Biomedical subjects

Natalie A Ceballos

Publications and source records attributed to Natalie A Ceballos.

13 recordsLinked to original sources

PubMed2006

Influence of naltrexone administration on dehydroepiandrosterone sulfate levels in male and female participants.

Dehydroepiandrosterone sulfate (DHEAS) is an excitatory neurosteroid with anti-glucocorticoid properties. Endogenous opioid system blockade is known to activate the hypothalamic-pituitary-adrenal axis and other hormonal systems. However, the literature is sparse regarding the extent to which this blockade acutely influences DHEAS activity. Further, the stability of DHEAS concentrations across short term laboratory studies is not well established. The current study examined these issues in human participants. Using a double-blind, counterbalanced design, 50mg of naltrexone and placebo were administered. Repeated salivary samples were then obtained over a 3h period while participants completed a nociceptive testing paradigm. DHEAS and cortisol concentrations were determined. Naltrexone administration was associated with an increase in cortisol concentrations; however, DHEAS was unaffected by naltrexone and did not vary across the course of the study. This finding is an important contribution to the methodological literature, and may be used to verify the stability of DHEAS for future investigations.

Adult↗

PubMed2006

Dehydroepiandrosterone sulfate, cortisol, mood state and smoking cessation: relationship to relapse status at 4-week follow-up.

It has been hypothesized that increased baseline dehydroepiandrosterone sulfate (DHEAS) levels may act as a natural antidepressant to attenuate negative affect during cocaine withdrawal and abstinence, decreasing the probability of relapse. The current study extends this model to assess factors related to risk of relapse in a sample of 68 nicotine dependent participants. Repeated measures ANOVAs were used to examine mood state, salivary DHEAS and cortisol levels across three assessment periods in participants who had relapsed over a 4-week follow-up period (n=51, 23 women) compared to those who maintained abstinence (n=17, 8 women). Total scores on the Profile of Mood States differed between those who had relapsed and those who maintained abstinence (p=0.008). However, DHEAS and cortisol levels, as well as the ratio of cortisol to DHEAS, did not differ significantly between groups. These findings suggest that, although DHEAS-related enhancement of resiliency to withdrawal may occur, the extent of this protective effect may be modulated by additional factors that warrant further research.

Adult↗

PubMed2006

Brain maturation in conduct disorder versus borderline personality disorder.

Conduct disorder (CD) and borderline personality disorder (BPD) have been associated with abnormalities in brain function. The present study assessed whether adolescents with significant symptoms of CD and BPD display abnormal brain maturation. Participants recruited from the community were categorized as CD only, BPD only, CD plus BPD, or controls with neither CD nor BPD. Brain maturation was estimated by the amplitude difference in the P300 event-related brain potential between participants < versus > or = 17 years old. With increasing age, controls and BPD only participants exhibited a P300 amplitude decline. This pattern was not evident in the CD only and CD plus BPD groups. The different brain maturation patterns seen in adolescents with CD versus BPD symptoms may contribute to differences in age-of-onset, clinical course, and resistance to treatment.

Adolescent↗

PubMed2006

Nicotine and cognitive efficiency in alcoholics and illicit stimulant abusers: implications of smoking cessation for substance users in treatment.

Cigarette smoking is prevalent among alcoholics and illicit substance abusers. However, the potentially confounding effect of nicotine on studies of cognition in detoxified substance users has rarely been addressed. In the current study of 87 participants, behavioral and electrophysiological indices of cognitive efficiency were measured in tobacco smokers from four groups: alcoholics, illicit stimulant abusers, concurrent abusers, and control subjects. Data were collected from 2001 to 2003. We hypothesized that acute nicotine administration would modify cognitive deficits in alcoholics and illicit stimulant abusing groups. An adaptation of the Rapid Visual Information Processing task was administered after stabilization of nicotine levels via a high- or low-dose transdermal nicotine patch. Across groups, increased nicotine dose was associated with decreased reaction time (p = .03). A group x nicotine dose interaction trend was noted in which increased nicotine was associated with increased correct responding within the alcoholic group (p = .02). No significant differences in electrophysiology were observed. These results suggest that nicotine may modify cognitive efficiency in alcoholics and illicit stimulant abusers, a concept with relevance to both the design of experimental work and the treatment of alcohol and illicit stimulant dependence. Further work is needed to determine whether this effect predominantly reflects facilitation of cognition function or alleviation of nicotine withdrawal.

Administration, Cutaneous↗

PubMed2006

Interactive effects of hypertension and alcohol dependence on the P300 event-related potential in African-Americans.

Although hypertension and alcohol dependence have been linked by epidemiological surveys and clinical observations, their interactive effects on brain function have rarely been tested. The present study involved the recording of P300 event related potentials (ERP) from 106 middle-aged African-American adults assigned to one of four groups: normotensive/nondependent (n=56), hypertensive/nondependent (n=11), normotensive/dependent (n=27), and hypertensive/dependent (n=12). The numbers of Nicotine Dependence, Major Depressive Disorder, and Conduct Disorder symptoms were specified as covariates within a 2 by 2 factorial design. ERPs were recorded during separate visual and auditory oddball tasks. The major result was a synergistic effect of hypertension and alcohol dependence on auditory P300 latency: the combination of both factors was associated with greater slowing than the sum of their independent effects. Future studies should continue to examine the potential synergistic effects of alcohol dependence and hypertension with a view toward identifying and reducing neurophysiological decrements and stroke risk among middle-aged patients.

Adolescent↗

PubMed2006

Tobacco use, alcohol dependence, and cognitive performance.

Chronic alcohol abuse has long been associated with a mild, generalized pattern of cognitive decrements. However, it is important to note that problem drinking rarely occurs in isolation from abuse of other drugs. For people dependent upon alcohol, tobacco is one of the mostly commonly coabused substances. Recent research suggests that individuals with alcohol dependency may gravitate toward tobacco use, in part, because of the positive effects of nicotine on aspects of cognitive performance that may be compromised as a consequence of chronic alcohol misuse. In this article, the author focuses on the effects of nicotine on behavioral and electrophysiological indexes of cognitive performance, and the impact of these effects on alcohol-related cognitive decrements. The author discusses implications of these findings in the context of treatment and recovery of people with alcoholism.

Alcohol Drinking↗

PubMed2005

Borderline personality disorder features in adolescent girls: P300 evidence of altered brain maturation.

OBJECTIVE: To examine brain maturation in adolescent girls with borderline personality disorder (BPD) features using the P300 event-related potential. METHODS: One hundred twenty-three girls, aged 14-19 yrs, were assigned to one of 4 groups formed by the crossing of BPD features (vs. > or =5 BPD criteria) and median age (vs. >16.5 yrs). P300 responses were measured while subjects performed a complex visual oddball task. RESULTS: ANCOVAs of P300 amplitude-adjusting for variability associated with comorbid conduct disorder and depression symptoms--revealed a significant interaction. Among subjects without BPD features, aging was associated with the normal reduction in visual P300 amplitude. Among subjects with BPD features, there were no age-related changes. Additional analyses, which tested the effects of BPD features across the full age range, supported these findings. CONCLUSIONS: The present findings suggest abnormal brain maturation among adolescent girls exhibiting features of BPD. SIGNIFICANCE: These results support a hypothesis of altered brain maturation in adolescents exhibiting BPD features at an early age. It is suggested that measures of brain maturation obtained during adolescence may improve our ability to predict BPD and comorbid disorders in adulthood.

Adolescent↗

PubMed2005

Sensorimotor dysfunction in HIV/AIDS: effects of antiretroviral treatment and comorbid psychiatric disorders.

OBJECTIVES: Balance and gait problems have repeatedly been mentioned in case descriptions of patients infected with Human Immunodeficiency Virus (HIV-1). Objective evidence of these problems has rarely been reported, however. Furthermore, the extent to which balance and gait are influenced by antiretroviral medications or comorbid psychiatric disorders has rarely been examined. DESIGN: The study compared 78 HIV-1 seronegative volunteers to 28 HIV/AIDS patients receiving no antiretroviral therapy, 25 patients receiving only nucleoside analogue therapy, and 37 patients receiving Highly Active Antiretroviral Therapy (HAART). METHODS: The dependent measures included Equilibrium Quotient scores recorded during 3 subtests of the Sensory Organization Test (SOT), the number of falls during each subtest, the functional base of support, gait speed and cadence, single leg balance time, proximal strength, and vibrotactile threshold of the foot. The analysis employed the number of alcohol and drug abuse problems, depression severity, and body mass index as covariates. RESULTS: ANCOVAs revealed significant decrements in the 3 HIV-1 seropositive groups relative to the control group on Equilibrium Quotient scores during the most difficult of the SOT subtests (sway-referenced support surface with eyes-closed). HIV/AIDS patients also exhibited a smaller functional base of support and greater vibrotactile thresholds. Antiretroviral treatment did not affect balance; but, it did alter sensory threshold in a complex manner. CONCLUSIONS: HIV/AIDS is associated with reliable decrements in balance and peripheral sensory function which are variably sensitive to antiretroviral treatment. The implications of these findings for mobility, and workplace or operator safety, should be contemplated.

Acquired Immunodeficiency Syndrome↗

PubMed2005

N400 as an index of semantic expectancies: differential effects of alcohol and cocaine dependence.

BACKGROUND: Chronic substance abuse has been associated with decrements in the processing and expression of language. The present study utilized the N400 event-related electroencephalographic potential to index semantic processing in 133 adults with (n=49) or without (n=84) a history of alcohol and/or cocaine dependence. The contributions of age, gender, and comorbid marijuana and nicotine dependence, and antisocial symptomology to N400 decrements were either covaried or controlled. METHODS: A continuous series of 300 stimuli was presented for 150 ms each (interstimulus interval=1475 ms) on a computer screen. The series was arranged such that a word (approximately 17% of stimuli) immediately preceded presentations of its antonym (primed condition; approximately 17% of stimuli), or a semantically unrelated word (unprimed condition; approximately 17% of stimuli). The remaining 50% of stimuli consisted of unpronounceable letter combinations (non-word condition). EEG responses to the antonyms, unrelated words, and letter jumbles were retained for analysis. Throughout the task, the subject pressed response keys to discriminate words from non-words. RESULTS: Analyses revealed a detrimental effect of alcohol dependence on N400 amplitude and no significant main or interactive effects of cocaine dependence. CONCLUSION: The present findings suggest that alcohol-dependent individuals may exhibit verbal processing decrements. These findings also challenge hypotheses suggesting that the combined use of cocaine and alcohol is more deleterious to brain function than alcohol use alone.

Adolescent↗

PubMed2004

Visual-spatial attention in alcoholics and illicit stimulant abusers: effects of nicotine replacement.

Reports of alcohol or illicit drug-related cognitive impairments have frequently disregarded the potentially confounding effects of smoking status and nicotine withdrawal on these measures. This study addressed this issue by measuring visual-spatial attention via an adaptation of the Posner paradigm in three groups of tobacco smokers: controls without a history of alcoholism or illicit drug use (n=27; 20 male), chronic alcoholics (n=22; 18 male), and illicit stimulant abusers (n=36; 21 male). Throughout testing, nicotine levels were stabilized by the double-blind administration of a high (14 or 21 mg) or low (7 mg) dose transdermal nicotine patch. A significant effect of group was observed for number of correct responses to restriction trials (F=5.48, 2/79 df; p=.006). Performance was normalized in the illicit stimulant group, and alcoholic participants exhibited superior performance relative to both illicit stimulant abusers (p=.002) and controls (p=.01). These findings support the hypothesis that nicotine may have a compensatory or normalizing effect on attentional functions in substance abusers. Whether these results reflect the central nervous system-activating effects of nicotine or merely alleviation of nicotine withdrawal is a topic of ongoing research.

Administration, Cutaneous↗

PubMed2004

Effects of antisocial personality, cocaine and opioid dependence, and gender on eye movement control.

Substance-dependent patients have been reported to exhibit abnormal smooth pursuit and saccadic eye movements. However, contrasts of the effects of different substances and the effects of comorbid psychiatric symptoms such as antisocial personality have rarely been performed. Separate analyses examined the effects of cocaine dependence, opioid dependence, or antisocial personality disorder. In each analysis, sex was included as an additional grouping factor. The dependent measures were the gain of smooth pursuit eye movement and the delay and accuracy of saccadic eye movement. Analyses of covariance indicated that both cocaine dependence and antisocial personality, but not opiate dependence, were associated with a significant reduction in gain of smooth pursuit eye movement. Cocaine dependence and antisocial personality also slowed the onset of saccadic eye movements, but only in men. No group differences were found in the accuracy of saccadic eye movements. The results suggest that the neurophysiological effects of cocaine dependence and antisocial personality overshadow the effects of heroin. The significance of these findings for visual attention and reading skill has yet to be assessed.

Antisocial Personality Disorder↗

PubMed2003

Substance abuse-related P300 differences in response to an implicit memory task.

The current study examined electrophysiological measures of cognitive efficiency in alcoholics and controls using a negative priming paradigm derived from DeSchepper and Treisman (J. Exp. Psychol. Learn. Mem. Cog. 22 (1996) 27). In this task, sets of novel shapes were presented: Two overlapping green and red shapes on the left and a single white shape on the right. Participants were instructed to ignore the red shape, but to determine whether the green shape was the same as or different from the white shape. On primed trials, previously red (to be ignored; i.e., irrelevant) shapes became green (relevant) shapes in a second component of the task. Participants who were capable of ignoring irrelevant stimuli were expected to experience more difficulty in the primed condition. Therefore, we predicted that, if alcohol-related impairment in cognitive efficiency is due to inability to respond "appropriately" (i.e., ignore irrelevant stimuli), alcoholics would experience less negative priming than normal controls. Both amplitude and latency of the P300 component of the event-related potential were measured in response to each trial condition. Using a 2 x 2 (group x condition) ANOVA with repeated conditions, a significant pattern of group x condition interactions was observed at right frontal, F4 (p=.05) and central parietal, Pz (p=.03) electrode sites on measures of P300 amplitude. A significant group x condition latency interaction was observed at the central parietal electrode, Pz (p=.006). Overall, controls exhibited increased P300 amplitude and latency in response to negatively primed trials. As predicted, alcoholics did not demonstrate this pattern, a finding consistent with alcohol-related cognitive inefficiency.

Adult↗

PubMed2003

Semantic processing in alcoholics with and without antisocial symptomatology.

OBJECTIVE: Chronic alcoholics with a comorbid diagnosis of antisocial personality (ASP) symptomatology often exhibit early onset, severe course, and poor treatment outcomes. In addition, antisocial characteristics have been associated with a variety of cognitive deficits, including abnormalities of semantic processing, a deficit also found in alcoholics. Using the N400 task, this study investigated whether comorbid ASP symptomatology in alcoholics and community controls contributes to deficits in cognitive efficiency. METHOD: The N400 component of the event-related potential was elicited in detoxified alcoholics (n = 71; 56 male) and community controls (n = 36; 22 female) by sentences with congruent, related/incongruent or unrelated/incongruent terminal words. Difference waveforms were derived, and both amplitude and latency measures were obtained. Antisocial personality symptomatology was assessed using the ASP section of the Diagnostic Interview Schedule IV. RESULTS: Data were analyzed via linear regression using alcoholism, ASP positive (ASP+) status and their interaction term as predictors of N400 amplitude and latency. Significant latency findings were noted in the related/incongruent sentence condition. Increased N400 latency was predicted by ASP+ status at electrode site Pz (p = .01). The interaction of alcoholism and ASP+ status predicted increased N400 latency at electrode site P4 (p = .009), with ASP+ alcoholics demonstrating the greatest latency. CONCLUSIONS: The presence of N400 latency differences in response to related/incongruent semantic information in the current study differs from previous findings in studies of chronic alcoholism that do not account for ASP. These data suggest that antisocial personality disorder and alcoholism may affect cognitive function via different underlying mechanisms.

Adult↗