Airborne Stability of Simian Virus 40

The influence of relative humidity on the airborne survival of simian virus 40 (SV40) was studied by allowing virus aerosols to age in rotating drums at 21 or 32 C and at a relative humidity (RH) value ranging from 22 to 88%. Airborne SV40 virus was stable at every RH tested at 21 C, but aerosols maintained at 32 C were inactivated within 60 min at mid-range RH values. The unusual stability at 21 C over a broad RH range indicates that potentially biohazardous situations may occur under laboratory conditions if this virus becomes accidentally airborne.     

The investigation of the combined effects of gamma irradiation and environmental manipulation on mortality and sterility of Rhyzopertha dominica (Fabricius) (Coleoptera: Bostrichidae)

With respect to the limitations use of methyl bromide and phosphine, employing ionizing radiation to control stored product pests has attracted great attention. The aim of this study is the investigation of the combined effects of gamma irradiation as viable alternatives to synthetic insecticides and environmental management on mortality and sterility of Rhyzopertha dominica (Fabricius) in a wheat cultivar (Gascogen). The effect of doses range from 30 to 2000?Gy gamma irradiation in combination with manipulation of temperature (15, 21, 27 and 32?°C) and relative humidity (20%, 50%, 65% and 85%) on 5–10?days old adults of R. dominica in Gascogen cultivar of wheat were explored. The experiments were repeated three times and conducted in The Nuclear Agriculture Research School in Karaj and laboratory of shahid steki silo in shahre-kord. Probit analysis revealed that both temperature and relative humidity had combined effects when used with gamma irradiation. The lowest doses of gamma ray required to kill 25% (14.2?Gy) and 50% (610.8?Gy) of the population (LD₂₅ and LD₅₀) were recorded at 21?°C and 85% relative humidity respectively. The low dose for 99% mortality (LD₉₉; 2386.7?Gy) was recorded for beetles maintained at 21?°C and 50% relative humidity. The effect of temperature (15, 21, 27 and 32?°C) on sterility caused by gamma irradiation was also investigated. The results showed that the F₁ generation emerged only when the beetles were treated with doses of 0–100?Gy at 32?°C and 0–70?Gy at 27?°C. These results indicate that temperature and relative humidity play an important role in the susceptibility of the lesser grain beetle to gamma irradiation. The results suggest that controlling the efficiency of gamma radiation through environmental control allows the use of low doses of gamma radiation that have a less harmful effect on human health, non-target organisms and seed agronomic features.     

Response of Airborne Mycoplasma pneumoniae to Abrupt Changes in Relative Humidity

The effect of an abrupt change in the relative humidity on the viability of airborne Mycoplasma pneumoniae has been examined. When the microbial aerosols were permitted to equilibrate in air held at either low or high humidities and were then subjected to a sudden shift to a mid-range humidity, a significant loss (>90%) of the colony-forming units per liter of aerosol occurred within 8 min. In contrast, a change in the relative humidity of more than 18% in either direction from a lethal mid-range humidity noticeably decreased the rate of biological decay. Double humidity shifts (i.e., from dry to a mid-range level and then to a high humidity range) were very detrimental, with very few survivors after 8 min. These results indicate that the biological stability of airborne M. pneumoniae may be easily modified by a sudden change in the relative humidity, such as occurs in natural atmospheres. This increased sensitivity brought about by producing changes in relative humidity through the lethal humidity range may provide a method whereby the control of these organisms in naturally contaminated indoor air environments may be eventually achieved.     

Structure of the filamentous bacteriophage,Pf3, by X-ray fiber diffraction

Fiber diffraction data have been obtained for the filamentous bacteriophage Pf3. The virus crystallizes on a hexagonal net with lattice constants a = b = 5.61 nm and c = 7.50 nm at 0% relative humidity and a = 6 = 6.20 nm and c = 7.99 nm at 98% relative humidity. The X-ray diffraction pattern resembles those of two other bacteriophages, Pf 1 and Xf, and therefore belongs to class II. The data are consistent with a 27₅ helix symmetry with an axial rise of 0.277 (dry) to 0.296 (wet) nm.     

Effects of Environmental Factors on the Survival of Airborne T-3 Coliphage

Experiments were conducted to determine the effects of storage temperatures, relative humidity, and additives on the survival of aerosolized Escherichia coli phage T-3. The aerosol stability of the coliphage, calculated as per cent recovery, was not affected by storage at 10 or -70 C for up to 4 months. However, an increase in aerosol decay rate of coliphage stored at 10 C was observed. The effect of humidities ranging from 20 to 90% relative humidity was studied, and it was observed that humidities lower than 70% relative humidity significantly reduce the survival of airborne coliphage. The effect of various compounds on the aerosol decay rate of T-3 coliphage was studied at 50 and 85% relative humidity. Addition of dextrose in 0.1 M concentrations to the disseminating fluid significantly reduced aerosol decay rate at 50% relative humidity without affecting the decay at 85%. Addition of spermine, spermidine-phosphate, thiourea, galacturonic acid, and glucosaminic acid, individually or in combination, had no effect on aerosol decay rates. The use of deuterium oxide as the suspending fluid for dissemination had no effect on aerosol stability of the coliphage.     

Transfer Efficiency of Bacteria and Viruses from Porous and Nonporous Fomites to Fingers under Different Relative Humidity Conditions

Fomites can serve as routes of transmission for both enteric and respiratory pathogens. The present study examined the effect of low and high relative humidity on fomite-to-finger transfer efficiency of five model organisms from several common inanimate surfaces (fomites). Nine fomites representing porous and nonporous surfaces of different compositions were studied. Escherichia coli, Staphylococcus aureus, Bacillus thuringiensis, MS2 coliphage, and poliovirus 1 were placed on fomites in 10-μl drops and allowed to dry for 30 min under low (15% to 32%) or high (40% to 65%) relative humidity. Fomite-to-finger transfers were performed using 1.0 kg/cm² of pressure for 10 s. Transfer efficiencies were greater under high relative humidity for both porous and nonporous surfaces. Most organisms on average had greater transfer efficiencies under high relative humidity than under low relative humidity. Nonporous surfaces had a greater transfer efficiency (up to 57%) than porous surfaces (<6.8%) under low relative humidity, as well as under high relative humidity (nonporous, up to 79.5%; porous, <13.4%). Transfer efficiency also varied with fomite material and organism type. The data generated can be used in quantitative microbial risk assessment models to assess the risk of infection from fomite-transmitted human pathogens and the relative levels of exposure to different types of fomites and microorganisms.     

Accelerated testing of mold growth on traditional and recycled book paper

The growth of molds on paper containing cellulose is a frequent occurrence when the level of relative air humidity is high or when books become wet due to water leaks in libraries. The aim of this study is to differentiate the bioreceptivity of different types of book paper for different fungi. Laboratory tests were performed with strains of Aspergillus niger, Cladosporium sp., Chaetomium globosum and Trichoderma harzianum isolated from books. Four paper types were evaluated: couché, Pólen (offset), recycled and a reference paper containing only cellulose. The tests were carried out in chambers with relative air humidity of 95% and 100%. Mold growth was greatest in the tests at 100% relative humidity. Results of stereoscopic microscopy observation showed that Cladosporium sp. grew in 74% of these samples, A. niger in 75%, T. harzianum in 72% and C. globosum in 60%. In the chambers with 95% air humidity Cladosporium sp. grew in only 9% of the samples, A. niger in 1%, T. harzianum in 3% and C. globosum did not grow in any sample. The most bioreceptive paper was couché and the least receptive was recycled paper. The composition of the recycled paper, however, varies depending on the types of waste materials used to make it.     

Flowering and Growth Response of Peanut Plants (Arachis hypogaea L. var. Starr) at Two Levels of Relative Humidity

Peanut plants (Arachis hypogaea L. var. Starr) grown under two different relative humidities were used in all experiments. All plants were germinated and grown to flowering in the greenhouse. At this time, one group was moved to a growth room under 95% relative humidity. After 50 days the humidity of the growth room was lowered to 50%. The second group was moved into a growth room at 50% relative humidity and after 50 days the humidity was raised to 95%.     

Gene–Gene and Gene-Sex Epistatic Interactions of MiR146a,IRF5, IKZF1, ETS1 and IL21 in Systemic Lupus Erythematosus

Several confirmed genetic susceptibility loci involved in the interferon signaling and Th17/B cell response for SLE in Chinese Han populations have been described. Available data also indicate that sex-specific genetic differences contribute to SLE susceptibility. The aim of this study was to test for gene–gene/gene-sex epistasis (interactions) in these known lupus susceptibility loci. Six single-nucleotide polymorphisms (SNPs) in MiR146a, IRF5, IKZF1, ETS1 and IL21 were genotyped by Sequenom MassArray system. A total of 1,825 subjects (858 SLE patients and 967 controls) were included in the final analysis. Epistasis was tested by additive model, multiplicative model and multifactor dimensionality reduction (MDR) method. Additive interaction analysis revealed interactions between IRF5 and IKZF1 (OR 2.26, 95% CI 1.48–3.44 [P = 1.21×10⁴]). A similar tendency was also observed between IL21 and ETS1 by parametric methods. In addition, multiple high dimensional gene-gene or gene-sex interactions (three-and four-way) were identified by MDR analysis. Our study identified novel gene–gene/gene-sex interactions in lupus. Furthermore, these findings highlight sex, interferon pathway, and Th17/B cells as important contributors to the pathogenesis of SLE.     

Population dynamics of mosquitoes (Diptera: Culicidae) and their disease-harboring rates in Gyeonggi province,South Korea

Population dynamics and species composition of mosquitoes were monitored in a suburban residential area and rural areas, including a migratory bird refuge area and a cattle farm area, from 2017 to 2019. Mosquitoes were collected every two weeks using one BG sentinel trap and two black-light traps in a suburban residential area and a migratory bird refuge area, and one black-light trap in a cattle farm area from March to November. From the surveillance, a total of 13,267, 9,697 and 6,688 mosquitoes were collected in 2017, 2018, and 2019, respectively. The peak of the mosquito population was observed in August and September in both the suburban residential area and rural areas. In general, Culex pipiens pallens was the dominant species in the suburban residential area, whereas Aedes vexans nipponii and Anopheles spp. were the most dominant in the rural areas. Collected mosquitoes were pooled into groups for each collection site and species to investigate flavivirus harboring. Three pools were positive for Japanese encephalitis virus type V, one pool was positive for Chaoyang virus, and six pools were positive for Culex flavi virus from the 731 pools tested. When total numbers of collected mosquitoes were further analyzed by linear regression analysis for their interaction with ambient temperature and relative humidity, the number of mosquitoes were significantly affected by the ambient temperature. In contrast, relative humidity was significantly affecting the total number of mosquitoes only for the migratory bird refuge area.     

Overexpression of microRNA-155 increases IL-21 mediated STAT3 signaling and IL-21 production in systemic lupus erythematosus

IntroductionInterleukin (IL)-21 is a key cytokine in autoimmune diseases such as systemic lupus erythematosus (SLE) by its regulation of autoantibody production and inflammatory responses. The objective of this study is to investigate the signaling capacity of IL-21 in T and B cells and assess its possible regulation by microRNA (miR)-155 and its target gene suppressor of cytokine signaling 1 (SOCS1) in SLE.MethodsThe signaling capacity of IL-21 was quantified by stimulating peripheral blood mononuclear cells (PBMCs) with IL-21 and measuring phosphorylation of STAT3 (pSTAT3) in CD4+ T cells, B cells, and natural killer cells. Induction of miR-155 by IL-21 was investigated by stimulating purified CD4+ T cells with IL-21 and measuring miR-155 expression levels. The functional role of miR-155 was assessed by overexpressing miR-155 in PBMCs from SLE patients and healthy controls (HCs) and measuring its effects on STAT3 and IL-21 production in CD4+ and CD8+ T cells.ResultsInduction of pSTAT3 in CD4+ T cells in response to IL-21 was significantly decreased in SLE patients compared to HCs (p < 0.0001). Further, expression levels of miR-155 were significantly decreased and SOCS1 correspondingly increased in CD4+ T cells from SLE patients. Finally, overexpression of miR-155 in CD4+ T cells increased STAT3 phosphorylation in response to IL-21 treatment (p < 0.01) and differentially increased IL-21 production in SLE patients compared to HCs (p < 0.01).ConclusionWe demonstrate that SLE patients have reduced IL-21 signaling capacity, decreased miR-155 levels, and increased SOCS1 levels compared to HCs. The reduced IL-21 signaling in SLE could be rescued by overexpression of miR-155, suggesting an important role for miR-155 in the reduced IL-21 signaling observed in SLE.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0660-z) contains supplementary material, which is available to authorized users.     

IL2/IL21 region polymorphism influences response to rituximab in systemic lupus erythematosus patients

To determine whether the IL2/IL21 region, a general autoimmunity locus, contributes to the observed variation in response to rituximab in patients with systemic lupus erythematosus as well as to analyze its influence in a cohort including other autoimmune diseases. rs6822844 G/T polymorphism at the IL2–IL21 region was analyzed by TaqMan assay in 84 systemic lupus erythematosus (SLE) and 60 different systemic autoimmune diseases Spanish patients receiving rituximab. Six months after the first infusion patients were classified, according to the EULAR criteria, as good responders, partial responders and non-responders. A statistically significant difference was observed in GG genotype frequency between responder (total and partial response) (83.56 %) and non-responder (45.45 %) SLE patients (p = 0.010, odds ratio (OR) = 6.10 [1.28–29.06]). No association with the response was evident in the group of patients with autoimmune diseases other than lupus. Furthermore, when both groups of patients were pooled in a meta-analysis, a reduced statistical significance of the association was observed (p = 0.024, OR = 3.53 [1.06–11.64]). Our results show for a first time that IL2–IL21 region seems to play a role in the response to rituximab in SLE patients but not in other autoimmune diseases.     

High Humidity Leads to Loss of Infectious Influenza Virus from Simulated Coughs

Background

The role of relative humidity in the aerosol transmission of influenza was examined in a simulated examination room containing coughing and breathing manikins.

Methods

Nebulized influenza was coughed into the examination room and Bioaerosol samplers collected size-fractionated aerosols (<1 µM, 1–4 µM, and >4 µM aerodynamic diameters) adjacent to the breathing manikin’s mouth and also at other locations within the room. At constant temperature, the RH was varied from 7–73% and infectivity was assessed by the viral plaque assay.

Results

Total virus collected for 60 minutes retained 70.6–77.3% infectivity at relative humidity ≤23% but only 14.6–22.2% at relative humidity ≥43%. Analysis of the individual aerosol fractions showed a similar loss in infectivity among the fractions. Time interval analysis showed that most of the loss in infectivity within each aerosol fraction occurred 0–15 minutes after coughing. Thereafter, losses in infectivity continued up to 5 hours after coughing, however, the rate of decline at 45% relative humidity was not statistically different than that at 20% regardless of the aerosol fraction analyzed.

Conclusion

At low relative humidity, influenza retains maximal infectivity and inactivation of the virus at higher relative humidity occurs rapidly after coughing. Although virus carried on aerosol particles <4 µM have the potential for remaining suspended in air currents longer and traveling further distances than those on larger particles, their rapid inactivation at high humidity tempers this concern. Maintaining indoor relative humidity >40% will significantly reduce the infectivity of aerosolized virus.     

Pollen content in the atmosphere of Lugo (NW Spain) with reference to meteorological factors (1999–2001)

This study shows the results of monitoring thepollen present in the atmosphere of the city ofLugo for three years (1999–2001) using a Hirstvolumetric trap (model Lanzoni VPPS-2000). During the three-year study, 61,381 pollengrains were counted. Poaceae represents 39.5%of the total pollen identified, Pinus12.3%, Quercus 8.7% and Betula8.4%. More than half of the total annualpollen was recorded in June and July. Itscorrelation was positive with temperature,hours of sun and wind speed, and negative withrainfall and relative humidity. The maximumvalues were recorded between 11 am and 8 pm,coinciding with the highest temperatures andlowest relative humidity.     

Diapause pupal color diphenism induced by temperature and humidity conditions in Byasa alcinous (Lepidoptera: Papilionidae)

We investigated whether diapause pupae of Byasa alcinous exhibit pupal color diphenism (or polyphenism) similar to the diapause pupal color polyphenism shown by Papilio xuthus. All diapause pupae of B. alcinous observed in the field during winter showed pupal coloration of a dark-brown type. When larvae were reared and allowed to reach pupation under short-day conditions at 18 °C under a 60 ± 5% relative humidity, diapause pupae exhibited pupal color types of brown (33%), light-brown (25%), yellowish-brown (21%), diapause light-yellow (14%) and diapause yellow (7%). When mature larvae reared at 18 °C were transferred and allowed to reach pupation at 10 °C and 25 °C under a 60 ± 5% relative humidity after a gut purge, the developmental ratio of brown and light-brown, yellowish-brown, and diapause light-yellow and diapause yellow types was 91.2, 8.8 and 0.0% at 10 °C, and 12.2, 48.8 and 39.0% at 25 °C, respectively. On the other hand, when mature larvae reared at 18 °C were transferred and allowed to reach pupation at 10 °C, 18 °C and 25 °C under an over 90% relative humidity after a gut purge, the developmental ratio of brown and light-brown, yellowish-brown, and diapause light-yellow and diapause yellow types was 79.8, 16.9 and 3.3% at 10 °C, 14.5, 26.9 and 58.6% at 18 °C, and 8.3, 21.2 and 70.5% at 25 °C, respectively. These results indicate that diapause pupae of brown types are induced by lower temperature and humidity conditions, whereas yellow types are induced by higher temperature and humidity conditions. The findings of this study show that diapause pupae of B. alcinous exhibit pupal color diphenism comprising brown and diapause yellow types, and suggest that temperature and humidity experienced after a gut purge are the main factors that affect the diapause pupal coloration of B. alcinous as environmental cues.     

Studies with dried airborne vaccinia virus in a small environmental chamber

Dried vaccinia virus was found to be very stable in aerosol form in our chamber at a temperature of 75°F and a relative humidity (RH) of 85% when the virus was protected with 1.5% lysine, 1.5% sodium glutamate, 0.5% isoniazid, 0.5% thiourea, and either 2.5% heart infusion broth (HIB) or a combination of 3.75% lactose plus 1.25% raffinose prior to freeze-drying. Utilization of the Environmental chamber technique resulted in (a) selection of two diluents which protected vaccinia virus against the effects of high relative humidity, (b) measurement of the effect of various chemical additives in the diluents, and (c) quantitative measurement of the moisture absorbed by the various dried products.     

Multiple conformations coexist and interchange in natural B DNA fibers

³¹P nuclear magnetic resonance (n.m.r.) of highly oriented NaDNA and LiDNA fibers was measured as a function of relative humidity over the range from 66% to 98%. The humidity dependence of the spectral patterns of NaDNA fibers shows that the A form has a single conformation while the B form has multiple conformations, and that interconversion between the A and B conformers in the transition region is slow compared to the n.m.r. time-scale (~10^?5 s). Two major conformations of the B form of LiDNA are found to be stable at low relative humidity and they rapidly interchange at high relative humidities. The spectral patterns of immobilized LiDNA are compatible with the single-crystal structure of double-stranded oligo nucleic acids.     

The association of interleukin-21 polymorphisms with interleukin-21 serum levels and risk of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is one of the common autoimmune diseases, with complex genetic components. Interleukin-21 (IL-21) is the most recently discovered member of the type-I cytokine family, which has a variety of effects on the immune system, including B cell activation, plasma cell differentiation, and immunoglobulin production. Previous studies have identified that IL-21 was associated with different autoimmune and inflammatory diseases, such as rheumatoid arthritis, multiple sclerosis and SLE. Variations in the DNA sequence in the IL-21 gene may lead to altered IL-21 production and/or activity, and thus this can modulate an individual's susceptibility to SLE. To test this hypothesis, we investigated the association of the IL-21 polymorphisms and its serum levels with the risk of SLE in a Chinese population. We analyzed three single nucleotide polymorphisms of IL-21 gene rs907715 C/T, rs2221903 T/C and rs2055979 C/A in 175 patients with SLE and 190 age- and sex-matched controls, using Snapshot SNP genotyping assays and DNA sequencing method. Soluble IL-21 (sIL-21) levels were measured by ELISA. There were significant differences in the genotype and allele frequencies of IL-21 gene rs2055979 C/A polymorphism between the group of patients with SLE and the control group (P < 0.05). sIL-21 levels were increased in patients with SLE compared with controls (P < 0.01). Moreover, genotypes carrying the IL-21 rs2055979 A variant allele were associated with increased IL-21 levels compared to the homozygous wild-type genotype in patients with SLE. The rs2055979 C/A polymorphism of IL-21 and its sIL-21 levels were associated with SLE in the Chinese population. Our data suggests that IL-21 gene may play a role in the development of SLE.     

Inhibition of Aberrant Circulating Tfh Cell Proportions by Corticosteroids in Patients with Systemic Lupus Erythematosus

Objective

To observe the proportion of peripheral T follicular helper (Tfh) cells in patients with systemic lupus erythematosus (SLE) and to assess the role of steroids on Tfh cells from SLE patients.

Methods

Peripheral blood mononuclear cells (PBMCs) from 42 SLE patients and 22 matched healthy subjects were collected to assess proportions of circulating CXCR5⁺PD1⁺/CD4⁺ T cells (Tfh), CD4⁺CCR6⁺ T cells (Th17-like) and CD19⁺CD138⁺ plasma cells by flow cytometry. 8 of the patients had their blood redrawn within one week after receiving methylprednisolone pulse treatment. Disease activity was evaluated by SLE disease activity index. To test the effect of IL-21 and corticosteroids on Tfh cells in vitro, PBMCs harvested from another 15 SLE patients were cultured with medium, IL-21, or IL-21+ dexamethasone for 24 hours and 72 hours. PBMCs from an independent 23 SLE patients were cultured with different concentrations of dexamethasone for 24 hours.

Results

Compared to normal controls, percentages of circulating Tfh cells, but not Th17 cells, were elevated in SLE patients and correlated with disease activity. Proportions of Tfh cells in SLE patients were positively correlated with those of plasma cells and serum levels of antinuclear antibodies. After methylprednisolone pulse treatment, both percentages and absolute numbers of circulating Tfh cells were significantly decreased. In vitro cultures showed an increase of Tfh cell proportion after IL-21 stimulation that was totally abolished by the addition of dexamethasone. Both 0.5 and 1 µM dexamethasone decreased Tfh cells dose dependently (overall p = 0.013).

Conclusions

We demonstrated that elevated circulating Tfh cell proportions in SLE patients correlated with their disease activities, and circulating levels of plasma cells and ANA. Corticosteroids treatment down-regulated aberrant circulating Tfh cell proportions both in vivo and in vitro, making Tfh cells a new treatment target for SLE patients.