The treatment of Wilms' tumor: results from Royal Children's Hospital, Melbourne, 1967-1977

A retrospective review of the treatment of Wilms' tumor from 1967 to 1977 at the Royal Children's Hospital, Melbourne, was undertaken, allowing a minimum 2-yr followup. Fifty-four (77%) of the 70 patients in the study are alive, with 23/25 (92%) in Stage I, 12/16 (75%) in Stage II, 12/19 (63%) in Stage III, and 7/9 (78%) in Stage IV. Survival was significantly better in Stage I disease, and those patients less than 5-yr-old at presentation. Recurrence of disease was significantly lower after the introduction of multiple courses of chemotherapy in 1971. Sixteen deaths occurred during the period: three infants from drug toxicity, four patients with "unfavorable" sarcomatous histology, and four patients with recurrent local disease, where irradiation had been confined to the tumor bed after tumor spill with recurrence beyond the irradiated field.

Estrogen inhibition of Mullerian inhibiting substance in the chick embryo

Diethylstilbestrol (DES) feminizes the embryonic chick testes and causes retention of the Mullerian duct, an observation made by Etienne Wolff in 1939. The present study was designed to determine if the feminized testis could produce Mullerian Inhibiting Substance (MIS). DES in various doses was injected into the air sac or yolk of 5-day chick embryos, with removal of the gonads at 13-16 days of incubation. That the DES-treated testis was feminized was documented by the development of a left "ovarian" cortex, yet this gonad continued to produce MIS as estimated by a graded organ-culture assay. The male chick Mullerian ducts, exposed to both endogenous MIS and exogenous estrogen (DES), however, were preserved, indicating that the Mullerian duct retention seen in DES-treated embryos was not caused by suppression of MIS secretion. These data support the hypothesis that MIS and estrogens interact at the target-organ (i.e., Mullerian duct), resulting in Mullerian duct retention. The implications of this hypothesis for mammalian sexual development especially in regard to the effect of DES-treatment on male fetuses, and the possible role of MIS and estrogens in testicular descent are considered.

Steroid enhancement of Mullerian duct regression

The biologic activity of the glycoprotein, Mullerian Inhibiting Substance (MIS), was enhanced by added testosterone, medroxyprogesterone acetate, and progesterone, although these steroids did not cause Mullerian duct regression when added alone. Statistically significant augmentation by testosterone and medroxyprogesterone was observed at concentrations of 10(-7) and 10(-8) M. Progesterone enhanced MIS activity at a concentration of 10(-6) M. By contrast, dihydrotestosterone, estradiol, and corticosterone at concentrations of 10(-9) to 10(-5) M produced no significant effect on MIS activity. Since MIS does not bind directly to the steroids studied, we suspect that the enhancement effect occurs at the receptor level, probably at the mesenchyme as observed in other developmental systems.

Compensatory renal growth in the mouse. I. Allometric approach to the effect of age

Allometry, defined as the relationship between the growth rates of organs to the weight of the whole body (38), was used to study the effect of age on the degree of compensatory renal growth (CRG) in the mouse. The normal growth of the kidneys relative to body weight (BW) was determined in animals between 5 to 50 days of age. In one group, nephrectomy and sham operations were performed at 5, 15, and 35 days of age. The remaining ("renoprival") kidney was removed 15 days postnephrectomy. In a second group, nephrectomy was performed on 5-day-old animals, the renoprival kidney being removed after 30 or 45 days. Regression equations were calculated by least-squares after logarithmic transformation and different groups were compared by analysis of covariance. The regression equation for the control kidney was kidney weight (KW) = 0.0093 BW0.86 (r = 0.96). The regression for renoprival kidneys in females was KW = 0.0142 BW0.83 (R = 0.96) after 15 days and, in comparison, was not significantly different from 30 to 45 days. The interval between control and renoprival regressions was equivalent to a difference of congruent to 43% KW. In male mice, the regression for renoprival kidneys after 15 days was KW = 0.0103 BM0.96 (r = 0.98) and was not significantly different from 30 to 45 days. This study suggests that in young mice the time required for complete CRG may be a maximum of 15 days and that the amount of CRG does not depend on the age at operation. After CRG, a new equilibrium is reached which is thereafter maintained up to a minimum of 50 days of age.

Compensatory renal growth in the mouse. II. The effect of growth hormone deficiency

Allometry was used to study the effect of growth hormones (GH) deficiency on compensatory renal growth (CRG) in a dwarf mouse strain (Little). Nucleic acid and protein estimations were used to assess changes in cellular hyperplasia and hypertrophy. Nephrectomy was performed at 5, 15, or 35 days of age with removal of the renoprival kidney 15 days later. Controls underwent sham nephrectomies at 35 days of age. The allometric growth of the normal kidney in the homozygote dwarf (lit/lit) between 8 and 50 days of age was closely related to that of the normal heterozygote (lit/+). A regression line for the renoprival kidneys in lit/lit animals was parallel to that of the control right kidney (P less than 0.001). The interval between the regression lines was equivalent to a constant difference of approximately 40% between renoprival and control right kidneys and was similar to that found in the normal heterozygote (43%). Increases in DNA, RNA, and protein in control animals during CRG indicate that cell division and hypertrophy were occurring in similar proportions. In the GH-deficient mouse, the total amount of DNA in renoprival kidneys was 0.451 mg compared with 0.439 mg in controls (NS). This suggests that cell replication was suppressed. The protein:DNA ratio increased from 20.91 to 24.27 (P less than 0.001) and the RNA:DNA ratio increased from 0.732 to 0.912 (P less than 0.001), suggesting that cell size was markedly increased. These findings suggest that reduced amounts of GH may produce a dissociation between hyperplasia an hypertrophy, with CRG occurring predominantly by cellular hypertrophy.