Akiko Ishigami

Microglial and astrocytic changes in the striatum of methamphetamine abusers.

Little is known about the role of glial cells in the striatum of chronic methamphetamine (METH) users. In this study, we immunohistochemically examined glial reactions in the striatum of chronic METH users who did not abstain from METH use and died of drug intoxication. Human glucose transporter 5 (hGLUT), a useful marker of microglia, and CR3.43, a major histocompatibility complex class II antigen specific for reactive microglia, were immunostained. Glial fibrillary acidic protein (GFAP) and S100 Beta were used for astrocyte immunohistochemistry. We analyzed 12 chronic METH users and 13 control subjects, and detected a 200-240% increase in the number of hGLUT5-positive cells in chronic METH users (p<0.01). However, we did not detect any proliferation of CR3.43-positive cells. The number of GFAP-positive astrocytes increased, but this increase was not significant (p>0.05). Moreover, S100B-positive cell density between the two groups was not significant (p>0.05). This study demonstrates the absence of reactive gliosis in the striatum of chronic METH users who did not abstain for prolonged periods from METH use. The results suggest that chronic METH use by itself did not activate glial cells in humans and reactive gliosis may not be involved in the mechanism underlying the loss of control in drug intake, which is a characteristic feature of drug addiction.

Toluene inhalation induces glial cell line-derived neurotrophic factor, transforming growth factor and tumor necrosis factor in rat cerebellum

Rats were exposed to toluene (1500 ppm for 4 h per day) for 7 days. After toluene inhalation, only granule cells in the dentate gyrus of the hippocampus were slightly shrunken. In the cerebellum, several Purkinje cells were shrunken and lost, and the white matter was thinner than in controls. Microtubule-associated protein 2 (MAP2)-immunopositive filaments of neuronal processes were slightly disarrayed in the radial layer of the hippocampus, and were fragmented in the molecular layer of the cerebellum. It was considered that toluene induced neuronal changes both in the cerebellum and the hippocampus. To elucidate the effect of neurotrophic factors on those neuronal changes, glial cell line-derived neurotrophic factor (GDNF), transforming growth factor (TGF) and tumor necrosis factor (TNF) in rat brain were examined immunohistochemically. In control rats, TNF-alpha was not stained in either the hippocampus or the cerebellum, while TGF-beta1 was scarcely expressed in the cerebellum. GDNF was minimally expressed in the Purkinje cells in the cerebellum. After toluene-treatment, TGF-beta1 was over-expressed in the endothelium of the capillary vessel walls in both regions. In the cerebellum, TNF-alpha was induced only in the granule cells, while GDNF expression was enhanced in the Purkinje cells. These data suggest that toluene induces astrocyte activation through TGF-beta1 upregulation, which then induces GDNF in the Purkinje cells and TNF-alpha in the granule cells of the cerebellum. The differences in the expression of the neurotrophic factors may account for neurobehavioral changes after toluene exposure.

An autopsy case of rhabdomyolysis related to vegetamin and genetic analysis of the rhabdomyolysis-associated genes

We report an autopsy case of a man who died 2 days after taking an overdose of vegetamin. The autopsy findings were as follows: the epidermis on the axillary fossa and the inguinal skin had become macerated. Skeletal muscle was discolored. Concentrations of urea nitrogen, creatinine and urine myoglobin were 1.95 g/day, 0.66 g/day and 1100 ng/mL, respectively. Immunohistochemically, myoglobin was strongly stained at the Bowmans capsule, and tubular lumen and epithelium. 8-OH-dG was strongly stained in renal tubular epithelium in which cell nuclei were strongly stained. ORP-150 was observed in intraglomerular cells and renal tubular epithelium. The concentrations of phenobarbital, promethazine and chlorpromazine ranged from therapeutic to toxic levels, from toxic to lethal levels and toxic level, respectively. His cause of death was considered to be vegetamin-induced rhabdomyolysis. In genetic analysis of this subject, there were two heterozygous silent mutations in the three hot-spot regions in the RYR1 gene. In the CPT II gene, the subject was found to be heterozygous for an amino acid substitution in exon 4, (1203)G>A causing a (368)Val>Ile amino acid substitution. There was no mutation in the VLCAD gene or CYP2C19 gene. The subject was heterozygous for CYP2D6*1 and CYP2D6*2.

Neuronal changes in the arcuate and hypoglossal nuclei of brain stem induced by head injury.

Abstract In head injury, assessing the damage not only to the cerebrum and the cerebellum but also to the brain stem is very important. In this paper, we report neuronal changes of the arcuate nucleus (ARC) and the hypoglossal nucleus (HN) in the brain stem. We investigated these changes immunohistochemically with antibodies against microtubule-associated protein 2 (MAP2), muscarinic acetylcholine receptor (mAChR), c-fos gene product (c-Fos), and the 72 kD heat-shock protein (HSP70). We measured the percentage of immunopositive neurons among the total neurons of the ARC and the HN. The investigation of neuronal changes in relation to the type of head injury showed different results. In cases of tonsillar herniation, immunoreactivity to MAP2 and mAChR in the ARC was significantly lower than in the HN (p < 0.01). Moreover, MAP2, HSP70 and c-Fos reactivities in the ARC were significantly lower than in other types of head injuries (p < 0.01). In the HN, diffuse axonal injury produced slightly higher immunoreactivity to mAChR and c-Fos (p < 0.1). Our observations indicate that immunohistochemical examination of brain stem nuclei can provide useful information for estimating damage to the brain stem.

Genetic analysis of ryanodine receptor 1 gene and carnitine palmitoyltransferase II gene: an autopsy case of neuroleptic malignant syndrome related to vegetamin.

We report an autopsy case of a man in his forties who died 2 days after taking an overdose of vegetamin. The autopsy findings were as follows: externally, the upper epidermis of some parts of the body had become loosened. The epidermis was easily detached from the dermis using the fingers. Viscous fluid adhered around the nose and mouth. The brain was edematous and weighed 1520 g. Skeletal muscle was discolored. The urine was a slightly red-tinged yellow. The organs showed congestion. Urine tests: urea nitrogen: 1.95 g/day; creatinine: 0.66 g/day; urine myoglobin: 1100 ng/mL. Blood level of drugs: phenobarbital: 38.2 microg/ml; promethazine: 2.22 microg/ml; chlorpromazine: 0.96 microg/ml. Immunohistochemistry identified myoglobin in the kidney. From these findings, his cause of death was considered to be vegetamin-induced neuroleptic malignant syndrome and rhabdomyolysis. Mutation of the ryanodine receptor 1 gene is associated with malignant hyperthermia. However, there was no mutation which causes amino acid substitution in the three hot-spot regions of the ryanodine receptor 1 gene. Partial deficiency of carnitine palmitoyltransferase II is the commonest cause of recurrent rhabdomyolysis in adults. The subject was found to be heterozygous for an amino acid exchange in exon 4, (1203)G-->A causing a (368)Val-->Ile amino acid substitution. It is necessary to examine other candidate gene mutations.

Sudden cardiac death during first-time jogging

With increased interest in fitness and health care, jogging has become more popular as an exercise to promote health. However, sudden cardiac death during sports or exercise has also been reported. Some apparently healthy elderly individuals take up sports for both recreation and health improvement based only on completion of a questionnaire, without undergoing medical evaluation. We report the case of a 66-year-old Japanese man who suddenly died of acute ischemic heart disease during first-time jogging. He collapsed an hour after starting. A trainer promptly started cardiopulmonary resuscitation. An automated external defibrillator (AED) was applied, and defibrillation was attempted once by bystanders. However, he remained in cardiopulmonary arrest until he reached the emergency department, where he was pronounced dead. The autopsy found concentric hypertrophy of the left ventricular wall without fibrosis or degeneration, atherosclerotic changes in the coronary arteries, and severe lung congestion. We diagnosed death from acute myocardial ischemia. We suspect that many healthy elderly individuals have provoked a heart attack by prematurely attempting moderate or vigorous exercise, as in this case. The elderly require comprehensive medical assessment before exercise can be started. Moreover, this case shows that an AED is not always helpful. J. Med. Invest. 64: 184-186, February, 2017.

Postmortem Diagnosis of Anorexia Nervosa: An Endocrinological and Immunohistochemical Approach

A female in her 30s was found dead after a fire. She was severely emaciated and had been diagnosed with anorexia nervosa (AN) about 5 years ago, but had not been treated recently. Therefore, we investigated not only her cause of death but also her condition of AN. Some of her organs weighed less than normal although no clear lesions were observed. In the pituitary gland, the number of follicle-stimulating hormone-immunopositive cells was markedly decreased although a normal number of thyroid-stimulating hormone-positive cells were detected. A histological examination of the ovary suggested that she had been suffering from amenorrhea. The thyroid gland was atrophic, and marked variations in follicle size were observed. Because we could not obtain enough volume of her blood for endocrinological examinations, we tried to investigate her endocrinological condition by immunohistochemistry. Immunohistochemical staining detected decreased triiodothyronine immunoreactivity and normal thyroxine immunoreactivity. The adrenal glands were also atrophic. Based on these findings, it was considered that she had been suffering from AN at the time of her death. The autopsy and other findings revealed that she had died of burning with carbon monoxide intoxication. J. Med. Invest. 63: 305-309, August, 2016.

An autopsy case of severe pleuritis induced by misinsertion of a nasogastric nourishment tube: Diagnostic significance of multinucleated giant cells

An 87-year-old female who had been hospitalized due to pneumonia was administered nourishment through a nasogastric tube. She collapsed as a result of dyspnea after the insertion of a new tube and administration of nourishment. Chest X-rays revealed that the tube was inserted into the left pleural cavity passing the trachea and left bronchi and that the nourishment pooled. In spite of immediate treatment including removal of the tube and insertion of a drain, she died 12 days later. Autopsy findings: Both the left pulmonary and parietal pleurae were thickened and covered with a dirty gray-yellowish moss-like paste. The left lower lobe was softened, and this region was suspected as the ruptured site of the pleura. Histological findings: A part of the thick pleura with inflammatory cells, including multinucleated giant cells, was positive-stained for anti alpha-lactalbumin antibody immunohistochemically. These giant cells are often observed in granulomatous inflammation against a foreign material. It was considered that those in the pleura had been induced by the nourishment, and that those in the pulmonary parenchyma had been affected by the insertion of the tube. The multinucleated giant cells clarified the cause of fatal pleuritis and pneumonia and the misinsertion of the tube.