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Biomedical subjects

J L Huffman

Publications and source records attributed to J L Huffman.

At least 37 records · Page 2Linked to original sources
PubMed1991

Urinary tract stones: a complication of the Kock pouch continent urinary diversion.

Urinary tract stone disease has been found to be a later complication associated with the construction of the Kock pouch continent urinary diversion. Of 383 patients who underwent Kock pouch diversion between August 1982 and December 1986 stones developed in the pouch in 64 (16.7%), usually on exposed staples or eroded Marlex used to construct the nipple valves. Stones have recurred in 13 of the 64 patients (22%). Most stones were removed endoscopically with techniques similar to those used for percutaneous stone removal. Risk factors for stone formation include Marlex collar erosion and acute pyelonephritis. Changes in surgical techniques with elimination of the Marlex collar and a reduction in the number of staples have reduced the incidence of this later complication to 10%.

Female↗
PubMed1989

Early experience with the 8.5 F compact ureteroscope.

The clinical evaluation of the recently introduced 8.5 F rigid ureteroscope is presented. This instrument is for diagnosis and surgical intervention within the ureter and renal pelvis and is specifically designed for use in small caliber adult and adolescent ureters. Twenty-four patients have been examined for diagnosis, removal of calculi, treatment of fistula, and resolution of prior iatrogenic injuries. Only one patient could not be examined due to fixation of the mid ureter.

Endoscopes↗
PubMed1989

Treatment options for proximal ureteral urolithiasis: review and recommendations.

The treatment of proximal ureteral calculi has been altered markedly by recent developments in shock wave lithotripsy (bypass, pushback and in situ), ureterorenoscopy and percutaneous stone removal. In an effort to discern the proper role of these newer treatment options with respect to ureterolithotomy (flank approach or dorsal lumbotomy), we completed a multicentered study in which 142 upper ureteral stone patients in 7 different treatment categories were reviewed retrospectively and contacted for convalescence data. From these data we conclude that before extracorporeal shock wave lithotripsy an upper ureteral stone should be manipulated until it is either pushed back to the kidney or bypassed with a stent. This maneuver should result in successful extracorporeal shock wave lithotripsy in more than 90 per cent of the patients. For those few patients with an impacted upper ureteral calculus ureterorenoscopy is recommended. Given the presently available treatment modalities we conclude that less than 3 per cent of all upper ureteral calculi will require ureterolithotomy. In this last circumstance a dorsal lumbotomy incision appears to be less morbid and yet as effective as anterior ureterolithotomy.

Algorithms↗
PubMed1989

Ureteroscopic injuries to the upper urinary tract.

Kaufman reported a severe ureteral injury following ureteroscopy in 1984. His commentary summarizes the important messages in this article well: The intent of this report is not to denegrate the splendid advances in nephroscopy and ureteroscopy, but rather to introduce a sobering message that the patient must be informed of the inherent risk of such procedures and that the urologist must be wary of the problems that might occur. Problems have been known ever since endoscopic instrumentation was first introduced, and every experienced urologist has had his share of problems associated with stone extraction and other endoscopic procedures. Traditional teaching in urology has been to eschew manipulation of stones in the upper two thirds of the ureter because the lumbar ureter is mobile and more easily damaged by instrumentation than the pelvic segment. Endoscopic visualization of stones in the upper ureter allowing accurate grasping of calculi would appear at first to provide an element of security heretofore unachievable, but urologists nonetheless should be mindful of the hazards of any type of stone extraction from the upper ureter. Urologists must be ready and equipped to handle emergencies associated with new instruments and techniques, and the patients must be apprised of the exigencies. "Caveat emptor" (buyer beware) could not be a more apt or timely maxim in our specialty. Ureteroscopy has greatly aided many patients, and a large number of urologists have integrated this procedure into their daily practices.(ABSTRACT TRUNCATED AT 250 WORDS)

Endoscopy↗
PubMed1988

Anticarcinoma activity of rhodamine 123 against a murine renal adenocarcinoma.

The mitochondria of carcinoma cells retain the permeant cationic compound rhodamine 123 longer than the mitochondria of normal epithelial cells. The possibility of exploiting this difference in the chemotherapy of a murine renal adenocarcinoma was investigated. Rhodamine 123 exhibited anticarcinoma activity in mice and this activity was potentiated by 2-deoxyglucose and methylglyoxal bis(guanylhydrazone), a chemotherapeutic agent that is toxic to mitochondria. Prolonged retention of rhodamine 123 by renal tumor cells compared with normal renal epithelial cells was demonstrated by flow cytometry, perhaps explaining its antitumor activity. A combination of both mitochondrial toxins, rhodamine 123 and methylglyoxal bis(guanylhydrazone) produced the longest survival and had the greatest antitumor effect.

Adenocarcinoma↗
PubMed1988

Balloon dilation of the ureter for ureteroscopy.

Balloon dilation catheters have been used extensively for percutaneous transluminal dilation of vascular narrowings. A recent urological application has been the use of a balloon to dilate acutely the normal ureteral orifice and intramural ureter for the purpose of performing transurethral ureteroscopy. Complications of balloon dilation may result if over inflation and bursting of the balloon occur followed by ureteral injury. We report the pressure needed to dilate the ureter adequately in 122 patients during an 18-month period. Adequate dilation was achieved in 93 patients (78 per cent) at pressures of 8 atmospheres or less, while 27 (22 per cent) required more than 10 atmospheres of pressure. Balloon dilation was not satisfactory in 2 patients (2 per cent) but it was accomplished by metal bougies. Our results confirm the safety and efficiency of balloon dilation to facilitate ureteroscopy. Important safeguards when using this method include the use of balloons designed specifically for ureteral dilation, slow balloon inflation to allow for ureteral accommodation and the use of fluoroscopy to judge the end point of dilation.

Catheterization↗
PubMed1988

Ureteroscopic management of transitional cell carcinoma of the upper urinary tract.

Upper tract tumors may be diagnostic problems, and the importance of obtaining tissue in a closed fashion has been illustrated. This is probably the most important advantage of the ureteroscopic approach to these tumors. Ureteroscopy is safe and reliable and allows examination of about 95 per cent of all patients evaluated. Success rates will continue to improve with the expanded use of flexible instruments. Ureteroscopy may also be used for treatment. However, before this mode of therapy can be accepted, further work must be done comparing the findings of the endoscopic biopsy with the pathologic stage of the cancer. Nevertheless, it does appear that low-grade localized distal ureteral tumors can be managed effectively by ureteroscopic means. Possibly low-grade tumors in the renal pelvis can also be managed by this method (see also following article). Again, methods of surveillance such as radiographic studies and urinary cytology must be used in addition to endoscopic examination for follow-up (Table 2). Extensive pyelocaliceal tumors, high-grade pelvic tumors, and high-grade ureteral tumors probably cannot be managed effectively by ureteroscopic means. Either polychronotropism or failure to control a primary tumor may prove an indication for adjuvant topical therapy. Potential side effects such as systemic absorption resulting in myelosuppression need to be considered. However, if standard dosages known to be relatively safe intravesically are employed, there should be no significant problems.

Biopsy↗
PubMed1987

Flexible ureteropyeloscopy: diagnosis and treatment in the upper urinary tract.

Flexible ureteropyeloscopy was performed on 59 patients with 2.7, 3.2 or 3.6 mm. endoscopes with a deflectable tip. Techniques for use of these flexible endoscopes are discussed in detail. The endoscope could be passed into the ureter in 58 patients and into the kidney in 52 (88 per cent). The entire collecting system was visualized in 23 of the most recent 29 patients (79 per cent). A diagnosis was achieved in all 23 patients with an intrarenal filling defect demonstrated radiographically. The source of gross hematuria alone could be defined in 9 of 17 patients. Surveillance for tumor was achieved in 5 of 5 patients and for residual calculus in 4 of 4. The endoscope was used to establish continuity successfully in 3 patients with an obstructed ureteropelvic junction. An instrument with a deflectable tip and some technique for irrigation are essential for intrarenal inspection and complete visualization of the ureter. This procedure is valuable in selected patients and it rapidly may become the technique of choice for the diagnosis of intrarenal filling defects. It also is of value in patients with benign, essential hematuria.

Aged↗
PubMed1986

Phase I/II trial of intravesical methotrexate for superficial bladder tumors.

Twenty-one patients with superficial transitional cell carcinoma of the bladder received a total of 121 doses of intravesical methotrexate (MTX) at 11 different concentrations of drug, ranging from 40 mg/m2 (mean concentration of 2.9 X 10(-3) M) to 500 mg/m2 (4.9 X 10(-2) M). Biochemical evidence of absorption was minimal in all cases. The maximum serum level was observed within 0.5-2 h in all patients and ranged from 1.8 X 10(-8) M to 5.0 X 10(-7) M. By 24 h the serum levels were negligible and ranged from 5.5 X 10(-9) M (the lowest limit detectable by the assay) to 4.4 X 10(-8) M in the patient who received the highest dosage of 500 mg/m2. Biologic evidence of absorption was minimal. Myelosuppression, mucositis, and nausea were not observed. Eighteen patients received six consecutive weekly doses ranging from 40 to 500 mg/m2. All patients had repeat cytoscopy performed within 2-4 weeks after six consecutive doses to evaluate local toxicity and efficacy. Flow cytometry was performed on the bladder washings of 22 patients, illustrating the use of flow cytometry, in conjunction with conventional cytology, as an additional means of objectively quantifying results. Despite MTX's established activity in systemic treatment of advanced bladder carcinoma, this study failed to demonstrate any clinical response to intravesically administered MTX, in doses of up to 500 mg/m2, and in concentrations of up to 4.9 X 10(-2) M.

Adult↗
PubMed1985

Endoscopic diagnosis and treatment of upper-tract urothelial tumors. A preliminary report.

The technique of transurethral ureteropyeloscopy allows many standard cystoscopic procedures to be extended into the upper urinary tract. This endoscopic method was used to evaluate 31 patients suspected to have urothelial malignancies of the ureter or renal pelvis. Twenty-eight of the patients had the procedure successfully completed (90%), 11 of whom were found to have urothelial tumors. Diagnostic ureteroscopic biopsy in three of these patients revealed high-grade, multifocal tumors and was followed by nephroureterectomy (two patients) or partial ureterectomy (one patient). However, in eight patients, ureteroscopy and biopsy revealed apparently localized, low-grade tumors which were treated by ureteroscopic fulguration or resection. The latter patients have undergone endoscopic surveillance every 3 months (average follow-up, 21 months). The technique of ureteropyeloscopy permits endoscopic access into the ureter and renal pelvis, enabling tissue diagnosis and better preoperative cancer staging without surgical exploration. Although follow-up is short, selected patients with low-grade tumors may be treated primarily by endoscopic means.

Aged↗
PubMed1985

Effect of intravesical Bacillus Calmette-Guérin on detection of a urothelial differentiation antigen in exfoliated cells of carcinoma in situ of the human urinary bladder.

Flow cytometry was used to detect and quantify expression of a urothelial differentiation antigen (Om5) and nuclear DNA in exfoliated epithelial cells of the urinary bladder from 15 patients with nonpapillary carcinoma in situ during and after intravesical therapy with Bacillus Calmette-Guérin (BCG). Before BCG treatment exfoliated cells reacting with the mouse monoclonal antibody Om5 were found in 13 cases. Following treatment Om5 positive cells were still present in 9 cases but 4 patients who had had Om5 positive cells prior to BCG therapy no longer had detectable antigen-positive cells after therapy. Thus intravesical BCG therapy can alter detection of a urothelial differentiation antigen in exfoliated bladder epithelial cells. It is not certain whether this antigen or other differentiation antigens measured by flow cytometry will advance our present techniques for assessing effects of therapy on carcinoma in situ and other bladder tumors. However, five of nine patients showing persistence of Om5 positive cells after therapy were found to have recurrent tumor by biopsy and two others had positive cytology (median follow-up, 13 months). None of the four without detectable antigen-positive cells after therapy had clinical evidence of tumor by cystoscopy, biopsy, or cytology (median follow-up, 12 months). It now appears feasible and desirable to initiate clinical investigations of this and other differentiation antigens in combination with DNA by flow cytometry of bladder irrigation specimens.

Antigens, Neoplasm↗
PubMed1985

Consideration for treatment of upper urinary tract tumors with topical therapy.

The use of topical chemotherapy for the treatment of upper urinary tract urothelial tumors and the selection of patients to receive this treatment remain problematic because of the relatively infrequent occurrence of these tumors compared with similar tumors within the bladder. The lack of clinicopathologic information on upper urinary tract urothelial tumors makes pretherapy diagnosis and clinical staging difficult. In addition, there are problems associated with delivery of the agent, and there is not as yet an effective method of surveillance after treatment. Only continued investigation with endoscopic diagnosis and treatment, as well as longitudinal follow-up, will determine methods of patients selection and the optimal use of topical chemotherapy.

Administration, Topical↗