Porcine circovirus type 2 (PCV2) vaccination reduces PCV2 in a PCV2 and Salmonella enterica serovar Choleraesuis coinfection model.

We previously reported that prior porcine circovirus type 2 (PCV2) infection potentiates the severity of clinical signs, lung lesions, and fecal shedding and tissue dissemination of Salmonella enterica serovar Choleraesuis in infected pigs. Here, we evaluated whether PCV2 vaccination is effective in reducing fecal shedding and tissue dissemination of S. Choleraesuis and improving clinical signs associated with PCV2 and S. Choleraesuis infection in 15 Cesarean-derived, colostrum-deprived pigs randomly assigned to 3 groups (n=5/group). The vaccinated and co-infected (VAC-COINF) group received 2 ml of a commercial PCV2 vaccine at age 3 weeks. The VAC-COINF and co-infected (COINF) groups were inoculated intranasally with PCV2 and S. Choleraesuis at 5 and 7 weeks of age, respectively. The CONTROL group pigs received a similar volume of PBS for sham-vaccination and sham-inoculation. PCV2 vaccination clearly reduced PCV2 DNA load in the serum and postmortem tissue samples and decreased PCV2 antigen levels in tissue samples of the VAC-COINF group. After S. Choleraesuis infection, the incidence of several clinical signs increased in the VAC-COINF group compared to that in the COINF group. The microscopic lung lesions and weight gain, fecal shedding and tissue dissemination of S. Choleraesuis except in the spleen were not significantly different in the VAC-COINF and COINF groups. Thus, PCV2 vaccination reduced PCV2 in the S. Choleraesuis and PCV2 coinfection model and the effects on S. Choleraesuis were minimal.

Mechanisms of age-related decline in insulin-like growth factor-I dependent proteoglycan synthesis in rat intervertebral disc cells.

STUDY DESIGN: Age-related fluctuations in insulin-like growth factor-I dependent proteoglycan synthesis in rat intervertebral disc cells were investigated. OBJECTIVES: The purpose of this study was to determine whether synthetic responses to insulin-like growth factor-I decline with age and to explore the possibility that an age-related increase in the expression of insulin-like growth factor binding proteins suppresses matrix synthesis in intervertebral disc cells. SUMMARY AND BACKGROUND DATA: Several studies have reported that the responsiveness of chondrocytes to insulin-like growth factor-I decreases with age and furthermore that this phenomenon may be related to increased expression of insulin-like growth factor binding proteins by chondrocytes. MATERIALS AND METHODS: Nucleus pulposus tissue and cells were obtained from the coccygeal vertebrae of 8-week-old, 40-week-old, and 120-week-old rats. Age-related changes in the expression of insulin-like growth factor-I and its receptor were assessed together with insulin-like growth factor-I dependent proteoglycan synthesis by the cultured nucleus pulposus cells. Also, western blot analysis of insulin-like growth factor binding protein-1 was carried out, and further examination was performed of insulin-like growth factor-I signal transduction through tyrosine phosphorylation of insulin receptor substrate-1, which is a signal transducer of insulin-like growth factor-I. RESULTS: Semiquantitative reverse transcription polymerase chain reaction analysis indicated that the expression of insulin-like growth factor-I receptor in 120-week cells decreased clearly in comparison with the cells of younger animals. By contrast, insulin-like growth factor-I dependent proteoglycan synthesis decreased with age, and the sharpest decline of synthesis was found between 8-week and 40-week cells, although the level of insulin-like growth factor-I/insulin-like growth factor-I receptor gene expression was maintained in 40-week-old animals. Consistent with the results of proteoglycan synthesis, the expression of phosphorylated insulin receptor substrate-1 decreased with age. Thus, the expression of insulin-like growth factor binding protein-1 and proteoglycan synthesis was investigated by use of Long R3 insulin-like growth factor-I, which was not influenced by insulin-like growth factor binding proteins. Insulin-like growth factor binding protein-1 was strongly expressed in 40-week cells in comparison with the expression in 8-week cells. Furthermore, proteoglycan synthesis in 40-week cells supplemented with Long R3 insulin-like growth factor-I was upregulated in comparison with that in 40-week cells supplemented with insulin-like growth factor-I. CONCLUSION: The present findings indicate that the age-related decline in insulin-like growth factor-I dependent proteoglycan synthesis in nucleus pulposus is caused, at least in part, by the increase in insulin-like growth factor binding proteins at the early stages of aging, and further suggest that a loss of proteoglycan synthesis during the late stages of aging is caused by the downregulation of insulin-like growth factor-I receptor in addition to an increase in insulin-like growth factor binding proteins.

MR-based temperature monitoring for hot saline injection therapy.

We applied magnetic resonance (MR) phase mapping methods to monitor the thermal frequency shift of water in order to study temperature changes from percutaneous hot saline injection therapy (PSIT) using in vitro swine livers and in vivo rabbit livers. The thermal coefficients calculated from the shifts of the water frequency with thermocouple based temperature measurements were -0.0085 +/- 0.0019 ppm/ degrees C for the in vitro studies and -0.0089 ppm/ degrees C for the in vivo studies. The error range was estimated to be +/- 3 degrees C and +/- 4.5 degrees C, respectively. Color-coded temperature maps were compared with macroscopic lesion sizes of the specimen. Regions defined using a 20 degrees C elevation in the initial images following hot saline injection (around 55 degrees C in absolute temperature) closely correlated with visible coagulation in size. We conclude that MR temperature monitoring of PSIT is quite feasible and may be helpful in expanding the clinical use of this thermal therapeutic tool for liver tumors.

Tetrahydrobiopterin restores endothelial function in long-term smokers.

OBJECTIVES: We sought to test whether tetrahydrobiopterin (BH4) supplementation improves nitric oxide (NO) bioactivity in smokers. BACKGROUND: In smokers, endothelium-derived NO bioactivity is impaired. BH4 is an essential cofactor of NO synthase, and its deficiency decreases NO bioactivity. METHODS: Sapropterin hydrochloride, an active analogue of BH4 (2 mg/kg body weight), was administered orally to healthy male smokers and age-matched nonsmokers. Before and 3 and 24 h after sapropterin, we measured plasma levels of BH4 and examined flow-mediated vasodilation (FMV) of the brachial artery by high resolution ultrasonography, a noninvasive test of endothelial function. RESULTS: Basal plasma levels of BH4 were not different between smokers and nonsmokers. Sapropterin administration increased plasma levels of BH4 by threefold at 3 h, which returned to the baseline at 24 h. Before sapropterin, FMV was significantly smaller in smokers (p = 0.0002). Sapropterin significantly augmented endothelium-dependent vasodilation in smokers, but did not affect it in nonsmokers (p = 0.001 by analysis of variance [ANOVA]). Coadministration of N(G)-monomethyl-L-arginine (L-NMMA), an NO synthase inhibitor (20 micromol), into the brachial artery completely abolished the vasodilatory effects of sapropterin (p = 0.002 by ANOVA). Endothelium-independent vasodilation by glyceryl trinitrate was not different between smokers and nonsmokers and was not altered by BH4. CONCLUSIONS: We demonstrated that BH4 supplementation improved bioactivity of endothelium-derived NO in smokers. These observations strongly suggest that decreased NO-dependent vasodilation in smokers could be related to reduced bioactivity of BH4.

Endothelial dysfunction by acute hyperhomocyst(e)inaemia: restoration by folic acid.

Recent evidence demonstrates that hyperhomocyst(e)inaemia is a novel risk factor for cardiovascular diseases. In patients with chronic hyperhomocyst(e)inaemia, endothelial function is impaired. However, whether hyperhomocyst(e)inaemia per se is a cause or an epiphenomenon of endothelial dysfunction remains unknown. In this study, we examined the effects of methionine-induced acute hyperhomocyst(e)inaemia on human endothelial function. In healthy volunteers we administered methionine (0.1 g/kg body weight, per os), a substrate of homocyst(e)ine, with or without folic acid (20 mg, per os) and examined flow-mediated vasodilatation of the brachial artery by high-resolution ultrasonography as a non-invasive measure of endothelial function. We also measured plasma levels of homocyst(e)ine before and 3, 8 and 24 h after methionine loading. Methionine administration increased plasma levels of homocyst(e)ine by four times the basal level at 8 h (P<0.0001, ANOVA). The plasma levels returned to baseline at 24 h. Flow-mediated vasodilatation was significantly decreased to half of the baseline value at 8 h and returned to baseline at 24 h (P<0.0001, ANOVA), whereas endothelium-independent vasodilatation by glyceryl trinitrate was not affected by the methionine loading. Co-administration of folic acid did not attenuate methionine-induced hyperhomocyst(e)inaemia but completely prevented endothelial dysfunction. Our results suggest that in humans a methionine-rich diet may acutely impair endothelial function, which can be prevented by folic acid supplementation.

Chronic inhibition of nitric oxide in central nervous system does not cause hypertension.

Acute inhibition of nitric oxide (NO) synthase in the brain causes elevation of blood pressure and sympathetic excitation under anesthetized conditions. To investigate chronic effects of NO synthase inhibition in the central nervous system on blood pressure regulation in conscious unrestrained animals, we administered NG-monomethyl-L-arginine (L-NMMA), a potent NO synthase inhibitor, at low (22.5 mumol/kg) and high (67.5 mumol/kg) doses for 1 wk into the cisterna magna with an osmotic pump and measured mean arterial pressure (MAP) and heart rate (HR) by a telemetry method. The same dose of NG-monomethyl-D-arginine (D-NMMA), an inactive isomer of L-NMMA, was administered to control rats. Chronic intracisternal administration of low-dose L-NMMA significantly decreased the brain nitrite/nitrate and NO metabolite contents as compared with D-NMMA (p < 0.05). However, MAP and its variability, HR and its variability, and plasma norepinephrine levels did not differ between the two groups of rats at either low- or high-dose treatment. Thus, chronic NO synthase inhibition in the central nervous system did not affect systemic hemodynamics or plasma norepinephrine concentrations despite the inhibition of brain NO. Our results suggest that endogenous NO in the central nervous system, at least as a whole, may not affect the systemic hemodynamics of chronic unanesthetized rats.

Dose-dependent incorporation of tea catechins, (-)-epigallocatechin-3-gallate and (-)-epigallocatechin, into human plasma.

Tea catechins, (-)-epigallocatechin-3-gallate (EGCg) and (-)-epigallocatechin (EGC), have been reported to suppress oxidation of plasma low density lipoprotein (LDL) in vitro. If dietary catechins can be efficiently incorporated into human blood plasma, anti-atherosclerotic effects in preventing oxidative modification of LDL would be expected. In this study, a newly developed chemiluminescence detection-high pressure liquid chromatography (CL-HPLC) method for measuring plasma catechins was used and the incorporation of EGCg and EGC into human plasma was investigated. Healthy subjects orally ingested 3, 5, or 7 capsules of green tea extract (corresponding to 225, 375, and 525 mg EGCg and 7.5, 12.5, and 17.5 mg EGC, respectively). The plasma EGCg and EGC concentrations before the administration were all below the detection limit (< 2 pmol/ml), but 90 min after, significantly and dose-dependently increased to 657, 4300, and 4410 pmol EGCg/ml, and 35, 144, and 255 pmol EGC/ml, in the subjects who received 3, 5, and 7 capsules, respectively. Both EGCg and EGC levels detected in plasma corresponded to 0.2-2.0% of the ingested amount. Catechin intake had no effect on the basal level of endogenous antioxidants (alpha-tocopherol, beta-carotene, and lycopene) or of lipids in plasma. These results suggested that drinking green tea daily would contribute to maintain plasma catechin levels sufficient to exert antioxidant activity against oxidative modification of lipoproteins in blood circulation systems.

Ameliorative effects of tea catechins on active oxygen-related nerve cell injuries.

Active oxygen species are suggested to be concerned with various senile disorders. Tea catechins, (+)catechin (CA), (-)epicatechin (EC) and (-)epigallocatechin gallate, are polyhydroxy-fravan derivatives from tea leaves and have been proposed to possess active oxygen scavenging effect. Tea catechins protected the cultured newborn-mouse cerebral nerve cells from death induced by glucose oxidase. The protective potency of (-)epigallocatechin gallate was weaker than those of EC and CA. Learning ability of mice was assessed by a step-down-type passive avoidance test, and memory impairment of mice was achieved by intracisternal injection of glucose oxidase or cerebral ischemia induced by 10 min occlusion of the common carotid arteries. Intracisternal injection of EC improved the memory impairment induced by intracisternal glucose oxidase, and i.v. injection of CA or EC improved that induced by the cerebral ischemia. CA and EC depressed carrageenin-induced edema in rat hind paw, but (-)epigallocatechin gallate did not. These results suggest that tea catechins ameliorate the injuries or impairments induced by active oxygens through scavenging intracellular active oxygens, and might become useful for protecting human from senile disorders such as dementia.

[Analysis of cases with liver abscess following transcatheter arterial chemoembolization (TAE) for malignant hepatic tumors].

A total of 182 TAE procedures were carried out in 98 patients with malignant hepatic tumors during the last five years. Liver abscess following TAE occurred in 3 cases (3.1%) and in 3 procedures (1.7%). All cases were discharged after successful percutaneous transhepatic abscess drainage. One case had hepatocellular carcinoma. Another case had undergone total gastrectomy and esophagojejunostomy with Roux-Y reconstruction for gastric leiomyosarcoma. The other had undergone right hemicolectomy and pancreatoduodenectomy for colon cancers and carcinoma of the ampulla of Vater. Communication between the abscess and the intrahepatic bile duct was recognized in 2 cases. In the abscess culture, E. coli and Citrobacter freundii were detected. These results suggest the major factor leading to abscess formation is biliary infection. Therefore, a previous bilio-enteric anastomosis should be regarded as a risk factor for liver abscess following TAE.

Clival chordoma associated with pathological laughter. Case report.

The case of a 40-year-old man with a clival chordoma who presented with symptoms of pathological laughter and left sixth cranial nerve paresis is reported. Laughing and talking during sleep were noted on polygraphic and videotape recordings of nocturnal sleep. Selective disorganization of sleep was observed, with laughing facial expressions and a lack of muscular atonia. The tumor developed in the prepontine cistern, compressing the pontomesencephalic structures backward and involving the upper clivus and the left cavernous sinus. No recurrence of laughter attacks were noted after total removal of the tumor. The sleep patterns observed were similar to those of experimental animals with lesions of the peri-alpha locus ceruleus. The importance of uncontrolled laughter as a sign of a ventral brain-stem mass is emphasized.

Effect of different doses of aluminium hydroxide on renal deterioration and nutritional state in experimental chronic renal failure.

To investigate the effects of aluminium hydroxide (AH), a phosphate binder, on the progress of chronic renal diseases, high doses (9.6 g/kg/day, group ADR-H), moderate doses (2.4 g/kg/day, group ADR-M), and low doses (1.2 g/kg/day, group ADR-L) of the compound, were orally administered for 34 weeks to rats with Adriamycin (ADR)-induced focal glomerular sclerosis. Serum creatinine and blood urea nitrogen were significantly lower in either group ADR-H or ADR-M than in group ADR at week 34. Urinary protein excretion was significantly lower in group ADR-H than in group ADR in all observation periods and was also lower in group ADR-M than in group ADR at weeks 28 and 32. Both glomerular sclerosis and tubular change were significantly less severe in group ADR-H, while tubular change was less marked in group ADR-M than in group ADR. These results revealed that phosphate depletion was induced, and progressive renal failure was ameliorated in proportion to the dosing of AH. On the other hand, body weight was significantly smaller in group ADR-H than in group ADR in more than half of the observation period. In conclusion, a high dose of AH may adversely affect the nutritional state irrespective of having an extremely protective effect on progress of renal dysfunction. Appropriate doses of AH should be used to prevent the renal deterioration.

[Chemoembolization therapy with lipiodol, cisplatin and etoposide for hepatocellular carcinoma].

Chemoembolization using CDDP, VP-16 and lipiodol was carried out for 7 patients with hepatocellular carcinoma (HCC). CDDP/lipiodol, CDDP/VP-16, CDDP/lipiodol (lipiodol 2-10 ml, CDDP 1-2 mg/kg, VP-16 100 mg/body) and gelatine sponge were administered in that order through the catheter located in the proper, or right or left hepatic artery. Three patients underwent hepatic resection 38-50 days after this treatment. Complete necrosis of the tumor was recognized in the one case, although the portion of necrosis did not exceed 70% in large sized HCC as the diameter of more than 10 cm. In 4 unresectable cases the decreases in tumor size were observed by ultrasonography and computed tomography. The response was: 3 partial responses and 1 no change. One out of 4 cases could undergo hepatic resection 17 months after this treatment. Two patients are alive 20 months after this treatment, although one patient died of HCC after 25 months. Serious side effect was not observed.

Protection by oral phenylalanine against gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats.

The effect of oral administration of L-phenylalanine on the incidence and histology of gastric adenocarcinomas induced by N-methyl-N'-nitro-N-nitrosoguanidine was investigated in inbred Wistar rats. Oral administration of 6% phenylalanine after 25 weeks of treatment with the carcinogen significantly reduced the incidence and number of adenocarcinomas of the glandular stomach at experimental week 52. Oral administration of high dose phenylalanine significantly increased the basal serum gastrin level and significantly decreased the norepinephrine concentration in the antral portion of the gastric wall, as well as the labelling indices of antral mucosa. These findings indicate that orally administered phenylalanine inhibits the development of gastric cancers.

Treatment of hepatocellular carcinoma by transcatheter arterial embolization combined with intraarterial infusion of a mixture of cisplatin and ethiodized oil.

The therapeutic effectiveness of transcatheter arterial embolization (TAE) with intraarterial infusion of cisplatin/ethiodized oil mixture in treatment of resectable and unresectable hepatocellular carcinoma was compared with TAE with intraarterial infusion of doxorubicin mixed with and without ethiodized oil. The series included 97 patients with unresectable hepatocellular carcinoma and 40 patients with resectable hepatocellular carcinoma. With TAE using doxorubicin infusion, a partial response of the tumor was seen in only 11%, and the 2-yr survival was calculated to be only 5%. Histologic examination of the specimens obtained by hepatectomy also showed that this treatment was relatively ineffective in daughter tumor and portal tumor thrombi. In contrast, TAE with infusion of cisplatin/ethiodized oil mixture significantly increased the rate of partial response (38%), and significantly prolonged the 2-yr survival (45%). Histologically this treatment gave severe necrosis in daughter tumors (69%) and tumor thrombi (78%) as well as main tumor (75%). This treatment was significantly better than TAE with doxorubicin and ethiodized oil infusion in terms of the tumor regression and histologic responses of main tumor and portal vein tumor thrombi, but not in terms of the 2-yr survival. However, 2 patients (8%) died within 4 wk of the latter treatment, whereas no deaths were reported after the former treatment. Therefore, TAE combined with intraarterial infusion of cisplatin/ethiodized oil mixture may be a safe and useful treatment modality for hepatocellular carcinoma.

Studies on macrocyclic lactone antibiotics. VII. Structure of a phytotoxin "rhizoxin" produced by Rhizopus chinensis.

A new 16-membered macrolide designated as rhizoxin was isolated as a toxin produced by Rhizopus chinensis, the causal agent of rice seedling blight . The skeletal structure was determined by detailed NMR spectroscopic investigation of this compound and of its derivatives. Rhizoxin induced at a concentration of 10 ng/ml abnormal swelling of rice seedling roots, which is one of the characteristic symptoms of this disease. This compound also exhibited potent antifungal activity but little effect against bacteria.