REMI mutagenesis and identification of pathogenic mutants in blast fungus (Magnaporthe grisea)

Blast fungus' mutant, which is very difficult to obtain, is the key substance in the study of the relation between pathogen and plant. Rice-Aichi-ashahi was used as the host and plasmid pBF101 or pCSN43 as foreign DNA fragment, and REMI mutagenesis was applied to tag the pathogenic sequence in rice blast fungus M.grisea. Three mutants (R2H65, R2H69 and R2B1565) related to pathogenicity were recovered from several hundreds of transformants. R2H69 and R2H65 produced merely strange conidia which could not form appressorium or yield abnormals, and pathogenicity test further confirmed that they were unable to cause disease. R2B1565 possesses the same phenotypes as those of the wild type except that the ability of causing disease was much reduced.

Neurotrophins and the anti-inflammatory agents interleukin-4 (IL-4), IL-10, IL-11 and transforming growth factor-beta1 (TGF-beta1) down-regulate T cell costimulatory molecules B7 and CD40 on cultured rat microglia

Microglia are essential for T cell activation in the CNS. Since T cell activation requires costimulation by B7 and/or CD40, we examined the regulation by cytokines of B7-1, B7-2 and CD40 mRNA expression in cultured rat microglia in serum-free medium. All three ligands are expressed constitutively, but are profoundly up-regulated by granulocyte-macrophage colony-stimulating factor (GM-CSF). By contrast, interferon-gamma raises only B7-2 and CD40 mRNA, and the B7-2 increase is inhibited by IL-10. IL-4, transforming growth factor-beta1, and nerve growth factor (NGF) repress GM-CSF-induced B7-2 and CD40, but not B7-1. NGF also down-regulates its own high-affinity trkA receptor. IL-11, unrecognized for its effect on antigen presentation, represses GM-CSF-induced B7-2.

[Analysis of MRI and CT manifestations of paranasal sinuses and orbitocranial disorders with secondary exophthalmos]

OBJECTIVE

To study the MRI and CT manifestations of paranasal sinuses and orbitocranial disorders with secondary exophthalmos.

METHODS

MRI and CT scans of 51 patients were examined.

RESULTS

MRI offers more information for evaluation of soft tissue lesions; the cavernous hemangioma and dermoid cyst were found to present rather characteristic images. Whereas in evaluation of lesions involving bony structures and calcifications, CT was superior to MRI.

CONCLUSION

CT and MRI may evaluate the tumor location, extension into adjacent areas and are valuable in differential diagnosis of paranasal sinuses and orbitocranial disorder with secondary exophthalmos.

Neurotrophins and the anti-inflammatory agents interleukin-4 (IL-4), IL-10, IL-11 and transforming growth factor-beta1 (TGF-beta1) down-regulate T cell costimulatory molecules B7 and CD40 on cultured rat microglia

Microglia are essential for T cell activation in the CNS. Since T cell activation requires costimulation by B7 and/or CD40, we examined the regulation by cytokines of B7-1, B7-2 and CD40 mRNA expression in cultured rat microglia in serum-free medium. All three ligands are expressed constitutively, but are profoundly up-regulated by granulocyte-macrophage colony-stimulating factor (GM-CSF). By contrast, interferon-gamma raises only B7-2 and CD40 mRNA, and the B7-2 increase is inhibited by IL-10. IL-4, transforming growth factor-beta1, and nerve growth factor (NGF) repress GM-CSF-induced B7-2 and CD40, but not B7-1. NGF also down-regulates its own high-affinity trkA receptor. IL-11, unrecognized for its effect on antigen presentation, represses GM-CSF-induced B7-2.

Neurotrophins and the anti-inflammatory agents interleukin-4 (IL-4), IL-10, IL-11 and transforming growth factor-beta1 (TGF-beta1) down-regulate T cell costimulatory molecules B7 and CD40 on cultured rat microglia

Microglia are essential for T cell activation in the CNS. Since T cell activation requires costimulation by B7 and/or CD40, we examined the regulation by cytokines of B7-1, B7-2 and CD40 mRNA expression in cultured rat microglia in serum-free medium. All three ligands are expressed constitutively, but are profoundly up-regulated by granulocyte-macrophage colony-stimulating factor (GM-CSF). By contrast, interferon-gamma raises only B7-2 and CD40 mRNA, and the B7-2 increase is inhibited by IL-10. IL-4, transforming growth factor-beta1, and nerve growth factor (NGF) repress GM-CSF-induced B7-2 and CD40, but not B7-1. NGF also down-regulates its own high-affinity trkA receptor. IL-11, unrecognized for its effect on antigen presentation, represses GM-CSF-induced B7-2.

[The observation of proliferative cell nuclear antigen and AgNORs in ocular adnexal lymphoid hyperplasia]

PURPOSE

To investigate the expression of proliferative cell nuclear antigen and Nuclear Organizer Region in ocular adnexal lymphoid hyperplasia and its histopathologic classification.

METHOD

Using anti-proliferative cell nuclear antigen monoclonal antibody (PC10) and AgNORs method, the proliferative cell in 34 cases of ocular adnexal lymphoid neoplasms (benign lymphoid lesion, BLL, 14 cases; atypical lymphoid hyperplasias, AH, 9 cases; malignant lymphomas, ML, 11 cases) were detected in formalin fixed and paraffin-embeded tissue.

RESULTS

A significant difference between BLL and AH, BLL and ML was observed (PCNA P < 0.001, P < 0.001; AgNORs P < 0.01, P < 0.001); similar result was observed between AH and ML in PCNA index (P < 0.01). But there was not a significant difference in AgNORs count (P > 0.05). The linear regression coefficient between PCNA index and AgNORs number was excellent (0.8693).

CONCLUSION

The two methods may be helpful to distinguish ocular adnexal lymphoid reactive hyperplasia and malignant lymphoma.

[A study on diagnosis of ocular adnexal lymphoid hyperplasia by polymerase chain reaction amplified IgH CDR-III sequence]

OBJECTIVE

To study the diagnosis and classification of ocular adnexal lymphoid hyperplasia and investigate its cell origin by using some molecular biological techniques.

METHODS

29 cases (31 eyes) of ocular adnexal lymphoid hyperplasia were examined for immunoglobulin heavy-chain (IgH) gene rearrangements by means of polymerase chain reaction (PCR) to amplify the complementarity determining region III (CDR-III) with formalin-fixed and paraffin-embedded tissue combining with histopathologic examination and immunophenotypic analysis.

RESULTS

17 eyes of malignant lymphoma and 5 eyes of reactive lymphoid hyperplasia demonstrated clear single band of the rearranged gene for the IgH chain between 100 bp. to 120 bp. The bilateral ocular adnexal lymphoma occurring simultaneously in 4 eyes (two individuals) exhibited identical band. 1 eye of malignant lymphoma, 8 eyes of atypical lymphoid hyperplasias and 6 eyes of reactive lymphoid hyperplasia showed no band or a smear band.

CONCLUSIONS

The results show that this method can determine the clonality of the lymphoid hyperplasias. It may be as well in the examination of small monoclonal B cell populations for which immunophenotypical analysis is difficult. The method is an objective, accurate and useful approach for the diagnosis of ocular adnexal lymphoid hyperplasias.

A novel method for DEAE-dextran mediated transfection of adherent primary cultured human macrophages

Primary cultured human macrophages are difficult to transfect. We have developed a DEAE-dextran DNA transfection method that mediates the reproducible transfection of primary cultured adherent human macrophages. Three factors essential for successful transfection were identified: DEAE-dextran concentration, the quantity of DNA per transfection and the incubation time of the macrophages with the transfection medium. Maximum levels of luciferase expression were attained within 24 h and maintained for at least 56 h after transfection. While serum in the transfection medium attenuated transfection, the treatment of the macrophages with chloroquine, DMSO, or glycerol did not enhance transfection within this system. A CMV enhancer/promoter mediated substantially greater luciferase expression in the macrophages than either HIV or RSV LTRs. DEAE-dextran facilitated superior transfection compared to either cationic liposome and calcium phosphate methods, and was more practical compared to electroporation for multiple transfections. This transfection protocol provides a simple, inexpensive, reproducible method for the evaluation of gene expression in primary cultured adherent human macrophages.

Random amplified polymorphic DNA markers in crosses between inbred lines of Rhode Island red and White Leghorn chickens

Reciprocal crosses and backcrosses were conducted between inbred Rhode Island Red and White Leghorn chickens differentiated for egg production and egg quality traits. Random amplified polymorphic DNA (RAPD) markers distinguishing inbred lines were detected. Twenty-two polymorphic bands were found from screening 120 single 10-mer random primers of which two were consistent with sex-linked markers. Of 90 pairwise two-point linkage analyses completed for the autosomal markers, four close linkages (8.2 cM to 14.9 cM) were significantly different from zero.

Alcohol dehydrogenase-catalyzed reduction of protein carbonyl derivatives

A simple method for measuring protein carbonyl derivatives is described. The assay is based on the catalytic reduction of protein carbonyl derivatives by NADH-dependent alcohol dehydrogenase at pH 7.5. Bovine serum albumin, oxidized by a system that generates highly reactive hydroxyl radicals via a Fenton-type reaction, is reacted with NADH in the presence of the enzyme. The carbonyl derivatives are quantitated on the basis of absorbance changes at 340 nm using millimolar absorptivity of 6.2 mM-1 cm-1. The method correlates well with a method that utilizes 2,4-dinitrophenylhydrazine.

[Automated perimetry analysis of optic nerve compression caused by orbital tumors and tumor-like lesions]

OBJECTIVE

In order to evaluate the relationship between the orbital neoplasms and the resulting visual field damage.

METHOD

22 cases of orbital tumors and tumor-like lesions were examined with automated perimetry.

RESULTS

Visual field alterations varied from arcuate, inferior altitudinal, ceeocentral scotomas, to temporal hemianopsia and diffuse defect. The surgical removal of the tumor or steroid administration was followed by partial or full perimetric recovery.

CONCLUSIONS

Visual field alteration reflects the severity of the optic nerve damage. The impairment is reversible. Apical masses may cause severe optic neuropathy. Axonal and vascular factors are involved in the main pathological mechanisms of the disease.

Conditioned medium from activated microglia promotes cholinergic differentiation in the basal forebrain in vitro

In earlier studies we found that treatment with interferon-gamma (IFN-gamma) produced an 8- to 11-fold increase in choline acetyltransferase (ChAT) in cultured cells taken from Embryonic Day 16 (E16) septal nuclei with adjacent basal forebrain (SN/BF). Since younger cultures responded even more profoundly to IFN treatment, we have tested the possibility that the action of IFN (or its intermediate; see below) is to prompt the cholinergic differentiation of neuronal precursors. SN/BF cultures of various ages were labeled with a retrovirus engineered to express beta-galactosidase (Lac-Z), and ChAT-positive descendants of the retrovirally labeled precursors were counted. IFN-gamma treatment of cultures caused as much as an 8.8-fold increase in the proportion of ChAT-positive cells present in Lac-Z-positive clones, suggesting that IFN promoted cholinergic differentiation in precursor populations. By contrast, bFGF increased clone size but did not change the proportion of ChAT-positive cells. NGF affected neither. Only ameboid microglia present in the cultures responded to IFN with characteristic nuclear translocation of the signal transducing molecule p91, suggesting that a microglial-derived molecule may mediate the action of IFN. Consistent with this hypothesis, conditioned media from cultures of enriched, activated microglia also increased ChAT activity in a dose-dependent fashion. Conditioned media from an unstimulated macrophage/monocyte cell line (RAW 264.7) also proved extremely efficacious in raising ChAT activity. In addition, conditioned media from both activated microglia and RAW 264.7 cells increased the proportion of ChAT-positive cells in retrovirally labeled clones to the same extent as IFN itself, suggesting the possibility that they contain the molecule(s) that mediates the action of IFN. Preliminary characterization of this molecule suggests that it is a very stable and large protein. Together these data suggest that a molecule promoting cholinergic differentiation is produced by activated microglia and other macrophage-like cells. The identity of this molecule and its precise role in normal development await its further purification.

Interferon-gamma promotes cholinergic differentiation of embryonic septal nuclei and adjacent basal forebrain

In cultured rat embryonic septal nuclei with adjacent basal forebrain, murine interferon-gamma (IFN gamma) produces a striking increase in choline acetyltransferase (ChAT) activity and mRNA. The effect of IFN gamma on cholinergic differentiation is more potent in E14 cultures than in older cultures. IFN gamma does not cause a change in the affinity of ChAT for choline, nor does it affect cell proliferation. Whereas IFN gamma doubles neuronal cell number, the cholinergic cell number increases more than 7-fold. Ameboid microglia respond to IFN gamma with the translocation of p91 to the nucleus. The action of IFN gamma is not mediated by NGF or bFGF. The enhancement of cholinergic expression that occurs with increased cell density may be partly attributable to an endogenous IFN gamma-like molecule, since antibodies to IFN gamma offset the effects of increased cell density.

Reinfection with Schistosoma japonicum after treatment with praziquantel in Poyang lake region, China

The study on reinfection with Schistosoma japonicum after treatment was carried out in a cohort of subjects in a heavy endemic village of Poyang lake region, China. After mass treatment with praziquantel in non-transmission time, detailed observations of water contact were estimated using the mean area of skin exposed daily. One year after treatment, the prevalence of infection in study subjects was 54.48%, returning to 83% of initial prevalence. The peak prevalence occurred the 11-15 year age class, but intensity of exposure also varies with age and that age group supporting the higher prevalence of reinfection had high levels of exposure. Among groups of subjects with a similar exposure stratum, young subjects under the age of 21 years were more heavily reinfected, while no heavy reinfection was observed in adults (> or = 25 years). These observations suggest that subjects in this area slowly acquire an increasing degree of immunity to lighten the intensity of infection with S. japonicum.

Fatal pulmonary embolism in spinal cord injury

Fatal pulmonary embolism (PE) is a major cause of mortality in patients with spinal cord injury. In order to ascertain those characteristics that might predict this event, we reviewed the records of all patients with autopsy-proven massive PE admitted to a regional spinal cord care center over a 5-year period. The information analyzed included patient age, sex, race, height, weight, type of accident, prior use of tobacco, alcohol, or narcotic drugs, level of injury, presence of spasticity, surgical procedures, infections, transfusions, and type of anticoagulant prophylaxis. Forty-two concurrently hospitalized patients with spinal cord injury served as control subjects. Significant differences between cases and control subjects were observed for level of injury (fewer thoracic and lumbar injuries in cases, p = 0.04), less spasticity in cases (p = 0.01), and greater body mass index in cases (p = 0.01). There was also a trend toward more advanced age in the cases (p = 0.1) and more frequent serious infections (p = 0.08). Lastly, low molecular weight heparin had been used as thromboprophylaxis in a greater proportion of control subjects than cases (60 percent vs 22 percent, p = 0.07), suggesting that low molecular weight heparin may be more effective in preventing fatal PE than unfractionated heparin.

A synthetic early promoter from a baculovirus: roles of the TATA box and conserved start site CAGT sequence in basal levels of transcription

Many baculovirus early genes and insect genes transcribed by RNA polymerase II have a conserved transcription start site sequence (CAGT) located downstream of a consensus TATA box. To examine the functions and interactions of these two motifs in initiating accurately positioned basal transcription, a 43-nt synthetic promoter was synthesized from the TATA box and start site sequences of the gp64 early promoter from the Orgyia pseudotsugata multicapsid nuclear polyhedrosis virus (OpMNPV). The synthetic promoter initiated accurately and was also transactivated by the baculovirus transcriptional activator, IE1. To determine the roles of sequences within the 43-nt synthetic promoter, a series of linker-scanning and spacing mutations were analyzed for transcriptional activity, start site selection, and transactivation. Linker-scanning mutations were examined in vivo by transient expression and reporter gene assays. To examine transcription start site selection, promoter constructs were used for in vitro transcription in nuclear extracts from uninfected Spodoptera frugiperda (Sf9) cells. In vivo and in vitro analyses show that the TATA box, and not the start site CAGT, is the primary element controlling start site selection. Substitution of the conserved start site CAGT sequence resulted in a reduction of both reporter gene activity and in vitro transcripts, although transcripts initiated accurately. Data from linker-scanning and spacing mutations indicate that the conserved start site CAGT sequences are not required for accurate initiation but sequences at the start site play an important role in initiation efficiency.

Inheritance of tinted eggshell colors in white-shell stocks

The present study was conducted to study the genetics of tinted eggshell colors in two breeds of chickens laying white-shell eggs. Reciprocal crosses were made between an inbred White Leghorn line (ES) and an inbred Ancona line (ANC). The F1 birds were intercrossed and F1 females were backcrossed to each of the original lines. Eggshell color from each resultant group was measured using a Minolta chromometer, and a value (e) representing the color intensity adjusted by hue and saturation was used as the measurement criterion. Age, hatch group, and crosses each contributed significantly to the variation seen in eggshell color. Distribution comparisons indicated that two major autosomal loci affected the trait in these lines: one gene having incomplete dominance controls the amount of pigment deposition; the second completely inhibits pigment deposition when homozygous recessive. A test of goodness of fit supported this hypothesis. Genetic components were estimated by linear models. Epistasis, dominance, and additive effects contributed significantly to this trait. No sex-linked effects were noted.

[Effect of radix Astragali and radix ginseng in enhancing the metabolism of human myocardial cells in vitro]

Our experiment indicated that in Radix Astragali and Radix Ginseng treated human myocardial cell cultures the level of LDH and SDH elevated in varying degrees and in Radix Ginseng treated cells the cAMP showed higher levels but in Radix Ginseng treated ones the same was not observed. This suggests that the metabolism of myocardial cells is enhanced by Radix Astragali or Radix Ginseng.

Structural determination of the conjugated metabolites of ritodrine

Ritodrine is a beta-2 adrenergic agonist which is used clinically for the management of preterm labor. Since ritodrine is resistant to the action of monoamine oxidase and catecholamine-O-methyltransferase, conjugation is a major route of metabolism. Glucuronide and sulfate conjugates of ritodrine are found in maternal urine. However, the structure of these metabolites has not been determined. The purpose of this study was to determine the structure of these conjugates. Urine from patients on ritodrine therapy was purified by QAE Sephadex ion exchange chromatography. The partially purified conjugates were derivatized and analyzed by GC/MS. The data did not indicate an exclusive site of conjugation. Analysis of both the glucuronide and sulfate conjugates indicates that either of the two phenolic hydroxyl groups may be involved in the formation of conjugated metabolites. However, conjugation of the [2-(p-hydroxyphenyl)-2-hydroxy-1-methylethyl]amine phenolic hydroxyl is more prevalent for both conjugates. This phenolic hydroxyl group is unique since it is located on the portion of the ritodrine molecule which more closely resembles the structure of endogenous catecholamines.

Maternal and neonatal urinary excretion of sulfate and glucuronide ritodrine conjugates

Ritodrine is a beta 2-adrenergic agonist that is used clinically for the management of preterm labor. The beta 2 activity of ritodrine produces the relaxation of smooth muscles and is believed to act directly on the beta 2-receptors of the myometrium. Reports in the literature suggest that ritodrine is inactivated by sulfate and glucuronide conjugation, but this has not been verified in humans. Studies on animal models indicate that the sulfate conjugate is a major urinary metabolite of ritodrine. Recent investigations of maternal and neonatal urinary excretion of ritodrine indicate that 80% to 90% of the drug is in the form of conjugates. The purpose of this study was to determine the nature of these conjugates. Our study indicates that both the mother and neonate excrete glucuronide and sulfate conjugates of ritodrine. The sulfate conjugate accounts for 45% of maternal excretion and 66% of neonatal excretion; the glucuronide conjugate accounts for 38% and 23% of maternal and neonatal excretion, respectively. Significantly different metabolic profiles suggest that the neonate may be capable of forming conjugated metabolites of ritodrine.

Reduction of iodonitrotetrazolium violet by superoxide radicals

p-Iodonitrotetrazolium (2-(4-iodophenyl-3-(4-nitrophenyl)- 5-phenyltetrazolium; INT) was reduced to a water-soluble product with an absorbance maxima at about 505 nm (reddish pink) by superoxide anion (O2-.) generated by xanthine/xanthine oxidase. The rate of INT reduction was linearly related to the xanthine oxidase activities, and was inhibited by superoxide dismutase. The soluble product may further be converted to an insoluble product, presumably nonionic formazan, with an absorbance maxima of 490 nm (purplish), under certain conditions, and the rate of the formazan formation depended on pH and protein concentration.

The HAP3 regulatory locus of Saccharomyces cerevisiae encodes divergent overlapping transcripts

Activation of the CYC1 upstream activation site, UAS2, and transcription of several other genes encoding respiratory functions requires the product of the regulatory gene HAP2. We report here the isolation and characterization of a second UAS2 regulatory gene, HAP3. Like mutations in HAP2, a mutation in HAP3 abolishes the activity of UAS2 and prevents growth on nonfermentable carbon sources. The HAP3 gene was cloned and, surprisingly, was found to encode two divergently transcribed, overlapping transcripts: a 570-base RNA and a 3-kilobase (kb) RNA. Chromosomal disruption experiments defined the critical region for HAP3 function to a 1.3-kb segment in which the two transcripts overlap. Analysis of the HAP3 DNA sequence showed that the 570-base transcript could encode a protein of 144 amino acids. Synthesis of the 144-amino-acid protein under regulatory control in vivo demonstrated that this protein is essential for activity of UAS2 as well as for growth on nonfermentable carbon sources. The largest open reading frame in the critical region of the 3-kb transcript is only 86 amino acids. Using site-directed mutagenesis, we demonstrated that the 86-amino-acid open reading frame was not involved in UAS2 activity. The possible role of this 3-kb antisense RNA in HAP3 expression or function is discussed.

Two or more copies of Drosophila heat shock consensus sequence serve to activate transcription in yeast

A synthetic oligonucleotide bearing the Drosophila heat shock consensus sequence confers heat inducibility on a CYC1-lacZ gene in Saccharomyces cerevisiae. This sequence CTGGAATTTTCTAGA was inserted in place of the upstream activation sites of the CYC1 promoter adjacent to CYC1 TATA boxes. These constructs were transformed into yeast and found to be heat-inducible when two or more inserts were present. The level of inducibility seemed to increase with the number of inserted sequences: however, the orientations of these sequences relative to each other did not have much effect.

Measurement of total HDL, HDL2 and HDL3 by dextran sulfate-MgCl2 precipitation technique in human serum

We describe a simple and reliable method for determination of total HDL, HDL2, and HDL3 by a precipitation technique using dextran-sulfate (Mr 50,000)-Mg2+. A combined solution of dextran sulfate and Mg2+ at their respective final concentration of 0.9 g/l and 27 mmol/l was optimal for separating total HDL from the other lipoproteins. The present method compares favorably with a heparin-MnCl method (r = 0.998). The HDL was further resolved into HDL2 and HDL3 by addition of a combined solution of dextran sulfate and Mg2+ (1.5 m/l and 10 g/l) to the total HDL solution. Comparison of this precipitation method with the well-established ultracentrifugation method yielded the mean correlation coefficient of 0.941 and 0.869 for HDL2 and HDL3, respectively.

Mucin biosynthesis. Properties of a bovine tracheal mucin beta-6-N-acetylglucosaminyltransferase

We have characterized a bovine tracheal mucin beta-6-N-acetylglucosaminyltransferase that catalyses the transfer of N-acetylglucosamine from UDP-N-acetylglucosamine to the C-6 of the N-acetylgalactosamine residue of galactosyl-beta 1----3-N-acetylgalactosamine. Optimal enzyme activity was obtained between pH 7.5-8.5, at 5mM-MnCl2, and at 0.06-0.08% (v/v) Triton X-100 (or Nonidet P-40), or 0.5-5.0% (v/v) Tween 20. Ba2+, Mg2+ and Ca2+ could partially replace Mn2+, but Co2+, Fe2+, Cd2+ and Zn2+ could not. Sodium dodecyl sulphate, cetylpyridinium chloride, sodium deoxycholate, octyl beta-D-glucoside, digitonin and alkyl alcohols were less effective in enhancing enzyme activity, and dimethyl sulphoxide was ineffective. The apparent Michaelis constants were 1.25 mM for UDP-N-acetylglucosamine, 0.94-3.34 mM for freezing-point-depressing glycoprotein and 0.19 mM for periodate-treated blood-group-A porcine submaxillary mucin. Asialo ovine submaxillary mucin could not serve as the glycosyl acceptor. The structure of the 14C-labelled oligosaccharide obtained by alkaline-borohydride treatment of the product was identified as Gal beta 1----3(Glc-NAc beta 1----6)N-acetylgalactosaminitol by beta-hexosaminidase treatment, gas chromatography-mass spectrometry and 1H-n.m.r. (270 MHz) analysis. The enzyme is important in the regulation of mucin oligosaccharide biosynthesis.

Properties of creatine kinase-BB from canine and human brain tissues

Creatine kinase (EC 2.7.3.2) BB isoenzyme (CK-BB) was purified to homogeneity from canine and human brain tissues. The purified protein from both sources exhibits Mr of 84,700 daltons. The canine isoenzyme exhibits several properties similar to human isoenzyme with respect to reactive and total thiol groups, UV spectra, isoelectric points and reaction kinetics. While both canine and human CK-BB isoenzymes are unstable compared to other CK isoenzymes, canine CK-BB is even less stable than the human enzyme, losing most of its activity within 20 h at 4 degrees C at pH 5.0. Addition of 2-mercaptoethanol does not prevent rapid loss of the enzyme activity. Increasing the pH to 9.0, however, increases the stability of both CK-BB isoenzymes. Agarose electrophoresis demonstrated the presence of MM as well as BB isoenzyme in various parts of brain tissues. BB was present at an activity of 90.8-93.3 U/mg and MM at 6.7-9.2 U/mg.

Purification of creatine kinase-BB isoenzymes from human and canine tissues

We describe a procedure for the purification of creatine kinase BB isoenzyme from canine and human brain tissue. The purification involves sequentially 50-70% (NH4)2SO4 fractionation, DEAE-Sephacel, Blue-Sepharose CL-6B, and chromatofocusing chromatography. This method produces a homogeneous protein purification as verified by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and isoelectric focusing chromatography.

Inaccuracy of estimated creatinine clearance for prediction of iothalamate glomerular filtration rate

The clinical practice of estimating creatinine clearance (Ccr) from a patient's serum creatinine value by use of various nomograms and prediction formulas is widespread. The predictive accuracy of such Ccr estimates as substitutes for measured values of glomerular filtration rate (GFR) has not been determined. In addition, the effect of patient physical parameters on GFR prediction accuracy has not been assessed. To investigate these issues, 500 predicted Ccr values from each of four versions of the formula of Cockcroft and Gault were statistically compared with GFR values measured by sodium iothalamate clearance (Cio) in 394 human subjects representing every level of renal function. We conclude that (1) the original formula of Cockcroft and Gault is an inaccurate predictor of GFR; (2) correction of the formula for patient physical parameters does improve its accuracy for GFR prediction; (3) the best formula is not accurate enough to replace laboratory measurement of GFR; and (4) GFR prediction inaccuracy is more often associated with extremes in patient age, weight, serum creatinine, body surface area, and measured GFR but may occur for any value of each of these parameters.

Genetic effects of PR toxin in eukaryotic microorganisms

The genetic activity of PR toxin, a mycotoxin from Penicillium roqueforti, was studied in Saccharomyces cerevisiae and Neurospora crassa. The results show that PR toxin, without enzymic activation, causes gene conversion in S. cerevisiae strains D4 and D7, reverse mutation in S. cerevisiae strain D7 and N. crassa strain N24, and mitotic crossing-over in S. cerevisiae strain D7, In the log phase cells of S. cerevisiae the effects are more pronounced at alkaline than at acid pH. The active site responsible for the genetic activity and toxicity is known. The carbonyl groups appear to play an important role in the biologic activity of this molecule.

Preparation of a phospholipase C-antihuman IgG conjugate, and inhibition of its enzymatic activity by human IgG

We labeled IgG with phospholipase C, using 1-cyclohexyl-3-(2-morpholinoethyl)-carbodiimide. Enzymaticactivity of the resulting conjugate was inhibited when it was complexed with human IgG, but rabbit or goat IgG was not effective in suppressing the enzyme activity. Normal erythrocytes were used as substrate for the enzyme, enzymatic activity being assessed by measuring the release of hemoglobin. The substrates for phospholipase C are phospholipids, which are major components of the erythrocyte membranes. Hence, the phospholipids in the membranes are viewed as being "immobilized." Perhpas such immobilization of substrate may be a requisite to the inhibition phenomenon.

Preparation of a phospholipase C-antihuman IgG conjugate, and inhibition of its enzymatic activity by human IgG

We labeled IgG with phospholipase C, using 1-cyclohexyl-3-(2-morpholinoethyl)-carbodiimide. Enzymaticactivity of the resulting conjugate was inhibited when it was complexed with human IgG, but rabbit or goat IgG was not effective in suppressing the enzyme activity. Normal erythrocytes were used as substrate for the enzyme, enzymatic activity being assessed by measuring the release of hemoglobin. The substrates for phospholipase C are phospholipids, which are major components of the erythrocyte membranes. Hence, the phospholipids in the membranes are viewed as being "immobilized." Perhpas such immobilization of substrate may be a requisite to the inhibition phenomenon.

Solid-phase enzyme immunoassay for hepatitis B surface antigen

A solid-phase enzyme immunoassay is described for measuring hepatitis B surface antigen in human serum or plasma. Immunologically purified antibody labeled with horseradish peroxidase was used as the indicator. In the assay system, antibody-coated controlled-pore glass is used as a solid support and there are three sequential incubations, totaling 2 h, at room temperature. Results for serially diluted positive and reference sera compare favorably to radioimmunoassay in sensitivity and specificity.

Solid-phase enzyme immunoassay for hepatitis B surface antigen

A solid-phase enzyme immunoassay is described for measuring hepatitis B surface antigen in human serum or plasma. Immunologically purified antibody labeled with horseradish peroxidase was used as the indicator. In the assay system, antibody-coated controlled-pore glass is used as a solid support and there are three sequential incubations, totaling 2 h, at room temperature. Results for serially diluted positive and reference sera compare favorably to radioimmunoassay in sensitivity and specificity.

Phospholipase C-labeled anti-human IgG: inhibition by human IgF

We report here the inhibition of enzyme activity of phospholipase C-anti-human rabbit IgG conjugate complexed with human IgG. Phospholipase C activity was measured by assaying the release of hemoglobin from erythrocytes. The degree of inhibition varies depending on the relative amount of IgG utilized. A water soluble carbodiimide linking yields a conjugate which is inhibited by IgG, while conjugate prepared by glutaraldehyde is not. Immunodiagnostic assays requiring detection of low levels of antigen or antibody may be possible utilizing the phospholipase C-erythrocyte technique.

Liposome spin immunoassay: a new sensitive method for detecting lipid substances in aqueous media

A new sensitive immunoassay procedure is described for quantitative detection of glycolipids and other lipids in aqueous media. As with other immunoassays specific antiserum is first reacted with the free lipid hapten. The amount of antibody activity remaining is measured by assaying the release, in the presence of complement, of spin label marker from liposomes containing the same lipid hapten. Using this method, 2.6 pmol of aqueous Forssman hapten was detected, and the sensitivity could be increased further.

Preparation of beating heart cells from adult rats

Suspensions of cardiac cells have been prepared from fragments of hearts from adult rats by prolonged incubation with trypsin and collagenase. In these preparations, about 50 percent of the viable cells routinely exhibit spontaneous contractions ranging from 20 to 120 beats per minute at room temperature. The contractile activity is essentially lost at 2 degrees C but returns to normal as the temperature is increased. The rate of cellular contractions and the percentage of total cells exhibiting contractility are influenced by experimental conditions of cell preparation and the composition of the suspending medium.