Biomedical subjects

M Altemus

Publications and source records attributed to M Altemus.

At least 19 recordsLinked to original sources

PubMed2001

Variable foraging demand rearing: sustained elevations in cisternal cerebrospinal fluid corticotropin-releasing factor concentrations in adult primates.

BACKGROUND: The authors previously reported elevated cerebrospinal fluid (CSF) corticotropin-releasing factor (CRF) concentrations in juvenile primates nursed by mothers undergoing experimentally imposed unpredictable foraging conditions in comparison to normally reared controls. The purpose of the present study was to determine if these changes would endure into young adulthood. METHODS: Cisternal CSF samples were obtained from those unpredictably reared young adult primates who had been previously studied as juveniles and age-matched ad libitum normally reared controls. Samples were assayed for CSF CRF. RESULTS: Concentrations of CSF CRF were significantly elevated in the unpredictably reared sample in comparison to the ad libitum-reared control group. A significant positive correlation was noted between juvenile and young adult CSF CRF values within the unpredictably reared cohort. CONCLUSIONS: Disturbances of maternal-infant attachment processes have an enduring impact on primate CRF function into young adulthood. The CRF elevations following unpredictable maternal foraging conditions appear traitlike in nature.

Age Factors↗

PubMed2001

Neuroendocrine and emotional changes in the post-partum period.

As well as having widespread effects on many aspects of mammalian physiology, the hormones of both the reproductive and stress axes can directly and indirectly influence behavior. Here we review possible mechanisms through which centrally active hormones of the female reproductive system and the hypothalamo-pituitary-adrenal stress axis may interact to influence behavior and mood states during the post-partum period. We will focus primarily on the behavioral effects of selected neuropeptide hormones, in particular oxytocin, vasopressin and corticotrophin-releasing hormone. The literature documenting central behavioral effects of these neuropeptides arises almost exclusively from research in experimental animals. In particular, it has been reported that during lactation in rats there are high blood and brain levels of oxytocin. At the same time there is a reduction in corticotrophin-releasing hormone in the brain and in its secretion in response to stress. These changes may contribute to optimal maternal care of the offspring. Correlational studies of peptides and behavior in the post-partum period also support the hypothesis that neuropeptides may influence human physiology and behavior. Studies of post-partum women reveal powerful regulatory effects of lactation on the reactivity of the hypothalamo-pituitary-adrenal axis and of autonomic and immune systems, especially in the face of challenge. The integrative function of neural systems that influence both reproduction and the hypothalamo-pituitary-adrenal axis suggests one central mechanism for mediating the effects of environmental challenges.

Animals↗

PubMed2001

Abnormalities in response to vasopressin infusion in chronic fatigue syndrome.

Several neuroendocrine studies have suggested hypoactivation of the hypothalamic-pituitary-adrenal axis in chronic fatigue syndrome. One possible determinant of this neuroendocrine abnormality, as well as the primary symptom of fatigue, is reduced hypothalamic secretion of corticotropin-releasing hormone (CRH). Because CRH and vasopressin secreted from the hypothalamus act synergistically at the pituitary to activate ACTH secretion, the ACTH response to peripheral infusion of vasopressin can provide an indirect measure of hypothalamic CRH secretion. We measured the ACTH and cortisol response to a one hour infusion of arginine vasopressin in 19 patients with chronic fatigue syndrome and 19 age and sex matched healthy volunteers. Patients with chronic fatigue syndrome had a reduced ACTH response to the vasopressin infusion and a more rapid cortisol response to the infusion. These results provide further evidence of reduced hypothalamic CRH secretion in patients with chronic fatigue syndrome.

Adrenocorticotropic Hormone↗

PubMed2001

Lymphocyte responses to stress in postpartum women: relationship to vagal tone.

Although women spend their lives in various phases of the reproductive cycle, including menstrual, pregnancy, postpartum, lactation and menopause, few studies have examined immune responses to stress in women as a function of events associated with reproduction. The objective of this study was to evaluate differential effects of breastfeeding (n = 16), bottlefeeding (n = 10) and non-postpartum (n = 10) status on lymphocyte responses to stressful tasks (public speaking and mental arithmetic). To measure cellular immune responses, lymphocyte proliferation to plant lectins, poke weed mitogen (PWM) and phytohemagglutinin (PHA) were used. The autonomic measures, heart rate, vagal tone, blood pressure and the hormones of the HPA axis, ACTH and cortisol, were measured and their possible roles in mediating lymphocyte proliferation responses were examined. Recently parturient women who were breastfeeding or bottlefeeding had attenuated stress-induced change in lymphocyte responses to PWM compared with non-postpartum women, tested in the follicular phase of their cycle (P < 0.05). Also, lymphocyte responses to PHA were higher in the breastfeeding group compared with non-postpartum controls (P < 0.05). Regression analyses revealed that an index of cardiac vagal tone, but not other autonomic or endocrine measures, was positively predictive of lymphocyte proliferation to PWM. To summarize, these findings suggest that lactation and parturition can influence lymphocyte proliferation and that activity in the vagal system may influence lymphocyte responses to stress.

Adult↗

PubMed2001

Effects of estrogen antagonists and agonists on the ACTH response to restraint stress in female rats.

Previous studies have found that female rats are less sensitive than males to hypothalamic-pituitary-adrenal axis feedback inhibition by exogenous glucocorticoid administration. To determine whether estrogen contributes to this sex difference, we examined the effects of the estrogen antagonists tamoxifen and C1628 on the ACTH and corticosterone responses to restraint stress. CI628 increased both the ACTH and corticosterone response to restraint stress, and tamoxifen increased the ACTH response to restraint. Using overiectomized female rats, we also examined the effects of seven days of estradiol and/or progesterone replacement. Low dose estradiol decreased the ACTH but not the corticosterone response to restraint stress while progesterone had no effect on ACTH or corticosterone responses. The combination of estradiol and progesterone also decreased the ACTH response to stress, and the magnitude of the effect did not differ from that found with estradiol treatment alone. These data suggest that in the physiological range estradiol is an important inhibitory factor in the hypothalamic-pituitary-adrenal stress response of females.

Adrenocorticotropic Hormone↗

PubMed2001

Stress-induced changes in skin barrier function in healthy women.

Despite clear exacerbation of several skin disorders by stress, the effect of psychologic or exertional stress on human skin has not been well studied. We investigated the effect of three different stressors, psychologic interview stress, sleep deprivation, and exercise, on several dermatologic measures: transepidermal water loss, recovery of skin barrier function after tape stripping, and stratum corneum water content (skin conductance). We simultaneously measured the effects of stress on plasma levels of several stress-response hormones and cytokines, natural killer cell activity, and absolute numbers of peripheral blood leukocytes. Twenty-five women participated in a laboratory psychologic interview stress, 11 women participated in one night of sleep deprivation, and 10 women participated in a 3 d exercise protocol. The interview stress caused a delay in the recovery of skin barrier function, as well as increases in plasma cortisol, norepinephrine, interleukin-1beta and interleukin-10, tumor necrosis factor-alpha, and an increase in circulating natural killer cell activity and natural killer cell number. Sleep deprivation also decreased skin barrier function recovery and increased plasma interleukin-1beta, tumor necrosis factor-alpha, and natural killer cell activity. The exercise stress did not affect skin barrier function recovery, but caused an increase in natural killer cell activity and circulating numbers of both cytolytic T lymphocytes and helper T cells. In addition, cytokine responses to the interview stress were inversely correlated with changes in barrier function recovery. These results suggest that acute psychosocial and sleep deprivation stress disrupts skin barrier function homeostasis in women, and that this disruption may be related to stress-induced changes in cytokine secretion.

Adolescent↗

PubMed2001

Increased vasopressin and adrenocorticotropin responses to stress in the midluteal phase of the menstrual cycle.

Accumulating evidence indicates that gonadal steroids modulate functioning of the hypothalamic-pituitary-adrenal (HPA) axis, which has been closely linked to the pathophysiology of anxiety and depression. However, the effect of the natural menstrual cycle on HPA axis responsivity to stress has not been clearly described. In nine healthy women, metabolic and hormonal responses to treadmill exercise stress during the early follicular phase of the menstrual cycle, when gonadal steroid levels are low, were compared with responses in the midluteal phase of the cycle, when both progesterone and estrogen levels are relatively high. Exercise intensity was gradually increased over 20 min to reach 90% of each subject's maximal oxygen consumption during the final 5 min of exercise. Basal plasma lactate, glucose, ACTH, vasopressin, oxytocin, and cortisol levels were similar in the two cycle phases. However, in response to exercise stress, women in the midluteal phase had enhanced ACTH (P < 0.0001), vasopressin (P < 0.01), and glucose (P < 0.001) secretion. These findings suggest that relatively low levels of gonadal steroids during the early follicular phase of the menstrual cycle provide protection from the impact of stress on the HPA axis.

Adrenocorticotropic Hormone↗

PubMed2000

Growth hormone response to clonidine in adversely reared young adult primates: relationship to serial cerebrospinal fluid corticotropin-releasing factor concentrations.

A reduction of the growth hormone (GH) response to the alpha(2) adrenergic agonist clonidine is a neuroendocrine abnormality observed with reasonable consistency among human patients with mood and anxiety disorders. In previous primate studies, in comparison to predictably reared controls, monkeys exposed as infants to maternal variable foraging demand (VFD) rearing exhibited persistent elevations of cerebrospinal fluid (CSF) corticotropin-releasing factor (CRF), as well as other biological disturbances. As CRF has been demonstrated to inhibit GH release, the authors hypothesized that within VFD-reared subjects, animals with relatively high CRF concentrations would exhibit relatively diminished GH responses to clonidine. The current study examined the relationship between the GH response to clonidine in VFD-reared adult primates in relation to a range of both juvenile and follow-up CSF CRF concentrations. Nine bonnet macaques (Macaca radiata) were given ascending dosages of clonidine under ketamine anesthesia. Plasma samples for GH-like immunoreactivity were obtained throughout the session. A significant positive correlation was noted between juvenile CSF CRF concentrations and the levels of the neuropeptide observed in young adults. The mean of the serial CSF CRF concentrations exhibited a significant inverse relationship towards the GH response to clonidine in young adulthood, with relatively high CSF CRF associated with relatively attenuated GH responses to clonidine. These data raise the possibility that a reduced GH response to clonidine may inversely reflect trait-like increases of central nervous system (CNS) CRF activity.

Adrenergic alpha-Agonists↗

PubMed2000

CSF oxytocin and vasopressin levels after recovery from bulimia nervosa and anorexia nervosa, bulimic subtype.

BACKGROUND: When ill, people with eating disorders have disturbances of the neuropeptides vasopressin and oxytocin. METHODS: To avoid the confounding effects of the ill state, we studied women who were recovered (more than 1 year, normal weight, and regular menstrual cycles, no bingeing or purging) from bulimia nervosa (rBN) or binge eating/purging-type anorexia nervosa (rAN-BN), and matched healthy control women. RESULTS: Vasopressin was elevated in rAN-BN and showed a trend towards elevation in rBN. In rBN, elevated cerebrospinal fluid vasopressin may be related to having a lifetime history of major depression. In comparison, cerebrospinal fluid oxytocin was normal in recovered subjects, but elevated levels in some rBN might be related to birth control pill use. CONCLUSIONS: These data confirm and extend the possibility that elevated cerebrospinal fluid vasopressin may be related to the pathophysiology of eating disorders, and/or a lifetime history of major depression.

Adult↗

PubMed2000

Autoimmune mechanisms in movement disorders.

A number of disorders, including childhood-onset obsessive compulsive disorder (OCD) and Gilles de la Tourette's syndrome (TS), are known to be neurobiological in nature. Both TS and OCD are neuropsychiatric diagnoses that involve congitive and perceptual dysfunction in addition to motor and psychiatric manifestations. The association of the B-cell marker with both Sydenham's chorea and a group of neuropsychiatric disorders, such as OCD, tics, and TS, has been useful as a marker in these diseases. This evidence, coupled with the recent finding of anti-brain antibodies in the sera of these patients, raises a number of interesting questions concerning the pathological mechanisms involved in these diseases. Thus, further molecular characterization of the brain and streptococcal antigens will be crucial to our understanding of the neurophysiological processes involved in these disorders.

Antibodies, Monoclonal↗

PubMed1999

Leptin, neuropeptide Y, and peptide YY in long-term recovered eating disorder patients.

BACKGROUND: Disturbances of leptin, neuropeptide Y (NPY), and peptide YY (PYY) have been found in women who are ill with anorexia or bulimia nervosa. It is not certain whether peptide disturbances are cause or consequence of eating disorders. METHODS: Plasma leptin and cerebrospinal fluid leptin, NPY, and PYY concentrations were measured in women who were recovered from anorexia or bulimia nervosa to determine whether alterations persisted after recovery. RESULTS: NPY, PYY, and leptin concentrations were similar across all diagnostic groups. CONCLUSIONS: Alterations in NPY, PYY, and serum leptin concentrations are probably secondary to pathological eating behaviors. Alterations of these peptides are unlikely to be trait-related disturbances that contribute to the etiology of eating disorders.

Adipose Tissue↗

PubMed1999

Normal CSF oxytocin and NPY levels in OCD.

BACKGROUND: Attention has recently been focused on central nervous system neuropeptides as potential mediators of the symptom profile of obsessive-compulsive disorder (OCD). Increased CSF levels of the anxiolytic neuropeptide oxytocin have been reported in OCD. CSF levels of NPY, another anxiolytic neuropeptide, have not been studied. METHODS: We measured CSF oxytocin and NPY in 14 OCD patients and 26 healthy normal volunteers. RESULTS: There were no significant differences between the OCD patients and control subjects in CSF oxytocin or NPY levels. In both the OCD and control groups, women had significantly higher CSF oxytocin levels than men. CONCLUSIONS: These results do not support a prior finding of elevated CSF oxytocin in OCD patients and do not provide any evidence for an abnormality of NPY regulation in OCD.

Adult↗

PubMed1999

No coding variant of the tryptophan hydroxylase gene detected in seasonal affective disorder, obsessive-compulsive disorder, anorexia nervosa, and alcoholism.

BACKGROUND: The goal of this study was to evaluate the role of genetic variation in the coding sequence of tryptophan hydroxylase (TPH) in the pathogenesis of several psychiatric diseases in which altered serotonin function has been implicated: bipolar affective disorder (BP), obsessive-compulsive disorder (OCD), anorexia nervosa (AN), seasonal affective disorder (SAD), panic disorder (PD), and alcoholism (Alc). METHODS: Ninety-three percent of the TPH coding sequence was screened by polymerase chain reaction single-strand conformation polymorphism (SSCP) for DNA sequence variations in 128 AN, 88 OCD, 72 SAD, 45 PD, and 36 BP patients and 142 normal volunteers. Also included in the screening were 61 Alc randomly selected from a Finnish alcoholic population in which an association of a TPH intron 7 polymorphism with suicidality was previously observed. Polymorphisms detected by SSCP were characterized by DNA sequencing and by allele-specific restriction enzyme digestion. Genotyping was then performed in 34 Finnish alcoholic suicide attempters. RESULTS: A rare silent mutation was identified in exon 10 and is designated T1095C. The C1095 allele was found in 1 OCD and in 2 AN subjects; all 3 individuals were heterozygous (C1095/T1095) for the variant allele. No association was observed between this TPH T1095C variant with either OCD, AN, Alc, or suicidality. CONCLUSION: These results suggest that the coding sequence of the TPH gene does not contain abundant variants, and may not play a major role in vulnerability to several psychopathologies in which reduced serotonin turnover has been implicated.

Alcoholism↗

PubMed1999

Association of the serotonin transporter promoter regulatory region polymorphism and obsessive-compulsive disorder.

Although modulation of symptoms of obsessive-compulsive disorder (OCD) by serotonergic agents is well established, it is unclear whether an abnormality in the central serotonergic system is involved in its etiology. The serotonin (5-HT) transporter (5-HTT), which is the key modulator of serotonergic neurotransmission, is the target for serotonin reuptake inhibiting drugs (SRIs) that are uniquely effective in the treatment of OCD. In this preliminary study we report an association of a functional polymorphism in the 5-HTT 5' regulatory-region and OCD. Seventy-five OCD Caucasian patients and 397 ethnically-matched individuals from a non-patient control group were genotyped for the 5-HTTLPR. Population-based association analysis revealed that patients with OCD were more likely to carry two copies of the long allele (l) as compared to controls (46.7% vs 32.3%: chi2 = 5.19, P = 0.023). This finding replicates a recent family-based study of this polymorphism in OCD, and thus indicates that the 5-HTTLPR may be associated with susceptibility to OCD.

Alleles↗

PubMed1999

Preliminary research on plasma oxytocin in normal cycling women: investigating emotion and interpersonal distress.

The neurohormone oxytocin is responsible for initiating childbirth and the let-down reflex in lactating women and is released during sexual orgasm. Oxytocin has been thought of as an affiliation hormone because research on nonhuman mammals has demonstrated that it plays a key role in the initiation of maternal behavior and the formation of adult pair bonds. It has been speculated that social stimuli may induce oxytocin release and that oxytocin may make positive social contact more rewarding. Data are presented from an initial study to examine change in plasma oxytocin in response to a standard imagery task that elicits emotion related to attachment. Twenty-five normal cycling, healthy women underwent imagery tasks and completed questionnaires on attachment and interpersonal problems. Blood draws (5 ml) were bone via an indwelling catheter before, during, and after three interventions (massage, positive emotion, and negative emotion) and to establish baselines. Overall, the data showed a tendency for oxytocin levels to be elevated in response to relaxation massage and decreased in response to sad emotion. There were individual differences in response to the interventions. Those who showed evidence of increased oxytocin levels for positive emotion and massage and who maintained oxytocin levels during negative emotion were less likely to report interpersonal problems associated with intrusiveness. Maintaining oxytocin levels during sadness was also correlated with lower anxiety in close relationships. Women who were in a couple relationship had greater increases in oxytocin in response to positive emotion. In contrast, higher basal levels of oxytocin were associated with greater interpersonal distress. These data suggest that peripheral secretion of oxytocin in response to emotional stimuli is associated with the individual's interpersonal characteristics.

Adult↗

PubMed1999

Open trial of flutamide for treatment of obsessive-compulsive disorder.

BACKGROUND: Several lines of evidence suggest that gonadal steroid hormones play a role in the onset and exacerbation of obsessive-compulsive disorder (OCD). In this study, we examined the effects of treatment with flutamide, a synthetic, nonsteroidal, competitive antagonist of the androgen receptor, on OCD symptoms. METHOD: Eight outpatients meeting DSM-III-R criteria for OCD participated in an 8-week open trial of flutamide. The dose was increased from 250 mg/day to 750 mg/day over the first 4 weeks and maintained at 750 mg/day for the final 4 weeks. The primary outcome measures for OCD symptoms were the Yale-Brown Obsessive Compulsive Scale and the Maudsley Inventory and for anxiety symptoms, the Beck Anxiety Inventory and the Hamilton Rating Scale for Anxiety. Subjects also provided self-ratings of aggression and sexual interest and activity. RESULTS: There were no reductions in measures of obsession and compulsions or measures of anxiety over the 8-week trial. However, self-ratings of feelings of aggression did fall significantly over the 8-week trial (p < .001). CONCLUSION: The lack of response to treatment with flutamide, an androgen receptor antagonist, suggests that any effects of gonadal steroids to exacerbate OCD symptoms are more likely to be mediated through estrogen receptors or through mechanisms that do not involve classical intracellular androgen receptors. Future treatment trials should examine agents that antagonize estrogen receptors or otherwise inhibit estrogen activity.

Adult↗

PubMed1998

Delayed obsessive-compulsive disorder symptom exacerbation after a single dose of a serotonin antagonist in fluoxetine-treated but not untreated patients.

Enhanced serotonergic transmission may underlie therapeutic effects of serotonin reuptake inhibitors in obsessive-compulsive disorder. However, such treatment may decrease serotonin receptor responsivity. We investigated whether the serotonin antagonist metergoline would exacerbate or further improve systems in fluoxetine-responsive patients. Pilot results suggested open metergoline produced delayed symptom worsening in fluoxetine-treated patients. Fourteen patients continuing fluoxetine received metergoline and placebo (double-blind, randomized). Symptom ratings continued for 1 week afterwards. Ten unmedicated patients underwent the same procedures. Symptoms improved 4 h after both metergoline and placebo. The day after metergoline but not placebo, fluoxetine-treated patients had significantly increased anxiety, obsessions and compulsions, abating over several days. Depression was unchanged. Metergoline had no similar delayed effects in unmedicated patients. Metergoline levels were higher in fluoxetine-treated patients. These results, consistent with less conclusive earlier findings, suggest that prolonged changes in brain serotonin function underlie symptom re-emergence following administration of metergoline to fluoxetine-treated patients with obsessive-compulsive disorder.

Adult↗

PubMed1997

Genotype determining low catechol-O-methyltransferase activity as a risk factor for obsessive-compulsive disorder.

In the present study, we address the role of the gene for catechol-O-methyltransferase (COMT), a key modulator of dopaminergic and noradrenergic neurotransmission, in the genetic predisposition to obsessive-compulsive disorder (OCD). We show that a common functional allele of this gene, which results in a 3- to 4-fold reduction in enzyme activity, is significantly associated in a recessive manner with susceptibility to OCD, particularly in males. This association is further supported by psychiatric evaluation of patients who carry microdeletions encompassing the comt gene. The mechanism underlying this sex-selective association remains to be defined and may include a sexual dimorphism in COMT activity, although close linkage with a nearby disease susceptibility locus cannot be excluded at this point.

Alleles↗