Contrast-enhanced MR cholangiography: comparison of Gd-EOB-DTPA and Mn-DPDP in healthy volunteers

OBJECTIVE

The purpose of this study was to compare the biliary enhancement dynamics of gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic-acid (Gd-EOB-DTPA) and mangafodipir trisodium (Mn-DPDP) for contrast-enhanced MR cholangiography (MRC) in healthy subjects.

METHODS

15 healthy volunteers underwent MRI at 1.5 T with volumetric interpolated breath-hold examination sequence. Each volunteer was scanned once for each contrast agent. The signal-to-noise ratio (SNR) of the liver parenchyma and common hepatic duct (CHD) and the contrast-to-noise ratio (CNR) of CHD to liver parenchyma were evaluated and compared before and at several time points (5, 15, 30, 45, 60, 90, and 120 min) after injection of each agent.

RESULTS

SNR was significantly higher for Gd-EOB-DTPA than for Mn-DPDP in liver parenchyma after 5 min and in CHD after 15 min (p<0.05). CNR of CHD to liver parenchyma using Gd-EOB-DTPA showed an initial decrease at 5 min post-injection followed by a steep increase to a peak at 15 min post-injection. CNR using Mn-DPDP showed a steady increase to a peak at 15 min post-injection without an initial decrease. At 15 min, the value of CNR was significantly higher for Gd-EOB-DTPA than for Mn-DPDP (p<0.05).

CONCLUSION

For both contrast agents, CNR reached a peak at 15 min after contrast injection. At this time point, CNR of Gd-EOB-DTPA was significantly higher than that of Mn-DPDP. Therefore, Gd-EOB-DTPA may provide better contrast-enhanced MRC than Mn-DPDP at 15 min after contrast administration.

Patterns of missing mini mental status exam (MMSE) in radiation therapy oncology group (RTOG) brain cancer trials

The Mini Mental Status Exam (MMSE) instrument has been commonly used in the Radiation Therapy Oncology Group (RTOG) to assess mental status in brain cancer patients. Evaluating patient factors in relation to patterns of incomplete MMSE assessments can provide insight into predictors of missingness and optimal MMSE collection schedules in brain cancer clinical trials. This study examined eight RTOG brain cancer trials with ten treatment arms and 1,957 eligible patients. Patient data compliance patterns were categorized as: (1) evaluated at all time points (Complete), (2) not evaluated from a given time point or any subsequent time points but evaluated at all the previous time points (Monotone drop-out), (3) not evaluated at any time point (All missing), and (4) all other patterns (Mixed). Patient characteristics and reasons for missingness were summarized and compared among the missing pattern groups. Baseline MMSE scores and change scores after radiation therapy (RT) were compared between these groups, adjusting for differences in other characteristics. There were significant differences in frequency of missing patterns by age, treatment type, education, and Zubrod performance status (ZPS; P < 0.001). Ninety-two percent of patients were evaluated at least once: seven percent of patients were complete pattern, 49% were Monotone pattern, and 36% were mixed pattern. Patients who received RT only regimens were evaluated at a higher rate than patients who received RT + other treatments (49-64% vs. 27-45%). Institutional error and request to not be contacted were the most frequent known reasons for missing data, but most often, reasons for missing MMSE was unspecified. Differences in baseline mean MMSE scores by missing pattern (Complete, Monotone dropout, Mixed) were statistically significant (P < 0.001) but differences were small (<1.5 points) and significance did not persist after adjustment for age, ZPS, and other factors related to missingness. Post-RT change scores did not differ significantly by missing pattern. While baseline and change scores did not differ widely by missing pattern for available measurements, incomplete data was common and of unknown reason, and has potential to substantially bias conclusions. Higher compliance rates may be achievable by addressing institutional compliance with assessment schedules and patient refusal issues, and further exploration of how educational and health status barriers influence compliance with MMSE and other tools used in modern neurocognitive batteries.

Travoprost 0.004%/timolol 0.5%-fixed combination with and without benzalkonium chloride: a prospective, randomized, doubled-masked comparison of safety and efficacy

PURPOSE

The purpose of this study is to compare the safety and intraocular pressure (IOP)-lowering efficacy of travoprost/timolol in a benzalkonium chloride (BAK)-free fixed combination preserved with polyquaternium-1 (TRA/TIM BAK-free), with travoprost/timolol-fixed combination preserved with BAK (TRA/TIM), in patients with open-angle glaucoma or ocular hypertension.

METHODS

In this prospective randomized controlled trial, subjects with IOP of at least 22  mm Hg in one or both eyes at 0900  h, and IOP of at least 21  mm Hg in one or both eyes at 1100  h and 1600  h at two eligibility visits were randomly assigned to receive either TRA/TIM BAK-free (n=195) or TRA/TIM (n=193), dosed once daily in the morning (0900  h) for 6 weeks. IOP was assessed at 0900  h, 1100  h, and 1600  h at each scheduled visit (baseline, 2 and 6 weeks after randomization).

RESULTS

Mean IOP reduction across all visits and time points was 8.0  mm Hg in the TRA/TIM BAK-free group and 8.4  mm Hg in the TRA/TIM group (P=0.0943). The difference in mean IOP between groups ranged from 0.2 to 0.7  mm Hg across visits and time points, with a mean pooled difference of 0.4  mm Hg (95% CI: -0.1 to 0.8), demonstrating equivalence of the two formulations. The most common drug-related adverse event was hyperemia of the eye (ocular hyperemia and conjunctival hyperemia combined), occurring in 11.8% of the TRA/TIM BAK-free group and 13.0% of the TRA/TIM group.

CONCLUSION

Travoprost/timolol BAK-free demonstrated equivalence to travoprost/timolol preserved with BAK in efficacy. No clinically relevant differences in the safety profiles of travoprost/timolol BAK-free and travoprost/timolol preserved with BAK were identified.

Impact of ultrahigh baseline PSA levels on biochemical and clinical outcomes in two Radiation Therapy Oncology Group (RTOG) prostate clinical trials

5123

Background: Controversy exists regarding the outcomes of prostate cancer patients (PCP) presenting with ultra-high (UH; defined as PSA ≥ 50 ng/ml) PSA levels. The objectives of this study were to assess the outcome of this patient population compared to other high-risk patients and to identify predictors associated with biochemical/clinical outcomes. Methods: PCP from two phase III RTOG PC clinical trials (9202 and 9413) were divided into two groups; high-risk patients with and without UH baseline PSA level. Predictive variables included age, Gleason score, T stage, KPS, and treatment arm. Outcomes included overall survival (OS), distant metastasis (DM), and biochemical failure (BF) by Phoenix definition. A Cox proportional hazards regression model was used for OS, and Fine and Gray's regression model was used for DM and BF to test the hypotheses that a difference in each outcome exists between the two groups. Results: There are 401 PCP in the UH PSA and 1792 in the non-UH PSA cohort. Median age was 70 years and PCP were evenly distributed across the Gleason groups (2–6, 7, 8–10) for the non-UH (median PSA 22.4 ng/ml) and the UH PSA (median PSA 72.8ng/ml) cohort. The UH PSA cohort had a larger proportion of T1-T2 disease (p = 0.01) and a smaller proportion of Gleason 8 disease (p = 0.04) than the non-UH group. PCP with UH PSA was found to have inferior OS (HR 1.19, 95% CI 1.02–1.39), DM rate (HR 1.51, 95% CI 1.19–1.92), and BF rate (HR 1.50, 95% CI 1.29–1.73) when compared to other high-risk PCP in multivariable modeling. In the UH cohort, PSA level was found to model risk of DM (HR 1.01, 95% CI 1.001–1.02) but not OS and BF. Gleason grade 8–10 was found to consistently predict for poor OS, DM, and BF outcomes (with HR estimates ranging from 1.41 to 2.36) in both the overall and UH cohort multivariable analyses. Conclusions: UH PSA levels at diagnosis are related with detrimental changes in OS, DM, and BF. All three outcomes assessed in this investigation can be modeled by various combinations all predictive variables tested. Supported by RTOG U10 CA21661, CCOP U10 CA37422, and Stat U10 CA32115 grants from the NCI. This abstract's contents are the sole responsibility of the authors and do not necessarily represent the official views of the NCI.

No significant financial relationships to disclose.

A phase III comparison of prophylactic cranial irradiation versus observation in patients with locally advanced non-small cell lung cancer: Initial analysis of Radiation Therapy Oncology Group 0214

7506

Background: The incidence of central nervous system (CNS) metastases is high in patients with locally advanced non-small cell lung cancer. Brain as an only site of relapse appears increasingly common as loco-regional and extra-cranial systemic treatment improves. There is not standard agreement as to how to address this risk. Methods: Patients with stage III NSCLC without progression of disease after loco-regional treatment with surgery and/or radiation therapy with or without chemotherapy were eligible. Participants were randomized to prophylactic cranial irradiation (PCI) or observation and stratified by stage (IIIA or B), histology (non-squamous or squamous) and therapy (surgery or no surgery). PCI was delivered once daily at 2Gy per fraction to 30Gy. The primary endpoint of the study was overall survival (OS). Secondary endpoints were disease free survival (DFS) and the impact of PCI on incidence of CNS metastases, neuropsychological function, and quality of life (QoL). Kaplan- Meier estimation with the log-rank test was used for OS and DFS and the logistic regression model was used for calculating the incidence of CNS metastasis. Results: Total accrual was 356 patients of the targeted 1058 between 9/19/02 and 8/30/07. The study was closed early due to slow accrual. 340 patients were evaluable. One year OS (p=0.86, 75.6 % and 76.9% for PCI and observation) and one year DFS (p=0.11, 56.4% and 51.2% for PCI and observation) were not statistically significantly different. However, CNS metastatic rate at 1 year was statistically significantly different with CNS relapse 7.7% vs. 18% for PCI vs. observation (p=0.004). Logistic regression showed that the patients in the observation arm are 2.52 times more likely to develop CNS metastases than those in the PCI arm (odds ratio=2.52, 95% CI=(1.32–4.80)). Conclusions: PCI in patients without progressive disease after loco-regional therapy for III NSCLC significantly decreases the rate of CNS metastases. This study did not show a statistically significant difference in OS or DFS. Forthcoming analysis of the impact of PCI on neuropsychological function and QoL will influence the recommendations regarding the standard use of PCI.

No significant financial relationships to disclose.

Protective action of honokiol, administered orally, against oxidative stress in brain of mice challenged with NMDA

Neuroprotective effect of honokiol (HK), orally administered, on oxidative damage in the brain of mice challenged with N-methyl-d-aspartic acid (NMDA) was examined. HK (1-100 mg/kg) was administered to Institute of Cancer Research (ICR) male mice through a gavage for 3 days consecutively, and on the third day, NMDA (150 mg/kg) was intraperitoneally (i.p.) administered. Administration of NMDA, causing a lethality of approximately 60%, resulted in a significant decrease of total glutathione (GSH) level and increase of thiobarbituric acid-reactive substances (TBARS) value in brain tissue. Meanwhile, oral administration of HK (> or = 3 mg/kg) for 3 days reduced the lethality (60%) in NMDA-treated group to 10% level, and alleviated the behavioral signs of NMDA neurotoxicity. Moreover, HK pretreatment restored the levels of total GSH and TBARS in the brain tissue to control levels (p<0.01). Additionally, GSH peroxidase activity in cytosolic portion of brain homogenate was also restored significantly (p<0.01), whereas GSH reductase activity was not. Separately, compared to vehicle-treated control, no significant changes in body and brain weight were observed in mice administered with HK. Based on these results, oral intake of HK is suggested to prevent oxidative stress in the brain of mice.

A phase I and pharmacologic study of belotecan in combination with cisplatin in patients with previously untreated extensive-stage disease small cell lung cancer

18053

Background: Belotecan (CKD602) is a novel camptothecin derivative antitumor agent. This phase I study was designed to determine the maximum-tolerated dose (MTD), toxicity profile, and dose-limiting toxicity (DLT) of belotecan in combination with cisplatin in patients with previously untreated extensive-stage disease small-cell lung cancer (ED SCLC). Furthermore, pharmacokinetics (PK) and preliminary antitumor activity of belotecan against SCLC were evaluated. Methods: Patients with ED SCLC, age 18–70, ECOG PS 0–2, no prior chemotherapy and adequate organ function were eligible. Cisplatin with fixed dose of 60 mg/m2 was administered intravenously (i.v.) over 2 hours on day 1. Belotecan was administered iv as intermittent 30-minute infusions on days 1 to 4, starting dose of 0.40 mg/m2/day with increment of 0.05 mg/m2/day. Modified Fibonacci escalation was used (3 to 6 patients per cohort) and intra-patient dose escalation was not allowed. PK of belotecan was determined during the first treatment using non-compartmental pharmacokinetic analysis. Results: Seventeen patients were treated at 4 dose levels (0.40 to 0.55 mg/m2/day). At 0.55 mg/m2/day of belotecan, the DLT of grade 4 neutropenia with fever occurred in 2 of 5 patients, and therefore the MTD was 0.50 mg/m2/day. Interestingly, out of 17 patients, there were 14 partial responses (82.4%; 95% CI, 63.4% to 100.0%). PK analysis revealed that at 0.50 mg/m2/day, plasma clearance of belotecan was 5.78 ± 1.32 L/hr and terminal half-life was 8.55 ± 2.12 hr. Fraction of excreted amount in urine was 37.36 ± 5.55 %. PK of belotecan were not altered by administration of cisplatin, as compared with historical control. Conclusions: The MTD of belotecan was 0.50 mg/m2/day for intermittent 30-min i.v. infusion for 4 days in combination with cisplatin 60 mg/m2 on day 1 every 3 weeks. Furthermore, very promising antitumor activity against SCLC was observed. The phase II study is being conducted now.

No significant financial relationships to disclose.

Body mass index and mortality in men treated for locally advanced prostate cancer: An analysis of RTOG 85–31

5128

Background: Greater body mass index (BMI) is associated with shorter time to prostate-specific antigen (PSA) failure following radical prostatectomy. We investigated whether BMI is associated with prostate cancer-specific mortality (PCSM) in a large randomized trial of men treated with radiation therapy (RT) and androgen deprivation therapy (ADT) for locally advanced prostate cancer. Methods: Between 1987 and 1992, 945 eligible men with locally advanced prostate cancer were enrolled on a phase III trial (RTOG 85- 31) and randomized to RT and immediate goserelin (Arm I) or RT alone followed by goserelin at relapse (Arm II). Height and weight data were available at baseline for 788 (83%) subjects. Cox regression analyses were performed to evaluate the relationships between BMI and all-cause mortality, PCSM, and non-prostate cancer mortality. Covariates included age, race, treatment arm, history of prostatectomy, nodal involvement, Gleason score, clinical stage, and BMI. Results: The 5-year PCSM rate for men with BMI<25kg/m2 was 6.5%, compared to 13.1% and 12.2% in men with BMI=25-<30 and BMI=30, respectively (Gray’s p=0.005). In multivariable analyses, as shown in the Table , greater BMI was significantly associated with higher PCSM [for BMI=25-<30, hazard ratio (HR) 1.52, 95% confidence interval (CI) 1.02–2.27, p=0.04; for BMI=30, HR 1.65, 95% CI 1.02–2.66, p=0.04]. BMI was not associated with non-prostate cancer or all-cause mortality. Conclusions: Greater baseline BMI is independently associated with higher PCSM in men with locally advanced prostate cancer. Further studies are warranted to evaluate the mechanism(s) for increased mortality and to assess whether weight loss after prostate cancer diagnosis alters disease course.

[Table: see text]

No significant financial relationships to disclose.

The impact of the duration of adjuvant hormonal therapy in patients with unfavorable prognosis prostate cancer treated with radiotherapy: Secondary analysis of RTOG 85–31

5062

Background: RTOG 85–31 was a Phase III trial of androgen suppression for life as an adjuvant to radiotherapy. However not all patients continued on the protocol-mandated long-term hormonal therapy despite no evidence of recurrent disease. This analysis correlates duration of adjuvant hormonal therapy and outcomes among patients who prematurely discontinued long-term hormonal therapy. Methods: The protocol mandated pelvic radiotherapy (60–66 Gy) followed by goserelin 3.6 mg monthly given indefinitely or until disease progression. To avoid potential bias due to early progression/death, only patients who were alive with no evidence of disease at the time of cessation of hormonal therapy were included. There were 377 analyzable patients. Patients were divided in groups based on the hormonal therapy duration (HTD), as follows: = 1 year (27.3%), 1< and =2 years (11.4%), 2< and =4 years (13.3%), 4< and =6 years (10.6%) and > 6 years (37.4%). End-points were overall survival, disease-free survival, disease-free survival with PSA <1.5 ng/mL, disease-specific survival, local failure and distant failure. Cox-proportional hazards regression model was used to test the outcomes among the 5 groups. Results: The median follow-up time of surviving patients is 11.27 years. Pretreatment characteristics by hormone duration groups were well balanced except for age. The median duration of adjuvant hormonal therapy was 3.59 years. For each outcome, there are statistically significant differences among the 5 HTD groups in all outcomes without adjusting for other covariates. Pairwise comparisons show that HTD > 6 year group is significantly associated with having an improved survival and fewer failure events than all other HTD groups (HR < 1, p-value <0.0001). Adjusted for age and stratification variables, the HTD>6 year group remains the only group significantly associated with having fewer failure events in all outcomes. Conclusions: Prolonged HTD of > 6 years is significantly associated with improvements in all end-points studied. Based on these data, decreasing HTD to < 6 years may have a detrimental effect in patients with unfavorable prostate cancer.

No significant financial relationships to disclose.

Beta-secretase (BACE1)-inhibiting stilbenoids from Smilax Rhizoma

In the course of searching for BACE1 (beta-secretase) inhibitors from natural products, the ethyl acetate soluble fraction of Smilax Rhizoma (the dried rhizomes of Smilax china L.) showed potent inhibitory activity. The active compounds were identified as a trans/cis-resveratrol mixture, oxyresveratrol, veraphenol, and cis-scirpusin A. They were shown to non-competitively inhibit BACE1 with the Ki values of 5.4 x 10(-6), 5.4 x 10(-6), 3.4 x 10(-6), and 5.4 x 10(-6)M and IC(50) values of 1.5 x 10(-5), 7.6 x 10(-6), 4.2 x 10(-6), and 1.0 x 10(-5)M, respectively. The active compounds were less inhibitory to alpha-secretase (TACE) and other serine proteases such as chymotrypsin, trypsin, and elastase, suggesting that they were relatively specific inhibitors of BACE1.

CT findings of malarial spleen

Malaria is one of the most frequent causes of fever among travellers to tropical countries. We report the CT imaging findings of poor contrast enhancement of the spleen on arterial phase in a case of malaria presenting as splenomegaly. To the best of our knowledge, this is the first report of malarial spleen diagnosed by these CT results.

A new diterpenoid alkaloid from Aconitum jaluense

A new diterpenoid alkaloid, jaluenine (1), has been isolated from the roots of Aconitum jaluense. The structure of jaluenine was determined by spectroscopic methods including two dimensional NMR (1H-1H COSY, HMQC, HMBC, NOESY).

Looking for new targets for prostate cancer therapy: Nuclear factor kappa B and CXCR4 co-expression in prostate specimens from RTOG-8610

14578

Background: The transcription factor Nuclear Factor-kappa B (NFκB) promotes the production of angiogenic, anti-apoptotic and prometastatic factors that are involved in carcinogenesis. The chemokine receptor CXCR4, which is under the control of NFκB, has been implicated in regulating metastasis of breast, pancreatic, and prostate cancer. This retrospective cohort study evaluated the frequency and co-expression of NFκB and CXCR4 in human prostate cancer specimens. Methods: Paraffin embedded samples from a subset of patients in the RTOG 8610 trial underwent immunohistochemical staining for NFκB and CXCR4. This study compared radiotherapy plus hormonal therapy to radiation therapy alone. The amount of NFκB and CXCR4 was scored by a blinded pathologist for the percentage of cells stained (0 to 100%) and staining intensity (0 to 3+). Results: NFκB and CXCR4 status was determined for 55 and 63 patients, respectively. Both NFκB and CXCR4 status were available for 51 of these patients. Of these, 51% were 2/3+ for NFκB and 61% were 2/3+ for CXCR4. There was a trend towards correlation between CXCR4 and NFκB staining as 18 of the 36 patients who were 2/3+ positive for NFκB were 2/3+ for CXCR4. 10 of the 11 pts with 3+ NFκB had 2/3+ CXCR4. This was consistent with the understanding that CXCR4 is regulated by NFκB, but did not reach statistical significance (p = 0.1298). Neither NFκB or CXCR4 were statistically significantly prognostic factors in this small subset of patients. Conclusion: NFκB and CXCR4 are expressed in a significant number of patients with organ confined prostate cancer. Neither predicted outcomes in this analysis, which may be due to the small sample size. This data supports the notion that NFκB regulates CXCR4 expression in prostate cancer and that one or both may be potential new targets for therapeutic intervention. Studies in larger prospective studies to determine the utility of NFκB and CXCR4 as predictive biomarkers and/or therapeutic targets is warranted. [Table: see text]

No significant financial relationships to disclose.

Does timing of androgen deprivation influence radiation-induced toxicity? A secondary analysis of Radiation Therapy Oncology Group protocol 9413

4655

Background: We conducted a secondary analysis of RTOG 9413 to compare if the timing of antiandrogen-therapy, concomitant versus adjuvant, influences the incidence of rectal toxicity in whole pelvic radiotherapy. Methods: For the purpose of this secondary analysis, we analyzed the 2 of the 4 arms of the study, in which all patients received radiotherapy to the whole pelvis followed by a boost to the prostate and excluded the two arms that received prostate only radiotherapy. The 2 arms differed only in the timing of the total of 4 months of total androgen deprivation (TAD): arm I (320 patients), TAD was begun 2 months before the start of radiotherapy and continued during radiotherapy. Arm III (319 patients), TAD started immediately after the completion of radiotherapy. Both acute rectal and acute urinary toxicities (CTC v.2.0), testosterone (measured at baseline and yearly after) and other patients data were modeled using the multivariate logistic regression and the multivariate Cox-proportional hazards regression. Results: Median follow up for all patients is 6.0 and 5.8 years (arm I and II, resp.). 43 (13%) patients in each arm had abnormally low testosterone before start of TAD. Late grade 2 - 5 rectal toxicity occurred in 16% and 13% and urinary toxicity in 18% and 20% (arm I and II, resp.). Frequency (or occurrence) of late rectal toxicity (grade 0–1 vs. 2–5, p = 0.2170) and late urinary toxicity (grade 0–1 vs. 2–5, p = 0.4204) are not significantly different between the two arms. The only risk factors for late rectal toxicity in a multivariate regression model was acute rectal toxicity (OR 1.48, p = 0.025), but not abnormal testosterone level at baseline (p = 0.718) or treatment arm (p = 0.874). For late urinary toxicity: age (OR = 1.588, p = 0.010), RT field size (OR 1.004, p < 0.025), baseline testosterone (OR 1.718, p = 0.028), and acute (grade 2–4) toxicity (OR = 1.664, p = 0.006) but not treatment arm (p = 0.928) were risk factors. Conclusions: While late toxicity was not different for concomitant vs. adjuvant hormonal therapy, an abnormally low testosterone level at baseline is a risk factor for late urinary toxicity and not late rectal toxicity.

No significant financial relationships to disclose.

Effect of water-soluble reduced chitosan on Streptococcus mutans, plaque regrowth and biofilm vitality

The purpose of the present study was to examine the effects of a newly developed water-soluble reduced chitosan on Streptococcus mutans, plaque regrowth, and biofilm vitality. A 1.0%, water-soluble reduced chitosan, with pH ranging from 6.0 to 6.5, molecular weights between 3,000 and 5,000 Da, and 70% degree of deacetylation, was used. To determine antibacterial and antiplaque potency of chitosan, minimal inhibitory concentrations (MICs) for S. mutans and S. sanguinis (formerly S. sanguis), short-term exposure to S. mutans, and clinical trial of plaque regrowth and biofilm vitality were conducted. Twelve dental students volunteered to participate in the 6-week, double blind, randomized clinical trial using the classical 4-day plaque regrowth design. The MIC of water-soluble reduced chitosan for S. mutans was 1.25 g/l. While the cells exposed to distilled water (DW) grew rapidly, with a maximum turbidity reached by 16 h postinoculation, S. mutans exposed to chitosan (5.0 g/l) exhibited a substantial delay in growth and reached a maximum turbidity by 32 h postinoculation. The chitosan solution reduced the plaque index and the vitality of the plaque flora significantly when compared to DW, but this was less than the reductions found with the positive control of 0.1% chlorhexidine solution. The water-soluble reduced chitosan exhibited potent antibacterial effect on S. mutans, and displayed a significant antibacterial and plaque-reducing action during the 4-day plaque regrowth.

Cytotoxic triterpenoides from Alismatis Rhizoma

Four prostane-type triterpenes were isolated from a methanol extract of Alismatis Rhizoma by bioassay-guided isolation using in vitro cytotoxic assay. The compounds were identified as alisol B 23-acetate (1), alisol C 23-acetate (2), alisol B (3), alisol A 24-acetate (4) by spectroscopic methods. Amongst the compounds, alisol B (3) showed significant cytotoxicity against SK-OV3, B16-F10, and HT1080 cancer cell lines with ED50 values of 7.5, 7.5, 4.9 microg/ml, respectively.

A new naphthoquinone from Pyrola japonica

A new naphthoquinone, 5,8-dihydro-2,7-dimethyl-[1,4]naphthoquinone (1), which was named 5,8-dihydrochimaphilin, isolated from an ethyl acetate soluble fraction from the root of Pyrola japonica, together with chimaphilin (2). Compound 1 was transformed rapidly to 2 upon exposure to air by HPLC analysis. This fact supported that chimaphilin (2) may be an artifact from 1.

A cytotoxic secocycloartenoid from Abies koreana

Two triterpenoids, 24-methylene-3,4-seco-cycloart-4(28)-en-3-oic acid (1) and 3-oxo-9beta-lanosta-7,22Z,24-trien-26,23-olide (6) were isolated from Abies koreana, together with beta-sitosterol (2), maltol (3), beta-sitosterol-O-beta-D-glucoside (4), and hexacosylferulate (5). The structures of the compounds were established based on the spectroscopic data. The cytotoxic activities of triterpenoids have been evaluated using the sulforhodamine B (SRB) method. Compound 1 showed moderate cytotoxicities against human lung carcinoma (A549), ovarian carcinoma (SK-OV-3), malignant melanoma (SK-MEL-2), and colon carcinoma (HCT-15) cell lines.

Differential functions of mPer1, mPer2, and mPer3 in the SCN circadian clock

The role of mPer1 and mPer2 in regulating circadian rhythms was assessed by disrupting these genes. Mice homozygous for the targeted allele of either mPer1 or mPer2 had severely disrupted locomotor activity rhythms during extended exposure to constant darkness. Clock gene RNA rhythms were blunted in the suprachiasmatic nucleus of mPer2 mutant mice, but not of mPER1-deficient mice. Peak mPER and mCRY1 protein levels were reduced in both lines. Behavioral rhythms of mPer1/mPer3 and mPer2/mPer3 double-mutant mice resembled rhythms of mice with disruption of mPer1 or mPer2 alone, respectively, confirming the placement of mPer3 outside the core circadian clockwork. In contrast, mPer1/mPer2 double-mutant mice were immediately arrhythmic. Thus, mPER1 influences rhythmicity primarily through interaction with other clock proteins, while mPER2 positively regulates rhythmic gene expression, and there is partial compensation between products of these two genes.

Resistance exercise training reduces hypertriglyceridemia in HIV-infected men treated with antiviral therapy

Hypertriglyceridemia, peripheral insulin resistance, and trunk adiposity are metabolic complications recently recognized in people infected with human immunodeficiency virus (HIV) and treated with highly active antiretroviral therapy (HAART). These complications may respond favorably to exercise training. Using a paired design, we determined whether 16 wk of weight-lifting exercise increased muscle mass and strength and decreased fasting serum triglycerides and adipose tissue mass in 18 HIV-infected men. The resistance exercise regimen consisted of three upper and four lower body exercises done for 1-1.5 h/day, 4 days/wk for 64 sessions. Dual-energy X-ray absorptiometry indicated that exercise training increased whole body lean mass 1.4 kg (P = 0.005) but did not reduce adipose tissue mass (P = NS). Axial proton-magnetic resonance imaging indicated that thigh muscle cross-sectional area increased 5-7 cm(2) (P < 0.005). Muscle strength increased 23-38% (P < 0.0001) on all exercises. Fasting serum triglycerides were decreased at the end of training (281-204 mg/dl; P = 0.02). These findings imply that resistance exercise training-induced muscle hypertrophy may promote triglyceride clearance from the circulation of hypertriglyceridemic HIV-infected men treated with antiviral therapy.

Platelet-activating factor (PAF)-dependent transacetylase and its relationship with PAF acetylhydrolases

Platelet-activating factor (PAF)-dependent transacetylase (TA) is an enzyme that transfers an acetyl group from PAF to acceptor lipids such as lysophospholipids and sphingosine. This enzyme is distributed in membrane and cytosol of the cells. We previously revealed that TA purified from rat kidney membrane showed an amino acid sequence similarity to that of bovine PAF-acetylhydrolase (AH) (II). In the present study, we purified TA from the rat kidney cytosol and analyzed its amino acid sequence. The amino acid sequence of the cytosolic TA is similar to that of bovine PAF-AH (II) and membrane TA. To clarify the relationship between TA and PAF-AH (II), we isolated cDNA of rat PAF-AH (II). The predicted amino acid sequence of rat PAF-AH (II) from isolated cDNA included all the sequences found in TAs purified from the membrane and cytosolic TAs. In addition, monoclonal antibody to recombinant PAF-AH (II) cross-reacted with both cytosolic and membrane TAs. Consistent with sequence identity, recombinant PAF-AH (II) showed TA activity, whereas recombinant PAF-AH Ib, which is a different subtype of intracellular PAF-AHs, did not possess TA activity. Analysis of a series of site-directed mutant PAF-AH (II) proteins showed that TA activity was decreased, whereas PAF-AH activity was not affected in C120S and G2A mutant proteins. Thus, Cys(120) and Gly(2) are implicated in the catalysis of TA reaction in this enzyme. Furthermore, the transfer of acetate from PAF to endogenous acceptor lipids was significantly increased in a time-dependent manner in CHO-K1 cells transfected with PAF-AH (II) gene. These results demonstrate that PAF-AH (II) can function, as a TA in intact cells, and PAF-AH (II) and TA are the same enzyme.

Role of follicular dendritic cells in the apoptosis of germinal center B cells

Follicular dendritic cells (FDCs) provide the most obvious source of antigens, which are essential for the differentiation of GC B cells. It has been reported that most proliferating B cells in germinal centers undergo apoptosis. Quantitative histology shows macrophages with apoptotic debris throughout the germinal center, the highest frequency of these cells being found in the dense FDC network. Based on these findings, we hypothesized that FDC may be involved in an apoptotic pathway of the germinal center B cells. To prove this hypothesis, we performed double immunohistochemical analysis using anti-FDC mAb and peanut agglutinin (PNA), with their respective TUNEL kits. Collated data showed that a great proportion of the apoptotic cells, most of which were positive for PNA, were in close contact with FDC, which indicated an interaction between FDC and B cells in the apoptotic pathway. Further studies using double immunohistochemical staining and FACS analyses demonstrated the expression of Fas-ligand (FasL) in a subset of the FDC. These results suggest that FDC may play a role in the apoptosis of germinal center B cells via Fas-FasL interaction.

Cytotoxic triterpenes from Crataegus pinnatifida

Bioassay-guided fractionation of Crataegus pinnatifida (Rosaceae) gave two cytotoxic ursane-type triterpenes which were identified as uvaol (1) and ursolic acid (2) by physicochemical and spectroscopic methods. 3-Oxo-ursolic acid (3) was synthesized from ursolic acid (2) by Jones method. The cytotoxic activities of these compounds were tested against murine L1210 and human cancer cell lines (A549, SK-OV-3, SK-MEL-2, XF498, and HCT15) in vitro. Compounds 1 and 2 showed moderate cytotoxicities against L1210, whereas they showed weak activities against human cancer cell lines. However, compound 3 exhibited potent cytotoxic activities both in murine and in human cancer cell lines.

dCLOCK is present in limiting amounts and likely mediates daily interactions between the dCLOCK-CYC transcription factor and the PER-TIM complex

In Drosophila melanogaster four circadian clock proteins termed PERIOD (PER), TIMELESS (TIM), dCLOCK (dCLK), and CYCLE (CYC/dBMAL1) function in a transcriptional feedback loop that is a core element of the oscillator mechanism. dCLK and CYC are members of the basic helix-loop-helix (bHLH)/PAS (PER-ARNT-SIM) superfamily of transcription factors and are required for high-level expression of per and tim and repression of dClk, whereas PER and TIM inhibit dCLK-CYC-mediated transcription and lead to the activation of dClk. To understand further the dynamic regulation within the circadian oscillator mechanism, we biochemically characterized in vivo-produced CYC, determined the interactions of the four clock proteins, and calculated their absolute levels as a function of time. Our results indicate that throughout a daily cycle the majority of the dCLK present in adult heads stably interacts with CYC, indicating that CYC is the primary in vivo partner of dCLK. dCLK-CYC dimers are bound by PER and TIM during the late evening and early morning, suggesting the formation of a tetrameric complex with impaired transcriptional activity. Although dCLK is present in limiting amounts and CYC is by far the most abundant of the four clock proteins that have been examined, PER and TIM appear to interact preferentially with dCLK. Our results suggest that dCLK is the main component regulating the daily abundance of transcriptionally active dCLK-CYC complexes.