CDK2 and CDK1 specific activities: A novel prognostic indicator in early breast cancer

10592

Background: Cyclin-dependent kinases (CDKs) are expressed almost constantly but their activities change according to cell cycle phase. We studied the specific activity (SA; activity/expression) of CDKs to accurately evaluate their role in cell proliferation. We focused on the ratio of CDK2 SA to CDK1 SA because this ratio has been associated with rapid tumor growth in human breast cancer xenografts. Our goal was to investigate the prognostic significance of CDK2/1 ratio in node-negative breast cancer. Methods: We used a novel assay to measure SAs of CDK2 and CDK1 in 365 primary breast tumors. All tumors were histologically confirmed invasive breast cancer without lymph node involvement. The primary endpoint was relapse-free survival (RFS). Cut-off values for CDK2/1 ratio were defined as those points that best discriminated groups according to RFS. Tumors were grouped as low (136pts), intermediate (84pts), and high (145pts) CDK2/1 ratio. The median follow-up was 59 months (range 4–102). Results: Pts characteristics are described as follows: menopausal status: pre- 42%, post- 58%; tumor size: =20mm 48%, >20mm 52%; histologic grade (HG): I 28%, II 47%, III 23%; ER: (+) 57%, (-) 42%; PR: (+) 51%, (-) 48%. Pts with HG III or high CDK2/1 ratio showed significantly lower 5y-RFS rates than those with HG I/II or low/intermediate CDK2/1 ratio, respectively (HG: I 97%, II 91%, III 85%, P=0.040; CDK2/1 ratio: low 97%, intermediate 92%, high 85%, P=0.017). In univariate analysis, PR (- vs +, P=0.088) had a tendency to associate with relapse, and HG (III vs I, P=0.024) and CDK2/1 ratio (high vs low, P=0.011) also had a significant correlation with relapse. However, only CDK2/1 ratio showed a significant independent prognostic indicator in multivariate analysis (hazard ratio 2.86, 95% CI 1.25–6.58, P=0.01). More important, among women (n=185) with hormone receptor (HR) positive disease given adjuvant hormone therapy alone, who have had no useful factors to predict their outcomes, high CDK2/1 ratio was also associated with worse prognosis than low CDK2/1 ratio (5y-RFS 84% vs 100%, P=0.007). Conclusions: For patients with node- negative disease, especially those with HR positive tumors given adjuvant hormone therapy alone, the CDK2/1 ratio might be useful as a routine laboratory test to predict outcome.

No significant financial relationships to disclose.

Cyclin-dependent kinase (CDK) activity as a prognostic marker in primary epithelial ovarian cancer

5575

Background: The unpredictable nature of primary epithelial ovarian cancer (EOC) response to treatment necessitates the identification of factors that predict long-term outcome. CDK activity is the core regulator of the cell-cycle checkpoint for cancer cells. We previously found that cell death induced by taxanes requires increased activity of CDK1 and CDK2- fundamental kinases in cell proliferation. Thus, we hypothesized that CDK1/2 activities can determine the prognosis of patients with primary EOC. Methods: We retrospectively analyzed frozen ovarian cancer specimens from 72 women treated with cytoreductive surgery and adjuvant chemotherapy for newly diagnosed EOC. Median patient age was 61 years (range, 38–80), 91% had FIGO stage III/IV disease, and 86% were treated with platinum- or taxane-based regimens. Median follow-up was 32 months; median time to treatment failure (TTF), defined as time from surgery to first relapse for patients who had achieved complete response or time to disease progression for those who had persistent disease, was 15 months. Enzymatic activity of CDK1/2 in the tumor tissues was determined by a modified in vitro kinase activity assay using a C2P device (Sysmex Inc.). Recursive partitioning and regression trees algorithm (RPART) was used to identify the cohorts based on CDK1/2 activities. Results: In the univariate analysis, disease stage (p=0.021), type of surgery (optimal vs. suboptimal) (p=0.004), presence of ascites (p=0.043), and CA125 after the adjuvant therapy (p=0.005) were significant predictors of TTF. The cohort with CDK2 activity = 87.3 had a significantly shorter TTF (p=0.014) and the cohort with CDK1 activity = 226.35 showed a trend toward longer TTF (p=0.094). Multivariate Cox proportional hazards regression analysis revealed CDK2 activity (<87.3 vs. = 87.3) (p=0.012) and CA125 level at completion of the adjuvant chemotherapy regimen (p=0.02) to be independent predictors of TTF. Conclusion: Our data supports kinase activity of cell cycle as a clinically significant prognostic factor. To extend these findings, we plan to conduct a large prospective study to determine whether CDK1/2 profiling can predict long-term outcome in primary EOC.

[Table: see text]

Prospective study of changes in spindle assembly checkpoint (SAC) to predict breast tumor response to taxanes

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Background: Increased cyclin-dependent kinase 1 (CDK1) and reduced CDK2 activity reflects taxane chemosensitivity via regulation of SAC. Novel C2P device (Sysmex Inc.) measures CDK1/2 activity in human tissue within a few hours. We hypothesized that SAC functionality in breast cancer predicts taxane sensitivity. Methods: Biopsy samples obtained before preoperative therapy from 69 pts with primary breast cancer (median age 52, St II, 56%, St III, 40%, HER2 36%, HR 52%) ex vivo with paclitaxel (100 nM) for 24 h, then measured for CDK1/2 activity. Tumors with CDK1/2 ratio > 0.7 were denoted “responders” (CR, PR) based on preclinical testing. Clinical responses were evaluated with sonography. Results: 24 pts could not be evaluated because of unmeasurable or invalid CDK (n=3), no receipt of taxane (n=10), incomplete treatment/lack of imaging (n=10), or receipt of taxane as adjuvant therapy (n=1). Among the 45 evaluable pts, 30 obtained reading to determine the C2P-predicted response, which was significantly associated with the clinical response to preoperative therapy with paclitaxel, docetaxel, docetaxel/doxorubicin, paclitaxel/trastuzumab or lapatinib, or docetaxel/capecitabine (P=0.002; sensitivity 0.83; specificity 0.86; positive predictive value [PPV] 0.95; and negative predictive value [NPV] 0.60). For HER2- tumors, the sensitivity was 0.94; specificity 0.83; PPV 0.94; and NPV 0.83. We fit a series of logistic regression models to assess the relationship between C2P predicted response and clinical outcome. Each model included 1 clinical prognostic factor (HR status, stage, NG, histology, HER2) as well as the C2P prediction factor. In all 5 models C2P remained a statistically significant predictor of clinical response while adjusting for the other prognostic factor. Conclusions: CDK1/2 activity is a promising novel predictive marker to predict response to taxane- containing regimens for HER2- breast cancer. We could not predict taxane sensitivity in HER2+ tumors; this finding is consistent with preclinical findings that HER2 overexpression is involved in abnormal SAC functionality. Thus, the functional SAC reflects taxane sensitivity in HER2- tumors. We are planning a large prospective study to validate these findings.

No significant financial relationships to disclose.

Endoscopic submucosal dissection for rectal tumors

BACKGROUND AND STUDY AIM

Endoscopic submucosal dissection (ESD) has recently been developed for one-piece resection of gastric tumors. In order to improve patients' quality of life, it may be desirable to use the same technique for rectal tumors.

METHODS

35 consecutive patients with rectal tumors were enrolled. ESD was carried out using the same technique as for the stomach. The efficacy, technical feasibility, operation time, complications, and follow-up results were assessed.

RESULTS

The mean size of the epithelial tumors was 26.2 +/- 14.0 mm, and the rates of one-piece resection and one-piece resection with tumor-free margins were 73.3% (22 of 30) and 70.0% (21 of 30), respectively. The median operation time was 70 min (range 8-360 min). All five carcinoid tumors were completely resected. No patient needed blood transfusion or had the complication of problematic bleeding. Perforation during ESD occurred in one patient (2.9%), who was managed with conservative medical treatment after endoscopic closure of the perforation. Excluding seven patients, who either underwent additional surgery or whose follow-up period was less than 1 year, all 23 patients with epithelial tumors were free of recurrence during a mean follow-up period of 25.7 months (range 12-53 months).

CONCLUSIONS

ESD was thus found to be feasible for the treatment of rectal tumors, with promising results although the follow-up periods were short. ESD may therefore be indicated for rectal tumors which are not resectable en bloc by conventional procedures, in order to improve the patients' quality of life.

Endoscopic submucosal dissection for early gastric cancers and large flat adenomas

BACKGROUND AND STUDY AIM

Endoscopic submucosal dissection (ESD) is a new diagnostic and treatment technique for early gastric cancer (EGC). The present study aims to identify the technical feasibility, operation time, and complications associated with ESD.

METHODS

We reviewed the patients who underwent ESD for EGCs at Maebashi Red Cross Hospital.

RESULTS

There were 160 patients with 171 EGCs treated by ESD. The mean age was 71.4 +/- 8.9 years (median 72). The rate for one-piece resection with tumor-free margins was 94.2 % (161/171), and was 93.2 % (82/88) for large lesions (> 20 mm) and 92.1 % (35/38) for ulcerative lesions. The median operation time was 80 min (range 10-600 min). Evidence of immediate bleeding was found in 2.9 % (5/171), delayed bleeding was seen in 7.6 % (13/171), and perforation was observed in 3.5 % (6/171) of the lesions. All patients with complications, including perforation, were successfully treated endoscopically. There were no local or distant metastases in the lesions which met our indication criteria for ESD.

CONCLUSION

The present study shows the technical feasibility of ESD, which provides the capability of one-piece resection even in large and ulcerative lesions.

Percutaneous transluminal angioplasty and stenting for chronic total occlusion of intracranial carotid artery: a case report

SUMMARY

Chronic total occlusion of cerebrovascular lesions is regarded as a contraindication to revascularization. We describe a case of chronic total occlusion of intracranial internal carotid artery that iwass successfully recanalized by endovascular treatment. A 72-year-old man who presented with slight right hemiparesis was proved to have chronic total occlusion of the left intracranial internal carotid artery. Percutaneous transluminal angioplasty/stenting was achieved using reversal of flow with the Parodi Anti-Embolic System. The present case indicates that percutaneous transluminal angioplasty/stenting can be an effective therapeutic option in selected patients with chronic total occlusion of cerebrovascular lesions.

Genomic analysis of the rhg1 locus: candidate genes that underlie soybean resistance to the cyst nematode

The rhg1 gene or genes lie at a recessive or co-dominant locus, necessary for resistance to all Hg types of the soybean (Glycine max (L.) Merr.) cyst nematode (Heterodera glycines I.). The aim here was to identify nucleotide changes within a candidate gene found at the rhg1 locus that were capable of altering resistance to Hg types 0 (race 3). A 1.5 +/- 0.25 cM region of chromosome 18 (linkage group G) was shown to encompass rhg1 using recombination events from four near isogenic line populations and nine DNA markers. The DNA markers anchored two bacterial artificial chromosome (BAC) clones 21d9 and 73p6. A single receptor like kinase (RLK; leucine rich repeat-transmembrane-protein kinase) candidate resistance gene was amplified from both BACs using redundant primers. The DNA sequence showed nine alleles of the RLK at Rhg1 in the soybean germplasm. Markers designed to detect alleles showed perfect association between allele 1 and resistance to soybean cyst nematode Hg types 0 in three segregating populations, fifteen additional selected recombination events and twenty-two Plant Introductions. A quantitative trait nucleotide (QTN) [corrected] in the RLK at rhg1 was inferred that alters A87 to V87 in the context of H274 rather than N274. [corrected] Contiguous DNA sequence of 315 kbp of chromosome 18 (about 2 cM) contained additional gene candidates that may modulate resistance to other Hg-types including a variant laccase, a hydrogen-sodium ion antiport and two proteins of unknown function. A molecular basis for recessive and co-dominant resistance that involves interactions among paralagous disease-resistance genes was inferred that would improve methods for developing new nematode-resistant soybean cultivars.

The role of intraoperative monitoring of oculomotor and trochlear nuclei -safe entry zone to tegmental lesions

OBJECTIVE

A safe entry zone to tegmental lesions was identified based on intraoperative electrophysiological findings, the compound muscle action potentials (CMAP) from the extraocular muscles, and anatomic considerations. This entry zone is bordered caudally by the intramesencephalic path of the trochlear, laterally by the spinothalamic tract, and rostrally by the caudal margin of the brachium of the superior colliculus.

METHODS

Four intrinsic midbrain lesions were operated upon via the safe entry zone using the infratentorial paramedian supracerebellar approach. All lesions involved the tegmentum and included an anaplastic astrocytoma, a metastatic brain tumor, a radiation necrosis, and a cavernous angioma. CMAP were bilaterally monitored from the inferior recti (for oculomotor function) and superior oblique (for trochlear nerve function) muscles.

RESULTS

In three of four cases, CMAP related to the oculomotor nerve were obtained upon stimulation at the cavity wall after removal of the tumor. Stimulation at the surface of the quadrigeminal plate, however, did not cause any CMAP response. Using this monitoring as an indicator, the lesions were totally removed.

CONCLUSIONS

In the surgery of tegmental lesions, CMAP monitoring from extraocular muscles is particularly helpful to prevent damage to crucial neural structures during removal of intrinsic lesions, but less so to select the site of the medullary incision. The approach via the lateral part of the colliculi is considered to be a safe route to approach the tegmental lesions.

Endoscopic submucosal dissection for early gastric cancers and large flat adenomas

BACKGROUND AND STUDY AIM

Endoscopic submucosal dissection (ESD) is a new diagnostic and treatment technique for early gastric cancer (EGC). The present study aims to identify the technical feasibility, operation time, and complications associated with ESD.

METHODS

We reviewed the patients who underwent ESD for EGCs at Maebashi Red Cross Hospital.

RESULTS

There were 160 patients with 171 EGCs treated by ESD. The mean age was 71.4 +/- 8.9 years (median 72). The rate for one-piece resection with tumor-free margins was 94.2 % (161/171), and was 93.2 % (82/88) for large lesions (> 20 mm) and 92.1 % (35/38) for ulcerative lesions. The median operation time was 80 min (range 10-600 min). Evidence of immediate bleeding was found in 2.9 % (5/171), delayed bleeding was seen in 7.6 % (13/171), and perforation was observed in 3.5 % (6/171) of the lesions. All patients with complications, including perforation, were successfully treated endoscopically. There were no local or distant metastases in the lesions which met our indication criteria for ESD.

CONCLUSION

The present study shows the technical feasibility of ESD, which provides the capability of one-piece resection even in large and ulcerative lesions.

Force control between quantum dots by light in polaritonic molecule states

Photomediated force between quantum dots (QDs) is theoretically studied. An attractive (repulsive) interparticle radiation force (IRF) arises by selectively exciting the lower (higher) split state of coupled polaritons in QDs. Since these states are analogous to bonding and antibonding states of a diatomic molecule, we term this system the "polaritonic molecule (PM)". IRF in PM states is controlled by the photon energy, polarization, and phase at each QD. This mechanism can be used to probe internal quantum properties of nano-objects and to manipulate collective dynamics of QDs.

The Role of Cyberknife Radiosurgery/Radiotherapy for Brain Metastases of Multiple or Large-Size Tumors

OBJECTIVE

Focused, highly targeted radiosurgery and fractionated radiotherapy using the Cyberknife are useful treatments for multiple or large metastases. Here we present our results of Cyberknife radiosurgery for 71 patients with 148 metastatic brain lesions.

METHODS

There were 32 women and 39 men with a median age of 63 (range: 30-88) years. Radiographic follow-up was available for 60 patients with 104 lesions. The mean and median initial volumes of the tumor per lesion were 6.6 and 2.9 cm(3) (range: 0.1-53.2 cm(3)), respectively, at the time of the initial Cyberknife treatment. Forty patients (56%) had a single lesion, and 31 (44%) had multiple lesions (range: 2-7) at initial treatment. The number of fractions ranged from 1 to 3, and forty (27%) of 148 lesions were treated by a fractionated course of Cyberknife therapy. The mean marginal dose was 20.2 Gy (range 7.8-30.1 Gy, median: 20.7 Gy).

RESULTS

At 44 weeks of median follow-up, there were no permanent symptoms resulting from radiation necrosis. Overall 6-month and 1-year survival rates were 74% and 47%, respectively, and the median survival time was 56 weeks. The Karnofsky performance score and extracranial metastasis were significant prognostic factors at 6 months and 1 year, respectively, in both univariate and multivariate analyses. Age or multiple metastases did not influence prognosis at 6 months and 1 year. Local control was achieved in 83% (86 lesions). After additional radiosurgical or surgical salvage, no patient died as a result of intracranial disease. Twenty-five patients developed 92 new metastases (range 1-13) outside of the treated lesions with 22.4 weeks of median follow-up. Among them, 21 patients (84 lesions) were treated by salvage Cyberknife.

CONCLUSION

Despite the inclusion of an unfavorable group of patients with large tumors, our results for survival and tumor control rates are comparable to those of published series. The Cyberknife provides the advantage of allowing for fractionated treatment to multiple or large-size tumors.

CyberKnife Stereotactic Radiotherapy for Patients with Malignant Glioma

OBJECTIVE

The CyberKnife is a new frameless image-guided radiosurgical modality. The authors report on their experience using the CyberKnife in 25 patients with malignant gliomas.

METHODS

Twenty-five patients with histologically proven malignant gliomas (18 glioblastoma: GB, 7 anaplastic astrocytoma: AA) were treated with the CyberKnife at Konan St. Hill Hospital between June 1998 and November 2002. CyberKnife therapy was performed on 44 lesions (31 GB lesions, 13 AA lesions) in the 25 patients. The median target volume was 19.1 mL (range: 0.3 - 90.2). The median prescribed dose was 20.3 Gy (range: 13.9 - 26.4). Patient-, tumor-, and treatment-related variables were analyzed by univariate analysis, and survival curves were generated by the Kaplan-Meier product limit.

RESULTS

In the 18 GB patients, the median survival after diagnosis was 20.7 months (82.6 weeks) with a mean follow-up of 85.7 weeks. Of the 7 AA patients, 6 were alive at the time of analysis with follow-up periods ranging from 11.4 to 52.8 months. Patients younger than 70 years had a median survival after diagnosis of 37.1 months, compared to 12.4 months for older patients (p = 0.003). Similarly, patients with well-controlled lesions had a median survival after diagnosis of 39.8 months compared to 16.0 months for those with uncontrolled lesions (p = 0.031). Late delayed radiation necrosis was seen in 1 GB patient. No other patient suffered acute or delayed neurological morbidity after CyberKnife therapy.

CONCLUSION

This is the first report of CyberKnife stereotactic radiotherapy applied to the treatment of malignant gliomas. The frameless and painless CyberKnife stereotactic radiotherapy has the potential to be as useful for treatment of malignant glioma as other radiosurgical modalities.

Computed Tomography Angiography of Carotid Stent. Comparison of Various Self-expandable Stent in a Phantom Model

SUMMARY

We evaluated Computed Tomography Angiography (CTA) of four different self-expandable stents in phantom model. Three stents ware made of nitinol and one was made of cobaltbased alloy. Each stent placed in plastic injector, filled with diluted iodinated contrast material, and placed on a plastic case filled with saline. CTA was performed on a four-detector CT scanner (detector collimation, 0.5mm: helical pitch 3.5). Axial and longitudinal reconstructions of CT imaging were compared with the instent attenuation. Three nitinol stents showed few artifact, and cobalt-based alloy stent was appeared artificial narrowing. In conclusion, CTA is useful for follow-up examination after carotid artery stenting (CAS) as a less invasive evaluation method.

Kojic acid production in an airlift bioreactor using partially hydrolyzed raw corn starch

In a culture of Aspergillus oryzae MK-107-39 in a 3-l airlift bioreactor, kojic acid was not produced when glucose/wheat germ medium (GM1) was used. However, when a jar fermentor was used, the kojic acid yield was high. A suitable medium for culture in an airlift bioreactor consisting of partially hydrolyzed corn starch and a small amount of corn steep liquor (CSL) (SM1) was selected. In the cultivation in the airlift bioreactor using SM1, nearly 40 g/l of kojic acid was produced, which was the same as the amount produced in the jar fermentor containing GM1. The optimum aeration rate for the airlift bioreactor was 2.0 vvm (0.66 cm/s of superficial linear velocity (Vs)). The cost of SM1 using the airlift bioreactor was reduced to 40% that of GM1 using the jar fermentor. Furthermore, the energy cost of kojic acid production using SM1 in the airlift bioreactor was less than one-fourth of that for the jar fermentor using GM1.

Initial distribution volume of glucose is correlated with intrathoracic blood volume in hypovolaemia and following volume loading in dogs

BACKGROUND AND OBJECTIVE

Initial distribution volume of glucose (IDVG) reliably measures the central extracellular fluid volume in the presence of fluid gain or loss. We hypothesized that IDVG has a close relationship with intrathoracic blood volume (ITBV), which has recently been used as an indicator of cardiac preload. We therefore examined whether IDVG can correlate with ITBV in various fluid volume states.

METHODS

Fourteen anaesthetized mongrel dogs were mechanically ventilated. ITBV and cardiac output were measured by single transpulmonary thermodilution technique. IDVG and indocyanine green derived plasma volume (PV-ICG) were determined by the administration of 100 mg kg(-1) glucose and 0.5 mg kg(-1) indocyanine green solutions, respectively, and calculated by applying a one-compartment model. Three sets of measurements were performed before and after haemorrhage (30 mL kg(-1) and subsequent fluid volume loading (90 mL kg(-1) of lactated Ringer's solution).

RESULTS

A linear correlation was observed between IDVG and ITBV (r2 = 0.52, n = 42, P < 0.001) and between PV-ICG and ITBV (r2 = 0.44, n = 42, P < 0.001) throughout the procedures. A linear correlation was also observed between changes in IDVG and those in ITBV (r2 = 0.76, n = 28, P < 0.001). The ITBV/IDVG ratio during normovolaemia was 0.26 +/- 0.04, which remained unchanged during the procedure.

CONCLUSION

Results showed that that IDVG has a linear correlation with ITBV, and support the concept that IDVG measurement has potential as a surrogate measure of ITBV in various fluid volume states.

Impact of the liver-specific expression of SHIP2 (SH2-containing inositol 5'-phosphatase 2) on insulin signaling and glucose metabolism in mice

We investigated the role of hepatic SH2-containing inositol 5'-phosphatase 2 (SHIP2) in glucose metabolism in mice. Adenoviral vectors encoding wild-type SHIP2 (WT-SHIP2) and a dominant-negative SHIP2 (DeltaIP-SHIP2) were injected via the tail vein into db/+m and db/db mice, respectively. Four days later, amounts of hepatic SHIP2 protein were increased by fivefold. Insulin-induced phosphorylation of Akt in liver was impaired in WT-SHIP2-expressing db/+m mice, whereas the reduced phosphorylation was restored in DeltaIP-SHIP2-expressing db/db mice. The abundance of mRNA for glucose-6-phosphatase (G6Pase) and PEPCK was increased, that for glucokinase (GK) was unchanged, and that for sterol regulatory element-binding protein 1 (SREBP)-1 was decreased in hepatic WT-SHIP2-overexpressing db/+m mice. The increased expression of mRNA for G6Pase and PEPCK was partly suppressed, that for GK was further enhanced, and that for SREBP1 was unaltered by the expression of DeltaIP-SHIP2 in db/db mice. The hepatic expression did not affect insulin signaling in skeletal muscle and fat tissue in both mice. After oral glucose intake, blood glucose levels and plasma insulin concentrations were elevated in WT-SHIP2-expressing db/+m mice, while elevated values were decreased by the expression of DeltaIP-SHIP2 in db/db mice. These results indicate that hepatic SHIP2 has an impact in vivo on the glucose metabolism in both physiological and diabetic states possibly by regulating hepatic gene expression.

Impact of SRC homology 2-containing inositol 5'-phosphatase 2 gene polymorphisms detected in a Japanese population on insulin signaling

Src homology 2-containing 5'-inositol phosphatase 2 (SHIP2) is known to be one of lipid phosphatases converting PI(3,4,5)P3 to PI(3,4)P2 in the negative regulation of insulin signaling with the fundamental impact on the state of insulin resistance. To clarify the possible involvement of SHIP2 in the pathogenesis of human type 2 diabetes, we examined the relation of human SHIP2 gene polymorphisms to type 2 diabetes in a Japanese population. We identified 10 polymorphisms including four missense mutations. Among them, single nucleotide polymorphism (SNP)3 (L632I) was located in the 5'-phosphatase catalytic region, and SNP5 (N982S) was adjacent to the phosphotyrosine binding domain binding consensus motif in the C terminus. SNP3 was found more frequently in control subjects than in type 2 diabetic patients, suggesting that this mutation might protect from insulin resistance. Transfection study showed that expression of SNP3-SHIP2 inhibited insulin-induced PI(3,4,5)P3 production and Akt2 phosphorylation less potently than expression of wild-type SHIP2 in CHO-IR cells. Insulin-induced tyrosine phosphorylation of SNP5-SHIP2 was decreased compared with that of wild-type SHIP2, resulting in increased Shc/Grb2 association and MAPK activation. These results indicate that the polymorphisms of SHIP2 are implicated, at least in part, in type 2 diabetes, possibly by affecting the metabolic and/or mitogenic insulin signaling in the Japanese population.

Image-Guided Stereotactic Radiosurgery with the CyberKnife for Pituitary Adenomas

This study demonstrates the clinical usefulness of image-guided fractionated stereotactic radiosurgery with the CyberKnife system. Twenty-one patients with pituitary adenomas received image-guided stereotactic radiosurgery with the CyberKnife, and were followed up for more than 18 months. The patients consisted of 14 with non-functioning adenomas, 3 with prolactinomas, 2 with acromegaly, and 2 with ACTH-producing tumors. In 20 cases, fractionated radiosurgery was performed. The change in the tumor volume, visual acuity, hormonal function, and complications by this therapy were analyzed in each case. The volume of the tumors ranged from 0.2 cm (3) to 34.9 cm (3) (mean +/- SD: 11.3 +/- 9.2 cm (3)). The mean volumes of the non-functioning and functioning adenomas were 13.3 cm (3) and 7.5 cm (3), respectively. The marginal irradiation dose ranged from 6.4 Gy to 27.7 Gy (mean: non-functioning adenomas 12.6 Gy, functioning adenomas 17.5 Gy), as a dose of a single fraction. The follow-up periods ranged from 18 months to 59 months (mean +/- SD: 35.3 +/- 10.7 months). The tumor control rate was 95.2 %. In 1 case, visual acuity worsened due to cystic enlargement of the tumor. Hormonal function improved in all of the 7 functioning adenomas. The hormone level normalized in 1 prolactinoma, and decreased to less than normal in 1 ACTH-producing adenoma. In 2 cases, hypopituitarism occurred after the therapy. Image-guided stereotactic radiosurgery with the CyberKnife is effective and safe against relatively large pituitary adenomas. Careful long-term follow-up of the patients is necessary because of delayed cystic enlargement of the tumor in rare cases.

Inhibition of endogenous SHIP2 ameliorates insulin resistance caused by chronic insulin treatment in 3T3-L1 adipocytes

AIMS/HYPOTHESIS

SHIP2 is a physiologically important negative regulator of insulin signalling hydrolysing the PI3-kinase product, PI(3,4,5)P3, which also has an impact on insulin resistance. In the present study, we examined the effect of inhibiting the endogenous SHIP2 function on the insulin resistance caused by chronic insulin treatment.

METHODS

The endogenous function of SHIP2 was inhibited by expressing a catalytically inactive SHIP2 (DeltaIP-SHIP), and compared with the effect of treatments designed to restore the levels of IRS-1 in insulin signalling systems of 3T3-L1 adipocytes.

RESULTS

Chronic insulin treatment induced the large (86%) down-regulation of IRS-1 and the modest (36%) up-regulation of SHIP2. Subsequent stimulation by insulin of Akt phosphorylation, PKClambda activity, and 2-deoxyglucose (2-DOG) uptake was markedly decreased by the chronic insulin treatment. Coincubation with the mTOR inhibitor, rapamycin, effectively inhibited the proteosomal degradation of IRS-1 caused by the chronic insulin treatment. Although the coincubation with rapamycin and advanced overexpression of IRS-1 effectively ameliorated subsequent insulin-induced phosphorylation of Akt, insulin stimulation of PKClambda activity and 2-DOG uptake was partly restored by these treatments. Similarly, expression of DeltaIP-SHIP2 effectively ameliorated the insulin-induced phosphorylation of Akt without affecting the amount of IRS-1. Furthermore, the decreased insulin-induced PKClambda activity and 2-DOG uptake following chronic insulin treatment were ameliorated by the expression of DeltaIP-SHIP2 more effectively than by the treatment with rapamycin.

CONCLUSIONS/INTERPRETATION

Our results indicate that the inhibition of endogenous SHIP2 is effective in improving the state of insulin resistance caused by chronic insulin treatment.

Simulation Study of Distal Balloon Protection Systems during Carotid Artery Stenting

The purpose of our experimental study was to assess the pitfalls of distal balloon protection systems and to learn any technique tips to increase safety.

Silicone carotid artery models were connected to a circulatory system to simulate arterial flow. A distal balloon protection device, PercuSurge GuardWire Plus (GWP, Medtronic Vascular) was delivered to the internal carotid artery (ICA), then was inflated to occlude ICA flow temporarily. A debris aspiration catheter (Export catheter) was delivered just proximal to the GuardWire Plus balloon coaxially, in order to introduce and diffuse particulate debris (200–500 micro meter in diameter) in the ICA stump. Then, after debris in the stump was aspirated, the GWP balloon was deflated. We recorded all the processes of our simulation experiments on a digital video and observed the movements of debris during these experiments.

Exp 1) We simulated the movements of debris in the ICA stump when the GWP balloon was gradually deflated to produce a crevice between the balloon and vessel wall, simulating accidental movement of the GWP balloon during the procedure.

Exp 2) In order to assess the optimal placement of the tip of aspiration catheter, the debris in the ICA stump was aspirated from three different sites (from just below the GuardWire balloon, from 2 cm below it, and from 5 cm below it).

Exp 1) When the crevice appeared between GuardWire balloon and silicone tube, simulated debris began to concentrate just below the balloon. Then, some debris migrated distally from the crevice, and another part crowded in the crevice so that was impossible to aspirate and migrated in the end.

Exp. 2) Debris aspiration was most effective from immediately below the GuardWire balloon, and the aspiration ability declined as the distance between the balloon and aspiration catheter became longer. According to our simulation studies, when the GWP balloon was moved accidentally during CAS procedures, or when the aspiration catheter was not delivered all the way to the GuardWire Plus balloon, distal embolization might still occur, even under protection.

Evaluation of two-photon nonlinearity by a semiclassical method

In order to discuss the two-photon nonlinearity theoretically, both photons and nonlinear materials should be treated quantum mechanically, which usually is a heavy theoretical task. Contrarily, nonlinear optics for classical light has been developed well and a detailed analysis is possible for realistic complex nonlinear systems. Here we show that the two-photon nonlinearity can be evaluated from the linear and third-order nonlinear output fields against a classical input pulse, which contains 2(-1/2) photons on average.

Hepatic vein anastomotic stricture after living donor liver transplantation

This report discusses the pathophysiology of and therapeutic methods to address hepatic vein anastomotic stricture after living donor liver transplantation (LDLT). From 1994 to 2002, our 15 LDLTs using the lateral segments or left lobes included four recipients who experienced 28 occurrences of this complication after the operation. The period between LDLT and the first stricture was 4.0 +/- 1.2 months. The age of the affected recipients (31.0 +/- 8.2 years) was significantly higher than that of the nonaffected patients (7.0 +/- 4.1 years, P < .05). Graft liver/standard liver volume ratio was 39.1% +/- 3.8% in the former and 77.9% +/- 12.7% in the latter cases (P < .05). Initial symptoms of stricture were ascites (42.9%), abdominal distention (42.9%), liver enzyme elevation (10.7%), and gastrointestinal bleeding (3.6%). In addition, 14 of 28 stricture cases (50%) showed increased blood trough levels of tacrolimus. Doppler ultrasonography was used for diagnosis, and balloon dilatations performed in all stricture patients, thereby hepatic significantly reducing venous blood pressure from 33.5 +/- 1.7 to 20.3 +/- 1.5 cmH2O. All patients finally resolved the strictures after several treatments. The stricture after LDLT was associated with small-for-size grafts, suggesting that liver regeneration may lead to anatomical changes and strictures. Since tacrolimus is metabolized by the liver, its blood trough level is one initial symptoms of stricture. Balloon dilatation was useful and safe as the treatment, while problems have been reported after stent insertion in the hepatic vein.