Cerebral angiography using transauricular access in a rabbit model: a new technique.

BACKGROUND: Cerebral angiography in a rabbit model is widely used in the field of interventional radiology. Conventionally, the femoral artery is used for cerebral angiography in radiology departments. However, angiographic studies require surgical cutdown of the femoral artery, which is technically difficult. PURPOSE: To evaluate a new cerebral angiography technique involving a transauricular approach in a rabbit model. MATERIAL AND METHODS: In each of 10 rabbits, central auricular arteries were punctured in the right or left ear with a 20-gauge i.v. catheter. A microcatheter (2.0 F) with a 0.016-inch guide wire was introduced through the i.v. catheter and advanced to the aortic arch. The microcatheter and guide wire were advanced selectively into cerebral arteries and angiography was performed. RESULTS: Central auricular arteries were successfully punctured with 20-gauge i.v. catheters. After approaching the aortic arch, microcatheter tips and guide wires were advanced manually to cerebral arteries on both sides. Difficulties in selecting the carotid arteries were resolved by using a looping technique within the cardiac chamber. Microcatheter loops within the cardiac chamber disappeared or remained during artery superselection. CONCLUSION: Transauricular cerebral angiography appears to be a feasible technique for brain or carotid intervention studies in rabbits. In addition, vertebral angiography using a transauricular approach is possible using the looping technique. Selection of carotid or vertebral arteries on each side was not difficult when the microcatheter and guide wire were looped within the cardiac chamber. The ear chosen for the initial puncture does not appear to be important.

Caffeic Acid Phenethyl Ester-Incorporated Radio-Sensitive Nanoparticles of Phenylboronic Acid Pinacol Ester-Conjugated Hyaluronic Acid for Application in Radioprotection.

We synthesized phenylboronic acid pinacol ester (PBPE)-conjugated hyaluronic acid (HA) via thiobis(ethylamine) (TbEA) linkage (abbreviated as HAsPBPE conjugates) to fabricate the radiosensitive delivery of caffeic acid phenetyl ester (CAPE) and for application in radioprotection. PBPE was primarily conjugated with TbEA and then PBPE-TbEA conjugates were conjugated again with hyaluronic acid using carbodiimide chemistry. CAPE-incorporated nanoparticles of HAsPBPE were fabricated by the nanoprecipitation method and then the organic solvent was removed by dialysis. CAPE-incorporated HAsPBPE nanoparticles have a small particle size of about 80 or 100 nm and they have a spherical shape. When CAPE-incorporated HAsPBPE nanoparticles were irradiated, nanoparticles became swelled or disintegrated and their morphologies were changed. Furthermore, the CAPE release rate from HAsPBPE nanoparticles were increased according to the radiation dose, indicating that CAPE-incorporated HAsPBPE nanoparticles have radio-sensitivity. CAPE and CAPE-incorporated HAsPBPE nanoparticles appropriately prevented radiation-induced cell death and suppressed intracellular accumulation of reactive oxygen species (ROS). CAPE and CAPE-incorporated HAsPBPE nanoparticles efficiently improved survivability of mice from radiation-induced death and reduced apoptotic cell death. We suggest that HAsPBPE nanoparticles are promising candidates for the radio-sensitive delivery of CAPE.

Doxorubicin concentration in brain remains high for one day after triolein emulsion infusion induced BBB opening.

Aim: The purpose of this study was to assess changes in doxorubicin concentration in rabbit brain with respect to time after BBB opening induced by triolein emulsion infusion via a carotid artery and the mechanism of BBB opening.Materials and Methods: Doxorubicin (2.4 mg/kg) was infused immediately after triolein emulsion (1%) into rabbit carotid arteries. Bilateral hemispheres were harvested 2, 4, 6 12 and 24 h later and doxorubicin concentrations were measured fluorometrically. Doxorubicin concentration ratios of ipsilateral versus contralateral hemispheres were calculated, and a TEM study was performed to investigate the mechanism responsible for the increased vascular permeability induced by triolein.Results: Doxorubicin concentrations were higher in ipsilateral hemispheres at all time points, and peaked at 2 h after treatment. Doxorubicin was still detected in ipsilateral hemispheres at 24 h after treatment. TEM showed tight junction opening by triolein emulsion with lanthanum tracer spillage into neural interstitium and transcytotic vesicles.Conclusion: Doxorubicin was delivered into neural interstitium because of the increased vascular permeability of the BBB induced by triolein emulsion. Doxorubicin concentrations in brain peaked within 2 h of triolein and doxorubicin administration and remained high for 24 h. The study shows increased vascular permeability induced by triolein emulsion may involve paracellular and transcellular pathways.

Synthesis and Evaluation of Manganese(II)-Based Ethylenediaminetetraacetic Acid-Ethoxybenzyl Conjugate as a Highly Stable Hepatobiliary Magnetic Resonance Imaging Contrast Agent.

In this study, we designed and synthesized a highly stable manganese (Mn2+)-based hepatobiliary complex by tethering an ethoxybenzyl (EOB) moiety with an ethylenediaminetetraacetic acid (EDTA) coordination cage as an alternative to the well-established hepatobiliary gadolinium (Gd3+) chelates and evaluated its usage as a T1 hepatobiliary magnetic resonance imaging (MRI) contrast agent (CA). This new complex exhibits higher r1 relaxivity (2.3 mM-1 s-1) than clinically approved Mn2+-based hepatobiliary complex Mn-DPDP (1.6 mM-1 s-1) at 1.5 T. Mn-EDTA-EOB shows much higher kinetic inertness than that of clinically approved Gd3+-based hepatobiliary MRI CAs, such as Gd-DTPA-EOB and Gd-BOPTA. In addition, in vivo biodistribution and MRI enhancement patterns of this new Mn2+ chelate are comparable to those of Gd3+-based hepatobiliary MRI CAs. The diagnostic efficacy of the new complex was demonstrated by its enhanced tumor detection sensitivity in a liver cancer model using in vivo MRI.

Lipo-poly(L-histidine) hybrid materials with pH-sensitivity, intracellular delivery efficiency, and intrinsic targetability to cancer cells.

Biocompatible lipo-histidine hybrid materials conjugated with IR820 dye show pH-sensitivity, efficient intracellular delivery of doxorubicin (Dox), and intrinsic targetability to cancer cells. These new materials form highly uniform Dox-loaded nanosized vesicles via a self-assembly process showing good stability under physiological conditions. The Dox-loaded micelles are effective for suppressing MCF-7 tumors, as demonstrated in vitro and in vivo. The combined mechanisms of the EPR effect, active internalization, endosomal-triggered release, and drug escape from endosomes, and a long blood circulation time, clearly prove that the IR820 lipopeptide DDS is a safe theranostic agent for imaging-guided cancer therapy.

Prominent hypointense veins on susceptibility weighted image in the cat brain with acute infarction: DWI, SWI, and PWI.

BACKGROUND: The multiple prominent hypointense veins on susceptibility-weighted imaging (SWI) have been found in the ischemic territory of patients with acute ischemic stroke. Venous side is the unknown area in the hemodynamics of brain infarction. PURPOSE: To evaluate the venous aspect in acute brain infarction through an animal study. MATERIAL AND METHODS: The acute infarction in cat brains was induced with a bolus infusion of 0.25 mL of triolein through one side of the common carotid artery. The magnetic resonance (MR) images, including diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC) map, SW, and perfusion-weighted (PWI) images, were obtained serially at 2 h (n = 17), 1 day (n = 11), and 4 days (n = 4) after triolein infusion. The obtained MR images were evaluated qualitatively and quantitatively. For qualitative assessment, the signal intensity of the serial MR images was evaluated. The presence or absence and the location with serial changes of infarction were identified on DWI and ADC map images. The presence or absence of prominent hypointense veins and the serial changes of cortical veins were also evaluated on SWI. Quantitative assessment was performed by comparing the relative cerebral blood volume (rCBV), cerebral blood flow (rCBF), and mean transit times (MTT) of the lesions with those of the contralateral normal side calculated on PWI. The serial changes of rCBV, rCBF, and MTT ratio were also evaluated. RESULTS: Acute infarction in the first and second medial gyrus of lesion hemisphere was found by qualitative evaluation of DWI and ADC map images. On the serial evaluation of SWI, the cortical veins of cat brain with infarction were obscured at 2 h and then re-appeared at 1 day. The hemorrhage transformation and prominent hypointense veins were seen at 4 days on SWI. The quantitative evaluation revealed increased MTT ratios and decreased rCBV and rCBF ratios on PWIs in the acute infarction of cat brain. CONCLUSION: The prominent hypointense veins on SWI were seen in the half of the acute infarction at 4 days. The prominent hypointense veins on SWI may have good agreement with the increased MTT ratio.

Saturated Fatty Acid Emulsions Open the Blood-Brain Barrier and Promote Drug Delivery in Rat Brains.

We performed this study to evaluate whether saturated fatty acid (SFA) emulsions affect the BBB and determine the duration of BBB opening, thereby promoting drug delivery to the brain. Butyric, valeric, caproic, enanthic, and caprylic acid emulsions were infused into the carotid artery of the rat model. We evaluated the BBB opening and drug delivery over time. The trypan blue and doxorubicin delivery studies were repeated from 30 min to 6 h. In the 1 h rats in each group, transmission electron microscopy (TEM) was performed to morphologically evaluate tight junctions, and the delivery of temozolomide was assessed by desorption electrospray ionization mass spectrometry. The ipsilateral hemisphere was positive for trypan blue staining in all the five SFA emulsion groups. In the valeric, enanthic, and caprylic acid emulsion groups, RGB ratios were significantly higher at 30 min and decreased thereafter. Doxorubicin delivery increased in all emulsion groups at all time points. Tight junctions were observed to be open in all groups. TMZ delivery was significantly higher in the ipsilateral hemisphere. In conclusion, intra-arterially infused SFA emulsions opened the BBB and promoted drug delivery within 30 min, which decreased thereafter. Therefore, SFA emulsions may aid BBB research and promote drug delivery to the brain.

[Development of Rabbit Brain Tumor Model Using VX2 Cells and Verification with the MRI in Neuroradiologic Research]. / Neuroradiology 연구를 위한 VX2 세포를 이용한 í† ë¼ ë‡Œì¢ ì–‘ 모델 ì œìž‘ê³¼ MRI를 이용한 검증.

Purpose: To evaluate the development, location, and volume of a VX2 carcinoma using four inoculation methods in a rabbit brain. Materials and Methods: Inoculation of a VX2 cell suspension was performed 1) on the appointed day, 2) seven days after storing a VX2 carcinoma in a freezer or 3) seven days after storing a VX2 carcinoma in a deep freezer after sacrificing the donor rabbits. 4) Without sacrificing the rabbits, the VX2 cell suspension was obtained using a gun biopsy, inoculation was performed on the appointed day. MR imaging was performed 10 days after inoculation. Brain tissues were obtained the day after. The development, location, and volume of the tumor were evaluated. Results: Seventeen of the 18 rabbits inoculated on the appointed day developed tumors (average tumor volume, 106.32 mm3). One of five inoculated seven days after storing the VX2 tumor in the freezer, and three of five inoculated seven days after storing the VX2 tumor in the deep freezer developed tumors. Inoculation with a VX2 cell suspension obtained with a gun biopsy from five rabbits revealed development of tumors in only two rabbits. The tumors mostly developed in the superficial cortex. Conclusion: TVX2 rabbit brain tumor model is easy to develop and revealed variable reproducibility. This model can be applicable in radiologic imaging, treatment planning, interventional treatment and drug delivery research. VX2 cell can be successfully innoculated into the brain using variable methods under researcher's variable conditions.

Unsaturated free fatty acid emulsion infusion into carotid artery enhances drug delivery to the rat brain.

AIMS: To determine whether the blood-brain barrier (BBB) opens to enhance drug delivery during the acute stage of unsaturated fat embolism. METHODS: We infused oleic, linoleic, and linolenic acid emulsions through the right common carotid artery of rats, followed by trypan blue for gross and lanthanum for electron microscopic (EM) examination. Doxorubicin and temozolomide were also administered, and then the rats were euthanized at 30 min, 1 h, and 2 h. Trypan blue hue was analyzed to semiquantitatively measure BBB opening. Desorption electrospray ionization-mass spectrometry (DESI-MS) imaging was used to evaluate drug delivery. RESULTS: Trypan blue staining observed in each group 30 min after emulsion infusion increased at 1 h and decreased after 2 h in the oleic acid group. The linoleic and linolenic acid groups showed weak staining over time. The hue and trypan blue analysis results were corroborative. EM showed tight junction opening, whereas DESI-MS imaging showed increased doxorubicin and temozolomide signal intensities in ipsilateral hemispheres of all three groups. CONCLUSION: We demonstrated that oleic, linoleic, and linolenic acid emulsions opened the BBB, promoting drug delivery to the brain. Hue analysis and DESI-MS imaging are appropriate for analysis of doxorubicin and temozolomide concentrations in brain tissue.

Trichinella spiralis infection suppressed gut inflammation with CD4(+)CD25(+)Foxp3(+) T cell recruitment.

In order to know the effect of pre-existing Trichinella spiralis infection on experimentally induced intestinal inflammation and immune responses, we induced colitis in T. spiralis-infected mice and observed the severity of colitis and the levels of Th1, Th2, and regulatory cytokines and recruitment of CD4(+)CD25(+)Foxp3(+) T (regulatory T; T(reg)) cells. Female C57BL/6 mice were infected with 250 muscle larvae; after 4 weeks, induction of experimental colitis was performed using 3% dextran sulfate sodium (DSS). During the induction period, we observed severity of colitis, including weight loss and status of stool, and evaluated the disease activity index (DAI). A significantly low DAI and degree of weight loss were observed in infected mice, compared with uninfected mice. In addition, colon length in infected mice was not contracted, compared with uninfected mice. We also observed a significant increase in production of pro-inflammatory cytokines, IL-6 and IFN-γ, in spleen lymphocytes treated with DSS; however, such an increase was not observed in infected mice treated with DSS. Of particular interest, production of regulatory cytokines, IL-10 and transforming growth factor (TGF)-ß, in spleen lymphocytes showed a significant increase in mice infected with T. spiralis. A similar result was observed in mesenteric lymph nodes (MLN). Subsets of the population of T(reg) cells in MLN and spleen showed significant increases in mice infected with T. spiralis. In conclusion, T. spiralis infection can inhibit the DSS-induced colitis in mice by enhancing the regulatory cytokine and T(reg) cells recruitment.

Macrophage migration inhibitory factor homologs of anisakis simplex suppress Th2 response in allergic airway inflammation model via CD4+CD25+Foxp3+ T cell recruitment.

We have cloned the macrophage migration inhibitory factor (MIF)-like protein (Anisakis simplex (As)-MIF) from larvae of the whale worm (Anisakis simplex third-stage larvae). Asthma was induced in the mice using OVA/alum, with or without various concentrations of rAs-MIF treatment before OVA/alum challenge. Treatment with rAs-MIF coupled with OVA/alum during the challenge period induced a complete inhibition of eosinophilia and goblet cell hyperplasia within the lung and profoundly ameliorated the development of lung hyperreactivity. Also, rAs-MIF was shown to reduce profoundly the quantity of Th2-related cytokines (IL-4, IL-5, and IL-13) in the bronchial alveolar lavage fluid and allergen-specific IgG2a in sera. IL-10 and TGF-beta levels in the bronchoalveolar lavage fluid of the rAs-MIF-treated group were significantly higher than in the other groups. Additionally, CD4(+)CD25(+)Foxp3(+) T cells (regulatory T) were recruited to the spleen and lungs of the rAs-MIF-treated mice, but this recruitment was inhibited by anti-rAs-MIF Ab.

Trichinella spiralis: infection reduces airway allergic inflammation in mice.

In an effort to define the mechanism underlying the host immune downregulation inherent to Trichinella spiralis infection, we compared the levels of Th1, Th2, and regulatory cytokines and CD4(+)CD25(+) forkhead box P3 (FoxP3)(+) T (T(reg)) cell recruitment, as well as cellular pathology in the airway between T. spiralis infected and uninfected asthma-induced mice. After the induction of allergic airway inflammation, we noted influxes of inflammatory cells into the peribronchial tree. However, in the T. spiralis infection groups, cellular infiltration was minimal around the bronchial tree, with only a smattering of inflammatory cells. In the OVA-challenged group after T. spiralis infection, the numbers of macrophages and eosinophils in the bronchial alveolar lavage fluid were reduced by 23% and 52%, respectively, as compared to those of the OVA-challenged group. Airway hyperresponsiveness of OVA-challenged mice after T. spiralis infection was significantly suppressed as compared to the OVA-only challenged mice. The T. spiralis-infected mice exhibited a significant reduction in IL-5 concentrations relative to that noted in the OVA-challenged group (p<0.01). Nevertheless, the regulatory cytokines IL-10 and TGF-ß levels were increased significantly as the result of T. spiralis infection, and we verified the recruitment of T(reg) cells in lung draining lymph nodes via T. spiralis infection. Therefore, T(reg) cells, which were recruited by T. spiralis infection, might ameliorate lung function and reduce allergic airway inflammation.

Seroprevalence of antibodies against Anisakis simplex larvae among health-examined residents in three hospitals of southern parts of Korea.

The present study was performed to estimate the seroprevalence of larval Anisakis simplex infection among the residents health-examined in 3 hospitals in southern parts of Korea. A total of 498 serum samples (1 serum per person) were collected in 3 hospitals in Busan Metropolitan city, Masan city, and Geoje city in Gyeongsangnam-do (Province) and were examined by IgE-ELISA and IgE-western blotting with larval A. simplex crude extract and excretory-secretory products (ESP). The prevalence of antibody positivity was 5.0% and 6.6% with ELISA against crude extracts and ESP, respectively. It was also revealed that infection occurred throughout all age groups and higher in females than in males. A specific protein band of 130 kDa was detected from 10 patients with western blot analysis against crude extract and ESP among those who showed positive results by ELISA. Our study showed for the first time the seroprevalence of anisakiasis in Korea. The allergen of 130 kDa can be a candidate for serologic diagnosis of anisakiasis.

Anisakis simplex larvae: infection status in marine fish and cephalopods purchased from the Cooperative Fish Market in Busan, Korea.

The infection status of marine fish and cephalopods with Anisakis simplex third stage larva (L3) was studied over a period of 1 year. A total of 2,537 specimens, which consisted of 40 species of fish and 3 species of cephalopods, were purchased from the Cooperative Fish Market in Busan, Korea, from August 2006 to July 2007. They were examined for A. simplex L3 from the whole body cavity, viscera, and muscles. A. simplex L3 were confirmed by light microscopy. The overall infection rate reached 34.3%, and average 17.1 larvae were parasitized per infected fish. Fish that recorded the highest infection rate was Lophiomus setigerus (100%), followed by Liparis tessellates (90%), Pleurogrammus azonus (90%), and Scomber japonicus (88.7%). The intensity of infection was the highest in Gadus macrocephalus (117.7 larvae per fish), followed by S. japonicus (103.9 larvae) and L. setigerus (54.2 larvae). Although abundance of A. simplex L3 was not seasonal in most of the fish species, 10 of the 16 selected species showed the highest abundance in February and April. A positive correlation between the intensity of L3 infection and the fish length was obvious in S. japonicus and G. macrocephalus. It was likely that A. simplex L3 are more frequently infected during the spring season in some species of fish. Our study revealed that eating raw or undercooked fish or cephalopods could still be a source of human infection with A. simplex L3 in Korea.

Triolein emulsion infusion into the hepatic artery increases vascular permeability to doxorubicin in rabbit liver.

BACKGROUND: The infusion of triolein emulsion (TE) induced increased vascular permeability and a negligible and temporary decrease in liver function without specific histopathological damage. AIM: To assess changes in doxorubicin concentration according to the percentage of TE infused via a hepatic artery to study the vascular permeability in the rabbit liver. METHODS: Thirty-nine healthy rabbits were divided into five groups according to the concentration of emulsified triolein infused into the hepatic arteries: Group 0, saline infusion (control group, n = 5); group 1, 0.3% TE (n = 13); group 2, 0.6% TE (n = 6); group 3, 0.9% TE (n = 8); and group 4, 1.5% TE (n = 6). Doxorubicin (2.4 mg/kg) was infused immediately after TE injection via the hepatic arteries. After 2 h, the livers were harvested, and doxorubicin concentrations were calculated fluorometrically. The doxorubicin concentrations were compared between TE groups and the control group, and the optimal concentrations within the TE groups were calculated. Statistical analysis was performed using the nonparametric Mann-Whitney U test and Kruskal-Wallis test. P < 0.05 were considered statistically significant. RESULTS: In the liver, doxorubicin concentrations were 2.06, 2.07, 2.16 and 1.66 times higher in groups 1 through 4, respectively, and significantly higher in the TE groups than in the control group (all P < 0.05). However, there were no significant differences in the mean doxorubicin concentrations between the four TE groups (P = 0.642). In the lungs, the mean doxorubicin concentrations were not significantly different between the control and TE groups (P > 0.05). CONCLUSION: TE infusion into the hepatic arteries significantly increased the doxorubicin concentration approximately twofold but was not different between the TE groups. These findings suggest that TE infusion might be a useful adjuvant treatment of liver cancers.

Reactive Oxygen Species-Sensitive Nanophotosensitizers of Methoxy Poly(ethylene glycol)-Chlorin e6/Phenyl Boronic Acid Pinacol Ester Conjugates Having Diselenide Linkages for Photodynamic Therapy of Cervical Cancer Cells.

The aim of this study is to fabricate nanophotosensitizers composed of methoxy poly(ethylene glycol) (mPEG), chlorin e6 (Ce6), and phenylboronic acid pinacol ester (PBAP) with diselenide linkages for reactive oxygen species (ROS)-sensitive photodynamic therapy (PDT) of cervical cancer cells. To fabricate nanophotosensitizers, Ce6 was conjugated with mPEG via selenocystamine linkage and then remaining carboxylic acid groups of Ce6 was attached to PBAP (mPEGseseCe6PBAP conjugates). Nanophotosensitizers of mPEGseseCe6PBAP conjugates were prepared by dialysis method. In transmission electron microscope (TEM) observation, nanophotosensitizers of mPEGseseCe6PBAP conjugates have spherical shapes and their diameters were less than 150 nm. The average diameter of mPEGseseCe6PBAP nanophotosensitizers was 92.7 ± 9.6 nm in particle size analysis. When H2O2 was added to the nanophotosensitizer solution, nanophotosensitizers were sensitively disintegrated according to the H2O2 concentration and then changed from monomodal distribution to multimodal distribution in particle size distribution. Furthermore, Ce6 release from nanophotosensitizers also increased according to the H2O2 concentration. When H2O2 was added to cell culture of HeLa human cervical cancer cells, intracellular Ce6 uptake of nanophotosensitizers were gradually increased according to the H2O2 concentration, indicating that nanophotosensitizers showed ROS-sensitive delivery of Ce6 against cancer cells.As well as free Ce6, nanophotosensitizers in the absence of light irradiation have low intrinsic cytotoxicity against RAW264.7 cells and HeLa cells. However, nanophotosensitizers induced cell death dose-dependently under light irradiation. Especially, nanophotosensitizers showed significantly higher ROS generation and phototoxicity against HeLa cells in vitro. When nanophotosensitizers were intravenously administered to animal tumor xenograft model of HeLa cells, tumor tissues revealed stronger fluorescence intensity than other tissues by light irradiation while absence of light irradiation induced relatively lower fluorescence intensity in tumor tissues, indicating that nanophotosensitizers have sensitivity against oxidative stress in tumor tissues. We suggest that nanophotosensitizers of mPEGseseCe6PBAP conjugates are promising vehicle for PDT of cervical cancer cells.

Triolein emulsion enhances temozolomide brain delivery: an experimental study in rats.

PURPOSE: To evaluate the enhancement of temozolomide (TMZ) delivery in the rat brain using a triolein emulsion. MATERIALS AND METHODS: Rats were divided into the five groups as following: group 1 (negative control), group 2 (treated with triolein emulsion and TMZ 20 mg/kg), and group 3 (TMZ 20 mg/kg treatment without triolein), group 4 (treated with triolein emulsion and TMZ 10 mg/kg), and group 5 (TMZ 10 mg/kg treatment without triolein). Triolein emulsion was infused into the right common carotid artery. One hour later, the TMZ concentration was evaluated quantitatively and qualitatively using high-performance liquid chromatography (HPLC-MS) and desorption electrospray ionization mass spectrometry (DESI-MS) imaging, respectively. The concentration ratios of the ipsilateral to contralateral hemisphere in each group were determined and the statistical analysis was conducted using an unpaired t-test. RESULTS: Quantitatively, the TMZ concentration ratio of the ipsilateral to the control hemisphere was 2.41 and 1.13 in groups 2 and 3, and were 2.49 and 1.14 in groups 4 and 5, respectively. Thus, the TMZ signal intensities of TMZ in group 2 and 4 were statistically high in the ipsilateral hemispheres. Qualitatively, the signal intensity of TMZ was remarkably high in the ipsilateral hemisphere in group 2 and 4. CONCLUSIONS: The triolein emulsion efficiently opened the blood-brain barrier and could provide a potential new strategy to enhance the therapeutic effect of TMZ. HPLC-MS and DESI-MS imaging were shown to be suitable for analyses of enhancement of brain TMZ concentrations.

MRI of the cat brain in the study of vascular permeability after intraarterial carotid injection of triolein.

BACKGROUND: Triolein emulsion embolization into the carotid artery depicts reversible increased vascular permeability that can promote the effect of chemotherapy or can reduce the amount of chemotherapeutic drugs for equivalent effectiveness. PURPOSE: To establish the minimum dosage of 0.5% triolein for studying vascular permeability changes in a triolein emulsion model. MATERIAL AND METHODS: Sixty-six cats were divided into six groups based on the amount of emulsified triolein (0.5%) infused into the carotid artery: group 1 (n=12, 6 ml/kg), group 2 (n=12, 4.5 ml/kg), group 3 (n=12, 3 ml/kg), group 4 (n=10, 1.5 ml/kg), group 5 (n=10, 1 ml/kg), and group 6 (n=10, 3 ml/kg of saline (control group)). T1-weighted, T2-weighted, and post-contrast T1-weighted MRI was performed 2 h after the infusion of the triolein emulsion. Contrast enhancement ratios (CERs) were obtained with pre- and post-contrast T1-weighted images in the ipsilateral and contralateral hemispheres. Signal intensity ratios (SIRs) of the ipsilateral and contralateral hemispheres were evaluated on T2-weighted images. After removal of the brain tissues, edema ratios in the ipsilateral and contralateral hemispheres were obtained from wet versus dry brain weights. Data were statistically evaluated by analysis of variance, followed by the Tukey honestly significant difference test to compare the difference in the mean CER of the ipsilateral and contralateral hemispheres, mean SIR on T2-weighted image, and mean edema ratio between each group when overall significance was attained. RESULTS: In the ipsilateral hemispheres, the difference in the CER between the control group and groups 1 (P=0.004), 2 (P=0.043), and 3 (P=0.008) were statistically significant. The difference in the CERs between the triolein emulsion groups was not statistically significant (P>0.05). The T2-weighted SIRs were significantly different between the control group and groups 1 (P=0.027) and 2 (P=0.004). However, the edema ratios of all doses in the triolein emulsion groups showed no significant differences compared with the control group. CONCLUSION: The minimum dosage of 0.5% triolein emulsion to achieve increased vascular permeability in the hemisphere in cat brains appears to be 3 ml/kg. This minimum dosage of triolein emulsion can be useful for acquiring basic data in further studies of vascular permeability changes in a triolein emulsion model.

Endosymbionts of Acanthamoeba isolated from domestic tap water in Korea.

In a previous study, we reported our discovery of Acanthamoeba contamination in domestic tap water; in that study, we determined that some Acanthamoeba strains harbor endosymbiotic bacteria, via our molecular characterization by mitochondrial DNA restriction fragment length polymorphism (Mt DNA RFLP). Five (29.4%) among 17 Acanthamoeba isolates contained endosymbionts in their cytoplasm, as demonstrated via orcein staining. In order to estimate their pathogenicity, we conducted a genetic characterization of the endosymbionts in Acanthamoeba isolated from domestic tap water via 16S rDNA sequencing. The endosymbionts of Acanthamoeba sp. KA/WP3 and KA/WP4 evidenced the highest level of similarity, at 97% of the recently published 16S rDNA sequence of the bacterium, Candidatus Amoebophilus asiaticus. The endosymbionts of Acanthamoeba sp. KA/WP8 and KA/WP12 shared a 97% sequence similarity with each other, and were also highly similar to Candidatus Odyssella thessalonicensis, a member of the alpha-proteobacteria. The endosymbiont of Acanthamoeba sp. KA/WP9 exhibits a high degree of similarity (85-95%) with genus Methylophilus, which is not yet known to harbor any endosymbionts. This is the first report, to the best of our knowledge, to show that Methylophilus spp. can live in the cytoplasm of Acanthamoeba.

The steroid effect on the blood-ocular barrier change induced by triolein emulsion as seen on contrast-enhanced MR images.

OBJECTIVE: The purpose of this study is to evaluate the effect of dexamethasone on the damaged blood-ocular barrier caused by triolein emulsion, using contrast-enhanced MR imaging. MATERIALS AND METHODS: An emulsion of 0.1-mL triolein in 20 mL of saline was infused into the carotid arteries of 32 cats, 12 cats were placed in the treatment group and 18 cats were placed in the Control group. Thirty minutes after the infusion of triolein emulsion, a set of orbital pre- and post-contrast T1-weighted MR images (T1WIs) were obtained. Infusion of 10 mg/kg dexamethasone into the ipsilateral carotid artery of each of the cats in the treatment group cats and 20 mL saline in each of the cats in the control group was given. A second set of pre- and post-contrast orbital T1WIs were obtained three hours following triolein emulsion infusion. Qualitative analysis was performed for the the anterior chamber (AC), the posterior chamber (PC), and in the vitreous humor of the ipsilateral and contralateral eyes. The signal intensity ratios of the ipsilateral eye over the contralateral eye were quantitatively evaluated in the three ocular chambers on the first and second set of T1WIs, and were then statistically compared. RESULTS: Qualitatively, the AC, the PC or the vitreous did not show immediate contrast enhancement on the first and the second set of post-contrast T1WIs. However, the AC and the PC showed delayed contrast enhancement for both groups of cats on the second pre-contrast T1WIs. No enhancement or minimally delayed enhancement was seen for the vitreous humor. Quantitatively, the signal intensity ratios in the PC of the treatment group of cats were statistically lower than the ratios of the control group of cats for the second set of T1WIs (p = 0.037). The AC and vitreous showed no statistically significant difference between the feline treatment group and control group (p > 0.05). CONCLUSION: Contrast-enhanced MR images revealed increased vascular permeability in the PC of the eye after infusion of triolein emulsion. Dexamethasone seems to decrease the breakdown of the blood-aqueous barrier in the PC.