19 results on '"Bentley SK"'
Search Results
2. High K+ effects on PAH transport and permeabilities in isolated snake renal tubules
- Author
-
Dantzler, WH, primary and Bentley, SK, additional
- Published
- 1975
- Full Text
- View/download PDF
3. A BN-Benzvalene.
- Author
-
Ozaki T, Bentley SK, Rybansky N, Li B, and Liu SY
- Abstract
The synthesis and crystallographic characterization of BN-benzvalene, the first second-row heteroatom-containing benzvalene, is described. BN-benzvalenes are produced via photoexcitation of C5-aryl-substituted 1,2-azaborines under flow conditions. Mechanistic studies support a boron-specific, two-step photoisomerization pathway involving a BN-Dewar benzene intermediate, which is distinct from the photoisomerization pathway proposed in benzene and phospha- and silabenzenes for the formation of their respective benzvalene analogues.
- Published
- 2024
- Full Text
- View/download PDF
4. Attending physicians as simulation learners: summary of current practices and barriers in emergency medicine.
- Author
-
Hock SM, Cassara M, Aghera A, Saloum D, and Bentley SK
- Published
- 2024
- Full Text
- View/download PDF
5. Enhancing Safety of a System-Wide In Situ Simulation Program Using No-Go Considerations.
- Author
-
Minors AM, Yusaf TC, Bentley SK, Grueso D, Campbell-Taylor K, Harford M, Mehri S, Williams LJ, and Bajaj K
- Subjects
- Pregnancy, Female, Humans, Heart Arrest therapy
- Abstract
Introduction: A large-scale in situ simulation initiative on cardiac arrest in pregnancy was implemented across NYC Health + Hospitals. In situ simulation must be safely balanced with clinical conditions such as through application of no-go considerations or standardized reasons to cancel or postpone the simulation. Our objective is to describe our findings on the application of no-go considerations during this simulation initiative., Methods: NYC Health + Hospitals/Simulation Center developed an in situ simulation program focused on cardiac arrest in pregnancy, implemented at 11 acute care facilities. The program's toolkit included no-go considerations for in situ simulation safety: situations prompting a need to cancel, reschedule, or postpone a simulation to ensure patient and/or staff safety., Results: Data were collected from June 2018 through December 2019. The simulation sites reviewed the 13 established no-go considerations before each simulation event to assess if the simulation was safe to "go". After the conclusion of the initiative, all data related to no-go considerations were analyzed.Two hundred seventy-four in situ simulations were scheduled and 223 simulations (81%) were completed. Fifty-one no-go events were reported, with 78% identifying a reason by category. Twenty-two percent did not report a reason or category. Four of the 13 suggested no-go considerations were not reported., Conclusions: The no-go considerations framework promotes standardized and strategic scheduling of in situ simulation. Analysis of no-go consideration application during this system-wide initiative provides a model for the usage of tracking no-go data to enhance safety and inform future simulation planning., (Copyright © 2023 Society for Simulation in Healthcare.)
- Published
- 2023
- Full Text
- View/download PDF
6. Workshop in Simulation Debriefing for Educators in Medicine: Creation, implementation, and evaluation of a debriefing curriculum for novice simulation educators.
- Author
-
Chen TH, Bentley SK, Nadir NA, Beattie LK, Lei C, Hock SM, Munzer BW, Moadel T, Paetow G, Young A, and Stapleton SN
- Abstract
Objectives: Debriefing is an integral component of simulation education, and effective debriefing education is required to maintain effective simulation programs. However, many educators report financial and logistical barriers to accessing formal debriefing training. Due to limited educator development opportunities, simulation program leaders are often compelled to utilize educators with insufficient debriefing training, which can limit the impact of simulation-based education. To address these concerns, the SAEM Simulation Academy Debriefing Workgroup authored the Workshop in Simulation Debriefing for Educators in Medicine (WiSDEM), a freely available, concise, and ready-to-deploy debriefing curriculum with a target audience of novice educators without formal debriefing training. In this study, we describe the development, initial implementation, and evaluation of the WiSDEM curriculum., Methods: The Debriefing Workgroup iteratively developed the WiSDEM curriculum by expert consensus. The targeted level of content expertise was introductory. The curriculum's educational impact was assessed by surveying participants on their impressions of the curriculum and their confidence and self-efficacy in mastery of the material. Additionally, facilitators of the WiSDEM curriculum were surveyed on its content, usefulness, and future applicability., Results: The WiSDEM curriculum was deployed during the SAEM 2022 Annual Meeting as a didactic presentation. Thirty-nine of 44 participants completed the participant survey, and four of four facilitators completed the facilitator survey. Participant and facilitator feedback on the curriculum content was positive. Additionally, participants agreed that the WiSDEM curriculum improved their confidence and self-efficacy in future debriefing. All surveyed facilitators agreed that they would recommend the curriculum to others., Conclusions: The WiSDEM curriculum was effective at introducing basic debriefing principles to novice educators without formal debriefing training. Facilitators felt that the educational materials would be useful for providing debriefing training at other institutions. Consensus-driven, ready-to-deploy debriefing training materials such as the WiSDEM curriculum can address common barriers to developing basic debriefing proficiency in educators., Competing Interests: The authors declare no conflicts of interest., (© 2023 Society for Academic Emergency Medicine.)
- Published
- 2023
- Full Text
- View/download PDF
7. In their own words: Experiences of emergency health care workers during the COVID-19 pandemic.
- Author
-
Blanchard J, Messman AM, Bentley SK, Lall MD, Liu YT, Merritt R, Sorge R, Warchol JM, Greene C, Diercks DB, Griffith J, Manfredi RA, and McCarthy M
- Subjects
- Health Personnel, Humans, Pandemics, United States epidemiology, Workplace, Burnout, Professional epidemiology, Burnout, Professional prevention & control, Burnout, Professional psychology, COVID-19
- Abstract
Background: During the COVID-19 pandemic, a substantial number of emergency health care workers (HCWs) have screened positive for anxiety, depression, risk of posttraumatic stress disorder, and burnout. The purpose of this qualitative study was to describe the impact of COVID-19 on emergency care providers' health and well-being using personal perspectives. We conducted in-depth interviews with emergency physicians, emergency medicine nurses, and emergency medical services providers at 10 collaborating sites across the United States between September 21, 2020, and October 26, 2020., Methods: We developed a conceptual framework that described the relationship between the work environment and employee health. We used qualitative content analysis to evaluate our interview transcripts classified the domains, themes, and subthemes that emerged from the transcribed interviews., Results: We interviewed 32 emergency HCWs. They described difficult working conditions, such as constrained physical space, inadequate personnel protective equipment, and care protocols that kept changing. Organizational leadership was largely viewed as unprepared, distant, and unsupportive of employees. Providers expressed high moral distress caused by ethically challenging situations, such as the perception of not being able to provide the normal standard of care and emotional support to patients and their families at all times, being responsible for too many sick patients, relying on inexperienced staff to treat infected patients, and caring for patients that put their own health and the health of their families at risk. Moral distress was commonly experienced by emergency HCWs, exacerbated by an unsupportive organizational environment., Conclusions: Future preparedness efforts should include mechanisms to support frontline HCWs when faced with ethical challenges in addition to an adverse working environment caused by a pandemic such as COVID-19., (© 2022 Society for Academic Emergency Medicine.)
- Published
- 2022
- Full Text
- View/download PDF
8. The perceived work environment and well-being: A survey of emergency health care workers during the COVID-19 pandemic.
- Author
-
Blanchard J, Li Y, Bentley SK, Lall MD, Messman AM, Liu YT, Diercks DB, Merritt-Recchia R, Sorge R, Warchol JM, Greene C, Griffith J, Manfredi RA, and McCarthy M
- Subjects
- Depression diagnosis, Depression epidemiology, Health Personnel, Humans, Pandemics, Surveys and Questionnaires, United States epidemiology, Workplace, Burnout, Professional epidemiology, Burnout, Professional psychology, COVID-19 epidemiology
- Abstract
Background: During the COVID-19 pandemic, health care provider well-being was affected by various challenges in the work environment. The purpose of this study was to evaluate the relationship between the perceived work environment and mental well-being of a sample of emergency physicians (EPs), emergency medicine (EM) nurses, and emergency medical services (EMS) providers during the pandemic., Methods: We surveyed attending EPs, resident EPs, EM nurses, and EMS providers from 10 academic sites across the United States. We used latent class analysis (LCA) to estimate the effect of the perceived work environment on screening positive for depression/anxiety and burnout controlling for respondent characteristics. We tested possible predictors in the multivariate regression models and included the predictors that were significant in the final model., Results: Our final sample included 701 emergency health care workers. Almost 23% of respondents screened positive for depression/anxiety and 39.7% for burnout. Nurses were significantly more likely to screen positive for depression/anxiety (adjusted odds ratio [aOR] 2.04, 95% confidence interval [CI] 1.11-3.86) and burnout (aOR 2.05, 95% CI 1.22-3.49) compared to attendings. The LCA analysis identified four subgroups of our respondents that differed in their responses to the work environment questions. These groups were identified as Work Environment Risk Group 1, an overall good work environment; Risk Group 2, inadequate resources; Risk Group 3, lack of perceived organizational support; and Risk Group 4, an overall poor work environment. Participants in the two groups who perceived their work conditions as most adverse were significantly more likely to screen positive for depression/anxiety (aOR 1.89, 95% CI 1.05-3.42; and aOR 2.04, 95% CI 1.14-3.66) compared to participants working in environments perceived as less adverse., Conclusions: We found a strong association between a perceived adverse working environment and poor mental health, particularly when organizational support was deemed inadequate. Targeted strategies to promote better perceptions of the workplace are needed., (© 2022 Society for Academic Emergency Medicine.)
- Published
- 2022
- Full Text
- View/download PDF
9. Hospital-wide cardiac arrest in situ simulation to identify and mitigate latent safety threats.
- Author
-
Bentley SK, Meshel A, Boehm L, Dilos B, McIndoe M, Carroll-Bennett R, Astua AJ, Wong L, Smith C, Iavicoli L, LaMonica J, Lopez T, Quitain J, Dube G, Manini AF, Halbach J, Meguerdichian M, and Bajaj K
- Abstract
Background: Cardiac arrest resuscitation requires well-executed teamwork to produce optimal outcomes. Frequency of cardiac arrest events differs by hospital location, which presents unique challenges in care due to variations in responding team composition and comfort levels and familiarity with obtaining and utilizing arrest equipment. The objective of this initiative is to utilize unannounced, in situ, cardiac arrest simulations hospital wide to educate, evaluate, and maximize cardiac arrest teams outside the traditional simulation lab by systematically assessing and capturing areas of opportunity for improvement, latent safety threats (LSTs), and key challenges by hospital location., Methods: Unannounced in situ simulations were performed at a city hospital with multidisciplinary cardiac arrest teams responding to a presumed real cardiac arrest. Participants and facilitators identified LSTs during standardized postsimulation debriefings that were classified into equipment, medication, resource/system, or technical skill categories. A hazard matrix was used by multiplying occurrence frequency of LST in simulation and real clinical events (based on expert opinion) and severity of the LST based on agreement between two evaluators., Results: Seventy-four in situ cardiac arrest simulations were conducted hospital wide. Hundreds of safety threats were identified, analyzed, and categorized yielding 106 unique latent safety threats: 21 in the equipment category, 8 in the medication category, 41 in the resource/system category, and 36 in the technical skill category. The team worked to mitigate all LSTs with priority mitigation to imminent risk level threats, then high risk threats, followed by non-imminent risk LSTs. Four LSTs were deemed imminent, requiring immediate remediation post debriefing. Fifteen LSTs had a hazard ratio greater than 8 which were deemed high risk for remediation. Depending on the category of threat, a combination of mitigating steps including the immediate fixing of an identified problem, leadership escalation, and programmatic intervention recommendations occurred resulting in mitigation of all identified threats., Conclusions: Hospital-wide in situ cardiac arrest team simulation offers an effective way to both identify and mitigate LSTs. Safety during cardiac arrest care is improved through the use of a system in which LSTs are escalated urgently, mitigated, and conveyed back to participants to provide closed loop debriefing. Lastly, this hospital-wide, multidisciplinary initiative additionally served as an educational needs assessment allowing for informed, iterative education and systems improvement initiatives targeted to areas of LSTs and areas of opportunity., (© 2022. The Author(s).)
- Published
- 2022
- Full Text
- View/download PDF
10. Leveling the field: Development of reliable scoring rubrics for quantitative and qualitative medical education research abstracts.
- Author
-
Jordan J, Hopson LR, Molins C, Bentley SK, Deiorio NM, Santen SA, Yarris LM, Coates WC, and Gisondi MA
- Abstract
Background: Research abstracts are submitted for presentation at scientific conferences; however, criteria for judging abstracts are variable. We sought to develop two rigorous abstract scoring rubrics for education research submissions reporting (1) quantitative data and (2) qualitative data and then to collect validity evidence to support score interpretation., Methods: We used a modified Delphi method to achieve expert consensus for scoring rubric items to optimize content validity. Eight education research experts participated in two separate modified Delphi processes, one to generate quantitative research items and one for qualitative. Modifications were made between rounds based on item scores and expert feedback. Homogeneity of ratings in the Delphi process was calculated using Cronbach's alpha, with increasing homogeneity considered an indication of consensus. Rubrics were piloted by scoring abstracts from 22 quantitative publications from AEM Education and Training "Critical Appraisal of Emergency Medicine Education Research" (11 highlighted for excellent methodology and 11 that were not) and 10 qualitative publications (five highlighted for excellent methodology and five that were not). Intraclass correlation coefficient (ICC) estimates of reliability were calculated., Results: Each rubric required three rounds of a modified Delphi process. The resulting quantitative rubric contained nine items: quality of objectives, appropriateness of methods, outcomes, data analysis, generalizability, importance to medical education, innovation, quality of writing, and strength of conclusions (Cronbach's α for the third round = 0.922, ICC for total scores during piloting = 0.893). The resulting qualitative rubric contained seven items: quality of study aims, general methods, data collection, sampling, data analysis, writing quality, and strength of conclusions (Cronbach's α for the third round = 0.913, ICC for the total scores during piloting = 0.788)., Conclusion: We developed scoring rubrics to assess quality in quantitative and qualitative medical education research abstracts to aid in selection for presentation at scientific meetings. Our tools demonstrated high reliability., Competing Interests: The authors have no potential conflicts to disclose., (© 2021 by the Society for Academic Emergency Medicine.)
- Published
- 2021
- Full Text
- View/download PDF
11. Debrief it all: a tool for inclusion of Safety-II.
- Author
-
Bentley SK, McNamara S, Meguerdichian M, Walker K, Patterson M, and Bajaj K
- Abstract
Safety science in healthcare has historically focused primarily on reducing risk and minimizing harm by learning everything possible from when things go wrong (Safety-I). Safety-II encourages the study of all events, including the routine and mundane, not only bad outcomes. While debriefing and learning from positive events is not uncommon or new to simulation, many common debriefing strategies are more focused on Safety-I. The lack of inclusion of Safety-II misses out on the powerful analysis of everyday work.A debriefing tool highlighting Safety-II concepts was developed through expert consensus and piloting and is offered as a guide to encourage and facilitate inclusion of Safety-II analysis into debriefings. It allows for debriefing expansion from the focus on error analysis and "what went wrong" or "could have gone better" to now also capture valuable discussion of high yield Safety-II concepts such as capacities, adjustments, variation, and adaptation for successful operations in a complex system. Additionally, debriefing inclusive of Safety-II fosters increased debriefing overall by encouraging debriefing when "things go right", not historically what is most commonly debriefed.
- Published
- 2021
- Full Text
- View/download PDF
12. Guidance and Patient Instructions for Proning and Repositioning of Awake, Nonintubated COVID-19 Patients.
- Author
-
Bentley SK, Iavicoli L, Cherkas D, Lane R, Wang E, Atienza M, Fairweather P, and Kessler S
- Subjects
- Humans, Hypoxia, SARS-CoV-2, COVID-19 therapy, Guidelines as Topic, Patient Positioning, Respiration, Artificial standards, Wakefulness
- Published
- 2020
- Full Text
- View/download PDF
13. CT overuse for mild traumatic brain injury.
- Author
-
Melnick ER, Szlezak CM, Bentley SK, Dziura JD, Kotlyar S, and Post LA
- Subjects
- Adult, Canada, Craniocerebral Trauma classification, Emergency Service, Hospital standards, Evidence-Based Practice, Female, Guideline Adherence statistics & numerical data, Humans, Male, Middle Aged, Practice Guidelines as Topic, Retrospective Studies, Tomography, X-Ray Computed adverse effects, Tomography, X-Ray Computed standards, United States, Craniocerebral Trauma diagnostic imaging, Emergency Service, Hospital statistics & numerical data, Tomography, X-Ray Computed statistics & numerical data
- Abstract
Background: Multiple, validated, evidence-based guidelines exist to inform the appropriate use of computed tomography (CT) to differentiate mild traumatic brain injury (MTBI) from clinically important brain injury and to prevent the overuse of CT. Yet, CT use is growing rapidly, potentially exposing patients to unnecessary ionizing radiation risk and costs. A study was conducted to quantify the overuse of CT in MTBI on the basis of current guideline recommendations., Methods: A retrospective analysis of secondary data from a prospective observational study was undertaken at an urban, Level I emergency department (ED) with more than 90,000 visits per year. For adult patients with minor head injury receiving CT imaging at the discretion of the treating physician, the proportion of cases meeting criteria for CT on the basis of the Canadian CT Head Rule (CCHR), American College of Emergency Physicians (ACEP) Clinical Policy, New Orleans Criteria (NOC), and National Institute for Health and Clinical Excellence (NICE) guidelines was reported., Results: All 346 patients enrolled in the original study were included in the analysis. The proportion of cases meeting criteria for CT for each of the guidelines was: CCHR 64.7% (95% confidence interval [CI], 0.60-0.70), ACEP 74.3% (95% CI, 0.70-0.79), NICE 86.7% (95% CI, 0.83-0.90), and NOC 90.5% (95% CI, 0.87-0.94). The odds ratio of the guidelines for predicting positive head CT findings were also reported., Discussion: Some 10%-35% of CTs obtained in the ED for MTBI were not recommended according to the guidelines. Successful implementation of existing guidelines could decrease CT use in MTBI by up to 35%, leading to a significant reduction in radiation-induced cancers and health care costs.
- Published
- 2012
- Full Text
- View/download PDF
14. Ultrasound-guided axillary vein approach to the subclavian vein for central venous access.
- Author
-
Bentley SK, Seethala R, and Weingart SD
- Subjects
- Aged, Female, Humans, Radiography, Ultrasonography, Axillary Vein diagnostic imaging, Catheterization, Central Venous methods, Vena Cava, Superior diagnostic imaging
- Published
- 2008
- Full Text
- View/download PDF
15. Effects of chloride substitutes on PAH transport by isolated perfused renal tubules.
- Author
-
Dantzler WH and Bentley SK
- Subjects
- Animals, Biological Transport, Active drug effects, Cell Membrane Permeability drug effects, Female, Isethionic Acid pharmacology, Male, Membrane Potentials drug effects, Perfusion, Snakes, Sulfuric Acid Esters pharmacology, Thiocyanates pharmacology, Water-Electrolyte Balance drug effects, Aminohippuric Acids metabolism, Chlorides physiology, Kidney Tubules metabolism, p-Aminohippuric Acid metabolism
- Abstract
Effects of substituting isethionate, methyl sulfate, or thiocyanate for chloride on p-aminohippurate (PAH) transport by isolated perfused snake (Thamnophis spp.) distal-proximal renal tubules were studied. In the perfusate, isethionate or methyl sulfate substitution irreversibly depressed net PAH secretion and the apparent PAH permeability of the luminal membrane by about 60-80%, whereas thiocyanate substitution had no effect. In the bathing medium, isethionate substitution reversibly stimulated net PAH secretion by about 35% without changing the apparent permeability of the peritubular membrane to PAH (Pp); thiocyanate substitution reversibly inhibited net PAH secretion by about 45% without affecting Pp; and methyl sulfate substitution had no effect. With simultaneous substitutions in perfusate and bath, isethionate depressed net PAH secretion irreversibly, whereas thiocyanate had no effect. Effects on PAH transport were not simply the result of changes in transepithelial potential or of the changes in net transepithelial fluid movement. These data strengthen the concept that net PAH secretion involves different mediated steps at the peritubular and luminal membranes. Since these tubules are highly permeable to thiocyanate and poorly permeable to isethionate and methyl sulfate, the data suggest that the mediated step from cells to lumen does not require chloride in the lumen but does require a highly permeant anion.
- Published
- 1981
- Full Text
- View/download PDF
16. Effects of inhibitors in lumen on PAH and urate transport by isolated renal tubules.
- Author
-
Dantzler WH and Bentley SK
- Subjects
- Animals, Biological Transport, Active drug effects, Female, In Vitro Techniques, Male, Phenolsulfonphthalein pharmacology, Probenecid pharmacology, Hippurates metabolism, Kidney Tubules, Proximal metabolism, Snakes metabolism, Uric Acid metabolism
- Abstract
Effects of the presence of unlabeled p-aminohippurate (PAH) or urate, probenecid, and phenol red in the lumen on labeled PAH or urate transport by isolated, perfused snake (Thamnophis spp.) proximal renal tubules were studied. Net secretion of labeled urate and luminal membrane permeability to urate were unaffected by the presence of unlabeled urate (up to 0.1 mM) or probenecid (up to 1.0 mM) in lumen only. The data are compatible with movement of urate from cells to lumen during urate secretion by a simple passive process. Net secretion of labeled PAH was rapidly and reversibly depressed to about 25-35% of control when unlabeled PAH (0.05 mM), phenol red (0.05 mM), or probenecid (0.1 mM) was added to the lumen only. During maximum depression of PAH transport, luminal membrane permeability to PAH was reduced by 60-70%. The data suggest that movement of PAH from cells to lumen down an electrochemical gradient during PAH secretion occurs by a readily inhibited, mediated process.
- Published
- 1979
- Full Text
- View/download PDF
17. Bath and lumen effects of SITS on PAH transport by isolated perfused renal tubules.
- Author
-
Dantzler WH and Bentley SK
- Subjects
- Animals, Biological Transport drug effects, Cell Membrane Permeability drug effects, Depression, Chemical, In Vitro Techniques, Mathematics, 4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid pharmacology, Aminohippuric Acids metabolism, Kidney Tubules, Proximal metabolism, Snakes metabolism, Stilbenes pharmacology, p-Aminohippuric Acid metabolism
- Abstract
Effects of 4-acetamido-4'-isothiocyano-2,2'-disulfonic stilbene (SITS) in bath or lumen on p-aminohippurate (PAH) transport by isolated perfused snake (Thamnophis spp.) distal-proximal renal tubules were studied. Addition of SITS to the bath in concentrations as low as 10(-10) M irreversibly depressed net PAH secretion. Addition of 10(-4) M SITS in the bath depressed net PAH secretion by about 60% without affecting apparent permeability of luminal membrane to PAH (PL) or net fluid absorption. Cellular PAH concentration was reduced by about 70% at this time but was still greater than that in the bath. Apparent permeability of peritubular membrane, determined from PAH efflux from tubules with oil-filled lumens, was unchanged even with 10(-3) M SITS in bath. These data indicate that SITS in the bath inhibits PAH transport from bath into cells without enhancing passive efflux from cells to bath. Addition of 10(-4) M SITS to the lumen alone depressed net PAH secretion and PL by about 60%, but this depression was reversed when SITS was removed from the lumen. These data suggest that PAH moves from cells to lumen by a mediated process distinctly different from that fro transport into cells from bath.
- Published
- 1980
- Full Text
- View/download PDF
18. Effects of sulfhydryl reagent, p-chloromercuribenzoate, on p-aminohippurate transport by isolated, perfused snake renal tubules.
- Author
-
Dantzler WH and Bentley SK
- Subjects
- Animals, Biological Transport, In Vitro Techniques, Perfusion, Snakes, Aminohippuric Acids metabolism, Chloromercuribenzoates pharmacology, Kidney Tubules, Proximal metabolism, p-Aminohippuric Acid metabolism
- Abstract
Effects of mercaptide-forming sulfhydryl reagent, p-chloromercuribenzoate (PCMB), on transport of p-aminohippurate (PAH) by isolated, perfused snake (Thamnophis species) renal tubules were studied. PCMB (10(-7) mol/l) in bathing medium irreversibly inhibited net transepithelial transport of PAH (JPAH) without affecting net fluid absorption (Jv). PCMB (10(-8) mol/l) in perfusate irreversibly inhibited JPAH without affecting Jv and markedly reduced the apparent permeability of the luminal membrane to PAH. These data suggest that sulfhydryl groups may be involved in the PAH transport steps at both the peritubular and luminal membranes.
- Published
- 1983
- Full Text
- View/download PDF
19. Fluid absorption with and without sodium in isolated perfused snake proximal tubules.
- Author
-
Dantzler WH and Bentley SK
- Subjects
- Animals, Buffers pharmacology, Choline pharmacology, Cyanides pharmacology, Dextrans pharmacology, Mathematics, Ouabain pharmacology, Perfusion, Snakes, Water-Electrolyte Balance, Kidney Tubules, Proximal physiology, Sodium physiology
- Abstract
Net fluid absorption (JV) was studied in isolated, perfused snake (Thamnophis spp.) proximal renal tubules. With standard (150 mmol/liter Na+) bicarbonate-buffered Ringer in perfusate and standard Ringer plus dextran (4 g/100 ml) in bath, JV was about 0.9 nl min-1 mm-1. Removing dextran from bath reduced JV by about 20 percent. When sodium in perfusate was replaced with choline JV approached zero. However, when sodium in bath as well as perfusate was replaced with choline, JV returned to control level. Results were the same when sodium was replaced with tetramethyl-ammonium, sodium chloride was replaced with sucrose or lactose, or chloride was replaced with methyl sulfate. In contrast, replacing sodium in perfusate or in both perfusate and bath with lithium did not reduce JV. Fluid absorption was always isosmotic. Replacing bicarbonate with phosphate or Tris in sodium-containing media had no effect on JV, but the presence of buffer in sodium-free or low-chloride media may have been important for JV. Reducing temperature 10 degrees C reduced JV by about 35 percent with either sodium chloride or sucrose in both perfusate and bath. The results indicate that isosmotic fluid absorption can occur when lithium is substituted for sodium or when some other substitution is made for sodium, chloride, or both in perfusate and bath simultaneously.
- Published
- 1978
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.