The future of chemical pleurodesis: A review of novel and investigational sclerosant agents

Chemical pleurodesis is a technique in which an injurious and inflammatory substance is instilled into the pleural cavity to cause adhesion and fibrosis. It is commonly used in the management of recurrent malignant pleural effusions. Historically, many different types of sclerosants have been described, though only a few, including talc, the tetracycline derivatives, and anti-septic compounds such as silver nitrate and iodopovidone, have found their way into mainstream use. However, over the past several years, there has been increasing interest in alternative pleurodesis agents. In this review, we will explore future directions in the field, with an eye toward novel and investigational agents.

A review of the mesotheliogenic potency of cleavage fragments found in talc

It has long been recognized that amphibole minerals, such as cleavage fragments of tremolite and anthophyllite, may exist in some talc deposits. We reviewed the current state of the science regarding the factors influencing mesotheliogenic potency of cleavage fragments, with emphasis on those that may co-occur in talc deposits, including dimensional and structural characteristics, animal toxicology, and the most well-studied cohort exposed to talc-associated cleavage fragments. Based on our review, multiple lines of scientific evidence demonstrate that inhaled cleavage fragments associated with talc do not pose a mesothelioma hazard.

Beyond diagnosis: a narrative review of the evolving therapeutic role of medical thoracoscopy in the management of pleural diseases

Background and Objective

Medical thoracoscopy (MT) is an endoscopic technique performed by interventional pulmonologists with a favorable safety profile and few contraindications, providing diagnostic and therapeutic intervention in a single sitting. This narrative review was designed to summarize the therapeutic role of MT based on the latest results from the available literature.

Methods

Pertinent literature published in English, relative to human studies, between 2010-2022 was searched in Medline/PubMed and Cochrane databases. Publications regarded as relevant were considered for inclusion in this review; additional references were added based on the authors' knowledge and judgment. The review considered population studies, meta-analyses, case series, and case reports.

Key Content and Findings

MT has mostly been described and is currently used globally in the diagnostic approach to exudative pleural effusion of undetermined origin. Carefully evaluating the literature, it is clear that there is initial evidence to support the use of MT in the therapeutic approach of malignant pleural effusion, pneumothorax, empyema, and less frequently hemothorax and foreign body retrieval.

Conclusions

MT is an effective procedure for treating the clinical entities presented in this document; it must be carried out in selected patients, managed in centers with high procedural expertise. Further evidence is needed to assess the optimal indications and appropriate patients' profiles for therapeutic MT. The endpoints of length of hospital stay, surgical referral, complications and mortality will have to be considered in future studies to validate it as a therapeutic intervention to be applied globally.

Influence of Talc on the Properties of Silicone Pressure-Sensitive Adhesives

The article describes new silicone self-adhesive adhesives modified with the addition of talc. The obtained self-adhesive materials were characterized to determine their adhesive properties (adhesion, cohesion, and adhesion) and functional properties (pot life of the composition, shrinkage, and thermal properties of adhesives). Novel materials exhibited high thermal resistance above 225 °C while maintaining or slightly reducing other values (adhesion, cohesion, shrinkage, and tack). Selected composition: T 0.1 was used to prepare self-adhesives in industrial-scale production. Moreover, conducted test results revealed that the addition of talc delayed the thermal decomposition of the adhesive and provided reduced intensity of smoke emissions during combustion as well as the flammability of the adhesive layer.

A Comparison of the Efficacies of OK-432 and Talc Slurry for Pleurodesis in Patients with Prolonged Air Leak after Pulmonary Resection

PURPOSE

A prolonged air leak (PAL) is one of the common postoperative complications of pulmonary resection. The aim of this study was to evaluate the efficacy and safety of pleurodesis with sterile talc or OK-432 for postoperative air leak.

METHODS

Patients with postoperative air leak who received chemical pleurodesis using sterile talc or OK-432 were retrospectively identified from medical records data. For pleurodesis with either agent, prior assessment and approval by the hospital safety department were carried out for each case, in addition to individual consent.

RESULTS

Between February 2016 and June 2022, 39 patients had PALs and underwent chemical pleurodesis. Among them, 24 patients received pleurodesis with talc (Talc group) and 15 with OK-432 (OK-432 group). The leak resolved after less than two pleurodesis treatments in 22 patients (91.7%) in the Talc group compared with 14 patients (93.3%) in the OK-432 group. Pleurodesis significantly increased white blood cell counts, C-reactive protein concentration, and body temperature in the OK-432 group compared with that in the Talc group (p <0.001, p = 0.003, and p <0.001, respectively).

CONCLUSIONS

Pleurodesis with talc may be an effective treatment option for postoperative air leak. Our findings suggest that talc was as effective as OK-432 and resulted in a milder systemic inflammatory response.

Gel Polymer Electrolytes with Talc as a Natural Mineral Filler and a Biodegradable Polymer Matrix in Sodium-Ion Batteries

A gel polymer electrolyte based on poly(vinyl alcohol) (PVA) is used in sodium-ion batteries (SIBs). The use of biodegradable and water-soluble polymer potentially reduces the negative environmental impact. The other components include sodium salt (NaPF6 ), sulfolane (TMS) as a plasticizer and talc. For the first time, natural and abundant talc has been used as an inert filler in a gel polymer electrolyte. The best results were obtained for moderate amounts of filler (1 and 3 wt%). Then, an increase in the conductivity, transference numbers, and thermal stability of the membranes was observed. Moreover, the presence of talc had a positive effect on the cyclability of the hard carbon electrode. The discharge capacity after 50 cycles of HC|1 % T_TMS|Na and HC|3 % T_TMS|Na was 243 and 225 mAh g-1 , respectively. The use of talc in gel polymer electrolytes containing sodium ions improves the safety and efficiency of SIBs.

Occupational exposure to cosmetic talc and mesothelioma in barbers, hairdressers, and cosmetologists: A systematic review of the epidemiology

Inhalation exposure to cosmetic talc has generated much scientific debate regarding its potential as a risk factor for mesothelioma, a rare, but fatal cancer. Barbers, hairdressers, and cosmetologists have regularly used cosmetic talc-containing products, but the collective epidemiological evidence for mesothelioma in these occupations has yet to be described. As such, we conducted a systematic review of PubMed and the National Institute for Occupational Safety and Health's (NIOSH) Numbered Publications list to identify original epidemiological literature reporting measures of association between these occupations and incidence of or death from mesothelioma. Literature screening was performed independently twice, the results of which were summarized and tabulated and underwent a review for their accuracy. A total of 12 studies met our inclusion criteria, including three cohort, six case-control, and three proportionate mortality/registration studies. The data from these studies were collected in 13 European and North American countries, spanning more than 50 years. We supplemented this review with queries of occupational mortality databases that are managed by the Washington State Department of Health and NIOSH for 26 U.S. states. Most findings were null and if statistically significant, nearly all showed an inverse relationship, indicative of a protective effect of these occupations on mesothelioma risk. Overall, the epidemiological evidence does not support an increased risk of mesothelioma for these occupations. This research fills an important data gap on the etiology of mesothelioma in barbers, hairdressers, and cosmetologists, and provides a benchmark for those with comparatively less exposure, such as non-occupational users of similar cosmetic talc-containing products.

"Skin Popping" and "Shooter's Patch" As Manifestations of Intradermal Drug Abuse

Talc, a common adulterant in injectable opioids and filler in oral tablets, is frequently abused as crushed suspensions in injections. This review aims to recognize intradermal drug injection referred to colloquially as "skin popping" or "shooter's patch" as a cause of granulomatous disease and prevention of systemic complications from cutaneous cues.

Systematic review of the association between talc and female reproductive tract cancers

Talc is a hydrous magnesium sheet silicate used in cosmetic powders, ceramics, paints, rubber, and many other products. We conducted a systematic review of the potential carcinogenicity of genitally applied talc in humans. Our systematic review methods adhere to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and incorporated aspects from the US Institute of Medicine (IOM, now the National Academy of Medicine) and several US EPA frameworks for systematic reviews, evaluating and integrating the epidemiological, animal, and mechanistic literature on talc and cancer. We conducted a comprehensive literature search. Detailed data abstraction and study quality evaluation, adapting the Toxic Substances Control Act (TSCA) framework, were central to our analysis. The literature search and selection process identified 40 primary studies that assessed exposure to talc and female reproductive cancer risks in humans (n = 36) and animals (n = 4). The results of our evaluation emphasize the importance of considering biological plausibility and study quality in systematic review. Integrating all streams of evidence according to the IOM framework yielded classifications of suggestive evidence of no association between perineal application of talcum powders and risk of ovarian cancer at human-relevant exposure levels. We also concluded that there is suggestive evidence of no association between genital talc application and endometrial cancer, and insufficient evidence to determine whether a causal association exists between genital talc application and cervical cancer based on a smaller but largely null body of literature.

Influence of talc and hydrogenated castor oil on the dissolution behavior of metformin-loaded pellets with acrylic-based sustained release coating

Multi-unit pellet system (MUPS) is of great interest as it is amenable to customization. MUPS comprises multi-particulates, usually as pellets or spheroids, which can be coated with diffusion barrier coatings. One commonly used diffusion barrier coating is the methacrylic acid copolymer, which can be used as a taste masking, enteric or sustained release polymer. While the versatility of methacrylic acid copolymers makes them pliable for pellet coating, there are impediments associated with their use. Additives commonly required with this polymer, including plasticizer and anti-adherent, have been shown to weaken the film strength. The objective of this study was to investigate the impact of osmotic pressure within the core on the sustained release coat integrity and functionality. Hydrogenated castor oil (HCO) was chosen as the additive to be studied. Metformin-loaded pellets, prepared via extrusion-spheronization, were coated with ethyl acrylate and methyl methacrylate copolymer (Eudragit RS 30 D) with talc, talc-HCO, or HCO to different coat thicknesses. Drug release was investigated using the USP dissolution apparatus 2 and an ultraviolet imager. The swelling of the pellets when wetted was monitored by video imaging through a microscope. When coated to 7.5 % coat weight gain, coats with HCO slowed down drug release more than the other pellets. The pellets also swelled the most, which suggests that they were more resistant to the osmotic pressure exerted by metformin. For drugs which exert high osmotic pressure, HCO can serve as an efficient alternative to talc in the preparation of methacrylic acid copolymer coatings.

Talc Inhalation in Rats and Humans: A Review and Appraisal of Available Evidence

BACKGROUND

Current information on the health effects and toxicology of talc suggests that this may lead to a specific target organ toxicity arising from repeated exposure (STOT-RE) classification.

OBJECTIVE

To provide an assessment of the currently available inhalation toxicity data on talc and to put these data in the perspective of other poorly soluble low-toxicity particles.

METHODS

A database of 177 articles was gathered from different sources.

RESULTS

Relevant animal data sets were subjected to a quality review, and epidemiological studies on talc and lung effects published since 2016 were reviewed.

CONCLUSIONS

Of nine original inhalation studies reviewed, only one study using rats and mice met the criteria that are needed to include for a reliable evaluation for STOT-RE. Together with the pulmonary effects observed in exposed talc miners, a STOT-RE 1 classification is warranted.

Liquid phase exfoliation of talc: effect of the medium on flake size and shape

Industrial applications of nanomaterials require large-scale production methods, such as liquid phase exfoliation (LPE). Regarding this, it is imperative to characterize the obtained materials to tailor parameters such as exfoliation medium, duration, and mechanical energy source to the desired applications. This work presents results of statistical analyses of talc flakes obtained by LPE in four different media. Talc is a phyllosilicate that can be exfoliated into nanoflakes with great mechanical properties. Sodium cholate at two different concentrations (below and at the critical micelar concentration), butanone, and Triton-X100 were employed as exfoliation medium for talc. Using recent published statistical analysis methods based on atomic force microscopy images of thousands of flakes, the shape and size distribution of nanotalc obtained using the four different media are compared. This comparison highlights the strengths and weaknesses of the media tested and hopefully will facilitate the choice of the medium for applications that have specific requirements.

Platelet-Rich Plasma for Pleurodesis: An Experimental Study in Rabbits

Background and Objectives: This study was designed to evaluate platelet-rich plasma (PRP) as a method of pleurodesis in a rabbit model. Pleurodesis with PRP was compared against the gold-standard use of talc. The secondary evaluation assessed the ideal time for achieving pleurodesis. Materials and Methods: 25 healthy New Zealand white rabbits were assigned to three groups, as follows: 12 animals in the first and second groups, as well as one animal with no intervention in the final group, which was used as a control. The talc pleurodesis group (baseline) underwent pleurodesis with sterile talc, which is the gold-standard sclerosing agent used for pleurodesis. The PRP group underwent pleurodesis using autologous PRP. The last group had one rabbit with no intervention. A total of 12 rabbits (n = 6 for the talc pleurodesis group and n = 6 for the PRP group) were sacrificed 3 days (72 h) after the intervention, and 12 rabbits (n = 6 for the talc pleurodesis group and n = 6 for the PRP group) were sacrificed 6 days (144 h) after the intervention. In both the talc and PRP group, FBC and CRP were measured before the intervention and in 3 or 6 days afterwards, respectively. The pleura and the lungs were evaluated histopathologically. Results: Macroscopically, there were no statistically significant differences between the two groups. In terms of microscopic findings, there were no statistically significant differences in inflammatory reactions provoked in the visceral and parietal pleura between the PRP and talc. In addition, with talc pleurodesis, a foreign-body reaction was observed in about 50% of the cases, which was not observed with PRP. In terms of inflammation between 3 and 6 days, there were no statistically significant differences with PRP, there was only a statistically significant difference between 3 and 6 days regarding the parietal pleura in the talc group. Conclusions: The instillation of autologous PRP in the pleural cavity shows promise in achieving pleurodesis. The efficacy of PRP as a pleurodesis agent should be examined further.

Systematic review of the scientific evidence of the pulmonary carcinogenicity of talc

We conducted a systematic review to assess the potential pulmonary carcinogenicity of inhaled talc in humans. Our systematic review methods adhere to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and incorporated aspects from the US Institute of Medicine (IOM) and several United States (US) Environmental Protection Agency (EPA) frameworks for systematic reviews. A comprehensive literature search was conducted. Detailed data abstraction and study quality evaluation, adapting the US Toxic Substances Control Act (TSCA) framework, were central to our analysis. The literature search and selection process identified 23 primary studies that assessed exposure to talc and pulmonary cancer risks in humans (n = 19) and animals (n = 3). Integrating all streams of evidence according to the IOM framework yielded classifications of suggestive evidence of no association between inhaled talc and lung cancer and pleural mesothelioma at human-relevant exposure levels.

Characterization of asbestos exposures associated with the use of facial makeups

There has been renewed interest in the safety of cosmetics that may contain asbestos or other elongate mineral particles at very low levels as a naturally occurring contaminant. The authors evaluated asbestos exposure during the application of facial makeups in a constructed chamber simulating a bathroom space. The facial makeups tested included products previously found to have very low or "trace" asbestos content by governmental and commercial laboratories using a variety of bulk analysis methods. Tremolite asbestos was detected in five of 54 personal air samples and three of 72 area air samples in 18 simulations. The calculated geometric mean and 95th percentile task-based asbestos concentration associated with personal facial makeup use in this study, incorporating censored data, is 0.0015 and 0.0018 fiber per cubic centimeter (f/cc), respectively, with a corresponding 95th percentile 24-h time-weighted average (TWA) asbestos concentration of 0.00008 f/cc for three applications per day in a simulated bathroom with no active ventilation. Based on these results, cumulative non-occupational asbestos exposures confer a less than one in 1,000,000 risk of asbestos-related disease based on many typical usage patterns and less than 1/100,000 risk with upper-end lifetime usage patterns, using the US Environmental Protection Agency asbestos risk model.

Diagnosis and Management of Malignant Pleural Effusion: A Decade in Review

Malignant pleural effusion (MPE) is a common complication of thoracic and extrathoracic malignancies and is associated with high mortality. Treatment is mainly palliative, with symptomatic management achieved via effusion drainage and pleurodesis. Pleurodesis may be hastened by administering a sclerosing agent through a thoracostomy tube, thoracoscopy, or an indwelling pleural catheter (IPC). Over the last decade, several randomized controlled studies shaped the current management of MPE in favor of an outpatient-based approach with a notable increase in IPC usage. Patient preferences remain essential in choosing optimal therapy, especially when the lung is expandable. In this article, we reviewed the last 10 to 15 years of MPE literature with a particular focus on the diagnosis and evolving management.

Surface Response Analysis for the Optimization of Mechanical and Thermal Properties of Polypropylene Composite Drawn Fibers with Talc and Carbon Nanotubes

A large portion of the produced Polypropylene (PP) is used in the form of fibers. In this industrially oriented study, the development of composite PP drawn fibers was investigated. Two types of fillers were used (ultra-fine talc and single-wall carbon nanotubes). Optimization of the thermal and mechanical properties of the produced composite drawn fibers was performed, based on the Box-Behnken design of experiments method (surface response analysis). The effect of additives, other than the filler, but typical in industrial applications, such as an antioxidant and a common compatibilizer, was investigated. The drawing ratio, the filler, and the compatibilizer or the antioxidant content were selected as design variables, whereas the tensile strength and the onset decomposition temperature were set as response variables. Fibers with very high tensile strength (up to 806 MPa) were obtained. The results revealed that the maximization of both the tensile strength and the thermal stability was not feasible for composites with talc due to multiple interactions among the used additives (antioxidant, compatibilizer, and filler). Additionally, it was found that the addition of talc in the studied particle size improved the mechanical strength of fibers only if low drawing ratios were used. On the other hand, the optimization targeting maximization of both tensile strength and thermal stability was feasible in the case of SWCNT composite fibers. It was found that the addition of carbon nanotubes improved the tensile strength; however, such improvement was rather small compared with the tremendous increase of tensile strength due to drawing.

Experimental Investigation of Polypropylene Composite Drawn Fibers with Talc, Wollastonite, Attapulgite and Single-Wall Carbon Nanotubes

Isotactic polypropylene (PP) composite drawn fibers were prepared using melt extrusion and high-temperature solid-state drawing at a draw ratio of 7. Five different fillers were used as reinforcement agents (microtalc, ultrafine talc, wollastonite, attapulgite and single-wall carbon nanotubes). In all the prepared samples, antioxidant was added, while all samples were prepared with and without using PP grafted with maleic anhydride as compatibilizer. Material characterization was performed by tensile tests, differential scanning calorimetry, thermogravimetric analysis and Fourier transform infrared spectroscopy. Attapulgite composite fibers exhibited poor results in terms of tensile strength and thermal stability. The use of ultrafine talc particles yields better results, in terms of thermal stability and tensile strength, compared to microtalc. Better results were observed using needle-like fillers, such as wollastonite and single-wall carbon nanotubes, since, as was previously observed, high aspect ratio particles tend to align during the drawing process and, thus, contribute to a more symmetrical distribution of stresses. Competitive and synergistic effects were recognized to occur among the additives and fillers, such as the antioxidant effect being enhanced by the addition of the compatibilizer, while the antioxidant itself acts as a compatibilizing agent.

Douching or Perineal Talc Use and Prevalent Fibroids in Young African American Women

Background: Black women are at an increased risk of developing fibroids, but the cause is unclear. Douching and perineal talc use are common lifestyle exposures among Black women, and may be risk factors for fibroid development. Materials and Methods: This cross-sectional study consisted of Black women 23-35 years of age in the metropolitan Detroit area (n = 1693) without prior diagnoses of fibroids and intact uteri. Main exposures were ever douching (yes/no) and any perineal talc use (ever/never). Main outcomes were prevalent fibroids at baseline (yes/no) and total fibroid volume at baseline (no fibroids/ Collapse

Key Words

• Women's Health
• douching
• health disparities
• talc
• uterine leiomyoma

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MESH Headings

• Black or African American
• Cross-Sectional Studies
• Female
• Humans
• Leiomyoma/epidemiology
• Prospective Studies
• Talc/adverse effects
• Therapeutic Irrigation
• Uterine Neoplasms

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Grants

• R00 NR017191 NINR NIH HHS

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Affiliation(s)

Maya A. Wright Department of Epidemiology, University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Chapel Hill, North Carolina, USA
Kristen R. Moore Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
Kristen Upson Department of Epidemiology and Biostatistics, College of Human Medicine, Michigan State University, East Lansing, Michigan, USA
Donna D. Baird Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
Helen B. Chin Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA

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Starch flow behavior alone and under different glidants action using the shear cell method

The objective of this work was to analyze the flow behavior of a commonly used filler (pregelatinised starch) and the effect of two of the most used lubricants (talc and colloidal silicon dioxide). The studies were carried out according to the conventional methods (Angle of Repose, Bulk and Tapped densities and from these the Compressibility Index) and shear cell methods (Brookfield Powder Flow Tester apparatus) described in European Pharmacopeia (Ph. Eur.). The results showed some surprising and unexpected values for the flow behavior of this filler under influence of the methods and the used glidants. Regarding pure starch and mixtures containing talc, the flow behavior was similar between them and the Flow Index (ff_c) values varied between 1.8 and 4 (very cohesive and cohesive) as consolidation stress (σ₁) increased. In this case, the glidant effect was not observed. However, for the mixtures of starch with colloidal silicon dioxide this effect was observed providing Flow Index (ff_c) values between 2.6 and 8.9 (cohesive and easy-flowing) as consolidation stress (σ₁) increased. Other parameters that are also used to characterize flow properties, more specifically, within silos, chutes and hoppers, such as effective angle of internal friction (φe), effective angle of wall friction (φx), critical arching and critical rathole values, provided similar information. Based in the obtained results from all tests it can be said that the talc did not induce improvement on the starch flow behavior in the used conditions in opposition to the effect produced by colloidal silicon dioxide.HighlightsExample 1. A good flowability of powders is needed in order to be compressed/filled;Example 2. The overcome the poor flow it is usual to use glidants;Example 3. CSD improved the pregelatinised starch (Starch 1500®) flow;Example 4. Talc do not have relevant effect in the pregelatinised starch (Starch 1500®) flow;Example 5. Powder FlowTester method showed more complete and consistent results.

Flow and performance effects of talc alternatives on powder cosmetic formulations

OBJECTIVE

To explore the performance effects of fumed silica and cornstarch as alternatives to talc in cosmetic powder formulations.

METHODS

FT4 Powder Rheometer from Freeman Technology was used to test the flowability and compressibility of compact powder formulation samples containing talc, fumed silica and cornstarch at varying concentrations. The colour of the samples is evaluated by physical observation.

RESULTS

The results show that the concentration of these additives influences the performance of cosmetic powder formulations. Improved compressibility is assessed as an increase in the compressibility percentage, while improved flowability is assessed by reduction in the flow energy of each sample. Talc shows improved compressibility at a minimum of 10% but would require more than 20% to impart improved flow performance. Fumed Silica shows improved compressibility from as low as 5% and this performance increases as the concentration is increased up to 20%. For the flow effects, fumed silica shows a reduction in the flow energy from as little as 5% and this effect is more drastic as the concentration is increased up to 20%. Cornstarch, however, shows a reverse effect for both compressibility and flowability with increasing flow energy and decreasing compressibility with increasing cornstarch concentration. It shows improved compressibility up to a maximum of 10% and improved flow only at concentrations lower than 5%. For a mixture of cornstarch and fumed silica at a total of 5%, both compressibility and flowability are increased as the concentration of cornstarch is reduced and that of fumed silica increased.

CONCLUSION

Fumed silica and cornstarch are suitable as alternatives to talc in cosmetic powder formulations. Of the two, Fumed silica showed better compressibility and flow effects. However, a mix of both powders had suitable effects on the compressibility, flow and colour of the formulation.

A pediatric case]

Talc is a hydrated magnesium silicate. It was part of traditional infant and young child care for decades. In children, its acute inhalation, generally accidental during diaper changes, although not frequent, is a potentially dangerous condition, and can cause severe respiratory distress and even death. We describe the case of a 14-month child who had an accidental inhalation of talc, chemical pneumonitis and severe respiratory compromise. The patient had acute respiratory distress syndrome requiring mechanical ventilation for one week. There is no standard treatment, we used systemic antibiotics and corticosteroids and aerosol therapy. He did not have complications in other organs or systems. He was hospitalized for ten days. In the follow up, he had isolated episodes of bronchial hyperresponsiveness.

Thermal Preparation and Application of a Novel Silicon Fertilizer Using Talc and Calcium Carbonate as Starting Materials

The deficiency of available silicon (Si) incurred by year-round agricultural and horticultural practices highlights the significance of Si fertilization for soil replenishment. This study focuses on a novel and economical route for the synthesis of Si fertilizer via the calcination method using talc and calcium carbonate (CaCO₃) as starting materials. The molar ratio of talc to CaCO₃ of 1:2.0, calcination temperature of 1150 °C and calcination time of 120 min were identified as the optimal conditions to maximize the available Si content of the prepared Si fertilizer. X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) characterizations elucidate the principles of the calcination temperature-dependent microstructure evolution of Si fertilizers, and the akermanite Ca₂Mg(Si₂O₇) and merwinite Ca₃Mg(SiO₄)₂ were identified as the primary silicates products. The results of release and solubility experiments suggest the content of available metallic element and slow-release property of the Si fertilizer obtained at the optimum preparation condition (Si-OPC). The surface morphology and properties of Si-OPC were illuminated by the results of scanning electron microscope (SEM), surface area and nitrogen adsorption analysis. The acceleration action of CaCO₃ in the decomposition process of talc was demonstrated by the thermogravimetry-differential scanning calorimetry (TG-DSC) test. The pot experiment corroborates that 5 g kg⁻¹ soil Si-OPC application sufficed to facilitate the pakchoi growth by providing nutrient elements. This evidence indicates the prepared Si fertilizer as a promising candidate for Si-deficient soil replenishment.

Genital powder use and risk of uterine cancer: A pooled analysis of prospective studies

When powder is applied to the genital area, it has the potential to reach internal reproductive organs and promote carcinogenesis by irritating and inflaming exposed tissues. Although many studies have considered the association between genital powder use and ovarian cancer risk, the relationship between genital powder use and uterine cancer is less well-studied. We pooled data from four large, prospective cohorts (the Nurses' Health Study, the Nurses' Health Study II, the Sister Study and the Women's Health Initiative - Observational Study). We used Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for prespecified confounders. In total, 209 185 women were included, with 37% reporting ever genital powder use. Over a mean 14.5 years of follow-up, 3272 invasive uterine cancers were diagnosed. There was no overall association between ever genital powder use and uterine cancer (HR = 1.01, 95% CI: 0.94-1.09), with little difference observed for frequent (≥1 times/week) vs never use (HR = 1.05, 95% CI: 0.95-1.16; P-for-trend = .46). Long-term use (>20 years; HR = 1.12, 95% CI: 0.96-1.31; P-for-trend = 0.14) was associated with a small, but not statistically significant, increase in risk, compared to never use. There were not clear differences by uterine cancer histologic subtypes or across strata of relevant covariates, including race/ethnicity, follow-up time, menopausal status and body mass index. The results of this large, pooled analysis do not support a relationship between the use of genital powder and uterine cancer, although the positive associations observed for long-term use may merit further consideration.

Primary Ovarian Mesothelioma: A Case Series with Electron Microscopy Examination and Review of the Literature

Primary ovarian mesothelioma is a rare, aggressive neoplastic disease with a poor prognosis. At onset, the tumor is only rarely limited to the ovaries and usually already widespread in the peritoneum. The rarity of this entity and the difficulties differentiating it from either ovarian carcinoma or peritoneal mesothelioma may lead to frequent misdiagnoses and may raise some concerns about its histogenesis. Thus, reporting such rare cases is fundamental to gain greater awareness of this neoplasm and try to answer unsolved questions. Herein, we described four cases of histological diagnoses of ovarian mesothelioma extrapolated by the regional mesothelioma register of Apulia (southern Italy). In all cases, a detailed medical history was collected according to national mesothelioma register guidelines. A broad panel of antibodies was used for immunohistochemistry to confirm the diagnoses. Moreover, ovarian tissue samples were also examined by transmission and scanning electron microscopy, detecting asbestos fibers and talc crystals in two cases. Because of the few cases described, we reviewed the English literature in the Medline database, focusing on articles about ovarian mesothelioma "misclassification", "misdiagnosis", "diagnostic challenge" or "diagnostic pitfall" and on unsolved questions about its histogenesis and possible risk factors.

Primary human mesothelial cell culture in the evaluation of the inflammatory response to different sclerosing agents used for pleurodesis

The mechanisms of chemical pleurodesis are still not fully explained. We aimed to evaluate the feasibility of using primary biopsy‐derived human mesothelial cells to establish an in vitro culture and to assess the response of pleural mesothelial cells to different sclerosing agents. Talc, povidone‐iodine, doxycycline, and TGF‐β were used at different doses to stimulate pleural mesothelial cells. After 6 and 24 h, mRNA expression of interleukin (IL)‐1β, IL‐6, IL‐8, TGF‐β, MCP‐1, IL‐17A, and MMP9 was measured in cultured cells, and the protein level of IL‐1β, IL‐6, and IL‐8 was measured in the culture supernatant. The most pronounced response was observed after talc exposure. It was expressed as an increase in IL‐1β concentration in culture supernatant after 24 h of higher talc dose stimulation compared to 6 h of stimulation (17.14 pg/ml [11.96–33.32 pg/ml] vs. 1.84 pg/ml [1.81–1.90 pg/ml], p = 0.02). We showed that culture pleural mesothelial cells isolated from pleura biopsy specimens is feasible. Inflammatory responses of mesothelial cells to different sclerosants were highly variable with no consistent pattern of mesothelium reaction neither in terms of different sclerosing agents nor in the time of the most significant reaction. We demonstrated that pro‐inflammatory mesothelial response includes an increase in IL‐1β mRNA expression and protein production. This may suggest the role of IL‐1β in the formation and maintenance of the inflammatory response during pleurodesis.

Immobilization of Caraway Essential Oil in a Polypropylene Matrix for Antimicrobial Modification of a Polymeric Surface

This study investigates antibacterial polymer composites based on polypropylene as modified by caraway essential oil at various concentrations, the latter immobilized on a talc. The caraway essential oil is incorporated in the polypropylene by a thermoplastic processing method. Analysis of the morphology of the composites was carried out by scanning electron microscopy. The chemical composition of the caraway essential oil in addition to its efficiency of incorporation and release were evaluated by GC/MS and Pyrolysis-GC/MS techniques, respectively. Determination was made as to the influence of such incorporation on thermal and tensile properties of the samples, while antibacterial activity was evaluated through conducting disk diffusion tests and measurement with adherence to the ISO 22196:2011 standard. It was found that incorporating the caraway essential oil in the samples did not affect the homogeneity of the thermoplastic-processed composites at any studied concentration. Stress–strain analysis confirmed the plasticizing effect of the essential oil in the polypropylene matrix, in addition to which, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) analysis revealed that the prepared compositions with essential oil exhibited similar thermal properties to neat polypropylene. Results indicated significant antibacterial activity against Staphylococcus aureus and Escherichia coli at the concentration of essential oil of 4.9 ± 0.2 wt% and higher.

Evaluation of the Antimicrobial Protection of Pharmaceutical Kaolin and Talc Modified with Copper and Zinc

Six pharmaceutical pastes were prepared using chemically modified kaolin and talc powders. Tests were conducted to determine their structural and chemical characteristics as well as their antimicrobial protection, thus rendering them suitable for cosmetic and pharmaceutical uses. Kaolin and talc were treated chemically via the cation exchange method to load the clay particles with copper and zinc ions, two cations well known for their antimicrobial properties. Mineralogical analyses were conducted by using X-ray diffraction (XRD) before and after the modification, confirming the mineralogical purity of the samples. Scanning electron microscopy was also used in conjunction with energy dispersed spectroscopy (SEM-EDS) to obtain chemical mapping images, revealing the dispersion of the added metals upon the clay minerals surfaces. Moreover, chemical analysis has been performed (XRF) to validate the enrichment of the clays with each metal utilizing the cation exchange capacity. All modified samples showed the expected elevated concentration in copper or zinc in comparison to their unmodified versions. From the X-ray photoelectron spectroscopy (XPS), the chemical state of the samples' surfaces was investigated, revealing the presence of salt compounds and indicating the oxidation state of adsorbed metals. Finally, the resistance of pastes in microbial growth when challenged with bacteria, molds, and yeasts was assessed. The evaluation is based on the European Pharmacopeia (EP) criteria.

A Review of the Talc Industry's Influence on Federal Regulation and Scientific Standards for Asbestos in Talc

The talc industry and Food and Drug Administration (FDA) have asserted that talc has been asbestos-free since 1976 when the industry created a voluntary specification for the asbestos content of cosmetic talc. However, recent evidence reveals that cosmetic talc is not and never was asbestos-free. This narrative review examines the talc industry's role in delaying and ultimately blocking federal regulation of cosmetic talc from the 1970s to today. We review primary source material, including corporate documents released in recent litigation and FDA documents released in response to Freedom of Information Act requests. Our results indicate that the talc industry exerted considerable influence over three key areas: regulatory proceedings at the FDA; testing methods and the manipulation of test results (including undisclosed results); and press coverage and the medical literature. The talc companies' actions and FDA indifference have had a lasting effect on consumer health, including the regulation of talc by other government agencies.

Asbestos Contamination in Talc-Based Cosmetics: An Invisible Cancer Risk

The lack of regulation and adequate testing of talc-containing personal care products in the U.S. has resulted in the contamination of cosmetics with asbestos. As such, the true exposure of consumers to asbestos is poorly characterized and likely underestimated. In this study, transmission electron microscopy analysis revealed that 3 of 21 powder-based cosmetic products tested were contaminated with amphibole asbestos. One of these contaminated products is expressly marketed for use by children. The presence of asbestos found in products demonstrates the urgency to revise cosmetics policy. Further, talc-based cosmetics may be an overlooked and difficult to characterize source of exposure to asbestos, a known carcinogen.

Evaluation of cellular alterations and inflammatory profile of mesothelial cells and/or neoplastic cells exposed to talc used for pleurodesis

Introdution: To determine the role of Pleural Mesothelial Cells (PMC) and/or Neoplasic Cells (NC) in the initiation and regulation of acute inflammatory response after exposure to talc for evaluating inflammatory mediators and cellular alterations.

Materials and Methods: PMC cultures, human lung (A549) and breast (MCF7) adenocarcinoma cells were divided in 5 groups: 100% PMC, 100% NC, 25% PMC + 75% NC, 50% of each type and 75% PMC + 25% NC. All groups were exposed to talc and measured IL-6, IL-1β, IL-10, TNF-α, TNFRI, pH, LDH, apoptosis and necrosis. Statistical Analysis: One-way Anova.

Results: High IL-6, IL-1β and TNFRI levels were found in PMC and NC exposed to talc. IL-6 was higher at the points of more confluence of PMC. The highest levels of IL-1β and TNFRI were found in mixed cultures. In pure cultures TNFRI was higher in A549 followed by PMC and MCF7. LDH was higher in A549 than PMC. The lowest pH was found in 100% NC. All cell line exposed to talc reduced viability and increased necrosis. Apoptotic cells exposed to talc were higher in pure cultures of NC than in PMC. Mixed cultures of PMC and A549 showed lower levels of apoptosis in cultures with more NC.

Conclusions: PMC after talc exposure participates in the inflammatory process contributing to production of molecular mediators, necessary for effective pleurodesis. Talc acted in NC causing higher rates of apoptosis, contributing in a modest way to tumoral decrease. Different types of tumor cells may respond differently to exposure to talc.

Inhalation Toxicity of Talc

Respirable talc powder (RTP) is a complex mineral mixture of talc along with accessory minerals, including tremolite, anthophyllite, quartz, magnesite, dolomite, antigorite, lizardite, and chlorite. The industrial mining, milling, and processing of talc ore is associated with elevated incidences of fibrotic and neoplastic diseases, which are also seen among workers exposed to RTP in secondary industries and individuals using processed cosmetic talc for personal use. There is controversial evidence of a link between the talc-induced lung diseases and a potential contamination with asbestos fibers. This controversy is fueled by inadequate exposure data and the complex mineralogy and terminology of the accessory minerals. Talc aerosols exhibit a wide range of mineral habits, including particulates and fibrous structures that have dimensional and compositional characteristics related to the development of asbestos-related lung disease. The inhalation toxicology of RTP is based on the analysis of occupational hygiene and animal inhalation studies conducted between the 1940s and the 1990s and more recent mechanistic studies conducted both in vivo and in vitro. The review of talc toxicity studies reveals that the occupational studies provide only equivocal links between any of the components of the aerosols and the development of pulmonary cancer; however, there is substantial evidence of an association between the aerosols and pleural and pulmonary fibrosis and the development of nonmalignant respiratory disease. The animal inhalation and implantation studies appear to be less than optimal, which also appears to be true for the in vivo and in vitro studies. The mechanistic studies have identified the key pathogenic characteristics of asbestos to be long and thin fibers that are durable in lung tissues and fluids. Talc toxicity studies show that talc particles and fibers are durable and can remain in the lung for up to 40 years after the end of exposure. This extended tissue residence is considered to constitute a continuing tissue exposure that is capable of inducing the documented inflammatory and proliferative response. There is less consensus as to whether there is a threshold fiber length effect, as long, thin fibers (>5 μm) form only a small fraction of talc aerosols and the possible role of fibers >5 μm in the translocation from the lung to the pleura and their association with pleural fibrotic and carcinogenic lesions. Long, thin fibers are preferentially deposited in hot spots in the lung, such as airway bifurcations, areas typically associated with the development of lung cancer. The platy structures typical of talc can form oblate structures behaving more as fibers in the air stream, and these have also been shown to deposit preferentially in such locations. The review of the inhalation toxicity of talc provides a plausible explanation for the carcinogenic potential of RTP.

Difficulties in establishing a causal link between chemical exposures and cancer cannot be overcome by court assessments

Scientific data are often used in lawsuits to prove, or dismiss, causation by a claimed factor of a claimed disease. Recent media reports of million-dollar compensations awarded to some cancer patients who had been exposed to certain chemical substances motivated me to examine how solid the causal links really were. Here, I discuss the limitations of epidemiological research on cancer causation and highlight how new knowledge of cancer genetics makes it unrealistic to expect that cancer causation can be clearly demonstrated. I then present two exposure-cancer cases, namely talcum powder-ovarian cancer and glyphosate-non-Hodgkin lymphoma, that led to civil lawsuits decided, in the United States, in favor of the claimants. Both these cancers have several risk factors, among which the claimed exposure presents only a minor, if any, increased risk. Through these cases, I explain why the use of epidemiological data is inappropriate to define causal associations in complex diseases like cancer. I close by suggesting a fairer approach, called proportional liability, to resolving future cancer litigation cases.

A New Animal Model for Pathological Subcutaneous Fibrosis: Surgical Technique and in vitro Analysis

Fibrosis is a condition that affects the connective tissue in an organ or tissue in the restorative or responsive phase as a result of injury. The consequences of excessive fibrotic tissue growth may lead to various physiological complications of deformity and impairment due to hypertrophic scars, keloids, and tendon adhesion without understating the psychological impact on the patient. However, no method accurately quantifies the rate and pattern of subcutaneous induced hypertrophic fibrosis. We, therefore, devised a rodent excisional model to evaluate the extent of fibrosis with talc. Tissue specimens were set on formalin, and paraffin sections for histological, immunohistochemical, and molecular analysis talc was used to induce the fibroproliferative mechanism typical of hypertrophic scars. This pathway is relevant to the activation of inflammatory and fibrotic agents to stimulate human hypertrophic scarring. This model reproduces morpho-functional features of human hypertrophic scars to investigate scar formation and assess potential anti-scarring therapies.

PI3K Catalytic Subunits α and β Modulate Cell Death and IL-6 Secretion Induced by Talc Particles in Human Lung Carcinoma Cells

Hydrated magnesium silicate (or "talc" particles) is a sclerosis agent commonly used in the management of malignant pleural effusions, a common symptom of metastatic diseases, including lung cancers. However, the direct effects of talc particles to lung carcinoma cells, which can be found in the malignant pleural effusion fluids from patients with lung cancer, are not fully understood. Here, we report a study of the signaling pathways that can modulate the cell death and IL-6 secretion induced by talc particles in human lung carcinoma cells. We found that talc-sensitive cells have higher mRNA and protein expression of PI3K catalytic subunits α and β. Further experiments confirmed that modulation (inhibition or activation) of the PI3K pathway reduces or enhances cellular sensitivity to talc particles, respectively, independent of the inflammasome. By knocking down specific PI3K isoforms, we also confirmed that both PI3Kα and -β mediate the observed talc effects. Our results suggest a novel role of the PI3K pathway in talc-induced cell death and IL-6 secretion in lung carcinoma cells. These cellular events are known to drive fibrosis, and thus further studies of the PI3K pathway may provide a better understanding of the mechanisms of talc sclerosis in the malignant pleural space.

Malignant mesothelioma following repeated exposures to cosmetic talc: A case series of 75 patients

BACKGROUND

Asbestos is the primary known cause of malignant mesothelioma. Some cosmetic talc products have been shown to contain asbestos. Recently, repeated exposures to cosmetic talc have been implicated as a cause of mesothelioma.

METHODS

Seventy-five individuals (64 females; 11 males) with malignant mesothelioma, whose only known exposure to asbestos was repeated exposures to cosmetic talcum powders, were reviewed in medical-legal consultation. Out of the 75 cases, 11 were examined for asbestiform fibers.

RESULTS

All subjects had pathologically confirmed malignant mesothelioma. The mean age at diagnosis was 61 ± 17 years. The mean latency from exposure to diagnosis was 50 ± 13 years. The mean exposure duration was 33 ± 16 years. Four mesotheliomas (5%) occurred in individuals working as barbers/cosmetologists, or in a family member who swept the barber shop. Twelve (16%) occurred in individuals less than 45 years old (10 females; 2 males). Forty-eight mesotheliomas were pleural (40 females; 8 males), 23 were peritoneal (21 females; 2 males). Two presented with concomitant pleural and peritoneal disease. There was one pericardial, and one testicular mesothelioma. The majority (51) were of the epithelioid histological subtype, followed by 13 biphasic, 8 sarcomatoid, 2 lymphohistiocytoid, and 1 poorly differentiated. Of the 11 individuals whose nontumorous tissues were analyzed for the presence of asbestiform fibers, all showed the presence of anthophyllite and/or tremolite asbestos.

CONCLUSIONS

Mesotheliomas can develop following exposures to cosmetic talcum powders. These appear to be attributable to the presence of anthophyllite and tremolite contaminants in cosmetic talcum powder.

Influence of the progression of pleural neoplasia on the outcome of pleurodesis in mice

Purpose: Experimental study aimed at evaluating whether pleural neoplastic disease is associated with the degree of pleural fibrosis over time caused by talc pleurodesis. The study describes changes in levels of inflammatory mediators and determines whether the course of time involved in progression of neoplastic pleural disease is the factor that influences safety of talc pleurodesis usage in mice.

Materials and Methods: Animals were randomized into two groups: Cancer group (CG) that received intrapleural injection of Lewis cells or Saline group (SG) that received saline injection. After, the animals were subdivided into Early (pleurodesis 3 days after pleural injection) and Late (pleurodesis 7 days after pleural injection) groups. Half of the animals in each group were euthanized 24 hours after pleurodesis (to obtain the inflammatory data); the remaining animals were killed after 8 days (to obtain the scores of pleural fibrosis).

Results: CGs had lower fibrosis scores than SGs comparing early phases to late phases. Inflammation scores were lower in CGs, particularly in Late group. In SGs the inflammation was intense in 100% of the animals.

In Late CG group pleural adhesions had the lowest scores; we found intense fibrosis only in SGs. VEGF and LDH levels had increased in animals with cancer, particularly in Late group. Systemic distribution of talc occurred only in Late CG.

Conclusions: The time for pleural neoplasia to evolve is inversely proportional to the degree of pleural fibrosis. Earlier pleurodesis yielded the best results related to fibrosis, with less systemic inflammation and is safer in mice.

Multimodal approach to the management of malignant pleural effusions: role of thoracoscopy with pleurodesis and tunneled indwelling pleural catheters

Malignant pleural effusion (MPE) is associated with a median survival of 3–6 months and causes significant symptoms affecting the overall quality of life in patients with advanced malignancies. Despite the high incidence of recurrent MPE, less than 25% of patients undergo a definitive pleural intervention as recommended by guidelines. In this review, we summarize the latest guidelines for management of MPE by various societies and discuss a multimodal approach in these patients using thoracoscopy with pleurodesis using talc insufflation and placement of tunneled indwelling pleural catheters (TIPC). We also address the role of diagnostic thoracoscopy for histologic and molecular diagnosis and outline our approach to patients with known or suspected MPE.

The Behavior of Gangue During the Flotation of a Sulfidic PGM-Bearing Ore in Response to Various Monovalent and Divalent Ions in Process Water

Mineral concentrators are becoming increasingly aware of the importance of the quality of the water that they feed into their milling and flotation circuits. It is speculated that different inorganic constituents of process water may yield different flotation results owing to the electrolyte–reagent–mineral interactions occurring in the pulp phase. These interactions are said to be specific to ion type, reagent type, and mineral or ore type. It therefore stands to reason that there is a need to develop an understanding of the specific ion effects on both the pulp phase and the froth phase phenomena, such that the chemistry and the quality of process water can be monitored and controlled in a manner that does not negatively affect the flotation performance. Previous research has shown that inorganic electrolytes may impact the hydrophobicity and the floatability of mineral particles and could in turn affect froth stability, entrainment, and thus mineral grades and recoveries. In this study, the floatability of a Cu-Ni-PGM-bearing Merensky ore is tested on a bench-scale flotation system in various single salt solutions, viz., CaCl₂, CaSO₄, Ca(NO₃)₂, MgCl₂, Mg(NO₃)₂, MgSO₄, NaCl, NaNO₃, and Na₂SO₄, in order to examine specific ion effects on gangue recovery. Coagulation and zeta potential tests are conducted in order to establish the nature of the impact that specific ions have on the behavior of gangue in flotation. The findings of this work have shown that single salt solutions containing NO3- ions resulted in a strong depression of gangue compared to those solutions containing Cl⁻ and SO₄²⁻ ions. It was also shown that the divalent Ca²⁺ and Mg²⁺ showed a stronger depression of gangue compared to the monovalent Na⁺. Ca²⁺, in comparison to Na⁺, resulted in an increase in the coagulation of the ore as well as an increase in the zeta potential of talc. Overall, the findings of this paper suggest that the presence of Ca²⁺ and Mg²⁺ in process water would most likely create conditions that promote gangue depression.

The Structure and Mechanical Properties of the Surface Layer of Polypropylene Polymers with Talc Additions

In the presented work the influence of different 3MgO·4SiO₂·H₂O (talc) contents in polypropylene samples on the structure, hardness, elasticity, and friction of the surface layer was investigated. The talc content ranged from 0 to 25 wt.%, and all the samples were obtained in the same conditions by the injection molding process. The analysis of the microstructure was performed by X-ray diffraction. Changes in the hardness and elasticity were determined for three different depths (300, 800, and 4000 nm) using an ultra nano tester. For the purpose of the examination of the friction properties of the obtained compounds, a nano-scratch tester was applied. Increasing the talc content caused growth in the indentation modulus and hardness values. Simultaneously, an effect of decreasing hardness and elastic modulus with increasing indentation depth was observed. The smallest effect size was observed for 25 wt.% talc content, which might suggest that talc addition increased the homogeneity of the observed composites. Scratch tests showed increasing scratch resistance along with increasing talc content for both constant and progressive loads. The growth in talc concentration led to a decrease in the degree of the polypropylene (PP) crystallinity of the surface layer. The exfoliation process occurred in PP composites.

Failure of talc seromadesis for the treatment of subcutaneous chronic seromas after incisional hernia surgery

BACKGROUND AND AIM

Talc poudrage has been used since many years for sclerosing chronic pleural effusion. Several reports have shown good results managing chronic seromas after breast, vascular, and incisional hernia surgeries. The purpose of this study is to determine the utility of talc seromadesis for the management of chronic seromas after incisional hernia surgery.

MATERIALS AND METHODS

Multicentric prospective observational study including patients diagnosed of chronic seromas after incisional hernia surgery. Under local anesthesia and ultrasonographic control, two percutaneous trocars were placed in the seroma, washing the seroma cavity with 0.9% saline solution and aspirating the remaining liquid. A sample of 4 g of talcum powder was introduced in the seroma cavity, and a 15-F drain was left in place. Patients were followed each week during at least 4 weeks after drainage removal.

RESULTS

Between January 2013 and December 2016, a total of six patients were enrolled in the study. Talc poudrage was performed without any complications. Drains were pulled out in a mean time of 3 (range: 2-4) weeks. One case of the chronic seromas was efficiently sclerosed with talc without recurrence in time. In three cases, the seroma recurred, and the final solution was surgical decortication of the seroma. In the other two cases, seroma also recurred and were managed with instillation of ethanol and iodine povidone.

CONCLUSION

In our experience, the management of chronic seromas after incisional hernia repair with talc seromadesis is ineffective and is associated with a high rate of seroma recurrence.

Perineal Talc Use, Douching, and the Risk of Uterine Cancer

BACKGROUND

Perineal talc use and douching could affect the risk of uterine cancer through several possible pathways, including inflammation response, microbiota changes, or endocrine disruption. Two previous cohort studies of the association between talc use and uterine cancer have reported weak positive associations, but we know of no previous evaluations of the relationship between douching and uterine cancer.

METHODS

Using a large prospective cohort, we examined the relationship between incident uterine cancer and self-reported use of talc or douche using Cox proportional hazards models.

RESULTS

After excluding those with prior hysterectomy, 271 of 33,609 women reported incident uterine cancer (mean follow-up = 8.3 years in noncases; maximum 12.6 years). Overall, 26% of women reported ever using talc and 15% reported ever having douched. Ever talc use was associated with an increase in risk of uterine cancer (adjusted hazard ratio [HR] = 1.2; 95% confidence interval [CI] = 0.94, 1.6), with some evidence of a dose-response for frequency of talc use (P-for-trend = 0.07). Ever douching was not associated with uterine cancer risk (HR = 1.0; 95% CI = 0.72, 1.5), with no evidence of a frequency dose-response (P = 0.96). The estimates were similar when we restricted to invasive endometrial cancers, but not when we further restricted to endometroid adenocarcinomas.

CONCLUSION

The positive association we observed between talc use and uterine cancer risk is consistent with findings from previous prospective cohort studies of endometrial cancer. The relationships between uterine cancer and both douching and talc use merit further consideration, particularly as both exposures are preventable.

Influence of the Conditions of Corotating Twin-Screw Extrusion for Talc-Filled Polypropylene on Selected Properties of the Extrudate

The aim of the study was to determine the effect of the application of processing screws with a modified test segment in a corotating twin-screw extruder on selected properties of talc-filled polypropylene extrudate. The test segment was built of trilobe kneading elements and its design modifications refered to changing the distance between the kneading elements and the angle of positions of kneading elements that are relative to each other. The performed tests included the production of extrudate with various degrees of talc-filling using five design solutions of the test segment and then measurements of selected properties, such as tensile strength, elongation at maximum tensile stress, and melt flow rate. Structural studies using scanning electron microscope (SEM) and differential scanning calorimetry (DSC) were also carried out. The study includes not only the description of experimental results but also the determination of empirical models describing the dependence of the properties of the obtained extrudate on the conditions of the extrusion process and the design features of the test segment.

An updated evaluation of potential health hazards associated with exposures to asbestos-containing drywall accessory products

Following a previously published (2012) evaluation of the potential health hazards related to the use of asbestos-containing drywall accessory products, additional information regarding asbestos exposures during the use of accessory products, as well as studies of chrysotile asbestos risk as a function of exposure, have been published in the peer-reviewed literature. The purpose of this analysis is to update the original evaluation with this new information. It was previously estimated that a professional drywaller performing joint compound-associated tasks could have a lifetime cumulative chrysotile exposure of 12-26 f/cc-year. Using conservative assumptions regarding airborne asbestos levels during different drywalling tasks, task duration, and job tenure, we found that a range of 4.3-36.3 f/cc-year is a plausible estimate of a career drywaller's cumulative asbestos exposure from historical joint compound use. The estimated range for bystander exposures would be below (sometimes significantly below) this range depending on the frequency and duration of work near drywallers. Further, the estimated drywaller and bystander total fiber exposures were well below a recently published "no-observed adverse effect level, best estimate" for predominately chrysotile exposures of 89-168 f/cc-year for lung cancer and 208-415 f/cc-year for mesothelioma. We also determined that, even if the chrysotile or possibly talc ingredients in the drywall products had contained asbestiform tremolite, the cumulative tremolite exposures would have been well below a recently published tremolite no-effect level of 0.5-2.6 f/cc-year. Based on our calculations, typical drywall work using asbestos-containing drywall accessory products is not expected to increase the risk of asbestos-related lung cancer or mesothelioma. These conclusions are consistent with the lack of epidemiological evidence that drywall work resulted in an increased incidence of asbestos-related disease in the drywall trades.

Natural Rubber Composites Filled with Crop Residues as an Alternative to Vulcanizates with Common Fillers

This present study is focused on exploring the possibility of using agricultural waste in the form of cereal straw as an active filler of biocomposites. The effect of lignocellulosic filler addition on the multifunctional properties of natural rubber composites was investigated. The results were compared with the properties of vulcanizates containing commonly used reinforcements in elastomer technology (carbon black, silica, chalk, talc). Rubber mixtures filled with straw showed the highest torque increase during rheometric measurements, which indirectly indicated a high degree of crosslinking and hardness of composites. It was found that the effect of straw addition on vulcanization time of elastomer blends was comparable with the results obtained for other conventional fillers. Moreover, the results confirmed that novel composites based on natural rubber filled with crop residues were attractive materials owing to their capacity for the formation of “structure” in combination with a good impact on reinforcement. Vulcanizates with the addition of straw showed the best barrier properties and resistance to thermo-oxidative aging from all tested samples. Furthermore, straw-based composites demonstrated that cereal straw waste could be used as an alternative, biodegradable and eco-friendly reinforcement of natural rubber composites.

The Influence of Talc Addition on the Performance of Polypropylene Membranes Formed by TIPS Method

The effect of talc addition on the morphology of capillary membranes formed by a thermally induced phase separation (TIPS) method was investigated in the presented work. The usability of such formed membranes for membrane distillation was evaluated. Two types of commercial capillary polypropylene membranes, fabricated for microfiltration process, were applied in the studies. A linear arrangement of polymer chains was obtained in the walls of membranes formed without a talc addition. In the case of membranes blended with talc, the linear structure was disordered, and a more porous structure was obtained. The changes in morphology enhanced the mechanical properties of blended membranes, and their lower thermal degradation was observed during 350 h of membrane distillation studies. Long-term studies confirmed the stability of talc dispersion in the membrane matrix. A leaching of talc from polypropylene (PP) membranes was not found during the membrane distillation (MD) process.

Shrinkage Optimization in Talc- and Glass-Fiber-Reinforced Polypropylene Composites

The shrinkage of reinforced polymer composites in injection molding varies, depending on the properties of the reinforcing agent. Therefore, the study of optimal reinforcement conditions, to minimize shrinkage when talc and glass fibers (GF) (which are commonly used as reinforcements) are incorporated into polypropylene (PP), is required. In this study, we investigated the effect of reinforcement factors, such as reinforcement type, reinforcement content, and reinforcement particle size, on the shrinkage, and optimized these factors to minimize the shrinkage of the PP composites. We measured the shrinkage of injection-molded samples, and, based on the measured values, the optimal conditions were obtained through analysis of variance (ANOVA), the Taguchi method, and regression analysis. It was found that reinforcement type had the largest influence on shrinkage among the three factors, followed by reinforcement content. In contrast, the reinforcement size was not significant, compared to the other two factors. If the reinforcement size was set as an uncontrollable factor, the optimum condition for minimizing directional shrinkage was the incorporation of 20 wt % GF and that for differential shrinkage was the incorporation of 20 wt % talc. In addition, a shrinkage prediction method was proposed, in which two reinforcing agents were incorporated into PP, for the optimization of various dependent variables. The results of this study are expected to provide answers about which reinforcement agent should be selected and incorporated to minimize the shrinkage of PP composites.

Stomach Cancer and Exposure to Talc Powder without Asbestos via Chinese Herbal Medicine: A Population-Based Cohort Study

The present investigation was designed to explore the risk of stomach cancer by oral intake of talc powder without asbestos. We conducted a population-based cohort study on a randomly sampled cohort from Taiwan's health insurance database, with population of 1,000,000. The study participants were followed up through 2013. The outcome event of interest was the diagnosis of stomach cancer. The exposure of interest was the prescription of talc powder. Cox regression analyses were performed respectively. There were 584,077 persons without talc exposure and 21,575 talc users, 1849 diagnosed with stomach cancer. Persons with exposure of talc had a higher hazard ratio of stomach cancer (adjusted hazard ratio, 2.13; 95% confidence interval (CI), 1.54⁻2.94; p < 0.001). Classification by cumulative exposure of talc yielded adjusted hazard ratios of stomach cancer of 1.58 (95% CI, 0.79⁻3.17; p = 0.19) and 2.30 (95% CI, 1.48⁻3.57; p < 0.001) among persons with high (>21 g) and medium (6⁻21 g) exposure of talc, as compared to the low-exposure counterparts. Our data demonstrated positive association between increased risk of stomach cancer and oral intake of talc without asbestos. Despite the absence of dose-response effect, there might be a link between stomach cancer and talc.

A case of lung adenocarcinoma complicated by pulmonary talcosis occurring in a patient employed in the confectionery industry

A 73-year-old Japanese man, who worked at a confectionery company for more than 20 years, was diagnosed with a 28 mm nodular lesion in the superior lobe of the right lung by whole-body computed tomography examination. A biopsy revealed the presence of adenocarcinoma. With a diagnosis of a primary lung cancer, a right upper lobectomy was performed. A nodular lesion, 25 × 23 mm in size, was observed in the upper right lobe lung field, and was diagnosed histopathologically as a papillary adenocarcinoma. In addition, fibrous scars in the central part of the tumor showed numerous Langhans and/or foreign body giant cells, and histiocytic cells that had phagocytized numerous small transparent crystals, together with coal powder deposition. The extracted crystals were observed with a scanning electron microscope, and although plate-like structures were observed, ferruginous bodies suggestive of asbestos were not found. The crystals were demonstrated to be talc by powder X-ray diffraction. Herein, we investigated a case of lung adenocarcinoma in a patient with talcosis, with discussions based on a literature search. This collision of talcosis and lung adenocarcinoma adds to an increasing body of knowledge on an apparent association between talc and cancer cases.

Recent developments in pleurodesis for malignant pleural disease

OBJECTIVE

Metastatic pleural effusion (MPE) is one of the most frequent causes of pleural effusion. The aims of the therapeutic management are palliation of symptoms and improvement in patient's quality of life. The first step is a therapeutic thoracentesis. In case of a recurrent MPE, pleural maneuvers can be used to manage symptoms based on either ambulatory pleural drainage or pleurodesis to prevent fluid accumulation. The aim of this review is to describe recent advances, according to the best available evidence, in the field of pleurodesis for the management of MPE.

DATA SOURCE AND STUDY SELECTION

Three different searches of the most clinically relevant articles and up-to-date results in the field of pleurodesis for the management of MPE were performed using PubMed. Different indexing terms and time restriction were chosen. From these PubMed searches, 322 articles were respectively found. After cross-checking these three lists and the selection of articles published after January 2010 specially dedicated to the management of MPE by pleurodesis, the abstracts of 106 articles were extracted to feed the corpus of this review.

RESULTS AND CONCLUSION

Treatment approaches of recurrent MPE should take into account multiple factors in particular patient's life expectancy and preference. If talc is the best sclerosing agent alone or in combination with indwelling pleural catheter which is a promising strategy, the pathophysiology of MPE has to be revisited in order to propose a personalized management targeting intrapleural key molecules involved in the genesis of malignant process.