Performance assessment of 11 commercial serological tests for SARS-CoV-2 on hospitalised COVID-19 patients.

BACKGROUND: Commercial availability of serological tests to evaluate immunoglobulins (Ig) targeting severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has grown exponentially since the start of the coronavirus disease 2019 (COVID-19) outbreak. Thorough validation of these tests is important before use as epidemiological tools to infer seroprevalence in specific populations and as diagnostic tools to complement molecular approaches (e.g., quantitative reverse transcription-polymerase chain reaction). METHODS: Commercial serological tests from 11 suppliers were assayed side-by-side using 126 samples from SARS-CoV-2-infected inpatients and 36 from healthy and HIV-infected individuals. RESULTS: The majority of the tests assayed have >95% specificity. For the sensitivity calculation, samples were stratified by days since symptoms onset; sensitivity peaks at 16-21 days for IgM and IgA (maximum 91.2%, Euroimmun) and, dependant on the test, at 16-21 or >21 days for IgG (maximum 94.1%, Snibe). Data from semiquantitative tests show that patients with a severe clinical presentation have lower levels of Ig targeting SARS-CoV-2 at <10 days since symptoms onset and higher levels at >21 days, compared to patients with a non-severe presentation. CONCLUSIONS: This study highlights the heterogeneity of sensitivity and generally high specificity of the serological tests and establishes a basis for their usefulness to complement diagnostic techniques and population seroprevalence studies.

Disposable microfluidic micromixers for effective capture of Cryptosporidium parvum oocysts from water samples.

BACKGROUND: Protecting drinking water supplies from pathogens such as Cryptosporidium parvum is a major concern for water utilities worldwide. The sensitivity and specificity of current detection methods are largely determined by the effectiveness of the concentration and separation methods used. The purpose of this study is to develop micromixers able to specifically isolate and concentrate Cryptosporidium, while allowing in situ analysis. RESULTS: In this study, disposable microfluidic micromixers were fabricated to effectively isolate Cryptosporidium parvum oocysts from water samples, while allowing direct observation and enabling quantification of oocysts captured in the device using high quality immunofluorescence microscopy. In parallel, quantitative analysis of the capture yield was carried out by analyzing the waste from the microfluidics outlet with an Imaging Flow Cytometer. At the optimal flow rate, capture efficiencies up to 96% were achieved in spiked samples. CONCLUSIONS: Scaled microfluidic isolation and detection of Cryptosporidium parvum will provide a faster and more efficient detection method for Cryptosporidium compared to other available laboratory-scale technologies.

T-tube Systematic Use in the Biliary Anastomosis: Comparison of Two Consecutive Series of Liver Transplantation.

OBJECTIVES: The authors sought to check the frequency of biliary complications with the use of a T-tube. In 2012, throughout the year, it was carried out systematically in all liver transplantations regardless of the characteristics of the bile duct. Despite the long experience, biliary complications remain a common cause of postoperative morbidity and mortality. MATERIAL AND METHODS: In this study we compared complications in 23 consecutive transplantation cases using T-tube biliary anastomosis during the year 2012 with 23 consecutive transplantation cases without T-tube during the year 2013. We evaluated postoperative complications and long-term outcomes (for 2 years to 3 years). RESULTS: Of the 23 patients with anastomosis with a T-tube, 2 patients (8.69%) had biliary stricture that required prosthesis by endoscopic retrograde cholangiopancreatography, 1 of them (4.34%) was operated by incorrect placement of the T-tube, and in 4 patients (17.39%) bile leakage (endoscopic retrograde cholangiopancreatography prostheses in 3 cases and hepaticojejunostomy in 1). During follow-up at 3 years, only 2 patients had minimal bile duct dilatation without clinical relevance. In the patients who underwent transplantation without a T-tube, 18 (78.26%) had no complications, 3 (13.04%) showed stenosis (prosthesis placement), and 2 (8.69%) had bile leakage (hepaticojejunostomy and prosthesis). During follow-up at 2 years to 3 years, no patient had biliary dilatation or alteration of cholestatic parameters. In the comparative study of both groups we found no statistically significant differences. CONCLUSIONS: We have not seen an improvement in complications with the use of T-tube (69.56% vs. 78.23%) that encourage us to work systematically, although the small number of cases does not allow statistically significant conclusions.

Collateral Development in Thrombosis of the Hepatic Artery After Transplantation.

OBJECTIVES: The authors sought to identify strictures or hepatic artery obstruction with posterior collateral transformation in our series of liver transplantation, treatment, and evolution. The thrombosis or severe hepatic artery stenosis sometimes presents a compensation mechanism, the collateral transformation of the artery. MATERIAL AND METHODS: From April 2002 to December 2011 we collected 18 cases of collateral transformation. We analyzed data regarding the transplantation, diagnosis, treatment, clinical evolution, liver function, and Doppler-ultrasound. RESULTS: The main indication was alcoholic cirrhosis, followed by hepatocellular carcinoma - hepatitis C virus. The mean cold ischemia time was 292.2 minutes mean hot ischemia was 48.8. The anastomosis was performed on the gastroduodenal-splenic patch donor in 14 cases, the celiac trunk in 2 cases, and on grafts to the aorta in another 2. Doppler ultrasound showed 8 cases without complications, 8 with low flows, and 2 cases with alterations of the right hepatic artery. Computed tomographic (CT) angiography was performed in patients with impaired eco-Doppler and found 4 obstructions, 2 cases with kinking, 1 stenosis, and 3 normal cases. Three patients with low flows were re-operated and another re-transplanted. After diagnosis of collateral transformation, all were treated with antiplatelet agents. Two cases of angioplasty were associated. The collaterals were diagnosed 1 month to 44.8 months after transplantation. Five patients died. In the latest data, 10 patients do not have analytical alteration. The Doppler ultrasound shows 7 cases being normal and 6 with flow but low resistances. CONCLUSIONS: In our series, all patients with collateral transformation, except one who was transplanted, maintain good liver function with permeable vessels.

Efficient microfluidic negative enrichment of circulating tumor cells in blood using roughened PDMS.

Efficient isolation strategies not based on epithelial biomarker expression are required to enable non-biased enrichment of circulating tumor cells (CTCs). CTCs undergoing epithelial-mesenchymal transition (EMT) may be prognostically relevant, and importantly are not detected with conventional epithelial based approaches such as CellSearch®. A method for the non-biased isolation of cancer cells within a peripheral blood sample utilizing microfluidic mixing PDMS devices functionalized with anti-CD45 is reported. The introduction of micro and nanoscale roughness using a single step treatment with sulfuric acid significantly increases the binding yield of white blood cells (WBCs) to the anti-CD45 conjugated surfaces. Up to 99.99% WBC depletion is achieved with a tumor cell recovery yield of 50%. This high level of CTC enrichment is expected to facilitate the detailed characterization of CTCs using for instance, imaging flow cytometry as demonstrated here.

Occurrence of endocrine disrupting compounds in five estuaries of the northwest coast of Spain: Ecological and human health impact.

The occurrence and spatial distribution of alkylphenols (4-tert-octylphenol, 4-n-octylphenol, 4-n-nonylphenol, nonylphenol) and bisphenol A were examined in five estuaries along the Northwest coastal area of Spain. As far as we know, no previous works about this topic could be found in the literature. A total of 98 seawater samples were collected during May 2011-July 2012 and analyzed by a highly sensitive DLLME-LC-MS/MS methodology recently developed. Results indicated nonylphenol was the most ubiquitous compound with maximal concentration of 0.337 µg L(-1) (Ría de Vigo). The environmental quality standards (EQS) established in Directive 2013/39/EU for 4-tert-octylphenol were slightly exceeded in some sampling points. Fishing harbours, water treatment plant and industrial discharges were supposed as the main sources of contamination. Low and medium ecological risk was determined in all estuaries. Possible endocrine effects on biota and population were estimated in terms of estrogenic activity and daily intake respectively, and no risk was found in any case.

Detection of markers of cardiovascular and renal risk in Cuba: Isle of Youth Study (ISYS).

UNLABELLED: Chronic vascular diseases constitute a growing global health problem. OBJECTIVES: To (a) determine marker positivity for renovascular damage in the total adult population of the Isle of Youth, Cuba; (b) describe marker association with common risk factors for renal and related chronic vascular conditions, and (c) identify best predictors of renovascular damage. METHODS: Previous informed consent was obtained, the population studied was 55,646, and subjects were aged ≥20 years. Blood pressure, weight and height were measured and a questionnaire applied. Urine markers for renovascular damage (hematuria, proteinuria and microalbuminuria) were also determined. RESULTS: Positive markers were detected in 21.3%: hematuria (12.6%), microalbuminuria (6.8%), proteinuria (0.9%), and proteinuria + hematuria (0.9%). Risk factors were highly prevalent: 15.1% were aged ≥60 years; 32.3% overweight, 13.9% obese, and 25.1% smokers. Prevalence of high blood pressure (30%), diabetes mellitus (5.4%) and cardiovascular disease (5%) was also high, while cerebrovascular disease registered 0.9%. Markers were more prevalent in older people and in those suffering from diabetes mellitus, high blood pressure, cardiovascular and cerebrovascular disease, overweight or obesity. Risk factor regression tree analysis identified hypertension as the best predictor of renovascular damage. CONCLUSIONS: Adult population-wide screening revealed hidden morbidity and permitted better risk stratification. Results serve to inform community-based multidisciplinary and intersectoral disease prevention and management.

Liver transplantation complications in the intensive care unit and at 6 months.

OBJECTIVE: This study sought to determine the factors that influence the 6-month outcomes of liver transplants. PATIENTS AND METHODS: One hundred ninety-six variables (donor, recipient, operation, intensive care unit [ICU], evolution at 3 and 6 months) were collected from the first 74 consecutive liver transplantation performed from 2002 to 2004. The primary endpoint was patient survival at 6 months. The statistical analysis included a screening univariate analysis followed by a stepwise logistic regression with forward inclusion to test independent associations and finally generation of receiver-operator characteristic (ROC) curves to evaluate predictive factors. RESULTS: Patient survival at 6 months was 86%, namely 10 deaths, including 4 intraoperatively and 6 postoperatively due to sepsis. Complications in the ICU were classified as reoperations due to biliary problems, vascular complications, and peritonitis. Late complications included 51% rejection episodes, 24% infections, 11% pleural effusions, and 16% diabetes mellitus. Logistic regression analysis showed independent negative predictors of survival were the number of packed red cells during transplantation, the number of fresh frozen plasma units administered in the ICU, blood urea nitrogen (BUN) concentration in the ICU, and graft complications. The odds ratios of these variables were 10.2, 5.2, 42.1, and 36.9, respectively. The area under the curve (AUC) of the ROC was 0.99; the sensitivity was 94%; and the specificity was 100%. The independent predictors of surgical complications were the length of the operation, the need for pressor support, and the number of fresh frozen plasma units administered in the operating room, with odds ratios of 1.0, 7.7, and 1.1, respectively. CONCLUSION: This study revealed specific operative and ICU variables that correlated with the evolution of our patients.

Study of the renal function in nonrenal organ transplantation.

Kidney disease after transplantation of a nonrenal organ has been described to be the result of the nephrotoxicity from the commonly used calcineurin-inhibitors as well as other factors. The aim of this study was to evaluate renal function and potential risk factors for the development of chronic renal failure among nonrenal organ recipients. We designed a single-center retrospective study including all 165 of our cardiac and liver recipients between February 1998 and October 2003, collecting clinical, analytic, and therapeutic data. We excluded double transplants and patients with survival less than 6 months. Creatinine clearance was calculated according to the Cockcroft-Gault and the Levey Modification of Diet in Renal Disease (MDRD)-5 equations. Although 165 patients received a cardiac or liver transplantation, 17 died in the first 6 months and three were double transplants; therefore we analyzed 145 patients: 107 (74%) cardiac transplantations and 38 (26%) liver transplantations. There were 106 male and 39 female recipients. The mean age (+/-SD) at the time of transplantation was 54 +/- 10 years and the mean follow-up was 2.9 +/- 1.7 years. Urinalysis before transplantation was only performed in 33 patients (22.8%) including three (2.1%) who had proteinuria. Serum creatinine increased until 12 months after transplantation (P < .001), then it recovered its average level. Creatinine clearance calculated using the aforementioned equations showed a similar pattern, with a progressive decline to 12 months (P < .05), with eventual stabilization or even improvement. The factors that we observed to increase the risk of renal damage were age, female sex, obesity, and the presence of proteinuria prior to transplantation. There was a good correlation (r = 0.96) between cyclosporine but not tacrolimus trough levels and serum creatinine at 48 hours after transplantation.

[Hematophagic activity of and environmental effect on the main malaria vector in Cuba: Anopheles albimanus]. / Análisis de la actividad hematofágica y de la influencia ambiental sobre el principal vector de la malaria en Cuba: Anopheles albimanus.

An ecological study of Anopheles (N) albimanus in a suburban population of Camagüey province was carried out using a human bait in two trap points (indoor and outdoor). A higher quantity of females in the rainy season was observed together with a marked exophagic trend with peak activity in the early hours of the evening outdoor and in the early hours of the morning indoor. The abiotic influence on the fluctuation of the anophele population in both trap station was proved.

[3 combinations of esterases and their relation with the resistance to organophosphate, carbamate, and pyrethroid insecticides in Culex quinquefasciatus Say, 1823 (Diptera: Culicidae) in Cuba]. / Tres combinaciones de esterasas y su relación con la resistencia a insecticidas organofosforados, carbamatos y piretroides en Culex quinquefasciatus Say, 1823 (Diptera: Culicidae) de Cuba.

The possible relationship between different patterns of esterases and the resistance to various types of insecticides was analyzed by bioassays, biochemical tests, and electrophoresis carried out in a population of Culex quinquefasciatus from Camagüey and in three colonies obtained from it by family selection. The original population was heterogeneous and presented 8 combinations of esterases in polyacrylamide gel. A3A6B6, B1B6 and B1A6B6 were the most frequent of them and characterized each selected colony. Every studied colony, including the parental one, showed different levels of resistance to diverse insecticides. Only the resistance to propoxur showed less variation. In every colony it seems to exist a combination of resistance mechanisms; however, the differences found in tests with DEF synergized insecticides show that the different bands of zymograms may represent esterases contributing in a different way to resistance.

[The evolution of resistance in a Culex quinquefasciatus strain starting from selection with the pyrethroid insecticide lambdacyhalothrin]. / Evolución de la resistencia en una cepa de Culex quinquefasciatus a partir de la selección con el insecticida piretroide lambdacialotrina.

The resistance change to different insecticides in Culex quinquesfasciatus strain select at the laboratory with doses of pyrethroid lambdacyhalothrin that would cause a larva mortality of 90% were studied. It was attained an increase of the resistance to this insecticide of 144.5 times compared with the original level, and it was obtained a resistant strain (287x). There was an increase of the levels of resistance to methyl-pyrimifos (2.4 times), propoxur (6 times), DDT (5.2 times), clorpirifos (22 time), cypermethrin (67.5 times), and deltamethrin (20.2 times). The frequencies of the genes that codify for the elevated esterases enzymes and for the modified acetylcholinesterase reached their maximum value. Significant changes were observed in the phenotypes for esterases in the electrophoresis in polyacrylamide gels. It was detected synergism of DEF and PB with lambdacyhalothrin. Therefore, the elevated esterases and the esterases of multiple function may contribute to resistance.

Morphometric characterization of normal and abnormal human zygotes.

Human zygotes (n = 278) from 96 in-vitro fertilization gonadotrophin-stimulated cycles were photographed in their pronuclear stage (16-18 h post-insemination). Normal morphological fertilization (two pronuclei) was observed in 215 zygotes, 17 showed only one pronucleus, 40 showed three pronuclei and six showed four. Area, perimeter and maximum and minimum diameters of each zygote and pronucleus were measured using an IBAS 2000 (Kontron) image analyser. When the four groups were compared, whole zygotes did not show any morphometric difference. However, pronuclei from these groups showed that a high number of pronuclei was directly related to small pronuclei. Differences in pronuclear size and a linear increase in the nucleus/cytoplasm relationship were found which varied with the number of pronuclei.

Refractory anemia with monosomy 2 and a double minute chromosome.

We present a case of refractory anemia with monosomy 2 in the 41 cells of the bone marrow studied and a double minute chromosome (dmin) in 68% of these cells. The illness developed over a period of 3 years and the patient died of cerebral hemorrhage without developing leukemia.

Trisomy 4: another specific anomaly in acute nonlymphocytic leukemia.

We present herein a case of acute nonlymphocytic leukemia, type M2 of the FAB classification, in which the cytogenetic study of the bone marrow cells showed a trisomy 4 as the only alteration. This case was detected from among 118 cases of acute nonlymphocytic leukemia under cytogenetic study.