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A lower compression ratio has been demanded for diesel engines in recent years to improve fuel consumption, exhaust emissions and maximum power recently. However, low compression ratio may have combustion instability issues under cold temperature condition, especially just after engine started. As the first step in this study, cold temperature combustion was investigated on the basis of an in-cylinder pressure analysis, and it was found that higher heat release around top dead center, which was mainly attributed to pilot injection, was a key factor in reducing engine speed fluctuation. Three-dimensional computational fluid dynamics simulations were conducted to obtain a better understanding of combustion under cold condition, particularly mixture formation near the glow plug. Specifically, for this purpose, a time-scale interaction combustion model was developed for simulating combustion phenomena. This model was based on a reasonable combustion mode, taking into account the characteristic time scale of chemical reactions and turbulence eddy breakup. In addition, the parameters of the ignition model and computational grids near the glow plug were improved for application to cold start conditions.

The present study reports a rare case of large capillary hemangioma of the temporal bone with a dural tail sign. A 57-year-old female presented with pulsatile tinnitus and episodic vertigo associated with a ten-year history of an intermittent faint headache. Magnetic resonance imaging revealed a mass in the right petrous bone, which was hypointense on T1-weighted images and heterogeneously hyperintense on T2-weighted images, and showed a dural tail sign following gadolinium administration. Pre-operatively, this tumor was believed to be a meningioma. During surgery, the vascular tumor was removed by a modified pterional approach. A histopathological examination indicated that the tumor was a capillary hemangioma. Although intraosseous capillary hemangiomas are rare, they most frequently affect the temporal bone. Hemangiomas of the temporal bone may mimic other more common basal tumors. The diagnosis is most often made during surgical resection. The dural tail sign is not specific for meningioma, as it also occurs in other intracranial or extracranial tumors. The treatment of intratemporal hemangiomas is complete surgical excision, with radiotherapy used for unresectable lesions. To the best of our knowledge, the present study is the fourth case of intraosseous intracranial capillary hemangioma, but the largest intratemporal hemangioma to be reported in the literature to date.

On November 22, 2010, a simulation-based hands-on education course for medical staff in the neurosurgical fields was held in 8 th Asian Congress of Neurological Surgeons (ACNS) in Kuala Lumpur, Malaysia. The present education course called Primary Neurosurgical Life Support (PNLS) course had been started by the Japan Society of Neurosurgical Emergency since 2008. This report summarizes the international version of PNLS course in 8 th ACNS.

MicroRNAs (miRNAs) are small noncoding RNAs that take part in diverse biological processes by suppressing target gene expression. Elevated expression of miR-21 has been reported in many types of human cancers. Radiotherapy is a standard adjuvant treatment for patients with glioblastoma. However, the resistance of glioblastoma cells to radiation limits the success of this treatment. In this study, we found that miR-21 expression was upregulated in response to ionizing radiation (IR) in U251 cells, which suggested that miR-21 could be involved in the response of U251 cells to radiation. We showed that a miR-21 inhibitor enhanced IR-induced glioblastoma cell growth arrest and increased the level of apoptosis, which was probably caused by abrogation of the G(2)-M arrest induced by IR. Further research demonstrated that the miR-21 inhibitor induced the upregulation of Cdc25A. Taken together, these findings suggest that miR-21 inhibitor can increase IR-induced growth arrest and apoptosis in U251 glioblastoma cells, at least in part by abrogating G(2)-M arrest, and that Cdc25A is a potential target of miR-21.

Even when we successfully perform a total extirpation of glioblastoma macroscopically, we often encounter tumor recurrence. We examined seven autopsy brains, focusing on tumor cell infiltration in the peripheral zone of a tumor, and compared our findings with the MR images. There has so far been no report regarding mapping of tumor cell infiltration and DNA histogram by flow cytometry, comparing the neuroimaging findings with the autopsy brain findings. The autopsy brain was cut in 10-mm-thick slices, in parallel with the OM line. Tissue samples were obtained from several parts in the peripheral zone (the outer area adjacent to the tumor edge as defined by postcontrast MRI) and then were examined by HE, GFAP, and VEGF staining. We defined three infiltrating patterns based on number of infiltrated cells as follows: A zone, 100%-60% of the cells infiltrated tumor cells compared with tumor cell density of the tumor mass; B zone, 60%-20%; C zone, 20%-0%. In the autopsy brain, the tumor was easily identified macroscopically. We found that (1) the tumor cells infiltrated the peritumoral area; and (2) tumor cell infiltration was detected over an area measuring from 6 to 14 mm from the tumor border in the A zone. When performing surgery on glioblastoma, a macroscopic total extirpation of the tumor as defined by the contrast-enhanced area in MRI is therefore considered to be insufficient for successfully reducing tumor recurrence.

Cancer stem-like cells (CSLCs) are potential targets for treatment of glioblastoma multiforme (GBM) due to their role in tumorigenesis and recurrence. In this study, we investigated the inhibitory effect of arsenic trioxide (As(2)O(3)) on CSLCs of GBM in human glioma cell lines (U87MG, U251MG and U373MG) in vivo and in vitro. Immunofluorescence staining and flow cytometry revealed that the percentage of Nestin-positive cells in the aforementioned cell lines was diminished by 12%, 14% and 7%, respectively, after treatment with 2 microM As(2)O(3). Furthermore, we used soft-agar in U87MG and tumor xenografts in nude mice to demonstrate the ability of As(2)O(3) to inhibit the formation of tumor in the three cell lines. These results indicate the negative regulation of CSLCs by As(2)O(3). In addition, a Western blot analysis revealed decreased levels of Notch1 and Hes1 proteins due to As(2)O(3) treatment. We conclude that As(2)O(3) has a remarkable inhibitory effect on CSLCs in glioma cell lines in vivo and in vitro; in addition, we determined that the mechanism of CSLC inhibition involves the deregulation of Notch activation.

Spontaneous spinal epidural hematoma (SSEH) is rare. Its etiology remains controversial; however, spinal venous wall susceptibility to intravenous pressure change and the resultant venous rupture seem to be involved. The authors report a case of SSEH dorsal to the spine producing acute anterior spinal cord syndrome. A posterior SSEH between the C-3 and T-5 levels caused progressive tetraparesis and the disappearance of superficial body sensation below the level of C-8, although deep sensation remained completely intact. This neurological false localizing sign seems to have resulted from counterforce by preexisting asymptomatic cervical intervertebral disc herniation at the C6–7 levels inducing direct pressure on the anterior spinal cord. This case is the first reported instance of posterior cervical SSEH manifesting acute anterior spinal cord syndrome as its false localizing sign.

We attempted to rescue supralethally irradiated (SLI) mice by transplantation of hematopoietic stem cells (HSCs) plus thymus from variously aged donors (fetus, newborn and adult). Although the transplantations of these kinds of HSCs alone showed a very short survival, newborn liver cells (NLCs) (as the source of HSCs) plus newborn thymus (NT) transplantation markedly improved the survival rate. The transplantation attenuated severe damage in the small intestine, which is one of the major causes of death by SLI. In addition, the donor-derived CD4(+) T cells significantly increased with additional NT transplantation. The production of interleukin (IL)-7 and keratinocyte growth factor, which plays a crucial role in protection against radiation injury in the intestine, was the highest in NT. Finally, SLI mice that had received NLC plus IL-7(-/-) NT transplantation plus IL-7 injection showed improved survival, weight recovery and an elevated number of CD4(+) T cells compared with the mice that had received NLC plus IL-7(-/-) NT or plus IL-7 injection alone. These findings suggest that NLCs plus NT transplantation can rescue SLI mice most effectively, and that high production of IL-7 in NT plays a crucial role with induction of CD4(+) T cells.

We removed 12 intraorbital tumors (5 schwannomas, 3 meningiomas, 2 cavernomas, 1 pleomorphic adenoma, and 1 neuroblastoma) using the frontozygomatic approach. No patients died. Postoperatively, 1 patient developed transient ptosis, and 3 patients had mild enophthalmos. Two patients with a meningioma developed transient worsening of their visual acuity and visual field. The frontozygomatic approach for surgical treatment of intraorbital tumors provides a wide visual field exposing the entire optic nerve. This approach is indicated for large intraorbital tumors, tumors affecting the optic nerve or orbital apex, intraorbital tumors that have extended into the intracranial cavity, and intracranial tumors that have extended into the orbit. The operative procedure for intraorbital tumor is determined by the location of the lesion and by the direction of its growth. The procedure is applicable to all intraorbital tumors. It reduces discomfort for surgeons while providing a relatively wide surgical field.

Numerous studies have shown that some populations of bone marrow cells (BMCs) have the capacity to differentiate into neural cells, which is useful for repairing brain lesions. In this paper, we analyze neural differentiation features of lineage-negative/CD34-negative (Lin − CD34 − ) cells in the bone marrow of adult mice. The population of Lin − CD34 − in BMCs was isolated by magnetic bead sorting and fluorescence-activated cell sorter (FACS) using specific lineage (CD4, CD8a, CD11b, CD45R, Gr-1 and TER-119) antibodies and CD34 antibody. First, we cultured Lin − CD34 − BMCs in the presence of RNIF: vitamin A derivative retinoic acid (RA) and neural-inducing factors (platelet-derived growth factor BB (PDGF-BB), epidermal growth factor (EGF) and fibroblast growth factor-basic (FGF-b)). Analyses of RT-PCR and immunocytochemistry indicated that RNIF-treated Lin − CD34 − BMCs expressed neural phenotypes as well as neurogenic transcription factors. When we implanted the Lin − CD34 − BMCs isolated from enhanced green fluorescent protein (eGFP) transgenic mice into the subventricular zone (SVZ) of postnatal mice, eGFP-positive cells survived 3 weeks after the injection in the various brain regions, some of which expressed the neural phenotypes. Our data suggest that certain subsets in the CD34 − populations of adult bone marrow could have the capacity to differentiate into neural cells in a suitable environment.

We report a rare case in which a myxoid chondrosarcoma originated from the petrous bone and invaded the cerebellar hemisphere with hemorrhage. Neuroimaging showed the characteristic feature of multiple small cysts along the solid tumor, and the cystic formation was confirmed as a mucoid secretion by Alcian blue staining and electron microscopic examination. This tumor recurred following partial removal and stereotaxic radiosurgery.

In an attempt to assess the permeability of microvessels in the experimental brain tumor model, lanthanum ion (La3+) was used as a low-molecular weight electron microscopic probe. Rat glioma 9 L and adenocarcinoma ACL15 were transplanted to the brain and subflank of rats. The rats were then anesthetized sequentially perfused with saline, saline plus La3+ followed by a fixative in phosphate buffer. The brain and subcutaneous tumors were removed, further fixed, and processed for electron microscopy. La3 did not pass through the tight junctions of the normal cerebral endothelium. Similarly, La3+ did not penetrate the endothelial cell wall of the microvessels in the transplanted brain tumors. In contrast, extravasation of La3+ from the microvessels in the transplanted subcutaneous tumors was observed. The electron microscopy examination results indicate that the vesicular transport was a predominant mechanism in the penetration of La3+ through the endothelial cell wall. Since most chemotherapeutic agents similar as La3+ are of low molecular weight, we can suggest from the results of our present study that the blood tumor permeability of the anti-cancer agents in the rat model of brain glioma transplantation differs from that in the rat model of subcutaneous glioma transportation. In other words, our results indicate that when the subcutaneous glioma transplantation model is used in sensitivity tests of anti-cancer agents, it will possibly be very difficult to predict the anti-neoplastic effect in vivo.

Ewing's sarcomas account for approximately 10% of primary malignant bone tumors. While most of the primary Ewing's sarcomas occur in the long bones, pelvis, or ribs, approximately 1-6% of these sarcomas arise in the skull. We found approximately 50 cases of Ewing's sarcoma of the calvarium reported in our search of the literature. Of these, 36 cases were reported in detail.In this article we describe a rare case of primary Ewing's sarcoma of the occipital bone presenting with acute obstructive hydrocephalus and review the literature.

To set up long-term in vitro culture system of the human neural stem cells (hNSC) and to study their biological properties.Human fetuses aged about 20 weeks following spontaneous abortion were adopted. A serum-free medium containing basic fibroblast growth factor and epidermal growth factor was used to make the hNSCs divide continuously in the culture. The growth curve of continually passaged cells was examined. The effects of long-term culture on the cell cycle, cell differentiation were analyzed. The cell cycles of these cells were analyzed using flow cytometry.The cells from the human embryonic cortical tissue could be maintained and propagated in the presence of growth factors. Neurospheres were generated continually. Only one month after the primary culture, the precursors could be effectively discarded. The cells could be cultured for ten months. The cells had an exponential, consistent growth. The cell cycle analysis indicated that the hNSCs maintained remarkable proliferation. Upon differentiation, the hNSCs gave rise to mature cells. The multi-lineage potential of differentiation after different passages remained unchanged.The hNSCs isolated from the human embryonic tissues retained their biological features after long-term culture in vitro.

Cultured rat astrocytes were incubated in the presence of cycloheximide (CHX; 20 microg/mL), a potent neuroprotective agent. Then cells were subjected to DNA gel electrophoresis. Electrophoresis showed DNA ladder formation, which is characteristic of apoptosis. Inhibitors of interleukin-1beta-converting enzyme (ICE) and caspase 32(CPP32), which play critical roles in certain apoptotic pathways, did not block the cycloheximide-induced apoptosis of cultured astrocytes. This observation indicates that the role of ICE and CPP32 is not significant in the CHX-induced astrocyte apoptosis process. When the blood-brain barrier was disrupted in the rat, the number of brain cells undergoing apoptosis was significantly higher after cycloheximide administration, in contrast to controls. Of the cells that produced glial fibrillary acidic protein, some were observed to undergo apoptosis. Although CHX has been shown to be useful as a neuroprotective agent against ischemic neuronal death, astroglial toxicity may be problematic, depending on CHX concentration. Therefore, a prudent use of this compound is recommended.

In an attempt to investigate the tumor type-specific ultrastructure of cultured brain tumors, a collagen gel culture was utilized instead of the conventional monolayer culture. To avoid intermingling of the normal brain cells, tumors with a clear margin and a portion typical of invasive tumors were sampled. The tumors were minced, and small fragments were prepared and embedded in the collagen gel in an aseptic manner. Tumors were observed on a daily basis under a phase contrast microscope. When sprouting of the tumor cells from a tumor fragment was confirmed, the samples were fixed with 2.5% glutaraldehyde and then processed for electron microscopy. Ultrastructurally, meningioma has been shown to form a whorl-like structure. The cell processes have a complex interrelationship, but this phenomenon cannot be regarded as the so-called interdigitation. A basement membrane was formed surrounding the tumor cell processes facing the collagen gel in two ependymomas. Lipid droplets were contained in great numbers inside a chordoma cell. These findings suggest the usefulness of collagen gel culture in analyzing the tumor type-specific ultrastructure of cultured brain tumors, and possibly in studying cellular differentiation.

DZ-2640 is the ester-type oral carbapenem prodrug of an active parent compound, DU-6681. The pharmacokinetics and safety of DU-6681 were investigated in six studies after oral administration of a single dose of DZ-2640 to healthy male Japanese volunteers at doses of 25, 50, 100, 200, and 400 mg (as the equivalents of DU-6681) in the fasted state. The same volunteers received the drug at a dose of 100 mg in the fasted and fed states to examine the effect of food intake on the bioavailability of DZ-2640. The concentrations of DU-6681 in plasma and urine were determined by a validated high-performance liquid chromatography method and a bioassay. A good correlation between both methods was seen, indicating an absence of major active metabolites. The mean maximum concentrations of DU-6681 in plasma ( C max ) ranged from 0.263 μg/ml (25-mg dose) to 2.489 μg/ml (400-mg dose) and were reached within 1.5 h following drug administration. After reaching the C max , plasma DU-6681 concentrations declined in a monophasic manner, with a half-life of 0.47 to 0.89 h. The area under the concentration-time curve (AUC) and C max increased almost linearly with the dose up to the 200-mg dose. The AUC and C max increased less than proportionally after administration of the 400-mg dose, suggesting a reduction in drug absorption. The plasma protein binding of DU-6681 was in the range of 23.3 to 25.6%. The cumulative urinary recoveries (0 to 24 h) were in the range of 31.9 to 44.9%. The AUC was slightly but statistically significantly reduced by food intake. However, the C max , half-life, and recovery in urine were not affected by food intake. The renal clearance (402 to 510 ml/min) was much greater than the mean glomerular filtration rate (ca. 120 ml/min), which indicated active tubular secretion of the drug. A mild transient and moderate diarrhea was observed in two of six volunteers in the study with a single dose of 25 mg. Mild soft stools were observed in two of six volunteers who received a 400-mg dose of the drug.

Scalp electroencephalograms (EEGs) of brain dead patients are macroscopically flat under 7 or 10 microV/mm electroencephalograph sensitivity, but significant noises are detected in EEGs under 2 microV/mm sensitivity, interfering with the analysis. EEGs of 20 brain dead patients (17-76 years old) were therefore analyzed quantitatively as equivalent electric potentials in frequency bands delta, theta, alpha and beta using the automatic EEG analysis system developed in Kansai Medical University. The equivalent electric potentials in each band were about or less than 1 microV, which is used as a criterion of judgment of flat-line EEGs or brain death. Then, macroscopically flat EEGs of 12 comatose patients including infants (3-67 years old) were analyzed by the system, confirming their brain death. Thus, the automatic EEG analysis system could be used as a supporting tool to confirm flat-line EEGs of brain dead patients. ATAMAP II for Windows software was also evaluated.

A 23-year-old Japanese woman presented with a newly developed spinal extradural arteriovenous fistula (AVF) during pregnancy. She had been followed up for a suspected spinal cavernous angioma and became unable to walk during the 29th week of her pregnancy. Magnetic resonance (MR) imaging showed a spinal extradural AVF at the T3 to T4 levels compressing the spinal cord. After delivery by cesarean section, her neurological symptoms gradually began to resolve, and she was able to resume walking without assistance. MR imaging confirmed spontaneous regression of the AVF. This case suggests that exacerbated neurological symptoms and AVF growth triggered by pregnancy can improve after delivery without interventional treatment. Careful follow up of neurological findings is required to prevent unnecessary interventional procedures in pregnant women with spinal AVF.

In an attempt to investigate the tumor type-specific ultrastructure of cultured brain tumors, collagen gel culture was utilized instead of the conventional monolayer culture. In order to avoid intermingling of the normal brain cells, tumors with a clear margin were chosen. The tumors were cultured first in the monolayer culture for a few passages, and then tumor cell pellets were prepared and embedded in the collagen gel. In the event that tumors failed to grow in the monolayer culture, small fragments of tumor tissue were embedded. Ultrastructurally, the tumor cell processes of central neurocytoma contained numerous dense-core vesicles. The formation of desmosomes was observed in the meningioma cell processes. The development of polypoid microvilli similar to those of the normal choroid plexus epithelium was observed in a case with ependymoma. A continuous basement membrane was seen surrounding the tumor cell processes facing the collagen gel in two ependymomas. These findings suggest the usefulness of the collagen gel culture in analyzing the tumor type-specific ultrastructure of cultured brain tumors and possibly in studying cellular differentiation.

Background and Purpose— Hyponatremia is common after aneurysmal subarachnoid hemorrhage (SAH). It is caused by natriuresis, which induces osmotic diuresis and decreases blood volume, contributing to symptomatic cerebral vasospasm (SCV). Hypervolemic therapy to prevent SCV will not be efficient under this condition. We conducted a randomized controlled trial to assess the efficacy of hydrocortisone, which promotes sodium retention in the kidneys. Methods— Seventy-one SAH patients were randomly assigned after surgery to treatment with either a placebo (n=36) or 1200 mg/d of hydrocortisone (n=35) for 10 days and tapered thereafter. Both groups underwent hypervolemic therapy. The primary end point was the prevention of hyponatremia. Results— Hydrocortisone prevented excess sodium excretion ( P =0.04) and urine volume ( P =0.04). Hydrocortisone maintained the targeted serum sodium level throughout the 14 days ( P P =0.007) supplementation. Hydrocortisone kept the normal plasma osmolarity ( P Conclusions— Hydrocortisone overcame excess natriuresis and prevented hyponatremia. Although there was no difference in outcome, hydrocortisone supported efficient hypervolemic therapy.

In order to elucidate the mechanisms of cisplatin (cis-diamminedichloroplatinum; CDDP)-resistant tumor cells, we previously established a CDDP-resistant KB cell line (KBrc cells) from a parental KB cell line derived from epidermoid carcinoma (KB cells). The KBrc cells were resistant to 5 kinds of platinum (Pt) drugs. Intracellular Pt concentrations in KBrc cells were lower than in KB cells. Decrease of intracellular Pt concentrations was one of the CDDP-resistant mechanisms. When we measured changes of intracellular calcium ion concentration ([Ca2+]i) during exposure to high-dose CDDP, a sustained elevation of the [Ca2+]i level was observed in the KB cells. These results suggest that the mechanisms underlying CDDP resistance involve changes in calcium channels and an alteration of calcium homeostasis in the tumor cell line.

The effect of the antitubulin agent colcemid on human glioma cells was investigated by sorting cells with different DNA content and subjecting them to confocal laser microscopy and transmission electron microscopy. The human glioma cell line U251MG was exposed to colcemid at a concentration of 0.05 microg for 16 h. Flow cytometric analysis revealed the accumulation of cells in S/G2M phase. Cells harvested from each of G0/G1 and S/G2M peaks were then analyzed by confocal laser microscopy and transmission electron microscopy. Confocal laser microscopy revealed that colcemid-treated cells harvested from the G0/G1 peak contained mitotic and apoptotic cells in addition to interphase cells. Electron microscopy confirmed that colcemid-treated cells in the G0/G1 peak had fragmented nuclei typical of apoptotic cells and mitotic cells with altered chromatin structure. Some mitotic cells obtained by mitotic shake-off after treatment with colcemid showed DNA strand breaks defined by in situ nick end labeling. The present study indicates that mitotic as well as interphase apoptosis occurs in U251MG cells following colcemid treatment.

Central neurocytoma is a rare brain tumor with neuronal differentiation. Cultured central neurocytoma cells are poorly described because of the tumor's scarcity. Two central neurocytomas were cultured using a monolayer culture for first few passages, and then a portion of each specimen was cultured in a collagen gel. Immunostaining for synaptophysin or glial fibrillary acidic protein performed on the primary culture revealed the presence of cells expressing synaptophysin and cells expressing glial fibrillary acidic protein. Cells expressing synaptophysin tended to disappear in passage 2, whereas the cells expressing glial fibrillary acidic protein remained. Ultrastructurally, samples in passage 5 obtained from the collagen gel cultures revealed neuron-like cells with prominent nucleoli, cell processes containing dense core vesicles and clear vesicles, and synapse-like structures. By contrast, samples obtained from passage 5 of monolayer cultures failed to reveal ultrastructural neuronal characteristics. These results suggest that spatial cell growth and the presence of collagen, i.e., extracellular matrix, may be necessary to retain neuronal differentiation in a central neurocytoma.

To assess the effect of 1-(4-amino-2-methyl-5-pyrimidil)methyl-3-(2-chloroethyl)3-nitrosourea hydrochloride (ACNU) on human glioma, we performed cell-cycle-specific cell sorting followed by electron microscopic observation. Cells sorted from an accumulated SG2M peak caused by treatment with 10μg/ml ACNU showed a number of cells similar to S-phase cells in the untreated samples, having no microvilli. Cell organelles were intact, and no ultrastructural evidence for cell injury was observed. In contrast, many cells sorted from nonstagnated G0G1 and SG2M peaks in the samples treated with 100μg/ml ACNU showed mitochondrial swelling that suggested cell necrosis.

Potential molecular targets in neuroblastoma include ALK mutations, p16 deletion and CDK2A mutations; however, targeted therapeutics have not been developed for these factors. We developed Wr-T, a new system for intracellular peptide and protein delivery with a 30-residue sequence that mediates molecule entrapment and intracellular permeability. Wr-T was used to introduce the p16INK4a functional peptide to restore the tumor suppressor function of p16INK4a. Introduction of Wr-T into rats with subcutaneous grafts of neuroblastoma produced an astonishing 75.6% tumor suppression (p

We examined the in vivo effect of paraquat on the cell cycle in rat liver and lung tissues and the protective effect of tungsten (a xanthine oxidase inhibitor) on paraquat toxicity. The bromodeoxy- uridine/propidium iodide double-staining method and flow cytometry were used for cell cycle assessment. Wistar rats were fed a standard diet or a tungsten-enriched diet were injected intravenously with 20 mg/kg paraquat, while uninjected rats served as controls. At 1, 3, and 5 days after paraquat injection, the liver and lungs were removed for examination following in vivo labeling with 20 mg/kg bromo- deoxyuridine for 1 h. Liver and lung cells were isolated and incubated with an anti-bromodeoxyuridine antibody and with propidium iodide for DNA staining. Flow cytometry showed that the S-phase cell populations in the liver and lungs of paraquat-injected rats fed a standard diet were increased markedly on days 1 and 3 after injection compared with the control levels. However, on day 5 the liver cells had nearly returned to normal, while the S-phase population remained high in the lungs. In contrast, the S-phase cell populations of liver and lung tissue showed no increase after paraquat injection in rats fed a tungsten-enriched diet. These findings suggest that paraquat-induced cytotoxicity is more prolonged in the lungs than in the liver. In addition, paraquat toxicity appears to be mediated by xanthine oxidase and xanthine oxidase inhibitors may be useful as an antidote.

頭頸部腫瘍をはじめとする固形癌に対して抗癌剤を用いた治療は集学的治療の一つとして有用である。しかし, いまだにその効果の限界があり, その問題点の一つはプラチナ系薬剤に対する固形癌の獲得耐性がある。特に臨床上, 固形癌の耐性発現は単一回もしくは低頻度複数回のプラチナ系薬剤の薬剤投与で観察されることがある。その発現機序は詳細に検討されておらず, 今回著者等はヌードマウス移植固形癌を用いプラチナ系薬剤 (254-S) を低頻度複数回 (1～5回) 投与することで, 固形癌の254-Sに対する耐性発現の検討を行なった。一次治療としての初回治療で, 1回単一投与, 3回, 5回, 分割頻回投与における, 腫瘍増殖抑制効果に差を認めなかった。しかしながら, 二次治療として254-Sの再単一投与での腫瘍増殖抑制効果を比較すると, 分割頻回投与群のほうが, 1回単一投与群より効果の低下があり, 分割頻回投与群における固形癌の薬剤感受性の低下が示唆された。

臨床的に脳死に近い4症例(41～62歳)と脳死と判定された3症例(39～57歳)について,通常の脳波検査で採取された標準脳波と鼻咽頭後壁から得られたnasopharyngeal EEGとを脳波自動解析システムを用いて解析・検討した。そのうち脳死に近い2症例では,肉眼的にnasopharyngeal EEGに低電位で10～30μVのθ波がみられたが,他の5症例ではnaso-pharyngeal EEGもほとんど平坦化していた。さらに脳波自動解析システムを用いて脳波をデジタル化したところ,標準脳波の等価電位は健常人の等価電位よりも低値を示したのに対し,nasopharyngeal EEGの等価電位はいずれかの周波数領域において,低電位ながら健常人の等価電位分布の範囲内に留まっていた(7例中δ:2例,θ1:5例,θ2:2例,α1:2例,α3:5例,β1:5例)。このようなnasopharyngeal EEGの詳細な解析は「脳死」状態の把握に有用であると思われた。

In adult rat cerebellum, HPC-1/syntaxin 1 is detected at high density on the plasma membrane of the non-synaptic region of parallel fibers in addition to the synaptic terminal membranes and the synaptic vesicles (Koh, S., Yamamoto, A., Inoue, A., Inoue, Y., Akagawa, Y., Kawamura, Y., Kawamoto, Y., and Tashiro, Y. (1993). J. Neurocytology 22: 995-1005). To assess the possibility that HPC-1/syntaxin 1 participates in the morphogenesis of the nervous system, we examined changes in the localization of HPC-1/syntaxin 1 during postnatal development of the molecular layer of the rat cerebellum. HPC-1/syntaxin 1 appeared in the granule cells in the outer granule cell layer in 3-days-old rat cerebellum when the formation of synapses and the appearance of a synaptic vesicle protein, synaptophysin, had not yet been observed in the molecular layer. At this stage, the granule cells began to form parallel fibers. Confocal laser microscopy and immune-electron microscopy showed that HPC-1/syntaxin 1 was localized on the extruding plasma membrane of the granule cells to form parallel fibers. In 8-days-old rats, synapses formed between the parallel fibers and the developing dendrites of Purkinje cells, and the HPC-1 immunoreactivity appeared on the axons of parallel fibers and on the synapses. In 21-days-old rats, the HPC-1/syntaxin 1 immunostaining pattern was similar to that of adult rats. These results suggest that HPC-1/syntaxin 1 is involved in the formation of the molecular layer, especially in the axonal growth of the parallel fibers.

We used flow cytometry to assess the cell cycle kinetics of cultured Maden Darby canine kidney cells after exposure to paraquat. Fluorescein diacetate fluorescence was used as a marker of cell viability, while bromodeoxyuridine incorporation was detected with a monoclonal antibody and propidium iodide staining to assess DNA synthesis. Flow cytometry was performed immediately, 48 h and 96 h after exposure to paraquat for 24 h. Lactate dehydrogenase release was also measured to determine the extent of cytolysis. Flow cytometry of paraquat-treated cells showed a marked increase of the S phase population immediately after exposure, at a time when there was no increase of lactate dehydrogenase release. In contrast, the cell cycle profile returned towards normal at 48 and 96 h after paraquat exposure, but lactate dehydrogenase release increased. These findings indicate that paraquat arrested cells in the S phase and that inhibition of DNA synthesis by this agent appeared to influence cell viability because S phase block occurred before cytolysis. In addition, this method proved useful for assessing the effects of paraquat on DNA synthesis by cultured cells.

The management of posthemorrhagic hydrocephalus is difficult and not well standardized. We evaluated our management protocol for infants with intraventricular and/or periventricular hemorrhage (IVH and PVH, respectively). There were four deaths and two significant treatment-related complications in our series. We also observed two cases of isolated ventricle in patients treated with reservoir placement. After evaluating our series, we modified our protocol from reservoir placement to either cerebrospinal fluid (CSF) drainage or ventriculosubgaleal shunt directly. We will reevaluate this new protocol in the near future.

The management of posthemorrhagic hydrocephalus is difficult and not well standardized. We evaluated our management protocol for infants with intraventricular and/or periventricular hemorrhage (IVH and PVH, respectively). There were four deaths and two significant treatment-related complications in our series. We also observed two cases of isolated ventricle in patients treated with reservoir placement. After evaluating our series, we modified our protocol from reservoir placement to either cerebrospinal fluid (CSF) drainage or ventriculosubgaleal shunt directly. We will reevaluate this new protocol in the near future.

Programmed cell death, currently termed apoptosis plays a key role in the maintenance of the steady state in continuously renewing tissues. Since little is known of apoptosis in head and neck tumors, we studied morphological changes in head and neck tumor-derived cell lines (KB, KBrc, HSC-2,3,4), induced by anti-Fas antibody. Light and electron microscopic examinations were carried out after culturing these cell lines with the antibody for 1-2 days. The antitumor effect of anti-Fas antibody on tumor cells differed with the cell lines. Most of the cell lines that were sensitive to anti-Pas antibody showed evidence of enhanced apoptosis when the cells were pretreated with interferon-gamma. The results suggest that the strategy of induction of apoptosis by anti-Fas antibody may be considered in treatment of some tumors of head and neck.

The emergence of resistance to platinum analogues is considered to be a major problem in the treatment of head and neck cancer. Therefore, it is important to clarify the mechanisms of resistance to these analogues and the mechanisms of the processes related to this resistance. The study of emergence of resistance in the solid tumors is particularly relevant. Ln the present study, the effect of a platinum analogue (254-S), on the response of an oral carcinoma cell line grown as a xenograft in nude mice, was studied. The effect of a full dose administered as a single intraperitoneal injection of 254-S (15 mg/kg X 1) on tumor growth was not significantly different from the effect of repeated intraperitoneal injections of 254-S, administered 3 times at 1/3 of this dose (5 mg/kg x3), or 5 times at 1/5 of this dose (3 mg/kg x5). However, when a single full-dose intraperitoneal injection of 254-S (15 mg/kg x1) was administered to each group of mice again at the 9th and 12th weeks after the initial treatment, different effects on tumor growth were observed among each group. The groups which received repeated treatment with 254-S (5 mg/kg, x3, or 3 mg/kg x5) showed a decrease in the inhibition of tumor growth, suggesting the emergence of resistance to 254-S. The study of platinum accumulation in the tumor tissues and a flow cytometric analysis of proliferating cell nuclear antigen (PCNA) supported the possibility that resistance to 254-S increases in tumor tissues treated repeatedly. These observations suggest that the potential use of this experimental assay as a model, may provide further insights into the therapeutic mechanisms of resistance to antineoplastic agents in the treatment of solid cancerous head and neck tumors.

The patient was a 72-year-old woman who had previously undergone treatment for femoral chondrosarcoma (histologically rated as myxofibrosarcoma). She suddenly developed left homonymous hemianopsia and was diagnosed with cerebral embolism. Because she had atrial fibrillation, we treated her for cardiogenic cerebral embolism. About 3 months later, however, she developed left hemiplegia, and head magnetic resonance imaging revealed multiple tumorous lesions affecting the previously detected infracted area and several new areas. We assumed that a tumor embolus had caused cerebral embolism, which resulted in growth of the tumor from the embolus and formation of a metastatic brain tumor. The metastatic foci formed from the tumor embolus were visualized by diagnostic imaging, and histological examination of the resected tumor confirmed that the brain tumor had occluded the brain vessel (tumorigenic cerebral embolism). No such case has been reported to date, and this case seems to be important.

HPC-1 antigen is a neuron-specific 34 kDa protein, identical to p35A (syntaxin), and is thought to play important roles in docking or fusion of synaptic vesicles to presynaptic active zones. In the present study we analyze the distribution of HPC-1 antigen in rat cerebellum by a cryoimmunogold technique using an antibody against the fusion protein of beta-galactosidase and the HPC-1 antigen. HPC-1 antigen was detected at high density on the plasma membranes and synaptic vesicles of presynaptic boutons which formed synapses with dendrites of Purkinje cells, and on the plasma membranes of parallel fibres in the cerebellar molecular layer. In the granule cell layer, gold particles were also detected on the endoplasmic reticulum, nuclear membranes and the plasma membranes of granule cells. Presynaptic membranes and synaptic vesicles in glomeruli were also labelled by gold particles. To determine the topology of HPC-1 antigen on the membranes, the synaptosome fraction prepared from rat cerebellum was embedded in agarose, and processed for the pre-embedding protein A-gold technique. Intact synaptosomes were not labelled by gold particles. However, when fixed in hypotonic fixative to rupture plasma membranes, or when ruptured after fixation in normotonic fixative, the cytoplasmic surfaces of presynaptic membranes and synaptic vesicles were labelled by gold particles. These results suggest that most of the epitopes of HPC-1 antigen are located on the cytoplasmic surface of plasma membranes and synaptic vesicle membranes.

Cisplatin (CDDP) is one of the most potent and useful anticancer agents for head & neck cancers. The cytotoxicity of this drug is known to include inhibition of DNA synthesis. However, the development of resistance by tumor cells to this drug is an important problem. In order to elucidate the mechanism of CDDP resistance, we established CDDPresistant KB cell lines (KBrc cells) from oral epidermal carcinoma cell lines (KB cells). In this study, we investigated the mobilization of intracellular free calcium ion concentration ([Ca2+]i) to elucidate the mechanism of CDDP resistance in case of contact with a high dose of CDDP (500μg/ml) using these cell lines. Incubation with CDDP markedly increased [Ca2+]i in both cell lines. In contrast, a low dose of CDDP resulted in the reduction of [Ca2+]i toward the resting level. Furthermore, the peak and plateau of [Ca2+]i were higher in KB cells than in KBrc cells, and the speed toward the plateau phase was later in KB cells in comparison with that in KBrc cells. This increase in [Ca2+]i was thought to be due mainly to an influx of extracellular calcium ions. Moreover, the viability of KB cells was lower than that of KBrc cells. It was speculated that KBrc cells possesed the ability to protect CDDP compared with KB cells and the change of [Ca2+]i in KBrc cells was less than that in KB cells. It appears that CDDP can injure cell membranes as well as inhibit DNA synthesis.

As a basic study, an analysis was made, using flow cytometry (FCM), of a mixture of KB cells and lymphocytes after Propidium Iodide (PI)- Fluorescein Isothiocyanate (FITC) double strain. As a result, DNA histogram of only KB cells could be drawn. As a clinical application an analysis was made, using FCM, of tumor of the head and neck after double stain. It enabled the drawing of DNA histogram of only epithelial cells (cancer cells). Changes in DNA histogram of keratin positive cells were classified into three types: Type I: the same diploid type as whole cells, Type II: the same aneuploid type as them, and Type III: the different aneuploid type as them. Among 22 cases of malignant tumor there were 3 cases of Type I, 6 cases of Type II, and 13 cases of Type III. This method could contribute greatly to the detection of cancer cells and DNA diagnosis, and thus be useful clinically.