Alleviation of Abeta-induced cognitive impairment by ultrasound-mediated gene transfer of HGF in a mouse model

A new therapeutic approach to treat Alzheimer's disease (AD) is needed, and the use of growth factors is considered to be a candidate. Hepatocyte growth factor (HGF) is a unique multifunctional growth factor, which has the potential effect to exert neurotrophic action and induce angiogenesis. In this study, we examined the effects of overexpression of human HGF plasmid DNA using ultrasound-mediated gene transfer into the brain in an Abeta-infused cognitive dysfunction mouse model. We demonstrated that HGF gene transfer significantly alleviated Abeta-induced cognitive impairment in mice in behavioral tests. These beneficial effects of HGF might be due to (1) significant recovery of the vessel density in the dentate gyrus of the hippocampus, (2) upregulation of BDNF, (3) a significant decrease in oxidative stress and (4) synaptic enhancement. A pharmacological approach including gene therapy to increase the HGF level in combination with anti-Abeta therapy might be a new therapeutic option for the treatment of AD.     

Correction of a genetic defect in multipotent germline stem cells using a human artificial chromosome

Human artificial chromosomes (HACs) have several advantages as gene therapy vectors, including stable episomal maintenance that avoids insertional mutations and the ability to carry large gene inserts including regulatory elements. Multipotent germline stem (mGS) cells have a great potential for gene therapy because they can be generated from an individual's testes, and when reintroduced can contribute to the specialized function of any tissue. As a proof of concept, we herein report the functional restoration of a genetic deficiency in mouse p53-/- mGS cells, using a HAC with a genomic human p53 gene introduced via microcell-mediated chromosome transfer. The p53 phenotypes of gene regulation and radiation sensitivity were complemented by introducing the p53-HAC and the cells differentiated into several different tissue types in vivo and in vitro. Therefore, the combination of using mGS cells with HACs provides a new tool for gene and cell therapies. The next step is to demonstrate functional restoration using animal models for future gene therapy.     

Importance of fixation angle in posterior instrumented occipitocervical fusion

Occipitocervical fusion with the head in a functionally neutral position is critically important. Various methods have been proposed for measuring the angle of the craniovertebral junction based on lateral radiography. We describe a simple and reliable measurement of fixation angle during occipitocervical fusion using the line parallel to the bony palate and the posterior longitudinal line of the C2 vertebra. The normal range of the angle of the craniovertebral junction was measured in 30 normal healthy volunteers, 15 males and 15 females aged from 17 to 77 years (mean 45.1 years), without symptoms of neck pain or limitations of neck movement. The angle ranged from 85 to 118 degrees. The mean angle was 97.1 degrees in males and 102.6 degrees in females, with overall mean +/- standard deviation of 99.9 +/- 8.1 degrees. Careful adjustment of the angle of the craniovertebral junction can help to avoid postoperative complications such as dysphagia, dyspnea, and subaxial subluxation.     

Synovial chondromatosis of the temporomandibular joint with intracranial extension

A 52-year-old man presented with an extremely rare case of synovial chondromatosis in the temporomandibular joint (TMJ) with extension into the middle cranial fossa manifesting as swelling and exacerbation of pain. He had a long history of right TMJ disorders. Computed tomography and magnetic resonance imaging showed a mass in the right TMJ with extension into the intracranial part through the destroyed temporal skull base. The preoperative diagnosis was chondrosarcoma or osteosarcoma. The patient underwent surgery via combined trans-zygomatic temporal skull base and pre-auricular approaches and the mass was totally removed. Histological examination found an enormous number of closely packed loose bodies of various sizes, consisting of hyaline chondrocytes. The histological diagnosis was synovial chondromatosis. This rare lesion is difficult to discriminate from chondrosarcoma, so total removal is essential for correct diagnosis and cure.     

Tracheal resection and reconstruction for tracheal stenosis

Five patients underwent surgery for tracheal stenosis. The cause of stenosis was congenital tracheal stenosis in 1 case, post-intubation tracheal stenosis in 1 case, and tracheal stenosis due to thyroid cancer invasion in 3 cases. All 5 patients required circumferential tracheal resection and end-to-end anastomosis using 4-0 or 5-0 absorbable sutures. The number of tracheal rings removed ranged from 3 to 6. There was no anastomotic complication. Technical points of this procedure were summarized as follows : 1) the circumferential dissection of the trachea should be made only at the level of the lesion that is to be excised, 2) preserve at least one side of recurrent nerve, 3) the traction sutures facilitate tensionless knot of the sutures, 4) prevention of excessive extension of the neck in the immediate postoperative period.     

Attenuation of nitric oxide- and prostaglandin-independent vasodilation of retinal arterioles induced by acetylcholine in streptozotocin-treated rats

Diabetes alters retinal hemodynamics, but little is known about the impact of diabetes on the role of endothelium-derived hyperpolarizing factor (EDHF) in the regulation of retinal circulation. Therefore, we examined how diabetes affects the nitric oxide- and prostaglandin-independent vasodilation of retinal arterioles induced by acetylcholine. Male Wistar rats were treated with streptozotocin (80 mg/kg, i.p.) and experiments were performed 6-8 weeks later. Under artificial ventilation, rats were treated with tetrodotoxin (100 microg/kg, i.v.) to eliminate any nerve activity and prevent movement of the eye. Methoxamine was used to maintain adequate systemic circulation. Fundus images were captured by a digital camera that was equipped with a special objective lens. The vasodilator responses of retinal arterioles were assessed by measuring changes in diameters of the vessels. In streptozotocin-induced diabetic rats and the age-matched controls, acetylcholine increased diameters of retinal arterioles in a dose-dependent manner. The vasodilator responses to acetylcholine in diabetic rats were smaller than those in control rats. The nitric oxide- and prostaglandin-independent vasodilation of retinal arterioles observed under treatment with combination of N(G)-nitro-l-arginine methyl ester (30 mg/kg, i.v.) and indomethacin (5 mg/kg, i.v.) were also attenuated by diabetes. Diabetes did not alter the dilator responses of retinal arterioles to sodium nitroprusside and forskolin. These results suggest that diabetes impairs EDHF-mediated vasodilation of retinal arterioles induced by acetylcholine. The impaired EDHF-mediated vasodilation may contribute to alteration of retinal hemodynamics in diabetes.     

Advanced glycation end products (AGEs) and cardiovascular disease (CVD) in diabetes

Accelerated atherosclerosis and microvascular complications are perhaps the leading cause of coronary heart disease, blindness and renal failure, which could account for disabilities and high mortality rates in patients with diabetes. Several mechanisms including endothelial cell damage, platelet activation and aggregation, hypercoagulability, and impaired fibrinolysis are involved in the pathogenesis of thrombogenic diathesis in diabetes. However, the underlying molecular mechanism is not fully elucidated. A recent clinical study, the Diabetes Control and Complications Trial-Epidemiology of Diabetes Interventions and Complications (DCCT-EDIC) Research, has revealed that the reduction in the risk of progressive retinopathy and nephropathy resulting from intensive therapy in patients with type 1 diabetes persist for at least several years, despite increasing hyperglycemia. In addition, intensive therapy during the DCCT also reduced the risk of cardiovascular events by about 50 % in type 1 diabetic patients 11 years after the end of the trial. These clinical studies strongly suggest that so-called 'hyperglycemic memory' causes chronic abnormalities in diabetic vessels that are not easily reversed, even by subsequent, relatively good control of blood glucose. Among various biochemical pathways implicated in diabetic vascular complications, the process of formation and accumulation of advanced glycation end products (AGEs) and their mode of action are most compatible with the theory 'hyperglycemic memory'. In this review, we discuss the role of AGEs in thrombogenic abnormalities in diabetes, especially focusing on the deleterious effects of these macroproteins on endothelial cell function, platelet activation and aggregation, coagulation and fibrinolytic systems.     

Histological analysis of microbleed after surgical resection in a patient with moyamoya disease

A 65-year-old male with moyamoya disease underwent surgical resection of a microbleed simultaneously with revascularization surgery. Histological examination identified several fragile arteries surrounding the microbleed. Microbleeds detected by T2*-weighted magnetic resonance imaging are considered to be a general marker of vascular vulnerability in cerebral angiopathy with a tendency to bleeding. The microbleeds observed in patients with moyamoya disease probably originate in bleeding from the fragile arteries.     

Effects of resveratrol, a grape polyphenol, on catecholamine secretion and synthesis in cultured bovine adrenal medullary cells

We report the effects of resveratrol, a polyphenol found in the skins of red grapes, on catecholamine secretion and synthesis in cultured bovine adrenal medullary cells. Resveratrol suppressed catecholamine secretion and (22)Na(+) and (45)Ca(2+) influx induced by acetylcholine, an agonist of nicotinic acetylcholine receptors, in a concentration-dependent manner (IC(50)=20.4, 11.0, and 62.8 microM, respectively). Resveratrol also inhibited catecholamine secretion induced by veratridine, an activator of voltage-dependent Na(+) channels, and 56 mM K(+), an activator of voltage-dependent Ca(2+) channels, at concentrations similar to those for (45)Ca(2+) influx. Resveratrol directly inhibited the current evoked by acetylcholine in Xenopus oocytes expressing alpha3beta4 neuronal nicotinic acetylcholine receptors (IC(50)=25.9 microM). Furthermore, resveratrol (IC(50)=5.32 microM) attenuated (14)C-catecholamine synthesis induced by acetylcholine. The present findings suggest that resveratrol inhibits acetylcholine-induced catecholamine secretion and synthesis through suppressing ion influx in cultured bovine adrenal medullary cells.