[The syndrome of inappropriate diuretic hormone secretion (SIADH) ending lethal during the use of paliperidon and lamotrigine]. / Het syndroom van inadequate secretie van het antidiuretisch hormoon (SIADH) met letale afloop tijdens gebruik van paliperidon en lamotrigine.

Hyponatremia, as a result of the syndrome of inappropriate antidiuretic hormone secretion (SIADH), is well known with the use of nearly all antipsychotics and mood stabilizers. The first symptoms are atypical and are not always mentioned by the patient. However, not recognising the syndrome in due time can be lethal. We describe a 35-year-old woman who died due to lack of recognition of SIADH. The patient, who had a bipolar disorder and was for a long time on a paliperidone depot, developed complaints of nausea, vomiting and thirst after lamotrigine was prescribed. A few days after increasing the dose, she died; no evidence was found of suicide. The SIADH was probably triggered by the use of lamotrigine and paliperidone. Paying sufficient attention to the symptoms that may cause this syndrome, as well as their early recognition, could save lives.

[Downbeat nystagmus - a rare side-effect of lithium carbonate]. / Downbeatnystagmus als zeldzame bijwerking van lithiumcarbonaat.

A 52-year-old woman who had been treated with lithium carbonate for 10 years developed a downbeat nystagmus. The literature describes downbeat nystagmus as a rare side-effect of lithium carbonate. In this patient other causes of downbeat nystagmus were ruled out. In most cases stopping lithium carbonate does not alleviate the symptoms, which are often debilitating. At the moment there is no adequate treatment for the condition. In some cases, however, the symptoms subside after the patient stops taking lithium. Therefore, we consider that early recognition of downbeat nystagmus in patients being treated with lithium carbonate is vitally important.

[Monumental books by Jelgersma and Rümke]. / Monumentale boeken van Jelgersma en Rümke en invloeden op hun werk.

BACKGROUND: Now that we are in the DSM-5 period, interest in the older psychiatric literature seems to be gradually waning. AIM: To provide a brief survey of important books by Jelgersma and Rümke, to show how these authors were influenced by Kraepelin, Bleuler, Jaspers, Lombroso and Pavlov, and thereby demonstrate how the older literature helped to shape the development of psychiatry. METHOD: The study is based on a selection of the older psychiatric literature in book form. RESULTS: It is evident that even today much of the older literature is still influencing current concepts and descriptions of symptoms and the development of concepts such as schizophrenia, and is still guiding psychiatrists on the best moment to begin psychiatric treatment. CONCLUSION: The older psychiatric literature should not be forgotten or overlooked. It is an invaluable source of in-depth knowledge about psychiatry.

Recurrence-free survival more than 10 years after liver resection for hepatocellular carcinoma.

BACKGROUND: High recurrence rates after liver resection with curative intent for hepatocellular carcinoma (HCC) remain a problem. The characterization of long-term survivors without recurrence after liver resection may help improve the therapeutic strategy for HCC. METHODS: A nationwide Japanese database was used to analyse 20 811 patients with HCC who underwent liver resection with curative intent. RESULTS: The 10-year recurrence-free survival rate after liver resection for HCC with curative intent was 22.4 per cent. Some 281 patients were recurrence-free after more than 10 years. The HCCs measured less than 5 cm in 83.2 per cent, a single lesion was present in 91.7 per cent, and a simple nodular macroscopic appearance was found in 73.3 per cent of these patients; histologically, most HCCs showed no vascular invasion or intrahepatic metastases. Multivariable analysis revealed tumour differentiation as the strongest predictor of death from recurrent HCC within 5 years. CONCLUSION: Long-term recurrence-free survival is possible after liver resection for HCC, particularly in patients with a single lesion measuring less than 5 cm with a simple nodular appearance and low tumour marker levels.

[The complexity of repatriating psychiatric patients]. / Complexe psychiatrische repatriëring.

This article describes the method by which the repatriation to the Netherlands of psychiatric patients living abroad is carried out. On the basis of one case, namely that of a psychotic male with low Hb and fear of HIV, it is shown that the repatriation of psychiatric patients can be extremely complex and that a psychiatrist's active involvement in the patient's repatriation can be extremely important.

Effector cells in allelic H-2 class I-incompatible skin graft rejection.

The cellular mechanisms of skin graft rejection with allelic H-2 class I differences were studied by examining the effect on graft survival of in vivo administration of anti-Lyt-2.2 mAb, anti-L3T4 mAb, or both to recipient mice. The injections of anti-Lyt-2.2 mAb and anti-L3T4 mAb caused selective depletions of Lyt-2+ cells and L3T4+ cells, respectively. Injection of anti-Lyt-2.2 mAb significantly prolonged graft survival in 7 of 12 combinations of H-2D-end difference, but did not prolong graft survival in 5 other combinations of H-2D-end difference, or in 2 combinations of H-2K-end difference. Injection of anti-L3T4 mAb did not prolong graft survival in any combinations with class I difference tested. Injection of anti-L3T4 mAb plus anti-Lyt-2.2 mAb markedly prolonged graft survival in the combinations with class I difference in which anti-Lyt-2.2 mAb had no effect and overcame the effect of anti-Lyt-2.2 mAb in those in which anti-Lyt-2.2 mAb had an effect in prolonging graft survival. These results indicated that in combinations in which anti-Lyt-2.2 mAb did not prolong graft survival, class I antigen stimulated L3T4+ effector cells when Lyt-2+ cells were blocked and Lyt-2+ effector cells when L3T4+ cells were blocked. On the other hand, in the combinations in which anti-Lyt-2.2 mAb prolong graft survival, these antigens initially caused preferential stimulation of Lyt-2+ but not L3T4+ effector cells, although delayed activation of L3T4+ effector cells occurred when Lyt-2+ cells were blocked. Furthermore, a significant correlation was found between the effect of anti-Lyt-2.2 mAb in prolonging graft survival and the failure of recipient mice to produce H-2 antibody. These results can be taken as evidence that L3T4+ effector cells are not involved in the initial phase of graft rejection in these combinations.

Differential involvement of CD4+ cells in mediating skin graft rejection against different amounts of transgenic H-2K(b) antigen.

Differential involvement of CD4+ cells in mediating class I-disparate skin graft rejection was investigated using quantitatively different Kb transgenic mice as donors under conditions in which CD8+ cells were blocked in vivo by administration of anti-CD8 monoclonal antibody (mAb). Tg.H-2Kb-1 and -2 are C3H transgenic mice with 14 and 4 copies, respectively, of the H-2Kb gene. Cell surface expression of Kb antigen and the Kb antigenicity of skin for eliciting graft rejection with homozygous and heterozygous transgenic mice were correlated with the copy number. In vivo administration of anti-Lyt-2.1 (CD8) mAb markedly prolonged survival of heterozygous and homozygous C3H Tg.H-2Kb-2 skin grafted onto C3H mice, but prolonged survival of heterozygous Tg.H-2Kb-1 skin grafts much less and did not prolong survival of homozygous Tg.H-2Kb-1 grafts. Administration of anti-L3T4 (CD4) mAb alone did not have any effect on skin graft rejection. Administration of anti-L3T4 (CD4) mAb with anti-Lyt-2.1 (CD8) mAb blocked rejection in all combinations. These findings indicate that a quantitative difference of class I antigen caused differential activation of CD4+ cells under conditions in which CD8+ cells were blocked.

Activation of Wnt/beta-catenin signalling pathway induces chemoresistance to interferon-alpha/5-fluorouracil combination therapy for hepatocellular carcinoma.

Type I IFN receptor type 2 (IFNAR2) expression correlates significantly with clinical response to interferon (IFN)-alpha/5-fluorouracil (5-FU) combination therapy for hepatocellular carcinoma (HCC). However, some IFNAR2-positive patients show no response to the therapy. This result suggests the possibility of other factors, which would be responsible for resistance to IFN-alpha/5-FU therapy. The aim of this study was to examine the mechanism of anti-proliferative effects of IFN-alpha/5-FU therapy and search for a biological marker of chemoresistance to such therapy. Gene expression profiling and molecular network analysis were used in the analysis of non-responders and responders with IFNAR2-positive HCC. The Wnt/beta-catenin signalling pathway contributed to resistance to IFN-alpha/5-FU therapy. Immunohistochemical analysis showed positive epithelial cell adhesion molecule (Ep-CAM) expression, the target molecule of Wnt/beta-catenin signalling, only in non-responders. In vitro studies showed that activation of Wnt/beta-catenin signalling by glycogen synthesis kinase-3 inhibitor (6-bromoindirubin-3'-oxime (BIO)) induced chemoresistance to IFN-alpha/5-FU. BrdU-based cell proliferation ELISA and cell cycle analysis showed that concurrent addition of BIO and IFN-alpha/5-FU significantly to hepatoma cell cultures reduced the inhibitory effects of the latter two on DNA synthesis and accumulation of cells in the S-phase. The results indicate that activation of Wnt/beta-catenin signalling pathway induces chemoresistance to IFN-alpha/5-FU therapy and suggest that Ep-CAM is a potentially useful marker for resistance to such therapy, especially in IFNAR2-positive cases.

A randomised phase III trial comparing gemcitabine with surgery-only in patients with resected pancreatic cancer: Japanese Study Group of Adjuvant Therapy for Pancreatic Cancer.

BACKGROUND: This multicentre randomised phase III trial was designed to determine whether adjuvant chemotherapy with gemcitabine improves the outcomes of patients with resected pancreatic cancer. METHODS: Eligibility criteria included macroscopically curative resection of invasive ductal carcinoma of the pancreas and no earlier radiation or chemotherapy. Patients were randomly assigned at a 1 : 1 ratio to either the gemcitabine group or the surgery-only group. Patients assigned to the gemcitabine group received gemcitabine at a dose of 1000 mg m(-2) over 30 min on days 1, 8 and 15, every 4 weeks for 3 cycles. RESULTS: Between April 2002 and March 2005, 119 patients were enrolled in this study. Among them, 118 were eligible and analysable (58 in the gemcitabine group and 60 in the surgery-only group). Both groups were well balanced in terms of baseline characteristics. Although heamatological toxicity was frequently observed in the gemcitabine group, most toxicities were transient, and grade 3 or 4 non-heamatological toxicity was rare. Patients in the gemcitabine group showed significantly longer disease-free survival (DFS) than those in the surgery-only group (median DFS, 11.4 versus 5.0 months; hazard ratio=0.60 (95% confidence interval (CI): 0.40-0.89); P=0.01), although overall survival did not differ significantly between the gemcitabine and surgery-only groups (median overall survival, 22.3 versus 18.4 months; hazard ratio=0.77 (95% CI: 0.51-1.14); P=0.19). CONCLUSION: The current results suggest that adjuvant gemcitabine contributes to prolonged DFS in patients undergoing macroscopically curative resection of pancreatic cancer.

Regulation mechanism of ERM (ezrin/radixin/moesin) protein/plasma membrane association: possible involvement of phosphatidylinositol turnover and Rho-dependent signaling pathway.

The ERM proteins, ezrin, radixin, and moesin, are involved in the actin filament/plasma membrane interaction as cross-linkers. CD44 has been identified as one of the major membrane binding partners for ERM proteins. To examine the CD44/ERM protein interaction in vitro, we produced mouse ezrin, radixin, moesin, and the glutathione-S-transferase (GST)/CD44 cytoplasmic domain fusion protein (GST-CD44cyt) by means of recombinant baculovirus infection, and constructed an in vitro assay for the binding between ERM proteins and the cytoplasmic domain of CD44. In this system, ERM proteins bound to GST-CD44cyt with high affinity (Kd of moesin was 9.3 +/- 1.6nM) at a low ionic strength, but with low affinity at a physiological ionic strength. However, in the presence of phosphoinositides (phosphatidylinositol [PI], phosphatidylinositol 4-monophosphate [4-PIP], and phosphatidylinositol 4.5-bisphosphate [4,5-PIP2]), ERM proteins bound with a relatively high affinity to GST-CD44cyt even at a physiological ionic strength: 4,5-PIP2 showed a marked effect (Kd of moesin in the presence of 4,5-PIP2 was 9.3 +/- 4.8 nM). Next, to examine the regulation mechanism of CD44/ERM interaction in vivo, we reexamined the immunoprecipitated CD44/ERM complex from BHK cells and found that it contains Rho-GDP dissociation inhibitor (GDI), a regulator of Rho GTPase. We then evaluated the involvement of Rho in the regulation of the CD44/ERM complex formation. When recombinant ERM proteins were added and incubated with lysates of cultured BHK cells followed by centrifugation, a portion of the recombinant ERM proteins was recovered in the insoluble fraction. This binding was enhanced by GTP gamma S and markedly suppressed by C3 toxin, a specific inhibitor of Rho, indicating that the GTP form of Rho in the lysate is required for this binding. A mAb specific for the cytoplasmic domain of CD44 also markedly suppressed this binding, identifying most of the binding partners for exogenous ERM proteins in the insoluble fraction as CD44. Consistent with this binding analysis, in living BHK cells treated with C3 toxin, most insoluble ERM proteins moved to soluble compartments in the cytoplasm, leaving CD44 free from ERM. These findings indicate that Rho regulates the CD44/ERM complex formation in vivo and that the phosphatidylinositol turnover may be involved in this regulation mechanism.

Integrative approach for differentially overexpressed genes in gastric cancer by combining large-scale gene expression profiling and network analysis.

Gene expression profiling is a valuable tool for identifying differentially expressed genes in studies of disease subtype and patient outcome for various cancers. However, it remains difficult to assign biological significance to the vast number of genes. There is an increasing awareness of gene expression profile as an important part of the contextual molecular network at play in complex biological processes such as cancer initiation and progression. This study analysed the transcriptional profiles commonly activated at different stages of gastric cancers using an integrated approach combining gene expression profiling of 222 human tissues and gene regulatory dynamic mapping. We focused on an inferred core network with CDKN1A (p21(WAF1/CIP1)) as the hub, and extracted seven candidates for gastric carcinogenesis (MMP7, SPARC, SOD2, INHBA, IGFBP7, NEK6, LUM). They were classified into two groups based on the correlation between expression level and stage. The seven genes were commonly activated and their expression levels tended to increase as disease progressed. NEK6 and INHBA are particularly promising candidate genes overexpressed at the protein level, as confirmed by immunohistochemistry and western blotting. This integrated approach could help to identify candidate players in gastric carcinogenesis and progression. These genes are potential markers of gastric cancer regardless of stage.

Long-term and short-term evaluation of esophageal reconstruction using the colon or the jejunum in esophageal cancer patients after gastrectomy.

For esophageal cancer patients, the gastric tube is the first choice as an esophageal substitute, with the colon or the jejunum being used when the stomach cannot be used. We retrospectively compared these two methods from the viewpoint of peri-operative complications and long-term bodyweight alteration. From 1998 to 2005 53 patients who had undergone subtotal esophagectomy due to thoracic esophageal cancers were given reconstruction with the colon (28 cases) or the jejunum (25 cases). Both intestines were reconstructed via the subcutaneous route and were anastomosed to the internal mammalian artery and vein for a supercharged blood supply. There was no difference in operating time and blood loss. Compared with the colon reconstruction group, the hospital stay of the jejunum reconstruction group was significantly shorter (65 days vs 45 days, P = 0.0120) and the incidence of anastomotic leakage tended to be less (13 cases, 46%vs 6 cases, 24%, P = 0.1507), while other operative morbidity did not differ between the two groups. Bodyweight loss, which is a serious postoperative sequela after esophagectomy, was less in the jejunum group than in the colon group, showing a significant difference at 12 months after surgery. Our retrospective study revealed the jejunum to be superior to the colon for the reconstruction after esophagectomy along with gastrectomy, with respect to anastomotic leakage and bodyweight loss. The next step will be to conduct a prospective large cohort study.

Evaluation of clinical significance of 18F-fluorodeoxyglucose positron emission tomography in superficial squamous cell carcinomas of the thoracic esophagus.

(18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is used for pre-treatment staging and evaluation of response to pre-operative therapy in advanced thoracic esophageal cancers. To evaluate the clinical significance of PET diagnosis of superficial thoracic esophageal cancers, FDG-PET was conducted preoperatively in 41 patients with such cancers without pre-operative therapy. We compared the PET diagnosis with clinicopathological findings with respect to both the primary tumor and lymph node (LN) metastasis. Of the 41 superficial thoracic esophageal cancers, 21 (51.2%) were PET positive for primary tumors. Although tumor length and histological type did not correlate with FDG uptake by primary tumors, non-flat (elevated or depressed) tumors showed significantly stronger FDG uptake than flat ones. Of 28 tumors infiltrating the deep submucosal layer, 19 (67.9%) were PET positive, while only two (15.4%) of 13 tumors infiltrating only the mucosa or shallow submucosal layer were PET positive. Manova identified FDG uptake as the only independent risk factor for deep submucosal invasion (odds ratio, 7.407; P = 0.0279). In 13 patients with pathological LN metastasis, although no LN metastasis was detected by FDG-PET, FDG uptake by the primary tumors was the only risk factor for LN metastasis (P = 0.0318). PET-negative tumors tended to reflect longer disease-free survival than PET-positive tumors, although this was not significant. FDG-PET is useful for detecting tumors infiltrating the middle or deep submucosal layer (sm2/sm3), and for predicting LN metastasis in patients with superficial thoracic esophageal cancers. FDG-PET is helpful for decision-making regarding treatment of such patients.

Interleukin 6 receptor antibody inhibits muscle atrophy and modulates proteolytic systems in interleukin 6 transgenic mice.

The muscles of IL-6 transgenic mice suffer from atrophy. Experiments were carried out on these transgenic mice to elucidate activation of proteolytic systems in the gastrocnemius muscles and blockage of this activation by treatment with the anti-mouse IL-6 receptor (mIL-6R) antibody. Muscle atrophy observed in 16-wk-old transgenic mice was completely blocked by treatment with the mIL-6R antibody. In association with muscle atrophy, enzymatic activities and mRNA levels of cathepsins (B and L) and mRNA levels of ubiquitins (poly- and mono-ubiquitins) increased, whereas the mRNA level of muscle-specific calpain (calpain 3) decreased. All these changes were completely eliminated by treatment with the mIL-6R antibody. This IL-6 receptor antibody could, therefore, be effective against muscle wasting in sepsis and cancer cachexia, where IL-6 plays an important role.

Evaluation of the technical difficulty performing laparoscopic resection of a rectosigmoid carcinoma: visceral fat reflects technical difficulty more accurately than body mass index.

BACKGROUND: In general, visceral fat and adhesion greatly influence the technical difficulty in performing abdominal surgery. Body mass index (BMI) has been widely used to express the degree of obesity, but it does not always properly reflect the degree of visceral fat. This retrospective study investigated the impact of visceral fat on the operation time to examine whether a quantified visceral fat area (VFA) could be used as a sensitive predictor of technical difficulty in performing a laparoscopic resection of rectosigmoid carcinoma. METHODS: Between February 1999 and April 2004, 58 consecutive patients underwent a laparoscopically assisted sigmoidectomy or anterior resection. After a review of the medical charts, the relationship between the operation time and the following variables was analyzed: sex, depth of invasion, approach (medial-to-lateral, lateral-to-medial), subjectively graded degree of visceral fat and adhesion, history of previous abdominal surgery, and BMI. The correlations between VFA, VFA/body surface area (BSA) measured by the "FatScan," software package for quantifying the VFA from the preoperative CT images, and operation time were investigated. Next, the impact of the VFA amount on the early surgical outcome was examined. RESULTS: According to the intraoperative findings, two patients with a severe adhesion required a significantly longer operation time. A history of previous abdominal surgery was not a significant factor in the operation time. Instead, the VFA/BSA had a stronger correlation with the operation time than the BMI. A significantly longer operation time (209 +/- 42 vs 179 +/- 37 min; p = 0.031) was observed for the patients in the high VFA/BSA group (> or =85 cm(2)/m(2)) group than in the normal VFA/BSA group (<85 cm(2)/m(2)). CONCLUSION: For predicting the technical difficulty of performing a laparoscopic resection of rectosigmoid carcinoma, VFA/BSA may be a more useful index than BMI.

Distinct actions and cooperative roles of ROCK and mDia in Rho small G protein-induced reorganization of the actin cytoskeleton in Madin-Darby canine kidney cells.

Rho, a member of the Rho small G protein family, regulates the formation of stress fibers and focal adhesions in various types of cultured cells. We investigated here the actions of ROCK and mDia, both of which have been identified to be putative downstream target molecules of Rho, in Madin-Darby canine kidney cells. The dominant active mutant of RhoA induced the formation of parallel stress fibers and focal adhesions, whereas the dominant active mutant of ROCK induced the formation of stellate stress fibers and focal adhesions, and the dominant active mutant of mDia induced the weak formation of parallel stress fibers without affecting the formation of focal adhesions. In the presence of C3 ADP-ribosyltransferase for Rho, the dominant active mutant of ROCK induced the formation of stellate stress fibers and focal adhesions, whereas the dominant active mutant of mDia induced only the diffuse localization of actin filaments. These results indicate that ROCK and mDia show distinct actions in reorganization of the actin cytoskeleton. The dominant negative mutant of either ROCK or mDia inhibited the formation of stress fibers and focal adhesions, indicating that both ROCK and mDia are necessary for the formation of stress fibers and focal adhesions. Moreover, inactivation and reactivation of both ROCK and mDia were necessary for the 12-O-tetradecanoylphorbol-13-acetate-induced disassembly and reassembly, respectively, of stress fibers and focal adhesions. The morphologies of stress fibers and focal adhesions in the cells expressing both the dominant active mutants of ROCK and mDia were not identical to those induced by the dominant active mutant of Rho. These results indicate that at least ROCK and mDia cooperatively act as downstream target molecules of Rho in the Rho-induced reorganization of the actin cytoskeleton.

Rho and Rab small G proteins coordinately reorganize stress fibers and focal adhesions in MDCK cells.

The Rho subfamily of the Rho small G protein family (Rho) regulates formation of stress fibers and focal adhesions in many types of cultured cells. In moving cells, dynamic and coordinate disassembly and reassembly of stress fibers and focal adhesions are observed, but the precise mechanisms in the regulation of these processes are poorly understood. We previously showed that 12-O-tetradecanoylphorbol-13-acetate (TPA) first induced disassembly of stress fibers and focal adhesions followed by their reassembly in MDCK cells. The reassembled stress fibers showed radial-like morphology that was apparently different from the original. We analyzed here the mechanisms of these TPA-induced processes. Rho inactivation and activation were necessary for the TPA-induced disassembly and reassembly, respectively, of stress fibers and focal adhesions. Both inactivation and activation of the Rac subfamily of the Rho family (Rac) inhibited the TPA-induced reassembly of stress fibers and focal adhesions but not their TPA-induced disassembly. Moreover, microinjection or transient expression of Rab GDI, a regulator of all the Rab small G protein family members, inhibited the TPA-induced reassembly of stress fibers and focal adhesions but not their TPA-induced disassembly, indicating that, furthermore, activation of some Rab family members is necessary for their TPA-induced reassembly. Of the Rab family members, at least Rab5 activation was necessary for the TPA-induced reassembly of stress fibers and focal adhesions. The TPA-induced, small G protein-mediated reorganization of stress fibers and focal adhesions was closely related to the TPA-induced cell motility. These results indicate that the Rho and Rab family members coordinately regulate the TPA-induced reorganization of stress fibers and focal adhesions that may cause cell motility.

alpha-catenin-independent recruitment of ZO-1 to nectin-based cell-cell adhesion sites through afadin.

ZO-1 is an actin filament (F-actin)-binding protein that localizes to tight junctions and connects claudin to the actin cytoskeleton in epithelial cells. In nonepithelial cells that have no tight junctions, ZO-1 localizes to adherens junctions (AJs) and may connect cadherin to the actin cytoskeleton indirectly through beta- and alpha-catenins as one of many F-actin-binding proteins. Nectin is an immunoglobulin-like adhesion molecule that localizes to AJs and is associated with the actin cytoskeleton through afadin, an F-actin-binding protein. Ponsin is an afadin- and vinculin-binding protein that also localizes to AJs. The nectin-afadin complex has a potency to recruit the E-cadherin-beta-catenin complex through alpha-catenin in a manner independent of ponsin. By the use of cadherin-deficient L cell lines stably expressing various components of the cadherin-catenin and nectin-afadin systems, and alpha-catenin-deficient F9 cell lines, we examined here whether nectin recruits ZO-1 to nectin-based cell-cell adhesion sites. Nectin showed a potency to recruit not only alpha-catenin but also ZO-1 to nectin-based cell-cell adhesion sites. This recruitment of ZO-1 was dependent on afadin but independent of alpha-catenin and ponsin. These results indicate that ZO-1 localizes to cadherin-based AJs through interactions not only with alpha-catenin but also with the nectin-afadin system.

Expression and mutation of SMAD4 in poorly differentiated carcinoma and signet-ring cell carcinoma of the colorectum.

Poorly differentiated adenocarcinoma (Por) and signet-ring cell carcinoma (Sig) are rare but highly malignant types of colorectal cancer. To explore their genetic backgrounds we investigated TGF-beta type II receptor (TGF-beta RII) and SMAD4 in the TGF-beta signaling pathway, and to identify their mutator phenotype we examined microsatellite instability (MSI) status. Loss of SMAD4 expression was significantly more frequent in Por (12 of 38; 31%) and Sig (4 of 5; 80%) tumors than in well (Well) and moderately differentiated (Mod) carcinomas (p = 0.04, 0.003, respectively). Mutation of the SMAD4 gene was detected in 2 of 26 Por tumors. MSI was positive in 14 of the 38 Por tumors and in 1 of the 5 Sig tumors, but in none of the Well or Mod tumors examined. We also found mutation of TGF-beta RII, a putative target of MSI, in 10 of 35 Por tumors (28.6%), but in none of 3 Sig tumors. As a whole, about 50% of the Por tumors and 80% of the Sig tumors showed abnormalities of either TGF-beta RII or SMAD4 expression. This suggests that disruption of the TGF-beta signaling pathway may play a central role in the pathogenesis of Por and Sig tumors of the colorectum.

Analysis of chemical modification of RNA from formalin-fixed samples and optimization of molecular biology applications for such samples.

Formalin-fixed archival samples are known to be poor materials for molecular biological applications. We conducted a series of experiments to understand the alterations in RNA in fixed tissue. We found that formalin-fixed tissue was resistant to solubilization by chaotropic agents. However, proteinase K completely solubilized the fixed tissue and enabled the extraction of almost the same amount of RNA as from a fresh sample. The extracted RNA did not show apparent degradation. However, as reported, successful PCR amplification was limited to short targets. The nature of such 'fixed' RNA was analyzed using synthetic homo-oligo RNAs. The heterogeneous increase in molecular weight of the RNAs, measured by MALDI-TOF mass spectrometry, showed that all four bases showed addition of mono-methylol (-CH(2)OH) groups at various rates. The modification rate varied from 40% for adenine to 4% for uracil. In addition, some adenines underwent dimerization through methylene bridging. The majority of the methylol groups, however, could be removed from bases by simply elevating the temperature in formalin-free buffer. This demodification proved effective in restoring the template activity of RNA from fixed tissue. The improvement in PCR results suggested that more than half of the modification was removed by this demodification.