Pulmonary Dysfunction Augmenting Bacterial Aerosols in Leather Tanneries of Punjab, Pakistan

BACKGROUND

Particulate matter-associated microbes in the workplace are a burning issue in occupational toxicology. Studies have reported on respiratory infections among tannery cohorts. This study uniquely presents measurements of airborne bacterial concentrations associated with varied particulate-matter sizes, their exposure, and consequent severity in occupational respiratory problems, all for different microenvironments within leather tanneries.

METHODS

Analyses included molecular identification of isolates, computation of mass median aerodynamic diameter of aerosols, tannery process-exposure dose (TPED) to bacterial aerosols, and spirometry and symptom assessment of impaired pulmonary function.

RESULTS

The highest bacterial concentrations were for rawhide treatment and finishing units, showing 3.6×103 and 3.7×103 CFU/m3, respectively. Identified bacterial species included Ochrobactrum pseudogrignonense, Neisseria bacilliformis, Enterobacter cloacae, Alcaligenes faecalis, Klebsiella pneumoniae, and Corynebacterium spp. Maximum and minimum values of mass median aerodynamic diameter were 8.3 µm and 0.65 µm for buffing and snuffing and production units, respectively. The highest TPED was 1,516.9 CFU/kg for finishing units. Respiratory symptoms in order of incidence were dyspnea > phlegm > cough > wheezing and tachypnea (equivalent). Bronchodilator measurements of FEV1, FVC, and PEF represent decline in lung function. Of 26 patients identified with COPD, most were working in rawhide treatment.

CONCLUSION

We conclude that exposure-infection synergy is also a cause of pulmonary ailments and COPD development, rather than the better-known exposure-smoking synergy.

Particle size dynamics and risk implication of atmospheric aerosols in South-Asian subcontinent

Presented here are size-resolved aerosol measurements conducted using cascade impactor set at breathing zone in indoor-outdoor residential microenvironments. PM_2.5 contributed about 64-80% of PM₁₀ in which over 29% of mass was shared by PM_0.25. Total PM concentration varied from 261 ± 22 μg/m³ (indoors) to 256 ± 64 μg/m³ (outdoors) annually; whilst summer and monsoon demonstrated 1.2- and 1.9- times lower concentration than winters. The measured metals ranged between 9% (in PM_2.5-10) to 18% (in PM_1-2.5) of aerosol concentration; whereby crustal elements dominated coarse fractions with relatively higher proportion of toxic elements (Ba, Cd, Co, Cr, Cu, Ni) in ultrafine range. Considering lognormal particle size distribution (PSD), accumulation mode represented the main surface area during entire monitoring period (Mass Median Aerodynamic Diameter (MMAD) < 1). PSD of metal species reflected their different emission sources with respect to season integrated samples. High air exchange conditions permitted the shift of indoor PSD pattern closer to that of outdoor air while low ventilation in winters reflected modal shift of metals (Pb, Mg. K) towards larger size particles. Relative surge towards smaller diameter size of soluble metal fraction relative to the total concentration of toxic elements was noted on an annual basis with high infiltration capacity of smaller size particulates (Finf =1.36 for ultrafine particles in summers) identified through indoor-outdoor regression analysis. Principal Component Analysis identified sources such as vehicular traffic, combustion, crustal emission with activities viz. smoking and those involving use of electric appliances.

Aerosolization of Zn-DTPA Decorporation Agent Using Jet and Ultrasonic Nebulizers

BACKGROUND

Chelating agents such as diethylenetriamine pentaacetic acid (DTPA) can be used as a decorporation drug in the zinc (Zn) form to treat internal radioactive contamination after exposure to plutonium or americium in a nuclear accident. Although Zn-DTPA is normally administered intravenously, inhalation of Zn-DTPA in aerosol form is a better route for direct delivery to the lungs. This work investigates the feasibility of synthesizing Zn-DTPA from three common chemicals and aerosolizing it using a jet or ultrasonic nebulizer.

METHODS

The particle size distribution (PSD) of this decorporation agent at different concentrations were tested in vitro using two different methods: inertial impaction and aerodynamic time of flight. The particles were generated using either a jet nebulizer or an ultrasonic nebulizer. Two parameters, namely the mass median aerodynamic diameter and the geometric standard deviation, were assessed to determine the PSD of the generated aerosols. These parameters were obtained for different concentrations of Zn-DTPA using both nebulizers.

RESULTS AND CONCLUSIONS

Zn-DTPA was successfully synthesized for decorporation purposes. Aerosol particles within the inhalable range were successfully generated by both nebulizers from four different concentrations of Zn-DTPA. It was found that the medication concentration did not affect the PSD of Zn-DTPA. The ultrasonic nebulizer was observed to produce a slightly larger aerosol particle size and required slightly longer treatment periods to deliver an effective dose to the lungs when compared with the jet nebulizer. Both nebulizers can be sustainably run to administer the agent for effective decorporation treatment of a large population after any major nuclear accident.

Studies on Trans-Resveratrol/Carboxymethylated (1,3/1,6)-β-d-Glucan Association for Aerosol Pharmaceutical Applications

A resveratrol/carboxymethylated glucan (CM-glucan) combination is known to inhibit rhinovirus replication and expression of inflammatory mediators in nasal epithelia. The aim of this study was to develop an aerosol formulation containing an association of the two molecules which could reach the lower respiratory tract. Mass median aerodynamic diameter (MMAD) of a resveratrol/CM-glucan combination was lower than that shown by resveratrol or CM-glucan alone (2.83 versus 3.28 and 2.96 µm, respectively). The resveratrol/CM-glucan association results in the finest and most monodispersed particles in comparison to the two single components. The association also evidenced lower values for all particle size distribution parameters, suggesting that the pharmacological synergy observed in previous studies may be accompanied by a pharmaceutical one. Moreover, we showed that the CM-glucan matrix did not exert an inhibitory effect on resveratrol nebulization, demonstrating the good suitability of these two molecules in association for simultaneous aerosol volatilization.

Toxicology Studies for Inhaled and Nasal Delivery

This review examines issues related to the toxicological testing of pharmaceuticals delivered by the inhalation or nasal route. The purpose of the toxicology studies is to conduct studies in animals that will aid the assessment of the safety of these agents delivered to patients. Inhalation toxicology studies present some unique issues because the dosing method differs from more standard administration methods such as oral or injection administration. Also, dose determination issues are more complex, particularly for inhalation administration since it is often difficult to determine the amount of material delivered to the lung both for patients and in animal toxicology studies.

Short term inhalation toxicity of a liquid aerosol of glutaraldehyde-coated CdS/Cd(OH)2 core shell quantum dots in rats

Quantum dots exhibit extraordinary optical and mechanical properties, and the number of their applications is increasing. In order to investigate a possible effect of coating on the inhalation toxicity of previously tested non-coated CdS/Cd(OH)2 quantum dots and translocation of these very small particles from the lungs, rats were exposed to coated quantum dots or CdCl2 aerosol (since Cd(2+) was present as impurity), 6h/d for 5 consecutive days. Cd content was determined in organs and excreta after the end of exposure and three weeks thereafter. Toxicity was determined by examination of broncho-alveolar lavage fluid and microscopic evaluation of the entire respiratory tract. There was no evidence for translocation of particles from the respiratory tract. Evidence of a minimal inflammatory process was observed by examination of broncho-alveolar lavage fluid. Microscopically, minimal to mild epithelial alteration was seen in the larynx. The effects observed with coated quantum dots, non-coated quantum dots and CdCl2 were comparable, indicating that quantum dots elicited no significant effects beyond the toxicity of the Cd(2+) ion itself. Compared to other compounds with larger particle size tested at similarly low concentrations, quantum dots caused much less pronounced toxicological effects. Therefore, the present data show that small particle sizes with corresponding high surfaces are not the only factor triggering the toxic response or translocation.

Effects of inhalable microparticle of flower of Lonicera japonica in a mouse model of COPD

ETHNOPHARMACOLOGICAL RELEVANCE

Flower of Lonicera japonica (FLJ) is a traditional herbal medicine widely used in East Asia as an anti-inflammatory and anti-oxidative agent. The purpose of this study is to develop an inhalable powder formulation of FLJ and to evaluate its biological effects in a mouse model of chronic obstructive pulmonary disease (COPD).

METHODS

Inhalable dry powder containing FLJ was produced by spray-drying with leucine as an excipient. Its aerodynamic properties and anti-inflammatory activities were evaluated using the Anderson cascade impactor (ACI) and a mouse model of COPD, respectively.

RESULTS

FLJ microparticle (FLJmp) had a hollow spherical shape in electron microscopy and showed aerodynamic properties suitable for inhalation (fine particle fraction of 54.0 ± 4.68% and mass median aerodynamic diameter of 4.6 ± 0.34μm). FLJmp decreased TNF-α and IL-6 expression in RAW264.7 cells activated by lipopolysaccharide (LPS). In mice challenged with LPS and cigarette smoke solution (CSS) to develop COPD, FLJmp decreased the levels of TNF-α and IL-6 in bronchoalveolar fluidas well as the number of inflammatory cells including neutrophils in peripheral blood. In addition, FLJmp induced recovery of elastin and collagen distribution, reduction of caspase-3 expression in lung tissues of COPD mice.

CONCLUSIONS

Inhalational delivery of FLJ using a microparticle system is a promising strategy for the treatment of COPD.