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Biomedical subjects

C A Sandman

Publications and source records attributed to C A Sandman.

137 records · Page 8Linked to original sources

Memory deficits associated with chronic fatigue immune dysfunction syndrome.

Performance on tests of memory in 39 patients who met Center for Disease Control (CDC) criteria for chronic fatigue immune dysfunction syndrome (CFIDS) was compared with 23 depressed patients (DSM-III-R) and 129 healthy controls. Although the CFIDS patients had normal neuropsychological profiles, they significantly overestimated their ability (metamemory), performed significantly worse on tests of recall as context increased (e.g., recognition), made more errors when rehearsal was prevented, and had delayed mental scanning as memory load increased. The overall pattern indicated that CFIDS patients had a significant memory deficit, far worse than implied by CDC criteria. The pattern for CFIDS patients was consistent with temporal-limbic dysfunction and significantly different than depressed patients and control subjects.

Adult↗

MSH affects regional perfusion of the brain.

With the single exception of the occipital cortex, the flow of blood to most regions of the brains of conscious, unrestrained rats was reduced within 10 min after intravenous administration of alphaMSH. Though these effects were transitory for most regions of the brain, perfusion of cerebellum, pons and medulla, hippocampus, and parietal cortex was still significantly low by 20 min. Assuming that flow changes reflect functional changes, these early responses to alphaMSH suggest an explanation for the effects of this hormone in which visual learning is improved.

Animals↗

Central nervous system and peripheral effects of ACTH, MSH, and related neuropeptides.

Adrenocorticotropic Hormone (ACTH), Melanocyte-Stimulating Hormone (MSH), and related peptides have been shown to have several neurogenic effects: alteration of cerebral protein synthesis, RNA synthesis, protein phosphorylation, and neurotransmitter turnover. Furthermore, there appears to be an ACTH containing circuit in the CNS which originates in the arcuate nucleus. Changes in concentration of the peptides in this family have been shown to alter electrophysiology, neuromuscular function, and behavior (e.g., grooming, learning) in infrahuman subjects. These findings suggest that the neuropeptides MSH and ACTH influence the capacity of an organism to efficiently evaluate information and influence the affective functioning of humans.

Adrenocorticotropic Hormone↗

Attenuation of morphine analgesia by alpha-MSH, MIF-I, melatonin and naloxone in the rat.

In two experiments the effects of the pituitary peptide alpha-MSH, the hypothalamic tripeptide MIF-I (P-L-G-NH2) and the pineal hormone melatonin were investigated on the attenuation of morphine analgesia measured by a tail flick test. In Experiment 1, alpha-MSH had minimal effect on morphine analgesia, whereas, MIF-I and melatonin clearly delayed the onset of morphine analgesia, and melatonin also shortened the duration of analgesia. Experiment 2 was designed to investigate the possible synergistic effect of MIF-I and melatonin. The combined treatment of MIF-I and melatonin significantly delayed the onset of morphine analgesia, and melatonin alone shortened the duration of analgesia. The relationships among the pituitary, hypothalamus and the pineal for the modulation of pain and response to morphine were discussed.

Analgesia↗

ACTH 4-9 effects on the human visual event-related potential.

Three oral doses (5, 10 and 20 mg) of an analog of ACTH 4-9 were compared with a vehicle control and d-amphetamine (10 mg). In a double-blind procedure, five men and five women were tested at weekly intervals with each treatment. In each session, four visual event-related potentials (ERPs) were recorded at hourly intervals. Visual ERPs were averaged from the electroencephalogram recorded from the left and right hemisphere. Dosage, time after administration, hemisphere of the brain and sex of the subject influenced the ERP. The ACTH 4-9 analog decreased amplitude of P100 but increased integrated activity of the ERP. This effect peaked at 60 minutes then "recovered." The effects of the peptide were more pronounced with doses of 5 and 10 mg, in the right hemisphere of men and in the left hemisphere of women. The findings indicated that the ACTH 4-9 analog influenced components of ERP commonly related to the perceptual/attentional state of the organism in a sexually dimorphic manner.

Adrenocorticotropic Hormone↗

Prenatal psychosocial factors and the neuroendocrine axis in human pregnancy.

OBJECTIVE: Physiological processes including neuroendocrine function have been proposed as mediators of the relationship between prenatal psychological state and pregnancy outcome; however, there are virtually no human studies that have systematically assessed such mechanisms. Neuroendocrine processes are significantly altered during pregnancy, and are characterized by the evolution of a transient neuroendocrine system, the placenta, and modifications in endocrine control mechanisms. Because these alterations have implications for neuroendocrine responsivity to exogenous conditions, the aim of the present study was to examine the cross-sectional association between prenatal psychosocial factors and stress-related neuroendocrine parameters during human pregnancy. METHOD: Fifty-four adult women with a singleton, intrauterine pregnancy were recruited before 28 weeks of gestation. Maternal antecubital venous blood samples were withdrawn at 28 weeks of gestation for bioassays of adrenocorticotropin hormone (ACTH), beta-endorphin (beta E), and cortisol. Measures of prenatal stress, social support, and personality were collected using a two-part, self-report questionnaire administered at 28 and 30 weeks of gestation. Biomedical data were obtained from the medical record. Factors known to influence neuropeptide and hormone levels during pregnancy were controlled, including gestational age, circadian variation, and obstetric risk. RESULTS: In the present sample, prenatal psychosocial stress, social support, and personality variables were associated with neuroendocrine parameters in two primary ways. First, certain psychosocial factors were significantly associated with plasma levels of ACTH, beta E, and cortisol, and second, psychosocial factors were associated with a measure of disregulation of the normal relationship between two pro-opiomelanocortin (POMC) derivatives, ACTH and beta E. Furthermore, a combination of the maternal psychosocial and sociodemographic factors during pregnancy accounted for 36% of the variance in ACTH, 22% of the variance in the ACTH-beta E disregulation index, 13% of the variance in cortisol, and 3% of the variance in beta E. CONCLUSIONS: The present findings are consistent with the premise that maternal-placental-fetal neuroendocrine parameters are significantly associated, both in magnitude and specificity, with features of maternal psychosocial functioning in pregnancy despite the systemic alterations associated with the endocrinology of pregnancy. These findings provide a basis for further investigations of the role of the neuroendocrine system as a putative mediating pathway between prenatal psychosocial factors and birth outcome, and possibly also as a mechanism linking features of the maternal psychosocial environment to fetal/infant brain development.

Adrenocorticotropic Hormone↗

Maternal social support predicts birth weight and fetal growth in human pregnancy.

OBJECTIVE: Low birth weight is a primary cause of infant mortality and morbidity. Results of previous studies suggest that social support may be related to higher birth weight through fetal growth processes, although the findings have been inconsistent. The purpose of this investigation was to test a model of the association between a latent prenatal social support factor and fetal growth while taking into account relations between sociodemographic and obstetric risk factors and birth weight. METHOD: A prospective study was conducted among 247 women with a singleton, intrauterine pregnancy receiving care in two university-affiliated prenatal clinics. Measures of support included support from family, support from the baby's father, and general functional support. Sociodemographic characteristics were also assessed. Birth outcome and obstetric risk information were abstracted from patients' medical charts after delivery. RESULTS: Structural equation modeling analyses showed that a latent social support factor significantly predicted fetal growth (birth weight adjusted for length of gestation) with infant sex, obstetric risk, and ethnicity in the model. Marital status and education were indirectly related to fetal growth through social support. The final model with social support and other variables accounted for 31% of the variance in fetal growth. CONCLUSIONS: These findings suggest that prenatal social support is associated with infant birth weight through processes involving fetal growth rather than those involving timing of delivery. Biological and behavioral factors may contribute to the association between support and fetal growth, although these mechanisms need to be further explored. These results pave the way for additional research on fetal growth mechanisms and provide a basis for support intervention research.

Adolescent↗