Biomedical subjects

K Ishida

Publications and source records attributed to K Ishida.

At least 91 records · Page 5Linked to original sources

PubMed2001

Extended aortic grafting for acute ascending dissection after type B dissection.

A 31-year-old man was diagnosed with acute ascending aortic dissection and massive aortic regurgitation following acute type B dissection during drug treatment. Although the aortic arch was not dissected, we performed aortic replacement from the aortic root to the proximal portion of the descending aorta. The aim of the operation was the prevention of aortic arch dissection, and closure of initial entry of type B dissection.

Adult↗

PubMed2001

[Radiographic examination of skeletalized remains of an abandoned infant: a case report with special reference to odontological findings].

A homeless couple confessed that they had buried their baby, who died at the age of three months, in the graveyard two years earlier. The recovered infantile remains had been already completely skeletonized and dismembered. However, the maxilla and mandibula of the average matured infants, the age of the body was estimated to be 1 to 2.5 months old on the basis of the degree of calcification of deciduous teeth.

Age Determination by Teeth↗

PubMed2000

Timing of N-methyl-N-nitrosourea administration affects gastric carcinogenesis in Mongolian gerbils infected with Helicobacter pylori.

In Mongolian gerbils, the gastric mucosa shows dramatic changes after Helicobacter pylori inoculation. The influence of the timing of N-methyl-N-nitrosourea (MNU) administration after H. pylori inoculation on gastric carcinogenesis was investigated. Ninety-two gerbils were divided into four groups. One group was given MNU at 24 weeks, and another at 1 week, after H. pylori inoculation. The other groups received only MNU. Stomachs were excised for histological examination 20 weeks after completing the MNU treatment. Carcinomas arose only in animals given MNU 1 week after H. pylori inoculation. In the relationship between H. pylori and gastric carcinogenesis, H. pylori is a promoter rather than an initiator, and other environmental factors (the timing of MNU administration) play important roles.

Adenocarcinoma↗

PubMed2000

Kasumigamide, an antialgal peptide from the cyanobacterium Microcystis aeruginosa.

Kasumigamide (1), a novel antialgal tetrapeptide containing an N-terminal alpha-hydroxy acid, was isolated from the freshwater cyanobacterium Microcystis aeruginosa (NIES-87). Its structure was elucidated by two-dimensional (1)H-(1)H and (1)H-(13)C NMR correlation experiments and confirmed by mass spectral and amino acid analyses. The absolute stereochemistry of 1 was determined by chemical studies. This peptide showed an antialgal activity against the green alga Chlamydomonas neglecta (NIES-439).

Amino Acids↗

PubMed2000

Child and elderly victims in forensic autopsy during a recent 5 year period in the southern half of Osaka city and surrounding areas.

To outline the recent features of child and elderly victims from the medico-legal perspective with special reference to abuse and neglect, a retrospective investigation of forensic autopsy cases over a 5 year period (1994-1998) in the southern half of Osaka city and surrounding areas (a population of 1.57 million) was undertaken. Among 646 autopsy cases, there were 53 child cases (under the age of 15 years, about 80% below 6) and 121 elderly cases (65 years old and above). Nearly half of the child deaths and more than half of the elderly deaths were described as accidental. Fire and traffic victims were much more frequent in the elderly. Child victims included those of neonaticide/infanticide (n=6), physical abuse (n=10), unintentional fatal infliction (n=2), neglect (n=2), mutual suicide (n=2), suicide (n=1) and murder (n=3). Child abuse and neglect were domestic maltreatment by the parents. In this series, there was a comparable number of fatalities due to maltreatment in the elderly (n=13) and in children, and non-domestic violence was more frequent in the elderly than domestic violence. Elderly females tended to be battered by their sons or grandsons in domestic violence cases, whereas males were predominantly attacked by younger males in non-domestic violence. The other elderly victims included those of self-neglect (n=2), murder (n=7) and suicide (n=9). Non-domestic homicide of the elderly occurred mainly in the center of the city, whereas domestic maltreatment of children and the elderly was sporadic, although somewhat more frequent in the peripheral zone of the city and the surrounding areas. The above profile of child and elderly abuse suggests a substantial influence of social and familial backgrounds.

Accidents↗

PubMed2000

Automated determination of carboxyhemoglobin contents in autopsy materials using head-space gas chromatography/mass spectrometry.

To establish a method for the routine analysis of carboxyhemoglobin (COHb) in autopsy materials including those which have undergone postmortem changes, e.g. thermo-coagulation, putrifaction and contamination, an automated head-space gas chromatography/mass spectrometry (GC/MS) analysis was utilized. The procedure consisted of preparation of the sample in a vial and a carbon monoxide (CO) saturated sample, for estimation of hemoglobin content, in another vial, the addition of n-octanol, potassium ferricyanide and an internal standard (t-butanol), GC separation and determination of CO using a GC/MS system equipped with an automated head-space gas sampler. The method was practical not only with the blood and bone marrow aspirates to confirm the findings on the CO-oximeter system, but also with the thermo-coagulated and putrified blood.

Automation↗

PubMed2000

Novel approach to quantitative reverse transcription PCR assay of mRNA component in autopsy material using the TaqMan fluorogenic detection system: dynamics of pulmonary surfactant apoprotein A.

A novel approach to quantitative reverse transcription (RT)-PCR assay of mRNA component using fluorescent TaqMan methodology and a new instrument (ABI Prism 7700 sequence detection system) was developed for autopsy materials. Pulmonary surfactant apoprotein A (SP-A) mRNA from a cadaveric lung was quantitated in real-time. The target SP-A gene and the endogenous reference of glyceraldehyde-3-phosphate (GAPDH) were amplified in the same tube, and an amount of the target was normalized to the reference. This assay had a high reproducibility and discrimination even in forensic autopsy materials up to 96 h postmortem. Elevated SP-A expressions were determined in some cases. This system without post-PCR sample handling would be a very useful tool in pathological diagnosis and DNA analysis.

Adolescent↗

PubMed2000

Immunohistochemical distribution of C-reactive protein in the hepatic tissue in forensic autopsy.

Previously, we examined the expression of C-reactive protein (CRP) in hepatic tissues in fatal injuries (injury deaths) immunohistochemically, and classified the CRP distribution into three patterns: diffuse (D-) pattern, diffuse with strong positivity in the hepatic lobules; periportal (PP-) pattern, characterized by positive cells in the periportal region of some lobules; focal (F-) pattern, showing small islands of positive cells in some lobules. There was a relationship between the CRP distribution and the survival time. In this study, we further analyzed the deaths including those due to other than fatal injuries (non-injury deaths), and a study of a total of 314 deaths from various causes was performed. Generally, non-injury deaths showed findings similar to those in injury deaths. PP- and/or F-patterns were observed in 43.7% of cases having a short survival time (<6 h), but found in only 3% of those surviving longer (>6 h), showing that such findings are suggestive of a short survival time. D-pattern was found more frequently in non-acute deaths (60.4%), than in acute deaths (10.9%). In acute deaths, D-pattern was found in some cases showing extensive tissue injuries, such as burns and polytrauma, and inflammative predisposition. Immunohistochemical findings also showed some correlation with the serum CRP level. Our data suggest that hepatic CRP immunohistochemistry may be a useful tool for elucidating the dying process.

Acute Disease↗

PubMed2000

Immunohistochemistry of pulmonary surfactant apoprotein A in forensic autopsy: reassessment in relation to the causes of death.

To reassess the immunohistochemical distribution of pulmonary surfactant apoprotein A (SP-A) in relation to the causes of death, 282 forensic autopsy cases were reviewed. The most intense and dense granular immunostaining of intra-alveolar SP-A was observed in the hyaline membrane syndrome from various traumas, protracted death from drowning, and perinatal aspiration of amniotic fluid. Similar granular staining pattern was found in fatal poisoning by a muscle relaxant and organophosphate pesticides. An evident increase of intra-alveolar granular staining was noted in most fatalities from mechanical asphyxia and drowning, and some cases of fire death. SP-A staining was usually very weak or sparse in alcohol intoxication, poisoning by hypnotics and also carbon monoxide poisoning. These findings suggest that the amount of intra-alveolar granular SP-A staining may be a possible indicator of severity and duration of respiratory distress (agony) from peripheral (non-central nervous system) origin and alveolar damage.

Asphyxia↗

PubMed2000

Methamphetamine-related fatalities in forensic autopsy during 5 years in the southern half of Osaka city and surrounding areas.

To outline the recent features of methamphetamine-related fatalities from the medico-legal point of view, a retrospective investigation of forensic autopsy cases involving methamphetamine during a 5-year period (1994-1998) in the southern half of Osaka city and surrounding areas (about 1.57 million population) was undertaken. Among 646 autopsy cases, methamphetamine was detected in 15 victims (nine males, six females; 16-71 years of age; most frequently in males in their thirties). Primary scenes of fatal events were concentrated in the middle of the city. About half of them were transferred from emergency medical centers (survival time, up to 30 h). The cause and manner of death were: methamphetamine poisoning (n=4), homicide (n=4), accidental falls and aspiration from drug abuse (n=4), fire death (n=1), myocardial infarction (n=1), and cerebral hemorrhage (n=1) under drug influence. Usually injection scars and fresh puncture sites were found. Blood methamphetamine concentrations were 2.29-17.05 micromol/dl in the fatal poisoning, 0. 44-3.80 micromol/dl in deaths from other extrinsic causes (trauma), and 1.35-2.17 micromol/dl in cardio- and cerebrovascular strokes. Common complications were cardiomyopathy, cerebral perivasculitis and liver cirrhosis/interstitial hepatitis. Fatal and nonfatal methamphetamine poisonings are separately dealt with by the administrative medical examiner's office and in emergency medical centers. Tightly cooperative approaches of clinical and medico-legal experts are required for the effective social and medical management of drug abuse.

Adolescent↗

PubMed2000

Anisotropic superconducting gap in the spin-triplet superconductor Sr2RuO4: evidence from a Ru-NQR study

We have investigated a gap structure in the spin-triplet superconductor Sr2RuO4 through the measurement of the 101Ru nuclear spin-lattice relaxation rate (101)(1/T1) down to 0.09 K at zero magnetic field. In the superconducting state, 1/T1 in a high-quality sample with T(c) approximately 1.5 K exhibits a sharp decrease without the coherence peak, followed by a T3 behavior down to 0.15 K. This result is in marked contrast to the behavior observed below approximately 0.4 K in samples with lower T(c), where T1T is a constant. This behavior is demonstrated to be not intrinsic. We conclude that the gap structure in Sr2RuO4 is significantly anisotropic, consistent with line-node-like models.

Journal Article↗

PubMed2000

The alkaline single cell electrophoresis assay with eight mouse organs: results with 22 mono-functional alkylating agents (including 9 dialkyl N-nitrosoamines) and 10 DNA crosslinkers.

The genotoxicity of 22 mono-functional alkylating agents (including 9 dialkyl N-nitrosoamines) and 10 DNA crosslinkers selected from IARC (International Agency for Research on Cancer) groups 1, 2A, and 2B was evaluated in eight mouse organs with the alkaline single cell gel electrophoresis (SCGE) (comet) assay. Groups of four mice were treated once intraperitoneally at the dose at which micronucleus tests had been conducted, and the stomach, colon, liver, kidney, bladder, lung, brain, and bone marrow were sampled 3, 8, and/or 24 h later. All chemicals were positive in the SCGE assay in at least one organ. Of the 22 mono-functional alkylating agents, over 50% were positive in all organs except the brain and bone marrow. The two subsets of mono-functional alkylating agents differed in their bone marrow genotoxicity: only 1 of the 9 dialkyl N-nitrosoamines was positive in bone marrow as opposed to 8 of the 13 other alkylating agents, reflecting the fact that dialkyl N-nitrosoamines are poor micronucleus inducers in hematopoietic cells. The two groups of mono-functional alkylating agents also differ in hepatic carcinogenicity in spite of the fact that they are similar in hepatic genotoxicity. While dialkyl N-nitrosoamines produce tumors primarily in mouse liver, only one (styrene-7,8-oxide) out of 10 of the other type of mono-functional alkylating agents is a mouse hepatic carcinogen. Taking into consideration our previous results showing high concordance between hepatic genotoxicity and carcinogenicity for aromatic amines and azo compounds, a possible explanation for the discrepancy might be that chemicals that require metabolic activation show high concordance between genotoxicity and carcinogenicity in the liver. A high percent of the 10 DNA crosslinkers were positive in the SCGE assay in the gastrointestinal mucosa, but less than 50% were positive in the liver and lung. In this study, we allowed 10 min alkali-unwinding to obtain low and stable control values. Considering that DNA crosslinking lesions can be detected as lowering of not only positive but also negative control values, low control values by short alkali-treatment might make it difficult to detect DNA crosslinking lesions. In conclusion, although both mono-functional alkylating agents and DNA crosslinkers are genotoxic in mouse multiple organs, the genotoxicity of DNA crosslinkers can be detected in the gastrointestinal organs even though they were given intraperitoneally followed by the short alkali-treatment.

Alkylating Agents↗

PubMed2000

Presynaptic impairment of cerebellar inhibitory synapses by an autoantibody to glutamate decarboxylase.

Glutamic acid decarboxylase (GAD), the enzyme responsible for converting glutamate to gamma-aminobutyric acid (GABA), is a target of humoral autoimmunity in stiff-man syndrome and subacute cerebellar ataxia. Recently, we found that an anti-GAD autoantibody in the CSF of an ataxic patient selectively suppressed GABA-mediated transmission on cerebellar Purkinje cells without affecting glutamate-mediated transmission. Here, we examine the mechanism by which the autoantibody impaired the inhibitory transmission, using immunohistochemistry and whole-cell recording in rat cerebellar slices. The present results indicate that CSF immunoglobulins prepared from an ataxic patient acted on the presynaptic terminals of GABAergic interneurons and decreased GABA release onto Purkinje cells.

Action Potentials↗

PubMed2000

Pulmonary surfactant-associated protein A levels in cadaveric sera with reference to the cause of death.

Pulmonary surfactant-associated protein A (SP-A) is an exclusively lung specific protein, and is considered to leak into the blood stream in alveolar septal damage. In this study we examined the serum SP-A level in forensic autopsy materials using an enzyme immunoassay with monoclonal antibodies to assess the postmortem level in relation to the cause and mode of death. Although a gradual postmortem degradation should be taken into consideration, topological relationship of serum level seemed to be fairly stable (arterial> or =venous blood in most cases), indicating no evident influence of postmortem diffusion. Significant elevation of serum SP-A (76.7-250 ng/ml in left heart blood) was observed in hyaline membrane diseases from various causes independent of the postmortem intervals (<30 h). However, mean SP-A levels in postmortem heart blood were usually low in asphyxia including hanging, strangulation and choking (left, 25.5 ng/ml; right, 22.3 ng/ml), polytrauma (left, 13.1 ng/ml; right, 9.0 ng/ml) and stab wound to the neck (left, 34.1 ng/ml; right, 29.4 ng/ml). Prominent elevation was noted in a case of fatal strangulation with complication of idiopathic interstitial pneumonia, and also in some deaths due to drowning, burns in fires, blunt and gunshot chest injuries. These findings indicated that postmortem elevation of serum SP-A levels was associated with alveolar septal damage due to inflammation, mechanical and physical stresses, which caused leakage of SP-A into the bloodstream.

Adolescent↗

PubMed2000

The comet assay in eight mouse organs: results with 24 azo compounds.

The genotoxicity of 24 azo compounds selected from IARC (International Agency for Research on Cancer) groups 2A, 2B, and 3 were determined by the comet (alkaline single cell gel electrophoresis, SCG) assay in eight mouse organs. We treated groups of four mice once orally at the maximum tolerated dose (MTD) and sampled stomach, colon, liver, kidney, bladder, lung, brain, and bone marrow 3, 8, and 24 h after treatment. For the 17 azo compounds, the assay was positive in at least one organ; (1) 14 and 12 azo compounds induced DNA damage in the colon and liver, respectively, (2) the genotoxic effect of most of them was greatest in the colon, and (3) there were high positive responses in the gastrointestinal organs, but those organs are not targets for carcinogenesis. One possible explanation for this discrepancy is that the assay detects DNA damage induced shortly after administration of a relatively high dose, while carcinogenicity is detected after long treatment with relatively low doses. The metabolic enzymes may become saturated following high doses and the rates and pathways of metabolic activation and detoxification may differ following high single doses vs. low long-term doses. Furthermore, considering that spontaneous colon tumors are very rare in rats and mice, the ability to detect tumorigenic effects in the colon of those animals might be lower than the ability to detect genotoxic events in the comet assay. The in vivo comet assay, which has advantage of reflecting test chemical absorption, distribution, and excretion as well as metabolism, should be effective for estimating the risk posed by azo dyes to humans in spite of the difference in dosage regimen.

Animals↗

PubMed2000

Type II pneumocytes are preferentially located along thick elastic fibers forming the framework of human alveoli.

Type II pneumocytes were found to be preferentially located on thick elastic fibers which formed the main structural framework of the alveoli in humans. Eight lobes resected from eight patients with adenocarcinoma or atypical adenomatous hyperplasia and two lobes from two necropsies were examined. Four small specimens of normal lung tissue were obtained from each lobe fixed in a buffered formalin. Thick sections (200-300 microm) were stained with hematoxylin to contrast nuclei or with elastica staining to demonstrate elastic fibers and immunostained with an antibody against Thomsen-Friedenreich antigen after pretreatment with sialidase to visualize type II pneumocytes. Alveolar structure and the distribution of type II pneumocytes were examined in 3D reconstructions generated using a standard microscope, a personal computer and NIH-Image software. Nuclei including those of type I and type II pneumocytes and endothelial cells were distributed diffusely throughout the alveolar wall. Thick elastic fibers constructed the main structural framework of the alveoli and formed the sides of the polygonal alveoli. Type II pneumocytes were found to be linearly located along these thick elastic fibers. This previously undisclosed distribution of type II pneumocytes may be concerned with alveolar rapid movement.

Adult↗

PubMed2000

Ataxin-3 is translocated into the nucleus for the formation of intranuclear inclusions in normal and Machado-Joseph disease brains.

Machado-Joseph disease (MJD)/spinocerebellar ataxia type 3 (SCA3) is one of the dominantly inherited cerebellar ataxias. The gene responsible for the disease, a novel gene of unknown function, encodes ataxin-3 containing a polyglutamine stretch. Although it has been known that ataxin-3 is incorporated into neuronal intranuclear inclusions (NIIs) in neurons of affected regions, the relationship between NII formation and neuronal degeneration still remains uncertain. In the present study we show two different conditions in which ataxin-3 is recruited into the nucleus and suggest a process to form nuclear inclusions. In normal brains, wild-type ataxin-3 localizes within the ubiquitin-positive nuclear inclusion, the Marinesco body, indicating that ataxin-3 is recruited into the nuclear inclusion even in the absence of pathologically expanded polyglutamine. In MJD/SCA3 brains, immunohistochemical analyses with anti-ataxin-3 antibody, anti-ubiquitin antibody, and monoclonal antibody 1C2 known to recognize expanded polyglutamine revealed differences in frequency and in diameter among NIIs recognized by each antibody. These results were confirmed in the same inclusions by double immunofluorescent staining, suggesting that expanded ataxin-3 forms a core, thereby recruiting wild-type ataxin-3 into the nucleus around the core portion, and then followed by activation of the ubiquitin/ATP-dependent pathway. Recruitment of ataxin-3 into the nucleus and formation of nuclear inclusion under two different conditions suggest that ataxin-3 may be translocated into the nucleus under certain conditions stressful on neuronal cells such as aging and polyglutamine neurotoxicity.

Ataxin-3↗

PubMed2000

Improved recovery of trace amounts of gold (III), palladium (II) and platinum (IV) from large amounts of associated base metals using anion-exchange resins.

The adsorption and desorption behaviors of gold (III), palladium (II) and platinum (IV) were surveyed in column chromatographic systems consisting of one of the conventional anion-exchange resins of large ion-exchange capacity and dilute thiourea solutions. The noble metals were strongly adsorbed on the anion-exchange resins from dilute hydrochloric acid, while most base metals did not show any marked adsorbability. These facts made it possible to separate the noble metals from a large quantity of base metals such as Ag (I), Al (III), Co (II), Cu (II), Fe (III), Mn (II), Ni (II), Pb (II), and Zn (II). Although it used to be very difficult to desorb the noble metals from the resins used, the difficulty was easily overcome by use of dilute thiourea solutions as an eluant. In the present study, as little as 1.00 microg of the respective noble metals was quantitatively separated and recovered from as much as ca. 10 mg of a number of metals on a small column by elution with a small amount of dilute thiourea solution. The present systems should be applicable to the separation, concentration and recovery of traces of the noble metals from a number of base metals coexisting in a more extended range of amounts and ratios.

Journal Article↗