Impaired osmoregulation in anorexia nervosa: review of the literature

BACKGROUND: Anorexia nervosa (AN) is a serious eating disorder associated with numerous medical complications, including alterations in water balance and impaired osmoregulation. OBJECTIVE: The aim of this paper is to review the evidence-based literature and discuss the potential pathophysiological mechanisms of impaired osmoregulation observed in patients with AN. MAIN DATA: Although limited, the evidence suggests that the pathophysiological mechanisms causing impaired osmoregulation in AN is multifactorial and includes abnormalities in osmoregulation of vasopressin, intrinsic renal defects and the influence of antidepressants often used in the treatment of patients with AN. Physicians treating patients with AN should be aware of this complication and the possible multifactorial etiology contributing to this medical complication.     

Major depressive disorder: probiotics may be an adjuvant therapy

Major depressive disorder (MDD) is an extremely complex and heterogeneous condition. Emerging research suggests that nutritional influences on MDD are currently underestimated. MDD patients have been shown to have elevated levels of pro-inflammatory cytokines, increased oxidative stress, altered gastrointestinal (GI) function, and lowered micronutrient and omega-3 fatty acid status. Small intestinal bacterial overgrowth (SIBO) is likely contributing to the limited nutrient absorption in MDD. Stress, a significant factor in MDD, is known to alter GI microflora, lowering levels of lactobacilli and bifidobacterium. Research suggests that bacteria in the GI tract can communicate with the central nervous system, even in the absence of an immune response. Probiotics have the potential to lower systemic inflammatory cytokines, decrease oxidative stress, improve nutritional status, and correct SIBO. The effect of probiotics on systemic inflammatory cytokines and oxidative stress may ultimately lead to increased brain derived neurotrophic factor (BDNF). It is our contention that probiotics may be an adjuvant to standard care in MDD.     

Effects of tryptophan depletion on central and peripheral chemoreflexes in man

Klein (Arch. Gen. Psychiatry 50, 306-317, 1993) suggests that panic attacks are the result of a defective 'suffocation alarm' threshold that presents with carbon dioxide (CO(2)) hypersensitivity, exaggerated ventilatory response and panic in panic disorder (PD) patients. Serotonergic deficiencies enhance this ventilatory response in PD patients, as per 'suffocation alarm' theory predictions, suggesting that serotonin (5-HT) normalizes the ventilatory response. Other research supports a serotonin system-mediated stimulation of ventilation. Knowledge of 5-HT's role on ventilatory output and its neurophysiological sources impacts on the 'suffocation alarm' theory validity and predictive value. We used tryptophan depletion (TRP-) in concert with a modified Read rebreathing test to determine the effect of deficient serotonergic modulation on the central and peripheral chemoreflex threshold and sensitivity of response to CO(2) in 11 healthy men. TRP- did not affect central or peripheral chemoreflex threshold or sensitivity of response to CO(2). However, basal ventilation was significantly elevated during TRP-. In contrast to 'suffocation alarm' theory predictions, decreased 5-HT neurotransmission does not significantly affect the respiratory chemoreflex response to CO(2), impacting on non-chemoreflex drives to breathe. Panic associated respiratory abnormalities may be related to defective 5-HT modulation of non-chemoreflex drives to breathe, unrelated to any respiratory chemoreflex abnormality.     

Decreased bone density in adolescent girls with anorexia nervosa

Osteoporosis develops in women with chronic anorexia nervosa. To determine whether bone mass is reduced in younger patients as well, bone density was studied in a group of adolescent patients with anorexia nervosa. With single- and dual-photon absorptiometry, a comparison was made of bone mineral density of midradius, lumbar spine, and whole body in 18 girls (12 to 20 years of age) with anorexia nervosa and 25 healthy control subjects of comparable age. Patients had significantly lower lumbar vertebral bone density than did control subjects (0.830 +/- 0.140 vs 1.054 +/- 0.139 g/cm2) and significantly lower whole body bone mass (0.700 +/- 0.130 vs 0.955 +/- 0.130 g/cm2). Midradius bone density was not significantly reduced. Of 18 patients, 12 had bone density greater than 2 standard deviations less than normal values for age. The diagnosis of anorexia nervosa had been made less than 1 year earlier for half of these girls. Body mass index correlated significantly with bone mass in girls who were not anorexic (P less than .05, .005, and .0001 for lumbar, radius, and whole body, respectively). Bone mineral correlated significantly with body mass index in patients with anorexia nervosa as well. In addition, age at onset and duration of anorexia nervosa, but not calcium intake, activity level, or duration of amenorrhea correlated significantly with bone mineral density. It was concluded that important deficits of bone mass occur as a frequent and often early complication of anorexia nervosa in adolescence. Whole body is considerably more sensitive than midradius bone density as a measure of cortical bone loss in this illness.(ABSTRACT TRUNCATED AT 250 WORDS)     

Central and peripheral chemoreflexes in panic disorder

Klein (Arch Gen Psychiatry, 50, 1993, 306-317) has suggested that panic disorder patients have a false suffocation alarm that may be associated with a lowered threshold for carbon dioxide detection. We compared the thresholds and sensitivities of the central and peripheral chemoreflexes between panic disorder patients and age- and sex-matched healthy volunteers to test this aspect of the hypothesis. We used a modified version of Read's rebreathing technique in 11 panic disorder patients and 10 healthy volunteers to examine the peripheral and central chemoreflex characteristics in these two populations. Subjects were examined during three rebreathing tests: training, hyperoxic (central chemoreflex alone) and hypoxic (combined central and peripheral chemoreflex). Panic symptoms were retrospectively assessed between groups using a DSM-IV derived Panic Symptom Scale. Comparisons of panic disorder patients with agoraphobia and healthy volunteers showed no significant differences in sensitivities or thresholds. Klein's hypothesis is not supported by these data. If a false suffocation alarm exists, its triggering may not be implemented within the respiratory chemoreflexes.     

Maternal Floor Infarction and Massive Perivillous Fibrin Deposition: Histological Definitions, Association with Intrauterine Fetal Growth Restriction, and Risk of Recurrence

Maternalfloor infarction (MFI) is a poorly understood placental lesion reportedly associated with intrauterine growth restriction (IUGR) and recurrence. In this study of MFI and the related placental disorder, massive perivillous fibrin deposition (MFD), semiquantitative histologic criteria for these diagnoses are defined and rates of IUGR and recurrence are assessed. Pathologic slides of 80 placentas diagnosed as MFI or MFD at the Brigham and Women's Hospital (1989–99) were reviewed and reclassified as classic MFI, transmural MFD, borderline MFD, or neither MFI or MFD. The prevalence of IUGR was determined, and placental slides from additional pregnancies were reviewed to evaluate recurrence. Among 25 cases originally diagnosed as MFI, 5 (20%) were reclassified by study criteria as classic MFI, 9 (36%) as transmural or borderline MFD, and 11 (44%) as neither lesion. Among 55 cases originally diagnosed as MFD, 27 (49%) were reclassified as transmural or borderline MFD, 4 (7%) as classic MFI, and 24 (44%) as neither lesion. IUGR was identified in no case with classic MFI, in 31% of cases with transmural or borderline MFD (P = 0.02), and in 11% of cases with neither lesion. Recurrence was documented in 1 of 7 (14%) second- or third-trimester placentas. Possible recurrence was suggested in 3 of 6 (50%) first-trimester spontaneous abortion specimens. Classification of intraplacental fibrin is subjective and problematic; almost half of potential cases of MFI or MFD did not fulfill our study's diagnostic criteria. MFD may be more common and more strongly associated with IUGR than classic MFI. Recurrence of these lesions appears to be infrequent among second- and third-trimester placentas, but may be relatively common in first-trimester spontaneous abortions. Received April 20, 2001; accepted October 2, 2001.     

Luigi Amaducci memorial award winner's paper 2003. A neurologist's view of Alzheimer's disease and dementia

Senile dementia was the third most common admission diagnosis for New York psychiatric hospitals at the start of the twentieth century and the distinction between vascular and senile dementia was understood by psychiatrists even then. The term Alzheimer's disease (AD) was originally introduced to distinguish a pre-senile dementia from the common general paresis, but Alzheimer raised the possibility that pre-senile AD might not be distinguishable in clinical or histological terms from senile dementia. By the late 1970s it had become clear that the most common disorder producing dementia in elderly people was clinically and pathologically identical to pre-senile AD. AD is malignant, reducing remaining life expectancy by almost half and raising the risk of death over five years threefold (cancer raises it fourfold). Synapse loss associated with beta amyloid oligomers is a strong determinant of cognitive decline in patients with AD. Tau-containing neurofibrillary tangles usefully track disease severity. Unmodifiable risk factors include mutations in three genes which affect the production or metabolism of beta amyloid, the risk factor gene for Apolipoprotein [see symol in text]4 and female gender. The overriding risk factor is age, the prevalence of AD doubling with every five years of age until 90. Low education, head injury and low folate levels are examples of potentially modifiable risk factors. Since a delay of onset of five years would halve the number of patients with the disease, clinical trials for such putative protective factors as estrogens, folic acid, vitamin E, statins, and NSAIDs have begun. Cognitive and leisure activity may be protective against the development of AD but any protective function can only be confirmed by clinical trials.