The trajectory of the sympathetic nerve fibers to the rat cochlea as revealed by anterograde and retrograde WGA-HRP tracing

Wheat germ agglutinin-horseradish peroxidase conjugate was injected in the unilateral superior cervical ganglion (SCG), and the projection pathways of postganglionic sympathetic nerve fibers innervating the cochlea were traced in the rat. The labeled axons advanced along the internal carotid artery (ICA), and a few advanced caudally in the major petrosal nerve (MPN) and entered the facial nerve, while the majority ran rostral to the pterygopalatine ganglion at the point where they crossed the MPN in the carotid canal. The rest of the labeled fibers remained on the surface of the ICA and advanced to the cranial cavity. Most of the labeled fibers along the facial nerve joined the cochlear nerve and finally reached the osseous spiral lamina through the spiral ganglion. Some of the labeled fibers ran along the anterior inferior cerebellar artery from the basilar artery which was previously thought to have been the only pathway. We could not find any labeled fiber on the modiolar artery from anterior inferior cerebellar artery in the cochlea. These observations are consistent with our hypothesis that the sympathetic fibers innervating the neural tissues or related structures follow nerve fibers and meninges as matrices of projection pathways rather than arteries.     

Anticonvulsant effect of liposome-entrapped superoxide dismutase in amygdaloid-kindled rats.

Amygdaloid-kindled rats received intravenous human copper-zinc superoxide dismutase (CuZn-SOD) either in free form or entrapped within liposomes (SOD-L), at 5, 10 or 20 mg/kg. The animals were stimulated at the generalized seizure-triggering threshold 5 min, 2 h and then every 24 h after the drug was given, until 5 consecutive stage 5 seizures were induced. Free CuZn-SOD had little or no effect. However, SOD-L, particularly at 10 mg/kg, had a prolonged anticonvulsant effect, although there was great individual variation in the onset and duration of seizure suppression. This effect of SOD-L may be due to the ability of liposomes to act as a depot for the sustained release of drugs.     

Correlation between epidermal growth factor receptor concentration and the growth of human gastric cancer xenografts in nude mice.

Seven human gastric cancer xenografts with different concentrations of EGF receptor were established in nude mice. The expression of EGF receptor in the tumors was demonstrated by Western blotting with anti-EGF receptor antibody, binding assay with 125I-EGF and immunohistochemistry with anti-EGF receptor antibody. Western blotting revealed EGF receptor doublet bands at molecular masses of 150 KDa and 170 KDa in all of the samples. The concentration of 125I-EGF binding activity in the tumors ranged from 36.0 to 11,000 fmol/mg protein, with a mean of 345 fmol/mg protein. EGF receptor was also demonstrated immunohistochemically on the apical border of the glands and the cell membrane of the tumor cells. There seemed to be a close correlation between the concentration of 125I-EGF binding activity and the doubling time of these tumors in nude mice (gamma = -0.68). However, no definite correlation was observed between EGF ligand binding and histological features of intestinal type or diffuse type. The expression of EGF receptor appears to facilitate the growth of human gastric cancer xenografts in nude mice.     

Relationship between the number of steps taken and body mass index for male workers in the metropolitan area]

The present study examined the relationship between number of steps and body mass index (BMI) among male workers in the metropolitan area. The number of subjects were 310 (aged 30-59) and they were studied for seven consecutive days. The number of steps was measured by a pedometer. Energy expenditure was assessed by the activity record method. Energy intake was assessed by a food frequency questionnaire. Height and body weight were examined by a self-administered questionnaire. BMI of 81 subjects (26.1%) was greater than 25 kg/m2. The number of steps was 10,682 +/- 4,365 on working days, and 7,135 +/- 4,536 on holidays. Average energy expenditure in seven days was 2,259 +/- 378 kcal/d. The physical activity level (PAL) was 1.5 +/- 0.1. There was a significant correlation between BMI and the number of steps in a working day (r=-0.188, p<0.01). In addition, there were significant correlations between PAL and daily steps on working days (r=0.301, p<0.001), and on holidays (r=0.296, p<0.001). Subjects were divided into four groups according to the median number of steps on working days and energy intake (I; > or =9,894 steps, <1,901 kcal, II; > or =9,894 steps, > or =1,901 kcal, III; <9,894 steps, <1,901 kcal, IV; <9,894 steps, > or =1,901 kcal). BMI of Group IV (24.7 kg/m2) was significantly higher than that of the other Groups. Group III had the highest proportion of subjects (15.7%) with lifestyle related diseases.     

Relationship between the thromboxane A2 receptor gene and susceptibility to cerebral infarction.

The risk of cerebral infarction (CI) in an individual is dependent on the interplay between genetic risk factors and environmental influences. Binding of thromboxane A2 (TXA2) to its receptor (TP) modulates thrombosis/hemostasis and plays a significant role in the pathogenesis of CI. The aim of the present study was to investigate the relationship between human TP gene single nucleotide polymorphisms (SNPs) and haplotypes and CI in a Japanese population. A genetic association study was performed in 194 CI patients and 365 non-CI subjects by specifically characterizing 6 SNPs in the human TP gene (rs2271875, rs768963, rs2238634, rs11085026, rs4523 and rs4806942). Analysis demonstrated that there were significant differences in the overall distribution of genotypes and dominant or recessive models of rs2271875 and rs768963 between the CI and the non-CI groups. Multiple logistic regression analysis revealed that the C allele of rs768963 was significantly associated with CI (p = 0.029), even after adjusting for confounding factors (odds ratio: 2.41). Further, the C-T-C haplotype of rs768963-rs2238634-rs4806942 was significantly more frequent in the CI group (23.0%) than in the non-CI group (17.7%). These results suggest that specific SNPs and haplotypes may have utility as genetic markers for the risk of CI and that TP or a neighboring gene is associated with the increased susceptibility to CI.     

Enhancement of the intrinsic defecation reflex by mosapride, a 5-HT4 agonist, in chronically lumbosacral denervated guinea pigs.

The defecation reflex is composed of rectal distension-evoked rectal (R-R) reflex contractions and synchronous internal anal sphincter (R-IAS) reflex relaxations in guinea pigs. These R-R and R-IAS reflexes are controlled via extrinsic sacral excitatory nerve pathway (pelvic nerves), lumbar inhibitory nerve pathways (colonic nerves) and by intrinsic cholinergic excitatory and nitrergic inhibitory nerve pathways. The effect of mosapride (a prokinetic benzamide) on the intrinsic reflexes, mediated via enteric 5-HT(4) receptors, was evaluated by measuring the mechanical activity of the rectum and IAS in anesthetized guinea pigs using an intrinsic R-R and R-IAS reflex model resulting from chronic (two to nine days) lumbosacral denervation (PITH). In this model, the myenteric plexus remains undamaged and the distribution of myenteric and intramuscular interstitial cells of Cajal is unchanged. Although R-R and R-IAS reflex patterns markedly changed, the reflex indices (reflex pressure or force curve-time integral) of both the R-R contractions and the synchronous R-IAS relaxations were unchanged. The frequency of the spontaneous R and IAS motility was also unchanged. Mosapride (0.1-1.0 mg/kg) dose-dependently increased both intrinsic R-R (maximum: 1.82) and R-IAS reflex indices (maximum: 2.76) from that of the control (1.0) 6-9 days following chronic PITH. The dose-response curve was similar to that in the intact guinea pig, and had shifted to the left from that in the guinea pig after acute PITH. A specific 5-HT(4) receptor antagonist, GR 113808 (1.0 mg/kg), decreased both reflex indices by approximately 50% and antagonized the effect of mosapride 1.0 mg/kg. This was quite different from the result in the intact guinea pig where GR 113808 (1.0 mg/kg) did not affect either of the reflex indices. The present results indicate that mosapride enhanced the intrinsic R-R and R-IAS reflexes and functionally compensated for the deprivation of extrinsic innervation. The actions of mosapride were mediated through endogenously active, intrinsic 5-HT(4) receptors which may be post-synaptically located in the myenteric plexus of the anorectum.     

Dental management of a patient with takotsubo cardiomyopathy: a case report.

Takotsubo cardiomyopathy (TCM) is a relatively new concept in cardiovascular disease. The clinical symptoms of TCM are similar to those of a myocardial infarction, but both the mechanism and the management of TCM are different from those of myocardial infarction. The cause of TCM is unclear, but it is suggested to occur in conjunction with excessive circulating catecholamines due to stress. Thus, control of the stress reaction and restriction of catecholamine levels are considered important for prevent of TCM onset. We report the dental management of a patient with intellectual disability who had anamnesis of TCM and cardiopulmonary arrest under restraint during a previous dental appointment in another dental clinic. We used intravenous sedation with both midazolam and propofol, by which the excessive hormonal reaction that caused TCM onset and cardiopulmonary arrest was controlled, for dental treatment in our facility. All planned dental treatment was then performed without any problems.     

Role of leukotrienes in airway hyperresponsiveness in guinea-pigs.

1. Repeated aerosolization of leukotriene C4 (LTC4) to guinea-pigs produced leftward shift in their pulmonary resistance (RL) dose-response curves to inhaled acetylcholine (ACh) without increasing the maximum responses. 2. Repeated LTC4 aerosolization did not increase airway eosinophils. 3. The 5-lipoxygenase-activating protein (FLAP) inhibitor, MK-886, prevented the leftward shift in RL dose-response curves to ACh following repeated antigen challenge in guinea-pigs. 4. MK-886 did not inhibit the increased maximal RL produced by repeated antigen challenge, nor inhibit the airway eosinophilia induced by repeated antigen challenge. 5. Our findings suggest that leukotrienes may account for the leftward shift in pulmonary resistance responses caused by antigen but do not cause the airway eosinophilia nor enhanced maximum broncho-constrictor response to antigen.