Beta-2-microglobulins as a differentiation marker in bladder cancer

The transformation of a normal cell through dysplasia to the malignant state usually is associated with changes at the molecular level within the nucleus, cytoplasm and cell surface. These changes can be monitored by the loss of normal cell surface antigens, such as the blood group antigen ABO(H) and major histocompatibility complex antigens, which in the human correlate with the histocompatibility locus antigens. A group of patients with bladder biopsy and diagnosis ranging from normal through severe dysplasia to papillary transitional cell carcinoma, invasive transitional cell carcinoma and carcinoma in situ were evaluated for the presence or absence of beta-2-microglobulin. This 11,000 molecular weight protein was used as an indirect marker for the major histocompatibility complex antigens on the cell surface. With immunoperoxidase as a marker, the presence of beta-2-microglobulin was seen in all patients with normal epithelium as well as benign disease. However, with progression through dysplasia to carcinoma there was progressive deletion of the beta-2-microglobulin. Carcinoma in situ exhibited minimal expression of the beta-2-microglobulin. The use of beta-2-microglobulin as a marker for major histocompatibility complex antigens on the cell surface may prove to be useful for monitoring transitional cell carcinoma.     

Cdx2与食管炎、Barrett's食管及腺癌的关系

同源异型盒转录因子2是新发现的尾相关同源异型盒转录因子家旅中的一个成员,特异地表达于从十二指肠至肛管齿状线的肠道绒毛上皮,在其他空腔脏器黏膜上皮异位表达时可诱导相应部位的肠化生或腺癌发生.在胃十二指肠反流-食管炎- Barrett's食管-食管腺癌演化过程中,同源异型盒转录因子2起着重要的调控作用,并与p63基因、维甲酸、MUC2、骨形态发生蛋白4等多因素共同作用促进了这一过程的发展.     

Hepatocyte antigen as a marker of intestinal metaplasia

Intestinal metaplasia is a histologic hallmark of Barrett's esophagus and chronic gastritis. Intestinal metaplasia may progress to dysplasia or carcinomas without proper treatment. Most cases of intestinal metaplasia are easily recognized on hematoxylin and eosin-stained sections. However, some cases of intestinal metaplasia may be hard to recognize if they lack the characteristic mucin-producing cells and Paneth cells, or if they are small in size. Recently, keratin 7, keratin 20, and MUC2 expression patterns were reported to be useful in confirming the diagnosis of intestinal metaplasia. We studied hepatocyte (Hep) antigen (a hepatocellular antigen mainly expressing in normal and neoplastic hepatic tissues) in 33 cases of Barrett's esophagus (9 cases associated with esophageal adenocarcinoma) and 13 cases of chronic gastritis associated with intestinal metaplasia and gastric adenocarcinoma. Hep monoclonal antibody recognizes intestinal metaplasia in all cases. We also compared expression of Hep with that of keratin 7, keratin 20, and MUC2 in intestinal metaplasia. The specificity and sensitivity of Hep for intestinal metaplasia were higher than that of keratin 7 and keratin 20, or MUC2. We conclude that Hep may be used as a single diagnostic marker for intestinal metaplasia.     

肠型脂肪酸结合蛋白对肠缺血早期诊断的意义

目的　探讨肠型脂肪酸结合蛋白 (IFABP)对肠缺血早期诊断的意义。方法　将SD大鼠随机分成对照组和肠系膜上动脉结扎组 (SMA组 ) ,分别于术前及术后 1,2 ,4h取血 ,检测各时点的血清IFABP、肌酸激酶 (CK )、肌酸激酶BB型同工酶 (CK BB)和乳酸脱氢酶 (LDH )。结果　对照组血清I FABP水平在各时点均无明显差异 (P >0 .0 5 )。SMA组结扎后 1h血清IFABP水平迅速增加 ,与对照组相比 ,差异具显著性 (P <0 .0 1) ;结扎 2h达高峰。血清中CK ,CK BB和LDH活性均随缺血时间的延长而出现升高趋势。与对照组相比 ,各组CK ,CK BB和LDH出现显著性升高的时间依次为缺血后1,2 ,4h(P <0 .0 5 )。结论　IFABP是小肠缺血性疾病的早期、特异、敏感的生化诊断指标。     

Palisade vessels as a new histologic marker of esophageal origin in ER specimens from columnar-lined esophagus

It is difficult for surgical pathologists to determine the origin of tissues in samples taken from the columnar-lined esophagus (CLE) or stomach by biopsy or endoscopic resection (ER) on the basis of histologic examination alone. We examined histopathologically a single section (5 to 22 mm in size; mean, 12 mm) from each of 66 cases of CLE (36 short segments, 30 long segments) from German patients with reference to 3 histologic markers of esophageal origin: esophageal glands proper and/or ducts, squamous islands, and double muscularis mucosae, all of which had been reported previously, and palisade vessels as a new histologic parameter as well. Palisade vessels were defined histologically as veins >100 μm in size in and above the original muscularis mucosae. Esophageal glands proper and/or ducts, squamous islands, and double muscularis mucosae were seen in 33%, 18%, and 71% of the specimens, respectively. Palisade longitudinal vessels were observed in 78% and 63% of specimens of short-segment and long-segment CLE, respectively. Palisade vessels were never seen in ER specimens from the stomach or in the middle esophagus and stomach among control autopsy specimens. At least 1 of these 4 markers was seen in 88% of the sections. Therefore, ER specimens were confirmed to originate from CLE in 88% of single histologic sections of CLE on the basis of histologic examination alone.     

CDX-2 homeobox gene product expression in neuroendocrine tumors: its role as a marker of intestinal neuroendocrine tumors

CDX-2 is a homeobox gene product essential for intestinal development and differentiation. It can be used as a specific marker of colorectal adenocarcinomas and other tumors with intestinal differentiation, but little is known about its expression in endocrine and neuroendocrine (NE) cells and NE primary and metastatic tumors. Using the Cdx-2-88 monoclonal antibody, we evaluated CDX-2 expression in routine samples of 20 normal endocrine/NE tissues and of 299 samples of well-differentiated NE tumors (WDNET) and high-grade NE carcinomas (NEC) from different sites. For 17 cases, we examined primary and corresponding metastatic lesions. We also examined 8 cytologic samples of liver metastases derived from 4 ileal WDNETs, 1 lung WDNET, and 3 pancreatic endocrine tumors. CDX-2 mRNA expression with RT-PCR technique on frozen material was evaluated in 5 WDNETs. CDX-2 was expressed in normal NE cells of the intestine and gastric fundus. High CDX-2 expression was seen in all ileal and appendiceal WDNET, while low levels were seen in WDNETs from stomach, duodenum, and rectum; no reactivity was seen in other WDNETs. Low levels of CDX-2 expression were seen in one third of nonfunctioning pancreatic WDNET where it was more frequently observed in cases with metastatic disease (P = 0.002). CDX-2 was identified in all cytologic specimens of metastatic ileal WDNETs. CDX-2 mRNA analysis confirmed immunohistochemical results. CDX-2 was expressed at high levels in 81% of intestinal NEC. Unexpectedly, variable levels of expression of CDX-2 were seen also in 39% of NEC of other sites, without any relation with the site of origin. This reactivity frequently overlapped TTF-1 expression, suggesting deregulated expression of homeobox genes in NEC. The restricted pattern of CDX-2 expression may have diagnostic value in the identification of the primary site of a metastatic WDNET. Conversely, a limited diagnostic role is suggested for CDX-2 in NEC because of its frequent expression in nongastrointestinal tumors.     

MUC2 is a highly specific marker of goblet cell metaplasia in the distal esophagus and gastroesophageal junction

Currently, the American College of Gastroenterology requires identification of goblet cells in mucosal biopsies from the esophagus to diagnose Barrett esophagus (BE). Identification of goblet cells in mucosal biopsies is fraught with limitations such as sampling and interpretation error. One previous study by our group suggested that MUC2 expression in esophageal nongoblet columnar cells represents a late biochemical reaction in the conversion of mucinous columnar cells to goblet cells in BE. We conducted this study to evaluate the prevalence, sensitivity, and specificity of MUC2 positivity in nongoblet columnar epithelium for detection of goblet cells in the distal esophagus and gastroesophageal junction (GEJ) region. We also sought to identify associations between MUC2 positivity and clinical and endoscopic risk factors for BE. This analysis utilized mucosal biopsies of the distal esophagus or GEJ from 100 patients who participated in a community clinic-based study of patients with chronic gastroesophageal reflux disease evaluated prospectively in the western part of Washington state. We randomly selected 50 patients who had columnar epithelium with goblet cells, representing the study group and 50 patients without goblet cells, representing the comparison group. Immunohistochemistry for MUC2 was performed on samples in a blinded manner without knowledge of the clinical or endoscopic features of the patients. The presence of staining was noted in both goblet and nongoblet epithelium, both close to and distant from the mucosa with goblet cells, when the latter were present. All study patients showed MUC2 positivity in goblet cells. MUC2 was present in nongoblet columnar epithelium in 78% of study patients with goblet cells, but in only 4% of controls without goblet cells (P<0.0001) (sensitivity, 78%; specificity, 96% for goblet cell metaplasia). MUC2 was significantly more common in nongoblet columnar cells close to, rather than distant from, the mucosa with goblet cells (P<0.00001). Finally, MUC2 was significantly associated with endoscopic evidence of columnar metaplasia in the distal esophagus, and with known risk factors for BE, such as older age, white race, frequent heartburn, and elevated body mass index. We conclude that goblet cells likely develop from a field of MUC2-positive mucinous columnar cells, and as such, MUC2 represents a late event in the development of goblet cells. MUC2 staining in nongoblet columnar cells is a reasonably sensitive and highly specific marker for goblet cells in the distal esophagus and GEJ, and its presence is predictive of endoscopic columnar metaplasia of the esophagus, even in patients without goblet cells.     

短肠综合征患者血清瓜氨酸水平与小肠吸收面积和功能的相关性

目的研究短肠综合征患者血清瓜氨酸水平的变化及其与肠道面积及吸收功能的相关性。方法采用高效液相色谱法测定22例短肠患者（短肠组）和33例健康人（对照组）血清瓜氨酸水平。短肠患者残存小肠长度及直径采用X线造影检测，并测定短肠患者尿D-木糖排泄率和肠道蛋白吸收度。分析短肠患者血清瓜氨酸与残存小肠长度、面积、蛋白及D-木糖吸收的相关性。6例行肠康复治疗的患者测定康复治疗前后瓜氨酸、D-木糖及蛋白吸收水平的变化。结果短肠组血清瓜氨酸水平显著低于健康对照组[（5．94±2．65）比（16．87±5．97）μmol／L，P〈0．01]。短肠组患者血清瓜氨酸水平与残存小肠长度（r=0.82）及表面积（r=0.86）呈正相关，与尿D-木糖排泄（r=0.56）及肠道蛋白吸收（r=0.48）也呈正相关。6例行肠康复治疗的患者治疗后血清瓜氨酸水平、蛋白及D-木糖吸收均显著增加，但3者增加百分比之间并无相关。结论血清瓜氨酸水平与短肠患者的小肠吸收面积和吸收功能呈正相关，能反映短肠患者小肠功能和衰竭程度，是康复疗效的良好指标。     

Glucagon-like peptide 2 enhances intestinal epithelial restitution

BACKGROUND: Glucagon-like peptide 2 (GLP-2) is a potent intestinotrophic peptide that enhances recovery following intestinal injury. We tested the hypothesis that GLP-2 acutely enhances intestinal epithelial restitution. MATERIAL AND METHODS: Rat jejunal segments were mounted in Ussing chambers. HCl (10 mM) was applied to the mucosal surfaces for 10 min to induce injury. Tissues were then lavaged with modified Ringer's solution and maintained in the chambers for an additional 3 h. Tissues were treated with 10 microM GLP-2 or vehicle alone (control). Electrical parameters were recorded, and tissues were salvaged for morphometric analysis. RESULTS: GLP-2-treated tissues exhibited a significantly greater recovery of potential difference and resistance (P < 0.05) than did controls. Morphometric analysis revealed that columnar cells covered a greater percentage of the epithelial surface in GLP-2-treated tissues than in controls (P < 0.05). CONCLUSIONS: These results suggest that GLP-2 acutely enhances intestinal epithelial restitution following acid-induced injury. This novel biological action of GLP-2 may contribute to its therapeutic effect in models of intestinal disease.     

Amniotic fluid ferritin as a marker of intestinal damage in gastroschisis: a time course experimental study

Background/Purpose

Intestinal damage (ID) is closely related to morbidity and mortality in gastroschisis. This study was performed to determine the intraamniotic substances that may correlate ID and also to verify their time course levels that would be useful for determining when ID starts in gastroschisis.

Methods

In this study, 13-day-old fertilized chick eggs were used. The amnioallantoic membrane was perforated to create amnioallantoic cavity in all embryos. Gastroschisis was created in gastroschisis group to simulate human gastroschisis. Amnioallantoic fluid samples were collected from the embryos on the 13th to 19th gestational days, and the intestines of each group were harvested for evaluation. Amnioallantoic levels of interleukin-8, ferritin, alkaline phosphatase, and amylase were measured. Serosal thickness of the intestines in each group was evaluated.

Results

Increasing amnioallantoic fluid levels of interleukin-8, alkaline phosphatase, and amylase were found in both groups. In contrast to control group, ferritin levels, as a sign of inflammation, were found increased only in gastroschisis group. Histopathologic examination of intestines in the gastroschisis group showed a significant increase in the serosal thickness especially after the 16th day.

Conclusion

Increases in amnioallantoic fluid levels of ferritin show promise as a marker for determining ID encountered in gastroschisis but warrant further investigation.     

The alpha2 and alpha3 integrins are required for morphologic differentiation of an intestinal epithelial cell line

BACKGROUND: The molecular mechanisms controlling intestinal epithelial cell differentiation are poorly defined because of the difficulty of growing normal intestinal cells. We have taken advantage of the ability of the Caco-2 cell line to acquire a glandular phenotype in 3-dimensional (3-D) culture systems to investigate the role of alpha2 and alpha3 integrins in morphologic differentiation. METHODS: Caco-2 cells transfected with sense or antisense DNA constructs of alpha2 or alpha3 integrins were grown in 3-D Matrigel or collagen I in the presence or absence of integrin function-blocking antibodies. We used light and confocal microscopy, BrDU incorporation, TUNEL assay, a fluorometric adhesion assay, FACS analysis, and Western blot analysis to study the effect of extracellular matrix (ECM) and integrins on morphology, polarization, proliferation, apoptosis, cell adhesion, and integrin expression. RESULTS: Compared to collagen I, Caco-2 cells cultured in 3-D Matrigel display cytoskeletal and adherens junction rearrangements and decreased proliferation consistent with cellular differentiation. These changes, which are inhibited by alpha2 and alpha3 blocking monoclonal antibodies and alpha2 and alpha3 antisense DNA transfection, were associated with an increase in alpha3 integrin expression. CONCLUSIONS: We demonstrated that signaling through both constitutively expressed alpha2 integrin and Matrigel-induced alpha3 integrin expression is required to acquire a differentiated phenotype in Caco-2 cells.     

Effects of glutamine isomers on human (Caco-2) intestinal epithelial proliferation, strain-responsiveness, and differentiation

Enteral feeding with small amounts to stimulate bowel motility, and glutamine supplementation, which provides nutrients selectively used by intestinal epithelial cells, might preserve the gut mucosa during fasting. We evaluated the effects of the interaction between mechanical strain and glutamine supplementation in human Caco-2 intestinal epithelial cells, and pursued the finding of equivalent effects of L- and D-glutamine in Caco-2, HT-29, and primary malignant human colonocytes. Caco-2 cells were subjected to repetitive strain in media containing 2 mmol/L of L-glutamine and media supplemented with L- or D-glutamine. Proliferation was determined by automated cell counting. Differentiation and cellular production of L-glutamine were determined spectroscopically. Rhythmic deformation stimulated Caco-2 proliferation in a frequency-dependent manner. Maximal stimulation occurred at 10 cpm, consistent with in vivo frequencies of peristalsis and villous motility. Deformation at 10 cpm and L-glutamine supplementation from 2 to 5 mmol/L concentrations independently stimulated Caco-2 proliferation; the combination further increased proliferation. D-Glutamine supplementation yielded similar results, although with lesser potency. Furthermore, both L- and D-glutamine equivalently reduced Caco-2 dipeptidyl dipeptidase activity. The effects of each isoform were blocked by 1 to 3 mmol/L acivicin, a selective antagonist of glutamine metabolism. Indeed Caco-2 and HT-29 cells and primary malignant colonocytes each metabolized D-glutamine to L-glutamine. Glutamine supplementation in fasting patients might prove synergistic with stimulation of bowel motility by non-nutritive feeding, whereas tissue-specific variations in D-glutamine metabolism might facilitate selective nutripharmaceutical targeting of the gut mucosa. Supported in part by a VA Merit Award (Dr. Basson).