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Union in Lateral Column Lengthening by Plate Fixation Without Bone Graft in Flexible Flatfoot: A Case Series. Indian J Orthop 2023; 57:1283-1289. [PMID: 37525734 PMCID: PMC10387035 DOI: 10.1007/s43465-023-00945-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 06/22/2023] [Indexed: 08/02/2023]
Abstract
Purpose This study's goal was to evaluate the outcomes of lateral column lengthening by plate fixation without bone graft in the management of symptomatic flexible flatfoot. Methods A prospective randomized trial study included 30 feet (27 patients) and was performed from March 2017 to December 2019. Functional and radiological evaluations were done pre-operative and at the final post-operative follow-up. The functional assessment was done using the American Orthopaedic Foot and Ankle Society (AOFAS) score. Results The mean follow-up was 16.5 ± 3.027 months. The mean age of patients was 22.6 ± 6.29 years. All cases showed union ranging from 8 to 12 weeks, with a mean of 10 ± 1.88 weeks. The mean AOFAS score improved from 51.6 ± 6.75 to 92.2 ± 6.21. The mean anteroposterior (AP) talo-first metatarsal angle improved from 25.3° ± 8.31° to 3.4° ± 5.10°. The mean anteroposterior (AP) talo-navicular coverage improved from 22.10° ± 4.28° to 2.3° ± 3.46°. The mean Lateral talo-first metatarsal angle improved from 18.6° ± 4.79° to 3.3° ± 3.16°. The calcaneal pitch angle improved from 9.6° ± 4.14° to 15.1° ± 4.43°. The mean lateral talo-calcaneal angle improved from 45.7° ± 3.77° to 37.5° ± 3.47°. Conclusion Using an interposition wedge plate for LCL without bone graft leads to a high union rate, maintains the correction, and avoids possible complications of autografts and allografts.
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Utilization of the emergency department by kidney transplant recipients: a retrospective cohort study from a high-volume transplant center. Ann Med Surg (Lond) 2023; 85:1496-1501. [PMID: 37228953 PMCID: PMC10205359 DOI: 10.1097/ms9.0000000000000481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 03/18/2023] [Indexed: 05/27/2023] Open
Abstract
This study aims to assess the trends of emergency department (ED) visits among kidney transplant recipients in a high-volume transplant centre. Methods This retrospective cohort study targeted patients who underwent renal transplantation at a high-volume transplant centre from 2016 to 2020. The main outcomes of the study were ED visits within 30 days, 31-90 days, 91-180 days, and 181-365 days of transplantation. Results This study included 348 patients. The median (interquartile range) age of patients was 45.0 years (30.8, 58.2). Over half of the patients were male (57.2%). There was a total of 743 ED visits during the first year after discharge. 19% (n=66) were considered high-frequency users. High-volume ED users tended to be admitted more frequently as compared to those with low frequencies of ED visits (65.2% vs. 31.2%, respectively, P<0.001). Conclusion As evident by the large number of ED visits, suitable coordination of management through the ED remains a pivotal component of post-transplant care. Strategies addressing prevention of complications of surgical procedures or medical care and infection control are aspects with potential for enhancement.
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Calciumantagonisten bei postoperativer Erythromelalgie. J Dtsch Dermatol Ges 2022; 20:348-350. [PMID: 35304955 DOI: 10.1111/ddg.14697_g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Post-operative erythromelalgia treated with calcium channel blockers. J Dtsch Dermatol Ges 2022; 20:347-349. [PMID: 35182099 DOI: 10.1111/ddg.14697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Suprameniscal Portal for Repairing Meniscal Root Tears. Arthrosc Tech 2021; 10:e1627-e1632. [PMID: 34258214 PMCID: PMC8252813 DOI: 10.1016/j.eats.2021.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 03/02/2021] [Indexed: 02/03/2023] Open
Abstract
Several techniques and portals have been described for meniscal root repairs. Some authors describe using anterior portals for suture passing and manipulation of meniscal tissue, with some risk of iatrogenic chondral injuries reported. Other authors describe using posterior portals to avoid this risk. In this technique, we used a suprameniscal portal, which allowed a good trajectory for passing sutures in the meniscal tissue with minimal risk of iatrogenic chondral damage without the need to use posterior portals. The meniscal bed is first prepared. The suprameniscal portal is created in 15° of knee flexion and used to pass 2 sutures through the meniscus by a Lasso. The sutures are tied in a cinch configuration, shuttled through the tibial tunnel, and tied over a Dog Bone button.
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Comparison between standard solid fuel and a new annular fuel performance in the core of a PWR. KERNTECHNIK 2021. [DOI: 10.3139/124.190020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
In new generation PWR the annular fuel has been proposed as one of the options to achieve higher power density, larger safety margin and reduced electricity generation cost. In the current work, RELAP5 code is used to compare the thermal hydraulic parameters for both solid fuel and internally and externally cooled annular fuel in a core of a PWR. MCNP6 code is used to evaluate the neutronic design and basic safety parameters of the annular fuel. To accomplish this goal, RELAP5 input files for both solid and annular fuels are developed. In these files, a 13 · 13 array annular fuel design is used while the 17 · 17 standard array design is used for the solid fuel. A 100% core power, steady state normal operation is assumed in the current investigation. Also, MCNP6 code input files for both fuels are prepared. It is found that annular fuel has lower peak fuel temperature than the standard solid fuel, which is an important advantage of the annular fuel rather than the solid one. Also, comparisons were performed for reactivity feedback coefficients of the two fuel types at BOC. Burnup calculations were performed to study the energy conversion capability of the annular fuel as well as rim effects.
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Incidence and Clinical Implications of Isolated Hepatitis B Core Antibody Serologic Profile Pattern Among Egyptian Patients with Chronic Hepatitis C. EGYPTIAN ACADEMIC JOURNAL OF BIOLOGICAL SCIENCES. C, PHYSIOLOGY AND MOLECULAR BIOLOGY 2020. [DOI: 10.21608/eajbsc.2020.133909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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The role of supportive supervision using mobile technology in monitoring and guiding program performance: a case study in Nigeria, 2015-2016. BMC Public Health 2018; 18:1317. [PMID: 30541512 PMCID: PMC6291920 DOI: 10.1186/s12889-018-6189-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Background Supportive supervision is one of the interventions that fosters program improvement by way of imparting knowledge and skills to health workers. The basic challenge in supportive supervision is the availability of data in real time for timely and effective feedback. Thus, the main objective of this study was to determine the contribution of real-time data collection during supportive supervision for timely feedback and generation of evidence for health intervention planning. Methods We analyzed supportive supervision records collected through handheld devices employing the open data kit (ODK) platform from July 2015 to June 2016. Supervision was conducted across the country by 592 World Health Organization (WHO) officers. The availability of real-time data and the distance of health facilities to the community were analyzed. Results During the study period, 90,396 health facilities were supervised. The average time spent during supervision varied from 1.53 to 3.78 h across the six geopolitical zones of the country. The average interval between completion of the supervisory checklist and synchronization with the server varied from 3.9 h to 7.5 h. The average distance between the health facility and a ward varied from 5 to 24 km. Conclusion The use of handheld devices for supportive supervision provided real-time data from health facilities to state and zonal levels for analysis and feedback. Program officers used the findings to rectify process indicators in time for a better outcome.
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Stump Incorporation for Anterior Cruciate Ligament Reconstruction: A Step Towards a More Anatomical Reconstruction. Arthrosc Tech 2017; 6:e1303-e1307. [PMID: 29354433 PMCID: PMC5622233 DOI: 10.1016/j.eats.2017.05.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 05/11/2017] [Indexed: 02/03/2023] Open
Abstract
In most anterior cruciate ligament (ACL) tears, the tear is at the femoral side leaving a robust stump attached to the tibia. Stump-preserving ACL reconstruction carries the advantage of rapid reinnervation and revascularization of the graft. In this technique, the femoral tunnel is created after exposing the femoral footprint. The ACL tibial stump is split and the tip of the ACL tibial guide is introduced through this split to reach the center of the tibial footprint. The tibial tunnel is then created and the ACL stump is bored to allow the passage of the graft. After the passage of the graft inside the stump and femoral and tibial fixation, 1 or 2 sutures are used to suture the graft to the stump by a suture passing device (Expressew II; Depuy Mitek, Raynham, MA). This technique, in addition to preservation of the mechanoreceptors and vascular channels for revascularization and reinnervation of the graft, allows preservation of the shape and surface area of the wide tibial origin of the ACL.
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Using a Posterolateral Portal to Pass and Tie the Suture of the Inferior Anchor During Arthroscopic Bankart Repair. Arthrosc Tech 2016; 5:e1467-e1470. [PMID: 28560145 PMCID: PMC5439272 DOI: 10.1016/j.eats.2016.08.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 08/25/2016] [Indexed: 02/03/2023] Open
Abstract
Using a posterolateral portal in passing and tying the inferior knot allows good labral reduction and adequate capsular shift to treat anterior shoulder instability. In this technique, the most inferior anchor is placed through a low anterolateral portal. A penetrating grasper is introduced from a posterolateral portal situated 2 to 3 cm distal and lateral to the viewing portal. This portal is used to pass the 2 limbs of the anchor suture as inferior as possible through the labrum and capsule close to 6 o'clock position to form the 2 limbs of the first mattress suture. Finally, knot tying is performed through this posterolateral portal, thus allowing better superior shift of the capsulolabral tissue. The other 2 anchor sutures are passed and tied through the low anterolateral portal.
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Three Gene Signature for Predicting the Development of Hepatocellular Carcinoma in Chronically Infected Hepatitis C Virus Patients. J Interferon Cytokine Res 2016; 36:698-705. [PMID: 27726464 DOI: 10.1089/jir.2016.0042] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Hepatitis C virus (HCV) is the leading cause of liver fibrosis and hepatocellular carcinoma (HCC). At present, there is no predictive biomarker for the patients at high risk of developing HCC. In this study, we examined the association between single-nucleotide polymorphisms (SNPs) in 3 innate immunity genes [2'-5'oligoadenylate synthetase 1 (OAS1) rs10774671, interleukin 28B (IL28B) rs12979860, and low molecular mass polypeptide 7 (LMP-7) at codon 49] besides cytomegalovirus (CMV) coinfection and susceptibility to HCC in genotype 4 (GT4) chronically infected Egyptian patients. SNPs were determined using restriction fragment length polymorphism analysis in DNA from HCC patients (n = 34) and compared with either controls (n = 70) or patients with early grades of liver fibrosis (n = 49). Our results demonstrated that patients bearing the genetic combination consisting of LMP-7 CA/AA [OR 4.75, 95% confidence interval (CI) 1.443-15.631, P = 0.007] and IL28B rs12979860 CT/TT (OR 6.00, 95% CI 1.603-22.455, P = 0.004) and positive for CMV viremia (OR 3.11, 95% CI 1.151-8.412, P = 0.02) were more likely to have HCC. However, OAS1 rs10774671 does not seem to contribute to the development of HCC. Binary regression analysis indicated that HCC risk significantly increases with the presence of each unfavorable genotype (LMP-7 CA/AA, IL28B rs12979860 CT/TT), when accompanied by the existence of CMV coinfection (probability of HCC risk is 0.8 for combined factors versus 0.14, 0.07, and 0.07 for individual factor IL28B, LMP-7, and CMV; respectively). These data suggest that the 2 SNPs and the coinfection in concert have potential in predicting the risk of HCC development in patients infected with HCV GT4.
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Validation of RELAP5 model of experimental test rig simulating the natural convection in MTR research reactors. KERNTECHNIK 2016. [DOI: 10.3139/124.110562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
In an attempt to understand the built-up of natural circulation in MTR pool type upward flow research reactors after loss of power, an experimental test rig was built to simulate the loop of natural circulation in MTR reactors. The test rig consisting of two vertically oriented branches, in one of them the core is simulated by two rectangular, electrically heated, parallel channels. The other branch simulates the part of the return pipe that participates in the development of core natural circulation. In the first phase of the work, many experimental runs at different conditions of channel's power and branch's initial temperatures are performed. The channel's coolant and surface temperatures were measured. The measurements and their interpretation were published by the first three authors. In the present work the thermal hydraulic behavior of the test rig is complemented by theoretical analysis using RELAP5 Mod 3.3 system code. The analysis consisting of two parts; in the first part RELAP5 model is validated against the measured values and in the second part some of the other not measured hydraulic parameters are predicted and analyzed. The test rig is typically nodalized and an input dick is prepared. In spite of the low pressure of the test rig, the results show that RELAP5 qualitatively predicts the thermal hydraulic behaviour and the accompanied phenomenon of flow inversion of such facilities. Quantitatively, there is a difference between the predicted and measured values especially the channel's surface temperature. This difference may be return to the uncertainties in initial conditions of experimental runs, the position of the thermocouples which buried inside the heat structure, and the heat transfer package in RELAP5.
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Characterization and Determination of Major Bioactive Acids in Camel Urine Using Gas Chromatography Mass-spectrometry. Indian J Pharm Sci 2016. [DOI: 10.4172/pharmaceutical-sciences.1000168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Abstract
Abstract
The present paper comes in the line with the international approach which use the best estimate codes, instead of conservative codes, to get more realistic prediction of system behavior under off-normal reactor conditions. The aim of the current work is to apply this approach using the thermal-hydraulic system code RELAP5/Mod3.3 in a reassessment of safety of the IAEA benchmark 10 MW Research Reactor. The assessment is performed for both slow and fast reactivity insertion transients at initial power of 1.0 W. The reactor power is calculated using the RELA5 point kinetic model. The reactivity feedback terms are considered in two steps. In the first step the feedback from changes in water density and fuel temperature (Doppler effects) are considered. In the second step the feedback from the water temperature changes is added. The results from the first step are compared with that published in IAEA-TECDOC-643 benchmarks. The comparison shows that RELAP5 over predicts the peak power and consequently the fuel, clad and coolant temperatures in case of fast reactivity insertion. The results from the second step show unjustified values for reactor power. Therefore, the model of reactivity feedback from water temperature changes in the RELAP5 code may have to be reviewed.
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Review of regulatory requirements relevant to calibration of monitoring instruments in research reactors. KERNTECHNIK 2015; 80:138-145. [DOI: 10.3139/124.110444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
Abstract
The objective of this work is to demonstrate the regulatory requirements pertaining to calibration of monitoring instruments in research reactors. The regulatory statements concerning this subject in IAEA safety standards and the implementation of such regulations in twelve countries with different levels of nuclear programs are surveyed: Australia, Bulgaria, Canada, Egypt, Finland, Germany, Hungary, Slovenia, South Korea, Spain, United Kingdom of England and United States of America. In addition, the requirements of ISO/IEC17025 and NUPIC (Nuclear Utilities Procurement Issues Committee) are compared. Seven technical and administrate aspects are suggested as the comparison criteria and the explicit expression of the statements, the level of document (i. e.: act, requirement or guide) are the considered resources. The main differences and similarities between the different approaches are identified in order to provide an input for future development of the national regulations.
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Enhancement of In Vitro Skin Transport and In Vivo Hypoglycemic Efficacy of Glimepiride Transdermal Patches. TROP J PHARM RES 2014. [DOI: 10.4314/tjpr.v13i8.3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Abstract
Abstract
The core cooling of upward flow MTR pool type Research Reactor (RR) at the later stage of pump coast down is experimentally handled to clarify the effect of some operating parameters on RR core cooling. Therefore, a test rig is designed and built to simulate the core cooling loop at this stage. The core is simulated as two vertical channels, electrically heated, and extended between upper and lower plenums. Two elevated tanks filled with water are connected to the two plenums. The first one constitutes a left branch, connected to the lower plenum, and is electrically heated to simulate the core return pipe. The second one constitutes the right branch, connected to the upper plenum, and is cooled by refrigerant circuit to simulate the reactor pool. Channel coolant and wall temperatures at different power and branch temperatures are measured, registered and analyzed. The results show that at this stage of core cooling two cooling loops are established; an internal circulation loop between the channels dominated by the difference in channel's power and an external circulation loop between the branches dominated by the temperature difference between branches. Also, there is a double inversion in core flow, upward-downward-upward flow. This double inversion increases largely the channel's wall temperature. Complementary safety analysis to evaluate this phenomenon must be performed.
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Management of displaced intra-articular calcaneal fractures using the limited open sinus tarsi approach and fixation by screws only technique. INTERNATIONAL ORTHOPAEDICS 2013; 38:601-6. [PMID: 24310507 DOI: 10.1007/s00264-013-2203-z] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 11/12/2013] [Indexed: 10/25/2022]
Abstract
PURPOSE Evaluation of management of the displaced intra-articular calcaneal fractures (DIACF) Sanders types II and III by using minimally invasive sinus tarsi approach and fixation by screws only technique. METHODS Open reduction using the limited lateral approach and internal fixation using screws only was studied in 33 patients with unilateral isolated simple DIACF with a mean age of 35 years (15 type II patients and 18 type III patients). All patients were evaluated both clinically and radiologically. RESULTS With a mean follow-up period of 28.8 months (range 12-53 months), no cases of failure of reduction or displacement of hardware were detected. The mean AOFAS was 91.73 points while the mean MFS was 95.09 points. Twenty-eight patients were able to resume their pre-injury level of work while the remaining five refrained to sedentary jobs. The mean pre-operative Bohlers' angle was 2.8° (range from -38º to 24º) while postoperatively it was 19.4° (range 5º to 49º). There was no statistically significant difference when comparing the results (AOFAS p-value 1.00, MFS p-value 0.81) between Sanders' type II and III fractures. One patient had postoperative superficial wound infection. Seven patients complained of prominent screw heads. Complex regional pain syndrome occurred in seven patients and was treated successfully at six months duration. CONCLUSION The limited open sinus tarsi approach can be used successfully to treat displaced Sanders type II and III fractures. It allows for adequate visualization and reduction. Fixation by screws only is also sufficient. It also clearly avoids the major wound complication problems.
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Abstract
An accurate, reproducible, and sensitive method for the determination of buspirone HCl and its potential impurities is developed and validated. The validated liquid chromaography method is conducted to meet the Food and Drug Administration/ International Conference on Harmonization requirements for the analysis of buspirone HCI in the presence of its impurities. Five buspirone HCI potential impurities, including 1-(2-pyrimidinyl)-piperazine (I), propargyl chloride (II), 3,3'-tetramethylene glutarimide (III), propargyl glutarimide (IV), and the Mannich base-condensate of I-IV fumarate (V), are separated using a microBondapack C18 column by gradient elution with a flow rate 2.0 mL/min. The initial mobile phase composition is 90:10 (v/v) 10mM KH2PO4 (pH 6.1)-acetonitrile. After a 1-min initial hold, a linear gradient is performed in 26 min to 35:65 (v/v) 10mM KH2PO4 (pH 6.1)-acetonitrile. The samples are detected at 210 and 240 nm using a photo-diode array detector. The linear range of detection for buspirone HCI was between 1.25 ng/microL and 500 ng/microL, with a limit of quantification of 1.25 ng/microL. The linearity, range, peak purity, selectivity, system performance parameters, precision, accuracy, and robustness for all of the impurities were also shown to have acceptable values.
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Abstract
The United States Pharmacopoeia high-performance liquid chromatographic (HPLC) assay method of buspirone is not able to discriminate buspirone from its degradation products. The purpose of this work is to develop a sensitive, selective, and validated stability-indicating HPLC assay for the analysis of a buspirone hydrochloride in a bulk drug. Buspirone HCI and its potential impurities and degradation products are analyzed on an Ultrasphere C18 column heated to 40 degrees C using a gradient program that contains monobasic potassium phosphate buffer solution (pH 6.9) and acetonitrile-methanol mixture (13:17) of 35% for 5 minutes, then increased to 54% in 5.5 minutes. The samples are monitored using a photo-diode array detector and integrated at 244 and 210 nm. The stress testing of buspirone HCI shows that buspirone acid hydrochloride is the major degradation product. The developed method shows a separation of buspirone degradation product and its potential impurities in one run. The stability of buspirone HCI is studied under accelerated conditions in order to provide a rapid indication of differences that might result from a change in the manufacturing process or source of the sample. The forced degradation conditions include the effect of heat, moisture, light, acid-base hydrolysis, sonication, and oxidation. The compatibility of buspirone HCI with some pharmaceutical excipients is studied under stress conditions. The linear range of buspirone HCI is between 5 and 200 ng/microL with a limit of quantitation of 2.5 ng/microL. The intraassay percentage deviation is not more than 0.38%, and the day-to-day variation was not more than 0.80%. The selectivity, repeatability, linearity, range, accuracy, sample solution stability, ruggedness, and robustness show acceptable values.
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3-Bromomethyl-propyphenazone as a new derivatization reagent for high performance liquid chromatography of captopril and hydrochlorothiazide with UV-detection. Biomed Chromatogr 1998; 12:57-60. [PMID: 9568270 DOI: 10.1002/(sici)1099-0801(199803/04)12:2<57::aid-bmc720>3.0.co;2-g] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
3-Bromomethyl-propyphenazone (BMP) was used as a derivatization reagent for the detection and quantification of captopril (CAP) and hydrochlorothiazide (HCT) by high performance liquid chromatography using Zorbax C8 column, and 0.05M sodium acetate, acetonitrile, methanol (14:17:4; pH 6.5) as mobile phase system with UV-detection at 254 nm. The cited reagent reacts with the mercapto and amino groups of CAP and HCT in acetone using anhydrous potassium carbonate as hydrobromide acceptor. The reaction was completed within 30 min for CAP and 60 min for HCT with heating at 105 +/- 5 degrees C in mini-reaction vial. The linear concentration ranges for both CAP and HCT were 8 to 160 and 6 to 140 ng per injection, respectively. The derivatized captopril was synthesized and confirmed with spectral analysis. This method was applied for determination of spiked captopril in human urine after extraction with Extrelut-20 column using ethyl acetate:isopropanol (85:15 v/v) as eluant.
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Abstract
Famprofazone (1) metabolites were studied in human urine after medication by 50 mg oral dose. The human urine was collected over 48 h from six volunteers at time intervals of 6, 12, 24 and 48 h. The amount of famprofazone metabolites were recovered from the urine samples by application of Extrelut extraction method. The resultant extracts were derivatized using N-methyl-N-trimethylsilytrifluoroacetamide (MSTFA) for trimethylsilylation followed by N-methyl-bis-trifluoroacetamide (MBTFA) for trifluoroacetylation. Methamphetamine (2) and 3-hydroxymethyl-propyphenazone (3), excreted in human urine, were identified as famprofazone metabolites by gas chromatography-mass spectrometry (GC-MS). The quantitative results revealed that the average amounts of 2 and 3, excreted in human urine were equal to 2.6 and 4 mg, respectively, through 48 h. However, 3 was analysed after enzymatic hydrolysis of the urine samples using beta-glucuronidase/arylsulphatase. The excreted methamphetamine enantiomers could be separated by application of indirect GC-technique using S-(-)-N-trifluoroacetylprolyl chloride (TPC) as a chiral derivatizing agent. The average amount of (-)-methamphetamine isomer excreted in the urine was found to be three fold those of the (+)-isomer.
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Abstract
A high-performance liquid chromatographic method involving on-line precolumn oxidative cleavage and fluorimetric detection was developed for the determination of methotrexate in plasma. Plasma samples were subjected to protein precipitation followed by solvent purification and then injection into the chromatographic system. Cerium (IV) trihydroxyhydroperoxide (CTH) was introduced as a packed oxidant before analytical column for the conversion of methotrexate into highly fluorescent 2,4-diaminopteridine derivatives. The oxidative cleavage of methotrexate occurs during the flow of 0.04 M phosphate buffer (pH 3.5) containing the drug through CTH column with a flow-rate of 0.2 mL/min at 40 degrees C. The separation was performed on a reversed-phase column (ODS/TM) using a mobile phase consisting of phosphate buffer (0.05 M, pH 6.6) and acetonitrile (90:10 v/v). The fluorescent products were monitored fluorimetrically at emission and excitation wavelengths of 463 and 367 nm, respectively. Validation of accuracy and precision were satisfactory for both within- and between-run assays. All coefficients of variance were less than 4% and mean relative errors were within 1.11% to 7.83%. The average recovery was found to be 93.74% to 98.11%. The proposed method is highly sensitive, specific and applicable to biological fluids.
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High-performance liquid chromatography of alpha-amino acids and aztreonam on reversed phase columns with aqueous Cu2+ as eluent. Biomed Chromatogr 1996; 10:167-71. [PMID: 8831960 DOI: 10.1002/(sici)1099-0801(199607)10:4<167::aid-bmc584>3.0.co;2-#] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Parameters affecting the separation of amino acids on different RP-HPLC columns were studied. Six amino acids were separated on Zorbax TMS, Zorbax CN, Zorbax ODS and Zorbax C8, using 1.8 x 10(-3) M copper sulphate at pH 4.1 as aqueous mobile phase. The best separation was shown by Zorbax TMS followed by Zorbax CN. The column performance was maintained by serial washing after 6 h continuous work with aqueous 10(-4) M disodium edetate, 10(-4) N sulphuric acid, water and gradient elution with aqueous methanol. The separation mechanism was interpreted. The method was applied for separation and quantification of aztreonam and L-arginine in Azactam vials.
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Abstract
A rapid and specific HPLC assay for quantiative determination of bupivacaine in human serum is described. The technique incorporates an on-line sample clean-up system followed by reversed-phase chromatography with UV detection. The proposed method uses a column-switching technique and protein-coated Lichrosorb RP-8 as a precolumn together with Lichrosorb RP-18 as an analytical column. The total run time for an injection of serum sample was 10 min. This procedure offers a sensitive assay without the need for time-consuming extractions. The average bupivacaine recoveries over a concentration range of 150-600 ng/mL ranged from 99.12 to 101.02%, and relative standard deviations ranged from 1.15 to 1.78%.
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