Evaluation of the potassium adsorption capacity of a potassium adsorption filter during rapid blood transfusion.

The concentration of extracellular potassium in red blood cell concentrates (RCCs) increases during storage, leading to risk of hyperkalemia. A potassium adsorption filter (PAF) can eliminate the potassium at normal blood transfusion. This study aimed to investigate the potassium adsorption capacity of a PAF during rapid blood transfusion. We tested several different potassium concentrations under a rapid transfusion condition using a pressure bag. The adsorption rates of the 70-mEq/l model were 76·8%. The PAF showed good potassium adsorption capacity, suggesting that this filter may provide a convenient method to prevent hyperkalemia during rapid blood transfusion.

Significant variation of surface spin polarization through group IV atom (C, Si, Ge, Sn) adsorption on Fe3O4(100).

The adsorption of group IV atoms (C, Si, Ge, Sn) on the magnetite Fe3O4(100) surface is investigated by density functional theory calculations. All these atoms prefer to bond to the surface oxygen atom which has no tetrahedral Fe(A) neighbor. The spin-up surface states of clean Fe3O4(100) are completely removed and half-metallicity is recovered by C adsorption. The spin-up band gap of the C-adsorbed Fe3O4(100) surface is wider than that of the H-adsorbed one and closer to the value of bulk Fe3O4. For the adsorption of other group IV atoms, the adsorbate-substrate interaction decreases and the adsorbate-adsorbate interaction increases with the increase of atomic number Z. As a consequence, the spin polarization varies from -99.4% (C adsorption) to +44.2% (Sn adsorption) for the electronic states of the adsorbed atom integrated from -0.5 eV to the Fermi level. The ability to tune the surface spin polarization by the choice of adsorbate is of significance for magnetite-based spintronic devices.

Development of a new measurement system to detect selectively volatile organic compounds derived from the human body.

A new concept expired gas measurement system used double cold-trap method was developed. The system could detect selectively volatile organic compound (VOC) derived from the human body. The gas chromatography (GC) profiles of healthy volunteer's expired gas collected by our system were analyzed. As a result, 60 VOCs were detected from the healthy volunteer's expired gas. We examined 14 VOCs among them further, which could be converted to the concentration from the GC profiles. The concentration of almost VOCs decreased when the subjects inspired purified air compared with the atmosphere. On the other hand, isoprene was almost the same. It was strongly suggested that these VOCs were derived from the human body because the concentration of these VOCs in the atmosphere were nearly zero. Expired gas of two sleep apnea syndrome (SAS) patients were analyzed as preliminary study. As a result of the study, the concentration of some VOCs contained in the expired gas of the SAS patients showed higher value than a healthy controls.

Silicon micro/nanofabrication using metastable helium atom beam lithography.

We utilize metastable helium (He*) atom beam lithography to pattern silicon substrates by using self-assembled monolayer (SAM) of octadecyltrichlorosilane (OTS) grown directly on silicon surface as resist. An improved wet-chemical etching method was used to transfer the resist pattern into silicon substrate. Negative and positive pattern formations with well-defined edges were observed for silicon(100) substrate with SAM after exposure to the He* atom beam followed by the etching. Results indicate a clear transition from positive to negative patterns relies on the He* dosage. The pattern sizes on silicon were successfully decreased to the order of 100 nm, even less than 50 nm.

Platelet-derived growth factor signals play critical roles in differentiation of longitudinal smooth muscle cells in mouse embryonic gut.

In the development of mouse gut, longitudinal smooth muscle cells (LMC) and interstitial cells of Cajal (ICC) originate from common precursor cells expressing c-Kit. Recently, some gastrointestinal stromal tumours, which develop from smooth muscle layers of the gut and have gain-of-function mutations of c-kit, have been reported to have gain-of-function mutations of platelet-derived growth factor (PDGF) receptor alpha gene. These data raise the possibility that PDGF signalling might be involved in the development of LMC. Therefore, we examined the expression pattern of the PDGF signal family of embryonic gut by immunohistochemistry and in situ hybridization, and investigated the role of PDGF signals in the development of smooth muscle layers in mouse gut using a new organ culture system. During embryonic development, the circular muscle layer expressed PDGF-A, enteric neurons expressed PDGF-B and common precursor cells of LMC and ICC expressed both PDGF receptor alpha and beta. The selective PDGF receptor inhibitor AG1295 suppressed the differentiation of LMC in gut explants. We conclude that PDGF signals play critical roles in the differentiation of LMC in mouse embryonic gut.

Spin dependence in the survival probability of metastable He (2(3)S) atoms during the scattering from ferromagnetic surfaces.

The use of a spin-polarized metastable helium (He(*)) atom beam has demonstrated that the survival probability (SP) of He(*) during the scattering from ferromagnetic surfaces depends on the electron spin of He(*). The spin asymmetry in the SP of He(*) scattered from a clean Fe/Cu(100) surface changed its polarity with H2O adsorption. We argue that the reversal is caused by the change in the spin polarization of the surface electronic states at around the Fermi level.

The effect of dietary consistency and water content on the parotid glands of submandibular and sublingual duct-ligated rats.

The aim here was to estimate the significance of oral sensation and mastication on functional changes in the parotid glands of partially desalivated rats. Submandibular and sublingual duct-ligated and sham-operated control rats were fed three diets of similar chemical composition but different physical presentations. Two were solid, either pellets or powder, and one was liquid. Water and food intakes were similar for both the duct-ligated rats and sham-operated control rats when they ate the pelleted or powdered-diet, though more food was wasted by the duct-ligated rats in the powdered-diet group than in the pelleted-diet group. No food was wasted in the rats fed the liquid-diet. Parotid gland weight and amylase activity were greatest with the submandibular and sublingual duct-ligated rats fed the powdered-diet and smallest with the duct-ligated and sham-operated control rats fed the liquid-diet. The amount of food wasted correlated positively with the parotid gland weight and parotid amylase activity of the rats. These findings support the view that it is the contact of dry food with the oral mucosa rather than the jaw movements involved in mastication that increases parotid gland weight and amylase activity in partial desalivated rats.

Spin polarized metastable He*(2(3)S, 1s2s) stimulated desorption of H(+) ions.

The yield of H(+) in the metastable He*(2(3)S, 1s2s) stimulated desorption (MSD) on an H2O/Na/Fe surface has been found to depend on the spin of the incident He*. By combination with the spin-resolved analysis for the surface electronic structure, it is indicated that the neutralization of the hole in the OH 3 sigma molecular orbital, which is created by the incident He*, by Na 3s electrons plays a crucial role in the spin polarization of the H (+) MSD intensity. The dependence of the spin polarization of H(+) MSD on the kinetic energy of the desorbed H(+) has been observed, and it is discussed based on the Menzel-Gomer-Readhead model.

Metastable helium atom stimulated desorption of H+ Ion

H+ desorption induced by the impact of metastable helium atoms has been found for H(2)O/Na/Ni(110) coadsorption systems. The measurements were carried out using a time-of-flight technique and a pulsed-discharge type metastable helium atom ( He(*)) source. It is concluded that the H+ desorption by He(*) is induced by a hole created on the valence levels via the Auger deexcitation of He(*). The H+ desorption by He(*) may be understood within the framework of the Menzel-Gomer-Readhead model.

Relationship between parotid amylase secretion and osmolality in the gastric contents of rats fed a pelleted or liquid diet.

The relationship between parotid amylase secretion and the osmolality in the gastric contents of rats fed a pelleted or liquid diet was investigated. In sham-operated rats fed a pelleted diet, amylase activity in the parotid glands decreased, amylase activity in the plasma increased, and there was strong amylase activity in the gastric contents. As a result, both reducing sugar concentration and osmolality in the gastric contents increased. In parotid duct-ligated rats, the feeding of a pelleted diet affected neither parotid nor plasma amylase activity and there was little amylase activity in the gastric contents; this resulted in decreased starch digestion. The amylase activity in the gastric contents of rats fed a liquid diet was lower than that of rats fed the pelleted diet. Both the reducing sugar concentration and osmolality in the gastric contents of rats fed the liquid diet were lower than those of rats fed the pelleted diet. However, both the reducing sugar concentration and osmolality in the gastric contents of rats fed the liquid diet were higher than those in the liquid diet itself. A small quantity of parotid amylase seems to effectively digest a large part of the starch in the stomaches of rats fed the liquid diet. These findings suggest that amylase secreted from parotid glands increases osmolality in the gastric contents via the production of reducing sugars from starch in rats when fed either pelleted or liquid diets.

Feasibility study on donor apheresis red cell and platelet simultaneous collection for blood center routine use.

This study was conducted to determine if single donor platelet and red cell simultaneous collection by apheresis technique can be applied to routine blood product collection at blood centers. Both apheresis red cell product and platelet product were successfully collected and mannitol, adenine, and phosphate (MAP) additive solution was added to the red cell concentrates during collection. During a 49 day storage study period, the red cell product quality was maintained and found to be equivalent to that of red cell products derived from whole blood collected by the traditional method. This study demonstrated the possibility of applying this collection method for routine use for single donor apheresis platelet product and red cell product preparation at blood centers.

Effects of dietary consistency and water content on parotid amylase secretion and gastric starch digestion in rats.

The aim was to estimate the significance of oral sensation and mastication in inducing amylase secretion from the parotid gland and subsequent starch digestion in the stomach. Rats were fed three diets of similar chemical composition but different physical presentations. Two were solid, either pellets or powder, and one was liquid. Oral sensory activity would be greatest with the pellets and least with the liquid. Only the pellets would require significant mastication. Three criteria were used to estimate amylase secretion, amylase activity in the stomach, the depletion of glandular amylase activity and plasma amylase concentrations. Gastric starch digestion was estimated by measuring the concentration of reducing-sugars in the stomach contents. Parotid amylase secretion and gastric starch digestion were similar whether rats were fed pelleted or powdered solid food but much lower in rats fed a liquid diet. These findings support the view that it is the contact of dry food with the oral mucosa rather than the jaw movements involved in mastication that stimulates parotid amylase secretion.

[Effect of ethanol on isometric tone of aorta from guinea pig].

Using aortic strips isolated from guinea pig, effects of ethanol on vascular smooth muscle tone were studied. Low concentrations (5, 50, 100 mM) of ethanol potentiated norepinephrine and serotonin-induced contractions, but not KCl-induced one. Ethanol (100 mM) potentiated calcium-induced contraction in the presence of norepinephrine, but not that in the presence of KCl. Ethanol (100 mM) showed no effects on norepinephrine-induced contraction in the calcium-free medium. Ethanol (100 mM) augmented 45Ca uptake stimulated with norepinephrine, but not that with KCl. Ethanol at the higher concentration of 600 mM by itself induced contraction, which was inhibited by trifluoperazine or in the calcium-free medium, but not by phentolamine, diphenhydramine, methysergide, indomethacin or nifedipine. Ethanol (600 mM) directly increased 45Ca uptake, which was not affected by nifedipine. These findings indicate that the low concentrations of ethanol potentiate receptor-mediated vascular smooth muscle contraction and the higher concentration of ethanol directly contracts it via facilitation of transmembranous calcium influx.

Effect of diethyldithiocarbamate on diabetogenic action of alloxan in rats.

To determine whether alloxan action is mediated by hydroxyl radicals in vivo, we assayed methane sulfinic acid (MSA), a product of the trapping reaction of dimethyl sulfoxide (DMSO) with hydroxyl radicals. In DMSO-treated rats, the plasma levels of MSA were increased after injection of alloxan (75 mg/kg). This supports the hypothesis that the diabetogenic action of alloxan is mediated by hydroxyl radicals in vivo. The role of cytosolic superoxide dismutase (SOD) in protecting B cells against chemically induced diabetes was studied in rats injected intraperitoneally with diethyldithiocarbamate (DDC). When rats were injected intraperitoneally with DDC (750 mg/kg), the SOD activity at 2.5 h was decreased by 44% in the whole pancreas. The decreased SOD activity was affected by DDC but not by alloxan. Intraperitoneal injection of rats with DDC (750 mg/kg) increased diabetogenic susceptibility to a nondiabetogenic dose of alloxan (20 mg/kg). Subcutaneous injection of vitamin E, prior to administration of both DDC and alloxan, provided partial protection to the rats against the diabetogenic action. These findings suggest that the susceptibility to diabetogenic action of alloxan in B cells is augmented when the cellular SOD activity is inhibited. Thus, cellular SOD may play an important role in the maintenance of B cell function.

[Changes in Po2, Pco2, pH, and HCO3 concentration and flow rates in human parotid saliva by tongue sour stimulation at various intervals].

The PO2, PCO2, pH, and HCO3- concentration and flow rates of parotid saliva were observed by tongue stimulation with 3% tartaric acid at various intervals in a human subject after about a one hour rest. The PO2, PCO2, pH, and HCO3- concentrations in parotid saliva were measured with a Blood Gas Analyzer System. The results are summarized as follows: 1) The mean PO2 and PCO2 of parotid saliva immediately before tongue stimulation were about 40 mmHg (range 33-44 mmHg) and 45 mmHg (41-48). There values were similar to those of venous blood. 2) PO2 increased to about 50 mmHg (46-54) 5 to 10 sec. after stimulation, and then 3 to 8 min. later, it decreased to a minimum value of about 28 mmHg (26-29) before returning to the resting level 15 min. after stimulation, when the intervals between stimulations were longer than 2 min., similar changes in PO2 were observed, whereas stimulations every 30 sec. or 1 min. had no effect on PO2. 3) PCO2 increased to about 98 mmHg (85-120) from the resting level of 45 mmHg (41-48) 5 to 10 sec. after stimulation, and returned to the resting level 1 min. after stimulation. When the intervals between stimulations were shorter than 20 min., the peak value of PCO2 by the first stimulation was higher than those induced by the following stimulations. When the interval was 30 sec. or 1 min., only the peak after the first stimulation was observed. 4) The pH of parotid saliva was about 7.4 (7.35-7.5) 30 to 50 sec. after stimulation, and it decreased below 6.5 about 12 min. after stimulation. When the interval between stimulations was 5 min., the pH of the parotid saliva after stimulation was always above 6.5. When the interval between stimulations was 1 min. or 30 sec., it remained at about 7.5. 5) The HCO3- concentration in parotid saliva depends almost exclusively on the pH when Pco2 remained unchanged. When Pco2 was high, however, the HCO3- concentration was affected by the change in Pco2. 6) There was no relationship between changes in the flow rate of parotid saliva and Po2, Pco2, pH, and the HCO3- concentration. Particularly, when the interval between stimulations was shorter than 5 min., the changes in flow rate had no effect on Po2, Pco2, pH, and the HCO3- concentration.

[Effect of bite force on parotid secretion in human].

To determine the physiological roles of periodontal mechanoreceptors in parotid salivary secretion, we studied the effects of strength and frequency of unilateral bites on the salivary secretion from both sides of human parotid glands. Parotid saliva was collected bilaterally via modified Lashley cups, and the flow rate of parotid saliva was measured with a device using a strain gauge. The bite force was monitored with a pressure transducer. In the first experiment, subjects were constantly occluded for one minute at 80 strokes per minute at strengths of 5, 10, and 20 kg. In the second experiment, subjects were occluded for one minute at a constant force of 10 kg at frequencies of 20, 40, 80, and 120 strokes per minute, or subjects were continuously clenching for one minute. The flow rate of parotid saliva gradually increased with increasing bite strength, while it gradually decreased with increasing bite frequency. In unilateral bites, the salivary flow rate of the ipsilateral parotid gland was greater than that of contralateral parotid gland, at any strength and frequency. These results suggest that periodontal mechanoreceptors are involved in parotid salivary reflexes initiated by bite force stimuli.

[Changes in the ions and protein concentrations and flow rate of parotid saliva by tongue sour stimulation].

Changes in the concentrations of ions (K+, Cl-, Na+), total protein, amylase activity and flow rate of parotid saliva were observed by tongue stimulation with 3% tartaric acid various intervals in a subject after about one hour rest. The results may be summarized as follows: 1) After about one hour rest state, the values of each item were K+: 42-56 mEq/l, Cl-: 8-28 mEq/l, Na+: 1-10 mEq/l, total protein: 5.7-11 mg/ml, amylase activity: 2-6.5 x 10(3)U/ml and flow rate: 0.03-0.05 ml/min. 2) The changes were classified into two groups based on the recovery from peak to rest values. One group showed short recovery times (Cl-: 20 min., Na+: 8 min. and flow rate: 2 min.) and the other group had rather longer recovery times (K+: 40 min., total protein: 55 min. and amylase activity: 40 min.). The differences between these two groups were clear when the stimulus intervals were 30 sec. to 5 min. 3) When the tongue was stimulated every 15 sec. all items showed first responses, after that, the all values except the flow rate remained unchanged. 4) Different values in ions and protein concentrations and amylase activity were observed when the flow rate was similar before and after stimulation. 5) The recovery time of the responses of protein concentration and amylase activity to stimulation was about one hour, and a rest period of more than one hour is necessary to analyze the concentration of total protein and amylase activity in parotid saliva.

Effect of age on contractile response to angiotensin II in rat aorta.

The effects of aging on contractile response to angiotensin II and tachyphylaxis to it were investigated using aortic strips from rats aged 1.5, 4 and 22 months. Whether the endothelium was present or not, the contractile response to angiotensin II was greater and tachyphylaxis to it was less in 1.5-month-old rats than in 4- and 22-month-old rats. The differences between 4- and 22-month-old rats were not significant. Removal of the endothelium enhanced angiotensin II-induced maximal contraction and depressed the tachyphylaxis, these endothelial effects being greater in 4- rather than in 1.5-month-old rats. When the contractile force of angiotensin II was adjusted to a similar level for 1.5- and 4-month-old rats, the endothelial effect on the tachyphylaxis was greater in the 4-month-old rats, but no significant difference was noted in the endothelial effect on the contractile force. These results suggest that during growth, the contractile response of rat aorta to angiotensin II decreases while the endothelial effect on it increases.