SHED repair critical-size calvarial defects in mice.

OBJECTIVE: Stem cells from human exfoliated deciduous teeth (SHED) are a population of highly proliferative postnatal stem cells capable of differentiating into odontoblasts, adipocytes, neural cells, and osteo-inductive cells. To examine whether SHED-mediated bone regeneration can be utilized for therapeutic purposes, we used SHED to repair critical-size calvarial defects in immunocompromised mice. MATERIALS AND METHODS: We generated calvarial defects and transplanted SHED with hydroxyapatite/tricalcium phosphate as a carrier into the defect areas. RESULTS: SHED were able to repair the defects with substantial bone formation. Interestingly, SHED-mediated osteogenesis failed to recruit hematopoietic marrow elements that are commonly seen in bone marrow mesenchymal stem cell-generated bone. Furthermore, SHED were found to co-express mesenchymal stem cell marker, CC9/MUC18/CD146, with an array of growth factor receptors such as transforming growth factor beta receptor I and II, fibroblast growth factor receptor I and III, and vascular endothelial growth factor receptor I, implying their comprehensive differentiation potential. CONCLUSIONS: Our data indicate that SHED, derived from neural crest cells, may select unique mechanisms to exert osteogenesis. SHED might be a suitable resource for orofacial bone regeneration.

Human periodontal ligament cells derived from deciduous teeth induce osteoclastogenesis in vitro.

The receptor activator of NF-kappa B ligand (RANKL) and its decoy receptor, osteoprotegerin (OPG), are the important proteins involved in osteoclastogenesis. In this study, we investigated the expressions of RANKL and OPG in cultured human periodontal ligament cells derived from deciduous teeth (DPDL cells) and their roles in osteoclastogenesis. Northern blotting revealed that the OPG mRNA was down-regulated by application of 10(-8) M 1 alpha, 25(OH)2 vitamin D3 [1,25-(OH)2D3] and 10(-7) M dexamethasone (Dex). In contrast, RANKL mRNA was up-regulated by the same treatment. Western blotting demonstrated a decrease in OPG following application of 1, 25-(OH)2D3 and Dex. Tartrate-resistant acid phosphatase (TRAP)-positive multinuclear cells (MNCs) were induced when DPDL cells were co-cultured with mouse bone marrow cells in the presence of 1,25-(OH)2D3 and Dex. TRAP-positive MNCs increased significantly when the DPDL cells were co-cultured with bone marrow cells in the presence of anti-human OPG antibody together with 1, 25-(OH)2D3 and Dex. These results indicate that PDL cells derived from deciduous teeth synthesize both RANKL and OPG and could regulate the differentiation of osteoclasts.

Low calcium environment effects osteoprotegerin ligand/osteoclast differentiation factor.

In coculture with osteoblastic cell line MC3T3-E1 (E1) and mouse bone marrow cells, we reported that numbers of osteoclasts rose significantly on exposure to a low-calcium environment. Here we examined how osteoblasts influence osteoclastogenesis under a low-calcium environment. Comparing low extracellular calcium with a regular calcium environment, osteoprotegerin ligand (OPGL)/osteoclast differentiation factor (ODF) mRNA expression show more increase in the culture of low-calcium environment than in that of a regular calcium environment. Calcium-sensing receptor (CaSR), which was supposed as one of the mechanisms of recognizing extracellular calcium, existedon the surface of E1 cells. When E1 cells stimulated with agonists of CaSR, gadolinium, and neomycin, OPGL/ODF mRNA expression decreased. Moreover, these agonists reduced osteoclast formation in coculture. Taken together, it is possible that osteoblasts may recognize extracellular calcium via CaSR and regulate osteoclastogenesis.

Cyclic tension force activates nitric oxide production in cultured human periodontal ligament cells.

BACKGROUND: Nitric oxide (NO) is involved in a number of physiological and pathophysiological processes. The aim of this study was to examine the ability of human periodontal ligament (PDL) cells to produce NO and whether mechanical forces could induce NO production in the PDL cells. METHODS: Human PDL cells were seeded onto flexible bottoms of a culture plate and subjected to cyclic tension forces. NO production was evaluated by measuring concentration of NO2- and NO3- (NO2-/NO3-), the oxidized products of NO, in the culture medium. We employed reverse transcription polymerase chain reaction (RT-PCR) methods to detect NO synthase mRNA in the PDL cells. NO synthase immunoreactivity was also evaluated in both stimulated and unstimulated PDL cells. RESULTS: In unstimulated PDL cell culture, NO2-/NO3- increased to 140% of the initial value in 12 hours. In contrast, NO2-/NO3- showed a 3-fold increase when the cells had been subjected to cyclic tension forces for 12 hours. The increase in NO production was blocked by NG-monomethyl-L-arginine (5 x 10(-4) M), an inhibitor of NO synthase. Endothelial NO synthase (ecNOS) mRNA was expressed in both stimulated and unstimulated PDL cells, whereas inducible NO synthase (iNOS) mRNA was detected in neither culturing condition. We found strong ecNOS but not iNOS immunoreactivity in the stimulated PDL cells. CONCLUSIONS: These results suggest that human PDL cells produce NO by ecNOS and that the production is enhanced by stimulating the cells with cyclic tension forces. Mechanically stimulated PDL cells may modulate the function of periodontium by the upregulated NO production.

Primary leiomyosarcoma of the heart subsequent to double carcinomas of the thyroid and lung.

A 63-year-old woman underwent surgical operations for left lower lung cancer and for thyroid cancer. Nine months later, a third cancer developed in her heart and this tumor was removed by open heart surgery. A pathologic study revealed that the tumor was primary leiomyosarcoma of the heart and thus independent from the previous lung and thyroid carcinomas. This case was regarded as a triple carcinoma including a primary leiomyosarcoma arising from the left atrium. Reports in the literature on primary malignant tumors of the heart are reviewed briefly.

Effect of extracellular calcium concentrations on osteoclast differentiation in vitro.

We have been researching with the purpose of understanding the hard organization mineralization-suppression mechanism under a low calcium environment. So far, we have discerned clearly that the femur of an incubated newborn rat under a low calcium environment will develop bone formation dyscrasia such as hypertrophy of the caput. In this experiment, MC3T3-E1 (E1) cells, which are osteoblast-like cells, and mouse bone marrow were incubated in a coculture system under a low calcium environment and manifestation of osteoblast cells and their ability to resorb were examined. The results suggested that as the calcium concentration in the medium decreased manifestation of osteoclast cells increased, and as the degree of mineralization of E1 cells advanced, the number of manifestation of osteoblast cells decreased. We, therefore, report that there is a possibility that extracellular calcium concentrations involve the process of differentiation of bone marrow cells into osteoblast cells.

Salivary catecholamine assay for assessing anxiety in pediatric dental patients.

For the behavioral management of pediatric dental patients, it is important to estimate the degree of anxiety during dental treatment. The purpose of this study was to investigate salivary catecholamine levels in children undergoing dental treatment and to assess the degree of anxiety at each dental procedure. The salivary norepinephrine (NE) level was not influenced by a subcutaneous injection of 50 micrograms of NE in 6 adult volunteers, suggesting a poor diffusive effect of plasma NE into the salivary gland. The salivary NE and epinephrine (E) were measured in 8 children between the ages of 3 and 7 years who underwent restorative dental procedures. Salivary NE significantly increased when the children lay on a dental chair and subsequently received infiltration anesthesia. The salivary E level did not show a significant change throughout the study. After the treatment, salivary NE returned to the pretreatment level. These findings suggest that the increase in salivary NE before infiltration anesthesia reflects enhanced peripheral NE release as a result of stress-induced sympathetic responses and that salivary NE assay is useful for the assessment of dental anxiety in children.

[A double-blind comparative study on the efficacy of S6472, cefaclor, in the treatment of bacterial bronchitis].

Clinical efficacy and safety of S6472 (long active cefaclor (CCL)) and CCL were compared by a double-blind study using 248 patients with bacterial bronchitis. Patients were orally administered with either 375 mg of S6472 2 times or 250 mg of CCL 3 times daily for 7 days, and the following results were obtained. Clinical efficacy judged by a committee: The efficacy rates on acute bronchitis were 87.2% for S6472 and 82.6% for CCL, and the efficacy rates on chronic bronchitis were 70.3% for S 6472 and 64.7% for CCL. There was no significant difference between the 2 drugs in clinical efficacy. Clinical efficacy judged by doctors in charge: Results of the clinical efficacy judged by doctors in charge were similar to the efficacy judged by the committee. Bacteriological efficacy judged by the committee: Eradication rate for the S6472 group was 71.1% (32 of 45 patients) and that for the CCL group was 67.4% (29 of 43 patients). There was no significant difference between the 2 drugs in the bacteriological efficacy. Side effects and abnormal laboratory findings: Side effects were observed in 5 cases (4.2%) in the S6472 group and in 5 cases (4.0%) in the CCL group. These side effects, however, were not serious, and no remarkable abnormal laboratory values were observed. There was no significant difference between the 2 drugs in the incidence of side effects or abnormal laboratory findings. Clinical utility: When the clinical utility was expressed by the utility rate (very useful and useful), it was 79.5% in the S6472 group (117 patients) and 76.2% in the CCL group (122 patients) (judged by the committee). When the utility was judged by doctors in charge, it was 73.3% in S6472 group (120 patients) and 71.4% in CCL group (126 patients). From the above results, it has been concluded that S6472 taken twice daily is equivalent to CCL in effectiveness on bacterial bronchitis.

[Clinical study on dosage schedule of tobramycin: controlled comparison between 180 mg b.i.d. and t.i.d].

The efficacy and safety of tobramycin (TOB) administration at 90 mg twice a day (90 mg group) to patients with respiratory tract infections (RTI) were objectively investigated by means of a well-controlled comparative study. The results in this 90 mg group were compared with the case of administering 3 times a day of 60 mg each (60 mg group) as the control. In both of these patient groups, TOB was administered by intramuscular injection for 10 consecutive days. This study included 85 patients (90 mg group: 43 patients; 60 mg group: 42 patients). The Committee, however, excluded 19 patients consisting of 13 cases of infection other than RTI and 6 cases of out of protocol drug administration. Thus, 66 patients (90 mg group: 32 patients; 60 mg group: 34 patients) were used for the efficacy analysis. All 85 patients were used, however, for the evaluation of the safety of TOB and for the usefulness of TOB as judged by the physicians in charge. A brief summary of the results is presented below. The cases employed by the Committee consisted of 8 and 17 cases in the 90 mg and 60 mg groups, respectively, with bacterial pneumonia and lung abscess, and 24 and 17 cases in the 90 mg and 60 mg groups, respectively, with chronic RTI. There was a tendency for the distribution of disease cases in the 2 drug groups to be significant. Within the chronic RTI disease classification, the number of patients with chronic bronchitis was almost equal in the 2 drug groups; 16 cases in the 90 mg group and 15 cases in the 60 mg group. However, secondary infections were diagnosed in 8 cases in the 90 mg group and 2 cases in the 60 mg group. The clinical efficacy judged for all cases investigated by the Committee showed efficacy ratios of 56.3% for the 90 mg group and 70.6% for the 60 mg group. The difference between the 2 drug groups was not statistically significant. In the treatment of bacterial pneumonia and lung abscess, the efficacy rate in the 90 mg group was 87.5%, while it was 88.2% in the 60 mg group; these high values were practically identical. Against chronic RTI, the efficacy rates were 45.8% in the 90 mg group and 52.9% in the 60 mg group; within that disease classification, the efficacy rates against the chronic bronchitis cases were nearly the same at 43.8% and 46.7%, respectively. These data showed no statistically significant differences between the 2 drug administration groups. (ABSTRACT TRUNCATED AT 400 WORDS)

[Double-blind comparative clinical evaluation of cefamandole and cefmetazole in the treatment of respiratory tract infections].

Cefamandole sodium (CMD), a new cephalosporin-derivative, was synthesized in the Laboratory of Eli-Lilly Co. Ltd. U.S.A. in 1972. CMD, which is several times more active than cefmetazole (CMZ, a cephamycin antibiotic) against Gram-positive cocci, is only as active as the latter antibiotic against Gram-negative bacilli. Against Haemophilus influenzae, CMD exhibits an antimicrobial activity which is as strong as that of ampicillin sodium. Our previous comparative tests on efficacy and safety of CMD versus cefazolin (CEZ) demonstrated that CMD was as effective and safe as CEZ in the treatment of respiratory tract infections. In the present clinical trial, the efficacy and safety of CMD are evaluated by a comparative double blind method using CMZ, a more recently synthesized cephamycin antibiotic, as a reference drug. For this purpose, a comparative double blind study was carried out in 50 institutions and clinics in Tohoku and Hokkaido districts in Japan. A total of 272 inpatients, who was aged over 16 years and was diagnosed as having pneumonia, lung abscess or acute infectious exacerbation of chronic obstructive pulmonary diseases, was included in this trial. They received 2 g of CMD or CMZ twice a day by intravenous drip infusions, as a rule, for 14 days. Of these patients, 264 (133 received CMD and 131 CMZ) were available for the evaluation of safety and usefulness. Two hundred and thirty-eight patients (122 received CMD and 116 CMZ) were adopted for the evaluation of efficacy. Prior to the treatment, there was no significant difference with respect to age, sex, severity of infection and underlying diseases between subjects in 2 treatment groups. An excellent or good clinical response was obtained in 82% of the patients treated with CMD, and in 81% of those treated with CMZ. Thus, there was no significant difference in cure rate between 2 treatment groups. However, an excellent clinical response was found in 12.3% of the patients treated with CMD, whereas only in 4.3% of those treated with CMZ. This difference in percentage of excellent clinical response between 2 treatment groups was statistically significant (P less than 0.05). Of the 87 patients with moderate to severe infection who were treated with CMD, 13 showed an excellent response. Only 4 of 90 patients treated with CMZ showed an excellent response. Statistically the difference in the rate of excellent response between these 2 groups was significant (P less than 0.05).(ABSTRACT TRUNCATED AT 400 WORDS)

[Clinical studies on tobramycin using intravenous drip infusion (author's transl)].

Clinical studies and serum levels on tobramycin (TOB) using intravenous drip infusion were carried out and the following results were obtained. 1. Clinical results Nineteen patients with various infections including 11 respiratory tract infections, 7 urinary tract infections and a wound infection were treated with TOB 20-60 mg b.i.d. and t.i.d. by intravenous drip infusion and for 1 hour during 4 to 16 days. Clinical effects were excellent in 10 cases, good in 4 cases, fair in 2 cases and failure in 3 cases. It was 73.7% of the efficacy rate of the drug. Side effects were observed in 2 cases of oliguria and increase in BUN, S-creatinine and S-potassium. 2. Serum levels of TOB Serum levels of TOB administrated 30 or 60 mg intravenous drip infusion for 1 hour were measured in first and final administration of 8 patients. The peak serum levels were 3.1-5.0 micrograms/ml at the end of infusion in first 60 mg administration of the drug, and 3.8-5.3 micrograms/ml in final 60 mg administration of the drug.