Search for η

We measured missing mass spectrum of the ^{12}C(γ,p) reaction for the first time in coincidence with potential decay products from η^{'} bound nuclei. We tagged an (η+p) pair associated with the η^{'}N→ηN process in a nucleus. After applying kinematical selections to reduce backgrounds, no signal events were observed in the bound-state region. An upper limit of the signal cross section in the opening angle cosθ_{lab}^{ηp}<-0.9 was obtained to be 2.2 nb/sr at the 90% confidence level. It is compared with theoretical cross sections, whose normalization ambiguity is suppressed by measuring a quasifree η^{'} production rate. Our results indicate a small branching fraction of the η^{'}N→ηN process and/or a shallow η^{'}-nucleus potential.

Differential Cross Section and Photon-Beam Asymmetry for the γ[over →]p → π

Differential cross sections and photon-beam asymmetries for the γ[over →]p→π^{-}Δ^{++}(1232) reaction have been measured for 0.7

Interference Effect between ϕ and Λ(1520) Production Channels in the γp→K

The ϕ-Λ(1520) interference effect in the γp→K^{+}K^{-}p reaction has been measured for the first time in the energy range from 1.673 to 2.173 GeV. The relative phases between ϕ and Λ(1520) production amplitudes were obtained in the kinematic region where the two resonances overlap. The measurement results support strong constructive interference when K^{+}K^{-} pairs are observed at forward angles but destructive interference for proton emission at forward angles. Furthermore, the observed interference effect does not account for the sqrt[s]=2.1 GeV bump structure in forward differential cross sections for ϕ photoproduction. This fact suggests possible exotic structures such as a hidden-strangeness pentaquark state, a new Pomeron exchange, or rescattering processes via other hyperon states.

Spin-density matrix elements for γp→K*0Σ+ at Eγ=1.85-3.0 GeV with evidence for the κ(800) meson exchange.

The exclusive reaction γp→K(+)π(-)Σ(+) was measured for the first time using linearly polarized photons at beam energies from 1.85 to 2.96 GeV. Angular distributions in the rest frame of the K(+)π(-) system were fitted to extract spin-density matrix elements of the K(*0) decay. The measured parity spin asymmetry shows that natural-parity exchange is dominant in this reaction. This result clearly indicates the need for t-channel exchange of the κ(800) scalar meson.

Near-threshold Lambda(1520) production by the gamma(p)-->K{+}Lambda(1520) reaction at forward K+ angles.

Differential cross sections and photon-beam asymmetries for the gamma(p)-->K{+}Lambda(1520) reaction have been measured with linearly polarized photon beams at energies from the threshold to 2.4 GeV at 0.6or=5/2 or by a new reaction process, for example, an interference effect with the phi photoproduction having a similar bump structure in the cross sections.

Understanding the Relationship between Social Cognition and Word Difficulty. A Language Based Analysis of Individuals with Autism Spectrum Disorder.

BACKGROUND: Few quantitative studies have been conducted on the relationship between society and its languages. Individuals with autistic spectrum disorder (ASD) are known to experience social hardships, and a wide range of clinical information about their quality of life has been provided through numerous narrative analyses. However, the narratives of ASD patients have thus far been examined mainly through qualitative approaches. OBJECTIVES: In this study, we analyzed adults with ASD to quantitatively examine the relationship between language abilities and ASD severity scores. METHODS: We generated phonetic transcriptions of speeches by 16 ASD adults at an ASD workshop, and divided the participants into 2 groups according to their Social Responsiveness Scale(TM), 2nd Edition (SRS(TM)-2) scores (where higher scores represent more severe ASD): Group A comprised high-scoring ASD adults (SRS(TM)-2 score: ≥ 76) and Group B comprised low- and intermediate-scoring ASD adults (SRS(TM)-2 score: < 76). Using natural language processing (NLP)-based analytical methods, the narratives were converted into numerical data according to four language ability indicators, and the relationships between the language ability scores and ASD severity scores were compared. RESULTS AND DISCUSSION: Group A showed a marginally negative correlation with the level of Japanese word difficulty (p < .10), while the "social cognition" subscale of the SRS(TM)-2 score showed a significantly negative correlation (p < .05) with word difficulty. When comparing only male participants, Group A demonstrated a significantly lower correlation with word difficulty level than Group B (p < .10). CONCLUSION: Social communication was found to be strongly associated with the level of word difficulty in speech. The clinical applications of these findings may be available in the near future, and there is a need for further detailed study on language metrics designed for ASD adults.

Correlation of the average water diffusion constant with cerebral blood flow and ischemic damage after transient middle cerebral artery occlusion in cats.

Magnetic resonance water diffusion imaging can detect early ischemic changes in stroke. Using a middle cerebral artery occlusion model, we examined which range of values of the orientation-independent diffusion quantity Dav = 1/3Trace(D) = 1/3(Dxx + Dyy + Dzz) is an early noninvasive indicator of reduced cerebral perfusion and focal brain injury. Cats underwent either a 30-min occlusion followed by 3.5 h reperfusion (n = 7) or a 60-min occlusion followed by 4-h reperfusion (n = 6). Repeated measurements of CBF were made with radiolabeled microspheres, and acute focal injury was measured with triphenyltetrazolium chloride (TTC) staining. During occlusion, the decrease in Dav correlated with CBF for caudate [30-min occlusion (n = 13): p < 0.0001: 60-min occlusion (n = 6): p < 0.02] and for cortex [30-min occlusion (n = 12): p < 0.0001: 60-min occlusion (n = 5): p < 0.04]. Variable caudate and hemispheric injury levels were found among cats in both groups. The area of tissue injury demarcated by TTC began to correlate with the area of reduced Dav by 30 min of occlusion (p < 0.02), and this correlation improved (p < 0.0001) at 1, 1.5, and 2.0 h after the onset of occlusion. The time necessary to reach a one-to-one correspondence between the percent of hemisphere injured and the percent of hemispheric area with Dav < 0.65 x 10(-9) m2/s was 2 h after occlusion. Thus, the absolute value of Dav is a good indicator of the risk of tissue injury, whereas the combination of Dav and the length of time of Dav reduction is an excellent predictor of acute focal tissue injury demarcated by TTC staining.

Nitric oxide in the liver may not be involved in blood redistribution during hemorrhagic shock in the dog.

We previously reported that nitric oxide (NO) in the brain cortex increases during hemorrhagic shock (HS) and then recovers to a baseline level by a retransfusion. Accordingly, we suggested that NO may play a role in blood redistribution during HS. To ascertain whether or not NO contributes to blood redistribution, we have investigated the changes in the liver's NO production during HS. Mongrel dogs were used in the study. After each dog was anesthetized with pentobarbital, an NO-selective electrode was placed in its liver, and a probe to measure hepatic blood flow (HF) was placed on the liver's surface. HS was induced until a mean arterial blood pressure of <40 mmHg was reached. In Group I (n=5), HS was maintained for 30 min. In Group II (n=7), shed blood was reinfused at 10 min after HS. In Group III (n=7), 10 min after NG-nitro-L-arginine methyl ester 30 mg/kg intravenously (i.v.), the same procedures were performed as in Group II. In Groups II and III, although 10 min of HS produced an increase in NO-related electrical current [Group II, 2,197+/-786 pA; Group III, 983+/-77 pA (mean+/-standard error)], reinfusion of shed blood restored the NO-related electrical current to its baseline value. HF in Groups I and II decreased continuously during HS, and it recovered to baseline after the restoration from HS in Group II. In Group III, NG-nitro-L-arginine methyl ester 30 mg/kg i.v. decreased HF 12.7+/-.7 to 10.2+/-.6 mL/min/100 g (mean+/-standard error, p < .05). In conclusion, although NO produced in the liver might play an important pathophysiologic role in HS, it may not affect the blood redistribution during HS, such as in mean arterial blood pressure <40 mmHg.

Nitric oxide in the brain increases during a short period of hemorrhagic shock in the rabbit.

We investigated the changes in nitric oxide (NO) concentration in the brain of the rabbit by measuring NO-related electrical current. Seventeen Japanese white rabbits were anesthetized with pentobarbital sodium and mechanically ventilated with tracheotomy tubes. An NO-selective electrode was used for the detection of NO. After a round craniotomy in the left parietal lobe, an NO-sensitive electrode was placed in the brain. Rabbits were hemorrhaged to a mean arterial blood pressure of 35 +/- 7 mmHg, from a baseline of 112 +/- 12 mmHg (mean +/- SD). The shock was maintained for 5 min. The mean extracted blood volume was 77 +/- 17 mL. Then, retransfusion of shed blood caused a rapid restoration of mean arterial blood pressure. The amount of time required to induce hemorrhagic shock was 261 +/- 34 s. The time required to retransfuse the extracted blood was 233 +/- 43 s (p > .05). During shock, the NO-selective electrode produced an extensive increase in current, from 110 +/- 94.5 pA to 1010 +/- 543 pA (mean +/- SD, p < .001). The current continued to increase for a few minutes after the recovery from shock, with a maximal increase reaching 1245 +/- 515 pA (p < .001). This enhanced release of NO-related current (1,132%) recovered to the baseline level at 44 +/- 7 min after retransfusion. When the same investigation was performed on the same animals on which had been placed the same electrode pretreated with NG-nitro-L-arginine methylester (L-NAME) 30 mg/kg intravenously, NO-related current increased from 101 +/- 158 to a maximum of 860 +/- 406 pA (752%). Our results suggest that NO may play an important role in the brain during the early period of hemorrhagic shock, and that L-NAME 30 mg/kg intravenously might not inhibit the NO production in the parietal lobe, probably due to a blood-brain barrier to the nitric oxide synthase-inhibiting drug.

Acute pulmonary edema associated with transfusion of packed red blood cells.

We experienced a patient who suffered noncardiogenic acute pulmonary edema after transfusion of packed red blood cells which contained antigranulocyte antibodies. The data suggested that complement activation and the release of polymorphonuclear protease were involved in the pathogenesis of the complication in the present patient. Furthermore, blood coagulative system was also activated after the transfusion. The underlying mechanisms of the complication are discussed.

Hypercapnia and response of cerebral blood flow to hypoxia in newborn lambs.

Individual effects of hypoxic hypoxia and hypercapnia on the cerebral circulation are well described, but data on their combined effects are conflicting. We measured the effect of hypoxic hypoxia on cerebral blood flow (CBF) and cerebral O2 consumption during normocapnia (arterial PCO2 = 33 +/- 2 Torr) and during hypercapnia (60 +/- 2 Torr) in seven pentobarbital-anesthetized lambs. Analysis of variance showed that neither the magnitude of the hypoxic CBF response nor cerebral O2 consumption was significantly related to the level of arterial PCO2. To determine whether hypoxic cerebral vasodilation during hypercapnia was restricted by reflex sympathetic stimulation we studied an additional six hypercapnic anesthetized lambs before and after bilateral removal of the superior cervical ganglion. Sympathectomy had no effect on base-line CBF during hypercapnia or on the CBF response to hypoxic hypoxia. We conclude that the effects of hypoxic hypoxia on CBF and cerebral O2 consumption are not significantly altered by moderate hypercapnia in the anesthetized lamb. Furthermore, we found no evidence that hypercapnia results in a reflex increase in sympathetic tone that interferes with the ability of cerebral vessels to dilate during hypoxic hypoxia.

Effect of plasma alpha1-acid glycoprotein concentration on the accumulation of lidocaine metabolites during continuous epidural anesthesia in infants and children.

OBJECTIVE: Alpha1-acid glycoprotein (AAG) is an acute-phase protein that is responsible for binding basic drugs such as lidocaine (LDC). The effect of AAG on the duration of LDC during continuous epidural anesthesia in infants and young children was investigated. PATIENTS, MATERIALS AND METHODS: Plasma levels of LDC and its active metabolites, monoethylglycinexylidide (MEGX) and glycinexylidide (GX), were monitored in 20 infants and children, 5 months to 6 years of age, who received continuous epidural infusion of 2.5 mg kg(-1) LDC hourly during abdominal or thoracic surgeries. RESULTS: Plasma LDC concentrations were constant after the first hour of injection. In contrast, the concentrations of MEGX and GX increased continuously during epidural infusion in all patients. The plasma AAG concentration correlated significantly (r = 0.814, p<0.001) with the steady-state LDC level. In addition, significant inverse correlation was observed between the plasma AAG concentration and the accumulation rate of MEGX (r = 0.742, p = 0.002). The plasma AAG concentration and the accumulation rate of GX correlated weakly (r = 0.474, p = 0.035). There was no correlation between the age of the patient and the plasma AAG concentrations (r = 0.295, p = 0.206). CONCLUSION: Our results suggest that the plasma AAG concentration is a valuable index in preventing the toxicity caused by accumulation of MEGX during continuous epidural anesthesia of LDC.

Chromatographic determination of free lidocaine and its active metabolites in plasma from patients under epidural anesthesia.

OBJECTIVE: We developed a simple and selective assay method for simultaneous determination of free lidocaine (LDC) and its active metabolites, monoethylglycinexylidide (MEGX) and glycinexylidide (GX) in plasma, by using high-performance liquid chromatography (HPLC). The method was applied to the plasma concentration monitoring in continuous epidural anesthesia with LDC. MATERIALS AND METHODS: Free fraction was separated from plasma by using an ultrafiltration technique. Free and total LDC, MEGX and GX in plasma were analyzed by HPLC equipped with ordinary octadecylsilyl silica (ODS) column and ultraviolet (UV) detector. PATIENTS: Five male patients with cancer who received epidural injection of 1.5% LDC for 5 hours in elective thoracic surgery, were enrolled to determine the plasma levels of total and free LDC, MEGX and GX. RESULTS AND DISCUSSION: The calibration curve for free LDC, MEGX and GX were linear at the concentration of 25 to 1,000 ng ml(-1) (r = 0.9998 - 0.9999). The recoveries for LDC, MEGX and GX from plasma water were ranged 73.2-89.1%. The coefficient variations for intra- and inter-day assay for LDC, MEGX and GX were less than 4.1%. The detection limit ofeach drug was 20 ng ml(-1). Plasma-free MEGX after 180 min epidural injection was higher than free LDC, even though the total concentration of MEGX was 4 times lower than that of LDC. The percentages of free fraction for LDC, MEGX and GX were 11.7, 48.5 and 78.3% after 5-hour epidural administration of LDC. Since the free fraction of MEGX and GX increases and exceeds the concentration of free LDC during continuous epidural anesthesia, accumulation of these toxic metabolites should be carefully monitored as well as LDC. CONCLUSION: The present method is a reliable technique and can be applied to monitoring free LDC, MEGX and GX, which provide us beneficial information as to the LDC metabolism and toxicity.

Plasma lidocaine, monoethylglycinexylidide, and glycinexylidide concentrations after epidural administration in geriatric patients.

BACKGROUND AND OBJECTIVES: The purpose of this study was to evaluate the effect of age on the pharmacokinetics of lidocaine after epidural administration. METHODS: Two percent lidocaine with epinephrine (5 microg/mL) was administered in two different age groups: an adult group (age 42 +/- 6 years, n = 10) and an elderly group (age 77 +/- 4 years, n = 10). Concentrations of lidocaine and its active metabolites, monoethylglycinexylidide (MEGX) and glycinexylidide (GX), were measured in plasma samples obtained after 15, 30, 45, 60, 90, 120, 150, and 180 minutes of administration using high-performance liquid chromatography with ultraviolet detection. RESULTS: No significant differences in plasma concentrations of lidocaine and its metabolites were observed between the two groups during the 3 hours of study. However, the elderly group showed significantly longer mean residence times (MRTs) and lower plasma clearance of lidocaine during the period compared with the adult group (P < .05). Plasma concentration ratios of MEGX/lidocaine were significantly lower in the elderly group after 2 hours of lidocaine administration (P < .05). CONCLUSIONS: The increase in plasma lidocaine concentration after epidural anesthesia in elderly patients was not as high as anticipated. However, the elderly patients showed longer MRTs, lower clearance, and lower ratios of MEGX/lidocaine than did the adult (middle-age) patients.

Plasma concentrations of lidocaine and its principal metabolites during continuous epidural infusion of lidocaine with or without epinephrine.

BACKGROUND AND OBJECTIVES: The purpose of this study was to evaluate the effect of epinephrine on the absorption of lidocaine and the accumulation of active metabolites of lidocaine during continuous epidural anesthesia. METHODS: Lidocaine was administered as an initial bolus of 5 mg/kg of 2% lidocaine solution followed by continuous infusion at 2.5 mg/kg/h. Patients in group I (n = 10) received lidocaine alone and patients in group II (n = 10) received lidocaine + epinephrine (5 pg/mL). Concentrations of lidocaine and its active metabolites, monoethylglycinexylidide (MEGX) and glycinexylidide (GX), were measured in plasma samples obtained after 15 minutes, 30 minutes, and 1, 2, and 3 hours of infusion using high-performance liquid chromatography with ultraviolet detection. RESULTS: Plasma lidocaine concentrations were higher in group I for the first 30 minutes; however, after 1 hour the levels were the same. Plasma MEGX and GX increased continuously in both groups. MEGX levels the were significantly higher in group I, but there was no significant difference in the sum of lidocaine + MEGX after 2 hours. There was no significant difference in GX levels between the two groups. CONCLUSIONS: With respect to continuous epidural administration, addition of epinephrine to lidocaine solutions is ineffective after 2 hours for reducing the potential for systemic toxicity, because the sum of the plasma concentrations of lidocaine and its principal active metabolite, MEGX, are unaffected.

A survey of ochratoxin A and aflatoxins in domestic and imported beers in Japan by immunoaffinity and liquid chromatography.

Analyses of ochratoxin A (OTA) and aflatoxins (AFs) in 94 imported beer samples from 31 producing countries and in 22 Japanese beer samples were performed by immunoaffinity column and reversed-phase liquid chromatography (LC) with fluorescence detection. Recoveries of OTA from beer samples spiked at 25 and 250 pg/mL were 86.1 and 88.2%, respectively. Recoveries of AFs were 98.4 and 98.9%, 95.4 and 95.5%, 101.2 and 97.8%, and 98.9 and 96.0%, respectively, from beer samples spiked at 4.1 and 41 pg AF B1, 4.45 and 44.5 pg AF B2, 4.7 and 47 pg AF G1, and 4.65 and 46.5 pg AF G2/mL. Detection limits were 1.0 pg/mL for OTA, 0.5 pg/mL for AFs B1 and B2, and 1.0 pg/mL for AFs G1 and G2. OTA was detected in 86 (91.5%) of 94 imported beer samples at a mean level of 10.1 pg/mL and in 21 (95.5%) of 22 Japanese beer samples at a mean level of 12.5 pg/mL. AF B1 was detected in 11 of 94 imported beer samples at a level of 0.5-83.1 pg/mL and in 2 of 22 Japanese beer samples at 0.5 and 0.8 pg/mL. Except for one beer sample from Peru, the samples contaminated with AFs were also contaminated with OTA. Although OTA was detected in most samples from various countries, AFs were detected in the beer samples from only a limited number of countries where AF contamination might be expected to occur because of their warm climate.

A case of acute pulmonary edema and bulbar paralysis after local epinephrine infiltration.

An unusual case in which pulmonary edema and intracranial hemorrhage occurred during adenotonsillectomy is presented. The possible causes of this intracranial hemorrhage are discussed, especially in relationship to local epinephrine infiltration.

[Estimation of daily dietary intake of aluminum].

The daily dietary intake of aluminum was estimated through a total diet study from 1996 to 1998. In ten institutes, total diet study samples were prepared and their aluminum concentration was determined. The average daily intake of aluminum was 3.5 mg and the range was 1.8-8.4 mg. The validity of the analytical result was supported by analyses of certified reference materials.

[Ketamine infusion therapy for refractory neuralgia in spinal disease: report of two cases].

We report two cases of refractory pain in a spinal disease. One case was a 60-year-old male who presented intractable pain in bilateral upper extremities after anterior fusion (C5/6, 6/7) for cervical spondylosis. The other was a 63-year-old female who also had intractable pain in the left anterio-lateral chest wall with no remarkable past history. Both cases were refractory to nonsteroidal anti-inflammatory drugs (NSAIDs) or minor tranquilizer or local anesthesia with bupivacaine. However, their pain was significantly relieved by the intravenous administration of a test dose (5mg) of ketamine which is a noncompetitive blocker of N-methyl-D-aspartate (NMDA) receptors. As for case 1, the effect of the injection of the test dose lasted, so continuing infusion therapy of ketamine was cancelled. In case 2, recurrence of the pain was recognized gradually. She underwent continuing infusion therapy of 2mg/kg of ketamine, and it brought about continued pain relief. We conclude that ketamine infusion therapy should also be considered for therapy of refractory neuralgia in spinal disease.

[An unusual cause of anesthetic ventilator malfunction].

We report a case of malfunction of an anesthetic ventilator by an unusual cause. A 48-year-old male with gastric cancer was scheduled for gastrectomy. Anesthesia was maintained with enflurane, N2O, O2 and epidural blockade using a semiclosed circuit system. The patient was ventilated using AV1 anesthetic machine (Dräger Co.). Forty minutes after induction of anesthesia, chest movement of the patient suddenly stopped. There was no gas flow to the patient during inspiratory phase. Air leak was not found in anesthetic respiratory circuit and at the bellows of the ventilator. The supply of oxygen and air to the anesthetic machine was sufficient. Since we could not find any cause of the ventilator failure, anesthesia was maintained with manual ventilation by using another anesthetic machine until completion of the surgery. After the surgery, we recognized that the controller unit of expiratory valve of the ventilator was obstructed by a Tamper Proof Film, which seals the outlet of a commercial bag of lactated Ringer's solution (Solulact, Terumo Co.). It seems that the film dropped accidentally between the main part and the ventilator system of anesthetic machine when the bellows was exchanged before the surgery, and moved on to the controller unit of the expiratory valve of the ventilatory system during surgery. In conclusion, it is necessary for anesthetists to understand the inner structure and system of the anesthetic machine and to check the anesthetic machine to avoid the troubles and accidents related to anesthetic machine.