Method to characterize inorganic particulates in lung tissue biopsies using field emission scanning electron microscopy.

Humans accumulate large numbers of inorganic particles in their lungs over a lifetime. Whether this causes or contributes to debilitating disease over a normal lifespan depends on the type and concentration of the particles. We developed and tested a protocol for in situ characterization of the types and distribution of inorganic particles in biopsied lung tissue from three human groups using field emission scanning electron microscopy (FE-SEM) combined with energy dispersive spectroscopy (EDS). Many distinct particle types were recognized among the 13 000 particles analyzed. Silica, feldspars, clays, titanium dioxides, iron oxides and phosphates were the most common constituents in all samples. Particles were classified into three general groups: endogenous, which form naturally in the body; exogenic particles, natural earth materials; and anthropogenic particles, attributed to industrial sources. These in situ results were compared with those using conventional sodium hypochlorite tissue digestion and particle filtration. With the exception of clays and phosphates, the relative abundances of most common particle types were similar in both approaches. Nonetheless, the digestion/filtration method was determined to alter the texture and relative abundances of some particle types. SEM/EDS analysis of digestion filters could be automated in contrast to the more time intensive in situ analyses.

Three-dimensional observation of electrophoretic migration of dsDNA in semidilute hydroxyethylcellulose solution.

Three-dimensional (3-D) video fluorescence microscopy is demonstrated for the investigation of biopolymer electrophoretic migration using double-stranded (ds)DNA in semidilute hydroxyethylcellulose (HEC) as a test system. It is shown that 3-D imaging enables visualization of segmental motion with greater detail than is available in conventional video microscopy. A high frame rate (50-110 frames per second (fps)) intensified progressive scan camera is used to acquire fifteen axial sections focused at different depths through the DNA molecule. A 3-D DNA image is generated from these sections using blind deconvolution image reconstruction and motion is represented as a succession of volume images. A 3-D extension of the Doi/Oana ellipsoidal model is used to fit the DNA envelope, allowing simple quantitative descriptions of the changing shape of the DNA as it interacts with the sieving polymer solution. With 3-D views of migrating DNA molecules we observe U-shaped conformations oriented at an angle to the microscope plane. We are also able to resolve ambiguities and artifacts resulting from loss of information from DNA segments that are not in focus.

Capillary electrophoresis of RNA in dilute and semidilute polymer solutions.

We report separations of RNA molecules (281-6583 nucleotides) by capillary electrophoresis in dilute and semidilute solutions of aqueous hydroxyethylcellulose (HEC) ether in varying buffers. RNA mobility and peak band widths are examined under both nondenaturing and also denaturing conditions. From studies of sieving polymer concentration and chain length, it is found that good separations can be obtained in semidilute solutions as well as in dilute solutions. The dependence of RNA mobility on its chain length is consistent with separation by a similar to transient entanglement mechanism in dilute solutions. In semidilute entangled solutions the separation proceeds by segmental motion.

[Microbial decontamination by aerobic purification of liquid manure from swine-breeding farm complexes]. / Mikrobna dekontaminatsiia pri aerobno prechistvane na techen tor ot svinekompleksi.

Studied was the microbial decontamination of swine mature with the employment of a laboratory model of an aerobic lagoon as well as in a purification station, having a mechanical step, two biologic steps, and a facultative lagoon. It was found under modelled conditions that a substantial decontaminating effect was produced with regard to coli bacteria and Salmonella organisms. The effect was less with regard to the microbial count. The studies carried out in stations showed the effectiveness of the individual steps in reducing the microbial content of manure.

[Allergic reactions in guinea pigs infected with Yersinia enterocolitica type 9 relative to homologous (Yersinia) and heterologous (Brucella) allergens]. / Alergichni reaktsii pri morski svincheta, zarazeni s Yersinia enterocolitica tip 9 spriamo khomolozhni (iersiniia) i kheterolozhni (brutsela) alergeni.

Obtained were allergens from Brucella abortus 99 and Yersinia enterocolitica Type 9 through hydrolysis with hydrochloric acid after M. M. Ivanov and with acetic acid after Kirzhaev. They were tested on guinea pigs that were infected with Yersinia enterocolitica Type 9 through different ways. To M. M. Ivanov's allergens all infected animals responded pronouncedly in the case of the homologous allergen, and half of them only and to a lower degree in the case of the heterologous Brucella allergen. To Kirzhaev's allergens the infected guinea pigs showed more strongly expressed skin reactions. In this case, too, the response was stronger to the homologous Yersinai allergen. The diameters of skin swelling were more than twice greater than with the use of the heterologous Brucella allergen, and the sum of the reacting skin sites was five times greater in the case of the homologous Yersinia allergen. No essential differences were observed between the oral and the plantar route of infection combined with the subcutaneous injection of carboneum tetrachloratum and the morphine preparation Omnopon.