University of Texas Medical Branch

About: University of Texas Medical Branch is a education organization based out in Galveston, Texas, United States. It is known for research contribution in the topics: Population & Virus. The organization has 22033 authors who have published 38268 publications receiving 1517502 citations. The organization is also known as: The University of Texas Medical Branch at Galveston & UTMB.

Responses of neurons in primate ventral posterior lateral nucleus to noxious stimuli

Abstract: 1. Recordings were made from the caudal part of the ventral posterior lateral (VPLc) nucleus of the thalamus in anesthetized macaque monkeys. In additon to many neurons that responded only to weak mechanical stimuli, scattered neurons were found that responded to both innocuous and noxious stimulation or just to noxious stimulation of the skin. A total of 73 such neurons were examined in 26 animals. 2. Noxious stimuli included strong mechanical stimuli (pressure, pinch, and squeezing with forceps) and graded noxious heat (from 35 degrees C adapting temperature to 43, 45, 47, and 50 degrees C). The responses of the VPLc neurons increased progressively with greater intensities of noxious stimulation. The stimulus-response function when noxious heat stimuli were used was a power function with an exponent greater than one. 3. Repetition of the noxious heat stimuli revealed sensitization of the responses of the thalamic neurons to such stimuli. The threshold for a response to noxious heat was lowered, and the responses to supra-threshold noxious heat stimuli were enhanced. 4. The responses of VPLc neurons to noxious heat stimuli adapted after reaching a peak discharge frequency. The rate of adaptation was slower for a stimulus of 50 degrees C than for one of 47 degrees C. 5. For the six neurons tested, responses to noxious heat were dependent on pathways ascending in the ventral part of the lateral funiculus contralateral to the receptive field (ipsilateral to the thalamic neuron). In two cases, the input to the thalamic neurons from axons of the dorsal column was also conveyed by way of a crossed pathway in the opposite ventral quadrant. In another case, access to the thalamic neuron by way of ascending dorsal column fibers was demonstrated. 6. The thalamic neurons had restricted contralateral receptive fields that were somatotopically organized. Neurons with receptive fields on the hindlimb were in the lateral part of the VPLc nucleus, whereas neurons with receptive fields on the forelimb were in medial VPLc. 7. Ninety percent of the VPLc neurons tested that responded to noxious stimuli could be activated antidromically by stimulation of the surface of SI sensory cortex. It was possible to confirm that many of these cells project to the SI sensory cortex by using microstimulation. Successful microstimulation points were either within the SI cortex or in the white matter just beneath the cortex. 8. We conclude that some neurons in the VPLc nucleus are capable of signaling noiceptive stimuli. The nociceptive information appears to reach these cells through the ventral part of the lateral funiculus on the side contralateral to the receptive field, presumably by way of the spinothalamic tract. The VPLc cells are somatotopically organized, and they are thalamocortical neurons that project to the VPLc nucleus and SI cortex play a role in nociception.

Total parenteral nutrition and cancer clinical trials

Abstract: Twenty-eight prospective randomized controlled clinical trials evaluating the use of total parenteral nutrition (TPN) in cancer patients were identified through a search of major indexing sources. The data were pooled across studies to increase the ability to detect therapeutic effects. The impact of publication bias and the quality of reporting each trial were used to critically assess the conclusions drawn from the pooled analysis. The authors conclude that TPN may be useful when used preoperatively in patients with gastrointestinal tract cancer. It appears to be beneficial in reducing major surgical complications (pooled P = 0.01) and operative mortality (pooled P = 0.02). No statistically significant benefit from TPN could be demonstrated in survival, treatment tolerance, treatment toxicity, or tumor response in patients receiving chemotherapy or radiotherapy. An increase in the risk of developing an infection in chemotherapy patients given TPN (pooled P less than 0.0001) underscores the importance of demonstrating significant benefits in randomized trials before TPN is used routinely in these patients.

Children's Activity Rating Scale (CARS): Description and Calibration

Abstract: A five-level Children's Activity Rating Scale (CARS) was designed to categorize the intensity of physical activities and discriminate between levels of energy expenditure in young children. The CARS was used by trained observers over a 12-month period to assess physical activities of 3-4 year-old children during field observations. Agreement among observers using the CARS was 84.1% for 389 paired observation periods. The energy expenditure for each level was assessed by measuring VO2s and heart rates of 5-6 year-old children (12 boys, 13 girls) while they performed eight activities representing the CARS levels. Mean VO2s for the eight activities in Levels 1-5 ranged from 7.1 to 37.5 ml kg BW−1 min−1 (1 to 5.42 METS; 145% to 80.6% of VO2max). Mean heart rates ranged from 89 to 183 b min−1 for activities in Levels 1-5. VO2s and heart rates at each level were significantly different from all other levels. These data demonstrate that the CARS encompasses a wide range of energy expenditures, discrimin...

Leucine-enriched nutrients and the regulation of mammalian target of rapamycin signalling and human skeletal muscle protein synthesis.

Abstract: Purpose of reviewTo highlight recent studies that have examined the cell-signalling mechanisms responsible for the amino acid (primarily leucine and the essential amino acids) stimulation of human skeletal muscle protein synthesis.Recent findingsIngestion of a leucine-enriched essential amino acid n