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Biomedical subjects

M R Butler

Publications and source records attributed to M R Butler.

At least 19 recordsLinked to original sources
PubMed1992

Treatment strategy for piezoelectric shock wave lithotripsy of upper ureteral calculi.

In situ piezoelectric lithotripsy monotherapy for upper ureteral stones is an attractive option because it can be conducted on an outpatient basis. Difficulty in calculus localization with ultrasound is the limiting factor. We reviewed our experience with 99 patients treated for upper ureteral calculi with the EDAP LT.01 lithotriptor. For stones above the lower renal border we achieved a 53% stone-free rate compared to 25% for calculi below the lower renal border. In situ piezoelectric lithotripsy of upper ureteral calculi may be considered for stones above the lower renal border.

Adolescent↗
PubMed1992

Effect of high-energy shock wave frequency on viability of malignant cell lines in vitro.

In this study, the effects of high-energy shock wave (HESW) frequency on the viability of three different malignant cell lines were evaluated using a piezo-electric generator. The cell lines studied were AR42-J, VX-2 and HeLa. These cells were targeted both in free suspension and immobilised in gelatine beads. All cell lines in free suspension were acutely sensitive to HESW over a range of frequencies. When cells were immobilised in gelatine, however, the effect on cell viability was not as pronounced. However, at frequencies of 80- and 160-Hz kill rates approaching 80 and 90%, respectively, were observed. Cell proliferation following HESW treatment was not adversely affected. This study demonstrates that single cell suspensions are not appropriate for assessing the in vitro cellular effects of HESW. However, even when cells were immobilised in gelatine, high-frequency HESW produced substantial kill rates. The effects of high-frequency HESW merit further evaluation particularly using in vivo tumour.

Animals↗
PubMed1991

Acute and chronic bioeffects of single and multiple doses of piezoelectric shockwaves (EDAP LT.01).

Piezoelectric second generation lithotriptors are an established means of administering extracorporeal shockwave lithotripsy (ESWL) enabling treatment to be performed without anaesthesia or analgesia, but higher shockwave doses and multiple or staged treatment are frequently required. The bioeffects of this modality of ESWL, therefore, require further assessment. Seven experimental groups of adult male rabbits were treated using the EDAP LT.01 in order to determine the acute and chronic bioeffects of clinical dose, excess dose, divided excess dose, high frequency and multiple treatment (X10) piezoelectric shockwaves (PSW). Renal function was measured before and after treatment using mercaptoacetyltriglycine (MAG 3) scans. Gross and histological morphological changes were assessed at one and 30 days following application of PSW. Application of single clinical dose PSW was not associated with any significant functional or morphological renal injury. Excess dose PSW caused transient gross renal contusion, which resolved in the majority of animals with no persistent microscopic abnormality. Divided excess dose PSW resulted in no gross or microscopic damage. High frequency PSW was associated with mild histological abnormality. Multiple PSW treatments caused small discrete fibrotic lesions in all cases, without any change in renal function.

Animals↗
PubMed1990

Ultrasonic imaging for extracorporeal shockwave lithotripsy: analysis of factors in successful treatment.

The emergence of real-time ultrasonic imaging for extracorporeal shockwave lithotripsy poses questions regarding the factors and techniques which facilitate stone imaging for clinicians with no previous practical experience in ultrasonography. The ability of these clinicians to assess when stone disintegration has been achieved also needs to be confirmed. A wide range of data was recorded from each of 2688 lithotripsy treatments performed over a 2-year period using the EDAP LT.01 ultrasound-imaged piezoelectric lithotriptor. An analysis of these data was performed using a comprehensive microcomputer-based statistics package. The mean time taken for stone imaging and positioning was reduced from 11.2 to 7.5 min over the 2-year period. Obese patients and those with renal pelvic stones were best imaged in a lateral position. Overall there was no difference in percentage stone disintegration or clearance between treatments in the supine or lateral positions, but a significant reduction in the clearance of small caliceal stones resulted when the lateral position was used. Factors associated with a significantly greater percentage of stone disintegration and clearance included pain experienced by the patient during fine adjustment of the processing head during treatment, acoustic focus attenuation and widening and acoustic shadow widening as detected by the urologist at the end of treatment. Among the factors not associated with significant alterations in the percentage of stone disintegration or clearance were the lithotriptor operator, the side or site of the calculus, obesity and shockwave frequency or power. This study confirmed the ability of urologists to develop expertise in ultrasonography for renal stone imaging and to interpret successfully the subtle signs of stone disintegration.

Adolescent↗
PubMed1990

Use of the double pigtail stent in stone retrieval following unsuccessful ureteroscopy.

Insertion of a double pigtail stent is known to cause ureteric dilatation. We analysed the effect of an indwelling double pigtail stent on the success rate of calculus extraction by second ureteroscopy when the initial ureteroscopy fails. Over a 12-month period, a first ureteroscopy failed in 42 patients; 30 were then treated by ureteroscopy combined with a ureteric stent and 12 were treated without a ureteric stent. The group with an indwelling stent had a successful second ureteroscopy or spontaneously passed the calculus in 24 cases (84%) compared with 5 unstented cases (45%). Ureterolithotomy was necessary in 2 patients with a stent and 3 with no stent. It was concluded that following failed ureteroscopic manipulation of calculi, insertion of a double pigtail stent was associated with a higher subsequent success rate for removal of stone by ureteroscopy and a consequent lower rate of ureterolithotomy.

Adult↗
PubMed1989

Endoscopic treatment of urinary tract calculi.

Removal of urinary tract calculi by endourological techniques is now widely practised and has reduced the indications for open surgical removal to a minority of cases. A review of 270 consecutive patients who presented to the Meath Hospital Urology department with urinary tract calculi and were treated by percutaneous or transurethral endoscopy is herein reported. The rates of successful clearance of renal (95%) and ureteric (78%) calculi compare well with previous reports. The majority of complications were minor and a low overall complication rate was experienced at ureterorenoscopy. In our experience, endourological treatment of urinary tract calculi is successful, efficient and safe and is the recommended approach to urinary tract calculi that require surgical intervention.

Adult↗
PubMed1989

Extracorporeal shockwave lithotripsy using ultrasonic imaging: urologists' experience.

The EDAP LT.01 is a second generation shockwave lithotripter which employs ultrasound imaging and piezoelectric shockwave generation. We describe the first 12 months of its use in the treatment of urinary calculi by urologists with no previous practical experience of ultrasonography. A total of 406 calculi (359 renal and 47 ureteric) in 317 patients were treated. Analgesia or sedation was not routinely used and 59% of all treatments were performed as outpatient procedures. The clearance rate of renal calculi smaller than 1 cm was 81%, while that of calculi larger than 3 cm was 80% (mean clearance 77.5%). Lithotripsy of ureteric calculi following retrograde manipulation to a renal site resulted in 94.4% clearance compared with 39% for those treated at a ureteric site; 93% of 684 lithotripsy treatments were either painless or caused only mild pain. Our experience with imaging and treating urinary calculi with the EDAP LT.01 lithotripter has been excellent. Patients are treated effectively and inexpensively as out-patients without analgesia or sedation.

Adolescent↗
PubMed1989

Study of appropriate antibiotic therapy in transurethral prostatectomy.

Septicaemia is the commonest cause of morbidity and mortality following transurethral prostatectomy. Routine blind antibiotic prophylaxis is not always effective and there is a tendency to over-use potent new and expensive antimicrobials. Attempts to "sterilise" the urine preoperatively are also expensive and disruptive. However, appropriate treatment/prophylaxis can be administered economically using rapidly obtained laboratory results. We describe here a technique of routine direct antibiotic sensitivity testing (DST) of the patient's urine pre-operatively and before catheter removal. Such testing can be performed by junior medical staff in a ward side-room. An appropriate antibiotic may then be administered parenterally 1 h before surgery or catheter removal. A total of 102 consecutive patients underwent TURP and only 1 of those with infected urine became septicaemic. In this instance, an appropriate antibiotic had been incorrectly given orally before removal of the catheter. If the antibiotic sensitivities of a patient's urine are known, and an appropriate antibiotic is given parenterally 1 h pre-operatively or before catheter removal, the incidence of septicaemia following transurethral surgery may be significantly reduced.

Anti-Bacterial Agents↗
PubMed1988

Transcriptional activation of the glutathione S-transferase pi gene in human ureteric and bladder carcinomas.

Using a cDNA clone derived from the rat Glutathione S-Transferase P (GST-P) gene, we have investigated homologous transcripts in a range of normal and malignant human tissues. A major transcript, of 0.75 Kb, representing human GST-pi mRNA, was present in total RNA purified from peripheral white blood cells, bladder, ureteric and prostate tissues. In total RNA derived from histopathologically benign/normal tissues, peripheral leucocytes and from hyperplastic and malignant prostates, levels of the mature transcript varied by less than 1.5-fold (n = 70). In contrast, levels of transcript were significantly elevated (up to 16-fold) in total RNA derived from bladder and ureteric carcinomas, with the highest levels of elevation approaching those previously found only for the GST-P gene in experimentally induced rodent hepatocellular carcinomas. A wide range of stage and grade of tumour has been investigated (pT1 to pT4; G1 to G3, respectively), suggesting that the transcriptional activation of the GST-pi gene is a characteristic common to many bladder/ureteric carcinomas in man.

Carcinoma↗
PubMed1988

Bilateral ureteric carcinoma.

We report two rare cases of bilateral simultaneous ureteric carcinoma. The radiological features and problems of management are discussed.

Carcinoma, Transitional Cell↗
PubMed1986

Superficial bladder tumors (stage pTa, grades 1 and 2): the importance of recurrence pattern following initial resection.

We treated 414 new patients with stage pTa, grades 1 and 2 bladder tumors by transurethral resection between 1970 and 1982. All of the patients with grade 3 or previous upper tract tumors, or who had been treated at some stage with intravesical chemotherapy were excluded. Followup for 5 or more years was available in 188 of the patients. There was a low increase in T stage (6 per cent). Of the patients followed for 5 or more years 46 per cent remained free of tumor. Only 16 per cent of the patients had multiple tumors at presentation and 20 per cent had tumors of 10 gm. or more. These factors were associated with a worse prognosis. Patients free of tumor at 3 months had an 80 per cent chance of having no further recurrences and this rate remained the same up to 2 years from the start of the disease. Patients with a recurrence at 3 months were much less likely to remain free of tumor, and had a higher chance of recurrence at every future visit.

Follow-Up Studies↗