Measurement of yield and quality of DNA in human buffy coat is extraction method dependent

During the last few years, an important element in the improvement of the molecular biology techniques has been the necessity for availability of high quality and functionality DNA. Several DNA extraction procedures with different results in both performance and quality, have been proposed. In this study our objective was to determine the most reliable extraction method that balances DNA quantity, and to assess the sample quantification of the fluorometric DNA quantification methods. For this, blood extracted by venopunction from 20 healthy volunteers was used to obtain DNA from buffy coat, and 4 commercial DNA extraction kits were assessed as well as two fluorometric DNA quantification methods with protocols of different complexity. Results suggest that manual methods achieve higher quality and larger yields of DNA. DNA purity obtained with the 4 extraction kits evaluated through the 260/280 and 260/230 ratio showed that the Qiacube kit fulfilled the criteria established in this work, followed very close by the Flexigene kit. On the other hand, the fluorometric DNA methods used in the samples quantification showed a higher variability when using QuantiFlour method, obtaining better results probably due to the simplicity of this protocol.

A critical race theory curriculum for emergency medicine learners

OBJECTIVES

We set out to develop and implement a critical race theory (CRT) curriculum to address an identified gap in emergency medicine education. Sessions explored concepts of CRT and issues of racism as they relate to the clinical and extraclinical environments.

METHODS

We developed a series of five virtual workshop sessions in 2019 that were held over Zoom in June and July 2020 in the setting of the COVID-19 pandemic. Eight learners completed the curriculum. Prior to each session, learners were provided presession materials including podcasts, recorded lectures, and readings. Thought-provoking questions were also provided with presession materials to facilitate discussion during sessions. Materials were curated to provide foundational knowledge on CRT and U.S. history as well as local history of the San Francisco Bay Area.

RESULTS

Participants found the curriculum useful, reported increased familiarity with CRT, and were more likely to have an analytic framework for topics of race and racism. Participants also reported that their perspective had been changed after completing the curriculum.

CONCLUSIONS

Our curriculum promoted effective engagement with topics of race and racism by learners. Opt-in participation contributed to an engaged cohort and the small cohort size encouraged participation by all learners. Semistructured facilitation allowed participants to guide conversations to their own topics of interest while also addressing specific topics at hand. Independent guided presession work allowed participants to gather knowledge at their own pace prior to each session, which likely contributed to more active and in-depth participation.

Porous Silicon Gas Sensors: The Role of the Layer Thickness and the Silicon Conductivity

We studied the influences of the thickness of the porous silicon layer and the conductivity type on the porous silicon sensors response when exposed to ethanol vapor. The response was determined at room temperature (27 ∘C) in darkness using a horizontal aluminum electrode pattern. The results indicated that the intensity of the response can be directly or inversely proportional to the thickness of the porous layer depending on the conductivity type of the semiconductor material. The response of the porous sensors was similar to the metal oxide sensors. The results can be used to appropriately select the conductivity of semiconductor materials and the thickness of the porous layer for the target gas.

Quality assessment on the long-term cryopreservation and nucleic acids extraction processes implemented in the andalusian public biobank

Human samples are commonly collected and long-term stored in biobanks for current and future analyses. Even though techniques for freezing human blood are well established, the storage time can compromise the cell viability as well as the yield and quality of nucleic acids (RNA and DNA) extracted from them. In this study, a protocol to obtain peripheral blood mononuclear cells (PBMCs) from 70 subjects, which were stored at - 196 °C from EDTA tubes for a long-term, was assessed. In parallel; a protocol to obtain DNA from the same subjects, which were stored at - 80 °C from citrate tubes, was also studied. Samples stored from 2008 to 2012 were studied and the results obtained showed that there were no statistically significant differences in the RNA or DNA extracted in terms of purity, integrity and functionality The freezing protocol used by the Málaga Biobank shows that viable PBMCs and DNA could be kept for a period of, at least, 10 years, with a high quality and performance. Furthermore, RNA extracted from these PBMCs presents also a good quality and performance. Therefore, the samples frozen according to the conditions of the protocols assessed in this study could be optimal for biomedical research.

Management of opioid-dependent patients: comparison of the cost associated with use of buprenorphine/naloxone or methadone, and their interactions with concomitant treatments for infectious or psychiatric comorbidities

The objective was to estimate the annual interaction management cost of agonist opioid treatment (AOT) for opioid-dependent (OD) patients with buprenorphine-naloxone (Suboxone®) (B/N) or methadone associated with concomitant treatments for infectious (HIV) or psychiatric comorbidities. A costs analysis model was developed to calculate the associated cost of AOT and interaction management. The AOT cost included pharmaceutical costs, drug preparation, distribution and dispensing, based on intake regimen (healthcare center or take-home) and type and frequency of dispensing (healthcare center or pharmacy), and medical visits. The cost of methadone also included single-dose bottles, monthly costs of custody at pharmacy, urine toxicology drug screenings and nursing visits. Potential interactions between AOT and concomitant treatments (antivirals, antibacterials/antifungals, antipsychotics, anxiolytics, antidepressant and anticonvulsants), were identified to determine the additional use of healthcare resources for each interaction management. The annual cost per patient of AOT was €1,525.97 for B/N and €1,467.29 for methadone. The average annual cost per patient of interaction management was €257.07 (infectious comorbidities), €114.03 (psychiatric comorbidities) and €185.55 (double comorbidity) with methadone and €7.90 with B/N in psychiatric comorbidities. Total annual costs of B/N were €1,525.97, €1,533.87 and €1,533.87 compared to €1,724.35, €1,581.32 and €1,652.84 for methadone per patient with infectious, psychiatric or double comorbidity respectively.Compared to methadone, the total cost per patient with OD was lower with B/N (€47.45-€198.38 per year). This is due to the differences in interaction management costs associated with the concomitant treatment of infectious and/or psychiatric comorbidities.

Synthesis and characterization of PbSe nanoparticles obtained by a colloidal route using Extran as a surfactant at low temperature

Lead selenide nanoparticles (PbSe NPs) have been obtained through an easy and low cost route using colloidal synthesis in aqueous solution. The synthesis was carried out at room temperature using Extran (Na₅P₃O₁₀, NaOH and H₂O) as surfactant. Hydrochloric acid (HCl) was used to eliminate the generated by-products. The size of PbSe NPs was varied by changing the Pb:Se molar concentration. The PbSe NPs were characterized by powder x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDAX), high-resolution transmission electron microscopy (HRTEM) and Raman spectroscopy. The XRD measurements showed that the PbSe NPs have the face-centered cubic phase structure. The crystal size was found to be between 14 and 20 nm as calculated from the XRD patterns and these values were corroborated with SEM and TEM. Additionally, HRTEM micrographs showed crystalline planes at (200), (220) and (111) of the PbSe NPs, in agreement with the XRD results.

Follicular dynamics, interval to ovulation and fertility after AI in short-term progesterone and PGF2α oestrous synchronization protocol in sheep

The study was aimed to assess the influence that short-term progesterone treatments have on follicular dynamics, oestrus and ovulation in sheep. The treatment was tested thereafter in a field trial to assess its fertility after AI with fresh semen. In a first experiment, 12 ewes without CL were grouped to receive a new (n = 6) or used CIDR (n = 6) for 7 days and blood samples were obtained to follow plasma progesterone profiles. In a second experiment, 39 cycling ewes were synchronized by a 7-day P4+PGF2α protocol using a new (n = 20) or a 7-day used CIDR (n = 19). Half of both groups received 400 IU eCG and half remained untreated as controls. Ultrasound ovarian examination and oestrous detection were used to compare follicular dynamics, oestrus and ovulation in both groups. In a third experiment, 288 ewes in 3 farms were synchronized by the short-term P4+PGF2α+eCG protocol and ewes were AI with fresh semen 24 h after oestrous detection. Lambing performance was used to test the fertility of the treatment. In Experiment 1, ewes with new inserts presented higher P4 concentration than ewes with used inserts throughout the sampling period (p < 0.05) and exhibited a P4 peak at days 1-2 of the treatment that was not observed in ewes with used inserts. In Experiment 2, ewes treated with new and used inserts show similar ovarian and behavioral traits (p > 0.10). However, ewes treated with eCG show shorter interval to oestrus (p = 0.004) and tend to have larger mature CL (p = 0.06). In Experiment 3, oestrous presentation and lambing performance after AI with fresh semen was considered normal compared to published results. Results suggest that the oestrous synchronization protocol based on P4+PGF2α allows little control of follicular dynamics without compromising fertility after AI with fresh semen provided that eCG is added at the end of the treatment.

Tumour CD133 mRNA expression and clinical outcome in surgically resected colorectal cancer patients

BACKGROUND

Human prominin-1 (CD133) is a novel pentaspan membrane protein which was originally classified as a marker of primitive haematopoietic and neural stem cells. Cancer stem cells have been isolated and expanded from leukaemia and several solid tumours, and have been associated with metastasis, chemoresistance and relapse. CD133 is recognised as a stem cell marker and is capable of identifying a tumour-initiating subpopulation in brain, colon, melanoma and other solid tumours.

METHODS

We assessed CD133 mRNA expression levels by RT-QPCR in tumour and matched normal tissue from 64 stages I-III colorectal cancer (CRC) patients and correlated tumour CD133 levels with clinicopathological characteristics and clinical outcome.

RESULTS

In four patients, CD133 mRNA was not expressed in tumour or in normal tissue. In the remaining 60 patients, expression levels were higher in tumour than in normal tissue (p=0.001). Higher levels of CD133 expression were associated with shorter relapse-free interval (RFI) (p=0.004) and overall survival (OS) (p<0.0001). In the multivariate analyses, CD133 levels emerged as a prognostic marker for RFI and OS.

CONCLUSIONS

We have observed longer RFI and OS in patients with lower levels of CD133, regardless of adjuvant treatment and other clinical characteristics. If these findings are confirmed in larger prospective studies, CD133 assessment may prove useful for new diagnostic and therapeutic procedures for CRC patients.

[Study of effectiveness of craving control with topiramate in patients with substance dependence disorders]

INTRODUCTION

Effectiveness and tolerability of topiramate at 3 and 6 months was assessed in patients requesting dehabituation programs.

METHODS

Observational, prospective, national and multicenter study of 6 months, in patients on treatment with topiramate, who fulfilled criteria for dependence of opiates according to ICD-10 participating in therapeutic programs of dehabituation, without concomitant psychiatric illnesses and any responsible relative. Main measures of effectiveness were retention rates, alcohol consumption and other illicit drugs by urine tests (opiates, cannabis, cocaine) and treatment needs by EuropASI scale. Other parameters were HAM-D, DAS-SV and SF-36.

RESULTS

Patients with consumption by urine tests decreased from 94.1 % (n = 64) at baseline to 39.6 % (n = 19) after 6 months of treatment, as was seen by means of the mean score in EuropASI scale, for all substances except methadone. No consumption was accompanied by a low rate of relapse of 33.3 % at 6 months. Twenty one patients had adverse reactions (28 %). The most frequent adverse reactions were somnolence (n = 9; 12 %), paraesthesia (n = 5; 6.7 %) and depression (n = 4; 5.3 %).

CONCLUSIONS

In real clinical practice, topiramate showed a good response with a relevant decrease of percent of patients with abuse or consumption, and a satisfactory tolerability profile for the treatment of patients with dependence on heroine, cocaine, and other opiates, showing better outcomes than those obtained in previous trials.

Antigen recognition characteristics and comparative performance in immunoaffinity purification of two monoclonal antibodies specific for the hepatitis B virus surface antigen

In this paper we describe the antigen recognition characteristics, variable region base and amino acid sequence, and performance as immunoaffinity chromatography ligands of two MAb specific to the alpha determinant of the HBsAg, derived from the same fusion. We show that the epitope recognized by CB-Hep.0 (IgM) is probably associated to an intrachain disulfide bond in the antigen. On the other hand, CB-Hep.1 (IgG2b) recognizes a heat-resistant non-conformation dependent antigenic determinant on HBsAg. PCR-cloning and sequencing of the variable regions of these two MAb indicated that both heavy chain variable regions were originated from the usage of the same germinal V and J genes. However, the outstanding differences in the size of the VH CDR3, and the absolute difference in the light chain sequences, suggest that the hybridomas were originated from different precursor B lymphocytes. With respect to their use as immunoaffinity chromatography ligands for the purification of a recombinant HBsAg, we found that the IgM immunogel exhibited increased performance with respect to amount of eluted antigen, and final recovery. This difference in overall performance could be attributed to a series of factors: the higher valence number of IgM, a dissimilar distribution of IgM and IgG in the activated gel particles, and differences in antigen recognition between both MAb. Our results suggest that IgM antibodies may be useful in immunopurification, particularly if the antigen is structurally complex and has a high density of repeating epitopes.

Plasma progesterone levels during the estrous cycle of Holstein and Brahman cows, Carora type and cross-bred heifers

Daily plasma progesterone (P(4)) was determined during one estrous cycle of 19 cows and 18 heifers of four different breeds: Holstein (H), Brahman (B), Carora-type (C) and crossbred (CB) females. Estrus detection was made by visual observation and using a teaser bull with a chin-ball marker. The P(4) profiles showed no differences among groups. In Group 1 (H), P(4) levels ranged from 0.5 ng/ml plasma on the day of estrus (Day 0) to 5.1 ng/ml at the luteal phase peak (Day 13). In Group 2 (B), P(4) levels ranged from 0.5 ng/ml on Day 0 to 9.2 ng/ml on Day 13. In Groups 3 (C) and 4 (CB), P(4) levels ranged from 0.5 ng/ml, on Day 0, to 13.7 ng/ml on Day 12 and 8.8 ng/ml on Day 13. These last two groups were moved to the same location and then compared. It was found that P(4) concentrations were significantly higher (P < 0.025) in Group 3 between Days 7 and 14 of the estrous cycle. In all groups, P(4) levels were lower than 1 ng/ml one day before the next estrus, and levels of 0.4, 0.5, 0.4 and 0.4 ng/ml were obtained the day of estrus in Groups 1 to 4, respectively. Results indicated that the pattern of P(4) for each one of the groups was similar to those reported by other investigators.