Effects of Surgery and Antiplatelet Therapy in Ten-Year Follow-Up from the Registry Study of Research Committee on Moyamoya Disease in Japan

BACKGROUND

Despite the common practice of surgery and antiplatelet therapy for the prevention of recurrent stroke in patients with moyamoya disease, the benefit of these treatments is controversial. We analyzed the stroke recurrence rate in the Registry Study of Research Committee on Moyamoya Disease in Japan funded by the Health, Labor and Welfare Ministry of Japan.

METHODS

An annual follow-up study of the registered cases was continued for 10 years. The rate of recurrent stroke, including cerebral infarction and hemorrhage but not transient ischemic attack and seizure, was evaluated with Kaplan-Meier analysis.

RESULTS

The proportion of childhood-onset cases decreased in recently registered cases (within 10 years, n = 541) compared to remote cases (> 10 years, n = 735). Among types at disease onset in adult-onset cases, intracerebral hemorrhage decreased recently. In recent cases, the rate of subsequent cerebral hemorrhage was much higher in the hemorrhagic group (10.9 ± 3.3%/5 years) than in the ischemic group (2.0 ± .9%/5 years). The recurrence rate of cerebral infarction was lower in the surgery group (1.8 ± .9%/5 years) than in the nonsurgery group (3.8 ± 2.2%/5 years). In the adult-onset ischemic group, the proportion of surgically treated patients increased and their recurrence rate was lower than that of nonsurgery patients. In the ischemic group, the rate of cerebral infarction was not significantly different between the antiplatelet subgroup and the non-antiplatelet subgroup, whereas the rate of cerebral hemorrhage was higher in the non-antiplatelet subgroup than in the antiplatelet subgroup.

CONCLUSIONS

Our results suggest revascularization surgery may suppress recurrent ischemic attacks in patients with moyamoya disease.

Human induced pluripotent stem cells improve recovery in stroke-injured aged rats

PURPOSE

Induced pluripotent stem cells (iPSCs) improve behavior and form neurons after implantation into the stroke-injured adult rodent brain. How the aged brain responds to grafted iPSCs is unknown. We determined survival and differentiation of grafted human fibroblast-derived iPSCs and their ability to improve recovery in aged rats after stroke.

METHODS

Twenty-four months old rats were subjected to 30 min distal middle cerebral artery occlusion causing neocortical damage. After 48 h, animals were transplanted intracortically with human iPSC-derived long-term neuroepithelial-like stem (hiPSC-lt-NES) cells. Controls were subjected to stroke and were vehicle-injected.

RESULTS

Cell-grafted animals performed better than vehicle-injected recipients in cylinder test at 4 and 7 weeks. At 8 weeks, cell proliferation was low (0.7 %) and number of hiPSC-lt-NES cells corresponded to 49.2% of that of implanted cells. Transplanted cells expressed markers of neuroblasts and mature and GABAergic neurons. Cell-grafted rats exhibited less activated microglia/macrophages in injured cortex and neuronal loss was mitigated.

CONCLUSIONS

Our study provides the first evidence that grafted human iPSCs survive, differentiate to neurons and ameliorate functional deficits in stroke-injured aged brain.

The Composition Pulling Effect in MOVPE Grown InGaN on GaN and AlGaN and its TEM Characterization

InGaN films have been grown on GaN and AlGaN epitaxial layers by metalorganic vapor phase epitaxy. The “composition pulling effect” during the initial InGaN growth stages has been studied as a function of the lattice mismatch between the InGaN and the underlying epitaxial layer. The crystalline quality of the InGaN is good near the InGaN/GaN interface and the composition is close to that of GaN. However, with increasing InGaN film thickness, the crystal quality deteriorates and the indium mole fraction increases. The composition pulling effect becomes stronger with increasing lattice mismatch. It is suggested that indium atoms are excluded from the InGaN lattice during the early growth stages to reduce the deformation energy from the lattice mismatch. TEM observations of the InGaN/GaN structure reveal that the degradation of the crystalline quality of InGaN films grown on GaN is caused by pit formation which arises from edge dislocations propagating through the InGaN film from the underlying GaN.

Marked improvement of insulin sensitivity without enhancement of GLP-1 and insulin secretion after Roux-en-Y gastric bypass surgery in a mildly obese patient with diabetes

Roux-en-Y gastric bypass is an option of treatment for morbidly obese patients with diabetes. However, the value of the operation in mildly obese patients is not established. We report the first prospective systematic endocrine and metabolic analysis in a mildly obese patient who underwent a Roux-en-Y gastric bypass. In a 49-year-old man with BMI 32.6 kg/m(2) having type 2 diabetes, intramucosal gastric cancer was treated by partial gastrectomy with Roux-en-Y gastric bypass. Pre-operatively, he received 53 U/day insulin and the HbA1c value was 63 mmol/mol: meal tolerance test showed diabetic hyperglycemia and low insulin sensitivity with attenuated insulin secretion and normal glucagon-like peptide 1(7-36) secretion. After the operation, hypoglycemic agent was stopped. Body weight reduced from 84.0 to 77.0 kg within 2 weeks and increased thereafter to 79.4 kg at 4 months later, when the degree of hyperglycemia was unchanged as indexed by a HbA1c value of 62 mmol/mol. Upon repeated meal tolerance test, no increase of glucagon-like peptide 1 and insulin secretion, but significantly improved hepatic and peripheral insulin sensitivity were found, compared to the preoperative meal tolerance test. Marked dissociation of endocrine and metabolic effects of Roux-en-Y gastric bypass, that is, absence of increased glucagon-like peptide 1/insulin secretion with improvement of insulin sensitivity, was found in a mildly obese patient with type 2 diabetes.

[Stem cell therapy for ischemic stroke using iPS cells]

Recently, several stem cell-based approaches have been considered as a novel treatment for stroke, such as delivery of non neural stem cells, stimulation of endogenous neural stem cells, and transplantation of neural stem cells. Among them, transplantation of neural stem cells is thought to have an advantage for functional recovery through neuronal replacement rather than other mechanisms. We demonstrated that human iPS cells derived neural stem cells form functional neurons and improve recovery after grafting in stroke-damaged rodents without tumor formation. Here we discuss about the potential and clinical application of iPS cells for stroke therapy.

Grafted human neural stem cells enhance several steps of endogenous neurogenesis and improve behavioral recovery after middle cerebral artery occlusion in rats

Neural stem/progenitor cells (NSPCs) in subventricular zone (SVZ) produce new striatal neurons during several months after stroke, which may contribute to recovery. Intracerebral grafts of NSPCs can exert beneficial effects after stroke through neuronal replacement, trophic actions, neuroprotection, and modulation of inflammation. Here we have explored whether human fetal striatum-derived NSPC-grafts influence striatal neurogenesis and promote recovery in stroke-damaged brain. T cell-deficient rats were subjected to 1h middle cerebral artery occlusion (MCAO). Human fetal NSPCs or vehicle were implanted into ipsilateral striatum 48 h after MCAO, animals were assessed behaviorally, and perfused at 6 or 14 weeks. Grafted human NSPCs survived in all rats, and a subpopulation had differentiated to neuroblasts or mature neurons at 6 and 14 weeks. Numbers of proliferating cells in SVZ and new migrating neuroblasts and mature neurons were higher, and numbers of activated microglia/macrophages were lower in the ischemic striatum of NSPC-grafted compared to vehicle-injected group both at 6 and 14 weeks. A fraction of grafted NSPCs projected axons from striatum to globus pallidus. The NSPC-grafted rats showed improved functional recovery in stepping and cylinder tests from 6 and 12 weeks, respectively. Our data show, for the first time, that intrastriatal implants of human fetal NSPCs exert a long-term enhancement of several steps of striatal neurogensis after stroke. The grafts also suppress striatal inflammation and ameliorate neurological deficits. Our findings support the idea that combination of NSPC transplantation and stimulation of neurogenesis from endogenous NSPCs may become a valuable strategy for functional restoration after stroke.

Human-induced pluripotent stem cells form functional neurons and improve recovery after grafting in stroke-damaged brain

Reprogramming of adult human somatic cells to induced pluripotent stem cells (iPSCs) is a novel approach to produce patient-specific cells for autologous transplantation. Whether such cells survive long-term, differentiate to functional neurons, and induce recovery in the stroke-injured brain are unclear. We have transplanted long-term self-renewing neuroepithelial-like stem cells, generated from adult human fibroblast-derived iPSCs, into the stroke-damaged mouse and rat striatum or cortex. Recovery of forepaw movements was observed already at 1 week after transplantation. Improvement was most likely not due to neuronal replacement but was associated with increased vascular endothelial growth factor levels, probably enhancing endogenous plasticity. Transplanted cells stopped proliferating, could survive without forming tumors for at least 4 months, and differentiated to morphologically mature neurons of different subtypes. Neurons in intrastriatal grafts sent axonal projections to the globus pallidus. Grafted cells exhibited electrophysiological properties of mature neurons and received synaptic input from host neurons. Our study provides the first evidence that transplantation of human iPSC-derived cells is a safe and efficient approach to promote recovery after stroke and can be used to supply the injured brain with new neurons for replacement.

Influence of Adrenal Subclinical Hypercortisolism on Hypertension in Patients with Adrenal Incidentaloma

The purpose of our study was to clarify whether subtle cortisol-producing tumors, such as not only subclinical Cushing’s syndrome (SubCS) but also subclinical hypercortisolism (SH), influence the prevalence of hypertension, since numerous basic research studies have noted that glucocorticoid excess influences blood pressure.

80 patients with adrenocortical adenomas (39 women and 41 men; mean age 62.1 years) were enrolled. SubCS was diagnosed using a diagnostic criteria, and SH was diagnosed as the presence of a serum cortisol level greater than 50 nmol/L following 1-mg dexamethasone suppression test (DST).

SubCS, SH, or non-functioning adrenocortical adenoma (NF) was diagnosed in 14, 13, or 53 patients, respectively. The prevalence of hypertension differed significantly among the diagnoses (SubCS, 78.6%; SH, 84.6%; NF, 39.6%; P=0.002), whereas no differences in other clinical characteristics such as age, sex, or waist girth were observed. The patients with SH had an 11.7-fold increased risk (95% confidence interval: 1.9–72.7, P=0.009) and those with SubCS had a 9.5-fold increased risk (95% confidence interval: 1.9–48.3, P=0.007) for hypertension compared to those with NF using a multivariate analysis.

We demonstrated that subtle cortisol-producing tumors, such as SH as well as SubCS, were an independent risk factor for hypertension. The cut-off value of the 1-mg DST would be appropriate to predict the development of hypertension.

Aberrant activation of ALK kinase by a novel truncated form ALK protein in neuroblastoma

Anaplastic lymphoma kinase (ALK) was originally identified from a rare subtype of non-Hodgkin's lymphomas carrying t(2;5)(p23;q35) translocation, where ALK was constitutively activated as a result of a fusion with nucleophosmin (NPM). Aberrant ALK fusion proteins were also generated in inflammatory fibrosarcoma and a subset of non-small-cell lung cancers, and these proteins are implicated in their pathogenesis. Recently, ALK has been demonstrated to be constitutively activated by gene mutations and/or amplifications in sporadic as well as familial cases of neuroblastoma. Here we describe another mechanism of aberrant ALK activation observed in a neuroblastoma-derived cell line (NB-1), in which a short-form ALK protein (ALK(del2-3)) having a truncated extracellular domain is overexpressed because of amplification of an abnormal ALK gene that lacks exons 2 and 3. ALK(del2-3) was autophosphorylated in NB-1 cells as well as in ALK(del2-3)-transduced cells and exhibited enhanced in vitro kinase activity compared with the wild-type kinase. ALK(del2-3)-transduced NIH3T3 cells exhibited increased colony-forming capacity in soft agar and tumorigenicity in nude mice. RNAi-mediated ALK knockdown resulted in the growth suppression of ALK(del2-3)-expressing cells, arguing for the oncogenic role of this mutant. Our findings provide a novel insight into the mechanism of deregulation of the ALK kinase and its roles in neuroblastoma pathogenesis.

Manifestation of preferred chewing side for hard food on TMJ disc displacement side

The purpose of this study was to reveal the relationship between chewing-side preference and anterior disc displacement (ADD) of the TMJ. Thirty-two healthy subjects with ages ranging from 26 to 34 years were selected from volunteer students at the Okayama University Dental School. Subjects were asked to chew freely with two kinds of test foods, beef jerky (hard food) and chiffon cake (soft food), thus expecting different amounts of mechanical loading on the TMJ. One, 4, and 7 s after starting the mastication, subjects were asked to open their mouth momentarily to have a digital image of their mouth taken. The bolus placement area was measured by processing the digital images, calculated as the number of pixel of bolus area. Area asymmetry index was used for the determination of preferred chewing side (PCS). Oblique sagittal MRI scanning in the closed mouth position was taken to evaluate the articular disc position. In asymptomatic subjects with ADD, a significant predominance of the PCS on the ipsilateral side of ADD was observed during the mastication of hard food. On the contrary, no correlation was found between unilateral ADD and PCS for the soft food. From the results of this study, it is suggested that ADD is the associating factor of PCS for hard food. Therefore, it would be necessary to break down the concept of PCS into at least two categories, one for hard food and one for soft food, considering the mechanical loading on the TMJ.