Characterization of the discriminative stimulus effect of quinpirole: Further evidence for functional interaction between central dopamine D1/D2-receptors.

Dysfunction of the central dopamine D2-receptor-related network has been proposed to play a critical role in dopamine-related diseases, such as schizophrenia and drug dependence. Generally, the stimulation of dopamine D2-receptors on medium spiny neurons (MSN) induces several behavioral effects, such as sedation, hallucination, aversion and motivation. Furthermore, such physiological responses through dopamine D2-receptor-containing MSN (D2-MSN) may be synchronized with the activity of dopamine D1-receptor-containing MSN (D1-MSN), or both may exhibit dual agonistic/antagonistic innervation. In the present study, we characterized the discriminative stimulus effect of the selective dopamine D2-receptor agonist quinpirole to further investigate the "D1/D2-MSN" interaction using dopamine-related agents, hallucinogens and sedatives in rats. Among dopamine receptor agonists, only selective dopamine D2-receptor agonists substituted for the discriminative stimulus effects of quinpirole. Neither the δ-opioid receptor agonist SNC80 nor the adenosine A2A-receptor antagonist istradefylline, both of which may act on D2-MSNs, substituted for the discriminative stimulus effects of quinpirole. Interestingly, the dopamine D1-receptor antagonist SCH23390 and the GABAB-receptor agonist baclofen, but not hallucinogens or sedatives, substituted for the discriminative stimulus effects of quinpirole. These results suggest that stimulation of central dopamine D2-receptors exerts a distinct discriminative stimulus effect, and blockade of dopamine D1-receptors and agonistic modulation of GABAB-receptors may share the discriminative stimulus effect via the activation of central dopamine D2-receptors.

A case report: Veno-venous extracorporeal membrane oxygenation for severe blunt thoracic trauma.

INTRODUCTION: The use of veno-venous extracorporeal membrane oxygenation (VV-ECMO) in trauma patients has been controversial, but VV-ECMO plays a crucial role when the lungs are extensively damaged and when conventional management has failed. VV-ECMO provides adequate tissue oxygenation and an opportunity for lung recovery. However, VV-ECMO remains contraindicated in patients with a risk of bleeding because of systemic anticoagulation during the treatment. The most important point is controlling the bleeding from severe trauma. CASE: A 32-year-old male experienced blunt trauma due to a traffic accident. He presented with bilateral hemopneumothorax and bilateral flail chest. We performed emergency thoracotomy for active bleeding and established circulatory stability. After surgery, the oxygenation deteriorated under mechanical ventilation, so we decided to establish VV-ECMO. However, bleeding from the bilateral lung contusions increased after VV-ECMO was established, and the patient was switched to heparin-free ECMO. After conversion, we could control the bronchial bleeding, especially the lung hematomas, and the oxygenation recovered. The patient was discharged without significant complications. VV-ECMO and mechanical ventilation were stopped on days 10 and 11, respectively. He was discharged from the ICU on day 15. CONCLUSION: When we consider the use of ECMO for patients with uncontrollable, severe bleeding caused by blunt trauma, it may be necessary to use a higher flow setting for heparin-free ECMO than typically used for patients without trauma to prevent thrombosis.

Intraoperative core needle biopsy under complete video-assisted thoracic surgery for indeterminate tumor of lung.

BACKGROUND: The accuracy, feasibility, and safety of intraoperative core needle biopsy under complete video-assisted thoracic surgery (VATS) (V-CNB) for indeterminate tumors are examined retrospectively, as well as the possibility of pleural dissemination. METHODS: The diagnostic yield and complications of V-CNB were evaluated for a total of 95 patients who underwent V-CNB for indeterminate tumor during the period of April 2002 through March 2012. Moreover, operation time, number of auto-suture instruments used for resection of the lung, and pleural dissemination were compared between the patients who underwent V-CNB (n = 44) and those who did not (n = 87, non-V-CNB) among stage I primary lung cancer patients, for whom lobectomy was performed under complete VATS during the same period. RESULTS: Of the 95 patients, eighty three had primary lung cancer, four had metastatic lung cancer, and eight had benign tumor. Sensitivity, specificity, and accuracy were 94.3, 87.5, and 93.7%, respectively. There were no complications associated with V-CNB. Among stage I primary lung cancer, for which lobectomy and lymph node dissection were performed, there was no significant difference between the V-CNB group and the non-V-CNB group for tumor size (23.5 and 24.7 mm, p = 0.482), distance between pleura and tumor (3.4 and 5.0 mm, p = 0.202), operation time (228 and 217 min, p = 0.186), and number of auto-suture instruments used for resection of the lung (4.77 and 4.61, p = 0.533). There was no pleural dissemination in the V-CNB group, although there were two cases (2.3%) in the non-V-CNB group. CONCLUSION: V-CNB diagnosed small-sized indeterminate lung tumors accurately during complete VATS operation, without any complications. V-CNB can reduce the use of auto-suture instruments necessary for performing wedge resection on frozen section diagnosis prior to lobectomy without increasing operation time and the risk of pleural dissemination.

Inflammatory malignant fibrous histiocytoma of thymus origin.

A 46-year-old man was referred to our department complaining of anterior chest pain. A chest computed tomographic scan revealed an anterior mediastinal tumor measuring 38 x 35 x 50 mm. Suspecting a thymoma, we performed extended thymectomy through a median sternotomy under general anesthesia. Pathologically, the tumor was composed of pleomorphic spindle-shaped cells arranged in a storiform pattern, with marked inflammatory cell infiltration. The tumor was contiguous with the thymus tissue. Based on these findings, we made the diagnosis of inflammatory malignant fibrous histiocytoma originating from the thymus. Until now, 12 months later, the patient has shown no evidence of tumor recurrence.

A case of epithelial-myoepithelial carcinoma of the bronchus - a review of reported cases and a comparison with other salivary gland-type carcinomas of the bronchus.

We present a case of a polypoid tumor located in the right middle lobe bronchus. The tumor was composed of bi-layered glandular or ductular structures consisting of inner cuboidal cells and outer multipolar cells. Immunohistochemical examinations confirmed epithelial and myoepithelial differentiation in the inner and outer components, respectively. Consequently, the tumor was diagnosed as an epithelial-myoepithelial carcinoma. Epithelial-myoepithelial carcinomas of the bronchus are very rare neoplasms with low-grade malignant potential. To date, including our case, only 27 cases have been reported in the English literature. Here, we review the reported cases and compare them with other salivary gland-type carcinomas regarding clinical, biological, and genetic features.

Monitoring and evaluation of intraperitoneal bleeding (IPB) by small portable ultrasonography during transcatheter arterial embolization (TAE) in abdominal-pelvic trauma patients with shock: as a monitor for early detection of increase of IPB.

BACKGROUND/AIMS: Blunt abdominal-pelvic trauma patients with shock often require transcatheter arterial embolization (TAE), and may also require surgery if intraperitoneal bleeding (IPB) becomes massive. Deciding whether the patient should undergo surgery is highly critical. We sometimes perform TAE without attention to IPB because it has been difficult to evaluate the volume of IPB exactly during TAE. Currently we use small portable ultrasonography (PUS) as a monitor of volume of IPB during TAE. The aim of this study is to clarify the usefulness of PUS for monitoring changes in IPB during TAE. METHODOLOGY: We examined the volume of IPB by PUS during TAE without disturbing the operators of TAE. In our protocol, if the volume of IPB showed rapid increase we tried to perform a surgical procedure. The design of this study was a prospective case series study. RESULTS: We examined 26 patients. Increase of IPB was detected in 3 cases; two were undergoing angiography for ileac and renal arteries when PUS indicated increase of IPB, which drew attention to their hepatic arteries. The other was examined initially for internal ileac artery and underwent surgery because of an increase of IPB. In the other 22 cases, we confirmed no increment of IPB by PUS and continued the procedure. CONCLUSIONS: PUS is useful for deciding the order of therapeutic procedure, and is a useful monitoring instrument for increase of IPB.