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Rangaswami XL, Goldsmith AM, Khan JM, Robertson CR, Lopez RR, Randklev CR. Thermal tolerances of Popenaias popeii (Texas hornshell) and its host fish from the Rio Grande Basin, Texas. Sci Rep 2023; 13:4603. [PMID: 36944661 PMCID: PMC10030872 DOI: 10.1038/s41598-023-29460-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 02/06/2023] [Indexed: 03/23/2023] Open
Abstract
Freshwater mussels are particularly sensitive to hydrologic changes, including streamflow and temperature, resulting in global decline. The Devils River in south-central Texas harbors the endangered freshwater mussel Popenaias popeii (Unionidae; Texas hornshell). There is concern that water withdrawals from the underlying aquifer may be negatively impacting this species. To assess this risk, we evaluated upper thermal tolerances (LT05 and LT50) of larvae (glochidia) and juveniles from two sites. After being acclimated to 27 °C, glochidia were subjected to five experimental temperatures (30, 32, 34, 36, and 38 °C) and non-acclimated control (20 °C) for 12-h and 24-h while juveniles were subjected to three experimental temperatures (30, 32, and 36 °C) and non-acclimated control (20 °C) for 96-h. We overlaid tolerance estimates against in situ water temperature and discharge data to evaluate thermal exceedances. Additionally, we reviewed upper thermal tolerances of P. popeii's presumed host fish (Carpiodes carpio, Cyprinellas lutrensis, and Moxostoma congestum) and their congeners. Stream temperatures only occasionally exceeded mussel LT05/50 and fish CLMax/LTMax, likely due to the Devils River's large spring input, highlighting the importance of protecting spring flows. We provide a practical framework for assessing hydrological needs of aquatic ectotherms, including the parasite-host relationship, which can be used to optimize environmental management.
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Affiliation(s)
- Xenia L Rangaswami
- Texas A&M Natural Resources Institute, 578 John Kimbrough Blvd. 2260 TAMU, College Station, TX, 77843, USA.
- Texas A&M AgriLife Research and Extension Center at Dallas, 17360 Coit Rd., Dallas, TX, 75252, USA.
| | - Amanda M Goldsmith
- Texas A&M Natural Resources Institute, 578 John Kimbrough Blvd. 2260 TAMU, College Station, TX, 77843, USA
- Texas A&M AgriLife Research and Extension Center at Dallas, 17360 Coit Rd., Dallas, TX, 75252, USA
| | - Jennifer M Khan
- U.S. Fish and Wildlife Service, 2005 Northeast Green Oaks Boulevard, Suite 140, Arlington, TX, 76006, USA
| | - Clinton R Robertson
- Texas Parks and Wildlife Department, River Studies Program, 505 Staples Rd., Bldg. 1, San Marcos, TX, 78666, USA
| | - Roel R Lopez
- Texas A&M Natural Resources Institute, 578 John Kimbrough Blvd. 2260 TAMU, College Station, TX, 77843, USA
| | - Charles R Randklev
- Texas A&M Natural Resources Institute, 578 John Kimbrough Blvd. 2260 TAMU, College Station, TX, 77843, USA
- Texas A&M AgriLife Research and Extension Center at Dallas, 17360 Coit Rd., Dallas, TX, 75252, USA
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2
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Smith CH, Robertson CR, Randklev CR. DNA barcoding identifies a novel population of the imperiled Trinity Pigtoe, Fusconaia chunii (Lea, 1862) (Bivalvia, Unionidae), in the San Jacinto River drainage in Texas. CheckList 2022. [DOI: 10.15560/18.6.1255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
The Trinity Pigtoe, Fusconaia chunii (Lea, 1862), is a freshwater mussel endemic to the Trinity River drainage in Texas. Here, we report the first population of F. chunii in the San Jacinto River drainage in Texas. We identified three specimens of F. chunii using DNA barcoding, which were morphologically indistinguishable from syntopic Fusconaia flava (Rafinesque, 1820). A similar issue occurs in the Trinity River drainage. Fusconaia chunii is listed as state threatened, and future research is necessary to assess its status within the San Jacinto River drainage
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3
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Moulpied M, Smith CH, Robertson CR, Johnson NA, Lopez R, Randklev CR. Biogeography of freshwater mussels (Bivalvia: Unionida) in Texas and implications on conservation biology. DIVERS DISTRIB 2022. [DOI: 10.1111/ddi.13555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Michael Moulpied
- Texas A&M Natural Resources Institute Texas A&M AgriLife Research Center at Dallas Dallas Texas USA
| | - Chase H. Smith
- Department of Integrative Biology University of Texas at Austin Austin Texas USA
| | - Clinton R. Robertson
- Inland Fisheries – Management and Conservation Branch Texas Parks & Wildlife Department San Marcos Texas USA
| | - Nathan A. Johnson
- U.S. Geological Survey Wetland and Aquatic Research Center Florida USA
| | - Roel Lopez
- Texas A&M Natural Resources Institute Texas A&M AgriLife Research Center at Dallas Dallas Texas USA
| | - Charles R. Randklev
- Texas A&M Natural Resources Institute Texas A&M AgriLife Research Center at Dallas Dallas Texas USA
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4
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Smith CH, Johnson NA, Robertson CR, Doyle RD, Randklev CR. Establishing conservation units to promote recovery of two threatened freshwater mussel species (Bivalvia: Unionida: Potamilus). Ecol Evol 2021; 11:11102-11122. [PMID: 34429906 PMCID: PMC8366875 DOI: 10.1002/ece3.7897] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 05/11/2021] [Accepted: 06/28/2021] [Indexed: 11/09/2022] Open
Abstract
Population genomics has significantly increased our ability to make inferences about microevolutionary processes and demographic histories, which have the potential to improve protection and recovery of imperiled species. Freshwater mussels (Bivalvia: Unionida) represent one of the most imperiled groups of organisms globally. Despite systemic decline of mussel abundance and diversity, studies evaluating spatiotemporal changes in distribution, demographic histories, and ecological factors that threaten long-term persistence of imperiled species remain lacking. In this study, we use genotype-by-sequencing (GBS) and mitochondrial sequence data (mtDNA) to define conservation units (CUs) for two highly imperiled freshwater mussel species, Potamilus amphichaenus and Potamilus streckersoni. We then synthesize our molecular findings with details from field collections spanning from 1901 to 2019 to further elucidate distributional trends, contemporary status, and other factors that may be contributing to population declines for our focal species. We collected GBS and mtDNA data for individuals of P. amphichaenus and P. streckersoni from freshwater mussel collections in the Brazos, Neches, Sabine, and Trinity drainages ranging from 2012 to 2019. Molecular analyses resolved disputing number of genetic clusters within P. amphichaenus and P. streckersoni; however, we find defensible support for four CUs, each corresponding to an independent river basin. Evaluations of historical and recent occurrence data illuminated a generally increasing trend of occurrence in each of the four CUs, which were correlated with recent increases in sampling effort. Taken together, these findings suggest that P. amphichaenus and P. streckersoni are likely rare throughout their respective ranges. Because of this, the establishment of CUs will facilitate evidence-based recovery planning and ensure potential captive propagation and translocation efforts are beneficial. Our synthesis represents a case study for conservation genomic assessments in freshwater mussels and provides a model for future studies aimed at recovery planning for these highly imperiled organisms.
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Affiliation(s)
- Chase H. Smith
- Department of Integrative BiologyUniversity of TexasAustinTexasUSA
- Texas A&M Natural Resources Institute, Texas A&M AgriLife Research Center at DallasDallasTexasUSA
- Biology DepartmentBaylor UniversityWacoTexasUSA
| | - Nathan A. Johnson
- U.S. Geological Survey, Wetland and Aquatic Research CenterGainesvilleFloridaUSA
| | | | | | - Charles R. Randklev
- Texas A&M Natural Resources Institute, Texas A&M AgriLife Research Center at DallasDallasTexasUSA
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5
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Randklev CR, Wolverton S, Johnson NA, Smith CH, DuBose TP, Robertson CR, Conley J. The utility of zooarchaeological data to guide listing efforts for an imperiled mussel species (Bivalvia: Unionidae:
Pleurobema riddellii
). Conservat Sci and Prac 2020. [DOI: 10.1111/csp2.253] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Charles R. Randklev
- Texas A&M Natural Resources InstituteTexas A&M AgriLife Research Center at Dallas Dallas Texas USA
| | - Steve Wolverton
- Department of Geography and the Environment & the Advanced Environmental Research InstituteUniversity of North Texas Denton Texas USA
| | - Nathan A. Johnson
- US Geological Survey, Wetland and Aquatic Research Center Gainesville Florida USA
| | - Chase H. Smith
- Department of Integrative BiologyUniversity of Texas Austin Texas USA
| | - Traci P. DuBose
- Oklahoma Biological Survey, Department of Biology, and Ecology and Evolutionary Biology Graduate ProgramUniversity of Oklahoma Norman Oklahoma USA
| | | | - Julian Conley
- Department of GeosciencesEast Tennessee State University Johnson City Tennessee USA
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6
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Inoue K, Harris JL, Robertson CR, Johnson NA, Randklev CR. A comprehensive approach uncovers hidden diversity in freshwater mussels (Bivalvia: Unionidae) with the description of a novel species. Cladistics 2020; 36:88-113. [PMID: 34618970 DOI: 10.1111/cla.12386] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/25/2019] [Indexed: 11/30/2022] Open
Abstract
Major geological processes have shaped biogeographical patterns of riverine biota. The Edwards Plateau of central Texas, USA, exhibits unique aquatic communities and endemism, including several species of freshwater mussels. Lampsilis bracteata (Gould, 1855) is endemic to the Edwards Plateau region; however, its phylogenetic relationship with other species in the Gulf coastal rivers and Mississippi River basin is unknown. We evaluated phylogenetic relationships, shell morphologies and soft anatomy characters of L. bracteata and a closely related congener, Lampsilis hydiana (Lea, 1838) throughout their ranges. Our results showed the presence of an undescribed species: Lampsilis bergmanni sp.n. Lampsilis bracteata and L. bergmanni sp.n. share similar shell morphologies and soft anatomy characters; however, they are genetically distinct. Geological processes, such as faulting and sea-level changes during the Miocene to Pliocene, are likely to have facilitated diversification of Lampsilis species, resulting in isolation of L. bracteata on the Edwards Plateau and diversification between L. bergmanni sp.n. and L. hydiana. We conclude that L. bracteata range is restricted to the Colorado River basin, whereas L. bergmanni sp.n. occurs only in upstream reaches of the Guadalupe River basin. Conservation actions are warranted for both species due to their restricted distributions and potential anthropogenic threats.
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Affiliation(s)
- Kentaro Inoue
- Texas A&M Natural Resources Institute, Texas A&M AgriLife Research Center at Dallas, Dallas, TX, 75252, USA.,Daniel P. Haerther Center for Research and Conservation, John G. Shedd Aquarium, 1200 South Lake Shore Drive, Chicago, IL, 60605, USA
| | - John L Harris
- Department of Biological Sciences, Arkansas State University, Jonesboro, AR, 72467, USA
| | - Clinton R Robertson
- River Studies Program, Texas Parks and Wildlife Department, San Marcos, TX, 78667, USA
| | - Nathan A Johnson
- Wetland and Aquatic Research Center, U.S. Geological Survey, Gainesville, FL, 32653, USA
| | - Charles R Randklev
- Texas A&M Natural Resources Institute, Texas A&M AgriLife Research Center at Dallas, Dallas, TX, 75252, USA
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7
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Randklev CR, Hart MA, Khan JM, Tsakiris ET, Robertson CR. Hydraulic requirements of freshwater mussels (Unionidae) and a conceptual framework for how they respond to high flows. Ecosphere 2019. [DOI: 10.1002/ecs2.2975] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
| | - Michael A. Hart
- Texas A&M Natural Resources Institute College Station Texas USA
| | | | - Eric T. Tsakiris
- National Conservation Training Center U.S. Fish & Wildlife Service Shepherdstown West Virginia USA
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8
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Randklev CR, Tsakris ET, Johnson MS, Popejoy T, Hart MA, Khan J, Geeslin D, Robertson CR. The effect of dewatering on freshwater mussel (Unionidae) community structure and the implications for conservation and water policy: A case study from a spring-fed stream in the southwestern United States. Glob Ecol Conserv 2018. [DOI: 10.1016/j.gecco.2018.e00456] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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9
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Hess MC, Inoue K, Tsakiris ET, Hart M, Morton J, Dudding J, Robertson CR, Randklev CR. Misidentification of sex for Lampsilis teres, Yellow Sandshell, and its implications for mussel conservation and wildlife management. PLoS One 2018; 13:e0197107. [PMID: 29768469 PMCID: PMC5955573 DOI: 10.1371/journal.pone.0197107] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 04/26/2018] [Indexed: 11/30/2022] Open
Abstract
Correct identification of sex is an important component of wildlife management because changes in sex ratios can affect population viability. Identification of sex often relies on external morphology, which can be biased by intermediate or nondistinctive morphotypes and observer experience. For unionid mussels, research has demonstrated that species misidentification is common but less attention has been given to the reliability of sex identification. To evaluate whether this is an issue, we surveyed 117 researchers on their ability to correctly identify sex of Lampsilis teres (Yellow Sandshell), a wide ranging, sexually dimorphic species. Personal background information of each observer was analyzed to identify factors that may contribute to misidentification of sex. We found that median misidentification rates were ~20% across males and females and that observers falsely identified the number of female specimens more often (~23%) than males (~10%). Misidentification rates were partially explained by geographic region of prior mussel experience and where observers learned how to identify mussels, but there remained substantial variation among observers after controlling for these factors. We also used three morphometric methods (traditional, geometric, and Fourier) to investigate whether sex could be more correctly identified statistically and found that misidentification rates for the geometric and Fourier methods (which characterize shape) were less than 5% (on average 7% and 2% for females and males, respectively). Our results show that misidentification of sex is likely common for mussels if based solely on external morphology, which raises general questions, regardless of taxonomic group, about its reliability for conservation efforts.
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Affiliation(s)
- Megan C. Hess
- Texas A&M Natural Resources Institute, Texas A&M AgriLife Research Center at Dallas, Dallas, Texas, United States of America
| | - Kentaro Inoue
- Texas A&M Natural Resources Institute, Texas A&M AgriLife Research Center at Dallas, Dallas, Texas, United States of America
| | - Eric T. Tsakiris
- Texas A&M Natural Resources Institute, Texas A&M AgriLife Research Center at Dallas, Dallas, Texas, United States of America
| | - Michael Hart
- Texas A&M Natural Resources Institute, Texas A&M AgriLife Research Center at Dallas, Dallas, Texas, United States of America
| | - Jennifer Morton
- Texas A&M Natural Resources Institute, Texas A&M AgriLife Research Center at Dallas, Dallas, Texas, United States of America
| | - Jack Dudding
- Texas A&M Natural Resources Institute, Texas A&M AgriLife Research Center at Dallas, Dallas, Texas, United States of America
| | - Clinton R. Robertson
- Texas Parks and Wildlife, Inland Fisheries Division, San Marcos, Texas, United States of America
| | - Charles R. Randklev
- Texas A&M Natural Resources Institute, Texas A&M AgriLife Research Center at Dallas, Dallas, Texas, United States of America
- * E-mail:
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10
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Abstract
Mathematical models can predict solute clearances and solute concentrations during renal replacement therapy. At present, however, most nephrologists cannot use these models because they require mathematical software. In this report, we describe models of solute transport by convection and diffusion adapted to run on the commonly available software program Excel for Macintosh computers and PCs running Windows. Two programs have been created that can be downloaded from http://www.stanford.edu/~twmeyer/ or http://dev.satellitehealth.com/research/journal.asp. The first, called 'Dr Addis Clearance Calculator', calculates clearance values from inputs including the blood flow Q(b), the hematocrit, the ultrafiltration rate Q(f), the dialysate flow rate Q(d), the reflection coefficient sigma and the mass transfer area coefficient K(o)A for the solute of interest, and the free fraction f if the solute is protein bound. Solute concentration profiles along the length of the artificial kidney are displayed graphically. The second program, called 'Dr Coplon Dialysis Simulator', calculates plasma solute concentrations from the clearance values obtained by the first program and from additional input values including the number of treatments per week, the duration of the treatments, and the solute's production rate and volumes of distribution. The program calculates the time-averaged solute concentration and provides a graphic display of the solute concentration profile through a week-long interval.
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Affiliation(s)
- J L Walther
- Department of Medicine, VA Palo Alto HCS and Stanford University, Palo Alto, California 94304, USA
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11
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Warner MS, Matsuno SJ, Virgin CJ, Masterson KB, Schneider GA, Wright TE, Robertson CR, Fives-Taylor P. Performance of the polypropylene fiber tailstring on the Copper 7 intrauterine device. J Appl Biomater 2001; 2:73-94. [PMID: 10149078 DOI: 10.1002/jab.770020203] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
New and used polypropylene tailstrings from the Copper 7 (Cu-7) intrauterine device were examined by a combination of analytical techniques. Optical microscopy, scanning acoustic and electron microscopy, x-ray diffraction, energy dispersive x-ray analysis, and chemical etching were employed to elucidate both the surface and interior morphology of new Cu-7 tailstrings. Tailstrings removed from women following varying periods of use were investigated with optical microscopy, scanning and transmission electron microscopy. In addition, a subset of the used tailstrings were cultured to identify the types of microorganisms associated with them. Our findings show that unused Cu-7 tailstrings are in various stages of degradation owing to a combination of factors which include the high-draw ratio employed during manufacturing, the method of packaging, and the use of a particulate colourant. Furthermore, it is evident that used Cu-7 tailstrings undergo major deterioration while in situ because of the unfavorable interactions between the highly drawn polypropylene and the physiological environment. These results indicate that the polypropylene tailstrings as manufactured for use with the Cu-7 IUD fail to meet accepted design criteria for biomedical implants.
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Affiliation(s)
- M S Warner
- Department of Chemical Engineering, Stanford University, CA 94305
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12
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Abstract
Two dimensional crystals of streptavidin grown on lipid monolayers can be viewed as model systems for the study of phase transitions and morphology. These crystals form a variety of macroscopic morphologies associated with different microscopic crystal structures. Observed morphologies are similar to those found in two-dimensional lipid systems, and growth of the protein arrays is somewhat analogous. Such solid state physical processes as nucleation, transformation between crystal phases, crystal phase coexistence, and roughening have been observed in the streptavidin system. In this review, we highlight observations that cause streptavidin to remain an interesting model system exhibiting a variety of intriguing phenomena.
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Affiliation(s)
- A P Gast
- Department of Chemical Engineering, Stanford University, CA 94305-5025, USA
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13
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Affiliation(s)
- S C Donnelly
- Rayne Laboratory, University of Edinburgh, Scotland
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14
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Trigiante G, Gast AP, Robertson CR. Pseudo First-Order Cleavage of an Immobilized Substrate by an Enzyme Undergoing Two-Dimensional Surface Diffusion. J Colloid Interface Sci 1999; 213:81-86. [PMID: 10191009 DOI: 10.1006/jcis.1999.6109] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In this paper we study the reaction kinetics of an enzyme adsorbed on a peptide substrate surface. Although the adsorption is effectively irreversible, the enzyme is able to diffuse on the surface. Our reaction system consisted of the enzyme collagenase and the oligopeptide FALGPA, a substrate for the enzyme. A quartz surface was coated with covalently bound substrate molecules. The extent of reaction was monitored continuously in a flow cell via UV absorption. The data are compatible with a kinetic model based on a pseudo first-order diffusion/orientation rate-limiting step followed by a relatively fast chemical cleavage step. This model was validated by examining the pH dependence of the rate constant. Copyright 1999 Academic Press.
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Affiliation(s)
- G Trigiante
- Department of Chemistry, Stanford University, Stanford, California, 94305-5025
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15
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Abstract
In 1994 the state of Minnesota filed suit against the tobacco industry. This trial is now history, but its legacy will carry on into the 21st century because of the revelations contained in the millions of pages of previously secret internal tobacco industry documents made public in the trial. In this article, we review representative documents relating to nicotine addiction, low-tar, low-nicotine cigarettes, and cigarette design and nicotine manipulation in cigarette manufacture. These documents reveal that for decades, the industry knew and internally acknowledged that nicotine is an addictive drug and cigarettes are the ultimate nicotine delivery device; that nicotine addiction can be perpetuated and even enhanced through cigarette design alterations and manipulations; and that "health-conscious" smokers could be captured by low-tar, low-nicotine products, all the while ensuring the marketplace viability of their products. Appreciation of tobacco industry strategies over the past decades is essential to formulate an appropriate legislative and public policy response. We propose key elements for such legislation and urge no legal or financial immunity for the tobacco industry.
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Affiliation(s)
- R D Hurt
- Nicotine Dependence Center, Mayo Clinic and Mayo Foundation, Rochester, MN 55905, USA
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16
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Abstract
To assess the effects of adsorption on protein structure, ultraviolet optical absorption spectra of myoglobin (Mb) bound to polydimethylsiloxane (PDMS) were measured. A flow cell, which enabled adsorption under controlled hydrodynamic conditions, was used in conjunction with a conventional spectrophotometer to obtain the spectra. Adsorption to PDMS reduced significantly the absorbance in the Soret region of the Mb spectrum, whereas the spectrum in the region near 280 nm was essentially unaffected. This result showed that disruption of the native structure of Mb occurs following interaction with PDMS. Furthermore, the change in the absorption spectrum may indicate loss of heme from the heme pocket of the adsorbed protein. Mb structure was altered from its solution configuration within fifteen min of contact with the surface. Exchange of adsorbed Mb with Mb in solution had little or no effect on the absorption spectrum of the surface-confined protein, indicating that exchange occurs only between conformationally altered species or between native species.
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Affiliation(s)
- A B Anderson
- Department of Chemical Engineering, Stanford University, California 94305, USA
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17
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Abstract
Vasculitis is a clinicopathologic process that involves inflammation and necrosis of blood vessels, resulting in a wide range of clinical diseases. The pathogenesis of vasculitis has been attributed to immunologic mechanisms, including immune complexes, cellular immunity, and humoral immunity, with numerous inciting events such as infection, drugs, malignancy, or toxins. Inflammatory cytokine production and adhesion molecule activation or upregulation are important determinants of the pathogenic inflammatory responses noted in vasculitis. Endothelial cells may be targeted by anti-endothelial cell antibodies and are central targets of numerous proinflammatory cytokines in vasculitis pathogenesis. Finally, antineutrophil cytoplasmic antibodies (ANCA) and T-cell responses to the protein targets of ANCA may play a role in vessel damage in ANCA-associated vasculitis.
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Affiliation(s)
- C R Robertson
- Duke University Medical Center, Durham, North Carolina
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18
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Donnelly SC, Strieter RM, Kunkel SL, Walz A, Robertson CR, Carter DC, Grant IS, Pollok AJ, Haslett C. Interleukin-8 and development of adult respiratory distress syndrome in at-risk patient groups. Lancet 1993; 341:643-7. [PMID: 8095568 DOI: 10.1016/0140-6736(93)90416-e] [Citation(s) in RCA: 535] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Neutrophils have been implicated in the pathogenesis of the adult respiratory distress syndrome (ARDS). We have measured concentrations of the neutrophil attractant interleukin-8 in blood and bronchoalveolar lavage fluid (BAL) from patients at risk of ARDS. We studied 29 patients from three groups at risk of developing ARDS: multiple trauma (n = 16), perforated bowel (n = 6), and pancreatitis (n = 7). ARDS developed in 7 of these patients. Interleukin-8 in BAL and blood samples taken on initial hospital presentation was measured by a sandwich enzyme-linked immunosorbent assay. The mean BAL interleukin-8 concentration was significantly higher for the patients who subsequently progressed to ARDS than for the non-ARDS group (3.06 [SE 2.64] vs 0.053 [0.010] ng/mL, p = 0.0006). There was no difference between the groups in plasma interleukin-8 (6.23 [2.60] vs 5.12 [2.22] ng/mL, p = 0.31). Immunocytochemistry suggested that the alveolar macrophage is an important source of interleukin-8 at this early stage in ARDS development. This study provides evidence of a relation between the presence of interleukin-8 in early BAL samples and the development of ARDS. The early appearance of interleukin-8 in BAL of patients at risk of ARDS may be an important prognostic indicator for the development of the disorder and reinforces the likely importance of neutrophils and the effects of their accumulation and activation in the pathogenesis of many cases of ARDS.
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Affiliation(s)
- S C Donnelly
- Respiratory Medicine Unit, University of Edinburgh, City Hospital, UK
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19
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Robertson CR, Pisetsky DS. Specificity analysis of antibodies to single-stranded micrococcal DNA in the sera of normal human subjects and patients with systemic lupus erythematosus. Clin Exp Rheumatol 1992; 10:589-94. [PMID: 1483310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
To evaluate the properties of antibodies to bacterial DNA in the sera of normal human subjects (NHS) and patients with systemic lupus erythematosus (SLE), the effects of ionic strength and pH on their binding to single-stranded DNA (ssDNA) from Micrococcus lysodeikticus (MC) were measured. By ELISA, antibodies to MC ssDNA in NHS showed greater activity at high ionic strength (0.2-1.0 M) than antibodies in lupus sera. Similarly, antibodies in NHS had higher activity at pH 9 than lupus anti-DNA. Competition binding assays indicated, moreover, that NHS anti-DNA showed greater inhibition by DNA than lupus anti-DNA at comparable inhibitor concentrations. Together, these results suggest that antibodies to MC ssDNA in NHS and SLE sera may differ in their mode of interaction with bacterial DNA and that NHS can generate high avidity antibodies to at least certain DNA determinants.
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Affiliation(s)
- C R Robertson
- Division of Rheumatology and Immunology, Durham VA Hospital 27705
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20
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Abstract
Defined minimal media conditions were used to assess and subsequently enhance the production of subtilisin by genetically characterized Bacillus subtilis strains. Subtilisin production was initiated by the exhaustion or limitation of ammonium in batch and fed-batch cultures. Expression of the subtilisin gene (aprE) was monitored with a chromosomal aprE::lacZ gene fusion. The beta-galactosidase production driven by this fusion reflected subtilisin accumulation in the culture medium. Subtilisin gene expression was temporally extended in sporulation-deficient strains (spoIIG), relative to co-genic sporogenous strains, resulting in enhanced subtilisin production. Ammonium exhaustion not only triggered subtilisin production in asporogenous spoIIG mutants but also shifted carbon metabolism from acetate production to acetate uptake and resulted in the formation of multiple septa in a significant fraction of the cell population. Fed-batch culture techniques, employing the spoIIG strain, were investigated as a means to further extend subtilisin production. The constant provision of ammonium resulted in linear growth, with doubling times of 11 and 36 h in each of two independent experiments. At the lower growth rate, the responses elicited (subtilisin production, glucose metabolism, and morphological changes) during the feeding regime closely approximated the ammonium starvation response, while at the higher growth rate a partial starvation response was observed.
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Affiliation(s)
- J A Pierce
- Department of Chemical Engineering, Stanford University, California 94305-5025
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Robertson CR, Pisetsky DS. Immunochemical properties of anti-DNA antibodies in the sera of patients with Escherichia coli bacteremia. Int Arch Allergy Immunol 1992; 98:311-6. [PMID: 1422260 DOI: 10.1159/000236204] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
To assess the role of infection in anti-DNA antibody production, the DNA-binding activity of sera from patients with Escherichia coli bacteremia was analyzed. Among 8 patients with bacteremia documented by blood culture, 5 demonstrated increased levels of antibodies to single-stranded DNA from E. coli as measured by enzyme-linked immunosorbent assay. Sera from these patients also reacted with single-stranded DNA from other bacterial and mammalian species as well as certain synthetic polynucleotides including poly-dT and poly-dC. The isotype distribution of these antibodies and their avidity as assessed by competition enzyme-linked immunosorbent assay resembled, moreover, responses of patients with systemic lupus erythematosus. These results suggest that, during the course of infection with E. coli, some patients may produce antibodies with immunochemical properties similar to those arising in systemic lupus erythematosus.
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Affiliation(s)
- C R Robertson
- Division of Rheumatology and Immunology, Duke University Medical Center, Durham, N.C
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Robertson CR, Gilkeson GS, Ward MM, Pisetsky DS. Patterns of heavy and light chain utilization in the antibody response to single-stranded bacterial DNA in normal human subjects and patients with systemic lupus erythematosus. Clin Immunol Immunopathol 1992; 62:25-32. [PMID: 1728977 DOI: 10.1016/0090-1229(92)90019-k] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Although anti-DNA antibodies are generally considered to be specific markers for systemic lupus erythematosus (SLE), antibodies binding DNA from certain bacterial species can be found in the sera of normal subjects. To characterize the immunochemical properties of these antibodies, the IgG subclass and light chain profile of antibodies to single-stranded micrococcal DNA (MC DNA) in the sera of normal subjects and patients with SLE was determined. The anti-MC DNA response in normal sera was predominantly of the IgG2 subclass with a marked predominance of kappa light chains. In contrast, anti-MC DNA antibodies in SLE sera exhibited all IgG subclasses with a predominance of the IgG1 subclass and both kappa and lambda light chains were represented. These results suggest that antibodies to bacterial DNA in the sera of normal subjects and patients with SLE differ in patterns of immunoglobulin gene expression; the restricted response of normal subjects may be related to the binding to a discrete DNA determinant.
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Affiliation(s)
- C R Robertson
- Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710
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Fowler JD, Robertson CR. Metabolic behavior of immobilized aggregates of Escherichia coli under conditions of varying mechanical stress. Appl Environ Microbiol 1991; 57:93-101. [PMID: 2036025 PMCID: PMC182669 DOI: 10.1128/aem.57.1.93-101.1991] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Experiments were conducted on immobilized aggregates of Escherichia coli cells. Mechanical stress was applied by forcing a convective stream of nutrient medium through the aggregate. It was shown to be possible to maintain uniform exponential growth with this convective supply of nutrients. Analysis of effluent from the system allowed investigation of metabolic responses unambiguously attributable to mechanical stress. A reversible increase in catabolic activity was observed after an increase in mechanical stress. Changes in the level of catabolism were accompanied by an alteration in the total acid yield on glucose and in the spectrum of organic acids produced during glucose fermentation. The behavior observed here was likely due to an osmoregulatory response induced by the mechanically stressed bacteria to counteract changes in shape.
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Affiliation(s)
- J D Fowler
- Department of Chemical Engineering, Stanford University, California 94305-5025
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24
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Abstract
A dense aggregate of cells was retained in a reactor by a supported porous membrane. A continuous flow of nutrient medium was maintained through the cell aggregate and membrane. The hydraulic resistance of the cell aggregate was monitored throughout experiments with either growing or chemically cross-linked cells, under conditions of varying flow rates. Digital image analysis was used to characterize the sizes, separations, and orientations of several thousand individual cells in electron micrographs of chemically cross-linked cell aggregates. Two nonlinear phenomena were observed. First, the hydraulic resistance varied in direct relation to and reversibly with flow rate. Second, in constant flow-rate experiments the hydraulic resistance increased with time at a faster rate than could be attributed to cell growth. Both of these phenomena were dependent upon and could be explained by the ability of cells to move with respect to one another, under the influences of Brownian motion and of convection. Such relative motion could allow changes in net alignment of cells in the direction of flow and in the volume fraction of cells in the aggregate. This explanation is consistent with image analysis data. The observed sensitivity of hydraulic resistance to flow rate was inconsistent with a model that assumed elastic deformation of individual cells, and no evidence of cell deformation was found in electron micrographs.
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Affiliation(s)
- J D Fowler
- Department of Chemical Engineering, Stanford University, Stanford, California 94305-5025
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25
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Tilton RD, Gast AP, Robertson CR. Surface diffusion of interacting proteins. Effect of concentration on the lateral mobility of adsorbed bovine serum albumin. Biophys J 1990; 58:1321-6. [PMID: 2291948 PMCID: PMC1281077 DOI: 10.1016/s0006-3495(90)82473-5] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Surface diffusion of bovine serum albumin absorbed from aqueous solution to poly(methylmethacrylate) surfaces is significantly hindered by protein-protein lateral interactions. The long-time self diffusion coefficient measured by fluorescence recovery after pattern photobleaching decreases by approximately one order of magnitude as the surface area fraction occupied by protein increases from 0.10 to 0.69. Qualitative features of the surface concentration dependence of the self diffusion coefficient can be described by several recent models for lateral diffusion of interacting species. The mobile fraction is independent of the surface concentration, and both the self diffusion coefficient and the mobile fraction are constant between 15 min and 7 h of adsorption.
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Affiliation(s)
- R D Tilton
- Department of Chemical Engineering, Stanford University, California 94305-5025
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Affiliation(s)
- T L Pallone
- Division of Nephrology, M. S. Hershey Medical Center, Hershey, Pennsylvania
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Affiliation(s)
- J D Fowler
- Department of Chemical Engineering, Stanford University, California 94305
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Abstract
Mass transfer-limited removal of metabolic products led to product-inhibited growth of Escherichia coli that was immobilized in a model system. Comparison of the growth kinetics of immobilized and free-living cells revealed no further physiological differences between cells in these two modes of existence beyond those manifested in the local concentrations of substrate and product. Bacteria were retained on a microporous membrane in a dense, planar aggregate and were grown anaerobically on a glucose-based minimal medium. Radioisotope labeling of the immobilized cell mass with 35S was used to determine growth kinetic parameters. Growth rates in the immobilized cell layer were measured by an autoradiographic technique which allowed comparison of the size of the growing region with the rate of cell convection caused by growth. Immobilized cell growth rates and growth yields ranged from near maximal (0.56 h-1 and 39 g of dry cell weight/mol of glucose, respectively) to substantially reduced (0.15 h-1 and 15 g/mol). The depression of these kinetic parameters was attributed to product inhibition arising from mass transfer-limited removal of acidic waste products from the cell mass. A simple one-dimensional reaction-diffusion model, which incorporated data on the product-inhibited growth kinetics of free-living cells collected in a product-limited chemostat, satisfactorily predicted product inhibition of immobilized cell growth.
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Affiliation(s)
- P S Stewart
- Department of Chemical Engineering, Stanford University, California 94305-5025
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Abstract
Five monoclonal antibodies against sperm whale myoglobin have been used to investigate the physical state of the antigen adsorbed onto a polydimethylsiloxane surface. The binding of each antibody is sensitive to the antigen's conformation in solution while the locations of the antigenic sites on the myoglobin molecule for three of the antibodies have been determined (Berzofsky, J.A., G.K. Buckenmeyer, G. Hicks, F.R.N. Gurd, R.J. Feldmann, and J. Minna. 1982. J. Biol. Chem. 257:3189-3198). The binding of the fluorescein isothiocyanate-labeled IgG and Fab antibodies to previously adsorbed myoglobin has been observed using total internal reflection fluorescence. Three of the antibodies bind specifically to surface-adsorbed myoglobin with affinities at least 50% relative to myoglobin in solution whereas two of the antibodies show affinities for the surface-adsorbed myoglobin diminished by at least two orders of magnitude relative to myoglobin in solution. The specific loss of certain antigenic determinants on the adsorbed myoglobin, coupled with the retention of others, indicates a nonrandom adsorption of the myoglobin molecules.
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Affiliation(s)
- S A Darst
- Department of Chemical Engineering, Stanford University, California 94305
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Affiliation(s)
- S F Karel
- Department of Chemical Engineering, Stanford University, California 94305
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Kiberd B, Robertson CR, Larson T, Jamison RL. Effect of V2-receptor-mediated changes on inner medullary blood flow induced by AVP. Am J Physiol 1987; 253:F576-81. [PMID: 2957929 DOI: 10.1152/ajprenal.1987.253.3.f576] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We have previously shown that arginine vasopressin (AVP) in physiological amounts reduces inner medullary blood flow and that the mechanism of this decrease is at least in part mediated by the vasopressor (V1-receptor) action of AVP. To determine whether the antidiuretic action of AVP (V2-receptor) also contributes to the reduction in inner medullary blood flow, we determined capillary blood flow (QVR) in individual descending vasa recta (DVR) and ascending vasa recta (AVR) using fluorescence videomicroscopy in the exposed renal papilla of the anesthetized rat. Three groups of chronically water-diuretic rats were studied in three consecutive periods: control (period 1), experimental (period 2), and recovery (period 3). Group I rats (designated the AVP group) received AVP, 45 ng X h-1 X kg body wt-1; group II (AVP + V2-inhibitor), AVP plus its specific antidiuretic antagonist d(CH2)5[D-Ile2,Thr4]AVP; and group III (V2-inhibitor), the antagonist alone, respectively, in the experimental period 2. Only group I rats concentrated their urine, urine osmolality (Uosmol) = 499 +/- 48 mosmol/kgH2O, whereas urine remained hypotonic throughout in groups II and III. In group I, QVR in DVR and AVR decreased in period 2; but in groups II and III, QVR tended to increase. These results suggest that the AVP-induced decrease in papillary vasa recta blood flow is in part mediated by its antidiuretic V2-receptor as well as by its vasopressor (V1-receptor). They also suggest that the rate of urinary flow in the medullary collecting ducts is a determinant of inner medullary blood flow.
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Abstract
To determine whether synthetic atrial natriuretic peptide (ANP) increases renal medullary blood flow and if so whether the increase mediates the diuresis and natriuresis induced by ANP, inner medullary vasa recta blood flow in the exposed left renal papilla of anesthetized Munich Wistar rats weighing between 102 and 161 g was measured by fluorescence videomicroscopy. The rats were maintained in a euvolemic state by the infusion of albumin. Synthetic ANP (Auriculin B) was administered intravenously as 2.5 micrograms/kg body wt prime and as a continuous infusion of 0.2 microgram X min-1 X kg body wt-1 to the experimental group (n = 7). Within 2 min after ANP was given, urine flow and sodium excretion increased (29.4 +/- 3.8 to 50.4 +/- 5.8 microliter X min-1 X kidney wt-1, P less than 0.01, and 3.39 +/- 0.57 to 6.05 +/- 0.95 mueq X min-1 X g kidney wt-1, P less than 0.01, respectively), but vasa recta blood flow in descending (DVR) or ascending (AVR) vasa recta did not change significantly (9.5 +/- 2.3 to 10.0 +/- 2.8 nl/min in DVR and 5.3 +/- 1.0 to 6.1 +/- 1.2 nl/min in AVR). Forty-five minutes after ANP was begun, urine flow and sodium excretion increased further (77.1 +/- 11.1 microliter X min-1 X g kidney wt-1 and 12.0 +/- 2.15 mueq X min-1 X g kidney wt-1, respectively), and by this time vasa recta blood flow had increased significantly to 14.0 +/- 2.6 in DVR, P less than 0.01, and 9.8 +/- 1.2 in AVR, P less than 0.01.(ABSTRACT TRUNCATED AT 250 WORDS)
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Abstract
Immobilized-cell aggregates have traditionally been approximated as effective continua within which the catalytic activity of the cells is homogeneously distributed. Chang & Park (1985), however, recently modelled the immobilized cells as discrete inclusions within a support matrix. With some modification, this theory is applicable to the analysis of microbial colonies growing within gel beads, and indicates that predictions obtained using the traditional approach may be significantly in error.
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Affiliation(s)
- P M Salmon
- Department of Chemical Engineering, Stanford University, CA 94305
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Abstract
Like other regional circulations, the medullary circulation supplies oxygen and other primary substrates to the medulla and removes carbon dioxide and other waste metabolites. It also acts as a countercurrent exchanger and simultaneously removes water reabsorbed from the renal tubule to preserve mass balance. Our present understanding of how the medulla serves both these functions at the same time is illustrated in Figure 3. Blood leaves the efferent arteriole with an elevated plasma protein concentration as a consequence of glomerular filtration, and flows down descending vasa recta within a vascular bundle. The increased interstitial osmotic-concentration coupled with a finite capillary reflection coefficient for small solutes causes additional water to be extracted so that at the termination of descending vasa recta, the plasma protein concentration exceeds that in the systemic circulation by approximately twofold. Solute, urea more than sodium chloride, also enters descending vasa recta. As blood flows through the interconnecting capillary plexus and up ascending vasa recta, transcapillary oncotic and osmotic pressure differences combine to cause capillary uptake of fluid. There is also simultaneous loss of urea such that the medullary trapping of urea is very effective. Countercurrent exchange of sodium chloride, however, appears to be less efficient and as a consequence, not only water but sodium chloride is removed from the medulla. Antidiuretic hormone reduces medullary blood flow, both directly by its vasoconstrictor (V1-receptor mediated) effect and indirectly by its antidiuretic (V2-receptor mediated) effects. Prostaglandins are able to enhance medullary blood flow by counteracting vasoconstrictive influences.(ABSTRACT TRUNCATED AT 250 WORDS)
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Robertson CR. Hallucinations after penicillin injection. Am J Dis Child 1985; 139:1074-5. [PMID: 4061399 DOI: 10.1001/archpedi.1985.02140130012011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Robertson CR. Mixed connective tissue disease in childhood: case report and literature review. J Miss State Med Assoc 1985; 26:279-81. [PMID: 3877170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Zimmerhackl B, Robertson CR, Jamison RL. Effect of arginine vasopressin on renal medullary blood flow. A videomicroscopic study in the rat. J Clin Invest 1985; 76:770-8. [PMID: 4031072 PMCID: PMC423899 DOI: 10.1172/jci112034] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The role of arginine vasopressin (AVP) in the regulation of renal medullary blood flow is uncertain. To determine if AVP has a direct vasoconstrictive action on vasa recta, the effect of AVP on erythrocyte velocity (VRBC), diameter, and blood flow (QVR) in descending vasa recta (DVR) and ascending vasa recta (AVR) was studied in the exposed renal papilla of four groups of chronically water diuretic rats using fluorescence videomicroscopy. There were three periods: control (period 1), experimental (period 2), and recovery (period 3). In periods 1 and 3, all groups received hypotonic saline. In period 2, group I rats (AVP) received AVP (45 ng/h per kg body wt); group II (time) received hypotonic saline alone; group III (AVP plus V1-inhibitor) received AVP plus its vascular antagonist, d(CH2)5Tyr(Me)AVP; and group IV (V1-inhibitor) received the vascular antagonist alone. Another group of rats (group V) was employed to demonstrate that the rise in blood pressure induced by a 3- or 10-ng/kg injection of AVP was virtually abolished by the prior infusion of the V1-inhibitor. The urine of group III as well as group I rats was concentrated (Uosm = 721 +/- 62 H2O vs. 670 +/- 39 mosM/kg), while urine remained dilute in groups II and IV. In period 2, VRBC and QVR in DVR and AVR decreased in group I, did not decrease in group III, and increased in groups II and IV. The vascular antagonist thus completely abolished the AVP-induced decrease in QVR in group III. These findings unequivocally establish that AVP in physiological amounts reduces medullary blood flow, at least in part, by a direct vasoconstrictive action on the medullary microcirculation. They also show that an effect of AVP on medullary blood flow is not necessary for its antidiuretic effect.
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Zimmerhackl B, Tinsman J, Jamison RL, Robertson CR. Use of digital cross-correlation for on-line determination of single-vessel blood flow in the mammalian kidney. Microvasc Res 1985; 30:63-74. [PMID: 4021838 DOI: 10.1016/0026-2862(85)90038-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The empirical relationship between erythrocyte velocity (Vrbc) and mean blood velocity (Vblood) was studied in quartz capillaries by television microscopy using the dual-slit technique. A newly designed desktop digital on-line cross-correlator was combined with a computer to determine Vrbc. The accuracy of the digital correlator was tested for velocities ranging from 0 to 3 mm/sec and compared with values determined using an analog tracking correlation device. There was good agreement. Small-bore glass tubes with diameters ranging from 12 to 26 micron were perfused with suspensions of erythrocytes having hematocrits between 10 and 37%. The relationship between mean blood velocity and erythrocyte velocity in these quartz tubes was found to be Vblood = 0.88 Vrbc - 0.11, and was independent of diameter and hematocrit within the range investigated. The mean ratio for Vrbc/Vblood was 1.42 +/- 0.06.
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Jamison RL, Zimmerhackl B, Robertson CR. Videomicroscopic method for direct determination of blood flow to the papilla of the kidney. Ann Biomed Eng 1985; 13:273-80. [PMID: 4037456 DOI: 10.1007/bf02584244] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We adapted the technique of videomicroscopy for direct determination of blood flow in individual capillaries of the papilla of the kidney, the ascending vasa recta (AVR) and descending vasa recta (DVR). The papilla was exposed in anesthetized rats and positioned under a video-camera-microscope and viewed under epiillumination. The intravenous infusion of fluorescein-isothiocyanate (FITC)-labeled gamma globulin was combined with fluorescence microscopy to enhance the contrast among plasma, red blood cells and capillary walls. On the television monitor, the walls were clearly outlined, enabling the measurement of capillary diameter. The velocity of red cells (Vrbc) in individual vasa recta was measured using the dual slit technique. From the videotape recorded microscopic image of a vas rectum, two photometric signals were obtained by integrating the light intensity from two electronic "windows" positioned closely together over the same capillary. Red cell velocity was calculated by dividing the distance between the two windows by the time delay between signals. The delay was determined using analog correlation tracking or digital cross correlation techniques. Single vasa recta blood flow was calculated from capillary diameter, Vrbc, and F (Fahraeus factor), which converts Vrbc to average whole blood velocity, Vblood. In quartz capillaries the same size as vasa recta, the ratio F = Vrbc/Vblood = 1.42 +/- 0.06. Total papillary blood inflow and outflow was calculated by multiplying the total number of DVR or AVR times the mean single capillary blood flow for DVR or AVR, respectively.
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Zimmerhackl B, Robertson CR, Jamison RL. Fluid uptake in the renal papilla by vasa recta estimated by two methods simultaneously. Am J Physiol 1985; 248:F347-53. [PMID: 3976897 DOI: 10.1152/ajprenal.1985.248.3.f347] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Fluid uptake by vasa recta was determined by two independent methods, videomicroscopy and the micropuncture technique, in the exposed papilla of nine antidiuretic rats to reconcile differences in values previously obtained by the two techniques. Erythrocyte velocity (Vrbc) and diameter (D) in descending vasa recta (DVR) (n = 22) and ascending vasa recta (AVR) (n = 31) near the "base" of the papilla were measured. Using a conversion function determined in vitro, Vrbc was transformed into mean blood velocity (Vblood). From D and Vblood, mean blood flow (Q) in DVR and AVR was calculated. In DVR, mean Vrbc, D, and Q were 1.06 +/- 0.01 mm/s, 16.3 +/- 0.4 micron, and 10.6 +/- 1.4 nl/min, respectively. In AVR, each corresponding value differed significantly, 0.47 +/- 0.06 mm/s (P less than 0.001), 19.8 +/- 0.8 micron (P less than 0.001), and 5.65 +/- 1.3 nl/min (P less than 0.025), respectively. Blood samples from DVR and AVR were obtained by micropuncture from the same location. Plasma protein concentration (g/dl) was 5.1 +/- 0.6 in DVR, 4.0 +/- 0.4 (P less than 0.05) in AVR, and 3.6 +/- 0.3 (P less than 0.025) in the renal vein. Assuming no net transcapillary loss of protein, total plasma outflow exceeded inflow by 29%, the excess representing fluid uptake; and to reconcile the blood flow and plasma protein concentrations found, functioning AVR should outnumber functioning DVR by a ratio of 2.1-2.4 to 1, depending on local hematocrit. Given the total number of AVR + DVR = 2,944 (at the base), capillary fluid uptake was calculated to range between 1.5 and 2.6 microliter/min.
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Lemley KV, Schmitt SL, Holliger C, Dunn MJ, Robertson CR, Jamison RL. Prostaglandin synthesis inhibitors and vasa recta erythrocyte velocities in the rat. Am J Physiol 1984; 247:F562-7. [PMID: 6496683 DOI: 10.1152/ajprenal.1984.247.4.f562] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Vasa recta erythrocyte velocities (VRBC) in the exposed renal papilla of anesthetized water-loaded rats were determined before and 60 min after intravenous administration of a prostaglandin synthesis inhibitor (indomethacin, meclofenamate) or the inhibitor vehicle alone. The change in VRBC of ascending and descending vasa recta for the inhibitor group [-17 +/- 5% (SE)] was different from that for controls (+12 +/- 4%, P less than 0.002). Erythrocyte velocities were also determined in vasa recta of antidiuretic rats before and 30 min after administration of indomethacin or vehicle alone. Prostaglandin synthesis inhibition was again associated with a significant decrease in VRBC compared with control (-24 +/- 4% vs. +28 +/- 20%, respectively, P less than 0.025). These findings suggest that prostaglandins play a similar role in regulating blood flow in the renal medulla in water diuresis and antidiuresis.
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Myers BD, Miller DC, Mehigan JT, Olcott CO, Golbetz H, Robertson CR, Derby G, Spencer R, Friedman S. Nature of the renal injury following total renal ischemia in man. J Clin Invest 1984; 73:329-41. [PMID: 6421876 PMCID: PMC425022 DOI: 10.1172/jci111217] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The effects of total renal ischemia (TRI) of 15-87 min duration due to suprarenal clamping of the aorta were studied in 15 mannitol-treated patients undergoing abdominal aortic surgery. 15 patients undergoing similar surgery but requiring only infrarenal clamping served as controls. 1-2 h following TRI, GFR was reduced to only 39% of that in controls, 23 +/- 5 vs. 59 +/- 7 ml/min (P less than 0.001). This could not be ascribed to impaired renal plasma flow (RPF), which was mildly reduced to 331 +/- 71 and was not different from the value in controls, 407 +/- 66 ml/min. However, impaired PAH extraction (43 +/- 7%) and isosthenuria, not present in controls, suggest a primary role for tubular injury in lowering GFR at this time. 24 h following TRI, the GFR remained depressed below controls, 45 +/- 8 vs. 84 +/- 8 ml/min (P less than 0.005), while the transglomerular sieving of neutral dextrans was significantly enhanced (radius interval, 24-40 A). A theoretical analysis of transcapillary solute exchange revealed that these findings could be largely explained by a selective reduction of either RPF (-61%) or of transmembrane hydraulic pressure difference (-18%) below control values. Alternately, a combination of these two factors with changes of smaller magnitude could explain the findings. In contrast, a selective increase in oncotic pressure or decrease of the glomerular ultrafiltration coefficient could be excluded as a cause of hypofiltration 24 h after TRI. These observations lead us to suggest that the transient azotemia observed following TRI is due to a self-limited injury to the nephron that is identical to that seen in overt and sustained forms of acute renal failure.
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Abstract
Blood flow in vasa recta capillaries of the exposed renal papilla of young antidiuretic rats (n = 18) was determined by an adaptation of the video-photometric technique of Intaglietta. The erythrocyte velocity and capillary diameter in vasa recta (n = 97) were measured at the same location by means of fluorescence video microscopy, with fluorescein-labeled bovine gamma-globulin as a plasma marker. A factor relating erythrocyte velocity to mean cross-sectional blood velocity was determined in vitro to permit the calculation of single vasa recta blood flows from the measured indices, erythrocyte velocity and capillary diameter. Mean blood flow in descending vasa recta was 8.83 +/- 0.96 (SE) nl/min, significantly greater than that in ascending vasa recta, 4.82 +/- 0.34 nl/min. The total numbers of ascending and descending vasa recta at the base of the exposed papilla were also determined. Over 1500 vasa recta were identified as ascending vasa recta or descending vasa recta in electron micrographs of three papillas. At this level in the papilla (2 mm from the tip), there were four ascending vasa recta for each descending vas rectum. From the total numbers of ascending vasa recta and descending vas rectum, single vessel blood flows were converted to total blood flow. Total blood outflow in all ascending vasa recta, 11.3 microliter/min, substantially exceeded total blood inflow in all descending vasa recta, 5.2 microliter/min. The difference between outflow and inflow (6.1 microliter/min) represents an estimate of water by the papillary microcirculation, and is more than adequate to accommodate the known rate of water reabsorption from the collecting ducts of the exposed papilla.
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46
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Inloes DS, Taylor DP, Cohen SN, Michaels AS, Robertson CR. Ethanol Production by
Saccharomyces cerevisiae
Immobilized in Hollow-Fiber Membrane Bioreactors. Appl Environ Microbiol 1983; 46:264-78. [PMID: 16346346 PMCID: PMC239298 DOI: 10.1128/aem.46.1.264-278.1983] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Saccharomyces cerevisiae
ATCC 4126 was grown within the macroporous matrix of asymmetric-walled polysulfone hollow-fiber membranes and on the exterior surfaces of isotropic-walled polypropylene hollow-fiber membranes. Nutrients were supplied and products were removed by single-pass perfusion of the fiber lumens. Growth of yeast cells within the macrovoids of the asymmetric-walled membranes attained densities of greater than 10
10
cells per ml and in some regions accounted for nearly 100% of the available macrovoid volume, forming a tissue-like mass. A radial distribution of cell packing existed across the fiber wall, indicating an inadequate glucose supply to cells located beyond 100 μm from the lumen surface. By comparison, yeast cell growth on the exterior surfaces of the isotropic-walled membranes resulted in an average density of 3.5 × 10
9
viable cells per ml. Ethanol production by reactors containing isotropic polypropylene fibers reached a maximum value of 26 g/liter-h based on the total reactor volume. Reactor performance depended on the fiber packing density and on the glucose medium flow rate and was limited by low nutrient and product transport rates. The inhibition of ethanol production and the reduction in fermentation efficiency arose primarily from the accumulation of CO
2
gas within the sealed reactor shell space.
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Affiliation(s)
- D S Inloes
- Departments of Chemical Engineering and Genetics, Stanford University, Stanford, California 94305
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48
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Abstract
The study investigated the relationships between specific demographic, psychosocial, and physiological variables and the severity of duodenal ulcer disease in a population of patients with proved duodenal ulcer. Intercorrelations between psychosocial and physiological variables were also studied. The study design was cross sectional and retrospectively assessed life change units and DUD severity during the previous 6 months in 39 male ulcer clinic outpatients. Anxiety, depression, life change units, the family environment, ABO blood type, secretor status, serum pepsinogen, and serum fasting gastrin were evaluated. A DUD severity score was calculated from self-reported ulcer pain symptoms and ulcer complications. Gastrin levels correlated significantly with three Family Environment Scale (FES) subscales, including: (a) independence, (b) achievement orientation, and (c) expressiveness. Duodenal ulcer disease severity scores correlated with Zung SDS scores, but not with state or trait anxiety, life change units, or the FES.
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Myers BD, Hilberman M, Carrie BJ, Spencer RJ, Stinson EB, Robertson CR. Dynamics of glomerular ultrafiltration following open-heart surgery. Kidney Int 1981; 20:366-74. [PMID: 6170777 DOI: 10.1038/ki.1981.148] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
To elucidate how individual determinants might lower the rate of glomerular ultrafiltration (GFR) in some patients following cardiac surgery, we performed hemodynamic measurements and clearance of inulin (as a measure of GFR), PAH (as a measure of effective renal plasma flow [ERPF]), and dextran-40. Two groups of 17 patients each were distinguished by the presence or absence of prerenal azotemia. Glomerular hypofiltration (GFR = 21 +/- 2 vs. 76 +/- 6 ml/min/1.73 m2, P less than 0.001) in the former was accompanied by depressed left ventricular function, arterial pressure, and ERPF (152 +/- 26 vs. 317 +/- 32 ml/min/1.73 m2, P less than 0.001). To determine if factors beside ERPF play a role in lowering GFR, we calculated the efferent oncotic pressure (pie). Failure of GFR to change over a 24-hour period despite increases in ERPF suggested that both patient groups were at filtration pressure disequilibrium (FPD). This condition permits calculation of a unique glomerular ultrafiltration coefficient (Kf). Over a range of pressures for transcapillary hydraulic pressure (deltaP), such that 3 less than or equal to (deltaP - pie) less than or equal to 10 mm Hg (to simulate FPD), Kf was less than 0.08 ml . sec-1 . mm Hg-1 . 1.73 m-2 in azotemic, but exceeded this value in nonazotemic patients. Although a selective reduction of Kf is predicted to lower the fractional clearance of dextrans, these were significant elevated in azotemic relative to nonazotemic patients (molecular radii 30 - 40 A). A theoretical analysis of the latter data suggests that over the foregoing range of FPD, a 15 to 30% decline in deltaP combined with a 30 to 0% reduction in Kf from values in nonazotemic patients best explains the experimental findings in azotemic patients.
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Winetz JA, Robertson CR, Golbetz HV, Carrie BJ, Salyer WR, Myers BD. The nature of the glomerular injury in minimal change and focal sclerosing glomerulopathies. Am J Kidney Dis 1981; 1:91-8. [PMID: 6174043 DOI: 10.1016/s0272-6386(81)80035-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Glomerular barrier function was evaluated in 12 healthy human volunteers and in 16 proteinuric patients in whom the nephrotic syndrome was associated with alteration of glomerular epithelial cells alone (minimal change nephropathy [MCN]) or in combination with focal glomerular sclerosis (FGS). We determined the glomerular sieving coefficient for each of nine narrow dextran fractions (Einstein Stoke radius [ESR] = 30 to 46 A), and directly measured, or indirectly estimated, values for the determinants of glomerular ultrafiltration. These quantities were then subjected to analysis based on an hydrodynamic theory of solute transport through an isoporous membrane. The results indicate that relative to normal subjects, effective pore radius is reduced from 59 to 55 and 53 A in McN and FGS, respectively; while the ratio, pore area to pore length (a measure of pore density) is correspondingly reduced from 21.7 X 10(6) to 10.1 X 10(6) and 4.7 X 10(6) cm. respectively, We suggest that collapse of the anionic glomerular membrane matrix in these proteinuric disorders may lead to pore shrinkage and reduced pore density, but that reduced electrostatic repulsion of anionic albumin (ESR = 36 A) facilitates its permeation into Bowman's space. The qualitatively similar disorder of glomerular barrier function in MCN and FGS is consistent with a unitary pathogenesis, but may represent a nonspecific response to depletion of glomerular polyanion.
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