Novel PAX9 mutations cause non-syndromic tooth agenesis.

PAX9 is a transcription factor expressed in the tooth mesenchyme during tooth morphogenesis. In Pax9-null mice, tooth development is arrested at the bud stage. In humans, heterozygous mutations in PAX9 have been associated with non-syndromic tooth agenesis, predominantly in the molars. Here, we report 2 novel mutations in the paired domain of PAX9, a three-nucleotide deletion (73-75 delATC) and a missense mutation (C146T), in two unrelated Japanese patients with non-syndromic tooth agenesis. The individual with the 73-75del ATC mutation was missing all maxillary molars and mandibular second and third molars. The individual with the C146T mutation was missing the mandibular central incisors, maxillary second premolars, and first molars, along with all second and third molars. Both mutations affected amino acids that are highly conserved among different species and are critical for DNA binding. When both mutants were transfected to COS7 cells, nuclear localization of PAX9 proteins was not affected. However, reduced expression of the mutant proteins and almost no transcriptional activity of the target BMP4 gene were observed, suggesting haploinsufficiency of PAX9 as the cause of non-syndromic tooth agenesis.

Down-regulation of Smad3 accelerates palatal wound repair.

Smad3-deficient mice exhibit accelerated re-epithelialization and tissue remodeling during palatal wound repair. In addition, transforming growth factor beta 1 (TGF-ß1) and other inflammatory factors are down-regulated compared with those in wild-type mice. The aim of this study was to examine whether targeting of Smad3 with small interfering RNA (siRNA) accelerates wound-healing and inhibits wound contraction in palatal mucoperiosteal wounds. An initial histological examination of wound closure in mouse palates treated with Smad3-targeted siRNA vs. a scrambled siRNA found that wound-healing was accelerated when levels of Smad3 were decreased. Furthermore, with real-time PCR, mRNA levels of Smad3, TGF-ß1, monocyte chemotactic protein-1 (MCP-1), and macrophage inflammatory protein-1α (MIP-1α) were found to be significantly down-regulated in palatal tissue treated with Smad3-targeted siRNA vs. a control siRNA. Protein and mRNA levels of α-smooth-muscle actin (α-SMA), type I collagen, and fibronectin were also lower in palates treated with Smad3-targeted siRNA vs. control siRNA. Taken together, these results indicate that down-regulation of Smad3 expression by siRNA can accelerate wound-healing and may inhibit wound contraction. Therefore, siRNA-targeted inhibition of Smad3 may represent a valuable therapeutic tool for palatal mucoperiosteal wound-healing.

A novel role for Twist-1 in pulp homeostasis.

The molecular mechanisms that maintain the equilibrium of odontoblast progenitor cells in dental pulp are unknown. Here we tested whether homeostasis in dental pulp is modulated by Twist-1, a nuclear protein that partners with Runx2 during osteoblast differentiation. Our analysis of Twist-1(+/-) mice revealed phenotypic changes that involved an earlier onset of dentin matrix formation, increased alkaline phosphatase activity, and pulp stones within the pulp. RT-PCR analyses revealed Twist-1 expression in several adult organs, including pulp. Decreased levels of Twist-1 led to higher levels of type I collagen and Dspp gene expression in perivascular cells associated with the pulp stones. In mice heterozygous for both Twist-1 and Runx2 inactivation, the phenotype of pulp stones appeared completely rescued. These findings suggest that Twist-1 plays a key role in restraining odontoblast differentiation, thus maintaining homeostasis in dental pulp. Furthermore, Twist-1 functions in dental pulp are dependent on its interaction with Runx2.

[Evaluation of chemosensitivity testing by CD-DST, and TS and DPD activity in cases of colorectal liver].

We evaluated the usefulness of the following three in vitro assays in cases of resected colorectal liver metastases. Chemosensitivity by collagen gel droplet drug sensitivity test (CD-DST) was very low in all cases, suggesting this method is not predictive for this disease. In contrast, thymidylate synthetase (TS) activity and dihydropyrimidine dehydrogenase (DPD) activity in tumor tissue were high in many patients with recurrent disease. Thus, these enzyme activities are promising for assessment of clinical outcome following hepatic resection of colorectal liver metastases. Further analyses with large numbers of cases are needed to determine the significance of these in vitro studies.

[Usefulness of hepatic arterial infusion chemotherapy for liver metastasis in gastric cancer].

UNLABELLED: We have performed intra-hepatic arterial chemotherapy for 9 patients with liver metastasis arising from gastric cancer. We mainly used 5-FU and CDDP as antineoplastic drugs. RESULTS: The median survival after gastrectomy was 600 days. Of 9 cases, 2 showed CR, 4 PR, 2 NC, 1 PD. The response rate was 67%. The 9 cases were classified into 2 groups. One group, the short-term survival group, concised of 5 patients that had no more than 2 years survival and the other, the long-term survival group, consisted 4 patients that had more than 2 years survival. We compared these 2 groups and found no difference in the primary lesions between the 2 groups. The patients in the long-term survival group had fewer and smaller metastatic lesions in the liver than the patients of the short-term survival group. The patients in the long-term survival group had no unresectable lesions except liver metastasis when gastrectomy was performed. However, 2 patients in the short term survival group had unresectable lymphatic involvement at the time gastrectomy was performed. Of 9 patients, 6 died from the extrahepatic lesion. CONCLUSION: The intra-arterial chemotherapy was effective and useful for liver metastasis arising from gastric cancer. However, the majority of patients died from extrahepatic lesions. We should therefore consider the use of systemic chemotherapy with intra-arterial chemotherapy.

Cloning and expression of the chick p63 gene.

We have isolated a chick cDNA for p63, a member of the p53 transcription factor family. This cDNA encodes a protein of 582 amino acids for an alpha isoform in the C-terminal region, while lacking the N-terminal transactivation domain. The chick p63 gene is first expressed in the prospective cutaneous ectoderm at stage 6 and later in the developing epithelia. The p63 expression is intense in specialized epithelial structures, such as apical ectodermal ridge of the limb bud, epithelia of branchial arches and feather buds. Furthermore, we have found that the transcripts are detected in the interdigital epithelium, intersomite epithelium, and epaxial dermamyotome.

[Evaluation of hepatic resection following hepatic arterial infusion chemotherapy for colorectal liver metastases].

We evaluated the significance of hepatectomy following hepatic arterial infusion (HAI) chemotherapy for colorectal liver metastases. The prognosis of 4 cases with initially resectable tumors was discouraging, indicating no benefit of preoperative HAI for resectable tumors. The 2- and 3-year survival of patients who underwent hepatectomy after downstaging by HAI of originally unresectable metastases were 100% and 67%, respectively, suggesting that hepatectomy combined with HAI is a promising modality for those patients. However, it seems that the control of extrahepatic disease and decision making for the timing for surgical therapy are issues requiring improvement.

[Malignant islet cell tumor of the pancreas with multiple liver metastases effectively treated by transcatheter arterial embolization with degradable starch microspheres--a case report].

A 57-year-old woman underwent distal pancreatectomy for malignant islet cell tumor of the pancreas in 1991. One year later, multiple liver metastases appeared. Although three transcatheter arterial embolizations (TAE) with spongel and nine ethanol injections were performed over seven years, the tumors were growing gradually. Therefore, TAE with degradable starch microspheres (DSM) was selected. Under angiography, TAE of the left hepatic artery was done using 900 mg of DSM following injection of Farumorubicin (20 mg), Lipiodol (3 ml) and cisplatin (90 mg). The tumors in the embolized hepatic area were remarkably decreased in size, and satisfactory local control was obtained. Thereafter, TAE with DSM was carried out twice, and she is still living with outpatient treatment. Thus, it is suggested that TAE with DSM could be a promising, alternative therapeutic modality for liver metastases from malignant islet cell tumor of the pancreas.

Effectiveness of house dust-mite allergen avoidance through clean room therapy in patients with atopic dermatitis.

We have investigated the effectiveness of house dust-mite (HDM) allergen avoidance through clean room (CR) therapy in patients with atopic dermatitis (AD) having high HDM-specific IgE RAST levels. All patients (N = 30) demonstrated marked improvement in symptom, a long-term remission (mean, 8.4 months), and significant decreases in eosinophil count (p less than 0.01), basophil count (p less than 0.05), serum lactate dehydrogenase activity (p less than 0.01), and HDM-specific IgG levels (p less than 0.05). By contrast, the patients with AD (N = 11), who scored 0 on HDM allergen-specific IgE RAST score underwent "CR" therapy, and the patients with AD (N = 10) having high HDM-specific IgE RAST levels were hospitalized in a common sickroom (nonclean room). All the patients (N = 21) exhibited slight improvement in symptoms and a significant decrease in serum lactate dehydrogenase activity. The period of recurrence after the therapy was brief. The results of measurement of airborne house-dust particles indicated that our "CR" fell within class 10,000. Therefore, it is very likely that the mechanism at work in the CR therapeutic approach is its ability to eliminate fecal pellets of the HDM.