Astrocytic proliferation in the piriform cortex of amygdala-kindled subjects: a quantitative study in partial versus fully kindled brains

Complex partial epilepsy is a seizure disorder in which attacks frequently arise from foci located in the temporal lobes. The amygdala-kindling model is a widely used model of complex partial epilepsy with secondary generalization. The present study was designed to quantitatively assess astrocytic changes in the rat piriform cortex in the amygdala-kindling model of epilepsy. Bromodeoxyuridine-injected subjects were sacrificed 24 h after the first stage 1 or fifth stage 5 seizure. Brain sections were prepared and examined quantitatively. A significantly higher number of dividing astrocytes (identified by co-labeling with antibodies to bromodeoxyuridine and to one of the astrocytic intermediate filament proteins glial fibrillary acidic protein or vimentin) was found in both partially kindled (stage 1) and fully kindled (stage 5) brains. The partially kindled brains had a significantly higher number of double-labeled cells on the side ipsilateral to stimulation. The opposite trend was observed in the fully kindled brains. Differences between the ipsilateral and contralateral sides of the kindled brain may suggest different role(s) for astrocytes in the development and progression of the seizure-prone state.     

Structural and functional probing of the biogenic amine transporters by fluorescence spectroscopy

Fluorescence spectroscopy techniques have proven extremely powerful for probing the molecular structure and function of membrane proteins. In this review, it will be described how we have applied a series of these techniques to the biogenic amine transporters, which are responsible for the clearance of dopamine, norepinephrine, and serotonin from the synaptic cleft. In our studies, we have focused on the serotonin transporter (SERT) for which we have established a purification procedure upon expression of the transporter in Sf-9 insect cells. Importantly, the purified transporter displays pharmacological properties in detergent micelles similar to that observed in membranes suggesting that the overall tertiary structure is preserved upon purification. Using this purified SERT preparation and the fluorescent cocaine analogue RTI-233 as a molecular reporter, we have been able to characterize the microenvironment of the cocaine-binding pocket. In current follow-up studies, we are attempting to map the relative position of this binding pocket using fluorescence resonance energy transfer (FRET) between RTI-233 and an acceptor fluorophore covalently attached to endogenous cysteines in the transporter. Finally, it will be described how we recently initiated the implementation of single-molecule confocal fluorescence spectroscopy techniques in our studies of the SERT.     

Pharmacodynamic mechanisms of monoclonal antibody-based antagonism of (+)-methamphetamine in rats

Our studies examined pharmacokinetic mechanisms involved in high-affinity (K(d) approximately 11 nM) monoclonal antibody-based antagonism of (+)-methamphetamine-induced locomotor effects. Male rats received (+)-methamphetamine (0.3, 1, or 3 mg/kg i.v.) followed 30 min later by saline or anti-(+)-methamphetamine monoclonal antibody. All groups received a constant dose of monoclonal antibody that was equimolar in binding sites to the body burden of a 1 mg/kg i.v. (+)-methamphetamine dose 30 min after administration. The monoclonal antibody antagonized locomotor effects due to 0.3 and 1 mg/kg (+)-methamphetamine. In contrast, monoclonal antibody treatment increased locomotor activity due to 3 mg/kg (+)-methamphetamine. We also investigated the serum and brain pharmacokinetics of (+)-methamphetamine without and with the monoclonal antibody. Rats received (+)-methamphetamine (1 mg/kg i.v.) followed by saline or monoclonal antibody treatment at 30 min. The monoclonal antibody significantly increased serum methamphetamine concentrations and significantly decreased brain methamphetamine concentrations. These data indicate that anti-(+)-methamphetamine monoclonal antibody-induced pharmacodynamics are complex, but are related to time-dependent changes in (+)-methamphetamine brain distribution.     

Tumor-derived aberrant methylation in plasma of invasive ductal breast cancer patients: clinical implications

Progressive p16 methylation has been associated with metastasis and invasive phenotypes in many cancers. Loss of E-cadherin (CDH1) function contributes to breast cancer progression by promoting cell proliferation, invasion and metastasis. Using methylation-specific PCR, aberrant hypermethylation of p16 and CDH1 in tumor and plasma was analyzed and correlated with levels of serum protein markers, carcinoembryonic antigen (CEA) and carcinoma antigen 15-3 (CA15.3), in 36 patients with invasive ductal breast cancer. Aberrant p16 methylation was found in 11% (4/36) of primary tumors and 8% (3/36) of plasma samples. Aberrant CDH1 methylation was detected in 25% (9/36) of primary tumors and 20% (7/36) of plasma samples. p16 and/or CDH1 hypermethylation was found in 31% (11/36) of primary breast carcinomas and 82% (9/11) of breast cancer patients with tumoral methylation showing identical epigenetic changes in plasma. The 25 patients without tumoral methylation did not show epigenetic changes in the plasma. Tumoral p16 methylation was significantly associated with advanced tumor stage (p=0.028; Fisher's exact test), tumor size (p=0.017) and nodal metastasis (p=0.002). However, p16 methylation in plasma was only associated with nodal metastasis (p=0.012). Altogether, aberrant p16 methylation in plasma and elevated serum CEA level were associated with advanced tumor stage (p=0.033), tumor size (p=0.022) and extensive nodal metastasis (p=0.003). With clinical implications, p16 hypermethylation in plasma and/or raised serum CEA levels may prove useful as diagnostic and prognostic markers for breast cancer.     

A study of the efficacy of cervical ripening with nitric oxide donor versus placebo for cervical priming before second-trimester termination of pregnancy

This was a double-blind randomized control study to evaluate the efficacy of cervical priming by nitric oxide donor before second-trimester induced abortion. One-hundred healthy women with a singleton pregnancy between 14 and 20 weeks of gestation were randomized into either 40 mg isosorbide mononitrate or placebo, given intravaginally 12 h before induction. This was followed by intravaginal misoprostol induction. The induction-abortion interval, abortion rate, side effects and the woman's acceptability of the priming agent were recorded. All women completed the study and there was no severe complication recorded. There was no significant difference in the induction-abortion interval and abortion rate between the two groups. Isosorbide mononitrate group reported significantly more side effects of headache. More than 90% of the women in both groups found the priming agent acceptable. The application of intravaginal nitric oxide donors prior to the prostaglandins induction did not significantly improve the second-trimester induced-abortion process.     

Attention‐deficit hyperactivity disorder reduces automatic attention in young adults

Previous ERP studies have provided mixed information about ADHD, especially in adults and when conscious attention to stimuli is not required. We used the auditory N1 to assess automatic attention in adults with and without ADHD. While participants watched a silent video, trains of 5 tones (400‐ms onset‐to‐onset time) were presented with intertrain intervals (ITIs) of 1 or 5 s. The P1, N1, P2, and N2 were analyzed. Compared to controls, participants with ADHD had relatively little N1 attenuation after the 5‐s ITI, which was driven by uniformly small N1s to all tones. However, after the 1‐s ITI, the ADHD group had relatively large N2s to all 5 tones in the train. The reduced N1 in adults with ADHD indicated reduced automatic attention to salient sound stimuli, which may be due to reduced function of brain‐stem arousal mechanisms. However, the increased N2 in these participants suggests they had developed certain compensatory mechanisms.     

Modeling the impact of comorbidity on breast cancer patient outcomes

The objective of this paper is to model the impact of comorbidity on breast cancer patient outcomes (e.g., length of stay and disposition). Previous studies suggest that comorbidities may significantly affect mortality risks for breast cancer patients. The 2006 AHRQ Nationwide Inpatient Sample (NIS) is used to analyze the relationships among comorbidities (e.g., hypertension, diabetes, obesity, and mental disorder), total charges, length of stay, and patient disposition as a function of age and race. A multifaceted approach is used to quantify these relationships. A causal study is performed to explore the effect of various comorbidities on patient outcomes. Least squares regression models are developed to evaluate and compare significant factors that influence total charges and length of stay. Logistic regression is used to study the factors that may cause patient mortality or transferring. In addition, different survival models are developed to study the impact of comorbidity on length of stay with censoring information. This study shows the interactions and relationship among various comorbidities and breast cancer. It shows that certain hypertension may not increase length of stay and total charges; diabetes behaves differently among general population and breast cancer patients; mental disorder has an impact on patient disposition that affects true length of stay and charges, and obesity may have limited effect on patient outcomes. Moreover, this study will help to better understand the expenditure patterns for population subgroups with several chronic conditions and to quantify the impact of comorbidities on patient outcomes. Lastly, it also provides insight for breast cancer patients with comorbidities as a function of age and race.