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Biomedical subjects

V Rivera

Publications and source records attributed to V Rivera.

13 recordsLinked to original sources

A role for the Na/K-ATPase in the control of human c-fos and c-jun transcription.

The c-fos proto-oncogene is known to be regulated by a variety of hormones, growth factors, and other conditions that alter cellular metabolism. The regulation of c-fos RNA concentrations is known to occur both by altered RNA half-life and/or changes in the transcription rate of the gene. In most cases thus far investigated, induction of c-fos transcription by growth factors occurs very rapidly and transiently. Results presented in this paper show that ouabain, a specific inhibitor of the Na/K-ATPase increases the transcription of c-fos, as well as c-jun, in a variety of cultured cells. However, in contrast to other agents that induce c-fos and c-jun expression, the increased transcription rate of these genes in the presence of ouabain required several hours and remained elevated for at least 16 h. NIH 3T3 cells that have been transfected with deletions of the human c-fos promoter have enabled us to define at least two elements within the promotor that are regulated by ouabain. These include the serum response element and a region between 123 and 222 base pairs 5' to the start site of transcription. We speculate that regulation of the intracellular ion balance through changes in Na/K pump activity may be a general mechanism by which basal transcriptional activity of c-fos is modulated.

3T3 Cells

FMRFamide-like immunoreactivity in cells and fibers of the holothurian nervous system.

Immunoreactivity to FMRFamide (FMRFa) was detected in several components of the nervous system of the sea cucumber, Holothuria glaberrima. Neurons and fibers expressing immunoreactivity to this peptide were found in the radial nerves, and in nerve plexuses of the esophagus, and large and small intestine. The neurons in the enteric nervous system were located in the serosal layer and immunoreactive fibers appeared to innervate the longitudinal muscle. Co-existence of immunoreactivities to FMRFa and cholecystokinin was detected in most of the enteric fibers. Therefore, in the holothurians, neurons expressing FMRFa and FMRFa/cholecystokinin might be involved in the physiology of the digestive tract.

Animals

A prospective randomized study of cerebrospinal fluid drainage to prevent paraplegia after high-risk surgery on the thoracoabdominal aorta.

This article is concerned with the study of the effect of several variables, principally that of cerebrospinal fluid drainage, on the incidence of neurologic deficit in a prospective randomized series of patients with extensive aneurysms of the descending thoracic and abdominal aorta (thoracoabdominal type I and II). Forty-six patients had cerebrospinal fluid drainage, and 52 were controls, with a total of 98 available for study. Cerebrospinal fluid pressure was continuously monitored in the former group and pressure maintained less than or equal to 10 mm Hg in 20, less than or equal to 15 mm Hg in 20, and greater than 15 mm Hg in 6 patients during period of aortic clamping. The method of treatment including reattachment of intercostal and lumbar arteries (p = 0.2), temporary atriofemoral bypass during aortic occlusion (p = 0.3), and spinal fluid drainage (p = 0.8) were not statistically significant in reducing the incidence of neurologic deficits. Thus cerebrospinal fluid drainage as we used it, was not beneficial in preventing paraplegia. On appropriate statistical analysis we found that the only significant predictor of delayed deficits was postoperative hypotension (p = 0.006).

Aortic Dissection

Spinal cord ischemia after resection of thoracoabdominal aortic aneurysms: MR findings in 24 patients.

MR images of the thoracic spinal cord were made in 24 patients who developed signs and symptoms of spinal cord ischemia or infarction following surgery for a thoracoabdominal aortic aneurysm. Findings consisted primarily of four different patterns of signal abnormalities in the distribution of the anterior spinal artery. These abnormalities were identified as types A-D, depending on the degree of involvement of the gray matter and surrounding white matter. We found good correlation between the distribution of the signal abnormalities in the cord, the severity of the neurologic deficits, and the clinical outcome. MR is the imaging method of choice for diagnosing spinal cord ischemia or infarction. A thorough knowledge of the spinal cord arterial territories is crucial for characterizing ischemic MR signal abnormalities and for differentiating them from other causes of myelopathy.

Adolescent

Abnormalities of the acoustic reflex in multiple sclerosis.

Acoustic reflect morphology was examined in 122 patients with a diagnosis of definite multiple sclerosis. Abnormality in some dimension of acoustic reflex morphology was observed in 75 per cent of the study population. The most commonly observed abnormality was an alteration in one or more of the three relative amplitude indices (afferent, efferent, or central pathway index). Other abnormalities included delayed onset latency, delayed offset latency, reduction in absolute amplitude, and threshold elevation.

Adolescent

Spinal cord ischemia after resection of thoracoabdominal aortic aneurysms: MR findings in 24 patients.

MR images of the thoracic spinal cord were made in 24 patients who developed signs and symptoms of spinal cord ischemia or infarction following surgery for a thoracoabdominal aortic aneurysm. Findings consisted primarily of four different patterns of signal abnormalities in the distribution of the anterior spinal artery. These abnormalities were identified as types A-D, depending on the degree of involvement of the gray matter and surrounding white matter. We found good correlation between the distribution of the signal abnormalities in the cord, the severity of the neurologic deficits, and the clinical outcome. MR is the imaging method of choice for diagnosing spinal cord ischemia or infarction. A thorough knowledge of the spinal cord arterial territories is crucial for characterizing ischemic MR signal abnormalities and for differentiating them from other causes of myelopathy.

Adolescent

The use of the Varney brace for subluxating shoulders in stroke and upper motor neuron injuries.

Applying the Varney shoulder brace for painful subluxating shoulders in stroke and head injury patients with or without spasticity has proved to be an extremely effective means of reducing the subluxed shoulder. Other causes for painful shoulders in these patients must be ruled out. Not every shoulder which subluxes with or without spasticity is painful. Correct diagnosis of the etiology of the pain is essential to help the patient. Rotator cuff tendinitis, reflex sympathetic dystrophy, glenohumeral arthritis, shoulder contracture, pain due to central nervous system origin (thalmic pain) and other intrinsic causes of referred pain must be ruled out. Once the subluxed shoulder is proven to be the cause of pain, the Varney brace is an excellent orthosis for the reduction and maintenance of position. Pain usually subsides completely within 5 to 7 days.

Braces