Akihiro Takatsu

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.

Intracranial vertebral artery dissection resulting in fatal subarachnoid hemorrhage: clinical and histopathological investigations from a medicolegal perspective

OBJECT Subarachnoid hemorrhage (SAH) due to a ruptured intracranial vertebral artery (VA) dissection sometimes results in a sudden fatal outcome. The authors analyzed the relationship between clinical features and histopathological characteristics among fatal cases to establish valuable information for clinical diagnostics and prophylaxis. METHODS This study included 58 medicolegal autopsy cases of ruptured intracranial VA dissection among 553 fatal nontraumatic cases of SAH that occurred between January 2000 and December 2007. Their clinical features were obtained from autopsy records. Histopathological investigations were performed on cross-sections obtained from all 4-mm segments of whole bilateral intracranial VAs and prepared with H & E and elastica van Gieson staining. RESULTS The autopsy cases included 47 males and 11 females, showing a marked predilection for males. The mean age was 46.8 +/- 7.7 years, with 78% of the patients in their 40s or 50s. Hypertension was the most frequently encountered history; it was found in 36% of cases from clinical history and in 55% of cases based on autopsy findings. Prodromal symptoms related to intracranial VA dissections were detected in 43% of patients. Headache or neck pain lasting hours to weeks was a frequent complaint. Of patients with prodromal symptoms, 44% had consulted doctors; however, in none of these was SAH or intracranial VA dissection diagnosed at a preventable stage. Autopsy revealed fusiform aneurysms with medial dissecting hematomas. Apart from ruptured intracranial VA dissection, previous intracranial VA dissection was detected in 25 cases (43%); among them, 10 showed previous dissection of the bilateral intracranial VAs. The incidence of prodromal symptoms (60%) among the patients with previous intracranial VA dissection was significantly higher than that (30%) among cases without previous dissection (chi-square test; p = 0.023). Most previous intracranial VA dissections formed a single lumen resembling nonspecific atherosclerotic lesions, with the exception of 3 cases (12%) with a double lumen. CONCLUSIONS Intracranial VA dissection resulting in fatal SAH frequently affects middle-aged men with untreated hypertension. Related to the high frequency of prodromal symptoms, latent previous intracranial VA dissection was histopathologically detected. Furthermore, intracranial VA dissection tends to induce multiple lesions affecting both intracranial VAs recurrently. This suggests the importance of an awareness of sustained whole intracranial VA vulnerability for the prevention of recurrence. The incidence of prodromal symptoms was significantly higher among patients with previous intracranial VA dissections. Thus, earlier diagnosis of intracranial VA dissections at the unruptured stage is desirable for prophylaxis against fatal SAH.

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.

Toxicological analysis of 17 autopsy cases of hydrogen sulfide poisoning resulting from the inhalation of intentionally generated hydrogen sulfide gas

Although many cases of fatal hydrogen sulfide poisoning have been reported, in most of these cases, it resulted from the accidental inhalation of hydrogen sulfide gas. In recent years, we experienced 17 autopsy cases of fatal hydrogen sulfide poisoning due to the inhalation of intentionally generated hydrogen sulfide gas. In this study, the concentrations of sulfide and thiosulfate in blood, urine, cerebrospinal fluid and pleural effusion were examined using GC/MS. The sulfide concentrations were blood: 0.11-31.84, urine: 0.01-1.28, cerebrospinal fluid: 0.02-1.59 and pleural effusion: 2.00-8.59 (μg/ml), while the thiosulfate concentrations were blood: 0-0.648, urine: 0-2.669, cerebrospinal fluid: 0.004-0.314 and pleural effusion: 0.019-0.140 (μmol/ml). In previous reports, the blood concentration of thiosulfate was said to be higher than that of sulfide in hydrogen sulfide poisoning cases, although the latter was higher than the former in 8 of the 14 cases examined in this study. These results are believed to be strongly influenced by the atmospheric concentration of hydrogen sulfide the victims were exposed to and the time interval between exposure and death.

A case of fatal benzalkonium chloride poisoning

Abstract Five elderly persons with senile dementia accidentally ingested Hoesmin, a 10% aqueous solution of benzalkonium chloride (BAC). The condition of one patient, an 84-year-old woman whose lips and oral cavity became erythematous, gradually deteriorated. Although gastric lavage was performed, the patient died 3 h after ingestion of Hoesmin. Autopsy revealed corrosive changes of the mucosal surfaces of the tongue, pharynx, larynx, esophagus and stomach which may have come in contact with BAC. In addition, BAC was detected in the serum.We conclude that the patient died of BAC poisoning. Fatal BAC poisoning is rare and autopsy findings in only a few cases of BAC poisoning have been reported. Our findings emphasize the risk of oral ingestion of BAC.

Simulator for virtual surgery using deformable organ models and force feedback system.

This paper describes a real-time surgery planning system using virtual reality techniques. This system allows us to simulate incision of skin and organs which respond as elastic objects with surgical tools in virtual space. Inner structures such as blood vessels and lesions can be seen and manipulated in the simulation. In addition to these functions we attempted to add a feedback function that responds to the operators hands. We developed a force feedback device to manipulate the elastic organ model based on pressure from the operators fingers.

Injuries of motorcyclists and bicyclists examined at autopsy.

Few studies of autopsy findings of persons dying of head and neck injuries in cyclists have been published. We performed a retrospective analysis of injury severity and the relation between head and neck injuries and helmet use. Seventy-six bicyclists and motorcyclists were collected from among the forensic autopsy at the Jikei University School of Medicine. From autopsy findings and accident reports, the abbreviated injury scale (AIS) and the injury severity score (ISS) were calculated and analyzed epidemiologically. As a result, helmet use significantly decreased the severity of head and neck injuries but had no effect on overall injury severity or the severity of injuries to other body regions. Furthermore, helmets had little effect on injuries remote from the point of impact, injuries resulting from angular acceleration, or injuries at the junction of the head and neck. These findings may be useful for both forensic pathologists and clinicians evaluating injuries in bicyclists and motorcyclists.

Segmental arterial mediolysis of varying phases affecting both the intra-abdominal and intracranial vertebral arteries: an autopsy case report

We report an autopsy case of segmental arterial mediolysis (SAM) of various phases occurring in both the intracranial vertebral artery (IVA) and intra-abdominal arteries. The patient was a 70-year-old male found dead in his house. The cause of death was massive intra-abdominal hemorrhage owing to a ruptured right gastroepiploic artery. Histopathological examination revealed that there was a broad arterial dissection as long as 20 cm in the right gastroepiploic artery associated with SAM in the injurious phase. In addition, SAM in the reparative phase was observed as organized arterial dissections in the left gastric artery. Furthermore, SAM in the reparative phase was detected as an arterial dissection in the right IVA undergoing an organizing process. These three lesions were considered to have developed at different times. SAM occurring in both the intra-abdominal and intracranial vertebral arteries is extremely rare. This coincidence may provide a clue to the relationship between SAM and spontaneous IVA dissection.

ANALYSIS OF FATAL INJURIES TO MOTORCYCLISTS BY HELMET TYPE

To clarify the characteristics of injuries of motorcyclists dying in accidents in relation to helmet type, we retrospectively analyzed forensic autopsies of 36 helmeted motorcycle riders. The presence of major injuries and injury severity were evaluated with the injury severity score and the 1990 revision of the Abbreviated Injury Scale. Persons with open-face helmets (19 cases) were significantly more likely to have sustained severe head and neck injuries, especially brain contusions, than were persons with full-face helmets (17 cases). Furthermore, major injuries of the chest or abdomen, rib fractures, lung injuries, and liver injuries were each present in more than one quarter of all cases (26.3% to 70.6%), but their prevalences did not differ significantly between riders with different types of helmet. Because many types of head and neck injuries cannot be prevented and fatal chest and abdominal injuries occur despite the use of full-face helmets, more effective helmets and devices for protecting the chest and abdomen are needed to decrease deaths from motorcycle accidents.

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.