Stress-induced suppression of hippocampal neurogenesis in adult male rats is altered by prenatal ethanol exposure

In adulthood, both alcohol (ethanol) and stress are known to suppress hippocampal neurogenesis in male rats. Similarly, most studies report that prenatal alcohol exposure (PAE) reduces cell proliferation and/or cell survival in the hippocampus of adult males. Furthermore, PAE is known to have marked effects on behavioral and hypothalamic-pituitary-adrenal (HPA) responsiveness to stressors. However, no studies have examined the modulation of adult hippocampal neurogenesis by stress in PAE animals. We hypothesized that, in accordance with previous data, PAE would suppress basal levels of adult hippocampal neurogenesis, and further that stress acting on a sensitized HPA axis would have greater adverse effects on adult hippocampal neurogenesis in PAE than in control rats. Adult male offspring from PAE, pair-fed (PF) control, and ad libitum-fed control (C) groups were subjected to restraint stress (9 days, 1 h/day) or left undisturbed. Rats were then injected with bromodeoxyuridine (BrdU) on day 10, perfused 24 h (proliferation) or 3 weeks (survival) later, and brains processed for BrdU immunohistochemistry. We found that (1) under non-stressed conditions, PAE rats had a small but statistically significant suppressive effect on levels of hippocampal neurogenesis and (2) unexpectedly, repeated restraint stress significantly reduced neurogenesis in C and PF, but not PAE rats. We speculate that the failure of PAE males to mount an appropriate (i.e. suppressive) neurogenic response to stressors, implies reduced plasticity and adaptability or resilience, which could impact negatively on hippocampal structure and function.

Effects of prenatal ethanol exposure on regulation of basal hypothalamic-pituitary-adrenal activity and hippocampal 5-HT1A receptor mRNA levels in female rats across the estrous cycle

Prenatal ethanol exposure, like other early adverse experiences, is known to alter hypothalamic-pituitary-adrenal (HPA) activity in adulthood. The present study examined the modulatory effects of the gonadal hormones on basal HPA regulation and serotonin Type 1A receptor (5-HT(1A)) mRNA levels in adult female rats prenatally exposed to ethanol (E) compared to that in females from pair-fed (PF) and ad libitum-fed control (C) conditions. We demonstrate, for the first time, long-lasting consequences of prenatal ethanol exposure for basal corticosterone (CORT) regulation and basal levels of hippocampal mineralocorticoid (MR), glucocorticoid (GR) and serotonin Type 1A (5-HT(1A)) receptor mRNA, as a function of estrous cycle stage: (1) basal CORT levels were higher in E compared to C females in proestrus but lower in E and PF compared to C females in estrus; (2) there were no differences among groups in basal levels of adrenocorticotropin (ACTH), estradiol or progesterone; (3) hippocampal MR mRNA levels were decreased in E compared to PF and C females across the estrus cycle, with the greatest effects in proestrus, whereas E (but not PF or C) females had higher hippocampal GR mRNA levels in proestrus than in estrous and diestrus; (4) 5-HT(1A) mRNA levels were increased in E compared to PF and C females in diestrus. That alterations were revealed as a function of estrous cycle stage suggests a role for the ovarian steroids in mediating the adverse effects of ethanol. Furthermore, it appears that ethanol-induced nutritional effects may play a role in mediating at least some of the effects observed. The resetting of HPA activity by early environmental events could be one mechanism linking early life experiences with long-term health consequences. Thus, changes in basal CORT levels, a shift in the MR/GR balance and alterations in 5-HT(1A) receptor mRNA could have important clinical implications for understanding the secondary disabilities, such as an increased incidence of depression, in children with FASD.

Prenatal alcohol exposure: foetal programming, the hypothalamic-pituitary-adrenal axis and sex differences in outcome

Prenatal exposure to alcohol has adverse effects on offspring neuroendocrine and behavioural functions. Alcohol readily crosses the placenta, thus directly affecting developing foetal endocrine organs. In addition, alcohol-induced changes in maternal endocrine function can disrupt the normal hormonal interactions between the pregnant female and foetal systems, altering the normal hormone balance and, indirectly, affecting the development of foetal metabolic, physiological and endocrine functions. The present review focuses on the adverse effects of prenatal alcohol exposure on offspring neuroendocrine function, with particular emphasis on the hypothalamic-pituitary-adrenal (HPA) axis, a key player in the stress response. The HPA axis is highly susceptible to programming during foetal and neonatal development. Here, we review data demonstrating that alcohol exposure in utero programmes the foetal HPA axis such that HPA tone is increased throughout life. Importantly, we show that, although alterations in HPA responsiveness and regulation are robust phenomena, occurring in both male and female offspring, sexually dimorphic effects of alcohol are frequently observed. We present updated findings on possible mechanisms underlying differential effects of alcohol on male and female offspring, with special emphasis on effects at different levels of the HPA axis, and on modulatory influences of the hypothalamic-pituitary-gonadal hormones and serotonin. Finally, possible mechanisms underlying foetal programming of the HPA axis, and the long-term implications of increased exposure to endogenous glucocorticoids for offspring vulnerability to illnesses or disorders later in life are discussed.

The utility of the MDASI-BT in assessing symptoms in patients with brain metastases

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Background: Symptom occurrence has been shown to predict treatment course and survival in patients with solid tumors. The M. D. Anderson Symptom Inventory-Brain Tumor Module (MDASI-BT) was recently validated in patients with primary brain. This study evaluated the reliability and validity of the MDASI-BT as well as symptom severity and prevalence in patients with brain metastases. Methods: Patients diagnosed with systemic cancer with brain metastases participated in this cross-sectional study. Data collection included demographic and clinical factors, and the MDASI-BT (0–10 scale). The average for the 22 symptoms and 6 interference items scores the MDASI-BT was computed. Construct validity was assessed using confirmatory factor analysis, and known-group validity was evaluated by detecting group differences due to disease severity and performance status. For reliability, Cronbach’s alpha values were computed for each subscale. Results: A sample of 124 patients participated, of which 53.2% females. Participants were primarily white (79.8%) and married (78.2%), with a variety of solid tumor malignancies represented. Factor analysis revealed six underlying constructs including affective, cognitive, focal neurologic deficit, constitutional, gastrointestinal, and interference with life. This solution explained 68.4% of the variance, and satisfied Harman’s criteria for model fit. Known-group validity was established for the MDASI-BT using the Karnofsky performance status (KPS). Mean symptom scores were 1.2 and 2.6, and mean interference were 1.8 and 4.3, for patients with good (90–100) and poor KPS (80 and below) respectively (p<0.001). These subscales were also sensitive to opioid analgesic use with group differences of 1.5 and 2.2 (p<0.001). Cronbach’s alpha was 0.9 for each of the two subscales. Fatigue, sleep disturbance, drowsiness, distress, and dry mouth were the most severe symptoms. Conclusions: The MDASI-BT demonstrated validity and reliability in patients with brain metastases and can be used to identify symptom occurrence related to the tumor and therapies.

No significant financial relationships to disclose.

Prenatal ethanol exposure alters the effects of gonadectomy on hypothalamic-pituitary-adrenal activity in male rats

Prenatal ethanol exposure has marked effects on development of the hypothalamic-pituitary-adrenal (HPA) and -gonadal (HPG) axes. In adulthood, ethanol-treated rats show altered gonadal hormone responses and reproductive function, and increased HPA responsiveness to stressors. Importantly, prenatal ethanol differentially alters stress responsiveness in adult males and females, raising the possibility that the gonadal hormones play a role in mediating prenatal ethanol effects on HPA function. To examine a possible testicular influence on HPA activity in males, we compared the effects of gonadectomy on HPA stress responses of adult male offspring from ethanol, pair-fed (PF) and ad libitum-fed control dams. Intact ethanol-treated rats showed increased adrenocorticotrophic hormone (ACTH) but blunted testosterone and luteinising hormone (LH) responses to restraint stress, and no stress-induced elevation in arginine vasopressin (AVP) mRNA levels compared to those observed in PF and/or control rats. Gonadectomy: (i) significantly increased ACTH responses to stress in control but not ethanol-treated and PF males; (ii) eliminated differences among groups in plasma ACTH and AVP mRNA levels; and (iii) altered LH and gonadotrophin-releasing hormone responses in ethanol-treated males. Taken together, these findings suggest that central regulation of both the HPA and HPG axes are altered by prenatal ethanol exposure, with normal testicular influences on HPA function markedly reduced in ethanol-treated animals. A decreased sensitivity to inhibitory effects of androgens could contribute to the HPA hyperresponsiveness typically observed in ethanol-treated males.

Surveillance and control of infectious diseases at local, national and international levels

New emerging and re-emerging threats, the weight of public opinion and new technology for surveillance and treatment are likely to impact on how, and if, effective surveillance can be performed in the future. If surveillance fails to address the needs of practitioners and policy-makers, it is likely that there will be loss of confidence. Current surveillance systems are reasonably effective at detecting significant events that are localised in time and space. It is more difficult to detect diffuse and progressive events with a slow increase over time or sporadic and widespread events without obvious links to time, place or person. Detection of these events relies on good data collection, comparative background data and sophisticated analytical tools. To improve surveillance systems, we need methods with the appropriate sensitivity and specificity for the outputs desired. Targeted surveillance should enable better ascertainment of those cases which must be considered and those which can be dismissed. New methods, such as mathematical modelling and geographical information systems, support conventional surveillance in moving events into the known and predictable category. It is important to integrate surveillance across local, regional and international levels and to base surveillance on local public health structures. The purpose and value of data aggregation at each level and the amount of detail needed at each level must be carefully evaluated. The key to all these improvements is developing the workforce. Surveillance needs individuals with a broad range of skills: clinical, epidemiological, anthropological, and mathematical; in particular, people who can think laterally. These individuals must be encouraged through effective training courses, good mentorship, networking and clear career structures.

Influence of material deprivation on hospital admissions for gynaecologic infections

This study was conducted to examine the relationship between age, material deprivation, and hospital admissions for selected gynaecologic infections in an English health region. Data from hospital episode statistics relating to hospital admissions for pelvic inflammatory disease (PID), infections of the uterus, and infections of the cervix, vagina, and vulva were obtained. Townsend deprivation scores (based on 1991 census data) were allocated by linking postcodes of cases to enumeration districts (EDs) and then assigning the EDs to appropriate quintiles of material deprivation. Both single variable and multivariable (Poisson regression) analyses were performed. For women with PID, the risk of hospitalisation increased with increasing deprivation (P<0.0001), and women in the most deprived quintile were at increased risk (relative risk [RR] 1.31; 95% confidence interval [95%CI] 1.24-1.39) for hospitalisation. Multivariable analysis identified an elevated risk of hospital admission in women aged 25-44 years for PID (RR 2.03; 95%CI 0.84-4.87) and infections of the cervix, vagina, and vulva (RR 1.47; 95%CI 1.16-1.87), and the incidence of both conditions increased significantly with age. In summary, the results obtained suggest that women from the most deprived areas are at greatest risk of hospitalisation for gynaecologic infections, particularly PID. Preventive measures together with earlier diagnostic, treatment, and referral procedures are required to reduce morbidity.

Affirmative action: the lessons for health care

Governments are becoming more assertive about reducing ethnic inequalities

A cost-effective particle agglutination assay to detect viral antibodies in dried blood spots--a simple solution to HIV and HCV screening

OBJECTIVES

To conduct a serological survey of human immunodeficiency virus (HIV) and hepatitis C virus (HCV) in Gabon and Ga-Rankuwa, South Africa. A secondary objective was to test a novel, simple, inexpensive agglutination assay for anti-HIV IgG and anti-HCV IgG from blood samples stored as spots dried onto filter paper.

DESIGN

Blood from heel pricks was dried onto filter paper and stored. Blood was eluted from the spots and serum antibody was then assayed using a modified agglutination assay--blood was added to gelatin agglutination beads that had been sensitised with viral antigen. A positive result showed as an agglutination pattern while a negative result appeared as a tight bead.

SUBJECT

This was a hospital-based study involving 271 neonates at Ga-Rankuwa Hospital, South Africa, and 856 patients ranging in age from three months to over 50 years who attended clinics in Gabon.

RESULTS

Seroprevalence to HIV was determined in Ga-Rankuwa to be just under 14% (13.8%). Antibodies to HCV were not detected. In Gabon, the prevalence to HIV was just under 1% (0.82%) with a relatively high incidence of HCV, nearing 4% (3.79%).

CONCLUSION

The sensitivity of the agglutination assay compared favourably to enzyme immune assay (EIA) with respect to sensitivity, simplicity and cost. This assay may be useful in sero-epidemilogical assays in developing countries.

Circadian clock resetting by arousal in Syrian hamsters: the role of stress and activity

Circadian rhythms in the Syrian hamster can be markedly phase shifted by 3 h of wheel running or arousal stimulation during their usual daily rest period ("subjective day"). Continuous wheel running is predictive but not necessary for phase shifts of this "nonphotic" type; hamsters aroused by gentle handling without running can also show maximal shifts. By contrast, physical restraint, a standard stress procedure and thus presumably arousing, is ineffective. To resolve this apparent paradox, phase-shifting effects of 3-h sessions of restraint or other stress procedures were assessed. In a preliminary study, phase shifts to arousal by gentle handling were significantly potentiated by the cortisol synthesis inhibitor metyrapone, suggesting that stress-related cortisol release may inhibit phase shifts to arousal. Next, it was confirmed that restraint in the subjective day does not induce phase shifts, but behavioral observations revealed that it also does not sustain arousal. Restraint combined with noxious compressed air blasts did sustain arousal and induced a significant cortisol response compared with arousal by gentle handling but did not induce shifts. Restraint combined with continuous horizontal rotation was also ineffective, as was EEG-validated arousal via confinement to a pedestal over water. However, 3 h of resident-intruder interactions (an intense psychosocial stress) or exposure to an open field (a mild stress) did induce large shifts that were positively correlated with indexes of forward locomotion. The results indicate that large phase shifts associated with arousal in the usual sleep period are neither induced nor prevented by stress per se, but are dependent on the expression of at least low levels of locomotor activity. Sustained arousal alone is not sufficient.

Polysomnography in Chronic Neuromuscular Disease

BACKGROUND

Sleep is a risk factor for respiratory failure in patients with chronic neuromuscular diseases (NMD).

OBJECTIVE

To explore the diagnostic value of monitoring sleep parameters in addition to nocturnal respiratory parameters.

METHODS

Thirty-one patients with chronic NMD underwent whole-night polysomnograms including EMG from accessory respiratory muscles.

RESULTS

Sleep macrostructure was normal on average. The number of respiratory arousals per hour of sleep was above the upper limit observed in a control group (>2.1) in 71% of the patients, but was moderate in most cases. Nadir oxygen saturation <85% was the most common finding indicating respiratory dysfunction and was present in 80% of the patients. Noninvasive blood gas monitoring identified all but 2 patients with respiratory-induced sleep abnormalities. The respiratory arousal rate was correlated with the oxygen desaturation index, but otherwise there were no significant correlations between sleep and nocturnal respiratory parameters. Vital capacity was significantly positively correlated with obstructive apnea index and daytime base excess to nadir oxygen saturation. Inspiratory activity in accessory respiratory muscles was present during REM sleep and/or slow wave sleep in 70% of the patients.

CONCLUSION

The severity of nocturnal respiratory dysfunction is not reflected in the extent of sleep impairment in patients with chronic neuromuscular diseases.

[Double blind randomized multicentre study of a seven-day eradication regime of Helicobacter pylori by omeprazole, clarithromycin and ornidazole vs. omeprazole, clarithromycin and metronidazole]

Effective eradication regimes of Helicobacter pylori infections are nowadays based on administration of a substance with a strong suppressive effect on production of gastric HCl combined with two antibiotics. As suppressor of gastric HCl production unequivocally some drug from the group of proton pump blockers is used. As to antibiotics, in first line therapy the following are recommended: clarithromycin, amoxicillin, metronidazole. A problem in the eradication therapy of Helicobacter pylori infection in recent years is the increasing resistance to clarithromycin and apparently also metronidazole. In the Czech Republic the resistance to clarithromycin in relation to Helicobacter pylori is stabilized at a level lower than 3.0 %. Resistance to metronidazole was reported in 1992 within the range of 24 % - 26 %, however in 2001 it was already 36.0 %. Therefore the question arises whether it is possible under our conditions to check the increasing metronidazole resistance by a drug which by its spectrum of action resembles metronidazole while it differs from it as to its chemical structure. This is the reason why the authors implemented a trial where metronidazole was replaced by tinodazole (Avrazor, Léciva Co.). The results revealed that in the group treated with tinidazole eradication was achieved after 7-day administration of ornidazole in 93.0 %, in the group where part of the eradication regime was metronidazole eradication was 82.6 %. The tolerance of both drugs was very good. The authors recommend to include the pattern omeprazole 2 x 20 mg, clarithromycin 2 x 500 mg and tinidazole 2 x 500 mg among first line therapeutic regimes.

Effects of social housing condition on chemotherapeutic efficacy in a Shionogi carcinoma (SC115) mouse tumor model: influences of temporal factors, tumor size, and tumor growth rate

OBJECTIVE

The objective of this study was to investigate 1) whether social housing condition, tumor size, and tumor growth rate alter responses to chemotherapy and 2) whether the timing of tumor cell injection or chemotherapy initiation (relative to housing condition formation) influences tumor growth rate or the efficacy of chemotherapy.

METHODS

Mice were reared individually (I) or in groups (G). In experiment 1, mice were rehoused (IG or GI) or left in group housing (GG) immediately after tumor cell injection. In experiment 2, housing conditions (II, IG, GG, or GI) were formed when tumors weighed 1 g. Chemotherapy (adriamycin 4 mg/kg and cyclophosphamide 61.5 mg/kg IP) and exposure to acute novelty stress (15 min/d, 5 d/wk) were initiated 1 day after housing condition formation.

RESULTS

If chemotherapy was initiated when the tumor burden was undetectable (experiment 1), housing condition did not alter tumor response to chemotherapy, although IG mice lost the most weight and overall had the lowest probability of survival. If chemotherapy was initiated when tumors weighed 1 g (experiment 2), both tumor and host responses to chemotherapy were poorest for IG mice. Timing of tumor cell injection relative to housing condition formation also differentially influenced the rate of tumor growth in mice treated with the drug vehicle; in experiment 1, tumor growth rate was faster in GI and GG mice than in IG mice, whereas in experiment 2, the rate of tumor growth was faster in II mice than in GG and IG mice.

CONCLUSIONS

Altering the temporal relationships among social housing condition formation, tumor cell injection, and chemotherapy initiation differentially influences the rate of tumor growth and the efficacy of chemotherapy. Effects of housing condition are independent of tumor growth rate at chemotherapy initiation and, in terms of host responses, independent of tumor burden.

Effects of prenatal ethanol exposure on hypothalamic-pituitary-adrenal regulation after adrenalectomy and corticosterone replacement

BACKGROUND

Previous studies have demonstrated that rats prenatally exposed to ethanol (E) exhibit hypothalamic-pituitary-adrenal (HPA) hyperresponsiveness, demonstrated by increased and/or prolonged elevations of adrenocorticotropin (ACTH) and/or corticosterone (CORT) after stress. This study investigated possible mechanisms of HPA hyperresponsiveness in E rats by manipulating CORT feedback regulation of HPA activity via adrenalectomy (ADX) with or without CORT replacement.

METHODS

Male Sprague-Dawley rat offspring from prenatal E, pair-fed (PF) and ad libitum-fed control (C) groups were tested at 90 to 120 days of age. Rats were either sham-operated or underwent ADX, with or without CORT replacement. CORT (25 microg/ml) was replaced via the drinking water to achieve basal plasma CORT levels and maintain a phasic CORT signal. Seven days after surgery, animals were decapitated at the diurnal peak either under basal conditions or after a 15-min restraint stress, and trunk blood was collected.

RESULTS

After ADX, loss of the CORT feedback signal resulted in increased plasma ACTH in all groups compared with those in sham animals. In addition, under basal conditions, ADX E rats had significantly greater plasma ACTH levels than both PF and C rats. However, no differences were seen in ADX rats after stress. CORT replacement after ADX was partially effective in normalizing ACTH levels under both basal and stress conditions, with no differences among E, PF, and C animals.

CONCLUSIONS

These results suggest that E males may exhibit enhanced stimulatory inputs to the hypothalamus, increased pituitary sensitivity to secretagogues, or both, which may be revealed after ADX. In contrast, E animals seem similar to controls in their ability to use an exogenous CORT signal to regulate HPA activity.

Variations in corticosterone feedback do not reveal differences in hpa activity after prenatal ethanol exposure

BACKGROUND

Prenatal ethanol exposure results in hypothalamic-pituitary-adrenal (HPA) hyperresponsiveness to stressors in adult animals. Possible mechanisms mediating this alteration in HPA responsiveness include stress-associated changes in corticosterone (CORT) feedback signals, alterations in CORT signals under basal conditions, and CORT-independent mechanisms.

METHODS

We examined the effects of adrenalectomy (ADX) and CORT replacement with a constant, low-level CORT signal via CORT/cholesterol pellets on HPA responses to restraint stress. Adult Sprague-Dawley rats from prenatal ethanol (E), pair-fed (PF), and ad libitum-fed control (C) groups underwent sham ADX (sham), ADX without CORT replacement, or ADX with CORT replacement. Animals were tested during the trough of the circadian rhythm.

RESULTS

In the sham condition, E females showed increased adrenocorticotropin hormone (ACTH) and CORT responses to restraint stress compared with C females. Basal and stress-induced ACTH levels were significantly increased in ADX compared with sham animals across all prenatal groups. Constant CORT replacement reduced basal ACTH levels compared with levels in the ADX group, although levels were still increased compared with those observed in the sham group. CORT replacement was minimally effective at reducing ACTH levels during stress.

CONCLUSIONS

Although the effects of ADX may have masked possible influences of circadian drive or prenatal group, these findings suggest that in the absence of a CORT feedback signal or in the presence of a constant, low-level CORT feedback signal, E, PF, and C animals do not differ in their abilities to regulate ACTH secretion during the trough of the circadian rhythm.

Effects of prenatal ethanol exposure and postnatal handling on conditioned taste aversion

Studies have shown that animals prenatally exposed to ethanol (E) exhibit deficits in conditioned taste aversion as well as displaying hypothalamic-pituitary-adrenal (HPA) hyperresponsiveness during exposure to stressors. In contrast, postnatal handling has been shown to attenuate both emotional and HPA reactivity under certain conditions. The present study tested the hypothesis that handling could attenuate adverse effects of prenatal ethanol exposure on consummatory behavior and HPA activity in a conditioned taste aversion task. We found that both prenatal ethanol exposure and handling independently increased saccharin consumption over 5 days of pretoxicosis exposure, suggesting that neophobia decreased at a faster rate in these animals. When conditioned aversion was assessed in handled animals under nondeprived conditions, E animals showed increased consumption compared to controls. Furthermore, across prenatal groups, lower corticosterone (CORT) levels were found in handled compared to nonhandled animals during reexposure under food-deprived conditions, emphasizing the importance of assessing both behavior and HPA function when examining an animal's response to a task and indicating that handling may not be effective at attenuating some deficits in E animals.