The Effect of Short-Term Exposure to Cadmium on the Expression of Vascular Endothelial Barrier Antigen in the Developing Rat Forebrain and Cerebellum: A Computerized Quantitative Immunofluorescent Study.

Clinical and laboratory studies have shown that environmental exposure to cadmium produces damage to several organs, including bones, lungs, and kidneys. The involvement of cadmium in central nervous system (CNS) disorders has also been widely reported, but the precise pathophysiological mechanism is not yet fully understood. Children who were exposed to cadmium during pregnancy are known to suffer from developmental delays, learning difficulties, attention deficit hyperactivity disorder (ADHD), and other cognitive and neurobehavioral deficits. Results from numerous studies suggest that dysfunction of the blood-brain barrier (BBB) structures is an important step in the neurotoxicity of cadmium. A rat-specific BBB marker protein, the endothelial barrier antigen (EBA), has been previously isolated and classified by Sternberger and others. The mouse IgG1 clone, anti-endothelial barrier antigen (anti-EBA), detects a protein triplet (23.5kDa, 25 kDa, and 30kDa) localized to the luminal surface of central and peripheral nervous system (CNS and PNS) vascular endothelial cells with selective permeability barrier functions. This marker has been widely used for characterizing BBB alterations under demyelinating, inflammatory, and other CNS pathologies. Many studies have been published using the rat model system for studying the neurotoxic effect of acute and chronic exposure to cadmium. We applied the indirect immunofluorescent techniques using the anti-EBA antibody in conjunction with the Olympus cellSens computerized image analysis to detect and quantify the surface areas of BBB-competent microvessel profiles in paraformaldehyde-fixed, paraffin-embedded brains of term-delivered young rats after intraperitoneal injection of a single dose of cadmium chloride. We detected a statistically significant reduction in EBA-positive microvessel surface areas in the forebrain (t = 5.86, df = 1789, p-value < 0.001) and cerebellum (t=73.40, df=1337, p < 0.001) of cadmium-treated rats compared to the normal controls. Thus, this study supports the hypothesis that the EBA is a sensitive and measurable indicator for quantitative assessment of the impact of cadmium exposure in the developing rat brain.

Effects of classroom cleaning on student health: a longitudinal study.

BACKGROUND: School districts across the world have been grappling with how to keep their schools open, students healthy, and prevent the spread of viruses in their communities. OBJECTIVE: The aims of this study included assessing both (1) the effectiveness of enhanced classroom cleaning and disinfecting protocol on surface biocontamination and (2) the associations between surface biocontamination and student absence due to illnesses. METHODS: Cleaning effectiveness was assessed using quantitative adenosine triphosphate (ATP) measurements during a 10-week study period in a sample of 34 public schools (15,814 students), of a district located in the Western US. The schools were randomly assigned to 17 intervention schools implementing enhanced cleaning and disinfecting protocol and 17 control schools cleaning as usual. General estimating equations (GEEs) were used for modeling associations between ATP levels and weekly aggregates of student absences due to respiratory and gastrointestinal illnesses, which were recorded by the schools according to district wide protocol. RESULTS: The weekly average ATP levels on logarithmic scale were 5.02 (SD 0.53) and 5.26 (SD 0.48) in the intervention and control schools, respectively, where the difference is statistically significant (p < 0.001). The probability of weekly absence due to gastrointestinal illness was significantly associated with ATP levels (parameter estimate 1.16, 95% CI 1.01-1.34, per unit (log) increase of weekly average ATP), where the model accounts for student level, gender, ethnic group, and socioeconomic status as well as for school level attendance, total absence ratio, and ventilation adequacy in classrooms. Associations were not found between ATP levels and weekly probability of any absence, or absence due to respiratory illness. SIGNIFICANCE: Enhanced cleaning resulted in a significantly lower level of biocontamination on desktops in the intervention group. In addition, a statistically significant association was established between ATP levels on classroom desks and probability of absence due to gastrointestinal illness. IMPACT: We found that enhanced cleaning protocol, including bi-weekly cleaning of classroom desks, as well as training of custodians and teachers, monitoring of effectiveness, and feedback, yielded a moderate but statistically significantly lower level of biocontamination on desktops, indicated by quantitative ATP monitoring. Within the range of weekly average desktop ATP levels observed, the probability of reported absence due to gastrointestinal illness is estimated to increase from 0.021 to 0.026. Based on the results, enhanced surface cleaning and monitoring its effectiveness is a possible district, state, or even national level policy to support healthy school environments.

Occurrence of respiratory viruses on school desks.

BACKGROUND: Schools represent high occupancy environments and well-documented high-risk locations for the transmission of respiratory viruses. The goal of this study was to report on the area density, occurrence, and type of respiratory viruses on desks in primary school classrooms. METHODS: Quantitative reverse transcription polymerase chain reaction (qPCR) techniques were employed to measure nucleic acid area densities from a broad range of human adenoviruses and rhinoviruses, as well as coronavirus OC43, influenza A, and norovirus GI. Every two weeks, virus monitoring was conducted on the desks of four primary school classrooms in Colorado, USA, during the 2019 respiratory virus season. RESULTS: DNA and RNA from respiratory viruses and norovirus were recovered from more than 20% of the desks sampled; occurrence patterns that indicate a greater than 60% probability of encountering any virus, if more than five desks were occupied in a day. Rhinoviruses and adenoviruses were the most commonly detected viruses as judged by the composite of occurrence and number of gene copies recovered. Desktop adenosine triphosphate monitoring did not predict the recovery of viral genomic materials on desks. School desks can be commonly contaminated with respiratory viruses. CONCLUSIONS: Genomic surveys of the identity, distribution and abundance of human viruses on "high-touch" surfaces, can help inform risk assessments, design cleaning interventions, and may be useful for infection surveillance.

Variación fenotípica del erizo Eucidaris tribuloides (Cidaroida: Cidaridae) en el Corredor Arrecifal del Suroeste del Golfo de México

Introducción: La variación morfológica intraespecífica puede ser el resultado del desarrollo ontogénico, la variación genética o la heterogeneidad ambiental. En el último caso, los organismos están expuestos a diversas condiciones ambientales, lo que puede influir en el comportamiento y las adaptaciones morfológicas de las especies. Precisamente, el Corredor Arrecifal del Suroeste del Golfo de México (CASGM) está compuesto por arrecifes separados geográficamente que están expuestos a diferentes factores oceanográficos, así como atributos propios con múltiples variables ambientales. Por lo tanto, es posible encontrar diferencias morfológicas de las poblaciones de especies que se distribuyen en el corredor. Objetivo: Determinar la variación morfológica de la linterna de Aristóteles del erizo de mar Eucidaris tribuloides a lo largo del CASGM. Métodos: Se analizó la relación alométrica entre la altura de la linterna versus diámetro de la testa en 104 especímenes, también realizamos un análisis de covarianza para detectar diferencias alométricas entre grupos. Se analizó la variación de la forma de una rótula y una semipirámide de cada erizo de mar mediante morfometría geométrica. Resultados: Existen diferencias alométricas entre sistemas arrecifales. La forma de la rótula y semipirámide de los erizos de mar del norte son diferentes a los erizos del centro y el sur; sin embargo, no hubo diferencias de forma entre el centro y el sur. El tamaño centroide de la rótula y semipirámide de los erizos de mar del norte son significativamente más grandes que los del centro y el sur. Conclusiones: A lo largo del Corredor Arrecifal del Suroeste del Golfo de México, los individuos de E. tribuloides mostraron variación morfológica en sus estructuras analizadas, dichos resultados, pueden ser explicados por los gradientes latitudinales y ambientales del CASGM, además de los hábitos alimenticios de la especie y la disponibilidad del recurso alimenticio en el ambiente donde se establecen.

Introduction: Intraspecific morphological variation can be attributed to the result of genetic variation or influence of environmental heterogeneity. In the latter case, organisms are exposed to diverse environmental conditions which have an influence on their biological processes and can be seen reflected in the morphological adaptations of species. Indeed, Reef Corridor in the Southwest Gulf of Mexico (CASGM, in its Spanish acronym) is constituted of geographically separated reefs that are exposed to different large-scale oceanographic factors and show their own attributes with multiple environmental variables. Therefore, this can stimulate morphological variations of species populations that are distributed in this corridor. Objective: The aim of this study was to determine the morphological variation of the Aristotle's lantern of the sea urchin Eucidaris tribuloides along CASGM. Methods: The allometric relation between height of the Aristotle's lantern and diameter of the test of 104 specimens was analyzed, and we also used a covariance analysis to detect allometric differences between groups. Apart from that, the variation of the shape of a rotule and a demi-pyramid for each sea urchin were analyzed using geometric morphometry. Results: There are allometric differences among reef systems in the north, center and south of Veracruz. The shape of rotula and demi-pyramid of sea urchins of the north zone are different from the central and south area. However, there were no differences in shape between the center and the South area. The centroid size of rotula and demi-pyramid of the sea urchins of the North are larger than those in the center and the South. Conclusions: Along the Corridor of the Southwest of the Gulf of Mexico, specimens of E. tribuloides showed a morphological variation in their analyzed structures, these results can be explained by the geographical and environmental gradients of the CASGM, in addition to the feeding habits of E. tribuloides and the availability of the food resource in the habitat where they are established. As a stimulus to the morphological variation found in this research, the distance among the reef systems and the marine currents patterns are also considered.

Reduction of the background magnetic field inhibits ability of Drosophila melanogaster to survive ionizing radiation.

The effects of exposure to an environment where the background magnetic field (BMF) has been reduced were studied on wild-type Drosophila melanogaster by measuring its ability to survive a single exposure to ionizing radiation (IR) during its larval stage. The experimental design presented shows a timeframe, IR dose, and BMF parameters that will cause a significant and reproducible reduction of survival on this insect model. These results suggest that BMFs may play a fundamental role in the recovery or harm of a biological system that is exposed to single doses of IR.

Reduction of the Earth's magnetic field inhibits growth rates of model cancer cell lines.

Small alterations in static magnetic fields have been shown to affect certain chemical reaction rates ex vivo. In this manuscript, we present data demonstrating that similar small changes in static magnetic fields between individual cell culture incubators results in significantly altered cell cycle rates for multiple cancer-derived cell lines. This change as assessed by cell number is not a result of apoptosis, necrosis, or cell cycle alterations. While the underlying mechanism is unclear, the implications for all cell culture experiments are clear; static magnetic field conditions within incubators must be considered and/or controlled just as one does for temperature, humidity, and carbon dioxide concentration.

Molecular thermometry.

Conventional temperature measurements rely on material responses to heat, which can be detected visually. When Galileo developed an air expansion based device to detect temperature changes, Santorio, a contemporary physician, added a scale to create the first thermometer. With this instrument, patients' temperatures could be measured, recorded, and related to changing health conditions. Today, advances in materials science and bioengineering provide new ways to report temperature at the molecular level in real time. In this review, the scientific foundations and history of thermometry underpin a discussion of the discoveries emerging from the field of molecular thermometry. Intracellular nanogels and heat sensing biomolecules have been shown to accurately report temperature changes at the nanoscale. Various systems will soon provide the ability to accurately measure temperature changes at the tissue, cellular, and even subcellular level, allowing for detection and monitoring of very small changes in local temperature. In the clinic, this will lead to enhanced detection of tumors and localized infection, and accurate and precise monitoring of hyperthermia-based therapies. Some nanomaterial systems have even demonstrated a theranostic capacity for heat-sensitive, local delivery of chemotherapeutics. Just as early thermometry rapidly moved into the clinic, so too will these molecular thermometers.

Comparative treatment of alpha-amanitin poisoning with N-acetylcysteine, benzylpenicillin, cimetidine, thioctic acid, and silybin in a murine model.

STUDY OBJECTIVE: The foraging of wild mushrooms can be complicated by toxicity from several mushroom types. Amatoxin, a peptide contained in several mushroom species, accounts for the majority of severe mushroom poisonings by binding to RNA polymerase II irreversibly, leading to severe hepatonecrosis. There is no effective antidote for severe amatoxin poisoning. We compare the effectiveness of 5 potential antidotal therapies in limiting the degree of hepatonecrosis in a randomized, controlled, murine model of amatoxin-induced hepatotoxicity. METHODS: One hundred eighty male Institute of Cancer Research mice were randomized into 6 equal groups. Within each group, 21 mice were intraperitoneally injected with 0.6 mg/kg of alpha-amanitin (amatoxin); the remaining 9 were injected with 0.9% normal saline solution. Four hours postinjection, each group of 30 mice was randomized to 1 of 5 intraperitoneal treatments (N-acetylcysteine, benzylpenicillin, cimetidine, thioctic acid, or silybin) or normal saline solution. Repeated dosing was administered intraperitoneally every 4 to 6 hours for 48 hours. After 48 hours of treatment, each subject was killed, cardiac blood was aspirated for hepatic aminotransferase measurements (alanine transaminase and aspartate transaminase), and liver specimens were harvested to evaluate the extent of hepatonecrosis. The degree of hepatonecrosis was determined by a pathologist blinded to the treatment group and divided into 5 categories according to percentage of hepatonecrosis. RESULTS: Amanitin significantly increased aspartate transaminase in treated mice compared with normal saline solution-treated controls (mean [SD] 2,441 [2,818] IU/L versus 310 [252]; P=.03). None of the antidotal therapies were found to significantly decrease the increase in aminotransferases compared with controls. Further, none of the antidotal therapies demonstrated an important decrease in hepatonecrosis compared with controls when a histologic grading scale was used. CONCLUSION: In this murine model, N-acetylcysteine, benzylpenicillin, cimetidine, thioctic acid, and silybin were not effective in limiting hepatic injury after alpha-amanitin poisoning. Increases of aminotransferases and degrees of histologic hepatonecrosis were not attenuated by these antidotal therapies.

Effects of ceiling-mounted HEPA-UV air filters on airborne bacteria concentrations in an indoor therapy pool building.

The purpose of this study was to assess the effectiveness of a new generation of high-volume, ceiling-mounted high-efficiency particulate air (HEPA)-ultraviolet (UV) air filters (HUVAFs) for their ability to remove or inactivate bacterial aerosol. In an environmentally controlled full-scale laboratory chamber (87 m3), and an indoor therapy pool building, the mitigation ability of air filters was assessed by comparing concentrations of total bacteria, culturable bacteria, and airborne endotoxin with and without the air filters operating under otherwise similar conditions. Controlled chamber tests with pure cultures of aerosolized Mycobacterium parafortuitum cells showed that the HUVAF unit tested provided an equivalent air-exchange rate of 11 hr(-1). Using this equivalent air-exchange rate as a design basis, three HUVAFs were installed in an indoor therapy pool building for bioaerosol mitigation, and their effectiveness was studied over a 2-year period. The HUVAFs reduced concentrations of culturable bacteria by 69 and 80% during monitoring periods executed in respective years. The HUVAFs reduced concentrations of total bacteria by 12 and 76% during the same monitoring period, respectively. Airborne endotoxin concentrations were not affected by the HUVAF operation.

Impact of environmental factors on efficacy of upper-room air ultraviolet germicidal irradiation for inactivating airborne mycobacteria.

This study evaluated the efficacy of an upper-room air ultraviolet germicidal irradiation (UVGI) system for inactivating airborne bacteria, which irradiates the upper part of a room while minimizing radiation exposure to persons in the lower part of the room. A full-scale test room (87 m3), fitted with a UVGI system consisting of 9 louvered wall and ceiling fixtures (504 W all lamps operating) was operated at 24 and 34 degrees C, between 25 and 90% relative humidity, and at three ventilation rates. Mycobacterium parafortuitum cells were aerosolized into the room such that their numbers and physiologic state were comparable both with and without the UVGI system operating. Airborne bacteria were collected in duplicate using liquid impingers and quantified with direct epifluorescent microscopy and standard culturing assay. Performance of the UVGI system degraded significantly when the relative humidity was increased from 50% to 75-90% RH, the horizontal UV fluence rate distribution was skewed to one side compared to being evenly dispersed, and the room air temperature was stratified from hot at the ceiling to cold at the floor. The inactivation rate increased linearly with effective UV fluence rate up to 5 microW cm(-2); an increase in the fluence rate above this level did not yield a proportional increase in inactivation rate.