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The effect of fluid percussion injury (FPI) on the propagation of neuronal activity in the rat hippocampus was investigated by using optical and extracellular recording techniques. Under anesthesia with pentobarbital sodium, a moderate impact (1.5-2.0 atm) was applied to the parietal cerebral cortex of the left hemisphere at -3 mm (i.e. caudal) from bregma, 3.5 mm lateral from the sagittal suture. Systemic oxygenation remained normal during the anesthesia. The rats recovered fully from anesthesia within 30-60 min, and their subsequent behavior, such as feeding and grooming, was normal. After a survival period of 1 week from the FPI or sham-operation, neuronal activities were recorded from the hippocampal CA1 region and the dentate gyrus (DG) in either coronal or horizontal brain slice preparations. In sham-operated rats, there was no significant difference in the neuronal activity between contralateral and ipsilateral hippocampal CA1 areas and DG. In coronal slices (-5.6(-)-6.4 mm from bregma), moderate impact (1.5-2.0 atm) markedly depressed the neuronal activity of the ipsilateral (impact side) CA1 region and of the DG directly under the cerebral cortex that received the impact. In horizontal slices, on the other hand, the neuronal activity was markedly enhanced in the ipsilateral hippocampal CA1 region and the DG adjacent the temporal lobe of the cerebral cortex. Field potentials were recorded from the dentate granule cell layer and the hippocampal CA1 pyramidal cell layer in either coronal or horizontal slice. Moderate impact strongly depressed the field potential in the ipsilateral CA1 region and DG directly under the injured cerebral cortex. In horizontal slices, the field potential was followed by multiple population spikes in ipsilateral hippocampal CA1 and the DG neurons. Bicuculline (15 microM) increased the number of spikes of the field potential even after the brain injury. These results suggest that FPI depresses the neuronal activity in the ipsilateral hippocampus directly under the injured parietal cortex, while it enhances the neuronal activity of the ipsilateral hippocampus adjacent to the temporal cortex. The facilitation of neuronal activity following FPI is not due to disinhibition resulting from depression of GABAergic interneuron activity.

A homicidal case by an air gun involving a 73-year-old woman who was found dead in her home is described. At autopsy, two gunshot wounds were observed on the left anterior chest and the right back. There was neither exit wound nor powder burns. The fatal pellet, 0.9 g and 5.5mm diameter, penetrated the left anterior chest and the heart to cause cardiac tamponade (200 ml) before lodging in the left subclavian artery. Death was due to cardiac tamponade. This case has exhibited two rare phenomena: homicide by an air gun and pellet embolisation. This is the first homicide case by use of air gun in Japan and demonstrates that although it may be rare, air guns can be used as potential homicidal weapons. This experience will alert our society and others on the potential hazards of air guns we have tended to regard as toys.

A suicide caused by ingestion of multiple psychoactive drugs is reported. A 42-year-old man with a history of psychosis was found dead in a blood pool in his room. The forensic autopsy revealed two stab wounds on his chest. However, these wounds could not explain the cause of death. Eighty-six tablets were found in his stomach. Four psychoactive drugs; clocapramine (CC), chlorpromazine (CP), promethazine (PM) and clotiazepam (CT) were detected in blood and tissues. The concentrations of CC, CP, PM and CT in the femoral vein (FV) blood were 0.39, 0.61, 1.23 and 0.09 microg/ml, respectively. The cause and manner of death were attributed to suicidal multiple psychoactive drug poisoning. Postmortem drug redistribution showed great site-dependent variations with the lowest level in the FV blood. Remarkable variations were observed in CC, CP and PM, but not in CT compared to other three drugs. The variations were dependent on the volume of distribution (Vd) of the drugs. Our human case has demonstrated drugs with higher Vd values showed higher degree of postmortem redistribution of the drug and vice versa.

A total of 1035 household dogs were examined for the presence of Giardia lamblia (G. lamblia) in their feces. Fecal samples from 151 (14.6%) of the dogs were positive for Giardia. The protozoan was more often detected in soft feces (26.4%) than in normal (10.0%) or diarrheic feces (13.7%) (p < 0.001 and p < 0.01, respectively). The forms of the organisms obtained from the 151 dogs were cysts (77.5%), trophozoites (9.9%), or both cysts and trophozoites (12.6%). Dogs kept indoors had a higher prevalence (18.5%) of Giardia than dogs kept outdoors (4.8%) (p < 0.001). Giardia infection was also more prevalent in 1-6 months old puppies (21.7%) compared to other groups (2.4%-7.5%) (p < 0.001). The prevalence of Giardia in dogs originally purchased from pet shops or breeding kennels was extremely high (21.5%) compared to that of dogs from individual households (4.3%) (p < 0.001). With regard to human public health, the high infection rate of Giardia in puppies and dogs kept indoors is a serious problem because G. lamblia in infected dogs may have zoonotic potential. No reports of human giardiasis transmitted from dogs have been made. However, the results of this study suggest that the risk of Giardia transmission from household dogs to humans is not negligible. Pet owners should be taught appropriate hygiene measures to prevent Giardia transmission from dogs to humans.

Changes in the membrane potential of neurons in the hippocampal CA2 and CA1 regions were recorded by optical recording techniques. After stimulation of the Schaffer collaterals at the hippocampal CA2 region, excitatory optical signals first occurred adjacent stimulus electrode and then flamed-up signals spread toward the hippocampal CA1 region. The optical signal was blocked by tetrodotoxin (TTX) (1 microM). Propagation of the optical signal was blocked in an artificial cerebrospinal fluid (ACSF) containing 0 mM Ca2+ and 6 mM Mg2+. 6,7-Dinitroquinoxaline-2,3 (1H,4H)-dione (DNQX) (20 microM) also blocked the optical signals that spread to the hippocampal CA1 region. The time course of the optical signal recorded at a unit area (49 pixels) on the propagation pathway was characterized by fast and slow components. TTX (1 microM) blocked both fast and slow components of the optical signal. The slow component of the optical signal was preferentially depressed by either removal of external Ca2+ or by bath-application of DNQX (20 microM). When bicuculline (15 microM) was applied to the bath-solution, the intensity and propagation area of the optical signal were increased. The results indicate that stimulation of the Schaffer collaterals in the hippocampal CA2 region produces the propagation of the optical signal to the hippocampal CA1 region, and that the optical signal involves the action potential and excitatory and inhibitory postsynaptic potentials.

We report a case of delayed cerebrospinal fluid (CSF) pseudocyst following shunt malfunction in a 20-year-old patient with myelomeningocele. Magnetic resonance (MR) images and a radioimmunoassay shunt-gram detected the CSF fistula at the old scar of the myelomeningocele repaired 20 years before. Since the revision of the shunt system failed to keep the pseudocyst, the lesion was successfully directly repaired. Treatment of the delayed CSF pseudocyst following shunt malfunction thus requires a radical operation of the lesion.

Purpose: To elucidate clinical features of Schwartz-Matsuo syndrome (photoreceptor outer segment glaucoma) occurring in retinal detachment with tears of the nonpigmented epithelium of the pars plana or plicata of the ciliary body., Methods: We reviewed retrospectively medical records of 17 consecutive patients (18 eyes) with retinal detachment caused by tears of the nonpigmented epithelium of pars plana (10 eyes) and pars plicata (8 eyes) of the ciliary body., Results: Aqueous cells, ranging from 1+ to 3+, were found in 15 eyes, in contrast with no cells in the other 3 eyes. Eleven of the 15 eyes with aqueous cells showed circadian fluctuation of the intraocular pressure with a range, 4 mmHg or wider compared with the range in the fellow eye, but only 4 of these 11 eyes had a maximum pressure of 21 mmHg or higher. Photoreceptor outer segments were detected in the aqueous humor of 8 eyes out of 14 eyes with aqueous cells in which aqueous tap was done. The remaining 6 eyes had too small a number of aqueous cells for electron microscopy., Conclusion: Marked fluctuation of the intraocular pressure compared with the fellow eye, which was not necessarily associated with its rise, was found in retinal detachment with tears of the nonpigmented epithelium of the ciliary body, and should be included as one of key features for diagnosis of Schwartz-Matsuo syndrome.

The authors presented a rare case of huge gravitation abscess. 67Ga scintigraphy was useful in the evaluation of the extent and activity of the disease. CT showed clearly the location and shape of the abscess. Enhanced MRI showed vertebral lesions as characteristic geographic and ring-like enhancement.

A rare case of malignant fibrous histiocytoma (MFH) of the ilium was presented and blood-pool scintigraphic images and angiographic images were correlated. Hypervascular tumor and lacking of contrast material with arteriovenous shunts were shown by angiography. Intensive tracer accumulation was shown by blood-pool scintigraphy. After radiation therapy and transcatheter arterial embolization of the tumor, tracer accumulation was noticeable reduced. These findings suggested a vascular tumor such as angiosarcoma, but surgery revealed MFH of the bone. Blood-pool scintigraphy was useful in the evaluation of the vascular characteristics of the tumor.

We diagnosed nine cases of nonmalignant extrahepatic portal venous obstruction on ultrasonography at Kitakyushu Municipal Kokura Hospital between 1983 and 1989. Among 40544 cases of routine abdominal ultrasound study, nine cases of nonmalignant extrahepatic portal venous obstruction were found. The sonographic feature of "cavernous transformation" of the portal vein was noted at an incidence of about 1/2000. We classified these nine cases into three groups according to past history. Four cases underwent abdominal surgery. (Two had two operations). Three had abdominal inflammation or trauma, and two had no significant history, although one had taken oral contraceptive pills intermittently during the last ten years.

Perinuclear clear cytoplasm observed in the light microscopic specimens of the tumor cells of smooth muscle origin is in general, understood as the artefact caused by the formalin fixation. However, the precise mechanisms of the histogenesis of clear cytoplasm are still not clear. We observed the clear cytoplasm directly by mean of the electron microscopy of materials detached from light microscopic specimen. Furthermore, we observed the light microscopic specimens made by varying types of methods, examining whether the clear cytoplasm was present or not. The electron microscopy of materials detached from light microscopic specimens revealed the band-like defects of cytoplasm along the long axes of tumor cells. These defects were thought to result from the falling off of cytoplasm. The 1 mu section of the epon embedded block derived from the paraffin embedded block for light microscopic specimen presented no clear cytoplasm, suggesting that the cytoplasm falls off at the procedure of deparaffinization and staining. Although the specimen of conventional frozen section showed no clear cytoplasm, the specimen made by the frozen sectioning after formalin fixation revealed clear cytoplasm. Consequently, it is thought that the fixation of the tissue before the sectioning makes the cytoplasm fragile, thereafter, the cytoplasm falls off at the procedure of deparaffinization and staining.