Robert G. Weaver

Intraureteric pressure above and below an area of compression

Abstract Ten dogs were studied to ascertain whether or not the ureter, when compressed to pressures near the normal systolic value, is able to react with increased systolic pressure or with other means of coping with an increased resistance caused by compressing tumor or pregnant uterus. The lower ureter was subjected to a compression of 50 or 100 cm. of water over a 1 cm. portion, above and below which intraureteric pressure was simultaneously recorded. Twenty-three compressions were performed. In one case the upper ureter was drained prior to the compression. Prior to compression. 1.1. Urine was expelled along the catheter in each case. 2.2. Pressure between contractions was low and ranged from 0 to 35 cm. of water. 3.3. Contractions lasted 2 to 4 seconds and increased pressure to 50 to 180 cm. of water. 4.4. The peristaltic waves traveled at 3 to 5 cm. per second and with a frequency ranging from 3 to 20 contractions per minute. 5.5. Retroperistaltic waves were frequently seen and could be provoked by mechanical stimulation of lower ureter. During compression. 1.1. No urine was expelled when the ureter was compressed to 100 cm. of water. 2.2. Urine continued to be expelled in 8 of 11 compressions to 50 cm. of water. 3.3. Pressure between contraction waves increased to 45 to 90 cm. of water in 11 cases. 4.4. Contraction waves above the compression were split, increased in frequency, and decreased in peak value. None of these changes were seen in the drained ureter. 5.5. Contraction waves below compression could completely disappear. Thus, only with an increase in frequency can the ureter cope with an augmented resistance. It is felt, however, that the relaxation of the ureter in pregnancy may be a safeguard against increase in intrapelvic pressure. The ureter may act as a low pressure reservoir which may empty when compression is released.

The Effect of Pyuria upon Experimentally Produced Renal Obstruction

Hydronephrosis and simulated intrapelvic calculi were produced in laboratory animals. Cultures of proteus and E. coli were introduced in these kidney preparations through an extreme

Isolation and Identification of 17α-Hydroxyprogesterone in Adrenal Venous Plasma of Normal Dogs.∗

Summary By criteria of paper chromatography in several systems, ultraviolet and infrared spectrophotometry, 4 pregnene-17 α-ol-3.20, dione has been isolated and identified in adrenal vein blood of normal dogs given adrenocorticotropin intravenously. This steroid could not be detected in blood from the systemic circulation of dogs given adrenocorticotropin. The authors wish to express gratitude to Dr. Leo T. Samuels for helpful criticism and to Dr. Gunter Zweig, University of California, Pesticide Residue Research, Davis, Cal., for infrared analysis.

Vesical Marsupialization for Access to Kidneys and Bladder Cavity

The term ‘marsupialization’ is offered to describe a new technique by which the bladder is utilized to study the urinary tract. A detailed account of the surgical procedure, maintenance, and advantages in producing the minimal amount of distortion of normal organs is presented.