Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where George W. Drach is active.

Publication


Featured researches published by George W. Drach.


The Journal of Urology | 1986

Report of the United States Cooperative Study of Extracorporeal Shock Wave Lithotripsy

George W. Drach; Study Coordinator; Stephen P. Dretler; William R. Fair; Birdwell Finlayson; Jay Y. Gillenwater; Donald P. Griffith; James E. Lingeman; Daniel M. Newman

Extracorporeal shock wave lithotripsy effectively fragments urinary calculi in the upper urinary tract and upper ureter. These fragments pass completely by 3 months in 77.4 per cent of the patients with single stones. Risk of obstruction, increased postoperative pain, need for additional urological operations and retained fragments are low for stones less than 1 cm. in size. As the number of stones treated or single stone size increases above 1 cm. the risk for these factors increases. Adjunctive urological surgical management is required in 9 per cent of the patients preoperatively and 8 per cent postoperatively. Only 0.6 per cent of the patients require some type of open operation to resolve the stone problems after extracorporeal shock wave lithotripsy. Hemorrhage, obstruction by fragments, severe pain and urinary infection all constitute known complications and require careful urological management of all patients. Hospitalization averages 2 days after treatment and patients usually return to work within a few days after they are discharged from the hospital.


The Journal of Urology | 1979

Patterns of Inflammation in Prostatic Hyperplasia: A Histologic and Bacteriologic Study

Paul W. Kohnen; George W. Drach

In a series of 162 cases of surgically resected hyperplastic prostates the incidence of inflammation is 98.1%. Six morphologic patterns of inflammation are described: 1) segregated glandular inflammation, 2) periglandular inflammation, 3) diffuse stromal inflammation, 4) isolated stromal lymphoid nodules, 5) acute necrotizing inflammation and 6) focal granulomatous inflammation. The most common pattern, segregated glandular inflammation, is characterized by intraluminal neutrophils and foamy macrophages and by chronic inflammatory cells in the surrounding stroma. No significant morphological differences are found among groups of cases with positive and negative evidence by culture of bacterial prostatic infection. Quantitative but not qualitative morphologic differences are found between cases of gram-negative infections and infection by gram-positive organisms that often are considered non-pathogens.


The Journal of Urology | 1992

The Clinical Usefulness of Serum Prostate Specific Antigen After Hormonal Therapy of Metastatic Prostate Cancer

Jeffrey I. Miller; Frederick R. Ahmann; George W. Drach; Scott S. Emerson; Manfred R. Bottaccini

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.


The Journal of Urology | 1979

Male peak urinary flow rate: relationships to volume voided and age.

George W. Drach; Terry N. Layton; William J. Binard

We performed 126 studies of replicate voiding in 7 individuals and 552 observations in normal, abnormal or treated male populations with a disposable device that measures peak flow and volume voided. These observations have led us to suggest that a voided volume of 150 ml. be used as the minimum acceptable volume for studies of male subjects in which peak flow is used to define normal versus abnormal voiding. At volumes greater than 150 ml. a straight line describes the relationship between volume voided and peak flow as accurately as the previously suggested hyperbolic curve. Increasing age of men again reveals progressive decrease in peak flow rate no matter what volume is voided. Comparison of peak flow rate, volume voided and age by 3-dimensional graphing was attempted but was found unsuccessful for clinical use. However, 3 biaxial linear graphs may be used to chart effectively the 3 parameters (age, volume and peak flow) and thereby judge normality or abnormality of peak flow rate for any age and volume voided.


The Journal of Urology | 1992

Emphysematous cystitis : a review of the spectrum of disease

Howard J. Quint; George W. Drach; William D. Rappaport; C.J. Hoffmann

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.


The Journal of Urology | 1994

Extracorporeal Shock Wave Lithotripsy: Multicenter Study of Kidney and Upper Ureter Versus Middle and Lower Ureter Treatments

Jeffrey T. Ehreth; George W. Drach; M. Lee Arnett; Robert B. Barnett; Duncan E. Govan; James E. Lingeman; Stefan A. Loening; Daniel M. Newman; John M. Tudor; Simon Saada

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.


The Journal of Urology | 1980

Effects of Urinary Organic Macromolecules On Crystallization of Calcium Oxalate: Enhancement of Nucleation

George W. Drach; Steven Thorson; Alan D. Randolph

The urine of normal persons, as well as that of stone formers, contains inhibitors to crystallization of calcium oxalate. To ascertain differences, if any, between these 2 groups we measured nucleation rate, growth rate and total mass produced in an analytic system with 5% urine added to 95% synthetic urine that did not contain large organic molecules. We also observed the effects of addition of uromucoid to the synthetic solution. Normal urine and stone-forming urine contained significant inhibitors to total mass of calcium oxalate dihydrate crystals precipitated but total crystal mass was not significantly different between the 2 groups. Growth rate was significantly less in experiments with the urine of stone formers. The other major difference found in stone-forming urine was significant enhancement of nucleation rate when compared to normal urine. Since addition of uromucoid produced these same growth inhibition and nucleation enhancement effects but did not affect total crystal mass, we hypothesize that uromucoid has an important part in producing the differences noted between normal and stone-forming urine.


The Journal of Urology | 1989

Effects of extracorporeal shock wave lithotripsy on the structure and function of rabbit kidney

Subramanian Gunasekaran; John M. Donovan; Milos Chvapil; George W. Drach

An animal model was developed to investigate the effect of extracorporeal shock wave lithotripsy (ESWL) on a normal kidney. Rabbits were treated with 3,000 shock waves at 18 kV to each kidney. Blood and urine samples were collected daily before and after shock wave treatment. Serum levels of hemoglobin, creatinine, lactic dehydrogenase (LDH), creatinine phosphokinase (CPK), and total protein were determined. Urine determination of volume, total protein, hemoglobin, and creatinine were also made. All kidneys, after sacrifice, were subjected to histologic analysis. The average pre-treatment creatinine clearance of our rabbits was 8.3 ml./min. After the treatment, a significant (p less than 0.01) reduction in creatinine clearance was noted for four days. The reduction was to 0.61 ml./min. on day one, 0.87 on day two, 1.04 on day three, and so forth. Urine hemoglobin rose significantly (p less than 0.01) for the first three days from 0.0 to 1.5 gm./dl. Histologic examination at seven days showed focal subcapsular hemorrhage, tubular dilation, and interstitial hemorrhage. Histologic evaluation at two months revealed focal interstitial fibrosis. In conclusion, this study reveals that shock waves to the kidney have short term physiologic effects on renal function and permanent focal histologic effects, which do not effect long term physiologic function. Further research on the effects of ESWL on renal function and structure could be facilitated with the use of this model.


The Journal of Urology | 1992

Injury of Rat Renal Vessels Following Extracorporeal Shock Wave Treatment

Christian Weber; Michael E. Moran; Eldon J. Braun; George W. Drach

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.


The Journal of Urology | 1977

Observations Upon Calcium Oxalate Crystallization Kinetics in Simulated Urine

John D. Miller; Alan D. Randolph; George W. Drach

Two major etiologic theories of urinary stones are excessive saturation of urine with crystallizable substances or defects in inhibitors that allow relative supersaturation to occur. To date, it has been difficult to confirm the supersaturation theory in experiments using diffusion-limited crystallization systems because direct measurements of the nucleation process of crystallization could not be performed. We used well developed, continuous crystallizer techniques and adapted them from industrial use to the study of stone disease. Data derived from the experiments allow the absolute measurement of crystal growth rate and determination of nucleation rate. These methods were applied to study the calcium oxalate dihydrate (weddellite) system in artificial urine that lacked only proteinaceous components. Based on these experiments it was not possible to grow crystals large enough within 5 to 20 minutes to obstruct the collecting ducts of the kidney. Therefore, it appears that other processes, such as aggregation or stasis within tissues, may well be related to initiation of stone disease. Under the experimental conditions of this study nucleation rate exceeded growth rate. Therefore, multiple small particles are created at the expense of allowing larger particles to grow. Inhibitors can be tested rapidly in this system by adding them in concentrations compatible with those found in urine.

Collaboration


Dive into the George W. Drach's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Thomas J. Guzzo

University of Pennsylvania

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge