Effects of NaCl and CaCl(2) on Cell Enlargement and Cell Production in Cotton Roots

In many crop species, supplemental Ca(2+) alleviates the inhibition of growth typical of exposure to salt stress. In hydroponically grown cotton seedlings (Gossypium hirsutum L. cv Acala SJ-2), both length and weight of the primary root were enhanced by moderate salinities (25 to 100 millimolar NaCl) in the presence of 10 millimolar Ca(2+), but the roots became thinner. Anatomical analysis showed that the cortical cells of these roots were longer and narrower than those of the control plants, while cortical cells of roots grown at the same salinities but in the presence of only 0.4 millimolar Ca(2+) became shorter and more nearly isodiametrical. Cell volume, however, was not affected by salinities up to 200 millimolar NaCl at either 0.4 or 10 millimolar Ca(2+). Our observations suggest Ca(2+)-dependent effects of salinity on the cytoskeleton. The rate of cell production declined with increasing salinity at 0.4 millimolar Ca(2+) but at 10 millimolar Ca(2+) was not affected by salinities up to 150 millimolar NaCl.

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.

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.

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.

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.

Is the Phytophthora citrophthora culture filtrate a reliable tool for the in vitro selection of resistant Citrus variants?

Nucellar calli from four Citrus cultivars with known resistance to the Phytophthora citrophthora pathogen were chosen as experimental material to test the pathogen's response to culture filtrate (CF). Sensitivity of the four calli to CF of the fungus was in reverse order to what is known on the susceptibility of the cultivars in vivo. Sensitivity of protoplasts derived from the same four calli to 2,4-dichlorophenoxyacetic acid (2,4-D) was in the same order as that of calli to CF. Protoplasts derived from calli selected for tolerance to CF showed a higher plating efficiency with increasing concentration of CF in the medium. TLC and GLC determinations showed the presence of indole acetic acid in the culture filtrate. Results indicate that CF of P. citrophthora cannot be used as a selection tool in vitro.

Effects of NaCl and CaCl(2) on Ion Activities in Complex Nutrient Solutions and Root Growth of Cotton

Sodium displaces Ca(2+) from membranes (GR Cramer, A Läuchli, VS Polito Plant Physiol 1985 79: 207-211) and this can be related to the (Ca(2+))/(Na(+))(2) activity ratio in the external solution (GR Cramer, A Läuchli 1986 J Exp Bot 37: 321-330). Supplemental Ca(2+) is known to mitigate the adverse effects of salinity on plant growth. In this report we investigated the effects of NaCl (0-250 millimolar) and Ca(2+) (0.4 and 10 millimolar) on the ion activities in solution and on root growth of cotton (Gossypium hirsutum L.). Ion activities were analyzed using the computer program, GEOCHEM. Most ion activities in a 0.1 modified Hoagland solution were significantly reduced by both NaCl and supplemental Ca(2+). Ion-pair formation and precipitation were significant for some ions, especially phosphate. Root growth of 6-day-old seedlings was stimulated by low NaCl concentrations (25 millimolar). At higher NaCl concentrations, root growth was inhibited; the concentration at which this occurred depended on the Ca(2+) concentration and the growth index used. Supplemental Ca(2+) mitigated the inhibition of root growth caused by NaCl. There was a curvilinear relationship between root growth and the (Ca(2+))/(Na(+))(2) ratio in the nutrient solution. The mechanisms by which Na(+) and Ca(2+) may affect root growth are discussed.

Salt sensitivity in wheat : a case for specific ion toxicity

Two selected lines of bread wheat, Triticum aestivum L., differing in their relative salt resistance, were grown in isosmotic solutions of different ionic compositions to investigate sensitivity to specific ions. Growth rates and ion accumulation were determined. The salt composition of the various solutions had little effect on the growth of the salt-resistant line, but significantly affected that of the salt-sensitive line. Specifically, solutions containing high Na(+) concentrations were more toxic than those containing high Cl(-) concentrations or high concentrations of nutrient ions. There were few differences in ion accumulation between lines in a given treatment, although the sensitive line tended to accumulate more Na(+) than the tolerant line in the salt treatments with high Na(+) concentrations. The overall results provide evidence that there is a definite specific ion effect which is related to salt sensitivity in wheat. It is suggested that superior compartmentation of toxic ions, principally Na(+), may be a mechanism of salt resistance in this case.

Identification of Indole-3-Acetylglutamate from Seeds of Glycine max L

Indole-3-acetylglutamate was isolated from seeds of Glycine max L. cv Hark and identified by gas chromatography/mass spectrometry of the bis-methyl ester. Quantitative evaluation indicated that Hark soybeans contain 7.4 micromoles per kilogram of the glutamate conjugate. Conjugates with aspartate and glutamate have now been shown to account for essentially all of the bound indole-3-acetic acid present in seeds of soybean.

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.

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(+).

Enzyme reagents for measurement of phospholipids of amniotic fluid

Enzymic procedures have been developed for the specific determination of three phospholipids in an effort to make the estimation of the phospholipids of amniotic fluid more sound analytically. Apart from the actual determination of these analytes (lecithin, sphingomyelin, and phosphatidylglycerol), these enzymic procedures facilitate the evaluation of a number of the basic premises and procedural steps involved with the traditional procedures for the evaluation of fetal lung maturity. To this end, the changes are reported in sphingomyelin concentrations with gestational age. Although lacking in sufficient clinical data to assign "cut-off" values as yet, the enzymic procedures seem to correlate well with the existing procedures and are analytically accurate and precise.

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.

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.

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.

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.

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.

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.