Tatsuaki Hattori

The relationship between Moyamoya disease and bacterial infection

To examine the relationship between Moyamoya disease and bacterial infections, authors studied the serum of 85 cases of Moyamoya disease and the influence of Propionibacterium acnes (P. acnes) infection on intracranial arteries in rats. The serum levels of P. acnes antibody, IgM, transferrin (Tf), alpha 2-macroglobulin (alpha 2M) were significantly higher in Moyamoya disease than in normal volunteers. Moyamoya-like changes of the intracranial internal carotid arteries were histopathologically demonstrated in P. acnes infectious rats. These findings suggest that P. acnes and immunological factors might play a role in the pathogenesis of Moyamoya disease.

Prognostic factors and therapeutic problems of primary intracranial choriocarcinoma/germ-cell tumors with high levels of HCG.

AbstractObjective: Primary intracranial choriocarcinoma (PICCC)/germ-cell tumors (GCTs) with high levels of human chorionic gonadotropin (HCG) (PICCC/GCTs with HL-HCG) are rare and malignant. The goal of this study was to report our 3 cases of PICCC/GCTs with HL-HCG and to review the literature to elucidate the clinical problems and prognostic factors and to discuss the therapeutic modalities of this rare tumor. Methods: Survival was analyzed in 66 previously reported PICCC/GCTs with HL-HCG including our 3 cases, of which the clinical results have been described in the literature since 1975. In the 66 cases (mean age: 12.1 years; male/female: 45/21), 35 were verified histologically as pure choriocarcinoma, 23 were as mixed GCTs with choriocarcinoma element, and 8 were not verified as including choriocarcinoma element histologically but with very high HCG levels. Significance of the differences among survival curves concerning each parameter (age, sex, tumor location, serum HCG/β-HCG level, precocious puberty, extent of surgery, radiotherapy, chemotherapy, mixture of other non-germinomatous GCT elements and extraneural metastasis) was tested using univariate and multivariate analyses. Results: The median survival time and the 1- and 2-year survival rates were 22 months, 61.2% and 49.8%, respectively. In univariate analysis, male, subtotal removal or more, radiotherapy and chemotherapy were revealed to be significantly good prognostic factors. However, suprasellar region and tumor hemorrhage were poor prognostic factors. Multivariate analysis showed that extent of surgery, radiotherapy and chemotherapy were independent prognostic factors. Conclusions: Although, we should mind the limitations of this study design because of case selection bias, different treatment protocols and incomplete follow-up of patients, this study led the following results and suggestive conclusions. Tumor hemorrhage and progressive extraneural and cerebrospinal fluid metastasis were characteristic clinical problems of PICCC/GCTs with HL-HCG. In the cases with extremely elevated levels of HCG, biopsy for histological diagnosis may be no longer needed. Initial biopsy and radiotherapy may lead to tumor hemorrhage. To prevent tumor hemorrhage, gross tumor removal followed by radiotherapy and chemotherapy should be aimed for. A few courses of chemotherapy before surgery may prevent metastasis. Stereotactic radiotherapy and high dose chemotherapy may be promising options for treatment.

Intracanalicular aneurysm at the meatal loop of the distal anterior inferior cerebellar artery: a case report and review of the literature

BACKGROUND Distal aneurysms of the anterior inferior cerebellar artery (AICA) are rare. Most of the reported cases have been located near the internal auditory meatus. Among these cases, only six located in the internal auditory meatus have been reported in the literature. METHODS A 64-year-old female presented with sudden onset of severe headache. Computed tomography (CT) revealed moderate subarachnoid hemorrhage and Gd-DTPA enhanced magnetic resonance imaging (MRI) showed a small high-intensity mass at the right cerebellopontine angle. Although initial digital subtraction angiography (DSA) showed no vascular abnormalities, repeated DSA disclosed a saccular aneurysm at the top of the meatal loop of the right AICA. The patient underwent a suboccipital craniectomy on the 18th day after the hemorrhage RESULTS . In this case, the aneurysm was completely buried in the internal auditory meatus. After unroofing the meatus, the aneurysm was successfully clipped. After 3 months of hospitalization, the patient was discharged with right-sided deafness, partial facial palsy, and no other complications. CONCLUSIONS We discuss some of the clinical features and pitfalls in the surgical management of intracanalicular AICA aneurysms and review previous reports of similar cases.

Persistent primitive trigeminal artery associated with absence of internal carotid artery

BACKGROUND Both a persistent primitive trigeminal artery (PTA) and the absence of an internal carotid artery are rare developmental anomalies. METHODS AND RESULTS Two cases with the unusual association of a persistent PTA and absence of the internal carotid artery on the left side are reported. The left anterior cerebral artery territory was supplied from the right internal carotid artery via the anterior communicating artery, and the left middle cerebral artery territory was supplied from the vertebrobasilar system via the persistent PTA antidromically. CONCLUSION This is the first report of such an association of developmental anomalies of cerebral vessels. Our cases are instructive for gaining insight into the involution and evolution processes of primitive cerebral arteries in the human embryo.

Fenestration of the supraclinoid internal carotid artery associated with carotid bifurcation aneurysm

Fenestration of the internal carotid artery is extremely rare. The authors describe a fenestration at the supraclinoid portion of the left internal carotid artery revealed after subarachnoid hemorrhage from an ipsilateral carotid bifurcation aneurysm. This is the third reported case of fenestration of the intracranial internal carotid artery. Fenestrated cerebral vessels and their possible genesis and surgical management are discussed.

Membrane phospholipid composition and membrane fluidity of human brain tumour: a spin label study

Membrane fluidity in membrane phospholipids of brain tumours was investigated and compared with those of white and grey matter. Fifteen brain tumours including 5 gliomas, 5 meningiomas and 5 metastatic cancers were examined. These samples were frozen immediately after extirpation in liquid nitrogen. After extraction of total lipids from the tumour tissues, membrane phospholipids were separated and analysed by thin-layer and gas-liquid chromatography. The fluidity of the phospholipid membrane was studied by electron spin resonance (ESR) spectroscopy, using a stearate spin probe. The fatty acid composition of total phospholipid of brain tumours was characterized by an increase in linoleic and arachidonic acids when compared to the control brain. The percentage of palmitoleic acid was higher in gliomas and metastatic tumours than in meningiomas. Furthermore, in the brain tumour tissues, the decreases of phosphatidylethanolamine and phosphatidylserine and the increase of phosphatidylcholine were observed when compared with grey or white matter with the exception of meningioma. There was some difference in phospholipid membrane fluidity between brain tumour and control brain tissue. The order parameter calculated from ESR spectra became higher in the following order: metastatic brain tumour, less than meningioma, less than grey matter, less than glioma, less than white matter. These results suggest that the phospholipid metabolism in the brain tumour is different from that of the normal brain, and this difference may affect the alteration of membrane physical properties which exhibit in part the character of the transformation.

Effects of dibutyryl cyclic AMP and forskolin on phospholipid biosynthesis in thrombin-stimulated human platelets.

The influence of forskolin, an adenylate cyclase activator, and of dibutyryl cyclic AMP (Bt2cAMP) on [3H]glycerol incorporation into glycerolipids was investigated in human platelets. It was found that preincubation with 2.5 mM Bt2cAMP produced a 2-4-fold increase in thrombin-induced incorporation into phospholipids compared to platelets activated by thrombin alone. Pretreatment with forskolin, which increased cellular cAMP content, also resulted in an increase in thrombin-stimulated [3H]glycerol incorporation into phospholipids. These findings demonstrate that a rise in platelet cAMP can accentuate thrombin-induced de novo synthesis of phospholipids from [3H]glycerol. Since the content of cellular cAMP was correlated with its ability to inhibit platelet activation monitored by serotonin release, it seems likely that glycerolipid, in particular phospholipid biosynthesis, is involved in controlling platelet activation by thrombin.

Attenuation by pentobarbital of free fatty acid and diacylglycerol liberation during global ischaemia in rat brain

The effects of global ischaemia and pentobarbital upon lipid metabolism were studied in the rat brain. Brain ischaemia was evoked by rat decapitation. Pentobarbital (60 mg/kg) was administered i.p. for 15 min prior to decapitation. The removed brains were incubated for 1, 5, 15 or 30 min at 37 degrees C and then quickly frozen in liquid nitrogen. After extraction of lipids from the brains, neutral lipid and phospholipid compositions were analysed by thin-layer and gas-liquid chromatography. The results demonstrated that free fatty acids (FFAs), either unsaturated or saturated, rapidly accumulated in the brain during the early period of ischaemia but attenuated significantly with pentobarbital pretreatment. Pentobarbital repressed the accumulations of stearate and arachidonate, with little effect on palmitate and oleate liberation. Diacylglycerols (DG) also were produced in the ischaemic brain, and their acyl chain composition was similar to that of liberated FFAs. However, the increase of DG was inhibited by pentobarbital anaesthesia. In particular, pentobarbital attenuated the formation of DG enriched in arachidonate and stearate. The fatty acyl composition of DG resembled that of phosphatidylinositol. These observations suggest that pentobarbital somehow may alter phospholipase C activity and influence inositol phospholipid breakdown during ischaemia, and this effect would be a membrane stabilizing action of pentobarbital.

Inhibitory effect of pentobarbital on phospholipase C activity in ischaemic rat brain

Ischaemic rat brains were examined for temporal changes in phospholipase C activity with phosphatidylinositol; the effects of pentobarbital on the activity also were investigated. Ischaemia was produced by decapitation. Pentobarbital (60 mg/kg) was administered i.p. for 15 min before decapitation. The removed heads were incubated at 37 degrees C for 1, 5, 15 or 30 min and then quickly frozen in liquid nitrogen. After isolation of subcellular fractions from the brains, phospholipase C activity was measured for cytosol and microsomes, using radioactive phosphatidylinositol as a substrate. The results demonstrated that brain phospholipase C predominantly localized in the cytosol was dependent on Ca2+ for full activity and had neutral pH optima. Although the enzyme activity did not increase during ischaemia, pentobarbital inhibited phospholipase C activity in the cytosol but not in the microsomes. These observations suggest that pentobarbital may exert a cerebral protective action due to, at least in part, the repression of phospholipase C followed by a reduction of phosphatidylinositol breakdown, preventing perturbation to the integrity of membranes, during ischaemia.

Effect of Cytochrome C on Formation of Lipid Peroxides in Rat Brain in vitro

Antioxidant activity of exogenous cytochrome c was investigated in vitro using the whole brain homogenate, mitochondrial fraction and postmitochondrial supernatant containing microsomes prepared from rat brains. Increments in the amount of lipid peroxides were observed in each fraction when incubated at 30 degrees C, while the addition of cytochrome c (200 mM) effectively suppressed the production of peroxides. This depressive effect of cytochrome c was more prominent in the supernatant than in the mitochondrial fraction. Although the peroxidation was enhanced markedly by the addition of NADPH (2 mM), particularly in the mitochondrial fraction, cytochrome c was able to prevent its acceleration. This inhibitory mechanism might be explained by the fact that cytochrome c deprived superoxide radicals of electrons generated in ischemic insult. The results of the present study suggest that exogenous cytochrome c has free radical scavenging or antioxidant activity, which might be responsible in part for its cerebral protective action during ischemia.