Filtration Efficiencies of Nanoscale Aerosol by Cloth Mask Materials Used to Slow the Spread of SARS-CoV-2.

Filtration efficiency (FE), differential pressure (ΔP), quality factor (QF), and construction parameters were measured for 32 cloth materials (14 cotton, 1 wool, 9 synthetic, 4 synthetic blends, and 4 synthetic/cotton blends) used in cloth masks intended for protection from the SARS-CoV-2 virus (diameter 100 ± 10 nm). Seven polypropylene-based fiber filter materials were also measured including surgical masks and N95 respirators. Additional measurements were performed on both multilayered and mixed-material samples of natural, synthetic, or natural-synthetic blends to mimic cloth mask construction methods. Materials were microimaged and tested against size selected NaCl aerosol with particle mobility diameters between 50 and 825 nm. Three of the top five best performing samples were woven 100% cotton with high to moderate yarn counts, and the other two were woven synthetics of moderate yarn counts. In contrast to recently published studies, samples utilizing mixed materials did not exhibit a significant difference in the measured FE when compared to the product of the individual FE for the components. The FE and ΔP increased monotonically with the number of cloth layers for a lightweight flannel, suggesting that multilayered cloth masks may offer increased protection from nanometer-sized aerosol with a maximum FE dictated by breathability (i.e., ΔP).

Occupational exposure to organic dusts and risk of developing rheumatoid arthritis: findings from a Swedish population-based case-control study.

Objectives: We estimated the association between occupational exposures to five different organic dusts: wood, animal, paper, textile and flour dust and the risk of developing rheumatoid arthritis (RA). Methods: This population-based case-control study analysed 12 582 incident cases and 129 335 controls. Participants were identified from national public authority and quality registers. Census data on occupations were collected 1960-2010 and we estimated the exposure to organic dust with the help of job-exposure matrices. We used logistic regression to assess the OR of seropositive or seronegative RA. Estimates were adjusted for the matching variables (sex, county, age and index year), education and occupational silica exposure. Results: Exposure to animal dust was associated with an increased risk of RA among both men and women. The OR was 1.2 (95% CI=1.1 to 1.4) for seropositive RA and 1.3 (95% CI=1.1 to 1.5) for seronegative RA among ever exposed participants compared with unexposed. The risk increased with duration of exposure for seropositive RA, and participants who had been exposed in five or more censuses had an OR of 1.6 (95% CI=1.1 to 2.2, p for trend=0.003). Exposure to textile dust also generated a significant dose-response relationship for seropositive RA (p for trend=0.014). We detected no association between exposure to wood, paper or flour dust and risk of RA. Conclusions: Overall, exposure to animal dust and textile dust was associated with an increased risk of developing RA. These observations give further support to the notion that airborne exposures are involved in the aetiology of RA.

Oral and pharyngeal cancer risk associated with occupational carcinogenic substances: Systematic review.

BACKGROUND: Oral and pharyngeal cancers (OPC) represent the seventh most common type of cancer and the seventh leading cause of deaths by cancer worldwide. Few studies have assessed the occupational exposure risks associated with OPC and in many cases the results are conflicting. The aim of this study was to determine, through a systematic review, the association of OPC and exposure to different occupational carcinogenic substances. METHODS: The addressed focused question was "Is there an association of occupational carcinogenic substances with OPC?" PubMed, MEDLINE, EMBASE, and ISI Web of Science databases were searched between January 1995 up to and including July 2016 using the keywords "oral cancer," "pharyngeal cancer," "pharyngeal neoplasms," "oral neoplasms," "occupational disease," "occupational exposure," and "occupational risk factor" in various combinations. Letters to the Editor, review articles, case reports, and unpublished articles were excluded. RESULTS: Fourteen original articles were included. Majority of the studies were conducted in European countries and used a case-control design. The results showed a significant association between formaldehyde, wood dust, coal dust, asbestos, welding fumes, and risk of developing OPC, while marginal association was observed with metal and leather dust. No associated risk was observed for textile fibers. CONCLUSION: There is some evidence to suggest associations of occupational substances with OPC, particularly in the pharynx. Future well-designed studies are required to confirm or rule out with confidence the associated exposure risk of these substances.

Cyclodextrin modified PLLA parietal reinforcement implant with prolonged antibacterial activity.

The use of textile meshes in hernia repair is widespread in visceral surgery. Though, mesh infection is a complication that may prolong the patient recovery period and consequently presents an impact on public health economy. Such concern can be avoided thanks to a local and extended antibiotic release on the operative site. In recent developments, poly-l-lactic acid (PLLA) has been used in complement of polyethyleneterephthalate (Dacron®) (PET) or polypropylene (PP) yarns in the manufacture of semi-resorbable parietal implants. The goal of the present study consisted in assigning drug reservoir properties and prolonged antibacterial effect to a 100% PLLA knit through its functionalization with a cyclodextrin polymer (polyCD) and activation with ciprofloxacin. The study focused i) on the control of degree of polyCD functionalization of the PLLA support and on its physical and biological characterization by Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC) and cell viability, ii) on the understanding of drug/meshes interaction using mathematic model and iii) on the correlation between drug release studies in phosphate buffer saline (PBS) and microbiological evaluation of meshes and release medium against E. coli and S. aureus. All above mentioned tests highlighted the contribution of polyCD on the improved performances of the resulting antibacterial implantable material. STATEMENT OF SIGNIFICANCE: 1. We managed for the first time, with well-defined parameters in terms of temperature and time of treatment, to functionalize a bio-absorbable synthetic material to improve drug sorption and drug release properties without affecting its mechanical properties. 2. We analyzed for the first time the degradation of our coating products by mass spectroscopy to show that only citrate and cyclodextrin residues (and glucose units) without any cytotoxicity are formed. 3. We managed to improve the mechanical properties of the PLA with the cyclodextrin polymer to form a composite. The assembly (cyclodextrin polymer and PLLA) remains biodegradable.

Sensitization to Formaldehyde in Northeastern Italy, 1996 to 2012.

BACKGROUND: Formaldehyde is a widely used organic compound, used in several applications (hard thermoset resins, adhesives, disinfectants, tissue fixatives, etc), in its free form or released by formaldehyde releaser products. Its use is under control due to its toxic, carcinogenic, and allergenic properties. OBJECTIVE: The aim of this study was to investigate the frequency of formaldehyde sensitization, time trend, and correlation to occupations. METHODS: This study is a cross-sectional study on a population of 23,774 patients tested from 1996 to 2012 in Northeastern Italy. RESULTS: Frequency of sensitization was 3.3%, without any significant time trend. Hands (39.8% overall) and face (25.6% females, 15.5% males) were mainly involved. We found a trend toward decrease by age in females (3.11% in first quintile [14-26 years], 2.29% in fifth quintile [59-97 years], P < 0.01). On a logistic regression analysis (control group: white-collar workers), we found associations in health care (odds ratio [OR], 1.37; 95% confidence interval [CI], 1.04-1.81), wood (OR, 2.14; 95% CI, 1.30-3.51), and textile (OR, 1.79; 95% CI, 1.14-2.79) sectors and professional drivers (OR, 1.94; 95% CI, 1.05-3.60). We found a high rate of cosensitization to formaldehyde in patients with positive patch test reactions to quaternium-15 (OR, 18.7; 95% CI, 12.6-27.7). CONCLUSIONS: Sensitization to formaldehyde is relevant in our population, especially in the health care sector, wood and textile industries, and professional drivers. No significant time trend was found.

Occupational exposure to textile dust increases the risk of rheumatoid arthritis: results from a Malaysian population-based case-control study.

OBJECTIVES: Lung exposures including cigarette smoking and silica exposure are associated with the risk of rheumatoid arthritis (RA). We investigated the association between textile dust exposure and the risk of RA in the Malaysian population, with a focus on women who rarely smoke. METHODS: Data from the Malaysian Epidemiological Investigation of Rheumatoid Arthritis population-based case-control study involving 910 female early RA cases and 910 female age-matched controls were analysed. Self-reported information on ever/never occupationally exposed to textile dust was used to estimate the risk of developing anti-citrullinated protein antibody (ACPA)-positive and ACPA-negative RA. Interaction between textile dust and the human leucocyte antigen DR ß-1 (HLA-DRB1) shared epitope (SE) was evaluated by calculating the attributable proportion due to interaction (AP), with 95% CI. RESULTS: Occupational exposure to textile dust was significantly associated with an increased risk of developing RA in the Malaysian female population (OR 2.8, 95% CI 1.6 to 5.2). The association between occupational exposure to textile dust and risk of RA was uniformly observed for the ACPA-positive RA (OR 2.5, 95% CI 1.3 to 4.8) and ACPA-negative RA (OR 3.5, 95% CI 1.7 to 7.0) subsets, respectively. We observed a significant interaction between exposure to occupational textile dust and HLA-DRB1 SE alleles regarding the risk of ACPA-positive RA (OR for double exposed: 39.1, 95% CI 5.1 to 297.5; AP: 0.8, 95% CI 0.5 to 1.2). CONCLUSIONS: This is the first study demonstrating that textile dust exposure is associated with an increased risk for RA. In addition, a gene-environment interaction between HLA-DRB1 SE and textile dust exposure provides a high risk for ACPA-positive RA.

Long-term MRI findings of muslin-induced foreign body granulomas after aneurysm wrapping. A report of two cases and literature review.

Muslin-induced foreign body granulomas are rare delayed complications after wrapping of intracranial aneurysms. Few small case series have been reported, with a paucity of documented MRI findings. In addition, there are no reports on long-term radiological appearances or temporal evolution of conservatively managed patients. We thus report on the long-term radiological and clinical follow-up of two patients with asymptomatic muslin-induced foreign body granulomas after wrapping of recurrent middle cerebral arterial aneurysms. Both patients were successfully managed conservatively and remain asymptomatic three and six years after diagnosis of their granulomas. A literature review confirms that MRI features of muslin-induced foreign body granuloma are typical. Features include focal areas of elevated T2 signal with increased diffusion-weighted signal and thin rim enhancement. To the best of our knowledge, this is the first report to confirm that there is a corresponding reduction in apparent diffusion coefficient, as typical in an intracranial abscess. Thus a history of aneurysm wrapping is critical for diagnosis. Accurate clinical recognition of this exuberant inflammatory response will avoid misdiagnosis as pyogenic abscess or tumor and prevent unnecessary or invasive treatment.

A strategy for in vitro safety testing of nanotitania-modified textile products.

Titanium dioxide nanomaterials are extensively used in many applications, also for modification of textile materials. Toxicological assessment of such textile materials is currently seldom performed, mainly because of lack of appropriate guidelines. The aim of the study was to assess cytotoxic and genotoxic potential of commercially available TiO2 and TiO2/Ag NMs in pristine form as well as polypropylene fibers modified with the NMs. Both titania NMs showed a cytotoxic effect on BALB/3T3 clone A31 and V79 fibroblasts after 72-h exposure. Both NMs induced a weak genotoxic effect in comet assay, with TiO2/Ag being more active. In vitro micronucleus test on human lymphocytes revealed a weak mutagenic effect of both materials after 24h of exposure. In contrast, no significant increase in micronuclei frequency was observed in the in vitro micronucleus test on V79 fibroblasts. The 24-h extracts prepared from polypropylene fibers modified with TiO2/Ag induced a cytotoxic effect on BALB/3T3 cells which strongly depended on the mode of the fibers manufacturing. The study presents a comprehensive approach to toxicity assessment of textile fibers modified with NMs. Proposed approach may form a good "starting point" for improved future testing strategies.

Modified classification of surgical meshes for hernia repair based on the analyses of 1,000 explanted meshes.

BACKGROUND: It is an undisputable fact that meshes have become standard for repair of abdominal wall hernias. Whereas in the late eighties there were only a couple of different devices available, today we have to choose among some hundreds, with lots of minor and major variations in polymer and structure. As most of the minor variations may not lead to significant change in clinical outcome and may be regarded as less relevant, we should focus on major differences. Eventually, this is used to structure the world of mesh by forming groups of textile devices with distinct biological response. Many experimental and some clinical studies have underlined the outstanding importance of porosity, which fortunately, in contrast to other biomechanical quanlities, is widely unaffected by the anisotropy of meshes. METHODS: In accordance with the major manufacturers of meshes, a classification of meshes was derived from a huge pool of textile data based briefly on the following: (1) large pores, (2) small pores, (3) additional features, (4) no pores, (5) 3D structure and (6) biological origin. At 1,000 explanted meshes the value of this classification was evaluated by group-specific assessment of inflammatory and connective tissue reaction. RESULTS: Application of this classification to common products has proved feasable, and each of the six different classes includes devices that in clinical trials failed to show relevant differences in patients' outcome when comparing products within the same group. Furthermore, histological analysis confirmed significant differences in tissue reactions between but not within the different classes. CONCLUSIONS: Classifying implants according to a similar response enables grouping patients into comparable cohorts despite implantation of different devices. Furthermore, it enables the examination of the impact of mesh classes for the various indications even from heterogenous data of registries. Finally and not the least, any grouping supports the surgeon to select the best device to meet the individual need and to tailor patients therapy.

["Teddy bear granuloma", a rare condition: a case report of a 3-year-old child]. / « Teddy bear granuloma ¼, une pathologie rare : à propos du cas d'un enfant de trois ans.

Conjunctival synthetic fiber granulomas, or "Teddy bear granulomas", are rare granulomatous responses to synthetic fabric fibers. We report the case of a 3-year-old boy with no prior infectious or traumatic history, brought in by his parents for an incidentally discovered conjunctival growth in his right eye. Slit lamp examination revealed a 10-mm growth in the inferior fornix surrounding a small greyish foreign body. Surgical excision and histopathology revealed granulomatous inflammatory cell response with foreign body giant cells surrounding exogenous material. This foreign material was birefringent in polarized light, very suggestive of synthetic fabric fibers, which permitted the diagnosis of Teddy bear granuloma. Synthetic fiber granulomas present in children as unilateral, more or less inflammatory growths in the inferior conjunctival fornix. Surgical excision with histopathology makes the diagnosis and effects the cure.

A case of textile dermatitis due to disperse blue on the surgical wound.

Disperse blue (DB) 106 and DB 124 are the most frequent fabric dye allergens inducing textile dermatitis, but contact allergy to them may easily undiagnosed because the clinical picture usually needs high index of suspicion. We present the case of a 35-year-old woman who was referred for a recurred lesion over the incision scar of right total hip replacement surgery, which did not respond to treatment with povidone-iodine, mupirocin, and rifampicin. Patch testing, conducted with a European standard series and therapeutics that were used in the treatment of the lesion, revealed a positive reaction to dispersion mix blue 106/124. The patient was questioned in detail and reported that she has been wearing dark-colored synthetic panties for long years. The correlation was done between the positive antigen in the patch test and the clinical findings. The patient was treated with a corticosteroid cream for 2 weeks. She did not wear any dark-colored synthetic panties afterward and no flare-up was seen in the follow-up period. In this report, we emphasize the importance of detailed questioning of patients and that contact dermatitis should be considered potential cause of dermatitis at skin sites where the barrier function is compromised.

Cytogenetic biomonitoring of carpet fabric workers using micronucleus frequency, nuclear changes, and the calculation of risk assessment by repair index in exfoliated mucosa cells.

The micronucleus (MN) assay in exfoliated buccal cells is a minimally invasive method for monitoring genetic damage in human populations and is used as an indicator of genotoxic exposition, as it is associated with chromosome aberrations. In this study, we evaluated MN frequencies and other nuclear changes (NCs), such as karyorrhexis (KR), karyolysis (KL), broken egg (BE), and binucleus in buccal mucosa cells of 50 carpet fabric workers (25 smokers and 25 nonsmokers) and 50 healthy control subjects (25 smokers and 25 nonsmokers). Microscopic observation of 2000 cells per individual was performed in both workers and control subjects. In both the control group and the exposed group, for each person a repair index (RI) was calculated via the following formula: (KR+KL)/(BE+MN). The results showed a statistically significant increase in the frequency of MN in buccal epithelial cells of exposed group compared with control group. There is a significant difference between worker and control groups (p<0.001) for RI. We believe that the calculation of RI values, in addition to nuclear changes, presents a new approach in risk assessment in relation to occupational exposure.

Textile allergy--the Melbourne experience.

BACKGROUND: Textile allergy is a well-established entity, but there are relatively few Australian reports in this area. OBJECTIVES: To report the combined experience of textile contact dermatitis from the general and occupational contact dermatitis clinics at the Skin and Cancer Foundation, Melbourne, Victoria, Australia. PATIENTS/METHODS: On the basis of the clinical suspicion of textile allergy, 2069 patients were tested with a textile series. RESULTS: One hundred and fifty-seven (7.6%) patients reacted to any of the textile-related allergens. The most common allergen was Basic Red 46 (20.2% of the positive reactions), followed by Disperse Blue 106 and Disperse Blue 124 (11.8% and 11.2%, respectively). Reactions to formaldehyde and formaldehyde-releasing chemicals accounted for 30.6% of the concomitant reactions, and reactions to p-phenylenediamine accounted for 12.6% of the concomitant reactions. The use of Disperse Blue mix yielded only 12.2% of patients sensitive to either of these two allergens, and it is not endorsed as a screening agent for textile dye allergy. CONCLUSION: Textile allergy is not uncommon. In Melbourne, Basic Red 46 in inexpensive, dark-coloured, acrylic-blend, men's work socks is the most important cause. It is important to test with samples of patients' clothing.

Long-term effects of work cessation on respiratory health of textile workers: a 25-year follow-up study.

RATIONALE: The degree to which chronic respiratory health effects caused by exposures to cotton dust and endotoxin is reversible after cessation of textile work is unknown. OBJECTIVES: To investigate changes in lung function and respiratory symptoms after cessation of textile work and to determine whether past exposure to cotton dust and endotoxin or smoking history modify the associations. METHODS: We performed a prospective cohort study consisting of 447 cotton textile workers exposed to cotton dust and 472 unexposed silk textile workers, with a 25-year follow-up. Spirometry testing and respiratory questionnaires were conducted at 5-year intervals. Generalized estimated equations were used to model the average 5-year change in FEV(1) and odds ratios of respiratory symptom prevalence. MEASUREMENTS AND MAIN RESULTS: Years since cessation of textile work was positively associated with 11.3 ml/yr and 5.6 ml/yr gains in 5-year FEV(1) change for cotton and silk workers, respectively. Among male cotton workers, smokers gained more FEV(1) per year after cessation of exposure than did nonsmokers, and the risk of symptoms of chronic bronchitis and byssinosis was larger for smoking than for nonsmoking male cotton workers. CONCLUSIONS: Cessation of textile work was significantly associated with improvement in lung function and respiratory symptoms. The positive effect of work cessation was greater for cotton workers than for silk workers. For cotton workers, the improvement in lung function loss after cessation of textile work was greater among smokers, but no differences were observed for silk workers.

Allergic contact dermatitis from formaldehyde textile resins.

Formaldehyde-based resins have been used to create permanent-press finishes on fabrics since the 1920s. These resins have been shown to be potent sensitizers in some patients, leading to allergic contact dermatitis. This review summarizes the history of formaldehyde textile resin use, the diagnosis and management of allergic contact dermatitis from these resins, and current regulation of formaldehyde resins in textiles.

Endotoxin exposure and lung cancer risk: a systematic review and meta-analysis of the published literature on agriculture and cotton textile workers.

OBJECTIVE: To examine the association between exposure to endotoxins and lung cancer risk by conducting a systematic review and meta-analysis of epidemiologic studies of workers in the cotton textile and agricultural industries; industries known for high exposure levels of endotoxins. METHODS: Risk estimates were extracted from studies published before 2009 that met predefined quality criteria, including 8 cohort, 1 case-cohort, and 2 case-control studies of cotton textile industry workers, and 15 cohort and 2 case-control studies of agricultural workers. Summary risk estimates were calculated using random effects meta-analyses. Potential sources of heterogeneity were explored through subgroup analyses. RESULTS: The summary risk of lung cancer was 0.72 (95% CI, 0.57-0.90) for textile workers and 0.62 (0.52-0.75) for agricultural workers. The relative risk of lung cancer was below 1.0 for most subgroups defined according to sex, study design, outcome, smoking adjustment, and geographic area. Two studies provided quantitative estimates of endotoxin exposure and both studies tended to support a dose-dependent protective effect of endotoxins on lung cancer risk. CONCLUSION: Despite several limitations, this meta-analysis based on high-quality studies adds weight to the hypothesis that occupational exposure to endotoxin in cotton textile production and agriculture is protective against lung cancer.

Lichen amyloidosis induced on the upper back by long-term friction with a nylon towel.

Primary localized cutaneous amyloidosis can take several clinical forms. In Asia, macular amyloidosis caused by prolonged friction from a rough nylon towel or brush is common, and macular amyloidosis and lichen amyloidosis occasionally occur together, as so-called biphasic amyloidosis. We report herein the case of an 83-year-old Japanese man with lichen amyloidosis caused by prolonged nylon towel friction. This patient presented with unique symmetrical papular lesions on the upper back and shoulders. Lesions comprised slightly shiny, brownish, fine uniform papules approximately 0.5 mm in diameter, showing a partially linear, annular or rippled arrangement. Although this case was caused by prolonged nylon towel friction, no coexisting macular lesions could be found. To the best of our knowledge, this represents the first case of lichen amyloidosis induced by nylon towel friction in the absence of the macular amyloidosis that is usually observed in such cases. We instructed the patient to stop the habit of nylon towel rubbing and prescribed a topical steroid ointment and cepharanthine. After 6 months of treatment, papular lesions became clearly flatter.

Experimental study of the impact of the textile structure of mesh endoprostheses for the efficiency of reconstruction of the anterior abdominal wall.

Endoprostheses made from knitted fabric of 3 loop types were used for hernioplasty in rats. Biocompatibility of implanted textile constructions was evaluated after 6 months. The intensity of inflammatory reaction and types of complications in animals depended on the loop type and method of finishing of the mesh endoprosthesis tissue.