bluuebunny/crossref_metadata_2025 huggingface dataset:
Anterior versus posterior approach in peroral endoscopic myotomy (POEM): a systematic review and meta-analysis
Authors: Mohan Babu P. , Ofosu Andrew , Chandan Saurabh , Ramai Daryl , Khan Shahab R. , Ponnada Suresh , Adler Douglas G.
Published: January 2020

Background Peroral endoscopic myotomy (POEM) is increasingly being used as the endoscopic treatment option for achalasia. Data are limited as to the comparative efficacy of anterior vs. posterior myotomy.

Methods We searched multiple databases from inception to August 2019 to identify studies reporting on POEM. We selected studies that reported on the outcomes of POEM, along with information on myotomy approach. We performed a comparative analysis of clinical success, gastroesophageal reflux disease (GERD), and adverse events with anterior and posterior myotomy in POEM by meta-analysis.

Results 1247 patients from 18 studies were analyzed: 623 patients (11 cohorts) were treated via anterior myotomy and 624 patients (12 cohorts) via posterior myotomy. The pooled rate for clinical success gave an odds ratio (OR) of 1.02 (95 % confidence interval [CI] 0.52 – 2.0; I
2 0; P = 0.9); for GERD by esophagogastroduodenoscopy (EGD) was OR 1.02 (95 %CI 0.62 – 1.68; I
2 0; P = 0.9), and for GERD by pH was OR 0.98 (95 %CI 0.59 – 1.63; I
2 34; P = 0.9). The individual pooled rates of clinical success at 12 months and > 12 months, GERD (by symptoms, EGD, pH), and adverse events (mild, moderate, severe) were comparable. The pooled total procedure time with anterior myotomy was 82.7 minutes (95 %CI 69.0 – 96.4; I
2 98) and with posterior myotomy was 62.1 minutes (95 %CI 48.5 – 75.7; I
2 90).

Conclusion Anterior and posterior myotomy in POEM seem comparable to each other in terms of clinical success, GERD, and adverse events. The total procedure time with posterior myotomy seems to be shorter than with anterior myotomy.
Challenges and Opportunities in Reporting Trauma-Related Research: A Case Study from Syria
Authors: Alothman Muhammad Hussam , Tamer Wardan Almir , Moscote-Salazar Luis Rafael , Ghosh Amrita , Pal Ranabir , Agrawal Amit
Published: January 2020

Background Reporting war trauma research is an arduous mission because it needs accurate data collection and it is considered a tough task as a result of the emergent management nature of such injuries which implies neglecting the medical records. The conflict in Syria involved extreme numbers of war trauma injuries which might be implemented in creating a prototype for preparedness plans which might decrease the number of casualties or, at the very least, minimize the damage for future combat trauma injuries.

Material and Methods Data were sought from the Department of Surgery at Hama National Hospital on war injuries during 2017 to make a research paper on the experience of Hama National Hospital, Syria, a nonmilitary hospital that treats war injuries.

Results In 2017, 2,912 war injury patients were admitted to the Hama National Hospital, among which 683 (23.455%) were dead-on-arrival and the remaining 2,229 patients (76.545%) were treated in emergency room (ER). Among those treated in the ER, shrapnel was the first cause of injury reported in 1,165 patients (52.26%), followed by bullets in 585 (26.24%) and trauma in 316 (14.17%). There were no data on the age of patients, the initial investigations done, the Glasgow Coma Scale score on admission, the primary management, the follow-ups, or even the mortality rates among hospitalized patients. The data were insufficient to write a well-balanced research paper because of the scarcity of information extracted from the medical records.

Conclusion Doing a research in conflict settings requires more attention to detail and the medical staff should be trained to take care of the medical records because even if it seems inappropriate to spend time on recording in conflict atmospheres, making well-established recordings would contribute to the enhancement of the health care management of future war trauma injuries.
Testing the Neutrino Mass Ordering with Four Years of IceCube/DeepCore Data
Authors: Leuermann Martin
Published: January 2020

The measurement of the Neutrino Mass Ordering (NMO), i.e. the ordering of the neutrino mass eigenstates, is one of the major goals of many future neutrino experiments. One strategy is to measure matter effects in the oscillation pattern of atmospheric neutrinos as proposed for the PINGU extension of the IceCube Neutrino Observatory. Already, the currently running IceCube/DeepCore detector can explore this type of measurement. Albeit with lower significance, such a measurement can contribute to the current understanding. Furthermore, such an analysis exercises the measurement principle and evaluation of systematic uncertainties and thus prototypes future analyses with PINGU. We present a likelihood analysis spanning multiple years of IceCube data searching for indications of the NMO with a data sample reaching to energies below 10 GeV.
Isolation of Cellulolytic Bacteria from Mangrove Sediment in Dumai Marine Station Riau and the Antibacterial Activity against Pathogens
Authors: Nursyirwani N , Feliatra F , Tanjung A , Harjuni F
Published: January 2020

Cellulolytic bacteria are a group of bacteria that have an ability to degrade material containing cellulose and have potency to inhibit the growth of pathogenic bacteria. The bacteria can be found in soil or sediment in the mangrove ecosystem. This research aimed to: 1) isolate cellulolylitic bacteria from mangrove sediments in Dumai Marine Station, of Riau, Indonesia, 2) to examine the antagonism against pathogenic bacteria (Escherichia coli, Pesudomonas aeruginosa, Vibrio alginolyticus), and 3) to identify and the phenotype and genetic characters of the potential isolates. The bacteria were isolated on Zobell Marine Agar 2216 added with carboxymethyl cellulose (CMC). Cellulolytic index value was obtained by reducing clear zone diameter with the bacterial colony diameter. Disc diffusion agar method was used to examine antagonism of selected isolates against pathogens. The isolates were observed for the colony and cell morphology, biochemical and genetically characters. Twenty four isolates showed cellulolytic activity and index values ranged from 1.00 to 2.86 and 0.01 to 2.12, respectively. Nine of selected isolates performed ranges of zone inhibition against E. coli, P. aeruginosa and V. alginolyticus from 2.38 ± 0.21 mm to 3.58 ± 0.83 mm, 2.75 ± 0. 59 mm - 4.81 ± 0.57 mm and 2.28 ± 0.45 mm - 4.68 ± 1.40 mm, respectively. Based on the 16S rDNA sequence analysis, three cellulolytic isolates indicated similarity to Bacillus toyonensis (99.53 %).
Effects of Various Carbon Doses on Tilapia (Orechromis sp) Culture with Biofloc Technology
Authors: Putra I , Efendi I , Lukisyowati I , Tang U M , Rusliadi R , Manik R A
Published: January 2020

The purpose of this study was to evaluate the growth and survival of red tilapia (Oreochromis sp) which were cultured using biofloc technology with different amounts of molasses as a source of carbon. This study was carried out for 35 days in August-September 2017 at the Laboratory of Aquaculture Technology, Faculty of Fisheries and Marine Science, Universitas Riau, Pekanbaru, Indonesia. The experiment was done using a completely randomized design (CRD) with the following treatments: A: 50 ml/m3 molasses, B: 100 ml/m3 molasses, C: 150 ml/m3 molasses, and D: 200 ml/m3 molasses. The test fish used was red tilapia with a size of 3.57±0.06 cm and a weight of 1.14±0.09 g. Fish were kept in containers with a volume of 100 liters that are filled with brackish water with a salinity of 17 ppt. Feed was given at 3 times per day. Results showed significant effect of each treatment on the absolute weight and specific growth, but did not significantly affect the survival rate of red tilapia. Best growth and utilization of feed in red tilapia culture using biofloc technology was supplementing with add molasses at a dose of 200 ml / m3 (D).
Density of Mangrove Snail (Telescopium telescopium) in the Mangroves Ecosystem of Mengkapan Village, Sungai Apit Subdistrict, Siak District, Riau Province
Authors: Adriman A , Sumiarsih E , Andriani N
Published: January 2020

Mangrove snails (Telescopium telescopium) are found in the mangrove ecosystem. Telescopium telescopium has significant ecological and economical role in the mangrove ecosystem. This study aims to determine the density of mangrove snails in the mangrove ecosystem of Mengkapan village. This research was conducted in February 2018. There were 3 transect and there were 6 plots (1m x 1m). The snails were collected once/2 weeks, 3 time. Densities of the snail were studied. Results shown that in the density of the snail was 4.33–5.17 organisms/m2. The density of mangrove snail population in the mangrove ecosystem in the Mengkapan Village has no disturbance.
Prediction and modeling of roughness in ball end milling with tool-surface inclination
Authors: Bilek O , Milde R , Strnad J , Zaludek M , Bednarik M
Published: January 2020

The quality of mill finishing of shaped surfaces is influenced by a number of input parameters. Current automated manufacturing systems allow adaptation of the machining process aiming at the final surface quality. Despite all the advantages, these systems require a behavioural model, a prediction of the output, based on the input parameters. Some of these models are summarized in this paper, including contemporary evaluated models as well as their functional dependencies; moreover, offers an application of mill finishing with a ball-end cutter incorporating tool axis or surface inclination.
Influence of focal length on depth of engraved PMMA surface
Authors: Knedlová J , Sýkorová L , Pata V , Škrobák A
Published: January 2020

The paper focuses on laser cutting of polymer material PMMA. Specifically, the influence of optics on the engraved surface is investigated with use focal length lenses of 1.5″ 2.5″ 4″. Commercial CO2 laser ILS 3NM by Laser Tools & Technics Corp. Taiwan, was used for experimental machining.
The physical – mechanical properties of low-density polyethylene films
Authors: Markovičová L , Zatkalíková V , Kojnoková T , Gaňa D , Liptáková T
Published: January 2020

Polyethylene (PE) is the most commonly used polymer. Most of the polymers are processed by the packaging sector. PE products are the most recycled plastic due to the short life of packaging materials. The experiment is based on real issues in the recycling of plastic waste in a world that is increasingly up to date. One way of recycling it is to produce returnable plastic bottles that can be used up to 50 times. The low-density polyethylene (LDPE) film is applied to the plastic bottles before filling with a specific medium. After the contents of the bottle have been consumed, the LDPE film is stripped. Subsequently, a new recyclable film is applied to the bottles used and the process is repeated. Changes in the properties of LDPE films applied to these returnable bottles have been evaluated by several tests (tensile test and water absorption test). The tests were performed on unused LDPE films and on used LDPE films, which were filled with the medium for 3 months. The fill media was chosen from commonly available goods.
Susceptibility to the intergranular attack in austenitic stainless steels
Authors: Zatkalíková V , Markovičová L , Uhríčik M , Hanusová P
Published: January 2020

Intergranular corrosion is very dangerous local corrosion form that often leads to the dislodgment of individual grains and to the intensive negative influence on the mechanical properties of the material. The susceptibility of the austenitic stainless steels to the intergranular corrosion is connected with their exposition in the temperature range of 500-800 °C (“critical temperatures”) and with consequent slow cooling in the air which leads to the precipitation of chromium-rich carbides at the grain boundaries. This process consumes chromium from a narrow band along the grain boundaries and the steel becomes to be sensitized and susceptible to the intergranular corrosion in aggressive environments. This article deals with the susceptibility to the intergranular corrosion of three austenitic stainless steels (AISI 304, 316L, 316Ti). Both “as received” and improperly heat treated specimens (sensitization for 10 hours at 650 °C, cooling in the air) were tested by ASTM A262 standard method, A and E practices. Optical microscopy and SEM analysis were used for the assessment of the obtained results.
Structural characteristics of NiTi alloys after thermal treatment
Authors: Drápala J , Losertová M , Štencek M , Konečná K , Matýsek D , Sevostyanov M A
Published: January 2020

The study of the effect of thermal treatment conditions on NiTi alloy used in biomedicine was carried out. The experimental samples of NiTi alloy with 55.8 wt% Ni were subjected to the heat treatment. The thermal regimes consisted of aging treatment at 300, 350 and 400 °C for 30 minutes followed by air cooling. The microstructures before and after the heat treatment were observed by optical microscopy. The study was completed by the microhardness measurement and XRD analysis. The obtained results show that the aging temperatures led to microstructural and microhardness changes for the investigated alloy.
Algorithm for J-Integral Measurements by Digital Image Correlation
Authors: Titkov V V , Eremin A V , Panin S V , Lyubutin P S , Kozulin A A
Published: January 2020

The work is devoted to the testing of the algorithm for calculating J-integral based on the construction of vector fields by digital image correlation (DIC) method. A comparative analysis of J-integral values calculated using DIC and instrumental data obtained in accordance with ASTM E 1820 “Standard Test Method for Measurement of Fracture Toughness” has made. It is shown that this approach can be used for cases when the standard technique for measuring the J-integral cannot be applied, or the standard technique does not allow achieving the required accuracy for the integral determination in local areas of the loaded material.
Research of the Materials and Reinforcement Schemes Effects on a Mechanical Behavior Smart Structure with Embedded Piezo Actuators
Authors: Anoshkin A N , Pisarev P V , Ashikhmin V A
Published: January 2020

The present work is devoted to the research of a helicopter blade segment stress-strain state. The segment was made of polymer composite materials with embedded piezoelectric actuators. The computational model of the blade segment takes into account the technological order of laying and the anisotropy of the reinforcing layers properties. The reinforcement schemes under consideration were [0°/90°], [45°/-45°], [0°/45°/-45°/90°]. The static strength margin was estimated using the criterion of maximum stresses. A layered analysis of the structure stress-strain state was carried out. It was shown that the most dangerous, determining the structure margin of safety, are normal interlayer stresses. It was found that the GFRP material and the structural reinforcement scheme [0°/90°], selected during the design, provide the greatest torsion angles.
Friction Induced Structural Changes of Mangalloy Observed by Synchrotron X-Ray Diffraction and Metallographic Analysis
Authors: Emurlaev K I , Ruktuev A. A. , Karmanova A E , Burov V G , Nikulina A A , Bataev I A
Published: January 2020

The effect of friction impact on structure and properties of mangalloy (Hadfield steel) was investigated. By means of metallographic analysis coupled with synchrotron X-ray diffraction in operando regime, the microstructural changes in specimen’ subsurface layer during pin-on-disk experiment were studied. Analysis of phase composition showed that formation of martensite side by side with austenite has a cyclic behavior. Besides, it was shown that overall hardening is associated with a set of structural transformations. Finally, the failure of surface layer was observed.
Research Methodology of Amplitude-Frequency Characteristics of Dental (Endodontic) Files
Authors: Avilov A V , Laktionov E V
Published: January 2020

Deformation and fracture of rotating nickel-titanium endodontic files is considered to be a serious problem among dentists. Therefore, the study of the causes of microcracks, the study of the stress-strain state of endodontic files, the development of methods for monitoring their performance are an urgent problem for dentistry. The purpose of this article is to describe the method of detection of functional endodontic files, based on the determination of their amplitude-frequency characteristics. A block diagram of the measuring complex for the study of free oscillations of endodontic files is proposed. The results of experimental studies are presented.
Van der Waals hetero-structures of 1H-MoS2and N-substituted graphene for catalysis of hydrogen evolution reaction
Authors: Dheer Lakshay , Bhattacharjee Satadeep , Lee Seung Cheol , Waghmare Umesh V
Published: January 2020

First-principles theoretical analysis of the catalytic activity of van der Waals hetero-structures of 1H-MoS2and graphene substituted with three chemical types of nitrogen species (i) Graphitic (G), (ii) Pyridinic (Pn) and (iii) Pyrrolic (Pr), for application in catalysis of hydrogen evolution reaction (HER) has been presented. Graphitic and pyrrolic N substituents result in n-type electronic structure, whereas substitution of pyridinic N imparts p-type electronic character to the hetero-structure. Work functions (φ) of the hetero-structures suggest that graphitic N-graphene:MoS2hetero-structure (φ=3.8eV) is expected to be effective in catalysing the reduction of H+to evolve H2. 1H-MoS2monolayer in the hetero-structure contributes by enabling increased H2O adsorption and offsetting the band edge energies optimal for the catalytic activity. Near optimum Gibbs free energy of H-adsorption (ΔGH) were obtained for graphitic (ΔGH ∼ 0.29 eV) and pyrrolic (ΔGH ∼ −0.2 eV) N-graphene:MoS2hetero-structures. Our work showcases how catalytic and electronic properties of the N-doped graphene:MoS2hetero-structure depends on the chemical identity of N-sites and uncovers a route to 2D hetero-structures with high catalytic activity.
Breathalyser-Based eHealth Data Suggest That Self-Reporting of Abstinence Is a Poor Outcome Measure for Alcohol Use Disorder Clinical Trials
Authors: Hämäläinen Markku D , Zetterström Andreas , Winkvist Maria , Söderquist Marcus , Öhagen Patrik , Andersson Karl , Nyberg Fred
Published: January 2020

Aims

To evaluate the efficacy and monitoring capabilities of a breathalyser-based eHealth system for patients with alcohol use disorder (AUD) and to investigate the quality and validity of timeline follow-back (TLFB) as outcome measure in clinical trials and treatment.

Methods

Patients (n = 115) were recruited to clinical trials from a 12-step aftercare programme (12S-ABS) and from hospital care with abstinence (HC-ABS) or controlled drinking (HC-CDR) as goal and randomly divided into an eHealth and a control group. The effect of the eHealth system was analysed with TLFB-derived primary outcomes—change in number of abstinent days (AbsDay) and heavy drinking days (HDDs) compared to baseline—and phosphatidyl ethanol (PEth) measurements. Validity and quality of TLFB were evaluated by comparison with breath alcohol content (BrAC) and eHealth digital biomarkers (DBs): Addiction Monitoring Index (AMI) and Maximum Time Between Tests (MTBT). TLFB reports were compared to eHealth data regarding reported abstinence.

Results

The primary outcome (TLFB) showed no significant difference between eHealth and control groups, but PEth did show a significant difference especially at months 2 and 3. Self-reported daily abstinence suffered from severe quality issues: of the 28-day TLFB reports showing full abstinence eHealth data falsified 34% (BrAC measurements), 39% (MTBT), 54% (AMI) and 68% (BrAC/MTBT/AMI). 12S-ABS and HC-ABS patients showed severe under-reporting.

Conclusions

No effect of the eHealth system was measured with TLFB, but a small positive effect was measured with PEth. The eHealth system revealed severe quality problems with TLFB, especially regarding abstinence—should measurement-based eHealth data replace TLFB as outcome measure for AUD?
The Use of Eye Tracking Technology in Aesthetic Surgery: Analyzing Changes in Facial Attention Following Surgery
Authors: Frautschi Russell S , Dawlagala Nadeera , Klingemier Eric W , England Hannah S , Sinclair Nicholas R , Zins James E
Published: January 2020

Background

The ability to quantitatively analyze how we look at a face and determine if this changes following facial surgery should be of interest to the plastic surgeon. Eye tracking technology (ETT) provides the ability to record where observers fixate when viewing a facial image, enabling quantitative data to be obtained comparing pre- and postoperative changes.

Objectives

The authors sought to investigate ETT as a novel outcome assessment tool, determining if facial rejuvenation surgery shifts attention away from the prominent signs of aging, and if so, where this attention shifts.

Methods

Twenty-five volunteers viewed 32 randomized frontal, oblique, and lateral images of 11 patients pre- and post-facelift. An eye movement monitoring system recorded the observer’s eye position, net dwell time, fixation count, fixation time, and revisits into predefined areas of interest. Data were grouped and analyzed by angle and areas of interest. Paired t tests were employed to detect significant differences in pre- and post-images.

Results

On frontal images, less dwell time, fixations, and revisits were noted on the bottom third, forehead, perioral region, and neck (P < 0.05). On the lateral view, less visual attention was given to the neck, upper third, and perioral region, with more time in the cheek, nose, and middle third (P < 0.05). On oblique images, less attention was given to the neck and upper lid with more aimed at the middle third of the face (P < 0.05).

Conclusions

ETT provides quantitative data post-facial rejuvenation. Facial aesthetic surgery does alter where observers look when viewing a face, decreasing the time spent inspecting the prominent signs of aging.
iPAC: a genome-guided assembler of isoforms via phasing and combing paths
Authors: Yu Ting , Liu Juntao , Gao Xin , Li Guojun
Published: January 2020

Motivation

Full-length transcript reconstruction is very important and quite challenging for the widely used RNA-seq data analysis. Currently, available RNA-seq assemblers generally suffered from serious limitations in practical applications, such as low assembly accuracy and incompatibility with latest alignment tools.

Results

We introduce iPAC, a new genome-guided assembler for reconstruction of isoforms, which revolutionizes the usage of paired-end and sequencing depth information via phasing and combing paths over a newly designed phasing graph. Tested on both simulated and real datasets, it is to some extent superior to all the salient assemblers of the same kind. Especially, iPAC is significantly powerful in recovery of lowly expressed transcripts while others are not.

Availability and implementation

iPAC is freely available at http://sourceforge.net/projects/transassembly/files.

Supplementary information

Supplementary data are available at Bioinformatics online.
Integrative analysis of cross-modal features for the prognosis prediction of clear cell renal cell carcinoma
Authors: Ning Zhenyuan , Pan Weihao , Chen Yuting , Xiao Qing , Zhang Xinsen , Luo Jiaxiu , Wang Jian , Zhang Yu
Published: January 2020

Motivation

As a highly heterogeneous disease, clear cell renal cell carcinoma (ccRCC) has quite variable clinical behaviors. The prognostic biomarkers play a crucial role in stratifying patients suffering from ccRCC to avoid over- and under-treatment. Researches based on hand-crafted features and single-modal data have been widely conducted to predict the prognosis of ccRCC. However, these experience-dependent methods, neglecting the synergy among multimodal data, have limited capacity to perform accurate prediction. Inspired by complementary information among multimodal data and the successful application of convolutional neural networks (CNNs) in medical image analysis, a novel framework was proposed to improve prediction performance.

Results

We proposed a cross-modal feature-based integrative framework, in which deep features extracted from computed tomography/histopathological images by using CNNs were combined with eigengenes generated from functional genomic data, to construct a prognostic model for ccRCC. Results showed that our proposed model can stratify high- and low-risk subgroups with significant difference (P-value < 0.05) and outperform the predictive performance of those models based on single-modality features in the independent testing cohort [C-index, 0.808 (0.728–0.888)]. In addition, we also explored the relationship between deep image features and eigengenes, and make an attempt to explain deep image features from the view of genomic data. Notably, the integrative framework is available to the task of prognosis prediction of other cancer with matched multimodal data.

Availability and implementation

https://github.com/zhang-de-lab/zhang-lab? from=singlemessage

Supplementary information

Supplementary data are available at Bioinformatics online.
Electronic Correction of Values That Are "Off-Scale" in the "SMA-6" System for Continuous-flow Analysis
Authors: Rosenfeld Louis
Published: January 2020

Data are presented for an electronic device that automatically halves "off-scale" signal voltages on the "SMA Flex-6" System (Technicon). This extends the usefulness of the system by obviating the need for most repeat analyses on dilutions of specimens containing constituents in concentrations that exceed the limits of the pre-calibrated chart paper. Accurate results are obtained because the chemical reactions are shown to be linear up to nearly twice the maximum calibration on the recorder paper for the following analytes: bilirubin, total and direct (20.0 mg/dl); alkaline phosphatase (700 U/ liter); lactate dehydrogenase (1200 U/liter); creatine kinase (2400 U/liter); and aspartate aminotransferase (600 U/liter). In contrast, dilution of sera 2-, 5-, and 10-fold with sodium chloride solution (8.5 g/liter) produces positive errors ranging from 6 to 38% for these enzymes, but has no significant effect on bilirubin.
Radioimmunoassay of Drugs Subject to Abuse: Critical Evaluation of Urinary Morphine—Barbiturate, Morphine, Barbiturate, and Amphetamine Assays
Authors: Mulé Salvatore J , Whitlock Eileen , Jukofsky Dennis
Published: January 2020

Radioimmunoassays for morphine—barbiturate (MOR-BARB), morphine, barbiturate, and amphetamine were evaluated by a direct comparison with differential elution extraction thin-layer chromatography, the "enzyme multiplied immunoassay technique," and XAD-2 resin extraction thin-layer chromatography for the detection in urine of drugs subject to abuse. Statistically significant (P < 0.01) concentrations for detection were: 50-100 µg/liter for MOR-BARB; 5 µg/liter for morphine, 10 µg/liter for barbiturate, and 500 µg/liter for amphetamine. Unconfirmed and unaccounted-for radioimmunoassay positives (false) were: 0% for morphine in the radioimmunoassay for MOR-BARB and that for morphine alone; 2.8% for barbiturates in the MOR-BARB assay and that for barbiturates alone; 0-6% when a combination of these drugs was present in the MOR-BARB, morphine, or barbiturate assay; and 2.4% in the amphetamine radioimmunoassay. Less than 1% of all radioimmunoassay-negative samples were unconfirmed (false). Cross-reactivity was observed with drugs of a similar chemical structure in each of the radioimmunoassays tested. All the radioimmunoassays were easy to use, highly sensitive, and extremely reliable for detecting drug use or abuse.
Determination of Phosphodiesterase I Activity in Human Blood Serum
Authors: Hynie Ivo , Meuffels Mary , Poznanski Wojciech Janusz
Published: January 2020

Phosphodiesterase I (EC 3.1.4.1) activity was detected in normal human blood serum. The enzyme is stable at laboratory temperature for three days, but is inactivated at pH <7. The pH for optimum activity increases with the substrate concentration (under the conditions used, from pH 9.0 to 10.2) and, conversely, the Km increases with pH and buffer concentration. The enzyme is inhibited by ethylenediaminetetraacetate but not by phosphate (0.1 mol/liter). We developed a simple quantitative method for its determination, based on hydrolysis of the p-nitrophenyl ester of thymidine 5'-monophosphate and subsequent measurement of the liberated p-nitrophenol at 400 nm in NaOH (0.1 mol/liter). Normal values (mean ± 2 SD) were determined to be 33 ± 6.4 U/liter. Preliminary studies indicate that phosphodiesterase I activity is greater than normal in serum of patients with necrotic changes in the liver or kidney or in cases of breast cancer, but not in that of patients with myocardial infarction, bone cancer, lung cancer, or chronic liver cirrhosis.
Influence of Age, Sex, and Oral Contraceptives on Human Blood Cholinesterase Activity
Authors: Sidell Frederick R , Kaminskis Andris
Published: January 2020

We estimated cholinesterase (EC 3.1.1.8) activities in erthrocytes and plasma of 443 men, 188 women not taking oral contraceptives, and 70 women who were taking oral contraceptives. Men in the first six decades of life had higher plasma cholinesterase activity than did women who were not taking oral contraceptives, and these women had higher plasma cholinesterase activity than women taking oral contraceptives. After the age of 60 there was no intersex difference. Activity of erythrocytes from the oral contraceptive group was higher than in the other groups, men had the lowest activity, and there was an increased activity with age in both sexes until the age of 60. These findings suggest that there is no single "normal" value for cholinesterase activity for adults.
Trend Detection in Control Data: Optimization and Interpretation of Trigg's Technique for Trend Analysis
Authors: Cembrowski George S , Westgard James O , Eggert Arthur A , Toren E Clifford
Published: January 2020

A method for trend detection, Trigg's technique [Oper. Res. Q. 15, 271 (1964)], has been investigated for use in monitoring trends in control data produced by multitest continuous-flow analyzers. Simulated trend data were used to optimize the method. Actual control data were analyzed retrospectively to determine the frequency of trends and the accuracy of several parameters obtained from Trigg's method. The prospective use of the technique has successfully uncovered important trends. Criteria for the interpretation of the Trigg's trend data are suggested and an algorithm for the computer implementation of Trigg’s calculations is included.
Erythrocyte 2,3-Diphosphoglycerate as Related to Diabetes and Obesity
Authors: Kalofoutis Anastasios , Jullien Gérard , Koutselinis Antonios , Miras Constantinos
Published: January 2020

2,3-Diphosphoglycerate was determined in the erythrocytes of 17 diabetic and 18 obese patients. Results for obese subjects were significantly (P < .01) different from those obtained for 21 healthy subjects. Results for obese and diabetic patients also differed significantly (P < .01), but not those for diabetic and healthy subjects. Hemoglobin, hematocrit, or bicarbonate measurements did not differ among the three groups.
New System for Automated Extraction and Simultaneous Determination of Serum Cholesterol and Triglycerides
Authors: Wease Dorothy F , Espinosa Eli S , Anderson Yvonne J
Published: January 2020

We describe an automated system for serum lipid extraction and simultaneous determination of cholesterol and triglycerides, with use of continuous-flow equipment. A sample volume of 100 µl of serum is required, and samples are processed at the rate of 20 per hour, which may be increased with slight loss in precision. Time from sample pickup to recorder readout is about 25 min. The system makes use of established colorimetric reactions, and the values obtained agree with ranges currently reported in the literature. Correlation coefficients for results of the automated and manual methods were 0.98 for cholesterol and 0.99 for triglycerides, and the day-to-day coefficients of variation were 1.8% for cholesterol (1 SD = 34 mg/liter) and 3.4% for triglycerides (1 SD = 37 mg/liter). The small sample volume, precision, accuracy, speed, and comparative economy of reagents make this system particularly suitable for multiphasic screening, pediatrics, and small-animal research.
Some Theory of Reference Values. I. Stratified (Categorized) Normal Ranges and a Method for Following an Individual's Clinical Laboratory Values
Authors: Harris Eugene K
Published: January 2020

The conventional population-based normal range has recently been shown to be a generally defective reference criterion for assessing individual laboratory test results. Applying a previously derived formula to published data, we find that the use of age-, sex-specific normal ranges may fail to produce a substantial improvement in sensitivity over nonspecific ranges, even when age-sex differences in mean values are statistically significant. This occurs when the difference in means is not accompanied by a sufficient reduction in the variation among individuals within a given class. Turning therefore to comparison of an individual's current measurement with his own previous value(s), I suggest a simple statistical model that leads to sequential testing of each new observation against an exponentially weighted moving average of previous results. Estimates of biological and analytical components of variance are required. The ability of this method to detect trends in very short series is explored with the aid of computer-simulated laboratory data. A sample of these data is also used to illustrate the application of these estimation and testing procedures by means of a graph.
Automated Immunochemical Method for Determination of Urinary Protein of Plasma Origin
Authors: Killingsworth Lawrence M , Britain Carol E , Woodard Linda L
Published: January 2020

An automated continuous-flow procedure has been developed for the rapid determination of urinary proteins of plasma origin. Antiserum to whole human plasma was used as the reagent, and the antigen—antibody reactions were quantitated by nephelometry. By adding polyethylene glycol (mol wt 6000-7500) to the reaction medium, reaction time was decreased to <3 min; no sample blanks were required; and samples were analyzed at a rate of 70 per hour. Recovery studies yielded an average of 98.5% of the added protein. In-run replicate precision (CV) of the method was 1.45%; day-to-day precision was 2.58%.
Lack of Significant Effect of L(+)-Glutamate on Serum γ-GlutamyItransferase Activity Determined in the Presence of Glycylglycine
Authors: Gerhardt Willie , Persijn Paul , Rosalki Sidney B
Published: January 2020

No increase in γ-glutamyltransferase activity determined in human sera at 25, 30, or 37 °C could be demonstrated when L(+)-glutamate, 10 to 5000 mol/liter, was incorporated into reaction media containing glycylglycine, 40 mmol/liter.
Indirect Assessment of Hydroxymethylglutaryl-CoA Reductase (NADPH) Activity in Liver Tissue
Authors: Rao A Venugopala , Ramakrishnan S
Published: January 2020

We describe an indirect method for assessing variation in 3-hydroxy-3-methylglutaryl-coenzyme A reductase (NADPH) activity in liver tissue. 3-Hydroxy-3-methylglutaryl-CoA and mevalonate concentrations in the tissue homogenate are estimated in terms of absorbances and the ratio between the two is taken as an index of activity of the enzyme, which catalyzes the conversion of 3-hydroxy-3-methylglutaryl-CoA to mevalonate. The ratio increases under conditions in which activity of this enzyme in liver reportedly decreases (e.g., fasting, cholesterol feeding) and decreases under conditions in which the activity of this enzyme reportedly increases (e.g., Triton injection, phenobarbital treatment). We assessed the magnitude of hepatic cholesterogenesis in intact male albino rats by using [1,2-14C] acetate, in fed controls, fasted, cholesterol-fed, Triton-treated, and phenobarbital-treated. The ratio, 3-hydroxy-3-methylglutarylCoA/mevalonate was estimated in liver tissue for all the above groups. The method is simple, reproducible, and does not require any unusual chemicals.
Single-Channel AutoAnalyzer Adapted for Multiple Tests without Manifold Changes
Authors: Shihabi Z K
Published: January 2020

A different approach to continuous-flow analysis is described, in which the initial reagent concentration is adjusted to fit a prefixed manifold while still providing optimum concentrations of the reactants in the mixing coils. A single-channel AutoAnalyzer so designed can perform multiple tests without the need to change manifolds. The system was assembled from a Technicon Sampler II and Pump II, a Gilford 300 N spectrophotometer, and a Varian recorder. Results for calcium, uric acid, glucose, phosphorus, chloride, urea nitrogen, and carbon dioxide, analyzed on this instrument at a speed of 60 samples/ h, compare favorably with those obtained with the AutoAnalyzer 12/60 and 6/60. The instrument is not restricted to certain methodologies and, in addition, can be used manually or for kinetic reactions
Chromatographic and Electrophoretic Separation of Creatine Kinase Isoenzymes Compared
Authors: Lum Gifford , Levy Arthur L
Published: January 2020

We compared two techniques for separating and evaluating serum creatine kinase isoenzymes—fluorometric agarose electrophoresis and Sephadex chromatography—in 50 patients, 25 of whom had confirmed acute myocardial infarction. In every case isoenzyme MB (heart isoenzyme) was detected with equal sensitivity by either procedure. Evidently, only the presence or absence of MB is clinically significant; none of the 25 patients without infarction had detectable MB activity in their serum. Columns connected to a continuous-flow sample line for analyses of the eluting stream without further modification produced satisfactory results
New Manual and Automated Method for Determining Activity of Creatine Kinase Isoenzyme MB, by Use of Dithiothreitol: Clinical Applications
Authors: Rao Parinam S , Lukes James J , Ayres Stephen M , Mueller Hiltrud
Published: January 2020

The method is based on the selective activating capacity of dithiothreitol on creatine kinase isoenzyme MB, after isoenzyme MM is activated by glutathione. Isolated isoenzymes MM and MB of human and canine origin were assayed individually and in mixtures of known activities. When glutathione was present in the assay medium the activity of each isoenzyme could be measured individually, but glutathione did not activate isoenzyme MB if it was present in a mixture with MM. Dithiothreitol, added to the serum before assay, activated the isoenzyme MB in the mixture. Values for MB activities obtained for isolated isoenzyme MB and for the isoenzyme mixture after dithiothreitol was added averaged 110 and 111 U/liter, respectively (r = 0.998; y = 1.007x + 0.298; n = 10). In the serum of 40 patients with documented acute transmural myocardial infarction, the mean proportion of isoenzyme MB activity measured in this way was 5.5% (coefficient of variation, 7.7%). Isoenzyme MB activities measured by use of dithiothreitol compared well with those obtained by conventional electrophoresis/spectrophotometry (r = 0.998; y = 1.09x -0.65) and spectrofluorometry (r = 0.996; y = 1.10x + 0.80). The assay of MB activity by the dithiothreitol method was automated, by use of an Abbott Bichromatic Analyser and a Calbiochem Super-Stat Pack Kit. In 60 isoenzyme MB determinations the manual and automated method correlated well (r = 0.990; y = 1.0x -1.36). The simplicity of isoenzyme MB determination by use of dithiothreitol and its ease of automation allow routine monitoring of the isoenzyme activity in patients with ischemic heart disease
Patients as Their Own Controls: Use of the Computer to Identify "Laboratory Error"
Authors: Ladenson Jack H
Published: January 2020

I describe a system of quality control based on computer detection of changes in individual patient test results. This system, called "delta check," was used to follow all the tests performed by the clinical chemistry laboratory in a 1200-bed hospital. Analysis of 22 months’ experience indicates that specimen misidentification is a serious problem in the clinical chemistry laboratory. Over a nine-month period, errors were most frequent in the results for total thyroxine, total calcium, and total protein. Instances of laboratory error detectable by the delta check system are not detected by other currently used methods of quality control. This system therefore appears to be a valuable asset to the clinical laboratory
Factors Affecting Assay of Myoglobin by Complement Fixation or Immunodiffusion
Authors: Olerud John E , Clark Donald L
Published: January 2020

Quantitative micro-scale complement-fixation and semiquantitative gel immunodiffusion assays for myoglobin have been evaluated experimentally and used to measure myoglobin in the sera of more than 1500 patients. We report certain problems, observations, and methodological improvements. Serum caused enhancement of precipitin lines in the immunodiffusion assay. In the complement-fixation assay, serum interfered both by enhancing or inhibiting complement fixation. Suggested modifications in the complement-fixation assay are: (a) routine threefold or greater dilution of serum with buffer and (b) use of serum-based rather than buffer-based calibration materials in preparing standard curves. Three cycles of freeze-thaw of serum or buffer decreased detectable myoglobin by 50-100%. We conclude that certain serum-related factors and freezethaw phenomena are important causes of error in immunological assays for myoglobin
Plasma Theophylline Concentrations Measured by High-Pressure Liquid Chromatography
Authors: Sitar Daniel S , Piafsky Kenneth M , Rangno Robert E , Ogilvie Richard I
Published: January 2020

We present a specific, sensitive high-pressure liquidchromatographic assay for theophylline in plasma. Only 0.5 ml of plasma is required for each determination, and the lower limit of detection by this method is 0.1 mg/ liter. Other xanthines and their metabolites do not interfere. This method is suitable for use in studying the pharmacokinetics of this drug in infants and children, from whom only small volumes of blood are available.
Fluorometric Method for Measuring Serum Lipase Activity
Authors: Rietz Bernd , Guilbault George G
Published: January 2020

We describe a method for determining lipase (triacylglycerol acyl-hydrolase, EC 3.1.1.3) activity in serum. Emulsified olive oil in tris(hydroxymethyl)aminomethane buffer is used as substrate. The course of the enzymatic reaction is followed by measuring the decrease in fluorescence with time of a fluorescent indicator, 4-methylumbelliferone, added to the substrate, caused by the change in the pH of the substrate solution resulting from the reaction. All measurements are performed at 37 °C. The reaction volume is about 2.3 ml, in a Pyrex cuvette. Change of fluorescence and of enzyme activity are linearly related in the range of 77.8 to 389.0 U/liter. An assay can be done in as little as 3 to 5 min, with excellent precision.
Screening for Drug Abuse: Use of NaCl to Increase Drug Recovery from Papers Coated with Ion-Exchange Resin
Authors: Alexander George J
Published: January 2020

Use of papers loaded with ion-exchange resins to adsorb drugs from urine specimens resulted in large losses during the procedure. The first step, removal of drugs from urine specimens, was 25-85% efficient. The second step, elution of drugs from paper for further processing, was approximately 40-70% complete. The efficiency of the first step was decreased and the efficiency of the second step was increased by addition of NaCl, except in the case of barbiturates. Presence of salt during elution increased the yield of dihydromorphine by 20%, of methadone by 16%, of amphetamine by 34%, and of chlorpromazine by 40%, but did not enhance the yield of pentobarbital. Overall recovery rates were: 51% for the opiates, 57% for methadone, 72% for a phenothiazine tranquillizer, but only 35% for amphetamine and 15% for a barbiturate.
Separation of Synthetic Mixtures of Sugars and of Sugars in Body Fluids with a High-Resolution Carbohydrate Analyzer
Authors: Voelter Wolfgang , Bauer Hermann
Published: January 2020

With use of a specially designed gradient-generating system, of anion-exchange resins of 10-20 µm particle diameter, and of an orcinol solution in concentrated sulfuric acid (1 g/liter) as detection reagent, a mixture of 16 carbohydrates can be separated in less than 4 h. The limit of detection for most sugars is in the 0.1-2.0 nanomole range. The detection reagent is stable for months and does not become colored. The reagent mixes with the column effluent in an exothermic reaction and allows use of relatively short mixing coils. The analyzer is appropriate for investigating body fluids rapidly and with high sensitivity.
Relative Efficacy of Separation of "Free" and "Bound" [3',5'-3H]Pteroylglutamate by Charcoal Coated with Various Materials
Authors: Zettner Alfred , Duly Peggy E
Published: January 2020

We studied the effectiveness with which various charcoal preparations separate free [3H]pteroylglutamate from that complexed with milk folate binder. We tested, in various concentrations, uncoated charcoals and charcoals coated with dextrans of various molecular weights, or with albumin, hemoglobin, or polyvinylpyrrolidone with an average molecular weight of 40 000. Although there was some distinction between the "bound" and "free" fractions with all charcoals, those treated with dextrans of average molecular weights of 43 500 or 70 000, or with polyvinylpyrrolidone gave the best separation over a greater range of charcoal concentration. Uncoated charcoal and charcoals coated with albumin, hemoglobin, or dextran T10 (average molecular weight, 10 500) were least effective.
Temporal Intrapersonal Physiological Variability of Cholinesterase Activity in Human Plasma and Erythrocytes
Authors: Sidell Frederick R , Kaminskis Andris
Published: January 2020

Erythrocyte and plasma cholinesterase activities were measured biweekly in one group of 22 subjects for a year and daily for three weeks in another group of nine men. The average range [i. e., (range/mean) x 100] of activity of erythrocyte cholinesterase in men during a year was 8% and during three weeks was 5%. For plasma, the corresponding values were 25% and 12%. The average ranges for erythrocyte and plasma cholinesterase activity in women during a year were 12% and 24%. Erythrocyte cholinesterase activity varies less than do hematocrit, hemoglobin, or erythrocyte count.
Comparison of Methods for Calculating Serum Osmolality from Chemical Concentrations, and the Prognostic Value of Such Calculations
Authors: Dorwart William V , Chalmers Leslie
Published: January 2020

Sodium, potassium, glucose, blood urea nitrogen, and osmolality were determined for 715 hospital-patient sera. The chemical concentrations were used to calculate osmolalities according to 13 different methods taken from the literature. The goodness of the comparison between calculated and measured osmolality was quite similar for several of the better methods. The agreement was unimproved when molal chemical concentrations were used instead of molar values. The difference between measured and calculated osmolality was unrelated to whether a patient was discharged from the hospital after a short or long period or ultimately died. The equation we found to yield the most accurately calculated osmolalities is