A mouse model using intraperitoneal inoculation of Streptococcus pneumoniae type 3 was used to compare in vitro and in vivo effects of 14 cephalosporins, selected to encompass a wide range of minimal inhibitory concentrations (MICs) against the organism. Antibiotics were subcutaneously administered as single doses 1 hr after inoculation of pneumococci, and the effect was measured as the 50% effective dose (ED50). The correlation between log ED50 and log MIC was highly significant (r = .87, P less than .001). Pharmacokinetic properties of the cephalosporins were estimated after a fixed dose of 5 mg per mouse (167 mg/kg) for all drugs. The only correlation that was significant was between log ED50 and the time the serum concentration remained above the MIC for each drug (r = -.90, P less than .001). Ceftriaxone was the most-effective cephalosporin in vivo because of a combination of high in vitro activity and prolonged serum elimination half-life.

The conjunctival flora of 499 patients was studied the day before cataract extraction, no antibiotics or chemotherapeutical agents had been used before admission. Staphylococcus albus was by far the most common micro-organism (95.4%), followed by corynebacteria (44%), Staphylococcus aureus (14.9%), gram-negative bacilli (7.8%) and pneumo-streptococci (4.4%). Corynebacteria was isolated more frequently in the presence of S. albus, while S. aureus and gram-negative bacilli were found more frequently in the absence of S. albus. No relationship could be demonstrated between the occurrence of pneumo-streptococci and S. albus. The flora of the nose and skin of the face were studied and compared with the conjunctival flora, and a similarity could be observed. Furthermore, strains of S. aureus isolated at the same time from the two or three regions, in most cases, showed the same bacterio-phage type complex. The conjunctival flora was further correlated with sex, age, season, and number of polymorphonuclear neutrophils recovered from the conjunctival fluid. The incidence of corynebacteria and gram-negative bacilli was found to be higher in males, while corynebacteria was the only organism to show seasonal variation, i.e. was isolated more frequently in the second and third quarters of the year. No correlation could be found between age or number of neutrophils.

Hccc ivc d 8 . x . 6~Mast ce ll s play an important ro le in th e physiology of co nnec tive li ssues. Th eir ca pability of synth es is and r elease of ground sub s tan ce compo n ents which ma y hind ti ssu e walc r places th ese cell s in a lwy p osi tion in lh e m ec hani sm of g row th , r egen e ration, and r epa ir as well a s in severa l palhological processes.

The paper presents a new test method for investigations of threshold curves for the resolving power of the eye and for exact measurements of visual acuity. This method measures static visual acuity within confidence limits of 9% compared to the acuity steps in Snellen notation of 33% to 50%. Furthermore, the method introduces the slope of the threshold curve as a parameter of suggested importance in the judgement of visual capability. The test mathematic is based on a method described by Finney (1952) for calculations on dose-response curves. To calculate the results and the test statistics an iterative curve fitting programme was designed to be run on a micro-computer. By connecting the presentation system and the response panel to the same computer the test could be performed almost automatically. The new test method was used to study visual acuity measured by projected ortotypes compared to acuity when measured by printed ortotypes. Tests using projected ortotypes were found to equal traditional acuity measurements, but the test results stressed the need for perfect and adjusted optics when projecting systems are used in visual acuity test.