Divalent cations enhance fluoride binding to Streptococcus mutans and Streptococcus sanguinis cells and subsequently inhibit bacterial acid production.

One preventive effect of topical fluoride application is derived from the fact that fluoride can inhibit bacterial acid production. Furthermore, divalent cations such as Ca(2+) and Mg(2+) increase the binding of fluoride to bacterial cells. These findings suggest that exposure of oral bacteria to fluoride in the presence of divalent cations increases fluoride binding to bacterial cells and subsequently enhances fluoride-induced inhibition of bacterial acid production. This study investigated the effects of fluoride exposure (0-20,000 ppm F) in the presence of Ca(2+) or Mg(2+) prior to glucose challenge on pH fall ability by bacterial sugar fermentation, as well as fluoride binding to bacterial cells by exposure to fluoride, and fluoride release from bacterial cells during bacterial sugar fermentation, using caries-related bacteria, Streptococcus mutans and Streptococcus sanguinis. The pH fall by both streptococci was inhibited by exposure to over 250 ppm F in the presence of Ca(2+) (p < 0.01), whereas in the presence of Mg(2+), the pH fall by S. mutans and S. sanguinis was inhibited after exposure to over 250 and 950 ppm F, respectively (p < 0.05). The amounts of fluoride binding to and released from streptococcal cells increased with the concentration of fluoride the cells were exposed to in the presence of Mg(2+), but were high enough even after 250 ppm F exposure in the presence of Ca(2+). The enhanced inhibition of acid production in the presence of divalent cations is probably due to the improved efficiency of fluoride binding to bacterial cells being improved via these divalent cations.

Beneficial effect of JTV-803, a new synthetic inhibitor of activated factor X, against both lipopolysaccharide-induced and tissue factor-induced disseminated intravascular coagulation in rat models.

We examined whether JTV-803, a specific activated factor X inhibitor independent of antithrombin III (ATIII), is effective against disseminated intravascular coagulation (DIC) in rat models induced by tissue factor (TF) or lipopolysaccharides (LPS). In male Wistar rats, DIC was induced by a 4 h infusion of thromboplastin (3.75 U/kg) or LPS (50 mg/kg). The rats were given JTV-803 (0.3 or 3 mg/kg, bolus intravenously) (JTV-803 groups) or low molecular weight heparin (LMWH groups) (200 U/kg, bolus intravenously) prior to an injection of TF or LPS. The results showed that JTV-803 was dose-dependently effective against DIC in both TF-induced and LPS-induced rat models. This anti-DIC effect of JTV-803 at higher doses was almost equivalent to that of LMWH in both types of DIC. Plasma ATIII activity was more prominent in the group treated with JTV-803 than in that treated with LMWH. None of rats died in the TF-induced DIC model with or without drug administration. On the contrary, seven of 22 rats died (mortality rate, 31.8%) in the LPS-induced DIC model without drug administration. Although the mortality rate of rats induced with LPS and treated with LMWH was quite high (6/16, 37.5%), none of the LPS-induced rats treated with JTV-803 died. These findings suggested that JTV-803 can treat both TF-induced and LPS-induced DIC models, and that this drug has greater potential in preserving ATIII and in improving the prognosis of DIC.

Purification and characterization of Delta(1)-pyrroline-5-carboxylate reductase isoenzymes, indicating differential distribution in spinach (Spinacia oleracea L.) leaves.

Delta(1)-Pyrroline-5-carboxylate reductase (P5CR) (EC 1.5.1.2. L-proline: NAD(P)-5-oxidoreductase), the second enzyme in the proline biosynthetic pathway, was purified from spinach (Spinacia oleracea L.) leaves. Following ammonium sulfate fractionation, purification was performed by several chromatographic methods: Blue Cellulofine, DEAE-TOYOPEARL, Sephacryl S-300 HR, and POROS QE/M. Two isoenzymes resolved by anion exchange chromatography were designated P5CR-1 and P5CR-2. Only P5CR-2 was purified from the intact chloroplasts, indicating differential distribution of the isoenzymes. P5CR isoenzymes, P5CR-1 and P5CR-2, are a homopolymer with an apparent molecular mass of 310 kDa, consisting of 10 to 12 subunits of about 28.5 kDa. P5CR-1 and P5CR-2 showed K(m) values of 9 and 19 microM for NADPH and values of 0.122 and 0.162 mM for Delta(1)-pyrroline-5-carboxylate (P5C), respectively. We decided partial amino acid sequences of P5CR-1 which showed the 70 to 80% homology to the deduced amino acid sequences of several plant P5CR cDNAs. Both isoenzymes had much lower affinity for NADH than for NADPH and were inhibited by free ATP and Mg(2+) ion. The inhibition was partially mitigated when ATP and Mg(2+) were added simultaneously to the reaction mixture. Cations at high concentration were inhibitory to P5CR activity. Interestingly, P5CR-2 was more stable to heat treatment at 40 degrees C than P5CR-1.

All-trans retinoic acid is partially effective against lipopolysaccharide-induced but not against tissue-factor-induced disseminated intravascular coagulation in rat models.

All-trans retinoic acid (ATRA) has been introduced to the management of acute promyelocytic leukemia (APL) as a differentiation treatment. This drug not only causes complete remission, but also improves disseminated intravascular coagulation (DIC) without adding anticoagulants in APL. We have attempted to determine whether ATRA is effective against DIC in rat models induced by tissue factor (TF) or lipopolysaccharide (LPS), because the anticoagulant effect of ATRA has been considered to induce thrombomodulin upregulation and TF downregulation on endothelial cells as well as on APL cells. In male Wistar rats, DIC was induced by a 4-h infusion of thromboplastin (3.75 U/kg) or lipopolysaccharide (30 mg/kg). The rats were given ATRA orally each day at a dose of 100 mg/kg per day for 1 week before the injection of TF or LPS in ATRA treatment groups, or given low molecular weight heparin (LMWH) 10 min before the injection of TF or LPS (200 U/kg, bolus intravenously) in LMWH treatment groups. No significant changes in hemostatic parameters or markers of organ dysfunction were caused by the ATRA administration, while DIC was significantly improved by LMWH in the TF-induced model. DIC was significantly improved by both ATRA and LMWH in the LPS-induced model. These findings suggested that ATRA was useful for treating DIC only in the LPS-induced model, and that drug efficacy should be carefully assessed because the agents used to induce DIC considerably influenced the outcome.

Oscillation and regulation of proline content by P5CS and ProDH gene expressions in the light/dark cycles in Arabidopsis thaliana L.

The fluctuation of proline content, and protein and mRNA levels of delta1-pyrroline-5-carboxylate synthetase (P5CS) and proline dehydrogenase (ProDH), both of which are involved in proline biosynthesis and degradation, in the shoots of Arabidopsis grown in light/dark cycles were demonstrated under salt-stressed and unstressed conditions. Proline content, as well as proteins and mRNAs of these enzymes, clearly oscillated in the light/dark cycles under the stressed and unstressed conditions. A reciprocal relationship between P5CS and ProDH was observed. Protein levels of P5CS and ProDH were well synchronized with their mRNA levels, although the fluctuation of protein levels was not as significant as that of their mRNA levels. Both mRNA and protein levels of the two enzymes as well as the proline content did not oscillate under the continuous light or the dark conditions. Thus, P5CS and ProDH gene expressions seemed to be involved in light irradiation. Moreover, relative water content (RWC) in the plants oscillated in the light/dark cycles. The fluctuations of proline content in shoot reversely responded to that of RWC. It is suggested that the expression of two genes responds sensitively to a subtle change of cellular water status, and accumulated proline keeps the osmotic balance between cells and the outer environment.

Transcatheter arterial embolization for impending rupture of an isolated internal iliac artery aneurysm complicated with disseminated intravascular coagulation.

A 90-year-old male, with impending rupture of an isolated internal iliac artery aneurysm (IIAA) complicated with disseminated intravascular coagulation (DIC) was successfully treated with transcatheter arterial embolization (TAE). After TAE, enlargement of the aneurysm was arrested and coagulation-fibrinolytic abnormalities induced by DIC improved without severe complications. Although IIAA is relatively rare, the post-operative mortality of patients with ruptures is reportedly high. We assessed the usefulness of this procedure for impending rupture of IIAA, especially for patients in high risk groups.

Treatment of disseminated intravascular coagulation (DIC) with all-trans retinoic acid in an endotoxin-induced rat model.

Anticoagulant drugs such as heparin are often administered to patients with disseminated intravascular coagulation (DIC) who are also being treated for their underlying disease. The pathophysiology of DIC is so varied that treatment with medications other than anticoagulants may be useful. All-trans retinoic acid (ATRA), which is used for the treatment of acute promyelocytic leukemia (APL), improves DIC in APL. In vitro studies have reported that ATRA caused downregulation of tissue factor and upregulation of thrombomodulin (TM) on endothelial cells as well as APL cells. We examined the effect of ATRA in an endotoxin-induced rat DIC model. DIC was induced in male Wistar rats with a 4-h sustained infusion of endotoxin at a dose of 30 mg/kg. ATRA (20 mg/day) was given every day for 1 week before the injection of endotoxin. ATRA improved the increase in thrombin-antithrombin III (TAT) complex and D-dimer in this model. Fibrin deposition in renal glomeruli was inhibited by ATRA administration, with an increase in the intensity of immunohistochemical TM staining. These findings suggest that ATRA has beneficial effects in the endotoxin-induced rat DIC model. The mechanism may be an upregulation of TM expression on endothelial cells.

Beta3-adrenoceptors mediate relaxation of guinea pig taenia caecum by BRL37344A and BRL35135A.

Beta-adrenoceptor-mediated relaxation of guinea pig taenia caecum was investigated by studying the effects of the beta3-adrenoceptor agonists, BRL37344A [(R*,R*)-(+/-)-4-[2'-[2-hydroxy-2-(3-chlorophenyl) ethylamino] propyl] phenoxyacetic acid sodium salt sesquihydrate] and BRL35135A [(R*,R*)-(+/-)-methyl-4-[2-[2-hydroxy-2-(3-chlorophenyl) ethylamine] propyl] phenoxyacetate hydrobromide]. BRL37344A and BRL35135A caused dose-dependent relaxation of the guinea pig taenia caecum. The concentration-response curves for BRL37344A and BRL35135A were unaffected by propranolol, ICI118551 [erythro-1-(7-methylindan-4-yloxy)-3-(isopropylamine)-but an-2-ol], atenolol, butoxamine, prazosin, yohimbine and phentolamine. Bupranolol produced shifts of the concentration-response curves for BRL37344A and BRL35135A. Schild regression analyses carried out for bupranolol against BRL37344A and BRL35135A gave pA2 values of 5.79 and 5.84, respectively. These results suggest that the relaxant response to BRL37344A and BRL35135A of the guinea pig taenia caecum is mediated by beta3-adrenoceptors.

The beta2- and beta3-adrenoceptor-mediated relaxation induced by isoprenaline and salbutamol in guinea pig taenia caecum.

To understand the receptor subtypes responsible for beta-adrenoceptor-mediated relaxation of guinea pig taenia caecum, we investigated the effects of isoprenaline and salbutamol. Isoprenaline and salbutamol caused dose-dependent relaxation of the guinea pig taenia caecum. Propranolol, bupranolol and butoxamine produced shifts of the concentration response curves for isoprenaline and salbutamol. Schild regression analyses carried out for propranolol against isoprenaline and salbutamol gave pA2 values of 8.43 and 8.88, respectively. Schild regression analyses carried out for butoxamine against isoprenaline and salbutamol gave pA2 values of 6.46 and 6.68, respectively. Schild regression analyses carried out for bupranolol against isoprenaline and salbutamol gave pA2 values of 8.60 and 8.69, respectively. However, in the presence of 3 x 10(-4) M atenolol, 10(-4) M butoxamine and 10(-6) M phentolamine to block the beta1-, beta2- and alpha-adrenoceptor effects, respectively, Schild regression analyses carried out for bupranolol against isoprenaline and salbutamol gave pA2 values of 5.77 and 5.97, respectively. These results suggest that the relaxant responses to isoprenaline and salbutamol in the guinea pig taenia caecum are mediated by both the beta2- and the beta3-adrenoceptors.

Chemotherapy targeting regional lymph nodes by gastric submucosal injection of liposomal adriamycin in patients with gastric carcinoma.

We investigated the delivery of adriamycin (ADR) to the regional lymph nodes of the stomach following the gastric submucosal injection of liposomal adriamycin (Lipo-ADR) in 34 gastric carcinoma patients, as well as following intravenous administration of free ADR (F-ADR) in another 18 patients. Prior to radical gastrectomy, Lipo-ADR was endoscopically injected into the gastric submucosa adjacent to the primary tumor via a needle-tipped catheter. After Lipo-ADR injection, the ADR concentration in the primary and secondary drainage lymph nodes was higher than in the other regional lymph nodes. Thus, the regional nodes more susceptible to metastasis showed higher levels of ADR. In contrast, the intravenous administration of F-ADR produced a similar and far lower ADR concentration in all the nodes. Delivery of ADR to the primary drainage lymph nodes following injection of 5 ml of Lipo-ADR was compared with delivery to the left gastric artery lymph nodes after intravenous administration of an equal dose of F-ADR. The ADR levels (micrograms/g) after gastric submucosal injection were 15.1 +/- 8.30 on day 1 (n = 4); and 11.9 +/- 4.80 on day 4 (n = 6). Those after intravenous administration were 0.29 +/- 0.10 on day 1 (n = 4); and 0.36 +/- 0.0 on day 4 (n = 2). The differences between the two groups were significant (P < 0.05). The ADR levels after the gastric submucosal injection were far higher than those after intravenous administration. These findings indicate that the gastric submucosal injection of Lipo-ADR can specifically deliver ADR to the regional lymph nodes at high concentrations. Such preoperative adjuvant chemotherapy targeting the regional lymph nodes may be useful for preventing the lymph node recurrence of gastric carcinoma.

Delivery of lymph node-targeted adriamycin by gastric submucosal liposomal injection in rabbits.

We investigated the feasibility of specifically delivering adriamycin (ADR) to the regional lymph nodes via gastric submucosal injection of liposomal adriamycin (Lipo-ADR) in a rabbit model. We determined the tissue distribution of ADR for up to 7 days after the gastric submucosal injection of Lipo-ADR (0.4 mg/kg of ADR potency) and i.v. administration of an equal dose of free adriamycin (F-ADR). The area under the ADR concentration-time curve (AUC) of the regional lymph nodes was 85.4 micrograms.day/g after gastric submucosal injection of Lipo-ADR and 8.44 micrograms.day/g after i.v. administration of F-ADR. The targeting index of the regional lymph nodes, defined as the ratio of the AUC after gastric submucosal injection of Lipo-ADR to the AUC after i.v. administration of F-ADR, was 10.1. Gastric submucosal injection of Lipo-ADR enhanced lymph node-specific delivery of ADR compared with i.v. administration of F-ADR. The targeting index was 0.47 for the heart, 0.25 for the bone marrow, and 0.41 for the spleen, indicating that gastric submucosal injection of Lipo-ADR reduced delivery of ADR to these organs, as compared with i.v. administration of F-ADR. These data demonstrate that gastric submucosal injection of Lipo-ADR is well suited for specific delivery of ADR to the regional lymph nodes, suggesting that this method of administration may be useful in delivering preoperative adjuvant chemotherapy for preventing gastric cancer recurrence.

[Antitumor effect of liposome-entrapped carboplatin after intraperitoneal administration in rats].

We examined the distribution in tissue and antitumor effects of freeze-dried liposome-entrapped carboplatin (Lipo-CBDCA) after intraperitoneal administration to rats bearing AH 130 tumors. Liposomes composed of egg lecithin and cholesterol were used as drug carriers. The serum concentration of platinum was decreased for a short time after the intraperitoneal administration of Lipo-CBDCA. After at least 3 hours, the serum concentration of platinum was higher with free CBDCA intraperitoneal or intravenous administration. The antitumor effects of Lipo-CBDCA were determined in rats with peritoneal dissemination due to AH 130 tumors. Intraperitoneal Lipo-CBDCA prolonged the life span of the tumor-bearing rats. No side effects of the chemotherapy were demonstrated in biochemical and histological studies in the liver, kidney, spleen and small intestine. These results indicate that intraperitoneal chemotherapy with Lipo-CBDCA may be more effective than that with free CBDCA managing in peritoneal dissemination, and may be therapeutically useful without toxic side effects.

[Efficacy of preoperative adjuvant chemotherapy using adriamycin targeting the regional lymph nodes for gastric cancer--lymph node-targeting delivery of adriamycin in rabbits].

Chemotherapy targeting the regional lymph nodes for gastric cancer may be more effective preoperatively than postoperatively since anticancer drugs can be transported to the regional lymph nodes via the lymphatic flow through the stomach. Distribution of Adriamycin (ADR) among the various organs was assessed following its intravenous injection in rabbits. The delivery index of the drug to each organ was assessed by the ratio of the area under the concentration-time curve (AUC) of each organ to the AUC of the regional lymph nodes following the intravenous administration. The delivery index was 0.14 for the stomach, 0.11 for the heart, 0.53 for bone marrow, 0.74 for the spleen, and 0.14 for the liver. These data suggest that preoperative adjuvant chemotherapy by intravenous administration of ADR may be effective in targeting ADR at the regional lymph nodes. Tissue ADR concentrations in the regional lymph nodes were assessed following gastric submucosal administration of ADR in rabbits. The targeting index for the regional lymph nodes was 8.20, measured by the ratio of AUC following a gastric submucosal injection to AUC after the intravenous injection of ADR. This suggests that it may be possible to selectively target chemotherapy to regional lymph nodes by employing a gastric submucosal administration of ADR.

[Endoscopic injection of liposomal adriamycin targeting lymph node metastasis of gastric cancer].

Gastric submucosal injection of 5 mg liposomal adriamycin (L-ADM) close to the main gastric cancer tumor was done in 15 patients by endoscopy. This approach was based on the idea that preoperative adjuvant chemotherapy targeting lymph node metastasis in patients with gastric cancer may be effective for prevention of lymph node recurrence. ADM concentrations in the regional lymph nodes were assessed and compared with those in patients who were administered 5 mg of free adriamycin (F-ADM) i.v. preoperatively. ADM concentrations in Group 7 lymph nodes (according to the General Rules for Gastric Cancer Study) were: After 2 days; 7.21 +/- 5.98 micrograms/g (n = 2) in the L-ADM group and 0.59 +/- 0.23 micrograms/g (n = 3) in the F-ADM group. After 4 days; 4.93 +/- 3.93 micrograms/g (n = 2) in the L-ADM group and 0.36 +/- 0.0 micrograms/g (n = 2) in the F-ADM group. After 6 days; 2.08 +/- 0.49 micrograms/g (n = 2) in the L-ADM group and 0.05 +/- 0.05 micrograms/g (n = 3) in the F-ADM group. L-ADM group: those who had L-ADM injected into the side of the lesser curvature of the stomach. F-ADM group: those who had F-ADM administered i.v. These data demonstrate that gastric submucosal injection of L-ADM is well suited for specific delivery to the regional lymph nodes, suggesting that this type of administration may prevent lymph node recurrence of gastric cancer by targeting lymph node metastasis.

[Clinical application of chemotherapy via the portal vein with liposome-encapsulated adriamycin in inoperable metastatic liver cancer].

We studied the effects of liposome-entrapped adriamycin (L-ADM) administered via the portal vein and the clinical application of this treatment in the therapy and inhibition of liver metastasis, experimentally and clinically. Liposomes composed of egg phosphatidylcholine (cholesterol 50 mol%) were used as drug carriers. We examined the distribution in tissues and antitumor effect of freeze-dried L-ADM administered via the portal vein to rabbits bearing VX2 tumors. The liver concentration of ADM increased after delivery and cardiac uptake decreased compared with free drug treatment. The life span was prolonged by L-ADM treatment compared with the control group and the free ADM group. This L-ADM administration was confirmed to be safe and revealed a decrease in the heart toxicities compared with free adriamycin. Nineteen cases were studied from Jan. 1986 to May 1991 via the portal vein and the clinical effects were evaluated. From Mar. 1988 to date, 10 cases were treated with L-ADM (20-30 mg every 2 weeks/body) in patients with inoperable cases using subcutaneously implanted reservoir. The median survival was 450 days; 275 days for colon cancer, 492 days for gastric cancer, and 1,052 days for uterine cancer (range: 136-1,152 days), compared with 141 days (range: 52-253 days) in 9 cases of historical control treated with free-ADM via the portal vein. These results suggest that chemotherapy via the portal vein with L-ADM for metastatic liver cancer may increase survival time.

Antitumor effect of liposome-entrapped adriamycin administered via the portal vein.

We examined the distribution in tissues and antitumor effect of freeze-dried liposome-entrapped adriamycin (Lipo-ADM) administered via the portal vein to rabbits bearing VX2 tumors. Liposomes composed of egg phosphatidylcholine (cholesterol 50 mol%) were used as drug carriers. The liver concentration of ADM increased after delivery and cardiac uptake decreased compared with free drug treatment. The in vivo antitumor effect of Lipo-ADM was determined in rabbits inoculated with VX2 tumor. Repeated injections of free ADM via the portal vein prolonged the life span of tumor-bearing rabbits. The life span was further prolonged by Lipo-ADM treatment compared with the control group and the free ADM group. Histological examination revealed that the damage to the liver caused by Lipo-ADM administered via the portal vein did not differ from that observed in animals treated with free ADM. These results indicate that portal vein administration of Lipo-ADM may be more effective in dealing with liver metastases than treatment with free ADM and may be therapeutically useful without toxic side effects.