Selective β2-adrenergic Antagonist Butoxamine Reduces Orthodontic Tooth Movement

Recently, involvement of the sympathetic nervous system in bone metabolism has attracted attention. β2-Adrenergic receptor (β2-AR) is presented on osteoblastic and osteoclastic cells. We previously demonstrated that β-AR blockers at low dose improve osteoporosis with hyperactivity of the sympathetic nervous system via β2-AR blocking, while they may have a somewhat inhibitory effect on osteoblastic activity at high doses. In this study, the effects of butoxamine (BUT), a specific β2-AR antagonist, on tooth movement were examined in spontaneously hypertensive rats (SHR) showing osteoporosis with hyperactivity of the sympathetic nervous system. We administered BUT (1 mg/kg) orally, and closed-coil springs were inserted into the upper-left first molar. After sacrifice, we calculated the amount of tooth movement and analyzed the trabecular microarchitecture and histomorphometry. The distance in the SHR control was greater than that in the Wistar-Kyoto rat group, but no significant difference was found in the SHR treated with BUT compared with the Wistar-Kyoto rat control. Analysis of bone volume per tissue volume, trabecular number, and osteoclast surface per bone surface in the alveolar bone showed clear bone loss by an increase of bone resorption in SHR. In addition, BUT treatment resulted in a recovery of alveolar bone loss. Furthermore, TH-immunoreactive nerves in the periodontal ligament were increased by tooth movement, and BUT administration decreased TH-immunoreactive nerves. These results suggest that BUT prevents alveolar bone loss and orthodontic tooth movement via β2-AR blocking.

Azulene derivatives as TXA2/PGH2 receptor antagonists--II. Synthesis and biological activity of 6-mono- and 6-dihydroxylated-isopropylazulenes

In order to examine the correlation between activity and hydrophilicity of the side chain of sodium 3-[4-(4-chlorobenzenesulfonylamino)butyl]-6-isopropylazulene -1-sulfonate (KT2-962), a non-prostanoid TXA2/PGH2 receptor antagonist, one or two hydroxyl groups were introduced into the isopropyl moiety. A series of 6-hydroxylated-isopropylazulenes were synthesized by regioselective oxidation of 6-isopropylazulenes and their in vitro and in vivo antagonistic activities were studied. Both the primary and tertiary alcohols, monohydroxylated derivatives, exhibited potent biological activities comparable to unmodified 6-isopropylazulenes both in vitro and in vivo. In contrast, the activities of 1,2- and 1,3-diols of 6-substituted derivatives, markedly decreased, but recovered by O-isopropylidenation of the dihydroxyl moiety. These findings indicate that the moderate hydrophobicity of substituent at the 6-position of the azulene ring might be required for the activity and the size of the substituent at this position, not so rigid for keeping potent biological activity.

[Pulmonary circulatory disturbance following endoscopic injection sclerotherapy]

We compared arterial blood gas analysis and 99mTc-MAA lung perfusion scintigraphy before and after endoscopic injection sclerotherapy (EIS) in 17 cases of esophageal varices complicating liver cirrhosis. EIS was performed by the intra-variceal injection method with 5% ethanolamine oleate (EO) as the sclerosant agent. In blood gas analysis, the mean values of partial arterial oxygen tension (PaO2) and oxygen saturation (SaO2) were decreased, and the mean value of alveolar-arterial O2 difference (AaDO2) was increased, compared with before EIS while breathing room air. On lung perfusion scintigram, the pulmonary blood flow was markedly decreased, demonstrating hypoperfusion and/or perfusion defect, compared with before EIS in most the cases. It was suggested that pulmonary embolism and/or pulmonary circulatory disturbance occurred after EIS. It is important to note that pulmonary circulatory disturbances potentially may occur after EIS without any accompanying symptoms such as dyspnea, cough, or hemoptysis.

[Correlation of the perfusion scintigram with pulmonary functions in chronic obstructive pulmonary disease]

We carried out ventilation-perfusion scintigraphy and pulmonary function tests in 21 patients with chronic obstructive pulmonary disease. We used 99mTc-macroaggregate for perfusion scintigram and 133Xe gas for ventilation scintigram. We added the radioactivities of rebreathing phase and made lung volume image using computer. Regions of interest (ROIs) were derived from radioactivities in each image. ROIs on lung volume image included each whole lung and those on perfusion image included the areas which had relatively high radioactivity. We counted the area of ROIs on lung volume (L) and perfusion (P) images. Then we used the ratio of perfusion to lung volume (P/L) as a parameter of pulmonary perfusion. P/L had the significant correlations with the vital capacity, the actual FEV1.0, arterial oxygen partial pressure, diffusing capacity, RV/TLC and peak flow rate. These results suggested that P/L was a useful parameter of pulmonary perfusion in chronic obstructive pulmonary disease.

Activity, cardiac and respiratory responses of blindfold preterm infants in a neonatal intensive care unit

The purposes of the present study were to examine 24-h periods in the life of preterm infants incubated in a Neonatal Intensive Care Unit (NICU) using indices of activity, cardiac and respiratory responses, and to examine the effects of blindfolding incubated infants upon these behavioural indices. Ten healthy preterm infants were individually observed for 2 days a week for a 24-h period, using a continuous video recording system. Each infant was blindfolded with an eye-mask and a black head-cap for approximately equal to 10 h during a night out of the 2 days. Analyses on activity, cardiac and respiratory responses were done for (1) 20 min sampled from every other hour during the 2 days, and (2) for 1 h during the night, both a blindfolded day and unblindfolded, respectively. The results showed that activity was less and respiration rate lower when blindfolded than when unblindfolded. Respiration rate was also found to be stable when blindfolded.