Biomedical subjects
Publications and source records attributed to D M Wallace.
The stability of cytoplasmic poly(A)-containing mRNA in unstimulated pig lymphocytes has been determined by [3H]poly(U) hybridization after actinomycin D treatment. This approach has shown that the majority of the mRNA is much more unstable than has been suggested by earlier pulse-chase experiments, and has a half-life of between 1 and 2 h.
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Inosine, a purine nucleotide, has been used in 33 patients as a method of preventing ischaemic renal damage. The long-term results have been reviewed with a mean follow-up of 28 months. Inosine was administered either intra-arterially or intravenously. Renal function was assessed by serum creatinine, creatinine clearance and divided function renography. Inosine afforded satisfactory protection in ischaemic periods of up to 60 min, particularly if pre-operative function was normal. It was less reliable if pre-operative function was poor or in ischaemic periods greater than 60 min. Inosine is a helpful aid in ischaemic renal surgery.
In a selected series of 14 patients, upper tract urothelial tumours were excised with preservation of the ipsilateral kidney. The 5-year survival rate was 83%. The ipsilateral local recurrence was 5/14 (36%) but in 4 cases salvage surgery was effective and in 2 cases a functioning kidney was still preserved. The results of conservative surgery and its indications are discussed.
Antisperm antibodies were measured in serum and seminal plasma in 130 males before and after vasectomy reversal and the occurrence of pregnancy was analysed in the partners of 77 who were followed for more than one year. Sperm-agglutinating antibodies were found in the serum of 79% of patients; seminal plasma antibodies were present in only 9.5% before reversal and this rose to 26% afterwards. Pregnancies occurred in the partners of 53% of those men who were trying to produce children. A pregnancy was significantly less likely when the pre-operative serum antisperm antibody titre was 512 or more, but no decrease in fertility was seen with titres below this. Several pregnancies were produced by patients with seminal plasma antibodies, but numbers and follow-up are too small to permit detailed analysis. A randomised controlled trial of per-operative steroids showed that they produced no benefit. The antisperm antibodies associated with vasectomy reversal appear to differ fundamentally from those occurring in naturally subfertile males.
Thirty-three patients with malignant testicular teratomas and para-aortic metastases exceeding 2 cm in diameter have been treated with radiotherapy, chemotherapy (vinblastine and bleomycin, with or without cis-platinum) or both, followed by surgical excision of the residual para-aortic mass. Removal of a poorly functioning ipsilateral kidney was necessary in 7 cases (21%) and a segment of vena cava was resected in 2 (12.5%) of 16 patients with primary right-sided tumours. Removal was incomplete in only one patient, who had femoral nerve root involvement, and he subsequently died of secondary haemorrhage (operative mortality 3%). Undifferentiated tumour was found in 8 (61%) of 13 patients (Group 1) after radiotherapy, compared with only 2 (15%) of 13 (Group 2) after chemotherapy and radiotherapy, and 4 (57%) of 7 (Group 3) who had chemotherapy only prior to surgery; however, 3 of the Group 3 patients were referred because of evidence of activity in the para-aortic region.
The use of the EMI CT 5005 scanner in patients with renal calculus disease is described. This investigation was found to be a useful aid in the accurate localisation of calculi within the renal collecting system prior to surgery.
Fifty-one patients with pure squamous cell carcinoma of the bladder were treated between 1958 and 1978. The overall 5-year survival rate was 16%. Ninety-two per cent of cancer deaths were caused by failure to control local disease; treatment by radiotherapy and elective cystectomy resulted in no long-term survivors. It is concluded that earlier diagnosis would reduce the number of cases presenting with advanced local disease and that future research should be directed towards adjuvant studies with chemotherapeutic agents known to have activity against bladder cancer.
Purified cytoplasmic poly(A)+ RNA isolated from unstimulated pig lymphocytes has the same ability to direct translation in a range of cell-free systems as the corresponding mRNA from 20h phytohaemagglutinin-activated lymphocytes. Additional methylation of the mRNA is not required for maximum protein synthesis in the wheat-germ cell-free system. Misleading results are obtained if the mRNA preparations used are not adequately purified, and a method suitable for routine assessment of the degree of purification achieved is described. Cell-free protein-synthesizing systems from unstimulated lymphocytes translate added lymphocyte mRNA with lower efficiency than do comparable systems from phytohaemagglutinin-activated lymphocytes, whatever the source of the mRNA used.
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The results of multiple biopsies from apparently non-tumour bearing bladder mucosa were studied in 154 patients with bladder cancer; 33% of the biopsies from apparently normal mucosa showed histological abnormalities including 4.5% with carcinoma. When the mucosa appeared red but flat, 52% of the biopsies showed histological abnormalities including 14% with carcinoma. Biopsies from mucosa that had a granular or mossy appearance showed carcinoma in 42%. A more aggressive management policy was adopted in 12 patients (8%) as a direct result of the biopsy findings.
The distribution, aetiology, pathology, and clinical aspects of urinary schistosomiasis are outlined and it is emphasised that mortality from the disease is not due to the parasitic ova passed in the urine and faeces but to the complications caused by fibrotic immunological reactions to the retained ova. The treatment both of these complications and of the infestation itself is discussed. The special circumstances governing the transmission of the disease in Saudi Arabia are described and it is suggested that in view of these the energetic application of hygienic, educational, and therapeutic measures should make the complete eradication of schistosomiasis possible in that country.
Bladder or urethral calculi in 50 patients were effectively fragmented and removed per-urethrally using an ultrasonic lithotriptor with the probe vibrating at 30,000 implulses/s. In adults, local anaesthesia was employed and the operation performed as an out-patient procedure. The method has the advantages over others discussed in that a small (23 F) sheath is used and that damage to the bladder or urethra by the probe is avoided. Using a newer, modified sheath resembling that for punch prostatectomy, larger stones can be fragmented by engaging the stone in the fenestrum of the sheath.
We have followed up 83% of a series of 166 patients with vesicoureteric reflux who were treated surgically more than 10 years ago. We found an incidence of hypertension of 12.8%. The need for careful follow-up of the blood pressure of patients with reflux nephropathy is stressed.
In a haematuria diagnostic service, covering experience with 95 patients, 12 new cases of cancer of the bladder, one of cancer of the kidney, and one of cancer of the penis were identified--all at an early stage. Patients presenting with haematuria were investigated rapidly without disruption of the routine work of the urological unit. Patients who identified the symptoms and sought advice early were given a definite diagnosis quickly, and treatment for any malignant disease was started early. The delay that undoubtedly endangers patients' lives has been considerably reduced by this service.
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Previous studies have shown that electronic lithoclast discharges produce effects resembling an underwater explosion. It was predicted that the shock wave produced by each discharge could damage nearby gas-containing gut through a mechanism known to be associated with underwater detonations. Effects associated with rapid oscillation of the vapour bubble produced could cause damage to the wall of the bladder. Investigation of lithoclast discharges in vivo on goat, and in vitro on sheep bladders demonstrated perforation of both. In vitro studies in the rabbit demonstrated the predicted greater susceptibility of air-filled gut over that filled with fluid. These hazards would be even greater in the ureter and caution in the use of electronic fragmentation of vesical and ureteric calculi is urged in the light of these findings.