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Laughlin MS, Vidal EA, Drtil AA, Goytia RN, Mathews V, Patel AR. Mortality After Revision Total Hip Arthroplasty. J Arthroplasty 2021; 36:2353-2358. [PMID: 33558045 DOI: 10.1016/j.arth.2021.01.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 01/04/2021] [Accepted: 01/11/2021] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND In counseling patients about the complications of revision total hip arthroplasty (revTHA), it is imperative that mortality be considered. The actual mortality rate by indication of revision is ill-defined. The purpose of this study is to determine the mortality rate after revTHA. METHODS An institutional database identified 596 patients who had undergone revTHA between 2012 and 2018. Medical records, national, state, and local death indexes were queried for mortality status and indication for revTHA. For survivors, the last clinical visit date was used for censoring in the mortality analysis. Mortality rates were calculated for all clinical patients and then by specific indication for revision. RESULTS The overall 2-year mortality rate following revTHA was 19.5 deaths per 1000 or 1 in 51 patients. Patients presenting with a periprosthetic fracture had a significantly higher 2-year mortality rate of 74.5 deaths per 1000 or 1 in 13 patients (P < .001), while an indication of dislocation or instability had a slightly higher 2-year mortality rate of 50.3 per 1000 (1 in 20) but this difference was not significant (P = .531). Other indications such as mechanical loosening or infection did not have a significantly different mortality rate. CONCLUSION The overall 2-year mortality rate following revTHA was 19.5 deaths per 1000 which was largely attributed to patients with a periprosthetic fracture (74.5 per 1000) with other indications not significantly impacting mortality. Mortality rates and specific rates by indication for revision should be considered when counseling patients prior to revTHA.
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Affiliation(s)
| | - Emily A Vidal
- Fondren Orthopedic Research Institute (FORI), Houston, TX
| | - Arin A Drtil
- Fondren Orthopedic Research Institute (FORI), Houston, TX; Baylor College of Medicine, Houston, TX
| | - Robin N Goytia
- Fondren Orthopedic Research Institute (FORI), Houston, TX; Fondren Orthopedic Group, Texas Orthopedic Hospital, Houston, TX
| | - Vasilios Mathews
- Fondren Orthopedic Research Institute (FORI), Houston, TX; Fondren Orthopedic Group, Texas Orthopedic Hospital, Houston, TX
| | - Anay R Patel
- Fondren Orthopedic Research Institute (FORI), Houston, TX; Fondren Orthopedic Group, Texas Orthopedic Hospital, Houston, TX
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2
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Singer AJ, Fuggle NR, Gill CB, Patel AR, Medeiros AP, Greenspan SL. COVID-19 and effects on osteoporosis management: the patient perspective from a National Osteoporosis Foundation survey. Osteoporos Int 2021; 32:619-622. [PMID: 33558958 PMCID: PMC7869916 DOI: 10.1007/s00198-021-05836-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 01/06/2021] [Indexed: 11/16/2022]
Affiliation(s)
- A J Singer
- Departments of Medicine and Obstetrics and Gynecology, MedStar Georgetown University Hospital and Georgetown University Medical Center, Washington, DC, USA.
- Department of Obstetrics and Gynecology, MedStar Georgetown University Hospital, Washington, DC, USA.
| | - N R Fuggle
- MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK
- Alan Turing Institute, London, UK
| | - C B Gill
- National Osteoporosis Foundation, Arlington, VA, USA
| | - A R Patel
- National Osteoporosis Foundation, Arlington, VA, USA
| | - A P Medeiros
- National Osteoporosis Foundation, Arlington, VA, USA
| | - S L Greenspan
- Department of Medicine, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA, USA
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3
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Carli AV, Patel AR, Cross MB, Mayman DJ, Carroll KM, Pellicci PM, Jerabek SA. Long-term performance of oxidized zirconium on conventional and highly cross-linked polyethylene in total hip arthroplasty. SICOT J 2020; 6:10. [PMID: 32378510 PMCID: PMC7204272 DOI: 10.1051/sicotj/2020010] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 04/16/2020] [Indexed: 11/14/2022] Open
Abstract
Introduction: Polyethylene wear and subsequent osteolysis remain obstacles to the long-term survivorship of total hip arthroplasty (THA). Highly cross-linked polyethylene (XLPE) with radical quenching represents a massive leap forward with dramatically improved wear rates compared to ultra-high molecular weight polyethylene (UHMWPE). In this study we evaluate the wear of UHMWPE and XLPE coupled with oxidized zirconium (OxZr) femoral heads. Methods: A longitudinal, retrospective analysis was performed identifying consecutive patients who received a 28-mm OxZr-on-polyethylene primary THA from 2003 to 2004 by a single, high-volume arthroplasty surgeon. Patients were divided into two groups: those that received (1) UHMWPE liner and (2) a highly XLPE liner. Patients were included if clinical follow-up was complete to 2014 or later. Radiographic analysis was performed by two blinded observers. Measures included cup position, annual linear wear rate, and presence of osteolysis. Pairwise comparisons, correlations, and inter-rater reliability were calculated. Results: Eighty patients were in the UHMWPE group with an average follow-up of 10 ± 1.23 years and 88 patients in the XLPE group with an average of 10 ± 1.03-year follow-up. Average age (68) was similar between groups (p = 0.288). Observer reliability was excellent for cup abduction (ICC = 0.940), anteversion (ICC = 0.942), and detection of osteolysis (ICC = 0.811). Annual linear wear rates were significantly higher (p = 1 × 10−19) with UHMWPE (0.21 ± 0.12 mm/year) compared to XLPE (0.05 ± 0.03 mm/year). Linear wear rate was significantly correlated to decreasing acetabular abduction (p = 0.035). Osteolysis was noted only in the UHMWPE group, with 17 patients (21.2%) exhibiting acetabular osteolysis and 37 (46.3%) patients exhibiting femoral osteolysis. Conclusions: OxZr coupled with XLPE showed minimal wear and no osteolysis at 10-year follow up. The yearly linear penetration rate is similar to that seen in other studies of XLPE THA. A careful longitudinal follow-up will be required to determine if advanced bearings such as OxZr or ceramic can show improved performance in the second decade of implantation.
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Affiliation(s)
- Alberto V Carli
- Hospital for Special Surgery, 535 E 70th St., New York, 10021 NY, USA
| | - Anay R Patel
- Fondren Orthopedic Group, 7401 Main St., Houston, 77030 TX, USA
| | - Michael B Cross
- Hospital for Special Surgery, 535 E 70th St., New York, 10021 NY, USA
| | - David J Mayman
- Hospital for Special Surgery, 535 E 70th St., New York, 10021 NY, USA
| | - Kaitlin M Carroll
- Hospital for Special Surgery, 535 E 70th St., New York, 10021 NY, USA
| | - Paul M Pellicci
- Hospital for Special Surgery, 535 E 70th St., New York, 10021 NY, USA
| | - Seth A Jerabek
- Hospital for Special Surgery, 535 E 70th St., New York, 10021 NY, USA
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Stathogiannis K, Mor-Avi V, Lang R, Patel AR. P5253Does regional myocardial strain by cardiac magnetic resonance feature tracking reflect scar in ischemic heart disease? Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz746.0224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Cardiac magnetic resonance (CMR) late gadolinium enhancement (LGE) is the gold standard for detection of myocardial scar. We hypothesized that CMR Feature Tracking (FT)-derived regional myocardial strain may reflect the presence of scar and could thus potentially be used instead of LGE imaging.
Purpose
The aim of this study was to determine the relationship between FT-derived regional myocardial strain and LGE in patients with coronary artery disease (CAD).
Methods
Seventy-five patients with CAD and typical ischemic LGE patterns on CMR (1.5T) were included (mean age 60±12 years, 70% males). Myocardial strain analysis and LGE identification were performed using dedicated commercial software. Scar was defined by presence of LGE in the same area of the myocardium in both short- and long-axis views. Peak systolic regional longitudinal and circumferential strain (RLS, RCS) values were calculated in the region of interest corresponding to the LGE area and also in a non-LGE myocardial region as a reference in each patient. These comparisons were repeated for a subgroup of 36 patients with left ventricular (LV) ejection fraction (EF) <40% to determine whether the relationship between strain and LGE holds in the presence of reduced LV function, when strain measurements may be altered as a reflection of reduced LVEF itself.
Results
Both global longitudinal and circumferential strain values were abnormal (−12.8±5.1% and −11.4±4.1%, respectively), reflecting LV dysfunction in this CAD cohort (EF = 40±16%). The magnitude of both RLS and RCS was significantly reduced in areas of LGE, compared to those without LGE: RLS −10.0±5.8% versus −20.4±7.5% (p<0.001); RCS −10.1±5.3±% versus −18.9±7.5%, respectively (p<0.001). Same pattern was noted in the reduced EF subgroup: RLS −8.0±4.7% versus −16.9±6.6% (p<0.001), RCS −7.7±4.3±% versus −16.0±7.9%, respectively (p<0.001). The figure depicts 2 representative cases in long and short axis views, LGE detection and concomitant regional strain analysis.
LGE and regional strain analysis.
Conclusion
Reduced magnitude of regional longitudinal and circumferential strain by CMR-FT correlates with presence of LGE. Pending further validation, this finding may constitute the basis for detection of scar without contrast enhanced imaging, and would result in reduced cost, scan time and risk associated with gadolinium.
Acknowledgement/Funding
ARP: Research support (software) from Neosoft and Philips
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Affiliation(s)
- K Stathogiannis
- University of Chicago Medicine, Chicago, United States of America
| | - V Mor-Avi
- University of Chicago Medicine, Chicago, United States of America
| | - R Lang
- University of Chicago Medicine, Chicago, United States of America
| | - A R Patel
- University of Chicago Medicine, Chicago, United States of America
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Bockhorn LN, Goytia RN, Laughlin MS, Patel AR. Increased Orthopedic Specialization Lowers Costs and Improves Outcomes in Total Joint Arthroplasty. J Arthroplasty 2019; 34:S76-S79. [PMID: 30935802 DOI: 10.1016/j.arth.2019.02.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 02/04/2019] [Accepted: 02/13/2019] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Total joint arthroplasty (TJA) volumes have risen in the past decade, resulting in increased national spending. Prior studies indicate that TJA performed at higher-volume hospitals result in better patient outcomes at lower costs. The purpose of this study is to determine whether increased orthopedic specialization has similar effects. METHODS Centers for Medicare and Medicaid Services Inpatient Charge Data queries identified 2677 hospitals that performed TJA in 2015. Hospitals were assigned an orthopedic specialization ratio (OSR), defined as the ratio of musculoskeletal discharges to total discharges. Average covered charges (ACC), average total payments, and average Medicare payments (AMP) of TJA were extracted. TJA-specific, risk-adjusted complication and readmission scores were obtained from the Centers for Medicare and Medicaid Services Hospital Compare database. Comparisons between orthopedic specialty hospitals and nonspecialty hospitals performing TJA were made with Student t-tests. Regression models analyzed the relationship between OSR, volume and cost, payments, readmission rate score, and complication rate score. RESULTS Orthopedic specialty hospitals had lower ACC, average total payments, AMP, readmission, and complication scores than nonspecialty hospitals (all P < .001). Regression models showed that as the OSR increased from 0 to 1.0, ACC decreased by $19,242.83 and AMP decreased by $2310.75 (P < .001). Readmission score decreased by 0.349 and complication score decreased by 0.346 (P < .001) when controlling for volume as the OSR increased from 0 to 1. CONCLUSION Hospitals with increased OSR appear to perform TJA for Medicare patients at a lower cost with lower complication and readmission risk. It may be beneficial to consider the OSR when determining the ideal settings for TJA.
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Affiliation(s)
| | - Robin N Goytia
- Fondren Orthopedic Group, Houston, TX; Fondren Orthopedic Research Institute, Houston, TX
| | | | - Anay R Patel
- Fondren Orthopedic Group, Houston, TX; Fondren Orthopedic Research Institute, Houston, TX
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6
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Ihekweazu UN, Sohn GH, Laughlin MS, Goytia RN, Mathews V, Stocks GW, Patel AR, Brinker MR. Socio-demographic factors impact time to discharge following total knee arthroplasty. World J Orthop 2018; 9:285-291. [PMID: 30598872 PMCID: PMC6306518 DOI: 10.5312/wjo.v9.i12.285] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 11/06/2018] [Accepted: 12/10/2018] [Indexed: 02/06/2023] Open
Abstract
AIM To determine social, logistical and demographic factors that influence time to discharge in a short stay pathway (SSP) by following total knee arthroplasty (TKA).
METHODS The study included primary TKA’s performed in a high-volume arthroplasty center from January 2016 through December 2016. Potential variables associated with increased hospital length of stay (LOS) were obtained from patient medical records. These included age, gender, race, zip code, body mass index (BMI), number of pre-operative medications used, number of narcotic medications used, number of patient reported allergies (PRA), simultaneous bilateral surgery, tobacco use, marital status, living arrangements, distance traveled for surgery, employment history, surgical day of the week, procedure end time and whether the surgery was performed during a major holiday week. Multivariate step-wise regression determined the impact of social, logistical and demographic factors on LOS.
RESULTS Eight hundred and six consecutive primary SSP TKA’s were included in this study. Patients were discharged at a median of 49 h (post-operative day two). The following factors increased LOS: Simultaneous bilateral TKA [46.1 h longer (P < 0.001)], female gender [4.3 h longer (P = 0.012)], age [3.5 h longer per ten-year increase in age (P < 0.001)], patient-reported allergies [1.1 h longer per allergy reported (P = 0.005)], later procedure end-times [0.8 h longer per hour increase in end-time (P = 0.004)] and Black or African American patients [6.1 h longer (P = 0.047)]. Decreased LOS was found in married patients [4.8 h shorter (P = 0.011)] and TKA’s performed during holiday weeks [9.4 h shorter (P = 0.011)]. Non-significant factors included: BMI, median income, patient’s living arrangement, smoking status, number of medications taken, use of pre-operative pain medications, distance traveled to hospital, and the day of surgery.
CONCLUSION The cost of TKA is dependent upon LOS, which is affected by multiple factors. The clinical care team should acknowledge socio-demographic factors to optimize LOS.
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Affiliation(s)
- Ugonna N Ihekweazu
- Fondren Orthopedic Group, Houston, TX 77030, United States
- Fondren Orthopedic Research Institute, Fondren Orthopedic Group, Houston, TX 77030, United States
| | - Garrett H Sohn
- Department of Orthopedic Surgery, Baylor College of Medicine, Houston, TX 77030, United States
| | - Mitzi S Laughlin
- Fondren Orthopedic Research Institute, Fondren Orthopedic Group, Houston, TX 77030, United States
| | - Robin N Goytia
- Fondren Orthopedic Group, Houston, TX 77030, United States
- Fondren Orthopedic Research Institute, Fondren Orthopedic Group, Houston, TX 77030, United States
| | - Vasilios Mathews
- Fondren Orthopedic Group, Houston, TX 77030, United States
- Fondren Orthopedic Research Institute, Fondren Orthopedic Group, Houston, TX 77030, United States
| | - Gregory W Stocks
- Fondren Orthopedic Group, Houston, TX 77030, United States
- Fondren Orthopedic Research Institute, Fondren Orthopedic Group, Houston, TX 77030, United States
| | - Anay R Patel
- Fondren Orthopedic Group, Houston, TX 77030, United States
- Fondren Orthopedic Research Institute, Fondren Orthopedic Group, Houston, TX 77030, United States
| | - Mark R Brinker
- Fondren Orthopedic Group, Houston, TX 77030, United States
- Fondren Orthopedic Research Institute, Fondren Orthopedic Group, Houston, TX 77030, United States
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7
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Sharma KK, Shukla VR, Patel AR, Vaghela KM, Patel HK, Shah PG, Banerjee H, Banerjee T, Hudait RK, Sharma D, Sahoo SK, Singh B, Tripathy V. Multilocation field trials for risk assessment of a combination fungicide Fluopicolide + Propamocarb in tomato. Environ Monit Assess 2016; 188:604. [PMID: 27709463 DOI: 10.1007/s10661-016-5610-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 09/21/2016] [Indexed: 06/06/2023]
Abstract
Dissipation kinetics of two systemic fungicides, namely fluopicolide and propamocarb used as a combination formulation (Infinito 68.75 SC), were studied on tomato at four different locations by the All India Network Project on Pesticide Residues to recommend their pre-harvest interval (PHI) and to propose the maximum residue limits (MRL) for the two fungicides based on chronic hazard exposure assessment. The combination fungicide was sprayed thrice at the recommended dosage of 93.75 g a.i./ha fluopicolide and 937.50 g a.i./ha propamocarb as well as at double the recommended dosage of 187.50 g a.i./ha fluopicolide and 1875.0 g a.i./ha propamocarb on tomato crops and the residues were monitored periodically by GC-MS. The fungicides dissipated to below the limit of quantification (LOQ) within 10 to 15 days, with a half-life of 2-4 days for fluopicolide and 1-2 days for propamocarb. Taking into consideration the MRLs of codex and calculations made using the method of MRL fixation of the Food Safety and Standard Authority of India (FSSAI) as well as the Organization for Economic Co-operation and Development (OECD) calculator, MRL of 5 mg/kg is proposed for fluopicolide and 15 mg/kg for propamocarb, following critical exposure of the commodity considering PHI of 1 day.
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Affiliation(s)
- K K Sharma
- All India Network Project on Pesticide Residues, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India.
| | - V R Shukla
- Anand Agricultural University, Anand, Gujarat, India
| | - A R Patel
- Anand Agricultural University, Anand, Gujarat, India
| | - K M Vaghela
- Anand Agricultural University, Anand, Gujarat, India
| | - H K Patel
- Anand Agricultural University, Anand, Gujarat, India
| | - Paresh G Shah
- Anand Agricultural University, Anand, Gujarat, India
| | - Hemanta Banerjee
- Bidhan Chandra Krishi Vishwavidyalaya, Kalyani, West Bengal, India
| | | | - Ram K Hudait
- Bidhan Chandra Krishi Vishwavidyalaya, Kalyani, West Bengal, India
| | - Debi Sharma
- ICAR-Indian Horticultural Research Institute, Bangalore, Karnataka, India
| | - S K Sahoo
- Punjab Agricultural University, Ludhiana, Punjab, India
| | | | - Vandana Tripathy
- All India Network Project on Pesticide Residues, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India
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8
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Goyal N, Patel AR, Yaffe MA, Luo MY, Stulberg SD. Does Implant Design Influence the Accuracy of Patient Specific Instrumentation in Total Knee Arthroplasty? J Arthroplasty 2015; 30:1526-30. [PMID: 25861920 DOI: 10.1016/j.arth.2015.03.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Revised: 03/19/2015] [Accepted: 03/20/2015] [Indexed: 02/01/2023] Open
Abstract
PSI software adjusts preoperative planning to accommodate differences in implant design. Such adjustments may influence the accuracy of intraoperative jig placement, bone resection, or component placement. Our purpose was to determine whether implant design influences PSI accuracy. 96 and 123 PSI TKA were performed by a single surgeon using two different implant systems and identical PSI software. Femoral coronal alignment outliers were greater for Implant 1 (23.9% Implant 1 vs. 13.4% Implant 2; P=0.050). Tibial coronal alignment outliers were greater for Implant 2 (10.9% Implant 1 vs. 22.7% Implant 2; P=0.025). There was no difference in overall mechanical axes. Differences in implant design can influence bone resection and component alignment. PSI software rationale must align with surgeons' intraoperative goals.
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Affiliation(s)
- Nitin Goyal
- Northwestern Feinberg School of Medicine Department of Orthopaedic Surgery, Chicago, Illinois
| | - Anay R Patel
- Northwestern Feinberg School of Medicine Department of Orthopaedic Surgery, Chicago, Illinois
| | - Mark A Yaffe
- Northwestern Feinberg School of Medicine Department of Orthopaedic Surgery, Chicago, Illinois
| | - Michael Y Luo
- Northwestern Feinberg School of Medicine Department of Orthopaedic Surgery, Chicago, Illinois
| | - S David Stulberg
- Northwestern Feinberg School of Medicine Department of Orthopaedic Surgery, Chicago, Illinois; Northshore Orthopaedics, Chicago, Illinois
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9
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Patel AR, Sweeney P, Ochenjele G, Wixson R, Stulberg SD, Puri LM. Radiographically Silent Loosening of the Acetabular Component in Hip Arthroplasty. Am J Orthop (Belle Mead NJ) 2015; 44:406-410. [PMID: 26372749] [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] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Polyethylene wear and subsequent osteolysis are major obstacles to the long-term success of total hip arthroplasty (THA). We conducted a study to determine the incidence of loose acetabular components that did not show frank signs of loosening on either plain radiography or computed tomography (CT), or radiographically silent loosening (RSL). In this retrospective study, we evaluated patients who underwent revision THA and were evaluated with plain radiography and CT between 2000 and 2012. Any patient with imaging that showed signs of component movement was excluded. Of the 104 patients who met the study inclusion criteria, 17 (16.3%) met the criteria for RSL of the acetabular shell. Patients with RSL presented at a similar age (P = .961) and with a similar sex profile (P = .185) compared with patients with stable acetabular components and were more likely to present with pain (P = .0487). Acetabular components may be loose even if there is no evidence of component migration on radiographic studies. Surgeons should be aware of the incidence of RSL and the potential of RSL to affect patient care and potential surgical options.
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Affiliation(s)
- Anay R Patel
- Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, NY.
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10
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Patel AR, Talati RK, Yaffe MA, McCoy BW, Stulberg SD. Femoral component rotation in total knee arthroplasty: an MRI-based evaluation of our options. J Arthroplasty 2014; 29:1666-70. [PMID: 24746490 DOI: 10.1016/j.arth.2014.02.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 02/11/2014] [Accepted: 02/26/2014] [Indexed: 02/01/2023] Open
Abstract
Proper femoral component rotation is crucial in successful total knee arthroplasty. Rotation using anatomic landmarks has traditionally referenced the transepicondylar axis (TEA), Whiteside's Line (WSL), or posterior condylar axis (PCA). TEA is thought to best approximate the flexion-axis of the knee, however WSL or PCA are common surrogates in the operating room. This study evaluated 560 knees using MRI-based planning software to assess the relationship of WSL and PCA to the TEA and determine if the relationships were influenced by pre-operative coronal deformity. Results showed the WSL-TEA relationship has more variability than PCA-TEA and that the PCA is more internally rotated in females and valgus knees. Axis options and historical assumptions about axis relationships may need to be reassessed as imaging technology advances.
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Affiliation(s)
- Anay R Patel
- The Department of Orthopaedic Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Rushi K Talati
- The Department of Orthopaedic Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Mark A Yaffe
- The Department of Orthopaedic Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Brett W McCoy
- The Department of Orthopaedic Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - S David Stulberg
- The Department of Orthopaedic Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois
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11
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Hansen JC, Patel AR, Nayak HN, Moss JD, Sweiss N, Beshai JF. Cardiac sarcoidosis and coronary artery disease: a two-hit mechanism to left ventricular dysfunction (or is it)? Sarcoidosis Vasc Diffuse Lung Dis 2013; 30:237-240. [PMID: 24284299] [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] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 11/25/2013] [Indexed: 06/02/2023]
Abstract
This report describes a case of cardiac sarcoidosis in a 40-year-old man with minimal risk factors for coronary artery disease who was found to have a critical coronary lesion on angiography performed for declining left ventricular function. The case highlights the diagnostic and therapeutic issues surrounding cardiac sarcoidosis and raises the question of a possible link between sarcoidosis and premature coronary artery disease. It also stresses the importance of ruling out ischemia in any patient with declining left ventricular function.
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Affiliation(s)
- J C Hansen
- Section of Cardiology, University of Chicago, Chicago, Illinois.
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12
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Patel AR, Patel RM, Thomas D, Bauer TW, Stulberg SD. Caveat Emptor: Adverse Inflammatory Soft-Tissue Reactions in Total Hip Arthroplasty with Modular Femoral Neck Implants: A Report of Two Cases. JBJS Case Connect 2012; 2:e80. [PMID: 29252376 DOI: 10.2106/jbjs.cc.l.00136] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Anay R Patel
- 676 North Saint Clair Street, Suite 1350, Chicago, IL 60611.
| | - Ronak M Patel
- 676 North Saint Clair Street, Suite 1350, Chicago, IL 60611.
| | | | - Thomas W Bauer
- Cleveland Clinic Main Campus, Mail Code L25, 9500 Euclid Avenue, Cleveland, OH 44195
| | - S David Stulberg
- Department of Orthopaedic Surgery, Northwestern University Feinberg School of Medicine, 680 North Lake Shore Drive, Suite 924, Chicago, IL 60611-3057
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13
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Abstract
OBJECTIVE To evaluate retention of two resin based fissure sealants (Embrace and Delton FS+) for a period of twelve months. MATERIALS AND METHODS Sixty eight first permanent molars were sealed for seventeen healthy children in the age group of six-eight years. According to random selection, the first permanent molars on the right side of both arches were sealed with Embrace (Group A) and on the left side of both arches were sealed with Delton FS+ (Group B). RESULTS The total retention of Embrace was 23.50% and for Delton FS+ was 17.60% at one year. CONCLUSION At one year the total retention of Embrace was 23.50% and for Delton FS+ was 17.60%, however the results were statistically insignificant.
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Affiliation(s)
- M R Bhatia
- Department of Pediatric and Preventive Dentistry, Bharati Vidyapeeth Dental College and Hospital, Pune, India.
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Pandher S, Sahoo SK, Battu RS, Singh B, Saiyad MS, Patel AR, Shah PG, Reddy CN, Reddy DJ, Reddy KN, Rao CS, Banerjee T, Banerjee D, Hudait R, Banerjee H, Tripathy V, Sharma KK. Persistence and dissipation kinetics of deltamethrin on chili in different agro-climatic zones of India. Bull Environ Contam Toxicol 2012; 88:764-768. [PMID: 22411176 DOI: 10.1007/s00128-012-0588-9] [Citation(s) in RCA: 2] [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] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Accepted: 02/28/2012] [Indexed: 05/31/2023]
Abstract
Multi-location supervised field trials were conducted at four different agro climatic locations in India to evaluate the dissipation pattern of deltamethrin on chili. Deltamethrin 10 EC was applied on chili @17.5 and 35 g a.i. ha(-1), samples of green chili were drawn at different time intervals and that of red chili and soil at harvest time and quantified by gas liquid chromatography equipped with electron capture detector. The identity of residues were confirmed by Gas Chromatograph-Mass Spectrophotometer in selective ion monitoring mode in mass range 181, 253 m/z. Limit of quantification of the method was found to be 0.01 mg kg(-1). Half-life of deltamethrin at application rate of 17.5 g a.i. ha(-1) varied from 0.36 to 1.99 days and at double the application rate was found to range from 0.38 to 2.06 days. Residues of deltamethrin were found below its determination limit of 0.01 mg kg(-1) in red chili and soil. On the basis of the data generated, Deltamethrin 10 EC has been registered for use on chili in India and its Maximum Residue Limit has been fixed as 0.05 μg/g.
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Patel AR, Crist MK, Nemitz J, Mayerson JL. Aspirin and compression devices versus low-molecular-weight heparin and PCD for VTE prophylaxis in orthopedic oncology patients. J Surg Oncol 2010; 102:276-81. [DOI: 10.1002/jso.21603] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Patel AR, Jones JS, Zhou M, Schoenfield L, Magi-Galluzzi C. Parasagittal biopsies are more important as part of an initial biopsy strategy than as part of a repeat biopsy strategy: observations from a unique population. Prostate Cancer Prostatic Dis 2007; 10:352-5. [PMID: 17420763 DOI: 10.1038/sj.pcan.4500966] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [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: 11/09/2022]
Abstract
Comparing the yield of parasagittal biopsies during initial saturation biopsy to the yield during repeat saturation biopsy for detection of prostate cancer. Office-based saturation biopsy (24 cores) with periprostatic lidocaine block was performed in 139 consecutive men who had never previously undergone prostate biopsy. Indication for biopsy was elevated prostate-specific antigen >2.5 ng/dl. Biopsy specimens were obtained and marked by location for histological examination. Subanalysis of patients from this unique study was performed to compare the location of saturation biopsy cancer detection in these patients to a cohort of 100 patients who had previously undergone biopsy with nonmalignant findings. In the initial biopsy group, cancer was detected in 62/139 patients (44.6%). Breakdown of cancer location demonstrated unique parasagittal cancers in 9/62 patients (14.5%). Laterally base cancer was found exclusively in 22/62 patients (35.5%). For the repeat biopsy population, cancer was found in 25 patients (25%); no patients (0%) had exclusive parasagittal cancer. To our knowledge, this is the first study to demonstrate a difference in the location of positive cores between initial and repeat biopsy status. The exclusive parasagittal cancer detection rate decreases significantly in the repeat biopsy population when using the same biopsy method. Our findings support including traditional template parasagittal sampling of the prostate on first-time biopsy in addition to lateral cores typical of extended field biopsies for a total of 10-12 cores. However, parasagittal sampling adds negligible additional information in repeat biopsy; thus we recommend obtaining primarily laterally based cores for repeat biopsy.
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Affiliation(s)
- A R Patel
- Cleveland Clinic, Department of Anatomic Pathology, The Glickman Urological Institute, Cleveland, OH, USA
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Patel AR, Vavia PR. Nanotechnology and pharmaceutical inhalation aerosols. Indian J Exp Biol 2007; 45:166-74. [PMID: 17375556] [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] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Pharmaceutical inhalation aerosols have been playing a crucial role in the health and well being of millions of people throughout the world for many years. The technology's continual advancement, the ease of use and the more desirable pulmonary-rather-than-needle delivery for systemic drugs has increased the attraction for the pharmaceutical aerosol in recent years. But administration of drugs by the pulmonary route is technically challenging because oral deposition can be high, and variations in inhalation technique can affect the quantity of drug delivered to the lungs. Recent advances in nanotechnology, particularly drug delivery field have encouraged formulation scientists to expand their reach in solving tricky problems related to drug delivery. Moreover, application of nanotechnology to aerosol science has opened up a new category of pharmaceutical aerosols (collectively known as nanoenabled-aerosols) with added advantages and effectiveness. In this review, some of the latest approaches of nano-enabled aerosol drug delivery system (including nano-suspension, trojan particles, bioadhesive nanoparticles and smart particle aerosols) that can be employed successfully to overcome problems of conventional aerosol systems have been introduced.
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Affiliation(s)
- A R Patel
- Pharmaceutical Division, Mumbai University Institute of Chemical Technology, Matunga, Mumbai 400019, India
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Ambrose MS, DeNofrio D, Kuvin JT, Pandian NG, Karas RH, Patel AR. Low levels of high-density lipoprotein cholesterol are associated with vascular remodeling in cardiac transplant recipients. Transplant Proc 2006; 38:3016-20. [PMID: 17112888 DOI: 10.1016/j.transproceed.2006.08.152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2006] [Indexed: 11/15/2022]
Abstract
BACKGROUND Early atherosclerosis may be associated with compensatory vessel enlargement, termed positive remodeling. Enlarged brachial artery diameter has been reported in patients with risk factors for atherosclerosis and in individuals with coronary atherosclerosis, indicating that brachial artery enlargement is a marker for the presence of atherosclerotic changes. Cardiac transplant recipients often have abnormal lipid levels, but the effect of specific lipid abnormalities on vascular remodeling in this population has not been evaluated. This study examined the relationship between lipid levels and brachial artery diameter in cardiac transplant recipients. METHODS Thirty-five stable cardiac transplant recipients underwent high-resolution brachial artery ultrasound to evaluate resting brachial artery diameter. Levels of high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides were determined and the presence of other cardiac risk factors was assessed. RESULTS Brachial artery diameter was larger (4.3 +/- 0.1 mm) in subjects with low levels of HDL-C (< 40 mg/dL, n = 11) compared to subjects with high HDL-C (> or = 40 mg/dL, n = 24), who had a mean brachial artery diameter of 3.7 +/- 0.1 mm (P = .006). Neither high LDL-C (> or = 100 mg/dL) nor high triglycerides (> or = 200 mg/dL) were associated with differences in brachial artery diameter. Multivariate analysis demonstrated that the relationship between low HDL-C and increased brachial artery diameter was independent of body surface area or statin use. CONCLUSIONS Low levels of HDL-C are an independent predictor of brachial artery enlargement in stable cardiac transplant recipients. These findings suggest that suboptimal HDL-C levels may be associated with the development of vascular remodeling and atherosclerosis in this population.
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Affiliation(s)
- M S Ambrose
- Tufts-New England Medical Center, Boston, Massachusetts 02111, USA
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Giardina A, De Castro S, Fedele F, Pandian NG, Patel AR. Noninvasive testing for coronary artery disease in women. Minerva Cardioangiol 2006; 54:323-30. [PMID: 16733506] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Coronary artery disease is a major cause of morbidity and mortality for women in North America and Europe. Given the significance of coronary disease as a public health problem among women, accurate diagnosis of this condition is of great importance. Several noninvasive testing modalities are available for the diagnosis of coronary heart disease. An understanding of gender-based differences related to noninvasive cardiac testing is useful in order to optimally utilize these tests and improve detection and clinical outcomes in women.
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Affiliation(s)
- A Giardina
- Department of Cardiovascular and Respiratory Sciences, Umberto I Polyclinic, La Sapienza University of Rome, Rome, Italy
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Abstract
Abstract
The incidence of head injury has risen in recent years and now accounts for almost one-third of acute male surgical admissions to the Western Infirmary, Glasgow. A prospective study has established that in Glasgow alcohol is a major associated factor, 62 per cent of males and 27 per cent of females having detectable levels in the blood (> 5 mg/100 ml); in these patients the mean level was 193 mg/100 ml in men and 165 mg/100ml in women. The alcohol level was significantly higher in patients who had had ‘a fall under the influence’, or had been the victims of assault, than in those involved in traffic or other accidents. This suggests that alcohol may be an important contributory cause of head injuries in this city. Depression of the conscious level occurred at blood alcohol levels around 200 mg/ 100 ml, but a significant number of patients in coma had a serious head injury.
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Affiliation(s)
- S Galbraith
- University Departments of Surgery and Medicine, Western Infirmary
- Department of Neurosurgery, Institute of Neurological Sciences, Glasgow
| | - W R Murray
- University Departments of Surgery and Medicine, Western Infirmary
- Department of Neurosurgery, Institute of Neurological Sciences, Glasgow
| | - A R Patel
- University Departments of Surgery and Medicine, Western Infirmary
- Department of Neurosurgery, Institute of Neurological Sciences, Glasgow
| | - R Knill-Jones
- University Departments of Surgery and Medicine, Western Infirmary
- Department of Neurosurgery, Institute of Neurological Sciences, Glasgow
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Abstract
OBJECTIVE To examine the effectiveness of the longer acting agent bupivacaine in providing periprostatic anaesthesia during transrectal ultrasonography (TRUS)-guided biopsy, as the periprostatic injection of lidocaine has been shown to significantly alleviate the pain of this procedure. PATIENTS AND METHODS Seventy-five patients were randomized to receive a periprostatic injection with either bupivacaine, a lidocaine/bupivacaine (1/1) combination, or no local anaesthesia. Immediately before biopsy 5 mL of the anaesthetic was injected under TRUS guidance into the periprostatic nerves bilaterally. After taking a 10-core biopsy the patients were given a visual analogue scale (VAS; 0-10) to assess their pain during the procedure. RESULTS The mean VAS scores were 2.04 in the bupivacaine group and 4.46 in the control (no local anaesthetic) group (P < 0.001). CONCLUSIONS Bupivicaine provides significant, immediate periprostatic anaesthesia for TRUS biopsy.
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Affiliation(s)
- J C Rabets
- Glickman Urological Institute, The Cleveland Clinic Foundation, Cleveland, Ohio, USA
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Kuvin JT, Patel AR, Sliney KA, Pandian NG, Rand WM, Udelson JE, Karas RH. Peripheral vascular endothelial function testing as a noninvasive indicator of coronary artery disease. J Am Coll Cardiol 2001; 38:1843-9. [PMID: 11738283 DOI: 10.1016/s0735-1097(01)01657-6] [Citation(s) in RCA: 195] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVES We studied whether assessment of endothelium-dependent vasomotion (EDV) with brachial artery ultrasound (BAUS) imaging predicts the presence or absence of coronary artery disease (CAD) as defined by exercise myocardial perfusion imaging (ExMPI). BACKGROUND Abnormalities in EDV can be detected in arteries before the development of overt atherosclerosis, and its presence may predict poor long-term prognosis. Brachial artery ultrasound during reactive hyperemia is a noninvasive method of assessing peripheral EDV. METHODS Clinically-indicated ExMPI along with BAUS were performed in 94 subjects (43 women, 51 men). Coronary artery disease was defined by myocardial ischemia or infarction on single photon emission computed tomography images. Flow-mediated dilation (FMD) after upper arm occlusion was defined as the percent change in arterial diameter during reactive hyperemia relative to the baseline. RESULTS Subjects with CAD by ExMPI (n = 23) had a lower FMD (6.3 +/- 0.7%) than those without CAD by ExMPI (n = 71) (10.5 +/- 0.6%; p = 0.0004). Flow-mediated dilation was highly predictive for CAD with an odds ratio of 1.32 for each percent decrease in FMD (p = 0.001). Based on a receiver-operator analysis, an FMD of 10% was used as a cut-point for further analysis. Twenty-one of 23 subjects who were positive for ExMPI had an FMD < 10% (sensitivity 91%), whereas only two of 40 subjects with an FMD > or =10% were ExMPI-positive (negative predictive value: 95%). There was a correlation between the number of cardiac risk factors and FMD. Individuals with an FMD < 10% exercised for a shorter duration than those with an FMD > or =10% (456 +/- 24 vs. 544 +/- 31 s, respectively; p = 0.02). CONCLUSIONS Assessment of EDV with BAUS has a high sensitivity and an excellent negative predictive value for CAD and, thus, has the potential for use as a screening tool to exclude CAD in low-risk subjects. Further standardization of BAUS is required, however, before specific cut-points for excluding CAD can be established.
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Affiliation(s)
- J T Kuvin
- Department of Medicine/Division of Cardiology, New England Medical Center Hospitals, Tufts University School of Medicine, Boston, Massachusetts, USA
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Abstract
Lower body negative pressure (LBNP) may provide an alternative test of cardiovascular autonomic function for patients unable to perform the Valsalva maneuver (VM). LBNP at -40 mmHg for 30 s was compared to the VM at 40 mmHg for 15 s with heart rate and blood pressure measured continuously in three age groups: 10-25 years; 26-40 years; and 41-55 years. Heart rate and blood pressure responses were comparable, with moderately diminished changes in blood pressure and heart rate in the LBNP test. When heart response to LBNP was converted to a ratio similar to that calculated for the VM, a high degree of correlation was found (R(2) = 0.5711). The LBNP test shows promise as an alternative test of cardiovascular autonomic function based on studies in normal subjects. The less marked changes may relate to the more passive nature of the applied stress. Future work should improve the device's accessibility and establish values for patients with autonomic disorders.
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Affiliation(s)
- A R Patel
- Autonomic Laboratory, Department of Neurology, University Hospitals of Cleveland, and Case Western Reserve University, Cleveland, Ohio, USA
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Abstract
Tensile stress and strain are known to induce vascular cell proliferation, a process that is physiologically counterbalanced by cell death. Here we investigate whether tensile stress and strain regulate vascular-cell death by using an end-to-end anastomosed rat vein graft model. In such a model, the circumferential tensile stress in the graft wall was increased by approximately 140 times immediately after surgery compared with that in the venous wall. This change was associated with an increase in the percentage of TUNEL-positive cells at 1, 6, 24, 120, 240, and 720h with two distinct peaks at 1 and 24h (10.1+/-3.5 and 14.4+/-3.2%, respectively) compared with that in control jugular veins (0.4+/-0.5 and 0.5+/-0.5% at 1 and 24h, respectively). When tensile stress and strain in the vein graft wall were reduced by using a biomechanical engineering approach, the rate of cell death was reduced significantly (3.6+/-1.1 and 1.6+/-0.5% at 1 and 24h, respectively). Furthermore, DEVD-CHO, a tetrapeptide aldehyde that inhibits the activity of caspase 3, significantly suppressed this event. These results suggest that a step increase in tensile stress and strain in experimental vein grafts induces rapid cell death, which is possibly mediated by cell death signaling mechanisms.
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Affiliation(s)
- M M Moore
- Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3107, USA
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Patel AR, Kuvin JT, Pandian NG, Smith JJ, Udelson JE, Mendelsohn ME, Konstam MA, Karas RH. Heart failure etiology affects peripheral vascular endothelial function after cardiac transplantation. J Am Coll Cardiol 2001; 37:195-200. [PMID: 11153738 DOI: 10.1016/s0735-1097(00)01057-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVES The goal of this study was to examine the effect of heart failure etiology on peripheral vascular endothelial function in cardiac transplant recipients. BACKGROUND Peripheral vascular endothelial dysfunction occurs in patients with heart failure of either ischemic or nonischemic etiology. The effect of heart failure etiology on peripheral endothelial function after cardiac transplantation is unknown. METHODS Using brachial artery ultrasound, endothelium-dependent, flow-mediated dilation (FMD) was assessed in patients with heart failure with either nonischemic cardiomyopathy (n = 10) or ischemic cardiomyopathy (n = 7), cardiac transplant recipients with prior nonischemic cardiomyopathy (n = 10) or prior ischemic cardiomyopathy (n = 10) and normal controls (n = 10). RESULTS Patients with heart failure with either ischemic cardiomyopathy or nonischemic cardiomyopathy had impaired FMD (3.6 +/- 1.0% and 5.1 +/- 1.2%, respectively, p = NS) compared with normal subjects (13.9 +/- 1.3%, p < 0.01 compared with either heart failure group). In transplant recipients with antecedent nonischemic cardiomyopathy, FMD was markedly higher than that of heart failure patients with nonischemic cardiomyopathy (13.0 +/- 2.4%, p < 0.001) and similar to that of normal subjects (p = NS). However, FMD remained impaired in transplant recipients with prior ischemic cardiomyopathy (5.5 +/- 1.5%, p = 0.001 compared with normal, p = 0.002 vs. transplant recipients with previous nonischemic cardiomyopathy). CONCLUSIONS Peripheral vascular endothelial function is normal in cardiac transplant recipients with antecedent nonischemic cardiomyopathy, but remains impaired in those with prior ischemic cardiomyopathy. In contrast, endothelial function is uniformly abnormal for patients with heart failure, regardless of etiology. These findings indicate that cardiac transplantation corrects peripheral endothelial function for patients without ischemic heart disease, but not in those with prior atherosclerotic coronary disease.
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Affiliation(s)
- A R Patel
- Cardiovascular Imaging and Hemodynamic Laboratory, New England Medical Center Hospitals Inc, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
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Abstract
Two-dimensional and Doppler echocardiography have become the major modalities for the assessment of mitral regurgitation. The combined use of these techniques provides information regarding the morphology of the valvular apparatus as well as the severity of regurgitation. Transesophageal and three-dimensional echocardiography provide a more-detailed evaluation of valve morphology, which can be valuable in determining suitability for valve repair. In patients with severe mitral regurgitation, echocardiographic assessment of ventricular size and function plays a critical role in determining the optimal timing of surgery.
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Affiliation(s)
- A R Patel
- Cardiovascular Imaging and Hemodynamic Laboratory, New England Medical Center, 750 Washington Street, Box 32, Boston, MA 02111, USA
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Abstract
Before the introduction of transesophageal echocardiography (TEE) in the operating room, intraoperative echocardiography relied on epicardial imaging. The disadvantages of this approach included interference with the surgical procedure, limited windows, and potential distortion of cardiac structures. Consequently, multiplane TEE has now emerged as the intraoperative imaging method of choice. It provides high-resolution images of cardiac structures and excellent portraits of flow abnormalities. Intraoperative TEE does not interfere with the surgical field and procedure. TEE provides better imaging of the valves, atria, aorta, pulmonic vasculature, and pericardium, which are sometimes difficult to visualize by transthoracic echocardiography. TEE is especially beneficial in surgeries for valve replacement, valve repair, cardiac mass, aortic disease, congenital heart disease, and pericardial disease. Presurgical TEE provides information for surgical planning. TEE is helpful for the assessment of the immediate result of surgery and detection of complications that may need a prompt response. Thus, intraoperative TEE has a vital impact on management of cardiac surgery.
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Affiliation(s)
- Y Mochizuki
- Division of Cardiology, Tufts-New England Medical Center Hospitals, 750 Washington Street, Boston, MA 02111, USA.
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Abstract
Activator protein 1 (AP-1) is a group of dimeric transcription factors composed of protooncogene (Jun and Fos) subunits that bind to a common DNA site, the AP-1 binding site. The proteins of c-Jun, JunB, and Fos are essential for initiation of the cell cycle. Conversely, the activation of the junD gene slows cell growth in some cell types. The current study tests the hypothesis that polyamines influence cell growth by altering the balance of positive and negative Jun/AP-1 activities in intestinal epithelial cells. Studies were conducted in the IEC-6 cell line derived from rat small intestinal crypt cells. Administration of alpha-difluoromethylornithine (DFMO), a specific inhibitor for polyamine synthesis, for 4 and 6 days completely depleted cellular polyamine levels, while AP-1 binding activity was significantly increased. Spermidine, when given together with DFMO, restored AP-1 binding activity toward normal. The increased AP-1 complexes in polyamine-deficient cells were dramatically supershifted by the anti-JunD antibody but not by antibodies against c-Jun, JunB, or Fos proteins. There were significant increases in JunD mRNA and protein in DFMO-treated cells, although expression of the c-fos, c-jun, and junB genes decreased. The increase in JunD/AP-1 activity in DFMO-treated cells was associated with a significant decrease in cell division. Exposure of control quiescent cells to 5% dialyzed serum increased c-Jun/AP-1 but not JunD/AP-1 activities. DFMO prevented the stimulation of c-Jun/AP-1 activity induced by 5% dialyzed serum. These results indicate that 1) polyamine depletion is associated with an increase in AP-1 binding activity and 2) the increase in AP-1 activity in the DFMO-treated cells was primarily contributed by an increase in the JunD/AP-1. These findings suggest that polyamines regulate cell growth at least partially by modulating the balance of positive and negative Jun/AP-1 activities in the intestinal mucosa.
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Affiliation(s)
- A R Patel
- Department of Surgery, University of Maryland Medical School and Baltimore Veterans Affairs Medical Center, Baltimore, Maryland 21201, USA
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Patel AR, Li J, Bass BL, Wang JY. Expression of the transforming growth factor-beta gene during growth inhibition following polyamine depletion. Am J Physiol 1998; 275:C590-8. [PMID: 9688614 DOI: 10.1152/ajpcell.1998.275.2.c590] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Polyamine depletion and cytokine transforming growth factor-beta (TGF-beta) inhibit cell proliferation. The current study tests the hypothesis that polyamine depletion results in growth inhibition by altering expression of the TGF-beta gene in intestinal epithelial cells. Studies were conducted in the IEC-6 cell line derived from rat small intestinal crypt cells. Cells were grown in DMEM in the presence or absence of alpha-difluoromethylornithine (DFMO), a specific inhibitor of polyamine biosynthesis, for 6 and 12 days. Administration of DFMO not only depleted intracellular polyamines but also significantly increased the mRNA levels of TGF-beta. Increased TGF-beta mRNA in DFMO-treated cells was paralleled by an increase in TGF-beta content. Depletion of intracellular polyamines by DFMO had no effect on the rate of TGF-beta gene transcription, as measured by nuclear run-on assay. The half-life of mRNA for TGF-beta in normal cells was approximately 65 min and increased to >16 h in cells treated with DFMO for 6 or 12 days. Exogenous polyamine, when given together with DFMO, prevented the increased half-life of TGF-beta mRNA in IEC-6 cells. TGF-beta added to the culture medium significantly decreased the rate of DNA synthesis and final cell number in normal and polyamine-deficient cells. Furthermore, growth inhibition caused by polyamine depletion was partially but significantly blocked by addition of immunoneutralizing anti-TGF-beta antibody. These results indicate that 1) depletion of intracellular polyamines induces the activation of the TGF-beta gene through posttranscriptional regulation and 2) increased expression of the TGF-beta gene plays an important role in the process of growth inhibition following polyamine depletion.
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Affiliation(s)
- A R Patel
- Department of Surgery, University of Maryland Medical School and Baltimore Veterans Affairs Medical Center, Baltimore, Maryland 21201, USA
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Abstract
Chagas' heart disease is a common form of cardiomyopathy in Latin America and an important cause of cardiac morbidity and mortality there. Left ventricular (LV) apical aneurysm and LV dysfunction are frequent findings in Chagas' cardiomyopathy. Because cardiac shape has important implications for LV function, we sought to characterize regional and global changes in LV geometry in Chagas' heart disease. Quantitative shape analysis was performed on 2-dimensional echocardiograms from 43 patients with Chagas' cardiomyopathy. Regional shape was quantitated by measuring endocardial curvature and global shape was evaluated by Fourier shape analysis of the endocardial contour. Data from 22 age- and sex-matched normal test subjects were used for comparison. Regional shape analysis demonstrated decreased apical curvature (consistent with blunting of normal apical shape) in the group with Chagas' disease compared with controls (apical 2-chamber view: 19 +/- 1 vs 24 +/- 1 [p = 0.0039] at end-diastole and 20 +/- 2 vs 29 +/- 3 [p = 0.0019] at end-systole). Fourier shape power index was decreased in the Chagas' group, consistent with a more spherical ventricle (apical 2-chamber view: 9 +/- 1 vs 17 +/- 2 [p <0.0001] at end-diastole and 12 +/- 1 vs 35 +/- 3 [p <0.0001] at end-systole). Shape changes among the population with Chagas' disease were further evaluated in those with end-diastolic volumes equal to or greater than the median for the group (104 ml) and those < 104 ml. Global shape did not differ between patients with dilated ventricles and those with relatively nondilated ventricles. Diastolic Fourier shape power index = 8 +/- 2 in dilated ventricles compared with 9 +/- 5 in nondilated ventricles (p = 0.53); systolic Fourier shape power index = 10 +/- 2 in dilated versus 14 +/- 2 in nondilated ventricles (p = 0.15) (apical 2-chamber view). In Chagas' cardiomyopathy, LV apical deformation results in disruption of the optimal global prolate-ellipsoid shape, even in patients with relatively preserved LV volumes.
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Affiliation(s)
- A R Patel
- Cardiovascular Imaging and Hemodynamic Laboratory, New England Medical Center, Tufts University School of Medicine, Boston, Massachusetts, USA
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Wang JY, Li J, Patel AR, Summers S, Li L, Bass BL. Synergistic induction of ornithine decarboxylase by asparagine and gut peptides in intestinal crypt cells. Am J Physiol 1998; 274:C1476-84. [PMID: 9696689 DOI: 10.1152/ajpcell.1998.274.6.c1476] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The objective of this study was to determine whether the amino acid asparagine stimulated the activity of ornithine decarboxylase (ODC) synergistically with epidermal growth factor (EGF) or gastrin in IEC-6 cells, a line of normal rat small intestinal crypt cells. Cells were grown in DMEM containing 5% dialyzed fetal bovine serum, and serum was deprived for 24 h before experiments. Exposure to EGF or gastrin alone increased ODC activity 4.5- to 6-fold. Asparagine alone increased the enzyme activity 10- to 13-fold in IEC-6 cells. Simultaneous addition of asparagine and EGF or gastrin, however, increased ODC activity more than 40-fold. In contrast, there was no synergistic induction of ODC activity when gastrin and EGF were added together. Increased ODC activity in cells treated with asparagine and EGF or gastrin was associated with an increase in ODC mRNA and protein levels. The rate of transcription of the ODC gene was significantly increased by exposure to EGF or gastrin. Asparagine alone had little or no effect on the rate of transcription of the ODC gene. When given together with EGF or gastrin, asparagine also had no additional effect on the transcription rate of the ODC gene. The half-life of mRNA for ODC in unstimulated IEC-6 cells was approximately 30 min and increased to more than 2 h in cells exposed to asparagine, although neither gastrin nor EGF prolonged the stability of ODC mRNA. The half-life of mRNA for ODC after combined addition of asparagine and EGF or gastrin was extended to approximately 2 h, similar to asparagine alone. Combined addition of asparagine and EGF or gastrin also significantly increased DNA synthesis compared with cells exposed to each of the three agents alone. In conclusion, 1) simultaneous addition of asparagine and EGF or gastrin increases ODC activity in a synergistic manner and 2) asparagine increases ODC mRNA levels through completely distinct mechanisms from EGF or gastrin. EGF or gastrin specifically stimulates transcription of the ODC gene, whereas asparagine affects a posttranscriptional process.
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Affiliation(s)
- J Y Wang
- Department of Surgery, University of Maryland Medical School, Baltimore 21201, USA
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Abstract
Polyamines serve as natural substrates for the transglutaminase that catalyzes covalent cross-linking of proteins and is involved in cellular adhesion and proliferation. This study tests the hypothesis that intracellular polyamines play a role in the regulation of transglutaminase expression in rat small intestinal crypt cells (IEC-6 cell line) and human colon carcinoma cells (Caco-2 cell line). Treatment with alpha-difluoromethylornithine (DFMO; a specific inhibitor of polyamine synthesis) significantly depleted the cellular polyamines putrescine, spermidine, and spermine in both cell lines. In IEC-6 cells, polyamine depletion was associated with a decrease in the levels of transglutaminase mRNA. In Caco-2 cells, however, polyamine depletion significantly increased the levels of transglutaminase mRNA and enzyme activity. In both cell lines, ornithine decarboxylase mRNA levels increased and protooncogene c-myc mRNA decreased in the presence of DFMO. Addition of polyamines to cells treated with DFMO reversed the effect of DFMO on the levels of mRNA for these genes in both lines. There was no significant change in the stability of transglutaminase mRNA between control and DFMO-treated IEC-6 cells. In contrast, the half-life of mRNA for transglutaminase in Caco-2 cells was dramatically increased after polyamine depletion. Spermidine, when given together with DFMO, completely prevented increased half-life of transglutaminase mRNA in Caco-2 cells. These results indicate that 1) expression of transglutaminase requires polyamines in IEC-6 cells but is inhibited by these agents in Caco-2 cells, 2) polyamines modulate transglutaminase expression at the level of mRNA through different pathways in these two cell lines, and 3) posttranscriptional regulation plays a major role in the induction of transglutaminase mRNA in polyamine-deficient Caco-2 cells.
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Affiliation(s)
- J Y Wang
- Department of Surgery, University of Maryland Medical School, Baltimore, USA
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Abstract
The goal of the current study was to examine whether polyamines are involved in the regulation of transcription and posttranscription of the protooncogenes c-myc and c-jun in intestinal epithelial cells. Studies were conducted in the IEC-6 cell line derived from rat small intestinal crypt cells. Administration of alpha-difluoromethylornithine (DFMO), a specific inhibitor of polyamine synthesis, for 4 or 6 days not only almost completely depleted total (whole) cellular and nuclear polyamines but also significantly decreased expression of the protooncogenes c-myc and c-jun in IEC-6 cells. Using nuclear run-on transcription assay, we demonstrated that the basal rate of transcription of c-myc was decreased by 55% at 4 days and by 60% at 6 days in the DFMO-treated cells. The c-jun transcription in DFMO-treated cells was decreased by 75% at 4 days and 85% at 6 days. The transcription rates of c-myc and c-jun were dramatically stimulated by 5% dialyzed fetal bovine serum (dFBS) in normal quiescent cells. However, polyamine depletion significantly prevented the increased transcription of these two genes in the DFMO-treated cells exposed to 5% dFBS. Furthermore, direct administration of spermidine to isolated nuclei from polyamine-deficient (caused by DFMO) cells resulted in a 2- to 2.5-fold increase in c-myc and c-jun transcription. There were no significant changes in the half-lives of c-myc and c-jun mRNAs between the controls and the DFMO-treated cells. These results indicate that 1) polyamines are required for the transcription of the protooncogenes c-myc and c-jun in IEC-6 cells and 2) depletion of intracellular polyamines has no effect on posttranscriptional regulation of c-myc and c-jun mRNAs. These findings suggest that polyamines play an important role in the regulation of the transcription of protooncogenes, and this may be one mechanism by which polyamines modulate mucosal cell division.
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Affiliation(s)
- A R Patel
- Department of Surgery, University of Maryland Medical School, Baltimore, USA
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Abstract
Adrenomedullin (ADM), a peptide with potent vasodilatory and natriuretic actions, is elevated in patients with essential hypertension. Because pharmacological doses of ADM result in renal vasodilation and natriuresis, it has been suggested that ADM may play a modulatory role in hypertension through potential actions on renal pressure natriuresis. However, it is unclear whether elevation of plasma ADM within the pathophysiological range has similar actions. To determine the effects of pathophysiological doses of ADM on blood pressure and on the relationship between renal perfusion pressure (RPP) and renal hemodynamics and sodium excretion, renal function was determined at RPPs of 80, 105, 130, and 155 mm Hg in spontaneously hypertensive rats (SHR) infused with ADM at 50 ng x kg(-1) x min(-1) (ADM-50, n=5) and at 100 ng x kg(-1) x min(-1) (ADM-100, n=5) and in control SHR (n=5). Decreasing RPP from 155 to 80 mm Hg in control SHR decreased (P<.05) absolute sodium excretion from 0.81+/-0.25 to 0.04+/-0.02 microEq/min, fractional sodium excretion from 0.32+/-0.11% to 0.06+/-0.04%, and urine flow rate from 11.5+/-2.8 to 1.03+/-0.31 microL/min. ADM infusion elevated (P<.05) plasma ADM levels in ADM-infused SHR (679+/-47 pg/mL in ADM-50, 858+/-79 in ADM-100) compared with control (79.5+/-27.8). However, although reduction of RPP from 155 to 80 mm Hg in ADM rats decreased absolute sodium excretion (ADM-50, 0.98+/-0.10 to 0.09+/-0.04 microEq/min; ADM-100, 0.95+/-0.09 to 0.07+/-0.02 microEq/min), fractional sodium excretion (ADM-50, 0.31+/-0.03% to 0.17+/-0.04%; ADM-100, 0.33+/-0.02% to 0.09+/-0.01%), and urine flow (ADM-50, 13.6+/-1.4 to 1.73+/-0.75 microL/min; ADM-100, 13.5+/-1.5 to 1.07+/-0.16 microL/min), these decreases were not different from values found in controls. Renal plasma flow and glomerular filtration rate were also similar in control and ADM-treated SHR at each level of RPP. Thus, acute increases in ADM to levels found in pathophysiological conditions have no effect on blood pressure, pressure natriuresis, or renal autoregulation in the SHR. These findings do not support the hypothesis that ADM serves as a modulating factor in hypertension, at least in the SHR.
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Affiliation(s)
- T Kurashina
- Department of Veterans Affairs Medical Center, Jackson, MS 39216, USA
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Abstract
This study was designed to characterize the geometry and function of the right ventricle and its prognostic significance in patients with primary (AL) cardiac amyloidosis. AL amyloidosis is an infiltrative systemic disease that can result in thickening of heart structures and rapidly progressive congestive heart failure due to restrictive ventricular physiology and eventual systolic dysfunction. Thirty-seven patients with AL amyloid heart involvement and 20 normal control subjects were evaluated using 2-dimensional and Doppler echocardiography. Based on the ratio of left-to-right end-diastolic ventricular chamber areas, patients were classified into 2 groups: 25 patients with disproportionate right ventricular (RV) dilation (left ventricular to RV ratio < or = 2) and 12 with a ventricular area ratio > 2. Patients with a relatively dilated right ventricle (ratio < or = 2) had a shorter median survival (4 months) compared with patients with an area ratio > 2 (10 months, p <0.003). Of multiple clinical, echocardiographic, and Doppler features entered into a multifactorial model, a ventricular area ratio < or = 2 remained the only independent predictor of survival. Patients with AL amyloid heart disease represent a heterogeneous population with regard to both prognosis and the relative degree of right to left ventricular dilation. RV dilation in patients with amyloid heart disease appears to be associated with more severe involvement and is associated with a very poor prognosis with a median survival of only 4 months.
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Affiliation(s)
- A R Patel
- Evans Memorial Department of Clinical Research, Arthritis Research Center, Boston University Medical Center, Massachusetts 02118, USA
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Abstract
1. According to the renal body fluid feedback mechanism for long-term control, persistent hypertension can only occur as a result of a reduction in renal sodium excretory function or a hypertensive shift in the pressure natriuresis relationship. Although an abnormal relationship between renal perfusion pressure and renal sodium excretion has been identified in every type of hypertension where it has been sought, factors responsible for this effect are still unclear. 2. Nitric oxide (NO) is produced within the kidney and plays an important role in the control of many intrarenal processes that regulate the renal response to changes in perfusion pressure and, thus, help determine systemic vascular volume and blood pressure. Numerous studies have shown that long-term inhibition of NO synthesis results in a chronic hypertensive shift in renal pressure natriuresis. 3. Recent studies have shown that certain animal models of genetic hypertension and forms of human hypertension areas are associated with a decrease in NO synthesis. Reductions in NO synthesis reduce renal sodium excretory function, not only through direct action on the renal vasculature, but through modulation of other vasoconstrictor processes and through direct and indirect alterations in tubular sodium transport. 4. The causes and consequences of the disregulation of NO in hypertension and other renal disease processes remain an important area of investigation.
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Affiliation(s)
- C Schnackenberg
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson 39216-4505, USA
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Abstract
We describe the case of a 34-year-old man with AIDS who developed severe anemia due to chronic pure red cell aplasia (PRCA) caused by parvovirus B19. Following initial treatment with an infusion of intravenous immunoglobulin (IVIg), 1 g/kg, PRCA resolved, but there was a recurrence of severe anemia in 3 months. Retreatment with 2 g/kg IVIg over 2 days resulted in normalization of hemoglobin and a significantly longer remission duration. Two doses of 0.4 g/kg IVIg q 4 wk failed to prevent a relapse of PRCA in our patient. The dose and schedule of IVIg in the treatment of PRCA caused by parvovirus B19 in AIDS requires further definition.
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Affiliation(s)
- P R Koduri
- Department of Medicine, Cook County Hospital, Chicago, IL 60612, USA
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Bentham PW, Goh SE, Gregg EM, Madeley P, Patel AR, Taylor AP. Do neuroleptic drugs hasten cognitive decline in dementia? Authors have not proved their argument. BMJ 1997; 314:1412. [PMID: 9161323 PMCID: PMC2126625] [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: 02/04/2023]
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Kurashina T, Kirchner KA, Granger JP, Patel AR. Chronic sodium-potassium-ATPase inhibition with ouabain impairs renal haemodynamics and pressure natriuresis in the rat. Clin Sci (Lond) 1996; 91:497-502. [PMID: 8983876 DOI: 10.1042/cs0910497] [Citation(s) in RCA: 15] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
1. Chronic Na+, K(+)-ATPase inhibition with ouabain induces hypertension in the rat. To examine the role of the kidney in this process, the effect of changes in renal perfusion pressure on glomerular filtration rate, renal blood flow and urinary sodium excretion were determined in rats treated intraperitoneally with ouabain (27.8 micrograms day-1 kg-1 body weight) or vehicle for 6 weeks. 2. After ouabain administration, baseline mean arterial pressure was significantly higher (P < 0.05) in ouabain-treated rats (151 +/- 2 mmHg; n = 9) than in control rats (116 +/- 4 mmHg; n = 8). 3. At equivalent renal perfusion pressures, glomerular filtration rate was significantly lower (P < 0.05) in ouabain-treated rats compared with control rats. Glomerular filtration rate was 721 +/- 73 microliters/min at 150 mmHg, and fell significantly to 322 +/- 64 microliters/min at 100 mmHg. In the control group, glomerular filtration rate was well autoregulated. The glomerular filtration rate autoregulatory index was calculated to determine the ability to maintain glomerular filtration rate during changes in renal perfusion pressure (0 reflects perfect autoregulation; > 1 reflects the absence of autoregulation). This index was greater in the ouabain group than in the control group (1.54 +/- 0.2 compared with 0.29 +/- 0.2; P < 0.05). Renal blood flow showed a similar pattern. 4. Absolute urinary sodium excretion rate was less in ouabain-treated rats than in control rats at equivalent renal perfusion pressures. The slope of the relationship between absolute urinary sodium excretion rate and renal perfusion pressure was greater (P < 0.05) in the control group than in the ouabain group (309.1 +/- 57.1 compared with 82.1 +/- 14.8 mumol min-1 mmHg-1). 5. Thus, chronic inhibition of Na+,K(+)-ATPase induces less efficient autoregulation of glomerular filtration rate and renal blood flow as well as a rightward shift in the pressure natriuresis relationship, such that a 25-30 mmHg higher renal perfusion pressure is necessary to excrete any given sodium load. These abnormalities may contribute to the development and maintenance of hypertension in this model.
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Affiliation(s)
- T Kurashina
- Medical Service, Department of Veterans Affairs Medical Center, Jackson, MS 39216, U.S.A
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Patel AR, Damle SG. The effect of carbon dioxide laser on acid resistance of human tooth enamel: an evaluation by wet chemical analysis and scanning electron microscopy. J Indian Soc Pedod Prev Dent 1996; 14:31-5. [PMID: 9522753] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The use of the laser in improving acid resistance of tooth enamel has captured the imagination of most researchers. Man's susceptibility to dental caries presents itself as one of the most complicated problems to solve. The carbon dioxide laser at a wavelength of 10.6 microns is highly efficient for dental purposes as this wavelength is close to optimum absorption of dental enamel. A study was carried out using a pulsed carbon dioxide laser to find the effects of laser beam on human tooth enamel in an energy range of 2-20 J/cm2 at a pulse rate of 5 Hz. The effective resistance to acid was determined by wet chemical analysis whereas superficial changes seen on the surface were determined using the scanning electron microscope.
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Affiliation(s)
- A R Patel
- Dept. of Pedodontics & Preventive Dentistry, Nair Hospital Dental College, Mumbai, India
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Abstract
Although it has been reported that Na+,K+-ATPase inhibition with bufalin induces acute and chronic hypertension in the rat, the mechanisms mediating this response are unclear. To examine the role of the kidney in this process, glomerular filtration rate, renal blood flow, and pressure natriuresis were determined in rats treated with bufalin or vehicle during changes in renal perfusion pressure. Mean arterial pressure increased from 123 +/- 4 to 149 +/- 3 mm Hg (P < .05) after 40 minutes of intravenous bufalin and remained at this level. In control rats, glomerular filtration rate was well autoregulated. In bufalin-treated rats, glomerular filtration rate fell with decreasing renal perfusion pressure. Glomerular filtration rate autoregulatory index was greater in bufalin-treated than control rats (P < .05). Renal blood flow showed a similar pattern. Urine flow and sodium excretion were less in bufalin-treated than control rats at equivalent renal perfusion pressures. The slope of the line describing the relation between urine flow and renal perfusion pressure was greater (P < .05) in control than bufalin-treated rats. Similarly, the slope of the line relating sodium excretion to renal perfusion pressure was greater (P < .05) in control than bufalin-treated rats. Thus, acute increases in blood pressure during Na+, K+-ATPase inhibition are associated with impaired renal autoregulation and pressure natriuresis. This effect may be important in chronic hypertension associated with Na+,K+-ATPase inhibition in the rat.
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Affiliation(s)
- A R Patel
- Medical Service, Department of Veterans Affairs Medical Center, Jackson, MS 39216, USA
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Koduri PR, Chundi V, DeMarais P, Mizock BA, Patel AR, Weinstein RA. Reactive hemophagocytic syndrome: a new presentation of disseminated histoplasmosis in patients with AIDS. Clin Infect Dis 1995; 21:1463-5. [PMID: 8749633 DOI: 10.1093/clinids/21.6.1463] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.8] [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: 02/02/2023] Open
Abstract
We report the cases of six patients with AIDS in whom reactive hemophagocytic syndrome (RHPS) secondary to disseminated histoplasmosis was diagnosed. RHPS was diagnosed by established criteria, including fever (duration of > or = 7 days, with peak temperatures of > 38.5 degrees C), unexplained thrombocytopenia with anemia and/or neutropenia, and bone marrow biopsy findings of hemophagocytic histiocytosis. Disseminated Histoplasma capsulatum infection was diagnosed on the basis of the results of cultures of the bone marrow sample. The serum lactate dehydrogenase (LDH) level was elevated (> 1,000 IU/L) in all patients, and five of six patients had hyperferritinemia (range of ferritin level, 15,848-425,984 ng/mL). Five patients had features resembling severe sepsis with multiorgan dysfunction. Three patients recovered, and the findings of RHPS resolved following therapy with amphotericin B. In patients with AIDS, the combination of fever, cytopenia, elevated serum LDH level (> 1,000 IU/L), and/or hyperferritinemia (ferritin level of > 10,000 ng/mL) is a clue to the diagnosis of RHPS and disseminated histoplasmosis; bone marrow biopsy is valuable in establishing the diagnosis.
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Affiliation(s)
- P R Koduri
- Department of Medicine, Cook County Hospital, Chicago, Illinois 60612-9985, USA
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Meng M, Sun WQ, Geelhaar LA, Kumar G, Patel AR, Payne GF, Speedie MK, Stacy JR. Denitration of glycerol trinitrate by resting cells and cell extracts of Bacillus thuringiensis/cereus and Enterobacter agglomerans. Appl Environ Microbiol 1995; 61:2548-53. [PMID: 7618866 PMCID: PMC167526 DOI: 10.1128/aem.61.7.2548-2553.1995] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [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: 01/26/2023] Open
Abstract
A number of microorganisms were selected from soil and sediment samples which were known to have been previously exposed to nitrate ester contaminants. The two most effective bacteria for transforming glycerol trinitrate (GTN) were identified as Bacillus thuringiensis/cereus and Enterobacter agglomerans. For both isolates, denitration activities were expressed constitutively and GTN was not required for induction. Dialysis of cell extracts from both isolates did not affect denitration, which indicates that dissociable and depletable cofactors are not required for denitration. With thin-layer chromatography and high-performance liquid chromatography, the denitration pathway for both isolates was shown to be a sequential denitration of GTN to glycerol dinitrate isomers, glycerol mononitrate isomers, and ultimately to glycerol. GTN was observed to be completely converted to glycerol during a long-term incubation of cell extracts.
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Affiliation(s)
- M Meng
- Department of Pharmaceutical Sciences, University of Maryland at Baltimore 21201-1180, USA
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49
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Abstract
Four patients were diagnosed with reactive hemophagocytic syndrome (RHPS) during a 7 month period. Of these, three patients were diagnosed with acquired immunodeficiency syndrome complicated by disseminated Mycobacterium tuberculosis infection, incompletely treated Pneumocystis carinii pneumonia and disseminated histoplasmosis respectively. The fourth patient had non-Hodgkin's lymphoma of the mature T-cell phenotype. Fever, bicytopenia, or pancytopenia, elevated serum lactate dehydrogenase (LDH) level (> 1,000 IU/L), and hemophagocytic histiocytosis in smears of bone marrow aspirate were present in all patients. Hyperferritinemia (> 10,000 ng/ml) was present in all (range 34,976 to 425,984 ng/mL) and showed a decrease in the two patients who responded to therapy. Hyperferritinemia (> 10,000 ng/ml) and elevated serum LDH (> 1,000 IU/L) are important clues to the diagnosis of RHPS in the febrile cytopenic patient with immunodeficiency.
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Affiliation(s)
- P R Koduri
- Department of Medicine, Cook County Hospital, Chicago, Illinois, USA
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50
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Patel AR, Obrams GI. Adenocarcinoma of the lung. Cancer Epidemiol Biomarkers Prev 1995; 4:175-80. [PMID: 7742726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Affiliation(s)
- A R Patel
- Division of Cancer Etiology, National Cancer Institute, Bethesda, Maryland 20892-7395, USA
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