Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 205
Filter
1.
Anaesth Rep ; 8(2): 152-155, 2020.
Article in English | MEDLINE | ID: mdl-33305289

ABSTRACT

A 31-year-old primiparous woman with a history of bigeminy as a teenager developed atrial fibrillation with rapid ventricular response during elective caesarean section. Initial postoperative medical management was undertaken on the maternal high dependency unit and involved the administration of beta-blockers and digoxin. On postoperative day 1 the patient was transferred to the coronary care unit where she subsequently required synchronised direct current cardioversion to restore sinus rhythm. The patient remained on the coronary care unit for 5 days before discharge. Magnetic resonance imaging undertaken 6 weeks postpartum showed non-ischaemic cardiomyopathy. In this report, we discuss tachycardia-induced and peripartum cardiomyopathies, along with their potential underlying pathologies, incidence and associated morbidity. We describe potential pharmacological therapies including beta-blockers and angiotensin-converting enzyme inhibitors, as well as the implications of such medications for breastfeeding mothers. Patients presenting with palpitations in the antenatal period should receive prompt investigation including electrocardiography with ambulatory monitoring considered for those with persistent symptoms. Anyone with a proven cardiac arrhythmia should undergo echocardiography. This report illustrates the importance of the investigation of the symptoms of arrhythmia during pregnancy and emphasises the role of multidisciplinary working in the management of obstetric patients with complex medical comorbidity.

3.
Transplant Proc ; 51(3): 722-728, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30979456

ABSTRACT

TruGraf v1 is a laboratory-developed DNA microarray-based gene expression blood test to enable proactive noninvasive serial assessment of kidney transplant recipients with stable renal function. It has been previously validated in patients identified as Transplant eXcellence (TX: stable serum creatinine, normal biopsy results, indicative of immune quiescence), and not-TX (renal dysfunction and/or rejection on biopsy results). TruGraf v1 is intended for use in subjects with stable renal function to measure the immune status as an alternative to invasive, expensive, and risky surveillance biopsies. MATERIALS AND METHODS: In this study, simultaneous blood tests and clinical assessments were performed in 192 patients from 7 transplant centers to evaluate TruGraf v1. The molecular testing laboratory was blinded to renal function and biopsy results. RESULTS: Overall, TruGraf v1 accuracy (concordance between TruGraf v1 result and clinical and/or histologic assessment) was 74% (142/192), and a result of TX was accurate in 116 of 125 (93%). The negative predictive value for TruGraf v1 was 90%, with a sensitivity 74% and specificity of 73%. Results did not significantly differ in patients with a biopsy-confirmed diagnosis vs those without a biopsy. CONCLUSIONS: TruGraf v1 can potentially support a clinical decision enabling unnecessary surveillance biopsies with high confidence, making it an invaluable addition to the transplant physician's tool kit for managing patients. TruGraf v1 testing can potentially avoid painful and risky invasive biopsies, reduce health care costs, and enable frequent assessment of patients with stable renal function to confirm the presence of immune quiescence in the peripheral blood.


Subject(s)
Gene Expression Profiling/methods , Graft Rejection/diagnosis , Kidney Transplantation , Oligonucleotide Array Sequence Analysis/methods , Adult , Biopsy , Female , Graft Rejection/immunology , Humans , Male , Middle Aged , Retrospective Studies , Sensitivity and Specificity , Transplant Recipients
4.
Transplant Proc ; 51(3): 729-733, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30979457

ABSTRACT

BACKGROUND: TruGraf v1 is a well-validated DNA microarray-based test that analyzes blood gene expression profiles as an indicator of immune status in kidney transplant recipients with stable renal function. METHODS: In this study, investigators assessed clinical utility of the TruGraf test in patient management. In a retrospective study, simultaneous blood tests and clinical assessments were performed in 192 patients at 7 transplant centers, and in a prospective observational study they were performed in 45 subjects at 5 transplant centers. RESULTS: When queried regarding whether or not the TruGraf test result impacted their decision regarding patient management, in 168 of 192 (87.5%) cases the investigator responded affirmatively. The prospective study indicated that TruGraf results supported physicians' decisions on patient management 87% (39/45) of the time, and in 93% of cases physicians indicated that they would use serial TruGraf testing in future patient management. A total of 21 of 39 (54%) reported results confirmed their decision that no intervention was needed, and 17 of 39 (44%) reported that results specifically informed them that a decision not to perform a surveillance biopsy was correct. CONCLUSIONS: TruGraf is the first and only noninvasive test to be evaluated for clinical utility in determining rejection status of patients with stable renal function and shows promise of providing support for clinical decisions to avoid unnecessary surveillance biopsies with a high degree of confidence. TruGraf is an invaluable addition to the transplant physician's tool kit for managing patient health by avoiding painful and invasive biopsies, reducing health care costs, and enabling frequent assessment of patients with stable renal function to confirm immune quiescence.


Subject(s)
Gene Expression Profiling/methods , Graft Rejection/diagnosis , Kidney Transplantation , Oligonucleotide Array Sequence Analysis/methods , Biopsy , Decision Making , Female , Graft Rejection/blood , Graft Rejection/immunology , Humans , Male , Middle Aged , Pathology, Molecular/methods , Physicians , Prospective Studies , Retrospective Studies
5.
Nature ; 551(7679): 187-191, 2017 11 09.
Article in English | MEDLINE | ID: mdl-29088701

ABSTRACT

Forest edges influence more than half of the world's forests and contribute to worldwide declines in biodiversity and ecosystem functions. However, predicting these declines is challenging in heterogeneous fragmented landscapes. Here we assembled a global dataset on species responses to fragmentation and developed a statistical approach for quantifying edge impacts in heterogeneous landscapes to quantify edge-determined changes in abundance of 1,673 vertebrate species. We show that the abundances of 85% of species are affected, either positively or negatively, by forest edges. Species that live in the centre of the forest (forest core), that were more likely to be listed as threatened by the International Union for Conservation of Nature (IUCN), reached peak abundances only at sites farther than 200-400 m from sharp high-contrast forest edges. Smaller-bodied amphibians, larger reptiles and medium-sized non-volant mammals experienced a larger reduction in suitable habitat than other forest-core species. Our results highlight the pervasive ability of forest edges to restructure ecological communities on a global scale.


Subject(s)
Biodiversity , Forests , Amphibians/anatomy & histology , Animals , Birds/anatomy & histology , Body Size , Geographic Mapping , Mammals/anatomy & histology , Population Dynamics , Reptiles/anatomy & histology
7.
Am J Transplant ; 17(12): 3123-3130, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28613436

ABSTRACT

Incompatible living donor kidney transplantation (ILDKT) has been established as an effective option for end-stage renal disease patients with willing but HLA-incompatible living donors, reducing mortality and improving quality of life. Depending on antibody titer, ILDKT can require highly resource-intensive procedures, including intravenous immunoglobulin, plasma exchange, and/or cell-depleting antibody treatment, as well as protocol biopsies and donor-specific antibody testing. This study sought to compare the cost and Medicare reimbursement, exclusive of organ acquisition payment, for ILDKT (n = 926) with varying antibody titers to matched compatible transplants (n = 2762) performed between 2002 and 2011. Data were assembled from a national cohort study of ILDKT and a unique data set linking hospital cost accounting data and Medicare claims. ILDKT was more expensive than matched compatible transplantation, ranging from 20% higher adjusted costs for positive on Luminex assay but negative flow cytometric crossmatch, 26% higher for positive flow cytometric crossmatch but negative cytotoxic crossmatch, and 39% higher for positive cytotoxic crossmatch (p < 0.0001 for all). ILDKT was associated with longer median length of stay (12.9 vs. 7.8 days), higher Medicare payments ($91 330 vs. $63 782 p < 0.0001), and greater outlier payments. In conclusion, ILDKT increases the cost of and payments for kidney transplantation.


Subject(s)
Blood Group Incompatibility/economics , Graft Rejection/economics , Histocompatibility Testing/economics , Kidney Failure, Chronic/surgery , Kidney Transplantation/economics , Living Donors , Postoperative Complications/economics , Case-Control Studies , Female , Follow-Up Studies , Glomerular Filtration Rate , Graft Rejection/epidemiology , Graft Survival , Humans , Kidney Function Tests , Male , Middle Aged , Prognosis , Quality of Life , Retrospective Studies , Risk Factors
8.
Am J Transplant ; 17(3): 782-790, 2017 03.
Article in English | MEDLINE | ID: mdl-27992110

ABSTRACT

Organ shortage is the major limitation to kidney transplantation in the developed world. Conversely, millions of patients in the developing world with end-stage renal disease die because they cannot afford renal replacement therapy-even when willing living kidney donors exist. This juxtaposition between countries with funds but no available kidneys and those with available kidneys but no funds prompts us to propose an exchange program using each nation's unique assets. Our proposal leverages the cost savings achieved through earlier transplantation over dialysis to fund the cost of kidney exchange between developed-world patient-donor pairs with immunological barriers and developing-world patient-donor pairs with financial barriers. By making developed-world health care available to impoverished patients in the developing world, we replace unethical transplant tourism with global kidney exchange-a modality equally benefitting rich and poor. We report the 1-year experience of an initial Filipino pair, whose recipient was transplanted in the United states with an American donor's kidney at no cost to him. The Filipino donor donated to an American in the United States through a kidney exchange chain. Follow-up care and medications in the Philippines were supported by funds from the United States. We show that the logistical obstacles in this approach, although considerable, are surmountable.


Subject(s)
Cost-Benefit Analysis , Directed Tissue Donation , Health Care Costs/legislation & jurisprudence , Kidney Failure, Chronic/economics , Kidney Transplantation/economics , Living Donors/supply & distribution , Tissue and Organ Procurement/economics , Developing Countries , Glomerular Filtration Rate , Graft Survival , Health Resources , Health Services Accessibility , Humans , Kidney Failure, Chronic/surgery , Kidney Function Tests , Kidney Transplantation/legislation & jurisprudence , Kidney Transplantation/methods , Philippines , Policy Making , Prognosis , Risk Factors , Tissue and Organ Procurement/methods , United States
9.
Am J Transplant ; 16(11): 3093-3104, 2016 11.
Article in English | MEDLINE | ID: mdl-27545282

ABSTRACT

This article is a review of the salient points and a future prospective based on the 2014 Organ Procurement and Transplantation Network (OPTN)/Scientific Registry of Transplant Recipients (SRTR) liver donation and transplantation data report recently published by the American Journal of Transplantation. Emphasis of our commentary and interpretation is placed on data relating to waitlist dynamics, organ utilization rates, the impact of recent advances in the treatment of hepatitis C, and the increases in end-stage renal disease among liver transplant candidates. Finally, we share our vision on potential areas of innovation that are likely to significantly improve the field of liver transplantation in the near future.


Subject(s)
Data Collection/statistics & numerical data , Liver Transplantation/statistics & numerical data , Registries/statistics & numerical data , Tissue Donors , Tissue and Organ Procurement/statistics & numerical data , Waiting Lists , Humans , Societies, Scientific , United States
10.
Am J Transplant ; 16(7): 1982-98, 2016 07.
Article in English | MEDLINE | ID: mdl-26990570

ABSTRACT

Interstitial fibrosis and tubular atrophy (IFTA) is found in approximately 25% of 1-year biopsies posttransplant. It is known that IFTA correlates with decreased graft survival when histological evidence of inflammation is present. Identifying the mechanistic etiology of IFTA is important to understanding why long-term graft survival has not changed as expected despite improved immunosuppression and dramatically reduced rates of clinical acute rejection (AR) (Services UDoHaH. http://www.ustransplant.org/annual_reports/current/509a_ki.htm). Gene expression profiles of 234 graft biopsy samples were obtained with matching clinical and outcome data. Eighty-one IFTA biopsies were divided into subphenotypes by degree of histological inflammation: IFTA with AR, IFTA with inflammation, and IFTA without inflammation. Samples with AR (n = 54) and normally functioning transplants (TX; n = 99) were used in comparisons. A novel analysis using gene coexpression networks revealed that all IFTA phenotypes were strongly enriched for dysregulated gene pathways and these were shared with the biopsy profiles of AR, including IFTA samples without histological evidence of inflammation. Thus, by molecular profiling we demonstrate that most IFTA samples have ongoing immune-mediated injury or chronic rejection that is more sensitively detected by gene expression profiling. These molecular biopsy profiles correlated with future graft loss in IFTA samples without inflammation.


Subject(s)
Atrophy/mortality , Fibrosis/mortality , Gene Expression Profiling , Graft Rejection/mortality , Kidney Transplantation/methods , Kidney Tubules/pathology , Nephritis, Interstitial/mortality , Atrophy/genetics , Fibrosis/genetics , Glomerular Filtration Rate , Graft Rejection/genetics , Graft Survival , Humans , Kidney Failure, Chronic/genetics , Kidney Failure, Chronic/surgery , Kidney Function Tests , Kidney Tubules/metabolism , Nephritis, Interstitial/genetics , Prognosis , Risk Factors , Survival Rate
11.
J Wound Care ; 24(10): 446-50, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26488735

ABSTRACT

OBJECTIVE: Epidermolysis bullosa (EB) describes a number of genetically inherited conditions which cause skin fragility and minor trauma leading to skin damage, skin loss and wounding. Owing to the fragility of the skin and requirement for frequent dressing changes, at present, the optimal dressing(s) is not clear. Our objective was to assess the use of a keratin gel in the management of wounds in patients with different forms of EB. METHOD: We treated patients with different types of EB and a range of wounds with a novel keratin gel. In a convenience sample of consecutive patients, we introduced the keratin gel into their treatment regimen maintaining other aspects of their care. RESULTS: Patients reported faster healing and more resilient healed skin. Of the ten patients treated in this pilot study, six found the gel effective; two found it ineffective; and in two patients, it caused itching leading to discontinuation of the treatment. CONCLUSION: The results of this case study series suggest that keratin gel can be useful in the management of EB and are consistent with previous published experiences.


Subject(s)
Bandages , Epidermolysis Bullosa/drug therapy , Keratins/therapeutic use , Skin Abnormalities/drug therapy , Wound Healing/drug effects , Adolescent , Child , Child, Preschool , Disease Management , Epidermolysis Bullosa/complications , Female , Gels/therapeutic use , Humans , Infant , Male , Pilot Projects , Skin Abnormalities/etiology , Treatment Outcome
12.
J Minim Invasive Gynecol ; 22(6S): S127, 2015.
Article in English | MEDLINE | ID: mdl-27678682
13.
Am J Transplant ; 14(7): 1573-80, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24913913

ABSTRACT

Incompatible live donor kidney transplantation (ILDKT) offers a survival advantage over dialysis to patients with anti-HLA donor-specific antibody (DSA). Program-specific reports (PSRs) fail to account for ILDKT, placing this practice at regulatory risk. We collected DSA data, categorized as positive Luminex, negative flow crossmatch (PLNF) (n = 185), positive flow, negative cytotoxic crossmatch (PFNC) (n = 536) or positive cytotoxic crossmatch (PCC) (n = 304), from 22 centers. We tested associations between DSA, graft loss and mortality after adjusting for PSR model factors, using 9669 compatible patients as a comparison. PLNF patients had similar graft loss; however, PFNC (adjusted hazard ratio [aHR] = 1.64, 95% confidence interval [CI]: 1.15-2.23, p = 0.007) and PCC (aHR = 5.01, 95% CI: 3.71-6.77, p < 0.001) were associated with increased graft loss in the first year. PLNF patients had similar mortality; however, PFNC (aHR = 2.04; 95% CI: 1.28-3.26; p = 0.003) and PCC (aHR = 4.59; 95% CI: 2.98-7.07; p < 0.001) were associated with increased mortality. We simulated Centers for Medicare & Medicaid Services flagging to examine ILDKT's effect on the risk of being flagged. Compared to equal-quality centers performing no ILDKT, centers performing 5%, 10% or 20% PFNC had a 1.19-, 1.33- and 1.73-fold higher odds of being flagged. Centers performing 5%, 10% or 20% PCC had a 2.22-, 4.09- and 10.72-fold higher odds. Failure to account for ILDKT's increased risk places centers providing this life-saving treatment in jeopardy of regulatory intervention.


Subject(s)
Antibodies/immunology , Blood Group Incompatibility/epidemiology , Graft Rejection/etiology , HLA Antigens/immunology , Kidney Transplantation/legislation & jurisprudence , Kidney Transplantation/statistics & numerical data , Living Donors/supply & distribution , Adult , Blood Group Incompatibility/diagnosis , Blood Group Incompatibility/immunology , Female , Follow-Up Studies , Graft Survival , Humans , Incidence , Kidney Failure, Chronic/mortality , Kidney Failure, Chronic/surgery , Male , Middle Aged , Postoperative Complications/mortality , Practice Patterns, Physicians'/statistics & numerical data , Prognosis , Risk Factors , Survival Rate
14.
Am J Transplant ; 14(5): 1164-72, 2014 May.
Article in English | MEDLINE | ID: mdl-24725967

ABSTRACT

There are no minimally invasive diagnostic metrics for acute kidney transplant rejection (AR), especially in the setting of the common confounding diagnosis, acute dysfunction with no rejection (ADNR). Thus, though kidney transplant biopsies remain the gold standard, they are invasive, have substantial risks, sampling error issues and significant costs and are not suitable for serial monitoring. Global gene expression profiles of 148 peripheral blood samples from transplant patients with excellent function and normal histology (TX; n = 46), AR (n = 63) and ADNR (n = 39), from two independent cohorts were analyzed with DNA microarrays. We applied a new normalization tool, frozen robust multi-array analysis, particularly suitable for clinical diagnostics, multiple prediction tools to discover, refine and validate robust molecular classifiers and we tested a novel one-by-one analysis strategy to model the real clinical application of this test. Multiple three-way classifier tools identified 200 highest value probesets with sensitivity, specificity, positive predictive value, negative predictive value and area under the curve for the validation cohort ranging from 82% to 100%, 76% to 95%, 76% to 95%, 79% to 100%, 84% to 100% and 0.817 to 0.968, respectively. We conclude that peripheral blood gene expression profiling can be used as a minimally invasive tool to accurately reveal TX, AR and ADNR in the setting of acute kidney transplant dysfunction.


Subject(s)
Biomarkers/blood , Gene Expression Profiling , Graft Rejection/blood , Graft Rejection/classification , Kidney Failure, Chronic/surgery , Kidney Transplantation , Postoperative Complications/genetics , Adult , Area Under Curve , False Negative Reactions , Female , Follow-Up Studies , Graft Rejection/etiology , Humans , Kidney Failure, Chronic/complications , Male , Middle Aged , Oligonucleotide Array Sequence Analysis , Postoperative Complications/blood , Predictive Value of Tests , Prognosis , Prospective Studies , Sensitivity and Specificity
15.
Am J Transplant ; 13(6): 1400-4, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23617244

ABSTRACT

Solid organ transplantation is encumbered by an increasing number of waitlisted patients unrequited by the current organ supply. Preclinical models suggest that advances in deceased donor management and treatment can increase the quantity and quality of organs available for transplantation. However, the science of donor intervention and the execution of high quality, prospective, multi-center, randomized-controlled trials are restricted by a myriad of logistical challenges mired in regulatory and ethical ambiguity. By highlighting the obstacles to conducting research in deceased donors, this report endeavors to stimulate the creation of a multi-disciplinary framework to facilitate the design, implementation and supervision of innovative trials that increase the quantity and/or quality of deceased donor organs.


Subject(s)
Biomedical Research , Organ Transplantation/statistics & numerical data , Tissue Donors/supply & distribution , Tissue and Organ Procurement/standards , Humans
17.
Anaesthesia ; 67(3): 226-31, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22321076

ABSTRACT

The Airtraq(™) optical laryngoscope became available in paediatric sizes in the UK in May 2008. We conducted a randomised, controlled trial comparing the Airtraq with conventional laryngoscopy during routine anaesthesia in children. We hypothesised that the Airtraq laryngoscope would perform as well as conventional laryngoscopy. Sixty patients (20 infants and 40 children) were recruited. The mean (SD) intubation time using the Airtraq was longer than conventional laryngoscopy overall (47.3 (32.6) vs 26.3 (11.5) s; p=0.002), though the difference was only significant for children (p=0.003) and not for infants (p=0.29). The Airtraq provided a better view of the larynx compared with conventional laryngoscopy (in infants (percentage of glottic opening scores 100 (95-100 [90-100]) vs 77 (50-90 [40-100]), respectively; p=0.001; visual analogue scores for field of view 9.2 (9.2-9.5 [8.2-10.0]) vs 6.8 (5.1-8.0 [4.7-10.0]), respectively; p=0.001). In children, the Airtraq provided a similar view of the larynx (percentage of glottic opening scores 100 (100-100 [40-100]) vs 100 (90-100 [50-100]), respectively; visual analogue scores for field of view 9.2 (8.6-10.0 [7.0-10.0]) vs 9.2 (8.6-10.0 [5.6-10.0]), respectively; both p>0.05), compared with conventional laryngoscopy.


Subject(s)
Laryngoscopes , Child , Child, Preschool , Humans , Infant , Intubation, Intratracheal/instrumentation , Laryngoscopy
18.
Methods Inf Med ; 51(3): 229-41, 2012.
Article in English | MEDLINE | ID: mdl-22311158

ABSTRACT

OBJECTIVE: To qualify the use of patient clinical records as non-human-subject for research purpose, electronic medical record data must be de-identified so there is minimum risk to protected health information exposure. This study demonstrated a robust framework for structured data de-identification that can be applied to any relational data source that needs to be de-identified. METHODS: Using a real world clinical data warehouse, a pilot implementation of limited subject areas were used to demonstrate and evaluate this new de-identification process. Query results and performances are compared between source and target system to validate data accuracy and usability. RESULTS: The combination of hashing, pseudonyms, and session dependent randomizer provides a rigorous de-identification framework to guard against 1) source identifier exposure; 2) internal data analyst manually linking to source identifiers; and 3) identifier cross-link among different researchers or multiple query sessions by the same researcher. In addition, a query rejection option is provided to refuse queries resulting in less than preset numbers of subjects and total records to prevent users from accidental subject identification due to low volume of data. This framework does not prevent subject re-identification based on prior knowledge and sequence of events. Also, it does not deal with medical free text de-identification, although text de-identification using natural language processing can be included due its modular design. CONCLUSION: We demonstrated a framework resulting in HIPAA Compliant databases that can be directly queried by researchers. This technique can be augmented to facilitate inter-institutional research data sharing through existing middleware such as caGrid.


Subject(s)
Databases, Factual , Medical Records Systems, Computerized/instrumentation , Privacy , Access to Information , Health Insurance Portability and Accountability Act , Humans , Pilot Projects , United States
19.
Nat Cell Biol ; 14(2): 159-67, 2011 Dec 18.
Article in English | MEDLINE | ID: mdl-22179046

ABSTRACT

PTEN (Phosphatase and tensin homolog deleted on chromosome 10) expression in stromal fibroblasts suppresses epithelial mammary tumours, but the underlying molecular mechanisms remain unknown. Using proteomic and expression profiling, we show that Pten loss from mammary stromal fibroblasts activates an oncogenic secretome that orchestrates the transcriptional reprogramming of other cell types in the microenvironment. Downregulation of miR-320 and upregulation of one of its direct targets, ETS2 (v-ets erythroblastosis virus E26 oncogene homolog 2) are critical events in Pten-deleted stromal fibroblasts responsible for inducing this oncogenic secretome, which in turn promotes tumour angiogenesis and tumour-cell invasion. Expression of the Pten-miR-320-Ets2-regulated secretome distinguished human normal breast stroma from tumour stroma and robustly correlated with recurrence in breast cancer patients. This work reveals miR-320 as a critical component of the Pten tumour-suppressor axis that acts in stromal fibroblasts to reprogramme the tumour microenvironment and curtail tumour progression.


Subject(s)
Gene Expression Profiling , Gene Expression Regulation, Neoplastic , MicroRNAs/genetics , PTEN Phosphohydrolase/genetics , Tumor Microenvironment/genetics , Animals , Blotting, Western , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , COS Cells , Cell Line, Tumor , Chlorocebus aethiops , Female , Fibroblasts/metabolism , Humans , Kaplan-Meier Estimate , Mammary Neoplasms, Experimental/genetics , Mammary Neoplasms, Experimental/metabolism , Mammary Neoplasms, Experimental/pathology , Mice , Mice, Knockout , MicroRNAs/metabolism , Oligonucleotide Array Sequence Analysis , PTEN Phosphohydrolase/metabolism , Proto-Oncogene Protein c-ets-2/genetics , Proto-Oncogene Protein c-ets-2/metabolism , RNA Interference , Reverse Transcriptase Polymerase Chain Reaction , Stromal Cells/metabolism
20.
J AOAC Int ; 93(2): 622-7, 2010.
Article in English | MEDLINE | ID: mdl-20480910

ABSTRACT

An AOAC collaborative study was conducted to evaluate an affinity LC procedure for measuring immunoglobulin G (IgG) in selected dairy powders. The powders were extracted with 0.15 M sodium chloride solution and the pH was adjusted to 4.6 to precipitate caseins, which would otherwise lead to an overestimation of IgG. The analyte was then bound to a commercially available Protein G affinity cartridge and selectively eluted with a glycine buffer at pH 2.5. Detection was at 280 nm and quantification was made against a calibration curve prepared from bovine serum IgG. The samples analyzed included the likely matrixes for which this assay will find commercial use, namely, high- and low-protein-content colostrum powders, tablets containing colostrum powder, and some IgG-containing dairy powders; milk protein isolate, whey protein concentrate, and skim milk powder. Eleven laboratories provided data for the study and assayed blind duplicates of six materials. The repeatability RSD values ranged from 2.1 to 4.2% and the reproducibility RSD values ranged from 6.4 to 18.5%. The Protein G method with casein removal has adequate reproducibility for measuring IgG in colostrum-derived powders that are traded on the basis of IgG content as a colostral marker.


Subject(s)
Chemistry Techniques, Analytical , Chromatography, Liquid/methods , Colostrum/metabolism , Immunoglobulin G/analysis , Milk/metabolism , Nerve Tissue Proteins/chemistry , Animals , Biomarkers , Calibration , Cattle , Hydrogen-Ion Concentration , Immunoglobulin G/chemistry , Powders , Reproducibility of Results , Time Factors
SELECTION OF CITATIONS
SEARCH DETAIL
...