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Biomedical subjects

F P Begun

Publications and source records attributed to F P Begun.

At least 19 recordsLinked to original sources
PubMed1999

Ureteral calculi: diagnostic efficacy of helical CT and implications for treatment of patients.

OBJECTIVE: The purpose of this study was to evaluate whether unenhanced helical CT of the abdomen and pelvis, supplemented as necessary with delayed enhanced CT of the pelvis, is sufficient for urologists to treat patients with acute renal colic. MATERIALS AND METHODS: CT scans from 99 patients were analyzed retrospectively for the presence, size, and location of ureteral calculi and the presence and severity of secondary signs of obstruction. Clinical follow-up was analyzed by reviewing charts, directly communicating with patients, and reviewing surgical reports. Clinical information was correlated with CT findings. RESULTS: The findings of 51 CT scans were positive for calculi, and the findings of 48 were negative for calculi. The findings from two CT scans were false-positive, and none of the findings were false-negative. The sensitivity, specificity, and accuracy of helical CT were 100%, 96%, and 98%, respectively. A significant difference in stone size was found between patients who were treated conservatively (3.3 +/- 1.3 mm) and patients who underwent a urologic procedure (7 +/- 6.2 mm) (p < .01) and between patients in whom successful ureteral stent placement was the sole intervention (3.9 +/- 2.8 mm) and patients in whom initial stent placement failed and who then underwent a second urologic procedure (7.4 +/- 3 mm) (p < .05). We found no statistically significant difference between the conservatively and interventionally treated groups with respect to stone location. The presence and severity of secondary signs of obstruction were not significantly different between the two groups. CONCLUSION: Stone size alone was found to correlate with patient treatment. Stone location and the presence and severity of secondary signs of obstruction did not affect patient treatment. Because the degree of obstruction and relative renal function are not relevant to the initial treatment of patients with ureteral stone obstruction, CT is adequate for both diagnosis and treatment.

Acute Disease↗
PubMed1997

Patient evaluation. Laboratory and imaging studies.

The evaluation of urolithiases, in terms of calculus detection and evaluation of the morphology and function of the kidneys, continues to be refined with advances in imaging technology. The most significant recent advance is use of helical or spiral CT scan for the accurate delineation of renal and ureteral calculi in the acute setting. This may provide an accurate, rapid, and cost-effective method of patient evaluation. The alternative approach is to use plain abdominal radiography to detect renal or ureteral calculi. Noncontrast-enhanced helical or spiral CT scanning has its greatest impact in patients with negative abdominal radiographs or in those patients with suspected urinary colic in whom renal but not ureteral calculi are seen. A supplemental intravenous urogram can be used, as appropriate, to evaluate renal function and degree of obstruction on both the involved and uninvolved side. Combined abdominal radiography and sonography may be used for calculus detection and demonstration of obstruction. Sonography is an operator-dependent technique requiring expertise, experience, and adequate imaging equipment for satisfactory results. Physiologic study of renal blood flow and urinary dynamics using Doppler techniques are possible, though considered to be in the realm of clinical investigation at this time. Sonography has a valuable role in the serial evaluation of chronic stone formers with a history of recurrent urinary infections related to obstruction or reflux. Radiography, fluoroscopy, and sonography are the imaging, methods used in ESWL treatment in preprocedure and postprocedure.

Humans↗
PubMed1995

Regional concentration of basic fibroblast growth factor in normal and benign hyperplastic human prostates.

Basic fibroblast grown factor (bFGF) is a potent mitogen for mesenchymal cells, including fibroblasts cultured from prostate, and has been postulated to play a role in the development of benign prostatic hyperplasia (BPH). If this is the case, it might be expected that bFGF levels would be elevated in the adenomas of BPH and in the periurethral region of the prostate where BPH is believed to arise. This study was undertaken to test this hypothesis. The concentration of bFGF was evaluated in 31 prostates, 13 normal glands and 18 with BPH. A method for quantitating bFGF by radioimmunoassay was developed that enabled growth factor levels to be correlated to the geographic region of the prostate and the histopathology of the specimen. A 2- to 3-fold higher concentration of bFGF (ng./g. of tissue) was noted in the benign hyperplastic prostates when compared with the adult normal glands. Pubertal specimens demonstrated low growth factor levels comparable to those observed in the normal adult group. Two prepubertal prostates analyzed had high levels similar to those measured in the hyperplastic glands. While the levels of bFGF in the normal adult prostates were highest in the periurethral region, statistical analysis failed to demonstrate a significant difference. Similarly, quantitative morphometric evaluation failed to demonstrate any significant differences in bFGF concentration related to the proportion of stromal, epithelial, or lumenal elements in the tissue sections.

Adolescent↗
PubMed1994

Modes of intracorporeal lithotripsy: ultrasound versus electrohydraulic lithotripsy versus laser lithotripsy.

It seems apparent, from the previous discussion, that no form of intracorporeal lithotripsy represents the perfect treatment modality for all upper urinary-tract calculi. In fact, the role of endoscopic techniques for treatment for upper-tract calculi must be carefully considered given the success of SWL. However, not all stones are amenable to extracorporeal treatment. Therefore, ureteroscopy, with the various forms of intracorporeal lithotripsy, represents an alternative means for successfully treating patients without having to resort to surgical intervention. Ultrasonic lithotripsy is probably the least preferable of the three forms of treatment, primarily because it must be carried out with rigid endoscopic equipment. In the future, if flexible or semirigid devices can be developed, ultrasonic lithotripsy may become a more useful option for the treatment of ureteral calculi. Laser lithotripsy and EHL seem to be equally well suited for use with flexible, actively deflectable ureteroscopes. The relative risks and benefits of these two modalities make their use a matter of clinician's choice. The greater risk of ureteral injury may make EHL somewhat less attractive to endoscopists. However, this must be balanced with the increased cost of the laser lithotripter. It has become apparent that a direct comparison of these three types of intracorporeal lithotripsy is difficult because of the lack of standardized data and the scarcity of randomized comparative trials. Despite this, it appears that all three forms of intracorporeal lithotripsy play an integral part in the treatment of upper-tract urinary calculus disease. Certainly, one of the more exciting areas in the field of endourology will be the continued emergence and development of new technologies and devices for these purposes.

Endoscopy↗
PubMed1993

Influence of transforming growth factor beta 1 and other growth factors on basic fibroblast growth factor level and proliferation of cultured human prostate-derived fibroblasts.

Basic fibroblast growth factor (bFGF) has been identified in the human prostate. The level of bFGF has been reported to be elevated in benign prostatic hyperplasia (BPH), compared with normal prostate, suggesting that the growth factor may play a role in this disease of the prostate. Basic FGF is a mitogen for cultured human prostate-derived fibroblasts (PF). PF also synthesize bFGF, suggesting that growth regulation of these cells may be under autocrine control. The current study was undertaken to identify factors that affect PF proliferation and bFGF expression. Transforming growth factor beta 1 (TGF-beta 1) inhibited PF proliferation. The inhibition by TGF-beta 1 was partially overcome by bFGF but not by epidermal growth factor (EGF), platelet-derived growth factor (PDGF), insulin-like growth factor type 1 (IGF-1), or insulin. Incubation of PF with TGF-beta 1 increased bFGF mRNA and immunoreactive bFGF levels in a dose- and time-dependent fashion. None of the other growth factor studies affected bFGF levels. PF were also found to express TGF-beta 1 mRNA, the level of which was increased two- to fivefold by TGF-beta 1. These observations suggest that PF proliferation is controlled by the interaction of two different growth factors. It is possible that bFGF/TGF-beta imbalance in favor of cell proliferation promotes prostatic stromal hyperplasia.

Blood Proteins↗
PubMed1992

Clinical trials of the Northgate SD-3 dual-purpose lithotriptor for renal calculi.

The Northgate SD-3 is a bathless, portable shock wave lithotriptor made in the United States. It uses ultrasound localization and spark-gap, electrode-generated shock waves to fragment calculi in the upper urinary tract. Since October 1987, 312 treatments have been performed on 281 patients (286 kidneys) with stone burdens less than 2 cm. during clinical trials at 6 investigational sites in the United States. A fragmentation rate of 94% was achieved. Of the treatments 78% were judged successful (stone-free or fragments of less than 5 mm. remaining in an asymptomatic patient) and a 3-month stone-free rate of 58% was noted. The retreatment rate was 9% and the ancillary procedure rate was 5%. The complications (hematuria, ecchymosis, pain, obstruction) were mild and not unlike those seen in patients undergoing lithotripsy with other devices.

Adult↗
PubMed1992

Color Doppler ultrasonography in the evaluation of the acute scrotum.

Color Doppler ultrasonography was used to assess 20 patients with the acute onset of scrotal pain. Patients were categorized into 3 groups according to the initial clinical impression of the examining physician: ischemia, inflammation or trauma. Color Doppler ultrasonography correctly predicted the need for surgery in 8 of 9 operated patients (89%) and correctly predicted the outcome in all 11 nonoperated patients (100%). The anatomical resolution possible, as well as information regarding blood flow made color Doppler ultrasonography a useful tool in the assessment of acute scrotal processes.

Acute Disease↗
PubMed1992

Penile replantation after self-inflicted amputation.

In 4 men with self-inflicted penile amputation, replantation was successful using microsurgical technique. Postoperative complications were minimal. In 1 man who had amputated his penis and then amputated his scrotum and testicles, a small skin graft was necessary to close a portion of the defect. A mild urethral stricture that developed in this man responded to dilation. Return of sensation was excellent. Normal erections were reported by all men. Microsurgical replantation is the treatment of choice for this injury and is superior to other techniques of penile reattachment, which have a high incidence of distal necrosis, fistula and stricture formation, as well as incomplete or absent sensation and compromised erectile function. Of concern in this group of men is the high incidence of previous or subsequent penile mutilation. Two of the 4 men have a history of recurrent self-mutilation. The follow-up in this series is longer than previously reported and the overall psychiatric pathology appears to be quite severe and persistent.

Adult↗
PubMed1992

Color Doppler sonography in the evaluation of the adult acute scrotum.

Color Doppler sonography (CDS) was used to evaluate 35 adult males with acute scrotal discomfort. Correlative nuclear scintigraphy was performed in 15 patients. Surgical correlation was available in 10 patients with clinical follow-up in the remaining 25. The complete absence of intratesticular color flow was used as our criterion for testicular ischemia. This was found to be 100% sensitive and 100% specific in 8 patients with surgically confirmed testicular ischemia. Spontaneous detorsion was noted in one patient with hyperemia demonstrated by color imaging. Increased color flow was found in 20 patients with the clinical impression of scrotal inflammation. Nuclear scintigraphy and color Doppler imaging had 100% agreement in 15 patients. Color Doppler sonography is a useful and highly accurate diagnostic method in the evaluation of patients with the acute scrotal syndrome. Color flow imaging is comparable to nuclear scintigraphy in the diagnosis of testicular ischemia.

Acute Disease↗
PubMed1991

Chronic effects of focused electrohydraulic shock waves on renal function and hypertension.

The chronic effects of focused electrohydraulic shock waves were studied in a minipig model. Fifteen animals underwent a unilateral nephrectomy and compensatory renal hypertrophy was allowed to take place over a minimum of six months. Baseline studies were then carried out consisting of 1) serum creatinine, blood urea nitrogen, and plasma renin levels 2) intra-arterial blood pressure measurement and 3) 3H-inulin clearance. Ten of the animals then underwent 8 shockwave treatments (2500 shocks per treatment), alternately to the upper and lower pole of the kidney, at two weeks intervals. A total of 20,000 shock waves were administered to each minipig over the four month period. The five control pigs underwent sham procedures. The renal function and blood pressure evaluations were then repeated. No significant decrease in renal function was noted in the experimental animals when compared to the controls. In addition, renin mediated hypertension was not observed despite the excessive number of total shock waves delivered to the kidney.

Animals↗
PubMed1990

Development and testing of second generation extracorporeal shock-wave lithotriptor.

The Northgate SD-3 extracorporeal shock-wave lithotriptor is a second generation device that utilizes an ultrasound-guided computer-assisted system for calculus localization. Focused electrohydraulic shock waves are generated in a movable membrane-covered ellipsoidal reflector. Pressure wave characteristics and energy output of the SD-3 and the Dornier HM-3 were tested and found to be comparable. The ultrasound unit was capable of identifying radiolucent calculi as well as calculus fragments 2-3 mm in size. The computer-assisted aiming system was found to be accurate to within 1 mm. The overall successful calculus fragmentation rate using an animal model was 80 percent with an 87.5 percent rate following machine modifications resulting in increased energy output.

Animals↗
PubMed1989

Cultured human prostate-derived fibroblasts produce a factor that stimulates their growth with properties indistinguishable from basic fibroblast growth factor.

Fibrostromal proliferation is believed to be important in the development of benign prostatic hyperplasia (BPH). We found that a mitogen for cultured mesodermal-derived cells was present in extracts of BPH tissue. The mitogen was identified as basic fibroblast growth factor (bFGF). Previous studies did not determine the cell population(s) responsible for bFGF production in the prostate. This information is important to the understanding of the role of bFGF in the etiology of BPH. Human prostate-derived fibroblasts (PF) were initiated in culture. Recombinant bFGF and PF lysates stimulated tritiated thymidine uptake by quiescent PF cells. Greater than 90% of the mitogen in PF lysates bound to heparin-Sepharose and had the same elution profile and apparent molecular weight as bFGF isolated from BPH tissue. The growth factor in PF lysates competed with recombinant iodinated bFGF for binding to antiserum to (1-24)bFGF. Cultured PF incorporated 35S-methionine into protein that was precipitated by antiserum to bFGF. The apparent molecular weight of the radiolabeled protein, about 17,000, was similar to authentic bFGF. The observations are consistent with the interpretation that cultured PF synthesize a growth factor that stimulates their growth with properties that are indistinguishable from bFGF.

Cell Survival↗
PubMed1989

Biliary lithotripsy. Determination of stone fragmentation success and potential tissue injury in swine.

Application of extracorporeal shock wave lithotripsy to gallbladder stones was studied in 37 adult female swine. Twenty-two sows underwent cholecystostomy with implantation of human gallstones. In 20 animals, after a 10-day recovery period, extracorporeal shock wave lithotripsy, 2000 shocks (an amount determined in preliminary water bath studies to be effective), was performed. In 10 of these implanted swine, frequent focal point refocusing and biplanar ultrasonography were employed. Two animals served as operative controls. Fifteen other animals without gallstone implantation were studied for adverse effects of extracorporeal shock wave lithotripsy on tissue. These animals (unimplanted) received 5000 shocks; 7 animals were killed 1 to 4 days after treatment and the others were killed after 4 weeks. Biochemical tests (total bilirubin, alkaline phosphatase, lipase, amylase, alanine aminotransferase, and lactate dehydrogenase determinations) were performed on all animals at entry and every second or third day until they were killed. Successful fragmentation, defined as all residual gallstone fragments being less than or equal to 4 mm in greatest dimension, was achieved in 14 of 20 animals overall, but in 10 of 10 animals in which focal point refocusing had been used. Slight perivascular hemorrhage and minimal coagulation necrosis were seen histologically only in the liver parenchyma adjacent to the gallbladder bed. The remainder of the liver was grossly and histologically normal. No injuries to the colon, duodenum, common bile duct, or pancreas were observed. No alterations suggesting injury or altered function occurred in any of the biochemical tests.

Animals↗
PubMed1989

Leukemia of the penis.

Leukemia of the penis is an extremely rare entity. A case involving the distal penis is described, and the relevant evaluation and treatment are discussed. Only 2 other documented cases of penile leukemia are found in the literature. Identification and treatment of the underlying etiology are important aspects of this unusual disease entity.

Aged↗
PubMed1989

Electrohydraulic shock wave induced renal injury.

The pathological effects of focused electrohydraulic shock waves on renal parenchyma were studied using a porcine model. Testing was carried out using the Northgate SD-3 and Dornier HM-3 shock wave lithotripters. Pigs received 3,000, 5,000 or 6,000 shocks at energy levels equivalent to 18 to 20 KV on the Dornier HM-3. The animals were sacrificed one or four weeks post treatment and evaluated for renal injury. Kidneys were serially sectioned and injury volume calculations carried out. The predominant injury pattern was interstitial and perivascular fibrosis with chronic lymphoid infiltration. Dense areas of fibrosis ranged from less than 0.01% to 0.13% and from less than 0.01% to 1.04% of renal volume in those kidneys treated on the SD-3 and HM-3 respectively. Surrounding areas of perivascular and interstitial fibrosis intercalated with areas of normal appearing parenchyma were noted and were more extensive than the central scar. While the calculated volumes of parenchymal scarring are probably insignificant with respect to renal function, the surrounding areas of partial injury may be related to the development of hypertension.

Animals↗