Analysis of liquid reservoir effect induced by pulsed laser liquid jet

A pulsed-laser-induced liquid jet (LILJ) is a new device used in neurosurgery to simultaneously crush, incise, and aspirate tissues and tumors, preserving blood vessels and nerves. In addition, a feature of a pulsed LILJ is its ability to excavate tissue at constant depth while a liquid jet is being repeatedly focused at the same point. To clarify the mechanisms of constant depth of excavation, we employed a gelatin phantom and extracted brain tissue using a high-speed camera, and we then confirmed that the liquid-reservoir-induced LILJ played an important role in enabling the safe usage of an LILJ.

International models of investigator-initiated trials: implications for Japan

BACKGROUND

Academic/institutional investigator-initiated clinical trials benefit individuals and society by supplementing gaps in industry-sponsored clinical trials.

MATERIALS

In May 2010, experts from Japan, the Republic of Korea, the UK, and the United States, met at a symposium in Tokyo, Japan, to discuss how policies related to the conduct of clinical trials, which have been shown to be effective, may be applied to other regions of the world.

RESULTS

In order to increase the availability of anticancer drugs world-wide, nations including Japan should examine the benefits of increasing the number of investigator-initiated clinical trials. These trials represent one of the most effective ways to translate basic scientific knowledge into clinical practice. These trials should be conducted under GCP guidelines and include Investigational New Drug application submissions with the ultimate goal of future drug approval.

CONCLUSIONS

To maximize the effectiveness of these trials, a policy to educate health care professionals, cancer patients and their families, and the public in general on the benefits of clinical trials should be strengthened. Finally, policies that expedite the clinical development of novel cancer drugs which have already been shown to be effective in other countries are needed in many nations including Japan to accelerate drug approval.

Antitumor effect of the angiogenesis inhibitor agm-1470 and its combination effect with tamoxifen in dmba induced mammary-tumors in rats

AGM-1470 is known to inhibit angiogenesis. It inhibited the mitogen induced cell growth in microvascular endothelial cells in vitro. Ten ng/ml AGM-1470 completely inhibited both basic fibroblast growth factor induced cell growth, and interleukin-4 induced cell growth. In an in vivo study, we invesigated the antitumor effect of AGM-1470 in dimethylbenz[a]anthracene (DMBA) induced rat mammary tumors. A dose dependent growth inhibition was seen between administered doses 10 mg/kg and 40 mg/kg. Forty mg/kg 2-week administration of AGM-1470 totally suppressed the tumor growth. In addition, an additive inhibitory effect of AGM-1470 with an antiestrogen tamoxifen was found (p<0.01). It is suggested that the combination of these two drugs might be effective for the treatment of breast cancer.

Prediction of the effect of 5'-deoxy-5-fluorouridine by the status of angiogenic enzyme thymidine phosphorylase expression in recurrent breast cancer patients

The anti-cancer drug, 5'-deoxy-5-fluorouridine (5'DFUR) is known to have antitumor activity through the conversion to 5FU by thymidine phosphorylase (TP). Recently, TP was demonstrated to be identical to angiogenic molecule platelet-derived endothelial cell growth factor (PD-ECGF) by cDNA cloning and subsequent biochemical analyses. We have examined the relationship between the clinical response of 5'DFUR and TP/PD-ECGF expression determined by immunocytochemical analysis in 24 recurrent breast cancer patients. Of 24, 13 were TP/PD-ECGF positive and 11 were TP/PD-ECGF negative. In 13 TP/PD-ECGF positive patients, 4 showed objective response (OR) and 3 showed stable disease (SD) with 5'DFUR treatment, however only one case showed OR and no case showed SD in 11 TP/PD-ECGF negative patients, suggesting that 5'DFUR was likely to be effective for TP/PD-ECGF positive patients. In another group of recurrent breast cancer patients treated by adriamycin containing regimen, no significant correlation was observed between the response of 5'DFUR and the status of TP/PD-ECGF expression. It was indicated that an angiogenic enzyme TP/PD-ECGF expression might be a predictor of the effect of 5'DFUR treatment in human breast cancer.

Immunocytochemical analysis of MDM2 protein expression and its relevance to tumor angiogenesis in primary breast cancer

MDM2 once-protein is known to be involved in the inactivation of p53 and RE functions. We have investigated the expression of MDM2 protein in breast cancer by immunocytochemical analysis. Out of 103 primary tumors 39 (38%) showed positive nuclear staining of MDM2, although its gene amplification was infrequent. There was no correlation between MDM2 expression and various clinicopathological factors. However, MDM2 expression was significantly associated with expression of angiogenesis factors including vascular endothelial growth factor and platelet-derived endothelial cell growth factor. Anti-endothelial immunostaining demonstrated a correlation between MDM2 expression and the increment of intratumoral microvessel density. It is suggested that altered MDM2 protein expression might be involved in the promotion of angiogenesis in human breast cancer.

Scleraxis modulates bone morphogenetic protein 4 (BMP4)-Smad1 protein-smooth muscle α-actin (SMA) signal transduction in diabetic nephropathy

Activation of mesangial cells (MCs), which is characterized by induction of smooth muscle α-actin (SMA) expression, contributes to a key event in various renal diseases; however, the mechanisms controlling MC differentiation are still largely undefined. Activated Smad1 induced SMA in a dose-dependent manner in MCs. As a direct regulating molecule for SMA, we identified and characterized scleraxis (Scx) as a new phenotype modulator in advanced glycation end product (AGE)-exposed MCs. Scx physically associated with E12 and bound the E-box in the promoter of SMA and negatively regulated the AGE-induced SMA expression. Scx induced expression and secretion of bone morphogenetic protein 4 (BMP4), thereby controlling the Smad1 activation in AGE-treated MCs. In diabetic mice, Scx was concomitantly expressed with SMA in the glomeruli. Inhibitor of differentiation 1 (Id1) was further induced by extended treatment with AGE, thereby dislodging Scx from the SMA promoter. These data suggest that Scx and Id1 are involved in the BMP4-Smad1-SMA signal transduction pathway besides the TGFβ1-Smad1-SMA signaling pathway and modulate phenotypic changes in MCs in diabetic nephropathy.

Tuberothalamic artery infarctions following coil embolization of ruptured posterior communicating artery aneurysms with posterior communicating artery sacrifice

BACKGROUND AND PURPOSE

Ischemic complications after coil embolization of the PcomA aneurysms are not thoroughly understood, especially in cases in which the PcomA is sacrificed. Our purpose was to examine the preoperative angiographic features and pattern of postoperative cerebral infarctions exhibited by patients who underwent embolization of ruptured PcomA aneurysms with PcomA sacrifice.

MATERIALS AND METHODS

A retrospective review identified 14 patients with ruptured PcomA aneurysms who underwent embolization of the aneurysms in combination with PcomA sacrifice. Preoperative angiographic data, including the Allcock test, postoperative DWI, and neurologic status, were examined.

RESULTS

Elimination of the aneurysm was complete in all cases. Postoperative DWI indicated 7 cases with infarctions (infarction group) and 7 cases without infarctions (noninfarction group). All patients in the infarction group developed infarctions in the vicinity of the tuberothalamic artery. In all 14 cases, a preoperative Allcock test demonstrated a retrograde filling of the PcomA through the P1 segment. The incidence of negative visualizations of the P1 segment on vertebral angiograms was significantly higher in the infarction group (100%) than in the noninfarction group (0%; P = .00058). The mean PcomA diameters, PcomA/P1 ratios, and aneurysm sizes observed in the infarction group were significantly greater than those in the noninfarction group (P < .05, P < .01, and P < .02, respectively). Tuberothalamic artery infarction caused hemiparesis and memory disturbance, which were associated with unfavorable outcomes.

CONCLUSIONS

After the coil occlusion of ruptured PcomA aneurysms with PcomA sacrifice, tuberothalamic artery infarctions tended to occur in cases exhibiting negative visualization of the P1 segment, even when collateral flow was observed with the Allcock test.

Preoperative evaluation of the deep cerebral veins using 3-tesla magnetic resonance imaging

BACKGROUND

Surgical treatment of deep-seated tumors such as supratentorial intraventricular and thalamic-pineal-tectal region tumors carries a risk of postoperative deficits due to possible damage to deep cerebral veins including the internal cerebral vein. It is often difficult to identify whether the vessel encountered during surgery needs to be preserved or not through the small operative field. Therefore, preoperative evaluation of deep venous structures is important. We evaluated the usefulness of 3-Tesla magnetic resonance imaging (3 T MRI) for this purpose.

METHODS

First, the ability to detect deep venous structures was compared with both 3-dimensional computed tomographical angiography (3D-CTA) and 3 T MRI in patients without any damage to deep venous structures. Images of 7 consecutive patients suffering from insulo-opercular gliomas who underwent both imaging modes for the identification of lateral striate arteries were reconstructed for evaluation of the deep cerebral veins. Subsequently, surgery for tumors at the supratentorial intraventricular and thalamic-pineal-tectal regions was prospectively performed with preoperative evaluation of deep venous system only using 3 T MRI.

RESULTS

Information on the deep venous systems acquired by 3 T MRI was as useful as that acquired by 3D-CTA. Until today, we have treated 8 cases of supratentorial intraventricular and thalamic-pineal-tectal region tumors with preoperative evaluation of the deep venous system using 3 T MRI without any morbidity.

CONCLUSION

Information on the deep venous system obtained with 3 T MRI aids the surgery of supratentorial intraventricular and thalamic-pineal-tectal region tumors. As the required sequences of 3 T MRI are same as those necessary for the neuronavigation system, and 3 T MRI can be achieved without the use of iodine-based contrast agents, 3 T MRI can be an alternative for preoperative evaluation of the deep venous systems.

SOX9 protein induces a chondrogenic phenotype of mesangial cells and contributes to advanced diabetic nephropathy

Diabetic nephropathy (DN) is the most important chronic kidney disease. We previously reported that Smad1 transcriptionally regulates the expression of extracellular matrix in DN. Phenotypic change in mesangial cells (MCs) is a key pathologic event in the progression of DN. The aim of this study is to investigate a novel mechanism underlying chondrogenic phenotypic change in MCs that results in the development of DN. MCs showed chondrogenic potential in a micromass culture, and BMP4 induced the expression of chondrocyte markers (SRY-related HMG Box 9 (SOX9) and type II collagen (COL2)). Advanced glycation end products induced the expression of chondrocyte marker proteins downstream from the BMP4-Smad1 signaling pathway in MCs. In addition, hypoxia also induced the expression of BMP4, hypoxia-inducible factor-1α (HIF-1α), and chondrocyte markers. Overexpression of SOX9 caused ectopic expression of proteoglycans and COL2 in MCs. Furthermore, forced expression of Smad1 induced chondrocyte markers as well. Dorsomorphin inhibited these inductions. Glomerular expressions of HIF-1α, BMP4, and chondrocyte markers were observed in diabetic nephropathy mice. These positive stainings were observed in mesangial sclerotic lesions. SOX9 was partially colocalized with HIF-1α and BMP4 in diabetic glomeruli. BMP4 knock-in transgenic mice showed not only similar pathological lesions to DN, but also the induction of chondrocyte markers in the sclerotic lesions. Here we demonstrate that HIF-1α and BMP4 induce SOX9 expression and subsequent chondrogenic phenotype change in DN. The results suggested that the transdifferentiation of MCs into chondrocyte-like cells in chronic hypoxic stress may result in irreversible structural change in DN.

Activation of bone morphogenetic protein 4 signaling leads to glomerulosclerosis that mimics diabetic nephropathy

Diabetic nephropathy (DN) is the most common cause of chronic kidney disease. We have previously reported that Smad1 transcriptionally regulates the expression of extracellular matrix (ECM) proteins in DN. However, little is known about the regulatory mechanisms that induce and activate Smad1. Here, bone morphogenetic protein 4 (Bmp4) was found to up-regulate the expression of Smad1 in mesangial cells and subsequently to phosphorylate Smad1 downstream of the advanced glycation end product-receptor for advanced glycation end product signaling pathway. Moreover, Bmp4 utilized Alk3 and affected the activation of Smad1 and Col4 expressions in mesangial cells. In the diabetic mouse, Bmp4 was remarkably activated in the glomeruli, and the mesangial area was expanded. To elucidate the direct function of Bmp4 action in the kidneys, we generated transgenic mice inducible for the expression of Bmp4. Tamoxifen treatment dramatically induced the expression of Bmp4, especially in the glomeruli of the mice. Notably, in the nondiabetic condition, the mice exhibited not only an expansion of the mesangial area and thickening of the basement membrane but also remarkable albuminuria, which are consistent with the distinct glomerular injuries in DN. ECM protein overexpression and activation of Smad1 in the glomeruli were also observed in the mice. The mesangial expansion in the mice was significantly correlated with albuminuria. Furthermore, the heterozygous Bmp4 knock-out mice inhibited the glomerular injuries compared with wild type mice in diabetic conditions. Here, we show that BMP4 may act as an upstream regulatory molecule for the process of ECM accumulation in DN and thereby reveals a new aspect of the molecular mechanisms involved in DN.