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Biomedical subjects

A Takatsu

Publications and source records attributed to A Takatsu.

At least 19 recordsLinked to original sources
PubMed2003

Determination of tributyltin in marine sediment: Comité Consultatif pour la Quantité de Matière (CCQM) pilot study P-18 international intercomparison.

The capabilities of National Metrology Institutes (NMIs-those which are members of the Comité Consultatif pour la Quantité de Matière (CCQM)of the CIPM) and selected outside "expert" laboratories to quantitate (C(4)H(9))(3)Sn(+) (TBT) in a prepared marine sediment were assessed. This exercise was sanctioned by the 7th CCQM meeting, April 4-6, 2001, as an activity of the Inorganic Analysis Working Group and was jointly piloted by the Institute for National Measurement Standards of the National Research Council of Canada (NRC) and the Laboratory of the Government Chemist (LGC), UK. A total of 11 laboratories submitted results (7 NMIs, and 4 external labs). Two external laboratories utilized a standard calibration approach based on a natural abundance TBT standard, whereas all NMIs relied upon isotope dilution mass spectrometry for quantitation. For this purpose, a species specific (117)Sn-enriched TBT standard was supplied by the LGC. No sample preparation methodology was prescribed by the piloting laboratories and, by consequence, a variety of approaches was adopted by the participants, including mechanical shaking, sonication, accelerated solvent extraction, microwave assisted extraction and heating in combination with Grignard derivatization, ethylation and direct sampling. Detection techniques included ICP-MS (with GC and HPLC sample introduction), GC-MS, GC-AED and GC-FPD. Recovery of TBT from a control standard (NRCC CRM PACS-2 marine sediment) averaged 93.5+/-2.4% ( n=14). Results for the pilot material averaged 0.680+/-0.015 micro mol kg(-1) ( n=14; 80.7+/-1.8 micro g kg(-1)) with a median value of 0.676 micro mol kg(-1). Overall, performance was substantially better than state-of-the-art expectations and the satisfactory agreement amongst participants permitted scheduling of a follow-up Key comparison for TBT (K-28), a Pilot intercomparison for DBT (P-43), and certification of the test sediment for TBT content and its release as a new Certified Reference Material (HIPA-1) with a TBT content of 0.679+/-0.089 micro mol kg(-1) (expanded uncertainty, k=2, as Sn) (80.5+/-10.6 micro g kg(-1)).

Journal Article↗
PubMed2001

Changes in blood viscosity by heparin and argatroban.

Anticoagulants are effective for preventing both venous and arterial thrombosis. Although antithrombotic agents have been reported to reduce thrombin formation, to our knowledge, the relation between blood viscosity (BV) and antithrombotic agents has not been examined. We examined the effects on whole BV of various dosages of the antithrombotic agents-heparin sodium and argatroban. Thirty microliters of either drug was added to 3-ml samples of blood obtained from healthy male volunteers. Whole BV was then immediately examined with an oscillation-type viscometer. When either agent was added, BV decreased and coagulation time increased dose dependently. BV was 4.5+/-0.3 mPa.s in untreated blood but decreased in a dose-dependent manner to a minimum of 2.5+/-0.3 mPa.s with heparin sodium and decreased dose dependently in a sigmoid manner with argatroban. Because thrombin generation is inhibited in all antithrombotic therapies, this inhibition might be reflected by changes in BV. Our results suggest that BV in accordance with blood coagulability are indexes of thrombotic tendency and that decreasing BV prevents life-threatening thromboembolic conditions.

Adult↗
PubMed2001

Immunohistochemistry of atrial natriuretic peptide in brain infarction.

Atrial natriuretic peptide (ANP) was originally isolated from cardiac atria, and has potent natriuretic, diuretic, and vasorelaxant properties. It has been localized in neurons and astrocytes in the cerebral cortex and the white matter. We hypothesize that glial ANP may contribute to the regulation of cerebral blood flow in brain infarction. In order to elucidate this possible role, the immunohistochemistry of ANP was studied in cases of brain infarction and in other cases of brain trauma for comparison. A statistically significant increase in the number of ANP-immunoreactive glial cells (mainly astrocytes) was observed in the white matter surrounding the brain infarction compared with the intact area. No statistically significant increase in ANP-immunoreactive glial cell number was observed in the cerebral white matter from brain haemorrhage, contusion and control cases. Our results indicate that glial ANP may increase in number in brain infarction, and that it may be involved in the regulation of the cerebral blood flow in the infarcted area.

Adult↗
PubMed2001

Incomplete decapitation of a motorcyclist from hyperextension by inertia: a case report.

This is a rare case involving a motorcyclist. A 57 year old motorcycle rider wearing a full face type helmet, suffered incomplete decapitation. The autopsy findings revealed a wide lacerated wound accompanied by extension marks in the front neck, atlanto-occipital dislocation and complete transection of the brainstem. According to the police traffic report, the man's head was stationary at the moment of impact and the remainder of the body continued in a backward motion. We concluded that the inertia of the torso caused hyperextension of the neck and subsequent incomplete decapitation.

Accidents, Traffic↗
PubMed2001

[An autopsy case of accidental hanging during home care].

A 73-year-old man who had suffered from old myocardial and cerebral infarction for 4 years had been secured in wheelchair due to left hemiplegia and aphasia and also been received a home care of his wife. One day, his wife tied a cloth belt around his head and secured it to the wheelchair to prevent the flexion of his neck. One hour later, he was found dead by his wife. He also had slipped down in his wheelchair. The autopsy performed 24 hours after death revealed a ligature marks on the front of the neck. Petechial hemorrhages, visceral congestion and fluid blood, compatible with asphyxial death, were also found. Although severe cerebral cortical atrophy, old myocardial infarction, moderate to severe atherosclerosis and decubitus of the back were also found, they were not considered primary cause of death. No other anatomical or toxicological cause of death was present. Therefore, we concluded that the man died of accidental hanging. Recently, the home care of aged or handicapped patient is a social problem in Japan due to the increase in the number of elderly people. The death was caused by the inappropriate restraints used by his wife. This case suggests the importance of proper advice to non-professional caretakers from care professionals.

Accidents, Home↗
PubMed2000

Rheologic changes in venous blood during prolonged sitting.

We examined blood rheologic changes, mainly blood viscosity, during long-term quiet sitting. Samples of blood were obtained from the arm and foot veins of the healthy adult male volunteers before and after 2 h of quiet sitting. Blood viscosity, was immediately determined with an oscillation viscometer, and blood count and blood chemistry were analyzed. We found that the viscosity in blood from a foot vein but not from an arm vein increased significantly after 2 h of sitting. Our results show that 2 h of quiet sitting can increase thrombotic tendency locally in the leg but not systemically and suggests the importance of measuring focal venous blood viscosity.

Adult↗
PubMed2000

Immunohistochemical localization of P-selectin in the glomeruli from forensic autopsies.

The expression of the adhesion molecule P-selectin is known to be up-regulated in several vital organs including the kidney after trauma in experimental animals. We examined the expression of P-selectin in the kidney by immunohistochemistry in 41 forensic autopsies mainly from trauma cases. P-selectin immunoreactivity was present in the glomerular capillary endothelial tufts and cortical interstitial vascular endothelial cells. The P-selectin immunoreactivity in the glomeruli was not co-localized with CD41 (platelet marker) immunoreactivity. The antemortem interval between the onset of injury and death (AMI) was statistically significantly longer in the cases with more P-selectin-positive capillary endothelial tufts in the glomeruli. Our results show that P-selectin immunoreactivity exists in the glomerular capillary endothelial cells rather than platelets. Our results also indicate that the P-selectin expression increases in the glomerular endothelial cells of the human kidney with the longer duration of the state under injury.

Journal Article↗
PubMed2000

A case of strangulation by a vehicle seat belt.

A healthy 23-year-old man wearing a three-point seat belt suffered from a roll-over traffic accident. When the man was found, the fastened seat belt had loosened and the diagonal belt was tightened against the neck. Autopsy findings revealed ligature marks on the surface of the neck, hemorrhages in the muscles of the neck, petechial hemorrhages in palpebral conjunctivae and viscera, dark red liquid blood in the heart cavities and visceral congestion. We concluded that the man died of strangulation by the seat belt. In this case, the loose belt allowed the body to move and subsequently the diagonal belt applied external pressure to the neck while the car was rolling over. Although there have been several reports of neck injuries due to diagonal belts, this is the first report of strangulation by a properly used three-point belt in a roll-over vehicle accident.

Journal Article↗
PubMed2000

Injury severity in motor vehicle occupants.

We performed a retrospective analysis of injury severity and the effect of seat belt use with findings from forensic autopsies of 50 persons who had died in motor vehicle accidents. From autopsy findings and accident reports, the abbreviated injury scale (AIS) and the injury severity score (ISS) were calculated and analyzed epidemiologically. Among unrestrained occupants, drivers usually sustained more severe chest and abdominal injuries. Furthermore, three-point seat belts significantly decreased the severity of drivers' chest and abdominal injuries. Our results may be useful for forensic pathologists and clinicians and for mechanical engineers who investigate new safety devices for vehicle occupants.

Journal Article↗
PubMed2000

An immunohistochemical study on cathepsin D in human hippocampus.

Cathepsin D is a lysosomal enzyme involved in neuronal degeneration. In this study, the immunohistochemistry of cathepsin D was studied in hippocampal CA1 neurons that are vulnerable to ischemia, and parahippocampal glial cells. CA1 neurons from the majority of cases showed cathepsin D immunoreactivity in the cytoplasm, whereas shrunk neurons were unstained in only one case. There was no statistically significant correlation between the postmortem interval between death and autopsy, and cathepsin D immunoreactivity in CA1 neurons. These observations indicate that cathepsin D immunoreactivity is not a sensitive marker for neuronal degeneration or postmortem changes. On the other hand, there was a statistically significant correlation between age and cathepsin D immunoreactivity in the cytoplasm of parahippocampal glial cells. This shows that senescence is correlated with cathepsin D expression in humans as has been reported previously in an animal study.

Adolescent↗
PubMed2000

An autopsy case of sudden death in a patient with idiopathic scoliosis.

A 38-year-old woman with idiopathic scoliosis (right convex thoracic scoliosis, 78 degrees; left convex lumbar curvature, 75 degrees) died suddenly. Forensic autopsy and histopathologic examination revealed chronic congestive oedema, numerous cavities and atrophic changes of heart. These changes, including both respiratory changes and biventricular failure caused by hypoplastic cardiac changes, were due to a deformed thoracic cage. This case illustrates that not only abnormalities of respiratory function and cor pulmonare, but also hypoplastic cardiac changes, may cause sudden death in a patient with untreated scoliosis.

Adult↗
PubMed2000

[A proposal of essentials for forensic pathological diagnosis of sudden infant death syndrome (SIDS)].

There are many sudden unexpected infant death cases which are easily diagnosed as sudden infant death syndrome (SIDS) both with or without autopsy in Japan. A SIDS diagnosis may provide a cover for accidental or criminal death. SIDS should not be a convenient diagnostic box that shelters the cases of unexpected infant death which lack the necessary antemortem information to make the correct diagnosis. The authors consider that SIDS should be diagnosed according to the direction of the international definition of SIDS, and propose the following essentials for a forensic pathological diagnosis. 1) A thorough autopsy should be performed based on precise autopsy protocol, including not only histological observation, but also, if necessary, toxicological, bacteriological, viral and/or biochemical examinations. 2) The forensic pathologist should be provided with pertinent information regarding antemortem health status, past clinical history, social circumstances, death scene investigation, etc. In order to collect more precise information, the authors recommend using a questionnaire such as the example in this report to record information from the deceased's guardians. 3) Suspicion of accidental death or infanticide should be completely ruled out. SIDS should be diagnosed only after these three essentials have been satisfied. When there is even a slight suspicion of accidental death or infanticide, or when the forensic pathologist can not obtain pertinent information about the deceased, the causes and classification of the death should be diagnosed as unspecified or undetermined. That is, the causes and classification of the death are undetermined as to whether it is a natural or unnatural death. Furthermore, several warning flags indicating a possible SIDS diagnosis were proposed: a case found dead in a supine position, the existence of a foreign body in the respiratory tract or mild infectious findings. The authors also emphasize the physician's responsibility to report a case found dead or dying of unnatural or clinically unexplained causes to the police. This is the crucial first step in getting an accurate diagnosis of SIDS.

Autopsy↗
PubMed2000

[Survey on postmortem examination to police surgeons and emergency physicians. Possibility of physicians' assist in mass-disaster].

We conducted a questionnaire survey of police surgeons and emergency physicians, inquiring about their experience of medicolegal investigation of death and their willingness to join a death investigation team in a major disaster. The questionnaire also asked about their knowledge about and interest in the forensic specialist system established by the Japanese Society of Legal Medicine. Police surgeons were generally willing to join an investigation team only if a disaster occurred in or close to their hometown, because they could not afford more than several days away from patient care. Although many of the emergency physicians were willing to join a death investigation team, they had difficulty in doing so without permission or orders from their employer or the authorities concerned. The survey found that the percentage of aged police surgeons was increasing among those surveyed. This fact, in combination with the current emphasis of postgraduate education on specialty training, threatens to cause a substantial lack of physicians available for medicolegal investigation of death. Therefore, it is urgently necessary to establish a system of training resident and emergency physicians in medicolegal investigation of death. In addition to providing postgraduate training in medicolegal investigation of death to prospective trainees who are emergency physicians at major hospitals in potential disaster-stricken areas, the medical school should incorporate forensic medicine in postgraduate training programs so that they can actively perform death investigation on disaster victims dying before or after arrival at their hospitals. Furthermore, the forensic community should make every effort to increase the number of autopsies in each department of forensic medicine and to expand the medical examiner system throughout Japan that is currently in practice only in the Metropolis of Tokyo and Yokohama, Nagoya, Osaka and Kobe Cities in order to incorporate forensic training in the postgraduate clinical training programs that will become compulsory in 2004.

Attitude of Health Personnel↗
PubMed1999

Immunohistochemical localization of c-fos in the nuclei of the medulla oblongata in relation to asphyxia.

The immediately early gene product c-fos is known to be induced in neurons under noxious stimuli. Therefore, the immunohistochemistry of c-fos expression in human brains might offer information on the localization of stimulated neurons. In this study, the immunohistochemical localization of c-fos was studied in the neurons of the hypoglossal nucleus (XII), the dorsal motor nucleus of the vagal nerve (X), the nucleus solitarius (Sol), the accessory cuneate nucleus (Cun), the spinal trigeminal nucleus (V) and the inferior olive (Oli) of the human medulla oblongata from forensic autopsy cases. The neurons in the X nucleus showed the highest percentage of positive reactions for c-fos, followed in descending order by the Cun, V, Oli, XII and Sol. The c-fos immunoreactivity in the Cun and X was statistically significantly higher than in the Sol, XII and Oli. Although neurons in the Sol are known to be involved in respiration, there was no statistically significant difference in the c-fos immunoreactivity in the neurons in the Sol between asphyxia and non-asphyxia cases. On the other hand, the percentage of neurons positive for the c-fos immunoreactivity was statistically significantly higher in the Oli of asphyxia cases than of non-asphyxia cases. Our results indicate the difference in the immunoreactivity of c-fos among the nuclei of the human medulla oblongata and that the c-fos immunoreactivity in the Oli might assist the diagnosis of asphyxia.

Adolescent↗
PubMed1999

Arsenic accumulation in organs of the fresh water fish Tribolodon hakonensis.

The fish Tribolodon hakonensis lives in good health in Lake Usoriko, which has been acidified and naturally contaminated with arsenic by volcanic activities. We have determined the contents of various metals in various fish organs of T. hakonensis, collected at Lake Usoriko. We found that a large amount of arsenic was accumulated in the eye, especially in the choroid-retina part. The arsenic concentrations in the liver and kidneys were about 0.4 microgram/g (wet), whereas the muscle contained less arsenic. The arsenic accumulation in the skin was also observed, especially in the epaxial part. Zinc and arsenic contents in various fish organs correlated well.

Animals↗
PubMed1999

The concept of the digital morgue as a 3D database.

The concept of the construction of a 3-dimensional database of a body structure, or a digital morgue, and its advantages to the field of forensic medicine was proposed. The digital morgue stores the body structure of each case as a 3D data set of sectioning planes of the whole body obtained from computer tomograms or magnetic resonance imaging figures. Furthermore, the medical virtual reality technique makes it possible to perform a simulated autopsy of the body in the digital morgue (virtual autopsy). Therefore, in the digital morgue, retrospective observation and quantitative analysis of the structural damage of the body are possible using high-dimensional medical imaging and medical virtual reality.

Journal Article↗