From the authors' experience, as well as a review of the literature, which includes an autopsy study of similar cases, it is inferred that these lesions are focal wall defects covered only with thin fibrous tissue and that they are therefore not true aneurysms. Direct clipping often causes laceration of the lesion, whereas complete wrapping or clipping after wrapping is effective, but may fail to prevent growth of the aneurysm. Endovascular occlusion of the cervical ICA with or without bypass surgery, which is less risky than direct surgery, is another option.

Cardiomyopathy (CM) is a primary degenerative disease of myocardium and is traditionally categorized into hypertrophic and dilated CMs (HCM and DCM) according to its gross appearance. Cardiomyopathic hamster (CM hamster), a representative model of human hereditary CM, has HCM and DCM inbred sublines, both of which descend from the same ancestor. Herein we show that both HCM and DCM hamsters share a common defect in a gene for ␦-sarcoglycan (␦-SG), the functional role of which is yet to be characterized. A breakpoint causing genomic deletion was found to be located at 6.1 kb 5 upstream of the second exon of ␦-SG gene, and its 5 upstream region of more than 27.4 kb, including the authentic first exon of ␦-SG gene, was deleted. This deletion included the major transcription initiation site, resulting in a deficiency of ␦-SG transcripts with the consequent loss of ␦-SG protein in all the CM hamsters, despite the fact that the protein coding region of ␦-SG starting from the second exon was conserved in all the CM hamsters. We elucidated the molecular interaction of dystrophin-associated glycoproteins including ␦-SG, by using an in vitro pull-down study and ligand overlay assay, which indicates the functional role of ␦-SG in stabilizing sarcolemma. The present study not only identifies CM hamster as a valuable animal model for studying the function of ␦-SG in vivo but also provides a genetic target for diagnosis and treatment of human CM.Cardiomyopathy (CM) manifests dyspnea, cardiac failure, or sudden death, causing serious morbidity and mortality. Clinical features and molecular genetic studies of CM demonstrate a wide variety of possible genetic causes of this disease but the causative genes and pathogenesis are poorly understood (1-3). Medical treatment for this progressive disease are only palliative with poor prognosis. Syrian hamsters with CM are known to inherit both CM and muscular dystrophy as an autosomal recessive trait but the genetic cause still remains to be elucidated (4-6). Recent studies on muscular dystrophy revealed the genetic importance of sarcoglycans (SGs), a subcomplex of dystrophin-associated glycoprotein complex (DAGC), in this disease (7-10).Distinct sublines of Syrian hamster manifesting hypertrophic CM (HCM; BIO 14.6 and its descendant UMX7.1) or dilated CM (DCM; TO-2) have been established from the original line BIO1.50 (5, 6). We have reported to the DDBJ (DNA Data Base of Japan) that no mutation exists in the coding regions of cDNAs of BIO14.6 for ␣-, ␤-, or ␥-SGs, all of which are lost in cardiac and skeletal muscles of this animal, where dystrophin is normally expressed (11). Our latest study revealed that these SGs are also deficient in UMX7.1 and TO-2 (vide infra), suggesting a hypothesis that both HCM and DCM share the loss of SG subcomplex as a common causative feature in hamster. In addition, ␦-SG, which was identified recently, seemed to constitute DAGC together with ␣-, ␤-, and ␥-SGs (12). These facts prompted us to identify the causative gene common to HCM and DCM wit...

We cloned a novel mouse cDNA, CORS26 (collagenous repeat-containing sequence of 26-kDa protein), encoding a secretory protein by suppression subtractive hybridization between transforming growth factor-␤1-treated and untreated C3H10T1/2 cells. The deduced amino acid sequence of CORS26 consists of 246 amino acids with a secretory signal peptide and contains a collagenous region (Gly-X-Y repeats) at the NH 2 terminus and a complement factor C1q globular domain at the COOH terminus. CORS26 is structurally similar to C1q and to adipocyte-specific protein Acrp30. Transfection analysis suggested that CORS26 is a secretory protein.Northern blot analysis revealed that CORS26 mRNA was present at high levels in rib growth plate cartilage and at moderate levels in kidney of adult mice. In skeletal development in vertebrates, the formation of chondrocytes from undifferentiated mesenchymal cells is one of the important processes, but the molecular mechanisms are not well understood. Identifying the genes underlying the induction of chondrocyte differentiation will provide powerful tools for understanding skeletal development. The induction of chondrogenesis has been extensively studied in vitro using primary cells and clonal cell lines from a variety of sources (1-4). The mouse embryonic fibroblast cell line, C3H10T1/2, are multipotential cells and have been induced to undergo differentiation into myocytes, adipocytes, osteoblasts, and chondrocytes under specific culture conditions and treatments (5-8). The frequency of chondrogenic conversion in C3H10T1/2 cells was much lower and irregular compared with other types of conversion (5, 8), but it was recently reported that the induction of chondrogenesis and the formation of spheroids in C3H10T1/2 cells preferentially occurred when treated with transforming growth factor (TGF) 1 -␤1 (9), bone morphogenetic protein-2 (10), or a combination of osteoinductive bone proteins (11) in high-density micromass cultures. The formation of the spheroids resembled the condensation of mesenchymal cells seen in precartilage. Thus, C3H10T1/2 cells in high-density micromass cultures are suited for studying the molecular mechanisms involved in skeletal development.In the present study, to help clarify the mechanism for skeletal development, mRNAs expressed in TGF-␤1-treated C3H10T1/2 cells were subtracted with those in untreated C3H10T1/2 cells using the suppression subtractive hybridization (SSH) technique (12), and we isolated a novel gene, CORS26 (collagenous repeat-containing sequence of 26-kDa protein). Sequence analysis revealed that CORS26 possesses a collagenous structure at the NH 2 terminus and a complement factor C1q globular domain at the COOH terminus. Due to the structural similarity between CORS26 and subunits of complement factor C1q, this novel protein is thought to be a member of the C1q-related protein family. The presence of the signal peptide, plus the hydrophilic nature of CORS26, suggests that CORS26 is a secretory protein. Indeed, the CORS26 protein was secreted from COS-...