Inappropriate laboratory test utilization in outpatient tertiary care: Implications for value-based healthcare.

OBJECTIVES: To assess the rate of inappropriate repetition of laboratory testing and estimate the cost of such testing for thyroid stimulating hormone (TSH), total cholesterol, vitamin D, and vitamin B12 tests. METHODS: A retrospective cohort study was carried out in the Family Medicine and Polyclinic Department at King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia. Clinical and laboratory data were collected between 2018-2021 for the 4 laboratory tests. The inappropriate repetition of tests was defined according to international guidelines and the costs were calculated using the hospital prices. RESULTS: A total of 109,929 laboratory tests carried out on 23,280 patients were included in this study. The percentage of inappropriate tests, as per the study criteria, was estimated to be 6.1% of all repeated tests. Additionally, the estimated total cost wasted amounted to 2,364,410 Saudi Riyals. Age exhibited a weak positive correlation with the total number of inappropriate tests (r=0.196, p=0.001). Furthermore, significant differences were observed in the medians of the total number of inappropriate tests among genders and nationalities (p<0.001). CONCLUSION: The study identified significantly high rates of inadequate repetitions of frequently requested laboratory tests. Urgent action is therefore crucial to overcoming such an issue.

Aortic Valve Calcium Score by Computed Tomography as an Adjunct to Echocardiographic Assessment-A Review of Clinical Utility and Applications.

Aortic valve stenosis (AS) is increasing in prevalence due to the aging population, and severe AS is associated with significant morbidity and mortality. Echocardiography remains the mainstay for the initial detection and diagnosis of AS, as well as for grading of severity. However, there are important subgroups of patients, for example, patients with low-flow low-gradient or paradoxical low-gradient AS, where quantification of severity of AS is challenging by echocardiography and underestimation of severity may delay appropriate management and impart a worse prognosis. Aortic valve calcium score by computed tomography has emerged as a useful clinical diagnostic test that is complimentary to echocardiography, particularly in cases where there may be conflicting data or clinical uncertainty about the degree of AS. In these situations, aortic valve calcium scoring may help re-stratify grading of severity and, therefore, further direct clinical management. This review presents the evolution of aortic valve calcium score by computed tomography, its diagnostic and prognostic value, as well as its utility in clinical care.

A Comparison of Checklist and Domain-Based Ratings in the Assessment of Objective Structured Clinical Examination (OSCE) Performance.

INTRODUCTION: The Objective Structured Clinical Examination (OSCE) is the mainstay of clinical assessment in the final-year undergraduate Family Medicine clerkship at King Faisal Specialist Hospital and Research Centre (KFSHRC). The gold standard for OSCE assessment is the checklist rating, completed by physician examiners. Numerous studies have suggested that global or domain-based OSCE ratings may be a better indicator of competence than checklist ratings. The aim of this study was to examine the utility of domain-based OSCE ratings in the context of final-year, undergraduate, Family Medicine OSCE examinations in Riyadh, Saudi Arabia. This is akin to an exercise in quality improvement, as we continuously look for ways to improve our OSCE assessment processes. METHODS: This study utilised a quantitative methodology. Three final year OSCE exams were chosen. Physicians rated each student using a checklist score and using a more holistic domain-based score. Physician checklist scores and physician domain-based scores were then compared, and correlation was assessed. We also looked at the internal consistency of the scoring methods. RESULTS: A significant correlation was found between checklist and domain-based scores by physicians for all exams (r=0.858, p<0.01), with a good internal consistency for these methodologies for all exams. CONCLUSION: The results demonstrate that both checklist and domain-based scores offer some benefit to the assessment, with a similar internal consistency and strong correlation. Domain-based ratings should be utilised for softer skills that are not easily assessed by checklists. There is clearly a need to rethink our OSCE assessment. The assessment should combine checklist and domain-based physician scores. As trainees become more experienced, checklist OSCE may penalise directness and efficiency, while domain-based ratings would offer a better appraisal of competence, and have been shown to be more sensitive to the level of training and expertise. Changing the assessment methods will lead to necessary changes in the student approach to the OSCE and improve authenticity and validity.

Inequalities in access to NHS primary care dental services in Scotland during the COVID-19 pandemic.

Introduction This study aimed to quantify the impact of the COVID-19 pandemic on access and inequalities in primary care dental services among children and adults in Scotland.Methods Access was measured as any NHS Scotland primary care dental contacts derived from administrative data from January 2019 to May 2022, linked to the area-based Scottish Index of Multiple Deprivation for children and adults, and related to population denominator estimates from National Record Scotland. Inequalities for pre-pandemic (January 2019-January 2020) and recent (December 2021-February 2022, and March 2022-May 2022) periods for both children and adults were calculated and compared using the slope index of inequality and relative index of inequality.Results Following the first lockdown (March 2020) there was a dramatic fall to near zero dental contacts, followed by a slow recovery to 64.8% of pre-pandemic levels by May 2022. There was initial widening of relative inequalities in dental contacts in early 2022, which, more recently, had begun to return to pre-pandemic levels.Conclusion COVID-19 had a major impact on access to NHS primary dental care, and while inequalities in access are apparent as services recover from lockdown, these inequalities are not a new phenomenon.

Assessment of plasminogen activator inhibitor-1(PAI1) and thrombin activitable fibrinolysis inhibitor (TAFI) in Egyptian children with hemophilia A.

Patients with hemophilia A display varied bleeding phenotypes not correlated with degree of deficiency of factor VIII level. We investigated Plasminogen Activator Inhibitor 1(PAI1) level and Thrombin Activatable Fibrinolysis Inhibitor (TAFI) also known as Carboxypeptidase B2 (CPB2) level in Patients with hemophilia A and their possible correlation with bleeding tendency. Twenty-six patients attending in hematology unit of pediatric department were included in this study. In addition, fourteen apparently healthy subjects matched ages and genders were included as control group. The International Society of Thrombosis Bleeding Assessment Tool (ISTH/BAT) was used to assess bleeding score in patients. Plasma levels of Plasminogen Activator Fibrinolysis Inhibitor (PAI1) and Thrombin Activatable Fibrinolysis Inhibitor (TAFI) zymogen were measured by enzyme-linked immunosorbent assay (ELIZA). As compared to controls, hemophilic patients had significantly high bleeding score, low PAI 1 level and high TAFI level. There was no significant correlation between bleeding score by ISTH/BAT and patient severity. PAI 1 and TAFI level have no significant correlation with patient severity. PAI 1 level was statistically significant different between intense and non-intense hemorrhagic groups, while TAFI level has no significant correlation with bleeding phenotype. PAI 1 and TAFI levels had significantly correlation between patients and controls. PAI-1 level had statistically significant correlation with bleeding phenotype, while TAFI level failed to show any correlation between intense and non-intense hemorrhagic groups. So, PAI-1 levels may have predictive value of bleeding tendency in hemophiliacs.

Virtual orthopedic assessment: Main principles and specific regions.

Telemedicine was originally created as a way to treat patients who were located in remote places far away from local health facilities or in areas with shortages of medical professionals. Telemedicine is still used today to address those problems, and is increasingly becoming a tool for convenient medical care. With the emergence of pandemics, telemedicine became almost a mandatory and valuable option for continuing to provide medical care in various specialties. As the threat of pandemic progress has continued for months and may continue for years, it is essential to validate existing tools to maintain clinical assessment and patient treatment to avoid negative consequences of the lack of medical follow-up. Therefore, the establishment of a virtual assessment technique that can be conducted effectively is of outmost importance as a way of adapting to the current situation. This study evaluated the role of telemedicine in the assessment of various orthopedic pathologies by means of a systematic virtual evaluation.

Simple Cost-Effective Reinsertion of Avulsed Medial Patellofemoral Ligament in Acute Patellar Dislocation.

The medial patellofemoral ligament (MPFL) is the main restraining force against lateral patellar displacement in the first 20° of flexion and is disrupted after patellar subluxation or dislocation. Management of acute patellar dislocations is controversial, and many clinicians opt for conservative treatment in the acute phase. However, a traumatic rupture of the MPFL warrants surgical attention. Several considerations must be made by surgeons attempting reinsertion of the MPFL, including the choice of implant and timing of surgery, to restore the anatomy and biomechanics of the patellofemoral joint. Our aim is to achieve robust reinsertion of the MPFL restoring the anatomy and biomechanics of the patellofemoral joint using a simple, reproducible, and economical technique. We present MPFL reinsertion to the medial border of the patella in an acute patellar dislocation with a braided No. 2 ultrahigh-molecular-weight polyethylene suture (No. 2 Ultrabraid; Smith & Nephew, Memphis, TN) that is passed through 3 transverse parallel tunnels and tied over a bone bridge on the lateral border of the patella. This technique is simple with no implanted hardware, does not have the risk of donor-site morbidity of MPFL reconstruction, and can be performed in skeletally immature patients without growth plate concerns.

Disparities in Cardiovascular Disease Outcomes Among Pregnant and Post-Partum Women.

Background The incidence of cardiovascular disease among pregnant women is rising in the United States. Data on racial disparities for the major cardiovascular events during pregnancy are limited. Methods and Results Pregnant and post-partum women hospitalized from January 2007 to December 2017 were identified from the Nationwide Inpatient Sample. The outcomes of interest included: in-hospital mortality, myocardial infarction, stroke, pulmonary embolism, and peripartum cardiomyopathy. Multivariate regression analysis was used to assess the independent association between race and in-hospital outcomes. Among 46 700 637 pregnancy-related hospitalizations, 21 663 575 (46.4%) were White, 6 302 089 (13.5%) were Black, and 8 914 065 (19.1%) were Hispanic. The trends of mortality and stroke declined significantly in Black women, but however, were mostly unchanged among White women. The incidence of mortality and cardiovascular morbidity was highest among Black women followed by White women, then Hispanic women. The majority of Blacks (62.3%) were insured by Medicaid while the majority of White patients had private insurance (61.9%). Most of Black women were below-median income (71.2%) while over half of the White patients were above the median income (52.7%). Compared with White women, Black women had the highest mortality with adjusted odds ratio (aOR) of 1.45, 95% CI (1.21-1.73); myocardial infarction with aOR of 1.23, 95% CI (1.06-1.42); stroke with aOR of 1.57, 95% CI (1.41-1.74); pulmonary embolism with aOR of 1.42, 95% CI (1.30-1.56); and peripartum cardiomyopathy with aOR of 1.71, 95 % CI (1.66-1.76). Conclusions Significant racial disparities exist in major cardiovascular events among pregnant and post-partum women. Further efforts are needed to minimize these differences.

Economic Reliable Technique for Tunnel Grafting Using Iliac Crest Bone Graft in Two-Staged Revision Anterior Cruciate Ligament Surgery.

Revision anterior cruciate ligament surgery is a technically demanding procedure. Mal-positioned tunnels together with bone loss and its management are some of the difficulties and challenges faced. Two-staged procedures have successfully been used to tackle those challenges. We present a technique that is safe, reliable, reproducible, and economic in the management of bone defects faced in anterior cruciate ligament revision surgery by using iliac crest bone graft. Preoperative assessment of tunnel position and size is done by computed tomography. Tri-cortical iliac crest bone graft is harvested through a trap door. It is then shaped to fit the tunnels to be filled. It is tapered at the advancing end to facilitate introduction. Mounted on a passing pin and a drill bit, the graft is arthroscopically introduced into the femoral and tibial tunnels. The second stage is performed after the graft has incorporated, as seen on postoperative computed tomography, done at approximately 3 months after the first stage. Iliac crest provides a natural abundant reservoir for bone graft and has all the advantages of being an autograft. With good meticulous technique, complications can be avoided with less donor-site morbidity. This technique is safe, reliable, and reproducible. It provides an ample amount of graft and harvest does not rely on implants; hence, it is economic.

Pharmacokinetic Assessment of Pre- and Post-Oxygenator Vancomycin Concentrations in Extracorporeal Membrane Oxygenation: A Prospective Observational Study.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is a form of cardiopulmonary life support frequently utilized in catastrophic lung and or cardiac failure. Patients on ECMO often receive vancomycin therapy for treatment or prophylaxis against Gram-positive organisms. It is unclear if ECMO affects vancomycin pharmacokinetics, thus we modeled the pharmacokinetic behavior of vancomycin according to ECMO-specific variables. METHODS: Adult patients receiving vancomycin and Veno-Arterial-ECMO between 12/1/2016 and 10/1/2017 were prospectively enrolled. Extracorporeal membrane oxygenation settings and four sets of pre- and post-oxygenator vancomycin concentrations were collected for each patient. Compartmental models were built and assessed ECMO flow rates on vancomycin clearance and potential circuit sequestration. Bayesian posterior concentrations of the pre- and post-oxygenator concentrations were obtained for each patient, and summary pharmacokinetic parameters were calculated. Simulations were performed from the final model for efficacy and toxicity predictions. RESULTS: Eight patients contributed 64 serum concentrations. Patients were a median (interquartile range) age of 58.5 years (50.8-62.3) with a calculated creatinine clearance of 39 mL/min (29.5-62.5) and ECMO flow rates of 3980 mL/min (interquartile range = 3493.75-4132.5). A three-compartment model best fit the data (Bayesian: plasma pre-oxygenation R2 = 0.99, post-oxygenation R2 = 0.99). Vancomycin clearance was not impacted by ECMO flow rate (p = 0.7). Simulations demonstrated that vancomycin 1 g twice daily was rarely sufficient for minimum inhibitory concentrations > 0.5 mg/L. Doses ≥ 1.5 g twice daily often exceeded toxicity thresholds for exposure. CONCLUSIONS: Extracorporeal membrane oxygenation flow rates did not influence vancomycin clearance between flow rates of 3500 and 5000 mL/min and vancomycin was not sequestered in ECMO. Common vancomycin regimens resulted in suboptimal efficacy and/or excessive toxicity. Individual therapeutic drug monitoring is recommended for patients on ECMO.

Temporal Trends in Percutaneous Coronary Intervention and Coronary Artery Bypass Grafting: Insights From the Washington Cardiac Care Outcomes Assessment Program.

Background Patient selection and outcomes for percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) have changed over the past decade. However, there is limited information on outcomes for both revascularization strategies in the same population. The study evaluated temporal changes in risk profile, procedural characteristics, and clinical outcomes for PCI- and CABG-treated patients. Methods and Results We analyzed all PCI and isolated CABG between 2005 and 2017 in nonfederal hospitals in Washington State. Descriptive analysis was performed to evaluate temporal changes in risk profile and, risk-adjusted in-hospital mortality. Over the study period, 178 474 PCI and 36 592 CABG procedures were performed. PCI and CABG volume decreased by 2.9% and 22.6%, respectively. Compared with 2005-2009, patients receiving either form of revascularization between 2014 and 2017 had a higher prevalence of comorbidities including diabetes mellitus and hypertension and dialysis. Presentation with ST-segment-elevation myocardial infarction (17% versus 20%) and cardiogenic shock (2.4% versus 3.4%) increased for patients with PCI compared with CABG. Conversely, clinical acuity decreased for patients receiving CABG over the study period. From 2005 to 2017, mean National Cardiovascular Data Registry CathPCI mortality score increased for patients treated with PCI (20.1 versus 22.4, P<0.0001) and decreased for patients treated with CABG (18.8 versus 17.8, P<0.0001). Adjusted observed/expected in-hospital mortality ratio increased for PCI (0.98 versus 1.19, P<0.0001) but decreased for CABG (1.21 versus 0.74, P<0.0001) over the study period. Conclusions Clinical acuity increased for patients treated with PCI rather than CABG. This resulted in an increase in adjusted observed/expected mortality ratio for patients undergoing PCI and a decrease for CABG. These shifts may reflect an increased use of PCI instead of CABG for patients considered to be at high surgical risk.

Health Risk Assessment of Exposure to Heavy Metals from Sheep Meat and Offal in Kuwait.

ABSTRACT: A total of 600 sheep samples (200 each of muscle, liver, and kidney) collected from 200 sheep carcasses slaughtered at abattoirs in Kuwait were analyzed by atomic absorption spectrophotometry for concentrations of mercury (Hg), arsenic (As), lead (Pb), cadmium (Cd), and chromium (Cr). These metals were detected in all (100%) examined samples; higher concentrations occurred in kidney followed by liver and muscle. The mean (±standard error of the mean) values of the metals detected in sheep muscle, liver, and kidney samples were 0.320 ± 0.061, 0.488 ± 0.042, and 0.791 ± 0.152 µg/g, respectively for Hg; 349 ± 0.074, 0.504 ± 0.049, and 0.642 ± 0.113 µg/g, respectively, for As; 0.482 ± 0.098, 0.567 ± 0.042, and 0.706 ± 0.098 µg/g, respectively, for Pb; 0.301 ± 0.344, 0.433 ± 0.032, and 0.586 ± 0.064 µg/g, respectively, for Cd; and 0.362 ± 0.064, 0.585 ± 0.044, and 0.738 ± 0.111 µg/g, respectively, for Cr. The concentrations of all heavy metals except Cr exceeded the maximum permissible limits set by various international food agencies. The estimated daily intake of each metal was lower than its provisional tolerable daily intake. The target hazard quotient and hazard index values for Hg were >1.0 in all examined sheep samples, suggesting significant health risks to the public from the consumption of sheep meat and offal marketed in Kuwait.

Heavy Metal Residues in Some Fishes from Manzala Lake, Egypt, and Their Health-Risk Assessment.

A total of 600 freshly caught fish samples (200 each of Nile tilapia, flathead grey mullet, and African catfish) were collected from Manzala Lake, Egypt, and analyzed for determination of heavy metal residues using an atomic absorption spectrophotometer. Metal concentrations (µg/g wet weight) were detected in all examined samples in quantities of 0.045, 0.0145, and 0.017 µg/g for Hg; 0.511, 0.621, and 0.568 µg/g for As; 0.704, 0.635, and 0.64 µg/g for Pb; and 0.024, 0.006, and 0.020 µg/g for Cd in Nile tilapia, flathead grey mullet, and African catfish, respectively. The mean concentrations of Hg, Pb, and Cd among the three fish species tested followed the order Nile tilapia > African catfish > flathead grey mullet; meanwhile, As concentration followed the order flathead grey mullet > African catfish > Nile tilapia. The contamination levels of Hg and Cd showed significant differences between summer and winter in the three different fish species examined. Both the mullet and catfish tested revealed significant negative correlations between fish size and their residual levels of Hg, Pb, and Cd. Health-risk assessment indices suggesting that consuming such fishes from Manzala Lake could have a potential health hazard to consumers.

Prevalence, Causes, and Predictors of 30-Day Readmissions Following Hospitalization With Acute Myocardial Infarction Complicated By Cardiogenic Shock: Findings From the 2013-2014 National Readmissions Database.

BACKGROUND: Prior studies have shown that survivors of acute myocardial infarction (AMI) complicated by cardiogenic shock are likely to have increased risk of readmissions in the early post-discharge period. However, the contemporary prevalence, reasons, and predictors of 30-day readmissions are not well known. METHODS AND RESULTS: Hospitalizations for a primary diagnosis of AMI complicated by cardiogenic shock, and discharged alive, were identified in the 2013 and 2014 Nationwide Readmissions Databases. Prevalence and reasons for 30-day unplanned readmissions were investigated. A hierarchical logistic regression model was used to identify independent predictors of 30-day readmissions. Among 1 116 933 patient hospitalizations with AMI, 39 807 (3.6%) had cardiogenic shock and were discharged alive. Their 30-day readmission rate was 18.6%, with a median time for readmission 10 days post discharge. Predictors of readmission included: non-ST-segment elevation myocardial infarction, female sex, low-income status, nonprivate insurance, chronic renal failure, long-term ventricular assist device or intra-aortic balloon placement, and tachyarrhythmia. The majority of readmissions were attributable to cardiac-related causes (52%); heart failure being the most frequent cardiac cause (39% of all cardiac causes). Noncardiac-related readmissions included infections (14.9%), bleeding (5.3%), and respiratory causes (4.9%). The median cost per readmission was $9473 US dollars ($5037-20 199). CONCLUSIONS: Among survivors of AMI complicated by cardiogenic shock who were discharged from hospital, almost 1 in 5 are readmitted at 30 days, mainly because of cardiac reasons such as heart failure and new AMI. The risk of readmission was associated with certain baseline patient/hospital characteristics.

Comparison Between Retrograde and Antegrade Peripheral Venous Cannulation in Intensive Care Unit Patients: Assessment of Thrombus Formation.

BACKGROUND: Antegrade cannulation of peripheral veins is the usual practice. Blood stasis between a catheter and the wall of the vein or at its tip in addition to catheter-induced phlebitis may initiate a thrombosis. The use of retrograde ventriculojugular shunts against the direction of the blood flow with resultant decrease in the incidence of venous thrombosis encouraged us to compare retrograde versus conventional antegrade peripheral venous cannulation. METHODS: Monocentric, nonblinded, prospective observational cohort of 40 intensive care unit patients receiving 2 peripheral venous catheters in upper limbs, 1 inserted in the direction of blood flow (antegrade cannula) and the other inserted in an opposite direction to blood flow (retrograde cannula). Daily ultrasound assessment of the angle between the catheter and the vascular wall was done to detect onset and progression of thrombus formation. RESULTS: The study included 40 patients, aged 46.7 ± 10.132 years. The incidence of thrombus formation was 100% in both techniques. The onset time of thrombus formation between the catheter and the wall of a vein was significantly longer with the retrograde catheters than with the antegrade catheters with median time (interquartile range [range]) 6 days (5-6.75 [4-8]) with 95% confidence interval (CI), 5.58-6.42 vs 3 days (3-4 [2-5]) with 95% CI (2.76-3.24), respectively, with a P value <.001. The time needed by the recently detected thrombus to reach the catheter tip determined by ultrasound with or without catheter failure was significantly longer in the retrograde catheters than in the antegrade catheter with median time (interquartile range [range]) 9 days (8-9 [7-10]) with 95% CI, 8.76-9.24 vs 4 days (4-5 [3-6]) with 95% CI, 3.76-4.24, respectively, with a P value <.001. CONCLUSIONS: Retrograde cannulation did not decrease the incidence of thrombus formation, but significantly increased the onset time until thrombus formation and prolonged the time needed by the newly formed thrombus to reach the catheter tip compared with conventional antegrade cannulation.

Bivalirudin in percutaneous coronary intervention, is it the anticoagulant of choice?

For decades, unfractionated heparin (UFH) has been widely used in catheterization laboratories for anticoagulation for percutaneous coronary intervention (PCI). The direct thrombin inhibitors, bivalirudin, has emerged as an alternative to UFH for PCI procedures, due to its lower bleeding risk. More recently, randomized trials and meta-analyses questioned the efficacy of bivalirudin, and demonstrated that bivalirudin might be associated with a higher incidence of ischemic events and in particular stent thrombosis. In this review, we discuss the pharmacology of bivalirudin along with the clinical evidence comparing bivalirudin versus UFH in patients undergoing PCI for various indications.

Noninvasive assessment of human jawbone using ultrasonic guided waves.

The problem of detecting defects in jawbones is an important problem. Existing methods based on Xrays are invasive and constrain the achievable image quality. They also may carry known risks of cancer generation or may be limited in accurate diagnosis scope. This work is motivated by the lack of current imaging modalities to accurately predict the mechanical properties and defects in jawbone. Ultrasonic guided waves are sensitive to changes in microstructural properties and thus have been widely used for noninvasive material characterization. Using these waves may provide means for early diagnosis of marrow ischemic disorders via detecting focal osteoporotic marrow defect, chronic nonsuppurative osteomyelitis, and cavitations in the mandible (jawbone). Guided waves propagating along the mandibles may exhibit dispersion behavior that depends on material properties, geometry, and embedded cavities. In this work, we present the first study in the theoretical and experimental analysis of guided wave propagation in jawbone. Semianalytical, finite-element (SAFE) method is used to analyze dispersion behavior of guided waves propagating in human mandibles. The geometry of the cross section is obtained by segmenting the computed tomography (CT) images of the jawbone. The cross section of the mandible is divided in two regions representing the cortical and trabecular bones. Each region is modeled as a linear Hookean material. The material properties for both regions are adopted from the literature. The experimental setup for the guided waves experiment is described. The results from both numerical analysis and guided waves experiment exhibit variations in the group velocity of the first arrival signal and in the dispersion behavior of healthy and defected mandibles. These results shall provide a means to noninvasively characterize the jawbone and accurately assess the bone mechanical properties. Our study is not aimed at characterizing the bone density in human mandibles. Rather, it is aimed to assess bone mechanical properties and defects that cannot be diagnosed by X-ray or other imaging modalities. This work may pave the way to the development of inexpensive noninvasive devices to detect small defects in human mandibles.

Assessment of indigenous Nepalese soybean as a potential germplasm resource for improvement of protein in North American cultivars.

Soybeans contain approximately 40% protein and 20% oil and represents an important source of protein in animal rations and human diets. Attempts are being made to increase further the overall protein content of soybeans by utilization of exotic germplasms. In this study, soybean cultivars from Nepal have been characterized and their potential as a germplasm resource for improvement of the protein content and quality of North American cultivars assessed. Soybean cultivars 'Sathia', 'Seti', 'Kavre', and 'Soida Chiny', indigenous to various regions of Nepal, contained 42-45% protein, which is significantly higher in comparison to that of the North American cultivar 'Williams 82' (39%). Fractionation of seed protein by high-resolution two-dimensional gel electrophoresis revealed differences in the protein profiles of these cultivars. Various isoelectric forms of glycinin and beta-conglycinin were identified by comparing the matrix-assisted laser desorption ionization time-of-flight mass fingerprinting data against the National Center for Biotechnology Information nonredundant database. Nepalese cultivar Sathia was distinct, lacking some isoelectric forms of acidic and basic glycinin subunits while expressing other unique forms. The contribution of these unique protein spots present in either Sathia or Williams 82 to the total protein content was quantified using scanning laser densitometry. Distinct restriction fragment length polymorphisms (RFLP) for group 1 glycinin genes were observed among the tested Nepalese genotypes, indicating sequence variation among the cultivars. Conversely, evaluation of RFLP for the genes encoding group 2 glycinins, beta-conglycinin, and Bowman-Birk proteinase inhibitors indicated a high degree of conservation in these genes. Determination of amino acid composition, a reflection of protein quality, indicated that the arginine content of the Nepalese soybeans ranged from 7.7 to 8.1%, which was 5-10% higher than the 7.4% expressed in Williams 82. Additionally, Karve and Seti contained significantly more cysteine than Williams 82. Nepalese high-protein soybeans having a desirable amino acid composition hold potential to increase the protein quality and diversity of North American cultivars.