Benidipine reduces ischemia reperfusion-induced systemic oxidative stress through suppression of aldosterone production in mice

Aldosterone is implicated in the pathogenesis of several cardiovascular diseases, including ischemia reperfusion (I/R) and myocardial infarction, and also causes oxidative stress and inflammation in cardiovascular systems. Benidipine, a long-acting T- and L-type calcium channel blocker, reduces infarct size following myocardial I/R in rabbits. Benidipine also inhibits the production of aldosterone in vitro. However, the precise mechanism of this phenomenon in vivo remains unknown. We therefore evaluated whether benedipine has a beneficial role through the regulation of oxidative stress in myocardial I/R. C57BL/6J mice were subjected to 30?min of left ascending coronary I/R. Benidipine was administered orally at 3?mg?kg(-1) daily for 3 weeks without any changes in hemodynamic variables. Benidipine significantly reduced infarction size (13.4±2.5%) compared with controls (25.5±3.6%). Urinary 8-hydroxy-2' deoxyguanosine (8-OHdG), a marker of oxidative DNA damage, increased significantly after I/R. I/R induced increases in 8-OHdG were significantly lower with benidipine. Local myocardial 8-OHdG was also elevated in I/R, but this augmentation was significantly suppressed with benidipine. The plasma aldosterone concentration (PAC) significantly increased 2 days after I/R and remained elevated at least 7 days after I/R. Treatment with benidipine significantly decreased I/R-induced elevation of the PAC. I/R-induced markers of fibrosis in hearts also reduced in benidipine. These results suggest that the administration of benidipine reduces myocardial infarct size as well as systemic oxidative stress after I/R. These phenomena are partially linked to reduced plasma aldosterone levels.     

Diagnosis of gallbladder diseases by contrast-enhanced phase-inversion harmonic ultrasonography

We evaluated the usefulness of contrast-enhanced ultrasonography(US) for detecting and differentiating gallbladder lesions. Contrast-enhanced coded phase-inversion harmonic US was performed on 90 patients with gallbladder abnormalities. After administering Levovist, we observed the gallbladders in real time. Contrast-enhanced coded phase-inversion harmonic ultrasonography was compared with B-mode US and contrast-enhanced computer tomography (CT) with regard to the sensitivity and specificity in depicting the elevated gallbladder lesions. Furthermore, we assessed how the vascular patterns of the elevated gallbladder lesions depicted by contrast-enhanced US correlated with the diagnosis. Contrast-enhanced US efficiently discriminated true lesions from biliary sludge, unlike B-mode US. Consequently, contrast-enhanced US was more specific (100%) than B-mode US (81%), although their sensitivities were similar (98% and 96%, respectively). Contrast-enhanced US was also more sensitive that contrast-enhanced CT (98% versus 79%), although the two methods were equally sensitive (100% versus 95%). We classified the vascular patterns of the abnormalities depicted by contrast-enhanced US in the 90 cases into types 1 to 4, which represent branch-like, heterogeneous, homogeneous, and avascular patterns, respectively. All type 1 and 2 lesions were over 10 mm in size while most (88%) type 3 lesions were 10 mm or less in size. While the majority of carcinomas (86%) were type 1 or 2, three benign lesions also showed these patterns. Thus, the vascular pattern may simply reflect the size of the lesion and therefore its usefulness in diagnosing gallbladder lesions may be limited. Nevertheless, contrast-enhanced US is clearly superior to the other techniques in discriminating biliary sludge from other lesions.     

Increased expression of collagenase-3 (MMP-13) and MT1-MMP in oesophageal cancer is related to cancer aggressiveness

BACKGROUND: Collagenase-3 (matrix metalloproteinase-13, MMP-13) is a recently identified human MMP with broad substrate specificity which can be activated by membrane type 1 (MT1) matrix metalloproteinase in vitro. These may play a critical role in cancer aggressiveness. AIMS: To examine the clinical significance of collagenase-3 expression and the cooperative role of MT1-MMP in human oesophageal carcinomas. PATIENTS: Forty five individuals with oesophageal carcinoma who underwent surgery without preoperative treatment. METHODS: The tumour/normal (T/N) ratios of collagenase-3 and MT1-MMP mRNA expression in 45 human oesophageal carcinomas were determined by northern blot analysis. The production and localisation of collagenase-3 and MT1-MMP proteins were investigated by immunohistochemistry, western blot analysis, and zymography. RESULTS: The mean T/N ratio of collagenase-3 mRNA was 3.5 and that of MT1-MMP 2.1. There was a significant correlation between collagenase-3 and MT1-MMP mRNA expression (p<0.001). Twenty two cases with a collagenase-3 T/N ratio >3.5 showed a significantly higher frequency of vascular involvement and lymph node metastasis, and tended to be at a more advanced stage than 23 cases with a T/N ratio < or =3.5 (p<0.05). Western blot analysis and zymography demonstrated production of collagenase-3 protein in tumour tissues but not in normal tissues. Immunohistochemical studies revealed that collagenase-3 was localised predominantly in tumour cells and MT1-MMP was detected in the same collagenase-3 positive cells; there was a significant association between collagenase-3 and MT1-MMP protein expression (p<0.05). With regard to prognosis, the survival time for subjects in the high collagenase-3 group (T/N ratio >3.5) was significantly worse (p<0.05). CONCLUSIONS: These data suggest that production of collagenase-3 together with MT1-MMP is implicated in tumour aggressiveness and prognosis in human oesophageal carcinomas.     

Hepatic artery pseudoaneurysm associated with cholecystitis that ruptured into the gallbladder

Pseudoaneurysm of the hepatic artery due to cholecystitis may be very rare, and in our survey of the literature, the present case report is the first case of such a pseudoaneurysm. A 64-year-old woman presented with upper gastrointestinal bleeding and severe epigastric pain. Upper gastrointestinal tract endoscopy revealed blood coming out of the papilla of Vater. Color-Doppler ultrasound imaging showed a pulsatile wave pattern in an echogenic lesion inside the gallbladder. Contrast-enhanced computed tomography demonstrated a 3-cm pseudoaneurysm in the distended gallbladder. Angiography disclosed extravasation originating from the right hepatic artery. Emergency selective transcatheter arterial embolization was performed, with intravascular stainless steel microcoils, and complete occlusion of the pseudoaneurysm was achieved. The patient underwent cholecystectomy with resection of the extrahepatic bile duct and biliary reconstruction in a Roux-en-Y fashion. Macroscopically, the resected gallbladder contained clotted blood and multiple cholesterol stones. Microscopically, the mucosa of the gallbladder showed extensive necrosis and many inflammatory cells. The final diagnosis was pseudoaneurysm of the hepatic artery associated with calculous gangrenous cholecystitis. Although the mechanism of the pseudoaneurysm remains speculative, severe inflammatory reaction in the gallbladder may have infiltrated the liver parenchyma and may have eroded the wall of the hepatic artery, thus forming a pseudoaneurysm. Hemobilia is one of the important differential diagnoses when unexplained gastrointestinal bleeding is observed, especially in patients with hepatobiliary diseases.     

CO2 pneumoperitoneum increases secretory IgA levels in the gut compared with laparotomy in an experimental animal model

Background

Secretory immunoglobulin A (s-IgA) plays an important role in both gut and systemic immunity. This study aimed to investigate the production of s-IgA resulting from a CO₂ pneumoperitoneum compared with a laparotomy.

Methods

Using enzyme-linked immunosorbent assays, s-IgA in stool, malondialdehyde (MDA), and Toll-like receptor 4 (TLR4) in the ileal tissue were evaluated as markers for gut and systemic immune responses in an animal model. The rats were randomly divided into (i) anesthesia-only as the control group; (ii) laparotomy-only as the open group; and (iii) CO₂ pneumoperitoneum-only as the pneumoperitoneum group. To evaluate the gut immune system in a time-dependent manner, each group was further divided into short- and long-time subgroups.

Results

s-IgA levels did not increase in the open group but significantly increased in the pneumoperitoneum group compared with the control group (p < 0.05). In addition, s-IgA levels in the long-time subgroup significantly increased compared with the short-time subgroup of the pneumoperitoneum group (p < 0.05). TLR4 levels steeply and gradually increased in the open and pneumoperitoneum groups, respectively. MDA levels in the pneumoperitoneum group increased during the early phase and were significantly higher than those in the open group at 24 h (p < 0.05).

Conclusions

This study demonstrated that s-IgA levels in stool increased in the pneumoperitoneum group compared with the open group, suggesting that CO₂ pneumoperitoneum may cause transitory damage to the intestinal mucosa.     

High-dose-rate brachytherapy and hypofractionated external beam radiotherapy combined with long-term hormonal therapy for high-risk and very high-risk prostate cancer: outcomes after 5-year follow-up

The purpose of this study was to report the outcomes of high-dose-rate (HDR) brachytherapy and hypofractionated external beam radiotherapy (EBRT) combined with long-term androgen deprivation therapy (ADT) for National Comprehensive Cancer Network (NCCN) criteria-defined high-risk (HR) and very high-risk (VHR) prostate cancer. Data from 178 HR (n = 96, 54%) and VHR (n = 82, 46%) prostate cancer patients who underwent ¹⁹²Ir-HDR brachytherapy and hypofractionated EBRT with long-term ADT between 2003 and 2008 were retrospectively analyzed. The mean dose to 90% of the planning target volume was 6.3 Gy/fraction of HDR brachytherapy. After five fractions of HDR treatment, EBRT with 10 fractions of 3 Gy was administered. All patients initially underwent ≥6 months of neoadjuvant ADT, and adjuvant ADT was continued for 36 months after EBRT. The median follow-up was 61 months (range, 25–94 months) from the start of radiotherapy. The 5-year biochemical non-evidence of disease, freedom from clinical failure and overall survival rates were 90.6% (HR, 97.8%; VHR, 81.9%), 95.2% (HR, 97.7%; VHR, 92.1%), and 96.9% (HR, 100%; VHR, 93.3%), respectively. The highest Radiation Therapy Oncology Group-defined late genitourinary toxicities were Grade 2 in 7.3% of patients and Grade 3 in 9.6%. The highest late gastrointestinal toxicities were Grade 2 in 2.8% of patients and Grade 3 in 0%. Although the 5-year outcome of this tri-modality approach seems favorable, further follow-up is necessary to validate clinical and survival advantages of this intensive approach compared with the standard EBRT approach.     

Changes in tissue oxygenation in response to sudden intradialytic hypotension

Journal of Artificial Organs - A 76-year-old woman on hemodialysis (HD) for diabetic nephropathy was admitted to our hospital with occasional intradialytic hypotension (IDH). We continuously...     

Evidence for the involvement of ecto-5′-nucleotidase (CD73) in drug resistance

Increased ecto-5′-nucleotidase (ecto-5′NT) protein expression in several multidrug-resistant (MDR) cell lines, documented previously by our group, suggests that this enzyme is involved in drug resistance. Here, Northern blot analysis of selected cell lines and their MDR variants positively correlated ecto-5′NT protein with its mRNA expression. An inhibitor of ecto-5′NT enzymatic activity, α,β-methyleneadenosine 5′-diphosphate (AMP-CP), was used to determine if functionally active enzyme had a role in drug resistance. AMP-CP (0.3 mM) reversed the resistance of ecto-5′NT-positive MDR cells (MCF7/A6, L1210/A) to doxorubicin, whereas it did not affect the doxorubicin sensitivity of the ecto-5′NT-negative parental cell lines or that of 2 ecto-5′NT-negative MDR cell lines (HL60/VCR and A2780/DX5). Furthermore, AMP-CP increased rhodamine uptake and inhibited rhodamine efflux from ecto-5′NT-positive MDR cells without affecting ecto-5′NT-negative MDR cells. The presence of exogenous adenosine (0.5 μM) circumvented AMP-CP-induced inhibition of rhodamine efflux from EL4/ADM cells. AMP-CP inhibited the growth of the ecto-5′NT-positive L1210/A MDR cells but had no effect on the growth of the parental cell line. Determination of intracellular ATP levels indicated that MDR cells which had increased ecto-5′NT expression also had a lower intracellular ATP level than their parental cells. Our results suggest that, in certain MDR cell lines, ecto-5′NT serves as a required accessory molecule in resistance mediated by ATP-dependent mechanisms and that growth-sustaining nucleosides are provided by this salvage pathway. © 1996 Wiley-Liss, Inc.