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Biomedical subjects

D G Assimos

Publications and source records attributed to D G Assimos.

70 records · Page 4Linked to original sources
PubMed1989

A lack of coordination in the release of urinary lysosomal and brush border enzymes following renovascular surgery.

The urinary secretion of two lysosomal enzymes, N-acetyl-D-glucosaminidase (NAG, EC 3.2.1.30) and beta-glucuronidase (GLR, EC 3.2.1.31), and two brush border enzymes, alanine aminopeptidase (AAP, EC 3.4.11.2) and gamma-glutamyltransferase (GGT, EC 2.3.2.2), was examined in apparently healthy individuals and in patients before and after renovascular surgery for treatment of hypertension. Eight out of nine patients had elevated levels of at least one enzyme before surgery. The ranking in their frequency of elevation was NAG greater than AAP greater than GLR greater than GGT. In comparing the release of any two enzymes in apparently healthy individuals, the release was coordinated except for GGT and GLR. In individual patients following surgery the excretion of the lysosomal enzymes was highly coordinated whereas the release of the brush border enzymes was less coordinated. Comparisons of lysosomal to brush border enzyme activities revealed dissimilar release patterns between these two classes of enzymes. Analysis of variance over the entire hospitalization period showed that NAG/GLR (p = 0.42) and AAP/GGT (p = 0.12) did not vary significantly whereas all comparisons of lysosomal to brush border enzymes varied significantly (p less than or equal to 0.03). These results indicate that enzymes derived from different subcellular organelles, lysosomes or brush borders, have similar release patterns. However, the lack of a significant correlation between lysosomal and brush border enzyme excretion implies that the two processes are not interdependent. These studies further suggest that the transient pathophysiological changes that occur within renal cells following renovascular surgery affect these cellular components in different ways.

Acetylglucosaminidase↗
PubMed1989

The role of open stone surgery since extracorporeal shock wave lithotripsy.

Of 893 stone procedures 37 (4.1 per cent) performed during the first 19 months after extracorporeal shock wave lithotripsy was instituted at our medical center were open operations. Procedures included ureterolithotomy in 23 patients (with simultaneous pyelolithotomy in 1), anatrophic nephrolithotomy in 8, pyelolithotomy in 3 (with concomitant pyeloplasty in 2), partial nephrectomy in 2 and nephrolithotomy with a bowel segment inlay in 1. The most common reasons for electing an open operation were unsuccessful endoscopic stone manipulation, presence of anatomical obstruction in the intrarenal collecting system or ureter, morbid obesity and underlying medical problems precluding lengthy repeated endourological procedures. Over-all surgical results were excellent. Our study indicates that patients who presently require an open stone operation have complex calculous disease associated with a variety of anatomical and physiological problems. Despite this finding good results may be attained.

Adult↗
PubMed1989

Selective elevation of urinary enzyme levels after extracorporeal shock wave lithotripsy.

Urinary enzyme testing has been used by many investigators to diagnose and monitor various types of renal injury. Three urinary enzymes, N-acetyl-beta-glucosaminidase, beta-galactosidase and gamma-glutamyl transferase were monitored in 17 patients before and after a single, unilateral extracorporeal shock wave lithotripsy treatment. Stones were in the renal pelvis or calices except for 1 treated in situ in the proximal ureter. Urine specimens were collected before extracorporeal shock wave lithotripsy and at 1, 3, 5, 7, 10, 14, 21 and 28 days after treatment. N-acetyl-beta-glucosaminidase and beta-galactosidase levels increased significantly after treatment (p less than 0.05). Gamma-glutamyl transferase levels increased after treatment but this was not statistically significant. All enzyme levels were highest on days 1 and 3 after lithotripsy and returned to baseline by day 28. Factors associated with post-treatment enzyme elevation included female sex, a lower pre-treatment creatinine clearance and stone size greater than 1 cm. These findings indicate that there is a transient selective increase in urinary enzyme excretion after extracorporeal shock wave lithotripsy.

Acetylglucosaminidase↗
PubMed1989

Effects of shock waves on the rat ovary.

The studies reported in this paper were undertaken to investigate the effect of shock waves on ovarian function. In an initial study, five female Wistar rats underwent general anesthesia. One ovary was then exposed to 1500 shock waves at 20 kV using the Dornier XL-1 experimental lithotripter. One week following this treatment, the animals were sacrificed and both ovaries were step sectioned. We counted all follicles that contained both an oocyte and antrum. These follicles in turn were classified further as being healthy or atretic. No statistical difference in these counts was observed between shocked and unshocked ovaries taken from the same animal. In the definitive study, thirty-one adult female Wistar rats underwent unilateral oophorectomy. These rats were then divided into treated, sham-treated and control groups. The eleven treated animals were given general anesthesia and received 1500 shocks at 15 kV directed at their remaining ovary using the Dornier XL-1 lithotripter. The ten sham treated animals received identical anesthesia and duration of waterbath immersion as the treated group. In contrast, however, sham treated animals were positioned outside the path of the focused shock wave. The control group received no treatment. Normal estrus cycle was maintained in all groups following shock wave exposure. Two weeks after this exposure, all three groups of animals were allowed to mate. All animals in each of the three groups became pregnant. There was no statistical difference in litter size or fetal weights at three weeks gestation. No gross teratogenic effects were observed. The rat ovary appears to be structurally and functionally resistant to the shock wave energy levels used in this experiment.

Animals↗
PubMed1989

Neoadjuvant treatment of stages T2 to T4 bladder cancer with cis-platinum, cyclophosphamide and doxorubicin.

In an ongoing phase II study 17 patients with potentially operable transitional cell carcinoma of the bladder (stages T2 to T4, Nx, Mo) have been treated with intravenous cis-platinum (50 mg.per m.2), cyclophosphamide (400 mg.per m.2) and doxorubicin (40 mg.per m.2). They were to receive 3 treatments at 3-week intervals before cystectomy and 2 treatments at 3-week intervals commencing 5 weeks after cystectomy. Of 17 patients 14 (82 per cent) completed all 3 preoperative treatments but only 7 (41 per cent) continued on to complete the entire 5 treatments. In most cases incomplete therapy was due to patient refusal. Toxicity was low as measured by World Health Organization standards. Of the 17 patients 9 (53 per cent) exhibited objective tumor response (pathological downstaging or greater than 50 per cent reduction of tumor volume determined by either computerized tomography scan and/or endoscopic examination. When the determination was made by endoscopy the changes were dramatic and not borderline.) No patient demonstrated a pathological complete response. All 9 of the responders (100 per cent) remain clinically free of disease at a median follow-up of 19 months (range 4 to 30 months). The 8 nonresponders have done poorly with 5 dead of disease, 1 alive with pelvic recurrence and 2 free of disease at 4 and 12 months. These tumor response rates compare favorably with other cis-platinum-based combination regimens. The response to the chemotherapy appears to be an important prognostic indicator. Phase III trials must be conducted to determine whether this neoadjuvant chemotherapy regimen has a significant effect on long-term patient survival.

Aged↗
PubMed1989

Pediatric urology.

Development of the genital and urinary systems is interwoven. Developmental abnormalities may cause problems in both systems, although the presenting problem may be ambiguous genitalia, hypospadias, undescended testis, or a urinary tract infection. The primary care physician must understand the underlying significance of pediatric urologic problems and seek appropriate consultation in a timely manner.

Child↗
PubMed1988

Urethrovasocutaneous fistula.

We report a case of urethrovasocutaneous fistula in an elderly man. There were several possible etiologic factors in this case including: prior vasectomy and transurethral prostatectomy, urinary tract infection, and neurogenic bladder.

Aged↗
PubMed1988

Radiologic contribution to the management of patients undergoing extracorporeal shock wave lithotripsy.

Since its first clinical application in 1980, the use of extracorporeal shock wave lithotripsy (ESWL) has dramatically changed the treatment of urinary tract stone disease. More than 80% of patients with urolithiasis will undergo ESWL as a first line therapy. Detection of stones, appropriateness of ESWL treatment, successful stone therapy, termination of the ESWL procedure, and evaluation of treatment complications are all dependent on radiologic input. The application of adjuvant interventional radiologic percutaneous techniques will extend the use of ESWL to an additional 15% of patients and reduce the need for surgical intervention. Additionally, percutaneous techniques can be used to improve success rates in problematic cases and to treat complications related to the ESWL procedure. This article discusses the pre- and postprocedural radiologic evaluation of patients undergoing ESWL. Adjuvant interventional radiologic techniques useful in the management of these patients are also discussed.

Humans↗
PubMed1987

Urinoma detected by dual isotope renogram-cystogram.

A case is reported in which a urinoma developed following a renal transplant. Dual isotope renography-cystography using Tc-99m DTPA and Ga-67 citrate revealed the diagnosis after ultrasonography and radiographic cystography were nondiagnostic.

Cysts↗
PubMed1986

Postoperative anatrophic nephrolithotomy bleeding.

We reviewed 530 patients treated with anatrophic nephrolithotomy during a 14.5-year period. Significant postoperative renal bleeding occurred in 34 cases (6.4 per cent). The average postoperative blood transfusion requirement in this group was 5,279 cc. Bleeding patients were significantly older and they had worse renal function compared to the nonbleeding group. If bleeding did not begin immediately it usually started 5 to 8 days postoperatively. Bleeding dyscrasias were identified in 6 patients and correction allowed nonoperative management in 4. Epsilon aminocaproic acid was helpful only in the treatment of patients with slow, lower volume bleeding. Eight patients required 9 open renal explorations to control bleeding. Two arteriovenous fistulas and 1 false aneurysm were identified. An attempt at angiographic embolization of an arteriovenous fistula was unsuccessful. Only 1 patient required a nephrectomy (1 of 34 or 2.9 per cent) and there was no mortality. A treatment plan for this complication is described.

Adult↗
PubMed1985

Pediatric anatrophic nephrolithotomy.

A 15-year experience with pediatric anatrophic nephrolithotomy was reviewed. There were 11 procedures performed in 10 patients. Average patient age was 9.43 plus or minus 1.54 years (standard error of the mean). Preoperative urine cultures were positive in 6 of 11 cases. Metabolic or structural defects were identified in all patients. Postoperative morbidity was minimal. Adequate followup was available in 9 patients, for an average length of 4.6 plus or minus 0.96 years. Stones recurred in 7 of 9 patients (78 per cent) but in 2 the new calculi were small and asymptomatic. Anatrophic nephrolithotomy can be performed safely in children but a high incidence of structural and metabolic abnormalities predisposes these patients to recurrent stones.

Adolescent↗
PubMed1984

Efficacy of polyglycolic acid (PGA) tubing stents in ureteroureterostomies.

Polyglycolic acid (PGA) tube stented, silastic stented and non-stented anastomoses were compared in 18 ureteroureterostomies performed in 13 dogs. Urinalysis, urine culture, BUN and serum creatinine and intravenous pyelograms were done periodically from 1 day to 6 months postoperatively and ureteral dynamics were performed at 6 months. Normal intravenous pyelograms were observed following 10 of 11 PGA stented, 3 of 4 silastic stented and 2 of 3 unstented anastomoses. PGA stents prevented extravasation and dissolved within 7 days without stone formation. Urodynamic and histopathologic studies revealed no significant differences among the 3 groups. The data suggest that PGA stents are as effective as silastic stents and do not require additional procedures for removal.

Animals↗
PubMed1983

Prognostic significance of tumor grade and stage in the patient with carcinoma of the prostate.

Available English language articles relating the grade, stage, and grade-stage of carcinoma of the prostate to evidence of tumor progression and survival in untreated and treated patients have been reviewed. Observations of the extremes of the spectrum of biological behavior of carcinoma of the prostate have been emphasized; for example, tumor progression, never or always; survival, never or always. The reported experiences indicated the following; namely, 1) reproducible biologically meaningful grading is achievable; however, grade cannot be utilized as a reliable indicator of stage; 2) accurate staging provides information that correlates with tumor progression and survival in groups of patients. However, unexpectedly prolonged or abbreviated progression-free survivals occur frequently enough in every stage, except perhaps patients with clinically unsuspected focal carcinoma, to indicate that the natural history and treatment response of individuals grouped by stage is far from homogeneous; 3) appropriate use of carefully obtained grade and stage information together maximizes the accuracy of prognostic attempts and is necessary to evaluate treatment results. At the present time, assessment and consideration of the grade and stage of carcinoma of the prostate is essential to formulate prognosis and advise and evaluate treatment in patients with this disease.

Adenocarcinoma↗