RITA/Registry of Industrial Toxicology Animal data: a comparative immunohistochemical study of 77 islet cell carcinomas in Sprague-Dawley and Wistar rats using antibodies against insulin, glucagon, somatostatin and gastrin.

The objective of this study was to investigate spontaneous islet cell carcinomas with particular reference to possible existing strain differences between Sprague Dawley (SD) and Wistar (W) rats in incidence and immunohistochemical staining pattern. Secondly the occurrence of somatostatin and/or gastrin-positive islet cell tumors should be tested. Islet cell adenocarcinomas (34 from SD, 43 from W-rats) were selected from the RITA-data base and company in-house data base out of an animal pool of 3915 (1681 SD, 2234 W-rats). They were untreated or sham-treated (vehicle) control animals from carcinogenicity studies and whole life-span experiments. Islet cell carcinomas occurred in a higher incidence in male rats (2.98% for SD, 3.23% for W) than in female rats (1.07% for SD, 0.63% for W). All specimens were immunohistologically stained with antibodies against insulin, glucagon, somatostatin and gastrin and, selected specimens with additional antibodies (pancreatic polypeptide, lipase, chymotrypsin, S100-protein, actin and cytokeratin). 94% (SD) and 93% (W), respectively, were insulin-positive and the mean staining intensity (on a scale ranging from 0-4) for insulin was 3.58 (SD) versus 3.37 (W). This high insulin staining incidence and intensity characterized most islet cell carcinomas as malignant insulinomas. 24% (SD) and 37% (W), respectively, were glucagon-positive. Except two tumors in W-rats with a focal strong glucagon expression, the mean staining intensity for glucagon was low (0.38 SD, 0.72 W). 38% (SD) and 44% (W), respectively, were somatostatin-positive, but except for five cases having a focal to multifocal, moderate to marked staining, only a few tumor cells were positive for somatostatin in the other cases and the mean staining intensity for somatostatin was low (0.50 SD, 0.84 W). 6% (SD) and 23% (W), respectively, were gastrin-positive, but only one case of a male Wistar rat exhibited a focal strong staining in parts of the tumor. The other cases showed only a few tumor cells which were positive for gastrin. The mean staining intensity for gastrin was low (0.06 SD, 0.35 W). In all tumors with marked glucagon, somatostatin or gastrin expression, the immunostaining for insulin was still predominating. Thus, insulin was the major hormone produced by most of the tumor cells. Five out of 77 tumors evaluated were immunohistologically negative with all applied antibodies. CONCLUSION: This study presents the first immunohistochemical survey on spontaneous islet cell carcinomas in SD and Wistar rats stained with antibodies against the endocrine pancreas hormones insulin, glucagon, somatostatin and gastrin. No major differences in incidence or immunohistochemical staining pattern between SD and W-rats could be detected. In contrast to SD rats, Wistar rats had multihormonal coexpression in 16.3%. The multihormonal appearance of the neoplasms is well comparable with the findings in other animal species and human insulinomas. Moreover, this is the first study in rats which reports five cases with a marked co-expression of somatostatin and one case with marked focal co-expression of gastrin in malignant islet cell adenocarcinomas.     

Direct effect of alginate purification on the survival of islets immobilized in alginate-based microcapsules

Alginate purification has been shown to decrease the host immune response to implanted alginate-based microcapsules, but the direct effect of contaminants on islet cell survival remains unknown. Wistar rat islets were immobilized in calcium alginate beads made with crude vs. purified alginate and then incubated in CMRL culture medium. Islet survival was evaluated at 1, 4, 7, 14 and 27 days post-encapsulation. Islet viability was investigated using a dual staining assay (propidium iodide and orange acridine). The islet cell necrosis and the proportion of apoptotic cells were quantified under optical microscopy and with a TUNEL assay, respectively. Islets immobilized in purified alginate were more viable, and had fewer necrotic centers, a smaller area of central necrosis and a lower number of apoptotic cells. At day 14 and 27 post-encapsulation, respectively, 48% and 23% of islets were viable with purified alginate vs. 18% and 8% with crude alginate (p < 0.05). At day 14, the surface area of central necrosis and the number of necrotic islets were more important with the impure alginate (65% vs. 45% and 73% vs. 53%, respectively; p < 0.05). We conclude that alginate purification improves the survival of islets that are immobilized in alginate-based microcapsules. These findings indicate that caution should be taken in the interpretation of in vivo experiments, as the results could be explained by either a direct effect on islet survival or a modification of the host reaction, or both. Moreover, it suggests that the effect on islet viability should be assessed during the development of biomaterials for cell encapsulation.     

Dual effects of prolonged ACTH stimulation on 4-hydroxyaminoquinoline 1-oxide-induced adrenocortical lesions in rats

The effects of a long-acting synthetic ACTH on 4-hydroxyaminoquinoline 1-oxide (4HAQO)-induced adrenocortical lesions were investigated in female rats. A total of 140 6-week-old rats were divided into 4 equal groups, given a single s.c. injection of 7 mg/kg 4HAQO or vehicle, followed by repeated sc administration of the synthetic ACTH or no further treatment. Subgroups of 10 rats in each group were sequentially sacrificed at weeks 20, 30, and 40. Adenomas and adenomatous nodules developed in the adrenal cortex of animals receiving 4HAQO and the chronic ACTH stimulation. Both lesions were located in the deeper zones of the adrenal cortex adjacent to the medulla and were composed of large-sized, clear-type cells. From week 20, middle zone, cortical cystic degeneration, which mimics the age-associated degenerative change named adrenal peliosis, was frequently observed in the adrenal glands of animals treated with 4HAQO alone. Its development was inhibited by ACTH. In the control animals, peliotic changes occurred at low incidence and only at the termination of experiment. These results indicate that long-term stimulation of ACTH promotes the development of adrenocortical tumors but suppresses the occurrence of adrenal peliosis in rats treated with 4HAQO.     

The effects of ad libitum overfeeding and moderate and marked dietary restriction on age-related spontaneous pancreatic islet pathology in Sprague-Dawley rats.

This study compared the effects of ad libitum (AL) overfeeding and moderate or marked dietary restriction (DR) on aged-related degenerative and proliferative changes of the endocrine pancreas in Sprague-Dawley (SD) rats. SD rats were fed Purina Certified Rodent Diet AL (group 1), DR at 72-79% of AL (group 2), DR at 68-72% of AL (group 3) or DR at 47-48% of AL (group 4) for 106 weeks. Interim necropsies were performed at 13, 26, and 53 weeks, after a 7-day 5-bromo-2-deoxyuridine (BrdU)-filled minipump implantation. Before each necropsy, glucose and serum insulin levels were measured. In addition to the routine histopathologic examination performed in both sexes, determination of 9 pancreatic islet stereologic parameters was done in males at 13, 26, and 53 weeks. In AL-fed rats, early changes in the islet morphology occurred, which resulted in a high incidence of islet fibrosis, focal hyperplasias and adenomas by two years. DR was dose-proportionally associated with decreased glucose and serum insulin levels, and delayed the onset, and decreased the incidence and severity of islet fibrosis and hyperplasia. Results of the stereology supported the histopathologic and clinical chemistry findings. It demonstrated that, compared to AL-fed rats, DR-fed rats had smaller pancreas, smaller pancreatic islets, smaller insulin secreting cell volumes, a lower degree of islet fibrosis and a lower islet cell BrdU labeling index, which correlated with a lower incidence of islet adenoma and carcinoma at study termination. Moderate and marked degrees of DR delayed the onset and severity of islet hyperplasia and fibrosis in a temporal- and dose-related manner. In contrast to marked DR, which dramatically prevented these changes, moderate DR delayed but not prevented onset of islet tumors. These findings support the concept that moderate DR results in a better-controlled animal model with a lower incidence or delayed onset of chronic spontaneous endocrine diseases in the rat bioassay.     

针刺提高2型糖尿病模型大鼠胰岛β细胞胰岛素的表达

背景：针刺治疗2型糖尿病具有很好的疗效。 目的：观察针刺对2型糖尿病模型大鼠胰岛β细胞胰岛素表达的影响。 方法：将糖尿病模型大鼠按随机化原则分为针刺组、西药组、模型组,同时设置正常对照组。针刺组大鼠取足三里、内庭和胰俞穴给予针刺治疗,西药组用罗格列酮0.2 mg/kg灌胃,模型组用双蒸水2 mL/kg灌胃,均1次/d,连续4周。 结果与结论：①血糖：针刺组明显低于模型组、西药组(P < 0.05)。②血脂：针刺组胆固醇和三酰甘油低于模型组 (P < 0.05);高密度脂蛋白胆固醇明显高于模型组(P < 0.01)。针刺组三指标与西药组比较差异无显著性意义。③胰岛β细胞胰岛素表达：针刺组显著高于模型组和西药组(P < 0.05)。④胰岛形态：模型组与西药组胰岛结构不完整,结构破坏,胰岛素染色效果差;针刺组胰岛结构趋向完整,胰岛素染色颗粒明显。说明针刺可显著提高2型糖尿病模型大鼠胰岛β细胞胰岛素表达水平,有效改善胰岛β细胞功能。     

Sequential alteration of apoptosis, p53 expression, and cell proliferation in the rat pancreas treated with 4-hydroxyaminoquinoline 1-oxide

Changes in p53 expression, apoptosis and cell proliferation after treatment with 4-hydroxyaminoquinoline 1-oxide (4HAQO) were investigated in the rat pancreas and liver, target and nontarget organs for tumorigenesis, respectively. Male rats were given a single intravenous injection of 4HAQO at a dose of 20 mg/kg body weight and control rats received vehicle alone and were euthanized after 2-72 hours. Pancreata and livers were removed for histopathological examination, immunohistochemistry for p53 protein, PCNA and Ki-67, and TUNEL labeling and electron microscopic observation for detecting apoptosis. In the pancreas, p53 expression and apoptosis were significantly increased first at 4 and 6 hours, respectively, while no change was evident in the liver. The rates peaked at 24 hours, consistent with the peak for PCNA-labeling, while Ki-67-labeling rates peaked at 72 hours. Electron microscopically, apoptotic changes in pancreatic acinar cells were observed after 2 hours. No significant apoptosis, p53 expression or cell proliferation were noted in the pancreatic tissues of the control rats nor in liver cells regardless of 4HAQO treatment. Taken together with our previous data, the results suggest that apoptosis, p53 expression, and enhanced cell replication are closely related phenomena involved in the carcinogenesis of 4HAQO following DNA adduct formation.     

长期高脂喂养大鼠胰岛功能改变与胰岛炎症反应有关

目的： 观察长期高脂喂养诱导的胰岛素抵抗大鼠胰岛炎症反应水平,并探讨其与胰岛功能改变的关联及机制。方法: 8周龄的Wistar大鼠随机分为正常对照组（NC,n=15）和高脂组（HF,n=15）,分别给予普通饲料及高脂饲料喂养。24周后行高胰岛素正葡萄糖钳夹试验检测胰岛素敏感性,行静脉葡萄糖耐量试验(IVGTT)检测β细胞功能,以免疫组化法检测胰岛β细胞内胰岛素相对含量（IRC）以及胰岛内NF-κB与caspase-3的相对浓度,以TUNEL法检测胰岛内细胞凋亡水平,以RT-PCR法检测胰岛内胰岛素原(INS)及白细胞介素（IL）-1β mRNA的相对表达量。结果: HF组葡萄糖输注率（GIR）较NC组显著降低［(5.32±0.90) mg·kg-1·min-1 vs (7.80±0.51) mg·kg-1·min-1,P<0.01］;NC组葡萄糖负荷后胰岛素分泌高峰出现于第5 min,而HF组延迟至第10 min,且10-60 min胰岛素曲线下面积（AUCI）较NC组增加了67.7％（P<0.01）。免疫组化显示,HF组IRC较NC组减少了25.6%,NF-κB、 caspase-3相对含量及单位面积胰岛凋亡细胞数分别增加20.5％、19.1%及2.43倍(均P<0.01)。HF组胰岛IL-1β mRNA相对表达量较NC组增加了1.95倍(P<0.01),INS mRNA 表达水平增加了12.0％（P<0.05）。结论: 长期高脂喂养诱导的胰岛素抵抗大鼠胰岛存在炎症反应,可能通过NF-κB及其介导的凋亡信号通路,与早期胰岛结构及功能损害有关。     

Down-Regulation of Renal Gluconeogenesis in Type II Diabetic Rats Following Roux-en-Y Gastric Bypass Surgery: A Potential Mechanism in Hypoglycemic Effect

ObjectiveThis study was initiated to evaluate the effects of Roux-en-Y gastric bypass surgery on renal gluconeogenesis in type 2 diabetic rats and its relationship with hormonal parameters.MethodsDiabetic rats were induced by intraperitoneal injection of streptozotocin (STZ; 35 mg/kg) combined with a high-fat diet. They were then randomly divided into three groups: diabetes model group (DM group, n = 8), sham Roux-en-Y gastric bypass group (SRYGB group, n = 8), and Roux-en-Y gastric bypass group (RYGB group, n = 14). Another 8 normal rats comprised the normal control group (NC group, n = 8). Body weight, glucose, serum lipid, insulin, glucagon-like peptide-1 (GLP-1), leptin, and adiponectin were measured pre- and postoperatively. Glucose-6-phosphatase (G6Pase), phosphoenolpyruvate carboxykinase (PEPCK), insulin receptor-α (IR-α), insulin receptor-β (IR-β), and glycogen synthase kinase 3 beta (Gsk3b) were measured in renal cortex by using RT-PCR and Western immune-blot analyses on the 4th week after operation.ResultsFollowing RYGB surgery, surgery-treated rats showed significantly improved oral glucose tolerance, dyslipidemia and insulin resistance as well as increased post-gavage insulin levels and serum circulating levels of GLP-1 and adiponectin. RT-PCR and Western immune-blot analyses showed PEPCK and G6Pase protein and mRNA to be significantly decreased in the renal cortex in the RYGB group (p < 0.05 vs. DM or SRYGB group); in addition, IR-α and Gsk3b phosphorylation levels increased in the RYGB group (p < 0.05 vs. DM or SRYGB group).ConclusionDown-regulation of renal gluconeogenic enzymes might be a potential mechanism in hypoglycemia. An improved insulin signal pathway in the renal cortex and increased circulating adiponectin concentrations may contribute to the decline of renal gluconeogenesis following RYGB surgery.Key Words: Type 2 diabetes mellitus, Gluconeogenesis, Gastric bypass surgery, Insulin, Adiponectin     

Immunohistochemical investigation of F344/N rat islet cell tumors from national toxicology program studies

In this study, we have investigated the immunoexpression of peptide hormones and mediators associated with human islet cell tumors in a group of proliferative islet cell lesions in F344 rats including islet cell hyperplasias, adenomas, and carcinomas, as defined by conventional histopathologic criteria. All proliferative islets expressed synaptophysin, although decreased expression intensity was observed in hyperplasias and adenomas. Most of the proliferative lesions expressed insulin, which generally decreased as lesions progressed toward malignancy. The distribution of glucagon, somatostatin, and gastrin-expressing cells was altered in proliferative islet lesions but did not comprise a large proportion of cells. Islet cell tumors were associated with increased nuclear expression of cyclin-dependent kinase 4 as well as increased proliferating cell nuclear antigen and decreased β-catenin expression. c-Myelocytomatosis oncogene expression was variable. This is the first study to describe the immunophenotype of islet cell tumors in the F344 rat and to show that islet cell tumors in the F344 rat exhibit similarities in protein expression to the human counterpart.     

Reduced Food Intake is the Major Contributor to the Protective Effect of Rimonabant on Islet in Established Obesity-Associated Type 2 Diabetes

Purpose

Although the presence of cannabinoid type 1 (CB1) receptor in islets has been reported, the major contributor to the protective effect of rimonabant on islet morphology is unknown. We determined whether the protective effect of rimonabant on pancreatic islet morphology is valid in established diabetes and also whether any effect was independent of decreased food intake.

Materials and Methods

After diabetes was confirmed, Otsuka Long-Evans Tokushima Fatty rats, aged 32 weeks, were treated with rimonabant (30 mg/kg/d, rimonabant group) for 6 weeks. Metabolic profiles and islet morphology of rats treated with rimonabant were compared with those of controls without treatment (control group), a pair-fed control group, and rats treated with rosiglitazone (4 mg/kg/d, rosiglitazone group).

Results

Compared to the control group, rats treated with rimonabant exhibited reduced glycated albumin levels (p<0.001), islet fibrosis (p<0.01), and improved glucose tolerance (p<0.05), with no differences from the pair-fed control group. The retroperitoneal adipose tissue mass was lower in the rimonabant group than those of the pair-fed control and rosiglitazone groups (p<0.05). Rimonabant, pair-fed control, and rosiglitazone groups showed decreased insulin resistance and increased adiponectin, with no differences between the rimonabant and pair-fed control groups.

Conclusion

Rimonabant had a protective effect on islet morphology in vivo even in established diabetes. However, the protective effect was also reproduced by pair-feeding. Thus, the results of this study did not support the significance of islet CB1 receptors in islet protection with rimonabant in established obesity-associated type 2 diabetes.     

骨髓间充质干细胞体外诱导分化为胰岛样细胞的降血糖作用

背景：移植胰岛及胰岛细胞治疗糖尿病已初见成效,但由于胰岛来源匮乏和免疫排斥反应而研究受阻。 目的：移植将大鼠骨髓间充质干细胞在体外诱导分化为胰岛样细胞,观察其对糖尿病大鼠的治疗作用。 方法：将大鼠骨髓间充质干细胞用碱性成纤维细胞生长因子、肝细胞生长因子等诱导,免疫细胞染色等检测诱导情况。SD大鼠腹腔注射链脲佐菌素建立糖尿病模型,建模成功后,随机分为对照组移植诱导胰岛样细胞的实验组,实验组经肾包囊移植诱导后的胰岛样细胞,对照组移植相同体积生理盐水,观察移植后糖尿病大鼠血糖和体质量变化。 结果与结论：大鼠骨髓间充质干细胞体外经肝细胞生长因子、碱性成纤维细胞生长因子等因子诱导后可以向胰岛样细胞转化。细胞移植后,对照组大鼠血糖无明显变化(P > 0.05),实验组大鼠血糖与对照组和移植前相比较,明显降低(P < 0.05)。大鼠骨髓间充质干细胞经含肝细胞生长因子、碱性成纤维细胞生长因子等的诱导体系可诱导成胰岛样细胞,经诱导的细胞有一定胰岛素分泌能力,将诱导后细胞通过肾包囊途径移植入糖尿病大鼠体内,可降低大鼠血糖水平。     

Cystic cholangiomas after transplantation of pancreatic islets into the livers of diabetic rats

Islet transplantation is increasingly used as a therapy for human type 1 diabetes mellitus. In our study, we investigated the effect of the transplantation of a low number (n=350) of pancreatic islets into the right liver part on the neighboring portal bile ducts. Male streptozotocin- diabetic Lewis or autoimmune-diabetic BB/Pfd rats (n=1065) were subdivided into 11 experimental groups. A few days after low-number islet transplantation, cholangiocytes adjacent to the grafts showed an increase in proliferative activity. During the next 12–24 months, many peri-insular ductules progressed via tumor-like cystic lesions to large cystic cholangiomas, accompanied by a translocation of the insulin receptor into the cytoplasm and an increase in expression of insulin-related signaling proteins (Insulin-receptor-substrate-1, Raf-1, Mek-1). After 24 months, 53% of rats with low-number transplantation exhibited at least one cholangioma >10 mm, significantly outnumbering tumor development in the transplant-free left liver part and in any control group. No cholangiocarcinomas emerged. A graft cell origin of the tumors was excluded by Y chromosome in situ hybridization in cross-gender transplantations. Conclusively, low-number intrahepatic islet transplantation, most likely acting by permanent local hyperinsulinism, leads to prolonged cholangiocellular proliferation in streptozotocin- and in autoimmune-diabetic rats, resulting in the development of benign cystic cholangiomas.     

Antigen expression of the pancreatic beta-cells is dependent on their functional state, as shown by a specific, BB rat monoclonal autoantibody IC2

Antigen expression is studied corresponding to a monoclonal autoantibody (IC2) derived from a hybridoma of rat myeloma Y3 cells and splenocytes of the diabetic BB rat. The selective reactivity of IC2 with islet cells has earlier been proven. We studied the possible specificity for beta islet cells, and the possible variation in autoantigen expression. Islet cells were isolated by cautious collagenase and dispase treatment. The cells were labelled with IC2 alone or together with anti-insulin immunoglobulin in double-labelling experiments. Extensive series of cells were examined by immunofluorescence microscopy, and some samples also by flow cytometry. In double-labelling examinations we found that only anti-insulin positive cells could bind the IC2 antibody, thus showing beta-cell selectivity. On the other hand, not all anti-insulin positive cells were IC2-positive. Since insulin treatment has been shown to decrease the incidence of diabetes in the BB rat, islet cells were examined after reduced beta-cell strain. Islet cells from Lewis and Wistar Furth rats display 21.4 +/- 1.4% IC2-positive cells, while islet cells from 24-hour fasting animals showed 7.0 +/- 1.4% (p less than 0.0001). Similar results were seen for BALB/c mice (25.0 +/- 1.8% vs. 13.7 +/- 2.3%, p less than 0.002). Also, after a week of insulin treatment, autoantigen expression was significantly decreased. Thus, the IC2 antibody is beta-cell-specific, and expression of the corresponding cell surface antigen depends on the functional state of the beta-cells.     

Magnesium and other bivalent cations influence upon sodium montelukast effect in experimental-induced thermoalgesia

We tested the influence of magnesium, zinc and copper upon the montelukast (MK, antagonist of cysteinyl leukotriene receptor type 1) effect in experimentally-induced thermoalgesia. We worked on 5 groups of 10 adults, each Wistar rats, that received: group I-control; group II: MK (10 mg/kg) unique administration; group III: MgCl2 (1 mM/kg/day) i.p., 3 days and MK (10 mg/kg) unique administration on the 3rd day; group IV: ZnCl2, (0.1 mM/kg/day), i.p., 3 days and MK (10 mg/kg) unique administration on the 3rd day; group V: copper acetate (0.05 mM/kg/day), i.p., 3 days and MK (10 mg/kg) unique administration on the 3rd day. We determined the thermoalgesic sensitivity (TS) using a tail flick analgesia meter, initially, 3 days after daily cation administration and 3 hours after MK administration. Our data show that MK has a statistically significant reduction of TS vs control group (3.76 +/- 1.04 s vs 1.81 +/- 0.98 s, p < 0.05). Copper and magnesium administration do not significantly change the MK effect to decrease TS. The co-administration of zinc and MK statistically significantly increased the TS of the group that received only MK (2.51 +/- 0.21 s vs 3.76 +/- 1.04 s, p < 0.05). Animals that received only cations (in the above mentioned doses) did not significantly change TS.     

Increased albumin concentration reduces apoptosis and improves functionality of human islets

Providing sufficient islet mass is important for successful islet transplantation. Apoptosis plays a major role in post-isolation islet cell death, and prevention of apoptosis could improve transplant outcomes. The purpose of this study was to determine whether increased concentration of human albumin (HA) in pre-transplantation culture of human islets would reduce apoptosis. Human islets were cultured in CMRL with 1.5 or 5% of HA for 24 h and apoptosis was evaluated indirectly by measuring caspase 3 activity and tetramethylrhodamine-ethyl-ester (TMRE) in dissociated islets. Islet function and viability were evaluated. Islets cultured in higher albumin concentration presented with lower caspase 3 activity (43.9 +/- 3.9 vs. 67.4 +/- 11.1, p = 0.011), and had increased insulin secretory capacity (Stimulation index 3.76 +/- 0.91 vs 1.23 +/- 0.21, p = 0.023). We conclude that an increase in albumin concentration can prevent apoptosis in isolated human islets. These findings may have implications for islet transplant outcomes.     

Correlation of histologic subtypes and replication error phenotype with comparative genomic hybridization in gastric cancer

To characterize phenotypic and genotypic changes in gastric cancer (GC), DNA copy number aberrations (CNAs) were assessed in 53 tumors using comparative genomic hybridization (CGH) and correlated with clinicopathologic characteristics and status of TP53 and replication error (RER). The number of CNAs per tumor was 6.8 (gain 5.3, loss 1.5), and the number of changes was significantly higher in tumors with advanced stage, TP53 mutation, and without RER than in those with early stage (7.7 vs. 3.0), no TP53 mutations (12.4 vs. 4.8) or RER phenotype (8.2 vs. 2.6). Frequent abnormalities included gains on chromosomal arms 8q (43%), 6q (26%), 11q (26%), 13q (24%), 7p (23%), 17q (23%), and 20q (23%), and losses on chromosomal arms 16q (26%), 19p (23%), 5q (19%), 3p (15%), 4q(15%), and 1p (15%). Advanced GC demonstrated a higher prevalence of gains of 8q (51% vs. 10%, P < 0.05) and loss of 16q (33% vs. 0%, P < 0.05) than early GC. Gains on 8q (64% vs. 20%, P < 0.05), 17q (39% vs. 4%, P < 0.05) and losses on 3p (25% vs. 4%, P = 0.05) and 5q (32% vs. 4%, P < 0.05) were higher in intestinal GC than in diffuse GC. On the other hand, gains on 13q were more common in the diffuse type (40% vs. 11%, P < 0.05). As compared with noncardia cancer, cardia cancer showed more gains on 7p (58% vs. 12%, P < 0.05) and 20q (58% vs. 12%, P < 0.05) and more losses on 4q (50% vs. 5%, P < 0.05). The finding of histology-related aberrations and the combination of CGH and molecular data thus provide additional evidence suggesting genetic heterogeneity of GC.     

Islet cell autoantibodies in cord blood from children with blood group incompatibility or hyperbilirubinemia

Blood group incompatibility is a risk factor for type 1 diabetes. Our aim was to test the hypothesis that islet cell autoantibodies, as markers for beta cell autoimmunity, are increased in cord blood from newborns with a diagnosis of blood group incompatibility. Using the diagnosis register of the Malm? University Hospital we obtained cord blood from 151 children with ABO immunization, 311 children with hyperbilirubinemia and a control group of 320 other children born during the same time period. The cord blood samples were analyzed for islet cell antibodies (ICA) by indirect immunofluorescence and autoantibodies against the Islet Cell Antigen-2 (IA-2Ab) and the 65 kDa isoform of glutamic acid decarboxylase (GAD65Ab) by standard radioligand binding assays. The prevalence of ICA was increased compared to controls (0.6%) not only in children with ABO immunization (4.0%, p = 0.02), but also in newborn children with hyperbilirubinemia (4.2%, p = 0.003). The prevalence of IA2Ab, but not of GAD65Ab, was increased in children with ABO immunization (3.3%) compared to the hyperbilirubinemia group without incompatibility (0.6%, p = 0.04), or the controls (0.3%, p = 0.02). Our findings that hyperbilirubinemia is associated with an increased prevalence of ICA, and blood group incompatibility with both ICA and IA-2, suggests that intra-uterine factors may be associated with islet cell autoimmunity.     

Selective cyclooxygenase-2 inhibitor prevents cisplatin-induced tumorigenesis in A/J mice

Cisplatin is used to treat lung cancer; however, it is also a known carcinogen. Cyclooxygenase-2 (COX-2) inhibitors have been shown to prevent carcinogen-induced experimental tumors. We investigated the effect of a COX-2 inhibitor, celecoxib, on cisplatin-induced lung tumors. One hundred twenty 4-week-old A/J mice were divided into 6 groups: group 1, no treatment; group 2, low-dose celecoxib (150 mg/kg); group 3, high-dose celecoxib (1,500 mg/kg); group 4, cisplatin alone; group 5, cisplatin plus low-dose celecoxib;and group 6, cisplatin plus high-dose celecoxib. Mice in groups 4-6 were administered cisplatin (1.62 mg/kg, i.p.) once a week for 10 weeks between 7 and 16 weeks of age. All mice were sacrificed at week 30. Tumor incidence was 15.8% in group 1, 25% in group 2, 26.3% in group 3, 60% in group 4, 50% in group 5, and 50% in group 6. Tumor multiplicity was 0.2, 0.3, 0.3, 1.3, 1.0, and 0.6 in groups 1-6, respectively. Tumor multiplicity in the cisplatin-treated mice was reduced by celecoxib treatment in a dose-dependent manner (p < 0.05, group 4 vs. group 6). Celecoxib significantly reduced COX-2 expression in cisplatin-induced tumors (p < 0.01, group 4 vs. group 6).     

Glutamic acid decarboxylase antibodies are more frequent than islet cell antibodies in islet transplanted IDDM patients and persist or occur despite immunosuppression

Pancreatic islet grafts transplanted into patients with autoimmune diabetes are potentially threatened by two immune responses, allograft rejection and the recurrence of autoimmune insulitis. In the present study we investigated the humoral autoimmune response directed to islet autoantigens by studying islet cell antibodies and glutamic acid decarboxylase (GAD 65) antibodies in twenty-one insulin-dependent diabetes-mellitus (IDDM) patients undergoing intraportal islet allotransplantation. Islet transplantation was performed according to the following recipient categories: Islet after kidney transplantation (n=10), simultaneous islet and kidney transplantation (n=6) and islet transplant alone (n=5). GAD 65 antibodies were detected in a radioligand GAD 65 antibody assay using recombinant, in vitro translated, human ³⁵S-methionin labelled GAD 65 as tracer. Islet cell antibodies were determined by indirect immunofluorescence technique on human pancreas. In six out of twenty-one patients we observed GAD 65 antibodies before islet transplantation and the GAD 65 antibodies persisted despite immunosuppression. In contrast only two subjects were concordantly islet cell antibody positive and the titre decreased post transplantation. In addition we observed occurrence of GAD 65 antibodies in five subjects that were shown to be antibody negative before islet transplantation with three of them subsequently becoming positive for islet cell antibodies. The remaining ten patients were GAD 65 antibody and islet cell antibody negative before islet transplantation and remained negative thereafter. Interestingly none of the patients was exclusively positive for islet cell antibodies without being positive for GAD 65 antibodies. In summary we have demonstrated in twenty-one islet grafted individuals that humoral autoimmunity to islet antigens can persist or occur despite immunosuppression. Islet cell antibodies appear to be less frequent (5 out of 21, 23%) compared to GAD 65 antibodies (11 out of 21, 52%) suggesting that they are more affected by immunosuppressive therapy. We conclude that GAD 65 antibodies are a useful tool to further evaluate a possible link between persistent autoimmunity and early or late graft failure after islet transplantation.