DPC in acute-phase inpatient hospital care. Visualization of amount of nursing care provided and accessibility to nursing care.

OBJECTIVE: The purpose of this study was to improve accessibility to nursing care by clarifying the relationship between patient characteristics and the amount of nursing care for the Diagnosis Procedure Combination system (DPC). METHOD: The subjects included 528 lung cancer patients; 170 gastric cancer patients; and 91 colon cancer patients, who were hospitalized from July 1, 2008, to March 31, 2010, at a university hospital. The patients were categorized into groups according to factors that could affect the amount of nursing care. Next, the relationship between the patient characteristics and the amount of nursing care was analyzed. Then the results from this study were used to classify patient characteristics according to the patient type and the amount nursing care required. RESULTS: The patient characteristics, which affected the amount of nursing care, varied according to each DPC code. The major factors affecting the amount of nursing care were whether the patient had received a surgical (under general anesthetics) treatment or a non-surgical treatment and the level of activities of daily living (ADL) of the hospitalized patients. For those who had received a surgical operation for colon cancer, the patient's age also affected the amount of nursing care. CONCLUSIONS: The findings show that the method for the visualization of the amount of nursing care based on the classification of patient characteristics can be implemented into the electronic health record system. This method can then be used as a management tool to assure appropriate distribution of nursing resources.

Development of hospital data warehouse for cost analysis of DPC based on medical costs.

OBJECTIVES: To develop a data warehouse system for cost analysis, based on the categories of the diagnosis procedure combination (DPC) system, in which medical costs were estimated by DPC category and factors influencing the balance between costs and fees. METHODS: We developed a data warehouse system for cost analysis using data from the hospital central data warehouse system. The balance data of patients who were discharged from Kagoshima University Hospital from April 2003 to March 2005 were determined in terms of medical procedure, cost per day and patient admission in order to conduct a drill-down analysis. To evaluate this system, we analyzed cash flow by DPC category of patients who were categorized as having malignant tumors and whose DPC category was reevaluated in 2004. RESULTS: The percentages of medical expenses were highest in patients with acute leukemia, non-Hodgkin's lymphoma, and particularly in patients with malignant tumors of the liver and intrahepatic bile duct. Imaging tests degraded the percentages of medical expenses in Kagoshima University Hospital. CONCLUSIONS: These results suggested that cost analysis by patient is important for hospital administration in the inclusive evaluation system using a case-mix index such as DPC.

Hypoxia accelerates cancer invasion of hepatoma cells by upregulating MMP expression in an HIF-1alpha-independent manner.

Tumor hypoxia has been reported to induce tumor progression in several carcinomas. Current studies have shown that hypoxia inducible factor-1alpha (HIF-1alpha) is stabilized under hypoxic conditions and transactivates various genes related to cancer aggressiveness. In the present study, we examined whether hypoxia affects cancer invasion in hepatocellular carcinoma. We aimed to solve the molecular mechanism of tumor invasion under the hypoxic condition. We showed that tumor hypoxia accelerated cancer invasion in two hepatoma cell lines. Using Western blot and RT-PCR analyses we demonstrated striking evidence that the expression of HIF-1alpha, ETS-1, MMP-7 and MT1-MMP was strongly upregulated by hypoxic stimulation. To examine whether these invasion-related genes are regulated by HIF-1alpha, we treated hepatoma cells with TX-402, which was reported to repress HIF-1alpha expression. HIF-1alpha expression was strongly repressed by the TX-402 treatment. In contrast, the expression of ETS-1, MMP-7 and MT1-MMP mRNA was not affected by TX-402 treatment. We further established stable transfectants in which HIF-1alpha dominant negative vector was introduced into Hep3B cells (pHIF-1alphaDN). In the pHIF-1alphaDN cells, the expression of ETS-1, MMP-7 and MT1-MMP was not repressed. Moreover, the invasion activity of pHIF-1alphaDN was not altered, compared with that of the mock. In hepatoma cells, we provided evidence that hypoxic stress accelerates cancer invasion by upregulating ETS-1 and the MMP family by an HIF-1alpha-independent pathway.

The usefulness of a continuous administration of tirapazamine combined with reduced dose-rate irradiation using {gamma}-rays or reactor thermal neutrons.

We clarified the usefulness of the continuous administration of tirapazamine (TPZ) in combination with reduced dose-rate irradiation (RDRI) using gamma-rays or reactor thermal neutrons. Squamous cell carcinoma (SCC) VII tumour-bearing mice received a continuous administration of 5-bromo-2'-deoxyuridine (BrdU) to label all proliferating (P) cells. Then, they received a single intraperitoneal injection or 24 h continuous subcutaneous infusion of TPZ in combination with conventional dose-rate irradiation (CDRI) or RDRI using gamma-rays or thermal neutrons. After irradiation, the tumour cells were isolated and incubated with a cytokinesis blocker, and the micronucleus (MN) frequency in cells without BrdU labelling ( = quiescent (Q) cells) was determined using immunofluorescence staining for BrdU. The MN frequency in the total tumour cells was determined using tumours that were not pre-treated with BrdU. The sensitivity of both total and Q cells, especially of Q cells, was significantly reduced with RDRI compared with CDRI. Combination of TPZ increased the sensitivity of both populations, with a slightly more remarkable increase in Q cells. Furthermore, the continuous administration of TPZ raised the sensitivity of both total and Q cell populations, especially the former, more markedly than the single administration, whether combined with CDRI or RDRI using gamma-rays or thermal neutrons. From the viewpoint of solid tumour control as a whole, including intratumour Q-cell control, the use of TPZ, especially when administered continuously, combined with RDRI, is useful for suppressing the reduction in the sensitivity of tumour cells caused by the decrease in irradiation dose rate in vivo.

The usefulness of continuous administration of hypoxic cytotoxin combined with mild temperature hyperthermia, with reference to effects on quiescent tumour cell populations.

To evaluate the usefulness of continuous administration of hypoxic cytotoxins in terms of targeting acute hypoxia in solid tumours and the significance of combination with mild temperature hyperthermia (MTH) (40 degrees C, 60 min), the cytotoxic effects of singly or continuously administered tirapazamine (TPZ) and TX-402 were examined in combination with or without MTH in vivo. Further, the effects were also analysed on total (=proliferating (P)+quiescent (Q)) and Q cell populations in solid tumours with the method for selectively detecting the Q cell response. C3H/He mice bearing SCC VII tumours received a continuous administration of 5-bromo-2'-deoxyuridine (BrdU) for 5 days to label all P cells. The tumour-bearing mice then received a single intra-peritoneal injection or 24 h continuous subcutaneous infusion of hypoxic cytotoxin, TPZ or TX-402, with or without MTH. On the other hand, to detect the changes in the hypoxic fraction (HF) in the tumours by MTH, another group of mice with or without MTH received a series of test doses of gamma-rays while alive or after tumour clamping. After each treatment, the tumour cells were isolated and incubated with a cytokinesis blocker (=cytochalasin-B) and the micronucleus (MN) frequency in cells without BrdU labelling (=Q cells) was determined using immunofluorescence staining for BrdU. The MN frequency in total tumour cells was determined from the tumours that were not pre-treated with BrdU. The sensitivity to TX-402 was slightly higher than that to TPZ in both total and Q tumour cells. Continuous administration elevated the sensitivity of both total and Q cells, especially total cells. MTH raised the sensitivity of Q cells more remarkably than that of total cells in both single and continuous administrations. It was thought to be probably because of the higher dose distribution of hypoxic cytotoxin in intermediately hypoxic areas derived mainly from chronic hypoxia through MTH. From the viewpoint of tumour control as a whole including both total and Q tumour cells, the continuous administration of hypoxic cytotoxin combined with MTH may be useful for sensitizing tumour cells in vivo.

The usefulness of 2-nitroimidazole-sodium borocaptate-10B conjugates as 10B-carriers in boron neutron capture therapy.

We evaluated the usefulness of five new (10)B-compounds (TX-2016, TX-2017, TX-2018, TX-2041, and TX-2042) as (10)B-carriers in boron neutron capture therapy (BNCT). They are 2-nitroimidazole-sodium borocaptate-(10)B (BSH) conjugates, that is, hybrid compounds that have both hypoxic tumor cell sensitizing unit under gamma-ray irradiation, 2-nitroimidazoles, and thermal neutron-sensitizing unit, BSH. (10)B distribution analyses in tumors and blood indicated that TX-2041 has the most favorable characteristics for localizing a sufficient amount of (10)B into tumors and keeping the (10)B concentration high during neutron beam irradiation. In addition, TX-2041 showed a significantly higher radio-sensitization effect with reactor thermal neutron beams than BSH on both total (=proliferating (P) + quiescent (Q)) and hypoxia-rich Q cell populations in solid tumors. Further, TX-2041 clearly demonstrated a radio-sensitization effect with gamma-rays on both cell populations, which could never be achieved by BSH. (10)B-carriers with a hypoxic tumor cell-sensitizing effect on tumors with gamma-rays as well as the potential to selectively localize and keep (10)B in tumors, such as TX-2041, are promising for use in actual BNCT.

A novel hypoxia-dependent 2-nitroimidazole KIN-841 inhibits tumour-specific angiogenesis by blocking production of angiogenic factors.

Tumour angiogenesis is initiated by angiogenic factors that are produced in large amounts by hypoxic tumour cells. The inhibition of this step may lead to tumour-specific antiangiogenesis because normal tissues are not usually hypoxic. On the other hand, blocking a biological function of endothelial cells is known to result in angiogenic inhibition. To produce a tumour-specific and powerful antiangiogenesis, we determined whether potent angiogenic inhibition could be achieved by inhibiting the production of angiogenic factors by hypoxic tumour cells and simultaneously blocking certain angiogenic steps in endothelial cells under normoxia. We focused on the 2-nitroimidazole moiety, which is easily incorporated into hypoxic cells and exhibits its cytotoxicity as hypoxic cytotoxin. We designed and synthesised 2-nitroimidazole derivatives designated as KIN compounds, and investigated their antiangiogenic activities under normoxia using a chick embryo chorioallantoic membrane. KIN-841 (2-nitroimidazole 1-acetylhydroxamate) showed a potent angiogenic inhibition in a dose-dependent manner. This compound inhibited the proliferation of bovine pulmonary arterial endothelial (BPAE) cells more strongly than that of tumour cells, such as Lewis lung carcinoma (3LL) cells, under normoxia. The inhibition of cell proliferation by KIN-841 under hypoxia increased about five-fold compared to that under normoxia. Moreover, under hypoxia, KIN-841 significantly decreased the excessive production of vascular endothelial cell growth factors induced by 3LL cells as determined by tritium-labelled thymidine ([(3)H]thymidine) incorporation into BPAE cells and by ELISA. Intraperitoneal administration of KIN-841 suppressed 3LL-cell-induced in vivo angiogenesis in the mouse dorsal air sac system. These results indicate that the regulation of the production of angiogenic factors by hypoxic tumour cells is a useful target for tumour-specific angiogenesis inhibition, and that KIN-841, which causes simultaneous direct inhibition of endothelial cell function and production of angiogenic factors by hypoxic tumour cells, is a very potent inhibitor of tumour-specific angiogenesis. Thus, the potential for clinical use of KIN-841 as an antitumour drug is very high.

Evaluation of the potential of p-boronophenylalaninol as a boron carrier in boron neutron capture therapy, referring to the effect on intratumor quiescent cells.

C57BL mice bearing EL4 tumors and C3H / He mice bearing SCC VII tumors received 5-bromo-2'-deoxyuridine (BrdU) continuously for 5 days via implanted mini-osmotic pumps to label all proliferating (P) cells. Three hours after oral administration of l-p-boronophenylalanine-(10)B (BPA), or 30 min after intraperitoneal injection of sodium borocaptate-(10)B (BSH) or l-p-boronophenylalaninol (BPA-ol), a newly developed (10)B-containing alpha-amino alcohol, the tumors were irradiated with thermal neutron beams. For the combination with mild temperature hyperthermia (MTH) and / or tirapazamine (TPZ), the tumors were heated at 40 degrees C for 30 min immediately before neutron exposure, and TPZ was intraperitoneally injected 30 min before irradiation. The tumors were then excised, minced and trypsinized. The tumor cell suspensions thus obtained were incubated with cytochalasin-B (a cytokinesis blocker), and the micronucleus (MN) frequency in cells without BrdU labeling ( = quiescent (Q) cells) was determined using immunofluorescence staining for BrdU. Meanwhile, 6 h after irradiation, tumor cell suspensions obtained in the same manner were used for determining the apoptosis frequency in Q cells. The MN and apoptosis frequency in total (P + Q) tumor cells were determined from tumors that were not pretreated with BrdU. Without TPZ or MTH, BPA-ol increased both frequencies most markedly, especially for total cells. However, as with BPA, the sensitivity difference between total and Q cells was much larger than with BSH. On combined treatment with both MTH and TPZ, this sensitivity difference was markedly reduced, similarly to when BPA was used. MTH increased the (10)B uptake of all (10)B-compounds into both tumor cells. BPA-ol has good potential as a (10)B-carrier in neutron capture therapy, especially when combined with both MTH and TPZ.

Radiosensitization effect by combination with paclitaxel in vivo, including the effect on intratumor quiescent cells.

PURPOSE: To evaluate the radiosensitization effect on solid tumors upon combination treatment with paclitaxel (TXL), including the effect on intratumor quiescent (Q) cells. METHODS AND MATERIALS: Mice bearing SCC VII or EL4 solid tumors received 5-bromo-2'-deoxyuridine (BrdU) continuously for 5 days to label all proliferating (P) cells. The mice then received gamma-irradiation with or without tirapazamine (TPZ) at various time points after TXL administration. Another group of mice received a series of test doses of gamma-rays while alive or after tumor clamping to obtain hypoxic fractions (HFs) in the tumors at various time points after TXL administration. Immediately after irradiation, the tumor cells were isolated and incubated with a cytokinesis blocker. The micronucleus (MN) frequency in cells without BrdU labeling (Q cells) was determined using immunofluorescence staining for BrdU. Meanwhile, 6 h after irradiation, the tumor cells were isolated from the solid tumors in another group of mice, and the apoptosis frequency in Q cells was also determined with immunofluorescence staining for BrdU. The MN and apoptosis frequency in total (P + Q) tumor cells were determined from the tumors that were not pretreated with BrdU. For the measurement of the HFs, the MN or apoptosis frequency of Q cells was then used to calculate the surviving fraction of Q cells from the regression line for the relationship between the MN or apoptosis frequency and the surviving fraction of total tumor cells. RESULTS: In both SCC VII and EL4 tumors, maximum values of mitotic index (MI) and apoptosis frequency were observed 9 and 24 h after TXL administration, respectively. However, on the whole, the apoptosis frequency for SCC VII was very low. gamma-Irradiation 9 h after TXL administration induced significant radiosensitization effects on the total cells of both tumors. Irradiation at 60 h had a more significant effect on total cells of EL4 tumor, but no significant effect on total cells of SCC VII tumor. Combined treatment with TXL induced no radiosensitization effect on Q cells in either tumor. The effect on Q cells was observed only after TPZ was administered. The HF of total cells in EL4 tumors decreased significantly 60 h after TXL administration. CONCLUSION: No radiosensitization effect upon combination treatment with TXL is induced in Q tumor cells. However, the effect on P cells is produced by irradiation at the time when the maximum values of MI are induced following TXL administration. In addition, for tumors that are susceptible to apoptosis after TXL administration alone, irradiation at the time of sufficient reoxygenation in tumors after TXL administration produces a greater radioenhancement effect on P cells.

New antimetastatic hypoxic cell radiosensitizers: design, synthesis, and biological activities of 2-nitroimidazole-acetamide, TX-1877, and its analogues.

We designed, based on the molecular orbital (MO) calculation, synthesized, and evaluated the biological activities of the new antimetastatic hypoxic cell radiosensitizer, 2-nitroimidazole-acetamide, TX-1877, and its analogues. Each analogue has an electron-affinic imidazole group, an acetamide group and a certain hydrophilic group to control its biological effect, toxicity, and pharmacokinetics. In in vitro radiosensitization assay, most TX-1877 analogues, which have an electron affinity (EA) of more than 0.9 eV and partition coefficient (P) of more than 0.021, showed satisfactory enhancement ratios (ER > 1.60) at doses of I mM. On the other hand, imidazole analogues, such as TX-1908 (EA = 0.67 eV), TX-1910 (EA = -0.34 eV) and TX-1931 (EA = -0.37 eV), which have low electron affinities, had an ER of 1.31 or less. TX-1877 and KIN-806 effectively inhibited tumor regrowth when administered with irradiation in vivo at a dose of 0.4 mg/g. Tumor lung metastasis was inhibited by treatment with either TX-1877 or KIN-806 without irradiation at a dose of 0.4 mg/g. TX-1877 reduced markedly the mean number of metastatic lung nodules in comparison with KIN-806. Moreover, TX-1877 and KIN-806 enhanced macrophage and helper T lymphocyte infiltration for 3 weeks after drug treatment. TX-1877 shows a high EA value and has the C2 of HOMO localizing on N-methylamide and the C2 of LUMO localizing on 2-nitroimidazole group. The MO data might be useful for designing a bifunctional hypoxic cell radiosensitizer. TX-1877 and its analogues are potential antimetastatic hypoxic cell radiosensitizers, which would improve the efficiency of radiotherapy and quality of life in cancer treatment.

Change in oxygenation status in intratumour total and quiescent cells following gamma-ray irradiation, tirapazamine administration, cisplatin injection and bleomycin treatment.

C3H/He mice bearing SCC VII tumours received 5-bromo-2'-deoxyuridine (BrdU) continuously for 5 days via implanted mini-osmotic pumps to label all proliferating (P) cells. The mice then received gamma-ray irradiation, or administration of tirapazamine (TPZ), cisplatin or bleomycin. At various time points after each treatment, tumour-bearing mice were irradiated with a series of test doses of gamma-rays, while alive or after being killed, to obtain hypoxic fractions (HFs) in the tumours. Immediately after gamma-ray test irradiation, the tumours were excised, minced and trypsinized. Tumour cell suspensions obtained were incubated with cytochalasin-B, a cytokinesis blocker, and the micronucleus (MN) frequency in cells without BrdU labelling (i.e. quiescent (Q) cells) was determined using immunofluorescence staining for BrdU. MN frequency in the total (P + Q) tumour cells was determined from the tumours that were not pre-treated with BrdU. MN frequency of BrdU-unlabelled cells was then used to calculate the surviving fraction of the unlabelled cells from the regression line for the relationship between the MN frequency and the surviving fraction of total tumour cells. TPZ and cisplatin reduced the HF after treatment, especially in Q cells, and this tendency was particularly marked with TPZ. In contrast, bleomycin increased the HF after treatment. Both reoxygenation following gamma-ray irradiation or bleomycin treatment and a subsequent return to pre-treatment levels of HF following TPZ or cisplatin treatment (rehypoxiation) occurred more rapidly in total (P + Q) cells than in Q cells. Based on our previous report that total (P + Q) and Q cells within this tumour have large acutely and chronically HFs, respectively, we conclude that acute hypoxic cells play a major role in reoxygenation and rehypoxiation in SCC VII tumours.

Treatment with alpha-glucosidase inhibitor for severe reactive hypoglycemia: a case report.

Gastrectomy or vagotomy may result in reactive hypoglycemia, which, in some cases, can reduce the plasma glucose levels to 30-40 mg/dl due to rapid digestion and absorption of food, especially carbohydrates. It also occurs sometimes in patients on hemodialysis, where it is a potentially lethal complication. Because insulin has a longer half-life due to lack of renal degradation, hypoglycemia can be induced by insulin in patients with renal failure. We treated a patient with frequent episodes of severe hypoglycemia, that were sometimes accompanied by convulsions. He had undergone total gastrectomy 8 years before and had been maintained on hemodialysis for 3 years. Hyperinsulinemia caused by oxyhyperglycemia associated with post-gastrectomy led to severe hypoglycemia in this patient because of the lack of renal insulin degradation. Since nutritional treatment did not successfully manage his reactive hypoglycemia, an alpha-glucosidase inhibitor, acarbose, was administered to treat his oxyhyperglycemia. This therapy was very effective and he has not had any recurrence of reactive hypoglycemia since the initiation of the therapy.

Association of postprandial hypertriglyceridemia and carotid intima-media thickness in patients with type 2 diabetes.

OBJECTIVE: Serum triglyceride levels are important in the development of atherosclerosis. Although triglyceride levels are generally increased in the postprandial periods, the association between postprandial triglyceride (pTG) levels and atherosclerosis has not been investigated in diabetic patients. To investigate the role of pTG levels in atherosclerosis, we examined the correlation between pTG levels and carotid intimal-medial thickness (IMT). RESEARCH DESIGN AND METHODS: Carotid IMT was measured by ultrasonography in 61 patients with type 2 diabetes. Plasma glucose (PG), insulin, total cholesterol, triglycerides, and HDL cholesterol levels were measured after overnight fasting and 4 h after a meal. RESULTS: Carotid IMT of the patients with fasting hypertriglyceridemia was greater than that of the patients with normal fasting triglyceride (fTG) levels (0.85+/-0.12 vs. 0.76+/-0.14 mm; P = 0.02). The carotid IMT was increased in the patients with pTG levels >2.27 mmol/l. The normo-normo (NN) and normo-hyper (NH) groups consisted of patients with normal fTG levels but with pTG levels <2.27 and >2.27 mmol/l, respectively. Patients with both hypertriglyceridemia and pTG levels >2.27 mmol/l formed the hyper-hyper (HH) group. Carotid IMT was significantly increased in the NH (0.86+/-0.13 mm) and HH (0.85+/-0.12 mm) groups compared with the NN group (0.73+/-0.13 mm; P<0.01). Although postprandial PG, pTG, and fasting LDL cholesterol levels were all independently correlated with carotid IMT, pTG levels had the strongest statistical influence (P = 0.002). CONCLUSIONS: Postprandial hypertriglyceridemia despite normal fTG levels may be an independent risk factor for early atherosclerosis in type 2 diabetes.

Changes in the sensitivity of intratumor cells during fractionated tirapazamine administration.

Mice bearing solid tumors received 10 intraperitoneal administrations of 5-bromo-2'-deoxyuridine (BrdU) to label the proliferating (P) tumor cells. Then, as a priming treatment, tirapazamine (TPZ) was intraperitoneally administered. Further, 0 through 48 h later, the tumor-bearing mice received TPZ again at various doses. The tumor cells were isolated and incubated with a cytokinesis blocker. The micronucleus (MN) frequencies in cells with and without BrdU labeling, which were regarded as P and quiescent (Q) cells at the priming treatment, respectively, were determined using immunofluorescence staining for BrdU. The MN frequency in the total (P + Q) tumor cells was determined from the tumors that were not pretreated with BrdU. In addition, P cell ratios in the tumors at the second treatment were determined using immunofluorescence staining for P cell nuclear antigen. In each cell fraction, the longer the interval between the two treatments, the higher was the sensitivity to TPZ, except 1 h after the priming treatment. More than 24 h later, total and P cells, especially P cells, showed significantly higher sensitivity to TPZ than in the case of a single TPZ treatment. The longer the period between the two TPZ treatments, the lower was the P cell ratio at the second treatment. These findings were thought to indicate that the use of TPZ in the treatment of solid tumors causes a shift from the P to the Q state in vivo.

Usefulness of tirapazamine as a combined agent in chemoradiation and thermo-chemoradiation therapy at mild temperatures: reference to the effect on intratumor quiescent cells.

C3H / He mice bearing SCC VII tumors received 5-bromo-2'-deoxyuridine (BrdU) continuously for 5 days via implanted mini-osmotic pumps to label all proliferating (P) cells. The mice then received one of six different DNA-damaging agents with or without mild temperature hyperthermia (40 degrees C, 30 min, MTH). These agents were adriamycin (ADM), mitomycin C (MMC), cyclophosphamide (CPA), bleomycin (BLM), cisplatin (CDDP), and tirapazamine (TPZ). After the drug treatment, the tumor-bearing mice were irradiated with a series of doses of gamma-rays. Immediately after irradiation, the tumors were excised, minced and trypsinized. The tumor cell suspensions thus obtained were incubated with cytochalasin-B (a cytokinesis blocker), and the micronucleus (MN) frequency in cells without BrdU labeling ( = quiescent (Q) cells) was determined using immunofluorescence staining for BrdU. The MN frequency in the total (P + Q) tumor cells was determined from the tumors that had not been pretreated with BrdU. MTH significantly increased the MN frequency of total cells in tumors irradiated with gamma-rays combined with CPA, BLM, CDDP or TPZ, and that of Q cells in tumors irradiated with gamma-rays combined with BLM or TPZ. The sensitivity difference in the MN frequency between total and Q tumor cells was significantly decreased by the combination with TPZ. TPZ combined with radiotherapy and TPZ combined with thermo-radiotherapy at mild temperatures appear to be promising modalities for sensitizing tumor cells in vivo, including Q tumor cells.

Combined effects of tirapazamine and mild hyperthermia on anti-angiogenic agent (TNP-470) treated tumors-reference to the effect on intratumor quiescent cells.

PURPOSE: To evaluate the efficacy of the use of tirapazamine (TPZ), especially combined with mild hyperthermia (40 degrees C, 60 min), in the treatment of solid tumors following an anti-angiogenic treatment with TNP-470. In addition, we assessed the effect of TPZ and/or mild hyperthermia (MHT) combined with conventional radiotherapy or chemotherapy on TNP-470 treated tumors. MATERIALS AND METHODS: C3H/He mice bearing SCC VII tumors subcutaneously received TNP-470 at two doses of 100 mg/kg after tumor cell inoculation. At the same time, the tumor-bearing mice received 5-bromo-2'-deoxyuridine (BrdU) continuously for 5 days via implanted mini-osmotic pumps to label all proliferating (P) cells. The mice then received TPZ administration combined with or without MHT, gamma-ray irradiation combined with or without TPZ and/or MHT, or cisplatin injection with or without TPZ and/or MHT. Another group of mice received a series of test doses of gamma-rays while alive or after being killed to obtain hypoxic fractions (HFs) in the tumors at various time points after the above-mentioned cytotoxic treatment point. After each treatment, the tumors were excised, minced, and trypsinized. The tumor cell suspensions thus obtained were incubated with cytochalasin-B (a cytokinesis blocker), and the micronucleus (MN) frequency in cells without BrdU labeling (or quiescent [Q] cells) was determined using immunofluorescence staining for BrdU. The MN frequency in the total (P + Q) tumor cells was determined from the tumors that were not pretreated with BrdU. For the measurement of the HFs, the MN frequency of BrdU-unlabeled cells was then used to calculate the surviving fraction of the unlabeled cells from the regression line for the relationship between the MN frequency and the surviving fraction of total tumor cells. RESULTS: TPZ administration combined with TNP-470 treatment and MHT increased the MN frequency more markedly than treatment with TPZ alone, and this tendency was more remarkable in Q cells than total cells. In both total and Q cells, combined treatment with TPZ and MHT produced significant increases in MN frequencies whether gamma-rays were delivered to TNP-470 treated tumors or cisplatin was injected into the TNP-470 administered mice. Although not significantly, the HFs of total and Q cell populations within solid tumors increased after TNP-470 treatment. CONCLUSION: Combined treatment with TPZ and MHT, whether other cytotoxic treatments such as gamma-ray irradiation or chemotherapy using cisplatin were combined or not, was useful for sensitizing tumor cells in vivo including Q cells even after TNP-470 treatment.

Synthesis of functionalized oxazolines and oxazoles with DAST and Deoxo-Fluor.

[formula: see text] A mild and highly efficient cyclization of beta-hydroxy amides to oxazolines is described using DAST and Deoxo-Fluor reagents. A one-pot protocol for the synthesis of oxazoles from beta-hydroxy amides is also presented.

Total synthesis and revision of stereochemistry of the marine metabolite trunkamide A.

The isolation of the cytotoxic Lissoclinum sp. metabolite trunkamide A was reported in 1996. After completion of a total synthesis in 1999, it became clear that the structure of this marine natural product had to be revised. We now report the first preparation of actual trunkamide A in a total synthesis that serves as an unambiguous structural and stereochemical proof. Highlights of our synthetic strategy are a Lewis acid assisted aziridine opening that was used for the preparation of the novel reverse-prenylated serine and threonine side chains as well as an efficient oxazoline-thiazoline interconversion on the macrocyclic skeleton. In addition, several stereoisomers prepared by complementary synthetic protocols serve to illustrate the general scope of our methodology and confirm the configurational assignment.

DNA sensing on a DNA probe-modified electrode using ferrocenylnaphthalene diimide as the electrochemically active ligand.

Naphthalene diimide derivative 1 carrying ferrocenyl moieties at the termini of imide substituents binds intact calf thymus DNA 4 times more strongly than the denatured DNA, and its complex with the intact DNA dissociates 80 times more slowly than that with the denatured DNA. On the basis of these observations, ligand 1 was applied to a probe of electrochemical DNA sensing. A thiol-linked single-stranded DNA probe was immobilized through the S-Au bonding to 20-30 pmol/mm2 on a gold electrode. Following hybridization with the complementary DNA, the electrode was soaked in a solution containing 1 (intercalation step) and then washed with buffer for 5 s. The cyclic voltammogram and differential pulse voltammogram for this electrode gave an electrochemical signal due to the redox reaction of 1 that was bound to the double-stranded DNA on the electrode. Thus, dA20 and the yeast choline transport gene were quantitated at the subpicomole level. The sensitivity of DNA detection was improved to 10 zmol by reducing the amount of immobilized DNA probe and protecting the uncovered surface of the electrode with 2-mercaptoethanol.