Comparative genomic hybridization analysis of genetic aberrations associated with development and progression of biliary tract carcinomas

BACKGROUND

Little is known about genetic aberrations associated with development and progression of biliary tract carcinomas.

METHODS

To study chromosomal aberrations associated with development and progression of biliary tract carcinomas, the authors used comparative genomic hybridization to examine 50 such carcinomas.

RESULTS

Gains in part or in whole of chromosomes 1q, 8q, and 20q and losses of 5q, 8p, 9p, and 18q were detected frequently in early stage (T1/T2 classification) biliary tract carcinomas (> or = 40% of 19 early stage tumors), and they also were found in advanced stage (T3/T4 classification) tumors. In particular, loss of 9p was the most frequently observed aberration in both early stage (15 of 19; 78%) and advanced stage tumors (21 of 31; 68%). The frequencies of gains of 7p12-p14 (P < 0.003), 7p21-pter (P < 0.007), and 7q31 (P < 0.01) differed significantly between biliary tract carcinoma with and without distant metastasis. Also, gains of 5p and 19q13 and loss of 6q14-q16 were more frequent in tumors with lymph node metastasis than in those without it (P < 0.02).

CONCLUSIONS

It is likely that loss of 9p is one of the genetic aberrations critical for the development of biliary tract carcinoma, whereas gains of 5p, 7p, 7q, and 19q and loss of 6q are considered later events associated with tumor progression and are thought to confer metastatic potential to biliary tract carcinomas.

Convenient formation of 4-hydroxyalk-2-en-1-one functionality via A knoevenagel-type carbon chain elongation reaction of aldehyde with 1-arylsulfinylalkan-2-one

A highly functionalized four-carbon unit, 4-hydroxyalk-2-en-1-one functionality [R2CH(OH)CH=CHCOR1], was conveniently prepared by a reaction of an aldehyde (R2CH2CHO) with a 1-(arylsulfinyl)alkan-2-one [ArS(O)CH2COR1] in the presence of diethylamine (Knoevenagel condition). Other functional groups, such as carbonyl and hydroxy groups, in both of the alkyl chains (R1, R2) did not prevent this reaction. This reaction was used to conveniently prepare (+/-)-(11E)-13-hydroxy-10-oxooctadec-11-enoic acid (14), having cytotoxic activity, and its analogues from undec-10-enoic acid in good yield.

Comparative genomic hybridization analysis of genetic aberrations associated with development and progression of biliary tract carcinomas

BACKGROUND

Little is known about genetic aberrations associated with development and progression of biliary tract carcinomas.

METHODS

To study chromosomal aberrations associated with development and progression of biliary tract carcinomas, the authors used comparative genomic hybridization to examine 50 such carcinomas.

RESULTS

Gains in part or in whole of chromosomes 1q, 8q, and 20q and losses of 5q, 8p, 9p, and 18q were detected frequently in early stage (T1/T2 classification) biliary tract carcinomas (> or = 40% of 19 early stage tumors), and they also were found in advanced stage (T3/T4 classification) tumors. In particular, loss of 9p was the most frequently observed aberration in both early stage (15 of 19; 78%) and advanced stage tumors (21 of 31; 68%). The frequencies of gains of 7p12-p14 (P < 0.003), 7p21-pter (P < 0.007), and 7q31 (P < 0.01) differed significantly between biliary tract carcinoma with and without distant metastasis. Also, gains of 5p and 19q13 and loss of 6q14-q16 were more frequent in tumors with lymph node metastasis than in those without it (P < 0.02).

CONCLUSIONS

It is likely that loss of 9p is one of the genetic aberrations critical for the development of biliary tract carcinoma, whereas gains of 5p, 7p, 7q, and 19q and loss of 6q are considered later events associated with tumor progression and are thought to confer metastatic potential to biliary tract carcinomas.

Evaluation of the reliability of chromosomal imbalances detected by combined use of universal DNA amplification and comparative genomic hybridization

Comparative genomic hybridization (CGH) analysis of microscopic tumor samples is allowed by universal DNA amplification using degenerate oligonucleotide primed-PCR (DOP-PCR). To evaluate the reliablity of DOP-PCR CGH, we performed DOP-PCR CGH and standard CGH in parallel using DNAs extracted from 10 malignant tumors of the hepatobiliary tract and pancreas. Similar results were obtained by both methods with a few exceptions, indicating that DOP-PCR CGH provides cytogenetic information equivalent to that obtained from standard CGH. We also investigated the sensitivity of DOP-PCR CGH using sequential dilutions of DNA from microdissected tumor cells. DOP-PCR using 100 to 800 pg of template DNA yielded successful CGH results. However, less than 50 pg of template DNA was not suitable because of the small amount of generated DNA. These findings suggest that DOP-PCR CGH is applicable for CGH analysis of tiny specimens which are too small for standard CGH. Accordingly, DOP-PCR CGH analysis may become a useful method in clinical laboratory examination.

Inhibition of calpain but not caspase protects the testis against injury after experimental testicular torsion of rat

Testicular torsion requires emergent release of the twisted spermatic cord. Ischemia/reperfusion (I/R) plays an important role in its pathogenesis, and recent data suggest that germ cells undergo apoptosis during I/R. In a model of torsion/detorsion (i.e., I/R) of the rat testis, involvement of calpain and caspase in necrotic and apoptotic cell death was examined. After 1 h of ischemia followed by 0, 0.5, 1, 6, or 24 h of reperfusion, the germ cells positively stained with in situ TUNEL, and DNA fragmentation, activation of caspase-3, and proteolysis of caspase substrates increased with time of reperfusion, demonstrating apoptosis. In addition, m-calpain activation and proteolysis of alpha-fodrin were increased during reperfusion, and its activation is thought to be involved in the necrosis. A calpain inhibitor, acety-leucyl-leucyl-norleucinal, inhibited the phenomena associated with apoptosis and necrosis induced by I/R, although a caspase inhibitor, Z-Val-Ala-Asp-fluoromethlyketone, only inhibited apoptotic changes. The inhibition of calpain but not caspase ameliorated the injury after 60 days of reperfusion following 1 h of ischemia. The calpain inhibitor injected just before reperfusion effectively suppressed alpha-fodrin proteolysis, suggesting its usefulness in the treatment of testicular torsion.

Increased frequencies of gene and chromosome mutations after X-irradiation in mouse embryonal carcinoma cells transfected with the bcl-2 gene

Preimplantation stage mouse embryos are known to be highly sensitive to the killing effect of DNA-damaging agents such as radiation. Interestingly, however, this stage of development is well protected from radiation induction of malformation and carcinogenesis in postnatal life. In recent years, it has become clear that the stem cells of preimplantation stage embryos undergo extensive apoptosis after DNA damage. It has been postulated that this apoptosis is likely to be responsible for the resistance to malformation, by excluding cells carrying deleterious DNA damage. We have tested the possible role of apoptosis in elimination of gene and chromosome mutations in undifferentiated mouse embryonal carcinoma cell line, F9, transfected with human bcl-2 cDNA. The colony radiosensitivity of F9 cells was not affected by overexpression of the bcl-2 gene, but the apoptotic cell death was suppressed, as examined by DNA ladder assay and Hoechst staining. This suppression was accompanied by an increase in the frequencies of hprt mutation and micronucleus formation after X-irradiation. These results support the idea that maintenance of genomic integrity during early development is likely to be executed by apoptotic elimination of cells at risk.

Calcium concentration and artificial precipitates in human pancreatic juice

We studied the role of the increase in the calcium concentration in pure pancreatic juice of alcoholic noncalcified chronic pancreatitis. Pure pancreatic juice was obtained endoscopically. The pancreatic juice from patients with chronic pancreatitis was adjusted to pH 7.5; then the calcium concentration was adjusted to 0.4, 2.9, 5.4, or 10.4 mmol/L. Artificial precipitates were produced by incubation of the samples at 37 degrees C for 6 hours. Proteins in the artificial precipitates were separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and the protein patterns were compared with the patterns of natural protein plugs from patients with chronic pancreatitis. The amount of the precipitate increased as the added calcium increased. The protein patterns of SDS-PAGE of the artificial precipitates were similar to those of protein plugs. Albumin, a-amylase, lipase, trypsinogen, and chymotrypsinogen were identified by immunoblotting both in the precipitate and in the protein plug. The increased calcium concentrations in pancreatic juice induced the formation of precipitates whose protein composition was similar to that of protein plugs. An increased calcium concentration in human pancreatic juice may play an important role in the pathogenesis of protein plugs.

The effect of caffeine on p53-dependent radioresponses in undifferentiated mouse embryonal carcinoma cells after X-ray and UV-irradiations

The effect of caffeine was studied on the radioresponses of undifferentiated mouse embryonal carcinoma cells (EC cells) with or without the functional p53. The radioresponses studied included radiosensitivity, the activation of p53, apoptosis with characteristic DNA ladder formation and cell cycle progression. An undifferentiated mouse EC cell line, ECA2, and a newly established p53-deficient EC cell line, p53 delta, were used in the present study. The status of the p53 gene did not significantly affect the colony survivals of undifferentiated EC cells to X-rays and UV. Although a post-irradiation treatment with caffeine sensitized both lines to X-rays marginally, the sensitization was prominent for UV regardless of the p53 status of the cells. The activation of a p53 responsible lacZ reporter construct was observed in stably transfected ECA2 cells after X-ray and UV irradiations. Caffeine suppressed the X-ray induced activation of the lacZ reporter, while it drastically enhanced the activation after UV irradiation. X-rays and UV readily triggered the apoptosis of ECA2 cells with the characteristic DNA ladder. Although UV-induced DNA ladder formation was enhanced by caffeine, that induced by X-rays was unaffected. Therefore, the effects of caffeine on the p53-dependent radioresponses were found to be agent specific: suppression for the X-ray induced and augmentation for the UV induced. In contrast to p53-proficient ECA2 cells, smear-like DNA degradation was observed for irradiated p53 delta cells, suggesting the presence of a mode of cell death without DNA ladder formation. UV induction of the smear-like DNA degradation was enhanced in the presence of caffeine. Regardless of the state of the p53 gene, G1/S arrest was not observed in X-ray and UV irradiated EC cells. X-ray induced G2/M arrest in both lines, which was abrogated by caffeine, while G2/M arrest after UV was unaffected by a caffeine treatment. These results indicate that the radioresponses of undifferentiated EC cells differ considerably from those of somatic cells, and that these radioresponses were modulated by a post-irradiation treatment with caffeine.

A novel locus for dominant cerebellar ataxia (SCA14) maps to a 10.2-cM interval flanked by D19S206 and D19S605 on chromosome 19q13.4-qter

Dominantly inherited, late-onset pure cerebellar ataxia is a group of genetically heterogeneous neurodegenerative disorders. Approximately half of these disorders in the Japanese population are caused by moderate expansion of a CAG repeat in the coding region of the CACNA1A gene on chromosome 19p13 (SCA6). However, neither the loci nor the specific mutations for the remaining disorders have been determined. We performed systematic linkage analysis in a three-generation Japanese family with a locus or mutation that differed from those of known spinocerebellar ataxias. The family members with a late onset (> or =39 years old) exhibited pure cerebellar ataxia, whereas those with an early onset (< or =27 years old) first showed intermittent axial myoclonus followed by ataxia. Other neurological signs were sparse, and neuroimaging studies revealed that atrophy was confined to the cerebellum. Multipoint analysis and haplotype reconstruction ultimately traced this novel spinocerebellar ataxia locus (SCA14) to a 10.2-cM interval flanked by D19S206 and D19S605 on chromosome 19q13.4-qter (Zmax = 4.08, corrected for age-dependent penetrance).

[Clinical study of infection associated hemophagocytic syndrome]

Hemophagocytic syndrome (HPS) causes pancytopenia, increased blood LDH level, liver dysfunction, DIC, etc. with macrophages appearing in the bone marrow, spleen, lymph nodes, etc. Adult HPS is mostly secondary to various infections, malignant tumors, etc. and sometimes has a serious outcome. Particularly infection associated HPS (IAHS) is triggered by viral, bacterial and fungal infections. The cases of unknown primary disease and suspected IAHS of unidentified pathogenic microorganism are often encountered in the clinical setting. The authors compared IAHS and malignant associated HPS (MAHS) and classified IAHS into viral associated HPS (VAHS), bacterial associated HPS (BAHS) and fungal types to compare the test values based on the test findings at the onset in the HPS cases treated at our Department. The patients consisted of 21 HPS cases, 11 IAHS cases (VAHS 4, BAHS 5, fungal 2) and 10 MAHS cases. Based on the test findings (WBC, Hb, Plt, LDH, ferritin, myelogram, cytokines, [IFN alpha, TNF gamma, IL-6, sIL-2R, M-CSF], adhesion molecules [sICAM-1, sVCAM-1, sELAM-1, sL-selectin]) at the onset, a comparison between IAHS and MAHS and among the IAHS cases classified by pathogenic microorganism was made. In the comparison between IAHS and MAHS, the Hb value was significantly decreased and sIL-2R tended to be increased at the onset in MAHS. When comparing the IAHS cases by pathogenic microorganism, Plt was significantly decreased and sICAM-1 and sVCAM-1 were increased at the onset in the BAHS, The BAHS cases had serious underlying diseases and poor prognosis with high incidence of DIC complications. We are going to accumulate more cases for early diagnosis and treatment of IAHS.

Analysis of serum lactate dehydrogenase and its isozymes during administration of granulocyte colony-stimulating factor in children

Serum lactate dehydrogenase (LDH) activity is known to become elevated following granulocyte colony-stimulating factor (G-CSF) therapy in some patients, but no extensive studies on this phenomenon have been performed. In 26 children with malignancies in complete remission who received recombinant human G-CSF intravenously after combined chemotherapy, we measured serum LDH and its isozymes (81 episodes) before chemotherapy (pre-Tx), during administration of G-CSF (mid-Tx), and after stopping G-CSF (post-Tx) and compared the obtained data using paired t test. Twelve episodes were excluded from analysis because of liver dysfunction (alanine aminotransferase > 45 IU/L). Serum LDH at mid-Tx (343.1+/-19.8 IU/L; mean +/- SE) was significantly higher than that at pre-Tx (186.9+/-6.7 IU/L) and post-Tx, but this difference was observed only when change in white blood cell counts (WBCs) (WBC at mid-Tx minus WBC at pre-Tx) was greater than or equal to 4000/microL (58 episodes). Percentages of LDH isozymes 3, 4, and 5 at mid-Tx (23.5+/-1.0, 11.7+/-0.8, and 8.3+/-0.7) were significantly increased compared with those at pre-Tx (19.5+/-0.7, 6.3+/-0.3, and 4.2+/-0.5) and post-Tx, resulting in a significant decrease in percentages of LDH isozymes 1 and 2 at mid-Tx. In episodes of change in WBCs > or =4000/microL, change in LDH significantly correlated to changes in WBCs and granulocytes but not to change in lymphocytes or monocytes. These results suggest that serum LDH is significantly elevated during G-CSF administration in accordance with the increase in peripheral granulocytes, which accompanies change in the pattern of percentages of LDH isozymes.

Identification of fractalkine, a CX3C-type chemokine, as a direct target of p53

Fractalkine is a CX3C-type chemokine that induces chemotaxis of monocytes and cytotoxic T cells. Using the differential display method for examining gene expression in p53-defective cells transfected by adenovirus containing wild-type p53, we observed that fractalkine was induced by ectopic expression of p53. An electrophoretic mobility shift assay showed that a potential p53-binding site present in the promoter of the fractalkine gene could bind to p53 protein. Moreover, a heterogeneous reporter assay indicated that this promoter sequence possessed p53-dependent transcriptional activity. The strong induction of fractalkine when p53 protein was expressed by a wild-type transgene in p53-defective cells brought to light a novel role for p53; that is, potential elimination of damaged cells by the host immune response system through transcriptional regulation of fractalkine. Our results imply a pivotal role of p53 in immunosurveillance to prevent cells from undergoing malignant transformation.

[A case of Kallmann syndrome: diagnostic usefulness of cranial magnetic resonance imaging]

We report a case of Kallmann syndrome in which the cranial magnetic resonance imaging (MRI) findings of the olfactory tract were useful in making the diagnosis. A 20-year-old male who complained of delayed puberty was referred to our hospital in November 1998. He presented with hypogonadism and anosmia. The plasma levels of testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH) were low. Pituitary and Leydig cell functions were normal by the LH-releasing hormone test and human chorionic gonadotropin (hCG) loading test, respectively. The karyotype was normal (46, XY). The smell test showed anosmia. After administration of hCG, a good response of plasma testosterone level and masculinization were recognized. Cranial MRI findings revealed an absence of olfactory bulbs and hypoplastic olfactory sulci. These MRI findings are characteristic of Kallmann syndrome and allowed us to confirm our diagnosis, in addition to classically used endocrinological and olfactory examination.

Current techniques of hyperthermic isolated limb perfusion for malignant melanoma

A retrospective study was conducted examining 25 patients with malignant melanoma who were treated by our new protocol for hyperthermic isolated limb perfusion. The characteristics of our techniques include: a lower priming volume of the extracorporeal circuit; a therapeutic temperature range of 40-41 degrees C with 60 min hyperthermic perfusion; a nominal perfusion flow rate of 500 ml/min in the lower limb and 200 ml/min in the upper limb; and combined carboplatin with interferon-beta as the adjuvant chemotherapy drug. In the lower extremity group, the arterial cannula size ranged from 8 to 14 F, while the venous cannula size ranged from 14 to 16 F. In the upper limb group, the arterial cannula size ranged from 6 to 8F and the venous cannula size ranged from 10 to 12F. No patient required any homologous blood transfusion postoperatively. No operative death or major complications occurred during the early postoperative period, confirming the safety of this treatment. Both optimal cannula size selection and maintaining perfusion temperature below 41 degrees C were judged to be important in elimination of vascular and deep tissue injury.

Effect of heat-pretreatment on interleukin-2-activated killer cells for in vitro purging

OBJECTIVE

Lymphokine-activated killer activity is effective in purging residual malignant cells from autologous bone marrow (BM) or leukapheresis collections for peripheral blood progenitor cells (PBPC). In this study, the effect of additional heat pretreatment on IL-2-activated cytotoxicity was examined.

METHODS

Nonadherent mononuclear cells from peripheral blood (PB), PBPC collections or BM were exposed to the desired temperature for 1 h, and successively cultured for 7 days in the presence of 1,000 units/ml of recombinant human interleukin-2 (IL-2). Cytotoxicity of IL-2-activated cells was determined by flow cytometry, using PKH-26-labelled K-562 or Raji target cells, and the cell surface antigens were also analyzed.

RESULTS

IL-2-activated cells from all specimens showed a distinct generation of cytotoxic activities. The activities were significantly decreased by heat at 42 degrees C, but not changed by heat pretreatment at 40 degrees C. In the surface expression of IL-2-activated cells, the increase of CD56+ cells from PB, PBPC collections and the decrease of CD28 cells from PBPC collections were shown to be significant (p < 0.05), but these changes were not found when the cells were heat-pretreated at 42 degrees C.

DISCUSSION

These results suggested that a tumor-killing therapeutic temperature (> or =42 degrees C) may lead to a disadvantage in posttransplantation immunity, and that this reduction of IL-2-activated cytotoxicity may partly be due to a lack of the enhancement of CD56+ cells or the reduction of CD28+ cells.

Prevalence of migraine and Raynaud's phenomenon in Japanese patients with vasospastic angina

The prevalence of migraine and Raynaud's phenomenon in Japanese patients with vasospastic angina (group I) were compared with those in 2 control groups: one with effort angina (group II) and the other group without known ischemic heart disease (group III). There were no significant differences among the 3 groups with respect to age and sex. The prevalence of migraine in group I was 23 of 100, as compared with 4 of 100 in group II (p<0.01) and 11 of 100 in group III (p<0.05). The prevalence of Raynaud's phenomenon in group I was 9 of 100, as compared with 3 of 100 in group II and 4 of 100 in group III. Thus, in Japan, the prevalence of migraine in patients with vasospastic angina was higher than those in the 2 control groups, whereas the prevalence of Raynaud's phenomenon did not differ significantly among the 3 groups. The prevalence of Raynaud's phenomenon in Japanese patients with vasospastic angina was different from that reported from North America, although the prevalence of migraine was the same. This may be partially explained by racial differences.

Scanning electron microscopic studies on morphological abnormalities of erythrocytes in alcoholic liver diseases

BACKGROUND

We previously reported that morphological abnormalities and the altered deformability of erythrocytes play important roles in disturbances of hepatic microcirculation associated with alcoholic liver disease.

METHODS

The subjects of this study were five patients with alcoholic liver cirrhosis, two patients with alcoholic fatty liver, and two healthy volunteers. Concentrating on erythrocyte morphology in the presence of alcoholic liver disease, we observed erythrocytes under a scanning electron microscope and examined their morphological changes in relation to the disease.

RESULTS

Among the five patients with alcoholic liver cirrhosis, stomatocytes accounted for about 14% and acanthocytes for about 10% of all erythrocytes. In the fatty liver group (n = 2), acanthocytes were absent, and stomatocytes accounted for 23% in one subject and 56% in the other, of the total. When the two patients with liver cirrhosis were examined over time, one of them was found to have 12% stomatocytes, 21% acanthocytes, and a filtration time of 14.7 sec at admission. Following 1 month of abstinence, this patient had 1% stomatocytes, 6% acanthocytes, and a filtration time of 10.4 sec, which were accompanied by improvements in peripheral blood parameters and liver function. In another patient with liver cirrhosis, there were no acanthocytes, 8% stomatocytes, and a filtration time of 5 sec at admission; this patient had 1% stomatocytes and a filtration time of 7.7 sec after 1 month of abstinence. In one patient with fatty liver who was examined over time, the percentage of stomatocytes was 56%, and the filtration time was 7.7 sec at admission; these parameters were 1% and 5.1 sec, respectively, after 1 month of abstinence.

CONCLUSIONS

The present study revealed that stomatocytes and acanthocytes are morphologically abnormal erythrocytes observed in the presence of alcoholic liver disease. These abnormal forms of erythrocytes tended to normalize as peripheral blood parameters and liver function were improved by abstinence, which suggests that erythrocyte morphology is related to the pathophysiology of alcoholic liver disease.

A ribonucleotide reductase gene involved in a p53-dependent cell-cycle checkpoint for DNA damage

The p53 gene is frequently inactivated in human cancers. Here we have isolated a p53-inducible gene, p53R2, by using differential display to examine messenger RNAs in a cancer-derived human cell line carrying a highly regulated wild-type p53 expression system. p53R2 contains a p53-binding sequence in intron 1 and encodes a 351-amino-acid peptide with striking similarity to the ribonucleotide reductase small subunit (R2), which is important in DNA synthesis during cell division. Expression of p53R2, but not R2, was induced by ultraviolet and gamma-irradiation and adriamycin treatment in a wild-type p53-dependent manner. Induction of p53R2 in p53-deficient cells caused G2/M arrest and prevented cells from death in response to adriamycin. Inhibition of endogenous p53R2 expression in cells that have an intact p53-dependent DNA damage checkpoint reduced ribonucleotide reductase activity, DNA repair and cell survival after exposure to various genotoxins. Our results indicate that p53R2 encodes a ribonucleotide reductase that is directly involved in the p53 checkpoint for repair of damaged DNA. The discovery of p53R2 clarifies a relationship between a ribonucleotide reductase activity involved in repair of damaged DNA and tumour suppression by p53.

A simple client-server system using a personal computer as the server

Hospital information systems have recently grown into huge, complex systems. As a result, the cost of development and maintenance of application programs has increased and become a serious problem. We have constructed an order entry system using server-client architecture as part of a hospital intranet information system in which a personal computer is used as a server. Using a commercial database management system and software development tools, an easily maintained order entry system was developed within only three months by one programmer. Since slow response when the number of clients increased was possible, we measured turn-around times when one or ten clients accessed simultaneously. Turn-around times were 8 and 10 sec, respectively. Because we expect much better performance from personal computers in the near future, application systems using personal computers as Intranet servers will be cost and time effective and easy to develop and maintain.

Contributions of 18 food categories to intakes of 232Th and 238U in Japan

Daily intakes of 232Th and 238U and contributions of food categories to those nuclide intakes in Japanese were estimated using a market basket study for 18 food categories. Food categories having higher 238U contents (per g-fresh) were found to be as follows: seaweeds 1,140 microBq; fishes and shellfishes 37 microBq; nuts and seeds 11 microBq; bean products 8.6 microBq; and cooked meals 7.3 microBq. Big contributors to the daily 238U intake in Japan were as follows: seaweeds (50%); fishes and shellfishes (26%); and bean products (4.3%). For 232Th, higher contents (per g-fresh) were found as follows: seaweeds 28 microBq; fishes and shellfishes 13 microBq; nuts and seeds 8.2 microBq; green vegetables 3.9 microBq; cooked meals 3.5 microBq; and bean products 2.9 microBq. Big contributors to the daily 232Th intake were as follows: fishes and shellfishes (44%); green vegetables (11%); bean products (7.4%); and seaweeds (6.0%). For both nuclides, marine food products were big contributors, while minor contributors were oil and fats, eggs, and cooked meals. Daily intakes of 232Th and 238U in Japan were estimated to be 2.7 mBq and 14 mBq per person from the intakes of the 18 categories, respectively. Annual effective doses were estimated to be 232Th, 2.2 x 10(-7) Sv, and 238U, 2.2 x 10(-7) Sv.

Protective effect of aminoguanidine on hypoxic-ischemic brain damage and temporal profile of brain nitric oxide in neonatal rat

Nitric oxide (NO) produced by inducible NO synthase contributes to ischemic brain damage. However, the role of inducible NO synthase-derived NO on neonatal hypoxic-ischemic encephalopathy has not been clarified. We demonstrate here that aminoguanidine, a relatively selective inhibitor of inducible NO synthase, ameliorated neonatal hypoxic-ischemic brain damage and that temporal profiles of NO correlated with the neuroprotective effect of aminoguanidine. Seven-day-old Wister rat pups were subjected to left carotid artery occlusion followed by 2.5 h of hypoxic exposure (8% oxygen). Infarct volumes (cortical and striatal) were assessed 72 h after the onset of hypoxia-ischemia by planimetric analysis of coronal brain slices stained with hematoxylin-eosin. Aminoguanidine (300 mg/kg i.p.), administered once before the onset of hypoxia-ischemia and then three times daily, significantly ameliorated infarct volume (89% reduction in the cerebral cortex and 90% in the striatum; p<0.001). NO metabolites were measured by means of chemiluminescence using an NO analyzer. In controls, there was a significant biphasic increase in NO metabolites in the ligated side at 1 h (during hypoxia) and at 72 h after the onset of hypoxia (p<0.05). Aminoguanidine did not suppress the first peak but significantly reduced the second one (p<0.05), and markedly reduced infarct size in a neonatal ischemic rat model. Suppression of NO production after reperfusion is a likely mechanism of this neuroprotection.