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At least 19 recordsLinked to original sources
PubMed1978

Mutagenicity in Salmonella typhimurium mutants of the benzene-soluble organic matter derived from air-borne particulate matter and its five fractions.

Air-borne particulate matter was collected on a filter, then extracted with benzene. The benzene-soluble material was separated into 5 fractions, namely acidic, basic, alipathic, polyaromatic and oxygenated fractions. The mutagenic activities of these fractions were examined with a set of Salmonella typhimurium mutants. The 6 mutants were from the TA1535 series, deep rough strains without excision repair, namely TA100 and TA98 (having a resistance-transfer factor) and the standard strain TA1535, TA1536, TA1537 and TA1538. Linear dose-response curves were obtained for the benzene-soluble organic matter, and its acidic, polyaromatic and oxygenated fractions with strain TA98 and a 9000 X g liver supernatant from both phenobarbital(PB)- and dibenz(a,h)anthracene(DBA)-treated rats. Among the 5 fractions tested, 3 fractions, namely the acidic, polyaromatic and oxygenated, played an important role in the mutagenicity of the benzene-soluble organic matter derived from air-borne particulate matter. The 9000 X g rat-liver supernatant was not required to make the acidic fraction mutagenic.

Air Pollutants↗
PubMed2026

Exposure to size-specific particulate matter accelerates DNA methylation aging in people with HIV.

BACKGROUND: People with HIV (PWH) face accelerated aging and increased health risks, with DNA methylation age (DNAmAge) as a critical senescence biomarker. Particulate matter is linked to DNAmAge acceleration (DNAmAA) in general population, but its impact in PWH remains unstudied. METHODS: Thirty-two PWH from Wuhan, China, were enrolled in a prospective panel study with follow-up, and each participant underwent at least two repeated measurements during the study period. Portable air quality monitor measured PM 1 , PM 2.5 , and PM 10 exposures 72 h preblood sampling. We analyzed genome-wide DNA methylation in peripheral blood and calculated six AA metrics. Linear mixed-effects and weighted quantile sum regression models evaluated associations between particulate matter exposure and DNAmAA. RESULTS: Significant associations between particulate matter exposure and DNAmAA were observed at various lag windows. For every 10 μg/m 3 increase in 24-h average PM 2.5 , Hannum DNAmAA, Pheno DNAmAA, Grim DNAmAA, SkinBlood DNAmAA, and Elastic DNAmAA increased by 0.266 years [95% confidence interval (CI): 0.035-0.480], 0.421 years (95% CI: 0.032-0.701), 0.336 years (95% CI: 0.073-0.546), 0.295 years (95% CI: 0.021-0.495), and 0.254 years (95% CI: 0.034-0.445), respectively. PM 10 contributed most substantially to the cumulative PM effect on epigenetic AA in the lag0-24 h window. CONCLUSION: Short-term particulate matter exposure, particularly PM 10 , significantly accelerates epigenetic aging in PWH, highlighting the need to integrate air quality management into healthy aging strategies for this vulnerable population.

China↗
PubMed1978

Comparison of two methods for obtaining size distribution characteristics of particulate matter in large-volume parenterals.

The size distributions of the particulate matter present in six types of large-volume parenteral solutions, as determined by an automatic particle counter and a microscopic counting technique, were compared by plotting log N greater than D versus log D. The resulting data were analyzed individually and also as averages. The data showed a linear relationship between log N greater than D and log D over the 1-100-micron particle-size range, indicating that both methods determine a similar particle-size distribution. The data also indicated that the particle-size distributions were largely independent of the type of solution and obeyed a power law of the form N greater than D = N greater than 1DK. These observations suggest that the major source of contamination is air-borne dust particles, which fall into a solution randomly, and that it may be possible to monitor the smaller, more abundant particles with the automatic particle counter to obtain a rapid estimate of parenteral cleanliness. The automatic particle counter thus appears to be a viable alternative to the microscopic counting technique for assessing the particulate matter content of parenterals.

Drug Contamination↗
PubMed2026

Multi-omics causal inference of childhood asthma triggered by ambient particulate matter.

BACKGROUND: The causal impact of fine particulate matter (PM2.5), an established environmental risk factor, on childhood asthma and its biological mechanisms remain to be elucidated. The objective of the present study was to evaluate the causal association between PM2.5 and childhood asthma and to dissect the mediating role of plasma proteins through a multi-omics integrated Mendelian randomisation (MR) framework. METHODS: Two-sample MR was performed on large-scale genome-wide association data to estimate the causal effect of PM2.5 on childhood asthma. Genes commonly associated with PM2.5 and childhood asthma were screened by transcriptome-wide association study (TWAS) and subjected to enrichment analyses and MR. Mediator proteins were identified by two-step MR. Potential adverse effects were scanned by phenome-wide MR (Phe-MR). RESULTS: MR revealed a significant positive causal effect of PM2.5 on childhood asthma (OR=1.897, 95% CI: 1.063-3.388, p=0.030). TWAS highlighted 70 genes co-expressed in PM2.5 and childhood asthma that were enriched in inflammatory pathways such as lysosome- and leukocyte-mediated immunity. MEAF6 was validated as a protective gene and RNF40 as a risk gene for childhood asthma. Two-step MR identified FUT10 as a positive mediator mediating 19.3% of the causal effect, and CD200 and MANBA as negative mediator proteins. Phe-MR indicated the association of these genes and proteins with multiple other diseases, implying possible adverse effects from therapeutic intervention. CONCLUSION: Long-term PM2.5 exposure is causally linked to childhood asthma with MEAF6, RNF40, CD200, MANBA and FUT10 identified as key molecules. The study provides new evidence for the biological mechanisms linking PM2.5 to childhood asthma.

Journal Article↗
PubMed1977

[Determination of the acidity of particulate matter in the urban and industrial atmospheres].

A new method is described for the determination of the strong acidity of particulate matter. The method consists in the volumetric titration of an aqueous extract by means of a strong acid. The titration is performed potentiometrically using a glass electrode and the end point is obtained by extrapolation using a Gran's plot. The lowest concentration of strong acid detectable in a sample is about 0.5 microgram/ml expressed as H2SO4. The method has been applied for the determination of the strong acidity content in airborne particulate matter samples and in dusts emitted from industrial sources.

Acids↗
PubMed1977

[Quantitative analysis of particulate matter in infusion solutions, administration sets and additives (author's transl)].

There have been recevitly many comments on clinical and experimental reports which have demonstrated the safety problems associated with parenteral drugs contaminated with particles. Some countries have developed recommendations with a standard for counting of particles and their limits. Based on these limits, we have made a critical quantitative analysis of particulate matter in the most common commercially produced solutions, of particles added during manipulations in clinics and addition of drugs. Most authorities agree that particulate contamination should be kept to a minimum, above all in an intensive-care-unit where patients receive large quantities of solutions. As the risk to the patient is unacceptably high, many authors ask for filters to prevent the injection of particles in the bloodstream and their pathological consequences. A filter pore-size of 5 to 10 micron should be able to reduce this problem in a sufficient manner, without decreasing the infusion flow; whereas membrane-filters (0.22 micron), with their own problems, could also eliminate bacteria together with their microbiological hazards. Another source of particulate matter is represented by the injection of two or more drugs, administered at the same time, which may lead to chemical incompatibilities. This problem is not yet defined very well. To complete our quantitative analysis, we decided to start a prospective clinical study.

Critical Care↗
PubMed2026

Prenatal exposure to particulate matter (PM) and autism spectrum disorder (ASD) among children: a systematic review and meta-analysis.

The global surge in Autism Spectrum Disorder (ASD) cases, coupled with evidence linking prenatal Particulate Matter (PM) exposure to developmental disruption, demands a comprehensive review to design targeted health interventions. This systematic review and meta-analysis aim to evaluate the strength and consistency of evidence linking prenatal PM exposure to ASD across studies, quantifying this relation to identify actionable environmental risk thresholds. This study employed PRISMA protocols to systematically extract and evaluate evidence from PubMed, Web of Science, Scopus, and ScienceDirect (2010-2024), and screened 4,013 articles to identify qualified case-control and cohort studies (n=29). Data synthesis employed random-effects modeling, accompanied by comprehensive assessment through I2 statistics, Q-tests, funnel plots, Duval and Tweedie's trim-and-fill analysis, and Egger's regression, to ensure validity. A meta-analysis of 16&#xa0;case-control studies revealed a 34&#x202f;% increased risk of ASD associated with prenatal PM exposure (pooled OR=1.34; 95&#x202f;% CI: 1.13-1.54), despite substantial between-study heterogeneity (I2=94.02&#x202f;%, p<0.001). Publication bias was not significant (Egger's test p value=0.114). Critical trimester-specific analysis uncovered that third-trimester exposure significantly increased ASD risk (OR=1.17; 95&#x202f;% CI: 1.01-1.34), while first-trimester (OR=1.02; 95&#x202f;% CI: 0.92-1.11; I2=49.18&#x202f;%, p<0.10) and second-trimester exposures (OR=1.13; 95&#x202f;% CI: 0.88-1.38; I2=92.59&#x202f;%, p<0.001) showed non-significant associations. This review identified prenatal and early life exposure to PM as a risk factor for ASD, indicating a trimester-specific vulnerability. It highlighted the necessity of focused air quality interventions and targeted guidance to reduce prenatal PM exposure to alleviate ASD risk during the critical-window.

Child↗
PubMed2024

Long-term exposure to particulate matter and all-cause and cause-specific mortality in an analysis of multiple Asian cohorts.

BACKGROUND: Exposure to ambient air pollution is associated with a significant number of deaths. Much of the evidence associating air pollution with adverse effects is from North American and Europe, partially due to incomplete data in other regions limiting location specific examinations. The aim of the current paper is to leverage satellite derived air quality data to examine the relationship between ambient particulate matter and all-cause and cause-specific mortality in Asia. METHODS: Six cohorts from the Asia Cohort Consortium provided residential information for participants, recruited between 1991 and 2008, across six countries (Bangladesh, India, Iran, Japan, South Korea, and Taiwan). Ambient particulate material (PM2&#xb7;5) levels for the year of enrolment (or 1998 if enrolled earlier) were assigned utilizing satellite and sensor-based maps. Cox proportional models were used to examine the association between ambient air pollution and all-cause and cause-specific mortality (all cancer, lung cancer, cardiovascular and lung disease). Models were additionally adjusted for urbanicity (representing urban and built characteristics) and stratified by smoking status in secondary analyses. Country-specific findings were pooled via random-effects meta-analysis. FINDINGS: More than 300,000 participants across six cohorts were included, representing more than 4-million-person years. A positive relationship was observed between a 5&#xa0;&#xb5;g/m (Dockery et al., 1993) increase in PM2&#xb7;5 and cardiovascular mortality (HR: 1&#xb7;06, 95&#xa0;% CI: 0.99, 1&#xb7;13). The additional adjustment for urbanicity resulted in increased associations between PM2.5 and mortality outcomes, including all-cause mortality (1&#xb7;04, 95&#xa0;% CI: 0&#xb7;97, 1&#xb7;11). Results were generally similar regardless of whether one was a current, never, or ex-smoker. INTERPRETATION: Using satellite and remote sensing technology we showed that associations between PM2.5 and all-cause and cause-specific Hazard Ratios estimated are similar to those reported for U.S. and European cohorts. FUNDING: This project was supported by the Health Effects Institute. Grant number #4963-RFA/18-5. Specific funding support for individual cohorts is described in the Acknowledgements.

Humans↗
PubMed1975

Peritoneal reactions to particulate matter in peritoneal dialysis solutions.

Peritoneal dialysis solutions were chemically injected into the peritoneal cavity of mice. A high percentage of the injected animals showed particulate matter in the peritoneal membranes associated with an inflammatory reaction. This was prevented by final filtration of the solutions through 0.22 and 0.45 mu filters. It is recommended that all chronic peritoneal dialysis be performed through a final filter.

Animals↗
PubMed1975

Particulate matter in reconstituted amphotericin B and assay of filtered solutions of amphotericin B.

Amphotericin B colloidal solutions were prepared according to the manufacturer's directions and filtered with membrane filters of different porosity to test for particulate matter; and the concentration and in vitro microbiological activity of filtered and nonfiltered solutions were determined. The amphotericin B solutions contained numerous particles. Filtration through 0.85- and 0.45-mum filters did not reduce the in vitro antimicrobial activity, and filtration through 5-, 0.45-, and 0.22-mum filters did not alter the concentration of the drug when assayed spectrophotometrically.

Amphotericin B↗
PubMed1977

Quantitative estimation of particulate matter in pharmaceutical preparations intended for intravenous administration.

A fast, reproducible, economical, and dependable automated counter method is recommended for the quality control of pharmaceutical preparations intended for intravenous administration. The USP gives no specifications on the limitations of particulate matter in intravenous products, while the BP specifies limitations on intravenous solutions of more than 500-ml volume. Out of 15 different marketed products, few passed the BP specifications. The microscopically identifiable particles included starch, cellulose fibers, glass, rubber, lacquer flakes, carbon black, and metal shavings. The proposed quality control method introduces a modification to the BP specifications. The method includes a standard log-log plot obtainable from a least-squares line fit to the data of the marketed products showing minimal particle contamination. The standard plot is compared to the experimental data obtained from any other product and, accordingly, it is decided whether the product is acceptable or not.

Anti-Bacterial Agents↗
PubMed1977

Use of three optical systems to obtain a microscopic profile of asbestos and other nonopaque particulate matter larger than 5 mum in parenteral drugs.

A comparative microscopic study of chrysotile fibers was conducted, using 3 sequential optical systems: plane polarized light (PL), phase contrast (PC), and Nomarski differential interference contrast (NDIC) for complementary image analyses. The introduction of NDIC for qualitative and quantitative analyses of particulate matter greater than 5 mum resolves the problem of diffraction halos encountered in PC microscopy. High optical contrast, the instrumental characteristic of NDIC, is particularly useful for the detection of chrysotile fibers at a magnification of 500 X.

Asbestos↗
PubMedDate not supplied

Inhalation experiments with 14C-labelled cigarette smoke. III. Body size dependent distribution of particulate matter in small rodents during cigarette smoke inhalation.

Syrian golden and European hamsters were exposed to 14C-labelled cigarette smoke. The deposition of the 14C activity in the respiratory and digestive tracts was determined immediately after the exposure. From the results obtained it can be seen that the distribution of particulate matter between the upper and lower respiratory tract, as well as, between the respiratory and digestive tracts is related to the body weight of the experimental animals.

Animals↗
PubMed1977

The identification of particulate matter in biological tissues and fluids.

Sections, 1-2 micron thick, of Araldite embedded tissue were prepared to provide a link between optical and electron microscopy for the identification of crystals. This technique permits examination of individual particles by means of polarising light microscopy, electron microscopy, X-ray energy spectroscopy and electron diffraction. It provides a reliable method for routine and research studies. It has led to the positive identification of individual crystals of calcium pyrophosphate dihydrate and hydroxyapatite in synovial fluids. The method can be applied to the identification of other particulate matter in a variety of biological specimens.

Aged↗
PubMed1977

Effects of agitation on size distribution of particulate matter in large-volume parenterals.

The particle-size distributions of six types of large-volume parenterals subjected to different degrees of agitation were determined using an automatic particle counter. Data acquired from each solution, which had been maintained in a stored condition, subjected to agitation by inverting 20 times, and then mechanically shaken for 30 min, produced a linear relationship between log N greater than D and log D. Both the slope (K) and the number of particles per milliliter exceeding 1 micrometer in diameter (N greater than 1) exhibited a dependence on the degree of agitation. Their combined effect indicates that agitation by 20 hand inversions removed particulate matter from the surface of the container, which increased the total number of particles in solution (greater than 1 micrometer) but did not significantly alter the relative size distribution. Agitation for 30 min, however, disintegrated agglomerates and produced a particle-size distribution with a greatly increased number of particles whose diameters were less than 1 micrometer and a corresponding decrease in the number of particles exceeding 1 micrometer in diameter. The particle-size distribution of a parenteral solution determined by this in situ instrumental method was, therefore, dependent upon the degree of agitation to which the parenteral was subjected prior to examination.

Chemistry, Pharmaceutical↗
PubMed1976

Residues in antibiotic preparations, ii: effect of pH on the nature and level of particulate matter in sodium cephalothin intravenous solutions.

The effect of pH on the extent and nature of particulate contamination in sodium cephalothin intravenous solutions was studied. The extent of particulate contamination was determined by microscopic and automatic electronic counting procedures, and the physical nature of the particles was determined using scanning electron microscopy. At low pH values (i.e., 4.9--5.9), an amorphous residue was predominant, while at higher pH values (6.9--7.8), the gelatinous nature of the residue disappeared and small crystalline particulates of varying sizes were predominant. The level of particulate contamination (particles over 10 mum in size) decreased with an increase in pH to a minimum level between pH 7 and 8. Advice is given to practitioners regarding the preparation of sodium cephalothin solutions.

Cephalothin↗
PubMed1978

Study of particulate matter in carbenicillin disodium using scanning electron microscopy and microbeam x-ray spectrography.

A scanning electron microscopy membrane filtration study was conducted to determine the particulate contamination of samples of carbenicillin disodium which had been manufactured by bulk filling and by lyophilization. The bulk-filled product contained more contaminating particles than the lyophilized product. In both products, the number of particles increased logarithmically with decreasing particle size in the range measured (exceeding 0.1 micron). X-ray spectrographic analysis of particles larger than 0.5 micron revealed that the major particulate contaminates in both products were composed primarily of elements below atomic number 10. It is concluded that packaging of carbenicillin disodium by lyophilization of a solution results in significantly less submicrometer particulate contamination than packaging by sterile bulk filling of spray-dried powder.

Carbenicillin↗