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Biomedical subjects

Laura Cousino Klein

Publications and source records attributed to Laura Cousino Klein.

17 recordsLinked to original sources
PubMed2006

Disruption in Th1/Th2 immune response in young adult smokers.

Interferon (IFN)-gamma and IL-10 cytokines, measures of Th1 and Th2 immunity, were examined in 20 healthy nonsmokers (12 males, 8 females) and 19 smokers (11 males, 8 females), aged 19-41 years (23.46+/-0.82 years). Nonsmokers came to the laboratory once; smokers came to the laboratory after ad lib smoking and following 24-h smoking abstinence. Salivary cotinine and expired CO confirmed smoking status. Plasma was collected at the end of each lab session and assayed for peripheral IFN-gamma and IL-10 levels. Among smokers, peripheral IFN-gamma, IL-10, or IFN-gamma/IL-10 ratio levels did not change in response to 24-h smoking abstinence. IFN-gamma levels and IFN-gamma/IL-10 ratios were higher among female smokers while smoking and following 24-h abstinence compared to male smokers in both conditions and compared to male and female nonsmokers. There was no sex or smoking status difference in IL-10 levels. Results suggest that cigarette smoking may have at least short-term damaging effects on the body's normal immune balance, particularly for women.

Adult↗
PubMed2006

'Return to home cage' as a reward for maze learning in young and old genetically heterogeneous mice.

Recent studies have shown that 'return to home cage' can serve as a reward for maze learning in adult male mice. The present study examined whether the same reward is an effective motivator of learning in young and old mice and included females in the study design. We tested 25- and 65-d-old HS mice and 85- and 800-d-old B6D2F2 mice in a Lashley III maze. Return to home cage motivated maze acquisition in all groups. Compared with 65-d-old HS mice, 25-d-olds acquired the maze more slowly, took longer to achieve the test criterion, and showed increased latency to reach the goal box. There was no difference between 85- and 800-d-old B6D2F2 mice in rate of acquisition. This reward procedure may reduce the potentially confounding effects of deprivation or aversive stimuli on maze performance and may be suitable as a motivational procedure for a wide range of subject groups.

Aging↗
PubMed2006

Fecal corticoid metabolites in aged male and female rats after husbandry-related disturbances in the colony room.

We applied novel noninvasive fecal steroid measures to characterize aged rats' responses to a series of common animal room disturbances, including a direct comparison of male and female immunoreactive corticosterone metabolites in feces. The fecal measure provides a unique method to measure the physiologic responses of laboratory animals to altered husbandry procedures. This assay is noninvasive and, because rodents produce fecal pellets throughout the day, long-term monitoring can be conducted to capture abnormal levels associated with alterations in husbandry procedures. Over a 3-h period, 10 male and 10 female Fischer 344 rats (age, 82 wk) were exposed to a series of events that can occur in a colony housing room (keys jingling, cage lids opening, alteration of the light cycle). Fecal samples were collected at timed intervals on the day before and several days after the exposure, extracted, and analyzed for fecal corticoid metabolites by use of a commercial enzyme immunoassay. Fecal metabolites in these aged rats were elevated 3- to 5-fold above baseline levels approximately 20 h after exposure to the experimental events. Overall, we detected more immunoreactive fecal corticoid metabolites in feces from male rats than female rats, even though female rats normally secrete greater amounts of glucocorticoids into circulation. Our results indicate that this assay can be used to identify marked elevations in corticoid metabolite levels after alterations in laboratory husbandry procedures. We discuss the implications of these findings for animal researchers and those involved in animal husbandry.

Age Factors↗
PubMed2004

Leptin, hunger, and body weight: Influence of gender, tobacco smoking, and smoking abstinence.

Leptin is a hormone involved in body weight and hunger regulation, and may contribute to the inverse relationship between cigarette smoking and body weight. Leptin levels, body mass indices (BMIs), and hunger ratings were determined in 22 nonsmokers (12 male, 10 female) and 19 cigarette smokers (11 male, 8 female). Smokers were tested after ad lib smoking and following a 24-h smoking abstinence period; nonsmokers came to the laboratory once. Leptin levels were not different among the groups. Hunger ratings, however, were higher after smoking abstinence compared to after ad lib smoking and nonsmokers (Ps<.05); levels of hunger did not differ between ad lib smokers and nonsmokers. Men reported higher hunger levels than did women, but women had higher serum leptin levels than did men, regardless of smoking condition (P<.05). Leptin levels were correlated with BMI (P<.05) among smokers only. This first study on leptin responses in female smokers suggests that leptin levels do not change following a 24-h smoking abstinence period and that leptin may not contribute to increased hunger following smoking abstinence.

Adolescent↗
PubMed2004

Sex differences in voluntary oral nicotine consumption by adolescent mice: a dose-response experiment.

Recent studies with adolescent rodents offer valuable information regarding the neurochemical and behavioral effects of adolescent nicotine exposure. One hundred twenty-one male and 125 female adolescent (35 days of age) C57BL/6J mice were tested for voluntary nicotine consumption by providing 24-h access to both saccharin-only (SAC) and one of six nicotine-containing solutions [10, 25, 50, 75, 100, 200 ug (-)-freebase nicotine/ml in 2% SAC] in the home cage for 7 days. Although males and females drank similar volumes (ml) of nicotine, the female mice consumed more nicotine adjusted for body weight (mg/kg) and as a percentage of total fluid intake than did the male mice. In contrast, there was no sex difference in overall serum cotinine levels (adjusted for liver weight). For all mice, nicotine consumption and serum cotinine levels increased in a dose-dependent manner, and the volume of nicotine intake (ml), percent nicotine intake, and nicotine dosage (mg/kg) on the last day of the experiment were positively correlated with cotinine levels. Cotinine levels were inversely related to body weight only for females. Sex differences in nicotine consumption, but not in cotinine levels, suggest sex differences in pharmacokinetic processes that may contribute to oral nicotine consumption behavior during periadolescence.

Administration, Oral↗
PubMed2004

Research on nicotine and tobacco: a decade of progress.

The 10th annual meeting of the Society for Research on Nicotine and Tobacco (SRNT) was held February 19-21, 2004, in Scottsdale, Arizona. With nearly 850 registered attendees, this year's meeting was the largest to date. The 3-day scientific program included William Corrigall as the keynote speaker, three theme lecturers, one award address, 10 symposia, nine oral paper sessions, and four poster sessions that contained over 100 presentations per session. The meeting content emphasized three major areas of SRNT's scientific focus: Preclinical, clinical, and epidemiology/public health research in the nicotine and tobacco field. The meeting provided many opportunities to interact with and learn from colleagues engaged in broad topics within nicotine and tobacco research. Additional events included two preconference meetings, an opening reception, several evening workshops, scientific and travel awards, and a members' meeting. The scientific excellence and innovation presented at this year's meeting represented SRNT's growth and continued contributions to advancing our understanding of nicotine addiction and tobacco use.

Biomedical Research↗
PubMed2003

C-reactive protein and depressed mood in a sub-group of smokers during nicotine abstinence.

Cigarette smokers frequently fail multiple attempts to quit smoking, often because of the unpleasant symptoms that accompany quitting. Similar unpleasant symptoms accompany inflammatory responses during infection and autoimmune disease. The hypothesis that smoking abstinence induces inflammation was tested. Eighteen smokers (n = 18) were evaluated while smoking freely and after 24 h of nicotine abstinence. Immune, cardiovascular and psychological measures were collected. Hunger, nervousness, anxiety, restlessness and irritability increased during abstinence (p < 0.05); systolic blood pressure and heart rate levels decreased (p < 0.05). Analysis demonstrated a split among smokers in response to abstinence compared with smoking freely; some smokers (n = 10) displayed increased C-reactive protein (CRP, p < 0.05) whereas others (n = 8) responded with decreased CRP (p < 0.05). An increase in symptoms of depressed mood and a fall in heart rate occurred only in those who displayed increased CRP with nicotine abstinence ( p < 0.05), while systolic blood pressure fell only in those whose CRP levels decreased with abstinence ( p < 0.05). Interleukin-1 and interleukin-6 did not change with abstinence. The results suggest that 24 h nicotine abstinence does not stimulate inflammation among all smokers, but that a sub-group of smokers do demonstrate an inflammatory response with significant negative psychological and physiological symptomatology.

Adolescent↗
PubMed2003

A novel mouse-friendly cognitive task suitable for use in aging studies.

Tests of cognition in mice frequently employ deprivations or aversive stimuli to motivate learning. Such manipulations may confound interpretation of differences in performance. Concerns arising from the potential confounding are accentuated when the object of the experiment is to compare cognitive function of young and old animals because aging alters many processes that affect maze performance. To assuage some of these concerns, we tested the potential of a novel reward procedure to motivate maze learning. Food-and water-satiated mice of two genetically heterogeneous groups that gained access to their home cage after reaching the goal box of a Lashley III maze attained the acquisition criterion as quickly as did mice motivated by hunger and given food reward. We suggest that "return to home cage" is a useful reinforcer in tests of cognition. This reward procedure is unusual in that it offers an important animal-friendly alternative to the usual ways of motivating cognitive performance, is economical of experimenter time, and may avoid the potentially confounding effects of physiological deprivations and aversive stimuli on maze performance of aged mice.

Aging↗
PubMed2003

Laternal nicotine exposure increases nicotine preference in periadolescent male but not female C57B1/6J mice.

Maternal cigarette smoking is a risk factor for adolescent smoking. One possible explanation for increased smoking by human adolescents after maternal nicotine exposure is that exposure increases nicotine preference. However, it is difficult to separate the biological and social causes of smoking behavior in humans. This experiment examined the relationship between maternal nicotine exposure and nicotine preference in periadolescent offspring using a mouse model of oral nicotine consumption. Pregnant females were provided saccharin-flavored water containing 50 microg/ml nicotine (n = 4) or no nicotine (n = 5) from the ninth day of gestation through weaning on postnatal day (PD) 21. Offspring from these females were tested for nicotine preference during periadolescence (PDs 35-42) by providing access to both saccharin-only and nicotine solutions (50 microg/ml) 24 hr a day in the home cage in a two-bottle choice test. Male mice exposed maternally to nicotine (n = 9) exhibited an increased nicotine preference in adolescence compared to non-nicotine exposed controls (n = 12). Maternal nicotine exposure did not alter nicotine preference by periadolescent female mice. Nicotine consumption was confirmed by serum cotinine measurement. These data are consistent with human epidemiological reports that maternal nicotine exposure is associated with increased risk of cigarette smoking. Differential outcomes for males and females suggest that different processes underlie sex differences in nicotine consumption following maternal nicotine exposure.

Age Factors↗
PubMed2003

Recent advances in nicotine and tobacco research. Ninth SRNT annual meeting. New Orleans, Louisiana, USA. 19-22 February 2003.

The ninth annual meeting of the Society for Research on Nicotine and Tobacco (SRNT) was held February 19-22, 2003, in New Orleans, Louisiana. With over 800 registered attendees, this year's meeting was the largest to date. The 3-day scientific program included C. Everett Koop as the keynote speaker, four exemplary plenary speakers, 10 symposia, nine oral paper sessions, and four poster sessions that contained nearly 100 presentations per session. The meeting content emphasized three major areas of SRNT's scientific focus: Epidemiology/public health research, preclinical research, and clinical research. Thus, the meeting was an outstanding opportunity to interact with and learn from colleagues engaged in the broad area of nicotine and tobacco research around the globe. Additional events included pre- and postconference meetings, evening workshops that ranged from future directions for global tobacco research to grant writing for the new investigator, several scientific and travel awards, a members' meeting, and an opening reception. The scientific excellence and innovation presented at this year's meeting signifies SRNT's continued contributions to advancing our understanding of nicotine addiction and tobacco use.

Ganglionic Stimulants↗
PubMed2003

Smoking abstinence impairs time estimation accuracy in cigarette smokers.

Time estimation is used as an index of attention processes and may be sensitive to self-administration and withdrawal of psychoactive drugs such as nicotine, the primary addictive ingredient in tobacco. To test this hypothesis, 22 nonsmokers (12 male, 10 female) and 20 daily cigarette smokers (12 male, 8 female) were asked to estimate the duration of a 45-second period of time in a laboratory setting. Smokers participated in two sessions: once after smoking ad-lib and once after objectively confirmed 24-hour smoking abstinence. In smokers, time estimation accuracy was impaired after smoking abstinence compared to accuracy after ad-lib smoking (P<.01). Relative to nonsmokers, smokers' time estimation accuracy differed significantly after the abstinence period only (P=.05). Smokers reported feeling more stressed and unable to focus after abstinence relative to nonsmokers (P<.05). No gender differences were observed on any outcome measures. These results suggest that, in a controlled laboratory setting, smoking abstinence has a negative impact on time perception, which may contribute to the performance decrements and discomfort that smokers report during an attempt to quit.

Adolescent↗
PubMed2002

Evidence for a relationship between daily caffeine consumption and accuracy of time estimation.

The present study examined the relationship between regular caffeine consumption and time estimation. Sixty participants (aged 18-57 years, mean 24 years) completed a 47 s time estimation exercise and questionnaires related to daily caffeine consumption and perceptions of time. We hypothesized that the effects of caffeine on time estimation would follow a U-shaped pattern such that individuals who reported moderate amounts of daily caffeine would be more accurate in their perceptions of time than would those who reported high amounts of caffeine intake or no daily caffeine consumption. Timing accuracy was computed by dividing participant-reported time by actual time (47 s). Timing accuracy followed a U-shaped curve such that those respondents who reported 'low' daily caffeine consumption (< or = 135 mg/day, n = 24) were the most accurate in their time estimates (mean= 44.2 s). Individuals who reported no caffeine (mean= 69.3 s; n= 7) or 'high' daily caffeine consumption (mean=56.2 s; >135 mg/day, n = 28) were less accurate in their time estimates [F(2, 56)= 3.34, p< 0.05]. Findings suggest that 'low' daily caffeine consumption may enhance time estimation accuracy above that of 'high' or no daily caffeine consumption.

Adolescent↗
PubMed2002

Seeing the unexpected: how sex differences in stress responses may provide a new perspective on the manifestation of psychiatric disorders.

In this report, the authors propose that underlying sex differences in the biobehavioral response to stress may contribute to the variance in prevalence of some psychiatric disorders based on sex. The authors begin with a discussion of stress physiology and review a new theory on sex differences in stress responses (ie, the "tend-and-befriend" response), which may provide a recent framework for considering sex differences in the manifestation of some psychiatric illnesses. The authors then move to a discussion of major depression and attention deficit hyperactivity disorder as examples of how sex differences in stress responses may influence the behavioral symptoms of psychiatric disorders that are more often diagnosed in one sex compared with another. The authors conclude with a brief discussion of the implications of this new perspective on treatment approaches and encourage further inquiry into the importance of sex-based differences in the behavioral manifestation of some psychiatric illnesses.

Adrenocorticotropic Hormone↗
PubMed2002

Predictors of fatigue in healthy young adults: moderating effects of cigarette smoking and gender.

Fatigue is a common complaint of patients seen in primary care. Factors that contribute to fatigue in a patient population include poor health status, psychological stress, poor nutrition, and pregnancy. Less well understood are factors that contribute to fatigue among healthy, nonpregnant individuals. Within the framework of the theory of unpleasant symptoms, 40 healthy young smoking and nonsmoking adults between the ages of 18 and 35 were evaluated to determine self-report level of fatigue and contributing physiological, psychological, and situational factors. Results indicate that while self-report of fatigue did not vary in this population based on gender, subjects who were moderate to heavy cigarette smokers were significantly more fatigued than were nonsmokers (F = 10.24, df = 1, 38, P < 0.01), with the effect being specific to male smokers. Self-report of fatigue did not correlate with body mass index, baseline inflammatory or immune status, or blood pressure. Positive psychological and situational predictors of fatigue included depression (r = 0.556, P < 0.001), state anxiety (r = 0.569, P < 0.001), sleep quality (r = -0.399, P < 0.05), and sleep quantity (r = -0.411, P < 0.05). These results suggest that psychological and situational factors are key contributors to fatigue in young adults and that smoking is a risk factor for fatigue in men.

Adult↗
PubMedDate not supplied

Risk indicators of metabolic syndrome in young adults: a preliminary investigation on the influence of tobacco smoke exposure and gender.

BACKGROUND: Metabolic syndrome is characterized by hypertension, dyslipidemia, insulin resistance, and obesity. Limited investigations have studied early indicators of metabolic syndrome in healthy young adults before diagnosis of disease. PURPOSE: The purpose of this investigation is to identify shifts in cardiovascular (CV), metabolic, and immune variables consistent with metabolic syndrome but occurring before development of the disorder, and to determine whether these variables are influenced by gender or cigarette smoking. METHODS: A pilot study of 41 subjects ages 18 to 39 years, with 20 smokers and 21 nonsmokers, was undertaken. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured to evaluate CV status; cholesterol, body mass index, leptin, percent glycated albumin, and homocysteine were measured to evaluate metabolic status; C-reactive protein, interleukin-1beta, and interleukin-10 were measured to evaluate immunologic status. Risk scores were assigned to each indicator, and total risk score was computed. RESULTS: Men had higher SBP (P<.001), DBP (P=.046), and body mass index (P=.01), whereas women had higher leptin (P=.002). Total risk scores in men were greater (P=.02). There was no effect of smoking on risk score, related to the increase in two risks for smokers (SBP, P=.04, DBP; P=.027) reciprocated by a decrease in another (percentage of glycated albumin; P=.02). CONCLUSION: Risk factors contributing to metabolic syndrome are present and highest in young men compared with women, whereas the effects of cigarette smoking on the syndrome are mixed. Early intervention to reduce modifiable risks may prevent full expression of disease.

Adolescent↗
PubMedDate not supplied

Relation of oxytocin to psychological stress responses and hypothalamic-pituitary-adrenocortical axis activity in older women.

OBJECTIVE: Animal research suggests that oxytocin (OT) plays a role in stress responses and that in females, this role is modulated by estrogen. Yet little is known about the relation of OT to human stress responses. This study was conducted to examine the relations between estrogen activity and OT, identify stressors distinctively associated with elevations in OT, and investigate whether OT is related to cardiovascular and hypothalamic-pituitary-adrenocortical (HPA) activity in a laboratory challenge paradigm. METHODS: Seventy-three postmenopausal women who were on hormone therapy (HT) or not completed questionnaires assessing psychological distress and social relationships and then participated in a laboratory stress challenge (Trier Social Stress Task), during which OT, cortisol, and blood pressure were assessed. RESULTS: HT was significantly associated with higher plasma OT. Controlling for HT, elevated plasma OT was significantly associated with gaps in social relationships, with less positive relationships with a primary partner, and with elevated cortisol levels. OT was not associated with stress reactivity or recovery. CONCLUSION: In women, plasma OT signals relationship stress and is associated with elevated cortisol; it does not appear to significantly affect cortisol or blood pressure responses to acute stress.

Aged↗