Biomedical subjects
Publications and source records attributed to B Lytton.
A case of endodermal sinus tumor of the infant vagina is reported with long-term survival after successful therapy by surgery, chemotherapy, and radiation. The previous 26 reported cases are reviewed and the problems of therapy and long-term management are discussed. Therapy of these tumors should be monitored by alpha-fetoprotein radioimmunoassay.
Rigid ureteroscopy is now an established technique for the management of ureteral stones. Manipulation of calculi can be done under direct vision using flexible forceps or stone baskets with increased safety and efficacy. We also have used a 5F electrohydraulic lithotripsy electrode to disintegrate stones that were too large to be removed by manipulation. Between October 1982 and January 1984, 36 ureteroscopies were performed for the removal of ureteral stones. In 26 cases (72 per cent) the stone was removed successfully. Electrohydraulic lithotripsy was used successfully to remove the stone in 9 cases (24 per cent) and there were no immediate complications. Followup with excretory urography in 7 of these patients 2 to 18 months after lithotripsy failed to reveal any evidence of long-term complications. We conclude that electrohydraulic lithotripsy under direct vision can be done safely if certain guidelines are adhered to strictly.
A number of disease states have been found to have a positive association with certain HLA antigens. Weak associations have been described for a number of cancers. Seventy patients with transitional cell carcinoma of the bladder underwent serotyping for HLA, A, B, C, and DR antigens. There were 54 men and 16 women patients with a mean age of 65.3 years. Noninvasive lesions (Ta and T1) were present in 50 and 20 were invasive (T2, T3, and T4). Low grade tumors (G1 and G4) were found in 53 and 17 were moderately or poorly differentiated (G3 and G4). Gene frequencies for the HLA determinants in the cancer patients were compared to those for normal English caucasoids. No significant differences were found at either the A, B, C, or DR loci. DR4 was the commonest antigen expressed in bladder cancer patients with an allelic frequency of 39% compared to 28% in the normal population. The presence or absence of the DR4 antigen was not related to the stage or grade of the tumor.
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A new application of electrical stimulation to inhibit detrusor activity has been used in 15 patients with a variety of neural lesions. The results were astonishingly good and the device was well tolerated. In patients treated successfully for detrusor instability an absence of urgency occurred as a by-product of electrical stimulation. Therefore, stimulation was used to treat uncomfortable bladder urgency without detrusor instability and was successful in the majority of patients.
Ultrasound is used currently to confirm the presence of stones pre-operatively as well as allowing localization of stones during operation. The great value of this technique lies in its capacity to distinguish between a non-opaque stone and a tumour of the collecting system. X-rays are said to be useful for demonstrating residual stones during nephrolithotomy, but this has the limitation of allowing only 2-D localization. On the other hand ultrasound using a sound, set at 7.5 MHz, and held in the hand allows precise localization of the depth of the stone relative to the kidney surface. This technique makes it possible to introduce a needle to probe the stone before effecting its removal by way of a small nephrotomic incision. The surgeon employing this method should have sound experience in order to recognize the brilliant resonance and the acoustic shadow of a stone. This method, tested on 44 patients was successful in 26, failed in 11 and was considered helpful in 7.
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Ischemic necrosis of the allograft ureter after renal transplantation most often results from failure to preserve adequately is vascularity during donor nephrectomy. An acute episode of rejection occurring within the first few weeks postoperatively may serve to compound the problem, producing even more extensive necrosis of the urinary collecting system. Secondary ureteropyelostomy using the recipient's own ipsilateral ureter is the salvage operation of choice in this situation and can be highly successful provided there is strict adherence to a number of important surgical principles.
The concept that the vertebral system of veins acts as a direct conduit in the spread of prostatic carcinoma to the skeletal system is based on the poorly documented observation that this tumor metastasizes preferentially to the pelvis, lumbar spine and sacrum. We analyzed 99mtechnetium bone scans in patients with skeletal metastases from assorted primary tumors and found that the distribution of metastases was virtually identical in patients with prostatic and nonprostatic tumors. Of the patients with prostatic carcinoma 25 per cent had bone scan lesions exclusively outside the region of the sacrum, pelvis and lumbar spine. The distribution of skeletal metastases from prostatic carcinoma does not support the concept that the vertebral veins have a substantial role in the dissemination of this tumor.
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Previous studies have shown that adenosine triphosphate-magnesium chloride (ATP-MgCl2) administered after 30 to 60 min of renal ischemia ameliorated the resulting acute renal failure in different species of animals. The purpose of this study was to determine whether addition of ATP-MgCl2 to the perfusate during renal preservation, prior to transplantation, might improve renal function. Dog kidneys were subjected to normothermic ischemia for 35 min, after which they were preserved by pulsatile perfusion for 24 hr at 7 C. The perfusate contained albumin in a balanced electrolyte solution with an without ATP-MgCl2. Following 24 hr of pulsatile perfusion, the kidneys were autotransplanted and renal function was determined 3 days post-transplantation. The results indicated that dog kidneys subjected to ischemia followed by perfusion preservation developed severe oliguric renal failure 3 days after transplantation. However, if ATP-MgCl2 was added to the perfusate, such kidneys demonstrated markedly improved renal function and ATP levels. These results indicate that kidneys which have been subjected to episodes of warm ischemia could be salvaged by addition of ATP-MgCl2 to the perfusate.
Removal of small stones and stone fragments from the kidney is difficult and can be an extremely frustrating experience for the surgeon. The major difficulty is the precise localization of the stone within the pelvicalyceal system. Conventional probing of individual calyces is unreliable, even with optimal exposure and direct visualization of the infundibula, using the extended pyelotomy technique. Intraoperative radiographic techniques can be use reliably to detect small stones and fragments. However, such two-dimensional localization limits their effectiveness. Radiographic methods are also cumbersome and require 10 to 15 minutes for each film. Ultrasonography is repeatable and noninvasive. It is a complementary study that offers precise, three-dimensional localization.
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Preoperative urodynamic testing for the identification of specific types of urinary incontinence was found useful to select an appropriate operative procedure. Failure of the operation to relieve stress incontinence was unusual in 346 patients followed for a minimum of 2 years. Of the total group of patients with stress incontinence 27 per cent also had detrusor instability identified urodynamically preoperatively. However, identification of the syndrome is of limited prognostic significance since the majority of these patients had no difficulty with the syndrome postoperatively and some other patients appeared to have the syndrome only postoperatively.
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Although a number of manipulations prior to or during the initiation phase of an acute renal injury will modify the degree of functional impairment, agents administered after the acute insult usually have been ineffective. In the present study, adenine nucleotides (AMP, ADP, or ATP) combined with magnesium chloride were infused after an ischemic renal injury. Twenty-four hours later: (1) rats that received no infusion or one of the components of the mixture alone had reduced CIn (355 +/- 40 microliter/min/100 g of body wt vs. 977 +/- 40 control value), decreased RBF (3550 +/- 205 microliter/min/100 g of body wt vs. 5095 +/- 171 control value), elevated FENa (0.65 +/- 0.10% vs. 0.17 +/- 0.04 control value), and diminished UOsm (862 +/- 110 mOsm/kg vs. 1425 +/- 132 control value); (2) rats given dopamine or phenoxybenzamine maintained low CIn (365 +/- 50) despite improved RBF (4678 +/- 222); (3) rats infused with either AMP, ADP, or ATP combined with magnesium chloride had markedly improved CIn (594 +/- 44, P < 0.01), increased RBF (4269 +/- 223, P < 0.01); normalized FENa (0.18 +/- 0.07%, P < 0.01), and improved UOsm (1201 +/- 106 mOsm/kg, P < 0.05). In animals given no infusion or only magnesium chloride, ultrastructural studies demonstrated focal cellular necrosis and marked generalized tubular cell and mitochondrial swelling, whereas rats infused with ATP and magnesium chloride had fewer ultrastructural changes with better preservation of cellular morphology. Rats treated with ATP and magnesium chloride had improved CIn despite ischemic periods of 30, 45, and 60- min; and the degree of improvement was directly related to the quantity of ATP and magnesium chloride administered. The cellular content of exogenously administered ATP was 2.5 times greater in previously ischemic kidneys than in nonischemic kidneys. The data indicate that adenine nucleotides combined with magnesium chloride when infused after the initiation of acute renal failure significantly improve both CIn and tubular function and suggest that these agents effectively enhance recovery following an ischemc renal insult.
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