Mechanical regulation of bone homeostasis through p130Cas-mediated alleviation of NF-κB activity.

Mechanical loading plays an important role in bone homeostasis. However, molecular mechanisms behind the mechanical regulation of bone homeostasis are poorly understood. We previously reported p130Cas (Cas) as a key molecule in cellular mechanosensing at focal adhesions. Here, we demonstrate that Cas is distributed in the nucleus and supports mechanical loading-mediated bone homeostasis by alleviating NF-κB activity, which would otherwise prompt inflammatory processes. Mechanical unloading modulates Cas distribution and NF-κB activity in osteocytes, the mechanosensory cells in bones. Cas deficiency in osteocytes increases osteoclastic bone resorption associated with NF-κB-mediated RANKL expression, leading to osteopenia. Upon shear stress application on cultured osteocytes, Cas translocates into the nucleus and down-regulates NF-κB activity. Collectively, fluid shear stress-dependent Cas-mediated alleviation of NF-κB activity supports bone homeostasis. Given the ubiquitous expression of Cas and NF-κB together with systemic distribution of interstitial fluid, the Cas-NF-κB interplay may also underpin regulatory mechanisms in other tissues and organs.

Role of Osteocyte-PDL Crosstalk in Tooth Movement via SOST/Sclerostin.

Sclerostin (Scl) negatively regulates bone formation and favors bone resorption. Osteocytes, the cells responsible for mechanosensing, are known as the primary source of Scl and are a key regulator of bone remodeling through the induction of receptor activator of NF-κB ligand (RANKL). However, the spatiotemporal patterns of Scl in response to mechanical stimuli and their regulatory mechanisms remain unknown. We investigated the regulatory dynamics of the SOST/Scl expression generated by orthodontic tooth movement (OTM) in vivo and in vitro. In 8-wk-old male mice, coil springs were used to move the first molar mesially for 0, 1, 5, or 10 d. A regional histogram and the distribution patterns of the Scl expression showed that the Scl expression in the alveolar bone was increased on the compression side and peaked on day 5, with a gradual increase in the degree of significance. On day 10, the expression around the periodontal ligament (PDL)-alveolar bone boundary returned to the control level. Conversely, the expression of Scl on the tension side was only significantly decreased on day 1. Compressive force biphasically modulated the SOST/Scl expression in the isolated human PDL and thereby upregulated osteocytic SOST via paracrine activation in an osteocyte-PDL co-culture system designed to mimic OTM. This system did not affect the RANKL or OPG expression in osteocytes, suggesting that the bone resorption pathways are acted upon in a PDL-dependent and osteocyte-independent manner through RANKL/OPG signaling. Moreover, sclerostin neutralizing antibody significantly attenuated the upregulation of SOST that was induced by compressive force. In conclusion, our results provide evidence to support that factors secreted by the PDL, including SOST/Scl, control alveolar bone remodeling through osteocytic SOST/Scl in OTM.

Role of the Inferior Alveolar Nerve in Rodent Lower Incisor Stem Cells.

In developing teeth, the sequential and reciprocal interactions between epithelial and mesenchymal tissues promote stem/progenitor cell differentiation. However, the origin of the stem/progenitor cells has been the subject of considerable debate. According to recent studies, mesenchymal stem cells originate from periarterial cells and are regulated by neurons in various organs. The present study examined the role of innervation in tooth development and rodent incisor stem/progenitor cell homeostasis. Rodent incisors continuously grow throughout their lives, and the lower incisors are innervated by the inferior alveolar nerve (IAN). In this study, we resected the IAN in adult rats, and the intact contralateral side served as a nonsurgical control. Sham control rats received the same treatment as the resected rats, except for the resection process. The extent of incisor eruption was measured, and both mesenchymal and epithelial stem/progenitor cells were visualized and compared between the IAN-resected and sham-operated groups. One week after surgery, the IAN-resected incisors exhibited a chalky consistency, and the eruption rate was decreased. Micro-computed tomography and histological analyses performed 4 wk after surgery revealed osteodentin formation, disorganized ameloblast layers, and reduced enamel thickness in the IAN-resected incisors. Immunohistochemical analysis revealed a reduction in the CD90- and LRIG1-positive mesenchymal cell ratio in the IAN-resected incisors. However, the p40-positive epithelial stem/progenitor cell ratio was comparable between the 2 groups. Thus, mesenchymal stem/progenitor cell homeostasis is more related to IAN innervation than to epithelial stem/progenitor cells. Furthermore, sensory nerve innervation influences subsequent incisor growth and formation.

Glycated albumin but not HbA1c reflects glycaemic control in patients with neonatal diabetes mellitus.

AIMS/HYPOTHESIS: It is difficult to use HbA(1c) as an indicator of glycaemic control in patients with neonatal diabetes mellitus (NDM) because of high levels of fetal haemoglobin (HbF) remaining in the blood. In this study, glycated albumin (GA), which is not affected by HbF, and HbA(1c) were compared to evaluate whether they reflect glycaemic control in patients with NDM. METHODS: This study included five patients with NDM. Age at diagnosis was 38 ± 20 days. Insulin therapy was started in all patients, and levels of GA, HbA(1c) and HbF were measured monthly for 6 months. One-month average preprandial plasma glucose (aPPG) was calculated using self-monitoring of blood glucose. RESULTS: Plasma glucose and GA were elevated (29.7 ± 13.1 mmol/l [n = 5] and 33.3 ± 6.9% [n = 3], respectively) but HbA(1c) was within normal limits (5.4 ± 2.6% [35.5 ± 4.9 mmol/mol]; n = 4) at diagnosis. With diabetes treatment, aPPG (r = -0.565, p = 0.002), GA (r = -0.552, p = 0.003) and HbF (r = -0.855, p < 0.0001) decreased with age, whereas HbA(1c) increased (r = 0.449, p = 0.004). GA was strongly positively correlated with aPPG (r = 0.784, p < 0.0001), while HbA(1c) showed no correlation with aPPG (r = 0.221, p = 0.257) and was significantly inversely correlated with HbF (r = -0.539, p = 0.004). CONCLUSIONS/INTERPRETATION: GA is a useful indicator of glycaemic control in patients with NDM, whereas HbA(1c) is influenced by age-related changes in HbF and does not accurately reflect glycaemic control.

Charcoal hemoperfusion in the treatment of phenytoin overdose.

In the case of phenytoin, a drug that is generally highly protein bound, there is a lack of consensus on the use of charcoal hemoperfusion in cases of overdose. We performed charcoal hemoperfusion on a phenytoin-overdosed patient to assess the effectiveness of this treatment. The plasma concentrations of total and free phenytoin fell rapidly, from 40.0 microg/mL and 3.6 microg/mL to 16.2 microg/mL and 1.5 microg/mL, respectively, after 3 hours of hemoperfusion. The total phenytoin elimination half-life was 3.9 hours. The fraction of protein-bound phenytoin was constant (90.8% +/- 0.5%) before, during, and after the procedure. The relations between the in vitro protein binding and adsorption of phenytoin to activated charcoal were also examined. Interestingly, bound phenytoin was found to dissociate from plasma proteins in the presence of activated charcoal and subsequently became adsorbed to the activated charcoal. Considering that phenytoin is bound to albumin with a large number of binding sites (n = 6) and a small binding constant (K = 6 x 10(3/)mol/L), the extent of adsorption to activated charcoal may depend on the magnitude of the binding constant of the drug to plasma proteins. The current results suggest that charcoal hemoperfusion is effective for the removal of drugs that bind to plasma proteins with a low binding constant.

Changes of serum amylase, its isozyme fractions and amylase-creatinine clearance ratio in dogs with experimentally induced acute pancreatitis.

To investigate the diagnostic application of amylase to canine pancreatic diseases, serum amylase activities, its isozyme fractions and amylase-creatinine clearance ratio (ACCR) were analyzed in normal intact dogs and dogs experimentally induced acute pancreatitis. There was no statistic difference between normal male and female dogs. Amylase specific activities in pancreatic tissue extracts were more than 2,300 times higher than that in serum, and were also higher than those in other tissues; parotid and mandibular salivary glands, lung, heart, liver, spleen, duodenum, jejunum, ileum and kidney. Following the chloroform injection into the pancreatic tissue, WBC increased from 6 to 240 hr and serum glucose significantly increased at 72 and 96 hr, and no urine glucose was detected. BUN as well as serum and urine creatinine showed normal levels. ACCR increased until 96 hr without statistic significance. Serum amylase activities increased significantly after 3 hr and its isozyme was separated into 4 fractions (Amy1-Amy4) in contrast to 3 fractions (Amy2-Amy4) in intact dogs. Since this extra Amy1 seen from 1 hr increasing after 6 hr similarly to other 3 fractions, the evaluation of serum amylase and its isozyme fractions was indicated to be useful for the diagnosis of acute pancreatitis in dogs.

HPLC-studies on nonmercapt-mercapt conversion of human serum albumin.

Human mercaptalbumin (HMA) and nonmercaptalbumin (HNA) could be separated by high-performance liquid chromatography (HPLC) at neutral pH. Using HPLC, the present authors found the nonmercapt-mercapt conversion (HNA----HMA) during hemodialysis and the mercapt-nonmercapt conversion (HMA----HNA) after hemodialysis in chronic renal failure, indicating HMA as the covalent carrier protein for sulfur-containing amino acids.

[Fundamental and clinical evaluation of ceftriaxone in the field of pediatrics].

Fundamental and clinical evaluation on ceftriaxone (Ro 13-9904, CTRX) was performed in the field of pediatrics and the following results were obtained. The antibacterial activity of CTRX was determined against clinically isolated strains at our department. CTRX was definitely superior to CEZ and CMZ and almost equal or slightly superior to CTX in activity against Gram-negative bacteria, while the MIC of CTRX against Gram-positive bacteria was higher than that of CEZ and CMZ and about equal to that of CTX. The blood concentration of CTRX after one shot intravenous injection with 10 mg/kg was 67.98 micrograms/ml at 15 minutes, 51.96 micrograms/ml at 30 minutes, 37.51 micrograms/ml at 1 hour, 28.91 micrograms/ml at 2 hours, 20.71 micrograms/ml at 4 hours, 13.97 micrograms/ml at 6 hours and 6.45 micrograms/ml at 12 hours, while the half-life time was 3.74 hours. The blood concentration of CTRX after one shot intravenous injection with 20 mg/kg was 179.55 micrograms/ml at 15 minutes, 120.01 micrograms/ml at 30 minutes, 100.01 micrograms/ml at 1 hour, 53.75 micrograms/ml at 2 hours, 33.13 micrograms/ml at 4 hours, 26.41 micrograms/ml at 6 hours and 21.49 micrograms/ml at 12 hours, while the half-life time was 4.15 hours. The blood concentration of CTRX after intravenous drip infusion for 1 hour with 10 mg/kg was 19.54 micrograms/ml at 15 minutes, 27.19 micrograms/ml at 30 minutes, 36.57 micrograms/ml at 1 hour, 23.83 micrograms/ml at 2 hours, 19.69 micrograms/ml at 3 hours, 14.46 micrograms/ml at 5 hours, 11.02 micrograms/ml at 7 hours and 7.27 micrograms/ml at 13 hours, while the half-life time was 6.59 hours. The blood concentration of CTRX after intravenous drip infusion for 1 hour with 20 mg/kg was 61.72 micrograms/ml at 30 minutes, 108.1 micrograms/ml at 1 hour, 54.95 micrograms/ml at 2 hours, 35.68 micrograms/ml at 3 hours, 28.13 micrograms/ml at 5 hours, 20.51 micrograms/ml at 7 hours and 11.43 micrograms/ml at 13 hours, while the half-life time was 4.23 hours. There was noticed a tendency of the blood level being elevated by consecutive administration. The urinary recovery rate of CTRX ranged from 36.5 to 71.6%. The excretion rate of CTRX into the cerebrospinal fluid ranged from 5.2 to 11.6%. The excretion rate of CTRX into the pleural fluid was 31.0%. The clinical efficacy rate was 87.5% (excellent or good) in 8 children with infections treated with CTRX. The eradication of bacteria was observed in all of 5 cases bacteriologically evaluation.(ABSTRACT TRUNCATED AT 400 WORDS)

[Fundamental and clinical studies of sulbactam/cefoperazone in the pediatric field].

Fundamental and clinical studies were carried out on sulbactam/cefoperazone (SBT/CPZ) in the field of pediatrics. The following results were obtained: A total of 185 clinical isolates that had been stocked at our department was employed to determine the minimum inhibitory concentrations (MICs) of SBT/CPZ against various bacterial species. SBT/CPZ showed strong antibacterial potency against E. coli, Salmonella, Klebsiella and P. mirabilis, and relatively strong potency against S. marcescens, P. aeruginosa and S. aureus. Antibacterial potency of SBT/CPZ was stronger than that of CPZ alone against E. coli, and it also showed strong activity against strains of Salmonella, S. marcescens and S. aureus, moderately or highly resistant to CPZ. SBT/CPZ was administered by intravenous bolus infusion to pediatric patients to determine the serum concentrations of SBT and CPZ. At a dose of 10 mg/kg the mean serum levels of SBT and CPZ were as follows; 17.8 micrograms/ml, 40.7 micrograms/ml at 15 minutes and 0.3 microgram/ml at 6 hours, respectively. The half-lives of SBT and CPZ in the serum were 1.05 hours and 1.76 hours, respectively. Similarly, at a dose of 20 mg/kg the mean serum levels of SBT and CPZ were; 31.9 micrograms/ml, 81.0 micrograms/ml at 15 minutes and 0.5 microgram/ml, 6.1 micrograms/ml at 6 hours, and the half-lives were 1.00 hour and 1.72 hours, respectively. At a dose of 40 mg/kg, only 1 case was determined. The serum levels of SBT and CPZ were 34.4 micrograms/ml, 74.8 micrograms/ml at 30 minutes and 0.2 microgram/ml at 6 hours, and the half-lives were 0.78 hour and 1.38 hours, respectively. SBT/CPZ was drip-infused intravenously over a period of 1 hour, and the serum concentrations of SBT and CPZ were determined. At the dose of 10 mg/kg or 20 mg/kg, the peak serum levels of SBT and CPZ were observed at 1 hour or at the end of drip infusion. At a dose of 10 mg/kg the mean serum levels of SBT and CPZ were 14.4 micrograms/ml, 33.7 micrograms/ml at 1 hour and 1.4 micrograms/ml, 4.6 micrograms/ml at 7 hours, respectively. The half-lives was 1.86 hours for SBT and 2.23 hours for CPZ, respectively. Similarly at a dose of 20 mg/kg, the mean serum levels of SBT and CPZ were, 22.2 micrograms/ml, 34.6 micrograms/ml at 1 hour and 0.5 microgram/ml, 2.8 micrograms/ml at 7 hours, and the half-lives was 1.17 hours and 1.75 hours, respectively. The urinary recovery rate was determined for the 6 hours period after administration.(ABSTRACT TRUNCATED AT 400 WORDS)

[Basic and clinical studies on ceftazidime in the pediatric field].

Basic and clinical studies were made on ceftazidime (CAZ) in pediatric field, and the following results were obtained. The antibacterial activity of CAZ against clinically isolated and maintained strains was examined. CAZ was unequivocally more active than CEZ and CMZ against Gram-negative rods, with MIC distribution similar to that of CTX, except for that for P. aeruginosa. The MIC of CAZ was lower than that of CTX for P. aeruginosa. Compared with the MICs of CEZ, CMZ and CTX, CAZ showed slightly higher MICs for Gram-positive bacteria. The blood concentrations of CAZ, at 0.25, 0.5, 1, 2, 4 and 6 hours after a one shot intravenous injection of 10 mg/kg of CAZ were 64.9, 36.9, 28.3, 14.7, 4.92 and 2.42 micrograms/ml, respectively, with the half-life of 1.27 hours. The blood concentrations of CAZ, at 0.25, 0.5, 1, 2, 4 and 6 hours after a 1-hour drip infusion of 10 mg/kg of CAZ were 16.6, 24.5, 41.4, 17.1, 5.38 and 2.62 micrograms/ml, respectively, with the half-life of 1.28 hours. The blood concentrations of CAZ, at 0.25, 0.5, 1, 2, 4 and 6 hours after a one shot intravenous injection of 20 mg/kg of CAZ were 73.1, 60.8, 39.3, 17.3, 8.23 and 4.45 micrograms/ml, respectively, with the half-life of 1.42 hours. The blood concentrations of CAZ, at 0.5, 1, 2, 4 and 6 hours after a 1-hour drip infusion of 20 mg/kg of CAZ were 55.1, 69.0, 32.1, 11.4 and 4.56 micrograms/ml, respectively, with the half-life of 1.27 hours. Urinary recovery rate of CAZ during the first 6 hours after a one shot intravenous injection of 10 mg/kg of CAZ was 86.7%. CAZ was administered to 17 children with infections, and the clinical response was excellent or good in 94%. CAZ was bacteriologically effective in 14 patients, all bacteria having been eradicated in them. The bacteria were E. coli in 10 patients, H. influenzae in 2, P. aeruginosa in 1 and S. pneumoniae in 1. As for side effects, slight elevation in GOT was observed in 1 case and eosinophilia, in another case.

[Experimental and clinical evaluation of cefpiramide in pediatrics].

Fundamental and clinical studies on cefpiramide (CPM), a new semisynthetic cephalosporin, were made and the following results were obtained. The antibacterial activities of CPM against clinical isolates were almost similar to those of conventional cephems except for Pseudomonas aeruginosa. The antibacterial activity of CPM against P. aeruginosa was excellent and superior than those of the others. Ten or twenty mg/kg of CPM was given intravenously at one shot to 11 cases. The mean serum levels of CPM reached 231 micrograms/ml at 15 minutes, 119 micrograms/ml at 30 minutes, 88 micrograms/ml at 1 hour, 65 micrograms/ml at 2 hours and 33 micrograms/ml at 6 hours after administration at a single dose of 10 mg/kg, respectively with the half-life of 3.42 hours. In case of 20 mg/kg, the mean serum levels attained 306 micrograms/ml at 15 minutes, 245 micrograms/ml at 30 minutes, 160 micrograms/ml at 1 hour, 118 micrograms/ml at 2 hours and 66 micrograms/ml at 6 hours respectively after administration with the half-life of 5.20 hours. CPM was given intravenously to 12 patients with various bacterial infections. The clinical effects were excellent in 5 cases, good in 6 cases and poor in 1 case and the effective rate was 92%. No side effect was observed in all cases.

[Experimental and clinical studies of an ampicillin suppository (KS-R1) in pediatrics].

Blood levels of ampicillin (ABPC) were measured in 10 childish patients with heart disease after the rectal administration of KS-R1 at doses of 125 mg and 250 mg. Average blood levels of ABPC at 15, 30 minutes, 1, 2 hours and 4 hours after the administration of KS-R1 were 6.8, 6.9, 3.1, 1.1 mcg/ml and 0.1 mcg/ml with half-life of 0.64 hours in patients of age from 1 year to 4 years 7 months old (dose level 8.9 approximately 13.9 mg/kg, average 10.5 mg/kg), and 5.2, 6.1, 3.4, 1.0 mcg/ml and 0.1 mcg/ml with half-life of 0.65 hours in patients of age from 7 years 10 months to 10 years 7 months old (dose level 8.3 approximately 13.9 mg/kg, average 9.8 mg/kg), respectively. Clinical effective rate (excellent and good) was 87% in 55 childish patients with infections. Bacteriologically, 13 strains (74%) out of 18 strains which were isolated from the patients were eradicated. No severe side effects were observed. Diarrhea was observed in 3 cases.

[Pharmacokinetics study on gentamicin intravenous drip infusion in children].

Pharmacokinetics of gentamicin in children after intravenous infusion over 60 minutes were compared with that after intramuscular injection. 1. Mean measured peak serum levels after intravenous infusion of 2.5 mg/kg and intramuscular injection of 2.0 mg/kg were 6.1 micrograms/ml at termination of infusion and 6.5 micrograms/ml at 30 or 60 minutes after injection, respectively. Older children showed higher serum levels. 2. There was no difference in serum half-life between both modes of administration. 3. The AUC after intravenous infusion was slightly larger than that after intramuscular injection. 4. It was suggested that the efficacy and safety of the treatment by intravenous infusion in children are comparable to that by the intramuscular injection, and optimum single dose is 1.5--2.5 mg/kg.