Human periodontal ligament cell sheets cultured on amniotic membrane substrate.

OBJECTIVE: Periodontal ligament (PDL) cells and their substrates play key roles in periodontal regeneration. However, there has been no report on the use of amniotic membrane (AM) as a substrate for culturing PDL cells. In the current study, we conducted an analysis of PDL cells cultivated on AM to determine the distribution of factors responsible for maintaining the characteristics of PDL. MATERIALS AND METHODS: Amniotic membrane was obtained from women undergoing cesarean sections, whereas PDL tissue was obtained from human maxillary third molars. The harvested PDL cells were maintained in explant culture for three or four passages, following which they were cultured on AM. RESULTS: After 3 weeks of culture, the PDL cells had grown well on AM. Immunofluorescence showed that these cells were capable of proliferating and potentially maintaining their PDL-like properties. In addition, strong cell-cell adhesion structures, namely desmosomes and tight junctions, were shown to be present between cells. Electron microscopy images showed that the cultured PDL cells had differentiated and proliferated on AM with lateral conjugation and adhesion to AM. CONCLUSION: We conclude that AM may represent a suitable substrate for culturing PDL cells and that PDL cells cultured on AM show sheet formation.

[Aircraft crashes in sky sports. Report of two autopsy cases and review of the accidents during 1981 to 1997 in Japan].

The authors report two forensic autopsy cases of pilots who died in glider and ultra-light plane crashes in Aso, Kumamoto and review sky sports accidents in Japan (1981-1997). In the glider crash, sharp abdominal pain due to gallstones in a 78-year-old pilot was a possible cause of the accident. In the ultra-light plane crash, unskillful control of the plane by a 38-year-old pilot was the cause of the accident. The incidence of sky sports accidents increased from 12 cases in 1981 to 62 cases in 1997. The mortality rate of the victims of the accidents is very high. Investigation of natural diseases in pilots as a cause of accidents and the mechanisms of fatal injuries will help to assess preventive measures against sky sports accidents.

Traumatic basal subarachnoid hemorrhage due to rupture of the posterior inferior cerebellar artery--case report.

A 20-year-old male presented with traumatic basal subarachnoid hemorrhage after being involved in a fight. Antemortem clinical examinations could not exclude the possibility of rupture of abnormal blood vessels because of the absence of external injuries. Careful postmortem examination of the head and neck regions and histological examination of the intracranial arteries demonstrated traumatic rupture of the left posterior inferior cerebellar artery due to a fist blow to the jaw. This case indicates the need for careful autopsy examination for the differentiation of traumatic and non-traumatic basal subarachnoid hemorrhages.

Medico-legal implications of acute subdural haematoma in boxing.

A 16-year-old male high school student with a history of fever (38-39 degrees C) for 4 days lost consciousness following the end of a three round boxing match. He was transferred to a neurosurgical unit located 48 km away 1 h 36 min after injury. Clinical assessment at the unit revealed a comatose patient with a left acute subdural haematoma, but because of advanced brain oedema surgical management was deemed futile. At autopsy an acute subdural haematoma and a severe brain oedema were confirmed. Evaluation of physical conditions before the fight should have been more rigorous in our patient. The observations in our case support the published literature that boxing matches should be held only where neurosurgical expertise is readily available.

Pink spots of Hedley-White in the brain. Evaluation of the significance in the forensic autopsy.

Pink spots are sharply demarcated round to oval discolorations with a white center in the deeper areas of the formalin-fixed brain. In 152 forensic autopsies with neuropathological examinations, the authors observed pink spots in three of 16 patients with bacterial infectious diseases. Pink spots could not be found in 136 patients without bacterial infectious diseases. These results verify the concept that pink spots correlate with bacterial infections. The presence of pink spots will be used as an indication of infectious diseases in the forensic autopsy.

Discrepancy of clinical symptoms and prognosis of a patient--forensic significance of "talk and die" head injury.

Deaths of patients who had talked after sustaining a head injury and were then assumed clinically to be recovering from the head trauma raise medicolegal questions about the precise causes of deaths. A forensic autopsy on a 77-year-old man who had been talking after a road traffic accident and died on the sixth day showed slight subdural hematoma, bifrontal cerebral contusions and diffuse axonal injury. No natural diseases or delayed complications of injury were found. The cause of death was certified as head injury due to a traffic accident. This is a case of "talk and die" head injury. Forensic autopsy is important in patients with "talk and die" to clarify the causal relation to the head trauma in relation to any further forensic dispute.

Accidental decapitation: an unusual injury to a passenger in a vehicle.

A case of decapitation of a vehicle passenger in an accident on a highway is reported. Evaluation of roadside evidence and the deceased's injuries revealed that the victim was partially ejected from a broken passenger-side window as the vehicle spun out of control, decapitation being due to the impact of his head against a barrier stanchion on the shoulder of the road. An unfastened seat-belt, high-speed driving and the construction of the road barrier were contributory factors.

Binswanger's disease. A rare cause of dementia in elderly persons.

A 80-year-old in-patient with abnormal behaviors was strangulated in a hospital bed by another in-patient while he could not escape from the violence because of being restrained to the bed with safety belts. Neuropathological examination of the victim's brain showed characteristic pathological changes of Binswanger's disease (BD), a rare cause of dementia inducing abnormal behaviors. The authors methodically documented BD of the victim and at least justified the restraint as a preventive measure of his abnormal behaviors. Although the etiology of BD is unknown, immunostaining for glial fibrillary acidic protein of the white matter lesions showed neither hyperplasia nor hypertrophy of astrocytes. This result suggested that astrocytes may play an important role in the pathogenesis of BD.

An 11-year-old girl with reflex sympathetic dystrophy successfully treated by thoracoscopic sympathectomy.

We report on an 11-year-old girl with reflex sympathetic dystrophy (RSD) complaining of severe pain in her right upper extremity. Oral administration of narcotics or non-steroid anti-inflammatory drugs gave no relief in pain. Thoracoscopic electrocauterization of the thoracic sympathetic ganglion at the level of T3 was performed 3 months after the start of symptoms, and brought complete resolution of pain.

[Neuropathological diagnosis of senile dementia of Alzheimer's type in forensic autopsy cases].

Senile dementia of Alzheimer's type is frequently an underlying cause of accidental death of elderly persons. Neuropathological diagnosis of dementia is therefore crucial to assess the contribution of dementia to the cause of accident. The authors applied two conventional neuropathological criteria described by Khachaturian and Mirra, et al. to three forensic autopsy cases of dementia-related accidental death. In all cases, the number of neocortical senile plaque, a hallmark of dementia, could not fulfill both criteria. This result indicates that foregoing neuropathological criteria derived from fully developed dementia are hardly applicable to elderly persons who died in an early stage of dementia in forensic settings. Further investigation will be required to establish a diagnostic criterion of early stage of dementia.

Inhibition of bacterial translocation from the gastrointestinal tract of mice injected with cyclophosphamide.

Effects of intraperitoneal injection of cyclophosphamide, an immunosuppressant, on the degree of bacterial translocation and morphological changes of Peyer's patches (PP) in the intestine were investigated with antibiotic-decontaminated SPF mice and germfree mice monoassociated with Escherichia coli C25. It has been reported that treatment with cyclophosphamide induces bacterial translocation. Cyclophosphamide treatment in this study, however, significantly decreased E. coli C25 translocation from the gastrointestinal tract to the mesenteric lymph nodes (MLN), although the numbers of lymphoid cells, especially B cells, in the PP, MLN, and spleen were remarkably reduced. Four injections of cyclophosphamide at a dose of 100 mg/kg inhibited bacterial translocation more than one injection at a dose of 200 mg/kg in SPF mice. Germfree mice, however, treated with one dose of 200 mg/kg showed the same inhibition of bacterial translocation as those given 100 mg/kg four times. In cyclophosphamide-treated mice, lymph follicles in the PP were obviously smaller than those in control mice, M-cells were similar in appearance to absorption epithelial cells except for short microvilli, and immune cells among the M-cells had disappeared. These data suggested that inhibition of bacterial translocation in mice treated with cyclophosphamide may be the result of morphological and physiological changes of epithelial cells in the gastrointestinal tract, especially M-cells, as a point of entry of invading bacteria, independent of the changes in immunological function.

Differentiation between bruises and putrefactive discolorations of the skin by immunological analysis of glycophorin A.

In a differential study to distinguish bruises from putrefactive discoloration, glycophorin A, a component of the erythrocyte membrane, was extracted from discolored skins and detected by immunological methods utilizing an anti-glycophorin A serum. Skin samples of 18 bruises, 8 postmortem hypostasises and 7 putrefactive discolorations were removed from 27 bodies in which postmortem intervals ranged from 4 h to 2.5 months. In 13 out of the 18 bruises (72.2%), glycophorin A was detected by the immunological methods. It was noted that glycophorin A was detectable even in a severely putrefied body 10 days after death. In contrast, no glycophorin A was detected in any of the postmortem lividities or the putrefactive discolorations. These results suggest that the absence of glycophorin A does not always indicate a skin discoloration of postmortem origin, but a positive glycophorin A reaction does indicate a skin discoloration due to bruise.

[Studies on quantitative analysis of paraquat in whole blood--the evaluation of pre-treatments and analytical methods].

Paraquat and diquat are bipyridylium herbicide, which fatal poisoning cases have been reported in recent years. There are a number of methods for the pre-treatment and analysis of paraquat in body fluids and postmortem tissues. But the combined evaluation of these pre-treatments and analytical methods can be hardly found in literatures. We have carried out quantification of paraquat in whole blood with various combinations of pre-treatments and analytical methods, and evaluated those with respect to the sensitivity, recovery, time and cost. Non-treatment sample was a diluted solution of whole blood containing an aliquot of paraquat. The pre-treatments were achieved using two sorts of protein precipitants or Sep-Pak C18 cartridge. HPLC, second-derivative spectroscopy and ELISA were selected as analytical methods for quantification of paraquat. The most sensitive methods were combination of protein precipitants or Sep-Pak C18 and ELISA, but a combination of protein precipitant of sulfosalicylic acid and second-derivative spectroscopy was found to be more rapid and economical method. These methods would be applicable in forensic and clinical laboratories.

Differentiation of discolouration in a body by an erythrocyte membrane component, glycophorin A.

In a differential study to distinguish antemortem bruise from postmortem infiltration of haemoglobin on the skin, a component of erythrocyte membrane, glycophorin A was extracted from experimental bruise and haemoglobin infiltration lesions over set periods of time. This extraction was accomplished by utilising anti-glycophorin A serum, after which the difference between the two lesions was evaluated. The glycophorin A was recovered from the bruise lesions satisfactorily up to the ninth to twelfth days and showed good resistance to putrefaction. In contrast, no glycophorin A was detected in haemoglobin infiltration lesions taken at any time. Glycophorin A was also detectable in human vital bruises which were taken in autopsies of four hours to ten days postmortem. These results suggest that a differential diagnosis of antemortem bruise and postmortem haemoglobin infiltration is possible in advanced stages of death.

Studies of felonious crimes by the University Department of Forensic Medicine in Kumamoto Prefecture, Japan.

This paper gives an understanding of Japan in the respect of forensic medicine. The fight against felonious crimes in Kumamoto is introduced by reference to the police system, crime statistics, an association of police surgeons and medico-legal autopsy in Kumamoto Prefecture. The police have 23 local police stations with 2,670 police officers and the unique Hashutsu-sho and Chyuzai-sho systems. The crime rate is not very high, but crimes committed by Yakuza groups and traffic accidents are major problems in Kumamoto. Medico-legal autopsy is performed in the university department on only criminal and suspected cases after examination of the body externally by a police surgeon. Two illustrative cases are also introduced in this report, which shows good cooperation among the police force, the university department of forensic medicine, and police surgeons in Kumamoto, Japan.

Role of the kallikrein-kinin system in human pancreatitis.

Various factors in the kallikrein-kinin system were evaluated in acute and chronic pancreatitis. It was noted in particular that plasma trypsin and glandular kallikrein increased markedly in acute phase of pancreatitis and its correlation with amylase was observed. Plasma prekallikrein (PPK) decreased in acute pancreatitis, but increased in chronic pancreatitis. A negative correlation was noted between PPK and kallikrein like activity. Both HMW and LMW kininogen decreased in acute pancreatitis. It was presumed from these findings that the increase in kinin and its activation at the acute phase of pancreatitis might be due to kallikrein or trypsin originating from the pancreas.

Evaluation of color discrimination in the white region.

Reference and test stimuli were produced on two separate color television screens to evaluate the color discrimination ability of the human eye for near-white colors. Each test stimulus had a luminance approximately equal to that of the reference, but was slightly different in chromaticity, e.g., [deltax] less than 0.01, [deltay] less than 0.01. The evaluation involved 20 persons observing 26 sets of color stimuli of 16-cd/m2 luminance, and 21 persons observing sets of color stimuli of 253 cd/m2. Observers were requested to categorize the color differences they perceived on a six-level rating scale. The results indicate that the differential thresholds for color difference of near-whites are between 4 and 8 CD (Color Difference), except in the bluish region.