Syntheses of novel antitumor dihydroxanthone derivatives with inhibitory activity against DNA topoisomerase II

A series of methoxycarbonyl group modified nidulalin A analogs were synthesized to improve stability against esterases. The amide derivatives showed cytotoxic activity along with inhibitory activity against DNA topoisomerase II. Among the analogs, amide 9a exhibited antitumor activity in Colon 26 murine tumor model.

A novel combretastatin A-4 derivative, AC-7700, shows marked antitumor activity against advanced solid tumors and orthotopically transplanted tumors

AC-7700, a novel combretastatin A-4 derivative, suppresses the growth of solid tumors by inhibiting tumor perfusion. We evaluated the antitumor activity of AC-7700 on solid tumors in two experimental models, an advanced tumor model (murine colon 26 (c26) adenocarcinoma, colon 38 (c38) adenocarcinoma, MethA fibrosarcoma, Sarcoma 180 (S180), Lewis lung carcinoma (3LL), human LS180 adenocarcinoma) and an orthotopically transplanted tumor model (c26), compared with that of cisplatin (CDDP). The maximum tolerable dose (MTD) of CDDP suppressed early-stage c26 and c38 tumor growth when treatment was started after the tumor volume (TV) reached 0.2-0.5 cm3, but it showed reduced activity against the same tumors at an advanced growth stage when TV exceeded 2 cm3. At its MTD, AC-7700 was active against all tumors tested except 3LL in both early and advanced growth stages, reducing the tumor mass and having a curative effect in advanced c38 tumors. AC-7700 was also effective on orthotopically transplanted c26 tumors, showing a comparable activity to that on subcutaneous tumors. Unlike flavon acetic acid, which damages tumor vasculature by inducing endogenous tumor necrosis factor-alpha production, AC-7700 potently suppressed the growth of advanced c26 tumors in athymic as well as euthymic mice. These results suggest that AC-7700 is a novel antivascular agent that may have potent activity against advanced-stage cancer in the clinical setting.

Efficacy of the mobilization of peripheral blood stem cells by granulocyte colony-stimulating factor in pediatric donors

The advantages/disadvantages of the use of peripheral blood stem cells (PBSCs) for allogeneic transplantation still need to be clarified, particularly in children. We compared the kinetics, efficacy, and safety of PBSC mobilization by granulocyte colony-stimulating factor (G-CSF) and collection by apheresis between healthy pediatric and adult donors. A total of 19 pediatric (median age, 6 years) and 25 adult healthy donors (median age, 37 years) were given 10 micro/kg/day of G-CSF for 5 consecutive days for PBSC mobilization, which were harvested by apheresis on days 5 and/or 6. All of the donors tolerated the whole procedures. Serum trough levels of G-CSF determined by ELISA were significantly lower in the 16 pediatric donors evaluated than in adults (n = 16) on days 3 and 4 (P < 0.05). Although the WBC counts on days 4 and 5 were significantly higher in adults than in children (P = 0.006 and 0.004, respectively), the numbers of circulating CD34+ cells/unit of blood were identical. The number of blood CD34+ cells collected per unit of blood processed was identical in both donor populations. We propose that PBSCs could be effectively mobilized and collected in small children so that they could be donors for adult patients.

Antitumor activity of alpha-galactosylceramide, KRN7000, in mice with EL-4 hepatic metastasis and its cytokine production

Liver metastasis of primary tumor is a clinically major problem. KRN7000, an alpha-galactosylceramide, significantly augments natural killer (NK) activity of spleen cells and shows strong antitumor activity in mice with lung metastasis of melanoma B16 cells. To test whether KRN7000 has an antitumor activity in mice with hepatic metastasis of tumors, we examined the effect of KRN7000 on NK activity of hepatic mononuclear cells (MNC) and the antitumor activity in mice with liver metastasis of EL-4 cells. The in vivo administration of KRN7000 significantly augmented NK activity of hepatic MNC and inhibited tumor growth of EL-4 cells in the liver more markedly than chemotherapeutic agents, leading to a relatively high rate of cured mice. In addition, it appeared that the KRN7000 treatment is effective in mice with established EL-4 tumors. Moreover, we found that KRN7000 can produce significant amounts of interleukin 2 (IL-2), IL-4, IL-12, and interferon-gamma in a dose-dependent manner. These results suggest that KRN7000 will be useful for the treatment of cancer liver metastasis.

Comparative evaluation of procedures with a Baxter CS-3000 cell separator for collecting peripheral blood cells from children

The safety and efficacy of apheresis using a newly developed procedure with a small volume separation container holder (SVSCH, Baxter) for the collection of PBSC from children with cancer were retrospectively compared with our historical experience with other procedures using different equipment and the CS-3000 plus cell separator. The procedures tested included the application of (a) specialized collection protocol 4 using the combination of an SVSCH and a small volume collection chamber (SVCC) (group A: 6 collections in 4 patients), (b) standard lymphocyte collection protocol 3 with GRANULO separation (G) and A-35 collection chambers (group B: 9 collections in 5 patients), and (c) modified collection procedure 1-120 with G and SVCC (group C: 7 collections in 3 patients). Although the retrospective nature of this study and the differences in the cohorts tested prevent a reliable analysis, the percent decrease in the peripheral platelet count after collection tended to be minimum in group A (11% +/- 5% versus 23% +/- 4% [B] or 17% +/- 4% [C]). Moreover, the largest number of CD34+ cells was collected in group A (8.7 +/- 9.4 x 10(5)/100 ml processed blood) compared with groups B (5.5 +/- 7.5 x 10(5)/100 ml processed blood) and C (4.0 +/- 2.8 x 10(5)/100 ml processed blood). These data suggest that a procedure incorporating SVSCH can be safely and effectively applied to small children and enables the selective collection of PBSC with less contamination by platelets, which is useful for subsequent cell processing.

Maternal body burden of organochlorine pesticides and dioxins

To investigate the body burden of organochlorine pesticides and dioxins in Japanese women, 125 milk samples were collected from 41 mothers in 1994, 42 in 1995, and 42 in 1996. Of the 125 samples, 82 were from primipara mothers (first delivery) and 43 were from multipara mothers (second or later delivery). By using capillary gas chromatography with electron capture detection, beta-HCH and p,p'-DDE were detected as the major chlorine pesticides in human milk. Average levels of beta-HCH and p,p'-DDE were 475 and 368 ng/g lipid, respectively, in primipara breast milk, 314 and 259 ng/g lipid in multipara breast milk, and 420 and 330 ng/g lipid in total breast milk. Dieldrin, heptachor epoxide, oxychlordane, trans-chlordane, and cis-chlordane were detected at lower average levels of 3, 4, 34, 41, and 5 ng/g lipid, respectively. By using high-resolution gas chromatography with mass spectrometric detection, dioxins were detected in all samples. Average levels of total polychlorinated dibenzo-p-dioxin (PCDD), total polychlorinated dibenzofuran (PCDF), total PCDD + PCDF, total coplanar polychlorinatedbiphenyl (CoPCB), and total dioxin were 10.0, 7.8, 17.7, 9.9, and 27.5 TEQ (toxic equivalent) pg/g lipid, respectively, in primipara breast milk; 7.0, 5.8, 12.8, 7.3, and 20.1 TEQ pg/g lipid in multipara breast milk; and 8.9, 7.1, 16.1, 8.9, and 25.0 TEQ pg/g lipid in total breast milk. In primipara breast milk, significant correlations were found among levels of beta-HCH, p,p'-DDE, total PCDD-TEQ, total PCDF-TEQ, total CoPCB-TEQ, and total TEQ except for less correlation between p,p'-DDE and total PCDF-TEQ. Levels of these analytes also significantly increased depending on mother's age, except for total Co-PCB-TEQ. For the correlation with food habit, the only positive correlation was between total PCDF-TEQs and fish intake.

[Blood PCB analysis by capillary column-gas chromatograph/quadruple mass spectrometer--comparison with packed column-electron capture detector/gas chromatograph]

The contents of polychlorinated biphenyls (PCBs) in the blood of Yusho patients (Y) and normal subjects (N) were analyzed, using a gas-chromatograph equipped with a capillary column/quadruple mass spectrometer (capillary column GC/MS). While the average of the content of blood PCBs was 679 ppt in N, those were 2960, 1480 and 1090 ppt in Y diagnosed previously as A, B and C patterns, respectively. The contents of non-ortho coplanar PCBs (3,3',4,4' Tetra-, 3,3',4,4',5-Penta- plus 3,3',4,4',5,5'-Hexa-CB) were 0.9-2.1 ppt in Y, and 0.8 ppt in N. The contents of eight mono-ortho coplanar PCBs having the toxic equivalency factors (TEFs) were 118-424 (Y) and 78 ppt (N), respectively. The differences between Y and N in the species of mono-ortho coplanar PCBs contained were observed as follows: 2,3,3',4,4',5- and 2,3,3',4,4',5'-Hexa-CB were predominant in Y, whereas 2,3,4,4',5-Penta-CB was a major congener in N. The levels of di-ortho coplanar PCBs (2,2',3,4,4',5,5' plus 2,2',3,3',4,4'5-Hepta-CB) were determined to be 195-608 and 98 ppt in Y and N, respectively. In both groups, the content of the former isomer was greater than the latter. Total TEQ values were 0.214-1.226 ppt in Y, and 0.148 ppt in N. The analyses were also performed by a conventional method in which a GC equipped with a packed column/electron capture detector (packed column GC/ECD) was used, and the results obtained were compared with those by capillary column GC/MS method. The results showed that the total PCB levels obtained by capillary column GC/MS method were 56-61% in Y and 67% in N of those obtained by packed column GC/ECD method.

Endogenous interleukin-8 (IL-8) surge in granulocyte colony-stimulating factor-induced peripheral blood stem cell mobilization

The relationship between stem cell mobilization with granulocyte colony-stimulating factor (G-CSF) and the endogenous production of interleukin-8 (IL-8), macrophage inflammatory protein-1alpha (MIP-1alpha), tumor necrosis factor-alpha (TNF-alpha), and interferon-gamma (IFN-gamma) was studied in normal donors for allogeneic peripheral blood stem cell (PBSC) transplantation. G-CSF was administered to 20 normal donors at a dose of 10 microg/kg/d for 5 days with aphereses on days 5 and 6 of G-CSF treatment. Cytokine serum levels were measured using an enzyme-linked immunosorbent assay (ELISA) before and during G-CSF treatment. Before treatment, the average level of IL-8 was 7.1 pg/mL, increasing to 207.0 pg/mL on day 5 and 189.1 pg/mL on day 6. Serum IL-8 levels correlated CD34(+) cell numbers (P =.0151 and P =.0005 on days 5 and 6, respectively) and colony-forming unit-granulocyte-macrophage (CFU-GM) numbers (P =.0019 and P =.0010 on days 5 and 6, respectively). Furthermore, preapheresis serum IL-8 levels correlated with the yield of CD34(+) cells (P =.0027). In contrast, before treatment, the average levels of MIP-1alpha, TNF-alpha, and IFN-gamma were 70.1, 4.03, and 3.84 pg/mL, respectively, and no significant changes in the levels of these cytokines were observed during G-CSF treatment. These studies suggest that IL-8 production may be critical to G-CSF-induced stem cell mobilization, although the underlying mechanism could not be clarified.

Surgical management of infants with mitral valve stenosis or atresia without diminutive ascending aorta

The surgical strategy in infants with mitral valve stenosis or atresia without diminutive ascending aorta remains to be established, including the potential for biventricular repair as a definitive operation. Our surgical experience of six infants with mitral valve stenosis (4 patients) or atresia (2 patients) without diminutive ascending aorta was evaluated based on three important factors: left ventricular volume; the nature of the systemic outflow obstruction; and the type of mitral valve anomaly. Two patients with systemic outflow tract diameter less than 65% of normal underwent systemic outflow tract reconstruction, and the other patients with outflow tract diameter more than 68% of normal were able to maintain systemic circulation without repair. Only one patient with mitral valve stenosis without left ventricular outflow tract obstruction underwent a successful open mitral valvotomy as a biventricular repair after first-stage palliation. The left ventricle of the other patients did not grow after first-stage palliation. Due to progressive subaortic narrowing, pulmonary artery banding should be avoided in patients with mitral atresia due to absent atrioventricular connection who are future Fontan candidates. Most patients with this lesion can be expected to become candidates for safe Fontan-type repair.

Prevalence of specific allergic diseases in school children as related to parental atopy

BACKGROUND

Our objective was to investigate the influence of parental allergy on the manifestations and course of allergic disease in children.

METHODS AND RESULTS

A total of 15,234 school children aged 6 and 9 years were evaluated by means of questionnaires completed by their parents in a cross-sectional survey conducted in Tokushima, Japan. The prevalence and relative risk ratio (RRR) for parental allergy in children with atopic dermatitis, asthma and allergic rhinitis were 6.4% (RRR 2.5), 3.2% (RRR 2.4) and 15% (RRR 2.4), respectively. The risk of atopic dermatitis was particularly high in children whose parent had atopic dermatitis, with an RRR of 2.8 (father) and 3.7 (mother). Children with a parental history of asthma also had a high risk of that disorder (RRR of father 5.3, mother 6.2). However, the risk of allergic rhinitis was no different in children with a parental history of allergic rhinitis or from children with a parental history of asthma and atopic dermatitis. A history of allergic disease in both parents, especially of asthma and atopic dermatitis, increased the risk of allergic disease in the child. Milder symptoms, such as wheezy bronchitis, in schoolchildren were similarly related with the same hereditary tendency as the identical allergic disease. The disappearance of allergic symptoms with age also related to a hereditary component, being less likely in children with a history of parental allergy than in those without such an atopic history.

CONCLUSIONS

The manifestations and course of allergic disease in school children relate to parental allergic disease.

Novel B-ring modified combretastatin analogues: syntheses and antineoplastic activity

A series of B-ring modified combretastatin analogues were synthesized and their inhibitory activity against microtubule assembly, cytotoxic activity against Colon 26 adenocarcinoma cancer cell line were evaluated. Among these, pyridone derivative (19) showed strong antimitotic activity and cytotoxicity, along with excellent water-solubility.

Syntheses and antitumor activity of cis-restricted combretastatins: 5-membered heterocyclic analogues

A series of cis-restricted combretastatin analogues with 5-membered heterocycles were synthesized and their inhibitory activity against microtubule assembly and cytotoxic activity against the colon 26 adenocarcinoma cancer cell line were evaluated. Some of the heterocyclic analogues showed potent antitubulin activity and cytotoxicity. Compounds 16 and 35 showed marked tumor growth suppression in the colon 26 murine tumor model.

Clinically applicable bulk isolation of blood CD34+ cells for autografting in children

CD34+ cells were purified in bulk from apheresis-collected cells of children with cancer using monoclonal antibody (MoAb) and magnetic beads (Baxter ISOLEX system). To improve the purity of the final product for possibly better tumor cell purging and to make the manufacturer's original procedure more cost-effective, we incubated the cells for 30 min with l-phenylalanine methylester hydrochloride (PME) to reduce the cell number by removing contaminating granulocytes and monocytes in the initial step before incubation with MoAb. Our modification prevented nonspecific interactions between MoAb and magnetic beads, and thereby saved expensive materials for purification. A total of 40 purifications were performed with samples containing a mean of 3.1 x 10(9) blood cells mobilized from 15 children by chemotherapy plus granulocyte colony-stimulating factor (G-CSF). The entire purification procedure, from the end of apheresis to storage, was completed within 5h. After incubation with PME and double-layered (40/60%) Percoll separation, the number of CD34+ cells was reduced to 48+/-29%, which suggests the possibility that half of the CD34+ cells in the inoculum were nonclonogenic in the hematopoietic progenitor assay. PME/Percoll-treated cells were then subjected to a final isolation procedure with MoAb according to the manufacturer's suggestions, and 52+/-42% and 32+/-22%, respectively, of the CFU-GM and CD34+ cells present in the initial bag inoculums were recovered. The recovery rates were, respectively, 54% and 67%, when the calculation was limited to the isolation procedure with MNoAb. The purity of isolated CD34+ cells and the plating efficiency in methylcellulose culture were, respectively, 77+/-24% and 33+/-13%. Fourteen children were subsequently autografted with purified CD34+ cells after marrow ablative chemotherapy. The median number of days to achieve an ANC of 0.5 x 10(9)/l was 12 and that to achieve a platelet count of 50 x 10(9)/l was 22.5, which were comparable to those in our historical group of 55 patients who underwent transplant with unmanipulated blood cells (13 and 16 days). These results suggest that our modified purification procedure with PME is useful for the initial reduction of cell numbers to save costly materials, and that cells isolated by this procedure can be directly used in clinical transplantation procedures.

Intra-apheresis recruitment of blood progenitor cells in children

BACKGROUND

Determination of the optimal duration of apheresis requires a careful examination of blood progenitor cell (BPC) kinetics during apheresis. Intra-apheresis recruitment of BPCs should be evaluated.

STUDY DESIGN AND METHODS

Twenty-six apheresis procedures were performed in 13 children with various malignant disorders (ages, 10 months to 17 years; median, 7 years) to collect BPCs for autologous transplant, using a blood cell separator with 2 to 5.2 blood volumes processed. The subjects were divided into three groups according to age: below 1 year (n = 4), 2 to 10 years (n = 5), and 11 to 20 years (n = 4). BPCs were mobilized by a combination of chemotherapy and granulocyte-colony-stimulating factor (G-CSF; 2-7.5 micrograms/kg/day intravenous drip). The levels of circulating CD34+ cells and colony-forming units-granulocyte-macrophage (CFU-GM) were monitored to examine intra-apheresis recruitment. For every 50 mL per kg or 2 L of processed blood, 5-mL blood samples were collected via a central line.

RESULTS

In the first apheresis procedure, more CD34+ cells were mobilized by the procedure itself in the infant group than in the older groups, and the number of cells decreased with the subject's age. When the same analysis was made during the second apheresis procedure, performed 1 day later, the levels of both CD34+ cells and CFU-GM had decreased to below the preapheresis values in all of the populations. Cell yields in the second apheresis procedure were significantly lower than those in the first.

CONCLUSION

Although several factors prevent a reliable analysis, the data suggest that the intra-apheresis recruitment of BPCs may be age-specific; the continuous and prolonged supply of cells from the bone marrow to peripheral blood that occurs during apheresis is more predominant in infants, which leads to the collection of proportionately more BPCs in younger children than in their older counterparts.

Change and behavior of residual mercury in paddy soils and rice of Japan

Paddy soils collected near Agano River, Niigata Prefecture in Japan. Agano River is located on an attack area of Niigata-Minamata disease. Soil samples were collected from 122 sites in 1989 and 120 sites in 1997. As a result, the total mercury concentrations were ranged from 0.019 to 0.62ppm based on dry weight with a mean 0.155ppm in 1989, and from 0.015 to 0.34 with a mean 0.146ppm in 1997. The decrease of residual mercury concentrations in paddy soils was only 0.009ppm in the interval of eight years. However, the mercury concentrations in paddy soils were about 3 times as large as that of uncultivated soils in its surroundings. It is suggested that the soils in paddy fields still contain the mercury residues to be influenced by some agricultural fungicide. Mercury concentrations in rice were natural background level. A comprehensive evaluation shows that the concentrations in boil rice with an average content of under 0.001ppm total mercury pose no health risk to Japanese people consuming rice of 200g/day.

Selection of DNA binding sites for human transcriptional regulator GATA-6

The DNA-binding sites for transcriptional regulator GATA-6 were selected and amplified by means of a PCR-mediated random-site selection method involving filter binding and gel-mobility shift analysis using the zinc finger region of human GATA-6 fused with GST. Sequencing and comparison of the selected clones suggested that (A/T/C)GAT(A/T)(A) is the consensus binding sequence, which is similar to the GATA motif (A/T)GATA(A/G) and the gastric motif (G/C)PuPu(G/C)NGAT(A/T)PuPy. GATA-6 also binds to a similar sequence containing the GATC but not the GATG sequence. These results indicated that GATA-6 shows broader sequence specificity as to DNA binding. However, adenine is favored on both sides of the core for strong binding [AGAT(A/T)A], and the order of binding is GATA > GATT > GATC. Full-length human GATA-6 expressed in COS-1 cells showed essentially the same binding specificity, suggesting that the zinc finger region of GATA-6 mainly contributes to the selection of the binding sequence. Furthermore, the non-RI method presented in this paper is convenient for determination of the binding sites of other DNA-binding proteins.

Novel combretastatin analogues effective against murine solid tumors: design and structure-activity relationships

A series of combretastatin A-4 (CA-4) analogues were synthesized, and their cytotoxic effects against murine Colon 26 adenocarcinoma and inhibitory activity on tubulin polymerization were evaluated. Since CA-4 has limited aqueous solubility, the target compounds were designed to improve solubility by introduction of a nitrogen-containing group. Among the compounds synthesized, those with an amino moiety in place of the phenolic OH of CA-4 showed potent antitubulin activity and cytotoxicity against murine Colon 26 adenocarcinoma in vitro. Some of the compounds which were potent in vitro were evaluated in the murine tumor model Colon 26 in vivo. Among these, 13bHCl, 21aHCl, and 21bHCl showed significant antitumor activity in the animal model, while CA-4 was ineffective. 13bHCl and 21aHCl were further evaluated in two murine tumor models (Colon 38 and 3LL) and human xenografts HCT-15. These compounds showed potent antitumor activity comparable or superior to that of CDDP. The structure-activity relationships of this series of compounds are also discussed.

[Postoperative analgesic effects of epidural bolus administration of bupivacaine and morphine in patients after vaginal hysterectomy and vaginoplasty]

This study was conducted to evaluate the postoperative analgesic effects of epidural bolus administration of bupivacaine and morphine in patients after vaginal hysterectomy and vaginoplasty. A total of 100 patients who had received the elective vaginal hysterectomy and vaginoplasty were investigated retrospectively by separating them into two groups. Fifty patients who had received epidural analgesics (E group) showed significantly lower pain scores for 12 hrs after the surgery compared with 50 patients who had received intramuscular buprenorphine hydrochloride (C group). The patients in E group needed significantly less supplemental analgesics than those in C group for 2 hrs after the operation. The incidence of side effects was not significantly different between the two groups. But the incidence of postoperative complications was significantly lower in the patients in E group than those in C group. These results show that epidural bolus administration of bupivacaine and morphine is effective for postoperative pain relief and decreases the incidence of postoperative complications after vaginal hysterectomy and vaginoplasty.

Variable gene segment-specific N-insertions at the signal joint of T-cell receptor Vbeta-Dbeta recombinations

The V(D)J recombination of immunoglobulin and a T-cell receptor generates two species of DNA junctions, a coding joint and a signal joint. Non-templated nucleotides (N-nucleotides) are inserted in these DNA junctions. We analyzed the N-insertion at signal joints generated by the Vbeta-Dbeta recombinations. N-insertions were detected at signal joints of Vbeta2, Vbeta3, Vbeta10, Vbeta18 and Vbeta14 but not in Vbeta8 and Vbeta7. These data show that the N-insertion at signal joints is dependent on the Vbeta locus used for the recombination. We suggest that the regional chromosomal configuration may differ in recombinase accessibility.

Treatment of hepatic metastasis of the colon26 adenocarcinoma with an alpha-galactosylceramide, KRN7000

Colorectal liver metastasis is clinically a major problem. We examined the antitumor activity of KRN7000, an alpha-galactosylceramide, on mice with liver metastases of adenocarcinoma Colon26 cells. KRN7000 treatment, beginning 1 day after tumor inoculation (day 1), significantly inhibited tumor growth in the liver, and its potency was equal to that of interleukin 12. KRN7000 treatment from day 3 caused regression of established Colon26 nodules. KRN7000 administration resulted in a high percentage of cured mice that acquired tumor-specific immunity. In addition, it appeared that highly activated, liver-associated natural killer cells made the major contribution to the killing of Colon26 cells in the liver. These results suggest that KRN7000 may be useful for the treatment of colorectal liver metastasis.

Total mercury intake from fish and shellfish by Japanese people

Elevated mercury concentrations have been reported in fish in recent years. Japanese people eat a great deal of raw fishes and shellfishes as "Sashimi" and "Sushi". The action level of large predatory fish such as tuna with total mercury levels exceeding the Japanese maximum permitted limit of 0.4 ppm is exempted from regulation in Japan. Therefore, current total mercury intake from fish and shellfish of Japanese people is unknown. The purpose of this investigation was to estimate the total mercury intake from fish and shellfish. It was found that the mean total mercury concentration of 1.11 ppm in tuna of eatable base as Sashimi or Sushi was clearly higher than the normal level. The mean total mercury intake from fish and shellfish was 0.17 mg per capita per week. According to the hypothesis that 75% of total mercury in fish and shellfish is methylmercury, the weekly intake of 0.13 mg as methylmercury was corresponding amount to about 74% of provisional tolerable weekly intake 0.17 mg of methylmercury set by the Welfare Ministry of Japan.

CD1d-restricted and TCR-mediated activation of valpha14 NKT cells by glycosylceramides

Natural killer T (NKT) lymphocytes express an invariant T cell antigen receptor (TCR) encoded by the Valpha14 and Jalpha281 gene segments. A glycosylceramide-containing alpha-anomeric sugar with a longer fatty acyl chain (C26) and sphingosine base (C18) was identified as a ligand for this TCR. Glycosylceramide-mediated proliferative responses of Valpha14 NKT cells were abrogated by treatment with chloroquine-concanamycin A or by monoclonal antibodies against CD1d/Vbeta8, CD40/CD40L, or B7/CTLA-4/CD28, but not by interference with the function of a transporter-associated protein. Thus, this lymphocyte shares distinct recognition systems with either T or NK cells.

Gastric GATA-6 DNA-binding protein: proteolysis induced by cAMP

The rat gastric GATA DNA-binding protein, GATA-6 (GATA-GT1), was stably expressed in CHO-K1 cells. The GATA-6 protein was localized in the nucleus but not in the cytoplasm. Interestingly, when cells were treated with dibutyryl cAMP, the GATA-6 protein was specifically degraded. Such a phenomenon was not observed in the presence of 5'-AMP or dibutyryl cGMP. The cellular level of the GATA-6 protein was restored upon removal of dibutyryl cAMP. Degradation was also induced by cholera toxin, which increased the cellular cAMP concentration, and was inhibited by a protein kinase A inhibitor. However, activators of protein kinase C did not have any effect. The degradation was inhibited by proteasome inhibitors (PSI (benzyloxycarbonyl-Ile-Glu(O-t-Bu)-Ala-leucinal) and MG115 (benzyloxycarbonyl-Leu-Leu-norvalinal)) but not by those of lysosomes and serine proteases. These results suggest that a kinase-mediated protein phosphorylation is the cellular signal for degradation of the GATA-6 protein. This finding constitutes a novel aspect of regulation by GATA DNA-binding proteins, which are essential for developmental processes and tissue-specific transcription.

[Concentrations of PCDDs, PCDFs and coplanar PCBs in blood of 83 patients with Yusho]

Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), coplanar polychlorinated biphenyls (Co-PCBs) and total polychlorinated biphenyls (PCBs) were analyzed in blood samples from 83 Yusho patients and 39 normal control subjects in 1995. The average concentrations of PCDDs, PCDFs and Co-PCBs in the blood of Yusho patients were 14, 128 and 14 pg toxic equivalent quantity (TEQ)/g, lipid, respectively. The levels of these compounds in the blood of normal subjects were 14, 10 and 8 pg/g lipid, respectively. Thus, although the average levels of PCDDs and Co-PCBs in the blood of Yusho patients were similar to those of control subjects, the PCDF level in Yusho patients was 12.8 fold higher than in normals. Average concentrations of total PCBs in the blood of Yusho patients and normal control subjects were 789 and 339 ng/g lipid, respectively. Thus, the PCB level in the blood of Yusho patients was 2.3 fold higher than in normal subjects. To test the reproducibility of determination of PCDDs, PCDFs and Co-PCBs, three normal blood samples were analyzed twice. These analyses gave similar results each time. Since, these compounds could be measured in five-milliliter blood samples, they can be monitored in Yusho patients.