Fire resistance of Douglas fir (Pseudotsuga menzieesi) treated with borates and natural extractives.

The objective of this study was to determine fire resistance of Douglas fir (Pseudotsuga menzieesi (Mirb.) Franco) specimens treated with borate supplemented aqueous solutions of brutia pine bark powder, acorn powder, sumach leaf powder, and gall-nut powder. Boric acid (BA) and borax (BX) were used as borates which are the most commonly used fire retardants in wood preservation industry. Natural extractives (brutia pine bark powder, sumach leaf powder, acorn powder, and gall-nut powder) were also used which have toxic efficiency against insects and fungi due to their tannin contents. A commercial treatment compound Tanalith-CBC (copper-borate-chromate), which is an impregnation chemical, is used for comparison. The fire test method was performed in three stages: flame stage, without flame stage, and glowing stage. Results indicated that the lowest temperature for flame stage, without flame stage, and glowing stage were obtained for specimens treated with BA and BX mixture (7:3; weight:weight). The lowest mass loss was found for the specimens treated with a mixture of BA and BX. Natural extractives did not improve fire resistance of the samples. However, boric acid and borax had excellent fire retardant effectiveness over untreated and treated samples with natural extractives.

Inhibitory effects of aloe carboxypeptidase fraction on streptozotocin-induced enhancement of vascular permeability in the pancreatic islets.

The protective actions of components isolated from Aloe arborescens Miller var. natalensis Berger (Kidachi aloe in Japanese) on streptozotocin (Sz)-induced necrosis of B cells in the pancreatic islets of the mouse were investigated to clarify its action mechanism involved in anti-diabetic effects. In this experiment, phenol low molecular weight components of aloin and aloin A that were anti-oxidants and derived from the leaf skin or pulp extract, an aloe carboxypeptidase fraction that is a inhibitor of enhanced vascular permeability and a glycoprotein component that decreases blood glucose were tested with mice precedently administered with Sz which is known as a cytotoxin specific to B cells. The results showed that the treatment group receiving Sz followed by the aloe carboxypeptidase fraction increased the inhibition of dye leakage by 75.8% (p<0.001) in the extract of whole pancreas in comparison to the control group and the aloe carboxypeptidase fraction group also increased the inhibition effect by 68.4% (p<0.001) in the extract of pancreatic islets as compared to the control group. The carboxypeptidase is an aloe-derived protease known to inhibit the acetic acid-related enhancement of intraperitoneal vascular permeability in mice. Further, the elevation of blood glucose in Sz-induced diabetic mice intraperitoneally given the aloe carboxypeptitase fraction was significantly (p<0.01-0.001) restrained at 3, 7 and 14 days after the injection as compared to the control group given solvent only. The results of this experiment suggested that the inhibitory effect on the enhancement of vascular permeability related to the vascular acute inflammatory response at Sz-induced lesions of pancreatic islets was involved in the action mechanism of this enzyme.

[Efficacy of lidocaine cream in protecting against thermal stress during hyperthermia].

Hyperthermia is performed in combination with chemotherapy as multimodal treatment for recurrent and advanced cancer. It is generally believed that the temperature cannot be raised higher because of thermal stress. In this study, we examined the efficacy of lidocaine cream in protecting against thermal stress during hyperthermia. We devised a new local anesthetic cream containing 5% lidocaine. The subjects were eighteen patients with stomach cancer, liver cancer, or large intestine cancer. This cream was applied locally to the skin with an occlusive dressing for about one hour before hyperthermia was performed, and was wiped away just before hyperthermia. The pain scores in the treatment group were significantly lower than in the no-treatment group (p < 0.05). The scores for sensation of heat in the treatment group were lower, though not to a significant extent, than those in the no-treatment group. No adverse effects were observed. Plasma concentrations of lidocaine were lower than 0.5 microgram/ml, and percutaneous absorption of lidocaine from the lidocaine cream was minimal.

A novel A-isoform-like inositol 1,4,5-trisphosphate 3-kinase from chicken erythrocytes exhibits alternative splicing and conservation of intron positions between vertebrates and invertebrates.

Based on the partial peptide sequence of inositol 1,4, 5-trisphosphate 3-kinase purified with 135 000-fold enrichment from chicken erythrocytes, cDNA-fragments were cloned by RT-PCR using degenerate oligonucleotides. Subsequent hybridization screening of an embryonic chicken cDNA library and 5'-RACE yielded a cDNA-contig of 2418 bp, encoding a 452 amino acid protein. The amino acid sequence shows the highest degree of homology with A-isoforms of inositol 1,4,5-trisphosphate 3-kinase (65% identities), whereas homology towards B and C isoforms was lower (57% and 52% amino acid identities respectively). These findings reveal a new tissue-specific pattern of A-isoform expression, a form which so far has only been found in brain and testes. Two overlapping lambda-genomic clones for chicken inositol 1,4,5-trisphosphate 3-kinase, isolated by hybridization screening, covered 18 499 bp of genomic sequence. This contig included four exons: three of them were present in all cDNA clones, whereas one was only represented in a single cDNA clone. In addition, the sequence of the latter differed from the other cDNAs by an in-frame deletion of 72 bp within the coding region for the catalytic domain of the enzyme. This divergent cDNA suggests the existence of alternative splice products, at least in embryonic tissue.A comparison of the position of introns, with the respective introns known from the corresponding gene from Caenorhabditis elegans, revealed a high degree of conservation of intron positions between vertebrates and invertebrates. Functional data for the enzyme suggests that the conserved exons represent defined functional protein modules.

Continuous measurement of temperature in non-24 hour sleep-wake syndrome.

The onset of the low temperature (LT) zone which was defined as a period when the rectal temperature was below its daily mean is a convenient circadian phase marker. In this study, we document three cases of non-24 h sleep-wake syndrome in which identification of the LT zone as an evening circadian phase marker contributed to clinical judgments. We found that the LT zone was correlated well with dim light melatonin onset. Moreover, calculating the LT zone was useful in determining phase position in irregular sleep pattern and in determining the timing of bright light therapy.

Trials of bright light exposure and melatonin administration in a patient with non-24 hour sleep-wake syndrome.

We report a patient with non-24 h sleep-wake syndrome (non-24) whose free-running sleep-wake cycle was successfully treated with both scheduled bright light exposure and melatonin treatment. In the present study, morning bright light as well as evening melatonin phase-advanced sleep-wake cycles and melatonin rhythm. Both these procedures achieved appropriate entrainment to a 24 h day. However, the patient did not continue morning bright light therapy after the discharge. Rising at appropriate times in the morning for bright light therapy was difficult for him to continue. Melatonin treatment was better tolerated because of its ease of application.

[Spinal cord stimulation therapy at an early stage for unresponsive patients with hypoxic encephalopathy].

Recently, spinal cord stimulation (SCS) has been used for the treatment of patients in prolonged coma. However, the results of SCS in unresponsive patients with hypoxic encephalopathy at the chronic stage have not been satisfactory. Considering these circumstances, we began SCS from one month after the onset of hypoxic encephalopathy and evaluated its effect. Twelve patients (5 males and 7 females) with hypoxic encephalopathy, ranging in age from 7 to 72 years, were treated with SCS. The causes of hypoxia were acute cardiac failure in 4, automobile exhaust gas poisoning in 2, and asthma, pneumothorax, anaphylaxis, asphyxia, drowning and hypotension during aortic surgery in one patient each. One month after the onset, an electrode for electrical stimulation was implanted in the epidural space at the C2-C4 level under general anesthesia. The spinal cord was stimulated for 8 hours each day, starting on the day after implantation, and was continued for 3 months. Magnetic resonance imaging (MRI), cerebral blood flow (CBF) measurement using xenon-computed tomography (Xe-CT), and measurement of auditory evoked potential (AEP) and somatosensory evoked potential (SEP) were carried out 3 weeks after the onset for presurgical evaluation. Among the 12 patients, 7 (58%) showed clinical improvement, beginning within two weeks after starting stimulation. They were able to communicate with others and to express their emotion. However, disturbance of writing, picture drawing and calculation were not improved by stimulation. From presurgical evaluation, cases in which SCS therapy was effective had the following features: 1) No hemorrhagic infarction in the basal ganglia was demonstrable by MRI. 2) Mean hemispheric CBF measured by the Xe-CT method exceeded 25 ml/100 g per min. 3) The mean increase in hemispheric CBF 20 min after acetazolamide administration exceeded 5 ml/100 g per min. 4) An N20 peak was evident on the median nerve SEP, SCS appears to be an effective supplementary for unresponsive patients with hypoxic encephalopathy at the subacute stage, in addition to rehabilitation and drug therapy.

Periodic fatigue symptoms due to desynchronization in a patient with non-24-h sleep-wake syndrome.

A 43-year-old man complaining of recurrent fatigue symptoms and sleep disorders occurring periodically every 4 weeks was studied. Using a wrist worn actigraphy and an ambulatory rectal temperature monitoring apparatus, his sleep-wake cycle and rectal temperature were measured continuously for 4 months, while diagnostic evaluation and therapeutic interventions were conducted. It was found that after he gave up an attempt to keep to a 24-h-day, a free-running sleep wake pattern appeared but his fatigue symptoms disappeared. An analysis of the relationship between his sleep-wake cycle and the rectal temperature rhythm found that his fatigue symptoms did not appear when both rhythms were synchronized with each other. Artificial bright light therapy entrained him to a 24-h day without relapsing of fatigue symptoms. Desynchronization between a 24-h sleep-wake schedule and his circadian pacemaker may have caused his periodically appearing fatigue symptoms.

Circadian rhythm sleep disorders in adolescents: clinical trials of combined treatments based on chronobiology.

Delayed sleep phase syndrome (DSPS) and non-24-h sleep-wake rhythm are circadian rhythm sleep disorders that are common in adolescents. Most patients have difficulty adjusting to school life, poor class attendance or refuse to go to school. Since a treatment has not been established, the present paper is presented to propose a strategy for treating circadian rhythm sleep disorders in adolescents, based on our clinical studies. Twenty subjects (12 males and eight females, mean age 16.2+/-1.7 years) participated in the study. The onset of sleep disorder occurred between the ages of 11 and 17. The most common factors affecting the onset of disorders were changes in social environment. The subjects kept a sleep-log for the periods before and during treatments. The treatments were based on chronobiology: resetting the daily life schedule, chronotherapy, regulation of the lighting environment, methylcobalamin, and/or melatonin. Bright light exposure was successful in 10 patients, of whom four were treated with methylcobalamin. Melatonin treatment was successful in two patients (one with and one without chronotherapy). Thirteen of the 20 patients were successfully, treated with therapies based on chronobiology. After consideration of these results, a step-by-step procedure of combined treatments for the circadian rhythm sleep disorders is proposed.

Kidney-specific expression of a novel mouse organic cation transporter-like protein.

Using the signal sequence trap method, we have cloned a novel 12-membrane-spanning transporter-like protein, termed renal-specific transporter (RST), from the mouse kidney. RST is a 553-amino-acid protein highly homologous to recently cloned organic cation transporters, e.g. it is 30% identical to rat organic cation transporter I at the amino acid level. Northern blot analysis has revealed that the RST gene is expressed abundantly and specifically in the kidney. In situ hybridization analysis has shown that RST gene expression is restricted to the renal proximal tubule, where various organic cations such as endogenous catecholamines and choline or clinically used cationic drugs are known to be actively excreted.

Potent neuropeptide Y Y1 receptor antagonist, 1229U91: blockade of neuropeptide Y-induced and physiological food intake.

Neuropeptide Y (NPY) is thought to increase food intake through the action of Y1 (-like) receptors in the hypothalamus. To confirm the involvement of Y1 receptors in feeding behavior, selective and potent antagonists for Y1 receptors are required. In the present study, we showed that a peptide, 1229U91 [(Ile,Glu,Pro,Dpr,Tyr,Arg,Leu,Arg, Tyr-NH2)2 cyclic (2,4'),(2',4)-diamide], is a potent and selective antagonist for Y1 receptors. 1229U91 displaced [125I]peptide YY (PYY) binding to membranes of human neuroblastoma-derived SK-N-MC cells that predominantly express Y1 receptors with a K1 value 0.10 nM and inhibited the NPY-induced increase in intracellular calcium levels(IC50 = 0.27 nM). In contrast, the K1 values for [125I]PYY binding to Y2 receptors in membranes of human neuroblastoma-derived SK-N-BE2 cells and rat hypothalamus were 700 nM and more than 1 microM, respectively. Although [125I]PYY could not detect Y1 receptors in the rat hypothalamic membranes, [125I]1229U91 revealed binding sites with a high affinity (Kd = 18 pM), indicating the presence of Y1 receptors in the hypothalamus. Intracerebroventricular injection of 1229U91 (30 micrograms) into male Sprague-Dawley rats completely inhibited NPY (5 micrograms)-induced food intake without any other behavioral change. Furthermore, intracerebroventricular injection of 1229U91 significantly suppressed physiological feeding behavior after overnight fasting. These results indicate that Y1 receptors in the rat hypothalamus mediate NPY-induced food intake, and that physiological feeding behavior after overnight fasting may be largely regulated by NPY via Y1 receptors. 1229U91 may be useful for further elucidating the pathophysiological roles of NPY in feeding behavior.

A new inositol 1,4,5-trisphosphate binding protein similar to phospholipase C-delta 1.

We have reported that two inositol 1,4,5-trisphosphate binding proteins, with molecular masses of 85 and 130 kDa, were purified from rat brain; the former protein was found to be the delta 1-isoenzyme of phospholipase C (PLC-delta 1) and the latter was an unidentified novel protein [Kanematsu, Takeya, Watanabe, Ozaki, Yoshida, Koga, Iwanaga and Hirata (1992) J. Biol. Chem. 267, 6518-6525]. Here we describe the isolation of the full-length cDNA for the 130 kDa Ins(1,4,5)P3 binding protein, which encodes 1096 amino acids. The predicted sequence of the 130 kDa protein had 38.2% homology to that of PLC-delta 1. Three known domains of PLC-delta 1 (pleckstrin homology and putative catalytic X and Y domains) were located at residues 110-222, 377-544 and 585-804 with 35.2%, 48.2% and 45.8% homologies respectively. However, the protein showed no PLC activity to phosphatidylinositol 4,5-bisphosphate and phosphatidylinositol. The 130 kDa protein expressed by transfection in COS-1 cells bound Ins(1,4,5)P3 in the same way as the molecule purified from brain. Thus the 130 kDa protein is a novel Ins(1,4,5)P3 binding protein homologous to PLC-delta 1, but with no catalytic activity. The functional significance of the 130 kDa protein is discussed.

Enzymatic resolution of racemic 1,2:5,6-di-O-cyclohexylidene and 1,2:3,4-di-O-cyclohexylidene-myo-inositol.

Enzyme-catalyzed regio- and enantioselective esterification of racemic 1,2:5,6-di-O-cyclohexylidene- and 1,2:3,4-di-O-cyclohexylidene-myo-inositol, which are key intermediates for syntheses of various naturally occurring myo-inositol phosphate derivatives, proceeded exclusively in organic solvent to give optically pure materials and selectively protected products in gram scale. Hydrolysis of mono-O-acetates of the corresponding racemic materials catalyzed by the same enzymes yielded complementary products. The present study provides a new and efficient method for obtaining optically pure myo-inositol derivatives.

Cloned protein antigen-specific, Ia-restricted T cells with both helper and cytolytic activities: mechanisms of activation and killing.

Myoglobin-specific, Iad-restricted cloned helper T cells and T hybridomas were found to directly kill Iad-bearing, myoglobin-pulsed B lymphoma targets and could also kill bystander targets, but only in the presence of antigen-pulsed antigen presenting cells (APC). The induction of the killing requires recognition of processed antigen in the context of class II major histocompatibility complex (MHC) molecules. Despite the specificity of induction, the bystander killing suggests a nonspecific lytic mechanism. The direct killing can be inhibited only by cold specific targets, whereas the bystander killing can be blocked by both specific and nonspecific targets. The cold target inhibition seems to be due to interference with effector-to-target contact or proximity rather than due to high-dose suppression of T-cell activation. Experiments using T-cell supernatants or cyclosporin A suggested that the helper T cells kill targets by synthesizing short-range soluble factor(s) with nonspecific killing activity de novo during the effector phase, but only while antigen-specific signal transduction is occurring. The mechanism of cold target inhibition appears to be absorption or consumption of a short-acting cytotoxic lymphokine by cells which must be able to interact closely with the effector cell. Normal spleen B cells, despite their capability for activating the helper T cells, cannot inhibit specific killing or be killed by helper T cells, even after lipopolysaccharide stimulation. Thus, although killing by helper T cells may play a negative feedback role in the normal immune response, our data raise the possibility that the helper T-cell-mediated killing may contribute to the immune surveillance against malignancy by virtue of the preferential killing of tumor cells either directly or indirectly.

Effects of verapamil on electrophysiological disturbances induced by lysophosphatidylcholine in isolated rabbit hearts.

Lysophosphoglycerides such as lysophosphotidylcholine (LPC) have been shown to accumulate in ischemic myocardium and may be important in the genesis of arrhythmias. In this study effects of verapamil on electrophysiological and biochemical derangements induced by LPC were evaluated in Langendorff-perfused rabbit hearts. LPC perfusion (10 microM) produced conduction disturbances and enhanced spontaneous firing concomitantly with increasing potassium and creatine phosphokinase contents in the coronary effluents. Although pretreatment with verapamil (2 microM) did not show any significant effects on the conduction delay and biochemical changes, it suppressed the occurrence of rapid spontaneous firing during LPC perfusion. These results suggest that relatively low concentration of LPC can induce electrophysiological and biochemical derangements comparable to those observed during myocardial ischemia and that verapamil may modify the dysrhythmias induced by LPC.