Adenosine – dopamine receptor interactions in the isolated rat nodose ganglion but not in membranes of dorsal vagal complex

The present study has employed in vitro electrophysiology and radioligand binding assays to determine whether dopamine and adenosine receptors interact with each other on rat vagal afferent neurons. Preincubation of the isolated rat nodose ganglion with the adenosine A_2a agonists CGS 21680 or DPMA (Both 1 μM) resulted in a functional antagonism of the ability of dopamine to depolarise the preparation. Specifically, the concentration-response curve to dopamine was significantly shifted to the right in the presence of CGS 21680 and DPMA. On the other hand, adenosine itself, A₁ and A₃ receptor agonists and ATP were all incapable of modulating the electrophysiological response to dopamine. In contrast to the nodose ganglion, CGS 21680 did not significantly affect the ability of the dopamine D₂ ligands quinpirole or raclopride to displace [¹²⁵I]NCQ298 binding to dopamine D₂ receptors in membranes prepared from rat dorsal brain stem. These data indicate the presence of an interaction between high affinity adenosine A₂ receptors and dopamine D₂ receptors on the soma of rat vagal afferent neurons, whereas the situation in the brain stem remains less clear. Received: 17 September 1996 / Accepted: 20 October 1996     

Alternative brain organization after prenatal cerebral injury: convergent fMRI and cognitive data.

The current study presents both longitudinal behavioral data and functional activation data documenting the effects of early focal brain injury on the development of spatial analytic processing in two children, one with prenatal left hemisphere (LH) injury and one with right hemisphere (RH) injury. A substantial body of evidence has shown that adults and children with early, lateralized brain injury show evidence of spatial analytic deficits. LH injury compromises the ability to encode the parts of a spatial pattern, while RH injury impairs pattern integration. The two children described in this report show patterns of deficit consistent with the site of their injury. In the current study, their longitudinal behavioral data spanning the age range from preschool to adolescence are presented in conjunction with data from a functional magnetic resonance imaging (fMRI) study of spatial processing. The activation results provide evidence that alternative profiles of neural organization can arise following early focal brain injury, and document where in the brain spatial functions are carried out when regions that normally mediate them are damaged. In addition, the coupling of the activation with the behavioral data allows us to go beyond the simple mapping of functional sites, to ask questions about how those sites may have come to mediate the spatial functions.     

Height, weight, and body mass index among Akwesasne Mohawk youth.

Information on the growth of contemporary Native American adolescents is limited. A few studies have shown that Native Americans have growth patterns that may differ from U.S. reference values. We describe basic anthropometric characteristics (height and weight) of Mohawk youth between the ages of 10.0 and 16.99 years from the Akwesasne Mohawk Nation. Body mass index (BMI) was calculated. Mean height of Akwesasne Mohawk youth approximates the 50th percentile of reference values as determined by the 2000 Center for Disease Control and Prevention (CDC) growth charts. At every age, weight means of males approximate or exceed the 90th percentile and all mean weights of females approximate the 85th percentile. Akwesasne males are significantly taller than females from age 14 on and significantly heavier at ages 14 and 16. All age-specific BMI means for males are at or above the 90th percentile and females' means are at or above the 85th. The potential for long-term health effects associated with being overweight has implications for the future health of young Native Americans.     

The witches’ brew of spirituality and medicine

Recent proposals to join spirituality and medicine are facile and ill defined. The notion that physicians have the time or training to make assessments and recommendations about spirituality is misguided. Whenever a physician demonstrates personal caring for a patient, the healing process is likely enhanced, and in that sense, physicians often promote the spirituality of the patient. However, recent proposals to extend the physician’s task to that of assessing religion and directing the patient toward approved forms of spirituality are inappropriate. The languages of religion and science are radically different. The cultural body-mind split will not be solved by such simplistic solutions as having physicians endorse spirituality, which will result only in denigration of both medicine and religion. Physicians are encouraged to rely on clinically trained ministers for assistance in understanding the patient’s state of mind or spirit and its possible effects on the course of illness and health.     

Dynamic MRI with projection reconstruction and KWIC processing for simultaneous high spatial and temporal resolution.

A method for dynamic imaging in MRI is presented that enables the acquisition of a series of images with both high temporal and high spatial resolution. The technique, which is based on the projection reconstruction (PR) imaging scheme, utilizes distinct data acquisition and reconstruction strategies to achieve this simultaneous capability. First, during acquisition, data are collected in multiple undersampled passes, with the view angles interleaved in such a way that those of subsequent passes bisect the views of earlier ones. During reconstruction, these views are weighted according to a previously described k-space weighted image contrast (KWIC) technique that enables the manipulation of image contrast by selective filtering. Unlike conventional undersampled PR methods, the proposed dynamic KWIC technique does not suffer from low image SNR or image degradation due to streaking artifacts. The effectiveness of dynamic KWIC is demonstrated in both simulations and in vivo, high-resolution, contrast-enhanced imaging of breast lesions.     

Olanzapine reduces craving for alcohol: a DRD4 VNTR polymorphism by pharmacotherapy interaction.

Separate investigations have suggested that olanzapine, a D4 antagonist, decreases craving after a priming dose of alcohol and that the DRD4 variable number of tandem repeats (VNTR) polymorphism influences the expression of craving after a priming dose of alcohol. The present study tested the hypothesis that olanzapine may be differentially effective at reducing cue-elicited craving based on individual differences in DRD4 VNTR in a sample of heavy social drinkers. Participants were randomly assigned to receive olanzapine (5 mg) or a control medication (cyproheptadine, 4 mg) prior to consuming three alcoholic drinks. Participants completed subjective measures of craving and euphoria after each drink. Participants who were homozygous or heterozygous for the 7 (or longer) repeat allele of the DRD4 VNTR were classified as DRD4 L, while the other participants were classified as DRD4 S. The findings indicated that olanzapine reduces craving for alcohol at baseline for both DRD4 S and DRD4 L individuals, but only reduces craving after exposure to alcohol cues and after a priming dose of alcohol for DRD4 L individuals.