Differential Effects of Etomidate and Midazolam on Vascular Adenosine Triphosphate-sensitive Potassium Channels: Isometric Tension and Patch Clamp Studies

Background: The aim of this study was to investigate the effects of two imidazoline-derived intravenous anesthetics, etomidate and midazolam, on vascular adenosine triphosphate-sensitive potassium (KATP) channel activity.

Methods: In isolated rat aorta, isometric tension was recorded to examine the anesthetic effects on vasodilator response to levcromakalim, a selective KATP channel opener. Using the patch clamp method, the anesthetic effects were also examined on the currents through (1) native vascular KATP channels, (2) recombinant KATP channels with different combinations of various types of inwardly rectifying potassium channel (Kir6.0 family: Kir6.1, 6.2) and sulfonylurea receptor (SUR1, 2A, 2B) subunits, (3) SUR-deficient channels derived from a truncated isoform of Kir6.2 subunit (Kir6.2[DELTA]C36 channels), and (4) mutant Kir6.2[DELTA]C36 channels with reduced sensitivity to adenosine triphosphate (Kir6.2[DELTA]C36-K185Q channels).

Results: Etomidate (>= 10-6 m), but not midazolam (up to 10-6 m), inhibited the levcromakalim-induced vasodilation, which was sensitive to glibenclamide (IC50: 7.21 x 10-8 m; maximum inhibitory concentration: 1.22 x 10-4 m). Etomidate (>= 3 x 10-6 m), but not midazolam (up to 10-4 m), inhibited the native KATP channel activity in both cell-attached and inside-out configurations with IC50 values of 1.68 x 10-5 m and 1.52 x 10-5 m, respectively. Etomidate (10-5 m) also inhibited the activity of various types of recombinant SUR/Kir6.0KATP channels, Kir6.2[DELTA]C36 channels, and Kir6.2[DELTA]C36-K185Q channels with equivalent potency.     

Case of ruptured gastroduodenal arterial pseudoaneurysm with penetration to the duodenum, successfully treated with transcatheter arterial embolization]

A 77-year-old man, who underwent segmental pancreatectomy for intraductal papillary mucinous adenoma in 2001, was referred to our hospital with complaints of hematemesis and melena on January, 2004. Emergency upper gastrointestinal endoscopy showed a pulsating submucosal protrusion in the duodenal bulb, which was identified as a gastroduodenal arterial aneurysm measuring 1.5cm on abdominal CT imaging. Transcatheter arterial embolization of the aneurysm with metallic coils was successfully performed. Periodically repeated endoscopic examination has revealed the coils protruding into the duodenal lumen without any serious complication.     

Surgical treatment of pseudoaneurysm of the sinus of valsalva after aortic valve replacement for active infective endocarditis.

Pseudoaneurysm is an uncommon and serious complication of infective endocarditis (IE). It is often fatal because of its rapid progress, high rates of rupture and recurrence, and worsening effects on the systemic condition. We report the rare case of a patient who developed a pseudoaneurysm of the sinus of Valsalva two months after emergency aortic valve replacement for active IE. At the previous operation, we had directly closed a small fistulous hole in the non-coronary sinus of Valsalva using two mattress sutures with autologous pericardial pledgets, because the tissue surrounding the hole did not appear to be infected on visual inspection. A pseudoaneurysm developed from this portion due to detachment of sutures. If the fistula had been completely resected during the first surgery instead of performing a simple closure, the pseudoaneurysm of the sinus of Valsalva would not have formed. However, the primary aim of the first emergency surgery was to spare the life of a critically ill patient. In the second surgery, the pseudoaneurysm was completely resected with the aortic wall--including the non-coronary sinus of Valsalva and the communicating hole. Then, patch plasty of the non-Valsalva sinus was successfully performed.     

Long-term survival of a pulmonary artery sarcoma produced by aggressive surgical resection and adjuvant chemoradiotherapy.

Malignant pulmonary artery tumors represented by sarcomas are rare, but fatal. Early diagnosis and radical surgical resection offer the only chance for survival. However, surgical intervention has some challenging aspects, and prognosis is poor even after tumor resection. We report a case of a pulmonary artery sarcoma between the right ventricular outflow tract and the pulmonary artery branches. The tumor was aggressively extracted with reconstruction using a cryopreserved pulmonary valved allograft, followed by adjuvant chemoradiotherapy. At 56 months after surgery, the patient is well without any evidence of recurrence, demonstrating that aggressive surgical resection with adjuvant chemoradiotherapy can prolong survival.     

STANDARD IMAGING TECHNIQUES OF ENDOSCOPIC ULTRASOUND‐GUIDED FINE‐NEEDLE ASPIRATION USING A CURVED LINEAR ARRAY ECHOENDOSCOPE

Standard imaging techniques using a curved linear array echoendocope are summarized to facilitate the attainment of expertise in endoscopic ultrasonography and endoscopic ultrasound‐guided fine needle aspiration, and to promote the widespread use of this diagnostic and therapeutic tool. Typical images of the mediastinal organs, the bilio‐pancreatic systems and neighboring organs by scanning from the esophagus, stomach, duodenal bulb, and descending portion of the duodenum, are shown in a sequential manner. The basic techniques of endoscopic ultrasound‐guided fine needle aspiration are also presented.     

Dental management of a patient with takotsubo cardiomyopathy: a case report.

Takotsubo cardiomyopathy (TCM) is a relatively new concept in cardiovascular disease. The clinical symptoms of TCM are similar to those of a myocardial infarction, but both the mechanism and the management of TCM are different from those of myocardial infarction. The cause of TCM is unclear, but it is suggested to occur in conjunction with excessive circulating catecholamines due to stress. Thus, control of the stress reaction and restriction of catecholamine levels are considered important for prevent of TCM onset. We report the dental management of a patient with intellectual disability who had anamnesis of TCM and cardiopulmonary arrest under restraint during a previous dental appointment in another dental clinic. We used intravenous sedation with both midazolam and propofol, by which the excessive hormonal reaction that caused TCM onset and cardiopulmonary arrest was controlled, for dental treatment in our facility. All planned dental treatment was then performed without any problems.     

Incidence and prognostic factors of Japanese breast cancer patients with bone metastasis

Background Few previous studies have analyzed the incidence of bone metastases in a defined population of Japanese breast cancer patients and their prognosis after chemotherapy. Methods This is a retrospective cohort study. We investigated 695 patients who underwent surgery for breast cancer. The strategy of adjuvant therapy was as follows. Patients with both estrogen receptors (ERs) and progesterone receptors (PgRs) had endocrine therapy as initial adjuvant therapy (n = 239). Patients with neither ERs nor PgRs had chemotherapy. When metastasis to other organs, including bone, was identified, patients received chemotherapy. The survival rates after surgery and after the onset of bone metastasis, as well as the incidence of bone metastasis, were calculated. We also evaluated the prognostic and predictive factors. Results Bone metastases developed in 148 of 695 patients. All 148 received chemotherapy, and 121 of them developed spinal metastases. The 5-year survival rate after bone metastases was 26.1%. Prognostic factors for bone metastases were visceral metastases and PgR status. Cord compression was observed in 17 of the 148 patients, with the thoracic spine being the most common. The 1-year survival rate for patients with bone metastases who received chemotherapy was 66.3%, whereas that of patients with paralysis after spinal metastases was 17.6%. Within 6 months of the development of spinal cord compression, 70.6% of the patients died. Conclusions We reported the incidence and prognostic factors for a defined population of Japanese breast cancer patients with bone and spinal metastases. Our results suggest that the expected survival time for patients with paralysis who received adequate endocrine therapy or chemotherapy is generally poor. However, to detect a predictive factor of long survival after paralysis and establish the indications for surgery, a comparative study among large groups of patients with paralysis and with different backgrounds is necessary.     

Ectopic Ureterocele with a Horseshoe Kidney in an Adult

A rare adult case of a left ectopic ureterocele associated with a duplex horseshoe kidney is reported. To the best of our knowledge, only one pediatric case of horseshoe kidney with an ectopic ureterocele has been reported. The present case was successfully treated by ureteropyelostomy, upper ureterectomy and unroofing of the ureterocele. The patient is currently followed with excretory urograms and renograms.     

Chromosomal Mapping of Genetic Locus Associated with Thymus-size Enlargement in BUF/Mna Rats

The thymoma-prone rat of the BUF/Mna strain is a useful model for human thymoma. In this strain thymoma development is regulated by a single autosomal susceptible gene, Tsr-1. At pre-thymoma age, BUF/Mna rats have extremely large thyrauses, when compared to those of other strains of rats. Genetic studies in crosses between BUF/Mna rats with large thymuses and WKY/NCrj rats with small thymuses suggested the presence of a major autosomal gene, Ten-1 , which contributes to thymus enlargement in a backcross population. Linkage studies between Ten-1 and microsatellite markers in backcross rats of (WKY/NCrj×BUF/Mna)Fl×BUF/Mna have led to the localization of Ten-1 in chromosome 1. This result may provide an approach to clone Tsr-1 , which could be allelic to Ten-1.     

Phosphorus-31 magnetic resonance spectroscopy of cerebral ischemia in cats

The energy metabolism of the brain was measured in three types of ischemic models in the cat using phosphorus-31 magnetic resonance spectroscopy. The cerebral ischemia was produced as follows. In Group 1, two balloons were inflated in the left subclavian artery and the brachiocephalic trunk. In Group 2, the left middle cerebral artery was occluded through a transorbital approach. A combination of the two was employed in Group 3. Phosphorus-31 magnetic resonance spectra were obtained serially during 2 hours of ischemia. Immediately after occlusion, peaks of phosphocreatine and adenosine triphosphate decreased, whereas the peak of inorganic phosphate increased and split in two. Intracellular pH determined by chemical shift of the inorganic phosphate peak decreased. These changes were more pronounced in Group 3 when compared with the other groups. Histological study showed no infarction in Group 1 and infarcted areas in Groups 2 and 3. The size of the infarcted area in Group 3 was larger than that in Group 2. These results suggest that the model of middle cerebral artery occlusion potentiated with the occlusion of the brachiocephalic trunk and the left subclavian artery by balloon catheters is a reliable stroke model and that phosphorus-31 magnetic resonance spectroscopy is useful to understand the pathophysiological state of cerebral ischemia in vivo.