Effect of Perilla frutescens on nitric oxide production and DNA synthesis in cultured murine vascular smooth muscle cells

The effects of perilla (Perilla frutescens, Labiatae) on murine cultured vascular smooth muscle cells (VSMC) were investigated. The water extract of perilla leaves induced nitric oxide (NO) production of VSMC and this effect was synergistically augmented when combined with interferon (IFN)-gamma or tumour necrosis factor (TNF)-alpha, while the perilla extract significantly inhibited NO production induced by IFN-gamma combined with lipopolysaccharide (LPS). Northern blot analysis revealed that these effects of the perilla extract paralleled mRNA expression of inducible nitric oxide synthase. However, the perilla extract significantly inhibited platelet derived growth factor (PDGF) or TNF-alpha-induced VSMC proliferation measured as DNA synthesis. The inhibitory effect of the perilla extract on TNF-alpha-induced VSMC proliferation was significantly suppressed by N(G)-monomethyl-L-arginine, a non-specific nitric synthase inhibitor, suggesting that this effect was partially mediated by NO production as an autocrine/paracrine factor. The present findings suggest that perilla would be useful for the prevention of vascular diseases such as arteriosclerosis.     

Proteomic study of granulocytic differentiation induced by apigenin 7-glucoside in human promyelocytic leukemia HL-60 cells

Background

Nutritional factors is one of the most important regulators in the progression of cancer. Some dietary elements promote the growth of cancer but others, such as plant-derived compounds, may reverse this process.

Purpose

We tried to investigate yet another approach of cancer prevention through cancer cell differentiation, using a common non-mutagenic flavonoid apigenin 7-glucoside.

Methods

HL-60 cells were treated with or without apigenin 7-glucoside. Cell proliferation was measured by MTT assay, and the cell cycle distribution was estimated by propidium iodide staining of DNA. To determine cellular differentiation, cell surface differentiation markers CD11b and CD14 were used. Two-dimensional gel electrophoresis was then performed to identify proteins that may be important in HL-60 cell differentiation following apigenin 7-glucoside treatment.

Results

Apigenin 7-glucoside inhibited HL-60 cell growth, dose- and time-dependently, but did not cause apoptosis. The distribution of cells at different stages in the cell cycle indicated an accumulation of treated cells in G₂/M phase. Moreover, apigenin 7-glucoside induced granulocytic differentiation of HL-60 cells. Ten proteins that might play essential role in granulocytic differentiation were identified by proteomics.

Conclusions

A complete understanding of the preventive effects of plant-based diet on cancer depends on the mechanisms of action of different plant components on processes. We hope these findings may contribute to the understandings of the different approaches for chemoprevention of cancer.     

Tubulointerstitial damage as the major pathological lesion in endemic chronic kidney disease among farmers in North Central Province of Sri Lanka

Chronic kidney disease of uncertain etiology (CKDu) in North Central Province of Sri Lanka has become a key public health concern in the agricultural sector due to the dramatic rise in its prevalence and mortality among young farmers. Although cadmium has been suspected as a causative pathogen, there have been controversies. To date, the pathological characteristics of the disease have not been reported. Histopathological observations of 64 renal biopsies obtained at Anuradhapura General Hospital from October 2008 to July 2009 were scored according to Banff 97 Working Classification of Renal Allograft pathology. The correlations between the histological observations and clinical parameters were statistically analyzed. Interstitial fibrosis and tubular atrophy with or without nonspecific interstitial mononuclear cell infiltration was the dominant histopathological observation. Glomerular sclerosis, glomerular collapse, and features of vascular pathology such as fibrous intimal thickening and arteriolar hyalinosis were also common. Although hypertension was identified as one of the common clinical features among the cases, it did not influence the histopathological lesions in all the cases. This study concludes that tubulointerstitial damage is the major pathological lesion in CKDu. Exposure(s) to an environmental pathogen(s) should be systematically investigated to elucidate such tubulointerstitial damage in CKDu.     

Discovery of novel 5,5-diarylpentadienamides as orally available transient receptor potential vanilloid 1 (TRPV1) antagonists

We have developed a novel and potent chemical series of 5,5-diphenylpentadienamides for targeting TRPV1 in vitro and in vivo. In this investigation, we examined a variety of replacements for the 5-position of dienamides with the goal of addressing issues related to pharmacokinetics. Our data suggest that substitution with alkoxy groups on the phenyl ring at the 5-position increases their ability to penetrate the blood-brain barrier. This investigation culminated in the discovery of compound (R)-36b, which showed a good pharmacokinetic profile. In vivo, compound (R)-36b was found to be effective at reversing mechanical allodynia in rats in a dose-dependent manner, and it reversed thermal hyperalgesia in a model of neuropathic pain induced by sciatic nerve injury.     

Pharmacokinetic change of nanoparticulate formulation "Lactosome" on multiple administrations

Lactosome, which is a polymer micelle composed of poly(lactic acid)-b-poly(sarcosine), was applied successfully for solid tumor imaging. Lactosome is considered to escape from the reticuloendothelial system recognition, and shows prolonged in vivo blood clearance time. In vivo disposition of Lactosome, however, changed upon multiple dosages. Lactosome at the 2nd dosage was cleared from the blood stream by trapping at liver. This accelerated blood clearance (ABC) phenomenon is explained by production of anti-Lactosome IgM and IgG(3) through the immune response related with B-lymphocyte cells. The memory effect of B-lymphocyte cells lasted nearly for six months in mouse. The epitope moiety of Lactosome is concluded to be poly(sarcosine) based on the competitive inhibition assay. Since the ABC phenomenon was also reported with PEGylated liposome, nanoparticles in general may be potential in triggering the immune system.     

Job characteristics and problems related to home care services for the elderly. A comparison among employment categories in Sapporo

OBJECTIVE: The aims of this study were to describe job characteristics for daytime and shift workers in home care services for the elderly and to clarify health care in the work setting, social support, and job satisfaction and possibilities. METHODS: A self-reported questionnaire was given to 433 home care workers, both full time and part time (more than 15 hours), at 35 institutions that provide home care services to residents of Sapporo (return rate; 80.2%). The following issues were investigated: job content (physical care, assistance with housework, and advice), specialty, job satisfaction, possibilities, job training, health care and social support. The results were compared among employed types: full-time and part-time daytime and shift workers using the t-test or the Fisher's test. RESULTS: The participants demonstrated high dissatisfaction with wages, physical uneasiness themselves and limited social support from their supervisors. Especially full-time workers were dissatisfied with the payment, whereas part-time workers complained about insufficient attention to the prevention of lumbago. It was found that part-time daytime workers were given insufficient on-job-training and education for prevention of infection, and that full-time shift workers greatly wished to leave the employment. However, the home care workers were satisfied with their job itself and expected to continue their work. Furthermore, half of the part-time workers hoped to work full time. CONCLUSIONS: Health management and educational training for part-time workers may be necessary to improve the quality of care services and protection of health. Promotion of full time employment and reconsideration of working condition might be necessary to provide sufficient home care services.     

Role of vitronectin receptor-type integrins and osteopontin in ischemia-induced retinal neovascularization

PURPOSE: It has been reported that vitronectin receptor-type integrins mediate vascular cell proliferation and migration. In this study, we investigated the expression of vitronectin receptor-type integrins and osteopontin in ischemia-induced retinal neovascularization, and examined the role of osteopontin in angiogenesis as a ligand of vitronectin receptor-type integrins. METHODS: Retinal neovascularization was produced by exposing C57BL/6J mice to 75% oxygen from postnatal day (P) 7 to P12. Expression of vitronectin receptor-type integrins and osteopontin was assessed by Northern blot analysis, in situ hybridization, and immunofluorescence. The role of osteopontin in retinal angiogenesis was evaluated by tube formation assay using cultured bovine retinal microcapillary endothelial cells. RESULTS: In the murine model, integrin alpha(v) mRNA was increased from P14 with a 2.6-fold peak response observed on P19, when retinal neovascularization was remarkable. Indirect immunofluorescence for vitronectin receptor-type integrins revealed prominent expression of integrin alpha(v)beta3/beta5 in the neovascular endothelial cells. Osteopontin mRNA was increased from P14, with a 2.0-fold peak response observed on P19. In situ hybridization demonstrated localization of osteopontin mRNA in neovascular tufts. Vascular endothelial growth factor-induced tube formation (8.3 +/- 0.6 mm/field) was inhibited significantly by treatment with anti-osteopontin antibody (4.8 +/- 0.7 mm/field, P <.001). CONCLUSIONS: These data suggest that increased expression of both vitronectin receptor-type integrins and osteopontin in ischemic retina contribute to vascular endothelial cell proliferation and to retinal vascular formation by promoting interaction between endothelial cells and extracellular matrix, which leads to retinal neovascularization.     

In vitro and in vivo potency of polymyxin B against IMP-type metallo-beta-lactamase-producing Pseudomonas aeruginosa

Multidrug-resistant Pseudomonas aeruginosa, especially metallo-beta-lactamase (MBL)-producing P. aeruginosa, is an important pathogen in nosocomial infection and emergence of this pathogen has revived interest in polymyxin B (PMB) and colistin (COL). In this study, we evaluated the efficacies of PMB, COL and other antipseudomonal agents against IMP-type MBL-producing P. aeruginosa both in vitro and in vivo. A total of 75 isolates of bla(IMP)-positive P. aeruginosa obtained from clinical specimens (94.6% of isolates demonstrated resistance to beta-lactam, fluoroquinolone and aminoglycoside agents) were evaluated in the in vitro study. More than 90% of the examined isolates were susceptible to PMB (minimum inhibitory concentration for 50/90% of the isolates (MIC(50)/MIC(90)) 4/4 mg/L), although COL was less potent (MIC(50)/MIC(90) 8/16 mg/L). Cyclophosphamide-treated mice were intraperitoneally inoculated with bla(IMP)-positive P. aeruginosa. Treatment with PMB, but not COL, imipenem/cilastatin or aztreonam, significantly improved the survival rate and decreased the number of bacteria in the blood in a dose-dependent manner. Our results indicate that, among the agents studied, PMB is the most effective agent against bla(IMP)-positive P. aeruginosa.     

Radiation effect on anti-tumor activity of C3H mouse spleen cells to MH134 hepatoma cells]

Tumor-specific immunity was induced in C3H mice by immunizing with syngeneic MH134 hepatoma cells. The radiation sensitivity of tumor-specific effector cells in the immunized spleen cells and that of non-specific effector cells in normal spleen cells were compared. The spleen cells, both immunized and normal, were irradiated in vitro, then mixed with the tumor cells. The anti-tumor activity of the cells was measured by Winn assay and by a cytostatic test in vivo with diffusion chambers, on the basis of growth inhibition of tumor cells. The growth of tumor cells was inhibited by immune spleen cells more effectively than by normal spleen cells. The anti-tumor activity of immunized and normal spleen cells decreased dose-dependently in the respective ranges of 2.5-20 Gy and 2.5-10 Gy irradiation. In the normal spleen cells, anti-tumor activity was mainly detected in the fraction of non-adherent cells, not in adherent cells. The anti-tumor activity of non-adherent cells was diminished with 2.5 Gy irradiation. These results indicated that the radio-resistance of anti-tumor effector cells in C3H mice was increased by immunization with syngeneic MH134 hepatoma cells. Based on these and other findings in this experimental system, we concluded that tumor-specific effector cells that were radiosensitive at 10-20 Gy might involve delayed-type hypersensitivity (DTH) effector cells (macrophages) and that non-specific effector cells that were radiosensitive at 2.5-10 Gy might involve natural killer cells and lymphokine-activated killer cells.     

Effects of inhibitors of nonselective cation channels on the acetylcholine-induced depolarization of circular smooth muscle from the guinea-pig stomach antrum.

In circular smooth muscle bundles isolated from the guinea-pig stomach antrum, the effects of quinidine, Ni2+, flufenamic acid, niflumic acid, La3+, SKF-96365 and 4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS) on acetylcholine (ACh)-induced depolarization were investigated. Recording membrane potentials from smooth muscle cells with intracellular microelectrodes revealed that ACh (1 microM) depolarized the membrane by 5-8 mV and increased the amplitude and frequency of slow potentials. These effects were inhibited by atropine. Quinidine (10 microM) increased the amplitude of ACh-induced depolarization, with no alteration to the properties of slow potentials. Ni2+ (50 microM) transiently (5-10 min) depolarized the membrane by about 5 mV, with an associated increase in frequency and amplitude of slow potentials. In the stabilized condition with Ni2+, the amplitude of ACh-induced depolarization remained unchanged. Flufenamic acid (10 microM) inhibited the generation of slow potentials, with no change in either the amplitude of ACh-induced depolarization or of the amplitude and frequency of slow potentials generated during ACh stimulation. A high concentration of flufenamic acid (100 microM) depolarized the membrane and increased the amplitude of ACh-induced depolarization. Niflumic acid (10 microM) hyperpolarized the membrane and increased the amplitude and frequency of slow potentials and also the amplitude of ACh-induced depolarization. DIDS (100 microM) hyperpolarized the membrane and inhibited the amplitude and frequency of slow potentials, with no alteration to the amplitude of ACh-induced depolarization. SKF-96365 (3-50 microM) depolarized the membrane in a concentration-dependent manner, but did not change the level of ACh-induced depolarization. La3+ (50 microM) did not alter the properties of the slow potentials or the ACh-induced responses. These results provide evidence that ACh-induced depolarization is not inhibited by chemicals known to inhibit non-selective cation channels. We suggest that muscarinic receptor-mediated signal transduction may be different in smooth muscle and interstitial cells.