Attenuated relationship between salivary oxytocin levels and attention to social information in adolescents and adults with autism spectrum disorder: a comparative study.

BACKGROUND: Previous research studies have assessed the relationship between attention to social information and peripheral (e.g., plasma and salivary) oxytocin (OT) levels in typically developing (TD) children and children with autism spectrum disorder (ASD). A relationship between them was observed in TD children, but not in children with ASD. However, this relationship remains unexamined in other age groups. To clarify whether this lack of association is maintained throughout development in individuals with ASD, we aimed to assess the relationship between salivary OT levels and attention to social information in adolescents and adults with and without ASD. METHODS: We recruited male adolescents and adults with ASD (n = 17) and TD participants (n = 24). Using the all-in-one eye-tracking system Gazefinder, we measured the percentage fixation time allocated to social information. We also measured the salivary OT levels and Autism Spectrum Quotient (AQ) of participants. Subsequently, we confirmed group differences and conducted a correlation analysis to investigate the relationships between these three measures. RESULTS: Salivary OT levels did not show any significant difference between the ASD and TD groups and were negatively correlated with the AQ in the whole-group analysis, but not in within-group analysis. Individuals with ASD had significantly lower percentage fixation times than did TD individuals for eye regions in human faces with/without mouth motion, for upright biological motion, and for people regions in the people and geometry movies. The percentage of fixation for geometric shapes in the people and geometry movies was significantly higher in the ASD than in the TD group. In the TD group, salivary OT levels were positively correlated with percentage fixation times for upright biological motion and people and negatively correlated with inverted biological motion and geometry. However, no significant correlations were found in the ASD group. CONCLUSIONS: Our exploratory results suggest that salivary OT levels in adolescents and adults with ASD are less indicative of attention to social stimuli than they are in TD adolescents and adults. It is suggested that their association is slightly weaker in adolescents and adults with ASD and that this attenuated relationship appears to be maintained throughout development.

Oxytocin efficacy is modulated by dosage and oxytocin receptor genotype in young adults with high-functioning autism: a 24-week randomized clinical trial.

Recent studies have suggested that long-term oxytocin administration can alleviate the symptoms of autism spectrum disorder (ASD); however, factors influencing its efficacy are still unclear. We conducted a single-center phase 2, pilot, randomized, double-blind, placebo-controlled, parallel-group, clinical trial in young adults with high-functioning ASD, to determine whether oxytocin dosage and genetic background of the oxytocin receptor affects oxytocin efficacy. This trial consisted of double-blind (12 weeks), open-label (12 weeks) and follow-up phases (8 weeks). To examine dose dependency, 60 participants were randomly assigned to high-dose (32 IU per day) or low-dose intranasal oxytocin (16 IU per day), or placebo groups during the double-blind phase. Next, we measured single-nucleotide polymorphisms (SNPs) in the oxytocin receptor gene (OXTR). In the intention-to-treat population, no outcomes were improved after oxytocin administration. However, in male participants, Clinical Global Impression-Improvement (CGI-I) scores in the high-dose group, but not the low-dose group, were significantly higher than in the placebo group. Furthermore, we examined whether oxytocin efficacy, reflected in the CGI-I scores, is influenced by estimated daily dosage and OXTR polymorphisms in male participants. We found that >21 IU per day oxytocin was more effective than ⩽21 IU per day, and that a SNP in OXTR (rs6791619) predicted CGI-I scores for ⩽21 IU per day oxytocin treatment. No severe adverse events occurred. These results suggest that efficacy of long-term oxytocin administration in young men with high-functioning ASD depends on the oxytocin dosage and genetic background of the oxytocin receptor, which contributes to the effectiveness of oxytocin treatment of ASD.

Phenoxazinone synthesis by human hemoglobin.

We found that 2-amino-5-methylphenol was converted to the dihydrophenoxazinone with a reddish brown color by purified human hemoglobin, lysates of human erythrocytes, and human erythrocytes. The reddish brown compound was identified as 2-amino-4,4 alpha-dihydro-4 alpha,7-dimethyl-3H-phenoxazin-3-one by the measurement of NMR spectra, IR spectra, EI mass spectra, and absorption spectra. The changes in this phenoxazinone were studied under various conditions after mixing 2-amino-5-methylphenol with purified oxy- or methemoglobin, or with human erythrocytes. The production of 2-amino-4,4 alpha-dihydro-4 alpha,7-dimethyl-3H-phenoxazine-3-one from 2-amino-5-methylphenol was found to be tightly coupled with the oxidation of ferrous hemoglobin and reduction of ferric hemoglobin under aerobic conditions. By studying the production rates of the dihydrophenoxazinone and the oxido-reduction rates of ferrous and ferric hemoglobins during the reactions of ferrous or ferric hemoglobin with 2-amino-5-methylphenol under aerobic and anaerobic conditions, the reaction mechanism was extensively proposed.

Antitumor effects of a novel phenoxazine derivative on human leukemia cell lines in vitro and in vivo.

2-Amino-4,4alpha-dihydro-4alpha,7-dimethyl-3H-phenoxazine-3-one (Phx) was synthesized by reacting 2-amino-5-methylphenol with bovine hemolysates. Because Phx is a phenoxazine derivative like actinomycin D, we examined its effects on the proliferation of the human leukemia cell lines K562, HL-60, and HAL-01. Phx inhibited proliferation and induced apoptosis in all of the leukemia cell lines we tested, in a dose-dependent manner. We further investigated the antitumor effect of this compound on HAL-01-bearing nude mice. Treatment with Phx markedly reduced the tumor growth rate in the experimental group, as compared with the control group. Moreover, Phx was found to have few adverse effects on weight loss and WBC count. In addition, we examined the effects of Phx on human normal hematopoietic progenitor cells by a clonogenic assay, and we observed less suppression of normal progenitor cells than of leukemic progenitors. These results suggest that Phx may be used to treat patients affected by different types of leukemia.

Disturbed circadian core body temperature rhythm and sleep disturbance in school refusal children and adolescents.

We examined the circadian rhythm of core body temperature (CBT) in 22 school refusal patients, ages between 12 and 18 years, who did not have any physical or psychiatric disorders, but had indefinite complaints, and were suspected to have a circadian rhythm disturbance. To obtain normal data for analysis, CBT in 9 healthy age-matched school attendants who did not have any sleep, psychiatric, or medical disturbance were monitored. Circadian variation of CBT in school refusal patients did not present a clear rhythm, and appearance time of their lowest CBT was markedly delayed compared to healthy subjects. Amplitude of circadian CBT changes, fitted to a cosinor curve by the least square method, was significantly smaller in school refusals than in healthy subjects. These findings suggest that in school refusal patients who do not have physical and psychiatric disorders, clinical psychosomatic symptoms (e.g., fatigue and memory disturbance) and school refusal could be closely related to the desynchronization of their biorhythms, particularly the circadian rhythm of body temperature and sleep-wake rhythm.

Effect of transmethylation-reaction and increased levels of cAMP on superoxide generation of guinea-pig macrophages induced with wheat germ agglutinin and phorbor myristate.

Superoxide (O2-) generation of guinea-pig macrophages induced by wheat germ agglutinin (WGA) was suppressed to a great extent by the inhibition of transmethylation with 3'-deazaadenosine. When macrophages were stimulated with phorbor myristate (PMA) instead of WGA, the suppression of O2- generation of macrophages was observed to be slight despite the presence of 3'-deazaadenosine. These results were confirmed under various conditions. Thus the WGA-stimulated O2- generation of macrophages is probably associated with transmethylation, but the PMA-stimulated O2- generation is not. WGA-stimulated O2- generation of macrophages was also inhibited in the presence of dibutyryl cAMP or prostaglandin E2 (PGE2), substances that increase intracellular cAMP, but PMA-stimulated O2- generation was only slightly affected by these compounds. These results suggest that the mechanism for O2- generation of macrophages caused by WGA is different from that for O2- generation caused by PMA.

Mechanism of o-aminophenol metabolism in human erythrocytes.

o-Aminophenol was found to be rapidly metabolized to a brown compound in the presence of purified human oxy- and methemoglobin, coupled with the oxidation and reduction of these hemoglobins by o-aminophenol. The final product of o-aminophenol was identified as 2-aminophenoxazine-3-one, by using spectrophotometry and HPLC. The metabolism of o-aminophenol was also observed in human erythrocytes. The production rates of 2-aminophenoxazine-3-one in the cells were very fast, but these were strongly decreased by bubbling carbon monoxide into the cell suspension when intracellular hemoglobin was in the ferrous state. The production of 2-aminophenoxazine-3-one from o-aminophenol in the cells was completely suppressed by cyanide and azide when intracellular hemoglobin was in the ferric state. These results suggest that oxy- and methemoglobin are involved in metabolism of o-aminophenol to 2-aminophenoxazine-3-one in human erythrocytes.

Spectroscopic studies of brunescent cataractous lenses.

The absorption spectra of brunescent cataractous lenses and their homogenates were analyzed under various conditions by using a double wavelength spectrophotometer. The absorption spectra of the samples were in good agreement with those of synthetic xanthommatin derived from 3-hydroxykynurenine. The results provided evidence that brown pigment in the brunescent cataractous lenses is mainly composed of xanthommatin.

Abolishment of inhibitory effects of 3'-deazaadenosine on superoxide generation of guinea pig phagocytes by pre-exposure to phorbol myristate acetate.

Superoxide generation by guinea pig macrophages and polymorphonuclear leukocytes induced by wheat germ agglutinin, immune complexes or formyl-methionyl-leucyl-phenylalanine was inhibited considerably by 3'-deazaadenosine. The pre-exposure of the 3'-dezazaadenosine-treated cells to a small amount of phorbol myristate acetate abolished the inhibitory effect of 3'-deazaadenosine on the generation of superoxide.

Atrophy of the cerebellum and brainstem in dentatorubral pallidoluysian atrophy. Influence of CAG repeat size on MRI findings.

To elucidate how the size of the expanded CAG repeat of the gene for dentatorubral pallidoluysian atrophy (DRPLA) and other factors affect the atrophy of the brainstem and cerebellum, and the appearance of high-intensity signals on T2-weighted MRI of the cerebral white matter of patients with DRPLA, we quantitatively analyzed the MRI findings of 26 patients with DRPLA, the diagnosis of which was confirmed by molecular analysis of the DRPLA gene. When we classified the patients into two groups based on the size of the expanded CAG repeat of the DRPLA gene (group 1, number of CAG repeat units > or = 66; group 2, number of CAG repeat units < or = 65), we found strong inverse correlations between the age at MRI and the areas of midsagittal structures of the cerebellum and brainstem in group 1 but not in group 2. Multiple regression analysis, however, revealed that both the patient's age at MRI and the size of the expanded CAG repeat correlated with the areas of midsagittal structures. Involvement of the cerebral white matter as detected on T2-weighted images was observed more frequently in patients belonging to group 2 than in group 1 patients. Furthermore it was demonstrated that high-intensity signals can be detected on T2-weighted images of the cerebral white matter of patients with a largely expanded CAG repeat (group 1) in their thirties. These results suggest that patient age as well as the size of the expanded CAG repeat are related to the degree of atrophy of the brainstem and cerebellum, and the white matter changes in patients with DRPLA.

Inhibitory action of chloramine on formate-metabolizing system. Studies suggested by an unusual case record.

We previously reported on a patient exposed simultaneously to methyl chloride and chloramine gas who developed metabolic acidosis and permanent blindness [M. Minami et al., Hum Exp Toxicol 11: 27-34, 1992]. The case report suggested the possibility of potentiation of methyl chloride toxicity by chloramine. The potentiating mechanism was investigated by exposing mice to methyl chloride followed by ammonia chloramine, and then the level of formate in urine samples was measured with an enzyme coupling method to detect disturbance of formate metabolism. Mice dosed with 0.05 mL 1.0 mM chloramine after methyl chloride exposure excreted a significantly larger amount of urinary formate than mice treated with only methyl chloride. There was no difference in urinary formate levels between mice treated with only 0.05 mL 1.0 mM chloramine and those given only the vehicle (0.1 M phosphate buffer pH 6.0) for chloramine. The underlying biochemical mechanism of deterioration of formate metabolism was found to be the inhibition of the enzyme, N10-formyl tetrahydrofolate (N10-f-THF) dehydrogenase by 0.56-3.35 microM chloramine in the in vitro experiment using the purified enzyme. Positive control mice, given orally 0.1 mL 10% methanol in 0.1 M phosphate buffer (pH 6.0) excreted the same amount of urinary formate as those receiving 0.05 mL 1.0 mM chloramine after methanol administration. This was ascribed to the inhibitory effect of chloramine on formaldehyde dehydrogenase and depletion of substrate for further metabolism. The inhibition of the enzyme by chloramine (2.7-100.8 microM) was confirmed by in vitro experiments, using the purified enzyme, formaldehyde dehydrogenase.

Antitumor activity of a phenoxazine compound, 2-amino-4,4alpha-dihydro-4alpha,7-dimethyl-3H-phenoxazine-3-one against human B cell and T cell lymphoblastoid cell lines: induction of mixed types of cell death, apoptosis, and necrosis.

PURPOSE: We studied the antitumor activity of 2-amino-4,4alpha-dihydro-4alpha,7-dimethyl-3H-phenoxazine-3-one (Phx), which was synthesized by the reactions of 2-amino-5-methylphenol with bovine hemoglobin, on human B cell lymphoblastoid cell lines, P3HR-1 and Raji derived from African Burkitt's lymphoma, and the human T cell lymphoblastoid cell line Molt-4. We also studied whether Phx might cause apoptosis and necrosis in these cells. METHODS: We evaluated cell viability and apoptosis and necrosis of the cells in the presence of Phx, by using agarose gel electrophoresis, flow cytometry, and fluorescence microscopy. RESULTS: Phx suppressed the viability of P3HR-1, Raji, and Molt-4 cells, though the suppression patterns were different, i.e., Phx suppressed the viability of P3HR-1, Raji, and Molt-4 cells at higher concentrations, while the drug enhanced the viability of Raji cells, but not those of P3HR-1 and Molt-4 cells at lower concentrations. To investigate which type of cell death - apoptosis or necrosis - is induced by Phx, induction of DNA ladder, phosphatidylserine externalization, and propidium iodide-permeable cells were examined in Phx-treated cells. Although Phx did not induce DNA ladder formation, it induced the phosphatidylserine externalization and propidium iodide-permeable cells, suggesting that Phx caused a mixed type of cell death, both apoptosis and necrosis. The population of early stage apoptotic cells was dominant in Raji cells, and that of the late stage apoptotic/necrotic cells was dominant in Molt-4 cells after 72-h treatment with Phx. The population of the early stage apoptotic cells and the late stage apoptotic/necrotic cells was almost equal in P3HR-1 cells in the presence of Phx, though the population of both types of cells increased with time. The nuclear morphological analysis of Phx-treated Raji, P3HR-1, and Molt-4 cells also showed that Phx induces apoptosis. CONCLUSIONS: The present results suggest that Phx shows antitumor activity against human B cell-derived and T cell-derived lymphoblastoid cell lines, in vitro, causing apoptosis and necrosis.

Oxidative condensation of 2-amino-4-methylphenol to dihydrophenoxazinone compound by human hemoglobin.

2-Amino-4-methylphenol was converted to a brownish yellow material by the lysates of human erythrocytes or purified human hemoglobin. The reaction proceeded oxidatively, coupled with the oxidation of hemoglobin. The major component of the brownish yellow material produced by oxidative condensation of 2-amino-4-methylphenol was identified as 3-amino-1,4 alpha-dihydro-4 alpha, 8-dimethyl-2H-phenoxazin-2-one on the basis of its spectral data including NMR spectra, IR spectra, EI mass spectra, and absorption spectra. The changes in 3-amino-1,4 alpha-dihydro-4 alpha,8-dimethyl-2H-phenoxazin-2-one during incubation of purified human hemoglobin and 2-amino-4-methylphenol were analyzed spectrophotometrically and by using HPLC. The reaction mechanism involved may be similar to that of actinomycin synthase, which oxidizes 2-amino-5-methylphenol to the dihydrophenoxazinone.

Intracellular pH (pHi) of red cells stored in acid citrate dextrose medium. Effects of temperature and citrate anions.

The intracellular pH (pHi) of red cells stored in acid citrate dextrose (ACD) medium was estimated by the 5,5'-dimethyloxazoldine,-2,4-dione (DMO) method. The initial pHi at 4degrees was about 7.6 and was higher than the extracellular pH (pHe) at 4degrees. During storage, both pHi and pHe decreased, but the former was always higher than the latter and the former decreased more slowly than the latter. The high pHi of ACD blood was a results of the temperature at which the pHe and the pHi were measured (4degrees) and the presence of citrate anions in the medium, and could be explained by application of the Donnan-Gibbs equilibrium. ATP and 2,3-diphosphoglycerate (DPG) were well-maintained in heparinized blood when it was acidified and pHe and pHi at 4degrees were both about 7.4, which suggests that improvement of blood preservation may be attained by suitable adjustment of the pHi and pHe of the blood.

Glycolysis of red cells suspended in solutions of impermeable solutes. Intracellular pH and glycolysis.

The glycolytic rate human red cells suspended in a sucrose medium of low or physiological pH was higher than that of the cells suspended in Ringer's medium of the same. pH. The medium pHP-glycolytic rate curve of red cells suspended in soucrose media shifted to the acidic side by about one unit compared with that of cells suspended in Ringer's medium. Similarly, the pattern of glycolytic intermediates in red cells suspended in a sucrose medium resembled that in cells suspended in Ringer's solution of about one unit higher pH. These phenomena could be ascribed to the change of intracellular pH, which was measured by the 5,5'-dimethyl-oxazolidine-2,4-dione method. A similar stimulation of glycolysis was observed when sodium citrate was added to red cells suspended in Ringer's solution at constant pH. These observations indicate that membrane-impermeable non-electrolytes or anions stimulate glycolysis of red cells by elevation ofthe intracellular pH. Red cell glycolysis is influenced mainly by the intracellular pH rather than by the pH of the suspending medium.

Accumulation of phosphoenolpyruvate in red cells incubated with the phosphate ester in an acidified isotonic sucrose medium.

Accumulation of exogenous phosphoenolpyruvate against the concentration gradient was observed when human red cells were incubated in an acidified isotonic sucrose medium. Fluoride increased the apparent accumulation by inhibition of the intracellular metabolic interconversion of the phosphate compound. The accumulation appeared to be specific for phosphoenolpyruvate and the accumulation rate for 3-phosphoglycerate, which has a molecular size and pKa similar to those of phosphoenolpyruvate, was less than one-tenth of the rate of phosphoenolpyruvate. Red cells incubated in the acidified sucrose medium tended to adhere to each other when examined with a scanning electron microscope.

Multi-effective properties of homogentisic acid revealed in reactions with human hemoglobin and human erythrocytic hemoglobin.

Homogentisic acid (HGA) causes oxidation of human oxyhemoglobin and reduction of methemoglobin. The rate of oxidation of oxyhemoglobin by HGA is greatly accelerated in the presence of myo-inositol hexakis-phosphate (P6-inositol) or superoxide dismutase (SOD), but is inhibited in the presence of catalase. The reduction rate of methemoglobin by HGA is accelerated in the presence of P6-inositol but is greatly inhibited in the presence of SOD. It is suggested that the semiquinone and quinone form of HGA and oxygen radicals may be involved in the mechanism of oxido-reductive reactions of human hemoglobin with HGA. In addition, a new anodic hemoglobin found by isoelectric focusing electrophoresis was produced during the reaction of oxyhemoglobin with HGA. When human erythrocytes were exposed to HGA for several hours at 37 degrees C (pH 7.4), the anodic oxyhemoglobin (HGA-modified hemoglobin) and its half met-form hemoglobin [(alpha3+beta2+)2 of HGA-modified hemoglobin] were produced in significant amounts. HGA-modified hemoglobin was stably purified and showed increased oxygen affinity, absence of titratable sulfhydryl groups, and the absorption spectrum of normal oxyhemoglobin. Our results demonstrate that HGA shows multiple effects on human hemoglobin and erythrocytic hemoglobin, which is consistent with the evidence that HGA is involved in various pathological conditions such as arthritis and carcinogenesis in humans.

Psychiatric disorders among Japanese children.

OBJECTIVE: To generate current data on the prevalence of psychiatric disorders among Japanese children, using DSM-III-R criteria. METHOD: As part of an ongoing longitudinal study in a Japanese community sample, 114 mother-child dyads were interviewed when the children were approximately 8 years old. DSM-III-R disorders of the children were diagnosed through the administration of a structured diagnostic instrument, the parent and child versions of the Child Assessment Schedule, to both the children and their mothers. RESULTS: The prevalence rate for any diagnosis was 49.1%, which is similar to that of U.S. children and adolescents. CONCLUSION: The Child Assessment Schedule is an appropriate scale for assessing the psychopathology of Japanese children, which is as prevalent as in a U.S. sample.

Hemolytic anemia in hereditary pyrimidine 5'-nucleotidase deficiency. II. Effect of pyrimidine nucleotides and their derivatives on glycolytic and pentose phosphate shunt enzyme activity.

We evaluated the glycolytic intermediate concentrations from the erythrocytes of a patient with hereditary pyrimidine 5'-nucleotidase (P5'N) deficiency. Conclusive evidence for a metabolic block was not found. We evaluated the effects of the pyrimidine (cytidine and uridine) tri- and diphosphate nucleotides (CTP, CDP, UTP, UDP) and the choline and ethanolamine derivatives of CDP (CDP-choline, CDP-ethanolamine) on the activities of key enzymes of the Embden-Meyerhof pathway. CTP and UTP inhibited fructose-6-phosphate competitively for phosphofructokinase and phosphoenolpyruvate competitively for pyruvate kinase. In both cases, the Ki of the pyrimidine nucleotide and Km of the glycolytic substrate were above their intraerythrocytic concentrations. CTP was a competitive inhibitor of ADP for pyruvate kinase with a Ki near its intraerythrocytic concentration. CDP-choline and CDP-ethanolamine had no effect on the activities of Embden-Meyerhof or pentose phosphate shunt enzymes. Thus, the nature of the hemolytic anemia in hereditary P5'N deficiency remains enigmatic.

Circadian rhythm abnormalities in adrenoleukodystrophy and methyl B12 treatment.

A 13-year-old male with adrenoleukodystrophy (ALD) developed a sleep-wake disorder after complete vision loss. He had a 25-h sleep-wake cycle. After methyl B12 therapy, circadian rhythms in his plasma melatonin and beta-endorphin levels approximated those of healthy volunteers, and his peak cortisol time shifted backward. Daily deep body temperature (DBT) amplitude was smaller than in healthy males before and after the treatment, and his acrophase did not change. However, his sleep-wake rhythm became normal. Methyl B12 is considered useful for treating circadian rhythm disturbances in patients having central nervous system disorders and blindness.