Prevalence and associated factors of retinal vein occlusion in the Korean National Health and Nutritional Examination Survey, 2008-2012: A cross-sectional observational study

Retinal vein occlusion (RVO) is the second most common retinal vascular diseases and there are only a few Asian population-based studies with small samples. Hypertension is one of a modifiable risk factor of RVO, but no recent studies have shown the relationship between RVO and hypertension control status. We aimed to investigate the prevalence of RVO and its associated factors in an adult Korean population.A nationwide population-based, cross-sectional study. We enrolled 37,982 participants from the Korea National Health and Nutrition Examination Survey who were 19 years or older and who had undergone ophthalmologic exams from 2008 through 2012. All participants underwent a comprehensive ophthalmic examination, standardized ophthalmic and health interviews, and laboratory investigations. Digital fundus photographs were interpreted by retinal specialists who investigated for the presence of RVO. The prevalence of RVO was then estimated. RVO-associated factors were determined using step-wise logistic regression analyses. We also performed a subgroup analysis to evaluate the association between hypertension and RVO according to hypertension control status and antihypertensive medication use.Of those enrolled participants, 25,765 participants met our study criteria and were included in the analyses. The overall RVO prevalence (n = 205) was 0.6 ± 0.1% (0.6 ± 0.1% for branch RVO and <0.1% for central RVO), and no sex differences were observed. In multivariate logistic regression analyses after adjusting for all potential risk factors, we found the following factors to be significantly associated with RVO: old age (odds ratio (OR) = 1.72, 95% CI: 1.27-2.34), hypertension (OR = 2.56, 95% CI: 1.31-5.08), history of stroke (OR = 2.08, 95% CI: 1.01-4.45), and hypercholesterolemia (OR = 1.84, 95% CI: 1.01-3.35). In a subset of participants with hypertension, participants with uncontrolled hypertension (OR = 3.46, 95% CI: 1.72-6.94) and unmedicated hypertension (OR = 4.12, 95% CI: 2.01-8.46) were more significantly associated with RVO than participants without hypertension.RVO prevalence in Korea was moderate relative to that in the rest of the world, and RVO-associated factors were similar to those identified in other population-based studies. Well-controlled hypertension and antihypertensive medication showed inverse association with RVO.

Conjugated polyelectrolyte nano field emission adlayers

Here we report on a straightforward and rapid means of enhancing the field electron emission performance of nascent vertically aligned multi-walled carbon nanotubes by introducing a polar zwitterionic conjugated polyelectrolyte adlayer at the vacuum-emitter interface. We attribute the observed 66% decrease in turn-on electric field to the augmented emitter micro-morphology and shifted surface band structure. The composite emitters can be optically modulated by exploiting the absorption cross-section of the solution cast adlayer, which increases the local carrier concentration which broadens the effective electrostatic shape of the emitter during optical excitation. Assessment via scanning anode field emission microscopy reveals a 25% improvement in DC time stability, a significant reduction in long-term hysteresis shift, and a threefold increase in bandwidth during pulsed mode operation.

Delayed Presentation of Catheter-related Subclavian Artery Pseudoaneurysm

Central venous catheterization is a common diagnostic and therapeutic procedure in modern clinical practice. Pseudoaneurysms of the subclavian artery are rare and usually occur immediately after the causative event, whether the cause was trauma or a medical procedure. Here, we report a case of a 71-year-old woman with delayed presentation of catheter-related subclavian pseudoaneurysm. The patient’s symptoms began two weeks after the initial catheterization, probably because of slow leakage of blood from the injured subclavian artery caused by incomplete compression of the puncture site and uremic coagulopathy. She was successfully treated with ultrasound-guided thrombin and angiography-guided histoacryl injection without stent insertion or surgery. Keywords: butyl 2-cyanacrylate; pseudoaneurysm; subclavian; thrombin.

The glutathione synthesis inhibitor buthionine sulfoximine synergistically enhanced melphalan activity against preclinical models of multiple myeloma

Melphalan (L-PAM) has been an integral part of multiple myeloma (MM) treatment as a conditioning regimen before stem cell transplant (SCT). After initial response, most treated patients experience relapse with an aggressive phenotype. Increased glutathione (GSH) in MM may mediate resistance to L-PAM. We demonstrated that the GSH synthesis inhibitor buthionine sulfoximine (BSO) synergistically enhanced L-PAM activity (inducing 2–4 logs of cell kill) against nine MM cell lines (also in the presence of marrow stroma or cytokines) and in seven primary MM samples (combination indices <1.0). In MM cell lines, BSO significantly (P<0.05) depleted GSH, increased L-PAM-induced single-strand DNA breaks, mitochondrial depolarization, caspase cleavage and apoptosis. L-PAM depleted GSH, but GSH rapidly recovered in a L-PAM-resistant MM cell line unless also treated with BSO. Treatment with N-acetylcysteine antagonized BSO+L-PAM cytotoxicity without increasing GSH. In human MM xenografted into beige-nude-xid mice, BSO significantly depleted MM intracellular GSH and significantly increased apoptosis compared with L-PAM alone. BSO+L-PAM achieved complete responses (CRs) in three MM xenograft models including maintained CRs >100 days, and significantly increased the median event-free survival relative to L-PAM alone. Combining BSO with L-PAM warrants clinical testing in advanced MM.

Ischemic diabetic retinopathy as a possible prognostic factor for chronic kidney disease progression

PURPOSE

To assess the value of diabetic retinopathy (DR) severity as a possible predictive prognostic factor for the progression of chronic kidney disease (CKD).

PATIENTS AND METHODS

Retrospective cohort study. Patients (51) who were initially diagnosed with DR and CKD were enrolled and their medical records were evaluated. The following ophthalmic factors were assessed by fluorescein angiography at the initial visit: area of capillary nonperfusion, presence of neovascularization and vitreous hemorrhage, and DR grade. The effect of these factors on CKD progression over the 2-year period of the study, defined as doubling of serum creatinine or the development of end-stage renal disease requiring dialysis or renal transplant, was evaluated.

RESULTS

The study included 51 patients with DR and CKD; of these, 11 patients (21.6%) were found to have proliferative DR (PDR) and seven patients (13.7%) had high-risk PDR at baseline. Patients with ischemic DR, who showed extensive capillary nonperfusion (≥ 10 optic disc areas) in the retina, had a greater risk for CKD progression (hazard ratio = 6.64; P = 0.002).

CONCLUSION

We found that extensive capillary nonperfusion in the retina greatly increased the risk of progression of CKD in patients with DR. This suggests that the retina and the kidney may have shared risk factors for microvascular disease secondary to diabetes mellitus, and emphasizes the need for a team approach to diabetes care.

Gene expression and localization of 20α-hydroxysteroid dehydrogenase (HSD) in reproductive tissues during early pregnancy of cattle

The enzyme 20α-hydroxysteroid dehydrogenase (20α-HSD) catalyzes the conversion of progesterone to its inactive form, 20α-hydroxyprogesterone, and this enzyme has an important role in the regulation of luteal function in mammals. It has previously been determined that the 20α-HSD gene is primarily expressed by large luteal cells during the late stage of the estrous cycle. In the present study, the amounts of mRNA were determined in cultured cells of the corpus luteum (CL) cells. The localization of 20α-HSD was also determined in ovaries, placenta, and endometrium during early pregnancy. The amount of 20α-HSD mRNA in cultured luteal cells increased with time and by treatment with the luteolysis agent prostaglandin F2α (PGF2α). Immunofluorescence assays detected increased protein in cultured luteal cells. The 20α-HSD mRNA and protein were present in the ovaries, placenta, and endometrium on Days 30, 60, and 90 of pregnancy. In particular, gene expression was much greater in the ovary than in the placenta and endometrium. Immuno-histochemical analysis indicated that bovine 20α-HSD was primarily localized in ovarian large luteal cells, placental cytotrophoblast villus, and glandular epithelial cells of the endometrium during early pregnancy. Furthermore, in situ analyses demonstrated colocalization of 20α-HSD mRNA and protein. Taken together, results of the present study indicate that 20α-HSD mRNA and protein are co-localized in large luteal cells, the placenta, and the endometrium during early pregnancy, suggesting that 20α-HSD regulates mechanisms involved in the maintenance of early pregnancy.

Unusual congenital pulmonary anomaly with presumed left lung hypoplasia in a young dog

A seven-month-old, entire, male miniature schnauzer dog was referred with acute vomiting, inappetence and depression primarily as a result of a gastric foreign body (pine cones). During investigations, thoracic radiographs revealed increased volume of the right lung lobes, deviated cardiomediastinal structures and elevation of the heart from the sternum. Thoracic computed tomography revealed left cranial lung lobe hypoplasia and extension of the right cranial lung parenchyma across the midline to the left hemithorax. Branches of the right pulmonary vessels and bronchi also crossed the midline and extended to the left caudal lung lobe. These findings suggested that the right and left lungs were fused. In humans this finding is consistent with horseshoe lung, which is an uncommon congenital malformation. To the authors' knowledge, this case represents the first report of such a pulmonary anomaly in a dog.

Cancel all Hollidays for SLX4 mutations: identification of a new Fanconi anemia subtype, FANCP

SLX4, a coordinator of structure-specific endo-nucleases, is mutated in a new Fanconi anemia subtype Stoepker et al. (2011) Nature Genetics 43:138-141. Mutations of the SLX4 gene in Fanconi anemia Kim et al. (2011) Nature Genetics 43:142-146.

Calf-contouring surgery of gastrocnemius hypertrophy: selective neurectomy of the sural nerve

Generally, Asians tend to have obese calves that are shorter and thicker than those of Caucasians. The cause of the enlarged calves is either an excess of subcutaneous fat or calf muscular hypertrophy, but some patients have both conditions. These features are accentuated by the contraction of the calf muscles when patients stand in tiptoe position or wear high heels. In the case of calf muscular hypertrophy without excessive subcutaneous fat, manipulation of the calf muscle is an effective method for reducing calf circumference. From January 2005 to December 2006, the authors performed selective sural neurectomy for 20 patients who complained of obese calves. Using a popliteal incision, the sural nerve branches to the medial and/or lateral gastrocnemius muscles were dissected from the posterior tibial nerve. Using a nerve stimulator, the branches with the most contractile portions were resected in 1 cm lengths at the distal ends. One medial branch was resected in 15 patients, and two branches were resected in 5 patients. In the case of a lateral neurectomy, only one branch was resected. Ultrasound-assisted liposuction was combined for five patients who also showed excessive subcutaneous fat. The patients ranged in age from 19 to 29 years (mean, 23 years). The follow-up period varied from 6 to 18 months. The circumferential change was checked 6 months postoperatively 15 cm below the medial condyle and 15 cm above the medial malleolus. These average circumferences were reduced, respectively, from 36.6 and 32.5 cm to 35.5 and 32.2 cm. In gait analysis performed at 6 months postoperatively, the calf muscle power was slightly reduced to 95% of the preoperative state, but still remained above the normal range. Subjectively, no patient complained of muscle weakness or gait disturbance. One patient showed lower leg edema after mountain climbing that subsided after 1 day of rest. The authors believe a selective neurectomy technique can be an effective method for treating obese calves.

Expression profiling of cyclin B1 and D1 in cervical carcinoma

AIM

Cyclins are a family of regulatory proteins that play a key role in controlling the cell cycle. Abnormalities of cell cycle regulators, including cyclins and cyclin dependent kinases, have been reported in various malignant tumors. This study was undertaken to quantitatively detect cyclin B1 and D1 in cervical cancer.

METHODS

A quantitative real-time reverse transcription polymerase chain reaction and Western blot assay were used to analyze the expression of cyclin B1/D1 mRNA and proteins, respectively, in fresh invasive cervical cancer (n = 41) and normal cervical tissues (n = 10).

RESULTS

There was significantly greater cyclin B1 expression in invasive cervical cancer than in normal cervical tissue (P = 0.019). However, cyclin D1 expression was not significantly different. A Western blot assay yielded similar results.

CONCLUSION

Our results were consistent with the concept that up-regulation of cyclin B1 expression occurred in cervical cancer and an aberrant expression of cyclin B1 might play an important role in cervical carcinogenesis.

Performance evaluation of leachate treatment system using innovative sulfur circulation method

A pilot-scale experimental study was carried out to evaluate the performance of an innovative method for early stabilization of landfill. This method employs sequential processes of: leachate collection; nitrification through aeration; sulfate addition in effluent tank; and leachate injection back to the landfill. This study focused on: 1) decomposition of recalcitrant organic matters, 2) the characteristics of denitrification, 3) sulfide oxidation for sulfate recovery, and 4) nitrification by aerating discharged leachate. It was found that, when sulfate (SO4(2-)) added leachate was introduced inside the landfill, sulfate-reducing bacteria decomposed recalcitrant organic matters like lignocellulose by using SO4(2-) as an electron acceptor and simultaneously sulfur-oxidizing bacteria denitrified the leachate using sulfides (H2S, HS-, S2-) as electron donors. These two types of bacteria existed not competitively but symbiotically on substrate utilization. Sulfate-reducing bacteria produced S2- while sulfur-oxidizing bacteria oxidized S2- to SO4(2-). During aeration, the concentration of NO3(-)-N increased from near zero up to 925 mg l(-1). Eventual denitrification efficiency in the simulated waste landfill was observed to be approximately 92.3%. Also, S2- present in the discharged leachate was converted to SO4(2-) again in the aeration process. Sulfate needed in this process could be recirculated. Therefore, the amount of sulfate required in the operation of this method could be maintained marginal after the initial addition of sulfate in the effluent tank. Decomposition of recalcitrant organic matters and denitrification hastened the stabilization of landfill. The results of this study indicated that this innovative method was effective and economic.

Implantation of penile prosthesis in a patient with severe corporeal fibrosis induced by cavernosal injection therapy

Implantation of a penile prosthesis in men with complicated fibrosis of corpus cavernosum is very difficult and even impossible. Cavernosal dilation requires sharp intracavernosal dissection to implant prosthesis, however complete removal of the fibrotic tissue is often impossible. We introduce a new technique using electric resection and electrovaporization of fibrotic tissue for implantation of penile prosthesis in a patient with severe corporeal fibrosis.

Vascular effects of estrogen in type II diabetic postmenopausal women

OBJECTIVES

We assessed the effects of estrogen on vascular dilatory and other homeostatic functions potentially affected by nitric oxide (NO)-potentiating properties in type II diabetic postmenopausal women.

BACKGROUND

There is a higher cardiovascular risk in diabetic women than in nondiabetic women. This would suggest that women with diabetes do not have the cardioprotection associated with estrogen.

METHODS

We administered placebo or conjugated equine estrogen, 0.625 mg/day for 8 weeks, to 20 type II diabetic postmenopausal women in a randomized, double-blinded, placebo-controlled, cross-over design.

RESULTS

Compared with placebo, estrogen tended to lower low-density lipoprotein (LDL) cholesterol levels by 15 +/- 23% (p = 0.007) and increase high-density lipoprotein (HDL) cholesterol levels by 8 +/- 16% (p = 0.034). Thus, the ratio of LDL to HDL cholesterol levels significantly decreased with estrogen, by 20 +/- 24%, as compared with placebo (p = 0.001). Compared with placebo, estrogen tended to increase triglyceride levels by 16 +/- 48% and lower glycosylated hemoglobin levels by 3 +/- 13% (p = 0.295 and p = 0.199, respectively). However, estrogen did not significantly improve the percent flow-mediated dilatory response to hyperemia (17 +/- 75% vs. placebo; p = 0.501). The statistical power to accept our observation was 81.5%. Compared with placebo, estrogen did not significantly change E-selectin, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, monocyte chemoattractant protein-1 or matrix metalloproteinase-9 levels. Compared with placebo, estrogen tended to decrease tissue factor antigen and increase tissue factor activity levels by 7 +/- 46% and 5 +/- 34%, respectively (p = 0.321 and p = 0.117, respectively) and lower plasminogen activator inhibitor-1 levels by 16 +/- 31% (p = 0.043).

CONCLUSIONS

The effects of estrogen on endothelial, vascular dilatory and other homeostatic functions were less apparent in type II diabetic postmenopausal women, despite the beneficial effects of estrogen on lipoprotein levels.

The P-glycoprotein antagonist PSC 833 increases the plasma concentrations of 6alpha-hydroxypaclitaxel, a major metabolite of paclitaxel

PURPOSE

Overexpression of P-glycoprotein (Pgp) is one mechanism of drug resistance in cancer chemotherapy. A Phase I trial was conducted using PSC 833, a Pgp antagonist, in combination with paclitaxel in patients with refractory cancer. The objective of this study was to assess the effect of PSC 833 on the metabolism of paclitaxel and characterize the differences in 6alpha-hydroxypaclitaxel pharmacokinetics. In addition, we examined the possibility of enhanced cytotoxicity of paclitaxel by the coexistence of 6alpha-hydroxypaclitaxel.

EXPERIMENTAL DESIGN

Patients received paclitaxel 35 mg/m(2)/day by continuous intravenous infusion (CIVI) x 4 days without PSC 833 in cycle 1 and escalating doses of paclitaxel (13.1, 17.5, or 21.3 mg/m(2)/day CIVI x 4 days) with 5 mg/kg PSC 833 by mouth every 6 h x 7 days in cycle 2. Plasma samples were analyzed for both paclitaxel and its major metabolite with high-performance liquid chromatography methods. Using human liver microsomes, we studied the effect of PSC 833 on the metabolism of paclitaxel. In addition, the in vitro cytotoxicity of 6alpha-hydroxypaclitaxel alone and in combination with paclitaxel was evaluated.

RESULTS

Twenty-one of 22 patients had a metabolite peak (6alpha-hydroxypaclitaxel) observed in the chromatogram of plasma samples from cycle 2 when they received paclitaxel in combination with PSC 833. This metabolite was not detectable in plasma obtained during the first cycle when they received paclitaxel without PSC 833. During cycle 2, the mean concentrations of 6alpha-hydroxypaclitaxel and paclitaxel were 0.10 +/- 0.074 and 0.079 +/- 0.041 microg/ml, respectively. A moderate association was observed between total bilirubin and 6alpha-hydroxypaclitaxel concentrations (P = 0.015, r = 0.52; n = 21). Human liver microsome experiments showed that a PSC 833 concentration as high as 10 microM did not affect the production of 6alpha-hydroxypaclitaxel. Paclitaxel cytotoxicity in HL60 and K562 human leukemia cells was increased in the presence of noncytotoxic concentrations of 6alpha-hydroxypaclitaxel.

CONCLUSIONS

PSC 833 increases the plasma concentration of 6alpha-hydroxypaclitaxel during paclitaxel therapy. Inhibition of cytochrome P-450 3A4 by PSC 833 may explain this in part, although other mechanisms cannot be excluded.

Vascular effects of synthetic or natural progestagen combined with conjugated equine estrogen in healthy postmenopausal women

BACKGROUND

Synthetic, not natural, progestagen may negate the favorable effects of estrogen. Nonetheless, observational studies report no differences in risk for clinical cardiovascular events between users of unopposed estrogen and users of estrogen combined with synthetic progestin.

METHODS AND RESULTS

In a double-blind study, we randomly assigned 20 healthy postmenopausal women to micronized progesterone (MP) 200 mg or medroxyprogesterone acetate (MPA) 10 mg for 10 days with conjugated equine estrogen (CEE) 0.625 mg for 25 days and the remaining 5 days off cyclically during 2 months, followed by crossover to the alternate therapy. CEE+MP and CEE+MPA significantly improved the percent flow-mediated dilator response to hyperemia relative to baseline measurements (P=0.004 by ANOVA) by a similar degree (P=0.863). Both therapies significantly decreased E-selectin, intercellular adhesion molecule (ICAM)-1, and vascular cell adhesion molecule (VCAM)-1 levels from baseline values (P<0.001, P=0.048, and P=0.016 by ANOVA, respectively) by a similar degree (P=0.977 for ICAM-1 and P=0.541 for VCAM-1, respectively). CEE+MPA decreased E-selectin levels more than CEE+MP did (P=0.040). Both therapies significantly decreased monocyte chemoattractant protein-1 levels from baseline values (P<0.005 by ANOVA) by a similar degree (P=0.194). Both therapies significantly decreased tissue factor antigen and increased tissue factor activity levels from baseline values (P=0.003 and P<0.001 by ANOVA, respectively) by a similar degree (P=0.652 for antigen and P=0.173 for activity). Both therapies significantly lowered plasma plasminogen activator inhibitor-1 levels from baseline values (P<0.001 by ANOVA) by a similar degree (P=0.533).

CONCLUSIONS

CEE+MP and CEE+MPA provide similar improvement in endothelium-dependent vasodilator responsiveness and effects on markers of inflammation, hemostasis, and fibrinolysis inhibition in healthy postmenopausal women.

Phase I study of infusional paclitaxel in combination with the P-glycoprotein antagonist PSC 833

PURPOSE

PSC 833 (valspodar) is a second-generation P-glycoprotein (Pgp) antagonist developed to reverse multidrug resistance. We conducted a phase I study of a 7-day oral administration of PSC 833 in combination with paclitaxel, administered as a 96-hour continuous infusion.

PATIENTS AND METHODS

Fifty patients with advanced cancer were enrolled onto the trial. PSC 833 was administered orally for 7 days, beginning 72 hours before the start of the paclitaxel infusion. Paclitaxel dose reductions were planned because of the pharmacokinetic interactions known to occur with PSC 833.

RESULTS

In combination with PSC 833, maximum-tolerated doses were defined as paclitaxel 13.1 mg/m(2)/d continuous intravenous infusion (CIVI) for 4 days without filgrastim, and paclitaxel 17.5 mg/m(2)/d CIVI for 4 days with filgrastim support. Dose-limiting toxicity for the combination was neutropenia. Statistical analysis of cohorts revealed similar mean steady-state concentrations (C(pss)) and areas under the concentration-versus-time curve (AUCs) when patients received paclitaxel doses of 13.1 or 17.5 mg/m(2)/d for 4 days with PSC 833, as when they received a paclitaxel dose of 35 mg/m(2)/d for 4 days without PSC 833. However, the effect of PSC 833 on paclitaxel pharmacokinetics varied greatly among individual patients, although a surrogate assay using CD56+ cells suggested inhibition of Pgp was complete or nearly complete at low concentrations of PSC 833. Responses occurred in three of four patients with non-small-cell lung cancer, and clinical benefit occurred in five of 10 patients with ovarian carcinoma.

CONCLUSION

PSC 833 in combination with paclitaxel can be administered safely to patients provided the paclitaxel dose is reduced to compensate for the pharmacokinetic interaction. Surrogate studies with CD56+ cells indicate that the maximum-tolerated dose for PSC 833 gives serum levels much higher than those required to block Pgp. The variability in paclitaxel pharmacokinetics, despite complete inhibition of Pgp in the surrogate assay, suggests that other mechanisms, most likely related to P450, contribute to the pharmacokinetic interaction. Future development of combinations such as this should include strategies to predict pharmacokinetics of the chemotherapeutic agent. This in turn will facilitate dosing to achieve comparable CPss and AUCs.

Mode of action of sesame lignans in protecting low-density lipoprotein against oxidative damage in vitro

We investigated the antioxidant properties of sesaminol, a major component of sesame oil, on the oxidative modification of human low-density lipoprotein (LDL) in vitro. Sesaminol inhibited the Cu2+-induced lipid peroxidation in LDL in a concentration-dependent manner with an IC50 36.0 +/- 10.0 nM. Sesaminol was a more effective scavenger than either alpha-tocopherol or probucol in reducing the peroxyl radicals derived from 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) in aqueous solution. In addition, as determined by the secondary products of lipid peroxidation identified by using immunochemical methods, sesaminol completely inhibited the formation of 4-hydroxy-nonenal (4-HNE)- and malondialdehyde (MDA)-adducts in a concentration-dependent manner. Probucol and alpha-tocopherol at the same concentration exhibited a lesser inhibitory effect. Our findings suggest that sesaminol is a potentially effective antioxidant that can protect LDL against the oxidation.

Origin of O 1s core-level shifts on oxygen adsorbed Si(111)-(7x7)

Density functional calculations are used to examine the chemical and structural origin of O 1s core-level shifts measured on the initial oxidation stage of Si(111)-(7x7). Our analysis of metastable core-level peaks leads to a conclusive identification of the long-sought metastable oxidation species as a tetrahedral SiO4 unit, formed by two successive O2 adsorptions on a Si adatom. The origin of a higher-binding core-level shoulder is clarified by the presence of a threefold-coordinated subsurface O atom, introduced as a decay product of the metastable SiO4 unit. The present study provides a detailed atomic-scale picture of the initial oxidation process of Si(111)-(7x7).

NMDA-Receptor-dependent synaptic activation of voltage-dependent calcium channels in basolateral amygdala

Afferent stimulation of pyramidal cells in the basolateral amygdala produced mixed excitatory postsynaptic potentials (EPSPs) mediated by N-methyl-D-aspartate (NMDA) and non-NMDA glutamate receptors during whole cell current-clamp recordings. In the presence of GABA(A) receptor blockade, the mixed EPSPs recruited a large "all-or-none" depolarizing event. This recruited event was voltage dependent and had a distinct activation threshold. An analogous phenomenon elicited by exogenous glutamate in the presence of tetrodotoxin (TTX) was blocked by Cd(2+), suggesting that the event was a Ca(2+) spike. Selective glutamatergic blockade revealed that these Ca(2+) spikes were recruited readily by single afferent stimulus pulses that elicited NMDA EPSPs. In contrast, non-NMDA EPSPs induced by single stimuli failed to elicit the Ca(2+) spike even at maximal stimulus intensities although these non-NMDA EPSPs depolarized the soma more effectively than mixed EPSPs. Elongation of non-NMDA EPSPs by cyclothiazide or brief trains of stimulation were also unable to elicit the Ca(2+) spike. Blockade of K(+) channels with intracellular Cs(+) enabled single non-NMDA EPSPs to activate the Ca(2+) spike. The finding that voltage-dependent calcium channels are activated preferentially by NMDA-receptor-mediated EPSPs provides a mechanism for NMDA-receptor-dependent plasticity independent of Ca(2+) influx through the NMDA receptor.

Liquid chromatographic resolution of 2-hydroxycarboxylic acids on a new chiral stationary phase derived from (S)-leucine

Enantiomers of racemic 2-hydroxycarboxylic acids have been resolved as their O-ethoxycarbonyl pi-basic anilide derivatives on a new chiral stationary phase (CSP) derived from N-(3,5-dinitrobenzoyl)leucine N-phenyl N-alkylamide and the resolution results have been compared with those on various commercial pi-acidic CSPs. The resolution results demonstrate that the new CSP derived from N-(3,5-dinitrobenzoyl)leucine N-phenyl N-alkylamide is most effective among the five CSPs tested for the resolution of 2-hydroxycarboxylic acid derivatives. In order to elucidate the chiral recognition mechanism exerted by the new CSP, the resolution of slightly differently modified derivatives of 2-hydroxycarboxylic acids on the new CSP has been investigated. Based on the resolution results, a chiral recognition mechanism utilizing three simultaneous interactions such as the face to face pi-pi interaction and the two hydrogen bonding interactions between the CSP and the more retained enantiomer of the analyte has been proposed.

Dietary defatted sesame flour decreases susceptibility to oxidative stress in hypercholesterolemic rabbits

Plant glucosides possess antioxidative properties due to their ability to scavenge free radicals. Sesame seeds contain a class of these compounds, the sesaminol glucosides. To evaluate their antioxidative activity in vivo, we fed rabbits diets containing 1% cholesterol (Chol) with or without 10% defatted sesame flour (DSF) (containing 1% sesaminol glucosides) for 90 d. We determined the susceptibility of their tissues to oxidation ex vivo as well as serum total cholesterol (TC), phospholipid (PL), triglyceride (TG) and HDL cholesterol (HDL-C) concentrations. Serum TC, HDL-C, PL and TG levels were unaffected by the addition of DSF. The HDL-C in the Chol + DSF group was greater than in the Chol group at 45 d. Both were greater than in the groups that did not consume cholesterol. Liver TC and TG were significantly lower in rabbits fed the diet containing DSF plus 1% cholesterol than in those fed 1% cholesterol alone. Lipid peroxidation activity, measured as 2-thiobarbituric acid reactive substances (TBARS), was lower in the liver (P < 0.05) and serum (P = 0.06) of rabbits fed DSF plus cholesterol than in rabbits fed the cholesterol diet. Although we did not detect sesaminol glucosides in peripheral tissues, we observed abundant quantities of sesaminol in rabbits fed DSF, the principal metabolite. Our findings suggest that feeding DSF to rabbits does not protect cholesterol-induced hypercholesterolemia, but may decrease susceptibility to oxidative stress in rabbits fed cholesterol, perhaps due to the antioxidative activity of sesaminol.

Status of lipidsoluble antioxidants and TRAP in patients with Crohn's disease and healthy controls

OBJECTIVE

To assess the status of lipidsoluble antioxidants (carotenoids, tocopherols, ubiquinone), retinol and their correlation with TRAP (total radical-trapping antioxidant potential) in patients with Crohn's disease.

DESIGN

Prospective case-control study.

SETTING

Clinic of Internal Medicine IV/Department of Gastroenterology and Hepatology, University of Vienna Medical School.

SUBJECTS/METHODS

Plasma antioxidant concentrations were determined in patients with Crohn's disease (n = 24) to evaluate the antioxidant capacity compared to healthy controls (n = 33). Additionally, plasma TRAP (total radical-trapping antioxidant potential) was measured in 13 patients and 22 controls.

RESULTS

All investigated carotenoids (alpha-carotene, beta-carotene and cryptoxanthin) were significantly decreased in patients with Crohn's disease (10.2 +/- 9.3, 16.2 +/- 12.4 and 7.8 +/- 5.5 microg/dl) compared to controls (13.3 +/- 5.1, 34.7 +/- 18.8 and 48.5 +/- 38.4 microg/dl respectively), whereas gamma-tocopherol and ubiquinone were significantly elevated in patients (0.14 +/- 0.07 microg/dl and 82.3 +/- 41.5 microg/dl, controls: 0.09 +/- 0.04 microg/dl and 60.8 +/- 30.0 microg/dl, respectively). Retinol and alpha-tocopherol did not significantly differ from controls. The total radical-trapping antioxidant potential (TRAP) was significantly lower in patients (1.11 +/- 0.28 micromol/l) compared to controls (1.34 +/- 0.26 micromol/l). Antioxidants were neither related to duration or severity of disease nor to disease activity.

CONCLUSIONS

In patients with Crohn's disease several plasma antioxidant parameters are altered and the total radical-trapping antioxidant potential is decreased.

Alteration in the sensitivity of GABA(A) receptors to allosteric modulatory drugs in rat hippocampus after chronic intermittent ethanol treatment

Chronic intermittent ethanol (CIE)-treated rats exhibited a kindling-like persistent increase in withdrawal hyperexcitability. The alteration of GABA(A) receptor (GABA(A)R) function in the hippocampus was suggested as a possible mechanism underlying the hyperexcitability observed in CIE rats, because (1) GABA(A)R agonist (muscimol)-evoked 36Cl- efflux was decreased; (2) paired-pulse inhibition in the CA1 area, predominantly due to GABA(A)R-mediated recurrent inhibition, was persistently decreased; and (3) GABA(A)R subunit expression was altered in the hippocampus from CIE rats. To further characterize the functional alteration of GABA(A)R after CIE treatment, their sensitivity to acute ethanol, a steroid anesthetic (alphaxalone), and a benzodiazepine inverse agonist (DMCM; methyl-6,7-dimethoxy-4-ethyl-beta-carboline-3-carboxylate) were studied using either synaptically evoked GABA(A)R responses or exogenously applied muscimol-evoked responses in hippocampal slices. Bath application of ethanol (60 mM) enhanced the area of GABA(A)R-mediated inhibitory postsynaptic potentials in the hippocampal CA1 region from control and CIE rats, and this potentiation was significantly (p = 0.027) greater in CIE rats (98%) than in control rats (53%). The positive modulatory effect of alphaxalone (1 microM) on GABA(A)R-inhibitory postsynaptic potentials was not significantly different between control and CIE rats (p = 0.375), whereas alphaxalone allosterically increased [3H]flunitrazepam binding in the CA1 area only in CIE rats (by 20 to 25%, p < 0.01), but not in controls. On the other hand, the negative modulatory effect of DMCM (1 microM) on muscimol-evoked responses was significantly larger in CIE rats (p = 0.002). These results suggest that the sensitization of GABA(A)R to acute ethanol and benzodiazepine inverse agonists, and possibly neurosteroids, may underlie ethanol dependence after multiple ethanol withdrawal episodes. These altered pharmacological properties are most consistent with changes in the subunit composition in the CA1 area of this rat model of alcohol dependence.

Inhibition of 2,2'-azobis(2,4-dimethylvaleronitrile)-induced lipid peroxidation by sesaminols

We found that sesaminols, a mixture of sesaminol and its stereoisomers, are potent inhibitors of the oxidation of low-density lipoprotein induced by 2,2'-azobis(2,4-dimethylvaleronitrile). Although sesaminols strongly inhibit lipid peroxidation related to their ability to scavenge free radicals, their antioxidant effects have not been investigated. To confirm the involvement of the phenolic moiety in the sesaminol structure in antioxidant activity, sesaminols were reacted with 2,2'-azobis(2,4-dimethylvaleronitrile). The reaction products were isolated by high-performance liquid chromatography and found to have a 1-cyano-1,3-dimethyl-butyl-peroxyl group in their structures. These chemical structures suggest that the sesaminols reacted with the alkylperoxyl radicals to form four major reaction products that are stereoisomers of each other, although the stereochemistry of each isomer has not yet been confirmed. Further instrumental analyses of the reaction products may increase our understanding of the antioxidant activity of sesaminols.

Simultaneous measurement of multichannel laser linewidths and spacing by use of stimulated Brillouin scattering in optical fiber

A novel method for measuring the linewidth of each laser and channel spacing in a multichannel transmission system is presented. Using the dependence of the Stokes frequency shift on the pump wavelength in stimulated Brillouin scattering, we are able to construct a delayed self-heterodyne interferometer that can measure the linewidths and channel spacing simultaneously.

Sesamolin inhibits lipid peroxidation in rat liver and kidney

Although the sesame lignans, sesaminol and sesamolinol, have been shown to possess antioxidative activity, less is known about the metabolism and antioxidative properties of sesamolin, a major constituent of sesame oil. To determine the ability of sesamolin to act as an antioxidant in vivo, we fed rats a diet containing 1% sesamolin for 2 wk and studied its metabolism and its effects on oxidative stress. About 75% of the ingested sesamolin was excreted unmetabolized in feces, but it was not detected in urine. Sesamolin and its metabolites, sesamol and sesamolinol, were excreted primarily as sulfates and glucuronides. The amount of sesamolin and its metabolites was lower in the plasma than in the liver or kidneys. When we compared rats fed a diet containing 1% sesamolin for 14 d with those fed a control diet, we found that liver weight was significantly greater in the former group. Lipid peroxidation activity, measured as 2-thiobarbituric acid reactive substances, was significantly lower in the kidneys and liver of the sesamolin-fed rats than in the controls. In addition, the amount of 8-hydroxy-2'-deoxyguanosine excreted in the urine was significantly lower in the sesamolin-fed rats. These results suggest that sesamolin and its metabolites may contribute to the antioxidative properties of sesame seeds and oil and support our hypothesis that sesame lignans reduce susceptibility to oxidative stress.

Increased sister chromatid exchanges in peripheral lymphocytes of patients with Crohn's disease

A cytogenetic study was performed using Crohn's disease patients to determine whether the presence of chromosome instability is related to Crohn's disease, a chronic inflammatory bowel disease. Sister chromatid exchange (SCE) frequencies in peripheral blood lymphocyte cultures from 22 Crohn's disease patients and an equal number of healthy controls matched for sex and age were analyzed. The mean of SCE frequency in Crohn's disease patients was 11.64 +/- 0.42 (SEM) per cell, which was significantly higher than the value of 8.38 +/- 0.22 per cell in the matched controls (p < 0.0001). The Crohn's disease patients showed significantly increased high frequency cells (HFC) as compared to those among the matched controls. There was a significant correlation between HFC frequencies of the Crohn's disease patients and the severity of their disease as determined by the number of relapses per year and the degree of chronic activity after adjusting for the smoking status (r = 0.54, p = 0.011). In both smokers and non-smokers, the mean SCE and HFC frequencies of the patients were significantly higher than those of the controls. These results suggest that Crohn's disease is a condition with increased chromosome instability characterized by a high level of SCE frequencies which are associated with the inflammatory condition itself.

Chronic intermittent ethanol treatment in rats increases GABA(A) receptor alpha4-subunit expression: possible relevance to alcohol dependence

Chronic administration of ethanol to rats on an intermittent regimen, for 60 repeated intoxicating doses and repeated withdrawal episodes, results in a long-lasting kindling phenomenon. This involves an increasing severity of withdrawal, including a reduced threshold to seizures produced by the GABA(A) antagonist, pentylenetetrazol. We have shown previously that muscimol-evoked 36Cl- efflux and paired-pulse inhibition (involving GABA(A)-mediated recurrent inhibition) were decreased persistently in the CA1 region of hippocampal slices from chronic intermittent ethanol (CIE)-treated rats. We now report elevated levels of mRNA in forebrain for the alpha4 subunit of the GABA(A) receptor (GABAR), considered to be a constituent of pharmacologically and physiologically novel subtypes of GABARs. Using in situ hybridization with digoxigenin-labeled RNA probes, we show that at 2 days withdrawal, 60-dose CIE leads to a significant 30% increase in alpha4 subunit mRNA levels in the dentate gyrus, 46% increase in the CA3, and 26% increase in the CA1 regions. In contrast, there was no significant change in the mRNAs for the alpha5 subunit or glutamic acid decarboxylase 67 in the same regions. This study suggests that GABAR subunit-selective alterations occur after CIE treatment, possibly resulting in the alteration of the subunit composition of GABARs, with presumably altered physiological functions. This plasticity of GABARs may contribute to the increased withdrawal severity, reduced hippocampal inhibition, and increased seizure susceptibility of this animal model of human alcohol dependence.

Chemopreventive effect of green tea (Camellia sinensis) against cigarette smoke-induced mutations (SCE) in humans

Green tea (Camellia sinensis) is consumed daily between the meals or after meals in Japan and other Asian countries. In recent years, green tea and its major polyphenolics have been demonstrated to prevent chemically induced tumors in a variety of experimental animal models system. The exact mechanism(s) of its anticarcinogenic activity remains to be elucidated, but green tea polyphenolics have demonstrated antimutagenic, anticarcinogenic, antioxidant, and antipromotional effects, including inhibition of Phase I and inducing Phase II enzymes. Enzyme activities of glutathione peroxidase, catalase, and quinone reductase, and glutathione S-transferase are also induced. However, a paucity of green tea effects in humans prompted us to investigate antimutagenic effects of green tea against smoke-induced mutation in humans. Chemopreventive effects of green tea and coffee among cigarette smokers were examined in 52 clinically healthy male subjects between 20-51 years of age. Blood specimens were obtained from non-smokers (Group I), smokers (II), smokers consuming green tea (III), and smoker/coffee drinkers (IV). The mean years of cigarette smoking (> 10 cigarettes/day) of Groups II, III, and IV ranged from 13.4-14.7 years. Daily intake of green tea and coffee was 3 cups/day/6 months (III and IV). The frequencies of sister-chromatid exchange (SCE) in mitogen-stimulated peripheral lymphocytes from each experimental group were determined and statistically analyzed. SCE rates were significantly elevated in smokers (9.46 +/- 0.46) vs. non-smokers (7.03 +/- 0.33); however, the frequency of SCE in smokers who consumed green tea (7.94 +/- 0.31) was comparable to that of non-smokers, implying that green tea can block the cigarette-induced increase in SCE frequency. Coffee, by contrast, did not exhibit a significant inhibitory effect on smoking-induced SCE.

Chemopreventive effect of green tea (Camellia sinensis) among cigarette smokers

Chemopreventive effects of green tea and coffee among cigarette smokers were examined in 52 clinically healthy male subjects between 20 and 52 years of age. Blood specimens were obtained from nonsmokers (group I), smokers (group II), smokers consuming green tea (group III), and smokers drinking coffee (group IV). The mean number of cigarette smoking years (> 10 cigarettes/day) in groups II-IV ranged from 13.4 to 14.7 years. Daily intake of green tea and coffee was 2-3 cups/day for 6 months (groups III and IV). The frequencies of sisterchromatid exchange (SCE) in mitogen-stimulated peripheral lymphocytes from each experimental group were determined and analyzed statistically. SCE rates were elevated significantly in smokers (9.46 +/- 0.46) versus nonsmokers (7.03 +/- 0.33); however, the frequency of SCE in smokers who consumed green tea (7.94 +/- 0.31) was comparable to that of nonsmokers, implying that green tea can block the cigarette-induced increase in SCE frequency. Coffee, in contrast, did not exhibit a significant inhibitory effect on smoking-induced SCE.

Piperine effects on the expression of P4502E1, P4502B and P4501A in rat

1. Treatment of rat with piperine (PIP) (1.4 mmol/kg, 3 days ip injections) resulted in an approximate two-fold increase in total liver microsomal P450 content relative to that in uninduced animals. 2. 4-Nitrophenol and aniline hyroxylase activities in the hepatic microsomes prepared from rat treated with PIP decreased by 30 and 28% respectively as compared with control. Immunoblot analyses also revealed decreased P4502E1 levels in hepatic microsomes from PIP-treated animals. 3. In contrast with P4502E1 suppression, hepatic 2B1 and 2B2 levels were significantly increased in PIP-induced animals, as evidence by both metabolic activity and immunoblot analysis of the liver microsomal fractions. The rate of hexobarbital hydroxylase activity in microsomes from PIP-treated animals was markedly elevated and was inhibited by approximately 62% in the presence of monoclonal anti-P4502B IgG. Immunoblot analyses demonstrated that P4502B1 and 2B2 levels in hepatic microsomes from PIP-treated animals were comparable with those from phenobarbital-treated animals. 4. 7-Ethoxycoumarin deethylase activity was elevated approximately two-fold in PIP-induced animals and was 17% of that derived from 3-methylcholanthrene-induced animals. 7-ethoxycoumarin deethylase activity in PIP-induced hepatic microsomes was inhibited 63% in the presence of monoclonal anti-P4501A antibody. Immunoblot analysis confirmed the increase in P4501A levels by PIP, which was 15% of that in hepatic microsomes from 3-methylcholanthrene-induced animals. 5. PIP treatment failed to affect microsomal epoxide hydrolase (mEH) and glutathione S-transferases (GST) expression, as indicated by immunoblot analyses using polyclonal antibodies toward mEH and GST subunits Ya, Yb1, Yb2 and Yc. 6. These results demonstrate that PIP treatment suppressed P4502E1 expression and enhanced 2B and 1A expression, whereas this agent failed to affect hepatic mEH and GST expression.