Automatic in-syringe dispersive liquid-liquid microextraction of ⁹⁹Tc from biological samples and hospital residues prior to liquid scintillation counting

A new approach exploiting in-syringe dispersive liquid-liquid microextraction (DLLME) for (99)Tc extraction and preconcentration from biological samples, i.e., urine and saliva, and liquid residues from treated patients is presented. (99)Tc is a beta emitter with a long half-life (2.111 × 10(5) years) and mobility in the different environmental compartments. One of the sources of this radionuclide is through the use of its father (99m)Tc in medical diagnosis. For the first time a critical comparison between extractants and disperser solvents for (99)Tc DLLME is presented, e.g., tributyl phosphate (TBP), trioctylmethylammonium chloride (Aliquat®336), triisooctylamine (TiOA), as extractants in apolar solvents such as xylene and dodecane, and disperser solvents such as acetone, acetonitrile, ethanol, methanol, 1-propanol, and 2-propanol. The system was optimized by experimental design, and 22.5% of Aliquat®336 in acetone was selected as extractant and disperser, respectively. Off-line detection was performed using a liquid scintillation counter. The present method has a (99)Tc minimum detectable activity (MDA) of 0.075 Bq with a high extraction/preconcentration frequency (8 h(-1)). Urine, saliva, and hospital residues were satisfactorily analyzed with recoveries of 82-119%. Thus, the proposed system is an automatic powerful tool to monitor the entry of (99)Tc into the environment. Graphical Abstract (99m)Tc is widely used in Nuclear Medicine for diagnosis. Its daugther (99)Tc is automatically monitored in biological samples from treated patients by in-syringe dispersive liquid-liquid microextraction.

Automation of ⁹⁹Tc extraction by LOV prior ICP-MS detection: application to environmental samples

A new, fast, automated and inexpensive sample pre-treatment method for (99)Tc determination by inductively coupled plasma-mass spectrometry (ICP-MS) detection is presented. The miniaturized approach is based on a lab-on-valve (LOV) system, allowing automatic separation and preconcentration of (99)Tc. Selectivity is provided by the solid phase extraction system used (TEVA resin) which retains selectively pertechnetate ion in diluted nitric acid solution. The proposed system has some advantages such as minimization of sample handling, reduction of reagents volume, improvement of intermediate precision and sample throughput, offering a significant decrease of both time and cost per analysis in comparison to other flow techniques and batch methods. The proposed LOV system has been successfully applied to different samples of environmental interest (water and soil) with satisfactory recoveries, between 94% and 98%. The detection limit (LOD) of the developed method is 0.005 ng. The high durability of the resin and its low amount (32 mg), its good intermediate precision (RSD 3.8%) and repeatability (RSD 2%) and its high extraction frequency (up to 5 h(-1)) makes this method an inexpensive, high precision and fast tool for monitoring (99)Tc in environmental samples.

Is nuchal translucency a useful aneuploidy marker in fetuses with crown-rump length of 28-44 mm?

OBJECTIVE

To investigate whether increased nuchal translucency (NT) in fetuses with a crown-rump length (CRL) below 45 mm needs to be re-evaluated at a later stage, or whether the early NT measurement can be used effectively as an aneuploidy marker.

METHODS

This was a prospective cohort study including all singleton fetuses with a CRL between 28 and 44 mm, scanned in our center during 2002-2012. The CRL, NT, fetal karyotype (when available) and pregnancy outcome were recorded. NT reference ranges were constructed using the Lambda-Mu-Sigma (LMS) method in non-referred pregnancies after exclusion of chromosomal anomalies. The 95(th) percentile was used to calculate detection rates for chromosomally abnormal fetuses.

RESULTS

NT was successfully measured in 643 of 672 fetuses with a CRL of 28-44 mm. Subsequent cytogenetic analysis revealed 11 cases of trisomy 21, 14 cases of trisomy 13 or 18, three cases of monosomy X, three sex trisomies, three triploidies and 12 balanced anomalies. NT was above the 95(th) percentile in 64% of the fetuses with trisomy 21, in 71% with trisomy 13 or 18 and in all three cases of monosomy X.

CONCLUSION

NT appears to be useful as a marker for the early detection of fetal trisomies at 9-10 weeks' gestation (28-44 mm CRL).

Who are the men who have sex with men in Spain that have never been tested for HIV?

OBJECTIVES

The aims of the study were to describe the sociodemographic profile of men who have sex with men (MSM) who have never been tested for HIV and to analyse factors associated with never having been tested.

METHODS

The European MSM Internet Survey (EMIS) was implemented in 2010 in 38 European countries on websites for MSM and collected data on sociodemographics, sexual behaviour, and other sexual health variables. A logistic regression analysis was conducted to assess variables associated with never having been tested for HIV.

RESULTS

Of the 13,111 respondents living in Spain, 26% had never been tested for HIV. Those who had never been tested were significantly more likely to live in a settlement with fewer than 100,000 inhabitants, be younger than 25 years old, have a lower education level, be a student, and identify themselves as bisexual. In the multivariate analysis, to have never been tested for HIV was associated with being born in Spain [odds ratio (OR) 1.35; 95% confidence interval (CI) 1.192-1.539], living outside large settlements (OR 1.37; 95% CI 1.216-1.534), being younger than 25 years old (OR 2.94; 95% CI 2.510-3.441), being out to no one or only a few people (OR 2.16; 95% CI 1.938-2.399), having had no nonsteady partners in the last 12 months (OR 1.26; 95% CI 1.109-1.422), and being not at all confident to access HIV testing (OR 3.66; 95% CI 2.676-5.003), among others factors.

CONCLUSIONS

The profile of the MSM who had never been tested for HIV indicates that most of them were men who were hard to reach (young, bisexual men, in the closet). Interventions should aim to improve access to and the convenience of testing.

The development, feasibility and acceptability of an Internet-based STI-HIV prevention intervention for young Chilean women

BACKGROUND

Young Chilean women between 18 and 24 years of age are at high risk of contracting sexually transmitted infection (STI) and human immunodeficiency virus (HIV). The literature shows a shortage of STI-HIV prevention interventions focused on this specific high-risk population and a unique set of barriers to receiving prevention messages. Internet-based interventions are promising for delivering STI-HIV prevention interventions and avoiding barriers to services.

AIMS

The study aimed to develop a culturally informed Internet-based STI-HIV prevention intervention for Chilean women between 18 and 24 years of age, to investigate its feasibility and acceptability, and to compile recommendations on what would make the intervention more acceptable and feasible for these women.

METHODS

The development of the Internet intervention was facilitated by a process that featured consultation with content and technology experts. A pre-post test design was used to test the acceptability and feasibility of the intervention with 40 young Chilean women between 18 and 24 years of age.

RESULTS

The intervention website consisted of four modules of content and activities that support learning. The intervention was feasible and acceptable for young Chilean women between 18 and 24 years of age.

DISCUSSION AND CONCLUSION

This study demonstrated the value of engaging multiple expert panels to develop culturally informed and technology-based interventions. The results of this study support the feasibility and acceptability of conducting an Internet-based intervention with multiple sessions, yielding high participation rates in a population in which there are barriers to discussion of STI-HIV prevention and sex-related content.

IMPLICATIONS FOR NURSING AND HEALTH POLICY

The outcomes have implications for nursing education and clinical practice and they can be used for the legal and judicial systems to promote or reinforce policies that encourage STI-HIV prevention strategies among women.

On-line monitoring of the photocatalytic degradation of 2,4-D and dicamba using a solid-phase extraction-multisyringe flow injection system

A fully automated on-line system for monitoring the photocatalytic degradation of herbicides was developed using multisyringe flow injection analysis (MSFIA) coupled to a solid phase extraction (SPE) unit with UV detection. The calibration curves were linear in the concentration range of 100-1000 μg L(-1) for 3,6-dichloro-2-methoxybenzoic acid (dicamba) and 500-3000 μg L(-1) for 2,4-dichlorophenoxyacetic acid (2,4-D), while the detection limits were 30 and 135 μg L(-1) for dicamba and 2,4-D, respectively. The monitoring of the photocatalytic degradation (TiO2 anatase/UV 254 nm) of these two herbicides was performed by MSFIA-SPE system using a small sample volume (2 mL) in a fully automated approach. The degradation was assessed in ultrapure and drinking water with initial concentrations of 1000 and 2000 μg L(-1) for dicamba and 2,4-D, respectively. Degradation percentages of approximately 85% were obtained for both herbicides in ultrapure water after 45 min of photocatalytic treatment. A similar degradation efficiency in drinking water was observed for 2,4-D, whereas dicamba exhibited a lower degradation percentage (75%), which could be attributed to the presence of inorganic species in this kind of water.

Superficial necrolytic dermatitis in a dog with an insulin-producing pancreatic islet cell carcinoma

A 10-year-old dog presented with convulsive crisis and symmetrical hyperkeratotic cutaneous lesions affecting the abdomen, inguinal area, eyelids, muzzles, both pinnae, and all the paw pads. Hypoglycemia and hyperinsulinemia were the main biochemical findings. A mass 2 cm in diameter was detected within the left pancreatic lobe by ultrasonography. It was surgically removed and histologically and immunohistochemically diagnosed as an insulin-producing pancreatic islet cell carcinoma. The animal was eventually euthanized due to lack of clinical improvement. At necropsy, metastatic nodules were observed in the pancreatic lymph nodes and liver. Histopathological findings of cutaneous lesions were highly suggestive of superficial necrolytic dermatitis and were interpreted as a paraneoplastic syndrome derived from the islet cell carcinoma. To the authors' knowledge, this is the first report of superficial necrolytic dermatitis associated with an insulin-producing pancreatic neuroendocrine carcinoma in dogs.

Automated method for simultaneous lead and strontium isotopic analysis applied to rainwater samples and airborne particulate filters (PM10)

A new automated, sensitive, and fast system for the simultaneous online isolation and preconcentration of lead and strontium by sorption on a microcolumn packed with Sr-resin using an inductively coupled plasma mass spectrometry (ICP-MS) detector was developed, hyphenating lab-on-valve (LOV) and multisyringe flow injection analysis (MSFIA). Pb and Sr are directly retained on the sorbent column and eluted with a solution of 0.05 mol L(-1) ammonium oxalate. The detection limits achieved were 0.04 ng for lead and 0.03 ng for strontium. Mass calibration curves were used since the proposed system allows the use of different sample volumes for preconcentration. Mass linear working ranges were between 0.13 and 50 ng and 0.1 and 50 ng for lead and strontium, respectively. The repeatability of the method, expressed as RSD, was 2.1% and 2.7% for Pb and Sr, respectively. Environmental samples such as rainwater and airborne particulate (PM10) filters as well as a certified reference material SLRS-4 (river water) were satisfactorily analyzed obtaining recoveries between 90 and 110% for both elements. The main features of the LOV-MSFIA-ICP-MS system proposed are the capability to renew solid phase extraction at will in a fully automated way, the remarkable stability of the column which can be reused up to 160 times, and the potential to perform isotopic analysis.

Comparisons of dosimetric approaches for fractionated radioimmunotherapy of non-Hodgkin lymphoma

AIM

The aim of this study was to compare different dosimetric approaches on therapy naïve patients enrolled in a multicentre fractionated radioimmunotherapy trial, to determine which methodological approach correlates with bone marrow toxicity.

METHODS

Twenty-height non-Hodgkin lymphoma patients were treated with one or two fractions of 90Y-Ibritumomab-Tiuxetan (11.1 MBq/kg) 8 to 12 weeks apart in four different institutions. Quantitative imaging with 111In-Ibritumomab-Tiuxetan (185 MBq) was performed at 0, 1, 4 and 7 days after infusion, starting two weeks before the therapeutic administration. A whole-body (WB) CT scan was also acquired prior to the 111In-Ibritumomab injection, for attenuation correction purposes and was segmented to derive patient-specific organ masses. All dosimetry processing was centralized in a single institution. The first method (M_2D) was based on geometric mean WB scans, corrected for attenuation, scatter and organs superposition. The second method (M_2.5D) was based on the computed assisted matrix inversion approach and used segmented CT scans. The third method (M_3D) used iterative reconstruction of tomographic scans, corrected for attenuation, scatter and collimator response. Absorbed doses were estimated for lungs, liver, kidneys and spleen using MIRD S values adjusted for organ masses. Bone marrow (BM) absorbed doses were evaluated according to imaging methods (3) and compared to blood-based approaches.

RESULTS

For some patients, organ masses such as liver or spleen significantly differed from male/female reference masses, whereas lungs and kidneys masses were relatively constant. Except for lungs, absorbed doses estimated by M_2D were higher than those from M_2.5D and these, in turn, were higher that those calculated from M_3D (Wilcoxon P<8.6e-4). Median organ absorbed dose estimates were equivalent for both fractions except for the spleen. In fact, spleen absorbed doses for the second fraction were lower than those for the first fraction, regardless of the approach. Possible explanations are that patient spleen masses were kept constant for analysis of both fractions and/or that spleen uptake was lowered after the first fraction. Estimation of BM absorbed doses from blood sampling was unable to predict platelet toxicity, but image-based methods performed better. Additionally, for most organs, the absorbed dose delivered by the first fraction could predict that delivered by the second fraction.

CONCLUSION

These results confirm that different acquisition/processing protocols will lead to statistically different absorbed doses. Additionally, image-based dosimetric approaches are needed in order to correlate absorbed dose to bone marrow toxicity.

A multisyringe flow injection method for the automated determination of sulfide in waters using a miniaturised optical fiber spectrophotometer

In this paper, a fully software-controlled multisyringe flow injection (MSFIA) spectrophotometric system is proposed for the determination of sulfide in environmental and waste waters. The implementation of ancillary solenoid valves into the flow network allows a multitude of injection modalities to be explored, the selected modality being directly dependent on the aim of the assays. The multicommuted sandwich-type approach is introduced in this work as an efficient means to warrant high sensitivity for the particular assay with excellent repeatabilities and a considerable reagent saving. Moreover, a high injection frequency may be easily attained by carrying out a multiple injection modality during a single forward displacement of the piston driver bar. The interfacing of the robust and versatile multisyringe piston pump with an optical fiber plug-in spectrophotometer furnished with a light emitting diode enables the miniaturization of the flow analyzer, which is thus readily adaptable to in-situ and real-time monitoring schemes. The flow method is based on the coupling Fischer's reaction of sulfide with N,N-dimethyl-p-phenylenediamine in the presence of Fe(III) as oxidizing reagent in a 0.7M HCl medium. Careful selection of the physical and chemical variables enabled coefficients of variations better than 1.5% (n = 10) at the 1mgl(-1) level for both injection modalities. Dynamic working ranges of 0.2-2.0 and 0.5-5mgl(-1) sulfide for sandwich and multiple injection techniques, and detection limits of 0.09 and 0.15mgl(-1), respectively, were obtained. Furthermore, the sandwich modality featured an average slope of 0.43 +/- 0.02lmg(-1) calculated from 10 day-to-day calibration plots. This result reveals better sensitivity than other flowing stream methods described in the literature. The multiple injection technique allowed an improvement of the injection throughput up to 80h(-1), although a decrease of sensitivity was concomitantly observed (average slope of 0.17 +/- 0.01lmg(-1)). The multisyringe flow method was successfully applied to the determination of sulfide in different spiked water matrices (namely, mineral, tap, freshwater, seawater and wastewater) with recoveries ranging from 96 to 104%. Good agreement was also found in water samples between the MSFIA results and those of the batch APHA-standard method.

Automated system for on-line determination of dimethylarsinic and inorganic arsenic by hydride generation-atomic fluorescence spectrometry

A multisyringe flow-injection approach has been coupled to hydride generation-atomic fluorescence spectrometry (HG-AFS) with UV photo-oxidation for dimethylarsinic (DMA), inorganic As and total As determination, depending on the pre-treatment given to the sample (extraction or digestion). The implementation of a UV lamp allows on-line photo-oxidation of DMA and the following arsenic detection, whereas a bypass leads the flow directly to the HG-AFS system, performing inorganic arsenic determination. DMA concentration is calculated by the difference of total inorganic arsenic and measurement of the photo-oxidation step. The detection limits for DMA and inorganic arsenic were 0.09 and 0.47 μg L(-1), respectively. The repeatability values accomplished were of 2.4 and 1.8%, whereas the injection frequencies were 24 and 28 injections per hour for DMA and inorganic arsenic, respectively. This method was validated by means of a solid reference material BCR-627 (muscle of tuna) with good agreement with the certified values. Satisfactory results for DMA and inorganic arsenic determination were obtained in several water matrices. The proposed method offers several advantages, such as increasing the sampling frequency, low detection limits and decreasing reagents and sample consumption, which leads to lower waste generation.