colon and liver for histology were obtained. Immunostaining of the cecum was performed using a polyclonal anti-Escherichia coli antibody.

RESULTS

A significantly greater proportion of rats with cirrhosis and ascites (5 of 9; 56%) had positive mesenteric lymph node cultures compared with cirrhotics without ascites (0 of 9) and normal controls (0 of 12) (P < 0.01). In one cirrhotic rat, E. coli was isolated from both mesenteric lymph nodes and ascites. Rats with cirrhosis and ascites had significantly greater cecal submucosal edema and inflammation than rats with no ascites and controls. Immunoreactivity with E. coli was present in the cecal wall in 3 of 5 animals with E. coli translocation to mesenteric lymph nodes.

CONCLUSIONS

In cirrhotic rats, bacterial translocation is increased after the development of ascites and may be a major factor in the development of spontaneous infections in cirrhosis.

Differences in laser-induced autofluorescence between adenomatous and hyperplastic polyps and normal colonic mucosa by confocal microscopy

Laser-induced autofluorescence has been used to discriminate normal from adenomatous colonic mucosa. However, few studies to date have studied the origin of colonic autofluorescence. Using confocal microscopy (excitation wavelength 488 nm), we have shown that autofluorescence at this wavelength is present predominantly in the lamina propria of normal mucosa but in the epithelium in adenomatous and hyperplastic polyps. The intensity ratio of epithelial cell to lamina propria fluorescence was significantly lower (P < 0.0001) in normal mucosa (0.52 +/- 0.01) compared with either adenomatous (1.6 +/- 0.2) or hyperplastic polyps (1.7 +/- 0.15). However, the ratios were not significantly different between hyperplastic and adenomatous polyps. Thus, confocal microscopy enables the detection of the sites of autofluorescence within colonic mucosa and the quantitation of differences in fluorescence between different tissue types.

Immunocytochemical evidence of Listeria, Escherichia coli, and Streptococcus antigens in Crohn's disease

BACKGROUND/AIMS

Infectious agents have long been suspected of playing a role in the initiation of Crohn's disease. The objective of this study was to search for likely microbial agents in diseased tissues using immunocytochemical techniques.

METHODS

Intestines and mesenteric lymph node specimens of 21 patients from two French families with a high frequency of Crohn's disease and from Connecticut were studied. The microbial agents searched for included Bacteroides vulgatus, Borrelia burgdorferi, Escherichia coli, Listeria monocytogenes, Streptococcus spp., bovine viral diarrhea virus, influenza A virus, measles virus, parainfluenza virus, and respiratory syncytial virus.

RESULTS

Seventy-five percent of the patients with Crohn's disease (12 of 16) were positively labeled with the antibody to Listeria. Macrophages and giant cells immunolabeled for this antigen were distributed underneath ulcers, along fissures, around abscesses, within the lamina propria, in granulomas, and in the germinal centers of mesenteric lymph nodes. In addition, 57% (12 of 21) of the cases contained the E. coli antigen, and 44% (7 of 16) contained the streptococcal antigen. The immunolabeling for the latter two agents also occurred within macrophages and giant cells, distributed in a pattern similar to that of Listeria antigen.

CONCLUSIONS

The results suggest that Listeria spp., E. coli, and streptococci, but not measles virus, play a role in the pathogenesis of Crohn's disease.

Multiple focal nodular hyperplasia of the liver associated with hemihypertrophy and vascular malformations

A case of multiple focal nodular hyperplasia of the liver occurring in a 22-year-old woman with musculoskeletal hemihypertrophy and anomalous vascular supply to the liver is described. The patient had Klippel-Trénaunay-Weber syndrome and abdominal pain and tender massive hepatomegaly. Visceral angiography showed marked dilatation of the celiac axis and both the main trunk and peripheral branches of the hepatic artery. Large abdominal veins drained from the dome of the liver into the hepatic veins. The vascular anomalies were evident on contrast-enhanced computed tomography and magnetic resonance imaging. Multiple focal nodular hyperplasia was confirmed by laparoscopic liver biopsy. The findings in this patient support the concept that multiple focal nodular hyperplasia characteristically occurs in a syndromic form and is induced by an irregular arterial supply in the liver, with localized hyperfusion that leads to nodular areas of hepatocyte hyperproliferation.

Glutaraldehyde colitis following endoscopy: clinical and pathological features and investigation of an outbreak

Although potentially noxious compounds are used routinely to disinfect endoscopes, reports of their inadvertent introduction to the gastrointestinal tract, usually attributed to the retention of disinfectant within endoscope channels, are rare. This case report describes the clinical features of glutaraldehyde-induced colitis and the pathology of the mucosal injury in four patients, in at least one of whom the disinfectant was not retained in the endoscope itself. Within 3 months, three patients experienced severe acute proctocolitis < 6 hours after a sigmoidoscopy showing no abnormalities, performed in a small endoscopy unit. Investigation of the unit's protocols suggested that the most likely cause was retention of 2% glutaraldehyde disinfectant in the endoscope channels, and changes were made to prevent this. When a fourth case occurred 5 months later, the source of the glutaraldehyde was found to be the tubing connecting water bottles to the endoscopes, which was disinfected rigorously but flushed inconsistently between cases. Glutaraldehyde-induced colitis seems similar to ischemic colitis in biopsy specimens and cannot be diagnosed by histological analysis alone. Acute colitis occurring within 24 hours of a colonoscopy showing no abnormalities should be considered iatrogenic and should lead to an investigation of procedures in use for cleaning and disinfecting endoscopic equipment.

Gastric carcinoid tumors: the biology and therapy of an enigmatic and controversial lesion

Gastric carcinoid tumors were previously believed to be rare lesions, representing less than 2% of all carcinoid tumors and less than 1% of all stomach neoplasms. More recent studies have demonstrated that they may constitute as much as 10-30% of carcinoid tumors. Patients with conditions associated with hypergastrinemia, such as chronic atrophic gastritis, Zollinger-Ellison syndrome with multiple endocrine neoplasia type 1 (ZES-MEN-1), and pernicious anemia, display a markedly elevated incidence of gastric carcinoid tumor formation. A classification system distinguishing three types of gastric carcinoid tumor has been proposed: 1) tumors associated with chronic atrophic gastritis, 2) tumors associated with Zollinger-Ellison syndrome, and 3) sporadic lesions. Tumors that develop in association with hypergastrinemia are usually composed of enterochromaffin-like (ECL) cells, in contrast to sporadic lesions that contain a variety of endocrine cell types (enterochromaffin, ECL, X). In both intact animal models such as the rat and Praomys (mastomys) natalensis and in isolated purified ECL cell preparations, gastrin has been demonstrated to exert a powerful trophic effect on ECL cells, in addition to stimulating histamine secretion. It is apparent that hypergastrinemia-associated gastric carcinoids display relatively benign biological behavior. Sporadic lesions require aggressive surgical management on diagnosis. Type I and type II (hypergastrinemia-associated) lesions can be managed initially by endoscopic excision of accessible tumors, followed by endoscopic surveillance. If tumors recur, antrectomy and local excision may be used to remove the source gastrin, resulting in cure in the vast majority of patients.

Gastric carcinoids. The Yale Experience

OBJECTIVES

To document our experience with gastric carcinoids over the past decade and to identify lesion frequency and the existence of a relationship to low acid states.

DESIGN

Retrospective case series.

SETTING

Tertiary care referral center.

PATIENTS

A consecutive sample of 16 patients with gastric carcinoids was evaluated over the last decade. Only two cases were recorded in the prior decade. Ages ranged from 30 to 93 years (mean, 65.9 years). There were eight men and eight women. Three patients were unavailable for follow-up.

INTERVENTIONS

Therapy included total gastrectomy (n = 4), subtotal gastrectomy (n = 3), endoscopic polypectomy (n = 3), and endoscopic surveillance (n = 6).

MAIN OUTCOME MEASURES

Pathobiological tumor characteristics and survival.

RESULTS

All carcinoids were of gastric fundic origin. None of the patients exhibited the carcinoid syndrome. Chronic atrophic gastritis was the most frequently observed comorbid pathologic condition (63%). Half of the patients had multiple polypi. Mean follow-up was 4.7 years (n = 13). There were 10 survivors. The only related death occurred in a patient with a solitary tumor.

CONCLUSIONS

Diagnosis of the complex and ill-defined entity of gastric carcinoid is increasing. This may be due to an increased awareness and increased upper gastrointestinal endoscopy rate rather than an increase in real incidence. Criteria for prediction of malignant progression are not available. Multiple gastric carcinoids associated with hypergastrinemia predominantly display nonaggressive behavior. Conservative gastric surgery may be appropriate therapy for such patients.

Enterocolic lymphocytic phlebitis. Clinical, radiologic, and pathologic features

Venous compromise as a cause of ischemic colitis and enteritis is infrequent. Enterocolic lymphocytic phlebitis, a rare cause of such compromise, to our knowledge has been reported in only three patients. We describe a patient with this condition who had hematochezia and a cecal mass that was mistaken endoscopically and radiologically for carcinoma and required resection. The mass, which was ulcerated, was due to intense submucosal edema. The patient had no history of taking hydroxyethylrutoside, a drug used in Europe in treating varicose veins that has been implicated in all three previously reported cases. This entity is characterized by a mixed T- and B-cell vasculitis affecting veins exclusively in the wall and mesentery of the colon and small bowel, without systemic involvement, leading to fibrointimal proliferation, thrombosis, venous occlusion, and subsequent edema and ischemic necrosis. It should be distinguished from other enterocolic phlebitides, including Behçet disease, systemic lupus erythematosus, and myointimal hyperplasia of mesenteric veins, and can be treated by local excision of the affected bowel.

Diagnosis of gastrointestinal T-cell lymphomas in routinely processed tissues

Diagnosis of primary gastrointestinal T-cell lymphomas is often problematic because lymphoma may not be suspected clinically or on resection, and tissue may not be frozen for immunophenotyping. Furthermore, ulceration and inflammation and the polymorphous character of the lesions makes evaluation difficult. Only approximately 150 cases have been reported, fewer than 20 from North America. We have tried to establish a reliable approach to the diagnosis of gastrointestinal lymphomas of T-cell phenotype in routinely processed tissue. Sections from five primary gastrointestinal T-cell lymphomas were stained with a panel of 13 antibodies reactive in routinely fixed, paraffin-embedded tissue. These included antibodies to pan-T- and pan-B-cell antigens (CD3, CD20), B- and T-cell-associated antigens (CD43, CD45R0; CDw75, CD74), antigens expressed by activated T-cells (HLA-DR, CD30), leukocyte antigens (CD45, CD15), and macrophage markers (MAC-387, HAM-56). All stained positively with T-cell markers MT-1 and Leu-22, four with UCHL-1, and three with anti-CD3 polyclonal antibody. B-cell markers identified by L-26 and LN-1 were negative in all five, whereas LN-2 was expressed in two. Two expressed HLA-DR; all were Ber-H2 negative. Two had an abnormal phenotype: one was Leu-M1 positive, and one LCA negative. Ten B-cell gastrointestinal lymphoma controls were negative for MT-1, Leu-22, and CD3, and nine were negative for UCHL-1. Nine were positive for the B-cell marker L-26, eight for LN-2, and seven for LN-1. All tumors were negative for monocyte-macrophage markers. This antibody panel provides a reliable means for identifying gastrointestinal T-cell lymphomas in paraffin sections. Use of a panel is advisable because of variation in expression and preservation of antigens, and to detect abnormal phenotypes. Application of this approach may facilitate the diagnosis of gastrointestinal T-cell lymphomas both prospectively and in archival material, and thereby encourage studies of the behavior and treatment of these neoplasms.

Bacterial translocation in acute and chronic portal hypertension

Patients with cirrhosis are predisposed to develop spontaneous bacteremias and peritonitis, mainly by enteric bacteria. Portal hypertension, by producing congestion and edema of the bowel wall, could increase the passage of bacteria from the intestinal lumen to regional lymph nodes to the systemic circulation or to both, a process termed bacterial translocation. The aim of this study was to investigate bacterial translocation at two stages of experimental portal hypertension: (a) acute (when shunting is minimal); and (b) chronic (when shunting is extensive and mimics the portal hypertension of cirrhosis). Rats were killed 2 days (acute) or 15 days (chronic) after partial portal vein ligation or control surgeries. Samples of mesenteric lymph nodes, blood, liver and spleen for standard bacteriological cultures and a fragment of ileum for histological examination were obtained. Two days after surgery, a significantly greater proportion of rats with acute portal hypertension (12 of 13 or 92%) had positive mesenteric lymph node cultures compared with both control groups: sham-operated (4 of 13 or 31%) and inferior vena cava-ligated (3 of 10 or 33%) animals (p < 0.01). However, 15 days after surgery no differences in translocation to mesenteric lymph nodes were found between rats with chronic portal hypertension (3 of 15 or 20%) and sham-operated controls (3 of 11 or 27%). In neither the acute nor the chronic rats were bacteria isolated from blood, spleen or liver. Rats with acute portal hypertension had significantly greater mesenteric inflammation than rats with chronic portal hypertension and control animals.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of bile acid feeding on the development of ileal bile acid transport

Sodium-dependent bile acid uptake is developmentally regulated in the rat ileum. Transport activity is abruptly expressed on postnatal d 17, although the mechanisms controlling this expression are poorly understood. Changes in bile salt metabolism and hepatic transport result in a marked increase in bile flow before postnatal d 17, and thus this study examined the effects of bile salt feeding on the development of ileal bile acid transport. Twelve-d-old rat pups were gavage-fed saline, taurocholate, or mannitol on a daily basis for 3 d. Sodium-dependent bile acid transport was studied by rapid filtration using ileal brush-border membrane vesicles prepared from the various experimental groups. Taurocholate feeding resulted in precocious development of sodium-dependent bile acid transport and induction of sucrase activity. Mannitol feeding, used as a control for the effects of diarrhea-induced stress, resulted in similar sucrase activity, yet sodium-dependent bile acid transport was induced to only half the level observed in taurocholate-fed animals (3.2 +/- 1.6 versus 6.9 +/- 2.0 pmol/mg protein/45 s, p < 0.001). Serum corticosterone levels were similar in the mannitol- and taurocholate-fed animals (3.8 +/- 1.3 versus 4.6 +/- 1.8 micrograms/dL). Both feedings lead to histologic maturation of the ileum, with a more pronounced effect in the taurocholate-fed pups. Bile salt feeding induces precocious expression of ileal bile acid transport, apparently by both diarrhea-induced stress and a bile salt-specific effect.

The morphologic features of diversion colitis: studies of a pediatric population with no other disease of the intestinal mucosa

Studies of diversion colitis have not shown a consistent pattern of histopathologic features, and many descriptions are difficult to interpret because of the presence of underlying intestinal mucosal disease. To define the histologic changes in patients free of other mucosal inflammatory disease, we studied the resected segments of bypassed colorectum from 37 patients with Hirschsprung's disease treated by a two-stage procedure, using rectal biopsy specimens taken for initial diagnosis and trimmings from proximal to the stoma as controls. Biopsy specimens from a further 14 patients of similar age but without colorectal mucosal disease were used as additional controls. The histology of the bypassed segment was abnormal in all patients. Twenty-six had diversion colitis characterized by diffuse follicular lymphoid hyperplasia; lamina propria expansion by plasma cells, lymphocytes, and some neutrophils; cryptitis; reactive epithelium; and mucin depletion. Crypt abscesses, aphthous ulcers, mild architectural distortion, and Paneth cell metaplasia were noted in more severe cases. The remaining 11 patients had mild follicular lymphoid hyperplasia and an increase in lymphoplasmacytic infiltrates, with absence of neutrophils, epithelial injury, and other changes seen in diversion colitis, a pattern we term "diversion reaction." Diversion colitis is common in children with a bypassed colorectum. It can be distinguished histologically from other mucosal diseases in most cases. We hypothesize that diversion reaction may be an inevitable consequence of colonocyte nutrient deficiency and that diversion colitis may be superimposed by a second insult, such as a low-grade pathogen.

Expression of steroid hormone receptors in benign hepatic tumors. An immunocytochemical study

Many hepatic adenomas have been demonstrated to have a clear relationship with oral contraceptive use, and it is presumed that there may be hormone receptors within the cytoplasm or nucleus of adenoma cells that mediate tumor growth in response to hormonal stimulation. Only a small number of examples of benign hepatic tumors have been analyzed for the presence of estrogen and progesterone receptors, and there has been a lack of consensus with regard to the findings. All previous studies have determined receptor levels by biochemical methods. In a retrospective study, we employed specific monoclonal antibodies against estrogen and progesterone receptors in 10 benign paraffin-embedded hepatic lesions: five examples of hepatic adenoma and five examples of focal nodular hyperplasia. All patients were female, except for one male with adenoma and one male with focal nodular hyperplasia. No patient had received tamoxifen citrate or any other form of hormonal therapy for their hepatic lesion. Positive controls included benign and malignant breast tissue. No positive staining was seen in hepatic adenoma, focal nodular hyperplasia, or normal adjacent liver parenchyma. Intense positive staining was seen in all positive control tissues. This negative result with the use of specific monoclonal antibodies in an established immunohistochemical method for analysis of estrogen and progesterone receptors does not exclude the presence of these receptors in benign hepatic lesions, but does suggest that, if present, they occur in much smaller amounts than in benign and malignant breast tissue. The presence of hormone receptors in benign hepatic tumors deserves further study.

A cecal diaphragm associated with the use of nonsteroidal anti-inflammatory drugs

In the small intestine, strictures and diaphragms causing obstructive symptoms are well known to occur in patients using nonsteroidal anti-inflammatory drugs. Recently, two cases of nonsteroidal anti-inflammatory drug (NSAID)-associated diaphragm-like colonic stricture were reported as unexpected findings in patients being investigated for iron-deficiency anemia. We present a third such case that occurred in the cecum in a 49-year-old woman with rheumatoid arthritis who had been taking NSAIDs for 5 years.

Diversion colitis--20 years a-growing

During the last decade, clinical and pathologic studies of diversion colitis have led to a better understanding of its nature. The clinical features are well described, and the endoscopic appearances, and gross and microscopic pathology are now defined. Thus, firm diagnosis and distinction from other colitides, notably ulcerative colitis and Crohn's disease, are possible in most cases. Restoration of the fecal stream cures diversion colitis, which in some cases may be successfully treated with short-chain fatty acid enemas, although the efficacy of this method remains to be substantiated. An understanding of the pathogenesis of diversion colitis (currently unknown) may lead to better methods of prevention and treatment.

Mantle zone lymphoma in a gastric glomus tumor

A 61-year-old man had an ileocolectomy for resection of an obstructing lesion of the terminal ileum, which proved to be a mantle zone variant of intermediate lymphocytic lymphoma. At laparotomy, an intramural nodule in the gastric antrum was observed; on resection, this was found to be a typical gastric glomus tumor, focally infiltrated by lymphoma. This combined tumor has not been described previously, to the knowledge of the authors, and could be misdiagnosed easily, although both components should be considered in the differential diagnosis of small cell gastric neoplasms and can be identified readily by immunohistochemical studies.

Effects of aspirin on pathways of ion permeation in Necturus antrum: role of nutrient HCO3

Intracellular microelectrodes were used to evaluate electrical properties of the cell membranes in Necturus antral mucosa during exposure to luminal acid alone (pH 4) or to 5 mmol/L aspirin [acetylsalicylic acid (ASA)] in the presence of luminal acid. When nutrient solutions were buffered by HCO3- (pH 7.3), ASA moderately depolarized and increased the resistances of both cell membranes. When nutrient solutions were buffered by HEPES (pH 7.3), ASA induced even greater depolarizations of the cell membranes. In addition, resistance of the apical membrane did not increase and resistance of the basolateral membrane decreased. The changes in basolateral membrane resistance were observed when tissues were exposed to 5 mmol/L salicylate but not during exposure to luminal acid alone or to acidified luminal solutions containing 5 mmol/L acetate, a small and permeable organic acid. Electron microscopy confirmed that these initial electrophysiological changes precede alterations in cell morphology. The findings suggest that nutrient HCO3- attenuates changes in membrane potentials caused by ASA. Loss of nutrient HCO3- seems to accelerate alterations in basolateral membrane resistance caused by ASA and its salicylate moiety.

Regulation of the reverse transcriptase of human immunodeficiency virus type 1 by dNTPs

Reverse transcriptase (RNA-directed DNA polymerase, EC 2.7.7.49) of human immunodeficiency virus type 1 has been examined with respect to the steady-state kinetics of polymerization of dNTPs into product DNA. With dNTPs as variable substrate, the kinetics of polymerization deviated from standard Michaelis-Menten kinetics. Substrate inhibition was observed at high substrate concentrations and negative cooperativity was seen at lower substrate concentrations. Examination of incorporation of substrate dNMPs in the presence of nucleotides not complementing the template demonstrated that dNTPs may act as noncompetitive inhibitors, as well as substrate. The Ki of the enzyme for dNTPs was 104 microM. A working model is presented that accounts for the substrate inhibition. In this model, the reverse transcriptase is a multisubunit holoenzyme, where noncompetitive inhibition is mediated by one subunit binding nucleotide and down-regulating the enzymatically active 64-kDa subunit. With additional assumptions, this model can accommodate the negative cooperativity observed.

Bacillary peliosis hepatis as a cause of acute anemia in a patient with the acquired immunodeficiency syndrome

A 33-year-old white homosexual man, infected with the human immunodeficiency virus, presented with acute anemia and thrombocytopenia not responsive to transfusions or to treatment with steroids and intravenous gamma-globulin. Hematologic workup was compatible with peripheral sequestration or loss of blood cells; however, there was no evidence of gastrointestinal or other sources of hemorrhage, and the only significant finding was a progressive liver enlargement. An abdominal computerized tomographic scan showed a massive homogeneous liver without focal lesions, a very small amount of ascites, and no retroperitoneal fluid collections. A transjugular liver biopsy specimen showed the cystic, blood-filled cavities characteristic of peliosis hepatis. Cavities varied in size, all contained pooled erythrocytes, and some had areas suggestive of thrombi in various stages of organization. Bacteria similar in morphology to those described in bacillary peliosis hepatis were seen in the peliotic spaces. The clinical picture began resolving shortly after treatment with zidovudine and ampicillin/sulbactam was started and had totally resolved 6 months after presentation. This case shows that bacillary peliosis hepatis is a reversible entity that may produce acute sequestration of blood in the liver.

Multiple glomus tumors of the stomach with intravascular spread

Gastric glomus tumors are characteristically benign solitary lesions. We present a case of multiple glomus tumors involving the stomach wall and perigastric adipose tissue. Histologically, the major portion of each tumor was composed of "typical" glomus cells arranged in a predominantly solid pattern. Cavernous hemangiomalike areas were present toward the periphery. The tumor cells were immunoreactive for alpha-smooth muscle actin, vimentin, laminin, and type IV collagen, but did not express desmin. There were several focal areas where the tumor cells had a signet-ring cell-like appearance, intermingled with cells having clear cytoplasm and hyperchromatic nuclei. Rare mitoses were noted. A striking feature was the presence of widespread but subtle extension of the glomocytes along venous channels subendothelially, with formation of intravascular nodules focally. The multiple separate tumor nodules found in perigastric fat are interpreted as having arisen in this manner. This entity is distinct from previously described typical and atypical solitary glomus tumors, glomangiosarcoma, and the syndrome of multiple glomus tumors of subcutaneous tissues. It may represent an early stage of development of the large, multilobulated glomus tumors that have rarely been reported to involve stomach and adjacent viscera.

Reversible hepatitis associated with diclofenac

We describe the clinical features, liver histology, and ultrastructure in reversible diclofenac-induced hepatitis and review previous reports of this entity. Although rarely reported, diclofenac hepatitis may be severe, and even fatal. Symptoms, which develop from 1 week to 11 months after starting the drug, include jaundice, pruritus, fever, abdominal pain, nausea, vomiting, and rash. Bilirubin and alkaline phosphatase are mildly elevated, transaminases often markedly so. The nature of the idiosyncratic injury appears variable, some cases having features of a hypersensitivity reaction, most being more suggestive of a toxic metabolic effect. Light microscopy shows a nonspecific hepatitis with portal and lobular activity, and focal hepatocellular injury that may progress to zonal or massive necrosis. The ultrastructural features in our case are typical of drug or toxin injury. This may be of value in distinguishing this entity from other forms of hepatitis, which is important in view of the frequent reversibility of this potentially lethal form of injury.

Malignant potential of juvenile polyposis coli. Report of a case and review of the literature

Juvenile polyps of the colon and rectum traditionally have been viewed as being benign inflammatory or harmartomatous lesions without potential for malignant change. The authors report a case of adenocarcinoma developing in a patient with sporadic juvenile polyposis. Juvenile polyposis was diagnosed in the patient at age 4 years. He underwent subtotal colectomy at age 6 years. At age 12, he underwent a proctectomy and a Swenson pull-through because of adenomatous changes in the rectal stump. At age 19 surveillance endoscopy revealed invasive cancer in a juvenile polyp.

Clinical and pathological characteristics of hepatotoxicity associated with occupational exposure to dimethylformamide

The clinical characteristics, laboratory results, and liver biopsy findings of seven workers with toxic liver injury associated with exposure to several solvents, including substantial levels of the widely used solvent dimethylformamide, are presented. Three patients had short exposure (less than 3 months), four long exposure (greater than 1 year). Among those with brief exposure, symptoms included anorexia, abdominal pain, and disulfiram-type reaction. Aminotransferases were markedly elevated with the ratio of alanine aminotransferase to aspartate aminotransferase always greater than 1. Liver biopsy showed focal hepatocellular necrosis and microvesicular steatosis with prominence of smooth endoplasmic reticulum, complex lysosomes, and pleomorphic mitochondria with crystalline inclusions. Among workers with long exposure, symptoms were minimal and enzyme elevations modest. Biopsies showed macrovesicular steatosis, pleomorphic mitochondria without crystalloids, and prominent smooth endoplasmic reticulum, but no evidence of persisting acute injury or fibrosis. Abnormal aminotransferases in both groups may persist for months after removal from exposure, but progression to cirrhosis in continually exposed workers was not observed. We conclude that exposure of these workers to solvents, chiefly dimethylformamide, may result in two variants of toxic liver injury with subtle clinical, laboratory, and morphological features. This may be readily overlooked if occupational history and biopsy histology are not carefully evaluated.

Liver cell adenoma: diagnosis and treatment of a rare hepatic neoplastic process

Liver adenomatosis is a rare entity in which multiple liver cell adenomas (more than 10) occur in patients with no prior history of steroid use or glycogen storage disease. This report describes a case of liver adenomatosis, distinguishes liver adenomatosis from other benign liver lesions, and discusses the diagnosis and treatment of this disorder.

Adenocarcinoid tumor of the periampullary region: a novel duodenal neoplasm presenting as biliary tract obstruction

An adenocarcinoid tumor of the duodenum, similar to those arising in the appendix, is reported. The tumor presented as a periampullary mass causing pancreaticobiliary obstruction. The microscopic features were typical of adenocarcinoid with diffuse infiltration of mucosa, submucosa, and smooth muscle by tubuloglandular structures lined by enteroendocrine and goblet cells. Signet ring cells were also present. It is desirable to distinguish adenocarcinoids from adenocarcinomas and typical carcinoids in this setting as, by analogy with appendiceal tumors, adenocarcinoids may be expected to have an intermediate prognosis.

Bleeding colonic ulcers secondary to atheromatous microemboli after left heart catheterization

Atheromicroembolism after aortic or cardiac catheterization is frequently found at autopsy but rarely recognized in life, perhaps because many cases are asymptomatic. We report two patients who, after left heart catheterization, developed gastrointestinal hemorrhage from a solitary colonic ulcer caused by occlusive atheromicroemboli in submucosal vessels. We briefly review the spectrum and pathogenesis of atheromicroembolic injury to the gastrointestinal tract. Atheromicroemboli, which occlude vessels too small to be visualized by angiography, should be considered in the differential diagnosis of gastrointestinal bleeding in patients who have undergone aortic instrumentation.

Benign peptic ulcers penetrating pericardium and heart: clinicopathological features and factors favoring survival

Penetration of the pericardium and heart by benign peptic ulcers is rare. Before 1965 it was almost invariably fatal, but about 20% of recently reported cases have survived. We report 4 representative cases and review 91 additional cases from the literature. The ulcers arose in esophagus, hiatus hernias, abdominal stomach, and near anastomoses, and the predominant predisposing factor was previous surgery to the esophagogastric region. Whereas penetrating esophageal ulcers had a slightly better prognosis than gastric lesions, the principal determinant of clinical presentation, findings, and prognosis was the site of cardiac involvement. The clinicopathological features of pericardial, atrial, and ventricular involvement are distinct. We evaluate the different implications of these features for diagnosis, management, and prognosis and make some tentative recommendations regarding diagnostic procedures and treatment. Early diagnosis and prompt surgical intervention are critical to successful treatment of this entity, which may present with predominantly cardiac or gastrointestinal symptomatology.

Inflammatory aortic aneurysm: report of a case suggesting athero-ischaemic aetiology

A case of inflammatory aortic aneurysm is presented in which histology revealed athero-emboli in the aortic vasa vasorum. It is suggested that ischaemic injury to the media, caused by lesions such as these and by other features of atherosclerosis, may be the initiating factor in some cases of idiopathic chronic periaortitis.

Experimental columnar metaplasia in the canine oesophagus

Regeneration of canine oesophageal mucosa was studied under basal conditions and in the presence of gastro-oesophageal reflux. In normal circumstances mucosal defects in the oesophagus regenerate by squamous epithelium. In the presence of gastro-oesophageal reflux of either acid or a combination of acid and bile, regeneration was frequently by columnar epithelium (Barrett's oesophagus). This columnar regeneration was not seen with bile reflux alone. By the use of squamous barriers to proximal migration of columnar epithelium in the stomach, it was demonstrated that columnar re-epithelialization may occur from cells intrinsic to the oesophagus and is not dependent on proximal migration of cardiac columnar epithelium. The cell of origin of this epithelium may be located in oesophageal gland ducts and is likely to be a multipotential stem cell since the regenerated columnar epithelium may contain goblet and parietal cells not normally found in the oesophagus. This epithelium is morphologically distinct on mucin histochemistry from cardiac columnar epithelium. These findings support the concept that Barrett's epithelium is metaplastic.

Localization of villin, a cytoskeletal protein specific to microvilli, in human ileum and colon and in colonic neoplasms

Villin is a cytoskeletal protein of microvilli of epithelial cell brush borders found principally in absorptive cells of the intestine and proximal renal tubule. A marker of both enterocyte differentiation and epithelial cell polarity, it has been studied mainly in experimental animals. We raised monoclonal antibodies to villin and used them to localize it in human ileum and colon and in 22 colonic neoplasms. Villin is localized in the brush border of normal ileum and in the luminal border of normal colon and is expressed with increasing staining intensity as cells migrate from crypt to surface. It was present in the luminal border in all five adenomas and in 16 of 17 adenocarcinomas studied. In addition, villin staining was observed in the cytoplasm of 10 tumors, and in the basement membrane area surrounding tumor in 10 cases. In "transitional" mucosa adjacent to carcinomas it was confined to the luminal border. Abnormal expression of villin by a significant proportion of colonic tumors suggests that it may have a role as a marker of colorectal neoplasia.

Characterization of intestinal brush border cytoskeletal proteins of normal and neoplastic human epithelial cells. A comparison with the avian brush border

The elaborate cytoskeletal matrix underlying the intestinal epithelial cell brush border (BB) is the hallmark of a mature enterocyte. As such, alterations in this structure are potentially useful as markers aiding in the recognition of subtle defects in cell maturation, such as those accompanying dysplasia and neoplasia. For exploration of this hypothesis, the BB components of human ileal and colonic enterocytes have been compared structurally and biochemically with the well-characterized avian BB, and alterations in the BB cytoskeleton in various states of dysplasia and neoplasia have been identified. Ultrastructural analysis of isolated human ileal BBs indicate that the human BB is structurally homologous to BBs isolated from chicken and other mammalian sources. Like other mammalian BBs (eg, from rat) the terminal web cytoskeleton of the human BB is less extensive than that in the avian BB. Immunochemical analysis of isolated human BBs indicates that the major proteins of the avian microvillar actin bundle, villin, fimbrin, and the 110-kd subunit of the 110K-calmodulin complex, are all present in the human BB. The terminal web protein myosin is also present. Unlike the terminal web of the avian BB, which contains a BB-specific isoform of spectrin, TW 260/240, the human BB contains the more widely distributed spectrin isoform, fodrin. In addition, the human BB contains multiple proteins immunoreactive with antibodies to protein 4.1, a spectrin/actin binding protein that is absent from the avian BB. Immunolocalization studies examining the distribution of the BB-specific microvillar protein, villin, in human colonic mucosa indicate that the localization of this protein is disrupted in certain dysplastic and neoplastic states. Thus, both the expression and/or distribution of BB-specific proteins such as villin may be useful markers for defects in the differentiation state of the enterocyte.

Yersinia infection and acute abdominal pain

In 194 patients presenting with acute abdominal pain from whom sequential serum samples were taken, the frequency of yersiniosis, established serologically, was significantly higher (23%) than in 320 control subjects (2%). Yersiniosis occurred in 31% of patients with acute appendicitis. Acute-phase serum samples only, obtained in a further 307 patients, yielded a falsely low frequency of yersiniosis (4%). Y pseudotuberculosis was five times more common than Y enterocolitica, and Y pseudotuberculosis type IV was the most common serotype, accounting for 43% of Yersinia infections. Yersinia may play a more important part in the aetiology of acute abdominal pain, and particularly acute appendicitis, than has been previously appreciated. Antibody titres to both Y enterocolitica and Y pseudotuberculosis frequently rise late in infections causing abdominal pain. Consequently analysis of acute-phase serum samples alone leads to underdiagnosis of yersiniosis.

High appendicectomy rates in Ireland: why?

Age-specific appendicectomy rates for Ireland have recently been reported to be substantially higher than those for Scotland. We attempted to determine the reason for this difference. Records of 940 appendectomies performed in one urban and one rural centre in Ireland over a 12 month period were examined to establish the frequency of acute appendicitis. Appendicitis rates were derived from these data. Appendicectomy rates are higher in Ireland because the incidence of acute appendicitis is greater than in Scotland or England and Wales and are not the result of variations in medical practice.

Superficial bladder tumors (stage pTa, grades 1 and 2): the importance of recurrence pattern following initial resection

We treated 414 new patients with stage pTa, grades 1 and 2 bladder tumors by transurethral resection between 1970 and 1982. All of the patients with grade 3 or previous upper tract tumors, or who had been treated at some stage with intravesical chemotherapy were excluded. Followup for 5 or more years was available in 188 of the patients. There was a low increase in T stage (6 per cent). Of the patients followed for 5 or more years 46 per cent remained free of tumor. Only 16 per cent of the patients had multiple tumors at presentation and 20 per cent had tumors of 10 gm. or more. These factors were associated with a worse prognosis. Patients free of tumor at 3 months had an 80 per cent chance of having no further recurrences and this rate remained the same up to 2 years from the start of the disease. Patients with a recurrence at 3 months were much less likely to remain free of tumor, and had a higher chance of recurrence at every future visit.

Percutaneous coagulum nephrolithotripsy: a new approach

Intrarenal scatter of stone fragments during percutaneous nephrolithotripsy is a complication which may predispose to post-operative pain and further stone formation. The use of a coagulum to prevent such a complication has proved difficult when introduced percutaneously. This experimental study describes a new gelatine (Lithogel) which is introduced through the nephroscope to coat the renal calculus; it allows easy disintegration of the calculus within the gel, is safe to use and effectively prevents the scatter of fragments into inaccessible calices.

Focal lymphoid hyperplasia (pseudolymphoma) of the esophagus

Focal lymphoid hyperplasia is an uncommon but ubiquitous lesion. It occurs most commonly in the gastrointestinal tract in association with chronic peptic ulcer disease of the stomach. We describe the hitherto unrecognized association of lymphoid hyperplasia in the esophagus with chronic stenosing ulcerating esophagitis and Barrett's mucosa. This association is considered to be analogous to the more prevalent coexistence of lymphoid hyperplasia and chronic peptic ulcer disease in the stomach.

Testicular tumors in subfertile men: report of 4 cases with implications for management of patients presenting with infertility

We report on 4 men attending our infertility clinic in whom seminomas developed. A review of testicular biopsies performed for investigation of subfertility in 2 patients revealed in situ and early invasive carcinoma. Infertile men have a prevalence of carcinoma in situ in the range of 1 per 100 to 200, with a high risk of progression to invasive germ cell tumor (50 per cent within 5 years of diagnosis). Biopsy is the only method of detection of the in situ lesion and, therefore, is recommended in the investigation of oligospermic and azoospermic male subjects. The surgical approach to and diagnostic sensitivity of testicular biopsy are reviewed, and the management of carcinoma in situ is discussed.

Detection and identification of group B streptococci by use of pigment production

Pigment production by group B streptococci (GBS) is a useful test for identification of the organisms. The test is positive in 99.5% of beta-haemolytic strains. No false-positives are noted. Non-haemolytic strains do not produce pigment. Islam's media less agar can be used as a one-step broth detector of GBS in mixed cultures. This may have application for the detection of GBS in women in labour. When used as an identification system for GBS, serum-starch broth can be further modified by reduction of serum and starch concentrations by at least 80%.

Extensive gas in tissues of the forearm after horsebite

A 44-year-old man sustained lacerations of the forearm as a result of a horsebite. His arm became swollen after primary closure of the wounds, and a roentgenogram showed gas in the tissues of the forearm. Streptococcus anginosus and S mutans were isolated from the wounds.