Report on the Bicarbonate Transport Satellite Meeting at the 53rd Annual Meeting of the Canadian Society of Biochemistry, Molecular and Cellular Biology

2011 ◽  
Vol 89 (2) ◽  
pp. 83-84
Author(s):  
Reinhart A.F. Reithmeier ◽  
Joseph R. Casey
Keyword(s):  
Annual Meeting ◽  
Cellular Biology ◽  
Bicarbonate Transport ◽  
Canadian Society ◽  
Electron Crystallography ◽  
Bicarbonate Transporter ◽  
Bicarbonate Transporters ◽  
History Of ◽  
Health And Disease

The Bicarbonate Transport Meeting was held as a satellite meeting of the 53rd Annual Meeting of the Canadian Society of Biochemistry, Molecular and Cellular Biology (CSBMCB): Membrane Proteins in Health and Disease. The meeting covered the modern history of bicarbonate transporter proteins and brought together the major workers in the field. Ron Kopito recounted the story of the first determination of the amino acid sequence for a bicarbonate transporter, AE1/Band 3, 25 years earlier while working with Harvey Lodish at Harvard, while Tomohiro Yamaguchi and Teruhisa Hirai presented up-to-date data on AE1 structure obtained using electron crystallography. The meeting further spanned the spectrum of bicarbonate transporters, with sessions devoted to Cl–/HCO3– exchangers, Na+/HCO3– co-transporters, the link to carbonic anhydrase, and the SLC26 family of bicarbonate transporters expressed broadly in humans, yeast, and bacteria.

Interactions of transmembrane carbonic anhydrase, CAIX, with bicarbonate transporters

2007 ◽  
Vol 293 (2) ◽  
pp. C738-C748 ◽  
Author(s):  
Patricio E. Morgan ◽  
Silvia Pastoreková ◽  
Alan K. Stuart-Tilley ◽  
Seth L. Alper ◽  
Joseph R. Casey
Keyword(s):  
Gastric Mucosa ◽  
Carbonic Anhydrase ◽  
Catalytic Domain ◽  
Hek293 Cells ◽  
Bicarbonate Transport ◽  
Physical Interaction ◽  
Human Gastric Mucosa ◽  
Bicarbonate Transporter ◽  
Bicarbonate Transporters ◽  
Physical Interactions

Association of some plasma membrane bicarbonate transporters with carbonic anhydrase enzymes forms a bicarbonate transport metabolon to facilitate metabolic CO2-HCO3−conversions and coupled HCO3−transport. The transmembrane carbonic anhydrase, CAIX, with its extracellular catalytic site, is highly expressed in parietal and other cells of gastric mucosa, suggesting a role in acid secretion. We examined in transfected HEK293 cells the functional and physical interactions between CAIX and the parietal cell Cl−/HCO3−exchanger AE2 or the putative Cl−/HCO3−exchanger SLC26A7. Coexpression of CAIX increased AE2 transport activity by 28 ± 7% and also activated transport mediated by AE1 and AE3 (32 ± 10 and 37 ± 9%, respectively). In contrast, despite a transport rate comparable to that of AE3, coexpressed CAIX did not alter transport associated with SLC26A7. The CAIX-associated increase of AE2 activity did not result from altered AE2 expression or cell surface processing. CAIX was coimmunoprecipitated with the coexpressed SLC4 polypeptides AE1, AE2, and AE3, but not with SLC26A7. GST pull-down assays with a series of domain-deleted forms of CAIX revealed that the catalytic domain of CAIX mediated interaction with AE2. AE2 and CAIX colocalized in human gastric mucosa, as indicated by coimmunofluorescence. This is the first example of a functional and physical interaction between a bicarbonate transporter and a transmembrane carbonic anhydrase. We conclude that CAIX can bind to some Cl−/HCO3−exchangers to form a bicarbonate transport metabolon.

Bicarbonate transport proteins

2002 ◽  
Vol 80 (5) ◽  
pp. 483-497 ◽  
Author(s):  
Deborah Sterling ◽  
Joseph R Casey
Keyword(s):  
Carbonic Anhydrase ◽  
Sodium Bicarbonate ◽  
Anion Exchange ◽  
Mammalian Cells ◽  
Ph Regulation ◽  
Transport Proteins ◽  
Bicarbonate Transport ◽  
Transport Mechanisms ◽  
Bicarbonate Transporter ◽  
Bicarbonate Transporters

Bicarbonate is not freely permeable to membranes. Yet, bicarbonate must be moved across membranes, as part of CO2 metabolism and to regulate cell pH. Mammalian cells ubiquitously express bicarbonate transport proteins to facilitate the transmembrane bicarbonate flux. These bicarbonate transporters, which function by different transport mechanisms, together catalyse transmembrane bicarbonate movement. Recent advances have allowed the identification of several new bicarbonate transporter genes. Bicarbonate transporters cluster into two separate families: (i) the anion exachanger (AE) family of Cl–/HCO[Formula: see text] exchangers is related in sequence to the NBC family of Na+/HCO[Formula: see text] cotransporters and the Na+-dependent Cl–/HCO[Formula: see text] exchangers and (ii) some members of the SLC26a family of sulfate transporters will also transport bicarbonate but are not related in sequence to the AE/NBC family of transporters. This review summarizes our understanding of the mammalian bicarbonate transporter superfamily.Key words: bicarbonate transport, anion exchange, pH regulation, sodium/bicarbonate co-transport, chloride/bicarborate exchange, carbonic anhydrase.

A Survey of the Publication History of Randomly Selected IADR/AADR Abstracts Presented in 1983 and 1984

1990 ◽  
Vol 69 (8) ◽  
pp. 1453-1455 ◽  
Author(s):  
A.M. Corry
Keyword(s):  
Annual Meeting ◽  
Research Projects ◽  
Review Of The Literature ◽  
Journal Articles ◽  
Dental Research ◽  
Publication History ◽  
History Of ◽  
Major Reference

IADR/AADR abstracts of research projects to be presented at the Annual Meeting are published each year in the Journal of Dental Research. An assumption often made is that the material in these abstracts is subsequently published as journal articles. The validity of this assumption was assessed in this study. Following a review of the literature to establish study criteria, the specific objectives of this study were to determine: (1) the percentage of IADR/AADR abstracts subsequently published as articles, (2) the length of time from abstract to publication, and (3) the amount of discrepancy between abstract and article. Ten percent of the IADR/AADR abstracts from the years 1983 (n = 125) and 1984 (n = 150) were randomly selected and surveyed for their publication history. Major reference sources were checked for determination of whether articles had resulted from the abstracts. Of the 1983-1984 abstracts surveyed, the results indicated that more abstracts were not published (78.5% in 1983/76.0% in 1984) than were published (21.6% in 1983/24.0% in 1984). Of those articles previously published as abstracts, the greatest number (44.4% in 1983/ 47.2% in 1984) were published within ten to 21 months following presentation. The greatest amount of discrepancy between the abstract and the article involved names and numbers of authors, titles, purpose statements, and results/conclusions. In other health disciplines, the percentage of abstracts subsequently published as articles ranged from 31.1% to 53.9%. Since a smaller percentage of the IADR/AADR abstracts surveyed in this study were ultimately published (21.6% to 24%), IADR/AADR should consider various strategies to improve the quality of abstracts and their accessibility.

Enhanced information from biological materials through technological improvements in cryo-electron microscopy

1992 ◽  
Vol 50 (1) ◽  
pp. 788-789
Author(s):  
Marc J.C. de Jong ◽  
Wim M. Busing ◽  
Max T. Otten
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Biological Materials ◽  
Electron Crystallography ◽  
Cryo Electron Microscopy ◽  
Transmission Electron ◽  
The Many ◽  
Technological Improvements ◽  
Beam Damage

Biological materials damage rapidly in the electron beam, limiting the amount of information that can be obtained in the transmission electron microscope. The discovery that observation at cryo temperatures strongly reduces beam damage (in addition to making it unnecessaiy to use chemical fixatives, dehydration agents and stains, which introduce artefacts) has given an important step forward to preserving the ‘live’ situation and makes it possible to study the relation between function, chemical composition and morphology.Among the many cryo-applications, the most challenging is perhaps the determination of the atomic structure. Henderson and co-workers were able to determine the structure of the purple membrane by electron crystallography, providing an understanding of the membrane's working as a proton pump. As far as understood at present, the main stumbling block in achieving high resolution appears to be a random movement of atoms or molecules in the specimen within a fraction of a second after exposure to the electron beam, which destroys the highest-resolution detail sought.

Direct phase determination in electron crystallography: small organic molecules

1992 ◽  
Vol 50 (2) ◽  
pp. 1166-1167
Author(s):  
Douglas L. Dorset
Keyword(s):  
Organic Molecules ◽  
Data Sets ◽  
Temperature Structure ◽  
3D Analysis ◽  
Intensity Data ◽  
Electron Crystallography ◽  
Phase Determination ◽  
Measured Intensity ◽  
3D Data

The quantitative use of electron diffraction intensity data for the determination of crystal structures represents the pioneering achievement in the electron crystallography of organic molecules, an effort largely begun by B. K. Vainshtein and his co-workers. However, despite numerous representative structure analyses yielding results consistent with X-ray determination, this entire effort was viewed with considerable mistrust by many crystallographers. This was no doubt due to the rather high crystallographic R-factors reported for some structures and, more importantly, the failure to convince many skeptics that the measured intensity data were adequate for ab initio structure determinations.We have recently demonstrated the utility of these data sets for structure analyses by direct phase determination based on the probabilistic estimate of three- and four-phase structure invariant sums. Examples include the structure of diketopiperazine using Vainshtein's 3D data, a similar 3D analysis of the room temperature structure of thiourea, and a zonal determination of the urea structure, the latter also based on data collected by the Moscow group.

State-by-State Use of AMA Guides

2019 ◽  
Vol 24 (5) ◽  
pp. 3-7, 16
Keyword(s):  
Expert Testimony ◽  
Narrow Range ◽  
The United States ◽  
Workers Compensation ◽  
Federal Employees ◽  
Permanent Disability ◽  
Sixth Edition ◽  
History Of ◽  
Canadian Provinces

Abstract This article presents a history of the origins and development of the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), from the publication of an article titled “A Guide to the Evaluation of Permanent Impairment of the Extremities and Back” (1958) until a compendium of thirteen guides was published in book form in 1971. The most recent, sixth edition, appeared in 2008. Over time, the AMA Guides has been widely used by US states for workers’ compensation and also by the Federal Employees Compensation Act, the Longshore and Harbor Workers’ Compensation Act, as well as by Canadian provinces and other jurisdictions around the world. In the United States, almost twenty states have developed some form of their own impairment rating system, but some have a narrow range and scope and advise evaluators to consult the AMA Guides for a final determination of permanent disability. An evaluator's impairment evaluation report should clearly document the rater's review of prior medical and treatment records, clinical evaluation, analysis of the findings, and a discussion of how the final impairment rating was calculated. The resulting report is the rating physician's expert testimony to help adjudicate the claim. A table shows the edition of the AMA Guides used in each state and the enabling statute/code, with comments.

A Method for the Colorimetric Determination of β-Glucuronidase in Urine, Serum, Tissue; Assay of Enzymatic Activity in Health and Disease

1959 ◽  
Vol 36 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Julius A. Goldbarg ◽  
Esteban P. Pineda ◽  
Benjamin M. Banks ◽  
Alexander M. Rutenburg
Keyword(s):  
Enzymatic Activity ◽  
Colorimetric Determination ◽  
Health And Disease ◽  
Urine Serum
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