Possible regulatory mechanism of DHA-induced anti-stress reaction in rats

To determine whether docosahexaenoic acid (DHA) affects stress responses in rats, we investigated its influence on several behavioral tests. Female rats were fed a diet deficient in (n-3) fatty acid from mating through pregnancy and lactation. Male pups fed the same diet as their dams were used for experiments. The effects of dietary (n-3) fatty acid deficiency and supplementation with DHA on psychological stress and conditioned-fear stress were investigated. The effect of DHA on psychological stress was examined by an elevated plus-maze test. The (n-3) deficient rats spent significantly (P<0.05) less time in the open arms; after 1 week of supplementation with DHA, they showed a significant (P<0.01) improvement. We then examined the paired effects of DHA and CRH on stress manifestations by an intracerebroventricular (i.c.v.) cannulation and behavior testing. An i.c.v. infusion of CRH (500 pmol) under resting conditions was shown to have stress-inducing effects on behavior such as decreases of rearing, smelling and feeding, and increases of face washing; the supplementation of DHA significantly improved these distress behaviors. Finally, conditioned fear was induced by 40 min forced exposure to a cage in which the rat had experienced footshocks (30 x 1 mA x 1 s) 1 day before. Freezing behavior was dramatically suppressed by the supplementation of DHA, even 48 h after the conditioning treatment. Furthermore, the effect of DHA on the conditioned fear stress response is maintained over a long-term period. The i.c.v. pre-treatment of rats with bicuculline, a GABA(A) receptor antagonist, enhanced the conditioned-fear-induced freezing time in a dose-dependent fashion in the (n-3) fatty acid deficient animals. Significantly, the DHA supplemented group was not affected by the pre-treatment with bicuculline. From these findings, it is concluded that the involvement of DHA in stress responses may act via a GABA(A) receptor-mediated mechanism.     

Vocal fold motion impairment in patients with multiple system atrophy: evaluation of its relationship with swallowing function

BACKGROUND: Vocal fold motion impairment (VFMI), especially vocal fold abductor paralysis, is frequently seen in multiple system atrophy (MSA). Since the regulation system of laryngeal function is closely related to swallowing function, swallowing function is considered to be more involved in MSA patients with VFMI than in patients that do not have VFMI. However, the relationship between dysphagia and VFMI in MSA patients has not been systematically explored. OBJECTIVE: To elucidate the relationship between VFMI and dysphagia in MSA. METHODS: We evaluated swallowing function of 36 MSA patients with and without VFMI, by videofluoroscopy, and investigated the relationship between VFMI and pharyngeal swallowing function. RESULTS: VFMI was found in 17 patients (47.2%). Patients with VFMI had advanced severity of the disease. Although there was a tendency for bolus stasis at the pyriform sinus and the upper oesophageal sphincter opening to be more involved in patients with VFMI, statistical analysis did not show significant differences in swallowing function of MSA patients between with and without VFMI. In contrast, patients who underwent a tracheotomy ultimately required tube feeding or a laryngectomy. CONCLUSIONS: Appearance of VFMI is a sign of disease progression but does not necessary mean patients should change their way of taking nutrition. However, MSA patients who need a tracheotomy might have advanced to a high-risk group for dysphagia. Appropriate evaluation and treatment for VFMI and dysphagia are required to maintain patients' quality of life in MSA.     

Physiological remineralization of artificially demineralized dentin beneath glass ionomer cements with and without bacterial contamination in vivo

This study evaluated the physiological remineralization of artificially demineralized dentin beneath glass ionomer cements with and without bacterial contamination. The artificially demineralized dentin was produced on 84 monkey teeth using a decalcifying solution. Half the samples were left open to the oral cavity for one week, then, all cavities were restored with two glass-ionomer cements: Fuji IX or Fuji II LC improved (n = 7). The nanohardness of the artificially demineralized dentin at 3, 90 and 360 days was measured using a nanoindentation tester (ENT-1100, Elionix) and compared statistically by two-way ANOVA and Fisher's PLSD test (p < 0.05). Each mineral (Ca, Mg, P, F) within the demineralized dentin was also analyzed using Electron Probe Microanalysis. For the samples, the mean nanohardness of the three-day samples was significantly lower than the 360-day samples (p < 0.05). Although there was no significant difference in the mean nanohardness within all the bacterially-contaminated groups through the experimental periods (p > 0.05), the mean nanohardness of the bacterial-contaminated samples were significantly lower than the non-bacteria-contaminated samples (p < 0.05). From the EPMA results, fluoride release from both cements to the bottom of the artificially demineralized dentin was detected within three days. Although Ca density was sparse within this demineralized dentin lesion, for the Fuji IX sample, a high Mg density within this lesion was detected at 360 days.     

Upper extremity deep vein thrombosis after radial artery harvesting

A 47-year-old diabetic man with unstable angina underwent coronary bypass surgery using bilateral radial arteries and left internal thoracic artery. After surgery, the patient suffered from severe right arm pain and swelling without any bleeding. The postoperative immediate digital subtraction angiogram detected thrombotic occlusion of the right axillary vein. We report here a rare case of deep vein thombosis related to radial artery harvesting.     

Impact of an aggressive surgical approach on surgical outcome in type A aortic dissection

BACKGROUND: To evaluate the impact of an aggressive surgical approach on early and late outcome in type A aortic dissection. METHODS: From 1983 to 2001, 240 patients underwent operation for acute (n = 138) and chronic (n = 102) type A aortic dissection. The extent of distal aortic resection included the ascending aorta in 39 (16%) patients, hemiarch (HAR) in 47 (20%), and total arch (TAR) in 154 (64%), including 19 patients who also had their descending aorta replaced (DAR). RESULTS: The in-hospital mortality did not differ between TAR with or without DAR and other more conservative techniques (12.3% versus 16.3%). Actuarial survival at 10 years including in-hospital mortality was 72.4% +/- 3.3% and freedom from reoperation was 77.2% +/- 3.6% for all patients: neither was influenced by the extent of distal aortic resection or acuity of aortic dissection. Multivariate analysis revealed younger age and failure to resect the intimal tear to be independent determinants for late reoperation. However, in contrast to 22 patients who had more conservative operations, none of the patients with TAR required reoperation on the aortic arch through a sternotomy incision. CONCLUSIONS: An aggressive surgical approach did not adversely influence early and late survival following type A aortic dissection; it reduced the necessity of late reoperation and facilitated distal aortic reoperation.     

Distraction osteogenesis enhanced by osteoblastlike cells and collagen gel

Femoral distraction was done in rats to determine whether the injection of osteoblastlike cells with collagen gel into the distracted callus was useful for new bone formation. The cells were obtained from the femoral marrow of Sprague-Dawley rats and cultured for approximately 3 weeks. These rats were divided into four groups. The rats in Group A received injections of physiologic saline, those in Group B received injections of collagen gel, those in Group C received injections of cells, and those in Group D received injections containing a mixture of cells and collagen gel. The distracted areas were harvested and evaluated by histologic analysis, radiography, three-point bending testing, and the weight of femoral ash. Histologic evaluation did not show an immunoreaction between the donor and recipient. Radiographs showed that Group D had the most callus, and the fracture strength in this group as determined by the three-point bending test was higher than in Group A at 2, 4, and 6 weeks after elongation was completed. Group D showed a significant difference in the ash weight of the distracted femurs at 2 weeks. The current study showed that osteoblastlike cells with collagen gel promoted new bone formation in the distracted gap, and shortened the consolidation period.     

Study of image findings in rapid eye movement sleep behavioural disorder

To elucidate the cause of idiopathic rapid eye movement (REM) sleep behavior disorder (RBD), magnetic resonance imaging and single-photon emission computed tomography of the brain were conducted on 20 patients with RBD. Blood flow in the upper portion of both sides of the frontal lobe and pons was significantly lower in patients with RBD than in the normal elderly group. Among the patients with RBD, decreased blood flow in the frontal lobe showed no correlation with the extent of frontal lobe atrophy. Decreased blood flow in the upper portion of the frontal lobe and pons might be associated with the pathogenesis of idiopathic RBD.     

Aquaporin-2 regulation by vasopressin in the rat inner ear

Our previous studies have suggested a close relationship between vasopressin and endolymphatic hydrops, or the increased volume of endolymph in the inner ear. Endolymphatic hydrops is also thought to occur in Ménière's disease patients. In the kidney collecting duct, vasopressin induces the expression of aquaporin-2 (AQP2), resulting in increased water reabsorption. We explored the possibility, using a quantitative PCR method, that vasopressin regulates the expression of AQP2 mRNA in the rat inner ear, as it does in the kidney. The levels of AQP2 mRNA in the cochlea and endolymphatic sac were significantly higher in rats treated with vasopressin than the levels in control animals. We speculate that over-expression of AQP2 may be involved in the formation of endolymphatic hydrops.