Decomposition method for fast computation of gigapixel-sized Fresnel holograms on a graphics processing unit cluster.

A parallel computation method for large-size Fresnel computer-generated hologram (CGH) is reported. The method was introduced by us in an earlier report as a technique for calculating Fourier CGH from 2D object data. In this paper we extend the method to compute Fresnel CGH from 3D object data. The scale of the computation problem is also expanded to 2 gigapixels, making it closer to real application requirements. The significant feature of the reported method is its ability to avoid communication overhead and thereby fully utilize the computing power of parallel devices. The method exhibits three layers of parallelism that favor small to large scale parallel computing machines. Simulation and optical experiments were conducted to demonstrate the workability and to evaluate the efficiency of the proposed technique. A two-times improvement in computation speed has been achieved compared to the conventional method, on a 16-node cluster (one GPU per node) utilizing only one layer of parallelism. A 20-times improvement in computation speed has been estimated utilizing two layers of parallelism on a very large-scale parallel machine with 16 nodes, where each node has 16 GPUs.

Cerebral ischemia or intrauterine inflammation promotes differentiation of oligodendroglial precursors in preterm ovine fetuses: possible cellular basis for white matter injury.

White matter injury in premature infants is known to be major cause of long-term neurocognitive disability, but the pathogenic mechanism remains unclear, hampering our ability to develop preventions. Periventricular leukomalacia is a severe form of white matter injury. In the present study, we explored the effects of cerebral ischemia and/or intrauterine inflammation on the development of oligodendroglia in the cerebral white matter using chronically instrumented fetal sheep. Each fetus received one of three insults: hemorrhage, inflammation and their combination. In the hemorrhage group, 40% of the fetoplacental blood volume was acutely withdrawn, and 24 hours after removal, the blood was returned to the fetus. The inflammation group received intravenous granulocyte-colony stimulating factor and intra-amniotic endotoxin and thus suffered from necrotizing funisitis and chorioamnionitis. The inflammatory hemorrhage group underwent acute hemorrhage under the inflammatory state. The sham group received no insults. Importantly, periventricular leukomalacia was not detected in the sham and the inflammation groups. Differentiating oligodendroglia at various developmental stages were identified by immunohistochemical analysis with specific antibodies. No difference in the density of oligodendroglial progenitors was detected among the four groups, whereas oligodendroglial precursors were significantly reduced in the three insult groups, compared to sham control. Moreover, the density of immature oligodendroglia was higher in the inflammation group and the inflammatory hemorrhage group, while the density of mature oligodendroglia was highest in the hemorrhage group. We propose that cerebral ischemia or intrauterine inflammation induces the differentiation of oligodendroglial precursors in preterm fetuses, eventually resulting in their exhaustion.

Renal vasodilatory action of arginine vasopressin in extremely low birth weight infants.

In extremely low birth weight (ELBW) infants, systemic hypotension is associated with poor neurological outcomes as a result of cerebral hypoperfusion. Treatment with arginine vasopressin (AVP) has been shown to increase blood pressure (BP) and urine output in ELBW infants suffering from refractory hypotension. The purpose of this study was to clarify whether low doses of AVP increased renal blood flow (RBF) in ELBW infants. We retrospectively analyzed data from the medical charts describing nine AVP infusions at 0.3-0.8 mU/kg/min in four ELBW infants. The median gestational age was 23 (22.5-23.5, interquartile range) weeks, and the median birth weight was 466 (414-563) g. Changes in the heart rate, BP, urine output, and RBF velocity patterns in response to the AVP infusions were compared using statistical analyses. The AVP infusion caused significant increases in systolic BP from 44 (41.0-47.0) to 50 (42.5-55.5) mmHg, diastolic BP from 17 (15.0-26.5) to 31 (28.5-33.0) mmHg, mean BP from 26 (24.5-30.5) to 36 (34.5-40.5) mmHg, and urine output from 1.4 (0.2-2.5) to 2.8 (1.0-8.6) mL/kg/hr. We also observed significant decreases in the resistance index from 1.0 (0.96-1.0) to 0.8 (0.71-0.91) and peak systolic flow velocity in the renal artery from 40 (27.2-50.6) to 28 (16.0-28.9) cm/s after AVP infusions. AVP infusions at 0.3-0.8 mU/kg/min in ELBW infants appeared to significantly increase the RBF by inducing renal vascular dilation and increasing the BP. Increasing the RBF most likely induces an increase in the glomerular filtration rate, resulting in the diuretic effect of AVP.

Novel modification of an artificial placenta: pumpless arteriovenous extracorporeal life support in a premature lamb model.

BACKGROUND: Previous studies aimed at developing an artificial placenta have had limited success. We hypothesized that the introduction of a high-performance membranous oxygenator to a pumpless artificial placenta could prolong the survival time of premature lambs. METHODS: Immediately after delivery of the fetuses, the umbilical vessels were cannulated and connected to the pumpless artificial placenta. Both the fetuses and the circuit were submerged in a warm saline bath. RESULTS: Five fetuses survived for 18.2 ± 3.2 (mean ± SEM) h after attachment to the artificial placenta, which maintained fetal circulation. Circuit blood flow was positively correlated with mean arterial pressure and negatively correlated with blood lactate levels. Milrinone administration transiently decreased lactate levels, although dopamine administration unexpectedly induced a marked increase in the lactate levels despite an elevated arterial pressure and improved circuit blood flow. CONCLUSION: We prolonged the survival of fetal lambs using a high-performance membranous oxygenator with a small priming volume. The increased systemic resistance induced by vasoconstrictors may increase the circuit blood flow excessively, resulting in circulation failure in systemic organs; therefore, vasodilators may be more useful than vasoconstrictors for maintaining organ blood flow within this circuit.

Antimutagenic; differentiation-inducing; and antioxidative effects of fragrant ingredients in Katsura-uri (Japanese pickling melon; Cucumis melo var. conomon).

Six fragrant ingredients were identified in fully-ripened Katsura-uri (Japanese pickling melon; Cucumis melo var. conomon). Four of them were sulfur-containing compounds [methylthioacetic acid ethyl ester (MTAE), acetic acid 2-methylthio ethyl ester (AMTE), 3-methylthiopropionic acid ethyl ester (MTPE), and acetic acid 3-methylthio propyl ester (AMTP)]; and the others were benzyl acetate and eugenol. The newly identified MTAE and AMTP possessed antimutagenic activity as determined by their ability to inhibit the UV-induced mutation in repair-proficient E. coli B/r WP2. MTAE and MTPE (esters with thiocarbonic acid and alkyl alcohol) induced the differentiation of human colon cancer cells (RCM-1 cells), but AMTE and AMTP (esters with carbonic acid and thioalkyl alcohol) did not. A specific thioester motif containing a thiocarbonic acid and alkyl alcohol correlated with these compounds ability to induce differentiation. AMTE, MTPE, AMTP, and eugenol had higher oxygen radical absorbing capacity than the antioxidative vitamin, ascorbic acid. The quantity of MTPE, AMTP and eugenol increased 49-fold, >1175-fold and 11-fold, respectively, in the fully-ripened fruit as compared to the mid-ripened fruit.

Actin and Vimentin proteins with N-terminal deletion detected in tumor-bearing rat livers induced by intraportal-vein injection of Ha-ras-transfected rat liver cells.

The introduction of the tumorigenic v-Ha-ras oncogene-transformed rat liver epithelial cells (WBras), which is deficient in gap junctional intercellular communication (GJIC), into F344 rats, induces significant formation of hepatocellular tumors. GJIC plays a major role in maintaining tissue homeostasis. Using this in vivo tumor model system, we used 2-dimensional electrophoresis with isoelectric focusing in the first dimension and SDS-PAGE in the second dimension to globally identify proteins that are uniquely expressed in the livers of WBras-treated rats as compared to the sham control. Immunoblotting was used to identify Ras and Connexin43, which were the positive and negative marker proteins, respectively, of the introduced WBras cells. As predicted, immunoblotting indicated that the whole liver of tumor-bearing animals exhibited a decreased level of Connexin43 and an increased level of Ras. Connexin43 and GJIC were expressed and functional in normal liver, but not in the tumor. In addition to these 2 markers, an additional 4 proteins exhibited decreased levels and 2 proteins exhibited increased levels in the livers of tumor-bearing animals. N-Terminal sequencing analysis was used to identify these proteins, which were glucose-regulated protein 78, 2 isoforms of heat shock protein 60, and the beta-chain of ATP synthase for the down regulated proteins, and beta-Actin with a 46 amino acid deletion from its N-terminus and Vimentin with a 71 amino acid deletion from its N-terminus for the up regulated proteins. These data offer potentially new markers of liver tumorigenicity, particularly, Vimentin. (