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Biomedical subjects

E Epstein

Publications and source records attributed to E Epstein.

At least 127 records · Page 7Linked to original sources
PubMed1986

Potential problems in serum protein electrophoresis.

Potential problems are described that one could encounter in carrying out an electrophoretic procedure including its ancillary phases of visualization (staining) and quantification (densitometry). Endpoint-like measurements for separated isoenzymes may provide artifactual kinetic values as well, because stain measurement is fixed at a single time whereas reagent blanking in the electrophoretic medium is substituted for the conventional serum initial absorbance readings of test-tube determinations. Truncation of separated electrophoretic zones or opacity of an electrophoretic anti-convection medium such as uncleared cellulose acetate may also interfere with absolute quantification procedures.

Albumins↗
PubMed1986

The clinical use of alkaline phosphatase enzymes.

The enzyme alkaline phosphatase is an important serum analyte and its elevation in serum is correlated with the pressure of bone, liver, and other diseases. The analysis of the isoenzymes of alkaline phosphatase is an aid in diagnosing liver and/or bone disease, especially the high molecular weight isoenzymes that appear in cholestatic liver disease.

Alkaline Phosphatase↗
PubMed1986

Effect of phospholipase C on high-molecular-mass alkaline phosphatase in serum.

Electrophoresis of some serum samples on polyacrylamide gel, followed by staining for alkaline phosphatase (EC 3.1.3.1), produces a band of activity at the gel origin. This high-Mr band consists of liver membrane fragments containing alkaline phosphatase and other enzymes. Alkaline phosphatase is closely associated with phosphatidylinositol in liver plasma membranes, and we have found that phospholipase C (EC 3.1.4.3) from Bacillus cereus, known to possess some phosphatidylinositol specificity, was able to release liver alkaline phosphatase from the high-Mr band. Two preparations of phospholipase C from Clostridium perfringens, however, which has no phosphatidylinositol specificity, had no effect on the alkaline phosphatase activity in the high-Mr band.

Adult↗
PubMed1985

Alkaline phosphatase in the assessment of choledocholithiasis before surgery.

The pre-operative diagnosis of choledocholithiasis, or common bile-duct stones, is important in patients with cholelithiasis. Intraoperative cholangiography or choledochoscopy followed by exploration of the common bile duct could be limited to those patients with stones, if an adequate pre-operative diagnosis could be made. Many clinicians use pre-operative total alkaline phosphatase level alone or in combination with bilirubin level to determine the presence or absence of choledocholithiasis. Predictive value theory was used to analyze data reported by others to assess the value of alkaline phosphatase level alone or in combination with bilirubin level in identifying patients with choledocholithiasis. The authors conclude that alkaline phosphatase level is not useful either alone or in combination with bilirubin level in determining the presence of common bile duct stones in patients with cholelithiasis.

Alkaline Phosphatase↗
PubMed1985

Magnifiers in dermatology: a personal survey.

Most dermatologists find some type of magnifying system useful in their practice. Over a period of 15 years, I evaluated magnifiers ranging from simple low-power, single-lens systems to a Zeiss operating microscope. This report reviews the various types of magnifiers available for examining the skin's surface and describes their optical characteristics. For the dermatologist a binocular loupe with magnification of 3X to 4X appears to be the most useful diagnostic magnifying device. Higher magnifications failed to yield additional clinically useful detail. Lower-power binocular magnifiers of 2X to 2.5X, although useful as a surgical aid, provided less-than-optimal magnification for diagnostic purposes. The ideal magnifier for each practitioner will depend on subjective needs, as well as optical characteristics. Currently available magnifiers are described and evaluated.

Dermatology↗
PubMed1985

Carbohydrates stimulate ethylene production in tobacco leaf discs : I. Interaction with auxin and the relation to auxin metabolism.

Various naturally occurring carbohydrates, applied at a concentration range of 1 to 100 mm, stimulated ethylene production for several days in indoleacetic acid (IAA)-treated or untreated tobacco (Nicotiana tabacum L. cv ;Xanthi') leaf discs. The lag period for this sugar-stimulated ethylene production was 8 to 12 hours after excision in the untreated leaf discs, but less than 2 hours in the IAA-treated ones. Among the tested carbohydrates, 12 were found to increase synergistically ethylene production, with d-galactose, sucrose, and lactose being the most active; mannitol and l-glucose had no effect. The extent and duration of the increased ethylene production was dependent upon the type of sugar applied, the tissue's age, and the existence of both exogenous IAA and sugar in the medium. Sucrose appeared to elicit a continuous IAA effect for 48 hours, as expressed by increased ethylene production, even when IAA was removed from the medium after a 4-hour pulse. Sucrose stimulated both the uptake and decarboxylation of [1-(14)C]IAA, as well as the hydrolysis of the esteric and amide IAA conjugates formed in the tissue after application of free IAA. This gradual hydrolysis was accompanied by a further accumulation of a third IAA metabolite. Moreover, synthetic indole-3-acetyl-l-alanine increased ethylene production mainly with sucrose, and this effect was accompanied by its increased decarboxylation and turnover pattern suggesting that release of free IAA was involved. An esteric IAA conjugate, tentatively identified by GC retention time was found to be the major component (84%) of the naturally occurring IAA conjugates in tobacco leaves. Accordingly the sucrose-stimulated ethylene production in tobacco leaves can be ascribed mainly to the sucrose-stimulated hydrolysis of the esteric IAA conjugate.

Journal Article↗
PubMed1985

Potassium and sodium absorption kinetics in roots of two tomato species : lycopersicon esculentum and lycopersicon cheesmanii.

Excised roots of the tomato species, Lycopersicon esculentum Mill. cv Walter (the commercial species) and of Lycopersicon cheesmanii ssp. minor (Hook.) C.H. Mull. (a wild species from the Galapagos Islands), were used in comparative studies of their absorption of K(+) and Na(+). Uptake of (86)Rb-labeled K(+) and (22)Na-labeled Na(+) by excised roots of ;Walter' and L. cheesmanii varied as a function of genotype and tissue pretreatment with or without K(+). Excised roots of ;Walter' consistently absorbed more (86)Rb-labeled K(+) than those of L. cheesmanii. Absorption of K(+) from solutions ranging from 0.01 to 0.2 millimolar KCl showed saturation kinetics in both K(+)-pretreated and K(+)-depleted roots of ;Walter,' and for K(+)-depleted roots of L. cheesmanii. K(+)-pretreated roots of L. cheesmanii had exceedingly low rates of K(+) uptake with strikingly different, linear kinetics. Pretreatment with K(+) caused a decrease in rates of K(+) uptake in both genotypes. Potassium depleted roots of L. cheesmanii absorbed Na(+) at a greater rate than those of ;Walter,' whereas K(+)-pretreated roots of ;Walter' absorbed Na(+) at a greater rate than those of L. cheesmanii. The results confirm and extend previous conclusions to the effect that closely related genotypes may exhibit widely different responses to the two alkali cations, K(+) and Na(+).

Journal Article↗
PubMed1985

Potassium transport in two tomato species : lycopersicon esculentum and lycopersicon cheesmanii.

The commercial tomato, lycopersicon esculentum Mill. cv Walter, and its wild relative, Lycopersicon cheesmanii ssp. minor (Hook.) C.H. Mull., were grown for 30 days under controlled conditions and in solution culture varying in its content of Na(+) and K(+). Subsequently, (86)Rb-labeled K(+) uptake and distribution were studied. From all solutions, ;Walter' consistently absorbed (86)Rb-labeled K(+) at a higher rate in micromoles per gram fresh weight per 30 minutes than L. cheesmanii. L. cheesmanii distributed a greater proportion of the absorbed K(+) from its root to its shoot. When 0.6 millimolar NaNO(3) replaced 0.6 millimolar KNO(3) in the pretreatment solution, intact plants of both genotypes followed a similar pattern as when they were pretreated with K(+) only, but a greater percentage of the absorbed K(+) remained in the roots. Leaf slices of L. cheesmanii plants deprived of K(+) for 6 days showed a greater rate of K(+) uptake than did slices from ;Walter' plants pretreated the same way. Stem slices of L. cheesmanii, however, had a lower uptake rate than did those of ;Walter'. Both leaf and stem slices of ;Walter' plants, pretreated 6 days with 0.6 millimolar NaNO(3) substituting for 0.6 millimolar KNO(3) in their growth medium, had greater rates of (86)Rb-labeled K(+) uptake from 0.5 and 20 millimolar KCl solutions than did slices of L. cheesmanii. These marked differences in patterns of ion uptake and translocation indicate that these genotypes of tomato have evolved different mechanisms to deal with K(+) and Na(+) in their environments.

Journal Article↗
PubMed1985

Fluorouracil paste treatment of thin basal cell carcinomas.

Treatment of thin (superficial) basal cell carcinomas (BCCs) with topical fluorouracil is widely accepted despite the absence of published five-year cure rates. The published short-term data disclose treatment failure rates substantially higher than other modalities. In trials to improve and standardize topical fluorouracil therapy, thin BCCs were treated with 25% fluorouracil in petrolatum under occlusion for three weeks using weekly dressing changes. Of 44 thin BCCs treated only with 25% fluorouracil under occlusion for three weeks, the five-year cumulative recurrence rate was 21%. In a second series of 244 BCCs, light curettage preceded the 25% fluorouracil treatment to yield a five-year cumulative recurrence rate of 6%. Cosmetic results were good to excellent in more than 80% of both series. While fluorouracil by itself is not a satisfactory treatment for thin BCC, when combined with light curettage, topical fluorouracil therapy is capable of cure rates competitive with other modalities.

Adult↗
PubMed1985

Three methods compared for determining phosphatidylglycerol in amniotic fluid.

Phosphatidylglycerol is one component of amniotic fluid that is unaffected by several of the reported interferences with conventional thin-layer chromatographic measurement of phospholipid. To compare a rapid immunological agglutination test, "Amniostat-FLM", with two-dimensional thin-layer chromatography, we determined phosphatidylglycerol by both methods in 41 amniotic fluid specimens obtained at 31 to 40 weeks of gestation. We also assayed phosphatidylglycerol in 14 of these specimens by an enzymic, colorimetric procedure. The agglutination test is rapid and simple but relatively insensitive; it yielded positive results for only seven of 23 specimens in which phosphatidylglycerol was detected by thin-layer chromatography. In 18 specimens in which no phosphatidylglycerol was detected by thin-layer chromatography, results by Amniostat-FLM were also negative; however, eight of these specimens, assayed by the enzymic method, had phosphatidylglycerol present. Apparently, the Amniostat-FLM detects phosphatidylglycerol only at concentrations exceeding 25 mumol/L, or more than 15% of the total phospholipid composition.

Agglutination Tests↗
PubMed1984

Hand dermatitis: practical management and current concepts.

hand dermatitis (HD) is a common clinical challenge, its management a clinical art. The vexing problem of etiologies is simplified by classifying causative factors as either exogenous or endogenous. Most patients respond to avoidance of irritants combined with appropriate topical corticoids and lubrication. While certain aspects of treatment must be individualized, many of the protective and lubricating measures are routine. Patient compliance with these routine, and necessarily involved, measures is greatly improved by using printed instruction forms. A minority of patients with HD will challenge the most skilled clinician. At present, technics for determining the role of endogenous versus exogenous factors are not satisfactory. Even repeated and involved patch testing combined with prolonged observation may leave a nagging uncertainty . . . is there an overlooked allergen responsible for this chronic dermatitis? The chronic, endogenous, palmar, vesicular dermatoses represent a stubborn therapeutic problem. Potent corticoids under occlusion, while often effective, tend to produce atrophy. Intralesional corticoids are practical only for small areas. Systemic corticoids, while producing dramatic relief, only postpone the problem, since their side effects preclude long-term usage. At times psoralens and ultraviolet A (PUVA) therapy provides effective control. With perceptive persistence, most chronic HD can be effectively controlled. It is worth the effort, for often it means restoring a social and economic outcast to a useful and happy life.

Adrenal Cortex Hormones↗