Pulvinar nuclei of the behaving rhesus monkey: visual responses and their modulation

We have examined the properties of neurons in three subdivisions of the pulvinar of alert, trained rhesus monkeys 1) an inferior, retinotopically mapped area (PI), 2) a lateral, retinotopically organized region (PL), and 3) a dorsomedial visual portion of the lateral pulvinar (Pdm), which has a crude retinotopic organization. We tested the neurons for visual responses to stationary and moving stimuli and for changes in these responses produced by behavioral manipulations. All areas contain cells sensitive to stimulus orientation as well as neurons selective for the direction of stimulus movement; however, the majority of cells in all three regions are either broadly tuned or nonselective for these attributes. Nearly all cells respond to stimulus onset, a significant number also give a response to stimulus termination, and rarely a cell gives only off responses. Nearly all cells increase their discharge rate to visual stimuli. Receptive fields in the two retinotopically mapped regions, PI and PL, have well-defined borders. The sizes of these receptive fields show a positive correlation with the eccentricity of the receptive fields. The receptive fields in the remaining region, Pdm, are frequently very large, but with these large fields excluded, show a similar correlation with eccentricity. All pulvinar cells tested (n = 20) were mapped in retinal coordinates; the receptive fields are positioned in relation to the retina. We found no cells with gaze-gated characteristics (2), nor cells mapped in a spatial coordinate system. The response latencies in PI and PL are shorter and less variable than the latencies in Pdm. Active use of a stimulus can produce an enhancement or attenuation of the visual response. Eye-movement modulation was found in all three subdivisions in about equal frequencies. Attentional modulation was common in Pdm and was rare in PI and PL. The modulation is spatially selective in Pdm and nonselective in PI for a small number of tested cells. These data demonstrate functional differences between Pdm and the other two areas and suggest that Pdm plays a role in selective visual attention, whereas PI and PL probably contribute to other aspects of visual perception.     

Quantitative assessment of psychologic state of patients with anorexia nervosa or bulimia: response to caloric stimulus

Hospitalized patients with anorexia nervosa (N = 17) or bulimia (N = 11) were given a standard liquid meal containing 400 calories. Using analogue scales, bulimic patients were found to have greater anxiety, lower mood, lower sexual arousal, and more fear of fatness than either control or anorectic patients. This finding of increased general "dysphoria" in bulimic patients persisted after the meal without any significant premeal to postmeal changes. Anorectic patients also differed from controls, but less than the bulimic patients. Some measures of anxiety correlated significantly with body mass index before the meal in bulimic patients, whereas in anorectic patients the correlation was significant only after the meal.     

Familial pericentric inversion of chromosome 8

Eight children from seven presumably unrelated families were identified independently as having an unbalanced recombinant chromosome resulting in the presence of extra material on the short arm of a chromosome 8. Parental chromosomes were analyzed, and one member of each couple (four fathers and three mothers) was found to carry a pericentric inversion of a chromosome 8 [inv(8)(p23q22)]. The propositi had an unbalanced recombinant chromosome [rec(8),dup q,inv(8)(p23q22)]. The affected infants all had developmental delay, congenital heart disease, and unusual appearance. A common origin of the pericentric inversion was suggested because of geographic location and Mexican--American ancestry of the seven families.     

Multiplex polymerase chain reaction.

The polymerase chain reaction (PCR) is a widely utilized assay for specifically amplifying small fragments of DNA. Multiplex PCR is the amplification of more than one DNA fragment per reaction and has many potential uses. When more than one primer set per reaction tube is utilized, the total number of tubes in any one experiment may be reduced, conserving expensive reagents and decreasing possible contamination. Multiplex PCR allows for an assay of the gene of interest and assures that the amplification process proceeds as expected with the use of a companion control genome primer set. Multiplex PCR is useful in assaying DNA extracted from samples of immunocompromised patients in which more than one infectious agent may be suspected such as simultaneous EBV and CMV detection. Multiplex PCR offers many advantages over single reaction PCR and has been found to be an useful adjunct in our laboratory.     

Partial pyruvate decarboxylase deficiency with profound lactic acidosis and hyperammonemia: responses to dichloroacetate and benzoate

We describe the successful use of sodium benzoate in a neonate with hyperammonemia associated with congenital lactic acidosis caused by a partial deficiency of the E1 component of pyruvate dehydrogenase (PDH); of note, this biochemical disturbance has not been previously described in PDH deficiency. The pyruvate dehydrogenase complex in skin fibroblasts had 48% of normal activity with a deficiency of the E1 component. The infant presented with rapid onset of a severe metabolic lactic acidosis, hyperventilation, hyperammonemia, and coma. At 30 hours of age continuous peritoneal dialysis was started; however, plasma NH3 concentrations remained in the 300-400 micrograms/dl range over the next 12 hours. Sodium benzoate, 250 mg/kg, was infused intravenously with a decrease in plasma ammonia of 25 micrograms/dl/hr. Hippurate was documented in the urine and peritoneal fluid after benzoate therapy. At 10.5 months of age, 50 mg/kg dichloroacetate was administered orally under fasting conditions, which resulted in a 56 and 62% reduction in the serum lactate and pyruvate levels, respectively; after 2 weeks on dichloroacetate his fasting levels were significantly decreased. Fibroblast PDH activity responded similarly to this drug. In our patient sodium benzoate was rapidly effective in producing a decline in plasma ammonia that was associated with clinical improvement. We feel that its use in organic acidemias deserves further evaluation and, furthermore, that any child with suspected PDH deficiency requires a clinical trial of dichloroacetate.     

Prevalence of generalized anxiety at eight weeks postpartum

Summary Objective: This study investigated the prevalence and nature of generalized anxiety symptoms in women who were eight weeks postpartum. Method: A community-based sample of 68 postpartum women completed an interview assessing generalized anxiety disorder and depression and a self-report measure of worry associated with concerns relevant to postpartum women. Results: Three women (4.4%) met DSM-IV criteria for generalized anxiety disorder, and an additional 19 women (27.9%) endorsed subsyndromal difficulties with generalized anxiety. Approximately one third of these women endorsed symptoms of depression. In contrast, only two woman met criteria for major depressive disorder. Conclusion: Postpartum generalized anxiety has a higher prevalence than postpartum depression. Received February 26, 2002; accepted November 11, 2002 Published online January 31, 2003 Acknowledgement This work was supported by a New Faculty Scholar Award and a Graduate Research Fellowship from the University of North Dakota. The authors would like to express their appreciation to Jennifer Brendle, Peter Schmutzer, Talia Tweten, and Chad Lystad for their assistance with this research. Correspondence: Amy Wenzel, Ph.D., Department of Psychology, University of North Dakota, Grand Forks, ND 58202-8380, U.S.A.; e-mail: amy_wenzel@und.nodak.edu