scholarly journals Graphic analysis of relaxation times of enzyme-catalysed reactions. An extension of the graphic method of King and Altman

1992 ◽  
Vol 287 (2) ◽  
pp. 391-393 ◽  
Author(s):  
M Zhao
Keyword(s):  
Relaxation Times ◽  
Graphic Method ◽  
Clear Cut ◽  
Graphic Analysis ◽  
Mathematical Operations ◽  
Easy Operation

An extension of the graphic method of King & Altman (1956) (J. Phys. Chem. 60, 1375-1378) is applied to the analysis of relaxation times of enzyme-catalysed reactions and a simple graphic method is presented. Clear-cut graphs, simple drawing, easy operation (without the need to perform the usual complex mathematical operations), and reliable results are the main characteristics of this kind of graphic method. A system of enzyme-catalysed reactions (E <--> ES <--> EP) is used as the actual example for illustrating the graphic method.

An emerging technology: Nuclear magnetic resonance microscopy

1988 ◽  
Vol 46 ◽  
pp. 1000-1001
Author(s):  
M.J. Hennessy ◽  
E. Kwok
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Relaxation Times ◽  
Basic Research ◽  
Local Environment ◽  
Magnetic Resonance Images ◽  
Nmr Microscopy ◽  
Mri Scans ◽  
Temperature Relaxation ◽  
Nuclear Magnetic

Much progress in nuclear magnetic resonance microscope has been made in the last few years as a result of improved instrumentation and techniques being made available through basic research in magnetic resonance imaging (MRI) technologies for medicine. Nuclear magnetic resonance (NMR) was first observed in the hydrogen nucleus in water by Bloch, Purcell and Pound over 40 years ago. Today, in medicine, virtually all commercial MRI scans are made of water bound in tissue. This is also true for NMR microscopy, which has focussed mainly on biological applications. The reason water is the favored molecule for NMR is because water is,the most abundant molecule in biology. It is also the most NMR sensitive having the largest nuclear magnetic moment and having reasonable room temperature relaxation times (from 10 ms to 3 sec). The contrast seen in magnetic resonance images is due mostly to distribution of water relaxation times in sample which are extremely sensitive to the local environment.

Shoulder Pain at Work: Causation Analysis

2017 ◽  
Vol 22 (1) ◽  
pp. 11-16
Author(s):  
Joel Weddington ◽  
Charles N. Brooks ◽  
Mark Melhorn ◽  
Christopher R. Brigham
Keyword(s):  
Epidemiological Data ◽  
Case Law ◽  
Individual Case ◽  
Shoulder Injury ◽  
Work Related ◽  
Clear Cut ◽  
The Individual ◽  
Causation Analysis ◽  
Injury Causation ◽  
Relevant Factors

Abstract In most cases of shoulder injury at work, causation analysis is not clear-cut and requires detailed, thoughtful, and time-consuming causation analysis; traditionally, physicians have approached this in a cursory manner, often presenting their findings as an opinion. An established method of causation analysis using six steps is outlined in the American College of Occupational and Environmental Medicine Guidelines and in the AMA Guides to the Evaluation of Disease and Injury Causation, Second Edition, as follows: 1) collect evidence of disease; 2) collect epidemiological data; 3) collect evidence of exposure; 4) collect other relevant factors; 5) evaluate the validity of the evidence; and 6) write a report with evaluation and conclusions. Evaluators also should recognize that thresholds for causation vary by state and are based on specific statutes or case law. Three cases illustrate evidence-based causation analysis using the six steps and illustrate how examiners can form well-founded opinions about whether a given condition is work related, nonoccupational, or some combination of these. An evaluator's causal conclusions should be rational, should be consistent with the facts of the individual case and medical literature, and should cite pertinent references. The opinion should be stated “to a reasonable degree of medical probability,” on a “more-probable-than-not” basis, or using a suitable phrase that meets the legal threshold in the applicable jurisdiction.

Time-resolved, contrast-enhanced 3D MR angiography in the subclavian steal effect

VASA ◽  
2010 ◽  
Vol 39 (1) ◽  
pp. 85-93 ◽  
Author(s):  
Schubert
Keyword(s):  
Mr Angiography ◽  
Time Resolved ◽  
Time To Peak ◽  
Vertebral Arteries ◽  
Subclavian Steal ◽  
Cerebrovascular Events ◽  
Graphic Analysis ◽  
Contrast Enhanced ◽  
Hemodynamic Information ◽  
Supraaortic Vessels

The subclavian steal effect indicates atherosclerotic disease of the supraaortic vessels but rarely causes cerebrovascular events in itself. Noninvasive imaging providing detailed anatomic as well as hemodynamic information would therefore be desirable. From a group of 25 consecutive patients referred for MR angiography, four with absent or highly attenuated signal in one of the vertebral arteries on 3D multislab time-of-flight MR angiography were selected to undergo 3D time-resolved contrast-enhanced MR angiography. The time-resolved 3D contrast series (source images and MIPs) were evaluated visually and by graphic analysis of time-intensity curves derived from the respective V1 and V3 segments of both vertebral arteries on the source images. In two cases with high-grade proximal left subclavian stenosis, time-resolved 3D ce-MRA was able to visualise retrograde contrast filling of the left VA. There was a marked delay in time-to-peak between the left and right V1 segments in one case and a shallower slope of enhancement in another. In the other two cases, there was complete or collateralised segmental occlusion of the VAs.

PET in patients with clear-cut multiple chemical sensitivity (MCS)

2002 ◽  
Vol 41 (06) ◽  
pp. 233-239 ◽  
Author(s):  
C. Hausteiner ◽  
A. Drzezga ◽  
P. Bartenstein ◽  
M. Schwaiger ◽  
H. Förstl ◽  
...  
Keyword(s):  
Single Photon ◽  
Photon Emission ◽  
Multiple Chemical Sensitivity ◽  
Environmental Chemicals ◽  
Chemical Sensitivity ◽  
Clear Cut ◽  
Positron Emission ◽  
Symptom Complex ◽  
Brain Changes ◽  
Multiple Chemical

SummaryAim: Multiple chemical sensitivity (MCS) is a controversially discussed symptom complex. Patients afflicted by MCS react to very low and generally nontoxic concentrations of environmental chemicals. It has been suggested that MCS leads to neurotoxic damage or neuroimmunological alteration in the brain detectable by positron emission tomography (PET) and single photon emission computer tomography (SPECT). These methods are often applied to MCS patients for diagnosis, although they never proved appropriate. Method: We scanned 12 MCS patients with PET, hypothesizing that it would reveal abnormal findings. Results: Mild glucose hypometabolism was present in one patient. In comparison with normal controls, the patient group showed no significant functional brain changes. Conclusion: This first systematic PET study in MCS patients revealed no hint of neurotoxic or neuroimmuno-logical brain changes of functional significance.

Effect of Anabolic Steroids on Plasma Antithrombin III

1975 ◽  
Vol 34 (01) ◽  
pp. 106-114 ◽  
Author(s):  
I. D Walker ◽  
J. F Davidson ◽  
P Young ◽  
J. A Conkie
Keyword(s):  
Heart Disease ◽  
Ischaemic Heart Disease ◽  
Oral Contraceptives ◽  
Disseminated Intravascular Coagulation ◽  
Fibrinolytic Activity ◽  
Antithrombin Iii ◽  
Anabolic Steroids ◽  
Intravascular Coagulation ◽  
Clear Cut ◽  
Α2 Macroglobulin

SummaryThe effect of seven different anabolic steroids (Ethyloestrenol, Methenolone acetate, Norethandrolone, Methylandrostenediol, Oxymetholone, Methandienone, and Stanozolol) on three α-globulin antiprotease inhibitors of thrombin and plasmin was studied in men with ischaemic heart disease. In distinct contrast to the oral contraceptives, five of the six 17-α-alkylated anabolic steroids studied produced increased plasma Antithrombin III levels and five produced decreased levels of plasma α2-macroglobulin. The effect on plasma α1antitrypsin levels was less clear-cut but three of the steroids examined produced significantly elevated levels. The increased plasma fibrinolytic activity which the 17-α-alkylated anabolic steroids induce is therefore unlikely to be secondary to disseminated intravascular coagulation.

Fibrinogen and Factor Vllag in Healthy Adolescents: The Floren-teen (Florence Teenager) Study

1996 ◽  
Vol 75 (05) ◽  
pp. 778-781 ◽  
Author(s):  
Domenico Prisco ◽  
Sandra Fedi ◽  
Tamara Brunelli ◽  
Anna Paola Cellai ◽  
Mohamed Isse Hagi ◽  
...  
Keyword(s):  
Risk Factors ◽  
Blood Pressure ◽  
Healthy Subjects ◽  
Cardiovascular Events ◽  
Independent Risk Factor ◽  
Factor Vii ◽  
Coronary Heart Disease Prevention ◽  
Familial History ◽  
Clear Cut ◽  
Adolescent Population

SummaryAt least five studies based on more than twenty thousand healthy subjects indicated that fibrinogen is an independent risk factor for cardiovascular events; less clear-cut is the relation between factor VII and risk for arterial thrombotic disorders, which was demonstrated in two of the three studies investigating this association. However, no study has investigated the behaviour of fibrinogen and factor VII in an adolescent population. In a study of Preventive Medicine and Education Program, fibrinogen (clotting method) and factor Vllag (ELISA), in addition to other metabolic parameters, life-style and familial history, were investigated in 451 students (313 females and 138 males, age 15-17 years) from two high schools of Florence. Fibrinogen levels were significantly higher in women than in men, whereas factor Vllag levels did not significantly differ. Both fibrinogen and factor Vllag significantly correlated with total cholesterol (p <0.05) while only fibrinogen correlated with body mass index (p <0.01). Factor Vllag was significantly correlated with systolic blood pressure (p <0.001). This study provides information on coagulation risk factors in a population of adolescents which may be of importance in planning coronary heart disease prevention programs.

F.N.A.C. AS DIAGNOSTIC TOOL OF PAROTID TUMORS AND ASSOCIATED PITFALLS IN CORRELATION WITH HISTOPATHOLOGY

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Bhawana Pant ◽  
Sanjay Gaur ◽  
Prabhat Pant
Keyword(s):  
Preoperative Diagnosis ◽  
Histopathological Examination ◽  
Clinical Information ◽  
Final Diagnosis ◽  
Needle Aspiration ◽  
Histopathological Diagnosis ◽  
Cytological Diagnosis ◽  
Tertiary Referral Centre ◽  
Clear Cut ◽  
Parotid Tumors

F.NA.C has been used for ages as a safe and economical tool for fast preoperative diagnosis of parotid tumors. It has certain pitfall which sometimes leads to misdiagnosis and consequently it may have affect on treatment of the tumors. Keeping in view of the diverse classification of parotid tumors’ information from cytology should be combined with radiology as well as clinical diagnosis. Aim: To discuss some cases where there was discrepancy between cytological diagnosis and histopathological result and also suggest measures to improve the efficacy of F.N.A.C. Material and methods: The study includes 50 cases of parotid tumours who presented to the  department of ENT at Government medical college Haldwani which is a tertiary referral centre during 2009 to 2016. Only adult patients were included and inflammatory swelling were excluded from the study. All patients evaluated  Contrast enhanced computerized tomography(CECT) and  Magnetic resonance imaging (MRI) followed by Fine needle aspiration cytology .Preoperative diagnosis was made upon the findings of the above investigations and different types of  parotid surgeries  were done. . Final diagnosis was made on  histopathological  examination. Result :The most common tumour  came out to be pleomorphic adenoma (23 cases-46%) followed by mucoepidermoid carcinoma(12cases-24%). In ten  cases there was no clear cut  association between cytological diagnosis and final histopathological diagnosis. Conclusion: FNAC is highly sensitive and specific technique for diagnosis of many salivary gland swellings. FNAC can be used preoperatively to avoid unnecessary surgery and biopsy. Details of clinical information and radiologic features may help the pathologist to arrive at the appropriate diagnosis and reduce false interpretation. Pitfalls may also occur with improper technique of FNAC which can be overcome by proper caution.

Joseph Sidebotham: vicissitudes of a Victorian collector

2015 ◽  
Vol 42 (2) ◽  
pp. 197-210 ◽  
Author(s):  
Laurence M. Cook
Keyword(s):  
Natural History ◽  
Species Limits ◽  
Clear Cut ◽  
Natural History Collections ◽  
As Species ◽  
Scientific World

Joseph Sidebotham (1824–1885) was a Manchester cotton baron whose natural history collections are now in the Manchester Museum. In addition to collecting he suggested a method for identifying and classifying Lepidoptera and investigated variation within species as well as species limits. With three close collaborators, he is credited with discovering many species new to Britain in both Lepidoptera and Coleoptera. A suspicion of fraud attaches to these claims. The evidence is not clear-cut in the Lepidoptera, but a possible reason is suggested why Sidebotham, as an amateur in the increasingly professional scientific world, might have engaged in deceit.

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