Comparison of various principles of coagulation tests in handling hemolysed blood samples

Background: Rejection of hemolysed samples for coagulation test is the standard practice.However, when clinicians deal with extremely sick patients where repeat sampling is difficult toobtain, rejection of the sample is a lost opportunity for the lab physician to assist inpatient care.Proceeding with the test and providing a clinically helpful interpretation of the results will ensure theactive participation of the laboratory physician. Different principles of coagulation testing handle thehemolysed samples differently. It is essential to know the best principle to proceed with thehemolysed sample if need be. This study set out to estimate the predictive values of post-hemolyticsample coagulation test results with various coagulation test principles. Methods: This is aprospective experimental study where the non-hemolysed samples were processed for coagulationtests. Part of the sample was deliberately hemolysed, and the coagulation tests were repeated.Results: Two hundred and forty-eight samples were studied. A median of 11% hemolysis wasachieved experimentally. The mean difference in prothrombin time between pre and post hemolyticsamples with normal PT was 0.9 and with abnormal PT, it was 1.1 seconds. The same for APTT was4.9 and 1.1 seconds, respectively. The majority of the samples showed prolonged coagulation posthemolysis. Positive (PPV) and negative (NPV) predictive values for prothrombin time are 97.3 and73.4%, respectively. Similarly, PPV and NPV for APTT are 97.4 and 47.1%, respectively.Conclusions: Samples with normal values after hemolysis are more likely to be normal.

Immunogenicity of mRNA-1273, BNT162b2 and Ad26.COV2.S COVID-19 vaccines

Background: Understanding variation in immunogenicity may help rationalize use of existing SARS-CoV-2 vaccines. Methods: We compared immune responses in ambulatory adults vaccinated with mRNA-1273 , BNT-162b2 or Ad26.COV2.S in Massachusetts, USA between February and May 2021. Control groups were pre-pandemic controls (n=1220) and individuals without (n=112) or with prior SARS-CoV-2 infection (n=130) sampled in mid-2020. We measured total anti-spike IgG/M/A antibodies (Roche Elecsys Anti-SARS-COV-2 S assay), anti-receptor-binding-domain (RBD) antibodies; neutralization of SARS-CoV-2 pseudovirus; and T-cell responses. Findings In individuals with prior infection, all vaccines were associated with higher antibody concentrations and neutralization than those in convalescent individuals, even after a single dose. In individuals without prior infection, a single dose of either mRNA vaccine yielded comparable concentrations and neutralization to convalescent unvaccinated individuals, and Ad26.COV2.S yielded lower antibody concentrations and neutralization titers. The second dose of either mRNA vaccine boosted responses. At a median of 24 days after vaccination, two of 21 (9.5%) Ad26.COV2.S recipients had a neutralization titer higher than pre-pandemic controls; repeat sampling at a median 66 days after vaccination found most (11/15 (73%) remained negative. Antibody concentrations and neutralization titers increased similarly after the first dose of either vaccine, and even further in recipients of a second dose of vaccine. T-cell responses were higher in mRNA1273 and BNT162b2 than Ad26.COV2.S recipients. Interpretation SARS-CoV-2 vaccines vary significantly in immunogenicity in individuals without prior infection. If confirmed in effectiveness studies, public health policy may need to be tailored to each vaccine, or even individual responses.

Evaluation of Peritoneal Deposits in Undiagnosed Ascites by Advanced Endoscopic Ultrasound Imaging Techniques

Etiology of ascites can be usually determined with ascitic fluid cytological and biochemical evaluation. Occasionally, the cause of ascites cannot be determined despite repeated ascitic fluid evaluations. These patients with undiagnosed ascites usually undergo diagnostic laparotomy/laparoscopy for etiological diagnosis. Endoscopic ultrasound (EUS) can help in resolving the diagnostic conundrum of undiagnosed ascites by visualizing as well as sampling peritoneal and omental deposits/thickening. However, rarely fine-needle aspiration from deposits may be falsely negative and patient may need repeat sampling. Newer EUS imaging techniques such as elastography and contrast-enhanced harmonic EUS by providing additive information on stiffness and enhancement pattern of the lesion can help in differential diagnosis.

Follow-up Study of Microflora Changes in Crevicular Gingival Fluid in Obese Subjects After Bariatric Surgery

The objective of our study was to investigate the effect of weight loss on the crevicular microflora following bariatric surgery. Crevicular fluid samples were taken from 57 subjects: 22 were in the normal control group; 18 in the obese control group; and 17 patients had had bariatric surgery, who underwent a repeat sampling 6 to 12 months after the operation. Crevicular fluid samples were analyzed by MALDI-TOF MS analysis. After surgery and weight loss, the mean germ count increased, albeit not significantly. Also, Candida albicans and non-albicans Candida species: C. dubliniensis, C. kefyr, and C. lusitaniae appeared after surgery (p < 0.05) in subjects where Neisseria was either absent throughout or eliminated after surgery. However, periodontitis did not develop during this time in our subjects.

Bilateral Aldosterone Suppression in Patients With Right Unilateral Primary Aldosteronism and Review of the Literature

Introduction Adrenal vein sampling (AVS) identifies unilateral primary aldosteronism but may occasionally show paradoxically low aldosterone–cortisol ratios bilaterally. Postulated reasons include venous anomalies, fluctuating aldosterone secretion, or superselective cannulation. We report our findings in patients who underwent repeat AVS and reviewed the current literature. Methods We performed a retrospective observational study of patients undergoing AVS in an experienced high-volume tertiary center over a 5-year period. Results From 2015 to 2019, 61 patients underwent sequential cosyntropin-stimulated AVS and all had bilateral successful cannulation (100%). Four of 61 (6.6%) patients had bilaterally low aldosterone–cortisol ratios. Three patients underwent repeat AVS, with all 3 cases demonstrating right-sided lateralization and cure of disease postadrenalectomy. Right-sided disease was also more common in other reports. This may be due to inadvertent superselective cannulation of the short right adrenal vein, resulting in sampling of the adjacent normal gland. Cortisol results cannot detect this problem. In 1 patient, computed tomography venography excluded any accessory right adrenal veins. In another patient, repeat bilateral simultaneous unstimulated AVS was done, and measurements of metanephrines aided in accurately identifying right-sided lateralization. Conclusion In addition to technical difficulties in cannulating the right adrenal vein, we also have to avoid performing superselective cannulation inadvertently. In cases of inconclusive AVS, repeat sampling may identify patients with potentially curable unilateral primary aldosteronism. The role of corticotropin stimulation and metanephrines measurements during repeat AVS requires further study.

Please come again: attractive bait augments recapture rates of capture-naïve snowshoe hares

ContextCapture–recapture sampling is one of the most commonly used methods for monitoring population demographics and is needed in a wide variety of studies where repeat sampling of individuals is desired. Although studies employing capture–recapture methods often assume unbiased sampling, it is well established that inherent capture biases can occur with these methods, including those related to baits. Reducing sources of sampling bias and augmenting recapture reliability is necessary for capture-dependent studies. However, few studies have examined the efficacy of baits on individuals with variable capture experience. AimsTo investigate the use of an attractant-augmented bait in enhancing capture–recapture probabilities for snowshoe hares (Lepus americanus). MethodsTo examine the efficacy of different attractant-augmented bait types, a variety of baits were created, with bait preference tested on a captive hare. Because a strawberry jam-based bait was preferentially consumed (in comparison with other tested baits), the effectiveness of this attractant in enhancing capture–recapture rates was subsequently examined in wild hares, using paired live-trapping field trials (n=6 trials). ResultsLive-trapping trials showed that although overall hare capture rates were not affected by the use of a jam-based bait, recaptures were 33.1% higher in capture-naïve individuals exposed to our attractant. This was not the case for hares with prior capture experience; such hares had an equal likelihood of being recaptured regardless of the bait type used. ConclusionsThe tested attractant improved recapture rates of capture-naïve hares. ImplicationsStudies relying on high recapture rates should use methods that maximise recapture rates wherever possible, including the use of baits that may augment recaptures in capture-naïve animals.

Primary Esophageal Mixed Sarcomatoid and Small Cell Neuroendocrine Carcinoma With Brain Metastasis: A Challenging Diagnosis on Biopsy

Mixed carcinomas in the esophagus are highly uncommon neoplasms that represent a diagnostic challenge on small tissue biopsies. We present a case of a primary mixed sarcomatoid–small cell carcinoma of the esophagus that was diagnosed after repeat sampling of the lesion. The components were morphologically distinct and could be further classified by immunohistochemistry. Next-generation sequencing identified mutations in PIK3CA and CDKN2A. The small cell component morphology was also identified in brain metastasis.

Books and Drawers full of Moths

The Otago Museum houses one of New Zealand’s largest Lepidoptera collections that consists of more than 31,000 macro moth specimens collected across New Zealand over the last 30 years. Alongside this collection, supplementary information is found in detailed field notebooks that cover, for most sites, the total abundance of the different species present in these samples. We have been able to use the notebooks to work out the sampling intensity and sites to map both the collections and the abundances to some degree. It is impractical to collect everything. As a result, the common species are left out of collections and the rare and unusual sightings fill the collections. When planning to resample collecting sites to investigate changes in ecosystems, just relying on collections for species presence and absence would skew the results. It should also be noted that field notebooks are not a panacea for biological information as the information in them ages, so too can the reliability and accuracy of the notes within. Here we discuss how the field notebook data compares with the information accompanying the specimens housed within the museum collection. This is a recently digitised collection and allows an insight into the collectors sampling, vouchering and data practices and how these can affect modern interpretation and variation in repeat sampling.

Optimal sampling effort required to characterize wetland fish communities

Wetlands are increasingly in peril as a result of human activities. In the Laurentian Great Lakes, coastal wetlands provide essential habitats for many fishes. Consequently, efficient sampling approaches for wetland fishes are needed for effective management. We employed a repeat-sampling strategy using a seine to collect fishes from seven wetlands. The data set was used to develop guidance for optimizing wetland fish sampling. To meet richness targets, the required number of sampling sites decreases as sampling intensity increases. Half the number of sites was required when three seine hauls per site were done compared with one haul. On average, 97 one-haul sites were required to detect 90% of species, whereas only 47 three-haul sites were required. Sampling effort is predicted to be greater in areas with more species and larger wetlands. The number of individuals and sites needed to detect 90% of species increased exponentially as species richness increased, and the number of individuals needed was positively related to wetland area. The use of block nets did not improve species detection or affect the composition.