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S R Potter

Publications and source records attributed to S R Potter.

At least 37 records · Page 2Linked to original sources
PubMed2000

Plain abdominal x-ray versus computerized tomography screening: sensitivity for stone localization after nonenhanced spiral computerized tomography.

PURPOSE: Urolithiasis followup with plain abdominal x-ray requires adequate visualization of the calculus on the initial x-ray or computerized tomography (CT) study. We compared the sensitivity of plain abdominal x-ray versus CT for stone localization after positive nonenhanced spiral CT. MATERIALS AND METHODS: We evaluated 46 consecutive nonenhanced spiral CT studies positive for upper urinary tract lithiasis for which concurrent plain abdominal x-rays were available. X-ray and CT studies were compared for the ability to visualize retrospectively a stone given its location by CT. A consensus of 1 radiologist and 3 urologists was reached in each case. Cross-sectional stone size and maximum length were measured on plain abdominal x-ray. RESULTS: Plain abdominal x-ray and scout CT had 48% (22 of 46 cases) and 17% (8 of 46) sensitivity, respectively, for detecting the index stone (p <0.00004). Of the 39 stones overall visualized on plain abdominal x-ray only 19 (49%) were visualized on scout CT. Mean cross-sectional area and length of the stones on scout CT were 0.34 cm.2 (approximately 6 x 5.5 mm.) and 6. 5 mm., respectively, while the average size of those missed was 0.11 cm.2 (approximately 4 x 3 mm.) and 3.6 mm. The mean size differences in the groups were highly significant (p <0.0009). CONCLUSIONS: Plain abdominal x-ray is more sensitive than scout CT for detecting radiopaque nephrolithiasis. Of the stones visible on plain abdominal x-ray 51% were not seen on CT. To facilitate outpatient clinic followup of patients with calculi plain abdominal x-ray should be performed when a stone is not clearly visible on scout CT.

Humans↗
PubMed2000

Seminal vesicle invasion by prostate cancer: prognostic significance and therapeutic implications.

When the pathologist's report following radical prostatectomy describes seminal vesicle invasion (SVI), generally the outlook for the patient is poor. But are we all on the same page of the same book when we talk about SVI? Does it mean muscular wall invasion? Does it include the ejaculatory duct? Getting a clear definition can have far-reaching clinical implications for patient prognosis and treatment.

Journal Article↗
PubMed1999

Significance of small foci of Gleason score 7 or greater prostate cancer on needle biopsy.

OBJECTIVES: With increased screening for prostate cancer, we have noted a greater number of patients with small foci of Gleason score 7 or greater prostate cancer on needle biopsy. The significance of these findings is unknown. METHODS: We studied 57 men with small foci of Gleason score 7 or greater on needle biopsy. Tumor length was less than 1.5 mm in all but 2 cases. In those 2 cases, there were two minute (less than 0.5 mm) foci of cancer separated by 1.8 mm. The length of cancer ranged from 0.2 to 1.8 mm (mean 0.63 mm). In all cases, only one core was involved. RESULTS: Thirty-three men underwent radical prostatectomy (RP), 14 received radiation, 8 underwent surveillance, and 2 received hormonal therapy. Men who underwent RP were younger (62 years) than those who had radiotherapy (69.1 years), who were younger than those who underwent surveillance (74.5 years). The mean prostate-specific antigen (PSA) for men undergoing RP was 8.0 ng/mL (range 1.4 to 22). Preoperative serum PSA values did not predict organ-confined status. Needle biopsy grades were as follows: 3 + 4 = 7 (n = 30); 4 + 3 = 7 (n = 17); 4 + 4 = 8 (n = 7); 5 + 4 = 9 (n = 1); and 5 + 5 = 10 (n = 2). We were able to review slides in 27 of the RP specimens, of which 24 were well sampled. Of these 24 cases, 33% had positive margins and 33% were not organ confined; the median tumor volume was 0.5 cc (mean 1.04). No difference in RP tumor volume was found between tumors with needle biopsy Gleason primary grade 3 and those with 4 or greater. The percentage of Gleason pattern 4 on needle biopsy weakly correlated with the percentage of Gleason pattern 4 in the RP specimen (P = 0.04). However, the percentage of Gleason pattern 4 only in the RP specimen, but not in the biopsy, correlated with whether the tumor was organ confined. CONCLUSIONS: The likelihood of having organ-confined disease with small foci of Gleason score 7 or greater on needle biopsy appears to be equivalent to that calculated from the Partin Tables for greater amounts of Gleason score 6 cancer on needle biopsy. In men who are considering RP, small foci of Gleason score 7 or greater adenocarcinoma on needle biopsy should not necessarily be considered an adverse finding.

Aged↗
PubMed1999

Endoscopic reconstruction of vesicourethral obliteration after retropubic prostatectomy.

Complete vesicourethral obliteration after retropubic prostatectomy presents a challenging reconstructive problem. We report on 4 men with complete vesicourethral obliteration after radical (n = 3) or simple (n = 1) retropubic prostatectomy in which an antegrade-retrograde endoscopic approach was used to obtain durable urethral patency, with preservation of urinary continence and potency.

Aged↗
PubMed1999

Genetically engineered neural networks for predicting prostate cancer progression after radical prostatectomy.

OBJECTIVES: To use pathologic, morphometric, DNA ploidy, and clinical data to develop and test a genetically engineered neural network (GENN) for the prediction of biochemical (prostate-specific antigen [PSA]) progression after radical prostatectomy in a select group of men with clinically localized prostate cancer. METHODS: Two hundred fourteen men who underwent anatomic radical retropubic prostatectomy for clinically localized prostate cancer were selected on the basis of adequate follow-up, pathologic criteria indicating an intermediate risk of progression, and availability of archival tissue. The median age was 58.9 years (range 40 to 87). Men with Gleason score 5 to 7 and clinical Stage T1b-T2c tumors were included. Follow-up was a median of 9.5 years. Three GENNs were developed using pathologic findings (Gleason score, extraprostatic extension, surgical margin status), age, quantitative nuclear grade (QNG), and DNA ploidy. These networks were developed using three randomly selected training (n = 136) and testing (n = 35) sets. Different variable subsets were compared for the ability to maximize prediction of progression. Both standard logistic regression and Cox regression analyses were used concurrently to calculate progression risk. RESULTS: Biochemical (PSA) progression occurred in 84 men (40%), with a median time to progression of 48 months (range 1 to 168). GENN models were trained using inputs consisting of (a) pathologic features and patient age; (b) QNG and DNA ploidy; and (c) all variables combined. These GENN models achieved an average accuracy of 74.4%, 63.1 %, and 73.5%, respectively, for the prediction of progression in the training sets. In the testing sets, the three GENN models had an accuracy of 74.3%, 80.0%, and 78.1%, respectively. CONCLUSIONS: The GENN models developed show promise in predicting progression in select groups of men after radical prostatectomy. Neural networks using QNG and DNA ploidy as input variables performed as well as networks using Gleason score and staging information. All GENN models were superior to logistic regression modeling and to Cox regression analysis in prediction of PSA progression. The development of models using improved input variables and imaging systems in larger, well-characterized patient groups with long-term follow-up is ongoing.

Adult↗
PubMed1999

Artificial neural networks in urology: Update 2000.

Artificial neural networks (ANNs) are widely available and have been demonstrated to be superior to standard empirical methods of detecting, staging and monitoring prostate cancer. These algorithms have been statistically validated in diverse, well-characterized patient groups and are now being evaluated for clinical use worldwide. New variables based on demographic data, tissue and serum markers show promise for improving our ability to predict disease extent and outcome and may be integrated in future ANN models. This review focuses on recently developed neural networks for detecting, staging and monitoring prostate cancer.

Journal Article↗
PubMed1999

Ductal adenocarcinoma of the prostate diagnosed on needle biopsy: correlation with clinical and radical prostatectomy findings and progression.

Ductal adenocarcinoma of the prostate, previously referred to as endometrioid cancer, is typically diagnosed on transurethral resection. When treated by radical prostatectomy (RP), it pursues a more aggressive clinical course than usual acinar prostate cancer does. The significance of prostate cancer with ductal features found on needle biopsies from the peripheral zone is unknown. We reviewed 58 prostate needle biopsy cases with ductal adenocarcinoma for which we were able to obtain clinical information. Patients had a mean age of 69 years (range, 50-89 years) and had a wide range of levels of serum prostate-specific antigen (median, 7.9 ng/mL) and clinical stages. Six (10%) had metastases at the time of diagnosis. Cribriform or papillary structures or a mixture of the two patterns were seen in 86% of cases, whereas in the remaining cases, discrete glands composed of tall columnar cells were present. Stromal fibrosis accompanied the ductal carcinoma in 67% of the cases. A coexisting acinar carcinoma component was identified in 48% of the biopsy specimens. On biopsy, the ductal component composed a mean of 82% of the tumor. Of the 20 tumors treated by RP, 63% had extraprostatic spread of tumor and 20% had positive margins. Two (10%) cases showed seminal vesicle invasion, but none had lymph node metastases. The number of positive needle cores correlated with RP margin status (p<0.004) and with likelihood of clinical progression (p<0.02), but not with organ-confined status. Tumor volume calculated on the 11 extensively sampled RPs ranged from 0.15 cm3 to 20.3 mL (mean, 2.8 cm3). Two years after therapy, the actuarial risk of progression was between 34% (RP patients) and 42% (all patients). A shortened average time to progression was observed relative to a previous study group of men with acinar carcinoma. Serum prostate-specific antigen levels correlated with neither RP organ-confined status nor tumor volume. We conclude that prostatic ductal adenocarcinoma seen on needle biopsy implies more advanced cancer with a shortened time to progression.

Aged↗
PubMed1991

The effects of prolonged hypertestosteronemia on adrenocortical biosynthesis in oophorectomized women.

Adrenal androgen production and adrenocortical biosynthesis are frequently abnormal in women with hyperandrogenism. It is possible that these abnormalities result from hypertestosteronemia of ovarian origin. We prospectively studied the effect of prolonged testosterone (T) administration on adrenocortical biosynthesis and basal hormone levels in seven oophorectomized euandrogenic volunteers, who received 20 mg T in oil (USP), im, three times weekly for 3 weeks. Blood was sampled before T administration (week 0), during therapy (weeks 1, 2, and 3), and 1 week after discontinuation of the medication (week 4). Acute adrenal stimulation using 250 micrograms ACTH-(1-24), iv, was performed on weeks 0, 2, and 3. Circulating T rose from an average of 1.53 nmol/L to 27.9 nmol/L by the end of week 3. Both LH and FSH decreased with T administration, while PRL rose slightly during the initial weeks of T therapy. Little change was observed in the basal levels of 17-hydroxyprogesterone, 11-deoxycortisol, 17-hydroxypregnenolone, estrone, and estradiol. Androstenedione (A) rose concurrent with T administration and normalized after therapy discontinuation. Dehydroepiandrosterone (DHA) decreased significantly with T administration, while DHA sulfate (DHS) increased, leading to an increased DHS/DHA ratio. Total cortisol (F) decreased during T therapy; however, corticosteroid-binding globulin levels also decreased, and the unbound F level remained unchanged. No significant change in adrenocortical response (measured by either the absolute poststimulation level or the net increment in steroid levels) for any steroid was noted after T administration. Although the absolute poststimulation level of A was higher during T administration, this change reflected the increased basal A levels, since the increment in A from 0-60 min was not different. In conclusion, raising endogenous T levels in oophorectomized healthy women 10- to 15-fold for a period of 3 weeks produced a decrease in circulating total F and corticosteroid-binding globulin levels, while maintaining normal levels of unbound F. Although the very high T levels produced in this study resulted in an increased DHS/DHA serum ratio, it remains to be proven that the lesser degree of hypertestosteronemia usually observed in hyperandrogenic patients is sufficient to alter DHS metabolism. With this exception, the adrenocortical biosynthetic abnormalities frequently noted in hyperandrogenism do not appear to result from the elevated circulating T levels.

17-alpha-Hydroxypregnenolone↗
PubMed1989

Isolation and propagation of endothelial cells derived from rheumatoid synovial microvasculature.

Synovial angiogenesis may play an important part in the destruction of articular cartilage in patients with rheumatoid arthritis (RA). As an important first step towards developing in vitro models of synovial angiogenesis, microvascular endothelial cells have been isolated, purified, and cultured from operative synovial specimens obtained from adult patients with RA.

Arthritis, Rheumatoid↗
PubMed1987

Particulate contaminants of intravenous medications and infusions.

Particulate contamination in small volume parenteral medications has been studied and compared with that found in a selection of large volume infusions. Particle counts in 39 commonly used small volume medications and 7 large volume infusions were performed by an automated light blockage method (HIAC) or by optical microscopy. Based on these results and a random survey of drug therapy of intensive care patients, it is concluded that the contribution of intravenous medications to the total particle load received by such patients is likely to be many times greater than from infusion fluids. Until firm evidence regarding the harmful systemic effects of drug particles is available and the manufacturing regulations adjusted appropriately, final in-line filtration of infusions immediately proximal to the intravenous cannula should be considered when drugs are being given intravenously.

Drug Contamination↗
PubMed1985

Fibroblast growth factors in scleroderma.

Sera from patients with progressive systemic sclerosis (PSS), compared to normal sera, contained increased fibroblast growth promoting factor(s) (FGPF) for autologous and heterologous PSS skin fibroblasts and fibroblasts from normal donors. The relative stimulatory effect of FGPF was unaltered by dilution, mixing with normal serum, or media refeeding. The mean value of 42 PSS sera tested showed growth promoting activity significantly greater than the mean level of activity obtained with 42 sex matched normals (p less than 0.001). FGPF in sera from 25 patients with rheumatoid arthritis did not differ from normal controls. No correlation was seen between growth enhancement and patient age or medications. FGPF was present in serum plasma and is unlikely from platelets because serotonin and purified platelet factor produced no equivalent growth stimulation. FGPF was nondialysable, heat labile and insensitive to ribonuclease A. Disulphide bond integrity was required since 20 mM dithiothreitol destroyed activity. FGPF was excluded by an XM-50 filter after Sephadex G100 gel filtration.

Cell Division↗