PubMed Health⌕ Search

Biomedical subjects

Toshiaki Nagai

Publications and source records attributed to Toshiaki Nagai.

At least 19 recordsLinked to original sources
PubMed2006

Changes in blood viscosity with the recombinant tissue plasminogen activator alteplase.

We measured whole blood viscosity to investigate the time course of the fibrinolytic activity of the recombinant tissue plasminogen activator alteplase. Changes in blood viscosity over time were determined using an oscillation-type viscometer at a shear rate of 400 to 500 per second. Blood viscosity initially increased with alteplase as in untreated blood, but then decreased, reflecting the fibrinolytic activity of generated plasmin. Blood viscosity subsequently stabilized at a level below the initial value owing to the dissolution of both fibrin and fibrinogen by alteplase. To our knowledge, the present study is the first to examine the time course of changes in BV during fibrin formation and degradation. The results indicated that the fibrinolyic agent alteplase might provide the additional benefit of increasing blood flow by lowering blood viscosity.

Blood Viscosity↗
PubMed2006

Fungi can be a useful forensic tool.

We present a practical case in which the fungi have contributed to the estimation of postmortem interval of the cadaver. A 71-year-old man wearing a shirt and pants was found dead at the bottom of an open well about 6m below the ground in his garden. Externally the face was dotted with colonies of white fungi, which was devoid of dipteran larvae and other insects. The fungi were identified as Penicillium sp. and Aspergillus terrous. These fungi, widely inhabit in the life circumstances, can generally colonize 3-7 days after attaching on the subjects. The appearance of the body surface, the state of decomposition of various organs, police information describing that the man had last been seen 12 days before discovery and the fungal evidence indicated that the man had been dead for about 10 days. We suggest that fungi can provide an useful means of estimating the minimum interval since death when forensic entomology is not applicable. Although, no data about growth rates of the fungi on human cadavers have been available, further researches should be needed to clarify the successive colonization of fungi on human cadavers.

Aged↗
PubMed2006

Accidental strangulation of a mentally retarded patient by a clothing collar: a case report.

A 40-year-old mentally retarded woman died of accidental strangulation in a nursing home. She was found in a kneeling position with her hands on her knees and the collar of her clothing compressing the front and sides of the neck. Before the accident, a nurse had dressed the patient in one-piece overall-style pyjamas put on back to front so that she could not remove the garment herself. The post-mortem findings and reconstruction of the scene of death suggested that the patient had been strangled by the collar of her backward-facing clothing while in a kneeling position. Because patients with psychiatric illnesses may have a limited ability to recognize or communicate symptoms of physical danger, they must be closely monitored by knowledgeable medical and nursing staff. This case highlights the importance of preventing the accidental deaths of mentally retarded patients in nursing homes.

Accidents, Home↗
PubMed2005

Accidental choking in a patient with Treacher Collins syndrome.

A 3-year-old boy with Treacher Collins syndrome had undergone tracheostomy and placement of a secured cannula at the age of 4 months. When he was 3 years old, he manually extracted the secured cannula by himself and choked to death. Autopsy revealed upper airway obstruction with posterior deviation and mucosal hyperplasia of the radix linguae, mandibular hyperplasia, and occlusion of the artifical airway owing to intratracheal granuloma due to the long-standing tracheotomy. For safe, long-term use of a tracheostomy to maintain the airway, children with craniofacial abnormalities should be carefully supervised by their families to prevent accidental decannulation.

Accidents↗
PubMed2005

3. Sudden death due to pulmonary thromboembolism after car driving: a case report.

An autopsy case of sudden death due to pulmonary thromboembolism after a car trip is reported. A 56-year-old Japanese man with hypertension and atrial fibrillation suddenly died immediately after having driven for two and a half hours. At autopsy, the pulmonary arteries were found to be filled with dark-red, coiling thrombi consisting of fibrin and red blood cells. In the dilated right popliteal vein, a thrombus consisting of fibroblasts, a large number of collagen fibres, and newly formed capillaries was attached to the vessel wall. The cause of death was determined to be pulmonary embolism due to the thrombus of the right popliteal vein. Two and a half hours of prolonged sitting while driving a car encouraged thrombus formation. We believe that this case, the first autopsy case of fatal pulmonary thromboembolism after a car trip to be reported, highlights the importance of predicting venous thrombosis of the leg or fatal venous thromboembolism after a car trip.

Automobile Driving↗
PubMed2005

An autopsy case of sudden death in a boy with primary pulmonary hypertension: a case report.

We report a rare autopsy case of sudden death due to primary pulmonary hypertension. A seven-year-old boy, who had been diagnosed with primary pulmonary hypertension at the age of four years, died suddenly. Forensic autopsy and histopathologic examination revealed extensive obstruction of small muscular pulmonary arteries by plexiform lesions and concentric intimal thickenings, compatible with primary pulmonary hypertension. We concluded that plexiform lesions of pulmonary arteries produced right ventricular hypertrophy and dilatation, decreased the preload of the left ventricle and subsequently led to biventricular failure. This autopsy and histopathologic examination suggested a possible pathophysiologic mechanism of sudden death due to primary pulmonary hypertension in a child.

Autopsy↗
PubMed2004

Changes in blood viscosity with mucopolysaccharide polysulfate.

We examined the dose-dependent effects of mucopolysaccharide polysulfate (MPS) on coagulation variables and whole-blood viscosity in human blood. Both 0.01% and 0.1% MPS significantly reduced levels of both fibrin monomer and thrombin-antithrombin III complex in a manner similar to that of 2.0 IU/ml heparin sodium. Furthermore, MPS dose-dependently decreased whole-blood viscosity, as measured with an oscillation viscometer. Because MPS can be applied in creams and gels, percutaneous application of MPS may effectively reduce whole-blood viscosity in local veins.

Adult↗
PubMed2004

Changes in blood viscosity with heavy and light exercise.

To clarify the relationship of the intensity of acute exercise to sudden cardiac death, we examined the effects of short-term heavy and light exercise on whole blood viscosity. Nine healthy sedentary male volunteers performed ten minutes of heavy (more than 95% of maximum oxygen consumption) or light (60% to 65% of maximum oxygen consumption) exercise. Blood samples were obtained before, immediately after, and one hour after exercise. The whole blood viscosity was immediately examined with an oscillation-type viscometer and was found to increase significantly after exercise and subsequently return to baseline levels within one hour after exercise. The whole blood viscosity increased by a similar degree after heavy or light exercise. Therefore, our results suggest that there is a similar risk of sudden cardiac death, due to increased whole blood viscosity, after short-term heavy or light exercise.

Adult↗
PubMed2004

An autopsy case of fatal anaphylactic shock following fluorescein angiography: a case report.

We present a rare autopsy case of fatal anaphylactic shock following fluorescein angiography. A 71-year-old Japanese woman undergoing retinal angiography to evaluate diabetic retinopathy died immediately after an injection of sodium fluorescein. Forensic autopsy and post-mortem biochemical analyses revealed an elevated serum level of tryptase which, in the absence of morphologic changes suggesting injury or disease, confirmed the diagnosis of fatal anaphylactic shock. Although serious adverse effects are rare after fluorescein angiography, patients should be observed, with appropriate resuscitation equipment available, for several hours after the administration of fluorescein.

Aged↗
PubMed2003

Facilitatory action of halothane at subanesthetic concentrations on glutamatergic excitatory synaptic transmission in the CA1 area of adult rat hippocampus.

Whole-cell recordings were made from pyramidal cells visually identified in the CA1 field of adult rat hippocampal slices, and the effects of subanesthetic concentrations of halothane on excitatory postsynaptic currents mediated by non-N-methyl-D-aspartate subtype glutamate receptors were investigated. Halothane concentrations were measured by gas chromatography. At concentrations of 0.2 mM and 0.6 mM, halothane reversibly decreased the amplitude of excitatory postsynaptic currents (EPSCs) evoked by electrical stimulation of Schaffer collateral fibers, and the decrease was accompanied by enhanced paired-pulse facilitation, consistent with the previously reported presynaptic site of halothane's inhibitory action. By contrast, at lower concentrations (0.02 mM and 0.05 mM), halothane increased the amplitude of EPSCs without any appreciable changes in paired-pulse facilitation. Moreover, the frequency of miniature EPSCs arising spontaneously in the presence of tetrodotoxin (mEPSCs) was increased by subanesthetic halothane, but the amplitude of the mEPSCs did not change significantly. These observations suggest that at subanesthetic concentrations halothane postsynaptically enhances glutamatergic excitatory synaptic transmission. This may provide a vital clue to elucidation of the neural mechanisms of the nociceptive reflex enhancement and excitatory state that occur at light levels of anesthesia.

Anesthetics, Inhalation↗