Age-dependent reduction of amygdala volume in bipolar disorder

The amygdala is hypothesized to play a critical role in mood regulation, yet its involvement in bipolar disorder remains unclear. The aim of the present study was to compare measurements of amygdala volumes in a relatively large sample of bipolar disorder patients and healthy controls ranging in age from 18 to 49 years. Subjects comprised 54 adult patients meeting DSM-IV criteria for bipolar disorder and 41 healthy controls matched for age, sex, and education. Magnetic resonance imaging (1.5 T) was performed to obtain volumetric measurements of the amygdala using a manual region-of-interest tracing method with software that allowed simultaneous visualization of the amygdala in three orthogonal planes. The anterior head of the hippocampus was removed in the sagittal plane prior to amygdala volumetry measurement. Multiple regression analysis was computed on amygdala volume measurements as a function of diagnosis, age, sex, and cerebral volume. Bipolar patients showed an age-related reduction of amygdala volume, but controls did not. Among bipolar subjects, amygdala volume was unrelated to medication history. There were no significant hemispheric or sex interactions with the main effects. Results support a role for amygdala dysfunction in bipolar disorder which appears most robustly in older relative to younger adult patients. Differential aging effects in bipolar disorder may compromise amygdala integrity and contribute to mood dysregulation.     

Inhibition of urea transport across renal tubules by pyrazinoylguanidine and analogs.

In addition to glomerular filtration and passive back diffusion of urea, there occurs across the renal tubule bidirectional transport of urea inhibitable in one or both directions by specific analogs of pyrazinoylguanidine (PZG). Effect of PZG on the profiles of sodium and urea concentrations along the tubule (stop flow) are consistent with their independent transport. Inhibition of urea and sodium reabsorption by PZG is dose dependent. PZG does not inhibit potassium excretion.     

The role of sediment ingestion in exposing wood ducks to lead

Waterfowl on lateral lakes of the Coeur d'Alene River and on Lake Coeur d'Alene have been poisoned for many years by lead (Pb) from mining and smelting. In 1992 we undertook a study in the area to determine the importance of sediment ingestion in exposing wood ducks (Aix sponsa) to Pb. Digesta were removed from the intestines of wood ducks collected from contaminated and reference areas. The mean Pb concentration in the digesta of wood ducks from the contaminated area was 32 p.p.m. dry weight. The sediment content was estimated to average less than 2% of the dry weight of the wood duck diet. The lead concentrations in the digesta were closely correlated with the concentrations of acid- insoluble ash, Al, Ti and Fe in the digesta and these four variables are associated with sediment. Samples containing low concentrations of these variables also had low concentrations of Pb. These results suggest that most of the Pb in the digesta came from ingested sediment, rather than from plant material in the diet. The importance of ingested sediment as a source of lead was unexpected, because wood ducks are surface feeders on aquatic plants and they rarely dabble beneath the surface or feed on the bottom. However, it appears that sediment ingestion is sometimes the principal route of exposure to environmental contaminants that are not readily taken up by plants and invertebrates and this route should be considered in risk assessments of waterfowl     

Determination of the modulus of elasticity of bone material by an acoustical approach at the forearm distinguishes women with and without vertebral fractures independent of bone mineral density.

The modulus of elasticity is a parameter characterizing fracture stability of bone independent of bone mineral density. Measurement of acoustical properties of the forearm by determination of the resonant frequency of the ulna in longitudinal direction as a function of sound transmission velocity after adjustment of the measuring result by ulna length yields information about the modulus of elasticity. It was the aim of this study to investigate whether this parameter may distinguish between subjects with and without vertebral fractures independent of bone mineral density. Fifty females (61.1 +/- 9.1 years) were enrolled into the study, 25 with, and 25 age-matched without prevalent osteoporotic vertebral fracture(s). Especially low bone mineral density was not considered an exclusion criteria for enrollment into the control group. Resonant frequency of the ulna multiplied by ulna length was significantly lower in the group with prevalent fractures (53.6 +/- 6.8 m/s versus 56.8 +/- 5.2 m/s) after adjustment for age and after additional adjustment for forearm bone mineral density. Linear regression analysis showed complete independence of the acoustical parameter from bone mineral density. This study demonstrates that the modulus of elasticity of bone material is an independent risk factor for osteoporotic fractures. Acoustical measurement at the forearm by analyzing the resonant frequency of the ulna and correcting it by ulna length as geometrical parameter is capable of determining the modulus of elasticity in vivo.     

Air-contrast barium enema studies after flexible proctosigmoidoscopy: randomized controlled clinical trial

The authors performed a randomized clinical trial to determine the effect of flexible proctosigmoidoscopy (FPS) on the quality of air-contrast barium enema (ACBE) studies performed on the same day and whether it mattered if air or carbon dioxide was used for endoscopic insufflation. One hundred twenty-one patients were randomly assigned to one of the following groups: Same-day studies were performed, with air used for insufflation, in group 1; same-day studies, with carbon dioxide, in group 2; and separate-day studies in group 3. Scout images obtained before the ACBE study were graded for the amount of air seen, and ACBE studies were graded for overall quality; each was graded on a scale of 0-3 in a blinded fashion. The air score was significantly greater in group 1 (2.69) than in group 2 (2.01) (P less than .001), which in turn was significantly greater than in group 3 (1.53) (P less than .01). The ACBE quality scores in the three groups were not significantly different. The authors conclude that FPS can be done before ACBE examination without impairing the quality of the ACBE study. Although carbon dioxide insufflation results in less intestinal air after FPS, the quality of the ACBE study is not affected.     

Digital subtraction angiography: The intravenous approach

Summary With further improvement of digital subtraction angiography (DSA) equipment, and the development of sophisticated soft-ware programs, the intravenous approach again has become an promissing diagnostic alternative in certain clinical settings, if the patient's cardiac output is not severely diminished.In many cases an additional arterial study is not neccessary. The diagnostic results, advantages and limitations of the intravenous approach in imaging the brachiocephalic, renal and peripheral vessels are discussed.     

Abnormal gangliosides in the plasma of alcoholics

Gangliosides were isolated from plasma of alcoholics. The pattern of gangliosides was compared with that of healthy humans. Up to seven fractions of gangliosides could be detected. In healthy subjects the following pattern was found: GM3 38.2%, SPG 6.0%, GD3 30.2%, GD1a 10.6%, GD1b 4.8%, GT1b 7.9%, GQ1b 2.2%. In alcoholics, significant differences were observed in the main ganglioside fractions GM3 (52.6%) and GD3 (17.5%).     

Exophtalmos and basilar impression. A contribution to differential diagnosis of endocrine orbitopathy

We report on a male patient with exophthalmos of unclear etiology, basilar impression, syringohydromyelia and type II Arnold-Chiari malformation. Two diseases involving the orbital region were to be considered in differential diagnostic terms: endocrine orbitopathy and osseous orbit dysplasia. The typical physical appearance associated with basilar impression as well as suppurative keratitis in Lagophthalmos was striking. Tetraspasticity with pareses, bulbar symptoms, proximally pronounced muscular atrophy as well as a left hemihypesthesia was shown neurologically. Although the orbit CT was normal, sonography revealed thickened ocular muscles. There was euthyroidism in diffuse goiter with negative thyroid autoantibody findings. Because of lack of definitive detection of muscular swelling, tumor, or vascular anomaly in the various images, orbital dysplasia in the context of a malformation syndrome affecting several organs is suggested as the cause of the exophthalmos.