Biomedical subjects

J A Belis

Publications and source records attributed to J A Belis.

At least 19 recordsLinked to original sources

PubMed1999

Application of retrograde cerebral perfusion and moderate systemic hypothermic circulatory arrest for cavoatrial tumor resection.

Renal tumors invading the inferior vena cava have proved to be surgically challenging. For suprahepatic and right atrial involvement, deep hypothermic circulatory arrest (HCA) has been the favored procedure. Retrograde cerebral perfusion (RCP) was combined with moderate HCA in an effort to improve cerebral protection and avoid neurological sequelae. Six patients (mean age 64.7 years) who were operated on using this technique underwent a retrospective medical record analysis. The six patients achieved a mean cardiopulmonary bypass, HCA, and RCP time of 2 hours 34 minutes, 26.5 minutes, and 22 minutes, respectively. There were no focal cerebral defects or mortalities. Transient cerebral events were avoided compared to previous patients subjected to deeper hypothermia. All patients are living with no evidence of cancer 16-30 months after surgery. The addition of RCP to HCA for resection of supradiaphragmatic renal carcinoma enhances cerebral protection and allows time for a more efficacious operative procedure.

Aged↗

PubMed1998

Endoscopic management of urolithiasis in the morbidly obese patient.

A retrospective review of 48 consecutive morbidly obese patients with urolithiasis who were treated successfully by endoscopic modalities over 3.5 years was performed. Of the 73 endoscopic procedures, 48 were ureteroscopic laser lithotripsy (UL), 4 were ureteroscopic basket extraction, and 21 were percutaneous nephrolithotripsy (PCNL). The patients' weight ranged from 205 to 385 lbs. (average 286 lbs.). Their abdominal girth ranged from 53 to 65 inches (average 59 inches). Twenty-six patients had one procedure, eight patients had bilateral procedures, eleven patients had two procedures, and three patients had three procedures with utilization of either multiple ureteroscopic treatments or the combination of percutaneous and ureteroscopic techniques. The stone-free rate after one procedure was 77.8% for UL and 60% for PCNL. The stone-free rate after planned repeat procedures was 97% for UL/UL and 89% for PCNL/UL. There were two minor complications. Forty-eight procedures were performed on an outpatient basis, and the remaining 25 procedures necessitated hospital admission (average 3.6 days). Morbidly obese patients with urolithiasis who are unable to have SWL because of their body weight and abdominal girth can be treated successfully with UL, ureteroscopic basket extraction, and PCNL with efficacy comparable to that in patients of normal weight and with minimal morbidity. Many renal calculi were treated with UL alone with a high success rate.

Adult↗

PubMed1996

Bladder dysfunction in the spontaneously diabetic male Abyssinian-Hartley guinea pig.

The spontaneously diabetic adult male Abyssinian-Hartley guinea pig develops bladder hypertrophy and voiding dysfunction. In contrast to animals with chemically induced diabetes, this animal demonstrates changes in bladder function in the absence of diuresis. The diabetic guinea pigs void a total daily volume similar to that of control animals, but have a greater mean volume per void and a longer interval between voiding. Cystometry demonstrates that the diabetic guinea pig produces greater intraluminal bladder pressure, but maintains voiding pressure for a shorter interval. A significantly decreased contractile response of the diabetic bladder base may be responsible for the bladder hypertrophy and voiding dysfunction.

Analysis of Variance↗

PubMed1996

Long-term ureteroscopic management of low-grade transitional cell carcinoma of the upper urinary tract.

Nephrouterectomy, or partial uterectomy, is the treatment of choice for transitional cell carcinoma (TCC) of the upper urinary tract. However, patients with solitary kidneys, bilateral tumors, renal insufficiency, or medical comorbidities require more conservative management. When the TCC is low grade, it would be desirable to manage such tumors endoscopically. Ten patients with low-grade TCC of the upper urinary tract have been managed for 2-6 years with ureteroscopy and electrofulguration or laser coagulation. All tumors have been managed successfully without evidence of progression. Recurrence is frequent in some patients and requires repeat treatment and vigilant surveillance.

Aged↗

PubMed1996

Treatment of ureteral calculi with an 8.3-Fr. disposable shaft rigid ureteroscope.

One hundred forty-two adult patients underwent ureteroscopy for treatment of ureteral calculi using a disposable shaft semirigid mini-ureteroscope. The ureteroscope has an 8.3-French (Fr.) outer diameter with a fiberoptic core that allows some flexibility of the shaft. It has a 4.0-Fr. working channel that allows simultaneous use of 3-Fr. instruments and irrigation. Twenty-nine patients had upper ureteral calculi and 113 patients had lower ureteral calculi. Forty-eight patients did not require ureteral dilation, and the remainder had minimal dilation to 10-12 Fr. One hundred fifteen patients underwent laser lithotripsy, 15 patients underwent basket extraction, and 12 patients underwent both. Ten patients required use of a flexible ureteroscope. Ninety-three percent of the patients went home the day of the procedure, 4% stayed one night in the hospital, and the remaining three percent had longer hospital stays. No major complications or infections were noted. Only 11% of the patients required intravenous or intramuscular narcotics for pain management postoperatively. The stone-free results at one month were 98% for lower ureteral calculi and 93% for upper ureteral calculi. We have found this ureteroscope to be similar to other rigid mini-ureteroscopes with some additional advantages. A larger working channel, increased flexibility, and improved optics make it useful for treating ureteral calculi in the lower ureter in men and the entire ureter in selected women.

Disposable Equipment↗

PubMed1994

Ureteral foreign body after laser lithotripsy.

We report an unusual ureteral foreign body resulting from a complication of pulsed-dye laser lithotripsy: a retained laser fiber fragment. It was removed with two endoscopic procedures without long-term problems.

Endoscopy↗

PubMed1994

Outpatient fragmentation of ureteral calculi with mini-ureteroscopes and laser lithotripsy.

Laser lithotripsy with mini-ureteroscopes is a minimally invasive method to fragment ureteral calculi. This study reviewed the efficacy and morbidity of outpatient laser lithotripsy for the treatment of ureteral calculi. The 248 patients were initially treated by outpatient ureteroscopy and laser lithotripsy with the Candela pulsed-dye laser over a period of 3 1/2 years. Thirty-six patients had prior unsuccessful fragmentation of ureteral calculi by SWL. Twenty-eight patients had undergone unsuccessful ureteroscopy with attempted basket extraction or attempted fragmentation with methods other than laser. Calculi were located in the upper ureter in 31% and in lower ureter in 69% of these patients. The 1-month stone-free rate was 92% for upper ureteral calculi and 96% for lower ureteral calculi, with an overall success rate of 94.7%. Ninety per cent of the patients were discharged the same day and 96% within 23 hours. Hospital admission was needed in only 4% of patients. Parenteral analgesia was required in 18% of patients, and major complications occurred in 0.8%. The combination of mini-ureteroscopes and laser lithotripsy is an effective method for fragmentation of ureteral calculi in outpatients with low morbidity and few complications.

Adolescent↗

PubMed1994

Comparison of computerized cystometry/micturition and contractile responses of the diabetic rat bladder.

Computerized data acquisition was used to achieve a comprehensive assessment of micturition and cystometry in rats made diabetic with streptozotocin. Diabetic rats had a greater mean voided volume and a significantly shorter interval between voiding during the light cycle. During volume expulsion, the rate of intraluminal pressure development was greater, but the mean duration of volume expulsion was less in the diabetic bladder. The increased rate of intraluminal pressure development in the diabetic bladder at the time of volume expulsion correlated with the greater tension development in bladder body strips in response to acetylcholine stimulation. The inability of the diabetic bladder body to maintain peak intraluminal pressure may contribute to the development of residual urine, increased bladder volume and increased voiding frequency in the diabetic rat.

Acetylcholine↗

PubMed1993

Atypical renal adenocarcinoma with features suggesting collecting duct origin and mimicking a mucinous adenocarcinoma.

We report a case of an atypical renal adenocarcinoma of the renal medulla associated with a marked desmoplastic response and interstitial mucin production. Collecting duct epithelium of the renal medulla throughout the kidney showed cytologic atypia. These features have been described by others as suggestive of a collecting duct histogenesis. This case represents the fifteenth reported case known to us of a renal adenocarcinoma of collecting duct origin. Prior reports, however, have not described the extensive mucin production that may be associated.

Adenocarcinoma↗

PubMed1993

Lasertripsy of upper urinary tract calculi after unsuccessful extracorporeal lithotripsy or ureteroscopy: comparison with primary lasertripsy.

Lasertripsy of upper urinary tract calculi after unsuccessful extracorporeal lithotripsy (SWL) or ureteroscopy (Group 1; N = 26 patients, 36 calculi) was compared with primary lasertripsy (Group 2; N = 56 patients, 79 calculi). Access to calculi was achieved by a Candela miniscope or flexible ureteroscope, and laser fragmentation was performed with the Candela pulsed-dye laser. Laser alone or laser plus 1.9F basket extraction produced a stone-free rate of 80.6% in Group 1 and 79.8% in Group 2. Additional treatment methods were needed in similar proportions of both groups and in most patients consisted of SWL of fragments displaced into the kidney. The laser fragmentation failures rates were 2.8% in Group 1 and 7.6% in Group 2. One-month stone-free rates and major complication rates were similar in the two groups. Lasertripsy after unsuccessful SWL or ureteroscopy was as effective as primary lasertripsy.

Endoscopy↗

PubMed1993

Treatment of ureteral calculi with an 8.3F disposable shaft rigid ureteroscope.

Seventy-one adult patients underwent ureteroscopy for treatment of ureteral calculi using the disposable shaft semirigid mini-ureteroscope. The ureteroscope has an 8.3F outer diameter with a fiber optic core that allows some flexibility of the shaft. It has a 4.0F working channel that allows simultaneous use of 3F instruments and irrigation. Twenty-three patients had upper ureteral calculi and 48 patients had lower ureteral calculi. Thirty-six patients did not require ureteral dilation and the remainder had minimal dilation to 10-12F. Fifty-one patients underwent laser lithotripsy, 14 patients underwent basket extraction, and six patients had both. Five patients required use of a second flexible ureteroscope. Seventy-seven percent of the patients went home the day of the procedure, 16% stayed one night in the hospital, and the remaining 7% had longer hospital stays. No major complications or infections were noted. Only 11% of the patients required IV or IM narcotics for pain management post-operatively. The stone-free results at 1 month were 96% for lower ureteral calculi and 91% for upper ureteral calculi. We have found this ureteroscope to be similar to other rigid mini-ureteroscopes with some additional advantages. A larger working channel, increased flexibility/steerability, and improved optics make it useful for treating ureteral calculi in the lower ureter in men and the entire ureter in women.

Adult↗

PubMed1992

Calcium channel agonist/antagonist effects on cholinergic stimulation of the diabetic rat bladder.

The in vitro effects of a calcium channel agonist (BAY K8644) and antagonist (nifedipine) on the cholinergic responses of the streptozotocin-induced diabetic rat bladder were investigated. the bladder body and bladder base were studied separately. There were significant differences in contractile responses to acetylcholine stimulation in the diabetic bladder body compared to the control body. Similarly, the diabetic bladder base demonstrated significantly increased contractile responses compared to the control base. Contractile responses in the diabetic bladder body and base were significantly increased from the control in the absence of extracellular calcium. Differences were found in the effects on maximum responses between diabetic and control tissues treated with nifedipine and BAY K8644. BAY K8644 did not completely reverse the effect of nifedipine on the contractile responses. Rates of contractile response were significantly different between controls and diabetics and between body and base. Alterations in calcium channel activity in diabetic bladder smooth muscle may be responsible at least in part for the nonspecific pharmacologic responses found in smooth muscle strips.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗

PubMed1992

Cytosol-free calcium concentration in single bladder smooth muscle cells from normal and diabetic rats.

The effect of diabetes mellitus on intracellular calcium concentration was measured in single rat bladder smooth muscle cells using the fluorescent calcium indicator dye fura-2 AM. Techniques were developed for isolation and short-term culture of rat bladder smooth muscle cells. Cytosol-free calcium concentrations were measured at rest and during carbachol stimulation. Peak intracellular calcium concentration, rate of increase in intracellular calcium concentration and the integral of accumulation of intracellular calcium were determined. The techniques used to isolate and culture bladder smooth muscle cells produced live, physiologically responsive cells. Resting intracellular free calcium levels and were similar in control and diabetic cells. Both control and diabetic cells responded to carbachol stimulation. No significant differences between these cells were noted in peak calcium concentrations, rate of response or integral of response, but standard errors were large. Two patterns of intracellular response to carbachol stimulation were identified, and may explain the large variability in intracellular calcium response to carbachol stimulation.

Animals↗

PubMed1992

Extracorporeal shock wave lithotripsy in the renal transplant patient: a case report and review of literature.

Renal allograft lithiasis is a rare complication of renal transplantation, which in the past has required various invasive procedures for adequate stone fragmentation and dissolution. Noninvasive techniques such as extracorporeal shock wave lithotripsy (ESWL) can now be extended to the renal transplant patient. Five cases have been previously reported in which ESWL was used effectively for dissolution of renal allograft calculi. We now report a 6th case in which a calculus, initially identified 2 weeks after renal transplantation, was effectively fragmented 3 years later using ESWL. Based on our experience and the reviewed composite experience in the literature, ESWL is a safe therapy for renal allograft calculi.

Adult↗

PubMed1991

Neurogenic function of the diabetic rat bladder: alteration by calcium channel effectors.

The in vitro effects of a calcium channel antagonist (nifedipine) and agonist (BAY K8644) on the neurogenic responses of the streptozotocin-induced diabetic rat bladder were investigated. The bladder body and bladder base were studied separately. There were no significant differences in neurogenic responses in diabetic bladder body compared to control body, but the diabetic bladder base demonstrated an increased contractile response at each frequency compared to control base. The rate of contractile response was similar in controls and diabetics but was significantly different between body and base. Although declining with time, contractile responses in the diabetic bladder body and base were increased from control in the absence of extracellular calcium. Differences were found in effects upon maximum responses between diabetic and control tissues treated with nifedipine and BAY K8644. BAY K8644 did not completely reverse the effect of nifedipine on the neurogenic responses in the diabetic bladder body. Effects of diabetes on the bladder body and base are associated with changes in calcium channel activity of bladder smooth muscle.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗

PubMed1991

The efficacy of transrectal ultrasound and prostate cancer.

An increased interest in the diagnosis and treatment of prostate cancer, particularly in the last few years, is reflected in the literature. Numerous articles have been published since 1980 on the subject of imaging of the prostate gland. This article is a review of transrectal ultrasound and its efficacy in the diagnosis and treatment of prostate cancer. Included is a review of the normal prostate anatomy, typical and atypical sonographic features, clinical and radiographic staging of prostate cancer, efficacy of the digital rectal examination, role of ultrasound in prostate cancer screening, surgical treatment, and radiotherapy of prostate cancer.

Adenocarcinoma↗

PubMed1990

Five-year survival following excision of renal cell carcinoma extending into inferior vena cava.

Fifteen consecutive patients having radical nephrectomy and excision of tumor extension from the inferior vena cava for pathologic Stage 3A renal cell carcinoma were followed up for a minimum of five years. Survival was compared with patients having radical nephrectomy for Stage 2 or Stage 3 renal cell carcinoma in the same time interval. Five-year survival in the Stage 3A group (47%) was similar to that for patients with Stage 2 tumors (54%) and significantly better than Stage 3 patients with positive lymph nodes at surgery (12%). Renal cell carcinoma with venous extension has a reasonable prognosis after surgical excision and warrants an aggressive surgical approach.

Carcinoma, Renal Cell↗

PubMed1989

Estradiol-progesterone-induced growth of the rat dorsolateral prostate: effects on protein phosphorylation.

The combination of estradiol and progesterone can affect growth of the rat dorsolateral prostate by a mechanism that appears to be independent from androgen-mediated activity. The effects of estradiol and progesterone on protein kinase activity and endogenous protein phosphorylation in the castrate rat dorsolateral prostate were compared with androgenic effects on these intracellular events. Differences in protein kinase activity and protein phosphorylation were found with each type of hormonal therapy. Changes in protein kinase activity and protein phosphorylation produced by estradiol and progesterone in the rat dorsolateral prostate were not found in the rat ventral prostate, which was not affected by these hormones in the 28 day length of this study.

Animals↗