Olmesartan is an angiotensin II receptor blocker with an inhibitory effect on angiotensin-converting enzyme.

Angiotensin II receptor blockers (ARBs) are widely used for the treatment of hypertension. It is believed that treatment with an ARB increases the level of plasma angiotensin II (Ang II) because of a lack of negative feedback on renin activity. However, Ichikawa (Hypertens Res 2001; 24: 641-646) reported that long-term treatment of hypertensive patients with olmesartan resulted in a reduction in plasma Ang II level, though the mechanism was not determined. It has been reported that angiotensin 1-7 (Ang-(1-7)) potentiates the effect of bradykinin and acts as an angiotensin-converting enzyme (ACE) inhibitor. It is known that ACE2, which was discovered as a novel ACE-related carboxypeptidase in 2000, hydrolyzes Ang I to Ang-(1-9) and also Ang II to Ang-(1-7). It has recently been reported that olmesartan increases plasma Ang-(1-7) through an increase in ACE2 expression in rats with myocardial infarction. We hypothesized that over-expression of ACE2 may be related to a reduction in Ang II level and the cardioprotective effect of olmesartan. Administration of 0.5 mg/kg/day of olmesartan for 4 weeks to 12-week-old stroke-prone spontaneously hypertensive rats (SHRSP) significantly reduced blood pressure and left ventricular weight compared to those in SHRSP given a vehicle. Co-administration of olmesartan and (D-Ala7)-Ang-(1-7), a selective Ang-(1-7) antagonist, partially inhibited the effect of olmesartan on blood pressure and left ventricular weight. Interestingly, co-administration of (D-Ala7)-Ang-(1-7) with olmesartan significantly increased the plasma Ang II level (453.2+/-113.8 pg/ml) compared to olmesartan alone (144.9+/-27.0 pg/ml, p<0.05). Moreover, olmesartan significantly increased the cardiac ACE2 expression level compared to that in Wistar Kyoto rats and SHRSP treated with a vehicle. Olmesartan significantly improved cardiovascular remodeling and cardiac nitrite/ nitrate content, but co-administration of olmesartan and (D-Ala7)-Ang-(1-7) partially reversed this anti-remodeling effect and the increase in nitrite/nitrate. These findings suggest that olmesartan may exhibit an ACE inhibitory action in addition to an Ang II receptor blocking action, prevent an increase in Ang II level, and protect cardiovascular remodeling through an increase in cardiac nitric oxide production and endogenous Ang-(1-7) via over-expression of ACE2.     

IMPROVED BALLOON‐TIPPED TRANS‐ANAL ILEUS TUBE

Background: For management of bowel obstruction due to colorectal cancer, endoscopic trans‐anal decompression technique has been first reported by Lelcuk et al. in 1986 using balloon dilatation technique. Since then, various types of trans‐anal decompression tubes have been clinically used for patients suffering from left side obstructing colorectal cancer as an emergent decompressing device. At present, two types of trans‐anal ileus tube (trans‐anal decompression tube) have been available for clinical use, but they have two main problems that are late colon perforations caused by the tip of the tube and tube obstruction by stool. Methods: Analysis on three late colon perforations experienced with the use of conventional devices drew possible improvements to make a trans‐anal ileus tube less harmful. To overcome the pitfalls inherent to conventional tubes, the author has developed an improved trans‐anal ileus tube with a balloon installed at the very end of the tube (‘balloon‐tipped type’) made of silicone, measuring 1200 or 1700 mm in total length and 22 Fr in outer diameter. It has been used for 12 cases with obstructing colorectal cancer etc. and its outcomes were compared with those obtained by the use of conventional trans‐anal ileus tube. Results: No late perforations have been encountered, but tube obstruction did occur in one of 12 cases. Conclusion: The new trans‐anal ileus tube with a balloon installed at the tip of ileus tube is considered to be safer and especially effective in preventing late colon perforation and tube obstruction.     

Osteoclastogenesis inhibitory factor exhibits hypocalcemic effects in normal mice and in hypercalcemic nude mice carrying tumors associated with humoral hypercalcemia of malignancy

Osteoclastogenesis inhibitory factor (OCIF) is a novel secreted protein that inhibits osteoclastogenesis both in vitro and in vivo. In this study, we examined the effects of OCIF on serum calcium (Ca) concentrations in normal mice and in hypercalcemic nude mice carrying tumors associated with humoral hypercalcemia of malignancy. In normal mice, a single intraperitoneal injection of OCIF reduced serum Ca levels in a dose-dependent manner. Significant decrease in serum Ca (by 1.6 ± 0.3 mg/dL, n = 5) was observed 2 h after the injection of OCIF at 20 mg/kg and the hypocalcemic effect continued for up to 12 h. Serum phosphate (Pi) concentrations also decreased in response to OCIF. Urinary excretion of Ca, Pi, and creatinine did not change significantly after injection of OCIF or vehicle. In hypercalcemic, tumor-bearing nude mice, a single intraperitoneal injection of OCIF at 20 mg/kg resulted in a dramatic decrease in serum Ca (maximal decrease 2.8 ± 0.37 mg/dL, n = 11), which continued for up to 24 h. The results suggest that OCIF decreased serum Ca through its inhibitory effect on bone resorption. Furthermore, it is suggested that OCIF has therapeutic potential for the treatment of hypercalcemic conditions such as malignancy-associated hypercalcemia.     

A case of pulmonary artery bypass surgery for a patient with isolated Takayasu pulmonary arteritis and a review of the literature.

A 45-year-old female was presented with progressive dyspnea and bilateral leg edema. Pulmonary angiography revealed total occlusion of the right pulmonary artery and significant stenosis of the left pulmonary artery. The inferior lobar artery as well as the segmental arteries were well patent. No pathology was detected elsewhere at the aorta and its branches. The diagnosis of chronic pulmonary arterial occlusion by isolated Takayasu arteritis was made because of the characteristic pattern of angiographic findings and the presence of unusual shunt formation from the coronary artery to the peripheral portion of the pulmonary artery, as well as a characteristic presentation of HLA typing in blood analysis, which strongly suggested the diagnosis of Takayasu arteritis. To restore the pulmonary blood flow, we employed reconstructive surgery by means of bypass procedure, using PTFE graft. Postoperatively there was marked improvement in cardiopulmonary function and the quality of life of the patient. The graft was proved to be patent at long-term follow-up study. An extremely rare case of chronic occlusive pulmonary arteritis, which was surgically treated by means of bypass procedure, is reported herein, and a brief review of previous reports on this subject was attempted.     

Pancreatic metastasis of malignant melanoma diagnosed by EUS-guided fine needle aspiration (EUS-FNA)]

Pancreatic metastasis of malignant melanoma is rarely diagnosed while the patient is alive. We report a case of metastatic melanoma of the pancreas in a 35-year-old woman presenting with a solid mass of the pancreas. Her past medical history included a radical hysterectomy 2 years previously for malignant melanoma of the vagina. Twelve months later, lung metastasis was also resected. EUS-guided fine needle aspiration (EUS-FNA) identified that the pancreatic tumor was histologically and immunohistochemically identical to the surgical specimen of her lung neoplasm. Imaging studies including US, CT, and MRI have limited value to distinguish the tumors from primary ductal adenocarcinoma. EUS-FNA can provide tissue diagnosis from pancreatic masses, specifically when other modalities have failed.     

A female case with Down syndrome and non-neurogenic neurogenic bladder

Although the prevalence of a learned voiding dysfunction and non-neurogenic neurogenic bladder (NNB), which is one type of dysfunctional elimination syndrome, is considered to be relatively rare, the association of NNB with Down syndrome (DS) has been elucidated in male patients. We herein describe the occurrence of NNB in an adult female with DS. The diagnosis was confirmed after completely ruling out any neurological or anatomical anomalies that could be related to a lower urinary tract dysfunction. She had renal dysfunction and multiple obstructive uropathies for which clean intermittent catheterization was successfully introduced.     

Influence of differences in tumor vascularity upon the effects of hyperthermia

Summary Utilizing two types of human renal carcinoma heterotransplanted in nude mice, we investigated the variations in hyperthermic effects (42.5°C for 30 min) caused by differences in tumor type with special reference to variations in tumor vascularity. In the hypovascular JRC1 strain, sporadic vascular dilation was observed throughout the tumors after heating. Destruction of tumor cells was observed mainly in the region of dilation. In the hypervascular JRC11 strain, homogenous vascular dilation was observed immediately after heating, mainly at the periphery of tumors. There was a decrease in the viability of cells in the center of the tumor. Therefore, the hypervascular tumors showed greater destruction mainly at the center where blood circulation was reduced. The range of necrosis was also greatly affected by the extent of vascular dilation caused by heating in hypovascular tumors.     

Malignant fibrous histiocytoma of the temporal bone with endocranial extension.

Cranial malignant fibrous histiocytomas are rare tumors. Most are hypervascular, destructive masses that are similar to other malignant lesions and to malignant fibrous histiocytomas found elsewhere in the body. We describe a myxoid malignant fibrous histiocytoma of the temporal bone, possibly of dural origin, with features that more closely resembled a meningioma at CT, MR imaging, and angiography.