bluuebunny/crossref_metadata_2025 huggingface dataset:
CYLD is a causative gene for frontotemporal dementia – amyotrophic lateral sclerosis
Authors: Dobson-Stone Carol , Hallupp Marianne , Shahheydari Hamideh , Ragagnin Audrey M G , Chatterton Zac , Carew-Jones Francine , Shepherd Claire E , Stefen Holly , Paric Esmeralda , Fath Thomas , Thompson Elizabeth M , Blumbergs Peter , Short Cathy L , Field Colin D , Panegyres Peter K , Hecker Jane , Nicholson Garth , Shaw Alex D , Fullerton Janice M , Luty Agnes A , Schofield Peter R , Brooks William S , Rajan Neil , Bennett Mark F , Bahlo Melanie , Shankaracharya  , Landers John E , Piguet Olivier , Hodges John R , Halliday Glenda M , Topp Simon D , Smith Bradley N , Shaw Christopher E , McCann Emily , Fifita Jennifer A , Williams Kelly L , Atkin Julie D , Blair Ian P , Kwok John B
Published: February 2020

Frontotemporal dementia and amyotrophic lateral sclerosis are clinically and pathologically overlapping disorders with shared genetic causes. We previously identified a disease locus on chromosome 16p12.1-q12.2 with genome-wide significant linkage in a large European Australian family with autosomal dominant inheritance of frontotemporal dementia and amyotrophic lateral sclerosis and no mutation in known amyotrophic lateral sclerosis or dementia genes. Here we demonstrate the segregation of a novel missense variant in CYLD (c.2155A>G, p.M719V) within the linkage region as the genetic cause of disease in this family. Immunohistochemical analysis of brain tissue from two CYLD p.M719V mutation carriers showed widespread glial CYLD immunoreactivity. Primary mouse neurons transfected with CYLDM719V exhibited increased cytoplasmic localization of TDP-43 and shortened axons. CYLD encodes a lysine 63 deubiquitinase and CYLD cutaneous syndrome, a skin tumour disorder, is caused by mutations that lead to reduced deubiquitinase activity. In contrast with CYLD cutaneous syndrome-causative mutations, CYLDM719V exhibited significantly increased lysine 63 deubiquitinase activity relative to the wild-type enzyme (paired Wilcoxon signed-rank test P = 0.005). Overexpression of CYLDM719V in HEK293 cells led to more potent inhibition of the cell signalling molecule NF-κB and impairment of autophagosome fusion to lysosomes, a key process in autophagy. Although CYLD mutations appear to be rare, CYLD’s interaction with at least three other proteins encoded by frontotemporal dementia and/or amyotrophic lateral sclerosis genes (TBK1, OPTN and SQSTM1) suggests that it may play a central role in the pathogenesis of these disorders. Mutations in several frontotemporal dementia and amyotrophic lateral sclerosis genes, including TBK1, OPTN and SQSTM1, result in a loss of autophagy function. We show here that increased CYLD activity also reduces autophagy function, highlighting the importance of autophagy regulation in the pathogenesis of frontotemporal dementia and amyotrophic lateral sclerosis.
Immunoglobulins in cerebrospinal fluid in various neurologic disorders.
Authors: Bouloukos A , Lekakis J , Michael J , Kalofoutis A
Published: February 2020

We determined the concentrations of immunoglobulins A, G, and M in cerebrospinal fluid of 16 patients suffering from multiple sclerosis, 13 with non-bacterial meningitis, 10 with stroke syndrome, and 13 with epilepsy. The differences in concentrations of immunoglobulins in these groups were remarkable in the patients with multiple sclerosis, meningitis, or stroke syndrome. We propose that the determination of the absolute immunoglobulin content in cerebrospinal fluid is of greater significance than the relative immunoglobulin concentration.
Evaluation of a radioenzymic kit for determination of plasma catecholamines.
Authors: Tasseron S J , Fiolet J W , Willebrands A F
Published: February 2020

We evaluated a commercially available reagent test-kit (Upjohn) for simultaneously determining norepinephrine, epinephrine, and dopamine in 50-microL of plasma. The three catecholamines are enzymically converted into the radioactive O-methyl derivatives and separated by thin-layer chromatography. Day-to-day precision (CV) was 11, 10, and 14% for norepinephrine, epinephrine, and dopamine, respectively. The relationship between concentration of catecholamine and radioactivity (net dpm) was linear to at least 8 ng (corresponding to 1 mumol/L in plasma). Sensitivity was approximately 2 pg for dopamine, 1 pg for each of the other two catecholamines. Under our conditions, epinephrine was not quite completely resolved from the other two fractions. Catecholamine values determined in normal humans, after 30 min supine and after normal laboratory activity, agreed well with those found by other investigators. Correlation was good between kit results and those obtained in another laboratory that used self-prepared reagents and "high-performance" liquid chromatography for the separation.
Continuous-flow analysis for glucose in serum, with use of hexokinase and glucose-6-phosphate dehydrogenase co-immobilized in tubular form.
Authors: León L P , Chu D K , Snyder L R , Horváth C
Published: February 2020

Hexokinase and glucose-6-phosphate dehydrogenase, co-immobilized at the inner wall of plastic tubing, were used with continuous-flow analyzers to measure serum glucose. The performance of the enzyme-containing coils meets the hydraulic requirements of the continuous-flow instruments, and the average carryover does not exceed 2.2%. A glucose concentration change of 1 g/L yields a 0.08 change in absorbance. There is no significant deviation from linearity for glucose concentrations up to 5 g/L. The method is similar to the Reference Method proposed by the Food and Drug Administration, and results by the two methods agree and correlate well (r = 0.999). The operational stability of the enzyme tubes is sufficient to allow the analysis of at least 10 000 serum samples. We investigated in detail the effect of reagent concentrations and temperature on the performance of the enzyme coils, and the results shed light on the nature of the heterogeneous dual-enzymic reaction.
Improved radiochemical method for measuring ferrochelatase activity.
Authors: Williams H L , Johnson D J , Haut M J , Slater S , Brennan R G , Altstatt L B
Published: February 2020

We describe a radiochemical method for measuring ferrochelatase activity in the in vitro incorporation of iron into mesoporphyrin-IX to form mesoheme. 59Fe is used to quantify ferrochelatase activity in rat liver. The uptake of iron is linearly related to the time allowed for it to occur, and the reaction proceeds optimally under reducing and anerobic conditions, maintained in sealed lyophilization vials under a positive pressure of nitrogen.
Mechanism of interference by hemoglobin in the determination of total bilirubin. II. Method of Jendrassik-Grof.
Authors: Shull B C , Lees H , Li P K
Published: February 2020

Oxyhemoglobin in erythrocyte hemolysates interferes with the Jendrassik-Grof assay. Destruction of azobilirubin occurs when oxyhemoglobin is oxidized to methemoglobin during diazotization or to alkaline hematin with addition of alkaline tartrate. The most probable mechanism is by oxidation with an agent such as hydrogen peroxide or a related species resulting from hemoglobin oxidation. Methemoglobin also appears to cause some destruction of azobilirubin during diazotization. Methemoglobin forms during diazotization because of reactions of oxyhemoglobin with both diazo reagent and nitrite ion. Formation of methemoglobin is, therefore, more rapid in the test than in the blank mixture and, under reaction conditions, its absorbance is less than that of oxyhemoglobin. This results in spectral interference when neutral azobilirubin is assayed. Alkaline tartrate abolishes this spectral error by causing rapid formation of alkaline hematin in both test and blank.
Maximizing the efficiency of an admissions test profile in a 680-bed hospital.
Authors: Cole G W
Published: February 2020

I describe the development and improved use of an efficient planned and scheduled approach to laboratory testing in a large tertiary-care hospital, which anticipates virtually all the usual needs of patient and clinician and which has been demonstrated to provide better service at lower cost.
A fluorometric determination of sphingomyelinase by use of fluorescent derivatives of sphingomyelin, and its application to diagnosis of Niemann-Pick disease.
Authors: Gatt S , Dinur T , Barenholz Y
Published: February 2020

We synthesized fluorescent derivatives of sphingomyelin (N-acyl-sphingosylphosphocholine) and used them as substrates for several sphingomyelinases. The following five fluorescent probes, each attached to the terminal carbon atom of the fatty acyl residue, were introduced into sphingomyelin: dansyl, pyrene, carbazole, 4-chloro-7-nitrobenz-2-oxa-1,3-diazole, and anthroic acid. We compared the rates at which the fluoro- and radiolabeled sphingomyelins were hydrolyzed. They were the same with the following three spingomyelinases: (a) a purified enzyme from Staphylococcus aureus; (b) at Triton X100-treated extract of human brain (assayed at pH 7.4 in the presence of Mg2+; and (c) aqueous extracts of brain lysosomes, skin fibroblasts, and amniotic cells, assayed at pH 5.0. Homogenates of skin fibroblasts of a patient with Niemann-Pick disease had practically no activity when assayed at pH 5, with fluorosphingomyelin as substrate. When fluorosphingomyelin was mixed in various proportions with natural sphingomyelin, enzymes from each of the three sources hydrolyzed the two substrates at equal rates. The fluorosphingomyelins can be used to estimate with great sensitivity the sphingomyelinase activity in extracts of tissues or cells, in tears, and probably in hair follicles, as well as diagnose Niemann-Pick disease, either pre- or post-natally
Pattern of urinary proteins and peptides in patients with rheumatoid arthritis investigated with the Iso-Dalt technique.
Authors: Clark P M , Kricka L J , Whitehead T P
Published: February 2020

Characteristic differences in the pattern of urinary proteins and peptides have been found in patients with rheumatoid arthritis, compared with patterns from healthy controls. These differences have been demonstrated with a two-dimensional gel electrophoretic technique (Iso-Dalt) involving isoelectric focusing in the first dimension, followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the second dimension. Using simple photographic techniques, one can obtain a composite pattern of the individual protein-stained gels for each group. Comparison of the composite patterns from the rheumatoid arthritis group and the control group revealed several proteins in the urine of the rheumatoid arthritis patients not found in the control group. Two groupings of these proteins were identified: acidic, high-Mr proteins and more basic, low-Mr proteins.
Radioimmunoassay for detection of latent chronic alcoholic pancreatitis, an unrecognized clinical syndrome.
Authors: Nerenberg S T , Prasad R , Pedersen L D , Biskup N S
Published: February 2020

We developed a radioimmunoassay procedure in which we used an antibody monospecific for pancreatic acinar antigen, to sensitively and specifically test for the presence of subclinical (latent) alcoholic pancreatitis. The antigen was isolated, purified, and partially characterized. Results of testing appropriate populations of patients support the idea that chronic alcoholism is associated with chronic, subclinical damage to the pancreas and concomitant continuous release of a pancreatic acinar protein into the peripheral circulation, where it can be detected and quantitated. About 40% of the samples from chronic alcoholics (whether during a bout of acute alcoholism or during abstinence) demonstrated the circulating antigen, strongly suggesting that those alcoholics who will develop symptomatic, chronic alcoholic pancreatitis can be readily detected during the non-symptomatic stage.
Improved electrothermal determination of aluminum in serum by atomic absorption spectroscopy.
Authors: Alderman F R , Gitelman H J
Published: February 2020

We describe an improved method for determination of aluminum in serum by atomic absorption spectrophotometry with a graphite furnace. Interferences have been controlled and total combustion of the samples achieved by the use of new diluent in a molybdenum-treated graphite tube. The detection limit of this method is 2 microgram/L.
Gas-chromatographic determination of amantadine in human urine.
Authors: Stumph M J , Noall M W , Knight V
Published: February 2020

We describe a gas--liquid-chromatographic method for determining the concentration of amantadine hydrochloride in urine with beta-phenylethylamine as internal standard. The urine sample is made alkaline and extracted with 0.5 mL of chloroform. After centrifugation the aqueous layer is aspirated, and an aliquot of the organic layer is injected directly into the gas chromatograph. Concentration and instrument response are linearly related between 2 and 125 mg/L. The limit of detection was 0.5 mg/L. Mean analytical recovery was calculated to be 97%.
Incidence of a split alpha 2-glycoprotein band in the electrophoretic pattern for serum of adenocarcinoma patients.
Authors: Dermer G B , Silverman L M , Gendler S J , Tökés Z A
Published: February 2020

We electrophoresed serum samples on Mylar-backed cellulose acetate membranes and stained for glycoproteins with the periodic acid—Schiff reagent. The samples were from untreated adenocarcinoma patients, adenocarcinoma patients receiving chemotherapy, and patients with other malignancies, and also from patients with benign proliferative diseases, inflammatory diseases, and other non-malignant conditions. Forty-five per cent of the sera from untreated adenocarcinoma patients and 80% of those from adenocarcinoma patients with progressive systemic disease exhibited a splitting of the alpha 2-glycoproteins into a fast and slow band. Such a pattern was seen in only 4% of the non-adenocarcinoma cancer patients and 4% of the control group. Serial studies indicated that electrophoretic patterns of alpha 2-glycoproteins change with clinical status. Non-cancer patients with high concentrations of acute-phase proteins in their serum did not exhibit two alpha 2-glycoprotein bands. Further characterization of serum proteins from the fast alpha 2 region suggest that alpha 1-acid glycoprotein and haptoglobin beta chains are the principal components staining with periodic acid—Schiff reagent. These components are markedly less apparent in, or are absent from, the fast alpha 2 region of normal sera.
Hemoglobin determined in 15 microL of whole blood by "front-face" fluorometry.
Authors: Blumberg W E , Doleiden F H , Lamola A A
Published: February 2020

We describe the rapid, inexpensive fluorometry of hemoglobin in undiluted whole blood. The procedure consists only of adding a standard quantity of a fluorescent dye to a measured volume (approximately 15 microL) of blood, together with some solubilizing detergent. The assay is based on the attenuation of the dye's fluorescence (excited within the region 400—440 nm) that results from the competitive absorption of exciting light by the hemoglobin present—the "inner filter effect." The wavelength that one can use is optional and will determine which dyes can be used. Measurements are made with the hematofluorometer, a "front-face" filter fluorometer (Blumberg et al., J. Lab. Clin. Med. 89: 712—723, 1977). We demonstrate the validity of the method for two dyes, rhodamine B and fluorescein dibutyrate, which we used with hematofluorometers that were designed to determine blood zinc protoporphyrin and bilirubin, respectively. Our method exhibited a standard error of about 4 g of hemoglobin per liter vs the comparison method (Coulter Counter method, for which the CV is 1.2%). The CV is about 3%. The method seems appropriate for "field" use (i.e., use outside the laboratory) in anemia-screening programs.
An interlaboratory study of the determination of digoxin by immunoassay.
Authors: Fast D M , Hannon W H , Burtis C A , Bayse D D
Published: February 2020

We conducted a voluntary survey of laboratories and manufacturers to assess the current quality of analytical assays for serum digoxin. More than 300 clinical laboratories and 18 manufacturers responded, giving data on methods, instruments, computational procedures, and results for five survey samples. We sorted the analytical data to provide statistical information on the grand mean values separately for manufacturers and clinical laboratories, the frequency distribution of all reported values, and the mean values by method of interpolation and algorithms used for linear transformation. There was no statistical difference (alpha = 0.05) between the means for each specimen as determined by the kit manufacturers as a group and the clinical laboratories as a group.
Semiautomated homogeneous enzyme immunoassay of total serum thyroxine with a kinetic analyzer.
Authors: Bhatia H
Published: February 2020

A new semiautomatic procedure for determination of total serum thyroxine was adapted to a kinetic analyzer, LKB 2086 Mark II. The ABA thyroxine assay kit was used, and although the assay procedure was modified, the advantage of small reagent volumes, short measuring times, and automation were retained. The results were analyzed off-line with a programmable desk-top calculator. The method has a precision of 7% (CV) and a sensitivity of 8 nmol/L. Values in sera from 64 patients analyzed by enzyme immunoassay and by radioimmunoassay correlated well (r = 0.975). One kit contains enough reagents for 500 assays, and an operator could do 25 samples (i.e., 64 assays) in about 4 h.
Transient increase in serum creatine kinase isoenzyme BB activity after prostatectomy in a patient with massive benign prostatic hyperplasia.
Authors: Goodman Z D , Hamilton S R
Published: February 2020

The activity of creatine kinase isoenzyme BB (CK-BB) in serum is rarely abnormally high (i.e., detectable). An increase in immunoreactive CK-BB or CK-BB activity in patients with prostatic disease has been proposed as an indication of prostatic adenocarcinoma. Here we report the case of an elderly man with massive benign prostatic hyperplasia but no clinical or pathological evidence of prostatic adenocarcinoma, whose serum CK-BB activity was found by agarose gel electrophoresis to be 1 U/L (normal: 0%), 10% of his total CK activity. Serum CK-BB activity was further increased to 16 U/L (20% of total CK activity) 1 h after prostatectomy, but became undetectable by the second day after the operation. The findings suggest that: (a) the source of the serum CK-BB activity was the enlarged prostate gland; (b) abnormally high CK-BB activity in serum of men with prostatic disease does not necessarily indicate the presence of prostatic adenocarcinoma; and (c) myocardial injury could be erroneously diagnosed postoperatively in prostatectomy patients if CK isoenzyme methods are used that do not consistently separate "heart-specific" CK-MB from CK-BB.
A radioimmunoassay for 1,25-dihydroxycholecalciferol.
Authors: Bouillon R , De Moor P , Baggiolini E G , Uskokovic M R
Published: February 2020

We describe a radioimmunoassay for 1,25-dihydroxycholecalciferol in human serum. We raised antisera in rabbits to 1,25-dihydroxycholecalciferol-3-hemisuccinate coupled to bovine serum albumin, and obtained sensitive, high-titer antibodies. These antibodies had a high affinity for 1,25-dihydroxycholecalciferol and cross reacted mainly with 25-hydroxycholecalciferol and 24,25-dihydroxycholecalciferol. Addition of 1 mL of normal rabbit serum per liter reduced this interference to 5 and 4%, respectively. However, these interfering steroids are present in large excess, so extensive purification of 1,25-dihydroxycholecalciferol from serum is necessary. The steroid was extracted with ethyl acetate/cyclohexane, purified on Sephadex LH-20, and then chromatographed on a column of silicic acid. The radioimmunoassay is sensitive to 5 pg/tube (3 ng/L of serum). The between-assay CV was 14%. The mean concentration of 1,25-dihydroxycholecalciferol in the serum of 54 healthy adults was 38 (SD 12) ng/L, with no sex-related difference. The assay was further validated by the finding of low or undetectable concentrations in patients with chronic renal failure and of increased concentrations in the serum of patients with primary hyperparathyroidism. In comparison with previously described methods, the major advantage of the present assay is the use of stable gamma-globulins, which are available in large amounts, as binding protein.
Automated creatine kinase-MB estimation by immuno-inhibition: a clinical evaluation.
Authors: Delahunty T J , Foreback C C
Published: February 2020

We detected the presence of creatine kinase (EC 2.7.3.2) MB isoenzyme (CK-MB) in serum by using an immunoinhibition technique to inactivate the creatine kinase isoenzyme of muscle origin (CK-MM). The GEMSAEC centrifugal analyzer is ideally suited for this procedure because it rapidly mixes reagents and has a throughput of 60 samples/h. The within-run CV was acceptable when the CK-MB value was 7.5 U/L or more. CK-MM was totally inactivated up to 5000 U/L, a value well above that usually seen in myocardial-infarct patients. We assessed the predictability of the assay for detecting myocardial infarction among 120 coronary-care patients when 2% of total CK activity was considered diagnostic and compared the results with those obtained with an electrophoresis technique. The positive predictive value of the immunoinhibition assay was 97.8%, as compared to 92% with the CK electrophoresis technique, when lactate dehydrogenase (EC 1.1.1.27) isoenzyme results were included in both cases. The optimal negative predictive value was 95.1% with the immunoinhibition assay vs 98.2% with electrophoresis. We conclude that the immunoinhibition technique for estimating CK-MB can be automated to assess myocardial status rapidly, precisely, inexpensively, and sensitively.
Serum high-density lipoprotein cholesterol concentrations in hypo- and hyperthyroidism.
Authors: Scottolini A G , Bhagavan N V , Oshiro T H , Abe S Y
Published: February 2020

We studied alterations in the concentration of high-density lipoprotein cholesterol and of other lipid categories (total cholesterol, low-density lipoprotein cholesterol, very-low-density lipoprotein cholesterol, and triglycerides) in serum in hypo- and hyperthyroid states, and compared these findings with those of a control group. In the latter group the lipids showed an age-related increase in concentration but with a decrease in the eighth decade in all categories. In untreated hypo- and hyperthyroid subjects, all of the lipid values differed significantly from those of the controls but promptly returned to normal values upon treatment. In hypothyroid patients who are prone to develop coronary heart disease, the concentrations of high-density lipoprotein cholesterol were high, suggesting protection against heart disease, while the ratio to total cholesterol indicated the contrary. The exact opposite of these relationships was seen in hyperthyroid disorders. This apparent paradox suggests that the low-density lipoprotein cholesterol in serum, with its established atherogenic effect, should be given at least equal, if not more, weight than the concentration of high-density lipoprotein cholesterol in serum, with its alleged protective effect.
Purification of an alkaline phosphatase-lipoprotein-X complex.
Authors: Weijers R N , Kruijswijk H , Baak J M
Published: February 2020

An alkaline phosphatase isoenzyme was observed in an abnormal position in the agar-agarose gel pattern of sera from several patients suffering from intrahepatic and extrahepatic cholestasis. We purified this isoenzyme, by gel filtration and affinity chromatography, from the serum of a patient suffering from extrahepatic cholestasis. Analysis demonstrated an alkaline phosphatase-lipoprotein-X complex with a relative molecular mass of at least 669,000. We discuss the interpretation of alkaline phosphatase isoenzyme patterns produced by different techniques.
Properties and clinical significance of an alkaline phosphatase-lipoprotein-X complex.
Authors: Weijers R N
Published: February 2020

The existence of an alkaline phosphatase-lipoprotein-X complex was demonstrated as an abnormally moving band in the agar-agarose gel alkaline phosphatase pattern of sera from 58 patients in a group of 72 patients whose sera contained lipoprotein-X. The position of the abnormally moving band in the agar-agarose gel alkaline phosphatase pattern and the percentage of alkaline phosphatase activity in the complex in relation to the total serum alkaline phosphatase activity depend on the serum lipoprotein-X concentration. The presence of the complex is a reliable indicator for cholestasis and of limited value in the differentiation between intrahepatic and extrahepatic cholestasis.
Improved separation of creatine kinase isoenzymes by use of DEAE-Sepharose Cl-6B.
Authors: Bondar R J , Shevchik D G , Hsu M Y , Kohler M M
Published: February 2020

We describe here a simple, rapid chromatographic procedure for quantitatively separating serum creatine kinase isoenzymes (EC 2.7.3.2), with diethylaminoethyl (DEAE)-Sepharose CL-6B as the anion-exchanger. We established the column bed height and the elution parameters by use of a simplex procedure. DEAE-Sepharose CL-6B equilibrated in tris(hydroxymethyl)aminomethane (50 mmol/L, pH 7.5, and containing 30 mmol of NaCl per liter) is packed into a miniature polystyrene column with bed dimensions of 0.7 x 1.5 cm. The DEAE-Sepharose column system was evaluated and compared with a DEAE-Sephadex A-50 column system. The results indicate that the Sepharose column yields MM, MB, and BB isoenzymes uniquely, without cross contamination. Coefficients of variation (CV’s) for 10 replicate column assays were 2.8, 5.9, and 15.2% for 569 U of MM per liter, 82.3 U of MB per liter, and 9.0 U of BB per liter, respectively. The serum sample was enriched with baboon heart extract. Day-to-day reproducibility for a serum control assayed on 10 days yielded CV’s of 4.6, 9.9, and 40.3% for 391, 45.3 and 1.9 U of isoenzymes MM, MB, and BB per liter, respectively. A reference interval for each isoenzymes was derived from data on 81 men and 63 women.
Restoration of lead-inhibited 5-aminolevulinate dehydratase activity in whole blood by heat, zinc ion, and (or) dithiothreitol.
Authors: Sakai T , Yanagihara S , Ushio K
Published: February 2020

We examined effects of heat, zinc, ion, and dithiothreitol in restoring the activity of lead-inhibited-5-aminolevulinate dehydratase (EC 4.2.1.24). The ratio of non-activated to activated activity produced by dithiothreitol correlated well with blood lead concentration among 35 lead workers. The individual effects of heat, zinc, or dithiothreitol differ from each other in the shift of pH optimum as well as in the extent to which activity is restored. Dual or triple combinations of these agents show additive or complementary restoration of activity. The combination of heat and zinc or zinc and dithiothreitol expands the range of optimum concentration of zinc in restoring activity. Using these combinations of agents, we can expect more accurate evaluation of lead exposure than by measuring only activation of zinc. Although dithiothreitol most powerfully restores activity, it restores not only the activity inhibited by lead exposure but also the activity removed by oxidation of SH-groups in the enzyme molecule.
Interferences appearing in fluorometrically measured liquid-chromatographic profiles of creatine kinase isoenzymes in serum.
Authors: Schlabach T D , Fulton J A , Mockridge P B , Toren E C
Published: February 2020

We observed nonenzymic peaks when serum isoenzymes of lactate dehydrogenase (EC 1.1.1.27; LD) and creatine kinase (EC 2.7.3.2.; CK) were separated by “high-performance” liquid chromatography and detected by continuously monitoring the column effluent for enzyme activity. Such background peaks were particularly apparent in CK isoenzyme profiles obtained from human sera. We observed two nonenzymic peaks with fluorescence detection, one in the CK-MB region, the other in the CK-BB region. Serum albumin was a major component in the artifactual CK-MB peak, with lipoprotein as a minor component. We present evidence that the material responsible for the other peak fluoresced quite strongly and is mostly pre-albumin.
Variability in the adsorption properties of microtitre plates used as solid supports in enzyme immunoassay.
Authors: Kricka L J , Carter T J , Burt S M , Kennedy J H , Holder R L , Halliday M I , Telford M E , Wisdom G B
Published: February 2020

We evaluated the variability in the amount of protein adsorbed onto the surface of individual wells of an assortment of microtitre plates by use of procedures involving enzyme-protein conjugates. Coefficients of variation in adsorbed protein ranged from 5.2 to 29.5%. Microtitre plates show a distinct “edge effect”; wells at the edges of a plate adsorb more protein than those in the interior, which markedly affects results from immunoassays involving such plates. In a sandwich enzyme immunoassay the results for an individual sample varied by +/− 18%; in a competitive assay, values read from different calibration curves in the same plate varied by +/− 11%. Scanning electron microscopy and birefringence studies demonstrated no marked physical differences between individual wells on a plate. The variability in the amount of protein adsorbed onto the surface of individual wells on the same microtitre plate seriously affects the reliability and interpretation of results of immunoassays in which such plates are used as solid supports.
Carcinoembryonic antigen assayed by column chromatography on polyacrylamide gel.
Authors: Weissman E B
Published: February 2020

I evaluated a commercially available polyacrylamide column (Clinetics Corp.) for use in assaying for carcinoembryonic antigen. The procedure eliminates the need for dialysis and 50 samples, assayed in duplicate, may be completed in 5 h. In general, results by this technique are 1.0 microgram/L (range 0.5-2.0) lower than by the conventional dialysis method (r = 0.9876). Sensitivity approximates 0.5 microgram/L. Within-day precision for two pools of patients’ plasma (n = 10) was mean = 2.29 (SEM 0.05) microgram/L with CV = 6.55% and mean = 10.61 (SEM 0.10) microgram/L with CV = 2.92%, respectively; between-day precision (n = 6) was mean = 3.90 (SEM 0.16) microgram/L with CV = 10.0% and mean = 10.1 (SEM 0.37) microgram/L, CV = 8.91%, respectively. The precentage analytical recovery of added carcinoembryonic antigen was about 80% at concentrations of approximately 8 and 12 microgram/L, 73% at 18 microgram/L.
A coupled-enzyme equilibrium method for measuring urea in serum: optimization and evaluation of the AACC study group on urea candidate reference method.
Authors: Sampson E J , Baird M A , Burtis C A , Smith E M , Witte D L , Bayse D D
Published: February 2020

We describe a coupled-enzyme equilibrium method for measuring urea in serum, which is performed on supernates prepared by treating each specimen with Ba(OH)2 and ZnSO4 (Somogyi reagent). Analytical recovery of [14C]urea added to a variety of matrices was essentially complete (mean, 100.6%) for the supernates after precipitation. Nine variables were univariately examined in arriving at the reaction conditions for the method: glutamate dehydrogenase, urease, 2-oxoglutarate, ADP, Tris . HCI, NADH, EDTA, pH, and temperature. The reagent is stable for at least 48 days at--20 degrees C and for 23 days at 4 degrees C. Mean analytical recovery of urea (14 mmol/L) added to seven different specimens (three different matrices) was 100.8%. The analytical linear range of the method extends to 30 mmol of urea per liter. Of 22 potential interferents, only bilirubin at 1 mmol/L (580 mg/L), hemoglobin at 10 g/L, and hydroxyurea at 6 mmol/L showed more than 2% interference. We discuss precision and effects of specimen dilution, and compare results for 100 human serum specimens with those measured for the same specimens with four other urea methods. We examined the effects of measuring a blank, consisting of sample and reagent without urease, with each specimen.
Liquid-chromatographic method for simultaneous determination of phenytoin and 5-(4-hydroxyphenyl)-5-phenylhydantoin in plasma and urine.
Authors: Sawchuk R J , Cartier L L
Published: February 2020

We describe a liquid-chromatographic assay for phenytoin and its para-hydroxylated metabolite, 5-(4-hydroxyphenyl)-5-phenylhydantoin, in plasma and urine. Unlike previously reported methods, this procedure is sensitive enough to allow quantitation of the unconjugated metabolite in plasma at concentrations observed clinically (50-500 microgram/L). Simultaneous measurements of the drug and its metabolite in plasma and urine may be helpful in explaining changes in the apparent clearance of phenytoin, assumed to occur through its metabolite. The method may also be used, without modification, for analysis for phenobarbital and carbamazepine in plasma. The accuracy of our method for these three drugs was assessed for 25 months in quality-assurance program for determining drug concentrations. Regression slopes for measured vs reported values for phenytoin, phenobarbital, and carbamazepine were 1.02, 0.99, and 0.99, respectively.
Creatine kinase radioimmunoassay and isoenzyme electrophoresis compared in the diagnosis of acute myocardial infarction.
Authors: Homburger H A , Jacob G L
Published: February 2020

We compared, in 116 patients, the relative usefulness of results of tests for creatine kinase B isoenzymes, as measured by radioimmunoassay, and the MB isoenzyme, as measured by electrophoresis, in diagnosis of acute myocardial infarction. The radioimmunoassay was specific for isoenzymes of creatine kinase containing the B subunit. All patients with acute transmural infarcts had positive test results by both techniques, but concentrations of B-isoenzymes were more frequently above normal than were MB bands in the case of patients with acute subendocardial infarcts and in the case of all patients with acute myocardial infarcts from whom sera were collected more than 24 h after onset of chest pain. Concentrations of B-isoenzymes also were increased, even when MB bands were not electrophoretically detectable, in specimens from several patients without documented actue myocardial infarcts. These abnormal results presumably were caused by increased concentrations of the BB isoenzyme in serum. Accordingly, an increased concentration of B-isoenzymes had less diagnostic specificity and predictive value for acute myocardial infarction than did a detectable MB band. Results of isoenzyme electrophoresis were more reliable for establishing this diagnosis, but the results of radioimmunoassay were more reliable for excluding it in patients with chest pain as the primary symptom.
Current results of left ventricular assist device therapy in France: the ASSIST-ICD registry
Authors: Anselmi Amedeo , Galand Vincent , Vincentelli André , Boule Stéphane , Dambrin Camille , Delmas Clément , Barandon Laurent , Pernot Mathieu , Kindo Michel , Tam Hoang Minh , Gaudard Philippe , Rouviere Philippe , Senage Thomas , Michel Magali , Boignard Aude , Chavanon Olivier , Verdonk Constance , Para Marylou , Gariboldi Vlad , Pelce Edeline , Pozzi Matteo , Obadia Jean-François , Anselme Frederic , Litzler Pierre-Yves , Babatasi Gerard , Belin Annette , Garnier Fabien , Bielefeld Marie , Guihaire Julien , Kloeckner Martin , Radu Costin , Lellouche Nicolas , Bourguignon Thierry , Genet Thibaud , D’Ostrevy Nicolas , Duband Benjamin , Jouan Jerome , Bories Marie Cécile , Vanhuyse Fabrice , Blangy Hugues , Colas Fabrice , Verhoye Jean-Philippe , Martins Raphael , Flecher Erwan
Published: February 2020

OBJECTIVES

Our goal was to provide a picture of left ventricular assist device (LVAD) activity in France between 2007 and 2016 based on the multicentric ASSIST-ICD registry.

METHODS

We retrospectively collected 136 variables including in-hospital data, follow-up survival rates and adverse events from 671 LVAD recipients at 20 out of 24 LVAD implant centres in France. The average follow-up time was 1.2 years (standard deviation: 1.4); the total follow-up time was 807.5 patient-years.

RESULTS

The included devices were the HeartMate II®, HeartWare LVAS® or Jarvik 2000®. The overall likelihood of being alive while on LVAD support or having a transplant (primary end point) at 1, 2, 3 and 5 years postimplantation was 65.2%, 59.7%, 55.9% and 47.7%, respectively, given a cumulative incidence of 29.2% of receiving a transplant at year 5. At implantation, 21.5% of patients were on extracorporeal life support. The overall rate of cardiogenic shock at implantation was 53%. The major complications were driveline infection (26.1%), pump pocket or cannula infection (12.6%), LVAD thrombosis (12.2%), ischaemic (12.8%) or haemorrhagic stroke (5.4%; all strokes 18.2%), non-cerebral haemorrhage (9.1%) and LVAD exchange (5.2%). The primary end point (survival) was stratified by age at surgery and by the type of device used, with inference from baseline profiles. The primary end point combined with an absence of complications (secondary end point) was also stratified by device type.

CONCLUSIONS

The ASSIST-ICD registry provides a real-life picture of LVAD use in 20 of the 24 implant centres in France. Despite older average age and a higher proportion of patients chosen for destination therapy, survival rates improved compared to those in previous national registry results. This LVAD registry contrasts with other international registries because patients with implants have more severe disease, and the national policy for graft attribution is distinct. We recommend referring patients for LVAD earlier and suggest a discussion of the optimal timing of a transplant for bridged patients (more dismal results after the second year of support?).
Catheter ablation of arrhythmogenic right ventricular cardiomyopathy ventricular tachycardia: 18-year experience in 284 patients
Authors: Liang Erpeng , Wu Lingmin , Fan Siyang , Hu Feng , Zheng Lihui , Liu Shangyu , Fan Xiaohan , Chen Gang , Ding Ligang , Niu Guodong , Yao Yan
Published: February 2020

Aims

The study aims to describe the long-term outcome of radiofrequency catheter ablation for ventricular tachycardia (VT) in a large cohort arrhythmogenic right ventricular cardiomyopathy (ARVC) patients.

Methods and results

Radiofrequency catheter ablation was performed in 284 ARVC patients due to VT between July 2000 and January 2019. An endocardial approach was used initially, with epicardial ablation procedures reserved for those patients who failed an endocardial ablation. Activation, entrainment, pace and substrate mapping strategies were used with regional ablation applied. A total of 393 ablation procedures were performed including endocardial approach only (n = 377) and endo and epicardial combined (n = 16). Right ventricular basal free wall was accounted as the primary substrate of VT in 258 (65.6%) patients. There were 81 patients underwent redo ablation procedure (second time = 81; ≥3 times = 28). New targets were observed in 68.8% of redo procedures. There were 171 VT recurrences and 19 deaths occurred during the follow-up. Ventricular tachycardia-free survival rate of the first, second, and last ablation procedure was 56.7%, 73.2%, and 78.1%, respectively. Multivariate analysis showed ≥3 induced VTs in the procedure was correlated with rehospitalized VT recurrence [hazard ratio (HR) 1.467, 95% confidence interval (CI) 1.052–2.046; P = 0.024]. For all-cause mortality, rehospitalized VT and ≥3 induced VTs were the independent risk factors (HR 2.954, 95% CI 1.8068.038; P = 0.034; HR 3.189, 95% CI 1.073–9.482; P = 0.037).

Conclusion

Endocardial ablation is effective to ARVC VT though it may require repeated procedures. Induced multiple VTs was correlated with worse outcomes.
Baby Genomics: Tracing the Evolutionary Changes That Gave Rise to Placentation
Authors: Hao Yue , Lee Hyuk Jin , Baraboo Michael , Burch Katherine , Maurer Taylor , Somarelli Jason A , Conant Gavin C
Published: February 2020

It has long been challenging to uncover the molecular mechanisms behind striking morphological innovations such as mammalian pregnancy. We studied the power of a robust comparative orthology pipeline based on gene synteny to address such problems. We inferred orthology relations between human genes and genes from each of 43 other vertebrate genomes, resulting in ∼18,000 orthologous pairs for each genome comparison. By identifying genes that first appear coincident with origin of the placental mammals, we hypothesized that we would define a subset of the genome enriched for genes that played a role in placental evolution. We thus pinpointed orthologs that appeared before and after the divergence of eutherian mammals from marsupials. Reinforcing previous work, we found instead that much of the genetic toolkit of mammalian pregnancy evolved through the repurposing of preexisting genes to new roles. These genes acquired regulatory controls for their novel roles from a group of regulatory genes, many of which did in fact originate at the appearance of the eutherians. Thus, orthologs appearing at the origin of the eutherians are enriched in functions such as transcriptional regulation by Krüppel-associated box-zinc-finger proteins, innate immune responses, keratinization, and the melanoma-associated antigen protein class. Because the cellular mechanisms of invasive placentae are similar to those of metastatic cancers, we then used our orthology inferences to explore the association between placenta invasion and cancer metastasis. Again echoing previous work, we find that genes that are phylogenetically older are more likely to be implicated in cancer development.
The Country That Never Retires: The Gendered Pathways to Retirement in South Korea
Authors: Lee Yeonjin , Yeung Wei-Jun Jean
Published: February 2020

Objectives

Among all Organization for Economic Cooperation and Development countries, South Korean older adults work until the latest age. We investigate the extent to which work experiences over the life course and family circumstances can be associated with older workers’ incentives to remain in the labor force beyond the statutory pension age. We explore gender-specific patterns of labor force exit and labor force re-entry in later life.

Methods

Using panel data of South Korean older workers and retirees from 2006 to 2016, we estimate multilevel discrete-time models with random effects to predict their labor force transition process that unfolds over time.

Results

Results show that skilled manual workers are less likely to exit employment and more likely to re-enter the labor force. A longer history of self-employment is related to later retirement. The relationship between career characteristics and the risk of retirement is only significant for men. Late-aged employment transition among women appears to be more related to family conditions. Women who receive financial support from adult offspring are more likely to remain out of the labor force but this relationship is not pronounced among men.

Discussion

Policies aimed at extending working lives need to provide various types of social support to older job seekers, especially those who had low-class jobs and those without family networks.
Technology and Caregiving: Emerging Interventions and Directions for Research
Authors: Lindeman David A , Kim Katherine K , Gladstone Caroline , Apesoa-Varano Ester Carolina
Published: February 2020

An array of technology-based interventions has increasingly become available to support family caregivers, primarily focusing on health and well-being, social isolation, financial, and psychological support. More recently the emergence of new technologies such as mobile and cloud, robotics, connected sensors, virtual/augmented/mixed reality, voice, and the evermore ubiquitous tools supported by advanced data analytics, coupled with the integration of multiple technologies through platform solutions, have opened a new era of technology-enabled interventions that can empower and support family caregivers. This paper proposes a conceptual framework for identifying and addressing the challenges that may need to be overcome to effectively apply technology-enabled solutions for family caregivers. The paper identifies a number of challenges that either moderate or mediate the full use of technologies for the benefit of caregivers. The challenges include issues related to equity, inclusion, and access; ethical concerns related to privacy and security; political and regulatory factors affecting interoperability and lack of standards; inclusive/human-centric design and issues; and inherent economic and distribution channel difficulties. The paper concludes with a summary of research questions and issues that form a framework for global research priorities.
The Emerging Intersection Between Injection Drug Use and Early Syphilis in Nonurban Areas of Missouri, 2012–2018
Authors: Reno Hilary , Fox Branson , Highfill Craig , McKee Angela , Trolard Anne , Liang Stephen Y , Stoner Bradley P , Meyerson Beth E
Published: February 2020

Background

The national rate of syphilis has increased among persons who inject drugs (PWID). Missouri is no exception, with increases in early syphilis (ES), congenital syphilis, and PWID, especially in nonurban counties.

Methods

Disease intervention specialist records for ES cases in Missouri (2012–2018) were examined. Drug use was classified as injection drug use (IDU) (opioid or methamphetamine) or non-IDU (opioid, methamphetamine, or cocaine). Rates were compared based on residence, sex of sex partner, and drug use.

Results

Rates of ES in Missouri increased 365%, particularly in small metropolitan and rural areas (1170%). Nonurban areas reported a higher percentage of persons with ES who used injection drugs (12%–15%) compared with urban regions (2%–5%). From 2012 to 2018, women comprised an increasing number of ES cases (8.3%–21%); 93% of women were of childbearing age. Increasingly more women in rural areas with ES also reported IDU during this time (8.4%–21.1%).

Conclusions

As syphilis increases in small metropolitan and rural regions, access to high-quality and outreach-based sexual health services is imperative. Healthcare policy to equip health departments with harm reduction services and drug treatment resources offers an opportunity to impact both syphilis increases as well as health outcomes associated with IDU.