Laboratory-scale mass production of a multi-micropatterned grafted surface with different polymer regions

In this article, we demonstrate laboratory-scale mass production of a regionally precise multi-micropatterned surface photo-graft-copolymerized with three water-soluble monomers based on the photochemistry of an iniferter, which means that it acts as an initiator, a transfer agent and a terminator, benzyl N, N-diethyldithiocarbamate. The surface was semi-automatically prepared using a combination of a custom-designed irradiation apparatus installed with a motor-controlled stage for a substrate and three photomasks with different line-patterned slits (number of slits 20, width 500 microm, length 10 mm), and carbon dioxide laser cutting apparatus. A particular region of poly(styrene-co-vinylbenzyl N,N-diethyldithiocarbamate) coated on a PET film was irradiated in a particular aqueous monomer solution while moving the irradiated portion stepwise after irradiation through each line of the photomask. Photo-graft-copolymerization was carried out sequentially with acrylic acid sodium salt (AANa), N-[3-(dimethylamino)propyl]acrylamide methiodide (DMAPAAm), and acrylamide (AAm) using differently patterned photomasks. Characterization of surface elemental distribution by X-ray photoelectron spectroscopy (XPS), and light microscopic visualization by dye staining revealed a microprocessed surface with 20 sets of micropatterns, each of which had three line regions grafted with three different polymers. The irradiation of a carbon dioxide laser manipulated via computer-aided design (CAD) software onto the microprocessed surface resulted in automatic circular cutting for each set of micropatterns to mass-produce multi-micropatterned substrates for the study of substrate-dependent endothelial cell responses.     

Effects of current intensity on behavioral and autonomic heat-loss responses in intracranial self-stimulating rats

We investigated the effects of current intensity on behavioral and autonomic heat-loss responses in intracranial self-stimulating (ICSS) rats. At an ambient temperature (Ta) of 22 degrees C, the tail vasodilation during ICSS behavior began at higher hypothalamic temperature (Thy) at higher current intensity. At a Ta of 36 degrees C, body extension, a typical heat-loss response in rats, appeared during ICSS behavior and frequently interrupted lever pressing. When the body extension first began, Thy was elevated if current intensity was high. In experiments in which current intensity was varied between two levels at a Ta of 22 degrees C, if current intensity was lowered after tail vasodilation began and Thy reached a steady level, the rat interrupted pressing the lever to lose heat through grooming or body extension. Rectal temperature (Tre) dropped in the process. If, on the other hand, current intensity was raised, the rate of lever pressing increased and Tre rose with tail vasoconstriction. The data suggest that the magnitude of the reward, as reflected in current intensity, affects both behavioral and autonomic heat-loss responses.     

Immunohistochemical study on tissue transglutaminase and copper-zinc superoxide dismutase in human myocardium: Its relevance to apoptosis detected by the nick end labelling method

The influence of free radicals on apoptosis was studied in the human heart; 45 autopsy cases were examined by the nick end labelling method (NELM) that detects DNA fragmentation. Immunostaining for copper-zinc superoxide dismutase (CuZn-SOD) and tissue transglutaminase (tTG) induced frequently during apoptosis were also studied. Positive immunoreaction for tTG was detected in mucinous degeneration of myocardial cells; these same cells were also positive for CuZn-SOD but negative for NELM. Myocardial cells showing basophilic alterations after haematoxylin and eosin staining were also positive for CuZn-SOD but negative for the other markers examined. Positive nuclear reaction by NELM was only observed in myocardial cells showing contraction band necrosis or irregularly shaped nuclei surrounding recent or long-standing infarcted foci. In these the other two markers were negative. Since mucinous degeneration lacks the distinguishing morphological features of apoptosis, immunoreactive tTG in this lesion may not imply that the cells are undergoing apoptosis. tTG can be induced in non-apoptotic conditions and may not be involved in apoptosis induced by infarction. Histological disassociation between CuZn-SOD expression and apoptosis suggests the possibility of a cytoprotective role played by endogenous CuZn-SOD against free radical generation in the human heart.     

The restorative effect of naps on perceptual deterioration

Human performance on visual texture discrimination tasks improves slowly (over days) in the absence of additional training. This 'slow learning' requires nocturnal sleep after training and is limited to the region of visual space in which training occurred. Here, we tested human subjects four times in one day and found that with repeated, within-day testing, perceptual thresholds actually increased progressively across the four test sessions. This performance deterioration was prevented either by shifting the target stimuli to an untrained region of visual space or by having the subjects take a mid-day nap between the second and third sessions.     

Dynamics of gastrin-producing cells in the rat after truncal vagotomy. Evaluation by double immunostaining for bromodeoxyuridine and little gastrin.

The mechanism of hyperplasia of gastrin-producing cells (G-cells) in the rat antral mucosa after truncal vagotomy was studied using double immunostaining for bromodeoxyuridine (BrdU) and little gastrin (G17). With single labeling of BrdU, a few G-cells (less than 1%) showed positive immunostaining for BrdU in the nucleus throughout the experimental period in both vagotomized rats and those given a sham operation. The labeled cells in both groups demonstrated a linear increase of BrdU labeling in an identical number of cells for each experimental time-point. The labeling index of the G-cells increased rapidly from day 2 to day 6 and attained a maximum level of 44.0% on day 10 in the vagotomized group after cumulative labeling. Even in this group, however, many G-cells showed no BrdU immunoreactivity throughout the experimental period. These cells did not replicate during the experimental period, but showed an intense reaction product for G17 in their cytoplasm after vagotomy. The present study indicates that the most important factor involved in G-cell hyperplasia observed after truncal vagotomy is the activation of pre-existing G-cells to synthesize and release hormone, together with the rapid maturation of progenitor cells to mature G-cells.     

Milrinone, a phosphodiesterase III inhibitor, antagonizes the neuromuscular blocking effect of a non-depolarizing muscle relaxant in vitro

Phosphodiesterase (PDE) inhibitors are occasionally used in patients receiving non-depolarizing muscle relaxants during anesthesia and intensive care. However, little is known about the influence of PDE III inhibitors on the effects of non-depolarizing muscle relaxants. The aim of this study was to elucidate the effects of milrinone, a PDE III inhibitor, on d-tubocurarine (dTc)-induced muscle relaxation in vitro and then to compare its effects with those of other activators of the adenylate cyclase (AC) system (aminophylline, a non-selective PDE inhibitor; forskolin, a direct AC activator; and isoproterenol, a beta-adrenoceptor agonist). Isometric twitch tensions of rat nerve-hemidiaphragm preparations elicited by indirect or direct stimulation (0.1 Hz) were measured. Indirectly elicited twitch tension partially depressed by dTc (1 microM) was antagonized by milrinone, aminophylline, and forskolin but was attenuated by isoproterenol. Directly elicited twitch tension was increased by aminophylline, forskolin, and isoproterenol but was not altered by milrinone. The results indicate that milrinone antagonizes dTc-induced muscle relaxation by recovering the neuromuscular transmission. It is noteworthy that PDE inhibitors and a beta-adrenergic agonist affect non-depolarizing muscle relaxation in opposite direction.     

The effects of midazolam and ketamine on D-tubocurarine-induced twitch depression in septic rat diaphragm

The aim of this study was to elucidate the effects of midazolam and ketamine on neuromuscular blockade induced by non-depolarizing muscle relaxants (NDMRs) under the condition of sepsis induced by panperitonitis. A CLP operation (laparotomy, cecal ligation, and puncture of the cecum; septic group) or sham laparotomy (sham group) was performed on rats under O2-isoflurane anesthesia. At 18 hours after the operation, isometric twitch tensions of rat nerve-hemidiaphragm preparations elicited by indirect or direct stimulation at 0.1 Hz were measured. Midazolam enhanced the dTc (1 microM)-induced twitch depression (p < 0.05) at a high concentration (10 microM) in the septic group but not in the sham group. Ketamine enhanced the dTc (1 microM)-induced twitch depression in the sham group (p < 0.01) but not in the septic group. Midazolam and ketamine had no effect on directly elicited twitch tensions in either group. The results indicate that sepsis facilitates the midazolam-induced enhancement of the neuromuscular blocking effect of dTc but, conversely, inhibits the ketamine-induced enhancement. Sepsis elicits manifold alterations in the influence of intravenous anesthetics and sedatives on NDMR-induced neuromuscular blockade.