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PubMed1982

Isolation and characterization of mucin-like glycoprotein in human milk fat globule membrane.

Milk fat globule membrane (MFGM) enclosing fat droplets in human milk was found to contain a high molecular weight glycoprotein which did not migrate in 10% acrylamide gel on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). This glycoprotein (termed PAS-0) was isolated by Sepharose CL-4B chromatography. Isolated PAS-0 gave one band on SDS-PAGE using 5% acrylamide gel (acrylamide : bisacrylamide = 4 : 1, w/w) and gave one peak on analytical ultracentrifugation, indicating its homogeneity. PAS-0 was rich in serine, threonine, proline, glycine, and alanine. In contrast, contents of sulfur-containing amino acids were very low. Fucose, galactose, N-acetylglucosamine, N-acetylgalactosamine, and sialic acid were detected as constituent sugars of PAS-0 and the total carbohydrate content was about 50%. Alkali-borohydride treatment suggested that the carbohydrate moiety was linked to the polypeptide core with O-glycosidic bond(s). There results suggested that PAS-0 was a mucin-like glycoprotein. PAS-0 was shown to be resistant to pepsin, trypsin and chymotrypsin digestion, but susceptible to Pronase and Subtilisin BPN'. Extraction of intact milk fat globules (cream) with MgCl2 and guanidine hydrochloride solutions suggested that PAS-0 was an intrinsic component of MFGM. Digestion of cream with Subtilisin BPN' demonstrated that PAS-0 was located on the external surface of fat globules and was accessible to molecules outside the globules. By agglutination-inhibition tests using eight lectins, PAS-0 was suggested to act as surface receptors for Ricinus communis agglutinin, wheat germ agglutinin and peanut agglutinin.

Electrophoresis, Polyacrylamide Gel↗
PubMed1976

Qualitative and quantitative studies on human myelin basic protein in situ with respect to time interval between death and autopsy.

Normal human frontal lobe white matter obtained at autopsy was used to determine the extent of in situ post-mortem degradation of myelin basic protein (BP). Effects of the following two factors were studied: 1) time interval between death and autopsy, and 2) freezing and thawing the tissue. Quantitative extraction of BP from the autopsy material showed only minimal loss of BP that could be attributed to the time interval between death and autopsy (up to 48 h). The purified BP from these samples was electrophoresed on acrylamide gels at pH 4.3 and it was found that the electrophoretic patterns were comparable to zero hour bovine BP samples. The BP obtained from the autopsy samples was found to be encephalitogenic in guinea pigs. When tested against rabbit anti-human-BP serum, the purified BP preparations gave a single arc in immunoprecipitin test. BP extracted and purified from tissue that was frozen once and processed before it could thaw showed yields, encephalitogenic activity and acrylamide disc gel electrophoretic patterns that were similar to those of BP from tissue that was never frozen. However, frozen tissue that was thawed and then incubated for 8 h at room temperature before processing yielded only 13-25% of the total extractable protein. This BP also was encephalitogenic and showed acrylamide banding pattern that was similar to BP from tissue that was never frozen. Samples of white matter were examined by electron microscope. Unfrozen autopsy material showed some separation of myelin lamellae. Myelin in sections of frozen and thawed white matter showed separation as well as disruption of the lamellae. Samples that were frozen, thawed and then incubated at room temperature for 8 h showed sporadic loss of dense line material in addition to lamellar separation and disruption. The results a) show that BP is quite resistant to autolytic changes and b) are consistent with the location of BP along the cytoplasmic surface of the myelin membrane.

Aged↗
PubMed1996

Clinical-epidemiologic study of alopecia areata.

BACKGROUND: Alopecia areata is a common disease and may be associated with autoimmune disease, atopy, Down syndrome, emotional stress, and foci of sepsis. METHODS: Seven cases of alopecia areata were diagnosed among workers in the Water and Effluent Treatment Sector (WETS) of a paper factory, representing a 0.6% incidence, when the value for the population at large is 0.1%. Three of these workers are assigned to the WETS on a permanent basis and four provide maintenance services. One of the latter patients had alopecia areata that fully regressed. Because biologic treatment of water and effluents involves saprophytic bacteria and fungi as well as chemical substances such as acrylamide, a clinical examination and laboratory tests were performed on all workers assigned permanently to the WETS (N = 9) and on 25% of the workers, selected at random providing services to the sector (N = 14). RESULTS: There was no association between alopecia areata and atopy, dermatophytosis, or bacteria isolated. Toxicologic evaluation revealed an acrylamide-like substance in 7 workers with alopecia areata, with a statistically significant correlation. Measures were taken at the workplace to decrease worker contact with the mists (probably containing acrylamide) in the pulp-pressing room; no other cases of alopecia areata had been detected 1 year after the study. CONCLUSIONS: A survey of the literature did not show reports of alopecia areata as an occupational dermatosis, but our conclusion is, that this dermatosis could be due to the professional activities of the workers at the paper factory studied.

Adult↗
PubMed1975

Heterogeneity of enterotoxin-like protein extracted from spores fo Clostridium perfringens type A.

Enterotoxin-like protein was extracted from spores of three enterotoxin-positive and three enterotoxin-negative strains of Clostridium perfringens type A by urea/mercaptoethanol, alkaline mercaptoethanol and alkaline dithiothreitol. Disc immunoelectrophoresis demonstrated that three distinct enterotoxin-like proteins could be extracted. In 7% acrylamide gels, type I, type II, and type III enterotoxinlike proteins had relative mobilities of 0.52, 0.63, and 0.73 respectively. In contrast to disc immunoelectrophoresis, immunoelectrophoresis in agar gel demonstrated identical electrophoretic properties for the various entertoxin-like proteins. Immunoelectrofocusing experiments gave isoelectric points of 4.43, 4.43, 4.36, and 4.52 for purified entertoxin and type I, type II, and type III enterotoxin-like proteins respectively. Ferguson plots (i.e., log relative mobility versus acrylamide concentration) yielded nonparallel lines which intersected at a nonsieving concentration of acrylamide indicating that the various species of enterotoxin-like protein differed in size. Estimation of the molecular weight of purified enterotoxin and the three species of enterotoxin-like protein was done by comparing the slopes obtained in Ferguson plots with those obtained using proteins of a known molecular weight. Molecular weights of 38000, 36500, 23000, and 15400 were obtained for purified enterotoxin, type I, type II, and type III enterotoxin-like protein respectively. Collectively, the evidence indicates that fractionation of the different species of enterotoxin-like protein was due primarily to differences in their size, and that different forms of enterotoxin-like protein can be extracted from spores of different strains of C. perfringens type A.

Clostridium perfringens↗
PubMed1981

Inhibition of lactate dehydrogenase activity by polymeric NAD derivatives with different NAD densities.

Polymeric NAD derivatives with different NAD densities were prepared by the copolymerization of NAD N6-[N-(N-acryloyl-1-methoxycarbonyl-5-aminopentyl)-propionamide] with acrylamide in different molar ratios, from 4 x 10(-4) to 1 x 10(-2). The cofactor activities of the polymeric NAD derivatives for lactate, yeast alcohol and horse liver alcohol dehydrogenases decreased with the increase in the NAD density of the polymer, and the lactate dehydrogenase showed no activity for the polymeric NAD derivatives with NAD densities of 2 x 10(-3) and 1 x 10(-2) mol/mol acrylamide polymerized. The polymeric NAD derivatives inhibited the activities of lactate and yeast alcohol dehydrogenases but did not inhibit those of horse liver alcohol and malate dehydrogenases. The polymeric NAD derivatives were competitive inhibitors with respect to NAD for the reaction of lactate dehydrogenase: the inhibition constant decreased from 2.2 microM to 0.02 microM with the increase in the NAD density from 4 x 10(-4) to 1 x 10(-2) mol/mol acrylamide polymerized.

Acrylic Resins↗
PubMed1983

Fluorescence and chemical modification of tryptophan as probes of structure of GTP:AMP phosphotransferase from beef heart mitochondria.

Selective modification of the two Trp residues of GTP:AMP phosphotransferase from beef heart mitochondria (Mr 26 000; MgGTP + AMP in equilibrium MgGDP + ADP) has been attained by treatment of the enzyme with N-bromosuccinimide at pH 4.0. Almost complete loss of activity is observed when one Trp is oxidized. Fluorescence emission spectra (lambda exc 295 nm) were recorded over the pH range 1.9-12.2. Quenching constants, K, with acrylamide were 4.9, 3.4, 3.1, 2.4, 9.2 and 9.4 M-1 at respective pH values of 11.1, 7.5, 5.5, 4.0, 1.9 and 7.5 with 6 M guanidine/HCl. Over the pH range 8.0-5.5 the fluorescence peak has a constant height with maximum at 333-334 nm, which can be segregated by acrylamide quenching into a peak with maximum at 338 nm and another with maximum at 330 nm. Dropping the pH from 5.5 to 4.0 results in the fluorescence at 338 nm decreasing to 335 nm (indicative of less exposure of the Trp) while that at 330 nm remains constant. Thus the limitation of reactivity to N-bromosuccinimide to pH 4.0 or lower cannot be accounted for by increased exposure of the Trp residues but rather must be explained by a change in the microenvironment of each Trp. As shown by K values above, at pH 2.0 Trp residues are exposed to the solvent, as in the case of treatment with 6 M guanidine hydrochloride. In raising the pH from 8.0 to 12.0 a number of changes occur: (a) the lambda max of emission shifts from 333-334 nm to 343 nm; (b) residue(s) become(s) more available to acrylamide quenching; (c) fluorescence decreases and enzymatic activity increases, both with a midpoint at about 10.6; (d) absorption difference spectra show a maximum at 295 nm typical of Tyr ionization. These data are consistent with conformational change as the pH becomes more alkaline making the Trp residue(s) more exposed to the solvent and/or to non-radiative energy transfer to tyrosinate.

Animals↗
PubMed1995

Intrinsic tryptophan fluorescence of equinatoxin II, a pore-forming polypeptide from the sea anemone Actinia equina L, monitors its interaction with lipid membranes.

Equinatoxin II is a cytolytic polypeptide from the sea anemone Actinia equina L. which forms pores in natural and artificial membranes. The intrinsic fluorescence of its five tryptophanyl residues was used to monitor the conformational changes induced by denaturing agents, pH and lipids. In the presence of denaturants, the emitted fluorescence peak, normally occurring at 335 nm, was reduced in height by about 65% and red-shifted to 354 nm indicating unfolding. The toxin fluorescence intensity reversibly decreased by increasing the pH, whereas lipid vesicles, at every pH, caused an increase and a blue shift. The amount of toxin binding to the lipid vesicle was increased by the presence of sphingomyelin. With sphingomyelin-containing vesicles half-saturation occurred at a lipid/toxin molar ratio of about 40, whereas with phosphatidylcholine no saturation appeared up to a ratio of 300. One hydrophilic neutral quencher (acrylamide) and two lipid-confined phosphatidyltype quenchers [bis(9,10-dibromostearoyl)-sn-glycero-3-phosphocholine and 1-palmitoyl-2-(1-pyrenedecanoyl)-sn-glycero-3-phosphocholine] were used to assess the exposure of the emitting centres to the solvent and/or to the lipid. Most of the indolyl residues were found to be solvent-exposed in the water-soluble form of the toxin, as inferred from acrylamide quenching. Upon association with lipid vesicles, the fraction accessible to acrylamide dropped considerably, meanwhile the toxin became sensitive to lipid-soluble quenchers. Taken together these results suggest that insertion of equinatoxin II into sphingomyelin-containing bilayers is facilitated by high pH and results in the transfer of one or more exposed tryptophanyl residues into the liquid phase. Calcein-loaded vesicles, with or without a lipid quencher, were used to monitor simultaneously the formation of pores and the transfer of the tryptophans to the lipid phase. We found that the rate constants for vesicles permeabilization and for changes of intrinsic tryptophanyl fluorescence had a different dependence on the lipid/toxin ratio suggesting they correspond to separate steps in the toxin lipid interaction.

Animals↗
PubMed1995

Somatostatin in a water-restricted environment: fluorescence and circular dichroism study in AOT reverse micelles.

Steady-state and time-resolved fluorescence emission from the single tryptophan residue of somatostatin, and the kinetics of quenching of this emission, were studied in aqueous solution and in reverse micelles of sodium bis (2-ethylhexyl) sulfosuccinate (AOT)/water/isooctane, a system that mimics the water-membrane interface well. Incorporation into micelles caused blue shifts and reduced band-widths of the emission peaks and altered the quantum yields with respect to emission from bulk water. Steady-state anisotropy values also increased considerably on micellization. These observations point to reduced polarity of the environment around the Trp residue of the peptide, as well as restricted freedom of its rotational motions, due to transfer from the aqueous to the micellar phase. Fluorescence emission kinetics of the Trp moiety followed biexponential decay laws in both aqueous and micellar media. Static and dynamic quenching constants were measured for acrylamide and CCI4 quenchers localized in the micellar and organic pseudophases, respectively, using both steady-state and time-resolved experiments. The efficiency of dynamic quenching by acrylamide became vanishingly small in going from water to reverse micelles, in sharp contrast to the comparable quenching efficiencies exhibited by CCI4 in micelles and acrylamide in water. The circular dichroic (CD) spectrum of the native peptide in water indicated the possibility of some amount of beta-type secondary structure being present. Conformational analysis of CD spectra in micelles showed that the relative amount of this structural feature was enhanced for the micellized peptide but was insensitive to the water content of micelles.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1976

Purification of cereolysin and the electrophoretic separation of the active (reduced) and inactive (oxidized) forms of the purified toxin.

Cereolysin was purified to apparent homogeneity by using ammonium sulfate fractionation, hydrophobic chromatography with AH-Sepharose, isoelectric focusing, and gel filtration. The active form of the toxin had an isoelectric point of 6.6, and the molecular weight of the protein was about 55,500 as judged by sodium dodecyl sulfate-gel electrophoresis, gel filtration, and gel electrophoresis using various concentrations of acrylamide. Cereolysin contained two half-cystine residues and was dependent on reducing agents, such as dithiothreitol, for maximal hemolytic activity and charge homogeneity. By using discontinuous acrylamide electrophoresis, two forms of the toxin could be observed: oxidized and reduced. If the toxin was purified in the absence of dithiothreitol, partial spontaneous oxidation resulted in the formation of an oxidized form of the toxin. Relative to the reduced form, the oxidized form moved slightly closer to the anode in gel electrophoresis at pH 9.0. If the toxin was purified in the presence of 5 mM dithiothreitol or if the spontaneously oxidized toxin was preincubated with dithiothreitol, only the reduced form of the protein was observed. When the logarithims of their relative mobilities were plotted against the concentration of acrylamide in the gels, the slopes for the reduced and oxidized forms were identical. This indicates that the two forms are identical in size and are separable because of different charges. The reduced protein could be inhibited by N-ethylmaleimide, 5,5'-dithiobis(2-nitrobenzoic acid), and p-hydroxymercuribenzoate. Inhibition by the latter two sulfhydryl reagents could be completely reversed by dithiothreitol. The reversibly oxidized form of the toxin did not appear to be inhibited by N-ethylmaleimide and apparently was either unable to bind to or had a decreased affinity for the erythrocyte membrane.

Amino Acids↗
PubMed1980

Virus-specific RNA synthesis in cells infected by infectious pancreatic necrosis virus.

Pulse-labeling experiments with [(3)H]uridine revealed that the rate of infections pancreatic necrosis virus-specific RNA synthesis was maximal at 8 to 10 h after infection and was completely diminished by 12 to 14 h. Three forms of RNA intermediates were detected: (i) a putative transcription intermediate (TRI) which comigrated in acrylamide gels with virion double-stranded RNA (dsRNA) after RNase treatment; (ii) a 24S genome length mRNA which could be resolved into two bands by polyacrylamide gel electrophoresis; and (iii) a 14S dsRNA component indistinguishable from virion RNA by gradient centrifugation and gel electrophoresis. The TRI (i) was LiCl precipitable; (ii) sedimented slightly faster and broader (14 to 16S) than the 14S virion dsRNA; (iii) had a lower electrophoretic mobility in acrylamide gels than dsRNA, barely entering acrylamide gels as a heterogenous component; (iv) yielded genome-sized pieces of dsRNA after RNase digestion; and (v) was the most abundant RNA form early in the infectious cycle. The 24S single-stranded RNA was thought to be the viral mRNA since it: (i) became labeled during short pulses; (ii) was found in the polysomal fraction of infected cells; and (iii) hybridized to denatured viral RNA, forming two segments of RNase-resistant RNA that comigrated with virion dsRNA in gels. The 24S mRNA component was formed before the synthesis of dsRNA, and radioactivity could be chased from 24S single-stranded RNA to dsRNA, indicating that 24S RNA may serve as template for the synthesis of complementary strands to form dsRNA. Similar to reovirus, infectious pancreatic necrosis viral 24S mRNA contained no polyadenylic acid tracts.

Journal Article↗
PubMed1972

Proteins specified by herpes simplex virus. V. Purification and structural proteins of the herpesvirion.

We are reporting a procedure for the purification of herpes simplex enveloped nucleocapsids (virions), an evaluation of the purification procedure and the results of analyses of the virion proteins by high-resolution acrylamide gel electrophoresis. The data may be summarized as follows. (i) The procedure for the purification of virions consists of careful extraction of cytoplasm to prevent nuclear breakage, separation of enveloped nucleocapsids from soluble proteins and membrane vesicles by rate zonal centrifugation of cytoplasmic extracts through dextran 10 gradients, treatment with urea to dissociate virus-debris aggregates, and, lastly, separation of virions from naked nucleocapsids and free membranes by isopycnic flotation in discontinuous sucrose gradients. (ii) Purity was evaluated in three ways, i.e., electron microscopic examination, analysis of purified virions produced in cells labeled with amino acids before infection, and analysis of purified virions from artificial mixtures of infected and labeled, uninfected cells. The extent of purification was 120-to 200-fold with respect to host proteins. Residual contaminants were identified as host and viral constituents of membrane vesicles. Residual host proteins are very likely contaminants and not structural components of the virion. (iii) Analyses by staining and autoradiography of structural proteins of purified virions in 6, 7, 8.5, 9, and 14% acrylamide gels revealed 24 bands of proteins and glycoproteins made and labeled after infection. Co-electrophoresis of viral proteins with six known standards ranging from 25,700 to 220,000 daltons in molecular weight in 6, 7, 8.5, and 9% acrylamide gels indicate that viral proteins range from 25,000 to 275,000 daltons. The sum of the molecular weights of viral proteins is 2,580,000 daltons. Assuming that messenger transcription is asymmetric and noncomplementary, this corresponds to 47% of the genetic information of the virus. (iv) The nonionic detergent NP-40 removes from purified virions some nonglycosylated proteins and a large fraction of the glycosylated proteins. It leaves behind traces of the envelope visible in the electron microscope as well as some glycoproteins thought to be in the envelope.

Amino Acids↗
PubMed2002

Structure of colloidal complexes obtained from neutral/poly-electrolyte copolymers and oppositely charged surfactants.

We report on the phase behavior and scattering properties of colloidal complexes made from block copolymers and surfactants. The copolymer is poly(sodium acrylate)-b-poly(acrylamide), hereafter abbreviated as PANa-PAM, with molecular weight 5000 g/mol for the first block and 30000 g/mol for the second. In aqueous solutions and neutral pH, poly(sodium acrylate) is a weak polyelectrolyte, whereas poly(acrylamide) is neutral and in good-solvent conditions. The surfactant is dodecyltrimethylammonium bromide (DTAB) and is of opposite charge with respect to the polyelectrolyte block. Combining dynamical light scattering and small-angle neutron scattering, we show that in aqueous solutions PANa-PAM diblocks and DTAB associate into colloidal complexes. For surfactant-to-polymer charge ratios Z lower than a threshold (Z(C) approximately 0.3), the complexes are single surfactant micelles decorated by few copolymers. Above the threshold, the colloidal complexes reveal an original core-shell microstructure. We have found that the core of typical radius 100-200 A is constituted from densely packed surfactant micelles connected by the polyelectrolyte blocks. The outer part of the colloidal complex is a corona and is made from the neutral poly(acrylamide) chains. Typical hydrodynamic sizes for the whole aggregate are around 1000 A. The aggregation numbers expressed in terms of numbers of micelles and copolymers per complex are determined and found to be comprised between 100-400, depending on the charge ratio Z and on the total concentration. We have also shown that the sizes of the complexes depend on the exact procedure of the sample preparation. We propose that the driving mechanism for the complex formation is similar to that involved in the phase separation of homopolyelectrolyte/surfactant systems. With copolymers, the presence of the neutral blocks prevents the macroscopic phase separation from occurring.

Journal Article↗
PubMed1983

Immobilization of S-methyltransferase.

S-methyltransferase was solubilized from pig liver microsomes by treatment with N-dodecyl-N,N-dimethyl-3-ammonio-1-sulfonate (Zwittergent). The soluble enzyme was immobilized by covalent binding to agarose and by copolymerization with acrylamide. The specific activity for the agarose-bound enzyme towards the substrate ethane thiol was 0.87 nmol/min/mg and for the acrylamide-bound enzyme 0.55 nmol/min/mg. The specific activity of the soluble enzyme was found to vary with increasing chain length of the substrate molecules from 0.5 nmol/min/mg for methane thiol (C1) to 6.3 nmol/min/mg for n-heptane thiol (C7). After binding of the enzyme to agarose beads, the increase in specific activity towards substrates with increasing chain length was no longer detectable. Instead, a relatively constant specific activity of 1.1 nmol/min/mg was observed for the whole range of substrates tested from C1 to C7. The stability of the agarose immobilized enzyme at -20 degrees C is twice as good as the soluble enzyme. The acrylamide immobilized enzyme is less stable than the soluble enzyme.

Animals↗
PubMed2006

Acrylic acid removal by acrylic acid utilizing bacteria from acrylonitrile-butadiene-styrene resin manufactured wastewater treatment system.

The aim of this study is to isolate the acrylic acid utilizing bacteria from the ABS resin manufactured wastewater treatment system. The bacteria should have the ability to remove acrylic acid and tolerate the acrylonitrile and acrylamide toxicity. The aim is also to understand the performance of isolated pure strain for treating different initial acrylic acid concentrations from synthetic wastewater. The results are: twenty strains were isolated from the ABS resin manufactured wastewater treatment system and twelve of them could utilize 600 mg/l acrylic acid for growth. Seven of twelve strains could tolerate the acrylonitrile and acrylamide toxicity, when the concentration was below 300 mg/l. Bacillus thuringiensis was one of the seven strains and the optimum growth temperature was 32 degrees C. Bacillus thuringiensis could utilize acrylic acid for growth, when the initial acrylic acid concentration was below 1,690.4 mg/l. Besides this, when the initial acrylic acid concentration was below 606.8 mg/l, the acrylic acid removal efficiency exceeded 96.3%. Bacillus thuringiensis could tolerate 295.7 mg/l acrylamide and 198.4 mg/l acrylonitrile toxicity but could not tolerate 297.3 mg/l epsilon-caprolactam.

Acrylates↗
PubMed1997

Reamplification of differential display products: more is not better.

Differential display polymerase chain reaction is technically challenging at a number of steps, including reliable reamplification of differentially expressed sequences after they are isolated from an acrylamide gel. As the only source of the sequence found to be of interest is the gel from which it was identified as being differentially expressed, failed attempts at reamplification can be particularly frustrating. In our laboratory, attempts to reamplify DNA sequences cut from a denaturing 6% acrylamide gel consistently failed when greater than 5 microliters of eluted product was used as template in a subsequent PCR reaction. If less template was used in subsequent PCR reactions, reamplification was consistently successful. This observation emphasized the importance of using limited amounts of template when reamplifying sequences that are differentially displayed on denaturing acrylamide gels

DNA↗
PubMed2000

Butyrylcholinesterase and C5+ variant in a Javanese ethnic group in Indonesia.

OBJECTIVE: This study was designed to investigate the butyrylcholinesterase (BChE) and C5 variant phenotypes in a Javanese ethnic group in Indonesia. BLOOD-DONORS, MATERIALS AND METHODS: Random blood samples from a Javanese ethnic group were obtained from the Indonesian Red Cross Service. The donors were 40.09 +/- 9.53 years old, consisting of 358 (89.45%) males and 42 females (10.55%). The plasma content of BChE was determined spectrophotometrically using benzoylcholine as substrate, and phenotyping of BChE was performed using the inhibitors 10 microM dibucaine and 50 microM sodium fluoride. Phenotyping of the C5+ variant was carried out by means of polyacrylamide gel electrophoresis using a 7.5% (w/v) acrylamide slab gel and a 3% (w/v) acrylamide stacking gel, and stained with fast red azo dye. RESULTS: The results show that of 398 samples studied, the average activities of BChE are 1.00 +/- 0.22 U/ml. 377 individuals (94.72%) show normal activities, whereas 21 individuals (5.78%) are below normal (< 0.690 U/ml). The mean +/- SD of dibucaine number (DN) is 83 +/- 5 and the fluoride number (FN) is 66 +/- 6. From this population we identified one individual with UA phenotype (total activity: 0.310 U/ml, DN: 62, and FN: 50). The frequency of C5+ variant in the population as detected by acrylamide electrophoresis is 21%. CONCLUSION: Our data indicate that the atypical allele of BChE is rare and that the C5+ variant is detected in high frequency in the ethnic Javanese of Indonesia.

Adult↗
PubMed1992

Anatomic and functional assessment of stenosis severity with intravascular ultrasound imaging in vitro.

An in vitro study was performed to evaluate the accuracy of intravascular ultrasound imaging compared with roentgenography for determining the cross-sectional area of a lumen; and to determine if the functional significance of an irregular stenosis is predicted more accurately by intravascular ultrasound than roentgenography. Varying degrees of stenosis were made in 17 rubber tubings by adjusting a plastic constrictor. The cross-sectional areas at the normal and the stenotic segments were determined by intravascular ultrasound, roentgenography, and then measured directly from an acrylamide gel cast of the lumen. To evaluate the functional significance of a stenosis, the pressure drop across the stenosis was measured using a fluid pumping circuit. The actual pressure drop was then compared with the predicted pressure drop derived from hydrodynamic equations using cross-sectional areas obtained by intravascular ultrasound or roentgenography. There was an excellent correlation between the cross-sectional areas at the tightest stenosis measured by intravascular ultrasound compared with the area from the acrylamide cast (7.2 +/- 2.6 v 6.6 +/- 2.4 mm 2, mean +/- SD, r = .93). Measurements of cross-sectional area from the roentgenograms (10.9 +/- 3.9 mm 2) also provided a relatively good correlation with those from the acrylamide casts (r = .84); however, the roentgenograms consistently overestimated the cross-sectional area of the stenosis. The mean values of the actual pressure drop and the predicted pressure drop by intravascular ultrasound and roentgenograms were 15.7 +/- 13.5, 11.3 +/- 11.9, and 4.3 +/- 4.5 mmHg, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography↗
PubMed1992

Spatial proximity of ATP-sensitive tryptophanyl residue(s) and Cys-697 in myosin ATPase.

The reactive thiol Cys-697 (SH2) in myosin ATPase was labeled with a fluorescent analog of maleimide, 2-(4'-maleimidylanilino)naphthalene-6-sulfonic acid (MIANS) (Hiratsuka, T. (1992) J. Biol. Chem. 267, 14941-14948). Although the tryptophan fluorescence of myosin subfragment-1 (S-1) was slightly affected by incorporation of the MIANS fluorophore, the tryptophan fluorescence of the resultant S-1 derivative (MIANS-S-1) was enhanced by ATP in a manner similar to that of unlabeled S-1. The quenching of tryptophan fluorescence of MIANS-S-1 was shown to result from a transfer of the excitation energy from tryptophanyl residue(s) to the MIANS fluorophore attached to SH2, which absorbed and fluoresced maximally at 325 and 418 nm, respectively. The energy transfer measurements were performed in the presence of acrylamide and compared to those performed in the absence of the quencher. The energy transfer efficiencies were found to be unaltered by acrylamide, indicating that the observed fluorescence energy transfer is originated exclusively from the tryptophanyl residue(s) that are not affected by acrylamide, i.e. the ATP-sensitive tryptophanyl residue(s) of S-1 (Torgerson, P. M. (1984) Biochemistry 23, 3002-3007). The distance between the tryptophanyl residue(s) and Cys-697 was calculated to be 27 A assuming a single donor-acceptor pair. Trp-510 is proposed to be one of the ATP-sensitive tryptophanyl residues.

Adenosine Diphosphate↗