Usos y limitaciones de la lámpara ultravioleta germicida portátil para la desinfección de superficies

RESUMENLa morbimortalidad causada por infecciones vinculadas a la atención sanatoria ha llevado a cuestionar si los métodos de desinfección convencionales son inadecuados y se requieren métodos complementarios, como la fumigación de la habitación y la irradiación ultravioleta. Ello ha dado lugar a la preocupación por que estos métodos alternativos puedan poner en riesgo al personal sanitario y a los pacientes.Objetivos. (1) Determinar la eficacia de la lámpara ultravioleta C germicida portátil para la desinfección de superficies, (2) evaluar el cambio de la humedad relativa (HR) y las distintas distancias específicas en las tasas de letalidad bacteriana, y (3) evaluar los posibles problemas a que conlleva la exposición.Métodos. En el presente estudio se investiga si una lámpara germicida portátil puede desinfectar de forma eficaz superficies tratadas con esporulación o germinación bacteriana y se evalúa el efecto de condiciones ambientales cambiantes, como la humedad relativa (HR), la posición y las distancias específicas, en las tasas de letalidad germicida.Resultados. Se constató una mejor tasa de letalidad con una HR de 40-65% y en un rango de temperatura de 21-24°C. Tanto la HR alta como la HR baja interfirieron con la capacidad de la radiación UV-C para inactivar la germinación microbiana. En el caso de la esporulación bacteriana, el aumento del secado de la superficie fue el factor de mayor importancia para aumentar la tasa de letalidad.Conclusiones. En esta investigación se demostró la eficacia de la radiación UV-C bajo condiciones óptimas, irradiación directa y una distancia específica corta (12.7 cm). Sin embargo, cuando es utilizada en condiciones que no son óptimas existen limitaciones. El aumento de la distancia y los ángulos de irradiación indirecta resultaron en tasas de letalidad más bajas. Cabe señalar que durante su uso es importante minimizar la exposición innecesaria de pacientes y personal sanitario.

Common genetic susceptibility loci link PFAPA syndrome, Behçet's disease, and recurrent aphthous stomatitis

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is the most common periodic fever syndrome in children. The disease appears to cluster in families, but the pathogenesis is unknown. We queried two European-American cohorts and one Turkish cohort (total n = 231) of individuals with PFAPA for common variants previously associated with two other oropharyngeal ulcerative disorders, Behçet's disease and recurrent aphthous stomatitis. In a metaanalysis, we found that a variant upstream of IL12A (rs17753641) is strongly associated with PFAPA (OR 2.13, P = 6 × 10-9). We demonstrated that monocytes from individuals who are heterozygous or homozygous for this risk allele produce significantly higher levels of IL-12p70 upon IFN-γ and LPS stimulation than those from individuals without the risk allele. We also found that variants near STAT4, IL10, and CCR1-CCR3 were significant susceptibility loci for PFAPA, suggesting that the pathogenesis of PFAPA involves abnormal antigen-presenting cell function and T cell activity and polarization, thereby implicating both innate and adaptive immune responses at the oropharyngeal mucosa. Our results illustrate genetic similarities among recurrent aphthous stomatitis, PFAPA, and Behçet's disease, placing these disorders on a common spectrum, with recurrent aphthous stomatitis on the mild end, Behçet's disease on the severe end, and PFAPA intermediate. We propose naming these disorders Behçet's spectrum disorders to highlight their relationship. HLA alleles may be factors that influence phenotypes along this spectrum as we found new class I and II HLA associations for PFAPA distinct from Behçet's disease and recurrent aphthous stomatitis.

Infusing CURE Into the Medical Laboratory Science Curriculum

Introduction

One of the challenges for Medical Laboratory Science (MLS) educators in a university-based program can be providing meaningful research experiences for all students. The availability of research positions for undergraduate MLS students in individual research labs is limited or not available, often due to time constraints within the MLS course schedule or other variables in the students’ lives outside of academe.

Methods

This study introduced a CURE (course-based undergraduate research experience) into a junior-level MLS microbiology course, where all students in the junior cohort participated in the same research agenda during the same semester. The objective was to provide equal access and an equitable experience for each MLS student in the cohort. The research question was determined with input from students and instructors and had application within the microbiology course where it was being infused. The study protocol was designed during class time and most tasks were completed in class as well. From a pedagogical perspective, the CURE model is designed around five basic parameters, including (1) use of multiple scientific practices, (2) the outcome is unknown, (3) there is a broader relevance or importance beyond this classroom experience, (4) collaboration is essential among students and instructors, and (5) iteration is built into the process.

Conclusion

We found this CURE resulted in useful data for both students and other outside stakeholders. This differs from basic inquiry models where students participate in the protocol, including interpretation of the data, but the answer or outcomes are already known by the instructors. While the learning curve for students and instructors can be steep when infusing a CURE into an already heavy content course, the rewards of providing equal access and an equitable experience for the entire cohort are well worth the additional time spent preparing for this challenge.

The uses and limitations of a hand-held germicidal ultraviolet wand for surface disinfection

The morbidity and mortality from healthcare associated infections has raised concern that conventional disinfection methods are inadequate and that other adjunct methods such as room fumigation and ultraviolet irradiation may be needed. There is also concern that these alternative methods may pose a risk to workers and patients.

OBJECTIVES

(1) Determine the efficacy of a germicidal UV-C wand for surface disinfection, (2) evaluate changing relative humidity (RH) and different target distances on bacteria kill rates, and (3) assess potential exposure concerns.

METHODS

This study investigates whether a hand-held germicidal wand can efficaciously disinfect surfaces treated with either a vegetative or spore forming bacterium and to evaluate the effect of changing environmental conditions such as relative humidity (RH), target position, and target distances on microbial kill rates.

RESULTS

Kill rate was best at 40-65% RH at a temperature range of 21-24°C. Both high and low RH interfered with the ability of UV-C to kill the vegetative microbe. In the case of the spore forming bacterium, increased surface drying time was the most significant factor increasing kill rate.

CONCLUSIONS

This research demonstrates that UV-C was efficacious under optimal conditions, a direct beam exposure, and a short target distance (12.7 cm). However, there are limitations when used in non-optimal conditions. Increased distance and indirect beam angles resulted in lower kill rates. It is also important to minimize unnecessary patient and worker exposure during its use.

Microarray-based gene expression profiling in patients with cryopyrin-associated periodic syndromes defines a disease-related signature and IL-1-responsive transcripts

OBJECTIVE

To analyse gene expression patterns and to define a specific gene expression signature in patients with the severe end of the spectrum of cryopyrin-associated periodic syndromes (CAPS). The molecular consequences of interleukin 1 inhibition were examined by comparing gene expression patterns in 16 CAPS patients before and after treatment with anakinra.

METHODS

We collected peripheral blood mononuclear cells from 22 CAPS patients with active disease and from 14 healthy children. Transcripts that passed stringent filtering criteria (p values≤false discovery rate 1%) were considered as differentially expressed genes (DEG). A set of DEG was validated by quantitative reverse transcription PCR and functional studies with primary cells from CAPS patients and healthy controls. We used 17 CAPS and 66 non-CAPS patient samples to create a set of gene expression models that differentiates CAPS patients from controls and from patients with other autoinflammatory conditions.

RESULTS

Many DEG include transcripts related to the regulation of innate and adaptive immune responses, oxidative stress, cell death, cell adhesion and motility. A set of gene expression-based models comprising the CAPS-specific gene expression signature correctly classified all 17 samples from an independent dataset. This classifier also correctly identified 15 of 16 post-anakinra CAPS samples despite the fact that these CAPS patients were in clinical remission.

CONCLUSIONS

We identified a gene expression signature that clearly distinguished CAPS patients from controls. A number of DEG were in common with other systemic inflammatory diseases such as systemic onset juvenile idiopathic arthritis. The CAPS-specific gene expression classifiers also suggest incomplete suppression of inflammation at low doses of anakinra.

Familial Mediterranean fever with a single MEFV mutation: where is the second hit?

OBJECTIVE

Familial Mediterranean fever (FMF) has traditionally been considered an autosomal-recessive disease; however, it has been observed that a substantial number of patients with clinical FMF possess only 1 demonstrable MEFV mutation. The purpose of this study was to perform an extensive search for a second MEFV mutation in 46 patients diagnosed clinically as having FMF and carrying only 1 high-penetrance FMF mutation.

METHODS

MEFV and other candidate genes were sequenced by standard capillary electrophoresis. In 10 patients, the entire 15-kb MEFV genomic region was resequenced using hybridization-based chip technology. MEFV gene expression levels were determined by quantitative reverse transcription-polymerase chain reaction. Pyrin protein levels were examined by Western blotting.

RESULTS

A second MEFV mutation was not identified in any of the patients who were screened. Haplotype analysis did not identify a common haplotype that might be associated with the transmission of a second FMF allele. Western blots did not demonstrate a significant difference in pyrin levels between patients with a single mutation and those with a double mutation; however, FMF patients of both types showed higher protein expression as compared with controls and with non-FMF patients with active inflammation. Screening of genes encoding pyrin-interacting proteins identified rare mutations in a small number of patients, suggesting the possibility of digenic inheritance.

CONCLUSION

Our data underscore the existence of a significant subset of FMF patients who are carriers of only 1 MEFV mutation and demonstrate that complete MEFV sequencing is not likely to yield a second mutation. Screening for the set of the most common mutations and detection of a single mutation appears to be sufficient in the presence of clinical symptoms for the diagnosis of FMF and the initiation of a trial of colchicine.

Migration, remittances, and inequality: estimating the net effects of migration on income distribution

"This paper examines the net effects of migration and remittances on income distribution. Potential home earnings of migrants are imputed, as are the earnings of non-migrants in migrant households, in order to construct no-migration counterfactuals to compare with the observed income distribution including remittances. The earnings functions used to impute migrant home earnings are estimated from observations on non-migrants in a selection-corrected estimation framework which incorporates migration choice and labor-force participation decisions. For a sample of households in Bluefields, Nicaragua, migration and remittances increase income inequality when compared with the no-migration counterfactual."

The "nest"--neurological environment for safe therapeutics

How to manage neurologically impaired patients is a challenge we all face. Lions Gate Hospital in North Vancouver, B.C. successfully developed a padded environment for confused, restless, and agitated patients. The following article describes how patients are managed without restraints in a safe environment.