Micromolar Levels of Sodium Fluoride Promote Osteoblast Differentiation Through Runx2 Signaling

Bone remodeling is a vital physiological process of healthy bone tissue in humans. Imbalances in this vital process lead to pathological conditions, including periodontal diseases. In this study, we characterized the effects of micromolar levels of NaF on the proliferation and osteogenic differentiation of MC3T3-E1 osteoblastic cells. NaF significantly enhanced the proliferation, alkaline phosphatase (ALP) activity, and mineralization of MC3T3-E1 cells. Quantitative real-time PCR analysis revealed that the expression of mRNAs encoding runt-related transcription factor 2 (Runx2), Osterix, Osteopontin and Osteocalcin was up-regulated in NaF-treated MC3T3-E1 cells compared with untreated controls. Western blot analysis demonstrated that Runx2 and Osterix were inhibited by Runx2 siRNA but were re-activated by treatment with NaF. Furthermore, in vivo evidence indicated that NaF protects against Porphyromonas gingivalis-induced periodontal inflammation and alveolar bone loss in a P. gingivalis-challenged experimental periodontitis animal model. These data suggest that NaF promotes the osteoblastic differentiation of MC3T3-E1 cells through the Runx2/Osterix pathway and may be effective for the treatment of bone-related disorders.

A gene cluster for the synthesis of serotype g-specific polysaccharide antigen in Aggregatibacter actinomycetemcomitans

Aggregatibacter actinomycetemcomitans is an important pathogen related to aggressively progressive periodontal breakdown in adolescents and adults. The species can be divided into six serotypes (a-f) according to their surface carbohydrate antigens. Recently, a new serotype g of A. actinomycetemcomitans was proposed. The aim of the present study was to sequence the gene cluster associated with the biosynthesis of the serotype g-specific polysaccharide antigen and develop serotype-specific primers for PCR assay to identify serotype g strains of A. actinomycetemcomitans. The serotype-specific polysaccharide (SSPS) gene cluster of the NUM-Aa 4039 strain contained 21 genes in 21,842-bp nucleotides. The similarity of the SSPS gene cluster sequence was 96.7 % compared with that of the serotype e strain. Seventeen serotype g genes showed more than 90 % homology both in nucleotide and amino acids to the serotype e strain. Three additional genes with 1,579 bp in NUM-Aa 4039 were inserted into the corresponding ORF13 of the serotype e strain. The serotype g-specific primers were designed from the insertion region of NUM-Aa 4039. Serotypes of the a-f strains were not amplified by serotype-specific g primers; only NUM-Aa 4039 showed an amplicon band. The NUM-Aa 4039 strain was three genes in the SSPS gene cluster different from those of serotype e strain. The specific primers derived from these different regions are useful for identification and distribution of serotype g strain among A. actinomycetemcomitans from clinical samples.

In vitro study of collagen coating of titanium implants for initial cell attachment

The aim of this study was to examine the influence of collagen coating on titanium on the initial attachment of human gingival fibroblasts for the development of the implant with periimplant soft tissue attachment. The morphological changes of cultured human gingival fibroblasts were investigated by scanning electron microcopy (SEM). Four different surfaces, i.e. non-coated mirror-polished titanium, collagen-coated titanium, non-coated tissue-culture polystyrene, and collagen-coated polystyrene were examined. Collagen coating of titanium was effective for enhancing the initial cell attachment. It is expected that collagen coating of titanium implants will improve the attachment of the peri-implant soft tissue to titanium at early stages after the implantation. SEM observation revealed the morphological effect of collagen coating on both titanium and polystyrene surfaces. Many lamellipodia and filopodia were recognized on collagen-coated titanium or polystyrene. Collagen coating improved the activity of human gingival fibroblasts.

Clinical study of refractory apical periodontitis treated by apicectomy. Part 1. Root canal morphology of resected apex

The morphology of the root apex was analysed by observation of the anatomy of specimens obtained by apicoectomy in cases of refractory apical periodontitis that did not respond to nonsurgical root canal treatment. Apical ramifications were present in 19 (70%) of the roots, while one were found in the remaining eight (3%) roots. This frequency is far higher than that reported by other investigators, suggesting that there is a close relationship between the anatomical complexity of the root canal and the occurrence of refractory apical periodontitis.

Treatment of large radicular cysts by modified marsupialization

We describe the enucleation of large radicular cysts to the maximum extent, and their treatment based on the concept of marsupialization and drainage after apicoectomy. Marsupialization requires a long period for healing, imposing a burden on the patient with regard to postoperative management. Considering this, together with the difficulty involved in the clinical diagnosis of radicular cysts, curettage of the cyst wall and drainage may be more effective for facilitating the healing process than use of marsupialization alone.

[A phase II study of intravenous VP-16-213 in small cell and non-small cell carcinoma of the lung]

A phase II clinical trial of VP-16-213 was carried out in 71 patients with small cell and non-small cell carcinoma of the lung. Forty-eight evaluable cases consisted of 36 small cell carcinomas, 7 epidermoid carcinomas, 4 adenocarcinomas and one unclassified carcinoma. VP-16-213 was administered by drip infusion at dosages of 60-100mg/m2/day for 5-consecutive days at 3-4 week intervals. Twelve of 36 (33.3%) small cell carcinomas had partial responses, while no responses were obtained in non-small cell carcinomas. Median duration of responses was 46 days (range 31-133 days). The dose limiting toxicity was leukopenia. Median number of days to nadir was 14 days and median numbers of days for recovery was 11 days. Nausea (38%), vomiting (12%), anorexia (45%) and alopecia (74%) were major clinical toxicities although these were mild or reversible. We concluded that VP-16-213 was useful in the treatment of small cell lung cancer and the dose schedule used in this study was recommendable with small dose reduction for further trial of combination chemotherapy.

[Clinical evaluation of sisomicin following intravenous drip infusion in respiratory tract infections]

The efficacy, safety and utility of sisomicin (SISO) followed intravenous infusion were evaluated in 35 cases with various respiratory infections. For many cases, SISO was given at a daily dosage of 100 mg, and a single dose was infused over about 1 hour. Clinical efficacy was evaluable in 28 cases including pneumonia (14 cases), bronchitis (8 cases), bronchiectasis (4 cases), pulmonary suppuration (1 case) and pulmonary abscess plus pyothorax (1 case). Almost cases had diagnosis of serious infection associated with various diseases. Clinical efficacy was evaluated as "excellent" in 2 cases, "good" in 15 cases, "fair" in 5 cases and "poor" in 6 cases, and efficacy rate in total case was 60.7%. Efficacy rate stratified by disease was calculated as 57.1% in pneumonia, 87.5% in bronchitis, 50.0% in bronchiectasis. Responses against pulmonary suppuration or pulmonary abscess with pyothorax were little or not. Bacteriologically, organisms isolated from sputum cleared in 7 out of 15 evaluable cases, thus the responses rate was 46.7%. Adverse reaction probably due to treatment observed in 2 cases with hepatic dysfunction. Blood levels of SISO at the end of infusion were ranged from 2.1 to 6.4 micrograms/ml, and no tendency of accumulation in blood after repeated infusion was showed.

[Therapeutic effect of an antineoplastic agent (peplomycin) adsorbed on activated charcoal (PEP-AC)]

Therapeutic effects of PEP-AC and PEP-saline on pulmonary growth of intratracheally implanted tumor and metastasis into the hilar lymph nodes were studied in mice. Pharmacokinetic studies of PEP-AC and PEP-saline were made by autoradiography (ARG) using 3H-PEP and microbial assay method using B. subtilis. The ARG using 3H-PEP-AC and 3H-PEP-saline demonstrated qualitatively slower elimination of PEP-AC from mouse lung than that of PEP-saline. The half-life time (t1/2) of PEP-AC was estimated to be about 3 days by bioassay method, while about 60 min. was given for PEP-saline. Intratracheal administration of PEP-saline produced no therapeutic effect to pulmonary growth of B16 melanoma, while that of PEP-AC gave a good response depending on doses. Furthermore, PEP-AC inhibited metastasis of B16 melanoma into the hilar lymph nodes. Better therapeutic effects were produced by PEP-AC when decreased inoculum sizes of B16 melanoma or P388 leukemia cells were transplanted.