Positive Needle Research Articles

Are prostate needle biopsies predictive of the laterality of significant cancer and positive surgical margins?

To determine whether data obtained from preoperative prostate needle biopsy can predict the laterality of significant cancer and positive surgical margins on final-specimen pathology after laparoscopic radical prostatectomy (LRP). Data from 490 patients undergoing LRP by one surgeon were reviewed retrospectively. The demographic characteristics, intraoperative data and pathological results were analysed. Univariate and multivariate analyses were used to determine which factors before and during LRP influenced the positive surgical margin status. There was only minor agreement between the laterality of positive needle biopsies and laterality of any cancer and significant cancer on final-specimen pathology (kappa = 0.135 and 0.151, respectively). This was irrespective of the number of needle cores obtained or final-specimen Gleason grade. Similarly, the laterality of dominant cancer on needle biopsy had only a minor agreement with the location of positive surgical margins (kappa = 0.050) and fair agreement with the location of extracapsular extension on final-specimen pathology (kappa = 0.235). Preoperative needle biopsy data have only a minor correlation with the laterality of significant cancer and positive surgical margins at final pathology of LRP specimens. Recognition of this fact, and the frequent bilaterality of significant cancer, with its potential for contralateral positive surgical margins even when the biopsies are positive only unilaterally, is an important consideration when planning nerve-sparing, and potentially for focal therapy.

Staphylococcus aureusis the most common identified cause of cellulitis: a systematic review

We utilized Medline to perform a systematic review of the literature to quantify the aetiology of cellulitis with intact skin. Of 808 patients with cellulitis, 127-129 (15.7-16.0%) patients had positive needle aspiration and/or punch biopsy cultures from intact skin. Of the patients with positive cultures, 65 (50.4-51.2%) had cultures positive for Staphylococcus aureus, 35 (27.1-27.6%) for group A streptococcus, and 35-37 (27.1-29.1%) for other pathogens. The most common aetiology of cellulitis with intact skin, when it can be determined, is S. aureus, outnumbering group A streptococcus by a ratio of nearly 2:1. Given the increasing incidence of community-associated methicillin-resistant S. aureus infections, our findings may have critical therapeutic implications.

Needle Puncture and Transcutaneous Bone Biopsy Cultures Are Inconsistent in Patients with Diabetes and Suspected Osteomyelitis of the Foot

Needle puncture has been suggested as a method for identifying bacteria in the bones in patients with diabetes with osteomyelitis of the foot. However, no studies have compared needle puncture with concomitant transcutaneous bone biopsy, which is the current standard recommended in international guidelines. We conducted a prospective study in 2 French diabetes foot clinics. Transcutaneous bone biopsy specimens, needle puncture specimens, and swab samples were collected on the same day for each patient. Overall, 31 patients were included in the study from July 2006 through February 2008. Twenty-one bone biopsy specimens (67.7%), 18 needle puncture specimens (58%), and 30 swab samples (96.7%) had positive culture results. Staphylococcus aureus was the most common type of bacteria that grew from bone samples, followed by Proteus mirabilis and Morganella morganii. The mean number of bacteria types per positive sample were 1.35, 1.32, and 2.51 for bone biopsy specimens, needle puncture specimens, and swab samples, respectively. Among the 20 patients with positive bone biopsy specimens (69%), 13 had positive needle puncture samples. Overall, the correlation between microbiological results was 23.9%, with S. aureus showing the strongest correlation (46.7%). Results of cultures of bone biopsy and needle puncture specimens were identical for 10 (32.3%) of 31 patients. Bone bacteria were isolated from the needle punctures in 7 (33.3%) of the 21 patients who had positive bone biopsy specimen culture results. If the results of cultures of needle puncture specimens alone had been considered, 5 patients (16.1%) would have received unnecessary treatment, and 8 patients (38.1%) who had positive bone culture results would not have been treated at all. Our results suggest that needle punctures, compared with transcutaneous bone biopsies, do not identify bone bacteria reliably in patients with diabetes who have low-grade infection of the foot and suspected osteomyelitis.

Laparoscopic pelvic lymph-node dissection in prostate cancer before external beam radiotherapy: Risk factors of nodal involvement and relapse following intended curative treatment

To report experience with laparoscopic pelvic lymph-node dissection (LPLND) in patients with prostate cancer before radiotherapy. Selection of risk factors for nodal involvement (N1) and recurrence following radiotherapy was made. From November 1999 to June 2007, 177 patients with prostate cancer underwent LPLND at this department. The lymphadenectomy was limited to the obturator fossa bilaterally. Patients without nodal involvement were offered external beam radiotherapy with adjuvant hormone treatment. Complications occurred in 17 patients (9%). The majority of these were minor and were managed by conservative methods. Twenty-six patients (15%) were diagnosed with N1. High Gleason score and a high percentage of positive needle core biopsies were both risk factors of N1 as well as recurrent disease following radiotherapy (p<0.01 and 0.01, respectively). Clinically, T3 disease was associated with a risk of recurrence but not N1. High prostate-specific antigen (PSA) nadir was also a significant predictor of recurrence. Neither pretreatment PSA nor prostate volume was associated with N1 or recurrence. LPLND is a safe, well-established staging modality in clinically localized prostate cancer before radiotherapy. Risk factors upon diagnosis may be useful in the estimation of N1 and risk of recurrence.

Residual Tumor Potentially Left Behind After Local Ablation Therapy in Prostate Adenocarcinoma

We examined contralateral prostate cancer potentially left behind by focal therapy. We investigated 100 completely embedded radical prostatectomy specimens in which needle biopsy predicted limited disease (less than 3 positive cores, 50% or less involvement of any positive core, Gleason score 6 or less) and all positive needle cores were unilateral. Clinical stage was T1c in 85 and T2a in 15 cases with the palpable lesion on the positive biopsy side. There was 1 positive core in 66 cases. On average 13.9% of each positive core was involved with tumor. The mean number of separate tumor nodules per radical prostatectomy was 2.9. In 65 radical prostatectomy specimens there was some tumor contralateral to the positive biopsy side. Total tumor volume in the radical prostatectomy contralateral to the positive biopsy side averaged 0.2 cm(3) (largest 1.3). In 23 cases contralateral tumor volume was greater than biopsy positive side tumor volume. There were 13 cases in which more than 0.5 cm(3) cancer was contralateral to the positive biopsy and 7 with predominantly anterior tumor. Volume contralateral to positive biopsy side could not be predicted by the number of positive cores (1 vs 2) or maximum percent of the core involved. Gleason pattern 4, extraprostatic extension or positive margins were seen contralateral to the positive biopsy side in 13, 1 and 2 cases, respectively. In a highly selected population with limited unilateral biopsy cancer, tumor contralateral to the positive biopsy side at radical prostatectomy is typically small. However, 20% of radical prostatectomy specimens had some contralateral adverse pathology in terms of size, extraprostatic extension, grade or margins.

Does Laterality of Positive Needle Biopsy in Clinical T2a Patients With Prostate Cancer Affect Biochemical Recurrence-Free Survival?

To test whether patients with clinical Stage T2a prostate cancer with biopsy-proven disease only contralateral to the palpable abnormality experience outcomes similar to those of patients with clinical Stage T1c. We identified 1567 patients who had undergone radical prostatectomy at our institution from 1995 to 2007 with a prostate-specific antigen level of less than 10 ng/mL and complete information regarding the laterality of positive biopsy cores. Of these patients, 1157 had clinical Stage T1c and 410 Stage cT2a. The patients with clinical Stage T2a were divided into two groups according to the laterality of the positive biopsy cores: ipsilateral only (n = 241) and contralateral only (n = 53). Kaplan-Meier analyses were used to compare the biochemical recurrence-free survival (BRFS) probabilities. The patients with clinical Stage T2a had significantly poorer 5-year BRFS than did the patients with clinical Stage T1c (83.5% versus 94.4%, P <0.001). The difference in BRFS between the contralateral and ipsilateral clinical Stage T2a groups was statistically insignificant. A significant difference was found in BRFS between patients with cT1c and cT2a ipsilateral disease. A statistically insignificant difference in BRFS was found between patients with cT1c and cT2a contralateral disease. The laterality of the needle biopsy in relation to the palpable abnormality in patients with clinical Stage T2a could affect BRFS. Our data have demonstrate an insignificant difference between patients with cT2a contralateral disease and those with contralateral cT1c disease.

Relationship of Biochemical Outcome to Percentage of Positive Biopsies in Men with Clinically Localized Prostate Cancer Treated with Permanent Interstitial Brachytherapy

Recent studies have demonstrated that the percentage of positive prostate needle biopsies (PPBs) is an independent predictor of biochemical failure (BF) after radical prostatectomy and external beam radiotherapy. Few studies have confirmed this phenomenon in patients treated with permanent interstitial brachytherapy. We conducted an analysis to determine the clinical utility of the PPBs in predicting BF after permanent interstitial brachytherapy for patients with clinically localized prostate cancer. The clinical and pathologic data from 245 hormone-naive patients with clinical Stage T1c-T2cNxM0 prostate cancer who had undergone permanent prostate brachytherapy from 1992 to 2002 at our institution were retrospectively evaluated. The PPBs, preimplant prostate-specific antigen, and biopsy Gleason score were evaluated as predictors of BF after brachytherapy. The risk of BF was calculated using logistic regression models. The time to BF was assessed using Cox proportional hazard models and Kaplan-Meier estimates. The median PPBs in our study cohort was 27%. The risk of BF was 10.9% for those with a PPBs less than the median versus 26.2% for those with a PPBs greater than the median. A PPBs greater than the median was an independent predictor of BF on multivariate analysis (relative risk 2.3, 95% confidence interval 1.21 to 4.39, P = 0.011). In the time-to-failure models, the PPBs, prostate-specific antigen level, and Gleason score were significantly associated with BF. Our data suggest that the PPBs is significantly associated with BF in patients undergoing permanent interstitial brachytherapy. The PPBs, along with the pretreatment prostate-specific antigen level and Gleason biopsy score, is a useful preoperative parameter in predicting for BF and the time to failure for patients treated with interstitial brachytherapy.

Prospective Cytologic Assessment of Gastrointestinal Luminal Fluid Acquired During EUS: Potential Source of False Positive FNA and Needle Tract Seeding

Background: EUS FNA has recently been reported to result in a 6% false positive cytology rate. EUS FNA can also cause needle tract seeding. Our goal was to evaluate a potential cause, namely the presence of malignant cells within GI luminal fluid, either as a result of tumor sloughing from luminal cancers or secondary to FNA of extraluminal sites. Aim: To prospectively determine the prevalence of malignant cells in GI luminal fluid. Methods: During EUS, luminal fluid is normally aspirated via the suction channel and discarded. We instead submitted the fluid for cytologic analysis among 4 patient subsets: 1) Luminal cancer (e.g. gastric), 2) Extra-luminal cancer (e.g. pancreas), 3) Non-neoplastic disease and abnormal mucosa, and 4) Non-neoplastic disease with normal mucosa. Pre and post FNA luminal fluid samples were collected in order to discern the potential role of FNA in inducing a positive cytology finding. When not performing FNA, one sample was collected for the entire exam. The final diagnosis was based on strict clinicopathologic criteria and >9 month follow-up. Results: 143 patients (85 male, 59 female) mean age 62Y, were prospectively enrolled. Three patients were excluded due to the indeterminate nature of their lesion. Data regarding the total volume of luminal fluid aspirated and rate of positive cytology are provided in table 1. Cytologic exam of luminal fluid aspirates showed malignant cells in 0% of patients with non-malignant disease. Patients with luminal and extra-luminal cancers displayed positive findings in 48% and 10%, respectively, including 8/23 esophageal, 4/5 gastric, and 9/15 rectal cancer. The positive luminal fluid cytology rate with luminal cancers was not affected by performing FNA. Fluid cytology was positive in 3/26 with pancreatic cancers, all of whom underwent FNA. Conclusions: Malignant cells are commonly present in the GI luminal fluid of patients with luminal cancers and can also be found in patients with pancreatic cancer undergoing EUS FNA. Further study is needed to determine the importance of these findings with regard to cytologic interpretation, staging, risk of needle tract seeding, and impact on patient care and outcomes. Strategies to cytologically “sterilize” the field at the time of EUS may be necessary. Tabled 1 Group Definitions # Luminal Fluid (Volume; mL) Luminal Fluid (Cytology Positive) 1 Cancer: Luminal 44 65.0 P = 0.001 when compared by ANOVA. 21 (48%) 2 Cancer: Extra-luminal ∗ Data for 31 pts with positive EUS FNA cytology. 10 pts with negative EUS FNA had negative luminal fluid cytology. 31 48.7 3 (10%) 3 No Neoplasia: Mucosa Abnormal 28 45.7 0 (0%) 4 No Neoplasia: Mucosa Normal 27 43.9 0 (0%) ∗ Data for 31 pts with positive EUS FNA cytology. 10 pts with negative EUS FNA had negative luminal fluid cytology. ∗∗ P = 0.001 when compared by ANOVA. Open table in a new tab

Prostate Cancer Presenting As A Chest Wall Tumour

Prostate cancer commonly metastasises to bone and lymph nodes. We report a case of metastatic prostate cancer presenting clinically as a chest wall tumour. Raised serum prostate specific antigen and positive fine needle aspiration cytology established the diagnosis. He was treated with standard hormonal therapy and is doing well 24 months post presentation with substantial regression of the chest wall mass.

Dynamic characteristics of positive hollow needle to plate atmospheric pressure discharge

We explored mean repetition frequency of filamentary streamers for the hollow needle to plate DC electrical discharge with the nitrogen flow through the needle. The frequency was determined by analyzing time-resolved discharge voltage and current waveforms together with emission intensity profiles induced by streamers. For the distance between the tip of the needle and the surface of the plate electrode between 2 ÷ 6 mm and nitrogen flow ranging between 1 ÷ 10 slm respectively, the streamers mean repetition frequency varies between 0.1 ÷ 15 kHz.

Single-Stage Treatment of Pyogenic Spinal Infection With Titanium Mesh Cages

Single institution retrospective review. To report a series of pyogenic spinal infections treated with single-stage debridement and reconstruction with titanium mesh cages. Various studies have reported surgical results of pyogenic spinal osteomyelitis with anterior debridement, strut grafting and fusion, including delayed posterior spinal instrumentation. Additionally, various authors have recommended against the use of instrumentation because of the concern about glycocalyx formation on the metal and chronic infection. At our institution, we routinely treat chronic vertebral osteomyelitis with single-stage debridement, reconstruction with a titanium mesh cage filled with allograft chips and demineralized bone matrix, and posterior pedicle screw instrumentation. To our knowledge, this is the largest single series reporting single-stage debridement and instrumentation of pyogenic spinal infection with titanium mesh cages and posterior instrumentation. We retrospectively reviewed the patient records and radiographs of 21 consecutive patients (average age 49.3 years, range 23 to 80 years) with pyogenic vertebral osteomyelitis, all treated with titanium mesh cages. Average follow-up was 44 months (range, 25 to 70 months). Spinal levels included 6 thoracic, 4 thoracolumbar, 9 lumbar, and 2 lumbosacral (L5-S1) lesions. All patients had preoperative serum evaluation, which usually included blood cultures, complete blood count, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP), in addition to plain radiographs and magnetic resonance imaging. A positive needle biopsy was available in only 2/7 patients (29%), and overall, preoperative pathogen identification was available in only 7/21 patients (33%). All patients were treated postoperatively with a minimum of 6 weeks of intravenous antibiotics, with a specific antibiotic regimen directed toward the postoperative pathogen when identified (17/21 cases). Extensive radiographic evaluation was also performed. ESR and CRP were routinely elevated (18/20 and 11/17 cases respectively), whereas the white blood count was elevated in only 8 out of 21 cases (38%). The average duration of symptoms to diagnosis was approximately 13.6 weeks (range 3 weeks to 10 months). The indications for surgery included neurologic compromise, significant vertebral body destruction with loss of sagittal alignment, failure of medical treatment, and/or epidural abscess. All patients had resolution of infection, as noted by normalization of the ESR and CRP. Further, 16 out of 21 patients also had a significant reduction of pain. There were no deaths or new postoperative neurologic compromise. The most common pathogen was Staphylococcus aureus. Two patients required a second surgery (posterior irrigation and debridement) during the same admission for persistent wound drainage. Radiographically, the average segmental kyphosis (or loss of lordosis) was 11.5 degrees (range, 0 to 24 degrees) preoperatively, and +0.8 degrees (range, -3 to +5 degrees) at latest postoperative follow-up. There was an average of 2.2 mm cage settling (range, 0 to 5 mm) on latest follow-up. There were no instrumentation failures, signs of chronic infection, or rejection. Titanium mesh cages present a viable option for single-stage anterior surgical debridement and reconstruction of vertebral osteomyelitis, without evidence of chronic infection or rejection. When used in conjunction with pedicle screw instrumentation, there is minimal cage settling without loss of sagittal alignment.

Conduction and breakdown mechanismsin transformer oil

With a fast coaxial test setup using high speed electrical and optical diagnostics, prebreakdown current pulses and shadowgraphy images are measured for direct current (dc) breakdown in Univolt 61 transformer oil. Also, dc currents across the gap are measured using a high sensitivity electrometer. The conduction and breakdown mechanisms in transformer oil as function of applied hydrostatic pressures are quantified. Together, this information provides data on the development of current flow in the system. We have identified three stages in the conduction process prior to breakdown for highly nonuniform fields. Stage 1 is characterized by a resistive current at low fields. Increasing the applied electric field lowers the effective barrier at the metal/dielectric interface allowing a "tunneling" mechanism to begin, leading to the rapid rise in the injection current observed in stage 2. In stage 3, at high fields, the current reaches space charge saturation with an apparent mobility of 3/spl middot/10/sup -3/ cm/sup 2//V/spl middot/s prior to breakdown. The processes of final breakdown show a distinct polarity dependence. A strong pressure dependence of the breakdown voltage is recorded for negative needle/plane breakdown; a 50% reduction in breakdown voltage is observed when the hydrostatic pressure is lowered from atmospheric pressure to hundreds of mtorr. Positive needle discharges show a reduction of only about 10% in breakdown voltage for the reduced pressure case. Weak pressure dependence indicates the breakdown mechanism does not have a strong gaseous component. We will discuss possible links between conduction current and dc breakdown.

Prostate Specific Antigen Remains an Independent Predictor of Cancer at Prostate Biopsy in Black American Men But Not in White Men: Results from a Consecutive Series of 914 Men

Black American men may be at increased risk for prostate cancer but differences in prebiopsy parameters between black and white men have not been fully examined. Therefore, we identified the prebiopsy parameters that may be predictive of prostate cancer in black and white men. From January 2000 to July 2004, 914 consecutive men undergoing prostate needle biopsy were prospectively examined by a single urologist. Urinary symptoms were measured by AUASS. Prebiopsy parameters recorded were PSA, free PSA, DRE, age, race, biopsy history, prostate volume, TRUS lesion and AUASS. Prostate biopsy was performed in 914 men with a mean age of 63.9 years. Mean PSA in the entire cohort was 11.2 ng/ml (median 5.8). Abnormal TRUS and abnormal DRE were found in 37% and 52% of men, respectively. Mean AUASS was 9.6. The overall positive biopsy rate was 37%. In black and white men the positive biopsy rate was 44% and 34%, respectively. Analysis of AUASS indicated that 47% of patients had low symptom scores (less than 7), 39% had moderate scores (8 to 19) and 14% had severe scores (20 to 35). Multivariate analysis revealed that PSA was an independent predictor of positive biopsy in black but not in white men (p = 0.001 and 0.79, respectively). Multivariate analysis also showed that race alone was an independent predictor of positive prostate biopsy (p = 0.013). PSA remains an independent predictor of positive prostate biopsy on multivariate analysis. Other independent predictors are black race, age, low AUASS, prostate volume, abnormal DRE, no previous biopsy and abnormal TRUS. In the black group low AUASS, PSA, no previous biopsy and DRE were unique independent predictors, while in the white group age and abnormal TRUS were unique predictors.

Predictive Value of the International Prostate Symptom Score for Positive Prostate Needle Biopsy in the Low-Intermediate Prostate-Specific Antigen Range

Purpose: Serum prostate-specific antigen (PSA) has a restricted predictive value for prostate cancer in the low-intermediate PSA range (2.5–10 ng/ml). Our aim was to determine the predictive value of the International Prostate Symptom Score (IPSS) for positive prostate needle biopsy (PNB) in patients who underwent transrectal ultrasound (TRUS)-guided prostate biopsy with a low-intermediate PSA level. Patients and Methods: Between 2001 and 2004, the data of 389 consecutive patients applying for any urologic complaint to our department and who underwent TRUS-guided prostate biopsy due to an elevated serum PSA and/or abnormal digital rectal examination (DRE) were retrospectively analyzed. A total of 158 eligible patients with a low-intermediate PSA level were included in the study. The patient’s age, PSA, free PSA, free/total PSA, prostate volume, PSA density (PSAD), pre-biopsy IPSS were compared in the positive and negative biopsy groups. Results: Fifty-eight of 158 patients (37%) who underwent TRUS-guided prostate biopsy had positive PNBs. Forty-eight patients (30%) had abnormal DREs. In the positive PNB group, the mean age was older and PSAD was higher, but the means of the prostate volumes and total IPSS were lower (p < 0.05). Multivariate analysis demonstrated that age and IPSS were independent predictors of a positive PNB (p < 0.05). The odds ratio of mild IPSS for positive PNB controlled for age was 3.0 (95% CI 1.5–6.7). Receiver-operating characteristics analysis revealed a mild IPSS (AUC = 0.640) and was a considerable predictor for positive PNB as well as PSAD (AUC = 0.648). The sensitivity and specificity of IPSS with a cutoff value of 7.5 points were 31 and 87% for prediction of prostate cancer detection. Conclusion: In the low-intermediate PSA range, mild IPSS may be a predictive factor for positive PNB with a similar specificity of PSAD.

Optimal treatment of intermediate‐risk prostate carcinoma with radiotherapy

The clinical heterogeneity of intermediate-risk prostate carcinoma presents a challenge to urologic oncology in terms of prognosis and management. There is controversy regarding whether patients with intermediate-risk prostate carcinoma should be treated with dose-escalated external beam radiotherapy (EBRT) (e.g., doses > 74 gray [Gy]), or conventional-dose EBRT (e.g., doses < 74 Gy) combined with androgen deprivation (AD). Data for this review were identified through searches for articles in MEDLINE and in conference proceedings, indexed from 1966 to 2004. Currently, the intermediate-risk prostate carcinoma grouping is defined on the basis of prostate-specific antigen (PSA), tumor classification (T classification), and Gleason score. Emerging evidence suggests that additional prognostic information may be derived from the percentage of positive core needle biopsies at the time of diagnosis and/or from the pretreatment PSA doubling time. Novel prognostic biomarkers include protein expression relating to cell cycle control, cell death, DNA repair, and intracellular signal transduction. Preclinical data support dose escalation or combined AD with radiation as a means to increase prostate carcinoma cell kill. There is Level I evidence that patients with intermediate-risk prostate carcinoma benefit from dose-escalated EBRT or AD plus conventional-dose EBRT. However, clinical evidence is lacking to support the uniform use of AD plus dose-escalated EBRT. Patients in the intermediate-risk group should be entered into well designed, randomized clinical trials of dose-escalated EBRT and AD with sufficient power to address biochemical failure and cause-specific survival endpoints. These studies should be stratified by novel prognostic markers and accompanied by strong translational endpoints to address clinical heterogeneity and to allow for individualized treatment.

Trends in fungal colonization of pancreatic necrosis in patients undergoing necrosectomy for acute pancreatitis

BackgroundThis study examines fungal colonization of post‐inflammatory pancreatic necrosis in a cohort of patients undergoing open surgical necrosectomy in a single, tertiary referral unit over a 10‐year period. MethodsThe charts of all patients with acute pancreatitis who underwent surgical necrosectomy during the period January 1992 to December 2001 were examined. Following exclusions a population of 30 patients were identified. There were 18 men with a median (range) age of 42 (20–69) years. Sixteen (53%) underwent surgery because of positive fine needle aspirates and the remainder underwent surgery on clinical grounds. Twenty‐nine (97%) received antibiotics prior to necrosectomy. Principal outcomes were the results of microbiological culture with reference to isolation of fungi, site of isolates, trends in colonization and outcome. ResultsCandida were cultured from pancreatic necrosis in 5 (17%). These 5 individuals also had positive candidal cultures from sputum or bronchial aspirates. There were no deaths in patients with fungal colonization of necrosis. There was no change in the annual incidence of fungal colonization of necrosis over the study period. ConclusionAlthough this is a small study, there are two consistent observations: mortality in fungal colonization of necrosis was low and there was no change in the annual incidence of fungal colonization of necrosis over the decade. Discrepancies between these findings and those of previous reports mandate larger prospective evaluation.

Electrode Configuration and Polarity Effects on Physicochemical Properties of Electric Field Treated Apples Post Harvest

The trial compared the use of needle and plate electrode configuration (corona discharge) with parallel plate electrode configuration for postharvest treatment of apples ( Malus domestica Borkh, cv. Fuji and Golden Delicious) during storage. The effect of electric field direction on physicochemical properties of fruit was also investigated. In Fuji apple storage, physicochemical parameters varied with water core content. Treatment of apples kept between parallel plate electric field suppressed weight loss unlike in the corona discharge field. Respiration and climacteric peak were suppressed in apples kept between parallel plate electric field. In corona discharge, after 7 days more respiration was noted in the treated than the untreated samples. The ‘reversed’ electric field treatment (apples on cathode plate) gave higher weight loss than the corresponding ‘forward’ electric field treatment (apples on anode plate) in the parallel plate arrangement. In corona discharge, the multiple of evaporation rate (ratio of water loss in treated sample to that of untreated sample) was higher for the ‘forward’ electric field direction (negative needle polarity) than the ‘reversed’ electric field direction (positive needle polarity).

Low AUA symptom score independently predicts positive prostate needle biopsy: results from a racially diverse series of 411 patients

Objectives To evaluate the prebiopsy parameters, including the American Urological Association symptom score (AUASS), that may be predictive of positive biopsy. Transrectal ultrasound (TRUS) biopsy of the prostate represents the reference standard in the diagnosis of prostate cancer. Methods A total of 411 consecutive men undergoing TRUS biopsy were prospectively evaluated. The indications for biopsy were abnormal digital rectal examination (DRE) findings and/or an elevated prostate-specific antigen (PSA) level. A single surgeon (C.R.P.) examined all the men. DRE and TRUS were each given a level of suspicion between 1 (low suspicion—smooth DRE, homogeneous TRUS) and 5 (high suspicion—hard DRE, hypoechoic lesion). A level of suspicion of 3 or greater was considered abnormal. The prebiopsy parameters examined included PSA level, age, race, biopsy history, prostate volume, TRUS-detected lesion, and AUASS. Results Of 411 men, 62% were African American and 38% were white. The mean PSA level was 11.6 ng/mL. The mean patient age was 65.3 years. Overall, 39% of men had abnormal DRE and 32% abnormal TRUS findings. The mean AUASS was 9.3. The positive biopsy rate was 40.8%. Univariate analysis demonstrated that age, PSA level, prostate volume, abnormal DRE findings, TRUS-detected lesion, and AUASS (less than 7, low) were all predictive of a positive biopsy ( P <0.05). Race was not statistically significant ( P = 0.38). Detailed analysis of the AUASS in the 411 men indicated that 41% had low symptom scores (less than 7), 32% had moderate scores (8 to 19), and 27% had severe scores (20 to 35). In the group of men with low symptom scores (n = 169), univariate analysis demonstrated that age, PSA level, prostate volume, and abnormal TRUS findings were all statistically significant predictors of positive biopsy ( P <0.05). Multivariate analysis of the data from the 411 men demonstrated that age, PSA level, prostate volume, abnormal DRE findings, and low AUASS were all independent predictors of positive biopsy ( P <0.05). Conclusions In this prospective study, the independent predictors of positive TRUS biopsy included age, PSA level, prostate volume, abnormal DRE findings, and low AUASS. A low AUASS may be an important variable to consider when counseling patients before biopsy and when designing patient algorithms for prostate biopsy.

Fractals with Positive Length and Zero Buffon Needle Probability

(2003). Fractals with Positive Length and Zero Buffon Needle Probability. The American Mathematical Monthly: Vol. 110, No. 4, pp. 314-325.

Fractals with Positive Length and Zero Buffon Needle Probability

Fractals with Positive Length and Zero Buffon Needle Probability