Phase I/II study of S-1 combined with triweekly irinotecan for advanced or recurrent colorectal cancer

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Background: A dose-escalation study of irinotecan (CPT-11) combined with S-1, an oral dihydropyrimidine dehydrogenase inhibitory fluoropyrimidine, was performed to determine the maximum-tolerated dose (MTD), recommended dose (RD), dose-limiting toxicities (DLTs), and objective response rate (RR) in advanced or recurrent colorectal cancer. Methods: The subjects were untreated patients with inoperable advanced or recurrent colorectal cancer aged 20–75 years. S-1 was administered orally at 80 mg m-2 day-1 from day 1 to 14 of a 21-day cycle and CPT-11 was given intravenously on day 1 at an initial dose of 80 mg m-2 day-1, stepping up to 150 mg m-2. The treatment was repeated every 3 weeks, unless disease progression was observed. Results: In the phase I portion, only one of six patients at level 1 (80 mg m-2 of CPT-11) developed DLT, grade 3 diarrhea. No other serious adverse reactions occurred (either hematological or non- hematological), and all patients at levels 2 (100 mg m-2) to 5 (150 mg m-2) could receive therapy safely on an outpatient basis. The final RD was determined to be 150 mg m-2. In the phase II portion, fourteen patients including three patients in the final RD phase I portion were evaluated. The median treatment course was six (range: 2–17). The incidences of severe (grade 3–4) haematological and nonhaematological toxicities were 41.7 and 8.3%, respectively, but all were manageable. The RR was 50% (7 of 14, 95%CI: 23.0–77.0%), and Disease Control Rate (PR + SD) was seen in 71.4%. MST is not reached. Conclusions: Our phase I/II trial showed that S-1 combined with CPT-11 achieved a high response rate and could be given safely on an outpatient basis. These findings suggest that the therapy has potential as first- line treatment for inoperable advanced recurrent colorectal cancer. The updated analysis will be presented at the meeting.

No significant financial relationships to disclose.

Knock-in mouse model of dilated cardiomyopathy caused by troponin mutation

We created knock-in mice in which a deletion of 3 base pairs coding for K210 in cardiac troponin (cTn)T found in familial dilated cardiomyopathy patients was introduced into endogenous genes. Membrane-permeabilized cardiac muscle fibers from mutant mice showed significantly lower Ca(2+) sensitivity in force generation than those from wild-type mice. Peak amplitude of Ca(2+) transient in cardiomyocytes was increased in mutant mice, and maximum isometric force produced by intact cardiac muscle fibers of mutant mice was not significantly different from that of wild-type mice, suggesting that Ca(2+) transient was augmented to compensate for decreased myofilament Ca(2+) sensitivity. Nevertheless, mutant mice developed marked cardiac enlargement, heart failure, and frequent sudden death recapitulating the phenotypes of dilated cardiomyopathy patients, indicating that global functional defect of the heart attributable to decreased myofilament Ca(2+) sensitivity could not be fully compensated by only increasing the intracellular Ca(2+) transient. We found that a positive inotropic agent, pimobendan, which directly increases myofilament Ca(2+) sensitivity, had profound effects of preventing cardiac enlargement, heart failure, and sudden death. These results verify the hypothesis that Ca(2+) desensitization of cardiac myofilament is the absolute cause of the pathogenesis of dilated cardiomyopathy associated with this mutation and strongly suggest that Ca(2+) sensitizers are beneficial for the treatment of dilated cardiomyopathy patients affected by sarcomeric regulatory protein mutations.

Antitumor effects of the MIG and IP-10 genes transferred with poly [D,L-2,4-diaminobutyric acid] on murine neuroblastoma

The number of tumor-infiltrating lymphocytes is known to be related to outcomes in patients with a variety of malignancies. Interferon (IFN) gamma-inducible protein-10 (IP-10) and monokine induced by IFNgamma (MIG) have chemotactic effects on activated T lymphocytes and natural killer (NK) cells. The aim of this study was to evaluate the antitumor effects of exogenous expression of the MIG and IP-10 genes delivered to solid tumors by poly [D,L-2,4-diaminobutyric acid] (PDBA). The murine MIG and IP-10 genes were transfected into mouse neuroblastoma cells with PDBA. MIG and IP-10 levels in supernatants of transfected cells were measured by enzyme-linked immunosorbent assay. The chemotactic activities of MIG and IP-10 in the supernatants of cell cultures were measured by chemotaxis assay. Tumors were injected in vivo with PDBA/pmMIGColon, two colonsIP-10 complexes to evaluate the effects of these genes on tumor volume and survival time of mice. Transfected PDBA/pmMIGColon, two colonsIP-10 complexes produced MIG and IP-10 protein in vitro. MIG and IP-10 proteins secreted into the culture medium showed chemotactic activity. MIG and IP-10 gene therapy with the PDBA system in vivo significantly inhibited tumor growth and prolonged survival time of mice. In conclusion, PDBA-mediated MIG and IP-10 gene therapy may be useful for treatment of solid tumors.

Prognosis and postoperative lymphocyte count in patients with hepatocellular carcinoma who received intraoperative allogenic blood transfusion: a retrospective study

AIMS

The effect of perioperative blood transfusion on the survival of hepatocellular carcinoma (HCC) has not been fully investigated. To clarify the prognostic value of intraoperative allogenic blood transfusion, we conducted a comparative retrospective analysis of 224 patients with HCC who underwent hepatic resection.

METHODS

We compared clinicopathologic background and survival after hepatic resection between patients who received intraoperative blood transfusion (n=101) and those who did not (n=123).

RESULTS

Patients with blood transfusion had a larger tumor and more frequent vascular invasion than those without blood transfusion. The 5-year cancer-related survival rate after hepatic resection, but not the disease-free survival rate, was significantly lower in patients who underwent blood transfusion than in those who did not (38.3% vs. 66.7%, P<0.01). Multivariate analysis showed intraoperative blood transfusion (P=0.02), microscopic portal invasion (P<0.01), and preoperative serum alpha-fetoprotein elevation (P=0.03) to be independent risk factors for poor outcome after hepatic resection. The negative effect of blood transfusion on postoperative survival was observed only in patients with a tumor larger than 50mm in diameter. The absolute peripheral blood lymphocyte count on postoperative day 1 was significantly lower in patients who underwent blood transfusion (880/mm(3)) than in those who did not (1081/mm(3)) (P<0.01).

CONCLUSIONS

Our data suggest that intraoperative blood transfusion results in immunosuppression in the early postoperative period, allowing for progression of residual HCC after resection. Therefore, intraoperative allogenic blood transfusion should be avoided in patients with resectable HCC, particularly in those with a large tumor.

Electroacupuncture suppresses myostatin gene expression: cell proliferative reaction in mouse skeletal muscle

Complementary and alternative medicine (CAM) may provide patients with an alternative to traditional medicine, but an assessment of its efficacy is required. One CAM method, electroacupuncture (EA) treatment, is a maneuver that utilizes stimulation of acupuncture needles with a low-frequency microcurrent. To study the effect of short-term EA, we evaluated the differential expression of genes induced by EA in mouse skeletal muscle for up to 24 h. We then used RT-PCR to confirm the expression patterns of six differentially expressed genes. Bioinformatics analysis of their transcription control regions showed that EA-inducible genes have numerous common binding motifs that are related to cell differentiation, cell proliferation, muscle repair, and hyperplasia. These results suggested that EA treatment may induce cell proliferation in skeletal muscle. To verify this possibility, we used EA to stimulate mouse skeletal muscle daily for up to 1 mo and examined the long-term effects. Immunohistochemical analysis showed that nuclei of muscle cells treated with EA for 1 mo, especially nuclei of satellite cells, reacted with anti-human PCNA. Also, expression of the gene encoding myostatin, which is a growth repressor in muscle satellite cells, was suppressed by daily EA treatment for 1 wk; EA treatment for 1 mo resulted in more marked suppression of the gene. These molecular findings constitute strong evidence that EA treatment suppresses myostatin expression, which leads to a satellite cell-related proliferative reaction and repair in skeletal muscle.

Measurement of elastic properties of blood vessels

This paper is related to the measurements of the modulus of elasticity of an artery by studying the deformations due to the inflation of an angioplasty balloon catheter used for Interventional Radiology (IR) procedures. Various types of balloons are studied in order to characterize and compare their behaviors at the time of inflation. A test bench, consisting of an angioplasty balloon, a Polyvinyl alcohol model and an actuator used to inflate a balloon, is developed for the realization of the experiments. The pressure-volume curve during the inflation of a balloon is observed. Elasticity modulus are derived with an analytical model of the measurement system. The results are then analyzed and compared to existing data from literature.

Measurement of internal constraints during an interventional radiology procedure

This paper presents a novel method for measurements of internal constraints during an Interventional Radiology procedure. Fiber-optic strain gauge, operating as a Fabry-Perot interferometer, is inserted and navigated inside a polyvinyl alcohol (PVA) model. The information obtained from deformation of the Fabry-Perot cavity is analyzed and the results are then rescaled through a calibration procedure for catheters. The measures help to locate the maximum interaction forces between catheter and blood vessel wall at approximately 1.3 N and to observe the shape of dynamic interaction during manipulation.

The evaluation of facial palsy by amount of feature point movements at facial expressions

At present, in the medical field 40-point method and facial nerve grading system are generally used for evaluation of facial palsy. However, these methods have limitation in the precise evaluation, because of subjectivity in diagnosis. Purpose of This work is to propose quantitative evaluation of facial palsy based on the amount of movements of the feature point on the face. Facial nerve symptoms generally appear in either side of the face. In facial expression movement, the motion in the palsy side becomes smaller than that of the healthy side. We defined some indices of palsy grade obtained by the observation of the facial motion. Those indices showed the asymmetry of the facial motion quantitatively. We confirmed that our proposed method is valid for estimation of facial palsy from comparison with 40 points method.

Absence of tyrosine kinase mutations in Japanese colorectal cancer patients

Tyrosine kinases, which are important regulators of intracellular signal-transduction pathways, have mutated forms that are often associated with oncogenesis and are attractive targets for therapeutic intervention. Recently, systematic mutational analyses of tyrosine kinases revealed that a minimum of 30% of colorectal cancer contain at least one mutation in the tyrosine kinases. To further explore these mutations, we examined all reported mutations of NTRK3, FES, KDR, EPHA3, NTRK2, JAK1, PDGFRA, EPHA7, EPHA8, ERBB4, FGFR1, MLK4 and GUCY2F genes in the 24 colorectal cancer cell lines. Unexpectedly, among 24 colorectal cancer cell lines, only two cell lines (LoVo and CaR1) harbored mutation C1408T (R470C) in MLK4 gene. The mutation rate was extremely low compared to that previously reported. Therefore, we analyzed mutations in 46 colorectal cancer samples resected from the same number of Japanese patients. Surprisingly, none of the 46 samples contained any of the mutations reported. Based on our study, we advise that a more comprehensive tyrosine kinase gene mutation assay is necessary in the future.

Inclusion of the transcervical approach in video-assisted thoracoscopic extended thymectomy (VATET) for myasthenia gravis: a prospective trial

BACKGROUND

Because evidence-based data regarding the quality of video-assisted thoracoscopic thymectomy for the treatment of myasthenia gravis are lacking, a prospective trial comparing three different operative approaches was conducted to evaluate their efficacy.

METHODS

This prospective study enrolled 20 consecutive patients with nonthymomatous myasthenia gravis. A series of three approaches for bilateral video-assisted thoracoscopic extended thymectomy (VATET) using the anterior chest wall-lifting method (original), the original method with a flexed-neck position (modified), and the original method with a transcervical approach (final) were prospectively performed in each patient for quantitative and pathologic evaluation of the residual thymus after each approach.

RESULTS

Complete VATET required 242 +/- 48 min, with the transcervical procedure requiring 23 +/- 12 min. After the modified method, the residual thymus in the cervical region was 1.5 cm in size and weighed 0.8 g (0.8% of the entire thymus), as compared with a size of 2.2 cm and a weight of 1.3 g (3.2%) after the original method. Each value is the result of comparison with the final method. Histopathologic studies showed residual tissue in the germinal center as well as Hassall's corpuscles in more than 70% of cases.

CONCLUSION

The findings show that VATET without the transcervical approach could be an immunologically incomplete treatment for myasthenia gravis. Therefore, the transcervical approach should be included in VATET procedures to ensure radicality.

Preoperative transcatheter arterial chemoembolization reduces long-term survival rate after hepatic resection for resectable hepatocellular carcinoma

AIMS

To study the effect of preoperative transcatheter arterial chemoembolization (TACE) on long-term survival after hepatic resection for hepatocellular carcinoma (HCC), we conducted a comparative analysis in 235 HCC patients who underwent hepatic resection with a curative intent.

METHODS

We compared clinicopathologic background, mortality, and survival rates after hepatic resection between those who underwent preoperative TACE (n=109) and those who did not (n=126).

RESULTS

One hundred and two patients in the TACE group (93.6%) received TACE only once. The mean interval between TACE and hepatic resection was 33.1days. Patients in the TACE group were younger than those in the non-TACE group, and liver cirrhosis and non-anatomical hepatic resection were more prevalent in this group. The 5-year overall survival rate after hepatic resection was significantly lower in the TACE group (28.6%) than in the non-TACE group (50.6%), especially in patients without cirrhosis or with stage I or II tumor. There was no difference between the two groups in mortality or disease-free survival after hepatic resection. Multivariate analysis showed preoperative TACE, preoperative aspartate aminotransferase elevation, and microscopic portal invasion to be independent risk factors for a poor outcome after hepatic resection.

CONCLUSIONS

Preoperative TACE should be avoided for patients with resectable HCC, especially for those without cirrhosis or with an early stage tumor.

The influence of tumor size, histological differentiation and smoking history in patients with completely resected stage I adenocarcinoma of the lung

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Background: To test the hypothesis that patients with completely resected p-stage I adenocarcinoma [Ad.] of the lung contain a favorable subgroup of patients with well differentiated histology and tumor 2.0 cm or less in greatest dimension, we analyzed the results of the JLCRG trial (a randomized prospective trial of adjuvant chemotherapy with Uracil-Tegaful for stage I adenocarcinoma of the lung) by tumor size, smoking history, degree of histological differentiation and more. Methods: Patients were randomized to receive either oral uracil-tegaful (250 mg of tegaful /m2/day) for 2 years postoperatively or no adjuvant treatment. Multivariate analyses and interactions with the Cox proportional-hazards model were used to estimate the simultaneous effects of prognostic factors on survival. Results: The 5-year survival rate of the 412 patients with tumor 2cm or less in size was 89.8% (95% confidence interval [CI]: 86.8 to 92.8) versus 84.4% (95% CI: 81.3–87.4) for the 569 patients with tumor more than 2cm in size (median follow-up 72 months, p = 0.002). Although univariate analysis demonstrated improved survival for the patients with no smoking history and female gender, the selected covariates by multivariate analysis were as follows: age (hazard ratio [HR] for patients aged 70 years or more, 2.25; 95% CI: 1.58 to 3.14, p < 0.0001), tumor size (HR for more than 2cm in size, 1.55; 95% CI: 1.10 to 2.21, p = 0.012), histological differentiation (HR for moderate and poor differentiation, 1.75, 95% CI: 1.25 to 2.47, p = 0.001), and treatment group (HR for the uracil-tegaful group, 0.68; 95% CI: 0.49 to 0.94, p = 0.02). For these prognostic factors, there was only one significant interaction between tumor size and the adjuvant treatment. Conclusions: 1) Patients with completely resected stage I Ad. of the lung contain a favorable subgroup of patients with aged less than 70 years, well differentiated histology, and a maximum tumor dimension of 2.0 cm or less. 2) Adjuvant chemotherapy with oral uracil-tegaful should also be considered for stage I Ad. patients more than 2 cm in tumor size. 3) 2cm in tumor size might be a good benchmark candidate of the description of T factor to facilitate treatment strategies and revisions of the TNM staging system.

No significant financial relationships to disclose.

Method to quantify flow reduction in aneurysmal cavities of lateral wall aneurysms produced by stent implants used for flow diversion

SUMMARY

Stent implants placed across the neck of cerebral aneurysms are capable of reducing aneurysmal flow when coils are not used for filling the aneurysms. It is important to evaluate the effects of flow reduction caused by stent implants used for the treatment of cerebral aneurysms. Subtracted vortex centers path line method (SVC method) is one of the image post processing methods employed for quantitative flow measurement. We developed a modified SVC method by employing Cinematic Angiography (25 frames/s) and digital video recording (30 frames/s) with a commercial digital camera.We successfully compared the flow effectiveness using a tubular silicon model with a sidewall aneurysm. The result suggests that our modified SVC method is useful for a comparative examination of the effect of aneurysmal flow reduction caused by stent implants.

Laparoscopy-assisted right hepatic lobectomy using a wall-lifting procedure

This article describes a new technique for performing a laparoscopy-assisted right hepatic lobectomy using a hanger wall-lifting procedure. The patient is placed in the left semi-lateral position. A cholecystectomy and hemi-hepatic vascular inflow control are then performed through a midline incision, through which the resected liver can be removed. Next, the right lower chest and right upper abdominal wall are lifted by two wires vertical to the abdominal wall. Two ports, a 5-mm port in right lateral abdomen for forceps and a 12-mm port just right of the umbilicus for the laparoscope, are inserted. The obtained view of the operative field in the right upper abdominal cavity is thus excellent. The laparoscopy-assisted mobilization of the right hepatic lobe is done with the assistance of a hand inserted through the midline incision, including a dissection of the hepato-renal ligament, the right triangular ligament, and the right coronary ligament. A parenchymal dissection is then performed using the Cavitron Ultrasonic Surgical Aspirator (CUSA) and the resected specimen is passed through the midline incision without any morcellation of the liver. This procedure can minimize the length of the wound, while avoiding the lethal complications associated with pneumoperitoneum.

Iron overload and antioxidative role of perivascular astrocytes in aceruloplasminemia

Aceruloplasminemia (ACP) is an inherited disorder of iron metabolism caused by the lack of ceruloplasmin activity; the neuropathological hallmarks are excessive iron deposition, neuronal loss, bizarrely deformed astrocytes, and numerous 'grumose or foamy spheroid bodies (GFSBs)'. We histopathologically examined two autopsied ACP brains, and observed for the first time that GFSBs form in clusters at the ends of perivascular astrocytic foot processes. Both the deformed astrocytes and the GFSBs contained ferric iron and were intensely immunolabelled with antibodies against the antioxidant proteins ferritin and manganese superoxide dismutase (Mn SOD). Ceruloplasmin is largely produced by perivascular astrocytes in the central nervous system and exhibits a ferroxidase activity that inhibits iron-associated lipid peroxidation and hydroxyl radical formation; therefore, the lack of ceruloplasmin causes direct oxidative stress on astrocytes. The intense immunolabelling of ferritin and Mn SOD most likely reflects a defensive response to iron-mediated oxidative stress. This study suggests that astrocytes play key roles in iron trafficking and the detoxification of iron-mediated free radicals at the blood-brain barrier and in the parenchyma in ACP brain. The antioxidative ability of astrocytes is one of their essential neuroprotective effects, and the decompensation of this ability may lead to secondary neuronal cell death in ACP.

The hepatitis B virus X protein enhances AP-1 activation through interaction with Jab1

Hepatitis B virus X protein (HBx) has many cellular functions and is a major factor in hepatitis and hepatocellular carcinoma caused by HBV infection. A proteomic approach was used to search for HBx-interacting proteins in order to elucidate the molecular mechanism of hepatocarcinogenesis. HBx was attached to myc and flag tags (MEF tags) and expressed in 293T cells; the protein complex formed within the cells was purified and characterized by mass spectrometry. COP9 signalosome (CSN) subunits 3 and 4 were subsequently identified as HBx-interacting proteins. In addition, CSN subunit 5, Jun activation domain-binding protein 1 (Jab1), was shown to be a novel cellular target of HBx. In vivo and in vitro interactions between HBx and Jab1 were confirmed by standard immunoprecipitation and GST pull-down assays. An analysis of HBx deletion constructs showed that amino acids 30-125 of HBx were responsible for binding to Jab1. Confocal laser microscopy demonstrated that HBx was mainly localized in the cytoplasm, while Jab1 was found mainly in the nucleus and partially in the cytoplasm, and that the two proteins colocalized in the cytoplasm. The cotransfection of HBx and Jab1 resulted in substantial activator protein 1 (AP-1) activation and knockdown of endogenous Jab1 attenuated AP-1 activation caused by HBx. In addition, the coexpression of HBx and Jab1 potentiated phosphorylation of JNK, leading to the subsequent phosphorylation of c-Jun, whereas the level of c-Jun and JNK phosphorylation induced by HBx was decreased in Jab1 knockdown cells. These results suggest that the interaction between HBx and Jab1 enhances HBx-mediated AP-1 activation.

The retroperitoneum protects prosthetic graft material from intraperitoneal contamination: an experimental study

OBJECTIVES

To evaluate the ability of the retroperitoneum to serve as a barrier, against bacterial contamination, between the peritoneal cavity to the retroperitoneal space.

METHODS

Seventy rats had a small piece of knitted Dacron graft placed in the retroperitoneal space and 10(6)-10(9) colony forming unit (cfu) Enterococcus faecalis was injected into the peritoneal cavity. In half the retroperitoneal (RP) group, the retroperitoneum was preserved and in the remainder, the open peritoneal (OP) group, needle holes were created. Grafts were harvested after 1, 4, or 7 days and cultured for E. faecalis. A blood sample was collected from three rats in each group for culture before the graft was harvested.

RESULTS

Graft infection did not develop in any rat injected with 10(6) or 10(7) cfu in the RP group, while seven out of the 10 graft cultures of the OP group grew E. faecalis (P = 0.003). In rats injected with 10(8) or 10(9) cfu, five out of the 10 graft cultures in the RP group and eight out of 10 in the OP group grew E. faecalis. All blood cultures were negative when the injected bacterial count was 10(7) cfu or less. One out of the three blood cultures was positive at 10(8) cfu, and all were positive at 10(9) cfu.

CONCLUSIONS

These results suggest that an intact retroperitroneum acts as a protective barrier against intraperitoneal bacterial contamination, particularly when blood cultures are negative.

Association of ghrelin receptor gene polymorphism with bulimia nervosa in a Japanese population

Eating disorders (EDs) have a highly heterogeneous etiology and multiple genetic factors might contribute to their pathogenesis. Ghrelin, a novel growth hormone-releasing peptide, enhances appetite and increases food intake, and human ghrelin plasma levels are inversely correlated with body mass index. In the present study, we examined the 171T/C polymorphism of the ghrelin receptor (growth hormone secretagogue receptor, GHSR) gene in patients diagnosed with EDs, because the subjects having ghrelin gene polymorphism (Leu72Met) was not detected in a Japanese population, previously. In addition, beta3 adrenergic receptor gene polymorphism (Try64Arg) and cholecystokinin (CCK)-A receptor (R) gene polymorphism (-81A/G, -128G/T), which are both associated with obesity, were investigated. The subjects consisted of 228 Japanese patients with EDs [96 anorexia nervosa (AN), 116 bulimia nervosa (BN) and 16 not otherwise specified (NOS)]. The age- and gender-matched control group consisted of 284 unrelated Japanese subjects. The frequency of the CC type of the GHSR gene was significantly higher in BN subjects than in control subjects (chi(2) = 4.47, p = 0.035, odds ratio = 2.05, Bonferroni correction: p = 0.070), while the frequency in AN subjects was not different from that in controls. The distribution of neither beta3 adrenergic receptor gene nor CCK-AR polymorphism differed between EDs and control subjects. Therefore, the CC type of GHSR gene polymorphism (171T/C) is a risk factor for BN, but not for AN.

Absence of PIK3CA hotspot mutations in hepatocellular carcinoma in Japanese patients

A recent study revealed that the p110alpha (PIK3CA), catalytic subunit of phosphatidylinositol 3-kinase (PI3K), is somatically mutated in many types of cancer. For example, PIK3CA is mutated in an estimated 35.6% of hepatocellular carcinoma (HCC) cases. To measure the frequency of PIK3CA hotspot mutations in Japanese HCC patients, exons 9 and 20 of the PIK3CA gene were sequenced in 47 clinical HCC samples. Contrary to expectations, no hotspot mutations were found any of the HCC samples. In addition, we found abnormally migrating waves near the end of exon 9 in the PCR chromatograms from 13 of the 47 samples. PCR amplification and subsequent cloning and sequencing revealed that these chromatograms contained two distinct sequences, the wild-type p110alpha sequence and a different sequence found on human chromosome 22q11.2, the Cat Eye Syndrome region, which contains a putative pseudogene of PIK3CA. These abnormally migrating waves were also found in noncancerous liver tissue, indicating that this was not a result of HCC-associated mutations. Therefore, it is likely that the percentage of hotspot mutations in the PIK3CA gene of Japanese HCC patients is lower than was previously reported.

Increased serum resistin levels in patients with type 2 diabetes are not linked with markers of insulin resistance and adiposity

The role of resistin in human biology remains uncertain. We measured serum resistin levels in Japanese patients with (n=111) and without (n=98) type 2 diabetes mellitus and investigated the significance of this hormone in the pathophysiology of diabetes. The levels of serum adiponectin and leptin were also measured. Resistin levels were increased significantly in patients with type 2 diabetes compared with non-diabetic subjects (24.7+/-2.6 vs. 15.0+/-1.2 ng/ml, p=0.0013). However, there was no correlation in either patient group between serum resistin levels and markers of insulin resistance, obesity or hyperlipidaemia. These results were in direct contrast to the data of leptin or adiponectin, both of which were closely related to these clinical markers of diabetes. Multivariate regression analysis on the combined data of the two groups demonstrated that the presence of diabetes and HDL cholesterol levels were significant predictors of serum resistin levels (diabetes: beta=0.159, p=0.035; HDL: beta=-0.172, p=0.039). No correlation was observed between C-reactive protein and resistin adjusted for BMI. Taken together, these findings demonstrate that serum resistin levels are increased in patients with type 2 diabetes, but this increase is not linked to markers of insulin resistance or adiposity. Further studies are necessary to elucidate the significance of serum resistin concentration in human pathophysiology.