Novel Functional Peptide for Next-Generation Vital Pulp Therapy.

Although vital pulp therapy should be performed by promoting the wound-healing capacity of dental pulp, existing pulp-capping materials were not developed with a focus on the pulpal repair process. In previous investigations of wound healing in dental pulp, we found that organic dentin matrix components (DMCs) were degraded by matrix metalloproteinase-20, and DMC degradation products containing protein S100A7 (S100A7) and protein S100A8 (S100A8) promoted the pulpal wound-healing process. However, the direct use of recombinant proteins as pulp-capping materials may cause clinical problems or lead to high medical costs. Thus, we hypothesized that functional peptides derived from recombinant proteins could solve the problems associated with direct use of such proteins. In this study, we identified functional peptides derived from the protein S100 family and investigated their effects on dental pulp tissue. We first performed amino acid sequence alignments of protein S100 family members from several mammalian sources, then identified candidate peptides. Next, we used a peptide array method that involved human dental pulp stem cells (hDPSCs) to evaluate the mineralization-inducing ability of each peptide. Our results supported the selection of 4 candidate functional peptides derived from proteins S100A8 and S100A9. Direct pulp-capping experiments in a rat model demonstrated that 1 S100A8-derived peptide induced greater tertiary dentin formation compared with the other peptides. To investigate the mechanism underlying this induction effect, we performed liquid chromatography-tandem mass spectrometry analysis using hDPSCs and the S100A8-derived peptide; the results suggested that this peptide promotes tertiary dentin formation by inhibiting inflammatory responses. In addition, this peptide was located in a hairpin region on the surface of S100A8 and could function by direct interaction with other molecules. In summary, this study demonstrated that a S100A8-derived functional peptide promoted wound healing in dental pulp; our findings provide insights for the development of next-generation biological vital pulp therapies.

Dynamic alterations of hepatocellular function by on-demand elasticity and roughness modulation.

Temperature-responsive cell culture substrates reported here can be dynamically programmed to induce bulk softening and surface roughness changes in the presence of living cells. Alterations in hepatocellular function following temporally controlled substrate softening depend on the extent of stiff mechanical priming prior to user-induced material transition.

Natural course of dissecting vertebrobasilar artery aneurysms without stroke.

BACKGROUND AND PURPOSE: The natural history and therapeutic management of dissecting vertebrobasilar aneurysms without ischemic or hemorrhagic stroke (nonstroke dissecting vertebrobasilar aneurysms) are not well-established. We conservatively followed patients with nonstroke dissecting vertebrobasilar aneurysms and evaluated the factors related to clinical and morphologic deterioration. MATERIALS AND METHODS: One hundred thirteen patients were enrolled and divided by clinical presentation at diagnosis: asymptomatic (group 1, n = 52), pain only (group 2, n = 56), and mass effect (group 3, n = 5). Patients were conservatively managed without intervention and antithrombotic therapy. Clinical outcomes and morphologic changes were analyzed. RESULTS: A total of 113 patients who were diagnosed with nonstroke dissecting vertebrobasilar aneurysm had a mean follow-up of 2.9 years (range, 27 days to 8 years). Throughout that period, 1 patient in group 1 (1.9%) and 1 patient in group 2 (1.8%) showed clinical deterioration due to mass effect, and 1 patient in group 3 (20%) developed ischemic stroke followed by subarachnoid hemorrhage. Most patients (97.3%) were clinically unchanged. Three patients who had clinical deterioration showed aneurysm enlargement (P < .001). Aneurysms remained morphologically unchanged in 91 patients (80.5%). Aneurysm enlargement was seen in 5 patients (4.4%); risk of enlargement was significantly associated with either maximum diameter (hazard ratio = 1.30; 95% CI, 1.11-11.52; P = .001) or aneurysm ≥10 mm (hazard ratio = 18.0; 95% CI, 1.95-167; P = .011). CONCLUSIONS: The natural course of these lesions suggests that acute intervention is not always required and close follow-up without antithrombotic therapy is reasonable. Patients with symptoms due to mass effect or aneurysms of >10 mm may require treatment.

Validation and initial application of a semiautomatic aneurysm measurement software: a tool for assessing volumetric packing attenuation.

BACKGROUND AND PURPOSE: Precise aneurysm measurements and volume embolization ratios are essential for long-term durability of endovascular coil embolization. We evaluated the accuracy of newly developed semiautomatic cerebral aneurysm measurement software, NeuroVision, and explored the value of volume embolization ratio in the prediction of re-treatment. MATERIALS AND METHODS: We compared software-derived volume measurements of 4 silicone aneurysm models with those calculated with an approximation formula and ground truth values (validation study). We used NeuroVision to retrospectively evaluate outcomes of 100 unruptured aneurysms (97 patients) treated with embolization (clinical study). Aneurysm size (height, width, and neck), volume, and volume embolization ratios were calculated for 3 groups (stable, recanalization, and re-treatment) and were compared. RESULTS: This validation study illustrated higher accuracy of NeuroVision in computing aneurysm volume compared with an approximation formula: percentage absolute errors were 4.50% ± 3.18% and 23.07% ± 17.60%, with maximal percentage absolute errors of 8.99% and 45.63%, respectively. Of 100 unruptured aneurysms, 20 recanalized and 12 were re-treated. Average volume embolization ratios of stable and re-treated aneurysms were 24.88% ± 5.91% and 20.50% ± 4.06%, respectively (P ≤ .01). The optimal volume embolization ratio cutoff point for re-treatment was < 19.15%, at which the Youden index was 0.50 (sensitivity, 58.33%; specificity, 87.50%; area under the receiver operating characteristic curve, 0.74). CONCLUSIONS: The NeuroVision software provided accurate aneurysm volume measurements and may be a useful standardized tool to measure aneurysm size and volume, especially for multicenter clinical studies. Volume embolization ratio may be a valuable predictor of aneurysm occlusion changes.

Justification of unruptured intracranial aneurysm repair: a single-center experience.

BACKGROUND AND PURPOSE: Whether to treat UIAs is controversial. The aim of the study was to compare the clinical outcome of patients with UIAs who were either treated conservatively or preventively. MATERIALS AND METHODS: Patients with UIAs referred to our institution were prospectively enrolled in the study. Data collected included baseline characteristics, aneurysmal features, and procedural and follow-up information. Preventive treatment was recommended if the aneurysm was larger than 5 mm and was considered safely treatable. Endovascular surgery was the first-line therapy if the aneurysmal shape was appropriate for coiling. RESULTS: From January 2003 through April 2008, a total of 879 patients with 1110 UIAs were enrolled; 325 patients with 369 UIAs (mean size, 7.8 mm) were treated (treatment group), and 603 patients with 741 UIAs (mean size, 4.4 mm) were managed conservatively (observation group). Mean follow-up was 692.5 days (1405.5 person-years). In the observation group, 26 aneurysms (3.5%) had ruptured (1.8% per year; 1405.5 person-years), 10 patients died, and 7 were disabled (mRS, 3-6: 2.8%). Aneurysmal size was a significant risk factor for rupture (P = .001). The treatment group included aneurysms treated either with coiling (n=315), clipping (n=32), or a combined approach (n=9); 1 patient died, and 3 were disabled (mRS, 3-6: 1.2%). Therapeutic intervention was equal (UIAs of all sizes) or superior (UIAs > 5 mm; P = .025) to conservative management. CONCLUSIONS: Treatment of UIAs was justified in aneurysms larger than 5 mm, and EVS can be safely applied to nearly 90% of UIAs.

Supramolecular approaches for drug development.

Various supramolecular systems can be used as drug carriers to alter physicochemical and pharmacokinetic characteristics of drugs. Representative supramolecular systems that can be used for this purpose include surfactant/polymer micelles, (micro)emulsions, liposomes, layer-by-layer assemblies, and various molecular conjugates. Notably, liposomes are established supramolecular drug carriers, which have already been marketed in formulations including AmBisome(®) (for treatment of fungal infection), Doxil(®) (for Kaposi's sarcoma), and Visudyne(®) (for age-related macular degeneration and choroidal neovascularization). Microemulsions have been used oral drug delivery of poorly soluble drugs due to improvements in bioavailability and predictable of absorption behavior. Neoral(®), an immunosuppressant used after transplant operations, is one of the most famous microemulsion-based drugs. Polymer micelles are being increasingly investigated as novel drug carriers and some formulations have already been tested in clinical trials. Supramolecular systems can be functionalized by designing the constituent molecules to achieve efficient delivery of drugs to desired sites in the body. In this review, representative supramolecular drug delivery systems, that may improve usability of candidate drugs or add value to existing drugs, are introduced.

Delayed hydrocephalus after embolization of unruptured aneurysms using bare platinum coils: report of 2 cases.

Postembolization hydrocephalus with bare platinum coils has not been reported, to our knowledge. We report 2 cases of unusual delayed hydrocephalus after treatment of unruptured intracranial aneurysms with bare platinum coils.

Patient skin dose during neuroembolization by multiple-point measurement using a radiosensitive indicator.

BACKGROUND AND PURPOSE: Although neuroembolization has recently spread quickly, sufficient attention has not been focused on the associated radiation exposure. The purpose of this research was to evaluate the patient's entrance skin dose (ESD) during neuroembolizations in 6 institutions. MATERIALS AND METHODS: This study was approved by all of the 6 institutional review boards, and all of the patients gave informed consent. This study included a total of 103 consecutive neuroembolizations in the 6 institutions. Patient ESDs during the procedures were evaluated by using caps that had 44 radiosensitive indicators adherent to the surface. The patient ESDs were calculated from the color difference of the indicators. To check for effects on the scalp, clinical follow-up was performed at 1-2 days, 2 weeks, and 3 months after the procedure. RESULTS: The averages of total fluoroscopic time, total number of digital subtraction angiography frames, and dose area product were 67.1 +/- 41.6 minutes, 883 +/- 626, and 257 +/- 150 Gy x cm(2), respectively. The average maximum ESD for each patient was 1.9 +/- 1.1 Gy (range, 0.4-5.6 Gy; median, 1.5 Gy). The average maximum ESDs of each institution ranged from 1.0 to 2.4 Gy. Epilation was observed in 6 patients. CONCLUSIONS: The maximum ESDs during neuroembolizations exceed the thresholds for radiation skin injuries in some cases.

Application of percutaneous ultrasound-guided treatment for ultrasonically invisible hypervascular hepatocellular carcinoma using microbubble contrast agent.

AIM: To evaluate the efficacy of contrast-enhanced ultrasound for the localization of ultrasonically invisible hypervascular lesions in the liver to facilitate percutaneous ultrasound-guided treatment. MATERIALS AND METHODS: Forty patients with 47 ultrasonically invisible hypervascular lesions (5-20mm) diagnosed on contrast-enhanced computed tomography were enrolled in the retrospective study. Contrast-enhanced ultrasound (CEUS) with Levovist was performed to localize the lesions both in the early phase and liver-specific phase. Diagnosis of was confirmed by percutaneous needle biopsy where feasible, and on the basis of on treatment outcomes or changes in computed tomography findings in those not amenable to biopsy. RESULTS: Thirty-two lesions were diagnosed as hepatocellular carcinoma (HCC). Contrast-enhanced ultrasound localized hepatocellular carcinoma in 24/32 (75%) lesions, the mean diameter (15.1+/-4.9mm), as measured using computed tomography, being significantly larger than that of the remaining eight lesions (10.5+/-2.1mm). Ultrasound-guided treatment was performed in 19 of the 24 lesions, and transarterial chemoembolization (TACE) was applied for the other five lesions because of difficult percutaneous access. Five of the eight non-visualised lesions were treated by transarterial chemoembolization, and the other three by surgical resection. The beneficial effect of CEUS was significantly greater when the reason for poor initial visualisation was the coarse liver architecture (17/17) than when it was due to adverse location (seven of 15, p<0.005). Fifteen of the CT-detected hypervascular lesions were considered to represent false positives for HCC, based on their behaviour during follow-up. CONCLUSION: Contrast-enhanced ultrasound with Levovist facilitates the application of percutaneous ultrasound-guided treatment by improving localization of ultrasonically invisible hypervascular hepatocellular carcinomas in the liver.

Gene expression of 5-fluorouracil metabolic enzymes in hepatocellular carcinoma and non-tumor tissue.

5-fluorouracil (5-FU) is a basic agent used in chemotherapy. The aim of this study is to investigate the gene expression of 5-FU anabolic and catabolic enzymes in hepatocellular carcinoma (HCC) and non-tumor tissue, respectively to increase our knowledge of resistant mechanisms to 5-FU in HCC. The relative mRNA level of orotate phosphoribosyltransferase (OPRT), ribonucleotide reductase (RNR), dihydropyrimidine dehydrogenase (DPD) and target enzyme thymidylate synthase (TS), were analyzed in 30 matched samples of HCC (T) and non-tumor tissue (NT) using quantitative RT-PCR. The expression of OPRT, RNR-M1, RNR-M2 and TS is significantly higher in T compared with in NT (1.3-fold increase, 1.6-fold, 7.1-fold, 1.9-fold, respectively), but that of DPD showed no difference between T and NT. Our results show that HCC should not be treated with 5-FU alone because of its instability in liver.

Radiation Exposure during Cerebral Artery Aneurysm Coil Embolization: the Current Situation and Measures to Prevent Radiation Injury.

SUMMARY: Coil embolization is the treatment of choice for cerebral artery aneurysms at our institution. The duration of a fluoroscopic study and frequency of radiation exposure are varied, and the safety measures against radiation injury have not yet been established. Guidelines about radiation injury prevention with IVR have been published. However, there is not yet a detailed report for the head region. We also report our measures to try to reduce the amount of radiation exposure during the embolization procedure in our institution.

Efficacy of 3-D Reconstructed Time of Flight MRA Follow-up of the Embolized Cerebral Aneurysms.

SUMMARY: A follow-up of the embolized cerebral aneurysm with Guglielmi Detachable Coils (GDC) were performed mainly using craniograms and digital subtraction angiograms (DSA) so far.Recently, several authors have reported about efficacy of the time of flight (TOF) magnetic resonance angiogram (MRA) as a follow-up for the embolized cerebral aneurysms. In our institution, 3-D reconstructed TOF MRAs have been performed as a follow-up of the embolized cerebral aneurysms.We examined efficacy of 3-D reconstructed TOF MRA. 3-D TOF MRA was performed for a followup of the embolized cerebral aneurysms at our outpatient clinic in 35 patients. Morphological examination of the 3-D images between 3-D TOF MRA and 3-D DSA was performed. Almost similar images of 3-D MRA were obtained after 3-D reconstruction as compared with those of 3-D DSA. In three cases, recanalization was suspected in the 3-D TOF MRA. And recanalization was confirmed in the 3-D DSA actually. A quality of 3-D TOF MRA for a diagnosis of recanalization was good and practical. However, in two cases, arteries were partially disappeared in the 3-D TOF MRA.These were the artifact due to coil mass and this is a current limitation of 3-D TOF MRA. The images of 3-D TOF MRA that were reconstructed in the 3-D workstation were very similar to those of 3-D DSA. 3-D reconstructed TOF MRA was very useful for a less-invasive diagnosis of a recanalization of the embolized cerebral aneurysms.

Thromboembolic Events during Endovascular Coil Embolization of Cerebral Aneurysms.

SUMMARY: Thromboembolic events was most important adverse event for coil embolization for intracerebral aneurysm. The present study investigated possible risk factors for thromboembolic events during coil embolization using diffusion-weighted imaging (DWI), comparing unruptured and ruptured lesions.

Endovascular treatment of experimental cerebral aneurysms using thermoreversible liquid embolic agents.

SUMMARY: We have developed a new embolic agent, thermoreversible gelation polymer (TGP). This polymer is unique in that solidification occurs at body temperature. The utility of this new liquid embolic agent for the treatment of large experimental aneurysms was evaluated angiographically. TGP remains liquid at temperatures below the sol-gel transition temperature (TT) and becomes gelatinous above the TT. TGP can also be used to slowly deliver biologically active substances such as growth factors or engineered cells. In this study, TGP was mixed with radiopaque material without solvent. Bilateral common carotid arteries of swine (n=5) were used for surgical creation of lateral aneurysms, then 1 aneurysm in each animal was embolized using TGP without any protection device. The remaining untreated aneurysm in each animal was used as a control. All aneurysms were successfully embolized using TGP. No distal migration of TGP was observed when aneurysms were embolized without using protection devices. TGP can be safely used to embolize experimental aneurysms. Embolization of aneurysms with a protection device needs to be evaluated. Further modifications such as mechanical stability and use as a drug delivery system will be necessary prior to the clinical application of TGP.

Balloon Test Occlusion with Perfusion CT Imaging Utilizing Intraarterial Contrast Injection.

SUMMARY: Balloon Test Occlusion (BTO) is performed to evaluate the collateral flow when a permanent therapeutic occlusion of unilateral carotid artery is planned. BTO with neurological evaluation alone, however, has a rather high false negative rate. In order to improve the sensitivity, several adjunctive procedures such as induced hypotension or cerebral blood flow (CBF) measurement with various modalities have been combined. Perfusion CT (PCT) is another imaging modality that is mainly used for the diagnosis of acute stroke. In this study, we evaluate the efficacy and the safety of BTO combined with PCT in the same procedure utilizing intraarterial contrast injection from the catheter. Seven patients underwent BTO with PCT in our institution. All the procedures were performed in the angio/CT combination suite. BTO was performed in the usual fashion and when the patient passed the 30 minutes' BTO clinically, PCT was performed subsequently. Contrast material was injected from a Pig Tail catheter placed in the ascending aorta. The obtained data were transferred to a workstation and perfusion maps of CBF, cerebral blood volume (CBV), and time to peak (TTP) were generated using software. In three patients, single photon emission CT (SPECT) was also obtained with administering 99 mTc-ethyl cysteinate dimer (99 mTc-ECD) intravenously during BTO. Although all the patients had passed the BTO clinically, the CBF maps of three patients revealed significant decrease in the occluded hemisphere. There was no procedure-related morbidity. PCT using intraarterial contrast injection during BTO was performed successfully and safely. Intraarterial injection allowed us to obtain excellent time-attenuation curves by utilizing less contrast material and less radiation doze.

A promoter region of the midkine gene that is frequently expressed in human hepatocellular carcinoma can activate a suicide gene as effectively as the alpha-fetoprotein promoter.

We examined the expression of the midkine (MK) and alpha-fetoprotein (AFP) genes in 15 paired human specimens obtained from hepatocellular carcinoma (HCC) and the corresponding noncancerous regions of the same patients. A total of 14 HCC but none of the noncancerous specimens were positive for the MK mRNA. In contrast, three HCC specimens and one corresponding noncancerous sample out of the three AFP-positive HCC cases expressed the AFP gene. A 2.3-kb genomic fragment in the regulatory region of the MK gene could activate a fused reporter gene in both AFP-producing and -nonproducing HCC lines, and the MK fragment-mediated transcriptional activity was comparable to the AFP enhancer-linked AFP promoter in AFP-producing cell lines. The AFP-producing but not AFP-nonproducing HCC cell lines that were transfected with the MK promoter-linked herpes simplex virus-thymidine kinase (HSV-TK) gene became susceptible to a prodrug ganciclovir to a similar degree of the HCC transfected with the enhancer-linked AFP promoter-fused HSV-TK gene. These data suggest that the MK promoter can activate a therapeutic gene preferentially in HCC and is as useful as the AFP promoter in clinical settings.

Irradiation with ultrasound of low output intensity increased chemosensitivity of subcutaneous solid tumors to an anti-cancer agent.

Ultrasound is a possible mechanical method to deliver small molecules into target cells. In order to evaluate the therapeutic potentials provided by ultrasound irradiation, we compared anti-tumor effects of electroporation- and ultrasound-mediated chemotherapy and efficacy of gene transfer by the two methods. Electric pulses (5 Hz, 100 V/cm, 8 square-wave/100 microsec) or ultrasound (1 MHz, 2 W/cm(2), 5 min) was delivered to subcutaneous solid tumors of murine lymphoma after the tumor-bearing mice received an intraperitoneal injection of bleomycin (BLM) (2.5 mg) or intratumoral injection of plasmid DNA containing the luciferase reporter gene. Administration of BLM alone did not affect the subsequent tumor growth but additive treatment with ultrasound irradiation suppressed the growth to the same level as electroporation. The luciferase activity of the DNA-injected tumors showed that ultrasound irradiation achieved better transfection efficiency than plasmid DNA injection alone but the efficacy was not as great as that by electroporation. The low energy level of ultrasound that is currently used for a diagnostic purpose and physical therapy in clinical fields can thereby increase the in vivo chemosensitivity of treated tumors but further modifications are necessary to achieve better efficacy of the ultrasound-mediated gene transfer.

Overexpression of mitochondrial manganese superoxide dismutase protects against radiation-induced cell death in the human hepatocellular carcinoma cell line HLE.

We investigated the potential role of mitochondrial manganese superoxide dismutase (Mn-SOD) in protective activity against irradiation by analyzing cell viability by a colony formation assay and by detecting apoptosis in stably human Mn-SOD gene-transfected HLE, a hepatocellular carcinoma cell line. We found that overexpression of Mn-SOD reduced the levels of reactive oxygen species in the mitochondria and intracellular phospholipid peroxidation product (4-hydroxy-2-nonenal) and prevented cell death. The production of intracellular nitric oxide after irradiation was not changed by Mn-SOD overexpression. The results suggested that Mn-SOD might play an important role in protecting cells against radiation-induced cell death by controlling the generation of mitochondrial reactive oxygen species and intracellular lipid peroxidation.

Long-term evaluation of extracorporeal shock-wave lithotripsy for cholesterol gallstones.

BACKGROUND: Extracorporeal shock-wave lithotripsy (ESWL) is a treatment that preserves the gallbladder. Problems after ESWL treatment include stone recurrence and the development of biliary symptoms. METHODS: Two hundred and sixty-two patients with cholesterol-type gallstones, the best indication for ESWL treatment, and 42 control patients with cholesterol-type gallstones who received no treatment entered this study. We evaluated the factors associated with recurrence of gallstones after stone clearance and the development of biliary symptoms after ESWL treatment. RESULTS: The 3-, 5- and 7-year cumulative probabilities of gallstone recurrence were 20.6, 27.1 and 33.1%, respectively, with the recurrence probability significantly lower in patients with good gallbladder contractility. In patients with recurrence, ursodeoxycholic acid (UDCA) treatment was effective. In 69 patients with residual gallstones, the 3-, 5- and 7-year cumulative risks of biliary symptoms were 17.3, 24.9 and 30.5%, respectively. With residual gallstones, the risk of biliary symptoms developing was significantly lower in patients with a < or = 3 mm fragment size at the end of ESWL treatment and in those treated consistently with UDCA for 6 months or more after treatment with ESWL. The risk of biliary symptoms was significantly lower in ESWL-treated patients with residual stones who had a < or = 3 mm fragment size after treatment compared to those of control patients. CONCLUSIONS: Ursodeoxycholic acid was effective in clearing stones in patients with gallstone recurrence. In patients with residual stones, the fragmentation of stones to < or = 3 mm and UDCA administration effectively reduced the risk of subsequent biliary symptoms.

Characterization of hyperplastic foci observed in surgical specimens of hepatocellular carcinoma.

By reviewing previous surgical specimens of hepatocellular carcinoma, 17 cases with hyperplastic foci (HPF) characterized by discernible increase in nuclear densities, could be histologically selected. Nuclear densities of HPF and control hepatic parenchyma were assessed quantitatively by counting the nuclear number of hepatic cells, and proliferating cell nuclear antigen labeling index was measured. HPF occurred multifocally, confined within a lobular unit, smoothly merging into surrounding hepatic parenchyma. Nuclear densities of HPF were 1.71 times greater than those of control hepatic parenchyma. The hepatocytes of HPF also showed significantly higher proliferative activities than those of control parenchyma. In addition, noticeable structural distortions, such as focal trabecular thickening or microacinar formation of hepatocytes, were sometimes observed in HPF. However, these HPF seemed to be distinguished from minute de novo hepatocellular carcinoma (HCC) or intrahepatic HCC metastasis, because of paucity of distinctive atypical changes, and intimate correlation with neighboring hepatocytes. Several adjacent HPF were aggregated to form a much larger unit of a hyperplastic area with loss of fibrous septa of liver cirrhosis. It was suggested that grossly detectable large regenerative nodules are produced via fusion of several adjacent HPF.