Biomedical subjects

D L Webster

Publications and source records attributed to D L Webster.

At least 19 recordsLinked to original sources

PubMed2002

Neurobehavioral and neurometabolic (SPECT) correlates of paranormal information: involvement of the right hemisphere and its sensitivity to weak complex magnetic fields.

Experiments were designed to help elucidate the neurophysiological correlates for the experiences reported by Sean Harribance. For most of his life he has routinely experienced "flashes of images" of objects that were hidden and of accurate personal information concerning people with whom he was not familiar. The specificity of details for target pictures of people was correlated positively with the proportion of occipital alpha activity. Results from a complete neuropsychological assessment, Single Photon Emission Computed Tomography (SPECT), and screening electroencephalography suggested that his experiences were associated with increased activity within the parietal lobe and occipital regions of the right hemisphere. Sensed presences (subjectively localized to his left side) were evoked when weak, magnetic fields, whose temporal structure simulated long-term potentiation in the hippocampus, were applied over his right temporoparietal lobes. These results suggest that the phenomena attributed to paranormal or "extrasensory" processes are correlated quantitatively with morphological and functional anomalies involving the right parietotemporal cortices (or its thalamic inputs) and the hippocampal formation.

Alpha Rhythm↗

PubMed1993

Ultrastructural changes in yeast following heat shock and recovery.

The effects of heat shock and heat stress on the ultrastructure of Saccharomyces cerevisiae is reported. Following a mild heat shock, referred to as an increase in temperature from 25 degrees C to 37 degrees C for 30 min, we observed contraction of the nucleolus, formation of electron-dense particles (90 nm) in mitochondria and heat-shock granules (30-40 nm) in the cytoplasm. The electron-dense particles in the mitochondria were similar in appearance to those previously reported in plant cells exposed to elevated temperatures. In a heat-sensitive yeast strain, the nucleolus was severely aggregated after a mild heat shock, a treatment which hardly affected relatively more heat-resistant strains. The nucleolus was aggregated in all strains after a more severe heat stress (50 degrees C for 2 or 4 min). When cells were observed during a recovery period after heat stress it was found that nucleolar ultrastructure was regained more rapidly in cells that were previously heat shocked compared to cells that were stressed directly with no prior heat shock.

Cell Nucleolus↗

PubMed1986

Increased activity on immediate phase of bone imaging does not always indicate increased blood volume.

The immediate Tc-99m MDP image of a neoplastic right wrist mass in a 10-year-old boy demonstrated intense focal accumulation that suggested a very vascular tumor, but delayed images showed only slightly increased activity in the mass. A Tc-99m labeled RBC study was performed to permit whole-body blood pool imaging for other vascular lesions, and it did not demonstrate an increased blood volume in the mass. Biopsy showed the tumor to be a Ewing's sarcoma, probably of soft tissue origin. The sarcoma was not very vascular. The intense immediate accumulation of Tc-99m MDP in this case may be attributed to increased microvascular permeability.

Biopsy↗

PubMed1984

Intracranial hemorrhage in the term newborn.

Over a five-year period we identified 22 term newborns with intracranial hemorrhage by computed tomography in an intensive care unit for newborns. Primary subarachnoid hemorrhage (diffuse or focal) was the most common type of hemorrhage. Diffuse subarachnoid hemorrhage was caused either by traumatic delivery or severe hypoxic-ischemic encephalopathy and caused seizures on the first day. Focal subarachnoid hemorrhage was associated with cerebral infarction. Intraventricular hemorrhage was always accompanied by bloody CSF. Somewhat more than half the newborns with intraventricular hemorrhage had a history of traumatic delivery. In the remainder there were no associated risk factors for the hemorrhage. Hemorrhage into the cerebral hemispheres occurred without any identifiable risk factors. Hemorrhage into the cerebellum was associated with traumatic delivery.

Birth Injuries↗

PubMed1984