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.     

Comparison of chemotherapeutic efficacy between LCNEC diagnosed using large specimens and possible LCNEC diagnosed using small biopsy specimens

Background

It is often difficult to diagnose large cell neuroendocrine carcinomas (LCNEC) of the lung using small biopsy specimens. Some recent studies attempted to diagnose LCNEC using biopsy specimens; in 2011, the International Association for the Study of Lung Cancer pathological panels suggested possible LCNEC as a diagnosis for LCNEC by using biopsy specimens. Here, we compared the chemotherapeutic efficacy in possible LCNEC and LCNEC diagnosed using surgically resected specimens.

Methods

We retrospectively reviewed patients who received platinum-based chemotherapy as first-line chemotherapy at our institution during September 2002–September 2011. Further, we compared the clinical characteristics, chemotherapeutic responses, and survival outcomes of patients diagnosed as having “LCNEC definite” with those diagnosed as having “possible LCNEC.”

Results

We selected 34 patients of whom 10 were diagnosed with LCNEC using surgically resected specimens and 24 patients with possible LCNEC were diagnosed using small biopsy specimens. In both groups, almost all patients were men and were smokers. Small-cell carcinoma-based chemotherapy, such as platinum plus irinotecan or platinum plus etoposide, was used for treating 60 % LCNEC patients (6/10) and 67 % possible LCNEC patients. In the LCNEC and possible LCNEC groups, respectively, the response rate was 70 and 54 % (p = 0.39), median progression-free survival was 2.9 and 4.4 months (p = 0.20), and median survival time was 12.8 and 9.1 months (p = 0.50).

Conclusion

No statistically significant differences were found in chemotherapeutic responses and survival outcomes between the 2 groups, which suggests that chemotherapeutic efficacy is similar in both possible LCNEC and LCNEC.     

Simple prediction of right ventricular ejection fraction using tricuspid annular plane systolic excursion in pulmonary hypertension

The present study examined whether tricuspid annular plane systolic excursion (TAPSE) can simply predict right ventricular ejection fraction (RVEF) in patients with pulmonary hypertension (PH). The TAPSE cut-off value to predict reduced RVEF was also evaluated. The association between TAPSE and cardiac magnetic resonance imaging (CMRI)-derived RVEF was examined in 53 PH patients. The accuracy of the prediction equation to calculate RVEF using TAPSE was also evaluated. In PH patients, TAPSE was strongly correlated with CMRI-derived RVEF in PH patients (r = 0.86, p < 0.0001). We then examined the accuracy of the two equations: the original regression equation (RVEF = 2.01 × TAPSE + 0.6) and the simplified prediction equation (RVEF = 2 × TAPSE). Bland–Altman plot showed that the mean difference ± limits of agreement was 0.0 ± 10.6 for the original equation and ?0.6 ± 10.6 for the simplified equation. Intraclass correlation coefficient was 0.84 for the original and 0.82 for the simplified equation. Normal RVEF was considered to be ≥40 % based on the data from 53 matched controls, and the best TAPSE cut-off value to determine reduced RVEF (<40 %) was calculated to be 19.7 mm (sensitivity 88.9 %, specificity 84.6 %). A simple equation of RVEF = 2 × TAPSE enables easy prediction of RVEF using TAPSE, an easily measurable M-mode index of echocardiography. TAPSE of 19.7 mm predicts reduced RVEF in PH patients with clinically acceptable sensitivity and specificity.     

Drug Screening for ALS Using Patient-Specific Induced Pluripotent Stem Cells

Amyotrophic lateral sclerosis (ALS) is a late-onset, fatal disorder in which the motor neurons degenerate. The discovery of new drugs for treating ALS has been hampered by a lack of access to motor neurons from ALS patients and appropriate disease models. We generate motor neurons from induced pluripotent stem cells (iPSCs) from familial ALS patients, who carry mutations in Tar DNA binding protein-43 (TDP-43). ALS patient-specific iPSC-derived motor neurons formed cytosolic aggregates similar to those seen in postmortem tissue from ALS patients and exhibited shorter neurites as seen in a zebrafish model of ALS. The ALS motor neurons were characterized by increased mutant TDP-43 protein in a detergent-insoluble form bound to a spliceosomal factor SNRPB2. Expression array analyses detected small increases in the expression of genes involved in RNA metabolism and decreases in the expression of genes encoding cytoskeletal proteins. We examined four chemical compounds and found that a histone acetyltransferase inhibitor called anacardic acid rescued the abnormal ALS motor neuron phenotype. These findings suggest that motor neurons generated from ALS patient-derived iPSCs may provide a useful tool for elucidating ALS disease pathogenesis and for screening drug candidates.     

A case of Mycobacterium intracellulare pulmonary infection with vertebral osteomyelitis

A 78-year-old woman seen in June 2005 for chest abnormal shadows after 3 months of steroid therapy for vasculitis associated with antineutrophil cytoplasmic autoantibodies was found in chest computed tomography (CT) revealed bronchiectasis and small nodules in the right middle lobe and left lingula. Sputum cultures were positive for Mycobacterium intracellulare. Based on a diagnosis of pulmonary nontuberculous mycobacteriosis, the woman underwent antimycobacterial therapy with clarithromycin, rifampicin, and ethambutol hydrochloride for 10 months. She was then admitted in June 2009 with right chest pain. Chest CT showed consolidation shadows with bronchiectasis in the right middle lobe and the left lingula and left pleural effusion. Magnetic resonance imaging (MRI) showed that Th7-Th8 vertebral bodies had collapsed. A vertebral body specimen obtained by CT-guided biopsy was positive for M. intracellulare. Based on a diagnosis of vertebral osteomyelitis due to M. intracellulare, she underwent antimycobacterial therapy with clarithromycin (800 mg), rifampicin (450 mg), ethambutol hydrochloride (750 mg), and streptomycin (750 mg). After 4 weeks of antimycobacterial therapy, she underwent radical debridement and decompression surgery with anterior and posterior spinal fusion. Four weeks postoperatively, streptomycin was discontinued. We continued clarithromycin, rifampicin, and ethambutol hydrochloride for 18 months, and no recurrence was detected. Although vertebral osteomyelitis due to nontuberculous mycobacteria is rare, clinicians should consider the combination of nontuberculous mycobacteriosis and vertebral osteomyelitis in cases such at these.     

Comparison of the efficacy between paroxetine and sertraline augmented with aripiprazole in patients with refractory major depressive disorder

Objective

Only two-thirds of depressive patients respond to antidepressant treatment. In recent years, addition of an atypical antipsychotic drug to ongoing treatment with an antidepressant has been considered effective and well-tolerated. In the present study, we compared the efficacy between paroxetine and sertraline augmented with aripiprazole in patients with refractory major depression.

Subjects and methods

Twenty-four patients who met the DSM-IV criteria for major depressive disorder who did not at least two different classes of antidepressants were enrolled in the study. Nine were male and thirteen were female, and their ages ranged from 28 to 66 (mean ± SD = 39 ± 12) years. Patients were prescribed paroxetine (n = 11) or sertraline (n = 13) for 4 weeks. Then, those whose scores on the 17-item Hamilton Rating Scale for Depression (HAMD17) decreased below 50% received adjunctive therapy of aripiprazole for 4 weeks.

Results

Although the use of either combination treatment decreased the HAMD17 scores compared to the respective monotherapy, there was no significant difference in HAMD17 scores between the paroxetine plus aripiprazole group and sertraline plus aripiprazole group.

Conclusion

Aripiprazole augmentation therapy with paroxetine or sertraline was equally effective and tolerated in patients with refractory major depressive order.     

B-cell populations are expanded in breast cancer patients compared with healthy controls

Background

Historically, humoral immunity was considered unimportant in anti-tumor immunity, and the differentiation and anti-tumor activity of B cells in breast cancer are poorly understood. However, it was recently discovered that B cells participate in tumor immunity through both antibody production and immunosuppressive mechanisms. We analyzed the expression of B-cell differentiation markers in detail using fluorescence-activated cell sorting to investigate the relationship between B-cell subsets and breast cancer etiology.

Methods

Blood samples were taken from breast cancer patients and healthy donors, and peripheral blood mononuclear cells were collected. B cells at various stages of differentiation were identified by the expression of combinations of the cell surface markers CD5, CD19, CD21, CD24, CD27, CD38, CD45, and IgD. Statistical analysis of the proportions of each B-cell subtype in the different patient groups was then performed.

Results

Twenty-seven breast cancer patients and 12 controls were considered. The proportion of total B cells was significantly higher in cancer patients than in controls (11.51 ± 2.059 vs 8.905 ± 0.379%, respectively; p = 0.001). Breast cancer patients were then classified as High-B or Low-B for further analysis. A significantly higher proportion of memory B cells was found in the High-B group than in the Low-B or control groups (p = 0.003 and p = 0.043, respectively).

Conclusions

Breast cancer patients generally have a higher proportion of B cells than healthy controls, but this is highly variable. Analysis of the major B-cell surface markers indicates that memory B cells in particular are significantly expanded, or more robust, in breast cancer patients.

     

Spatiotemporal characteristics of the neural activities processing consonant/dissonant tones in melody

To identify neural correlates underlying melody processing, we measured MEG responses elicited by keynote and out-of-key tones at the end of musical phrases. These melodies were newly composed and unknown to the subjects. Significant enlargements of N1m/P2m peaks at about 120–160 ms were observed in response to dissonant (out-of-key) tones compared to those in response to consonant (keynote) tones. The equivalent current dipoles (ECD) of the N1m were localized in areas centered at bilateral primary auditory cortices in the superior surface of the temporal lobe. Following the N1m/P2m, a late component occurring at 280–530 ms was observed. As the latency proceeded, the location of ECD sources of the late component shifted in the right hemisphere, but not in the left hemisphere, from the supratemporal auditory cortex to a posterior inferior auditory association cortex around the superior temporal sulcus (STS). The grand mean locations of the ECDs for consonant and dissonant tones were separated at a peak period of 380–410 ms of the late component but converged to the same region around the STS in the last period of 440–530 ms. These observations suggest that the neural activities generating the N1m component in the bilateral auditory cortices may play a role in automatic detection of tonality mismatch based on the pitch analysis. The activities of the late component around the posterior part of the right STS are thought to be involved in the analysis of pitch-sequence, such as how the pitch changes temporally, as a pre-process of melody perception.     

Targeting lipid metabolism in the treatment of hepatitis C virus infection

Recently, microdomains of organelle membranes rich in sphingomyelin and cholesterol (called "lipid rafts") have been considered to act as a scaffold for the hepatitis C virus (HCV) replication complex. Using the HCV cell culture system, we investigated the effect of myriocin, a sphingomyelin synthesis inhibitor, on HCV replication. We also investigated the combined effect of myriocin with interferon (IFN) and myriocin with simvastatin. Myriocin suppressed replication of both a genotype 1b subgenomic HCV replicon (Huh7/Rep-Feo) and genotype 2a infectious HCV (JFH-1 HCV) in a dose-dependent manner (for subgenomic HCV-1b, maximum of 79% at 1000 nmol/L; for genomic HCV-2a, maximum of 40% at 1000 nmol/L). Combination treatment with myriocin and IFN or myriocin and simvastatin attenuated HCV RNA replication synergistically in Huh7/Rep-Feo cells. Our data demonstrate that the sphingomyelin synthesis inhibitor strongly suppresses replication of both the subgenomic HCV-1b replicon and the JFH-1 strain of genotype 2a infectious HCV, indicating that lipid metabolism could be a novel target for HCV therapy.