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A method was developed to study the adhesion of Streptococcus pneumoniae to human pharyngeal epithelial cells. Epithelial cells from healthy persons, pneumococcal strains from patients with otitis media, meningitis, or septicemia, and pneumococcal cells from the nasopharynx of healthy carriers were used. Adhesion was found to be influenced by changes in the bacterial incubation medium and growth phase, the concentration of bacteria and epithelial cells, the epithelial cell donor, the incubation time and temperature, and the pH and osmolarity of the incubation medium. Pretreatment of bacteria with heat, Formalin, or trypsin decreased adhesion. The highest adhesion was obtained when 109 bacteria cultivated for 18 h in streptococcus cultivation broth were added to 104 pharyngeal cells and incubated at 37°C for 30 min. S. pneumoniae strains from patients with frequent episodes of otitis media and strains from healthy carriers had the highest adhesion values; septicemia and meningitis strains had the lowest. The capsular polysaccharide type did not determine the adhesive capacity of the strains, but otitis strains belonging to the capsular types often associated with otitis media adhered in high numbers. Adhesion may be important for pneumococci colonizing the nasopharynx or inducing otitis media. strains were isolated from the blood of patients with 311 on August 5, 2020 by guest http://iai.asm.org/ Downloaded from

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Tumour vascularization is based on two types of vessels, incorporated normal host tissue vessels and newly formed vessels, and is characterized by a wide heterogeneity. No adrenergic innervation has been related to newly formed tumour vessels but may still be found in incorporated normal vessels. In most studies vasoconstricting drugs were found to decrease tumour blood flow, while vasodilating drugs had no significant influence on tumour blood flow. From this it was concluded that the tumour vascular bed is normally in a state close to maximal dilatation, and this is supported by observations of hypoxia and local acidosis in tumour tissue. Some conflicting results have been reported with an increased tumour blood flow after administration of, for example, calcium channel blockers. Tumour blood modification is of interest in radiotherapy but also in tumour hyperthermia, where circulatory disturbances are explained on a multifactorial basis. Based on conflicting observations, with results varying with tumour-host systems studied and techniques for flow recording, it seems reasonable to concentrate further on methodological studies to develop clinically relevant techniques for tumour blood flow recording.

Serum levels of antibodies to lipid A were determined with an enzyme-linked immunosorbent assay in 26 girls with their first known symptomatic urinary tract infection (UTI) and in 15 girls with asymptomatic bacteriuria (ABU). Also included were six female patients with recurrence of acute upper UTI, five of whom had renal changes after the infections; 28 female patients with renal scarring but not symptomatic UTI at the time of investigation; and uninfected individuals. IgG and IgM antibodies to lipid A were found in approximately 50% of the uninfected children older than two years of age. Girls with acute cystitis, acute pyelonephritis, or ABU showed significantly elevated levels of IgG antibodies to lipid A as compared with children with no history of UTI. High levels of IgG antibodies to lipid A may be indicative of severe renal infection and development or progression of renal parenchymal reduction. The diagnostic value of determining levels of antibodies to lipid A is discussed.