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J D Watson

Publications and source records attributed to J D Watson.

284 records · Page 16Linked to original sources
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Acute ethanol ingestion modifies the circulating plasma levels of atrial natriuretic peptide.

Since ethanol ingestion is associated with a disruption of water and electrolyte balance in a variety of species, we sought to evaluate the regulatory control of atrial natriuretic peptide (ANP) in response to acute doses of ethanol. Male Sprague-Dawley rats were administered a 5-g/kg dose of ethanol (40% w/v) via a gastric tube, while control animals received an equivalent volume of water. Expressed as a percentage of control, plasma ANP levels were 39.0%, 28.5%, and 23.6% in the ethanol-treated animals at 30, 60, and 120 min postintubation, respectively. Ethanol-treated animals displayed blood alcohol concentrations of 89.0, 137.6, and 214.1 mg/dl at the same time periods. After 120 min, plasma renin activity was elevated from 8.7 to 20.3 ng/ml/h in conjunction with an increase in the levels of circulating aldosterone from 16.3 to 42.5 ng/dl and an increase in plasma vasopressin from 2.2 to 3.6 pg/ml. Levels of atrial ANP mRNA remained consistent over the time course of the experiment, and no changes in the amount of ventricular ANP transcript were observed. Tissue ANP levels were similar between ethanol-treated and water-loaded control animals. In vitro experiments using cultured cardiac myocytes suggest that ethanol exposure may not directly affect ANP secretion. We propose that acute ethanol treatment may inhibit atrial distension and subsequently modify the control of ANP release under volume loading conditions.

Aldosterone↗
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To the editor.

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Chronic Disease↗
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Area V5 of the human brain: evidence from a combined study using positron emission tomography and magnetic resonance imaging.

In pursuing our work on the organization of human visual cortex, we wanted to specify more accurately the position of the visual motion area (area V5) in relation to the sulcal and gyral pattern of the cerebral cortex. We also wanted to determine the intersubject variation of area V5 in terms of position and extent of blood flow change in it, in response to the same task. We therefore used positron emission tomography (PET) to determine the foci of relative cerebral blood flow increases produced when subjects viewed a moving checkerboard pattern, compared to viewing the same pattern when it was stationary. We coregistered the PET images from each subject with images of the same brain obtained by magnetic resonance imaging, thus relating the position of V5 in all 24 hemispheres examined to the individual gyral configuration of the same brains. This approach also enabled us to examine the extent to which results obtained by pooling the PET data from a small group of individuals (e.g., six), chosen at random, would be representative of a much larger sample in determining the mean location of V5 after transformation into Talairach coordinates. After stereotaxic transformation of each individual brain, we found that the position of area V5 can vary by as much as 27 mm in the left hemisphere and 18 mm in the right for the pixel with the highest significance for blood flow change. There is also an intersubject variability in blood flow change within it in response to the same visual task. V5 nevertheless bears a consistent relationship, within each brain, to the sulcal pattern of the occipital lobe. It is situated ventrolaterally, just posterior to the meeting point of the ascending limb of the inferior temporal sulcus and the lateral occipital sulcus. In position it corresponds almost precisely with Flechsig's Feld 16, one of the areas that he found to be myelinated at birth.

Adult↗
PubMedDate not supplied

Automated image registration: II. Intersubject validation of linear and nonlinear models.

PURPOSE: Our goal was to validate linear and nonlinear intersubject image registration using an automated method (AIR 3.0) based on voxel intensity. METHOD: PET and MRI data from 22 normal subjects were registered to corresponding averaged PET or MRI brain atlases using several specific linear and nonlinear spatial transformation models with an automated algorithm. Validation was based on anatomically defined landmarks. RESULTS: Automated registration produced results that were superior to a manual nine parameter variant of the Talairach registration method. Increasing the degrees of freedom in the spatial transformation model improved the accuracy of automated intersubject registration. CONCLUSION: Linear or nonlinear automated intersubject registration based on voxel intensities is computationally practical and produces more accurate alignment of homologous landmarks than manual nine parameter Talairach registration. Nonlinear models provide better registration than linear models but are slower.

Adult↗
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A study of multimodal motherese: the role of temporal synchrony between verbal labels and gestures.

This study examined European American and Hispanic American mothers' multimodal communication to their infants (N = 24). The infants were from three age groups representing three levels of lexical-mapping development: prelexical (5 to 8 months), early-lexical (9 to 17 months), and advanced-lexical (21 to 30 months). Mothers taught their infants four target (novel) words by using distinct objects during a semistructured play episode. Recent research suggests that young infants rely on temporal synchrony to learn syllable-object relations, but later, the role of synchrony diminishes. Thus, mothers' target and nontarget naming were coded for synchrony and other communication styles. The results indicated that mothers used target words more often than nontarget words in synchrony with object motion and sometimes touch. Thus, "multimodal motherese" likely highlights target word-referent relations for infants. Further, mothers tailored their communication to infants' level of lexical-mapping development. Mothers of prelexical infants used target words in synchrony with object motion more often than mothers of early- and advanced-lexical infants. Mothers' decreasing use of synchrony across age parallels infants' decreasing reliance on synchrony, suggesting a dynamical and reciprocal environment-organismic relation.

Adult↗
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Functional imaging studies of human visual cortex.

1. The past decade has seen a burgeoning of functional imaging studies of cerebral activity in normal humans. Much of this week has been performed on the visual system, which is an important and often conveniently studied part of the brain. 2. Previously, what we believed about the functional anatomy of the human visual system was almost entirely obtained by studying individual patients with cerebral lesions and from experiments in animals. Early functional imaging experiments were often quite simple, descriptive exercises. 3. Techniques such as positron emission tomography have become quite mature; with this and increasing experience on the part of the investigators, the experiments performed have become more novel. Functional imaging methods have become part of the mainstream of investigations to be used for research on vision. They already have led to novel hypothesis about how aspects of this system work.

Cerebrovascular Circulation↗
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Sixth Daniel C. Baker, Jr. Memorial Lecture, Induction of cancer by DNA viruses.

The life cycles of the tumor virus SV40 and polyoma are discussed with particular emphasis on the role of the viral coded proteins which mediate the transformation of normal cells into their cancerous equivalents. One of more of these proteins possibly act by stimulating directly the synthesis of cellular DNA, while others may mimic the action of polypeptide mitogens that act at the cell surface.

Animals↗