Dual Effects of Hexanol and Halothane on the Regulation of Calcium Sensitivity in Airway Smooth Muscle

Background: Contraction of airway smooth muscle is regulated by receptor-coupled mechanisms that control the force developed for a given cytosolic calcium concentration (i.e., calcium sensitivity). Halothane antagonizes acetylcholine-induced increases in calcium sensitivity by inhibiting GTP-binding (G)-protein pathways. The authors tested the hypothesis that hexanol, like halothane, inhibits agonist-induced increases in calcium sensitivity in airway smooth muscle by inhibiting G-protein pathways.

Methods: Calcium sensitivity was assessed using [alpha]-toxin-permeabilized canine tracheal smooth muscle. In selected experiments, regulatory myosin light chain phosphorylation was also determined by Western blotting in the presence and absence of 10 mm hexanol and/or 100 [mu]m acetylcholine.

Results: Hexanol (10 mm) and halothane (0.76 mm) attenuated acetylcholine-induced calcium sensitization by decreasing regulatory myosin light chain phosphorylation during receptor stimulation. Hexanol also inhibited increases in calcium sensitivity due to direct stimulation of heterotrimeric G-proteins with tetrafluoroaluminate but not with 3 [mu]m GTP[gamma]S, consistent with prior results obtained with halothane. In contrast, in the absence of receptor stimulation, both compounds produced a small increase in calcium sensitivity by a G-protein-mediated increase in regulatory myosin light chain phosphorylation that was not affected by pertussis toxin treatment.     

Triad of thymoma,myasthenia gravis and pure red cell aplasia combined with Sjögren’s syndrome

A 36-year-old woman complained of cough and high fever. Computed tomographic scans demonstrated a mediastinal mass. A couple of months later, she developed dryness in her eyes and mouth. Biopsy of the lip confirmed the diagnosis of Sjögren’s syndrome. She underwent thymo-thymomectomy. Pathological findings of the mass revealed thymoma. At two months after surgery, she developed ptosis and dysphagia that were compatible with myasthenia gravis. The clinical symptoms were adequately controlled with prednisolone. At eleven months after surgery, she presented with severe anemia, which led to the diagnosis of pure red cell aplasia. The following treatment with cyclosporin caused hemoglobin concentration to rise. However, she continues to suffer from dryness of her eyes and mouth. The case is the first to be reported with Sjögren’s syndrome and the triad of thymoma, myasthenia gravis and pure red cell aplasia, and is compared with previously reported cases of the three conditions.     

SUCCESSFUL ENDOSCOPIC CLOSURES OF COLONIC PERFORATIONS REQUIRING ABDOMINAL DECOMPRESSION AFTER ENDOSCOPIC MUCOSAL RESECTION AND ENDOSCOPIC SUBMUCOSAL DISSECTION FOR EARLY COLON CANCER

Endoscopic submucosal dissection (ESD) for colorectal cancer is not widely accepted because of its technical difficulty and the risk of perforation. In addition, the risk of peritonitis cannot be completely eliminated even if a perforation is closed successfully. Reported here are two cases of early colon cancer in which the patients sustained iatrogenic perforations of the ascending colon during conventional endoscopic mucosal resection and of the sigmoid colon during ESD, respectively, requiring abdominal decompression with an 18 G Medicut needle. Both of these perforations were successfully treated by endoscopic clipping. In conclusion, conservative medical management may be possible in patients who have undergone successful closure of colonic perforations using endoscopic clipping. In order to perform immediate endoscopic closure, abdominal decompression has been useful to decrease patient discomfort and colonic lumen collapse. Now, CO₂ insufflation is being used effectively for the prevention of pneumoperitoneum.     

Aortic root remodeling for root aneurysm with a uni-commissural aortic valve: report of a case.

A 23-year-old man was admitted for an aortic root aneurysm with mild aortic valve regurgitation (AR) and a small pressure gradient. At surgery, findings of aortic valve, one normal left posterior commissure and very rudimentary right anterior commissure, was compatible with the uni-commisural aortic valve. Aortic root replacement with valve-sparing technique was performed. Four years later no residual AR was observed.     

Characteristics of young-onset hypertension identified by targeted screening performed at a university health check-up.

Since the prevalence and clinical characteristics of young-onset hypertension are still to be elucidated, we performed targeted-screening at an annual university health check-up for two consecutive years. Out of 16,464 subjects in 2003 and 17,032 in 2004 that were aged less than 30 years, 22 and 26 students (all males) exhibited high blood pressure (BP), respectively, on three occasions during casual BP measurements at the Tohoku University Health Center (systolic and diastolic BP of 140 and/or 90 mmHg or greater, respectively). These students were asked to measure their BP at home, and 9 subjects in total were diagnosed as having essential hypertension (EH). The remaining students were diagnosed as having white coat hypertension (WCH). In 8 out of 9 EH students, their father and/or mother had also been treated with antihypertensive medication. Adjustment by attendance ratio for each BP measurement suggested that the incidence of EH was around 0.1% and that of hypertension (EH and WCH) was around 0.5% in university students aged less than 25 years, since most of the subjects and hypertensive students were between 18 and 24 years old. Body mass index of the EH, which was more than 25 kg/m2 (overweight), was significantly higher than that with WCH. In conclusion, the combination of repeated casual BP measurements and home BP effectively identified young-onset EH. The clinical parameters indicated that male gender, genetic background, and excessive weight were risk factors for young-onset hypertension.     

Extremely Well Differentiated Papillary Adenocarcinoma of the Lung with Prominent Cilia Formation

We describe a 54-year-old woman with primary pulmonary adenocarcinoma showing a characteristic papillary architecture and prominent cilia formation. Immunohistochemically, the tumor cells were positive for carcinoembryonic antigen (CEA), epithelial membrane antigen (EMA) and Leu Ml, and negative for lactoferrin and surfactant apoprotein. An ultrastructural study also indicated differentiation toward bronchial surface epithelial cells. To our knowledge, this type of neoplasm has not been reported as peripheral-type adenocarcinoma of the lung. Acta Pathol Jpn 42: 745–750, 1992.     

Familial spontaneous pneumothorax in three generations and its HLA

We experienced a case of familial spontaneous pneumothorax in three generations. Six of 13 family members had episodes of spontaneous pneumothorax. It is well established that there are some diseases associated with human leukocyte antigen (HLA). We performed HLA phenotyping for HLA of A, B and C. In our study, we detected the HLA haplotype A2, B61 in three of 4 who had episodes of spontaneous pneumothorax. The HLA haplotype A2, B70 were also detected in three of 4 who had episodes. This suggests that familial spontaneous pneumothorax might have hereditary factors.     

Immunohistochemical and biochemical identification of pepsinogen isozymes in the hamster lungs: induction by polychlorinated biphenyls.

Pepsinogens are acid protease enzymes of pepsin usually found in gastric mucosa. In the present study, we demonstrated the presence of pepsinogen isozymes in male Syrian golden hamster lung tissues by a combined immunohistochemical and biochemical approach. Immunohistochemically, using rat pepsinogen 1 antibody, pepsinogen positive cells were observed mainly in the epithelia of the terminal bronchioles. They demonstrated morphological features of Clara cells. The pepsinogen isozyme pattern of lung tissue determined by polyacrylamide gel electrophoresis was similar to that of stomach mucosa. Treatment of hamsters with polychlorinated biphenyls at a dose of 500 mg/kg body weight ip caused a 2.8-fold increase in pepsinogen content (p less than 0.01) as well as increase in numbers of pepsinogen positive cells in the lung.     

Metabolites of (+)-dehydroabietic acid in rabbits

The seven metabolites of (+)-dehydroabietic acid (DHA) were newly isolated from rabbit urine by liquid chromatography. On the basis of chemical and spectral data their structures were established to be (15S)-8,11.13-abietatrien-16,18-dioic acid, 2 alpha-hydroxy-8,11,13,15-abietatetraen-18-oic acid, (15R)-15,16-dihydroxy-8,11,13-abietatrien-18-oic acid, 2 beta,15-dihydroxy-8,11,13-abietatrien-18-oic acid, (15S)-2 beta,16-dihydroxy-8,11,13-abietatrien-18-oic acid, 2 alpha,15-dihydroxy-8,11,13-abietatrien-18-oic acid, and (15S)-2 alpha,16-dihydroxy-8,11,13-abietatrien-18-oic acid. The possible hydroxylation routes of DHA in rabbits and the difference between the metabolism of DHA in microorganisms and that in rabbits are discussed.