Identification of a specific ultrasonographic finding for differentiating hepatic angiomyolipoma from hepatocellular carcinoma.

OBJECTIVE: To identify specific ultrasonographic features that differentiate hepatic angiomyolipoma (HAML) from hepatocellular carcinoma (HCC). METHODS: Twelve patients with HAML and 73 patients with HCC, whose diagnosis were pathologically confirmed at a single center in Japan between 2006 and 2016, were included in this study. The HAML and HCC cases were histologically evaluated and their histological growth patterns were compared. Using ultrasonographic data, we evaluated the imaging features representing the distinct histological differences. Ultrasonographic findings, reviewed by two examiners, were compared via interobserver variability analysis. This retrospective study was approved by the institutional ethics committee at our institute (No. 2017-1004). RESULTS: The enrolled patients were carefully divided into two case sets: discovery case set (6 HAML patients and 37 HCC patients) and validation case set (6 HAML patients and 36 HCC patients). In the discovery case set, half of the HAML cases had intratumoral regions showing a reticular growth pattern. None of the HCC cases appeared as a region with the reticular growth pattern. The regions with the reticular growth pattern present as an intratumoral hyper echoic foci on ultrasound images. The presence of the intratumoral hyper echoic foci was significantly associated with HAML (P < .01). In the validation case set, the intratumoral hyper echoic foci predicted HAML at a specificity of 100% and a sensitivity of 50%. CONCLUSIONS: Intratumoral hyper echoic foci, representing reticular growth pattern, can be a promising ultrasonographic finding to help differentiate HAML from HCC.

Sonographic findings in three cases of carcinoma showing thymus-like differentiation.

Carcinoma showing thymus-like differentiation (CASTLE) is a rare tumor of the thyroid gland or soft tissues of the head and neck. To our knowledge, there have been only a few reports concerning imaging findings of CASTLE. We report herein the sonographic appearances of three cases of CASTLE. Two tumors were located at the lower part of the thyroid and one had spread throughout the thyroid. Sonograms showed heterogeneously solid tumors without cystic components or calcification. The central part of the tumor was slightly hyperechoic compared with the peripheral part of the tumor. Histologically, the tumors were composed of a mixture of fibrous stroma and epithelial nests.

Management of venous thromboembolism in colorectal cancer patients treated with bevacizumab.

Venous thromboembolism associated with use of a central venous access system is an urgent problem in patients treated with bevacizumab (bev). We investigated the effectiveness of Doppler ultrasound imaging (DUS) in the early detection of catheter-related thrombosis for avoidance of severe venous thromboembolism. Patients with metastatic colorectal cancer received either FOLFOX-4 + bev or FOLFIRI + bev. DUS was performed on the deep venous system for detection of thrombus formation during the initial cycle of treatment, followed by re-evaluation after the third cycle in patients with asymptomatic thrombus formation. All patients were followed up until treatment was interrupted. Median duration of follow-up was 484 days (range 72-574). Among 41 enrolled patients, curable symptomatic thrombosis occurred in one, and asymptomatic thrombosis in 21 (51.2%). Of 21 patients undergoing re-evaluation, thrombi remained without progression in 17 patients, and enlargement in 4 patients. In two of the patients in whom there was progression, pulmonary embolism occurred after the sixth cycle. In the asymptomatic group, no thrombi developed as far as the superior vena cava in any patient. In the cases of progression, thrombotic enlargement was observed in all the 4 patients, with decreased vascular flow in 2. Using DUS, we were able to detect asymptomatic thrombosis in the early cycles of treatment, indicating its potential in the monitoring of venous thrombi. In the event of an enlarging asymptomatic thrombosis developing into the superior vena cava along with decreased vascular flow, careful follow-up and appropriate anticoagulant therapy may be recommended without increased risk of bleeding.

Three cases of angiomyolipoma: diagnostic imaging by contrast-enhanced ultrasonography.

We used contrast-enhanced ultrasound using the Sonazoid microbubble contrast agent to diagnose three cases of hepatic angiomyolipoma, which is a rare benign tumor. Some characteristic findings are obtained in the early vascular phase, for example fork-like tumor vessels. However, a variety of findings are seen after the early vascular phase because of microbubbles circulating the vascular enriched tumor.

The intermediate-conductance calcium-activated potassium channel KCa3.1 contributes to atherogenesis in mice and humans.

Atherosclerosis remains a major cause of death in the developed world despite the success of therapies that lower cholesterol and BP. The intermediate-conductance calcium-activated potassium channel KCa3.1 is expressed in multiple cell types implicated in atherogenesis, and pharmacological blockade of this channel inhibits VSMC and lymphocyte activation in rats and mice. We found that coronary vessels from patients with coronary artery disease expressed elevated levels of KCa3.1. In Apoe(-/-) mice, a genetic model of atherosclerosis, KCa3.1 expression was elevated in the VSMCs, macrophages, and T lymphocytes that infiltrated atherosclerotic lesions. Selective pharmacological blockade and gene silencing of KCa3.1 suppressed proliferation, migration, and oxidative stress of human VSMCs. Furthermore, VSMC proliferation and macrophage activation were reduced in KCa3.1(-/-) mice. In vivo therapy with 2 KCa3.1 blockers, TRAM-34 and clotrimazole, significantly reduced the development of atherosclerosis in aortas of Apoe(-/-) mice by suppressing VSMC proliferation and migration into plaques, decreasing infiltration of plaques by macrophages and T lymphocytes, and reducing oxidative stress. Therapeutic concentrations of TRAM-34 in mice caused no discernible toxicity after repeated dosing and did not compromise the immune response to influenza virus. These data suggest that KCa3.1 blockers represent a promising therapeutic strategy for atherosclerosis.

PRODAN-conjugated DNA: synthesis and photochemical properties.

A solvatochromic fluorophore, PRODAN, has been used as a microenvironment-sensitive reporter. Based on the chemistry of PRODAN, we designed and synthesized four novel fluorescent nucleosides, PDNX (X = U, C, A, and G), to which a PRODAN fluorophore was attached at pyrimidine C5 or purine C8. The fluorescent nucleosides sensitively varied the Stokes shift values depending on the orientational polarizability of the solvent. The PDNX incorporated into DNA also changed the Stokes shift values depending on the DNA structure. In particular, the excitation spectrum of the PDNX-containing duplex shifted to a longer wavelength and gave a smaller Stokes shift value when the base opposite PDNX could form a Watson-Crick base pair with PDNX. A lower energy excitation of PDNX-containing DNA resulted in a strong fluorescence emission selective to the Watson-Crick pairing base. This unique photochemical character was applicable to the efficient typing of single-nucleotide polymorphisms of genes.

Development of novel PRODAN-labeled nucleosides as base-discriminating fluorescent probes.

We have developed a PRODAN-labeled uridine ((PDN)U), which contains a polarity-sensitive chromophore at the C-5 position of uracil. This paper describes the synthesis and fluorescent properties of oligodeoxy-nucleotides (ODNs) containing PRODAN-labeled nucleosides ((PDN)C, (PDN)A, and (PDN)G). PRODAN chromophore was attached to cytosine at the C-5 position and to purine bases at the C-8 position to extend into the major groove. When BDF probes containing a PRODAN-labeled nucleoside hybridize with a "full-matched" ODN, the fluorescence spectrum showed a strong emission around 520 nm on 450 nm excitation. In contrast, when PRODAN-labeled nucleoside analogs form a "mismatched" base pair, the fluorescence was weaker.

Nile Red nucleoside: design of a solvatofluorochromic nucleoside as an indicator of micropolarity around DNA.

The fluorophore, Nile Red, effectively works as a polarity-sensitive fluorescence probe. We have designed a new nucleoside modified by Nile Red for examining the change in the polarity of the microenvironment surrounding DNA. We synthesized a Nile Red nucleoside (1), formed by replacing nucleobases with Nile Red, through the coupling of a 2-hydroxylated Nile Red derivative and 1,2-dideoxyglycan. This nucleoside showed a high solvatofluorochromicity. The fluorescence of 1 incorporated into DNA was greatly shifted to shorter wavelength by the addition of beta-cyclodextrin. The photophysical function of the Nile Red nucleoside will be a good optical indicator for monitoring the change in the micropolarity properties at a specific site on target sequences with interaction between DNA and DNA-binding molecules.

Nile Red nucleoside: novel nucleoside analog with a fluorophore replacing the DNA base.

A solvatochromic dye is very useful in studies of local polarity and dynamics in biological systems. A novel solvatochromic chromophore, Nile Red beta-C-2'-deoxyriboside, has been synthesized to act as a photophysical probe, and incorporated site-selectively into an oligodeoxynucleotide. The absorption and fluorescence spectra of Nile Red nucleoside showed a remarkable sensitivity to the solvent polarity.

Pitavastatin inhibits upregulation of intermediate conductance calcium-activated potassium channels and coronary arteriolar remodeling induced by long-term blockade of nitric oxide synthesis.

UNLABELLED: We have reported that intermediate conductance Ca(2+)-activated K(+) channels (ImK) showed augmented expression in angiotensin II (AII) type 1 receptor-dependent manner in post-ischemic rat heart. ImK has tyrosine phosphorylation sequence in the C-terminus and motifs for NFkappaB and AP1 in the promoter. While statin inhibits AII-mediated vascular remodeling via anti-inflammatory effect independent of cholesterol lowering. To test the possible effect of statin on expression of ImK, Wistar-Kyoto rats received L-nitro-arginine methyl ester (LNAME: 1 mg/ml in drinking water) for 4 weeks in group L. While in L+P group, rats received both LNAME and pitavastatin (PTV: 1 mg/kg/day in drinking water). Temporal profile of ImK mRNA was examined by RT-PCR using specific primers for ImK. RESULTS: Long-term LNAME administration produced significant hypertension and resulted in marked microvascular remodeling characterized by medial thickening and perivascular fibrosis of coronary arterioles (100-200 microm in diameter). RT-PCR revealed significant up-regulation of ImK mRNA with two distinct peaks in L group in the early phase (days 3-7) and the late phase (4 weeks). PTV partially inhibited a rise in systolic blood pressure, but completely abolished the first peak of ImK upregulation (0.76 +/- 0.04 vs. 3.96 +/- 1.43 folds at day 7, p < 0.001). Co-treatments with PTV also significantly inhibited medial thickening and perivascular fibrosis. These findings indicate that statin inhibits microvascular remodeling induced by chronic inhibition of NO synthesis through the action independent of cholesterol lowering.

[Cardiomyopathy showing progression from diffuse left ventricular hypertrophy to dilated phase associated with mitochondrial DNA point mutation A3243G: A case report].

A 44-year-old man was admitted to our hospital because of congestive heart failure. He had various symptoms caused by insulin-dependent diabetes mellitus, sensorineural deafness, Wolff-Parkinson-White syndrome and cardiomyopathy associated with mitochondrial DNA point mutation A3243G. Echocardiography had showed symmetrical hypertrophy of the left ventricular wall and normal cardiac function (ejection fraction 55%) at age 32 years. However, echocardiography showed cardiac transformation, consisting of posterior wall thinning and significantly reduced cardiac function (ejection fraction 11%), at age 44 years. Electrocardiography showed lowered R-wave in the chest leads and QRS widening. Both lactic acid and pyruvate serum levels were increased. Mitochondrial respiratory enzyme analysis in gastrocnemius muscle tissue indicated a partial deficiency of rotenone-sensitive NADH cytochrome C reductase. He was discharged from our hospital, and medically treated with coenzyme Q10(30 mg/day). He had no progression of cardiomyopathy or congestive heart failure. However, he suddenly died of lactic acidosis at age 47 years.

L-nitro-arginine inhibits increase in endothelin binding sites induced by ischemia and reperfusion.

We have demonstrated that ischemia and reperfusion promoted augmented contractile response to endothelin-1 (ET) in coronary arteries in the presence of polymorphonuclear leukocytes (PMN). It has been also reported that ischemia and reperfusion increase ET binding sites in cardiac membrane in isolated rat heart perfused by blood cell-free system. To determine the role of PMN and L-arginine to nitric oxide (NO) pathway in these phenomena, isolated perfused rabbit hearts were subjected to 30 min of global ischemia followed by 30 min of reflow in the absence or presence of PMN and 10(-5)M of L-nitro-arginine (LNA). PMN was prepared with Percoll density gradients from peritoneal exudate elicited by glycogen. PMN activated with 10(-6)M of phorbol myristate acetate or their supernatant were infused into the coronary perfusion circuit after 5 min of reflow. LNA was added to perfusate also after reflow. The effect of superoxide dismutase (SOD: 50 IU/ml) was also determined. After the end of protocols, membrane fraction was isolated from the hearts for (125)I-ET-1 binding assay. ET-1 binding (Bmax) showed a significant increase by ischemia and reperfusion (P<0.01 vs control). That was markedly augmented with addition of activated PMN or their supernatant (both P<0.01), but abolished either by LNA or SOD (P<0.01 and P<0.05, respectively). These results indicate that increase in ET-receptor by ischemia and reperfusion is mediated by free radicals generated via L-arginine to NO pathway.

Role of augmented expression of intermediate-conductance Ca2+-activated K+ channels in postischaemic heart.

1. The rat intermediate conductance calcium-activated potassium channel (ImK) was cloned from a cDNA library of vascular smooth muscle cells (VSM) in rat pulmonary artery. The ImK distributes in a variety of tissue, including VSM, endothelial cells, leucocytes and fibroblasts. The ImK has a tyrosine phosphorylation consensus site in the proximal portion of the C-terminus and motifs exist for the DNA-binding protein AP-1 in the promoter, suggesting this channel is upregulated and active in cell cycle functions. The aim of the present study was to examine the role of ImK in postischaemic cardiovascular remodelling in relation to the angiotensin AT1 receptor-mediated AP-1 signalling pathway. 2. Rats underwent left coronary artery ligation for periods between 1 day and 3 weeks. The temporal profile of expression of ImK mRNA was analysed by RNase protection assay. To test the effect of AT1 receptor blockade, candesartan (3 mg/kg per day) was administered via an osmotic mini-pump implanted in the intraperitoneal space 3 days prior to coronary occlusion. 3. ImK expression in postischaemic hearts showed a significant increase with two distinct peaks; the first peak at day 3 (2.7-fold compared with control levels; P < 0.001) and the second after 2 weeks (1.5-fold; P < 0.01). Reperfusion following 30 min of ischaemia markedly accelerated and augmented the first peak at days 1-3 (4.8-fold), but completely abolished the second peak after 1-2 weeks (0.8-fold). In situ hybridization of ImK mRNA and immunostaining of ImK protein with specific antibody revealed that this was not only the result of the increase in ImK expression in vascular cells, but also related to infiltration of mononuclear leucocytes and fibroblasts into the ischaemic region. Candesartan inhibited cardiac hypertrophy and perivascular fibrosis of coronary arterioles in the non-ischaemic region. Candesartan also abrogated both peaks in ImK expression. 4. These findings indicate that both the inflammatory reaction and the postischaemic cardiovascular remodelling promote increased expression of ImK in postischaemic hearts via the AT1 receptor-mediated AP-1 signalling pathway.