Involvement of brain oxidation in the cognitive impairment in a triple transgenic mouse model of Alzheimer's disease: noninvasive measurement of the brain redox state by magnetic resonance imaging.

Oxidative stress is considered to be related to the onset and/or progression of Alzheimer's disease (AD), but there is insufficient evidence of its role(s). In this study, we evaluated the relationships between the brain redox state and cognitive function using a triple transgenic mouse model of AD (3 × Tg-AD mouse). One group of 3 × Tg-AD mice started to receive an α-tocopherol-supplemented diet at 2 months of age and another group of 3 × Tg-AD mice was fed a normal diet. The levels of α-tocopherol, reduced glutathione, oxidized glutathione, and lipid peroxidation were decreased in the cerebral cortex and hippocampus at 4 months of age in the 3 × Tg-AD mice fed a normal diet. These reductions were abrogated by the supplementation of α-tocopherol in the diet. During Morris water maze testing, the 3 × Tg-AD mice did not exhibit cognitive impairment at 4 months of age, but started to show cognitive dysfunction at 6 months of age, and α-tocopherol supplementation suppressed this dysfunction. Magnetic resonance imaging (MRI) using 3-hydroxymethyl-proxyl as a probe showed decreases in the signal intensity in the brains of 3 × Tg-AD mice at 4 months of age, and this reduction was clearly attenuated by α-tocopherol supplementation. Taken together, these findings suggest that oxidative stress can be associated with the cognitive impairment in 3 × Tg-AD mice. Furthermore, MRI might be a powerful tool to noninvasively evaluate the increases in reactive radicals, especially those occurring during the early stages of AD.

Isotopic investigations for the origin of relic from the Matsusaki site, Japan.

We measured the environmental radioactivity and isotope ratio, (87)Sr/(86)Sr ratio, (234)U/(238)U, delta(13)C, and (228)Ra/(226)Ra activity ratio, of adhesion that adhered to a wooden tubing vessel obtained from the Matsusaki site, one of the salt-production sites where Moshio is manufactured, in Aichi Prefecture, Japan. The environmental radioactivity and isotope ratio verified that the adhesion originated from the seaweed and/or sea grass.

Beneficial effect of hyperbaric oxygen therapy on liver regeneration after 90% hepatectomy in rats.

BACKGROUND/AIMS: Hyperbaric oxygen therapy (HBOT) has been reported to augment oxygen delivery to ischemic tissues and improve the liver dysfunction in clinical cases. HBOT was performed after 90% hepatectomy in rats to determine its effect on the regeneration of remnant liver. METHODS: After 90% hepatectomy was performed in 8-week-old male Wistar rats, the animals were subdivided into an HBOT (2 atm abs., 80% O2, 1 h/day, 3 days) group and a non-HBOT group. Members of both groups were sacrificed, usually every 4 h until a maximum of 50 h after hepatectomy, and the liver regeneration rate, the proportion of PCNA-positive cells and the ATP volume in the remnant tissues were examined. RESULTS: In the HBOT group, the liver regeneration rate at 36 h and 50 h after operation and the proportion of PCNA positive cells at 8 h was significantly increased compared with the non-HBOT group. The ATP volume in the remnant livers in the HBOT group was also significantly increased at 12 h. CONCLUSION: HBOT augmented liver regeneration after hepatectomy by stabilization of energy metabolism induced by oxygen delivery in rats.

A study on the spatial distribution of nitrogen and phosphorus balance, and regional nitrogen flow through crop production.

The spatial distribution patterns of the nitrogen and phosphorus input/intake amounts in crop production within two small basins are examined, based upon a cropping unit distribution map that is obtained from remote sensing data analysis. Firstly, we examine the availability and suitability of approaches to the spatial distribution analysis of cultivation patterns classified from material flow characteristics of crop production using seasonal remote-sensing data. Secondly, material flow units in crop production are grouped according to the cultivation patterns obtained from the remote-sensing data analysis. Consequently, the spatial patterns of the amounts of both nitrogen and phosphorus inputs/intakes through crop production on farmland are examined and their spatial distribution maps are prepared according to the material flow units. In addition, we developed a nitrogen flow and runoff model and the model is simulated based on the examination of the results of spatial distribution patterns of the material flow units. The annual nitrogen runoff from small catchments, where various crops are cultivated, varies from 2.7 kg ha(-1) year(-1) to 108 kg ha(-1) year(-1) and the annual balanced losses of nitrogen in small catchments varied from -30 kg ha(-1) year(-1) to 101 kg ha(-1) year(-1). Also, the monthly changes in soil nitrogen of each material flow unit is estimated at -55 kg ha(-1) as a maximum decrease and 114 kg ha(-1) as a maximum increase. These results indicate that the spatial distribution patterns of nutrient input and intake through agricultural activities should be considered when analyzing the material flows and nutritient movement in soil-water systems in rural areas for watershed environmental control and regional agricultural management.

Anti-tumour effects of nobiletin, a citrus flavonoid, on gastric cancer include: antiproliferative effects, induction of apoptosis and cell cycle deregulation.

AIM: To demonstrate the antitumour effects of nobiletin (5,6,7,8,3',4'-hexamethoxyflavone), a citrus flavonoid extracted from Citrus depressa Hayata, on human gastric cancer cell lines TMK-1, MKN-45, MKN-74 and KATO-III. MATERIALS AND METHODS: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, the TdT-mediated dUTP biotin nick-end labelling (TUNEL) method and cell-cycle analysis revealed that nobiletin acted on these cells in several ways, namely by direct cytotoxicity, induction of apoptosis and modulation of cell cycle. The efficacy of combined treatment of nobiletin with a conventional anticancer drug, CDDP, was also examined. Treatment with nobiletin 24 h prior to CDDP administration showed a synergistic effect compared to the control. CONCLUSIONS: Although the effective dose and administration route of nobiletin require further investigation, our study represents a potential successful linking of this compound with the treatment of gastric cancer.

The citrus flavonoid, nobiletin, inhibits peritoneal dissemination of human gastric carcinoma in SCID mice.

The flavonoid nobiletin (5,6,7,8,3',4'-hexamethoxyflavone), found in Citrus depressa Rutaceae, a popular citrus fruit in Okinawa, Japan, reportedly inhibits the production of pro-matrix metalloproteinase (proMMP)-1, 3, and 9 in rabbit synovial fibroblasts in vitro. In the present study, we demonstrated the inhibitory effects of nobiletin on the proliferation of the cancer cell line, TMK- 1, and its production of MMPs. In the SCID mouse model, we found that nobiletin inhibited the formation of peritoneal dissemination nodules from TMK-1. The enzymatic activity of MMP-9 expressed in culture medium obtained from a co-culture of TMK-1 and mouse fibroblastic cells was inhibited by nobiletin in a concentration-dependent manner. In the SCID mouse model, total weight of dissemination nodules was significantly lower in the treated group compared with the vehicle control group (0.07 g vs. 0.78 g, P = 0.0059). The total number of dissemination nodules was also significantly lower than in the vehicle control group (7.5 vs. 69.3 / body, P = 0.0001). These results suggest that nobiletin may be a candidate anti-metastatic drug for prevention of peritoneal dissemination of gastric cancer.

Xenon inhalation increases norepinephrine release from the anterior and posterior hypothalamus in rats.

PURPOSE: To investigate the effect of xenon (Xe) and nitrous oxide (N(2)O) on norepinephrinergic neuronal activity in the rat medial preoptic area (mPOA) and posterior hypothalamus (PH) using microdialysis. METHODS: Sixty male Wistar rats were equally allocated to two groups: mPOA and PH. A microdialysis probe was implanted into the mPOA or the PH. In both groups, each animal was exposed to one of the following inhalations: 25% oxygen (control, n=6), 30% Xe (n=6), 60% Xe (n=6), 30% N(2)O (n=6) or 60% N(2)O (n=6). Norepinephrine concentration in the perfused artificial cerebrospinal fluid was measured by high pressure liquid chromatography at ten-minute intervals. After plotting the time-norepinephrine concentration curve, the area under the curve (AUC) in each group was calculated. RESULTS: In the mPOA, 30 and 60% Xe, but only 60% N(2)O significantly increased norepinephrine release. The AUC in the 30% Xe, 60% Xe or 60% N(2)O group was 160 +/- 9 (P <0.05), 288 +/- 42 (P <0.01) or 237 +/- 46 pg x min/sample (P <0.01), respectively, compared to that in the control group: 77 +/- 14 pg x min/sample. In the PH, only 60% Xe significantly increased norepinephrine release compared to control (AUC: 191 +/- 38 vs. 71 +/- 1 pg x min/sample, P <0.01). CONCLUSION: The present data suggest that Xe stimulates norepinephrinergic neurons more potently than N(2)O; 1.2 times more in the mPOA and 2.5 times more in the PH. This stimulant effect may contribute to the hypnotic and sympathotonic effects of Xe in rats.

Adjuvant therapies using biliary stenting for malignant biliary obstruction.

The aim of this study was to analyze the patency of expandable metallic stents in malignant biliary obstruction and to evaluate the efficacy of adjuvant therapy accompanied by biliary stenting. We analyzed 29 patients in whom bile duct stenting was performed for malignant biliary obstruction. Their types of disease were: hilar ductal carcinoma (n = 8), gallbladder carcinoma (n = 11), and pancreatic carcinoma (n = 10). Initially, 46 expandable metallic stents were placed in 29 patients. In 23 of the 29 patients, adjuvant therapy was administered. Seventeen patients underwent radiotherapy, and 16 patients received various systemic chemotherapies. In principle, hyperthermia was performed twice a week, simultaneously with radiotherapy. Patient survival and the probability of stent patency were calculated using actuarial life table analysis. There was no significant difference in stent patency among the patients according to type of disease. Hyperthermia did not influence the stent patency rate. The median stent patency time was significantly greater in the chemo-radiation group than in the no-adjuvant therapy group: 182 days versus 68 days, respectively (P = 0.017). Moreover, a significant increase was seen in the median survival time in the chemo-radiation group: 261 days versus 109 days (P = 0.0337). Complications occurred in 9 patients (31.0%). Stent occlusion occurred in 6 patients (20.7%), with all of these patients managed successfully using a transhepatically placed new expandable metallic stent, employing the stent-in-stent method. Stent migration occurred in 2 patients after radiotherapy. Adjuvant therapies such as radiotherapy and systemic chemotherapy, in combination with stent insertion, resulted in an increase in the patency period of expandable metallic stents and in increased patient survival time.

Evidence for a single nucleotide polymorphism in the KCNQ1 potassium channel that underlies susceptibility to life-threatening arrhythmias.

INTRODUCTION: Congenital long QT syndrome (LQTS) is a genetically heterogeneous arrhythmogenic disorder caused by mutations in at least five different genes encoding cardiac ion channels. It was suggested recently that common polymorphisms of LQTS-associated genes might modify arrhythmia susceptibility in potential gene carriers. METHODS AND RESULTS: We examined the known LQTS genes in 95 patients with definitive or suspected LQTS. Exon-specific polymerase chain reaction single-strand conformation polymorphism and direct sequence analyses identified six patients who carried only a single nucleotide polymorphism in KCNQ1 that is found in approximately 11% of the Japanese population. This 1727G>A substitution that changes the sense of its coding sequence from glycine to serine at position 643 (G643S) was mostly associated with a milder phenotype, often precipitated by hypokalemia and bradyarrhythmias. When heterologously examined by voltage-clamp experiments, the in vitro cellular phenotype caused by the single nucleotide polymorphism revealed that G643S-KCNQ1 forms functional homomultimeric channels, producing a significantly smaller current than that of the wild-type (WT) channels. Coexpression of WT-KCNQ1 and G643S-KCNQ1 with KCNE1 resulted in approximately 30% reduction in the slow delayed rectifier K+ current I(Ks) without much alteration in the kinetic properties except its deactivation process, suggesting that the G643S substitution had a weaker dominant-negative effect on the heteromultimeric channel complexes. CONCLUSION: We demonstrate that a common polymorphism in the KCNQ1 potassium channel could be a molecular basis for mild I(Ks) dysfunction that, in the presence of appropriate precipitating factors, might predispose potential gene carriers to life-threatening arrhythmias in a specific population.

[Recent advance in gastric cancer chemotherapy].

Because of the low chemosensitivity of gastric cancer to conventionally available agents, several approaches were investigated to design "order made" treatments using chemosensitivity tests, including the histoculture drug response assay (HDRA) which was useful in evaluating the appropriate cancer chemotherapy for the patients with Stage III/IV gastric cancer. A recent investigation using a molecular biological method was introduced to predict the sensitivity of gastric cancer specimens to 5-fluorouracil (5-FU) by dihydropyrimidine dehydrogenase (DPD) activity and its mRNA. The low activity of DPD and DPD mRNA resulted in the low sensitivity to 5-FU, although thymidylate synthetase activity was not related to the sensitivity to 5-FU. This method is promising, since a small amount of material obtained through gastrofiberscopy will be adequate to assess DPD mRNA to predict the sensitivity to 5-FU. On the other hand, some randomized control trials with a huge cohort have indicated the usefulness of a "docetaxel + cisplatin + 5-FU" regimen for advanced and recurrent gastric cancer, and "5-FU + LV + radiation" as an adjuvant therapy for advanced gastric cancer. Furthermore, the efficacy of adjuvant chemotherapy after curative resection for gastric cancer was warranted by a meta-analysis of 19 published randomized trials. The "order made" and "standard" therapies will be complementary in the further development of chemotherapy against gastric cancer.

Hypothalamo-pituitary-adrenal axis activation by administration of cyanamide: a potent inhibitor of aldehyde dehydrogenase.

In this report, we investigated the effects of cyanamide (a potent inhibitor of aldehyde dehydrogenase (ALDH: EC 1.2.1.3)) on hypothalamo-pituitary adrenal (HPA)-axis using in situ hybridization histochemistry and radioimmunoassay. Cyanamide administration resulted in a dose-dependent increase in plasma corticosterone concentrations, significant increases in not only corticotrophin releasing factor (CRF) mRNA, but also arginine vasopressin (AVP) mRNA in the paraventricular nucleus (PVN) and proopiomelanocortin (POMC) mRNA in the anterior pituitary. These results suggest that cyanamide is able to activate the HPA axis at all levels of the axis.

Molecular genetic study of japanese patients with X-linked alpha-thalassemia/mental retardation syndrome (ATR-X).

X-linked alpha-thalassemia/mental retardation syndrome (ATR-X) is one of the many known X-linked mental retardation syndromes. Mutations in the ATR-X gene (ATRX) that encodes a putative global transcription factor have been identified in patients with ATR-X as well as those with other forms of X-linked mental retardation syndrome. To better understand the genetic basis of ATR-X, we investigated nine patients with the ATR-X phenotype from eight independent Japanese families for mutations in ATRX. We identified seven missense mutations, including six novel mutations, all of which were located either in the N-terminal region corresponding to the putative zinc finger domain (N179S, P190L, V194I, and R246C) or in the C-terminal region corresponding to the helicase domain (V1552F, L1645S, and Y1847C). R246C was found in two independent patients. Furthermore, we investigated the origin of the mutations in seven mothers. Five mothers were found to be carriers, and two were not, indicating de novo origin of the mutations. When we compared clinical manifestations with respective mutations, we could not find apparent phenotype-genotype correlation. Therefore, the putative zinc finger domain and the helicase domains may have similar functional significance for the function of ATRX.

Helicobacter pylori urease suppresses bactericidal activity of peroxynitrite via carbon dioxide production.

Helicobacter pylori can produce a persistent infection in the human stomach, where chronic and active inflammation, including the infiltration of phagocytes such as neutrophils and monocytes, is induced. H. pylori may have a defense system against the antimicrobial actions of phagocytes. We studied the defense mechanism of H. pylori against host-derived peroxynitrite (ONOO(-)), a bactericidal metabolite of nitric oxide, focusing on the role of H. pylori urease, which produces CO(2) and NH(3) from urea and is known to be an essential factor for colonization. The viability of H. pylori decreased in a time-dependent manner with continuous exposure to 1 microM ONOO(-), i.e., 0.2% of the initial bacteria remained after a 5-min treatment without urea. The bactericidal action of ONOO(-) against H. pylori was significantly attenuated by the addition of 10 mM urea, the substrate for urease, whereas ONOO(-)-induced killing of a urease-deficient mutant of H. pylori or Campylobacter jejuni, another microaerophilic bacterium lacking urease, was not affected by the addition of urea. Such a protective effect of urea was potentiated by supplementation with exogenous urease, and it was almost completely nullified by 10 microM flurofamide, a specific inhibitor of urease. The bactericidal action of ONOO(-) was also suppressed by the addition of 20 mM NaHCO(3) but not by the addition of 20 mM NH(3). In addition, the nitration of L-tyrosine of H. pylori after treatment with ONOO(-) was significantly reduced by the addition of urea or NaHCO(3), as assessed by high-performance liquid chromatography with electrochemical detection. These results suggest that H. pylori-associated urease functions to produce a potent ONOO(-) scavenger, CO(2)/HCO(3)(-), that defends the bacteria from ONOO(-) cytotoxicity. The protective effect of urease may thus facilitate sustained bacterial colonization in the infected gastric mucosa.

Effect of an antioxidant, ebselen, on development of chronic cerebral vasospasm after subarachnoid hemorrhage in primates.

BACKGROUND: Oxidation and/or free radical reactions after subarachnoid hemorrhage (SAH) may be involved in the development of chronic cerebral vasospasm. The inhibition of these reactions is thought to be one of the therapeutic strategies for prevention of cerebral vasospasm. We investigated the effect of Ebselen, a synthetic seleno-organic compound, which exhibits anti-oxidation by glutathione peroxidaselike activity to inhibit free radical reactions by lipid peroxidation on the development of chronic cerebral vasospasm in a primate model. METHODS: Seventeen monkeys were used. SAH was produced by introduction of a blood clot around the right middle cerebral artery and the right side of the circle of Willis in all animals. The monkeys were randomly divided into three groups according to Ebselen dosage: 1) no dosage or non-treated group; 2) high-dose Ebselen group; and 3) low-dose Ebselen group. The drug was administered at 10 mg/Kg in the high-dose group and 5 mg/Kg in the low-dose group twice a day in each group for 7 days after SAH. The vessel diameter was evaluated on angiograms before the induction of SAH and at Day 7 following SAH. RESULTS: In the untreated group, the angiograms showed significant (p < 0.05) reductions of the mean vessel caliber of the right internal carotid (ICA) (38 +/- 10% reduction) and the middle cerebral artery (MCA) (56 +/- 9.7%) compared with the baseline value before SAH. In the high-dose Ebselen-treated group, the mean percent reduction in vessel caliber of the right ICA (16 +/- 11%) and MCA (28 +/- 9.5%) on Day 7 angiograms were significantly (p < 0.05) lower than those in the nontreated group, whereas the mean percent reduction of these vessels in the low-dose Ebselen-treated group showed no significant difference compared with the untreated group. CONCLUSIONS: Chronic cerebral vasospasm was inhibited in the animals in which a relatively large amount of Ebselen was administered for 7 days after SAH. The results suggest that the oxidation or free radical reaction by lipid peroxidation after SAH might be involved in the pathogenesis of vasospasm, and that inhibition of these reactions by drugs, such as Ebselen, may have a promising effect for prevention of vasospasm.

[Interim report of JFMTC study no. 20 on the effectiveness of high dose CDDP plus 5-FU regimen as an adjuvant therapy for far-advanced cancer of the stomach].

This interim analysis of the JFMTC study as of May, 1998 covers 321 gastrectomized patients with far-advanced stomach cancer from 135 institutions between November, 1993 and March, 1996. The intensive therapy group (I-group) received CDDP i.p. administration on resective surgery with 70 mg/m2 followed by CDDP i.v. of 80 mg/m2 (day 1, i.v.), accompanying 5-FU of 350 mg/m2/day (day 1-5, c.v.i.) in the 4th, 8th and 12th weeks. The I-group was randomly compared with the standard therapy group (S-group) of MMC of 6 mg/m2 i.v. in the 4th, 8th and 12th weeks and UFT of 3-4 capsules daily for postoperative one year. The results obtained were that 1. adverse reactions were found more in the I-group than in the S-group, particularly notable in the decrease in blood cells, loss of appetite and nausea/vomiting, and incidence of grade 3 or more being 13% (neutrophile leukocytes), 26% and 21%, respectively; 2. there was no significant difference between I- and S-groups in terms of 3-year survival or disease-free survival rates. (JFMTC: Japanese Foundation of Multidisciplinary Treatment for Cancer).

PC-SPES: a unique inhibitor of proliferation of prostate cancer cells in vitro and in vivo .

BACKGROUND: Management of prostate cancer that has spread beyond the capsule is a difficult problem. Innovative and nontoxic approaches to the disease are urgently required. Recently, a commercially available herbal mixture called PC-SPES showed potent antitumor activities on a variety of malignant cells in vitro. METHODS: PC-SPES was evaluated for its ability to inhibit clonal growth, and to induce cell cycle arrest of three human prostate cancer cell lines (LNCaP, PC-3, and DU 145). Western blot analysis examined the effect of PC-SPES on levels of p21(waf1), p27(kip1), Bcl-2, and E-cadherin in the three cell lines; and telomerase activity was examined by telomeric repeat amplification protocol (TRAP) assay. Furthermore, the effect of oral PC-SPES (250 mg/kg/day) on growth of PC-3 and DU 145 tumors present in male BNX nu/nu triple immunodeficient mice was studied. LNCaP cells were not analyzed in mice because they grow only with difficulty in these immunodeficient mice. RESULTS: PC-SPES markedly inhibited clonal growth of LNCaP, PC-3, and DU 145 prostate cancer cells, with a 50% inhibition (ED50) at approximately 2 microl/ml. Pulse-exposure studies showed that a 5-day pulse-exposure to PC-SPES (2 microl/ml) in liquid culture achieved a 50% inhibition of PC-3 clonal growth in soft agar, suggesting that the growth inhibition mediated by the extracts remained after removal of PC-SPES. Cell cycle analysis using the prostate cancer cell lines found that PC-SPES induced a significant increase in the number of cells in G0-G1 and G2/M, with a concomitant decrease in the number of cells in S phase. PC-SPES (2 microl/ml, 4 days) increased slightly the levels of p21(waf1) in the three cell lines, decreased by 40% the levels of Bcl-2 in PC-3, and the levels of p27(kip1) and E-cadherin and telomerase were unchanged in each of the lines. In vivo treatment with oral PC-SPES of male BNX mice having DU 145 tumors produced significant inhibition of their growth (P < 0.001), with no objective side effects including blood chemistries, weights, or autopsy analysis. The PC-SPES showed no statistical effect on the in vivo growth of PC-3 cells. CONCLUSIONS: PC-SPES inhibits clonal proliferation of human prostate cancer cells both in vitro and in vivo, using a murine model.

Combination therapy of a vitamin D3 analog and all-trans-retinoic acid: effect on human breast cancer in nude mice.

BACKGROUND: Vitamin D3 analogs and all-trans-retinoic acid (ATRA) are able to inhibit the growth of a variety of malignant cells. MATERIAL AND METHODS: We examined the ability of three vitamin D3 analogs to inhibit the growth of a human mammary cancer cell line (MCF-7) in Beige Nude xid (BNX) mice either alone or with ATRA. Vitamin D3 analogs 1,25 dihydroxyvitamin D3 (code name, compound C), 1,25 (OH)2-16-ene-23-yne-19-nor-26,27-F6-D3 (compound LH) and 24a,26a,27a,-trihomo-22,24-diene-1,25(OH)2D3 (EB1089) were used. RESULTS: The antitumor effect of ATRA alone was greater than that of either of the vitamin D3 analogs alone, and an additive effect was observed when a vitamin D3 analog and ATRA were administered together. EB1089 was the most potent vitamin D3 analog; and EB1089 plus ATRA was the most potent combination decreasing the tumor mass nearly 3-fold compared to tumors of diluent control mice. None of the animals became hypercalcemic. Their complete blood counts, serum electrolyte analysis as well as their liver and renal functions were all fairly similar and within the normal range. CONCLUSION: This combination of a vitamin D3 analog and ATRA has the potential to be an adjuvant therapy for breast cancer.

Alterations of calcium/calmodulin-dependent protein kinase II activity in ischaemia-induced neuronal death and neuronal protection against ischaemia in the gerbil hippocampus.

To clarify the relation between neuronal protection against ischaemia and calcium/calmodulin-dependent protein kinase II (CaM kinase II) activity, we investigated temporal alterations of the kinase activity in the hippocampus after transient forebrain ischaemia under neuroprotective conditions, employing the gerbil bilateral carotid artery occlusion model. The hippocampal CA1 neuronal density at 2 hours after 5 minutes of forebrain ischaemia was 214.7 +/- 25.8/mm (mean +/- S.D.), and did not differ from the control significantly; however, it decreased to 11.7 +/- 4.2/mm at 7 days after the ischaemia. The neuronal density at 7 days after the ischaemia was 185.1 +/- 18.5 under the hypothermic conditions, 128.7 +/- 19.6 with the brief ischaemic pretreatment, 65.0 +/- 13.4 with administration of MK-801, and 20.5 +/- 4.2 with the repetitive hyperthermic pretreatment, respectively. The Ca2+/calmodulin-dependent activity of CaM kinase II in the hippocampal cytosolic fraction was decreased to 47.5% of the control value at 2 hours after the ischaemia, when CA1 neuronal death was not observed. In contrast, the activity was 98.8% of the control under the hypothermic conditions, 91.4% with the brief ischaemic pretreatment, 71.2% with administration of MK-801, and 47.9% with the repetitive hyperthermic pretreatment, respectively. These results indicated that the preservation of the Ca2+/calmodulin-dependent activity of cytosolic CaM kinase II after ischaemia parallelled the neuroprotective effect in the gerbil hippocampus. Thus, it is suggested that the preservation of the activity may be involved in the mechanism of neuronal protection against ischaemia.

Chemosensitivity test is useful in evaluating the appropriate adjuvant cancer chemotherapy for stage III non-scirrhous and scirrhous gastric cancers.

A total of 183 cases with gastric cancer was retrospectively analyzed in terms of their chemosensitivity as determined by the 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl-2H tetrazolium bromide (MTT) assay and their survival rates after surgery. After the patients were stratified into scirrhous or non-scirrhous carcinoma groups, they were tested for stage III or IV gastric cancer. In these four cohorts, the patients were categorized into sensitive and insensitive groups determined by the MTT assay. The sensitive group was treated with at least one drug that had been shown to be effective in the MTT assay, and the insensitive group was given a drug that had been shown to be ineffective in the MTT assay. In stage III gastric cancer, the sensitive group showed a favorable survival compared to the insensitive group in scirrhous and non-scirrhous carcinoma, while this difference was diminished in stage IV gastric cancer. There were no survival benefits in the sensitive group in stage III gastric cancer, when they were not treated with adjuvant cancer chemotherapy. These results suggested that MTT assay would be useful in evaluating the appropriate adjuvant cancer chemotherapy for stage III scirrhous and non-scirrhous gastric cancer.