Interaction of hydrophobic components in female urine before and after childbirth with P-glycoprotein in vitro

The first urine in the morning (total 15 samples) and whole day urine (total 4 days, 17 samples) were collected from a young healthy woman during the pregnancy and lactation period, to examine the possible interactions of urine components (methanol extracts) with P-glycoprotein (P-gp) and multidrug resistance-associated proteins (MRPs). The interaction was evaluated by measuring the intracellular accumulation of rhodamine123, a P-gp substrate, in LLC-GA5-COL150 cells, or calcein, an MRP substrate, in Caco-2 cells in the absence and presence of urine components. Four first urine samples out of 12 collected before childbirth and one sample out of three collected after childbirth suppressed P-gp function significantly. The effect of pregnancy and lactation on P-gp inhibitory potencies of urine components was not observed. The whole day urine samples showed a clear circadian rhythm, in which three first urine samples in the morning out of four showed greater P-gp inhibitory potencies than other daytime samples. Interaction of urine components with MRPs was not detected. In conclusion, the concentration of endogenous P-gp inhibitor(s) was higher in the first urine in the morning, showing a clear circadian rhythm. Normal pregnancy and lactation appeared not to significantly affect the P-gp inhibitory potencies of urine components.

Hepatitis C virus (HCV) reactivation caused by steroid therapy for dermatomyositis

A Japanese woman was treated with injectable methylprednisolone and oral prednisolone for dermatomyositis. On admission, her serum was positive for anti-hepatitis C virus (HCV) antibodies, although HCV RNA was undetectable on polymerase chain reaction. Glucocorticoid therapy improved the dermatomyositis; however, the serum alanine aminotransferase levels rapidly increased, with positive serum HCV RNA and a high viral titer. Both parameters decreased in association with prednisolone tapering, whereas dermatomyositis subsequently recurred and the administration of glucocorticoid therapy was repeated. The serum alanine aminotransferase and HCV RNA levels subsequently increased in a similar manner to that observed after the first course of therapy. Liver enzymes and the viral load should be monitored in anti-HCV-positive patients receiving immunosuppressives, even if serum HCV RNA is negative.

Abstract P3-01-01: Targeting glutamine metabolism in breast cancer for therapy

Metabolic reprogramming of cancer cells is observed in different types of tumors including breast. Oncogenic signals aid changes in metabolism that provide selective advantage to the cancer cells to meet their energy requirements to accomplish rapid proliferation. The increased dependence on the glycolytic pathway for energy called the “Warburg effect” was reported by Otto Warburg several decades ago. Our recent understanding of cancer metabolism has thrown light on alternative energy sources, especially glutamine and other branched chain amino acids. The role of glutamine in breast cancer cell growth has not yet been studied extensively.

In this study we found that a number of breast cancer cell lines, especially those negative for ER, PR, HER2, display a high dependence on glutamine for their survival and growth. Interestingly, most of these glutamine-dependent cell lines express high levels of c-myc protein. Consistent with their growth dependency on glutamine, transaminases responsible for entry of glutamine into the tricarboxylic acid cycle are transcriptionally up regulated under low glutamine conditions. Consequently, growth of these cancer cell lines was found to be specifically inhibited by the transaminase inhibitor, amino oxyacetate (AOA). Moreover, the AOA mediated cytotoxic effect was partially c-myc dependent. Through 1H-NMR studies of AOA-treated cells we show that in addition to glutamine, AOA treatment decreases the aspartate and alanine content in the cells. In line with these findings, exogenous supplementation with aspartate partially rescued the cells from the growth inhibitory effects of AOA. Flow cytometry analysis showed that AOA causes cell cycle arrest in the S phase. AOA also had significant inhibitory effect on in vivo growth of rapidly growing SUM 149 and SUM159 xenografts in immunodeficient mice. When combined with chemotherapeutic agents, doxorubicin and carboplatin, AOA inhibited growth of MDA-MB-231 xenograft tumors more effectively than AOA alone. Lastly we present evidence that the cytotoxic effect of AOA is mediated through activation of the ER stress pathway, combined with depletion of key amino acids and likely, a reduction in the nucleoside pool in the cells. Our preclinical studies, both in vitro and in vivo, combined with development of intermediate markers of response, provide a strong rationale for testing AOA for therapy in Phase 0 clinical trials.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-01-01.

Second hepatectomy for recurrent hepatocellular carcinoma achieved sustained virological response to interferon therapy for hepatitis C

BACKGROUND/AIMS

Interferon (IFN) improves the prognosis of HCV-related hepatocellular carcinoma (HCC) in patients. However, the effects of IFN therapy for second hepatectomy (Hx) for recurrent HCC have not been established.

METHODOLOGY

Subjects included 96 patients who underwent a second Hx for recurrence of HCV-related HCC. Forty-four patients received IFN therapy past or postoperatively of the first Hx. Twenty of those patients attained a sustained viral response (SVR). The other 24 were non-responders (NR) and 52 patients who had not received IFN therapy (non-IFN) were classified as the NR/non-IFN group.

RESULTS

Overall survival (SVR group vs. NR/non-IFN group: 5-yr, 91.7 vs. 51.0%; p = 0.012) and disease-free survival (SVR group vs. NR/non-IFN group: 3-yr, 64.7 vs. 25.9%; p = 0.006) rates were significantly different in both groups. By multivariate analysis, NR/non-IFN therapy, was the independent risk factor for overall survival (p = 0.025) and disease-free survival (p = 0.006) after second Hx.

CONCLUSIONS

SVR achieved past or postoperatively of the first Hx of HCV-related HCC significantly inhibits recurrence and consequently improves patient survival after second Hx for recurrent HCC. Patients with SVR to IFN therapy would be good candidates for second Hx for recurrent HCC.

Cosmic-ray positron energy spectrum measured by PAMELA

Precision measurements of the positron component in the cosmic radiation provide important information about the propagation of cosmic rays and the nature of particle sources in our Galaxy. The satellite-borne experiment PAMELA has been used to make a new measurement of the cosmic-ray positron flux and fraction that extends previously published measurements up to 300 GeV in kinetic energy. The combined measurements of the cosmic-ray positron energy spectrum and fraction provide a unique tool to constrain interpretation models. During the recent solar minimum activity period from July 2006 to December 2009, approximately 24,500 positrons were observed. The results cannot be easily reconciled with purely secondary production, and additional sources of either astrophysical or exotic origin may be required.

Intratumoral concentration of estrogens and clinicopathological changes in ductal carcinoma in situ following aromatase inhibitor letrozole treatment

Background:

Estrogens have important roles in ductal carcinoma in situ (DCIS) of the breast. However, the significance of presurgical aromatase inhibitor treatment remains unclear. Therefore, we examined intratumoral concentration of estrogens and changes of clinicopathological factors in DCIS after letrozole treatment.

Methods:

Ten cases of postmenopausal oestrogen receptor (ER)-positive DCIS were examined. They received oral letrozole before the surgery, and the tumour size was evaluated by ultrasonography. Surgical specimens and corresponding biopsy samples were used for immunohistochemistry. Snap-frozen specimens were also available in a subset of cases, and used for hormone assays and microarray analysis.

Results:

Intratumoral oestrogen levels were significantly lower in DCIS treated with letrozole compared with that in those without the therapy. A great majority of oestrogen-induced genes showed low expression levels in DCIS treated with letrozole by microarray analysis. Moreover, letrozole treatment reduced the greatest dimension of DCIS, and significantly decreased Ki-67 and progesterone receptor immunoreactivity in DCIS tissues.

Conclusion:

These results suggest that estrogens are mainly produced by aromatase in DCIS tissues, and aromatase inhibitors potently inhibit oestrogen actions in postmenopausal ER-positive DCIS through rapid deprivation of intratumoral estrogens.

The role of trigeminal nasal TRPM8-expressing afferent neurons in the antitussive effects of menthol

The cold-sensitive cation channel TRPM8 is a target for menthol, which is used routinely as a cough suppressant and as an additive to tobacco and food products. Given that cold temperatures and menthol activate neurons through gating of TRPM8, it is unclear how menthol actively suppresses cough. In this study we describe the antitussive effects of (-)-menthol in conscious and anesthetized guinea pigs. In anesthetized guinea pigs, cough evoked by citric acid applied topically to the tracheal mucosa was suppressed by menthol only when it was selectively administered as vapors to the upper airways. Menthol applied topically to the tracheal mucosa prior to and during citric acid application or administered continuously as vapors or as an aerosol to the lower airways was without effect on cough. These actions of upper airway menthol treatment were mimicked by cold air delivered to the upper airways but not by (+)-menthol, the inactive isomer of menthol, or by the TRPM8/TRPA1 agonist icilin administered directly to the trachea. Subsequent molecular analyses confirmed the expression of TRPM8 in a subset of nasal trigeminal afferent neurons that do not coincidently express TRPA1 or TRPV1. We conclude that menthol suppresses cough evoked in the lower airways primarily through a reflex initiated from the nose.

Domino model for geomagnetic field reversals

We solve the equations of motion of a one-dimensional planar Heisenberg (or Vaks-Larkin) model consisting of a system of interacting macrospins aligned along a ring. Each spin has unit length and is described by its angle with respect to the rotational axis. The orientation of the spins can vary in time due to spin-spin interaction and random forcing. We statistically describe the behavior of the sum of all spins for different parameters. The term "domino model" in the title refers to the interaction among the spins. We compare the model results with geomagnetic field reversals and dynamo simulations and find strikingly similar behavior. The aggregate of all spins keeps the same direction for a long time and, once in a while, begins flipping to change the orientation by almost 180 degrees (mimicking a geomagnetic reversal) or to move back to the original direction (mimicking an excursion). Most of the time the spins are aligned or antialigned and deviate only slightly with respect to the rotational axis (mimicking the secular variation of the geomagnetic pole with respect to the geographic pole). Reversals are fast compared to the times in between and they occur at random times, both in the model and in the case of the Earth's magnetic field.

Identification and phenology of Hyalesthes obsoletus (Hemiptera: Auchenorrhyncha: Cixiidae) nymphal instars

Urtica dioica and Convolvulus arvensis are the main host plants of Hyalesthes obsoletus and play an important role in the epidemiology of Bois noir of grapevines. The earliest survey, which was carried out to compare the phenology of nymphal instars on U. dioica and C. arvensis, had highlighted some problems in the identification of the instars. Therefore, the correct identification of nymphs to species and instar level became a preliminary aim of this research. Adults and nymphs attributable to H. obsoletus were collected during 2008-2010 in three flatland vineyard habitats of northern Italy on U. dioica, C. arvensis and Artemisia verlotorum. Nymphs and morphologically identified adults of H. obsoletus were submitted to molecular identification. Morphometric and morphological studies were carried out on nymphs collected in the field or obtained in laboratory rearings. Molecular methods not only confirmed the identity of adults, but also allowed the assignment of the nymphs to this species. Morphometric and morphological characteristics (e.g. body and head-thoracic lengths, number of thoracic pits) showed the existence of five nymphal instars. Morphometric differences between newly hatched and older first-instar nymphs were observed. A key to distinguish the five instars was proposed. Evident differences between H. obsoletus nymphs studied here and elsewhere were identified. According to differences in adult-flight period, an earlier phenology of nymphs on C. arvensis than on U. dioica was observed. In particular, the typical overwintering instar was the second on U. dioica and the third on C. arvensis.

Determinants of the clinical outcome of patients with severe acute exacerbation of chronic hepatitis B virus infection

BACKGROUND

Severe acute exacerbation of chronic hepatitis B can sometimes occur and lead to hepatic failure and death. The objective of this study was to elucidate the predictors of progression to hepatic decompensation during severe acute exacerbation.

METHODS

We prospectively analyzed 37 consecutive patients with acute exacerbation of chronic hepatitis B (accompanied by jaundice and coagulopathy) for clinical outcome and factors that influenced the development of severe acute exacerbation, including viral kinetics.

RESULTS

Fourteen (37.8%) patients progressed to severe acute exacerbation (accompanied by encephalopathy). Multivariate analysis identified serum bilirubin (>5 mg/dl, P = 0.002) as a significant determinant of progression to hepatic failure and prothrombin activity (<45%, P = 0.028) and as a determinant of liver-related death. The hepatitis B virus (HBV) DNA level before therapy was measured in 25 patients. HBV DNA levels increased or did not change from before commencement of treatment in all 11 patients who progressed to severe acute exacerbation. On the other hand, HBV DNA levels did not change or increased in 8 of 14 patients (57%) with acute exacerbation (P = 0.02).

CONCLUSIONS

Serum bilirubin and prothrombin activities were significant predictors of clinical outcome in patients with severe acute exacerbation of chronic hepatitis B. Viral kinetics until commencement of therapy can predict the severity of acute exacerbation of chronic hepatitis B.

Characterization of intestinal absorption of quinidine, a P-glycoprotein substrate, given as a powder in rats

The characteristics of intestinal absorption of quinidine, a P-glycoprotein (P-gp) substrate in biopharmaceutics classification system (BCS) Class I, after oral administration as a powder in No. 9 HPMC capsule (diameter 2.6 mm; length 8.4 mm, volume 25 microl) was examined in rats from the following viewpoints: (i) main absorption site of quinidine, (ii) effect of dosage amounts (or luminal concentrations) of quinidine (10 mg vs 0.1 mg/kg), (iii) contribution of P-gp in quinidine absorption (0.1 mg/kg), and (iv) effect of gastric pH on quinidine absorption. Quinidine administered orally at a dose of 10 mg/kg was discharged from the stomach steadily with time and disappeared rapidly from the proximal intestine, where P-gp expression was low. In contrast, quinidine administered at a dose of 0.1 mg/kg remained longer in the gastrointestinal lumen than that administered at a dose of 10 mg/kg. The pretreatment with cyclosporine A, a P-gp inhibitor, greatly increased the intestinal absorption of quinidine given at a dose of 0.1 mg/kg. The gastric pH in untreated control rats was pH 3.6, and the treatment with ranitidine (10mg/kg, ip), a H2 blocker, increased to pH 6.4. The recovered amounts of quinidine 30 min after administration were 21.1% of dose in control rats and 94.7% in ranitidine-treated rats. The value of plasma AUC(0-6h) of quinidine in ranitidine-treated rats was about 40% that in untreated control rats. In conclusion, quinidine was rapidly and efficiently absorbed at the proximal intestine under ordinary circumstances. However, the oral bioavailability was modulated by various factors including the dose (or luminal concentration at the absorption site), presence of P-gp inhibitors, and gastrointestinal pH.

A massive basal cell adenocarcinoma of the palatal minor salivary gland that progressed into the pterygopalatine fossa

Basal cell adenocarcinoma (BCAC) is a rare malignant neoplasm in the salivary glands and BCAC of the minor salivary glands is exceedingly rare. Only nine cases of palatal BCACs of the minor salivary gland have been reported. BCAC is a low-grade malignant tumour which shares many histologic characteristics with basal cell adenoma. Histological differentiation between the two is difficult and they are often discriminated only by invasion of local structures or by perineural or vascular invasive figures. The authors describe the case of a 69-year-old man with a massive BCAC of a palatal minor salivary gland that progressed into the nasal cavity and pterygopalatine fossa and was treated by a subtotal maxillectomy. This is a highly locally advanced case which required a wider surgical excision range than other previously reported BCAC cases of the palatal minor salivary glands. In this case, the proper diagnosis could not be made by local biopsy alone. It should be kept in mind that it may be difficult to distinguish BCAC from basal cell adenoma by microscopic examination of biopsy specimens alone.

Increased prevalence of Kaposi΄s sarcoma-associated herpesvirus in the Kaposi΄s sarcoma-endemic area of western Kenya in 1981-2000

Kaposi΄s sarcoma (KS) had been endemic in Africa before the appearance of human immunodeficiency viruses (HIV) in 1985. Incidence of African KS has increased over the time and the risk of contracting KS become greater in HIV-positive as opposed to HIV-negative individuals. KS specimens were collected in 1981-2000 from 228 surgical cases originating from a KS-endemic area of Western Kenya and examined for Kaposi΄s sarcoma-associated herpesvirus (KSHV) by an immunoperoxidase assay. The results showed that the specimens from 1981-1985 (before the HIV epidemic) were KSHV-positive in 10.3% in contrast to the KSHV positivity of 50.1-63.5% in 1986-2000. The linear increase of KSHV positivity in 1981-2000 was statistically significant. The most plausible explanation for the increased prevalence of KSHV in KS cases is that the endemic KS has changed to the epidemic one.

Measurement of radon concentration in water using the portable radon survey meter

A measurement method for measuring radon in water using the portable radon survey meter (RnSM) was developed. The container with propeller was used to stir the water samples and release radon from the water into the air in a sample box of the RnSM. In this method, the measurement of error would be <20 %, when the radon concentration in the mineral water was >20 Bq l(-1).

Cosmic-ray electron flux measured by the PAMELA experiment between 1 and 625 GeV

Precision measurements of the electron component in the cosmic radiation provide important information about the origin and propagation of cosmic rays in the Galaxy. Here we present new results regarding negatively charged electrons between 1 and 625 GeV performed by the satellite-borne experiment PAMELA. This is the first time that cosmic-ray e⁻ have been identified above 50 GeV. The electron spectrum can be described with a single power-law energy dependence with spectral index -3.18 ± 0.05 above the energy region influenced by the solar wind (> 30 GeV). No significant spectral features are observed and the data can be interpreted in terms of conventional diffusive propagation models. However, the data are also consistent with models including new cosmic-ray sources that could explain the rise in the positron fraction.

Modulation in concentrative nucleoside transporters-mediated intestinal absorption of mizoribine, an immunosuppressive agent, in lipopolysaccharide-treated rats

The characteristics of intestinal absorption of mizoribine and cephalexin, that are mediated by concentrative nucleoside transporters (CNTs) and PEPT1, respectively, was examined in lipopolysaccharide (LPS)-treated rats. LPS treatment is known to modify the expression of some transporters and induce cholestasis. At 24 h after the LPS treatment, averaged concentrations of IL-6 and total bile acids in plasma were 15-fold and 2-fold that in untreated control rats, respectively, and bile flow rate decreased by 40% of control, indicating the induction of inflammatory and cholestatic states. The oral bioavailability, estimated by urinary excretion percentage of unchanged form, of mizoribine in LPS-treated rats was 1.5-fold higher than that in control rats, whereas the bioavailability of cephalexin remained unchanged. When mizoribine and cephalexin were administered into in-situ jejunum loops, there were no differences in the absorption rates between control and LPS-treated rats. These results indicated that the functional expression of CNT1, CNT2, and PEPT1 were not modulated by LPS treatment. When mizoribine (a CNT1/CNT2 substrate) and gemcitabin (a CNT1 substrate) were administered as a solution dissolved in bile into the intestinal loop, their absorption rates decreased significantly. In contrast, the absorption rate of ribavirin (a CNT2 substrate) remained unchanged. In conclusion, LPS treatment exerted no significant effect on the expression of CNT1 and CNT2 in the intestine. Bile was found to suppress the CNT1-mediated intestinal absorption of mizoribine and gemcitabin. The increased oral bioavailability of mizoribine in LPS-treated rats could be ascribed to the less amount of bile or bile acids in the intestine under cholestatic state of rats.