MRI visualization of bilateral quadriceps tendon rupture in a patient with secondary hyperparathyroidism: implications for diagnosis and therapy

Many musculoskeletal conditions have in the past been best defined on a clinical basis. However, because of pain, limitation of motion and hematomas, tendon ruptures can often be misdiagnosed clinically and it would be quite helpful to the clinician to have a noninvasive imaging technique. This communication defines the role of MRI in the early diagnosis of a nontraumatic rupture of the quadriceps tendons bilaterally in a patient with renal failure and known secondary hyperparathyroidism. The imaging techniques accurately defined the presence of hemorrhage extending into muscle from the ruptured tendons as well as the actual site and extent of tendon rupture. Since tendons have low mobile proton content and have low signal on MRI--disruptions are easily seen--MRI is the ideal noninvasive imaging technique for tendon injury, acute.

Phosphatidylglycerol in amniotic fluid. Comparison of an "ultrasensitive" immunologic assay with TLC and enzymatic assay

Phosphatidylglycerol (PG) in amniotic fluid is recognized as a good indicator of fetal lung maturity and is unaffected by moderate amounts of blood or meconium contamination. A rapid immunologic agglutination assay, Ultrasensitive AmnioStat-FLM (FLM), was compared with two-dimensional thin-layer chromatography (TLC) and an enzymic, colorimetric procedure (E-PG). Eighty amniotic fluid specimens were analyzed. FLM results were reported as high (H), intermediate (I), or low positive (L). TLC was compared with FLM:H (n = 27), mean 0.14 (fraction of total phospholipids); I (n = 7), mean 0.11; L (n = 9), mean 0.03; negative results had no detectable PG by TLC. In 33 cases E-PG was compared with FLM:H (n = 9), mean 7.0 mumol/L; I (n = 5), mean 8.1 mumol/L; L (n = 3), mean 3.0 mumol/L; negative (n = 16), mean 3.2 mumol/L. Records were reviewed in 70 cases. Thirty cases were excluded: sample to delivery time was greater than 72 hours; steroids were given or sepsis was documented. Fetal lung immaturity was clinically present in six cases: respiratory distress syndrome in three cases and transient tachypnea of the newborn (TTN) in three cases. One false positive result was identified (TTN, FLM:H). FLM sensitivity for fetal lung maturity was 85.3%, specificity was 83.3%, and the positive predictive value for fetal lung maturity was 96.7%. FLM is a fast, reliable indicator of fetal lung maturity.

Marking the spot

Tattooing with India ink is a precise and practical method for identifying biopsy sites when there is a significant delay between biopsy and definitive surgery.

Allosensitization in IL-2-containing limiting dilution cultures generates cytotoxic T lymphocytes (CTL) rather than LAK cells reactive with a syngeneic nonimmunogenic murine tumor

We have previously demonstrated that high frequency (1/20) of potent cytotoxic cells reactive with the nonimmunogenic lymphoma PIR-2 of C57BL/6 (B6, H-2b) origin, can be obtained by allosensitization of syngeneic B6 splenocytes against BALB/c (H-2d) splenocytes in limiting dilution cultures (LDC). Since a high concentration (250 U/ml) of exogenous interleukin 2 (IL-2), sufficient for the elicitation of lymphokine-activated killer (LAK) cells, was used in the LDC, and because the LDC-derived cytotoxic cells were active against a wide spectrum of target cells, we investigated whether the anti PIR-2 effector cells are LAK cells or cytotoxic T lymphocytes (CTL). We found that depletion from the B6 responder cell population of Lyt2+ (CTL precursors), but not of asialo GM1+ (LAK cell precursors), prior to LDC, results in the ablation of anti PIR-2 activity. When B6 splenocytes were plated in LDC with IL-2, in the absence of allogeneic stimulating cells, the resulting anti PIR-2 activity was greater than 10- to 500-fold lower than that obtained in LDC in the presence of allogeneic stimulating cells and IL-2. These and other observations suggest that the cytotoxic response against syngeneic tumors elicited by alloantigens in LDC is mediated by CTL rather than LAK cells, and that allogeneic sensitization in LDC can provide a means for the generation of CTL against syngeneic, nonimmunogenic tumors.

Chemo-immunotherapy of murine tumors using interleukin-2 (IL-2) and cyclophosphamide. IL-2 can facilitate or inhibit tumor growth depending on the sequence of treatment and the tumor type

The antitumor effect of interleukin-2 (IL-2), alone and in combination with cyclophosphamide was assessed in mice with established sarcoma (MCA 105, H-2b), carcinoma (M109, H-2d) and T lymphoma (PIR-2, H-2b). Whereas administration of IL-2 alone (5 x 10(4)-10 x 10(4) U, i.p. twice daily, for 4-8 consecutive days) prolonged the survival of mice with the solid neoplasms, it enhanced tumor growth and decreased survival of mice with the lymphoma. In the PIR-2 lymphoma, no IL-2 receptor (TAC) could be detected, nor could we demonstrate IL-2 tumor growth stimulation in vitro. A synergistic therapeutic effect was achieved in mice with the solid tumors, but not in mice with the lymphoma, only when IL-2 was given 1-4 days after cyclophosphamide (100-200 mg/kg). Conversely, administration of IL-2 1-4 days prior to cyclophosphamide resulted, in all three tumor systems, in enhanced tumor growth and in decreased survival as compared with mice receiving cyclophosphamide alone. Similarly, treatment with IL-2 both before and after cyclophosphamide was less efficacious than a single course of IL-2 given afterwards. It is concluded that for maximal therapeutic efficacy, IL-2 should be administered following chemotherapy, and that certain tumors may respond adversely to IL-2 treatment.

Electrophoresis and the isomune-LD and LD-1 immuno methods compared for measurement of lactate dehydrogenase isoenzyme-1

We evaluated three different methods for measuring lactate dehydrogenase (EC 1.1.1.27) isoenzyme LD-1 activity--agarose gel electrophoresis and two immunoassays, Isomune-LD (Roche) and LD-1 Immuno (Seragen)--in patients' samples for which measurement of creatine kinase-MB was ordered. Regression analyses of the comparisons gave the following results: LD-1 (%) from Isomune-LD (y) vs electrophoresis (x) (n = 51), y = 1.05x + 1.99, r = 0.92; LD-1 (%) from LD-1 Immuno (y) vs electrophoresis (n = 27), y = 1.05x + 3.94, r = 0.88; LD-1 (%) from LD-1 Immuno (y) vs Isomune-LD (x) (n = 41), y = 1.06x + 0.48, r = 0.95. Comparison by Student's paired t-test yielded significant differences between the mean values by electrophoresis and both Isomune-LD (P less than 0.005) and LD-1 Immuno (P less than 0.001), but no significant difference between the two immunoassays (P greater than 0.2). Analyzing these results by the overlap index, we conclude that electrophoresis shows the best clinical correlation followed, in order, by the Isomune-LD and the LD-1 Immuno methods. Both immunoassays are simpler and more rapid than electrophoresis, but in our hands the Isomune-LD method demonstrated greater precision and better correlation with electrophoretic values.

Electrophoresis and the isomune-LD and LD-1 immuno methods compared for measurement of lactate dehydrogenase isoenzyme-1

We evaluated three different methods for measuring lactate dehydrogenase (EC 1.1.1.27) isoenzyme LD-1 activity--agarose gel electrophoresis and two immunoassays, Isomune-LD (Roche) and LD-1 Immuno (Seragen)--in patients' samples for which measurement of creatine kinase-MB was ordered. Regression analyses of the comparisons gave the following results: LD-1 (%) from Isomune-LD (y) vs electrophoresis (x) (n = 51), y = 1.05x + 1.99, r = 0.92; LD-1 (%) from LD-1 Immuno (y) vs electrophoresis (n = 27), y = 1.05x + 3.94, r = 0.88; LD-1 (%) from LD-1 Immuno (y) vs Isomune-LD (x) (n = 41), y = 1.06x + 0.48, r = 0.95. Comparison by Student's paired t-test yielded significant differences between the mean values by electrophoresis and both Isomune-LD (P less than 0.005) and LD-1 Immuno (P less than 0.001), but no significant difference between the two immunoassays (P greater than 0.2). Analyzing these results by the overlap index, we conclude that electrophoresis shows the best clinical correlation followed, in order, by the Isomune-LD and the LD-1 Immuno methods. Both immunoassays are simpler and more rapid than electrophoresis, but in our hands the Isomune-LD method demonstrated greater precision and better correlation with electrophoretic values.

Association of high-molecular-mass and electrophoretically atypical alkaline phosphatases

Polyacrylamide gel electrophoresis of alkaline phosphatase may yield abnormally migrating fractions; these include high-molecular-mass alkaline phosphatase, which remains at the gel origin, and immunoglobulin-alkaline phosphatase complexes, which have a mobility approximately 1/3 that of liver isoenzyme. We performed a retrospective study of 19 patients whose sera exhibited atypical alkaline phosphatase fractions, defined as bands whose mobility was slower than bone, liver, or intestinal alkaline phosphatase; 17 had a mobility approximately 1/3 that of liver isoenzyme and 16 also exhibited gel origin enzyme activity or high-molecular-mass bands. The strong association of the atypical and high-molecular-mass alkaline phosphatases suggests that they may be structurally related, both consisting of either immunoglobulin-enzyme complexes or membrane-alkaline phosphatase complexes. This hypothesis is supported by (1) one serum available for investigation containing alkaline phosphatase-immunoglobulin complexes in both abnormally migrating fractions, but on detergent treatment showing no evidence of membrane-bound enzyme; (2) detergent treatment of serum from patients with only high-molecular-mass alkaline phosphatase creating bands with a mobility of approximately 1/3 that of the liver isoenzyme.

Influx of na, k, and ca into roots of salt-stressed cotton seedlings : effects of supplemental ca

High Na(+) concentrations may disrupt K(+) and Ca(2+) transport and interfere with growth of many plant species, cotton (Gossypium hirsutum L.) included. Elevated Ca(2+) levels often counteract these consequences of salinity. The effect of supplemental Ca(2+) on influx of Ca(2+), K(+), and Na(+) in roots of intact, salt-stressed cotton seedlings was therefore investigated. Eight-day-old seedlings were exposed to treatments ranging from 0 to 250 millimolar NaCl in the presence of nutrient solutions containing 0.4 or 10 millimolar Ca(2+). Sodium influx increased proportionally to increasing salinity. At high external Ca(2+), Na(+) influx was less than at low Ca(2+). Calcium influx was complex and exhibited two different responses to salinity. At low salt concentrations, influx decreased curvilinearly with increasing salt concentration. At 150 to 250 millimolar NaCl, (45)Ca(2+) influx increased in proportion to salt concentrations, especially with high Ca(2+). Potassium influx declined significantly with increasing salinity, but was unaffected by external Ca(2+). The rate of K(+) uptake was dependent upon root weight, although influx was normalized for root weight. We conclude that the protection of root growth from salt stress by supplemental Ca(2+) is related to improved Ca-status and maintenance of K(+)/Na(+) selectivity.

Endogenous Auxin and Ethylene in the Lichen Ramalina duriaei

Indole-3-acetic acid (IAA) levels and ethylene evolution rates were measured in a fruticose lichen Ramalina duriaei collected from carob trees growing in northeast Israel. IAA levels were estimated by gas liquid chromatography with electron capture detection of the pentafluorobenzyl ester and also by enzyme-linked immunosorbent assay following methylation. The identity of the isolated IAA was confirmed by gas chromatography-mass spectrometry of both the methyl and the pentafluorobenzyl ester. IAA levels in lichens 1 year after transplanting to an air-polluted urban site were found to be lower than in the control thalli left at a nonpolluted, rural site. The material from the latter contained about 2.5 micrograms per gram fresh weight free IAA and 0.5 microgram per gram fresh weight conjugated IAA, while the urban material contained 0.3 microgram per gram each of free and conjugated IAA. Ethylene production rate was 1.0 nanoliter per gram fresh weight per hour in the material from the rural site and 1.5 nanoliters per gram fresh weight per hour in material from the urban site.

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.