[Neuroendocrine Tumor of the Ampulla of Vater and Gastrointestinal Stromal Tumor of the Duodenum in a Patient with Von Recklinghausen's Disease]

A 57-year-old woman with von Recklinghausen's disease presented with epigastralgia. Gastroduodenoscopy revealed swelling of the ampulla of Vater in the ventral and caudal direction, forming a hard, elastic mass. She was diagnosed with a tumor of the ampulla of Vater, and a subtotal stomach-preserving pancreaticoduodenectomy and D2 lymph node dissection were performed. The isolated specimen showed an intra-ampullary tumor of the ampulla of Vater and a submucosal tumor in the descending duodenum, which were diagnosed as a somatostatin-producing neuroendocrine tumor and gastrointestinal stromal tumor, respectively, on pathological examination. We believe that the neuroendocrine tumor of the ampulla of Vater and gastrointestinal stromal tumor of the duodenum are common gastrointestinal lesions in von Recklinghausen's disease.

Additional Surgery After Non-curative Resection of ESD for Early Gastric Cancer

AIM

The appropriate additional surgery after non-curative resection of Endoscopic Mucosal Resection (ESD) for early gastric cancer is herein discussed.

PATIENTS AND METHODS

Data on 54 patients after non-curative resection of ESD were evaluated. These patients were broadly classified according to the risk of lymph node metastasis with lesions into group A (without risk) (n=26) and group B (with risk) (n=28). Their treatment results were evaluated.

RESULTS

The incidence of residual lesion was 7.7% in group A and 14.3% in group B. Risk factors were piecemeal resection, involvement of the horizontal margin (HM1) or unclear involvement of the horizontal margin (HMX) and with ulceration. Lymph node metastasis was detected in one patient with lymphatic invasion, total diameter of 3 cm or more and submucosal invasion over 0.5 mm (SM2). The 5-year survival rate was 93% and none of the patients died of gastric cancer.

CONCLUSION

Follow-up observation was reasonable in group A. Patients who are judged as having undergone piecemeal resection, HM1 or HMX and with ulceration, should be treated by additional surgery and patients judged with SM2 or total diameter of 3 cm or more or lymphatic invasion should be treated by additional surgery with lymphadectomy in group B.

Randomized comparison of pitavastatin and pravastatin treatment on the reduction of urinary albumin in patients with type 2 diabetic nephropathy

The effect of pitavastatin and pravastatin treatment on renal function was compared in type 2 diabetic patients with nephropathy in a randomized, controlled, open-label, parallel and multi-centre study. Type 2 diabetic patients with modest renal impairment (serum creatinine level <1.4 mg/dl) accompanied by albuminuria (30-600 mg/g creatinine) were randomly assigned to receive 2 mg of pitavastatin (n = 44) or 10 mg of pravastatin (n = 43) for 12 months. At 12 months, pitavastatin significantly reduced urinary albumin-to-creatinine ratio than pravastatin in subjects with macroalbuminuria (-67.2% vs. +14.5%, p = 0.0040), but not in subjects with microalbuminuria. There was no significant difference in the change in estimated glomerular filtration rate between the two groups. Pitavastatin is more effective than pravastatin for the reduction of albuminuria in type 2 diabetic patients with early stage of diabetic nephropathy.

Biliverdin protects against the deterioration of glucose tolerance in db/db mice

AIMS/HYPOTHESIS

We have previously shown a negative correlation between serum bilirubin levels and prevalence of type 2 diabetes, suggesting that bilirubin inhibits development of this disease. To confirm this hypothesis, we investigated whether administration of biliverdin, the precursor of bilirubin, protects against the deterioration of glucose tolerance in db/db mice, a rodent model of type 2 diabetes.

METHODS

Biliverdin (20 mg/kg daily) was orally administered to 5-week-old db/db mice for 4 weeks. After 4 weeks of treatment, i.p. glucose tolerance and insulin tolerance tests were performed. Insulin content was evaluated by immunostaining and ELISA. Oxidative stress markers (8-hydroxy-2'-deoxyguansosine and dihydroethidium staining) and expression of NADPH oxidase components Pdx1 and Bax were also evaluated in isolated islets.

RESULTS

Treatment with biliverdin partially prevented worsening of hyperglycaemia and glucose intolerance in db/db mice. This effect was accompanied by a significant increase in insulin content and Pdx1 expression, and a significant decrease of apoptosis and Bax expression in pancreatic islets from db/db mice. At the same time, levels of oxidative stress markers and NADPH oxidase component production in islets were normalised. Biliverdin had little effect on HOMA of insulin resistance or insulin resistance evaluated by insulin tolerance tests.

CONCLUSIONS/INTERPRETATION

Biliverdin may protect against progressive worsening of glucose tolerance in db/db mice, mainly via inhibition of oxidative stress-induced beta cell damage.

Phase I study of peptide vaccine with chemotherapy in patients with unresectable colorectal cancer

3067

Background: RNF43 is a cancer testis antigen expressed in colorectal cancer (CRC) but not in normal organs. RNF43–721 induces HLA A24 restricted cytotoxic T lymphocytes (CTL) against RNF43 expressed target. S-1/CPT-11 chemotherapy (CT) is reported to be obtained the similar result to FOLFOX or FOLFIRI as first-line for advanced CRC. We plan phase I study to evaluate the safety of different doses of RNF43–721 emulsified with Montanide ISA51 in combination with S-1/CPT-11 CT expecting synergistic effect. Methods: Inclusion criteria as follows: HLA A24 positive, pathological CRC, life expectancy > 3 months, WBC>3000/mm3, Hb>10mg/dl, Plt>75000/mm3, creatinine<1.2mg/dl, T. bil.<1.5mg/dl, AST, ALT<3x normal limits, written informed consent. Other malignancy, infection, treatment with steroids and immunosuppressive agents, and HBV, HCV, HIV infection are excluded. The study design is dose escalation of peptide (0.5, 1.0, 3.0 mg) with three patients’ cohort. The study regimen is that oral administration of S-1 at 40 mg b.i.d. for 21 consecutive days followed by a 7-day rest period and intravenous infusion of CPT-11 at a dose of 80 mg on days 1 and 15 are performed with weekly subcutaneous injection of peptide vaccine. Two courses are study periods and there is no restriction of therapy after study. Primary endpoint is safety and secondary are CTL, objective response rate and TTP. Results: Twelve patients (pts) were enrolled and 3 pts canceled treatment due to patient's proposal. In 9 evaluable pts, median age of pts with 7 males and 2 females was 61. Standard chemotherapy for CRC were failed in 8 pts. Systemic toxicities were observed in one pt with grade 2 and others were grade 1. Skin reactions were occurred in 7 pts. No pts were obtained CR and PR, 6 pts were SD and 3 were PD. CTL response was observed in 5 pts. TTP was calculated as 204 days. Conclusions: Treatment with peptide vaccine and S-1/CPT-11 CT was well tolerated. These results encourage further clinical trials of peptide vaccine with standard CT for advanced CRC.

No significant financial relationships to disclose.

Epidermoid cyst of an accessory spleen at the pancreatic tail: diagnostic value of MRI

We report a rare case of an epidermoid cyst in an accessory spleen at the pancreatic tail. Only 12 cases have been reported. Among the different diagnostic modalities, magnetic resonance imaging was most useful for the differential diagnosis. Precise imaging of the cyst wall and its comparison with the surrounding organs are essential.

Modification of human T-cell responses by altered peptide ligands: a new approach to antigen-specific modification

Human CD4+ T-cells recognize antigenic peptides in the context of human leukocyte antigen (HLA) class II molecules and produce various lymphokines to proliferate and activate other cells. It was once considered that the T-cell response is an all or nothing type event, but recent studies have clearly indicated that T-cells show many different types of activation in recognition of altered ligands for T-cell receptors (TCR). In this review, we summarize our recent findings on the human CD4+ T-cell response to altered peptide ligands (APL); peptides carrying single residue substitutions in antigenic peptides. We observed the following: 1) TCR antagonism for T-cell clones reactive to non-self or autoantigenic peptides, 2) partial activation (agonism) without cell proliferation, including production of lymphokines and increases in cell size, and in expression levels of several cell surface proteins or survival time in the absence of antigenic stimulus, 3) augmentation in cell proliferation and production of interferon-gamma (IFN-gamma) and granulocyte monocyte colony stimulating factor (GM-CSF), 4) augmentation of interleukin (IL)-12 production by antigen presenting cell (APC) and the subsequent augmented production of IFN-gamma by T-cells. This information provides basic knowledge regarding the characteristics of T-cell recognition of antigens and the subsequent activation, and a novel method for modification of human T-cell responses by altered peptide ligands (APLs), as a possible candidate for antigen-specific immunopotentiating or immunosuppressive therapy against autoimmune diseases, allergies, infectious diseases and malignant tumors.

New method of Helmholtz coil alignment

A new alignment method for Helmholtz coils is proposed. This method is based on a probe, whose axis is the same as the alignment axis. This probe includes one magnetic sensor, whose position is slightly shifted from the probe axis, and which is set perpendicular to the axis. Using this probe, the tilt and shift of the magnetic centre of Helmholtz coils can be aligned to within an order of 0.1 mrad and 0.1 mm, respectively. Moreover, by this method, effects of terrestrial magnetism and tilt of the magnetic sensor can be removed from the measurement. This alignment method is presented along with an estimate of the alignment accuracy of the SPring-8 linac injector.

Evidence that HLA class II-restricted human CD4+ T cells specific to p53 self peptides respond to p53 proteins of both wild and mutant forms

By stimulating peripheral blood mononuclear cells of four healthy donors with a mixture of overlapping peptides representing the core domain of p53, we established two CD4+ alphabeta T cell clones and four lines that recognized wild-type and mutant p53 proteins as well as p53 self peptides in an HLA class II-restricted fashion. Two T cell lines established from two unrelated donors reacted to the p53 peptide (p)153-166 and p108-122, respectively, in the context of DP5 molecules. Two T cell clones established from two other unrelated donors were specific for p193-204 in the context of DRB1*1401 and for p153-165 in the context of DP5, respectively. These two T cell clones responded almost equally to both wild-type and four mutant recombinant p53 proteins. The proliferative responses of these T cell clones to p53 recombinant proteins were augmented by heat denaturing, thereby suggesting that altered conformation of the protein facilitates proteolytic processing to produce antigenic peptides. The DRB1*1401-restricted T cell clone specific for p193-204 killed a B lymphoblastoid cell line homozygous for HLA-DRB1*1401 when the cell line was pre-pulsed with p53 protein as well as peptide. These results indicate that CD4+ T cells reactive to p53 do exist in healthy individuals and the epitopes are probably ignored by the immune system under physiological conditions. It is suggested that such epitopes stimulate T cells to induce anti-p53 antibody production in cancer patients as previously reported by others. The possible involvement of p53-reactive T cells in anti-tumor immunity is discussed.

[A case report of choroid plexus carcinoma]

Choroid plexus carcinoma (CPC) is a rare tumor with poor prognosis, whose optimal treatment has not yet been established. We report a case of a one-year-old infant who has been treated with successive combined therapy. The therapy involved two operations for partial removal, interrupted radiotherapy up to 12Gy, 2 cycles of salvage chemotherapy, followed by an operation for total removal, and then a further 3 cycles of chemotherapy. CT scan after the preoperative salvage chemotherapy showed remarkable shrinkage of the residual tumor, which made operative procedure easier. The patient was disease-free for ten months after the last operation. Patients with combined preoperative chemotherapy and total resection seem to enjoy prolonged progression-free survival, so preoperative chemotherapy for choroid plexus carcinoma seems to be of benefit, despite the fact that its optimal recipe has not yet been established.

Augmentation of immune response by an analog of the antigenic peptide in a human T-cell clone recognizing mutated Ras-derived peptides

T-cells that recognize mutated p21 Ras are relevant to immune surveillance systems against cancer. We report here evidence that immune responses of a T-cell clone recognizing mutated p21 Ras can be augmented by an analog peptide. Using spleen cells from a gastric cancer patient, we established the CD4+ alpha beta Th1-like clone C27 that recognizes wild-type (3EYKLVVVGAGGVGKS17) and mutated p21 Ras protein molecules and peptides, in an HLA-DR1-restricted manner. C27 responded prominently to mutated Ras peptides carrying Val or Ala at position 12, as compared to wild-type and other mutated peptides. C27 also exhibited a much stronger response to a mutated p21 Ras whole-protein molecule-carrying Val at position 12, as compared with the wild-type protein. The proliferative response and production of GM-CSF, TNF-alpha, and IFN-gamma by C27 were further augmented by replacing the possible first DR anchor 4Tyr of the mutated Ras peptide with Trp, a more potent anchor residue for the DR1 molecule. Enhancement of peptide antigenicity by substituting the HLA anchor residue of an antigenic peptide recognized by tumor-reactive T-cells may prove to be a novel strategy for antigen-specific cancer immunotherapy.

Binding of mutated Ras- and p53-derived peptides to HLA-DR molecules

We investigated binding of p53- and Ras-derived peptides with frequently observed missense mutations, to various L cell transfectants expressing a single species of HLA-DR complex, and found that: (i) all the synthetic peptides bound to various DR complexes with a variable affinity; (ii) some DR allelic products had a high affinity for both p53- and Ras-derived peptides (e.g., DRB1*1502), whereas others almost no affinity (e.g., DRB1*1101); and (iii) DR-binding motifs described in the literature can explain some of the allele-specific interactions between mutated peptides and DR complexes. Therefore, some mutated Ras- and p53-derived peptides could be tumor-specific antigens recognized by CD4+ T cells in an HLA-DR allele-specific manner.

Unfolding of tertiary structures of proteins

The unfolding pathway of lysozyme was investigated by carrying out the computer simulation. Taking into account the simultaneous change of both the dihedral angels phi and psi of a residue, we explore the detailed features of the conformational energy profiles. The triangle distance map shows that the lysozyme molecule is divided into three domains, 1-40, 41-101 and 102-129 in amino acid residue numbers (referred to as the domains I, II and III, respectively). The calculated unfolding process indicates that in the early stage of unfolding domain III located at the C-terminal begins to be detached from the other two, and then domain I can be unfolded. The long-range interactions between domains I and III stabilize the whole molecule and give the cooperative nature of the folding. The calculated unfolding pathway of lysozyme is consistent with the folding pathway proposed by Anderson & Wetlaufer [J. Biol. Chem. (1976). 251, 3147-3153] who identified the disulfide bondings in the early stage of the glutathione regeneration. A simplified treatment of unfolding for myoglobin is also discussed in the Appendix.