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A combined hamartoma of the retinal pigment epithelium and the retina is a rare alteration of the ocular fundus. Knowledge of this mostly benign clinical picture is important to be able to differentiate it from malignant tumors such as choroidal melanoma. Occurrence in parallel with phacomatoses is known although it is not present in every case.

In 649 urological patients with urinary tract infections (UTI) a total of 1114 bacterial strains were isolated and their beta-lactamase production was investigated by a qualitative, micro-iodometric method. Approximately 40% of all strains, 33% of E. coli species and 8% of Proteus mirabilis species were enzyme producers. All of the isolates of E. coli and Proteus mirabilis defined as non-producers were sensitive to ampicillin and cephalothin in the agar diffusion test. The beta-lactamase producers of these two species did not show the same pattern: almost all of them were ampicillin-resistant, but most were cephalothin-sensitive. The other species were all found to be either producers or non-producers. Therapeutic comparisons in altogether 138 UTI patients treated with ampicillin or cephalexin, two antibiotics with different beta-lactamase stability, confirmed the positive correlation between enzyme production and therapeutic failure in both groups. Cephalexin, however, tended to be more effective than ampicillin against enzyme-producing species.

Cefroxadine and cephalexin were compared in a double-blind study in patients with complicated urinary tract infections. Patients were treated orally with 1 g t.i.d. for five days. Bacterial counts in the urine were determined 1, 3 and 8 hours after the first dose and on the second, third and fifth day of treatment. A decrease in the bacterial population below 10(4) organisms/ml of urine was taken as being indicative of chemotherapeutic effect. Urine specimens were inactivated enzymatically before culture to eliminate any residual cephalosporin. A significant reduction in the bacterial count was seen one and three hours after the first dose, and, to a much greater extent, after eight hours. Reduction in the bacterial count was more frequent in the group treated with cefroxadine. The results during the first eight hours indicate that cefroxadine kills more rapidly than cephalexin, which is in agreement with the experimental findings. Whether the transient differences observed in the rates of inhibition are of clinical relevance remains uncertain.