Operations in concomitant diseases of the abdominal organs

Under consideration are one-moment operations for associated lesions of abdominal organs. Based on the experience with 103 such operations, the authors subdivided patients into two groups: emergency operated patients and those in whom planned interventions were performed. It is believed by the authors, that a careful clinical preoperative examination of the latter and methodical revision of abdominal organs in urgent laparotomies make it possible to reveal an associated pathology of abdominal organs and to perform a radical one-moment operative procedure.     

Regulation of spore-formation in Streptomyces galbus mutants

Some asporogenous strains of Streptomyces galbus recover the capacity to form aerial mycelium and spores when they are grown together with the parent sporulating strain under the conditions of superficial cultivation. The sporulating strain of Str. griseus that produces the A factor, a bioregulator, does not restore sporogenesis in asporogenous variants of Str. galbus, in contrast to Str. griseus. Therefore, Str. galbus must liberate a specific compound which controls spore formation in this species.     

Arginine deprivation in KB cells. II. Characterization of the DNA synthesized during starvation

DNA synthesis in cells deprived of arginine was examined. Three lines of evidence indicated that tritiated thymidine ([3H]TdR) incorporation in arginine-starved cells was due to replicative rather than repair DNA synthesis. (a) When made in the presence of bromodeoxyuridine, the [3H]TdR-labeled DNA sedimented at hybrid density in isopycnic gradients. (b) As determined by the diphenylamine reaction, there was a 15% increase in the chemical amount of DNA per culture 30 h after arginine deprivation. (c) [3H]TdR incorporation was hydroxyurea-sensitive. Alkaline velocity sedimentation of the total DNA made during starvation revealed the existence of two distinct size classes: most of the DNA sedimented at a position analogous to that of control DNA, but 40% migrated one-third the distance of the bulk. After arginine restoration, these shorter pieces appeared to be chased into DNA of normal length; thus, one lesion in deprived cultures may cause an arrest in completion of DNA stretches to mature size. These findings, together with results of morphological studies of starved cells, suggest that changes induced by arginine deficiency effect the organization of nucleoproteins. These changes are reversible upon arginine restoration.     

Analysis of pesticide residues by chemical derivatization. V. Multiresidue analysis of eight phenoxyalkanoic acid herbicides in natural waters

A multiresidue method is presented for the gas-liquid chromatographic determination of phenoxyalkanoic acid herbicides in natural waters. Extraction efficiencies of different organic solvents are considered in developing a solvent extraction scheme for these herbicides from water. Reactions for derivatizing these compounds by using pentafluorobenzyl bromide, boron trichloride-2-chloroethanol, and dicyclohexylcarbodiimide-2-chloroethanol were studied in order to obtain extracts with low blanks to provide the lowest detection limits. Advantages and disadvantages of the 3 methods are discussed. Retention times are twice as long for the pentafluorobenzyl (PFB) esters as for the 2-chloroethyl (2-Cl) esters under the same conditions, although electron capture sensitivity to the former was greater. The PFB esters are easier to form, but the 2-Cl reaction is more specific for these herbicides. Solutions from the boron trichloride reaction gave the cleanest blanks.     

Non-thermal plasma for exhaust gases treatment

This article describes a study on a non-thermal plasma device to treat exhaust gases in an internal combustion engine. Several tests using a plasma device to treat exhaust gases are conducted on a Honda GX200-196 cm³ engine at different rotational speeds. A plasma reactor could be efficient in degrading nitrogen oxides and particulate matter. Monoxide and carbon dioxide treatment is minimal. However, achieving 1%–3% degradation may be interesting to reduce the emission of greenhouse gases.     

Bizarre parosteal osteochondromatous proliferation. An unusual bone tumor

Bizarre parosteal osteochondromatous proliferation of bone is a rare, benign bone tumor. The authors discuss two cases involving the bones of the feet, and review clinical, radiographic, and histopathologic characteristics. Awareness of this lesion is essential as bizarre parosteal osteochondromatous proliferation of bone can be mistaken for a malignancy.