Further observations on the effect of air ions on influenza in the mouse

In earlier papers we reported that the course of respiratory infections in mice produced by intranasal instillation of measured amounts of: (1) a fungus, COCCIDIOIDES IMMITIS, (2) a bacterium, KLEBSIELLA PNEUMONIAE and (3) a virus, PR8 strain of influenza virus was materially affected by the air ion environment. When the challenge dose of influenza virus was administered as an aerosol, as described here, the cumulative mortality rate was completely uninfluenced by shifts in the concentration of positive and negative air ions in the ambient atmosphere and by the accompanying electrical fields. A hypothetical mechanism accounting for the different results obtained with intranasal and aerosol challenge is presented.

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Zusammenfassung In früheren Arbeiten wurde über den Verlauf von Infektionen der Atemwege von Mäusen nach intranasaler Instillation bekannter Mengen (1) des Fungus COCCIDIOIDES IMMITIS, (2) KLEBSIELLA PNEUMONIAE und (3) PR8 Influenzavirus berichtet, die durch Luftionen beeinflusst waren. Hier wurde die Dosis von Influenzavirus als Aerosol verabreicht. Die kumulative Mortalitätsrate wurde durch den Wechsel der Konzentrationen von positiven und negativen Luftionen in der Umgebungsatmosphäre und begleitenden elektrischen Feldern nicht beeinflusst. Eine Erklärung für die unterschiedlichen Ergebnisse bei intranasaler und Aerosol-Virusapplikation wird diskutiert.

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Resume Dans des travaux précédents, on a montré que l'évolution de maladies du système respiratoire provoquées chez des souris par l'instillation intranasale de doses déterminées d'agents pathogènes était affectée de façon significative par le taux d'ionisation de l'air ambiant. Il s'agissait d'agents cryptogamiques (COCCIDIOIDES IMMITIS), bactériens (KLEBSIELLA PNEUMONIAE) et de virus (lignée PR8 du virus de la grippe). Lorsque la dose minimum de virus grippal est appliquée sous forme d'aérosole — selon la méthode décrite ici — le taux cumulatif de mortalité n'est aucunement influencé par les variations de concentration d'ions positifs ou négatifs de l'air ambiant ni par les champs électriques qui les accompagnent. On développe une hypothèse pour expliquer la diversité des résultats obtenus au moyen des infectations intranasales ou par aérosoles.

     

“Killer Character” of Saccharomyces cerevisiae: Curing by Growth at Elevated Temperature

Normal "killer" strains of Saccharomyces cerevisiae, when grown at 37 to 40 C, produce almost exclusively nonkiller cells due to loss or mutation of at least part of the non-chromosomal killer genome.     

Mutants of Saccharomyces cerevisiae That Incorporate Deoxythymidine-5′-Monophosphate Into Deoxyribonucleic Acid In Vivo

Spontaneous mutants of Saccharomyces cerevisiae able to incorporate deoxythymidine-5′-monophosphate (dTMP) into deoxyribonucleic acid (DNA) have been selected based on their ability to grow in the presence of aminopterin and sulfanilamide if dTMP is present. Essentially all mutants (called tup) selected in this way required dTMP for growth in the presence of the two drugs, but none required dTMP in the absence of the drugs. Neither thymine nor thymidine would satisfy this requirement. Equimolar amounts of ³²P- and ³H-base-labeled dTMP were incorporated by the mutants into alkali-stable, deoxyribonuclease-sensitive material. In the presence of aminopterin and sulfanilamide, this incorporation was sufficient to account for a substantial proportion of the thymine residues in the cellular DNA, whereas in the absence of the drugs only about 40% as much of the thymine residues originated from the medium. Of 29 mutants examined, all were recessive and 17 showed 2:2 segregation in crosses with a wild-type strain. The lesions in these mutants fell into four complementation groups: one (tup1) occurs on chromosome III; another (tup3) is on chromosome II; and a third (tup4) was centromere linked. Strains of the genotype α tup1 mated with lower than normal efficiency with a strains, but with higher than normal efficiency with α strains. Strains of genotype a/α tup1/tup1 failed to sporulate, whereas homozygous diploids for tup2, tup3, or tup4 sporulated normally, as did a/α tup1/+ strains.     

The inhibition of mitochondrial calcium transport by lanthanides and Ruthenium Red

An EGTA (ethanedioxybis(ethylamine)tetra-acetic acid)-quench technique was developed for measuring initial rates of (45)Ca(2+) transport by rat liver mitochondria. This method was used in conjunction with studies of Ca(2+)-stimulated respiration to examine the mechanisms of inhibition of Ca(2+) transport by the lanthanides and Ruthenium Red. Ruthenium Red inhibits Ca(2+) transport non-competitively with K(i) 3x10(-8)m; there are 0.08nmol of carrier-specific binding sites/mg of protein. The inhibition by La(3+) is competitive (K(i)=2x10(-8)m); the concentration of lanthanide-sensitive sites is less than 0.001nmol/mg of protein. A further difference between their modes of action is that lanthanide inhibition diminishes with time whereas that by Ruthenium Red does not. Binding studies showed that both classes of inhibitor bind to a relatively large number of external sites (probably identical with the ;low-affinity' Ca(2+)-binding sites). La(3+) competes with Ruthenium Red for most of these sites, but a small fraction of the bound Ruthenium Red (less than 2nmol/mg of protein) is not displaced by La(3+). The results are discussed briefly in relation to possible models for a Ca(2+) carrier.     

Effect of Lytic Enzymes of Acanthamoeba castellanii on Bacterial Cell Walls

Extracts of Acanthamoeba castellanii (Neff) contain alpha- and beta-glucosidase, beta-galactosidase, beta-N-acetylglucosaminidase, amylase, and peptidase. All of these activities are optimal between pH 3 and 4. These extracts also were found to clarify suspensions of cell walls from nine different gram-positive bacteria, including Micrococcus lysodeikticus. The pH optimum for the lytic activity was between 3 and 4. The extent of lysis of the various cell walls did not correlate with the release of free amino groups and of free N-acetylated sugars from the walls during digestion with these extracts. Suspensions of cell walls of Escherichia coli (a gram-negative bacterium), Cordiceps militaris (a fungus), and Acanthamoeba cysts, as well as of colloidal chitin, were not clarified by incubation with these extracts, although reducing sugars were released from each of these materials. Exhaustive digestion of M. lysodeikticus walls by lysozyme released no free N-acetylglucosamine. The products of exhaustive digestion of this cell wall with Acanthamoeba extracts were free N-acetylglucosamine, free N-acetylmuramic acid, glycine, alanine, glutamic acid, lysine, and N-acetylmuramic acid peptide fragments. These results suggest that the amoeba extracts contain endo- and exo-hexosaminidases, in addition to beta-hexosaminidase and peptide hydrolases.     

NON-INFECTIOUS INFLAMMATORY AND NEOPLASTIC DISORDERS OF THE MALE GENITALIA

The cutaneous manifestations of the male external genitalia are difficult to diagnose. They may be associated with systemic disease (Reiter''s disease, psoriatic arthritis, angiokeratoma corporis diffusum). In dealing with a lesion of this area that does not heal, adequate biopsy is advisable to rule out malignant disease (Bowen''s disease, melanoma, Kaposi''s sarcoma, Paget''s disease, erythroplasia).