Novel treatment system using endoscopic ultrasound-guided high-intensity focused ultrasound: A proof-of-concept study.

AIM: High-intensity focused ultrasound (HIFU) is a novel minimally invasive local treatment of solid tumors. Endoscopic ultrasound-guided HIFU (EUS-HIFU) using mechanical effects would have potential benefits, including precise detection of target lesions and enhance drug delivery. The aim of this study is to develop EUS-HIFU device and to prove our concept in porcine model using a locally injected phase change nano droplet (PCND) as the sensitizer. METHOD: A phospholipid PCND contained volatile perfluoro-carbon liquids. The prototype HIFU apparatus comprised a small (20 × 20 mm) transducer with center frequency of 2.1 MHz, attachable to a linear EUS transducer. Under general anesthetic, a single porcine received EUS-guided injection of PCND. The HIFU transducer was placed laparotomically in the stomach, and the liver was ablated through the gastric wall. RESULTS: PCND was injected successfully and a distinct lesion was generated at the HIFU transducer focus only in injected areas that received HIFU exposure at 4.7 kW/cm2 at a duty cycle of 5 % (mean temporal intensity, 0.245 kW/cm2) for 30 s. The generated lesions were mechanically fractionated in macroscopic view. CONCLUSION: The concept of transluminal HIFU ablation using novel EUS-HIFU system was proved in a porcine animal model. This novel treatment system has great potential for future cancer treatment although further investigation in more animals and different organs are warranted.

Fetal-onset malignant rhabdoid tumor: a case report.

BACKGROUND: A fetal-onset cervical mass may cause postnatal airway obstruction, and ex utero intrapartum treatment (EXIT) to secure the airway while maintaining fetal-placental circulation may be life-saving. Malignant rhabdoid tumors (MRT) are highly aggressive tumors, and when they develop in utero, the prognosis is even worse, with almost no reports of survival beyond the neonatal period. Herein, we report a case of a primary cervical MRT and describe our treatment using EXIT for securing the airway, wherein the infant's life was saved. CASE PRESENTATION: A 40-year-old Japanese woman with no relevant medical or surgical history was diagnosed with a fetal left cervical mass and polyhydramnios during the third trimester. Fetal magnetic resonance imaging indicated the possibility of postnatal airway obstruction, and delivery using EXIT was planned. The infant was delivered by a planned cesarean section at 39 weeks and 5 days gestation, and tracheostomy was performed using EXIT. Postnatal contrast-enhanced computed tomography revealed suspected metastatic lesions in the subcutaneous tissue, lungs, and thymus, in addition to the mass in the left cervical region. MRT was diagnosed by biopsy of a subcutaneous mass in the left thigh, and chemotherapy with vincristine, doxorubicin, cyclophosphamide, ifosfamide, and etoposide was initiated. The tumors regressed, and the infant was successfully weaned from artificial ventilation. After discharge from the hospital, she had a recurrent cervical mass and intracranial metastasis, and radiotherapy was initiated. CONCLUSIONS: In our case, fetal diagnosis enabled advance planning of delivery using EXIT, thus saving the infant's life. The use of chemotherapy for MRT, which has a poor prognosis, allowed tumor regression and enabled the infant to survive beyond the neonatal period.

Extreme Prematurity and Pulmonary Outcomes Program in Saitama: Protocol for a Prospective Multicenter Cohort Study in Japan.

BACKGROUND: Because of the improvements in survival rates for preterm infants, not only the rates of bronchopulmonary dysplasia (BPD) but also those of long-term respiratory complications of premature birth are increasing, resulting in financial and health burdens in developed countries. Thus far, the risk factors of respiratory morbidities in extremely preterm infants remain unknown. Furthermore, the definition and the predictive ability of BPD for long-term respiratory outcomes are yet to be determined. OBJECTIVE: The objective of our study, Extreme Prematurity and Pulmonary Outcomes Program in Saitama, is to develop the diagnostic criteria for BPD and to determine the prognostic factors contributing to the long-term pulmonary outcomes manifesting in extremely preterm infants. METHODS: The Extreme Prematurity and Pulmonary Outcomes Program in Saitama is an observational prospective cohort study performed by a consortium of six neonatal intensive care units (NICUs) in Saitama, Japan. The subjects included in this study are infants (from each clinical center) with gestational ages 22 to 27 weeks. The target is 400 subjects. This study aims to determine the definition of BPD and other perinatal factors that accurately predict the long-term pulmonary outcomes in survivors of extreme prematurity. Moreover, the association between BPD and postprematurity respiratory disease will be investigated using generalized linear models. RESULTS: The protocol and consent forms were evaluated and approved on September 5, 2019, by the Ethics Committee of Saitama Medical Center, Saitama Medical University. Enrollment began on April 1, 2020. It is expected to end on March 31, 2023. The follow-up for 1 year corrected age is expected to continue through the middle of 2024. CONCLUSIONS: The Extreme Prematurity and Pulmonary Outcomes Program in Saitama incorporates aspects of neonatal care in secondary- and tertiary-level NICUs to develop existing research studies on the definition of BPD, objective biomarkers, and outcome measures of respiratory morbidity in extremely preterm infants beyond NICU hospitalization, thereby leading to a novel understanding of the nature and natural history of BPD and potential mechanistic and therapeutic targets in at-risk subjects. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/22948.

Ultrasound Sub-pixel Motion-tracking Method with Out-of-plane Motion Detection for Precise Vascular Imaging.

Ultrasound vascularity imaging provides important information for differential diagnosis of tumors. Peak-hold (PH) is a useful technique for precisely imaging small vessels by selecting a maximum brightness in each pixel through the frames obtained sequentially. To use PH successfully one needs motion compensation to reduce image blur, but out-of-plane motion cannot be avoided. To address this problem, we developed a sub-pixel motion-tracking method with out-of-plane motion detection (OPMD). It is a combination of the sum of the absolute differences (SAD) method and the Kanade-Lucas-Tomasi method and can be accurately applied to various motions. The value from OPMD (γ) is defined as a statistical value obtained from the distribution of residual values in the SAD procedure with the obtained frames. The value is ideally 0, and the frames having large γ are removed from the PH procedure. The accuracy of the proposed tracking method was found by a simulation study to be approximately 20 µm. We also found, through a phantom experiment, that the value of γ sensitively increased enough to detect out-of-plane motion. Most important, γ begins to increase before tracking errors occur. This suggests that OPMD can be used to predict tracking errors and effectively remove frames from the PH procedure. An in vivo experiment with a rabbit showed that the PH image obtained with motion tracking clearly revealed peripheral vessels that were blurred in the PH image obtained without motion tracking. We also found that the image quality becomes better when OPMD was used to remove frames including out-of-plane motion.

Transluminal Approach with Bubble-Seeded Histotripsy for Cancer Treatment with Ultrasonic Mechanical Effects.

Bubble-seeded histotripsy (BSH) is a newly developed ultrasound-based mechanical fractionation technique using locally injected phase change nanodroplets (PCNDs) as sensitizers. The PCNDs are a kind of microbubble precursor compressed into submicron-size in droplets form, which were designed for local administration and will expand into microbubbles under ultrasound exposure. Previously, we reported that a combination of PCNDs injection and pulsed high-intensity focused ultrasound (pHIFU) with an acoustic intensity as low as about 3 kW/cm2 at 1.1 MHz, which is similar to the acoustic intensity of currently available HIFU coagulation therapy, was enough to induce tissue fractionation after significant antitumor effects in an in vivo study. Toward therapeutic application of BSH to deep-seated tissues such as the pancreas, the transluminal approach, using endoscopic ultrasound was thought to be ideal. Therefore, for a preliminary examination, we developed a new transducer with a small aperture (20- × 20-mm square) and long focal length (35 mm), operating at 2.1 MHz that could be attached to an EUS-mimicking probe. With the newly developed transducer and locally injected PCNDs, predictable tissue mechanical fractionation was observed in both ex vivo and in vivo studies at acoustic intensities that were too low to induce any significant bioeffects (around 4 kW/cm2) without using PCNDs. For in situ monitoring of the treatment site during a procedure, the degree of attenuation of microbubble motions after exposing the microbubbles to pHIFU was monitored, using ultrafast echographic imaging. Microbubble movements were observed to be largest at 25-30 s after pHIFU exposure. On the contrary, after 40 s, the movement of microbubbles decreased to the same level as at the start of the procedure, suggesting that an overdose of pHIFU exposure causes coagulation attributable to the thermal effect caused by absorption of the energy. Those results were promising for expanding the application of BSH for a transluminal approach, using a small transducer under real-time monitoring.

New approach for local cancer treatment using pulsed high-intensity focused ultrasound and phase-change nanodroplets.

PURPOSE: The aim of this study was to investigate the combination effects of pulsed HIFU (pHIFU) and phase-change nanodroplets (PCND) as a sensitizer on efficient induction of mechanical effects of pHIFU and chemically enhanced tumor growth inhibition for local anti-tumor therapy. METHOD: Changes in growth of colon 26 tumor tissue inoculated onto CDF1 mice were evaluated by the following treatments. (1) pHIFU exposure (1.1 MHz, 3.2 kW/cm(2), 300 cycles, and 50 ms interval) for 60 s, (2) PCND (1 %) injection, (3) adriamycin (4 mg/kg) injection, (4) pHIFU exposure after PCND injection, and (5) pHIFU exposure after PCND + adriamycin injection simultaneously. RESULTS: Significant changes in tumor growth were observed in the group with combination of pHIFU and PCND, although single therapy did not show any significant difference. PCND enhanced mechanical tissue fractionation by pHIFU, which was detectable by Real-time tissue elastography. Moreover, the combination of pHIFU and PCND + Adriamycin suppressed the tumor growth for 2 weeks, and 3 of 4 mice did not show any sign of regrowth during the 30-day observation. CONCLUSION: The combination of pHIFU and PCND exerted a significant anti-tumor effect and may be a new candidate for treatment of locally advanced cancer.

Assessment of carotid plaque neovascularization using quantitative analysis of contrast-enhanced ultrasound imaging is useful for risk stratification in patients with coronary artery disease.

BACKGROUND: Contrast-enhanced ultrasound (CEUS) of the carotid artery is a potential technique for imaging plaque neovascularization, a feature of unstable atherosclerotic plaques. This study examined whether assessment of intra-plaque neovascularization of the carotid artery using CEUS provides prognostic information in patients with coronary artery disease (CAD). METHODS: A total of 206 patients with stable CAD underwent a CEUS examination of the carotid artery and were followed up prospectively for <38 months or until a cardiac event (cardiac death, non-fatal myocardial infarction (MI), unstable angina pectoris (uAP) requiring unplanned coronary revascularization, or heart failure requiring hospitalization). The degree of contrast signals measured within the carotid plaque was quantified by calculating the mean gray scale level within the region of interest of the carotid plaque, expressed as plaque enhanced intensity. RESULTS: During the follow-up period, 31 events occurred (2 cardiac deaths, 7 non-fatal MIs, 16 uAP, and 6 heart failure). Multivariate Cox proportional hazard analysis showed that plaque enhanced intensity was a significant predictor of cardiac events independent of traditional risk factors (HR, 1.13; 95% CI, 1.05-1.21; p<0.001). The addition of the plaque enhanced intensity to traditional risk factors resulted in net reclassification improvement (NRI) and integrated discrimination improvement (IDI) (NRI 0.62, p=0.001; and IDI 0.106, p=0.002). CONCLUSIONS: The assessment of carotid plaque neovascularization using quantitative analysis of CEUS may be useful for risk stratification in patients with CAD.

The expression of groups IIE and V phospholipase A2 is associated with an increased expression of osteogenic molecules in human calcified aortic valves.

AIM: Eicosanoids play various pathogenic roles in aortic valve calcification. Eicosanoids are derived from the arachidonic acid generated by phospholipase A2 (PLA2). We therefore sought to determine whether PLA2s are expressed in human aortic valves and, if so, whether the expression of PLA2s is related to the expression of osteogenic molecules in these tissues. METHODS: Histological and gene expression analyses of 38 non-rheumatic aortic valves obtained at the time of cardiac valve replacement surgery were conducted. Moreover, gene expression analyses were performed using valve interstitial cells (VICs) obtained from human aortic valves. RESULTS: Among the PLA2s examined, the degree of immunoreactivity for PLA2s-IIE and -V was found to significantly correlate with the grade of calcification in the aortic valves. The degree of immunoreactivity and gene expression levels of PLA2s-IIE and -V significantly correlated with those of bone morphogenetic protein (BMP)-2, osteopontin and alkaline phosphatase (ALP). In addition, immunoreactivity for cyclooxygenase (COX)-1, COX-2 and 5-lipoxygenase, downstream enzymes of PLA2 in the arachidonic acid cascade, was co-localized with that for PLA2s-IIE and -V in cells expressing α-smooth muscle actin and macrophages expressing CD68. Furthermore, in the in vitro experiments using cultured VICs, the mRNA expression levels of BMP-2, osteopontin and ALP were suppressed by the inhibition of the expression of PLA2s-IIE or -V with specific siRNAs. CONCLUSIONS: The expression of PLA2s-IIE and -V correlates with the development of calcification as well as the expression of pro-osteogenic molecules in human aortic valves, and inhibiting the expression of PLA2s-IIE and -V suppresses the induction of osteogenic molecules in cultured cells. Therefore, PLA2s-IIE and -V may play a role in the pathogenesis of valve calcification.

Contrast-enhanced ultrasound imaging of carotid plaque neovascularization is useful for identifying high-risk patients with coronary artery disease.

BACKGROUND: Contrast-enhanced ultrasound (CEUS) in the carotid artery has potential as a technique for imaging plaque neovascularization. This study examined whether CEUS could provide information on the severity and instability of coronary artery disease (CAD). METHODS AND RESULTS: A total of 304 patients with CAD and carotid plaque underwent CEUS examination of the carotid artery. Intraplaque neovascularization was identified on the basis of microbubbles within the plaque and graded as: G0, not visible; G1, moderate; or G2, extensive microbubbles. The complexity and extent of the coronary lesions were assessed angiographically. A higher grade of CEUS-assessed plaque neovascularization of the carotid artery was associated significantly with greater complexity (ρ=0.48 by Spearman's rank correlation test) and extent (ρ=0.51) of coronary lesions. G2 plaque neovascularization was a risk for acute coronary syndrome, independent of traditional risk factors (odds ratio 1.91, 95% confidence interval 1.04-3.53, P<0.01). Subgroup analysis showed that carotid CEUS-assessed neovascularization regressed in 12 (46%) of 26 plaques in patients during 6 months of statin treatment, whereas regression occurred in 2 (14%) of 14 plaques in patients not taking a statin (P=0.04, Chi-square test). CONCLUSIONS: CEUS examination of the carotid artery may provide valuable information on the severity and instability of CAD and also the efficacy of antiatherosclerotic treatment.

Extramuscular manifestations in children with severe congenital myopathy due to ACTA1 gene mutations.

We examined three patients with a severe infantile type of congenital myopathy due to dominant, missense ACTA1 mutations. In addition to muscle weakness, all three patients showed developmental delay in word comprehension during early childhood. All also showed frontal lobe hypoplasia and lateral ventricular dilatation. One patient in addition exhibited features of multiple congenital malformations including skeletal dysplasia, hepatomegaly and urinary tract stenosis. These findings may suggest a link between extramuscular expression of α-skeletal muscle actin and clinical symptoms in non-skeletal muscle tissues of patients with ACTA1 mutations, and probably a functional role of α-skeletal muscle actin during fetal development.

Quantification of mouse pulmonary cancer models by microcomputed tomography imaging.

The advances in preclinical cancer models, including orthotopic implantation models or genetically engineered mouse models of cancer, enable pursuing the molecular mechanism of cancer disease that might mimic genetic and biological processes in humans. Lung cancer is the major cause of cancer deaths; therefore, the treatment and prevention of lung cancer are expected to be improved by a better understanding of the complex mechanism of disease. In this study, we have examined the quantification of two distinct mouse lung cancer models by utilizing imaging modalities for monitoring tumor progression and drug efficacy evaluation. The utility of microcomputed tomography (micro-CT) for real-time/non-invasive monitoring of lung cancer progression has been confirmed by combining bioluminescent imaging and histopathological analyses. Further, we have developed a more clinically relevant lung cancer model by utilizing K-ras(LSL-G12D)/p53(LSL-R270H) mutant mice. Using micro-CT imaging, we monitored the development and progression of solitary lung tumor in K-ras(LSL-G12D)/p53(LSL-R270H) mutant mouse, and further demonstrated tumor growth inhibition by anticancer drug treatment. These results clearly indicate that imaging-guided evaluation of more clinically relevant tumor models would improve the process of new drug discovery and increase the probability of success in subsequent clinical studies.

Statin reverses reduction of adiponectin receptor expression in infarcted heart and in TNF-alpha-treated cardiomyocytes in association with improved glucose uptake.

Statin treatment improves insulin resistance in skeletal muscle. Thus this study assessed whether statin may affect the myocardial expression levels of AdipoR1 and AdipoR2, receptors of adiponectin that enhance insulin sensitivity, and whether statin may improve insulin resistance in cardiomyocytes. Myocardial infarction (MI) was created by the ligation of the left coronary artery in male mice. Expression levels of mRNA and protein levels of AdipoR1 but not of AdipoR2 were significantly decreased in the remote area as well as in the healed infarcted area in the left ventricles 4 wk after MI. Oral administration of pravastatin (50 mg.kg(-1).day(-1) for 4 wk after MI) reversed the decrease in myocardial expression levels of AdipoR1 independently of changes in serum lipid profiles and insulin levels. With the use of cultured cardiomyocytes, incubation with tumor necrosis factor (TNF)-alpha, a mediator of postinfarction myocardial dysfunction, inhibited AdipoR1 mRNA and protein expression levels. Coincubation of the cells with pravastatin reversed the inhibitory effects of TNF-alpha on AdipoR1 expression. In parallel, pravastatin reversed the TNF-alpha-induced decrease in globular adiponectin-induced 2-deoxy-d-[(3)H]glucose uptake in insulin-treated cultured cells. Moreover, this effect of pravastatin was inhibited by the suppression of AdipoR1 expression by small-interfering RNA specific for AdipoR1. Incubation with H(2)O(2) reduced AdipoR1 expression in cultured cardiomyocytes that were attenuated by N-acetyl-l-cysteine or pravastatin. Pravastatin suppressed TNF-alpha-induced intracellular oxidants in cultured cardiomyocytes. In conclusion, pravastatin reversed the reduction of AdipoR1 expression in postinfarction mouse myocardium and in TNF-alpha-treated cardiomyocytes partly through an antioxidative mechanism in association with improved glucose uptake.

Sirolimus-eluting stent implantation aggravates endothelial vasomotor dysfunction in the infarct-related coronary artery in patients with acute myocardial infarction.

OBJECTIVES: This study examined whether sirolimus-eluting stent (SES) implantation may affect endothelial vasomotor dysfunction in resistance and epicardial infarct-related coronary arteries in acute myocardial infarction (AMI). BACKGROUND: Myocardial ischemia-reperfusion causes endothelial injury entirely in the vasculature of the infarct-related coronary artery. Sirolimus-eluting stent implantation inhibits re-endothelialization at the site of stenting. METHODS: This study included 29 patients with a first AMI due to occlusion of the left anterior descending coronary artery (LAD) and successful reperfusion therapy using a SES (n = 13) or bare-metal stent (BMS) (n = 16). The diameter of the epicardial segment distal to the site of SES deployment and coronary blood flow in the LAD in response to an intracoronary infusion of acetylcholine were measured at 2 weeks after AMI. Levels of vascular endothelial growth factor (VEGF) were measured by enzyme-linked immunoadsorbent assay in plasma obtained from the aortic root (AO) and the anterior interventricular vein (AIV) in all patients. RESULTS: The epicardial coronary artery was more severely constricted in response to acetylcholine in the SES than in the BMS group. The increase in coronary blood flow in response to acetylcholine was lower in the SES than in the BMS group. Vascular endothelial growth factor levels in the AIV were significantly lower than in the AO in the SES group but not in the BMS group. CONCLUSIONS: During the course of AMI, SES implantation adversely affects endothelium-dependent vasomotor function in resistance and epicardial coronary arteries after the ischemia-reperfusion in association with a reduction in myocardial VEGF secretion.

Apoptotic cell death and regeneration in the newborn retina after irradiation prior to bone marrow transplantation.

PURPOSE: We studied the contribution made by circulating bone marrow (BM)-derived cells to the newborn and mature retinas of BM-transplanted mice. METHODS: Newborn and adult C57BL/6J mice were administered a lethal dose of total-body irradiation, after which pathologic changes to the retinas were periodically assessed. In addition, mice received BM cells from 8-week-old green fluorescent protein (GFP) transgenic mice, and the subsequent differentiation of GFP+ cells was studied. RESULTS: Within 5 hr after irradiation of newborn mice, retinal cells began to die due to apoptosis. By contrast, irradiation of adult mice elicited no histologic changes in the retina. BM cells generally did not differentiate in adult mice, but numerous GFP+ BM cells were integrated into the retinal tissue of newborn mice, where they expressed various cell type-specific markers. Finally, examination of whole retina mounts showed that GFP+ cells also contributed to retinal vascularization. CONCLUSIONS: Our findings underscore the importance of careful evaluation of the biological effects of irradiation in models making use of BM transplantation.

Synthesis of amphiphilic derivatives of rose bengal and their tumor accumulation.

It is known that the combination of laser light and its sensitizer is effective for noninvasive tumor treatment, referred to as photodynamic therapy. Using the combination of ultrasound and its sensitizer has also been suggested for a similar kind of tumor treatment, referred to as sonodynamic therapy. The purpose of this paper is to obtain such sensitizers accumulating selectively in tumors. Amphiphilic derivatives of rose bengal (RB) were synthesized to add a tumor-accumulating property to RB. One type of the synthesized RB derivatives (RBD3), having an alkyl chain with a branching carboxyl group, was found to be superior in amphiphilicity to the other types. Tumor tissue distribution of the synthesized derivatives in mice bearing colon 26 carcinoma was evaluated. It was found that RBD3s with carbon chain lengths of 12, 14, and 16 had higher concentrations in the tumor tissue than RB by more than 1 order of magnitude, several hours after administration. The concentrations correlated well with their water/1-octanol partition coefficients. Since RB is known to induce in vitro cell damage in combination with either laser light or ultrasound, the newly synthesized amphiphilic RB derivatives may be potentially useful as a tumor-selective sensitizer for both light and ultrasound.

Relation between transcardiac gradient of VEGF and coronary flow response in humans.

BACKGROUND: Angiogenic growth factors, produced in the myocardium and coronary vascular bed, increase myocardial blood flow. This study examined whether plasma levels of vascular endothelial growth factor (VEGF) in coronary circulation may be related to coronary blood flow responses. METHODS: Blood flow responses in the left anterior descending coronary artery to an intracoronary infusion of acetylcholine (ACh) were measured by an intracoronary flow wire technique in 46 consecutive control subjects with normal coronary angiograms and left ventriculograms. Circulating VEGF levels were measured by ELISA in plasma obtained from the aortic root (AO) and anterior interventricular vein (AIV). RESULTS: The transcardiac gradient of VEGF, calculated by the difference in VEGF concentrations between the AIV and AO, showed a positive correlation with the coronary blood flow increase in response to ACh independently of traditional coronary risk factors. In patients with cardiac syndrome X (n=17), defined as a positive exercise stress test with a normal coronary angiograms and left ventriculogram, the transcardiac VEGF gradient was significantly lower than in the risk factors-matched control subjects (n=21). CONCLUSIONS: The transcardiac gradient of plasma VEGF was independently and positively correlated with the coronary blood flow increase in response to ACh. A reduced transcardiac VEGF gradient was present in cardiac syndrome X, a condition with a blunted coronary blood flow response.

Effect of echo-guided high-intensity focused ultrasound ablation on localized experimental tumors.

We fabricated a prototype 3.25-MHz split-focus therapeutic transducer combined with a small 6.5-MHz imaging ultrasonic probe for transrectal treatment of prostate cancer and evaluated the feasibility of using split-focus high-intensity focused ultrasound (HIFU) to ablate localized tumor tissue without injuring the surrounding organs. We therefore established a localized tumor model by inoculating VX2 tumor into rabbit livers. The localized VX2 tumors of nine rabbits were transdermally treated with split-focus ablation at a peak intensity in water of 6 kW/cm2 for 4 s (6 shots) under the guidance of ultrasonic B-mode imaging. Necropsy a day after treatment found the surface of the livers and gastrointestinal tracts to be grossly normal. The VX2 tumors were completely coagulated and were surrounded by ablated liver tissue. The six shots of split-focus HIFU destroyed the VX2 tumors without injuring the liver surfaces or the surrounding organs. These results suggest that split-focus HIFU ablation could be an effective treatment of localized tumors.

Chronic effect of transrectal split-focus ultrasonic ablation on canine prostatic tissue.

The treatment time needed for high-intensity focused ultrasound (HIFU) ablation might be decreased substantially by using the split-focus approach, so we made a prototype 4.2-MHz split-focus therapeutic transducer combined with a small 6.5-MHz imaging ultrasonic probe for transrectally treatment of canine prostatic cancer and used it to experimentally evaluate the feasibility of using split-focus transrectal HIFU to ablate canine prostatic tissue without injuring surrounding tissues. The prostates of 5 dogs were transrectally treated with split-focus ablation at a peak intensity in the water of 1.7 kW/cm(2) for 4 s (4 shots) under the guidance of ultrasonic B-mode imaging. After ultrasonic exposure, the prostates became stiff because of thermal effect of HIFU. For the first 3-5 days after treatment, dogs were catheterized daily for urinary management and treated with oral antibiotics to prevent urinary tract infection. The dogs were able to urinate normally by a week after. Within two weeks a large centrally located cystic cavity had formed in the prostate by replacing the necrotic parenchyma around the prostatic urethra. Necropsy three months after treatment found the rectum and prostate capsule to be normal grossly and histologically. The 4 shots of split-focus HIFU destroyed the prostatic parenchyma and created a prostatic cavity 0.34-0.45 cm(3) in volume without injuring surrounding tissues. These results suggest that split-focus HIFU ablation could be used for noninvasive treatment of prostatic cancer in dogs.

Atorvastatin increases plasma soluble Fms-like tyrosine kinase-1 and decreases vascular endothelial growth factor and placental growth factor in association with improvement of ventricular function in acute myocardial infarction.

OBJECTIVES: This study examined whether atorvastatin increases plasma levels of soluble Fms-like tyrosine kinase 1 (sFlt-1) and reciprocally decreases vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) levels in patients with acute myocardial infarction (AMI). BACKGROUND: Statins exert cardioprotective actions partly through anti-inflammatory actions. By capturing VEGF and PlGF in plasma, sFlt-1 acts as a natural inhibitor of VEGF and PlGF, which have proinflammatory properties. METHODS: Left ventriculography and enzyme-linked immunosorbent assay of plasma levels of sFlt-1, VEGF, and PlGF were repeated after AMI in 50 consecutive patients with a first AMI. Patients were randomized to treatment with atorvastatin (10 mg/day; n=25) or placebo (n=25) within 3 days after AMI, and therapy was continued for 6 months. RESULTS: The sFlt-1 levels were low in the acute phase, followed by an increase at 2 weeks after AMI, whereas free VEGF and PlGF levels were high in the acute phase, followed by a decrease at 2 weeks. Atorvastatin increased sFlt-1 levels and reciprocally decreased VEGF and PlGF levels at 6 months compared with placebo. The increase in sFlt-1 levels and the decrease in VEGF and PlGF levels were correlated with improvement of left ventricular ejection fraction during the follow-up period. CONCLUSIONS: There was a reciprocal relationship between changes in sFlt-1 levels and changes in VEGF and PlGF levels after AMI; and atorvastatin increased sFlt-1 levels while decreasing VEGF and PlGF levels. These changes were associated with late improvement of post-MI ventricular function, and may represent an additional benefit of statin therapy.

Ex vivo cell-mediated gene therapy for metachromatic leukodystrophy using neurospheres.

Metachromatic leukodystrophy (MLD) is an autosomal recessive disease caused by mutations in the gene encoding the lysosomal enzyme arylsulfatase A (ASA). In MLD, accumulation of the substrate, sulfated glycoprotein, in the central and peripheral nervous systems results in progressive motor and mental deterioration. Neural progenitor cells are thought to be useful for cell replacement therapy and for cell-mediated gene therapy in neurodegenerative diseases. In the present study, we examined the feasibility of ex vivo gene therapy for MLD using neural progenitor cells. Neural progenitor cells (neurospheres) were prepared from the striatum of E14 embryo MLD knockout mice or GFP transgenic mice and were transduced with the VSV pseudotyped HIV vector carrying the ASA gene (HIV-ASA). For in vivo study, neurospheres from GFP mice were transduced with HIV-ASA and inoculated into the brain parenchyma of adult MLD mice. HIV vector-transduced progenitor cells retained the potential for differentiation into neurons, astrocytes and oligodendrocytes in vitro. Expression of ASA in neurospheres transduced with HIV-ASA was confirmed by spectrophotometric enzyme assay and Western blotting. In vivo, GFP-positive cells were detectable 1 month after injection. These cells included GFAP- and MAP2-positive cells. Immunohistochemistry using anti-ASA antibody demonstrated localization of ASA in both GFP-positive and -negative cells. Partial clearance of accumulated sulfatide was confirmed in vivo in MLD knockout mice. The present findings suggest that ASA enzyme is released from migrated neurospheres and is able to digest sulfatide in surrounding cells. Our results suggest the potential of genetically engineered neural progenitor cells (neurospheres) for ex vivo therapy in MLD.