Sample Storage Research Articles

Long-term stability of five atypical antipsychotics (risperidone, olanzapine, paliperidone, clozapine, quetiapine) and the antidepressant mirtazapine in human serum assessed by a validated SPE LC-MS/MS method.

Long-term sample stability of five atypical antipsychoticdrugs risperidone, paliperidone, clozapine, quetiapine and olanzapine and the antidepressant drug mirtazapine in serum was studied by use of a newly developed and validated analytical method based on solid-phase extraction and liquid chromatography-tandem mass spectrometry. Ascorbic acid was used as an antioxidative agent to stabilize olanzapine during storage and sample preparation. We assessed analyte stability on long-term storage in serum samples at 25°C, 5°C, -20°C and -80°C, and during five freeze-thaw cycles. Analytes were stable for 23 days at room temperature except for olanzapine and mirtazapine (17 days). All analytes were stable for at least 30 days at 5°C. All analytes were stable for 270 days at -20°C, except for paliperidone and mirtazapine with 60 days and 180 days, respectively. All analytes were stable for 270 days at -80°C. Furthermore, all analytes were stable for five freeze-thaw cycles. We recommend storage at -80°C when samples drawn for analysis of antipsychotic drugs are stored for more than 60 days, whereas a temperature of -20°C is sufficient for storage less than 60 days.

Stimulating thyrotropin receptor antibodies in early pregnancy.

Thyrotropin-receptor antibodies (TRAb) are used to diagnose Graves' hyperthyroidism in pregnant women. Bioassays provide a measure of thyrotropin-receptor stimulatory antibodies (TSI) specifically. The objective was to measure TSI in pregnant women for establishment of a pregnancy-specific cut-off and comparison with immunoassay measurements of TRAb. The retrospective Danish study was performed within the North Denmark Region Pregnancy Cohort (2011-2015) that includes stored biobank samples from early pregnancy (median week 10) with immunoassay measurements of thyroid function parameters and TRAb. TSI were measured in the same samples using the Turbo TSI bioassay (Quidel/Ortho-Clinical Diagnostics) with a recommended cut-off of 0.0241 IU/L in non-pregnant adults. A pregnancy-specific TSI cut-off (95-percentile) was established using Regression on Order Statistics. The established TSI cut-off was 0.0418 IU/L (95 % CI: 0.0417-0.0419). Among women with early pregnancy hyperthyroidism (n=438), 43 women (9.8 %) were TSI positive using the established cut-off, and these women had lower TSH (median 0.008 mIU/L) compared to women with TSI levels below 0.0241 (median TSH 0.040 mIU/L) or in the range from 0.0241 to 0.0418 (median TSH 0.033 mIU/L). Among the 438 women with early pregnancy hyperthyroidism, 22 women were positive for TSI and TRAb, 388 were negative for both, and 28 women were positive for either TSI or TRAb. This is the first study on TSI measurements in a large cohort of early pregnant women. A pregnancy-specific cut-off for TSI was established and agreement in the classification with immunoassay measurements of TRAb was seen in 94 % of cases.

Evaluation of insulin-like growth factor-1 in apparently healthy infants and prepubertal Egyptian children with different nutritional statuses

Objectivesto estimate insulin-like growth factor-1 (IGF-1) levels in apparently healthy infants and prepubertal children and compare results among different nutritional statuses.MethodsOur cross-sectional work is a sub-study of a screening project for anemia and nutritional status. We included 252 apparently healthy infants and children with a mean age of 3.7 ± 1.3 years (1.1–6.6), with equal gender distribution. Data retrieved included breastfeeding and anthropometric measures. We tested the stored blood samples for IGF-1 levels. The sample size was reached when all kits were consumed.Resultsabnormal anthropometric measures were detected in 32.9%, either a single or multiple, and 86.5% were breastfed. Girls had significantly higher serum IGF-1 levels than boys (P: <0.001), which was noticeable in girls with abnormal nutritional status detected with anthropometry. Breastfeeding showed no significant association with IGF-1 levels. No significant difference was observed between IGF-1 levels between children with normal versus those with abnormal growth measures. Children with overweight or obesity had significantly lower IGF-1 than children with other body mass index (BMI) categories. Serum IGF-1 levels correlated positively with arm muscle area Z scores in infants and toddlers and weight and BMI Z scores in children between three and four. Also, IGF-1 correlated positively with the triceps skinfold Z score and arm muscle area Z score between four and five.ConclusionsAmong studied infants and prepubertal children, serum IGF-1 was significantly higher in girls than boys and was considerably lower in children with overweight or obesity. Breastfeeding showed no association with IGF-1 levels.

The associations between functional vitamin K status and all-cause mortality, cardiovascular disease and end-stage kidney disease in persons with type 1 diabetes.

Vitamin K deficiency is common in persons with kidney disease, which is a known complication of diabetes. We aimed to assess the association of vitamin K status as reflected by plasma dephosphorylated-uncarboxylated matrix Gla protein (dp-ucMGP) with mortality, cardiovascular disease (CVD) and progression to end-stage kidney disease (ESKD) in persons with type 1 diabetes. We analysed plasma dp-ucMGP in stored baseline samples from a cohort of 667 persons with type 1 diabetes (baseline visit: 2009-2011). Information on mortality and CVD was obtained through linkage to registers. Cox-proportional hazards models were applied to estimate hazard ratios (HRs) of mortality, CVD and ESKD per one doubling of dp-ucMGP. A total of 53 deaths were recorded during follow-up. Persons with higher dp-ucMGP (reflecting lower vitamin K status) had higher mortality in the unadjusted model (HR: 2.06 [95% confidence interval-CI: 1.22-3.45]), but not in the fully adjusted model (HR: 0.88 [95% CI: 0.44-1.73]). Particularly, adjustment for glomerular filtration rate and urinary albumin excretion rate attenuated the HR. A similar pattern was observed in unadjusted models for incidence of CVD (HR: 1.58 [95% CI: 1.03-2.42]) and risk of ESKD (HR: 7.62 [95% CI: 4.25-13.68]). In the fully adjusted models, the HRs became statistically insignificant. In persons with type 1 diabetes, lower vitamin K status was associated with higher mortality, CVD and progression to ESKD, however, not after adjustment for other risk factors. Interventional studies are needed to elucidate the role of vitamin K in persons with type 1 diabetes.

Effect of silver nanoparticles on the photostability and aging of CsPbBr3 nanocrystals

Abstract Perovskite nanocrystals may become a promising replacement for current phosphors in light-emitting diodes (LEDs) and screens, but the question of the stability of their optical properties remains open. One way to solve this problem could be to use plasmonic nanoparticles. In this work, we investigate the combination of all-inorganic perovskite nanocrystals synthesized by the hot-injection method with spherical Ag nanoparticles (mean diameter 53 nm). 3-fold enhancement of photoluminescence (PL) has been implemented in hybrid ‘silver-CsPbBr3-polymethyl methacrylate’ structures. The presence of silver nanoparticles reduces the likelihood of Auger processes and forms a possible silver bromide barrier layer which prevents photoinduced ion migration in the perovskite-polymer film. Plasmonic enhancement of PL partially presents during long-term samples storage within 75 days. This work may be useful in the creation of perovskite LEDs using remote phosphor technology.

Metagenome-based microbial community analysis of urine-derived fertilizer.

Phosphorus is essential for food production and its supply is limited. Urine is an excellent source of phosphorus and one way to produce fertilizer is through conversion of urine to struvite (MgNH3PO4.6H2O). The present study aimed to understand the bacterial portion of the microbial community composition and dynamics of plasmid-mediated antimicrobial resistant genes during the optimized process of struvite production from composite human urine. Samples for DNA extraction was collected from fresh urine, stored urine and struvite during the process of struvite production. Shotgun metagenomic analysis was employed to understand the bacterial community. The most dominant phyla in the fresh and stored urine samples were Pseudomonadata, which comprised of 60% and 43% respectively, followed by Bacillota, comprised of 25% and 39% respectively. The struvite sample was dominated by the phylum Bacilliota (61%), Pseudomonadota (18%) and bacteroidota (12%). Members of the above phyla persisted in dominating each sample accordingly. Member of the family Morganellaceae was dominant in the fresh sample while the stored urine and struvite samples were dominated by the family Clostridiaceae. A decrease of members of the class Gammaproteobacteria was observed from the fresh to the struvite sample though not statistically significant. The genus Pseudomonas remained to be the most dominant member of Gammaproteobacteria in the fresh and stored urine sample with OTU count of 12,116 and 6,155 with a marked decrease by half in the stored sample. On the other hand, members of the genera Clostridium, Enterococcus, Bacteroides in the stored samples and Clostridium, Alkaliphilus and Pseudomonas in the struvite samples were dominant. 96% of the identified genera were shared in all the samples and the antimicrobial resistance genes (ARGs) identified in the fresh urine were shared by the struvite but not by the stored urine (e.g. sul, cat, aph and aac members). The presence of high abundance of ARGs in struvite needs attention in the persistence and transmissibility of the ARGs before application for agriculture.

Tendons and table salt: A recipe to preserve human DNA.

For disaster victim identification, hundreds of samples of human remains have to be extracted from human bodies rapidly for later DNA analysis, often in situation with high humidity, high temperature and no access to cooling facilities. Genetic typing of these samples may be challenging due to degradation of DNA. Until today, bone and teeth are the preferred biological matrix for genetic identification of decomposed human remains. However, processing these samples is time and cost consuming. To address the challenges associated with workload, finances, and sample preservation in the genetic identification of unknown dead bodies, we tested 44 hand and foot tendons from deceased with advanced post mortem changes as alternative DNA material. In addition, we examined commercially available table salt as potential preservation method with 10 tendons over a period of 12 months. The parameters external appearance, DNA quantity and quality have been analysed. Overall, 39 of 44 tendons examined yielded valuable DNA profiles with at least ten autosomal STR loci. Storage in table salt not only increased DNA yield but also resulted in high quality STR profiles of the preserved tendons throughout the study period of 12 months compared to storage without salt. According to the results of this study, we recommend hand and foot tendons as alternative DNA material from bodies with advanced post mortem changes. We particularly recommend commercially available table salt as a storage medium for the preservation of DNA samples. Under field conditions without cooling facilities and the need to store samples prior to DNA analysis table salt is a good storage medium: it preserves DNA and is easily available.

Metabolic Syndrome, Adipokines, and Response to Advanced Therapies in Rheumatoid Arthritis.

We determined if metabolic syndrome, its components, and adipokines (adiponectin, leptin, Fibroblast Growth Factor-21) were associated with response to advanced therapies among patients with rheumatoid arthritis (RA). This study included participants with RA initiating either TNFi or non-TNFi biologic therapies from the Comparative Effectiveness Registry to studyTherapies forArthritis andInflammatory Conditions(CERTAIN) cohort within the CorEvitas registry. Metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III definition. Adipokines were assessed on stored samples from a sub-sample of responders and non-responders (N=200). The primary outcome was the achievement of a change as large as the minimal clinically important difference (MCID) for the Clinical Disease Activity Index (CDAI) at 6 months. Among 2,368 participants, 687 (29%) had metabolic syndrome. Metabolic syndrome was associated with lower odds of achieving CDAI MCID [OR (95% CI): 0.69 (0.56,0.86) p=0.001] with a dose-dependent decrease in response rate according to the number of components present. Model fit was superior for metabolic syndrome compared to BMI. Associations between metabolic syndrome and MCID achievement were similar between patients receiving TNFi [OR (95% CI): 0.65 (0.49,0.87) p=0.003] v. non-TNF therapies [OR (95% CI): 0.76 (0.55,1.04) p=0.08)] (p-for-interaction=0.49). Adipokines were not associated with MCID achievement. Metabolic syndrome is associated with lower response rates with the initiation of an advanced therapy in RA, with similar effects for both TNFi and non-TNFi agents. Adipokines were strongly associated with metabolic syndrome but were not associated with clinical response.

Functional and physicochemical characterization of a novel pearl millet—Soy milk‐based synbiotic beverage

AbstractThis study presents the physicochemical and functional characterization of a novel fermented pearl millet–soy milk‐based synbiotic beverage. The synbiotic fermented pearl millet beverage was optimized at 40% pearl millet and 10.41% sugar, with hedonic score of more than eight for all the responses, through response surface methodology. The fermented synbiotic beverage, with Lactiplantibacillus plantarum strains exceeding 108 colony‐forming units/mL, exhibited superior nutritional and physicochemical qualities when compared with the unfermented counterpart. The viability percent of lactic acid bacteria in the developed beverage was found to be significantly high (87.83%). The survivability of probiotic culture was 76.71% in simulated gastric juice and 73.87% in simulated intestinal juice after sample storage for 25 days. The result showed that millets stand out as a promising raw material for developing fermented nondairy synbiotic beverages, particularly when combined with microbial strains such as L. plantarum.

A Streamlined High-Throughput LC-MS Assay for Quantifying Peptide Degradation in Cell Culture.

Peptides are widely used in biomaterials due to their easy of synthesis, ability to signal cells, and modify the properties of biomaterials. A key benefit of using peptides is that they are natural substrates for cell-secreted enzymes, which creates the possibility of utilizing cell-secreted enzymes for tuning cell-material interactions. However, these enzymes can also induce unwanted degradation of bioactive peptides in biomaterials, or in peptide therapies. Liquid chromatography-mass spectrometry (LC-MS) is a widely used, powerful methodology that can separate complex mixtures of molecules and quantify numerous analytes within a single run. There are several challenges in using LC-MS for the multiplexed quantification of cell-induced peptide degradation, including the need for non-degradable internal standards and the identification of optimal sample storage conditions. Another problem is that cell culture media and biological samples typically contain both proteins and lipids that can accumulate on chromatography columns and degrade their performance. However, removing these constituents can be expensive, time consuming, and increases sample variability. Here we show that directly injecting samples onto the LC-MS without any purification enables rapid and accurate quantification of peptide concentration, and that hundreds of LC-MS runs can be done on a single column without a significantly diminish the ability to quantify the degradation of peptide libraries. We also show that column failure is evident when hydrophilic peptides fail to be retained on the column, and this can be easily identified using standard peptide mixtures for column benchmarking. In total, this work introduces a simple and effective method for simultaneously quantifying the degradation of dozens of peptides in cell culture. By providing a streamlined and cost-effective method for the direct quantification of peptide degradation in complex biological samples, this work enables more efficient assessment of peptide stability and functionality, facilitating the development of advanced biomaterials and peptide-based therapies.

A review of urinary HPV testing for cervical cancer management and HPV vaccine surveillance: rationale, strategies, and limitations.

Human papillomavirus (HPV) infections are the leading cause of cervical cancer, the fourth most common cancer among women worldwide. Despite concerted efforts to combat this preventable disease through HPV vaccination and cancer screening have helped reduce morbidity and mortality levels, the burden persists in both developing and developed countries due to insufficient vaccination and screening coverage. Urinary HPV testing has emerged as a noninvasive detection method, offering significant advantages in cervical cancer management and vaccine surveillance. Notably, it boasts high acceptance rates, ease of self-collection, user-friendly implementation, and relatively low cost. Various urinary HPV detection methods have been explored, predominantly relying on nucleic acid amplification and signal amplification, targeting a variety of biomarkers in urine, such as HPV DNA, RNA, and oncoproteins. Existing literature underscores urine as a promising specimen for HPV testing, demonstrating comparable detection performance to cervical and vaginal samples in several studies. However, the lack of standardized and authoritative protocols in sample collection, storage, preparation, DNA extraction, and amplification necessitates further evaluation for the comprehensive utilization of urinary HPV testing in clinical and epidemiological settings. This study aims to review pertinent publications and offer insights into the rationale, common strategies, and limitations of urinary HPV testing, with the ultimate goal of maximizing its utility in practice.

More Efficient Smaller Multi-Cancer Screening Trials.

The NHS-Galleri trial has demonstrated feasibility for multi-cancer screening trial design where all participants provide a 'sample' for screening, but only samples from the intervention arm are tested and acted upon during the trial. We assess efficiency of analysis methods when the control arm may be retrospectively tested at time of analysis. Analyses considered are: (1, traditional) by randomised allocation with all events included; (2, 'intended-effect') nested in those who tested positive in both arms and all events therein; and (3, targeted) by randomised allocation but with endpoint 'test-positive event'. They are compared using approximate statistical methods and scenario analysis. Provided the number who die from cancer after a test-positive sample is a small fraction of the total number who die from cancer, intended-effect and targeted analyses require a much smaller sample size to evaluate cancer-specific mortality than the traditional approach. Intended-effect analysis has a smaller sample size requirement than targeted analysis. This gain is only substantial when the risk of cancer death in test positives is high. Intended-effect or targeted analysis will substantially reduce the sample size needed to evaluate cancer-specific mortality in blood-based screening trials. Targeted analysis requires many fewer retrospective tests and avoids potential effects of needing to inform those whose stored samples test positive. Trialists should consider the trade-off of costs between sample size and retrospective testing requirements when choosing the analysis.

Investigation of heat leakage calculations and experiments for a wide-mouth liquid nitrogen tank

ABSTRACT With the continuous development of biomedicine, the long-term low-temperature storage of biological samples has become essential. In order to meet the demand for long-term storage of liquid nitrogen to keep samples safe, a study on the evaporated gas recycling storage of liquid nitrogen tanks will be carried out. This research utilizes new approach to accurately calculate the heat leakage of the liquid nitrogen tank. The experimental results show that the theoretical heat leakage is 6.16 W, and the actual heat leakage is 7.07 W. By incorporating the insulating plug, the actual heat leakage was reduced by 61.2%, decreasing to 2.74 W, and the calculated heat leakage is 2.47 W. The error margin in both cases was approximately 10%. Furthermore, in contrast to existing investigations, this experiment with the 8W@77K pulse tube cryocooler for recovering nitrogen is conducted under environmental pressure rather than overpressure, and it also takes into account the sensible heat issues caused by ambient pressure. The ratio of 1.81 W of sensible heat to 2.74 W of latent heat is 2:3, indicating that under ambient pressure conditions, the impact of sensible heat cannot be ignored. The key improvement methods are given to improve the success rate of the experiment. The research results provide a useful reference for the re-cycling and storage of liquid nitrogen.

Unravelling the threat of contamination in elite sports: Exploring diverse sources impacting adverse analytical findings and the risk of inadvertent exposure to prohibited substances

In recent years, increasing concerns have emerged regarding athletes being exposed to various sources of contamination that could result in an adverse analytical finding (AAF), which is considered a positive doping test and may lead to the athlete's sanction. This review aims to examine the potential sources of contamination. Firstly, exogenous sources such as food, water, supplements, and medications will be described, along with endogenous sources, primarily arising from the athlete’s physiological condition via the biotransformation of Medications. Finally, other hypothetical contaminations arising from sample collection procedures, poor transport or storage, and laboratory conditions will be discussed. Despite some legislative efforts to regulate the production of food and supplements, contamination remains a significant concern in the context of anti-doping, necessitating athletes to stay vigilant against the risks of inadvertent uptake of illicit products. Increased knowledge of the potential sources of contamination is essential for all parties involved in the fight against doping, including athletes, support personnel, legitimate supplement product manufacturers, and the anti-doping and scientific community. Such insights can contribute to developing the most effective strategy for preventing contamination and, most importantly, reducing the risk of inadvertent AAFs.

Deep silicification–assisted long-term preservation of structural and genomic information across biospecies: From micro to macro

The concurrent preservation of morphological, structural, and genomic attributes within biological samples is paramount for comprehensive insights into biological phenomena and disease mechanisms. However, current preservation methodologies (e.g., cryopreservation, chemical reagent fixation, and bioplasticization) exhibit limitations in simultaneously achieving these critical combined goals. To address this gap, inspired by natural fossilization, here we propose "deep silicification," a room temperature technology that eliminates fixation requirements and overcomes the cold chain problem. By harnessing the synergy between ethanol and dimethyl sulfoxide, deep silicification significantly enhances silica penetration and accumulation within bioorganisms, thereby reinforcing structural integrity. This versatile and cost-effective approach demonstrates remarkable efficacy in preserving organismal morphology across various scales. Accelerated aging experiments underscore a 4,723-fold enhancement in genomic information storage over millennia, with whole-genome sequencing confirming nearly 100% fidelity. With its simplicity and reliability, "deep silicification" represents a paradigm shift in biological sample storage.

The utility of an HPV genotype assay for cancer screening in self-collected urine/vaginal samples from Japanese women.

Objectives The high incidence of invasive cervical cancer among those who have not undergone cancer screening is a serious problem. This study aimed to investigate the utility of HPV test results from self-collected urine and vaginal samples as screening tools. Design The study was conducted in two steps. First, the appropriate storage container, temperature, and time until urine HPV assay performance were verified. Second, the results of spot urine testing under those conditions and of gynecologist-collected cervical and self-collected vaginal samples were compared to verify the feasibility of using the BD Onclarity® HPV assay for individuals with abnormal cervical cytology. Participants/Materials, Setting, Methods The participants were 121 women with abnormal cervical cytology. Self-collected urine and vaginal samples, along with gynecologist-collected cervical samples, were tested for HPV using the BD Onclarity® HPV assay. The optimal conditions for urine sample storage were identified by comparing the HPV detection rates under various conditions. Results Urine stored in a BD Probe Tec™ (QxUPT) for less than 72 hours at room temperature was found to have the highest HPV positivity rate. Under these conditions, the detection rates of HPV in urine, cervical, and vaginal samples were examined. HPV type 16 was detected in 41.7% of the cervical samples, type 18 in 10%, and types 31 and 52 in 12.6% each. The concordance rate for HPV testing between clinician-collected cervical and urine samples was 63.9% (kappa 0.34; 95% CI: 0.21-0.47), and that between clinician-collected cervical and self-collected vaginal samples was 77.8% (kappa 0.68; 95% CI: 0.53-0.83), indicating good concordance. In a population with an HPV-related lesion/tumor prevalence of approximately 70%, the sensitivity of HPV testing was 82.7% for the cervix, 46.4% for urine, and 75.7% for vaginal samples. Limitations The primary limitation is the lower detection rate of HPV in spot urine samples than in other sample types, indicating room for methodological improvement. The study's findings are based on a specific population, which may limit generalizability. Conclusions We investigated the optimal self-collected urine-to-testing time and temperature. Self-collected vaginal and urine HPV tests show moderate-high concordance with clinician-collected cervical HPV tests, suggesting their potential utility for women who do not undergo regular cancer screening. However, the sensitivity was not high in spot urine. Therefore, further large-scale studies are needed to verify these findings and optimize testing methods to encourage broader participation in cancer screening programs.

Standardised and Objective Dietary Intake Assessment Tool (SODIAT): Protocol of a dual-site dietary intervention study to integrate dietary assessment methods

Introduction Current dietary assessment methods face challenges in accurately capturing individuals’ dietary habits, undermining the efficacy of public health strategies. The ‘Standardised and Objective Dietary Intake Assessment Tool’ (SODIAT)-1 study aims to assess the effectiveness of three emerging technologies (urine and capillary blood biomarkers, and wearable camera technology) and two online self-reporting dietary assessment tools to monitor dietary intake. Methods This randomised controlled crossover trial will recruit 30 participants (aged 18-70 years and BMI of 20-30 kg/m2) from Imperial College London and the University of Reading. Exclusion criteria include recent weight change, food allergies/intolerances, following restrictive diets, certain health conditions and medication use. Interested volunteers will be directed to an online screening questionnaire via REDCap and eligible participants will attend a pre-study visit. Volunteers will consume, in a random order, two highly-controlled diets (compliant and non-compliant with UK guidelines) for four days each. Each study arm will be separated by at least one-week. During each test period, dietary intake will be monitored continuously using wearable cameras and self-recorded using eNutri (food frequency questionnaire) and Intake24 (24-hour dietary recall). Urine and capillary blood samples will be collected for biomarker analysis. Data analysis will assess the accuracy of dietary reporting across these methods using Lin’s concordance correlation coefficient. Discussion and ethical considerations This study introduces a novel approach to dietary assessment, addressing the limitations of traditional methods by reducing misreporting and enhancing inclusivity, particularly for underrepresented populations with literacy or language barriers. However, challenges persist, such as variability in biomarker data due to failure to adhere to sample storage requirements and the practicalities of continuously wearing cameras. To protect privacy, participants will be instructed to remove cameras at inappropriate times, and artificial intelligence will be used to blur all images captured apart from food.

Classification of Kudoa thyrsites infected and uninfected fish using a handheld near-infrared spectrophotometer, SIMCA and PLS-DA.

Kudoa thyrsites infection of marine fish typically results in myoliquefaction, which is only apparent 24 to 56 h post-mortem. The traditional methods for the detection of K. thyrsites infected fish are time-consuming and destructive, reducing its marketability. This poses a challenge for the fish industry to remove infected fish before it reaches the market or further processing activities. This study investigated the use of near-infrared (NIR) spectroscopy, in combination with soft independent modelling of class analogy (SIMCA) and partial least square discriminant analysis (PLS-DA), for discriminating K. thyrsites infected fish from uninfected fish. Performance of the classification models was evaluated by calculating the sensitivity, specificity and precision. A total of 334 fish samples (200 sardine, 64 hake and 70 kingklip) were used for this study. Infection of K. thyrsites was determined with the use of qPCR assays. Ninety per cent (90%) of the sardine samples, 78% of the hake samples and 37% of the kingklip samples were infected. Class groups of infected and uninfected fish samples were created for the purpose of generating SIMCA and PLS-DA classification models for each species of fish, as well as for a species independent data set. Principal component analysis (PCA) of NIR spectra did not show any clustering for infected and uninfected samples. Calibration and test sample sets were generated for the purpose of building and testing the SIMCA and PLD-DA classification models. SIMCA and PLS-DA were unable to classify test samples correctly into the two classes. The number of misclassifications (NMC) was higher for the SIMCA models than for the PLS-DA models, with more than 60% incorrectly classified. SIMCA classified most of the test samples into both classes. The precision for PLS-DA were 89% for sardine, 81% for hake, 0% for kingklip and 87% for species independent models, however, most samples were classified at infected. The use of NIR spectroscopy and classification models such as SIMCA and PLS-DA showed limited use as a method to distinguish between K. thyrsites infected and uninfected fish samples. Textural and chemical changes during extended frozen storage of the fish samples may have masked the effects associated with K. thyrsites infection. Further studies are suggested where NIR spectroscopy is used in combination with texture analysis and image spectroscopy.

12208 Impact Of Transition From The IDS-iSYS To The Roche Elecsys® Immunoassays On A Clinical Study Assessing Strict IGF-1 Control (I-Con) In Patients With Acromegaly

Abstract Disclosure: C.L. Chik: Advisory Board Member; Self; Ipsen, Novo Nordisk, Novartis Pharmaceuticals. Grant Recipient; Self; Pfizer, Inc.. C. Gandhi: None. J.A. Rivera: None. M. Denis: None. S. Van Uum: Advisory Board Member; Self; Ipsen, Pfizer, Inc., Novo Nordisk, Spruce. S.Z. Ezzat: Advisory Board Member; Self; Bayer, Inc., Eli Lilly &amp; Company, Ipsen, Novartis Pharmaceuticals, Merck, Eisai. D.T. Holmes: Other; Self; Roche Diagnostics. Objective: IGF-1 measurements were transitioned from the IDS-iSYS to the Roche Elecsys® immunoassays by the central laboratory during our clinical study that assessed strict IGF-1 control (I-Con) and quality-of-life scores in patients with acromegaly. Given the known variabilities of the IGF-1 measurements and the critical nature of IGF-1 results to the validity of the study, a retrospective analysis of the stored samples was completed using both methods. Methods: IGF-1 was measured in available stored samples (n=38) using IDS-iSYS at one of the hospital laboratories and the Roche Elecsys® at the central laboratory. In addition, the end-of-study (EOS) IGF-1 results were compared with IGF-1 measurements during the study (DTS) at the central and the local laboratory of the two sites with more than 10 stored samples, with one site using IDS-iSYS and the second site using IGF-1-RIACT. Bland-Altman plot, regression analysis and intra-class correlation were used to assess the reliability of the IGF-1 measurements. Results: Ten acromegaly patients from four sites in Canada participated in the clinical study. After six months of addition of pegvisomant to a somatostatin analog (n=6) or dose escalation of pegvisomant (n=4), IGF-1 decreased from 258.5 ± 59.2 µg/L [121.8 ± 14.4 % upper limit of normal (%ULN)] to 184.1 ± 41.1 µg/L (86.7 ± 20.0 %ULN) (p=0.001). Two to five stored samples were available from the 10 patients (n=38) and the mean difference of IGF-1 between the IDS-iSYS and Roche Elecsys® was 10.8 µg/L or 4.6% when expressed as %ULN, with a trend to a higher value at the central laboratory. Linear regression of the difference between IGF-1 measurements against their average showed a slope of 0.1 (p&amp;lt;0.001) or 0.15 (p=0.01) when expressed as %ULN. Intra-class correlations between the central laboratory DTS and EOS measurements were compared with those by the local laboratory. In the site that used IDS-iSYS for IGF-1 measurements, the intra-class correlations with the Roche Elecsys® was 0.99 (n=11) for DTS measurements and 0.98 (n=13) for EOS measurements. In the second site that used IGF-1-RIACT, the intra-class correlations with the IDS-iSYS was 0.38 (n=13) for DTS results, and with the Roche Elecsys® was 0.64 (n=15) for EOS results. Conclusion: Although there were variabilities between the IDS-iSYS and the Roche Elecsys® IGF-1 measurements, the small difference between the two IGF-1 assays confirmed that the transition from the IDS-iSYS to the Roche Elecsys® by the central laboratory had little impact on the IGF-1 results of our study. Using intra-class correlations to assess reliability of the IGF-1 measurements, the reliability of the IGF-1 results appeared dependent on the IGF-1 method used in the individual site. Presentation: 6/2/2024

The Antimicrobial Efficacy and Quality Changes in Pineapple Juice Treated with Natural Preservatives

The study investigated effects of natural preservatives on the quality of fresh pineapple fruit juice. The natural preservatives used are ginger, garlic, moringa seed and cloves and were processed into powder. The treatment of pineapple with the natural preservatives was at a concentration of 20% with 3 minutes dipping time. The enumeration and identification of microorganisms on the fresh pineapple fruit, shows that the total bacteria count was 1.8×105 colony forming unit per gram (CFU/g) and 4.6×103 CFU/g respectively. The identified bacteria are staphylococcus aureus and streptococcus spp and identified fungi were Aspergillus Niger, penicillin spp and Aspergillus perfrigens respectively. Moringa seed extract exhibited moderate antibacterial activity, with zones of inhibitions (ZOIs) of 16 mm against Staphylococcus aureus and 15 mm against Streptococcus spp. Garlic (GL) showed the least antibacterial activity among the natural preservative samples, with 9mm zones of inhibition against Staphylococcus aureus and 4 mm against Streptococcus spp. Clove extract displayed significant antibacterial activity, with 14 mm zones of inhibition against Staphylococcus aureus and 19 mm against Streptococcus spp. Ginger extract exhibited slight antibacterial activity, with zones of inhibition of 4 mm against both bacterial strains. Chemical composition of the treated pineapple juice result ranges from 0.77-0.865% TTA, 64.12-63.10 Vit C, 26.50-25.06 Brix Content,3.20-3.39 pH and 13.23-13.17 TSS respectively. The control (100% pineapple Juice) displayed balanced properties serving as an effective baseline3. Storage studies, ambient stored samples were analyzed at 0 day and 21 days intervals. All samples were subjected to standard analytical methods. Results showed increase in number of bacteria and fungi with increase in the number of days. The use of cloves, garlic, ginger, and moringa seeds as natural antimicrobial agents in pineapple juice is effective in controlling microbial growth, thus enhancing the safety and shelf life of the juice. These treatments also influence the chemical and sensory properties of the juice, contributing to consumer acceptability.