Search

Background: Measurement Uncertainty (MU) can assist the interpretation and comparison of the laboratory results against international diagnostic protocols, facilitate a reduction in health care costs and also help protect laboratories against legal challenges. Determination of MU for quantitative testing in clinical pathology laboratories is also a requirement for ISO 15189. Methods: A practical and simple to use statistical model has been designed to make use of data readily available in a clinical laboratory to assess and establish MU for quantitative assays based on internal quality control data to calculate Random Error and external quality assurance scheme results to calculate Systematic Error. The model explained in this article has also been compared and verified against quality specifications based on Biological Variation. Results: Examples that explain and detail MU calculations for the proposed model are given where different components of MU are calculated with tabulated results. Conclusions: The designed model is cost-effective because it utilises readily available data in a clinical pathology laboratory. Data obtained from internal quality control programs and external quality assurance schemes are used to calculate the MU using a practical and convenient approach that will not require resources beyond what is available. Such information can additionally be useful not only in establishing limits for MU to satisfy ISO 15189 but also in selecting and/or improving methods and instruments in use. MU can as well play an important role in reducing health care costs as shown by examples in the article.

SQ109 is a tuberculosis drug candidate that has high potency against Mycobacterium tuberculosis and is thought to function at least in part by blocking cell wall biosynthesis by inhibiting the MmpL3 transporter. It also has activity against bacteria and protozoan parasites that lack MmpL3, where it can act as an uncoupler, targeting lipid membranes and Ca2+ homeostasis. Here, we synthesized 19 analogs of SQ109 and tested them against bacteria: M. smegmatis, M. tuberculosis, M. abscessus, Bacillus subtilis and Escherichia coli, as well as against the protozoan parasites, Trypanosoma brucei, T. cruzi, Leishmania donovani, L. mexicana and Plasmodium falciparum. Activity against the mycobacteria was generally less than with SQ109 and was reduced by increasing the size of the alkyl adduct, but two analogs were ~4-8 fold more active than was SQ109 against M. abscessus, including a highly drug resistant strain harboring a A309P mutation in MmpL3. There was also better activity than found with SQ109 with other bacteria and protozoa. Of particular interest, we found that the adamantyl C-2 ethyl, butyl, phenyl and benzyl analogs had 4-10x increased activity against P. falciparum asexual blood stages, together with low toxicity to a human HepG2 cell line, making them of interest as new anti-malarial drug leads. We also used surface plasmon resonance to investigate the binding of inhibitors to MmpL3, and differential scanning calorimetry to investigate binding to lipid membranes. There was no correlation between MmpL3 binding and M. tuberculosis or M. smegmatis cell activity, suggesting that MmpL3 is not a major target, in mycobacteria. However, some of the more active species decreased lipid phase transition temperatures, indicating increased accumulation in membranes, expected to lead to enhanced uncoupler activity.

Resumen Objetivos La adulteración de una muestra de orina por parte de un paciente puede pasar inadvertida si no se realiza una prueba de validez de la muestra. En este estudio se ha comparado el método análisis de densidad (SG, según acrónimo inglés), pH, la tira para detección de adulterantes TECO™ (Dipstick) y el análisis de oxidantes, para determinar las diferencias entre los mismos y permitir una toma de decisiones informada, a la hora de seleccionar un método. Métodos El análisis de la creatinina, la SG y el pH es esencial a la hora de realizar una prueba de validez de la muestra. Se compararon los métodos químicos automáticos de análisis de SG y pH con la potenciometría para el análisis de pH, la refractometría para el análisis de SG, y el método dipstick. Así mismo, se realizó una comparación entre el análisis de oxidantes y el método Dipstick. Resultados Se observó una concordancia del 81,9% y del 64,7% entre el método químico de análisis de SG y la refractometría y el método Dipstick, respectivamente. La concordancia entre la refractometría y Dipstick fue del 66,1%. La concordancia entre el método químico de análisis del pH y la potenciometría y el método Dipstick fue del 74,3% y del 81,4%, respectivamente. La concordancia entre la potenciometría y el método Dipstick fue del 85,7%. El análisis de resultados se realizó mediante el método de regresión de Deming y la prueba F. Los resultados demuestran una mejor correlación entre el método químico de análisis de SG y la refractometría, que con el método Dipstick. El análisis de oxidantes mostró una buena correlación con Dipstick a la hora de detectar adulterantes como el clorocromato de piridinio, el nitrito y la lejía. Conclusiones Se observaron diferencias en la medición de SG y pH. Dichas diferencias se deben tanto a factores metodológicos como instrumentales. Se recomienda el empleo de métodos químicos automatizados, así como del análisis de oxidantes debido a sus consistencia, precisión y mejor tiempo de respuesta para realizar la prueba de validez de la muestra para detectar la presencia de drogas.

Objectives In the absence of sample validity testing, a healthcare provider may fail to identify a patient’s adulteration of their urine sample. This study compared different methods for specific gravity (SG), pH, TECO™ Drug Adulteration Test Strip (dipstick) and oxidant assay to explain the differences and also make an informative decision on method selection. Methods Creatinine, SG and pH measurements are essential in sample validity testing. SG and pH automated chemical methods are compared against pH meter method, SG refractometer and dipstick method. Also, oxidant assay was compared against dipstick method. Results SG chemical method agreement with refractometer is 81.9% and with dipstick method is 64.7%. The refractometer method agreement with dipstick method is 66.1%. pH chemical method agreement with pH Meter method is 74.3% and with dipstick method is 81.4%. pH meter method agreement is 85.7% with dipstick method. Results were analysed using Deming regression analysis and F-test. SG chemical method correlated better with refractometer than the dipstick method. Oxidant assay correlated well with dipstick method in detecting adulterants such as pyridinium chlorochromate, nitrite and bleach. Conclusions Varying degrees of differences were seen in the SG and pH measurements. These differences were both method and instrument dependent. The automated chemical methods are recommended alongside oxidant assay for consistency, accuracy and faster turn-around time as part of sample validity testing for drugs of abuse.

Background: Non-alcoholic fatty liver disease (NAFLD) encompasses a broad spectrum of disorders, ranging from non-progressive bland steatosis to non-alcoholic hepatitis (NASH), cirrhosis, and malignant transformation into hepatocellular carcinoma (HCC). Fibroblast growth factor 21 (FGF21) exerts a key role in lipid homeostasis and play a promising therapeutic candidate for the treatment of obesity, diabetes, and NASH. Small molecules like EPB-53 that are activators of heme-regulated inhibitor (HRI) of eukaryotic initiation factor 2α (eIF2α) kinase have been synthesized to induce FGF21. Previous study has shown that oral administration of EPB-53 alleviates NASH through increased FGF21 to prevent hepatic steatosis. However, it is unknown whether EPB-53 can prevent NASH-HCC transition. Aim: To investigate the effect of EPB-53 on NASH-HCC transition and the therapeutic mechanism, focusing on the lipid metabolic reprogramming and tumor immune microenvironment (TIM). Methods: NASH-HCC transition model was established in two-week-old male FGF21 knockout (KO) mice and wild type controls (C57BL/6J mice) by diethylnitrosamine (DEN) administration at 40 mg/kg body weight (i.p.). Four weeks after DEN administration, the mice were fed with western-style high fat diet (WSHFD, 60% kcal% fat and 19% kcal% fructose) for 3 months, and gavaged daily with either vehicle, 2% w/v, (2-hydroxypropyl)-β-cyclodextrin or EPB-53 (300 mg/kg/day) in vehicle for 4 weeks before sacrifice. The tumor incidence, lipid metabolism, and carcinogenesis signaling pathways were determined. Mass cytometry (CyTOF) analysis was performed to detect the cell subpopulations in the NASH microenvironment and NASH-HCC TIM. Results: Severe NASH with tumor cell detection, aberrant lipid components and HIPPO-YAP signaling were found in liver tissues of FGF21-KO mice compared to the WT controls. The upregulated sphingosine Kinase 1 (SPHK1)/sphingosine-1-phosphate (S1P) in liver subsequently induced YAP dephosphorylation and nuclear localization. EPB-53 treatment prevents NASH-HCC transition evident as decreased HCC incidence in WT mice but not in FGFKO mice. Continuously increased FGF21 production in WT mice contributes to down-regulation of SPHK1-S1P-HIPPO-YAP signaling. Interestingly, EPB-53 treatment can alleviate the compromised function of macrophages/Kupffer cells which render a TIM in the NASH-HCC mice. Conclusion: 1) Lack of FGF21 played a key role in lipid metabolic disorder and SPHK1-S1P-HIPPO signaling to promote NASH-HCC transition; 2) Lack of FGF21 rendered a TIM in NASH liver contributing to the NASH-HCC transition; 3) EPB-53 treatment can not only alleviate NASH, but also prevent NASH-HCC transition via lipid metabolic reprogramming, down-regulation of the SPHK1-S1P-HIPPO axis, and modulation of TIM. Citation Format: Min Tan, Eugenia Pujol, Santiago Vazquez, Jingwen Zhang, Jun Yan, Robert C. Martin, Manuel Vazquez-Carrera, Yan Li. EPB-53 prevents NASH-HCC transition via regulation of SPHK1-S1P-HIPPO signaling and immune modulation in a murine model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 638.

Buprenorphine is effective at reducing relapse to opioid misuse, morbidity and mortality in opioid-dependent patients. Urine drug screening (UDS) to assess adherence is used routinely in opioid agonist treatment (OAT). The primary aim of this study was to determine factors which may be associated with a negative qualitative urine drug screen for buprenorphine in OAT patients.This prospective pilot study was conducted at a tertiary addiction medicine centre. Twenty participants on stable treatment underwent supervised administration of sublingual buprenorphine. Matched urine and blood samples were collected prior to and 2, 4 and 6 hours after buprenorphine administration. Qualitative urine drug screen results were obtained using gas chromatography-mass spectrometry (GC-MS), while quantitative blood and urine results were obtained using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).Qualitative urine assay yielded a negative result for buprenorphine in 57% of tested samples. The median concentration of urinary buprenorphine was 167 mcg/L (range: 2-1730 mcg/L). Thirty percent of all blood samples did not detect buprenorphine (range 0-18 mcg/L). Positive qualitative urine drug screen results were associated with higher urine (343 mcg/L compared with 75 mcg/L; P .05) and blood (4 mcg/L compared with 2 mcg/L; P .05) buprenorphine concentrations. Median urine concentrations of buprenorphine were highest at 2 hours and were higher in participants receiving CYP3A4 inhibitors.Interpretation of qualitative urine drug screens to assess adherence in OAT is complex. Poor adherence with treatment cannot be assumed in patients returning a negative qualitative GC-MS urine drug screen.

Urinary creatinine is measured to assess kidney function and also as part of sample validity testing in drugs of abuse. Creatinine methods based on alkaline picrate Jaffe’s reaction require extra cleaning on chemistry analysers to minimise any interference from picric acid and sodium hydroxide on other reagents on board. Enzymatic methods reagents are not as invasive and more specific. Siemens enzymatic method is more sensitive and specific when compared to Thermo Fisher alkaline picrate method but there were no available analytical parameters to setup the Siemens enzymatic method on Beckman-Coulter AU5800 analyser as an open system analyser. Emulating setup parameters from Siemens chemistry analysers did not work. The analytical parameters were developed through systematic testing using different settings to adopt and optimise the method. A full correlation was performed using the developed parameters with alkaline picrate method. The Deming regression weighted analysis for 438 samples showed a good correlation at a 95% confidence interval. Slope is 1.029 to 1.041, Y-intercept when X=0.0 is -0.9156 to -0.7481 and correlation coefficient (r) is 0.998. Alkaline picrate method Mean and SD is 12.059 and 7.248 respectively and for the Enzymatic method is 11.653 and 7.504 respectively. Many interferences from drugs and other substances are eliminated when using the enzymatic method and the stability of other reagents on-board improved because the reagents used in the enzymatic method are less invasive.

Deaths caused by barbiturate overdoses have increased in the past decade, especially as a result of suicide attempts. Pentobarbitone is a central nervous system depressant used for sedation and euthanasia in veterinary medicine. However, pentobarbitone analysis is not commonly available in the hospital setting; hence, its occurrence in overdoses is under-reported. Herein we describe a patient who ingested pentobarbitone obtained from the Internet with the purpose of ending his life. He became comatose and required ventilation for 6 days. While critically ill, the drug and a barbiturate test kit were found in his room at his residence. Toxicological analysis of the patient’s blood determined the presence of pentobarbitone at levels of 91, 56, and 19 mg/L at 11, 59, and 107 h after ingestion, respectively. With supportive care, the patient made a full recovery. He stated that he believed the liquid was to be pentobarbitone, and that he had received advice on its use from an online forum that he had found on a dark web marketplace. In this report, we highlight the process by which we facilitated pentobarbitone analysis with a rapid turnaround time, which helped to inform clinical management and raise awareness among clinicians. The access was made through the Prescription, Recreational and Illicit Substance Evaluation (PRISE) programme, which is a collaborative network among the New South Wales (NSW) Ministry of Health, NSW Poisons Information Centre (PIC), and NSW Health Pathology Forensic & Analytical Science Service (FASS).Key points• We report a patient with confirmed severe pentobarbitone toxicity who developed coma, respiratory failure, barbiturate related skin and vascular manifestations who required intensive care for 6 days.• The diagnosis of pentobarbitone poisoning can be missed as it is not routinely included in Australian standard hospital urine drug screens, and it may not cross-react with phenobarbitone testing which may be more readily available.• Timely access to comprehensive toxicology testing with rapid turnaround time assists diagnosis for unknown toxicity, and enhances case management and public health interventions.• The PRISE programme in Australia is a collaboration between multiple health functional units in NSW, Australia that provides timely access to extensive toxicology testing for severe and unusual toxicity from drugs or substance-related toxicities.

Cut stumps are the legacy of forest harvesting and allow for the estimation of carbon loss from the ecosystem. The objective of this study was to estimate aboveground carbon storage and the impact of forest harvesting based on measurements of cut stumps in pine forests within the Area de Proteccion de Flora y Fauna Nevado de Toluca (APFFNT) in the state of Mexico. A total of 1621 circular 0.1-ha sampling plots were established in a 12,924 ha pine forest (1.25% sampling intensity). Biomass was calculated using conventional volumetric equations incorporating species-specific wood densities. Aboveground carbon storage in the biomass was stratified by forest type including dense forest (≥ 336 trees), semi-dense forest ( 150 trees), fragmented forest ( 20 trees), and stands with isolated trees (

Purpose To report an atypical bilateral hypopyon presentation of syphilitic uveitis. Observations A 38-year-old male presented with a 2-day history of bilateral progressive visual loss, conjunctival hyperemia, and photophobia. Initial ophthalmologic examination revealed bilateral hypopyon and vitritis that limited the examination of the posterior segment. The physical exam revealed cervical lymphadenopathy, glossal leukoplakia, erythematous maculae on the hard palate, erythematous macular lesions on both palms, onychodystrophy, onycholysis, and psoriasiform plaques on both plantar surfaces, testicular tenderness, and hypopigmented patches on the scrotal and perianal skin. A therapeutic and diagnostic vitrectomy was performed on the right eye, and the intraoperative findings were consistent with severe vitritis and pre-retinal precipitates. The cytopathologic analysis of the right vitreous revealed a mixed inflammatory process composed of lymphocytes, histiocytes, and neutrophils in a proteinaceous background. Laboratory testing revealed positive serum RPR, CSF FTA-Abs and VDRL, and HIV serology. Treatment with a 2-week course of intravenous penicillin G 4 million units every 4 hours and topical corticosteroids resulted in complete resolution of the uveitis. Conclusions and Importance Bilateral hypopyon uveitis may be a rare presentation of syphilitic uveitis. As with most forms of uveitis, syphilis should be considered in the differential diagnosis of patients presenting with bilateral hypopyon.

Pigmented lesions of the nail unit are commonly encountered in the clinical setting. Yet, they often present a unique challenge to clinicians because of a broad differential diagnosis or unfamiliarity with clinical and histopathologic features. A wide variety of causes exist ranging from benign lesions such as subungual hemorrhage to malignant lesions such as subungual melanoma. Identifying the underlying cause is key to appropriate management and follow-up in these patients. Although emerging clinical tools such as dermoscopy can be very useful in evaluation of these lesions, histopathologic analysis remains the gold standard. In this review, we discuss and provide a summary of important clinical and histopathological concepts of pigmented lesions of the nail unit with special focus on longitudinal melanonychia, melanotic macule, melanocytic nevus, subungual melanoma, along with discussion of some nonmelanocytic lesions.

The effect of forest harvesting on the composition and structure of a temperate coniferous forest in Mexico was evaluated after three harvesting periods from 2007–2015. In this forest, we identified seven families and eight tree species. The dominant species is Pinus pseudostrobus Lindl. which is also the most important commercial species. Harvesting was oriented towards increasing the abundance of the dominant pine species, resulting in a decrease in forest diversity and favoring a transition to a monospecific forest. The tree canopy structure following harvesting showed a gradual recovery in the number of individuals in each diameter class, but the diameter increment may not necessarily guarantee a sustainable harvest because cutting cycles appear to be too short. The size of harvesting gaps and overall forest cover determine the presence and/or abundance of regeneration (small seedlings, seedlings, saplings, large saplings, and young trees). The establishment of Pinus pseudostrobus and Ilex discolor Hemsl. differed according to their ecological groups.