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R Wolfram

Publications and source records attributed to R Wolfram.

10 recordsLinked to original sources
PubMed2003

Daily prickly pear consumption improves platelet function.

Prickly pear is traditionally used by Pima Indians as a dietary nutrient against diabetes mellitus. We examined the effect of daily consumption of 250 g in 8 healthy volunteers and 8 patients with mild familial heterozygous hypercholesterolemia on various parameters of platelet function. Beside its action on lipids and lipoproteins, prickly pear consumption significantly reduced the platelet proteins (platelet factor 4 and beta-thromboglobulin), ADP-induced platelet aggregation and improved platelet sensitivity (against PGI2 and PGE1) in volunteers as well as in patients. Also plasma 11-DH-TXB2 and the WU-test showed a significant improvement in both patients and volunteers. In contrast, collagen-induced platelet aggregation and the number of circulating endothelial cells showed a significant response in patients only. No influence of prickly pear ingestion on peripheral platelet count was monitored. The dietary run-in period did not influence any of the parameters of haemostasis examined. No sex difference was seen. Prickly pear may induce at least part of its beneficial actions on the cardiovascular system via decreasing platelet activity and thereby improving haemostatic balance.

Adenosine Diphosphate↗
PubMed2002

Have we solved the problem of late thrombosis?

Late thrombosis (angiographic total occlusion associated with an acute coronary syndrome) is potentially a life-threatening complication after intracoronary radiation therapy. This review is intended to explore the pre-clinical and clinical evidence for late thrombosis, discuss the etiology, and provide guidelines for future management. Although we have gained a greater understanding of this complex entity, further research is required to curtail late thrombosis rates.

Aged↗
PubMed2002

[Computed tomographic analysis of humeral retrotorsion and glenoid retroversion].

PURPOSE OF THE STUDY: Analysis of the anatomic relations of the humeral head and the glenoid cavity is particularly important for clinical study of shoulder arthroplasty and glenohumeral instability. Analysis of humeral retroversion and glenoid retroversion is quite difficult and data in the literature are scarse. We conducted a computed tomography (CT) analysis of stable shoulders to detail retroversion of the entire height of the glenoid cavity and to measure humeral retrotorsion using two comparative methods. We also compared glenoid retroversion and humeral retrotorsion observed in individual subjects. MATERIAL AND METHODS: This prospective study used a standardized CT analysis method. Both shoulders of 30 persons free of glenohumeral instability were studied. Two methods, described by Dähnert and Bernageau, were used to analyze humeral retrotorsion. The Benageau method was used to analyze glenoid retroversion. RESULTS: According to the Dähnert method, humeral retrotorsion was 10 degrees +/- 13 degrees; it was 24 degrees +/- 13 degrees with the Bernageau method; data dispersion was 60 degrees and 65 degrees respectively. According to the Dähnert method, retrotorsion was more pronounced on the dominant side compared with the non-dominant side. There was a significant correlation between retrotorsion values for the two sides. For 95% of the shoulders, glenoid retorversion decreased progressively from the superior part of the glenoid cavity (12.8 degrees +/- 6.4 degrees ) to the lower part (3.1 degrees +/- 4.4 degrees ). Glenoid retroversion was greater on the dominant side. For 21 of the 30 persons (70%), there was a significant correlation between retroversion for the two sides. Correlation coefficients between glenoid retroversion and humeral retrotorsion were negative. Greater humeral retrotorsion was thus related with less pronounced glenoid retroversion and vice versa. DISCUSSION: This study allowed quantification of glenoid retroversion and humeral retrotorsion. There is a spiral twist in the joint surface of the glenoid cavity with progressive decrease in glenoid retorversion from the upper to the lower part of the cavity for 95% of the shoulders. To our knowledge, this spiral twist in the glenoid cavity is not taken into consideration in any of the currently available implants. The correlation for both parameters between the right and left side is probably determined genetically. The influence of dominance could be explained by adaptation to more or less pronounced stress. The negative correlation between humeral retrotorsion and glenoid retroversion would improve glenohumeral stability. A comparative study with unstable shoulders would be required to verify this hypothesis. The validity of the Dähnert method for assessing humeral retorversion is, in our opinion, insufficiently established. The Bernageau method, which provides a direct measurement, appears to be preferable despite the difficulty in identifying anatomic landmarks.

Anthropometry↗
PubMed2001

Regular ingestion of opuntia robusta lowers oxidation injury.

The influence of opuntia robusta (prickly pear), a traditionally used dietary nutrient against diabetes mellitus among the American Indian population, was examined in 15 young patients suffering from familial heterozygous isolated hypercholesterolemia. Oxidation injury was determined via 8-epi-PGF(2 alpha)in plasma, serum and urine. Daily consumption of 250 g broiled edible pulp of prickly pear had no influence on body weight and body fat composition. Total cholesterol was lowered (P<0.01) as was LDL-cholesterol (P<0.04). No significant changes were observed either in triglycerides or in HDL. Prickly pear induced a significant decrease in plasma (27.9+/-3.3-->25.6+/-3.2;P<0.03), serum (302.0+/-11.4-->283.2+/-14.5;P<0.0003) and urinary (355.9+/-18.4-->323.9+/-16;P<0.00002) 8-epi-PGF(2alpha)values. The findings on a decrease of 8-epi-PGF(2alpha)were more pronounced in females than in males, the highest significance being found in urine, while, in contrast, the effects on total- and LDL-cholesterol were more pronounced in males. A prerunning 4 weeks period of dietary counseling had no significant effect on either of the parameters examined. These findings indicate that the regular ingestion of opuntia robusta is able to significantly reduce in-vivo oxidation injury in a group of patients suffering from familial hypercholesterolemia. This traditional food of the American Indians thus may have a significant cardiovascular benefit.

Adult↗
PubMed2000

Endovascular brachytherapy for prophylaxis of restenosis after femoropopliteal angioplasty : results of a prospective randomized study.

BACKGROUND: Inasmuch as endovascular brachytherapy (BT) has gained recent interest because of its inhibitory effect on mechanisms leading to restenosis after percutaneous transluminal angioplasty (PTA), we performed this randomized study to determine its efficacy for prophylaxis of restenosis after femoropopliteal PTA. METHODS AND RESULTS: One hundred thirteen patients (63 men, 50 women; mean age 71 years) with de novo or recurrent femoropopliteal lesions were included in this randomized trial comparing the restenosis rate after PTA plus BT (57 patients, PTA+BT group) versus PTA (56 patients, PTA group) without stent implantation. The mean treated length was 16.7 cm (PTA+BT group) versus 14.8 cm (PTA group). In patients randomized to PTA plus BT, a dose of 12 Gy was applied by an (192)Ir source 3 mm from the source axis. Follow-up examinations included measurement of the ankle-brachial index, color-flow duplex sonography, and angiography. The primary end point of the study was patency after 6 months. The overall recurrence rate after 6 months was 15 (28.3%) of 53 in the PTA+BT group versus 29 (53.7%) of 54 in the PTA group (chi(2) test, P<0.05). The cumulative patency rates at 12 months of follow-up were 63.6% in the PTA+BT group and 35.3% in the PTA group (log-rank test, P<0.005). CONCLUSIONS: This is the first randomized study to demonstrate the efficacy of endovascular BT for prophylaxis of restenosis after femoropopliteal PTA. The value of this approach should now be improved by modification of the BT procedure and by combination with stent implantation.

Aged↗
PubMed2000

Is one set of sextant biopsies enough to rule out prostate Cancer? Influence of transition and total prostate volumes on prostate cancer yield.

PURPOSE: Although the sextant biopsy technique has been widely used, concern has arisen that this method may not include an adequate sampling of the prostate, especially for large prostate volumes. We conducted a multicenter study in patients with PSA levels <10 ng/ml to determine the influence of the total and transition zone (TZ) volumes of the prostate for predicting whether one single set of biopsies was sufficient to rule out prostate cancer (PCa). These parameters were evaluated in patients in whom PCa was found after one set of systematic sextant biopsies and those in whom PCa was found after a repeat biopsy. MATERIALS AND METHODS: A total of 1,018 patients were included in this study. All underwent transrectal ultrasound-guided needle sextant and two TZ biopsies of the prostate. Total and TZ volumes of the prostate were measured (prolate ellipsoid method). From this cohort, all patients in whom a benign disease was found after the first set of biopsies underwent a second similar set of biopsies within 6 weeks. Only patients with PCa were included in this study, whether diagnosed on first or repeat biopsy. Uni- and multivariate statistical analysis using the SAS system (Cary, N.C., USA) and ROC curves were used to compare patients in whom the diagnosis was performed after the first set of biopsies and those who required a second set. RESULTS: Of the 1,018 patients, 344 (33.8%) had PCa diagnosed, 285 (28%) after the first set of biopsies, and 59 (8.1%) on repeat biopsy. As compared to patients diagnosed with PCa after the first set of biopsies, patients diagnosed after the second set had larger total prostate and TZ volumes (43.1+/-13.0 vs. 32.5+/-10.6 cm(3), p<0.0001 and 20.5+/-8.3 vs. 12.8+/-6.0 cm(3), p<0.0001). ROC curves showed that total and TZ volumes of 45 and 22. 5 cm(3), respectively, provided the best combination of sensitivity and specificity for discriminating between patients diagnosed with PCa after the first from those diagnosed after a second set. CONCLUSION: In patients with total prostate volume >45 cm(3) and TZ >22.5 cm(3), a single set of sextant biopsies may not be sufficient to rule out PCa. In these patients, a repeat biopsy should be considered in case of a negative first biopsy.

Aged↗
PubMed1999

Insulin-like growth factor 1 (IGF-1), IGF-1 density, and IGF-1/PSA ratio for prostate cancer detection.

OBJECTIVES: Recent studies suggest an association between increased serum levels of insulin-like growth factor 1 (IGF-1) and an increased risk of prostate cancer (PCa). We prospectively analyzed the value of IGF-1, IGF-density (IGFD), and IGF-1/prostate-specific antigen (PSA) ratio for early detection of prostate cancer. METHODS: IGF-1, IGFD, and IGF-1/PSA ratio were determined prospectively during an 11-month period in the serum from 245 consecutive white men with PSA levels between 2.5 and 15 ng/mL. Octant biopsy (including transition zone biopsy) was performed. A second biopsy was performed 6 weeks later if the first biopsy was negative. Prostate volume was measured using transrectal ultrasound and the prolate ellipsoid method. Receiver operating characteristic curves were performed to compare tests. RESULTS: No evidence of malignancy was found in 174 patients (71%), and PCa was found in 71 (29%). The mean age for patients with no evidence of malignancy and those with PCa was 67.7+/-9 and 65.7+/-6 years, respectively (P = 0.17). IGF-1, IGFD, IGF-1/PSA ratio, and PSA were significantly higher in patients with PCa than in those with benign disease (P = 0.03, P = 0.045, P = 0.001, and P = 0.018, respectively). The area under the curve value derived from the receiver operating characteristic curves for IGF-1/PSA ratio, PSA, IGFD, and IGF-1 was 71%, 61%, 60%, and 58%, respectively. At 95% sensitivity, the specificity of the IGF-1/PSA ratio was significantly greater than that of all other parameters (P<0.0001 ). An IGF-1/PSA cutoff value of 25 afforded a 95% sensitivity for detecting PCa and would have avoided unnecessary biopsies in 24.1% of patients. CONCLUSIONS: Although IGF-1 and IGFD were unable to enhance the performance of PSA in our study, the IGF-1/PSA ratio significantly improved PCa detection over the use of PSA alone. Thus, increased IGF-1 levels (i.e., the IGF-1/PSA ratio) may not only be associated with an increased PCa risk but may also be a useful tool for early detection.

Aged↗
PubMed1999

Total and transition zone prostate volume and age: how do they affect the utility of PSA-based diagnostic parameters for early prostate cancer detection?

OBJECTIVES: To define the role of total prostate (TP) volume, transition zone (TZ) volume, and age as determinants of the utility of prostate-specific antigen (PSA)-based diagnostic parameters for early detection of prostate cancer (PCa) in a prospective multicenter study. METHODS: The study participants were 974 consecutive men with serum total PSA (tPSA) levels of 4 to 10 ng/mL who were referred for early PCa detection or lower urinary tract symptoms. All patients underwent prostate ultrasound examination and sextant biopsy with two additional TZ biopsies. In patients with negative initial biopsies, repeated biopsies were performed at 6 weeks. tPSA, the free/total PSA ratio (f/t PSA), PSA density of the TZ (PSA-TZ), PSA density (PSAD), and PSA velocity (PSAV) were determined and compared across TP volume strata of 30 cm3 or less and greater than 30 cm3, TZ volume strata of 20 cm3 or less and greater than 20 cm3, and various age groups to evaluate the need for volume and/or age-specific reference ranges. RESULTS: PCa was found in 345 (35.4%) of 974 patients and benign prostatic tissue was found in 629 (64.6%) of 947 patients. Across TP volume strata, significantly higher values of tPSA (P <0.01), PSA-TZ, PSAD (P <0.001), and PSAV (P <0.05) and lower values of f/t PSA (P <0.001) were observed in patients with PCa than in those without PCa. Similar results were obtained with respect to TZ volume strata, except in the case of PSAV (P <0.05). tPSA, PSA-TZ, and PSAD were significantly higher (P <0.05) in patients with PCa than in those without PCa for all corresponding age ranges. In patients with PCa, f/t PSA was significantly lower (P <0.001) within the same age ranges. Within each group (PCa or benign), f/t PSA, PSAD, PSA-TZ, and PSAV values were unaffected by age strata. However, PSA parameters dependent on prostate volume (PSAD, PSA-TZ) were statistically lower (P <0.001) in prostates with a higher TP volume (greater than 30 cm3) and TZ volume (greater than 20 cm3); f/t PSA values were unaffected by TP and TZ volumes. CONCLUSIONS: f/t PSA and PSA-TZ were the most powerful parameters to differentiate between benign prostatic tissue and PCa. f/t PSA was the sole parameter unaffected by age and prostate volume. We believe new volume-specific cutpoints, as presented in the current study, should be employed when using PSAD and PSA-TZ for the early detection of PCa.

Adult↗
PubMed1999

Combination and multivariate analysis of PSA-based parameters for prostate cancer prediction.

The aim of this study was to evaluate the ability of prostate-specific antigen (PSA)-based parameters including PSA density (PSAD), PSAD of the transition zone (PSA-TZ), percent free PSA, PSA velocity, and their combination to enhance the specificity of PSA for prostate cancer detection in men with serum PSA levels between 4 and 10 ng/mL. We evaluated prospectively 559 consecutive men referred for early detection of prostate cancer who had serum PSA levels between 4 and 10 ng/mL. All men underwent prostatic ultrasonography and sextant biopsy with two additional TZ biopsies. In all cases, if first biopsies were negative an additional set of biopsies was obtained within 6 weeks. The ability of PSAD, PSA-TZ, PSA velocity, percent free PSA, and their combination to improve the detection of prostate cancer was evaluated by univariate and multivariate analysis as well as receiver operating characteristic (ROC) curves. In this prospective study of 559 patients, 217 had prostate cancer and 342 had histologically confirmed benign prostatic hyperplasia. Multivariate analysis and ROC curves showed that PSA-TZ and percent free PSA (f/t PSA) were the most powerful and highly significant predictors of prostate cancer. Areas under the ROC curve (AUC) for PSA-TZ and percent free PSA were 0.827 and 0.778, respectively (p = .01). Combination of f/t PSA with PSA-TZ (AUC = 88.1%) significantly increased AUC as compared to each of the other parameters alone as well as their combination (p = .02). The next best combinations were PSA-TZ + PSAD, PSA-TZ + PSA, and f/t PSA + PSA. PSA-TZ followed by f/t PSA and PSAD were the most powerful predictors of prostate cancer in referred patients with a serum PSA between 4 and 10 ng/mL. f/t PSA + PSA-TZ was the most effective combination. When volume-independent PSA parameters were taken into consideration, f/t PSA + PSA clearly outperformed the other options.

Aged↗