Hisae Niitsu

Studies on the mechanisms responsible for the formation of focal swellings on neuronal processes using a novel in vitro model of axonal injury

A novel in vitro model of axonal injury using PC12 cells was designed to introduce traumatic alterations on neuronal processes and to identify mechanisms responsible for the formation of focal swellings by observation with phase-contrast and transmission electron microscopes. The injury on the processes was produced by one-dimensional, horizontal oscillation. The fluid shear stress applied by the oscillation did not exceed 380 dyne/cm2. The injured processes showed two forms. One involved an increase in the terminal diameter of the processes and the other entailed beading along the injured portions. Long-term observation of cellular responses to the mechanical insult disclosed that the terminal swelling coincided with the detachment of growth cones from the culture plate. The finding suggests that the detachment of the growth cone destroys the cytoskeletal network, which determines and maintains the cell shape, resulting in spherical deformation of the processes. When the cytoskeletal destruction occurred at non-terminal sites along the processes, spherical deformations developed slowly, and these appeared as beads. The beading also caused the detachment of the growth cones. As the most proximal bead grew, they absorbed the distal segment and their growth cones were pulled proximally with the spreading cytoskeletal destruction. The processes with terminal swellings as well as the bead segments showed regeneration with time evidence of and growth cone formation.

A case of acute gasoline intoxication at the scene of washing a petrol tank.

We encountered a case of acute gasoline intoxication at the scene of washing the inner wall of a petrol tank. The decedent was a 50-year-old male, who was the supervisor. Two young workers wearing mask respirators began to wash the inner wall of the gasoline tank under poor ventilation. About 1 h later, because one of the workers lost consciousness, the supervisor entered the tank, without a mask respirator, to rescue the worker. However, the supervisor immediately fainted, and died 26 h after the accident. In the autopsy, blisters were observed on the skin of the face, neck, anterior chest, upper extremities, and back. The heart contained hemolyzed blood. Histologically, hemorrhagic pulmonary edema, pneumonia, and proximal tubular necrosis were found. In the toxicological analyzes, toluene, xylene, and trimethylbenzene were detected in the blood, brain, and gastric contents. Toluene concentrations in the blood and brain were 0.3 mug/ml and 3.7 mug/g, respectively. Since pathological findings were consistent with the reported findings concerning gasoline intoxication, and constituents of gasoline were in the body, death was attributed to acute gasoline intoxication. It was considered that sufficient ventilation and proper use of a mask respirator were essential for this kind of work.

Distribution of Aconitum alkaloids in autopsy cases of aconite poisoning

Aconite is a well-known toxic-plant containing Aconitum alkaloids such as aconitines, benzoylaconines, and aconins. We describe here the distribution of Aconitum alkaloids detected by liquid chromatography-tandem mass spectrometry (LC/MS/MS) in three autopsy cases of suicide by aconite poisoning. Case 1: a male in his fifties had eaten aconite leaves. The concentrations of jesaconitine in cardiac blood, urine, and kidney were 12.1 ng/ml, 993.0 ng/ml, and 114.2 ng/g, respectively. Case 2: a female in her fifties had eaten aconite root. The aconite root in the stomach included a high level of mesaconitine. The concentrations of mesaconitine in cardiac blood, liver, and kidney were 69.1 ng/ml, 960.9 ng/g, and 776.9 ng/g, respectively. Case 3: a male in his sixties had drunk liquor in which aconite root had been soaked. The concentrations of mesaconitine and aconitine in cardiac blood were 259.5 and 228.5 ng/ml, respectively. The Aconitum alkaloid levels were very high in the liver. The absorption of ethanol and Aconitum alkaloids might have been increased because of his having undergone total gastrectomy. In all three cases, the Aconitum alkaloid levels were high in the liver and kidney and low in the heart and cerebrum. The level in the cerebrum was lower than that in blood. Data on the distribution of the Aconitum alkaloids in the body in cases of aconite poisoning is useful to elucidate various actions of aconite alkaloids.

Forced oral opening for cadavers with rigor mortis: two approaches for the myotomy on the temporal muscles

Forensic dentistry plays an essential role in personal identification procedures. An adequate interincisal space of cadavers with rigor mortis is required to obtain detailed dental findings. We have developed intraoral and two directional approaches, for myotomy of the temporal muscles. The intraoral approach, in which the temporalis was dissected with scissors inserted via an intraoral incision, was adopted for elderly cadavers, females and emaciated or exhausted bodies, and had a merit of no incision on the face. The two directional approach, in which myotomy was performed with thread-wire saw from behind and with scissors via the intraoral incision, was designed for male muscular youths. Both approaches were effective to obtain a desired degree of an interincisal opening without facial damage.

Clinical and toxicological findings of acute intoxication with synthetic cannabinoids and cathinones

Reporting of the analytical and clinical findings of synthetic cannabinoids and cathinones is essential in carrying out a complete clinical assessment of new psychoactive substances.

Relationship between the matrix effect and the physicochemical properties of analytes in gas chromatography

The phenomenon “matrix-induced chromatographic response enhancement” (matrix effect) causes quantitative errors in gas chromatography (GC) analyses. This effect varies according to the analyte nature, matrix type and concentration, and GC-system parameters. By focusing on the physicochemical properties of analytes, a predictive model was developed for the matrix effect using quantitative structure–property relationships. Experimental values of the matrix effect were determined for 58 compounds in a serum extract obtained from solid-phase extraction as the matrix. Eight molecular descriptors were selected, and the matrix-effect model was developed by multiple linear regression. The developed model predicted values for the matrix effect without any further experimental measurements. It also indicated that the molecular polarity (particularly H-bond donors) and volume of the analyte increase the matrix effect, while hydrophobicity and increasing number of nonpolar carbon atoms in the analyte decrease the matrix effect. The model was applied to the analysis of barbiturates. The predicted values indicated that N-methylation decreases the matrix effect, and the relative predicted values were effective for the selection of an internal standard. The obtained insight into the matrix effect and the prediction data will be helpful for developing quantitative analysis strategies.

An autopsy case of aortitis resulting in sudden death due to a rupture of aneurysm of the aortic sinus

An autopsy case of spontaneous rupture of a clinically undiagnosed inflammatory aneurysm of the aortic sinus is presented. A 34-year-old man consulted a physician complaining of anterior chest pain and heartburn persisting for 2 days. Diagnoses of common cold and gastritis were made, but 3h later his condition deteriorated, leading to death. Autopsy revealed hemopericardium due to rupture of a saccular aneurysm of the aortic sinus. Histological examination of the aortic sinus disclosed aortitis characterized by fragmentation and loss of elastic tissues with fibrous thickening of the intima. Lymphocytes along with polymorphonuclear leucocytes and plasma cells infiltrated the adventitia and media at severely affected areas. These changes were limited to the aortic sinus, and other portions of the aorta and its main branches were essentially intact. An eccentric intimal thickening with medial degeneration was found within the anterior descending branch of the left coronary artery, and occasional collection of lymphocytes was noted in the epicardium. This case would be a rare and illustrative case for differentiation of aortitis, although we could not pinpoint the etiology of the aortitis because of non-specific histological findings and negative serological results for exogenous pathogens.

Application of quantitative ethanol detector (QED) test kit to measure ethanol concentration in blood samples.

In this paper, the applicability of the quantitative ethanol detector (QED) test kit for screening of ethanol concentrations in blood samples was investigated. The pretreatment of blood using the sulfosalicylic acid solution and the three-way stopcock followed by membrane filtration gave satisfactory results. The ethanol concentrations in whole blood samples (n=61) determined by QED correlated well with those determined by gas chromatography; the correlation coefficient indicated 0.990. Because a high correlation coefficient (0.928) was also confirmed in trial by investigators, QED test should be highly considered for ethanol screening in forensic praxis.

Pediatric autopsy case of asphyxia due to salmon egg (ikura) aspiration

Here we report an autopsy case of asphyxia due to aspiration of a salmon egg (ikura) into the airway. The patient was a 19‐month‐old girl. During breakfast, she put salmon eggs into her mouth, and began to walk. She slipped, fell down, and collapsed. She was pronounced dead following 2 h of resuscitation. The body was autopsied 28 h after death. The gastric contents consisted of rice, orange sections, and white salmon eggs. The lungs were deeply congested and over‐inflated. In the right lung, areas of atelectasis in the upper and middle lobes were seen. A yellow salmon egg (8 mm in diameter) was found in the trachea. Although fish eggs are consumed throughout the world, reports of this sort are limited. The aspiration of fish eggs is under‐acknowledged and underreported. The importance of preventive measures needs to be emphasized to parents and caregivers.

A case of Takayasu arteritis complicated by right atrium perforation and injuries of the right common iliac artery and vein caused by cannulation for percutaneous cardiopulmonary support.

We describe an autopsy case of Takayasu arteritis with right atrium perforation and injuries of the right common iliac artery and vein caused by cannulation for percutaneous cardiopulmonary support (PCPS). The decedent was an 8-year-old girl admitted for examination in respect to chest pain and syncope. During catheter angiography, she suddenly went into cardiac arrest. PCPS was attempted, whereupon bleeding into the abdominal cavity and an injury to the common iliac vein were observed. She was pronounced dead 78 hours after the initiation of PCPS. Autopsy revealed thickening of the aortic wall from the ascending aorta to the abdominal aorta, with narrowing of the proximal branches. Hemopericardium induced by right atrium perforation, and an injury of the right common iliac artery, were also found. Microscopic examinations of the aorta disclosed thickening of each layer of the vessel wall and inflammatory cell infiltration, mainly into the outer layer of the media. It was speculated that manipulation of the catheter and the underlying Takayasu arteritis caused cardiac arrest. It is also considered that hypovolemia was induced by the injuries of the right common iliac artery and vein caused during the insertion of the PCPS venous cannula. In addition, the right atrium was injured by the edge of the PCPS cannula, leading to hemopericardium. In pediatric cases involving PCPS, or in cases where cannulation is difficult, regular examination of the pericardial and abdominal cavities by echocardiography would provide useful information to prevent such accidents.