Examination of the exposome in an animal model: The impact of high fat diet and rat strain on local and systemic immune markers following occupational welding fume exposure

The goal of this study was to investigate the impact of multiple exposomal factors (genetics, lifestyle factors, environmental/occupational exposures) on pulmonary inflammation and corresponding alterations in local/systemic immune parameters. Accordingly, male Sprague-Dawley (SD) and Brown Norway (BN) rats were maintained on either regular (Reg) or high fat (HF) diets for 24wk. Welding fume (WF) exposure (inhalation) occurred between 7 and 12wk. Rats were euthanized at 7, 12, and 24wk to evaluate local and systemic immune markers corresponding to the baseline, exposure, and recovery phases of the study, respectively. At 7wk, HF-fed animals exhibited several immune alterations (blood leukocyte/neutrophil number, lymph node B-cell proportionality)-effects which were more pronounced in SD rats. Indices of lung injury/inflammation were elevated in all WF-exposed animals at 12wk; however, diet appeared to preferentially impact SD rats at this time point, as several inflammatory markers (lymph node cellularity, lung neutrophils) were further elevated in HF over Reg animals. Overall, SD rats exhibited the greatest capacity for recovery by 24wk. In BN rats, resolution of immune alterations was further compromised by HF diet, as many exposure-induced alterations in local/systemic immune markers were still evident in HF/WF animals at 24wk. Collectively, HF diet appeared to have a greater impact on global immune status and exposure-induced lung injury in SD rats, but a more pronounced effect on inflammation resolution in BN rats. These results illustrate the combined impact of genetic, lifestyle, and environmental factors in modulating immunological responsivity and emphasize the importance of the exposome in shaping biological responses.

Effects of whole-body vibration on reproductive physiology in a rat model of whole-body vibration

Findings from epidemiological studies suggest that occupational exposure to whole-body vibration (WBV) may increase the risk of miscarriage and contribute to a reduction in fertility rates in both men and women. However, workers exposed to WBV may also be exposed to other risk factors that contribute to reproductive dysfunction. The goal of this experiment was to examine the effects of WBV on reproductive physiology in a rat model. Male and female rats were exposed to WBV at the resonant frequency of the torso (31.5 Hz, 0.3 g amplitude) for 4 hr/day for 10 days. WBV exposure resulted in a significant reduction in number of developing follicles, and decrease in circulating estradiol concentrations, ovarian luteinizing hormone receptor protein levels, and marked changes in transcript levels for several factors involved in follicular development, cell cycle, and steroidogenesis. In males, WBV resulted in a significant reduction in spermatids and circulating prolactin levels, elevation in number of males having higher circulating testosterone concentrations, and marked alterations in levels of transcripts associated with oxidative stress, inflammation, and factors involved in regulating the cell cycle. Based upon these findings data indicate that occupational exposure to WBV contributes to adverse alterations in reproductive physiology in both genders that may lead to reduction in fertility.

OPTN/SRTR 2020 Annual Data Report: DOD

SRTR uses data collected by OPTN to calculate metrics such as donation rate, organ yield, and rate of organs recovered for transplant but not transplanted. In 2020, there were 12,588 deceased donors, an increase from 11,870 in 2019; this number has been increasing since 2010. The number of deceased donor transplants increased to 33,303 in 2020, from 32,313 in 2019; this number has been increasing since 2012. The increase may be due in part to the rising number of deaths of young people amid the ongoing opioid epidemic. The number of organs transplanted included 18,410 kidneys, 962 pancreata, 8350 livers, 91 intestines, 3722 hearts, and 2463 lungs. Compared with 2019, transplants of all organs except pancreata and lung transplants increased in 2020, which is remarkable despite the pandemic caused by the SARS-CoV2 virus. In 2020, 4870 kidneys, 294 pancreata, 861 livers, 3 intestines, 39 hearts, and 115 lungs were discarded. The number of discards was similar to that of the previous year. In 2019, 4,324 kidneys, 346 pancreata, 867 livers, 5 intestines, 31 hearts, and 148 lungs were discarded. These numbers suggest an opportunity to increase numbers of transplants by reducing discards. Despite the pandemic, there was no dramatic increase in number of discards and an increase in total number of donors and transplants.

OPTN/SRTR 2019 Annual Data Report: Deceased Organ Donors

SRTR uses data collected by OPTN to calculate metrics such as donation rate, organ yield, and rate of organs recovered for transplant but not transplanted. In 2019, there were 11,870 deceased donors, an increase from 10,721 in 2018; this number has been increasing since 2010. The number of deceased donor transplants increased to 32,313 in 2019, from 29,675 in 2018; this number has been increasing since 2012. The increase may be due in part to the rising number of deaths of young people due to the ongoing opioid epidemic. The number of organs transplanted included 17,425 kidneys, 1,018 pancreata, 8,275 livers, 81 intestines, 3,604 hearts, and 2,607 lungs. In 2019, 4,324 kidneys, 346 pancreata, 867 livers, 5 intestines, 31 hearts, and 148 lungs were discarded. These numbers suggest an opportunity to increase numbers of transplants by reducing discards.

OPTN/SRTR 2018 Annual Data Report: Deceased Organ Donation

SRTR uses data collected by OPTN to calculate metrics such as donation rate, organ yield, and rate of organs recovered for transplant but not transplanted. In 2018, there were 10,721 deceased donors, and this number has been increasing since 2010. The number of deceased donor transplants increased to 29,676 in 2018 from 28,582 in 2017, and this number has been increasing since 2012. The recent increase may be due in part to the rising number of deaths of young people due to the opioid epidemic. In 2018, 4994 organs were discarded, slightly more than 4813 in 2017. In 2018, 3755 kidneys, 278 pancreata, 707 livers, 3 intestines, 23 hearts, and 317 lungs were discarded. These numbers suggest an opportunity to increase numbers of transplants by reducing discards.

Functional motor control deficits in older FMR1 premutation carriers

Individuals with fragile X mental retardation 1 (FMR1) gene premutations are at increased risk for fragile X-associated tremor/ataxia syndrome (FXTAS) during aging. However, it is unknown whether older FMR1 premutation carriers, with or without FXTAS, exhibit functional motor control deficits compared with healthy individuals. The purpose of this study, therefore, was to determine whether older FMR1 premutation carriers exhibit impaired ability to perform functional motor tasks. Eight FMR1 premutation carriers (age: 58.88 ± 8.36 years) and eight age- and sex-matched healthy individuals (60.13 ± 9.25 years) performed (1) a steady isometric force control task with the index finger at 20% of their maximum voluntary contraction (MVC) and; (2) a single-step task. During the finger abduction task, firing rate of multiple motor units of the first dorsal interosseous (FDI) muscle was recorded. Compared with healthy controls, FMR1 premutation carriers exhibited (1) greater force variability (coefficient of variation of force) during isometric force (1.48 ± 1.02 vs. 0.63 ± 0.37%; P = 0.04); (2) reduced firing rate of multiple motor units during steady force, and; (3) reduced velocity of their weight transfer during stepping (156.62 ± 26.24 vs. 191.86 ± 18.83 cm/s; P = 0.01). These findings suggest that older FMR1 premutation carriers exhibit functional motor control deficits that reflect either subclinical issues associated with premutations independent of FXTAS, or prodromal markers of the development of FXTAS.

Language processing skills linked to FMR1 variation: A study of gaze-language coordination during rapid automatized naming among women with the FMR1 premutation

The FMR1 premutation (PM) is relatively common in the general population. Evidence suggests that PM carriers may exhibit subtle differences in specific cognitive and language abilities. This study examined potential mechanisms underlying such differences through the study of gaze and language coordination during a language processing task (rapid automatized naming; RAN) among female carriers of the FMR1 PM. RAN taps a complex set of underlying neuropsychological mechanisms, with breakdowns implicating processing disruptions in fundamental skills that support higher order language and executive functions, making RAN (and analysis of gaze/language coordination during RAN) a potentially powerful paradigm for revealing the phenotypic expression of the FMR1 PM. Forty-eight PM carriers and 56 controls completed RAN on an eye tracker, where they serially named arrays of numbers, letters, colors, and objects. Findings revealed a pattern of inefficient language processing in the PM group, including a greater number of eye fixations (namely, visual regressions) and reduced eye-voice span (i.e., the eyes' lead over the voice) relative to controls. Differences were driven by performance in the latter half of the RAN arrays, when working memory and processing load are the greatest, implicating executive skills. RAN deficits were associated with broader social-communicative difficulties among PM carriers, and with FMR1-related molecular genetic variation (higher CGG repeat length, lower activation ratio, and increased levels of the fragile X mental retardation protein; FMRP). Findings contribute to an understanding of the neurocognitive profile of PM carriers and indicate specific gene-behavior associations that implicate the role of the FMR1 gene in language-related processes.

Links between looking and speaking in autism and first-degree relatives: insights into the expression of genetic liability to autism

Background

Rapid automatized naming (RAN; naming of familiar items presented in an array) is a task that taps fundamental neurocognitive processes that are affected in a number of complex psychiatric conditions. Deficits in RAN have been repeatedly observed in autism spectrum disorder (ASD), and also among first-degree relatives, suggesting that RAN may tap features that index genetic liability to ASD. This study used eye tracking to examine neurocognitive mechanisms related to RAN performance in ASD and first-degree relatives, and investigated links to broader language and clinical-behavioral features.

Methods

Fifty-one individuals with ASD, biological parents of individuals with ASD (n = 133), and respective control groups (n = 45 ASD controls; 58 parent controls) completed RAN on an eye tracker. Variables included naming time, frequency of errors, and measures of eye movement during RAN (eye-voice span, number of fixations and refixations).

Results

Both the ASD and parent-ASD groups showed slower naming times, more errors, and atypical eye-movement patterns (e.g., increased fixations and refixations), relative to controls, with differences persisting after accounting for spousal resemblance. RAN ability and associated eye movement patterns were correlated with increased social-communicative impairment and increased repetitive behaviors in ASD. Longer RAN times and greater refixations in the parent-ASD group were driven by the subgroup who showed clinical-behavioral features of the broad autism phenotype (BAP). Finally, parent-child dyad correlations revealed associations between naming time and refixations in parents with the BAP and increased repetitive behaviors in their child with ASD.

Conclusions

Differences in RAN performance and associated eye movement patterns detected in ASD and in parents, and links to broader social-communicative abilities, clinical features, and parent-child associations, suggest that RAN-related abilities might constitute genetically meaningful neurocognitive markers that can help bridge connections between underlying biology and ASD symptomatology.

Inhalation of iron-abundant gas metal arc welding-mild steel fume promotes lung tumors in mice

Welding fumes were reclassified as a Group 1 carcinogen by the International Agency for Research on Cancer in 2017. Gas metal arc welding (GMAW) is a process widely used in industry. Fume generated from GMAW-mild steel (MS) is abundant in iron with some manganese, while GMAW-stainless steel (SS) fume also contains significant amounts of chromium and nickel, known carcinogenic metals. It has been shown that exposure to GMAW-SS fume in A/J mice promotes lung tumors. The objective was to determine if GMAW-MS fume, which lacks known carcinogenic metals, also promotes lung tumors in mice. Male A/J mice received a single intraperitoneal injection of corn oil or the initiator 3-methylcholanthrene (MCA; 10 μg/g) and, one week later, were exposed by whole-body inhalation to GMAW-MS aerosols for 4 hours/day x 4 days/week x 8 weeks at a mean concentration of 34.5 mg/m³. Lung nodules were enumerated by gross examination at 30 weeks post-initiation. GMAW-MS fume significantly increased lung tumor multiplicity in mice initiated with MCA (21.86 ± 1.50) compared to MCA/air-exposed mice (8.34 ± 0.59). Histopathological analysis confirmed these findings and also revealed an absence of inflammation. Bronchoalveolar lavage analysis also indicated a lack of lung inflammation and toxicity after short-term inhalation exposure to GMAW-MS fume. In conclusion, this study demonstrates that inhalation of GMAW-MS fume promotes lung tumors in vivo and aligns with epidemiologic evidence that shows MS welders, despite less exposure to carcinogenic metals, are at an increased risk for lung cancer.

The influence of inhaled multi-walled carbon nanotubes on the autonomic nervous system

Background

Heart rate and cardiovascular function are regulated by the autonomic nervous system. Heart rate variability (HRV) as a marker reflects the activity of autonomic nervous system. The prognostic significance of HRV in cardiovascular disease has been reported in clinical and epidemiological studies. The present study focused on the influence of inhaled multi-walled carbon nanotubes (MWCNTs) on autonomic nervous system by HRV analysis.

Methods

Male Sprague–Dawley rats were pre-implanted with a telemetry device and kept in the individual cages for recovery. At week four after device implantation, rats were exposed to MWCNTs for 5 h at a concentration of 5 mg/m³. The real-time EKGs were recorded by a telemetry system at pre-exposure, during exposure, 1 day and 7 days post-exposure. HRV was measured by root mean square of successive differences (RMSSD); the standard deviation of inter-beat (RR) interval (SDNN); the percentage of successive RR interval differences greater than 5 ms (pNN5) and 10 ms (pNN10); low frequency (LF) and high frequency (HF).

Results

Exposure to MWCNTs increased the percentage of differences between adjacent R-R intervals over 10 ms (pNN10) (p < 0.01), RMSSD (p < 0.01), LF (p < 0.05) and HF (p < 0.01).

Conclusions

Inhalation of MWCNTs significantly alters the balance between sympathetic and parasympathetic nervous system. Whether such transient alterations in autonomic nervous performance would alter cardiovascular function and raise the risk of cardiovascular events in people with pre-existing cardiovascular conditions warrants further study.

A model of the recruitment-derecruitment and volume of lung units in an excised lung as it is inflated-deflated between minimum and maximum lung volume

The role of the recruitment-derecruitment of small structures in the lung (lung units) as the lung increases and decreases in volume has been debated. The objective of this study was to develop a model to estimate the change in the number and volume of open lung units as an excised lung is inflated-deflated between minimum and maximum lung volume. The model was formulated based on the observation that the compliance of the slowly changing quasi-static pressure-volume (P-V) curve of an excised rat lung can differ from the compliance of a faster changing small sinusoidal pressure volume perturbations superimposed on the curve. In those regions of the curve where differences in compliance occur, the lung tissue properties exhibit nonlinear characteristics, which cannot be linearized using "incremental" or "small signal" analysis. The model attributes the differences between the perturbation and quasi-static compliance to an additional nonlinear compliance term that results from the sequential opening and closing of lung units. Using this approach, it was possible to calculate the normalized average volume and the normalized number of open units as the lung is slowly inflated-deflated. Results indicate that the normalized average volume and the normalized number of open units are not linearly related to normalized lung volume, and at equal lung volumes the normalized number of open units is greater and the normalized average lung unit volume is smaller during lung deflation when compared to lung inflation. In summary, a model was developed to describe the recruitment-derecruitment process in excised lungs based on the differences between small signal perturbation compliance and quasi-static compliance. Values of normalized lung unit volume and the normalized number of open lung units were shown to be nonlinear functions of both transpulmonary pressure and normalized lung volume.

Pulmonary and cardiovascular responses of rats to inhalation of a commercial antimicrobial spray containing titanium dioxide nanoparticles

Our laboratory has previously demonstrated that application of an antimicrobial spray product containing titanium dioxide (TiO(2)) generates an aerosol of titanium dioxide in the breathing zone of the applicator. The present report describes the design of an automated spray system and the characterization of the aerosol delivered to a whole body inhalation chamber. This system produced stable airborne levels of TiO(2) particles with a median count size diameter of 110 nm. Rats were exposed to 314 mg/m(3) min (low dose), 826 mg/m(3) min (medium dose), and 3638 mg/m(3) min (high dose) of TiO(2) under the following conditions: 2.62 mg/m(3) for 2 h, 1.72 mg/m(3) 4 h/day for 2 days, and 3.79 mg/m(3) 4 h/day for 4 days, respectively. Pulmonary (breathing rate, specific airway resistance, inflammation, and lung damage) and cardiovascular (the responsiveness of the tail artery to constrictor or dilatory agents) endpoints were monitored 24 h post-exposure. No significant pulmonary or cardiovascular changes were noted at low and middle dose levels. However, the high dose caused significant increases in breathing rate, pulmonary inflammation, and lung cell injury. Results suggest that occasional consumer use of this antimicrobial spray product should not be a hazard. However, extended exposure of workers routinely applying this product to surfaces should be avoided. During application, care should be taken to minimize exposure by working under well ventilated conditions and by employing respiratory protection as needed. It would be prudent to avoid exposure to children or those with pre-existing respiratory disease.

High-resolution, high-transmission soft x-ray spectrometer for the study of biological samples

We present a variable line-space grating spectrometer for soft x-rays that covers the photon energy range between 130 and 650 eV. The optical design is based on the Hettrick-Underwood principle and tailored to synchrotron-based studies of radiation-sensitive biological samples. The spectrometer is able to record the entire spectral range in one shot, i.e., without any mechanical motion, at a resolving power of 1200 or better. Despite its slitless design, such a resolving power can be achieved for a source spot as large as (30 x 3000) microm2, which is important for keeping beam damage effects in radiation-sensitive samples low. The high spectrometer efficiency allows recording of comprehensive two-dimensional resonant inelastic soft x-ray scattering (RIXS) maps with good statistics within several minutes. This is exemplarily demonstrated for a RIXS map of highly oriented pyrolytic graphite, which was taken within 10 min.

Inhaled particulate matter causes expression of nuclear factor (NF)-kappaB-related genes and oxidant-dependent NF-kappaB activation in vitro

High levels of ambient air pollution are associated with exacerbation of asthma and respiratory morbidity, yet little is known concerning the mechanisms of inflammation and toxicity by components of inhaled particulate matter (PM). Brief inhalation of PM(2.5) (particles of an aerodynamic diameter of < 2.5 microns) (300 microg/m(3) air for 6 h followed by a period of 24 h in clean air) by either C3H/HeJ or C57/BL6 mice caused significant (P </= 0.05) increases in steady-state messenger RNA (mRNA) levels of a number of nuclear factor (NF)-kappaB-associated and/ or -regulated genes, including tumor necrosis factor-alpha and -beta, interleukin-6, interferon-gamma, and transforming growth factor-beta. Lung mRNA levels of lymphotoxin-beta and macrophage migration inhibitory factor were unchanged. In murine C10 alveolar cells and an NF-kappaB-luciferase reporter cell line, exposure to PM(2.5) at noncytotoxic concentrations resulted in increases in transcriptional activation of NF-kappaB-dependent gene expression which were inhibited in the presence of catalase. Early and persistent increases in intracellular oxidants, as measured by flow cytometry and cell imaging using the oxidant probe 2'-7'-dichlorofluoroscin diacetate, were observed in epithelial cells exposed to PM(2.5) and ultrafine carbon black particles. Studies here are the first to show NF-kappaB-related inflammatory and cytokine gene expression after inhalation of PM(2.5) and oxidant-dependent induction of NF-kappaB activity by PM(2.5) in pulmonary epithelial cells.

Evidence for nosocomial transmission of Candida albicans obtained by Ca3 fingerprinting

The moderately repetitive sequence Ca3 was used to fingerprint Candida albicans isolates from 32 patients hospitalized for more than 3 days, 17 recent admissions or outpatients, and 8 recently readmitted patients and 10 commensal isolates from the community in Wellington, New Zealand, plus isolates from 21 hospitalized patients, 26 outpatients or recent admissions, 4 recently readmitted patients, and 10 healthy individuals in the community in Auckland, New Zealand. In Wellington, isolates from patients hospitalized in Wellington Hospital for more than 3 days were genetically significantly less diverse than were isolates from outpatients or recent admissions or isolates from healthy individuals in the community. In addition, two clusters of genetically similar strains were isolated from hospitalized patients significantly more often than from other individuals. These observations provide evidence (albeit indirectly) for nosocomial transmission of hospital-specific C. albicans strains. In contrast, no indication of hospital-specific transmission of C. albicans was found in Auckland Hospital. Since these results were obtained under conditions in which no candidiasis outbreak occurred in either hospital, they also suggest that Ca3 fingerprinting may be a useful tool in preventive nosocomial infection control programs, allowing assessment of the extent of C. albicans transmission occurring in a hospital.

Hereditary anemias in Hawaii. 1987

The differential diagnosis of microcytic anemias in Hawaii presents special problems because of the hereditary anemias prevalent in its large Asian subpopulations. Both the alpha- and beta-thalassemias are important because of morbidity and mortality. Heterozygous carriers for either type mimic iron deficiency, which may lead to inappropriate work-up or treatment. The thalassemias and hemoglobin (Hb) variants are all benign in heterozygotes, but if a couple are both heterozygous for the same or for incompatible variants, their children have 25% risk of inheriting a serious anemia. These can be prevented by detecting the heterozygotes, and by offering genetic counseling and fetal testing to couples at risk of having severely affected children. Early detection is also possible by the screening of newborns. Fetal diagnosis, or early detection and treatment, can greatly reduce the consequences of these anemias. Screening and prevention will cost far less than the cost of care for affected patients.

The Auckland skin clinic tinea pedis and erythrasma study

Three hundred consecutive patients attending the Auckland Hospital dermatology clinic were examined clinically and microbiologically for evidence of interdigital or plantar mycological or bacterial infection. One hundred and nine patients were shown by laboratory investigation to have an infection. Of these, only 89 displayed clinical signs of infection. Erythrasma, a desquamative condition caused by Corynebacterium minutissimum, was the commonest infection in this study. The commonest dermatophyte isolated was Trichophyton mentagrophytes var interdigitale. There was a significant rise in the incidence of both types of infection with age.

Thallium poisoning in group assassination attempt

The use of thallium in an attempted assassination of four members of a political organization is described. The intended victims first complained of abdominal pain within two days of eating a snack prepared by their host; painful peripheral neuropathy occurred within one week and loss of hair within three weeks. Swelling of the optic disk was observed in one patient. The diagnosis was made on clinical grounds and confirmed by the detection of high levels of thallium in serum, urine, and hair and/or nail samples. All patients recovered completely. The possibility of thallium poisoning should be considered in patients who present with acute onset of gastrointestinal symptoms, pain and paresthesias in the legs, and hair loss, so that appropriate treatment can be initiated at an early stage.

Doppler ultrasound scanning of the carotid bifurcation

The results of Doppler scanning of 146 carotid bifurcations in 86 patients were correlated with carotid arteriography. The correlations for normal carotid arteries ranged from 63% to 98%; the correlation for occlusions of carotid arteries was 100%. The Doppler scan correlated in 70% to 85% of stenoses of the internal or external carotid arteries near their origins. The technique may be performed by a well-trained technician or physician.