Both corticotropin-releasing factor receptor type 1 and type 2 are involved in stress-induced inhibition of food intake in rats

Rationale Stress-induced inhibition of food intake is reportedly blocked by a selective corticotropin-releasing factor (CRF) type 1 receptor (CRF₁) antagonist, suggesting the involvement of CRF₁ in the inhibitory mechanism. CRF₁ and CRF₂ are considered to function in the inhibition of food intake by CRF-related peptides with different time courses.Objectives This study was designed to clarify whether CRF₂ is also involved in stress-induced inhibition of food intake and to examine the relation of CRF₁ to CRF₂ in the inhibitory mechanism.Methods Antisauvagine-30 (AS-30), a selective CRF₂ antagonist, and/or CRA1000, a selective CRF₁ antagonist, were pre-administered intracerebroventricularly and intraperitoneally, respectively, to male Wistar rats deprived of food for 24 h before the animals were exposed to a 1-h period of stressors and food intake in 1 h after stress exposure was examined. The effect of both antagonists on locomotor activity was also examined.Results Pre-administration of 5–30 g of AS-30 attenuated inhibition of food intake induced by restraint, electric footshock or emotional stress using a communication box. CRA1000 also attenuated the restraint-induced inhibition of food intake at doses of 5 and 10 mg/kg body weight. The reversal of restraint-induced inhibition of food intake by co-administration of AS-30 and CRA1000 was not larger than that by AS-30 or CRA1000 alone. Both antagonists did not affect locomotor activity.Conclusions These results suggest that not only CRF₁, but also CRF₂, are involved in stress-induced inhibition of food intake, and that both subtypes of CRF receptor function probably in series in 1 h after stress exposure.     

Effects of Decreased Vitamin D and Accumulated Uremic Toxin on Human CYP3A4 Activity in Patients with End-Stage Renal Disease

In patients with end-stage renal disease, not only renal clearance but also hepatic clearance is known to be impaired. For instance, the concentration of erythromycin, a substrate of cytochrome P450 3A4 (CYP3A4), has been reported to be elevated in patients with end-stage renal disease. The purpose of this study is to elucidate the reason for the decrease in hepatic clearance in patients with end-stage renal disease. Deproteinized pooled sera were used to assess the effects of low-molecular-weight uremic toxins on CYP3A4 activity in human liver microsomes and human LS180 cells. Four uremic toxins (3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid, hippuric acid, indole-3-acetic acid, and 3-indoxyl sulfate) present at high concentrations in uremic serum were also studied. Simultaneous treatment of uremic serum (less than 10%) or uremic toxins did not affect testosterone 6β-hydroxylation in human liver microsomes. On the other hand, pretreatment of each serum activates CYP3A4 in LS180 cells, and the increased CYP3A4 activity in uremic serum-treated cells was smaller than normal serum-treated cells. In addition, CYP3A4 and CYP24A1 mRNA levels also increased in LS180 cells exposed to normal serum, and this effect was reduced in uremic serum-treated cells and in cells exposed to uremic serum added to normal serum. Furthermore, addition of 1,25-dihydroxyvitamin D to uremic serum partially restored the serum effect on CYP3A4 expression. The present study suggests that the decrease of 1,25-dihydroxyvitamin D and the accumulation of uremic toxins contributed to the decreased hepatic clearance of CYP3A4 substrates in patients with end-stage renal disease.     

Recent understanding of the molecular mechanisms for the efficacy and resistance of EGF receptor-specific tyrosine kinase inhibitors in non-small cell lung cancer

INTRODUCTION: The epidermal growth factor receptor (EGFR) and its family members are involved in many aspects of tumor biological processes. Aberrant activation of the EGFR tyrosine kinase by mutations or protein overexpression is observed in various types of human cancer, including lung cancer. EGFR tyrosine kinase inhibitors (EGFR-TKIs), such as gefitinib and erlotinib, are highly effective in lung cancer patients who harbor active mutations in the EGFR gene. However, patients who are initially sensitive to EGFR-TKIs eventually relapse within few years. AREAS COVERED: Non-small cell lung cancer (NSCLC) is the most common type of lung cancer and is associated with a high frequency of EGFR mutations. This review describes the EGFR mutations that determine the sensitivity to EGFR-TKIs and the current understanding of the molecular mechanisms of acquired resistance to EGFR-TKIs in NSCLC. Furthermore, the authors describe recent strategies developed to overcome acquired resistance using second-generation EGFR-TKIs and combination therapies with several molecular-targeting drugs. EXPERT OPINION: Although recent findings have contributed to our understanding of the mechanism of acquired resistance and helped the development of novel strategies to overcome such resistance, the underlying mechanisms are complex and additional research is necessary to develop effective therapeutic strategies for individual patients with lung cancer.     

Membrane transport mechanisms of choline in human intestinal epithelial LS180 cells

The aim of the present study was to investigate the membrane transport mechanisms of choline using human intestinal epithelial LS180 cells. The mRNA of choline transporter‐like proteins (CTLs) was expressed significantly in LS180 cells, and the rank order was CTL1 > CTL4 > CTL3 > CTL2 > CTL5. In contrast, the mRNA expression of other choline transporters, organic cation transporter (OCT) 1, OCT2 and high‐affinity choline transporter 1 (CHT1), was considerably lower in LS180 cells. Five mm unlabelled choline, hemicolinium‐3 and guanidine, but not tetraethylammonium, inhibited the cellular uptake of 100 µm choline in LS180 cells. The uptake of choline into LS180 cells was virtually Na⁺‐independent. The uptake of choline was significantly decreased by acidification of the extracellular pH; however, it was not increased by alkalization of the extracellular pH. In addition, both acidification and alkalization of intracellular pH decreased the uptake of choline, indicating that the choline uptake in LS180 cells is not stimulated by the outward H⁺ gradient. On the other hand, the uptake of choline was decreased by membrane depolarization along with increasing extracellular K⁺ concentration. In addition, the Na⁺‐independent uptake of choline was saturable, and the K_m value was estimated to be 108 µm . These findings suggest that the uptake of choline into LS180 cells is membrane potential‐dependent, but not outward H⁺ gradient‐dependent. Copyright © 2014 John Wiley & Sons, Ltd.     

A case of relapsed pulmonary carcinoma showing an interesting chemotherapeutic course

A patient with relapsed primary pulmonary carcinoma (T2N0M0 Stage II adenocarcinoma) showing contralateral metastasis after 4 postoperative years was given Carboquone (CQ), Cisplatin (CDDP) and OK-432, and positive therapeutic results were obtained. However, aggravation ensued and so UFT was given in combination with the above chemotherapy, resulting in repeatedly good results. The details of this case of relapsed pulmonary carcinoma, which was resistant to chemotherapy but showed positive therapeutic results with combined use of UFT, are reported.     

A case of relapsed gastric cancer treated successfully by chemotherapy--lung metastasis and relapsed cancer in the hepatic portal system

A case of relapsed gastric cancer postoperatively presenting obstructive jaundice due to metastases in the hepatic portal and periaortic lymph nodes and multiple lung metastases was given OK-432 continuously i.m. and UFT p.o., and then generally given cisplatin and massive doses of carboquone i.a. intermittently into the peritoneal cavity. The chemotherapy led to complete remission of the obstructive jaundice and disappearance of the metastases in the lungs and lymph nodes.     

Relationship between genetic polymorphisms of alcohol-metabolizing enzymes and changes in risk factors for coronary heart disease associated with alcohol consumption

BACKGROUND: There are large individual variations in the responses of risk factors for coronary heart disease to alcohol consumption. To clarify the factors responsible for these individual variations, we studied the relationship between blood pressure, serum lipids, and uric acid and the genetic polymorphisms of alcohol dehydrogenase (ADH) 2 and aldehyde dehydrogenase (ALDH) 2 in alcohol drinkers. METHODS: We examined 133 male workers who drank >300 g of alcohol per week. Information regarding lifestyle habits was obtained by questionnaire. The ADH2 genotype was determined by PCR and subsequent digestion with MaeIII. The ALDH2 genotype was determined based on amplified product length polymorphisms. RESULTS: When the workers were divided into three groups: the ADH2(1)/2(1), ADH2(1)/2(2), and ADH2(2)/2(2) groups, the mean triglycerides and gamma-glutamyl transpeptidase concentrations were significantly higher in the ADH2(2)/2(2) group than in the ADH2(1)/2(1) group. In addition, multiple logistic regression analysis showed that the frequencies of individuals whose systolic blood pressure, triglycerides, and uric acid values were in the highest one third were significantly higher in the ADH2(2)/2(2) group than in the ADH2(1)/2(1) group. In contrast, no difference was observed between the ALDH2(1)/2(1) and (ALDH2(1)/2(2) + ALDH2(2)/2(2)) groups with regard to the mean value of any variable and to the frequency of individuals with any variable value in the highest one third. CONCLUSION: Individuals with the ADH2(1)/2(1) genotype might suffer fewer negative effects of drinking.     

Development of a novel transdermal patch of alendronate,a nitrogen‐containing bisphosphonate,for the treatment of osteoporosis

Bisphosphonates are widely used for the treatment and prevention of bone diseases, including Paget disease, hypercalcemia of malignancy, and postmenopausal osteoporosis. In this study, we developed a novel transdermal patch of alendronate, a nitrogen‐containing bisphosphonate, for the treatment of bone diseases. The maximum permeation fluxes of alendronate through rat and human skin after application of this patch were 1.9 and 0.3 µg/cm² per hour, respectively. The bioavailability (BA) of alendronate in rats was approximately 8.3% after the application of alendronate patch and approximately 1.7% after oral administration. These results indicated that the transdermal permeation of alendronate using this patch system was sufficient for the treatment of bone diseases. The plasma calcium level was effectively reduced after application of the alendronate patch in 1α‐hydroxyvitamin D₃–induced hypercalcemia model rats. The alendronate patch also effectively suppressed the decrease in bone mass in model rats with osteoporosis. Modest alendronate‐induced erythema of rat skin was observed after application of the alendronate patch. Incorporation of butylhydroxytoluene in the alendronate patch almost completely suppressed this alendronate‐induced skin damage while maintaining the transdermal permeation and pharmacologic effects of alendronate. These findings indicate that our novel transdermal delivery system for alendronate is a promising approach to improve compliance and quality of life of patients in the treatment of bone diseases. © 2010 American Society for Bone and Mineral Research.     

Triacylglycerol deposition with group IVC phospholipase A2 expression in oleate- and linoleate-stimulated Huh-7 hepatocytes

The accumulation of hepatocellular triacylglycerol (TG), a major symptom of fatty liver, is associated with the excessive incorporation of exogenous free fatty acids into hepatocytes, the free fatty acids inducing an increase in TG bearing acyl chains derived from not only themselves but also endogenous fatty acids. However, the mechanisms responsible for the supply of endogenous fatty acids, which are mainly esterified into phospholipids, remain unclear. In the present study, we examined the possible involvement of intracellular phospholipase A(2) (PLA(2))s including group IVA, IVC, VIA, and VIB PLA(2)s, which catalyze the release of endogenous fatty acids, in the deposition of TG in hepatocytes. Stimulation of human hepatoma Huh-7 cells with oleate or linoleate for 48 h increased TG contents time-dependently. Under the conditions, increased expression of group IVC PLA(2) mRNA and protein was observed at 6-12 h and 24-48 h after the stimulation, respectively. However, mRNA levels of group IVA, VIA, or VIB PLA(2) did not change. When cells were treated with methyl arachidonyl fluorophosphonate used as an inhibitor of group IVC PLA(2), the fatty acid-induced deposition of TG was partially but significantly suppressed at 48 h, although no significant inhibition was observed at 24 h. Overexpression of wild-type group IVC PLA(2) but not a catalytically inactive mutant of group IVC PLA(2) tended to increase cellular TG levels. The present findings suggest that stimulation of Huh-7 hepatocytes with free fatty acids induces the expression of group IVC PLA(2), which is involved in the fatty acid-induced deposition of TG.