Morphological and biochemical signs of age-related neurodegenerative changes in klotho mutant mice

Klotho mutant mice, defective in the klotho gene, develop multiple age-related disorders with very short lifespans. Introduction of the exogenous klotho gene into these mutant mice leads to an improvement in their phenotypes, while overexpression of this gene in wild-type mice significantly extends their lifespan. These observations suggest that the klotho gene/protein has an anti-aging function. Since there have been only a few reports with some disagreement about results on the CNS of the mutant mice, we tried to clarify whether the CNS neurons generate aging-like features, even in premature stages, using biochemical and morphological approaches. Results obtained from the mutant mice, when compared with wild-type mice, were as follows. Neurofilaments (NFs) were increased significantly in axons, with the subunit proteins showing a significant enhancement in phosphorylation or expression of NF-H or NF-L, respectively. Microtubules in Purkinje cell dendrites were closer to each other, and in the CNS tissue tubulin was unaltered, but microtubule-associated protein (MAP) 2 was significantly reduced in expression. Neuronal cellular organelles were morphologically disordered. Lysosomes, cathepsin D and light chain 3 of MAP1A/B (LC3) were augmented with the appearance of putative autophagy-related structures. Antiapoptotic Bcl-xL and proapoptotic Bax were reduced and enhanced, respectively, and mitogen-activated protein kinase was reduced. Synapse-related proteins and structures were decreased. Neuronal degeneration was evident in hippocampal pyramidal cells, and possibly in Purkinje cells. Astrocytic glial filaments and glial fibrillary acidic protein were increased in density and expression, respectively. Together, the CNS neuronal alterations in klotho mutant mice were quite similar to those found in aged animals, including even premature death, so this mouse should be a more appropriate animal model for CNS aging than those previously reported.

Endotoxin-induced Injury of the Central, Autonomic and Enteric Nervous Systems and Intestinal Muscularis in Thoroughbred Horses

To evaluate the effects of endotoxin on the morphology of the equine central, autonomic and enteric nervous system and intestinal muscularis, six Thoroughbred horses with experimentally induced endotoxaemia were examined. The lesions in the central nervous system consisted of perivascular oedema around arterioles, suggesting brain oedema, and ring haemorrhages around veins, similar to those in human patients with septic shock. In the cranial mesenteric ganglia, neuronal cell bodies became pink or red, with shrinkage of cytoplasm indicative of ischaemic changes; intramural and perivascular infiltration by erythrocytes and neutrophils occurred around arterioles in the epineurium (acute focal interstitial inflammation). In addition, transmission electron microscopy revealed oedema of the endoneurium and mesoaxon in the nerve fascicles running inside or outside the ganglia. Myenteric neurons showed shrinkage of the cytoplasm with multiple cytoplasmic vacuoles, suggesting ischaemic changes. Oedematous degeneration and coagulation necrosis of smooth muscle cells, with dissociation of the cells, were prominent in the tunica muscularis. It is suggested that arterionecrosis elicited by endotoxin and frequently observed in the autonomic and enteric nervous system and intestinal muscularis, was the result of vasoconstriction or vasospasm.

Initial cytotoxicity of novel titanium alloys

We assessed the biological response to several novel titanium alloys that have promising physical properties for biomedical applications. Four commercial titanium alloys [Super-TIX(R) 800, Super-TIX(R) 51AF, TIMETAL(R) 21SRx, and Ti-6Al-4V (ASTM grade 5)] and three experimental titanium alloys [Ti-13Cr-3Cu, Ti-1.5Si and Ti-1.5Si-5Cu] were tested. Specimens (n = 6; 5.0 x 5.0 x 3.0 mm(3)) were cast in a centrifugal casting machine using a MgO-based investment and polished to 600 grit, removing 250 mum from each surface. Commercially pure titanium (CP Ti: ASTM grade 2) and Teflon (polytetrafluoroethylene) were used as positive controls. The specimens were cleaned and disinfected, and then each cleaned specimen was placed in direct contact with Balb/c 3T3 fibroblasts for 72 h. The cytotoxicity [succinic dehydrogenase (SDH) activity] of the extracts was assessed using the MTT method. Cytotoxicity of the metals tested was not statistically different compared to the CP Ti and Teflon controls (p > 0.05). These novel titanium alloys pose cytotoxic risks no greater than many other commonly used alloys, including commercially pure titanium. The promising short-term biocompatibility of these Ti alloys is probably due to their excellent corrosion resistance under static conditions, even in biological environments.

Cyclophosphamide augments the anti-tumor efficacy of uracil and tegafur by inhibiting dihydropyrimidine dehydrogenase

The present study assesses the effects of neo-adjuvant chemotherapy (NAC) with uracil and tegafur (UFT) alone vs UFT plus cyclophosphamide (CPA), on the activity of thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) in breast cancer tissues. Breast cancer patients were randomly assigned to 3 groups; the control (no-treatment) group (n=13), the UFT (5-8 mg/kg/day) alone group (n=10) and the UFT plus CPA (1 mg/kg/one day interval) (UC) group (n=9), and they received NAC for 2-4 weeks. A total of 32 invasive ductal breast carcinomas were used to assay for TS and DPD activity. There were no statistically significant differences in tumor size or stage classification between the 3 groups. The DPD activity was inversely and significantly correlated with the tumor size and pT, but the TS activity was not correlated with these clinicopathological factors. The TS activity was decreased by NAC with UFT, and the addition of CPA resulted in an increased inhibition of TS activity. In contrast, DPD activity was increased by NAC with UFT administration, but its increased activity was significantly inhibited by the addition of CPA. Multiple regression analyses demonstrated that the total dose of UFT was a significant variable for inhibiting TS activity, and that CPA was a significant variable for inhibiting DPD activity. The DPD activity increased by UFT can be inhibited by CPA, and this may represent one of the possible mechanisms responsible for the anti-tumor activity of 5-FU or its derivatives as enhanced by CPA.

Molecular basis for sensitivity and acquired resistance to gefitinib in HER2-overexpressing human gastric cancer cell lines derived from liver metastasis

Gastric cancer metastasised to the liver was found to overexpress HER2 at a significantly higher incidence than primary gastric cancers. The purpose of the present study was to investigate the possibility of molecular therapy targeting HER2 overexpression in gastric cancer liver metastasis. We developed three new HER2-overexpressing gastric cancer cell lines (GLM-1, GLM-2, GLM-4) without epidermal growth factor receptor (EGFR) mutations derived from such liver metastasis, two of which had HER2 gene amplifications. All these GLM series of cell lines were highly sensitive to gefitinib in vitro, a specific inhibitor of EGFR tyrosine kinase (Iressa) rather than anti-HER2 antibody trastuzumab (Herceptin), whereas most of the HER2 low-expressing counterparts were not. In these HER2-overexpressing GLM series, protein kinase B (Akt), but not extracellular signal-regulated kinase 1/2 (ERK1/2), was constitutively phosphorylated, and gefitinib efficiently inhibited this Akt phosphorylation, induced strong apoptosis in vitro and exhibited antitumour activity in tumour xenografts in nude mice. This gefitinib-mediated antitumour effect in xenograft was significantly potentiated by trastuzumab treatment. On the other hand, gefitinib-resistant cells (GLM-1R) exhibited increased EGFR expression, followed by constitutive activation of mitogen-activated protein kinase (MAPK) pathway. These results suggest that the antitumour effect of gefitinib is due to the effective inhibition of HER2-driven constitutive activation of phosphatidylinositol-3-kinase (PI3K)/Akt pathway, and that the acquired resistance to gefitinib is due to the constitutive activation of Ras/MAPK pathway in compensation for PI3K/Akt pathway. Gastric cancer liver metastasis with HER2 overexpression would be a potential molecular target for gefitinib and trastuzumab.

PAI-1 expression levels in esophageal and colorectal cancers are closely correlated to those in corresponding normal tissues

To investigate the mechanism of PAI-1 overexpression in esophageal and colorectal cancers, PAI-1 expression levels in these cancers were compared to those in corresponding normal tissues. Quantitative RT-PCR was performed for the PAI-1 gene in esophageal and colorectal cancer tissues and in the corresponding normal tissues and the association between PAI-1 expression levels in these tissues was evaluated. There was a significant correlation between esophageal and colorectal cancer and the corresponding normal PAI-1 expressions with a Spearman's rank correlation coefficient of 0.77 (p < 0.0001) and 0.81 (p < 0.0001), respectively. In previous studies, PAI-1 overexpression was found to be significantly associated with the malignancy of esophageal and colorectal cancers. Taken together, PAI-1 overexpression in esophageal and colorectal cancers might originate from higher PAI-1 expression in corresponding normal tissues and result in a malignant phenotype of these cancers.

PAI-1 (Plasminogen activator inhibitor-1) expression levels in colorectal cancers and corresponding normal tissues

10094

Background: We performed a quantitative RT-PCR for Plasminogen Activator Inhibitor-1 (PAI-1) gene in 55 surgical specimens of colorectal cancer (CRC) and corresponding normal mucosa. To test the hypothesis that PAI-1 may serve as a candidate marker for the malignant potential of CRC, we evaluated the possible relationship between PAI-1 gene expression levels and clinicopathological findings in CRC. Next, to investigate the mechanism of PAI-1 overexpression in CRC, we compared the PAI-1 expression levels in these cancers with those in the corresponding normal tissues. Results: A significant increase in PAI-1 expression scores was observed in node-positive CRCs (2.19Å}0.43) compared to negative ones (0.35Å}0.42) (P=0.0037) as well as in CRCs with distant metastasis (3.50Å}1.18) compared to negative ones (0.99Å}0.30). A significant increase in PAI-1 expression scores was observed in lymph node metastasis-positive CRCs (2.19Å}0.43) compared to negative ones (0.35Å}0.42) (P=0.0037) as well as in distant metastasis-positive CRCs (3.50Å}1.18) compared to negative ones (0.99Å}0.30). The PAI-1 expression score markedly increased with the tumor stage (P=0.0063; ANOVA test). Moreover, multivariate analysis revealed the PAI-1 expression score to be a strong and independent prognostic factor for CRC (P=0.0432). There was a significant correlation between CRC and corresponding normal PAI-1 expressions with a Spearman’s rank correlation coefficient of 0.81 (P < 0.0001). Conclusion: These results suggested that PAI-1 might serve as a new parameter for the prediction of prognoses in CRC. Taken together, PAI-1 overexpression in CRCs might originate from higher PAI-1 expression in the corresponding normal tissues and result in a malignant phenotype of these cancers.

No significant financial relationships to disclose.

Phase II study of weekly paclitaxel as a second line chemotherapy for metastatic/recurrent gastric carcinoma

14059

Background: There is currently no standard treatment for gastric carcinoma patients (pts) who failed initial chemotherapy. Since performance status of these pts deteriorates rapidly, moderate and dose-fractionated single agent regimens have been preferred in Japan in the second line setting. Weekly paclitaxel, one of commonly used regimens in this setting, was explored for the first time in a formal phase II study. Methods: Pts with histologically confirmed gastric carcinoma who had unresectable or recurrent disease with ≥1 measurable lesions per RECIST were eligible. Other eligibility criteria included confirmed progressive disease (PD) per RECIST during a front line chemotherapy, PS ≤2, adequate liver, kidney, and marrow functions, no active gastrointestinal bleeding, and written informed consent. Patients received 80 mg/m2 of paclitaxel weekly for 3 successive weeks with one week of rest. The cycle was repeated until objective disease progression or drug intolerance. Results: 35 pts were enrolled: 29 men and 6 women, age 62 (48∼74), 6 unresectable and 29 recurrent cancers, 13 with poorly differentiated phenotype and 20 with differentiated type, 22 PS0, 8 PS1, and 6 PS2. All front line treatments involved oral fluoropyrimidines and had been S-1 in 29, S-1/CDDP in 5, S-1/CPT-11 in one, and UFT in one patient. One pt declined to continue the treatment due to a Grade 2 taste disturbance after a single dose of paclitaxel, and 34 other pts were evaluable for response. Partial response was observed in 6 pts (response rate 17.6%). Median time to progression was 97 days and median survival time was 214 days (467 days among 22 PS0 patients). The incidence of ≥Grade 3 adverse events were as follows: neutropenia in 7 pts, leucopenia in 5, anemia in 4, anorexia in 4, neurological disorder, nausea, diarrhea, asthenia, and dyspnea in one. Conclusions: Activity of weekly paclitaxel was modest for pts with fluoropyrimidine-refractory gastric carcinoma, but median survival time was satisfactory, with a mild toxicity profile. Further phase II study under less strict eligibility criteria (e.g. inclusion of patients with elevated tumor markers or subjective evidence of clinical deterioration during the front line therapy as the sole indication of disease progression) is underway.

No significant financial relationships to disclose.

[Pancreatic acinar cell carcinoma successfully treated with combination of oral TS-1 and intra-arterial cisplatin]

Pancreatic acinar cell carcinomas are rare, and little is reported on their chemotherapy. We report a 49-year old male patient with pancreatic acinar cell carcinoma and multiple liver metastases, which responded to oral TS-1 and hepatic arterial infusion of cisplatin. The patient underwent a partial hepatectomy, MCT abrasions and excision of the pancreatic tumor. Postoperative pathological studies revealed metastases of acinar cell carcinoma to the liver and lymph nodes; the primary lesion was undetermined. After surgery, the patient was treated with hepatic arterial infusion of cisplatin and oral TS-1. Metastatic tumors completely disappeared, and serum lipase decreased to normal levels. Abdominal CT one year after surgery revealed a pancreatic body tumor, which was surgically removed. Pathological studies showed primary pancreatic acinar cell carcinoma, while previous metastases remained under control. To summarize, TS-1 and cisplatin can be effective treatments for pancreatic acinar cell carcinomas.

Quantitative analysis of allergenic ingredients in eluate extracted from used denture base resin

Allergenic ingredients extracted from used denture base resin were quantitatively analysed using a gas chromatograph/mass spectrometer and high performance liquid chromatography. Methyl methacrylate (MMA), hydroquinone (HQ), formaldehyde (FMA), benzoyl peroxide (BPO), benzoic acid (BA) and methyl benzoate (MB) were detected in a eluate from all of the dentures, while ethyleneglycol dimethacrylate (DME) was detected in the eluate from 87 dentures in use for <15 years. MMA, HQ, FMA, BPO and MB showed a decrease in correlation to the period of denture use, but continuing to be evident even after 29 years of use. The MMA showed the highest level of elution and a relatively moderate decrease over time. The elution of BA, on the contrary, showed an increase with the period of denture use up to about 10 years and subsequently reached a plateau. Our results indicate that purported allergens exist in the resin base and can be eluted into the oral cavity, even in patients using an old denture for a period of nearly 30 years.

Immunohistochemical expression of HER-1 and HER-2 in extrahepatic biliary carcinoma

The clinicopathological significance of HER-1- and HER-2-overexpressions (OE) (HercepTest score 2+ or 3+) in biliary cancer and their relationship to the efficacy of adjuvant chemotherapy (ACT) were assessed. In 72 biliary cancer (28 gallbladder and 44 bile duct cancer), HER-1 and HER-2 were stained immunohistochemically in formalin-fixed, paraffin-embedded specimens. The ACT included uracil and tegafur (UFT)-based chemotherapies. Out of the 72 cancer, OE was observed in 31 specimens (43%) for HER-1 and 47 (65%) for HER-2. However, their OEs were not correlated with each other. HER-2-OE was inversely correlated with the clinical stage (p=0.0482). HER-1-OE was correlated with distant metastasis (p=0.0263), but not with the clinical stage. Neither the OE of HER-1 or HER-2, nor their co-expression, showed any significant effect in term of patient survival. In the HER-1-OE (-) patients, the survival rate of the ACT group was significantly higher than that of the surgery-alone (SA) group (p=0.0423), but in the HER-1-OE (+) patients, there was no statistical difference in survival rate between the ACT and the SA group. In contrast, HER-2-OE had no significant effect on the efficacy of ACT. Multivariate analysis also demonstrated that the histological grade and ACT were significant variables, but T, N, M and HER-1 and HER-2 were not significant variables. In conclusion, neither HER-1-OE or HER-2-OE were prognostic factors of the biliary cancer. However, HER-1-OE may be a useful marker for the indication of ACT.

Plasminogen activator inhibitor-1 as a potential marker for the malignancy of colorectal cancer

To test the hypothesis that plasminogen activator inhibitor-1 (PAI-1) may serve as a candidate marker for the malignancy of colorectal cancer (CRC), we performed a quantitative RT–PCR for PAI-1 gene and evaluated the possible relationship between PAI-1 gene expression levels and clinicopathological findings in CRC. A significant increase in PAI-1 expression scores was observed in lymph node metastasis-positive CRCs (2.19±0.43) compared to negative ones (0.35±0.42) (P=0.0037) as well as in distant metastasis-positive CRCs (3.50±1.18) compared to negative ones (0.99±0.30). The PAI-1 expression score markedly increased with the tumour stage (P=0.0063; ANOVA test). Moreover, multivariate analysis revealed the PAI-1 expression score to be a strong and independent prognostic factor for CRC (P=0.0432). These results suggested that PAI-1 might serve as a new parameter for the prediction of prognoses in CRC.

Effects of long-term treatment with mizoribine in patients with proliferative lupus nephritis

AIM

Mizoribine (MZR) is a purine antimetabolic immunosuppressant agent that has few little severe adverse events. We studied whether maintenance therapy with MZR and prednisolone (PSL) in severe proliferative lupus nephritis patients could improve immunity, reduce proteinuria, prevent renal relapse, and reduce steroid dose.

METHOD

Long-term maintenance therapy with MZR and PSL was evaluated in ten patients with biopsy-proven proliferative lupus nephritis. Patients with severe lupus nephritis, who had proteinuria of 0.5 g or more even after treatments with plasma exchange and/or pulse methyl prednisolone, were recruited. MZR at an average dose of 140 +/- 10 (100 - 200) mg was administered two to three times/day in combination with PSL. The average period for the MZR maintenance therapy was 89.7 +/- 5.5 (70 - 126) months. Urine protein excretion, serum hemolytic complement activity (CH50), C3, serum creatinine, general and biochemical blood examinations, anti-ds-DNA antibody were collected at each monthly medical examination.

RESULTS

All patients were females, mean age 43.0 +/- 3.3 years. A significant decrease in proteinuria was noted two years after the combination therapy (p = 0.0016). Five patients experienced lupus nephritis relapse. Patients who did not experience relapses had their MZR combination therapy initiated earlier (p = 0.037) when compared with the patients who experienced relapses. Serum creatinine levels remained unchanged in all patients throughout treatment and follow-up, even during renal relapses. Levels of C3 and CH50 normalized as proteinuria decreased. None of the patients developed serious side effects during MZR treatment. A significant steroid-sparing effect was observed three years after initiating MZR (p = 0.0025).

CONCLUSION

From our long-term observation, maintenance therapy with low-dose PSL combined with MZR can eliminate proteinuria and have steroid-sparing effect. Early initiation of the therapy can protect against renal relapses among severe proliferative lupus nephritis patients without serious side effects.