A stroke patient with impairment of auditory sensory (echoic) memory.

A 42-year-old man suffered damage to the left supra-sylvian areas due to a stroke and presented with verbal short-term memory (STM) deficits. He occasionally could not recall even a single syllable that he had heard one second before. A study of mismatch negativity using magnetoencephalography suggested that the duration of auditory sensory (echoic) memory traces was reduced on the affected side of the brain. His maximum digit span was four with auditory presentation (equivalent to the 1st percentile for normal subjects), whereas it was up to six with visual presentation (almost within the normal range). He simply showed partial recall in the digit span task, and there was no self correction or incorrect reproduction. From these findings, reduced echoic memory was thought to have affected his verbal short-term retention. Thus, the impairment of verbal short-term memory observed in this patient was "pure auditory" unlike previously reported patients with deficits of the phonological short-term store (STS), which is the next higher-order memory system. We report this case to present physiological and behavioral data suggesting impaired short-term storage of verbal information, and to demonstrate the influence of deterioration of echoic memory on verbal STM.

Age-related DNA methylation analysis for forensic age estimation using post-mortem blood samples from Japanese individuals.

As one of external visible characteristics (EVCs) in forensic phenotyping, age estimation is essential to providing additional information about a sample donor. With the development of epigenetics, age-related DNA methylation may be used as a reliable predictor of age estimation. With the aim of building a feasible age estimation model for Japanese individuals, 53 CpG sites distributed between 11 candidate genes were selected from previous studies. The DNA methylation level of each target CpG site was identified and measured on a massive parallel platform (synthesis by sequencing, Illumina, California, United States) from 60 forensic blood samples during the initial training phase. Multiple linear regression and quantile regression analyses were later performed to build linear and quantile age estimation models, respectively. Four CpG sites on four genes- ASPA, ELOVL2, ITGA2B, and PDE4C -, were found to be highly correlated with chronological age in DNA samples from Japanese individuals (|R| > 0.75). Subsequently, an independent validation dataset (n = 30) was used to verify and evaluate the performance of the two models. Comparison of mean absolute deviation (MAD) with other indicators showed that both models provide accurate age predictions (MAD: linear = 6.493 years; quantile = 6.243 years). The quantile model, however, can provide the changeable prediction intervals that grow wider with increasing age, and this tendency is consistent with the natural aging process in humans. Hence, the quantile model is recommended in this study.

A new deleted allele in the human cytochrome P450 2A6 (CYP2A6) gene found in individuals showing poor metabolic capacity to coumarin and (+)-cis-3,5-dimethyl-2-(3-pyridyl)thiazolidin-4-one hydrochloride (SM-12502).

The S-oxidation of (4)-cis-3,5-dimethyl-2-(3-pyridyl)thiazolidin-4-one hydrochloride (SM-12502) and the 7-hydroxylation of coumarin are primarily catalyzed by cytochrome P450 2A6 (CYP2A6). The activities of SM-12502 S-oxidase and coumarin 7-hydroxylase were investigated with liver microsomes from 20 human individuals. Liver microsomes from individual H16 showed the lowest activities of both enzymes. The expression of CYP2A6 protein was not detectable in liver microsomes from individuals H4, H5, H7, H8, H12 and H16. CYP2A6 mRNA was hardly detectable in the liver of the individual H16. A new SacI-restriction fragment length polymorphism showing the lack of a 2.6 kb fragment was found in two of forty genomic DNA preparations from individuals H16 and No. 594, using CYP2A6 cDNA as a probe. This deletional 2.6 kb fragment was isolated from a genomic library prepared from one individuals showing normal coumarin 7-hydroxylase activity and was sequenced. This fragment contained a CYP2A6 gene region from 319 bp upstream of a putative exon 6 to a SacI site in exon 9, indicating that this region was deleted in the two individuals in this study. We also demonstrated by polymerase chain reaction analysis that the exon 8 of CYP2A6 gene was deleted in individuals H16 and No. 594. These results indicate that the reduced activity of SM-12502 S-oxidase and no activity of coumarin 7-hydroxylase are caused by the lack of CYP2A6 mRNA and CYP2A6 protein caused by the CYP2A6 gene deletion.

Cloning and expression localization of cDNA for rat homolog of TRP protein, a possible store-operated calcium (Ca2+) channel.

A 3.2 kbp cDNA clone encoding a possible candidate for the store-operated Ca2+ channel was isolated from a rat brain cDNA library. The deduced amino acid sequence was 51.8% identical to TRP encoded by a Drosophila trp (transient receptor potential) gene and contained ankyrin motifs, a coiled-coil structure and six transmembrane segments similar to the previously identified TRP family and named as TRP-R (rat TRP). By in situ hybridization histochemistry of rat body on embryonic day 15, no significant expression signal for TRP-R was detected. On embryonic day 20 and postnatal day 1, the expression signals were most evident in the septum, cerebral cortical plate and hippocampal neuronal layers. On postnatal day 7 and thereafter the expression in the cerebral cortex and the septum decreased progressively, and weak expression remained only in the CA1 and CA2 neuronal layers of the hippocampus in the brain on postnatal day 21 and 49. This limited spatiotemporal expression of this novel molecule. TRP-R, suggests that it is involved in some specific functions related to the neuronal differentiation.

Genetic polymorphism in the 5'-flanking region of human CYP1A2 gene: effect on the CYP1A2 inducibility in humans.

A genetic polymorphism was identified in the 5'-flanking region of human CYP1A2 gene, and its effect on the transcriptional activation of the CYP1A2 gene was investigated. Nucleotide sequence analysis revealed the existence of a point mutation from guanine (wild type) to adenine (mutated type) at position -2964 in the gene. This point mutation was detected by a polymerase chain reaction-restriction fragment length polymorphism method using DdeI or BslI restriction enzyme, and was proven to be genetically inherited. Allele frequency in 116 Japanese subjects showed 0.77 and 0.23 for the wild and mutated types of allele, respectively. The point mutation caused a significant decrease of CYP1A2 activity measured by the rate of caffeine 3-demethylation in Japanese smokers (p<0.05). Gel retardation analysis showed the existence of protein bound to the polymorphic locus. These results suggest that this polymorphism is a causal factor of decreased CYP1A2 inducibility.

Intracellular Ca2+ store-operated influx of Ca2+ through TRP-R, a rat homolog of TRP, expressed in Xenopus oocytes.

To elucidate whether rat transient receptor potential (TRP-R), a rat TRP4 homolog, functions as a store-operated Ca2+ channel (SOC), we have measured the Ca2+ entry after thapsigargin treatment in Xenopus oocytes injected with mRNA for TRP-R. While non-injected oocytes elicited an SOC response, significantly larger responses were observed in the oocytes expressing TRP-R. The oocyte-native SOC response was inhibited by injection of antisense oligodeoxyribonucleotide for mammalian TRP1. When Ca2+ concentration-SOC response curve was examined, the EC50 value was much smaller in oocytes expressing TRP-R than that of non-injected oocytes. These results suggest that TRP-R functions as SOC having higher sensitivity to external Ca2+ than amphibian TRP1 channel.

Changes in cerebral blood flow accompanied with reduction of blood pressure treatment in patients with hypertensive intracerebral hemorrhages.

Blood pressure usually is reduced in patients with hypertensive intracerebral hemorrhage for the prevention of the expansion of the hematoma and recurrent hemorrhage in acute stage. However, disturbed autoregulation of cerebral circulation is expected, and decreased cerebral blood flow (CBF) caused by excessive hypotension has been pointed out. There are different mechanisms of action in hypotensives, thereby the influence of hypotension on CBF in patients with the thalamic hemorrhage was investigated using nitroglycerin (TNG), diltiazem hydrochloride (DH) and trimethaphan camsilate (TC). Average CBF in a hemisphere on the hematoma side, the hemisphere without hematoma, and around the hematoma showed a slight decline after administration of TNG or DH. However, CBF declined more, after TC than DH. DH and TNG are preferable in descending order to control blood pressure of patients with intracerebral hemorrhage in the acute stages in view of a smaller decline in CBF.

Catecholaminergic neurons in the diencephalon and basal ganglia of SIDS.

The catecholaminergic systems of sudden infant death syndrome victims were examined in the diencephalon and basal ganglia, in addition to the midbrain, pons, and medulla oblongata, using the immuno-histochemical method involving tyrosine hydroxylase. A significant decrease in tyrosine hydroxylase immunoreactivity was demonstrated in the basal ganglia of sudden infant death syndrome victims between 2 to 12 months of age compared with age-matched control subjects. This change in the basal ganglia may be a secondary finding induced by chronic hypoxia or repeated ischemia in sudden infant death syndrome but suggests impairment of the development of the neuronal connection from the brainstem to the upper cardiorespiratory control in sudden infant death syndrome.

Immunochemical determinant of Candida parapsilosis.

Acetolysis of Candida parapsilosis cell-wall D-mannan, obtained by alkali extraction and purified as a copper complex, gave six oligosaccharides by Bio-Gel P-2 filtration. Their chemical structure was examined by 1H-n.m.r. spectroscopy, methylation analysis, and partial acid hydrolysis. The structures of the penta- and hexa-saccharide were alpha-D-Manp-(1 leads to 3)-alpha-D-Manp-(1 leads to 2)-alpha-D-Manp-(1 leads to 2)-alpha-D-Manp-(1 leads to 2)-D-Man (M5) and alpha-D-Manp-(1 leads to 2)-alpha-D-Manp-(1 leads to 3)-alpha-D-Manp-(1 leads to 2)-alpha-D-Manp-(1 leads to 2)-alpha-D-Manp-(1 leads to 2)-D-Man (M6), respectively. Inhibition of the oligosaccharides with anti-C. parapsilosis serum and homologous D-mannan indicated that although M5 and M6 exhibited strong inhibitory-activity, M6 was the more effective inhibitor, and suggested that M6 may be the immunodominant or may be responsible for the specificity of C. parapsilosis mannan in the precipitin-reaction system, or both.

Red cell phosphoglucomutase (PGM1) subtypes in Egyptians.

The polymorphism of the human red cell phosphoglucomutase 1 (PGM1) in samples from Egyptians (n = 134) was investigated using isoelectric focusing in thin-layer polyacrylamide gel. In the studied population samples nine common phenotypes were observed, and the calculated frequencies for the genes PGM1+1, PGM1-1, PGM2+1 and PGM2-1 were 0.6381, 0.0821, 0.2201 and 0.0597, respectively. The observed and expected phenotypes provide a good fit to Hardy-Weinberg equilibrium. The four alleles system will increase the probability of excluding a man falsely accused of paternity to 30% as compared with 16% if the two alleles system is used.

Detection of diatoms in blood by a combination of membrane filtering and chemical digestion.

An improved method for detecting diatom in blood is reported. Blood of cadavers was obtained by cardiac puncture at inquest or from the left atrium directly at autopsy. The blood was hemolyzed by sodium dodecyl sulfate (SDS) and filtered through membrane filter (47 mm in diameter and 5 microns in pore size). When the blood was putrefied, two or three pieces of membranes filters were needed because of choking membrane pore. The membrane filters were digested with fuming nitric acid and diluted with distilled water. The diluted solution was filtered through membrane filter (25 mm in diameter) again. After drying the membrane filter was immersed in oil. Diatoms on the membrane filter were clearly observed microscopically.

On an accident by liquid nitrogen--histological changes of skin in cold.

Two young researchers were found lying beside 3 Dewar flasks for liquid nitrogen in a cold experimental room of a university. They were sent to a hospital but died 1.5 h after cardiopulmonary resuscitation. One of the cadavers had dark red discoloration of the skin on the left arm at autopsy. By the histological investigation of the discolored region karyopyknosis and vacuolation of the keratinocytes were noticeably observed in the epidermis. In addition, hyperemia and edematous changes were seen. Hemoglobin (Hb) was not immunodetected in the skin tissue except intravascular erythrocytes. Therefore, these histological findings of the discolored skin can indicate that the skin damage was produced by cold due to liquid nitrogen before death. The cause of death was asphyxia due to oxygen deficiency. There were few autopsy findings which showed the participation of liquid nitrogen in the accident. But, the histological findings of the discolored region demonstrate that liquid nitrogen was involved in this accident.

Polymorphism of 17 STRs by multiplex analysis in Japanese population.

Genotype and distribution of allele frequencies at 17 STRs were studied in 526 unrelated Japanese individuals using the PowerPlex 16 system and the AmpFlSTR Identifiler.

Case report: repeated neonaticides in Hokkaido.

Five cases of repeated neonaticides were reported in Hokkaido, the northernmost island of Japan, during the 10 years from 1983 to 1992. Four or more neonates were involved in each case by each mother. All the suspected mothers were not mentally ill. Two of them were single and the rest were married. Each husband was not aware of the pregnancy of his wife, because he was away from home very often. The main motive of murder seemed to be economic and/or to save appearances. Sentences were 1 year penal servitude with a stay of 3 years for one case, but 30-42 months in prison for the other four cases. We rarely find reports of repeated infanticides committed by the same mother in European countries and the United States.

Paraquat myopathy: report on two suicide cases.

We describe two suicide cases in which old paraquat was ingested. In conjunction with lung involvement a pronounced degeneration was observed in skeletal muscle of one who died on the 14th day after the ingestion. The following sarcoplasmic or endoplasmic reticulum Ca2+ ATPase (SERCA) monoclonal antibodies were used for skeletal muscle fiber typing by an immunohistochemical method: NCL-SERCA1, reactive with type 2 fiber (fast-twitch), and NCL-SERCA2, reactive with type 1 fiber (slow-twitch). The examination revealed that the remarkably degenerated fibers belonged to type 1 muscle fibers. This case showed an abrupt increase of plasma CK levels (1796 mU/ml) on the fifth day after the ingestion. The authors presume that the damage to the skeletal muscle had occurred in this period. The degeneration of the muscle seemed to be attributable to the long retention of paraquat in the tissue because these findings were not observed in the other case who died on the fifth day. Paraquat-induced myopathy may develop in prolonged paraquat poisoning. The examination of CK levels in plasma will be useful for diagnosis of damage of skeletal muscle.

Distribution of Aconitum alkaloids in body fluids and tissues in a suicidal case of aconite ingestion.

A case involving a suicidal ingestion of Aconitum tubers is presented. A 40-year-old woman in Hokkaido, Japan ingested ground aconite and died of aconite intoxication about 4 h after ingestion. The Aconitum alkaloids were quantitated using gas chromatography-selected ion monitoring from extracts of the body fluids and organs. The blood and urine concentrations of jesaconitine, the main alkaloid of the aconite in this case, were 69.1 ng/mL and 237.8 ng/mL, respectively. Higher values of the alkaloid were demonstrated in the kidneys, the liver, and in the bile rather than other organs or serum, suggesting the alkaloids were eliminated by the liver and kidneys. In the gastrointestinal tract, the highest value of jesaconitine (471.3 ng/g) was in the ileal contents. These findings show that Aconitum alkaloids were found in the liver and kidneys in much higher concentrations than in serum and suggest that they were eliminated not only via urine but also in feces. Feces may be useful to detect Aconitum alkaloid if other biological samples are not available.

Acute hemorrhagic edema in a four-year-old Japanese boy.

A case of acute hemorrhagic edema (AHE), a unique form of leukocytoclastic vasculitis limited only to the skin, was seen in a four-year-old boy. It was characterized by an abrupt onset of fever, peripheral edema, and rosette-shaped purpuric plaques. Although the skin lesion might be confused clinically with other dermatoses such as Henoch-Schönlein purpura, Sweet's disease and erythema multiforme, his laboratory data were normal, and the disorder follows a benign course with spontaneous resolution within one week.

Regional differences in homicide patterns in five areas of Japan.

This article describes regional differences in the homicide patterns which occurred in Sapporo City and the surrounding area, and in Akita, Ibaraki, Chiba and Toyama prefectures in Japan. Information collected from each case of homicide included factors such as age, sex of the victim and assailant, causes of death, disposition of the offender, relationship between assailant and victim, reasons for criminal action, et al. The statistical features of homicidal episodes among the five different regions showed considerable variation, as follows. The mean death rates for homicide (number of victims per 100,000 of population) during the period 1986-1995 were 0.44 (Sapporo), 0.8 (Akita), 0.58 (Toyama), 0.7 (Ibaraki) and 0.75 (Chiba), respectively. Close family relationship between the victim and assailant was observed in the homicidal acts which occurred in Sapporo, Akita and Toyama. Assailant's relationship to victim was commonly extra-familial in Ibaraki and Chiba-neighboring megalopolis Tokyo, where some events of murder by a foreigner occurred. Homicide by female assailant, murder by mentally abnormal killers and homicide-suicide events were closely associated with family members. And these factors contributed to the considerable number of victims in Sapporo, Akita and Toyama. But, this close family relationship of the victim to the assailant did not correspond with the elevation in the number of deaths, and it was rather inversely related to the higher death rates recognized in Ibaraki and Chiba. This comparative study suggested that rapid urbanization considerably affects regional differences in homicide patterns.

Child death related to insulin omission by mother.

A 4-year-old child was found dead in her house. She had been suffering from insulin-dependent diabetes mellitus (IDDM) for 3 years. She had been admitted to hospital three times, and attended the hospital once a month. Her glycaemic control remained poor. Autopsy findings revealed a remarkably fatty liver and lack of beta cells in the pancreatic islets of Langerhans. The laboratory reported ketoacidosis, ketonuria, glycosuria, and high levels of vitreous glucose and ketones. Her father had been absent for the 3 days before her death, and the mother should have fed her. Her mother was found drunk on the floor. No detailed history was available because of the mother's death, but the probability of the mother's omission of the insulin injection was suggested. Poor control of IDDM might have also been closely connected to general neglect by the mother. This case was considered child abuse.