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Biomedical subjects

E E Furth

Publications and source records attributed to E E Furth.

At least 109 records · Page 6Linked to original sources
PubMed1991

cDNAs encoding members of a family of proteins related to human sterol carrier protein 2 and assignment of the gene to human chromosome 1 p21----pter.

Sterol carrier protein 2 (SCP2) is believed to play a key role in intracellular lipid movement. Here we report the cloning and nucleotide sequences of cDNAs encoding SCP2-related proteins of 58.85 kD and 30.8 kD and the assignment of the SCP2 gene to human chromosome 1 p21-pter. The SCP2-related proteins share common deduced carboxyl amino acid sequences with SCP2 and the cDNAs have a common 3' untranslated nucleotide sequence. The mRNAs encoding these proteins increased in a coordinate fashion as human placental cytotrophoblasts differentiated into syncytiotrophoblasts in culture. Our observations document the existence of a family of related proteins encoded by the human SCP2 gene.

Amino Acid Sequence↗
PubMed1990

Components of image intensive diagnosis. Codifying visual features for effusion cytology.

Components of visual assessment in the diagnosis of effusions were analyzed using relative operating characteristic. Diagnostic performance in the assessment of malignancy and the specification of metastatic origin was measured for two expert cytologists. The component of performance attributable to feature interpretation was measured in protocols which minimized the effects of clinical information and visual search in the decision process. Feature interpretation, as a process, contributed significantly to the evaluation of malignancy and marginally to the specification of metastatic origin. For each of these diagnostic tasks, the process of feature interpretation was codified in the construction of explicit models. The expert cytologists were asked to define a set of localized visual features that incorporate essential visual elements for diagnosis. These features were evaluated for a set of test cases, and regression models were constructed defining malignancy and metastatic origin. Relative operating characteristic analysis indicated that the predictive value of the models for diagnosis was very similar to the component of human performance attributable to feature interpretation.

Computers↗
PubMed1989

The effect of endogenous essential and nonessential fatty acids on the uptake and subsequent agonist-induced release of arachidonate.

We have demonstrated that the uptake and agonist-induced release of a pulse of arachidonate are influenced by the size and composition of preexisting endogenous fatty acid pools. EFD-1 cells, an essential fatty acid-deficient mouse fibrosarcoma cell line, were incubated with radiolabeled (14C or 3H] arachidonate, linoleate, eicosapentaenoate (EPA), palmitate, or oleate in concentrations of 0-33 microM for 24 h. After 24 h, the cells were pulsed with 0.67 microM radiolabeled (3H or 14C, opposite first label) arachidonate for 15 min and then stimulated with 10 microM bradykinin for 4 min. Because EFD-1 cells contain no endogenous essential fatty acids, we were able to create essential fatty acid-repleted cells for which the specific activity of the newly constructed endogenous essential fatty acid pool was known. Loading the endogenous pool with the essential fatty acids arachidonate, eicosapentaenoate, or linoleate (15-20 nmol of fatty acid incorporated/10(6) cells) decreased the uptake of a pulse of arachidonate from 200 to 100 pmol/10(6) cells but had no effect on palmitate uptake. The percent of arachidonate incorporated during the pulse which was released upon agonist stimulation increased 2-fold (4-8%) as the endogenous pool of essential fatty acids was increased from 0 to 15-20 nmol/10(6) cells. This 8% release was at least 3-fold greater than the percent release from the various endogenous essential fatty acid pools. In contrast, loading the endogenous pool with the nonessential fatty acids oleate or palmitate to more than 2-3 times their preexisting cellular level had no effect on the uptake of an arachidonate pulse. Like the essential fatty acids, increasing endogenous oleate increased (by 2-fold) the percent release of arachidonate incorporated during the pulse, whereas endogenous palmitate had no effect on subsequent agonist-induced release from this arachidonate pool. These studies show that preexisting pools of essential and nonessential fatty acids exert different effects on the uptake and subsequent releasability of a pulse of arachidonate.

Animals↗
PubMed1988

Mass quantitation of agonist-induced arachidonate release and icosanoid production in a fibrosarcoma cell line. Effect of time of agonist stimulation, amount of cellular arachidonate, and type of agonist.

The mass of total arachidonate released from phospholipids upon agonist stimulation of the cell and the fraction of released arachidonate which is converted to icosanoids are two parameters of arachidonate metabolism which have been difficult to quantitate because the mass of arachidonate released upon cell stimulation is very low. We have been able to quantitate both of these parameters under a variety of experimental conditions using a unique essential fatty acid-deficient mouse fibrosarcoma cell line (EFD-1), which when repleted with arachidonate, produces prostaglandin E2 (PGE2). Because there is no endogenous pool of arachidonate in these cells, the specific activity of exogenous arachidonate does not change upon incorporation into cells, an advantage which permits mass determination of very small quantities of arachidonate directly from radioactive counts. EFD-1 cells were incubated with various concentrations of [14C]arachidonate (for release studies) or unlabeled arachidonate (for PGE2 radioimmunoassays) for 24 h and then stimulated with bradykinin. The time courses for arachidonate release and PGE2 production demonstrated that free arachidonate was rapidly converted to PGE2 with plateau levels attained for both parameters within 240 s of agonist exposure for 2 microM and for 10 microM arachidonate-repleted cultures. There was a linear relationship (r = 0.94) between the mass of arachidonate in the cell and the mass of arachidonate released upon stimulation, up to a cellular concentration of 11 nmol of arachidonate/10(6) cells, a concentration 10-20% above normal for the parent mouse fibrosarcoma cell line (HSDM1C1) which is not essential fatty acid-deficient. Importantly, the percent of released arachidonate which was converted to PGE2 decreased from 90 to 15% with increasing concentrations of cellular arachidonate, because PGE2 production plateaued at greater than or equal to 6 nmol of arachidonate/10(6) cells, but total arachidonate release continued to rise. Finally, we demonstrated that agonist stimulation with thrombin, A23187, and bradykinin all showed the same percent conversion of released arachidonate to PGE2, implying that the determination of this fraction is not a function of the mechanism of release. These studies with our unique cell line indicate that, when the concentration of arachidonate in the cell is not elevated above amounts normally found in our HSDM1C1 cell line, released arachidonate is rapidly and almost quantitatively converted to PGE2, independent of the agonist used to stimulate the cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1988

Arachidonate released upon agonist stimulation preferentially originates from arachidonate most recently incorporated into nuclear membrane phospholipids.

When icosanoid-producing cells are stimulated by an agonist, 2-10% of total cellular arachidonate is released from phospholipids, and a variable percentage of the released arachidonate is subsequently converted into icosanoids. We used a mouse fibrosarcoma cell line (HSDM1C1) which synthesizes prostaglandin E2 in response to bradykinin stimulation to address the following questions: 1) upon cell stimulation is newly incorporated arachidonate preferentially released from phospholipids over previously incorporated arachidonate and 2) is there a corresponding change in phospholipid or membrane compartmentation of arachidonate to explain preferential release of newly incorporated arachidonate? To study changes in the availability of arachidonate for release from phospholipids, we incubated HSDM1C1 cells with 0.67 microM [14C]arachidonate for 15 min and chased the pulse of radiolabeled arachidonate with normal serum fatty acids. We found that of the [14C]arachidonate incorporated into phospholipids during the 15-min pulse, the percent released upon stimulation decreased nearly 3-fold from 8.9 +/- 0.5% at 5 min of chase to 3.6 +/- 0.2% (mean +/- S.E., n = 6, P less than 0.001) after only 60 min of chase. Percent release of arachidonate from nonpulsed controls was 3-4%. Although arachidonate release from phospholipids decreased significantly after 60 min of chase, the arachidonate which was released always originated predominantly from phosphatidylinositol. There was no decrease in the activities of enzymes required for arachidonate release during this time period. We also observed that throughout the period of the chase, the radiolabeled arachidonate remained esterified to the same phospholipid class into which it was initially incorporated (approximately 40% of [14C]arachidonate in diacyl phosphatidylcholine, 40% in phosphatidylinositol, and 15% in diacyl phosphatidylethanolamine. In cell fractionation experiments, we found that after 1-3 h of chase, [14C]arachidonate decreased in subcellular fractions containing nuclei, as it became progressively unavailable for release from phospholipids. Thus, our results indicate that 1) upon cell stimulation, the most recently incorporated pool of arachidonate, which is in high concentration in the nuclear membrane, is preferentially released and that 2) arachidonate rapidly moves out of the nuclear membrane into a less releasable pool while remaining esterified to the phospholipid moiety into which it was initially incorporated. This study indicates that the subcellular compartmentation of arachidonate has a marked influence on the cellular metabolism of arachidonate.

Animals↗
PubMed1988

Reversible phenotypic modulation induced by deprivation of exogenous essential fatty acids.

Essential fatty acid deficiency, produced by deprivation of omega-6 and omega-3 fatty acids, is a condition characterized by renal disease, dermatitis, and infertility. Although many of the biochemical aspects of this disorder have been investigated, little is known about the ultrastructural changes induced by essential fatty acid deficiency. Using a unique fatty acid-deficient cell line (EFD-1), which demonstrates the in vivo fatty acid changes of essential fatty acid deficiency, and the prostaglandin E2-producing mouse fibrosarcoma line from which it was derived (HSDM1C1), we correlated ultrastructural and biochemical changes induced by prolonged deprivation of all exogenous lipids and subsequent repletion of selected essential fatty acids. We found that in cells deprived of all exogenous lipids, there was dilation of rough endoplasmic reticulum and an associated defect in protein secretion; these changes were specifically reversed by arachidonate. There was also an accumulation of secondary lysosomes containing degraded membranes in these cells with an associated increase in phospholipids relative to parent HSDM1C1 cells. Cytoplasmic lipid bodies present in parent cells disappeared, with an associated decrease in triacylglycerol. After just 2 days in lipid-free medium, all these changes were apparent, and prostaglandin E2 production was markedly impaired despite normal amounts of cellular arachidonate. Incubation of EFD-1 cells with arachidonate, the major prostaglandin precursor fatty acid, induced a reversion to the HSDM1C1 phenotype, whereas other fatty acids were totally ineffective. These results indicate changes in fatty acid metabolism in essential fatty acid deficiency are associated with marked alterations in ultrastructure and secretion of protein from cells.

Animals↗
PubMed1980

Mutagenicity of hydroxamic acids and the probable involvement of carbamoylation.

A series of hydroxamic acids (aceto-, propiono-, benzo-, and p-nitrobenzo-) and seven derivatives of these were examined for biological activity using Salmonella typhimurium. Acylation to yield O-acetyl and O-benzoyl derivatives markedly enhanced toxic properties and was necessary for mutagenic activity for all but p-nitrobenzohydroxamic acid. The dose necessary to produce a minimum significant mutagenic response varied from 21 microM for O-benzoyl benzohydroxamate to 430 microM for O-acetyl acetohydroxamate. These two compounds were also tested with human lymphoblasts to which they were toxic at 100 microM but not mutagenic. O-Acetyl benzohydroxamate, a mutagen, was prepared wih a 14C label in the carbonyl carbon atom of the benzoyl group and was shown to form an adduct in vitro with DNA and polyguanylic acid. The level of binding was 1 mol of 14C per 5 X 10(4) mol of DNA phosphate and 1 mol of 14C per 10(5) mol of polyguanylic acid phosphate.

Cells, Cultured↗
PubMedDate not supplied

MR imaging of hepatic nodular regenerative hyperplasia.

Nodular regenerative hyperplasia (NRH), a rare condition that is commonly associated with noncirrhotic portal hypertension, is not well described in the MR literature. Three patients at two institutions were identified who had both abdominal MR imaging and pathologic evidence of NRH. All examinations were performed at 1.5 T and included axial T1- and T2-weighted spin-echo (SE) images. The MR studies were reviewed by two radiologists in consensus. Two patients had multiple liver lesions that had high signal components on T1-weighted images and were predominantly isointense with liver on the T2-weighted images. One patient had no focal lesions identified. NRH, when visualized on MR images, appears as multifocal masses with shortened T1 and T2 similar to liver. NRH should be considered in the differential diagnosis of hepatocellular tumors, especially in patients with a predisposing condition.

Adult↗
PubMedDate not supplied

Splenic implant in the jejunum: radiographic and pathologic findings.

We report a patient in whom barium studies and computed tomography revealed an intramural mass in the jejunum that consisted pathologically of ectopic splenic tissue. Because the patient had a prior splenectomy, the lesion probably represented splenosis rather than an accessory spleen. When intramural lesions are detected on barium studies in patients who have had prior abdominal trauma or splenectomy, 99mTc-tagged, heated-red blood cell scintigraphy may be performed to confirm the diagnosis, thereby eliminating the need for surgery in these patients.

Barium Sulfate↗
PubMedDate not supplied

Gastritis from NSAIDS to Helicobacter pylori.

Gastritis is a histologic diagnosis. To understand gastritis, the radiologist must have some working knowledge of gastric histology and pathology. Therefore, this article first describes normal histologic and radiologic anatomy. The pathology of gastritis is then presented to give the radiologist a basis for understanding the radiologic findings. Finally, gastritis is discussed from a clinical and radiologic perspective.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMedDate not supplied

Abdominal visceral calcification in primary amyloidosis: CT findings.

The computed tomographic (CT) findings of extensive visceral calcification involving both the liver and spleen in a patient with primary amyloidosis are presented. Although the CT imaging appearances of amyloidosis are often nonspecific, visceral calcification represents an important diagnostic clue for differentiating this entity from other infiltrative parenchymal diseases.

Adult↗