Avalanches and criticality in self-organized nanoscale networks.

Current efforts to achieve neuromorphic computation are focused on highly organized architectures, such as integrated circuits and regular arrays of memristors, which lack the complex interconnectivity of the brain and so are unable to exhibit brain-like dynamics. New architectures are required, both to emulate the complexity of the brain and to achieve critical dynamics and consequent maximal computational performance. We show here that electrical signals from self-organized networks of nanoparticles exhibit brain-like spatiotemporal correlations and criticality when fabricated at a percolating phase transition. Specifically, the sizes and durations of avalanches of switching events are power law distributed, and the power law exponents satisfy rigorous criteria for criticality. These signals are therefore qualitatively and quantitatively similar to those measured in the cortex. Our self-organized networks provide a low-cost platform for computational approaches that rely on spatiotemporal correlations, such as reservoir computing, and are an important step toward creating neuromorphic device architectures.

Synaptic dynamics in complex self-assembled nanoparticle networks.

We report a detailed study of neuromorphic switching behaviour in inherently complex percolating networks of self-assembled metal nanoparticles. We show that variation of the strength and duration of the electric field applied to this network of synapse-like atomic switches allows us to control the switching dynamics. Switching is observed for voltages above a well-defined threshold, with higher voltages leading to increased switching rates. We demonstrate two behavioral archetypes and show how the switching dynamics change as a function of duration and amplitude of the voltage stimulus. We show that the state of each synapse can influence the activity of the other synapses, leading to complex switching dynamics. We further demonstrate the influence of the morphology of the network on the measured device properties, and the constraints imposed by the overall network conductance. The correlated switching dynamics, device stability over long periods, and the simplicity of the device fabrication provide an attractive pathway to practical implementation of on-chip neuromorphic computing.

Long-term prognosis of IgA nephropathy presenting with minimal or no proteinuria: A single center experience.

The long-term prognosis of patients with IgA nephropathy (IgAN) who present with preserved renal function and minimal proteinuria is not well described. We investigated the long-term outcomes of IgAN patients with an apparently benign presentation and evaluated prognostic factors for renal survival and clinical remission. We studied Japanese patients with biopsy-proven IgAN who had an estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m(2) and proteinuria <0.5 g/day at the time of renal biopsy. The renal biopsies were reviewed using the Oxford classification. Twenty patients met the inclusion criteria. At diagnosis, the median eGFR (interquartile range) was 76.8 (65.2-91.1) mL/min/1.73 m(2), and the median proteinuria level was 0.31 (0.16-0.39) g/day. Only one patient had an increase in serum creatinine of over 50% and no patient progressed to end-stage renal disease. The 15-year renal survival rate was 93.8%. Clinical remission was observed in 9 (45%) patients. Baseline proteinuria was the only factor significantly associated with the absence of clinical remission. The long-term prognosis of Japanese patients with IgAN who presents with minor urinary abnormalities and preserved renal function is excellent.

Theoretical Insights into the Impact of Ru Catalyst Anchors on the Efficiency of Photocatalytic CO2 Reduction on Ta2O5.

We present a computational study of the dynamical and electronic structure origins of the impact of anchoring groups, PO3H2, COOH, and OH, on the efficiency of photochemical CO2 reduction in Ru(di-X-bpy)(CO)2Cl2/Ta2O5 systems. Recent experimental studies indicate that the efficiency may not directly correlate with the driving force for electron transfer (ET) in these systems, prompting the need for further investigation of the role of anchor groups. Our analysis shows that there are at least two key roles of the anchor in determining the efficiency of CO2 reduction by the Ru complex. First, depending on local steric interactions, different tilting angles and their fluctuations may emerge for different anchors, affecting the magnitude of the donor-acceptor coupling. Second, depending on localization of acceptor states on the anchor, determined by the anchor's tendency to form conjugate subsystems, the yields of ET to the catalytic center may vary, directly affecting the photocatalytic efficiency. Finally, our calculations indicate that surface modeling with N-doping and many-body effects are needed to describe the ET process in the systems properly. N-doping imparts the Ta2O5 surface with a dipole moment, while Coulomb and exchange contributions to the electron-hole interaction can produce excitons that should be taken into account.

Usefulness of mini-tracheostomy and torque controlled insertion of applicator in fractionated endobronchial brachytherapy.

Endobronchial brachytherapy was developed as effective treatment of endobronchial cancer and fractionated schedule is applied to decrease late toxicity. However, repeated bronchofiberscopy is onerous to the patient and restricts the treatment schedule itself. We applied mini-tracheostomy for a ready access route, and a torque controlled technique for easy insertion of the endobronchial applicator. Eight patients with tracheobronchial cancer invasion were treated with endobronchial brachytherapy of 18-30 Gy/3-5 fractions/1.5-2.5 weeks (median 24 Gy/4 fractions/2 weeks) at reference points of 5 mm from the bronchial surface. The averaged individual irradiation and single session times were 4 min and 24 min, respectively. There were no procedure-related complications. These technical improvements may facilitate flexible fractionated dose prescriptions.

Brachytherapy technique for abdominal wall metastases of colorectal cancer: ultrasound-guided insertion of applicator needle and a skin preservation method.

PURPOSE: To report a technique of interstitial brachytherapy for the treatment of subcutaneous metastatic abdominal wall tumors. MATERIAL AND METHODS: We developed a brachytherapy technique consisting of ultrasound-guided insertion of applicator needles to avoid the organs at risk, such as intestines, and saline injection into the subcutaneous tissue between the tumor and the skin to decrease the skin dose. We encountered three patients with painful metastases from rectal carcinoma in the abdominal wall refractory to external radiotherapy. They were subjected to this brachytherapy with a single dose of 20 Gy. RESULTS: The procedure was safely achieved in all three patients. Long-lasting pain reduction and tumor shrinkage was obtained without early or late complications. CONCLUSION: This interstitial brachytherapy technique seems to be feasible in the treatment of metastatic abdominal wall tumors.

Selective conformal radiotherapy for arteriovenous malformation involving the spinal cord.

Radiotherapy has seldom been used in the treatment of arteriovenous malformations (AVM) involving the spinal cord because of the cord's limited radiation tolerance. A 57-year-old woman with progressive myelopathy due to AVM was treated with a selective conformal radiation therapy (55.6 Gy/20 days) on the nidus region preserving the spinal cord, drainer veins and involved bones. The drainers and symptoms were minimized at the end of treatment and disappeared over 2 years. This case illustrates the usefulness of selective conformal radiation therapy.

Histopathological examination of two cases of anterior staphyloma associated with Peters' anomaly and persistent hyperplastic primary vitreous.

AIMS: To clarify the developmental mechanism and critical period for the uncommon complex of Peters' anomaly and persistent hyperplastic primary vitreous (PHPV). METHODS: Two eyes with Peters' anomaly and PHPV were histologically examined by serial section. One eye was enucleated at age 7 months (case 1) and the other at age 4 months (case 2) owing to severe anterior staphyloma. RESULTS: In both eyes, defects in the endothelium, Descemet's membrane, and posterior stroma were observed in the central cornea, and the degenerative lens adhered to the posterior surface of the defective corneal stroma. Also, in both eyes, the anterior chamber space was not formed and the undifferentiated iris stroma adhered to the posterior surface of the peripheral cornea. Mesenchymal tissue containing melanocytes was observed behind the degenerative lens, and the pigment epithelium was absent at the lower nasal side of the ciliary body in case 1. In case 2, mesenchymal tissue containing scattered melanocytes in the vitreous cavity was seen on the posterior retina. Based on the histological findings, both cases were diagnosed as Peters' anomaly caused by the faulty separation of the lens vesicle, PHPV, maldevelopment of the iris and ciliary body, and goniodysgenesis. CONCLUSION: Migratory disorders of neural crest cells from 4 to 7 weeks of gestation may be responsible for various ocular anomalies including Peters' anomaly and PHPV, as observed in these cases.

[A case of small cell lung cancer with paraneoplastic cerebellar degeneration and anti-voltage-gated calcium channel antibody].

A 55-year-old man presenting with 4 weeks of progressive dysarthria, gait ataxia and vertigo was admitted to our hospital. Chest X-ray films revealed a mass shadow in the right upper lobe of the lung, and transbronchial brushing specimens showed small-cell carcinoma. Extensive examination revealed metastatic lesions in the mediastinal lymph nodes and liver, but brain MRI showed no findings suggestive of metastasis or atrophy. A diagnosis of PCD associated with SCLC was made, and the patient had a high titer of anti-P/Q-type VGCC antibody. He was treated by chemotherapy and radiation therapy, which resulted in a transient improvement in the PCD symptoms.

Ocular and systemic features of Peters' anomaly.

BACKGROUND: To clarify the relationship between associated systemic anomalies and ocular manifestations in patients with Peters' anomaly, a retrospective study was conducted. METHODS: We classified 37 patients with Peters' anomaly into two groups, one with (+) and one without (-) systemic anomalies. RESULTS: The systemic anomaly (+) group consisted of 13 patients, eight males and five females, with mean age of 2.3 months. Peters' anomaly was bilateral in six cases and unilateral in seven. Corneolenticular adhesion was observed in 11 cases. Associated ocular anomalies were seen in 12 cases, and developmental glaucoma was present in eight cases. The systemic anomaly (-) group comprised 24 patients, 13 males and 11 females, with mean age of 28.3 months. Peters' anomaly was bilateral in 11 cases and unilateral in 13. Corneolenticular adhesion was observed in five cases. The associated ocular anomalies were observed in 10 cases, and developmental glaucoma was accompanied in six cases. The incidences of cases with corneolenticular adhesion, those with other ocular anomalies, and those with glaucoma were significantly higher in the systemic anomaly (+) group than in the systemic anomaly (-) group. CONCLUSIONS: Peters' anomaly accompanying corneolenticular adhesion and/or other ocular anomalies should be evaluated for the presence of systemic anomalies.

Ruptured aneurysm at the origin of the median artery of the corpus callosum associated with accessory middle cerebral artery--case report.

A 62-year-old male presented with ruptured anterior communicating artery (ACoA) aneurysm manifesting as severe headache associated with the rare combination of median artery of the corpus callosum (MACC) and accessory middle cerebral artery (MCA). Computed tomography demonstrated diffuse subarachnoid hemorrhage. Left carotid angiography demonstrated an anomalous vessel originating from the ACoA complex and passing forward in the interhemispheric fissure between the two companion A2 segments. This vessel was identified as the MACC. Another anomalous vessel originated from the left A1-A2 segment and passed into the sylvian fissure. This vessel was identified as the accessory MCA. Left frontotemporal craniotomy was performed to clip the neck of the aneurysm. After identifying both A1 and A2 segments, accessory MCA, and the MACC, the aneurysm neck was occluded successfully. The ACoA complex is one of the most frequent sites of vascular anomalies. Preoperative and intraoperative care is required to identify the presence of anomalies of the ACoA complex prior to clip placement, to avoid accidental damage or clipping, which may result in severe neurological deficits.

Anophthalmia in litters of female rats treated with the food-derived carcinogen, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine.

Anophthalmia in litters of pregnant rats treated with 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a food-derived carcinogen, was incidentally encountered in a risk-assessment study with 2-generation exposure to PhIP. Female Fischer 344 animals were given 200 ppm PhIP in the diet for 4 wk before mating with nontreated males and also during gestation and lactation periods. Mean numbers of newborn rats per litter in control and PhIP-treated groups were 7.9 +/- 2.9 and 7.1 +/- 1.6 in trial 1 and 8.3 +/- 1.9 and 6.1 +/- 2.4 in trial 2. Among 49 (trial 1) and 63 (trial 2) offspring from PhIP-treated dams, 9 (18.4%) and 32 (50.8%) demonstrated anophthalmia, and 1 (2.0%) and 8 (12.7%) demonstrated hydrocephaly. Five of 7 (71.4%) and 13 of 14 (92.9%) dams delivered pups with malformations in trials 1 and 2, respectively. Also, in a previous study that was carried out with the same protocol and that used the Sprague-Dawley strain of rats, anophthalmia and hydrocephaly were observed in 2 and 1 out of 175 pups, respectively, from 100 ppm PhIP-treated dams. No congenital malformations were found in control groups of the same size in either experiment. In addition to having been previously identified as a cause of carcinogenic activity, our findings suggest that PhIP is capable of causing anophthalmia in rats when administered during the gestational period.

[Sarcomatoid carcinoma of the urinary bladder in a hemodialysis patient: a case report].

The following is a case report bladder of sarcomatoid carcinoma in a Japanese 65-year old female patient treated with hemodialysis. She developed chronic renal failure due to chronic glomerulonephritis. Fifteen months after the beginning of the hemodialysis, continuous gross hematuria was noticed, and cystoscopy revealed a broad-based bladder tumor spreading from the right lateral wall to the posterior wall. The histopathologic diagnosis of the TUR-Bt specimens was sarcoma. Radical cystectomy was performed under the diagnosis clinical stage III, T3bN0M0. The post-operative histopathologic diagnosis of the tumor was sarcomatoid carcinoma, composed of nests of transitional cell carcinoma (G 3) and predominant areas of spindle cell sarcomatoid transformation. Sarcomatoid carcinoma of the bladder in a hemodialysis patient is extremely rare, and to date this may be only the second case in Japanese medical literature.

Anomalies associated with Axenfeld-Rieger syndrome.

BACKGROUND: To detect the associated anomalies in patients with Axenfeld-Rieger syndrome is clinically important, because early treatment for such anomalies is crucial to both visual and systemic development. This study was conducted to clarify the associated anomalies in the syndrome. METHODS: We evaluated 21 patients with Axenfeld-Rieger syndrome encountered at Nagoya City University Hospital over a 16-year period. Patients who presented with a prominent Schwalbe's line accompanying the iris strands were diagnosed as having Axenfeld-Rieger syndrome. RESULTS: The series consisted of 9 males and 12 females, ranging in age from 1 month to 41 years, mean 15.4+/-12.7 (SD) years. The syndrome was bilateral in 17 cases and unilateral in 4 cases. Hypoplasia of the iris was observed in 10 eyes of 6 patients. The associated ocular anomalies included sclerocornea in 6 eyes of 3 patients, developmental glaucoma in 5 eyes of 3 patients, persistent pupillary membrane in 4 eyes of 2 patients, microphthalmos in 3 eyes of 2 patients, and typical iris coloboma in 1 eye. Of 10 eyes with hypoplasia of the iris, 5 exhibited glaucoma. The accompanying systemic anomalies included 9 cases of dental anomalies, 5 of facial anomalies, and 3 of Alagille syndrome. CONCLUSIONS: All of the associated ocular and systemic anomalies appeared to arise from the maldevelopment of the neural crest cells. Patients with Axenfeld-Rieger syndrome should therefore be examined for the presence of anomalies in the tissues of neural crest origin. Patients with hypoplasia of the iris should be checked for glaucoma.

Role of endothelium-derived vasodilators and K(+) channels in ischemic vasodilation of guinea-pig choroidal arterioles.

PURPOSE: To assess the roles of endothelium-derived vasodilators and K(+) channels on metabolic ischemia-induced vasodilation from diameter changes in choroidal arterioles of the guinea-pig. METHODS: The choroid was isolated from the guinea-pig eye-ball, pinned flat on a silicone rubber plate, and superfused with oxygenated warmed (35 degrees C) Krebs solution. Diameters of choroidal arterioles were measured using video microscopy and a computer program for analysis. Vasodilatory effects were examined after the choroid was exposed to glucose-free/NaCN solutions for 10 minutes. The effects of Nomega-nitro-L-arginine (nitroarginine), indomethacin, and K(+) channel inhibitors (glibenclamide [Glib] and charybdotoxin [ChTX]) on ischemic vasodilation were assessed. RESULTS: Reversible vasodilation was observed when the choroid was exposed to glucose-free/NaCN (10(-3) M) solutions. Nitroarginine (10( -4) M), Glib (2x10(-5) M) and ChTX (10(-7) M) significantly inhibited glucose-free/NaCN (10(-3) M)-induced vasodilation by 47%, 62%, and 24%, respectively. No significant inhibitory effect was observed with indomethacin (10(-5) M). Simultaneous application of Glib and ChTX reduced vasodilation by 77%. When Glib and ChTX were added together to nitroarginine, dilation was reduced by 86%. With high K(+) ([K]o = 47.2 mM) Krebs solution, ischemia caused a slight vasodilation (11%), which was significantly inhibited by nitroarginine. CONCLUSIONS: In guinea-pig choroidal arterioles, glucose-free/ NaCN-induced ischemic vasodilation was mainly mediated by NO and K(ATP) channels. A part of NO-mediated vasodilation was induced independent of the opening of K(+) channels.

Effects of K+Channel blockers on acetylcholine-induced vasodilation in guinea-pig choroid.

The purpose of this study is to clarify which K+channels contribute to the acetylcholine (ACh)-induced vasodilation from the diameter changes in arterioles of the guinea-pig choroid. The choroid was isolated from the guinea-pig eyeball, pinned flat on a silicone rubber plate and superfused with warmed oxygenated (35 degrees C) Krebs solution. Diameters of choroidal arterioles were measured using video microscopy and a computer program for analysis. The effects of K+channel inhibitors (glibenclamide, tetraethylammonium [TEA], apamin and charybdotoxin [ChTX]) on the ACh-induced vasodilation were examined in arterioles which had been constricted by either norepinephrine (NE) or high K+solution. In NE (10(-5)m)-constricted arterioles, the combination of nitroarginine (10(-4)m) and indomethacin (10(-5)m) reduced ACh (10(-6)m)-induced vasodilatation by 24%. When high K+solution was used to constrict the arterioles, ACh-induced vasodilation was abolished by nitroarginine and indomethacin. In the presence of nitroarginine and indomethacin, the ACh-induced dilatation of NE-constricted arterioles was attenuated by TEA (10(-3)m), apamin (10(-7)m), and ChTX (10(-7)m) but not by glibenclamide (2x10(-5)m). Simultaneous application of apamin and ChTX inhibited the ACh (10(-6)m)-induced dilatation by 85%. In arterioles of guinea pig-choroid, nitric oxide and prostacyclin are not main mediators in ACh-induced vasodilation. Simultaneous activation of a set of Ca2+-sensitive K+channels may take most part of ACh-induced vasodilation.

A case of an intraocular foreign body due to graphite pencil lead complicated by endophthalmitis.

We report a case of an 8-year-old boy who presented with an intraocular foreign body composed of graphite pencil lead. The patient had been accidentally poked in the right eye with a graphite pencil. Primary care consisted of corneal suturing and lens extraction. Two pieces of the pencil lead remained in the vitreous cavity following surgery, and 2 days later the patient developed endophthalmitis. Pars plana vitrectomy was performed immediately and the intraocular foreign bodies were removed through the scleral wound. Cultures of the vitreous fluid revealed no bacterial organisms. X-ray fluoroscopic analysis of the vitreous detected 1 ppm of aluminum (a constituent of the pencil lead). Although the clinical presentation indicated probable bacterial endophthalmitis, the detection of elemental aluminum within the vitreous cavity also suggested the possibility of further retinal toxicity due to some dissolving of the pencil lead.

Critical period for retinoic acid-induced developmental abnormalities of the vitreous in mouse fetuses.

To elucidate the underlying developmental mechanisms of persistent hyperplastic primary vitreous (PHPV) in humans, we investigated a mouse model for PHPV induced by retinoic acid. We treated C57BL/6NJcl mice at various stages of pregnancy (gestation days 7, 8, 9, 10, 11, or 12) with the teratogen retinoic acid, which affects the migration of neural crest cells. Untreated pregnant mice served as a control group. The eyes of the fetuses were examined histologically on day 18 on gestation. Developmental abnormalities of the vitreous were defined as the presence of excessive mesenchymal tissue in the vitreous cavity. The incidence of developmental abnormalities of the vitreous in all groups, except for those treated on day 12 of pregnancy, significantly exceeded that in the control group (P<0.01). The histological characteristics of the observed vitreous abnormalities in mice resembled those found in PHPV clinically. Retinoic acid-induced abnormalities in mice can serve as an experimental model for PHPV by environmental factors. Results suggest that the critical period for these retinoic acid-induced abnormalities was during days 7 to 11 of gestation, which corresponds to a critical period of 2.5 to 7 weeks of gestation for PHPV in humans.

Epidermal nuclear CIq deposits in a patient with amyopathic dermatomyositis.

We report a case of amyopathic dermatomyositis, in which C1q deposits on the epidermal nucleus were immunohistologically found as well as Ig deposits at the dermoepidermal junction (DEJ). Direct immunofluorescence (IF) examination of infiltrated erythematous lesions revealed C1q deposits on the epidermal nucleus and fibrinogen at the DEJ, and examination of hyperkeratotic erythematous lesions showed linear deposits of Ig G and Ig A at the DEJ but not in the nuclei of epidermal cells. The authors discuss the direct in vivo interaction between nucleus and immunoreactants in dermatomyositis.