Ampicillin concentrations in human serum, gingiva, the mandibular bone, and dental follicle following a single oral administration

Ampicillin (ABPC) concentrations in human serum, gingiva, the mandibular bone, and dental follicle after a single oral administration of ampicillin (500 mg) were assayed by the agar diffusion (paper disc) method. The peak times of all specimens were identical, being 120 min after administration. The peak concentrations of the respective specimens were 2.01 micrograms/ml, 1.03, 0.34, and 0.72 micrograms/g, respectively. The concentration ratios of gingiva, the mandibular bone, and dental follicle to their corresponding serum at the peak time were 0.51, 0.16, and 0.35, respectively.

[Pharmacological studies of guanabenz. Effects on the peripheral nervous and other organ systems]

General pharmacological properties of guanabenz (GUB), a new anti-hypertensive agent, were studied in comparison with those of clonidine (CLD) and guanethidine (GUD). Intravenous or peroral administration of GUB caused a contraction of the nictitating membrane in cats and mydriasis in mice, while it produced an inhibitions of the gastrointestinal motility in dogs; the motility of isolated rabbit ileum; and chacol transport, salivation and gastric acid secretion in rats. GUB had no or slight inhibitory actions on contractile responses induced by peripheral sympathetic or parasympathetic nerve stimulation in various organs; however, it had antagonistic actions against the norepinephrine-induced contraction of isolated guinea-pig vas deferens. The contractile responses to epinephrine and tyramine in the nictitating membrane and to sympathetic nerve stimulation in isolated guinea-pig vas deferens were potentiated by GUB. GUB specifically antagonized the serotonin-induced contraction of the isolated rat fundus strip and nonspecifically inhibited acetylcholine, histamine or Ba2+-induced contractions of isolated guinea-pig ileum at higher concentrations. GUB exhibited local anesthetic actions and diuretic effects, but had no particular actions on neuromuscular transmission, isolated rat uterus, guinea-pig tracheal muscle and the hematic system. These effects of GUB were found to be almost identical with but less potent than those of CLD. The effects of GUD were basically different from GUB.

Amoxicillin concentrations in serum, jaw cyst, and jawbone following a single oral administration

Forty-four patient who underwent enucleation of jaw cysts were administered amoxicillin preoperatively. Specimens of venous blood (44), walls and fluids from periodontal (31) and dentigerous (13) cysts, and jawbone (26) were obtained during the operation and assayed for amoxicillin content. Measurable concentrations were found in all specimens. The levels were higher in periodontal cysts than in dentigerous cysts, and higher in maxillary bone than in mandibular bone. Since amoxicillin can easily and rapidly pass through the epithelial lining according to the change in concentration, the penetration by amoxicillin of blood/cyst wall/cyst fluid probably depends on simple diffusion.

[Effects of diltiazem on catecholamine release from cat adrenal glands (author's transl)]

Effects of diltiazem on catecholamine (CA) release evoked by several secretagogues were investigated in cat adrenal glands perfused in situ with Locke solution. All compounds were introduced into the perfusion medium. It was found that the release of CA stimulated by either acetylcholine (ACh) (10(-4) M) or high K+ (56 mM) was reduced by approximately 50 and 90% in the presence of 10(-5) and 10(-4) M diltiazem respectively, while diltiazem at 10(-6) M exhibited little or no influence on the Ca release. In addition, diltiazem at a concentration of 10(-6) M or higher produced a dose-related decrease in the CA release evoked by introduction of CaCl2 (2.2 mM) into Ca2+-free perfusion medium. On the other hand, removal of Na+ from the perfusion medium (osmolarity was adjusted with osmotically equal amount of sucrose) caused an increase in release of CA from the glands. Diltiazem (10(-5) M or higher) also reduced this CA release, but its activity was weaker than those found in experiments with ACh, high K+, and Ca2+. In all cases, the effects were reversible on washout. On the contrary, diltiazem, even at a higher concentration of 10(-4) M, exhibited no inhibitory effect on the release of CA induced by acetaldehyde (3 X 10(-3) M). It was suggested that diltiazem, through its Ca2+-antagonistic action, may reduce the evoked CA release which depends on extracellular Ca2+.

[Pharmacological study of mequitazine (LM-209) (II). Anti-allergic action (author's transl)]

The anti-allergic effect of Mequitazine (LM-209) which was found to have an anti-histaminic activity was investigated in guinea-pigs. The inhibitory activities of LM-209 on the Schultz-Dale reaction and ileum contraction by some mediators released from the sensitized guinea-pig lung were the same as those of clemastine fumarate (CL) but with 5 times the potency. LM-209 and CL, but these activities were less potent than in the case of disodium cromoglycate. The various anaphylactic reactions mediated by IgG in guinea-pigs were inhibited by LM-209, CL and chlorpheniramine maleate (CPM). The homologous PCA mediated IgE in rats was also inhibited by LM-209, CL and CPM, but the duration of the action with LM-209 was markedly longer. In experimentally-induced asthma, the decrease of respiratory rate and volume was significantly inhibited by LM-209, but was not affected by CL. Thus, LM-209 seems to inhibit the allergic reaction mainly by an antagonistic action on allergic mediators.

A pathological study of intracranial aneurysms particularly of aneurysms other than saccular ones

The author has investigated grossly and microscopically 90 intracranial aneurysms among 63 individuals, autopsied at the Tokyo-to Medical Examiner Office and partly at the 2nd Department of Pathology, Showa University School of Medicine. These aneurysms consisted of 74 of the saccular type, 5 of the arteriosclerotic type, 6 of the spindle-shaped aneurysm of the vertebrals and 5 of the dolichoectatic type, respectively. In this paper, the author has discussed the differences of pathogenesis of the above mentioned four types of aneurysms. The saccular aneurysm is thought to occur from turbulence of blood stream by intimal thickening developing from "Verzweigungspolster" (VP) of Rotter at the neck of the aneurysm, and the arteriosclerotic aneurysm to occur by the same manner as the saccular one, superimposed on severe atherosclerosis during a long time. The spindle-shaped aneurysm of the vertebral arteries is thought to be of inflammatory nature, relating to slowness of blood stream in the vertebral arteries, and the dolichoectatic aneurysm to be due to hemodynamic disturbance of the vertebro-basilar artery system by means of atherosclerosis of the arterial walls neighboring to the top of the basilar artery.

Effect of diltiazem on insulin secretion. II. Experiments on perfused rat pancreas, anesthetized dogs and conscious rats

Effect of diltiazem on insulin secretion was investigated in the perfused rat pancreas. Experiments were also carried out in anesthetized dogs and conscious rats with and without glucose loading. In the perfused rat pancreas, diltiazem reduced both glucose- and tolbutamide-induced insulin secretion and these effects of diltiazem were reversed with removal of the compound. Inhibition of the glucose-induced insulin secretion caused by diltiazem was counteracted by increasing the concentration of calcium ion. In experiments on intact animals, diltiazem at vasoactive doses produced no significant influence on the basal level of plasma insulin or glucose-induced insulin secretion. These data taken together with findings in previously reported work suggest that diltiazem reduces insulin secretion from pancreatic B-cells in vitro possibly by the calcium-antagonistic property, while the compound exhibits practically no inhibitory action on the insulin secretion in vivo.

Effect of diltiazem on insulin secretion. I. Experiments in vitro

Effect of diltiazem on glucose-induced insulin secretion was investigated in the rat islets of Langerhans isolated by a collagenase digestion technique. It was found that B-cells, main constituents of isolated islet preparations, had a well-preserved ultrastructural appearance immediately following isolation or after incubation with glucose or glucose and diltiazem. The islets released a large amount of insulin upon stimulation with glucose and CaCl2. Diltiazem (10(-6)-10(-4) M) produced a dose-related inhibition of glucose-induced insulin secretion and this effect was antagonized by the increase in extracellular concentration of CaCl2. The inhibitory effect of diltiazem on the insulin secretion was also counteracted by dibutyryl-3',5'-cyclic AMP or by theophylline. Among calcium-antagonists tested, nifedipine produced the most powerful inhibitory action on the insulin secretion, while the effect of verapamil was similar to or somewhat stronger than that of diltiazem. It was suggested that diltiazem may reduce the intracellular concentration of free calcium ion, thus causing an inhibitory effect on the glucose-induced insulin secretion by the isolated islets of Langerhans.