Search PubMed⌕ Search

Biomedical subjects

E Greene

Publications and source records attributed to E Greene.

At least 55 records · Page 3Linked to original sources
PubMed1989

Effects of recombinant human tumor necrosis factor alpha, lymphotoxin, and Escherichia coli lipopolysaccharide on hemodynamics, lung microvascular permeability, and eicosanoid synthesis in anesthetized sheep.

We infused recombinant human tumor necrosis factor alpha (rhTNF alpha), lymphotoxin (rhLT), and Escherichia coli 0111:B4 lipopolysaccharide (LPS) into anesthetized sheep with a lung lymph fistula to compare their effects on systemic and pulmonary hemodynamics, lung lymph dynamics, and eicosanoid release. rhTNF alpha (25-150 micrograms/kg, n = 6 sheep), but not rhLT (25 micrograms/kg, n = 3), rapidly increased lung lymph and plasma levels of 6-keto-prostaglandin F1 alpha (6-k-PGF1 alpha) and caused profound systemic vasodilation and hypotension. Meclofenamate pretreatment (10 mg/kg) of three other sheep given 25 micrograms/kg rhTNF alpha prevented the increase of lymph and plasma 6-k-PGF1 alpha levels, systemic vasodilation, and the early (less than 2 hrs) but not the late (4-6 hours) hypotension caused by rhTNF alpha. LPS (1 micrograms/kg, n = 11) induced a briefer increase of lymph 6-k-PGF1 alpha levels than did rhTNF alpha while plasma 6-k-PGF1 alpha levels did not increase. LPS induced more gradual hypotension than did rhTNF alpha but did not cause systemic vasodilation. LPS and rhTNF alpha, but not rhLT, increased lymph thromboxane B2 (TXB2) levels during the first hour of study, whereas only LPS acutely increased plasma TXB2 levels. LPS caused acute pulmonary vasoconstriction and greater acute pulmonary artery hypertension than did either rhTNF alpha or rhLT. Whereas LPS-treated sheep required less fluid transfusion than rhTNF alpha-treated sheep to maintain mean systemic arterial pressure greater than 50 mm Hg, LPS infusion caused a greater increase of lung lymph protein clearance. rhTNF alpha caused minimal alterations of lung microvascular permeability. We conclude that eicosanoid mediators contribute importantly to differences of systemic and pulmonary hemodynamics caused by these agents in sheep. rhTNF alpha cannot account for all of the LPS-induced hemodynamic, lung lymph, and eicosanoid responses in sheep.

6-Ketoprostaglandin F1 alpha↗
PubMed1988

The effect of stroke on object recognition.

Stroke patients were tested for their ability to recognize familiar objects shown in photographs, and we have confirmed previous reports that damage to the right hemisphere impairs recognition of objects shown at an "unusual angle". Additionally, these patients were impaired in matching unfamiliar (nonsense) objects which had been rotated. These impairments are discussed in the context of key task demands, particularly the need to extract depth cues from the photographs, and to rotate form elements to determine whether the samples provided different views of the same object. In the context of other work, these results suggest impairment of advanced perceptual skills which are needed to establish relationships of and among features of the forms.

Adult↗
PubMed1988

The corner Poggendorff.

With the classic Poggendorff illusion a set of parallel 'induction lines' will cause a set of oblique line segments to look misaligned even though they are collinear. A different kind of misalignment can be produced by placing the induction lines so that they form a corner. Under these conditions the obliques will appear to be angled slightly, one relative to the other. The effects are small, but can be seen and reliably reported by a group of naive subjects. The influence of the induction lines drops sharply as their relative position is moved from parallel to orthogonal, but there is a small residual influence which may be called the corner Poggendorff effect.

Attention↗
PubMed1987

The relative contribution of contact and target lines in the magnitude of the Poggendorff effect.

It is well known that a set of parallel lines can cause misperception of the projected path of an oblique. Most studies of this effect have emphasized either the proximal or the distal stimulus components--the line with which the oblique makes contact, or the line that serves as the target of the projection. An experiment is reported in which the relative contribution of the contact and target lines was examined. The results indicate that rotation of either line can determine the magnitude of the projection error.

Attention↗
PubMed1986

Thalamic role in spatial memory.

The contribution of structures in the limbic diencephalon to spatial memory function was investigated. Rats with lesions of either the anteroventral thalamus, anteromedial thalamus, dorsomedial thalamus or mammillary bodies were compared in their ability to perform a delayed alternation task. The results indicate the ablation of the thalamic nuclei did not impair delayed-alternation memory, but there was impairment following damage to the mammillary bodies. Placement of the discrete lesions was verified using Nissl sections and by tracing the pattern of projections using a silver degeneration stain. The results suggest that individual thalamic nuclei are not essential in the storage and/or retrieval of spatial memory. The data are discussed in terms of spatial deficits resulting from damage to the hippocampus proper or to the pathways connecting it to other brain structures.

Animals↗
PubMed1986

Selective culture medium enhances survival of neuroblasts from postnatal rodent brain.

One of the major limitations to the study of the development of the nervous system in aneuploid mammalian embryos is that the aneuploid condition is usually lethal in utero. Liveborn aneuploid individuals often succumb rapidly because they have a constellation of malformations incompatible with postnatal survival. We have developed a selective tissue culture medium (D-val) which can be used with fetal calf serum or in a serum-free defined composition and which permits neuroblasts and glioblasts present in postnatal rodent (rat, mouse) brain to proliferate and differentiate in vitro. These cells contain D-amino acid oxidase, but fibroblasts do not. In this medium, fibroblasts cannot grow and are eliminated from the cultures without the use of deleterious compounds such as antimitotic or chemotherapeutic agents. With this medium, cultures containing neuroblasts can be established from normal rat and mouse brain as late as postnatal days 11-20. Cultures with significant numbers of proliferating cells can also be established from perinatal aneuploid mouse embryos, 'rescuing' the cells for further study.

Animals↗
PubMed1986

Urine C-peptide and creatinine (Jaffe method) excretion in healthy young adults on varied diets: sustained effects of varied carbohydrate, protein, and meat content.

We studied effects of isocaloric diets of varied composition (each diet offered for 5 to 7 days) on urine C-peptide and creatinine excretion in eight healthy subjects. C-peptide excretion was higher on the high carbohydrate (60% CHO, 20% PRO) and high protein (45% CHO, 30% PRO) diets than on the low carbohydrate (30% CHO, 20% PRO) and low protein diets (45% CHO, 10% PRO). C-peptide excretion correlated with total kilocalories ingested (r = 0.594, p less than 0.001), and also with CHO (r = 0.469, p = 0.003) and PRO intake (r = 0.453, p = 0.004). Multiple regression analysis is given by the formula: Urine C-peptide (nmol/24 h) = 17.3 + 0.01 (kcal/24 h) + 0.021 (gm CHO/24 h) + 0.049 (gm PRO/24 h) Creatinine excretion was related to body weight (r = 0.959, p less than 0.001) and also to total PRO intake (r = 0.569, p less than 0.001) and meat intake (r = 0.367, p less than 0.05). We conclude that diet composition, especially protein intake, is an important stimulus to sustained insulin production as measured by C-peptide in healthy subjects. Diet composition has a significant impact on creatinine excretion. Urine creatinine cannot be assumed to reflect only lean body weight when it is used as a measure of the adequacy of timed urine collections.

Adult↗
PubMed1981

The influence of stroke on visual gestalt operations.

The hypothesis that the right hemisphere is specialized for "gestalt" perception was examined by testing stroke and control subjects in a "retrieval cuing" task which is an especially promising method for assessing integrative, brain activities. The results of the study indicate that the gestalt operations are modified by damage to either the right or left hemisphere. Stroke patients seemed to have difficulty inhibiting simple, organizing cue properties, and were especially sensitive to the influence of symmetry. The deficit might best be described as a "Gestaltbindung"--loss of ability to inhibit irrelevant or conflicting gestalts so that the form properties could be thoroughly examined and compared to material being held in memory.

Aged↗
PubMed1979

The influence of stroke on visual illusion magnitude.

In an attempt to resolve contradictory reports about the effect of right-versus left-hemisphere damage on perception of the Mueller-Lyer illusion, the present study examined judgments of stroke patients using this and several other visual illusions. The results provide some indication of abnormal perception of the Mueller-Lyer by patients with left-hemisphere damage. But the overall magnitude of illusion was normal in both groups of patients. It is possible that stroke damage did not affect the brain areas that are responsible for "gestalt" synthesis. However other recent studies using the Mueller-Lyer suggest that actual or incipient eye movements play an important role in the perception of this illusion, and under some conditions of testing, it is the activity of the left hemisphere that determines illusion magnitude.

Brain Mapping↗
PubMed1977

Syndrome of acquired factor X deficiency and systemic amyloidosis; in vivo studies of the metabolic fate of factor X.

To determine the metabolic fate of factor X in primary amyloidosis associated with factor X deficiency, we examined the pathways of its catabolism in a man with this syndrome. Intravenous infusion of human or bovine 131I-labeled factor X established a triphasic plasma clearance pattern for factor X. About 85 per cent of the factor X disappeared, with a disappearance half-time of less than 30 seconds. A second and third phase showed a T1/2 of 90 minutes and nine hours respectively. 131I-labeles factor X in plasma did not appear to be rapidly modified or degraded. Relatively minor quantities of 131I were cleared into the urine. We observed a diffuse distribution of radioactivity over the body surface, with a concentration in the hepatic and splenic regions. These studies demonstrate than factor X deficiency associated with systemic amyloidosis is due to binding of factor X to body tissue, probably within the circulatory system.

Amyloidosis↗
PubMed1976

Study of neonatal gastric aspirate related to amniotic fluid and to the occurrence of the idiopathic respiratory distress syndrome.

The lecithin/sphingomyelin ratio (L/S) has been shown to be of use in the prediction of the idiopathic respiratory distress syndrome (I.R.D.S) when performed on amniotic fluid. Gastric contents at birth consist mainly of amniotic fluid. Our study was designed to determine what the relationship was between the L/S ratios of amniotic fluid and gastric aspirate obtained at birth and to examine whether the L/S ratios of gastric aspirate was of any value in the prediction of I.R.D.S.

Amniotic Fluid↗