Inhibitory effect of activated protein C on platelet aggregation induced by the prothrombin-converting reaction

The present study was undertaken to elucidate the effect on platelet aggregation of the prothrombin-converting reaction on platelets with or without activated protein C (APC). A reaction mixture of washed platelets from human individuals, Factor Xa and prothrombin markedly induced platelet aggregation; maximum aggregation rates, 31.3–92.5%, and times to reach to maximum aggregation, 11.6 to 20.1 min. This aggregation was inhibited by the addition of APC with 50% inhibition concentration (IC₅₀) value of 14.4 U/ml. APC also inhibited thrombin generation in the reaction mixture in a dose-dependent manner with IC50 value of 0.96 U/ml. However, APC did not inhibit the thrombin (0.1 CU/ml)-induced platelet aggregation at concentrations of up to 30 U/ml. These findings suggest that APC has no direct inhibitory effect on platelet aggregation and that APC inhibits platelet aggregation through inhibition of thrombin generation.     

Cerebellopontine angle ganglioneuroblastoma

Summary The CT, MR and histological features of a rare ganglioneuroblastoma of the cerebellopontine angle and cavernous sinus are reported.     

Maintenance of Androgen-, Glucocorticoid- or Estrogen-responsive Growth in Shionogi Carcinoma 115 Subline Sustained in Castrated Mice with High Dose of Estrogen for 30 Generations (3 Years)

Shionogi carcinoma 115 (SC115), an androgen-dependent mouse mammary tumor, rapidly loses its androgen responsiveness after androgen withdrawal. The growth of this tumor can also be stimulated by high doses of estrogen or glucocorticoid. In the present study, the maintenance of hormone-responsive growth of SC115 tumors with a high dose of estrogen was examined in castrated male mice using an SCI 15 subline obtained by serial transplantations of SCI 15 tumors in estrogen-treated castrated mice for 3 years (30 generations) (subline E₂). Seed tumors from both SC115 and subline E₂ could rapidly grow in castrated mice given daily injections of testosterone propionate (TP), 17β-estradiol (E₂), or dexamethasone (Dex) (100 μg/mouse/day) but not in those given vehicle alone. Although SCI 15 and subline-E₂ tumors grown with TP or Dex showed temporary regression after steroid withdrawal, the tumors grown with E₂ did not show such temporary regression. The TP-, E₂-, or Dex-induced growth of subline-E₂ tumors was almost the same as that of the original SCI 15 tumors. However, responsiveness to androgen, estrogen or glucocorticoid of both tumors disappeared within one passage in steroid-depleted castrated mice. The present findings demonstrate that the loss of responsiveness to androgen as well as to high doses of estrogen or glucocorticoid of SCI 15 tumors can be prevented in castrated mice not only with androgen but also with high doses of estrogen.     

Case of Parkinson's disease presenting with unique dyspneic attacks caused by oromandibular dystonia and sleep apnea syndrome]

A 79-year-old woman with a 4-year history of Parkinson's disease was admitted due to unique dyspneic attacks with cyanosis while eating. Dyspneic attacks with cyanosis occurred mainly during actions such as taking meals or rehabilitation. Due to increased tonus of the orbicularis oris muscle, she was unable to open her mouth and breathe out, and finally experienced hypoxemia as revealed by pulse oxymetry. Dystonic hypertonus was relieved by touching the mandible with the fingers, and she was able to open her mouth again. These symptom was compatible with the sensory trick. Based on these findings, we considered that dyspneic attacks were produced by focal oromandibular dystonia. Polysomnography also showed central sleep apnea. We report herein a rare case of Parkinson's disease presenting with respiratory insufficiency caused by focal dystonia and central sleep apnea.     

DNA microarray analysis of white adipose tissue from obese (fa/fa) Zucker rats treated with a beta3-adrenoceptor agonist, KTO-7924.

We aimed to examine the effects of KTO-7924 (beta3-adrenoceptor agonist) on lipid metabolism and mRNA expressions in retroperitoneal white adipose tissue (RP WAT) in obese (fa/fa) Zucker rats using DNA microarray. Oral KTO-7924 for 28 days significantly decreased RP WAT weight, plasma triglyceride, free fatty acid, and insulin, and improved insulin resistance in oral glucose tolerance tests. In RP WAT of KTO-7924-treated rats, DNA microarray analysis revealed specifically enhanced mRNA expressions of uncoupling protein 1 (UCP1) and cytochrome c oxidase subunit VIII-H (COX8H), which are reportedly highly expressed in brown adipose tissue (BAT). Since these mRNA expression levels in RP WAT were significantly lower in obese (fa/fa) Zucker rats than in lean Zucker rats, these genes may be important in lipid metabolism. Our results imply that in obese (fa/fa) Zucker rats, continuous stimulation of beta3-adrenoceptors by KTO-7924 causes BAT-like adipocytes to appear in RP WAT, and improves lipid metabolism.     

Oxygen Hyperbaric Pressure Therapy (OHPT) for Decubitus Ulcers

Aim:  This study aims to establish a pressure ulcers model that visualizes the microcirculation, and to examine the participation of ischemia‐reperfusion injury in the pathophysiology of pressure ulcers.
Methods:  An original system composed of a new skinfold chamber and compression device allowed loading quantitative vertical stress to the skin. An intravital microscopic technique enabled direct visualization of the microcirculation in the physiological condition and in response to pressure application. To estimate the effect of ischemia‐reperfusion injury, animals were divided into two groups: the compression‐release group in which the animals received four cycles of compression‐release which consisted of 2 hours of compression followed by 1 hour of pressure release; and the compression alone group in which the animals underwent continuous compression for 8 hours. Functional capillary density was quantified before the compression procedure and on day1 (35 hours) after the first evaluation.
Results and Conclusions:  The cyclic compression‐release procedure significantly decreased functional capillary density as compared to continuous compression, indicating that in our experimental setting repetition of ischemia‐reperfusion cycle more severely damaged the microcirculation than single prolonged ischemic insult. The finding supports the significant contribution of ischemia‐reperfusion injury to the pathophysiology of pressure ulcers at the level of dynamic in vivo microcirculation.     

Left-side catamenial pneumothorax with endometrial tissue on the visceral pleura.

We present here a rare case of left-side catamenial pneumothorax, in which endometrial tissue pleura was found on the visceral pleura histologically. A chest roentogenogram confirmed the left pneumothorax, but did not reveal bullae or any associated anomalies, in a 41-year-old woman with three documented episodes of left-side pneumothorax occurring every menstruation. Video-assisted thoracoscopic surgery revealed not only tiny holes in the diaphragm, but also a scattered small brown spots on the visceral pleura. Histological examination of the lung sections revealed the existence of endometrial tissue on the visceral pleura with disrupted pleural elastic fibers. Our case suggests that cyclic erosion of the visceral pleura by the implanted endometrial tissue caused air leakage from the lung, in addition to the most accepted concept that air is aspirated into the thoracic cavity via the abdomen through the acquired fenestration of the diaphragm.     

Severely calcified constrictive pericarditis simulating a mediastinal tumor and obstructing the right ventricular inflow tract.

We report a rare case of constrictive pericarditis that stimulated a large mediastinal tumor obstructing the right ventricular inflow tract. A 58-year-old woman was referred to our hospital because of a recent increase of dyspnea and facial edema. Computed tomography revealed severely thickened calcification, including a low-density area, presenting as a mediastinal tumor, compressing the right ventricular inflow tract. A complete resection was performed, and her symptoms dramatically improved. Idiopathic constrictive pericarditis was diagnosed pathologically.     

Acute pulmonary embolism after cerebral infarction associated with a mobile thrombus in the ascending aorta

Although the causes of stroke are diverse, thromboembolism due to a mobile aortic thrombus is rare. We describe a surgical case of acute massive pulmonary embolism after critical cerebral infarction associated with a mobile ascending aortic thrombus in a 52-year-old woman. Concomitant surgical removal of the aortic thrombus and pulmonary embolectomy was performed successfully, and the patient has been stable without recurrent thromboembolic complications after 18 months of follow-up.