Biomedical subjects
Publications and source records attributed to R Kay.
Clean intermittent catheterization is a simple and widely used technique with relatively few complications. A child on intermittent catheterization recently was treated for a retained straight catheter. Removal of the catheter was accomplished by urethral dilation. Proper technique of catheter insertion can prevent this complication.
The good prognosis of synchronous bilateral Wilms tumor seems inappropriate for the magnitude of the disease process. Our experience with 11 cases demonstrates the unusual tumor response to chemotherapy and limited preservative surgery. Although 2 patients died 2 with metastatic disease have responded to chemotherapy and are alive at 5 and 8 years after treatment. In addition, 1 patient has survived with biopsy only and no definitive surgery. Although all surgical options have been used, ranging from biopsy alone to bench surgery with autotransplantation to bilateral nephrectomy, our experience demonstrates the effectiveness of a conservative approach with initial biopsy, chemotherapy and subsequent partial nephrectomy if needed. Our survival data and the histological examination of the tumors after chemotherapy suggest a strong relationship of bilateral Wilms tumor to the nodular renal blastema-nephroblastomatosis complex, and a mechanism to explain the excellent tumor response to chemotherapy.
In studies of serial cancer markers or disease states and their relation to survival, data on the marker or state are usually obtained at infrequent time points during follow-up. A Markov model is developed to assess the dependence of risk of death on marker level or disease state and inferences within this model are based directly on data collected in this haphazard way. An application relating changing levels of serum alpha-fetoprotein to death in hepatocellular carcinoma is discussed in detail.
Postoperative intrarenal pressure measurements may be an aid to the diagnosis of acute renal transplant rejection, especially in patients treated with cyclosporine. Serial measurements of intrarenal pressure were made in 38 recipients using a fine-needle technique. Thirty-two intraoperative and 207 postoperative measurements were made, and 39 clinical rejection episodes (23 confirmed by biopsy) monitored. Intraoperative pressures in grafts with immediate function (37.4 +/- 4.0 mmHg, mean +/- SEM) were not significantly different from those with delayed function (30.9 +/- 4.8 mmHg), whereas postoperative pressures were greater (P less than 0.01) in kidneys with acute tubular necrosis (29.4 +/- 1.9 mmHg) than in functioning grafts (20.4 +/- 0.9 mmHg). Pressures recorded during clinical rejection episodes (44.3 +/- 2.3 mmHg) exceeded (P less than 0.001) those during quiescent periods (23.6 +/- 1.0 mmHg). During rejection episodes, higher pressures (P less than 0.01) were recorded from tender or palpably enlarged grafts (52.5 +/- 3.0 mmHg) than in the absence of these signs (36.3 +/- 3.1 mmHg), and patients whose transplants biopsies showed cellular rejection tended to have greater pressures (50.1 +/- 4.1 mmHg) than those with concomitant vasculopathy (36.4 +/- 3.9 mmHg), but the latter did not reach statistical significance. In 7 cases of cyclosporine toxicity the intrarenal pressure was 17.8 +/- 4.2 mmHg. Using a diagnostic cut off point of 40 mmHg, the investigation failed to recognize 26% of acute rejection episodes--and, in the presence of acute tubular necrosis, it wrongly categorized 21% of nonrejectors. While its predictive capacity was limited, the test may occasionally be helpful in the differentiation of cyclosporine toxicity and rejection in functioning kidneys.
Augmentation cystoplasty is a useful adjunct to the surgical management of patients with a small contracted bladder. Although more conservative alternatives should be tried initially, augmentation cystoplasty will increase the volume and capacity of the bladder and may achieve an excellent result. This procedure must be used in properly selected patients with a full understanding of the indications, techniques, and complications.
Green and Byar (1980, Bulletin Cancer, Paris, 67, 477-488) have analysed some data from a randomised clinical trial comparing treatment for patients with prostate cancer in stages 3 and 4. These authors assessed the effects of treatment on survival using an exponential regression model with treatment by covariate interactions. Clinical considerations led to conclusions being drawn about the relationship between treatment and different causes of death. This paper presents a more direct approach for assessing treatment effect based on a model which recognizes the competing-risks nature of the problem. Methods for choosing the optimal treatment for particular patients, one of the aims of the Green and Byar work, are also discussed.
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From 1963 to 1983, 45 children with benign disease underwent urinary diversion with cutaneous ureterostomy. Patient selection for cutaneous ureterostomy was predicted on the presence of at least 1 dilated ureter. Followup ranged from 4 months to 20 years, with a mean of 7.9 years. Of the patients 29 (64 per cent) had a minimum followup of 5 years and 18 (40 per cent) were followed for more than 10 years. Postoperative complications, results of followup excretory urography and the ultimate fate of these children were analyzed. The results demonstrate the usefulness of cutaneous ureterostomy as a permanent form of urinary diversion in selected children.
Nephrogenic adenoma is a rare, benign lesion of the bladder, occurring as an epithelial response to infection or trauma. Characteristically, it presents as a papillary lesion resembling a low grade, low stage transitional cell carcinoma. Although usually occurring in adults, there have been 5 reports in children, in whom the adenoma occurred following either surgery or localized inflammation. We report on 2 additional children with nephrogenic adenoma, including one who presented with a bladder mass and total occlusion of the ipsilateral ureter, while in the other it was found incidentally during closure of a vesicovaginal fistula. Successful treatment consisted of transurethral resection and low dose suppressive antibiotics. Nephrogenic adenoma, while rare in children, appears to be a uroepithelial metaplastic response to trauma or inflammation and is treated best by conservative management.
The growth of all children from one referral centre alive and well more than three years following the diagnosis of malignancy was analysed. Those treated with chemotherapy alone showed significant catch up growth. Children treated with chemotherapy and spinal irradiation showed no overall height loss, but manifested significant reduction in sitting height. Those treated by cranial irradiation had a significant height loss in the first year from which no catch up growth occurred and also had significantly reduced sitting height.
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The body weight of rats at spontaneous vaginal opening (Wvo) was related to the weight at weaning (Ww) and the time elapsed between the two events (tvo) by the following equation: Wvo = aj + bWw + ctvo + residual where aj is the litter effect present when both the male and female young are reared together. When only female young are raised, aj may be replaced by a, so that in this instance there is no litter effect. Further model differences were noted for young raised under different conditions.
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As in adults, intraoperative consultations in children are not expected. If one has thought about possible situations in which consultations may occur, one may be prepared for the unusual event. Careful and thorough diagnosis will lead to correct conclusions, and we may then give appropriate consultation and fulfill a useful need to the operating surgeon and ultimately to the patient.
Human factor I is a two-chain plasma glycoprotein composed of disulfide-linked 50,000- and 38,000-dalton subunits. Analysis of its biosynthesis and postsynthetic processing demonstrated that factor I is synthesized as a single chain precursor (pro-I) that undergoes glycosylation and limited proteolysis to generate the native protein. One of three human hepatoma cell lines, HepG2 , secreted factor I predominantly (70-90%) in a single chain pro-I form. The other cell lines secrete factor I predominantly in its two chain native form. The defect in conversion of pro-I to I in HepG2 was protein specific since other multichain proteins, derived from single chain precursors, the third, fourth, and fifth components of complement were processed normally. Further analysis of the inefficient pro-I to I conversion by HepG2 revealed that Xenopus oocytes injected with HepG2 mRNA secreted factor I in a predominantly two-chain form. In addition, the apparent sizes of native factor I, transferrin, and alpha-1-antitrypsin secreted by the three hepatoma lines differed due to differences in postsynthetic processing.
Auditory brainstem evoked potentials were used to test hearing in dogs. A technique is described which can be carried out normally on conscious or sedated animals. Eleven normal adults, eight normal puppies and four deaf animals were rested. Reproducible brainstem evoked potentials were readily obtained from the normal adult dogs except when they became fractious (unsedated animals only). Usually the evoked waveform consisted of four peaks (I to IV) occurring in the first five milliseconds after the delivery of an auditory stimulus. In adults, the brainstem threshold for clicks varied between 5 and 25 dB normal hearing level. Brainstem evoked potentials were not detected in puppies at two weeks old but occurred at three weeks old. Between three and seven weeks of age the latencies of waves I and IV and the interval between these waves became shorter, to resemble the adult waveform. No brainstem evoked potentials were detected in the four deaf animals.
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