Differences in the localization of the adenomatous polyposis coli‐Asef/Asef2 complex between adenomatous polyposis coli wild‐type and mutant cells

The tumor suppressor adenomatous polyposis coli (APC) is mutated in familial adenomatous polyposis and in many sporadic colorectal tumors. Adenomatous polyposis coli is known to negatively regulate Wnt signaling by inducing the degradation of β‐catenin. Adenomatous polyposis coli also interacts with the guanine nucleotide exchange factors Asef and Asef2 and stimulates their activity, thereby regulating cell adhesion and migration. Here we show that in confluent, non‐motile MDCK II cells, Asef/Asef2 are colocalized with APC at the sites of cell–cell adhesion at the apical and junctional levels. In contrast, in colorectal tumor cells containing mutated APC, significant amounts of Asef/Asef2 and the truncated mutant APCs are localized mainly in the cytoplasm. These results suggest that localization of the Asef/Asef2‐APC complex at the sites of cell–cell contact is critical for the regulation of cell adhesion, and that the aberrant subcellular localization of these complexes in colorectal tumor cells may contribute to the cell's aberrant adhesive and migratory properties.     

Primary central nervous system anaplastic large-cell lymphoma mimicking lymphomatosis cerebri

Primary central nervous system lymphoma (PCNSL) is usually diffuse large B-cell lymphoma. Anaplastic large-cell lymphoma (ALCL) rarely occurs in the central nervous system. PCNSL always presents as single or multiple nodular contrast-enhancing mass lesions within T2-hyperintense areas on magnetic resonance imaging (MRI). Infrequently, diffuse infiltrating change with little contrast enhancement called lymphomatosis cerebri can be seen in PCNSL. In this report, we describe a 75-year-old immunocompetent man who had progressive dementia. On MRI, diffuse white matter lesions with little contrast enhancement were observed to gradually progress, which was clinically consistent with his worsening condition. A biopsy specimen revealed non-destructive, diffusely infiltrating, anaplastic large CD30-positive lymphoma, indicating a diagnosis of ALCL. After the biopsy, he was treated by whole brain irradiation (total 46 Gy) and focal boost irradiation (total 14 Gy). However, his performance status worsened and there was no symptom improvement. The patient died 8 months after symptom onset. The clinical course, diagnostic workup, pathologic correlates, and treatment outcomes are described herein.     

GABA(A) receptors in the nucleus accumbens core modulate turning behavior induced by dopamine receptor stimulation

The role of GABA(A) and GABA(B) receptors in the core of the nucleus accumbens in turning behavior of rats was investigated. Unilateral injections into the core of the nucleus accumbens of the GABA(A) receptor agonist (muscimol, 50 ng) and antagonist (bicuculline, 200 ng), and the GABA(B) receptor agonist (baclofen, 100 ng) and antagonist (2-hydroxysaclofen, 2 microg) did not produce turning behavior. In rats pretreated with unilateral injections of the dopamine D1-like/D2-like receptor antagonist, cis(Z)-flupentixol (10 microg), into the ventrolateral striatum and saline into the nucleus accumbens core of contralateral side, systemic injection of a mixture of dopamine D1-like (SKF 38393, 3 mg/kg) and D2-like (quinpirole, 1 mg/kg) receptor agonists has been found to elicit contraversive pivoting, namely pivoting away from the side of the core injection. This dopamine D1-like/D2-like receptor-mediated pivoting was significantly inhibited by injections into the core of the nucleus accumbens of muscimol (50 ng), but not bicuculline (200 ng). In contrast, the dopamine D1-like/D2-like receptor-mediated pivoting was suppressed by either baclofen (100 ng) or 2-hydroxysaclofen (2 microg) injected into the nucleus accumbens core. It is therefore concluded that neither GABA(A) nor GABA(B) receptor stimulation in the core of the nucleus accumbens produces turning behavior, and that GABA(A), but not GABA(B), receptors in the nucleus accumbens core may modulate dopamine D1-like/D2-like receptor-mediated pivoting.     

Dental treatment for the handicapped by a combination of public community, dental association and university hospital--a system of Suginoki Dental Clinic

Suginoki Dental Clinic, which is managed by Suginami Dental Association, financially supported by Suginami City, and technically assisted by the University Hospital, Tokyo Medical and Dental University, was established for dental treatment of handicapped persons living in Suginami City, Tokyo who are difficult to be treated by private practitioners. It has one full-time dentist, 12 part-time dentists, two dental hygienists, one nurse, and one clerk; one of the part-time dentists practices twice a week there. Since December 1994, 406 patients visited the clinic and the total cases was 9,273 in December 1999; 99 cases were mentally retarded, 36 autism, and 30 epileptic patients in the younger group; and 65 cases were cerebrovascular disease and 27 cardiac malfunction patients in the older group. Almost all the patients needed special care such as monitoring, intravenous sedation, nitrous oxide sedation, and general anesthesia. Four cases underwent general anesthesia, and no complication was seen among the cases. It was concluded that the clinic has been successful due to a good relationship among the Dental Association, Suginami City, and the dental hospital.