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Biomedical subjects

G W Drach

Publications and source records attributed to G W Drach.

At least 19 recordsLinked to original sources
PubMed2000

Secondary and miscellaneous urolithiasis. Medications, urinary diversions, and foreign bodies.

Secondary stones, those with no "classic" cause, provide unusual diagnostic and treatment challenges to the urologist. Stones related to medications, to urinary diversions or augmentation, or to presence of foreign bodies within the urinary tract occur rarely. Nevertheless, they represent situations that may be corrected fully by appropriate conservative or procedural therapy, and therefore they must be included in the differential diagnosis of many patients who present with symptoms of urolithiasis.

Foreign Bodies↗
PubMed1999

Renal calculi.

This past year produced some remarkable reports on renal (and other urinary) calculi. Randall's plaques have returned, phosphate relates to insulin and lipid metabolism, and sialic acid is out. Risk factors for astronauts, cystinuric individuals, older and indinavir patients achieve importance. Discovery by spiral computed tomography advances, teleconsultation emerges and shot-gun therapy with potassium-magnesium citrate succeeds. Endoscopic or shock wave lithotripsy vie for which is best, and both attempt to eliminate open surgery. Yet open surgery still has its place.

Animals↗
PubMed1998

Safety and efficacy of the Alexandrite laser for the treatment of renal and ureteral calculi.

OBJECTIVES: To assess the safety and efficacy of the Alexandrite laser for intracorporeal lithotripsy of renal and ureteral stones in conjunction with ureterorenoscopy or percutaneous nephrostolithotomy. METHODS: We retrospectively analyzed the records of 137 patients with 169 calculi in 143 renoureteral units who were treated with the Alexandrite laser via a retrograde (91.5%) or antegrade (8.5%) endoscopic approach. RESULTS: Adequate intraoperative fragmentation of the stone was observed in 88.8% of the cases. No intraoperative complications were attributable to the laser. At a mean follow-up of 34 days, the overall stone-free rate was 74.4%. The stone-free rate for ureteral stones (n = 115) was 80%, whereas the stone-free rate for renal stones (n = 22) was only 44%. In the best subgroup of ureteral stones (10 mm or less in the distal ureter), the stone-free rate was 97.4%. CONCLUSIONS: The Alexandrite laser is a safe modality for intracorporeal lithotripsy and is highly effective for ureteral stones less than 10 mm in size.

Adolescent↗
PubMed1996

Evidence for aggregation in oxalate stone formation: atomic force and low voltage scanning electron microscopy.

PURPOSE: The aim of this investigation was to differentiate between aggregation and crystal growth by studying the structure of oxalate stones at high spatial resolution using recently developed microscopy techniques. MATERIALS AND METHODS: Sections from 6 complete human oxalate stones and 4 stone fragments were prepared by ultramicrotomy and examined by both low voltage scanning electron microscopy and atomic force microscopy. RESULTS: The scanning electron microscopy showed lamellar structures up to 10 microns. in size, consistent with previous results, and provided evidence that these structures were composed of smaller particles. The atomic force microscopy clearly showed arrays of the small particles, whose size varied between 500A and 2800A. CONCLUSION: Our images suggest that an ordered aggregation of small crystallites is responsible for oxalate stone formation.

Humans↗
PubMed1995

Metabolic evaluation of pediatric patients with stones.

Metabolic evaluation of children with urinary stones begins with analysis of calculi or gravel if at all possible. If no stone is available, radiographic appearances may predict types. Once stone composition is known or suspected, a targeted testing program is performed. Serum and urinary tests define the causative abnormality. Therapy is then directed toward correcting this problem.

Child↗
PubMed1994

Ileal patch ureteroplasty for repair of ureteral strictures: clinical application and results in 4 patients.

Four patients with severe ureteral strictures recovered adequate renal and ureteral function after application of an ileal patch graft to the area of stenosis. No metabolic abnormalities resulted from use of the ileal patch graft. Candidates for this type of repair have severe ureteral strictures after prior attempts at repair. They have ureters encased in scar but lumens are maintained. Ileal patch graft construction is depicted graphically.

Adult↗
PubMed1994

Extracorporeal shock wave lithotripsy: multicenter study of kidney and upper ureter versus middle and lower ureter treatments.

Six institutions throughout the United States participated in this study. Each center used a multifunctional flat table lithotriptor (Dornier MFL-5000) to treat 658 patients with kidney and upper ureteral stones (766 treatments) and 323 with middle and lower ureteral stones (391 treatments), for a total of 925 patients (1,157 treatments). Some patients received more than 1 treatment (that is the kidney and ureter), for a total of 981 patient events. Complete followup was available for 81% of the patients. The overall stone-free rate at followup of approximately 90 days was greater in the middle and lower ureter group (83%) than in the kidney and upper ureter group (67%). The proportion of single stones treated was greater for the former group (89.5%) than for the latter group (72%). A larger proportion (18%) of the middle and lower ureter group required 2 or more treatments to the targeted stone than did the kidney and upper ureter group (13%). Anesthesia was required or selected in only 26.7% of the kidney and upper ureteral stone patients and in 18.5% of those with middle and lower ureteral calculi, usually at the request of the patient or physician, or for performance of an adjunctive procedure. The relative safety of this treatment is demonstrated by a low overall rate of complications reported during and after treatment, including a ureteral obstruction rate of 2.1% for kidney and upper ureteral stones and 2.5% for middle and lower ureteral stones. There were no demonstrated trends in a review of laboratory data to suggest significant treatment side effects. The diastolic blood pressure increased to more than 95 mm. Hg after extracorporeal shock wave lithotripsy (ESWL*) in 6% of the kidney and upper ureteral and 4% of the middle and lower ureteral stone patients, while pretreatment hypertension resolved after ESWL in 11% of both groups. The results of this clinical evaluation indicate somewhat greater effectiveness for the specified indications of ESWL of stones in the ureter below the upper rim of the bony pelvis, as opposed to those in the kidney and upper ureter, with a low incidence of complications and side effects.

Adolescent↗
PubMed1994

Leukemoid reaction: a rare paraneoplastic syndrome associated with advanced bladder carcinoma.

We report a case of leukemoid reaction associated with tumor recurrence and rapid progression in a patient following resection of a high-grade transitional cell carcinoma of the bladder. The clinical, pathologic, and etiologic features of tumor-associated leukemoid reactions are emphasized. In the setting of recurrent carcinoma, a leukemoid reaction suggests highly aggressive or metastatic disease.

Carcinoma, Transitional Cell↗
PubMed1993

Feasibility and toxicity of transrectal ultrasound hyperthermia in the treatment of locally advanced adenocarcinoma of the prostate.

PURPOSE: This Phase I trial tests the ability of a new hyperthermia device, the transrectal ultrasound probe, to heat the prostate gland, and evaluates the toxicity of transrectal ultrasound hyperthermia (TRUSH) given with concurrent standard external beam irradiation in the treatment of locally-advanced adenocarcinoma of the prostate. METHODS AND MATERIALS: Between June, 1990 and August, 1991, 14 patients with American Urological Society Stage C2 or D1 adenocarcinoma of the prostate were treated with TRUSH concurrently with standard external beam radiotherapy to the prostate. Twenty-two heat treatments were delivered in 14 patients; 8 patients received two TRUSH procedures, each separated by 1 week. Patient age ranged between 53-86 (mean: 72) years. Three patients had well-, 6 patients had moderately-, and 5 patients had poorly-differentiated adenocarcinoma of the prostate. Karnofsky status ranged from 70-90. Standard radiotherapy to the prostate and periprostatic tissues was delivered using a four-field approach with 1.8-2 Gy daily fractions delivered 5 x/week to a total dose of 67-70 Gy calculated to the minimum tumor volume. TRUSH was delivered after transperineal placement of multipoint thermometry probes by a urologist, under transrectal ultrasound guidance. Two to three thermocouple probes containing seven sensors each were placed in the prostate in an attempt to sample temperatures throughout the gland. The sensor depth from the rectal wall ranged from 5-25 mm. RESULTS: Thirty-six percent of all sensors were heated above 42.5 degrees C averaged over 30 min; and all patients had at least some sensors within the prostate heated to temperatures > or = 42.5 degrees C. The average temperature of all sensors of all sensors (T(ave) +/- s.d.) over all treatments, however, was only 41.9 degrees C +/- 0.9 degrees C over 30 min. The maximum temperature for normal tissues outside the gland was 41.1 degrees C +/- 1.3 degrees C. Treatments have been well-tolerated with few complications. Tolerance has been "good" in 17/22, "fair" in 3/22, and "treatment limiting" in 2/22 treatments secondary to position intolerance and/or pain. There has been one episode of hypotension related to narcotic administration and three episodes of rapidly resolving pain during hyperthermia treatment. Mild hematuria has occurred in 5/22, and moderate hematuria has occurred in 2/22 transperineal thermometer catheter placements. CONCLUSION: In conclusion, TRUSH is well-tolerated and has great potential for consistently heating the prostate gland. We anticipate that further equipment modifications will improve our ability to heat the entire prostate to temperatures > 42.5 degrees C.

Adenocarcinoma↗
PubMed1993

Effects of high-energy shock waves on rapidly proliferating cells: African clawed toad (Xenopus laevis) zygote model.

To date few studies have described the effects of high-energy shock waves (HESW) on benign, rapidly proliferating cells. In the African clawed toad (Xenopus laevis) model, previously described in vitro fertilization methods were used to study the effects of HESW on zygote cleavage and blastocytosis. Groups of 50 freshly fertilized ova were placed at the bottom of clear ultracentrifuge tubes filled with 5% DeBoers solution, positioned at the f2 focus utilizing the biprismatically split halogen red laser of a Dornier XL-1 experimental lithotripter, and treated using an 80-nF capacitor at various kilovoltages and shock wave (SW) numbers. Controls were treated in an identical fashion but kept outside the f2 focus. Cell lysis was the most notable finding at power settings in the standard treatment range (12 kV or greater). Increasing kilovoltage at a constant SW number (100) correlated linearly with the number of zygotes lysed in each group. There was an apparent logarithmic decrease in progression to cleavage and early development with increasing kilovoltage. At 10 kV, no effect on development was observed. Increasing SW numbers at a constant 19 kV correlated linearly with an increase in the number of lysed zygotes in each group. Increasing the SW number at constant kilovoltage correlated with an apparent logarithmic decrease in progression to cleavage and early development. This effect was observed with as few as 10 SW. These experiments have demonstrated a correlation between viability and lysis of zygotes with increasing treatment energies. The data suggest a threshold setting that minimally affects cellular activity (10 kV).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

The effect of single shock waves on the vascular system of artificially perfused rabbit kidneys.

Extracorporeally-perfused rabbit kidneys were exposed to five shock waves at 14 kV on the XL1 Dornier experimental lithotripter (Dornier Medical Systems, Inc., Germering, Germany). While the perfusion flow rate was kept constant, the arterial perfusion pressure was recorded to assess changes in vascular resistance. Immediately after shock wave application, perfusion pressure decreased by 20%-30%, followed by a short, relative pressure rise that did not reach pretreatment values. Fifteen-twenty minutes later, arterial perfusion pressure reattained pretreatment values. Subsequent to treatment, urine flow decreased by greater than 50%. The observed pressure rise was also induced in nontreated kidneys by perfusion with the effluent of treated kidneys indicating that this is based on a humoral mechanism. On the other hand, shock wave application to formalin fixed kidneys only caused a marked decrease in arterial perfusion pressure, suggesting that this effect is due to a pure mechanical interaction of the shock wave also found with denaturated kidneys. The observed decrease of urine flow is probably caused by a decreased filtration rate. Since this was not the case in nontreated kidneys being perfused with the effluent of treated kidneys, the reduction of urine flow after extracorporeal shock wave lithotripsy does not appear to be mediated by a humoral factor, but is more likely a result of the mechanically-induced vasodilation with consecutive decline of the glomerular filtration rate.

Animals↗
PubMed1992

Emphysematous cystitis: a review of the spectrum of disease.

Emphysematous cystitis is an uncommon condition in which pockets of gas are formed in and around the bladder wall by gas-forming organisms. Persons with diabetes, neurogenic bladder and chronic urinary infection are predisposed to the disease. Severity of illness ranges from an asymptomatic condition to life-threatening cystitis. We present 2 cases of emphysematous cystitis. One case was an incidental finding on evaluation of abdominal discomfort with resolution upon removal of predisposing factors. The other patient presented with an acute abdomen that progressed to severe necrotizing cystitis ultimately requiring cystectomy. The initial involvement of the urologist as a consultant is emphasized. A complete review of the literature describes the incidence, various presentations, associated diseases and organisms, pathogenesis, and available methods for diagnosis and treatment reported for this disease. Successful management depends on early diagnosis with correction of underlying causes, administration of appropriate antibiotics, establishment of adequate bladder drainage and surgical excision of involved tissue when required. Early detection and prompt treatment are encouraged.

Cystitis↗
PubMed1992

Injury of rat renal vessels following extracorporeal shock wave treatment.

The locations of extracorporeal shock wave treatment induced renal vascular injury and the sources of significant renal hemorrhage were determined in a rat model by means of two different vascular casting procedures. Silicone-rubber injected vascular preparations for light microscopy or corrosion casts for scanning electron microscopy were made following gross examination of the treated organs and their contralateral controls. After 1000 shock waves at 18 kV, five out of 20 treated kidneys appeared to be normal or minimally affected, while 15 showed gross evidence of marked vascular injury. Gross interstitial hemorrhage (15/20), subcapsular hematomas (7/20), and hemorrhages into the renal pelvis (5/20) were confirmed by extravasations of casting materials. These could be traced back to their vascular sources in several instances. Disruptions of interlobar and arcuate veins gave rise to most significant interstitial, subcapsular, and renal pelvic extravasations. On a microscopic scale cortical venules were among the most frequently injured vessels. The arterial vasculature was not spared. Arterial injury ranged from complete arcuate occlusion to small afferent arteriolar and glomerular capillary extravasations. The significance of shock wave induced vascular injury is discussed with respect to potential clinical side effects of ESWL.

Animals↗
PubMed1992

The clinical usefulness of serum prostate specific antigen after hormonal therapy of metastatic prostate cancer.

We longitudinally followed serum prostate specific antigen (PSA) levels in 48 patients who were treated with either orchiectomy, monthly luteinizing hormone-releasing hormone injection or continuous diethylstilbestrol for stage D2 prostate adenocarcinoma and achieved an objective response. Of the patients 34 had clinical evidence of disease progression (median remission duration 19 months). Median length of followup for the 14 patients who remained in remission was 42 months. Pretreatment performance status, pretreatment extent of metastases as measured by a bone scan and post-treatment nadir PSA level were univariately correlated with remission duration. After adjustment for the 2 former pretreatment variables, a highly significant independent effect of the nadir PSA level on remission duration persisted. Patients whose post-treatment nadir PSA level decreased below 4 ng./ml. had a significantly longer remission duration than those whose nadir PSA remained elevated (median 42 versus 10 months, p less than 0.0001). No cases were observed to progress (as defined by our criteria independent of PSA level) while the serial post-treatment PSA levels continued to decrease or remained at a plateau after reaching the nadir. The time at which the PSA began to increase once the nadir was reached predated objective evidence of progression in all patients except 2 in whom the 2 events occurred simultaneously (mean lead time 7.3 +/- 5.0 months). We conclude that following serial PSA levels in patients treated with androgen ablation for metastatic prostate cancer can aid in distinguishing favorable from nonfavorable responders early in the course of therapy and greatly assist in monitoring for progression.

Aged↗
PubMed1992

Venomous bites to the external genitalia: an unusual cause of acute scrotum.

The acute scrotum generates a long list of differential diagnoses. An unusual etiology includes insect envenomation, which typically is an acute process with rapid onset of symptomatologies. Two patients with genital envenomation are reported. We review the reported cases at our institution with all types of bites and stings. Symptoms of pain and pruritus, and signs of ecchymosis and edema preceding exfoliating dermatitis were evident in both cases. Mild analgesics and antihistamines promoted resolution in each instance.

Acute Disease↗
PubMed1992

Rupture of a hydrocele: an unusual event.

A rupture of a large, tense hydrocele is presented. The patient was chronically treated with steroids for asthma control. Scrotal ultrasound was used to document hydrocele presence, rupture and recurrence.

Aged↗