Changes in the cell wall of Clostridium species following passage in animals

Morphological changes in clostridial isolates after animal passage with other flora in mixed infections were studied by utilizing a subcutaneous abscess model in mice. We used 26 isolates of 7 clostridial species, and one isolate each of Bacteroides fragilis and Klebsiella pneumoniae. Abscesses were induced by all 7 Clostridium perfringens and 3 Clostridium butyricum isolates and by some of the other isolates. A thick granular wall prior to animal inoculation was shown only in C. perfringens, C. butyricum, and C. difficile. This structure was observed in other clostridia only following their animal passage alone or when co-inoculated with K. pneumoniae or B. fragilis.     

The role of encapsulation in the pathogenesis of anaerobic gram-positive cocci

The pathogenicity of 22 anaerobic and facultative Gram-positive cocci (AFGPC) was investigated by inoculating them into mice and determining their ability to cause subcutaneous abscesses. Only 11 heavily encapsulated isolates (greater than 50% of the cells were encapsulated) induced abscesses. However, when the other 11 isolates were injected with Bacteroides sp. or facultative and aerobic bacteria, abscesses were formed in 8 of the 11 combinations. The AFGPC recovered from the mixed infections contained many encapsulated cells. Encapsulation also occurred in cocci injected with capsular material or with Formalin-killed cells of Klebsiella pneumoniae or capsule-positive Bacteroides sp. After acquisition of capsules, these strains could induce abscesses on reinoculation in mice.     

Regional localisations and linkage relationships of seven RFLPs and myotonic dystrophy on chromosome 19

Summary We have studied the genetic linkage relationships of seven DNA polymorphisms on chromosome 19, with each other and with the myotonic dystrophy locus. The DNA sequences were localised to various regions of the chromosome using translocations in somatic cell hybrids. These results provide the basis for a linkage map of most of chromosome 19, and suggest that the myotonic dystrophy locus is close to the centromere.     

Dietary soya lecithin decreases plasma triglyceride levels and inhibits collagen- and ADP-induced platelet aggregation

Elevated plasma lipid concentrations and increased platelet activation are risk factors in the development of atherosclerosis. Nine patients with type IIa hyperlipoproteinemia and nine patients with type IV hyperlipoproteinemia were given soya lecithin, 12 g/day, for 3 months. Plasma cholesterol and triglycerides were reduced by 15 and 23%, respectively, and HDL-cholesterol increased by 16% in the hypercholesterolemic patients. Platelet function was unchanged. In the hypertriglyceridemic patients, total cholesterol fell by 18%, triglycerides by 36%, and HDL-cholesterol increased by 14%. There was a 27% reduction in platelet aggregation (P less than 0.01). Seventeen hypertriglyceridemic patients then received increasing doses of soya lecithin for 1-month periods (6, 12, and 18 g/day). The optimal lipoprotein-lowering effect was achieved with a daily dose of 12 g soya lecithin per day. Both low-density lipoprotein and very-low-density lipoprotein levels were reduced, and HDL-cholesterol and apolipoprotein levels were reduced, and HDL-cholesterol and apolipoprotein A-I concentrations were increased. Platelet aggregation in response to collagen and ADP was significantly reduced, parallel with the reduction in triglyceride level. Soya lecithin supplementing the diet may be useful in the management of the hypertriglyceridemic patient.     

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.