Use of Prospective Multiplex Immunohistochemistry to Redefine Tissue Pathways of Diagnostic Core Biopsy of Prostate

The incidence of prostatic cancer in the United Kingdom has increased over 40% in the past 30 years. The majority of these cancers are diagnosed by core biopsy, posing a considerable strain on a service that struggles to recruit sufficient histopathologists. The current methodology for tissue diagnosis has a significant false-negative rate, small false-positive rate, and a proportion of indeterminate diagnoses. Therefore, this area presents an opportunity both to improve diagnostic quality and to reduce the burden on resources. We investigated streamlining tissue pathways by increasing the utilization of readily available resources to reduce the burden on scarce resources and improve the accuracy of diagnosis. This involved applying prospective multiplex immunohistochemistry (IHC) using 4 different markers (CK5, p63, racemase, and Ki-67) and 2 chromogens. We conducted a prospective study using over 8000 cores and 3 consultant histopathologists. The pathologists assessed each core using either conventional stains (hematoxylin and eosin) only or multiplex IHC only. The results of this assessment were later compared with the overall assessment made for the final histologic diagnosis. Results show that IHC alone has a positive predictive value of 98.97% and a negative predictive value of 99.91%, while hematoxylin and eosin alone has a positive predictive value of 94.21% and negative predictive value of 99.07%, demonstrating improved diagnostic accuracy. When assessed against the use of on-demand IHC, prospective IHC improves turn-around-times, reduces indeterminate diagnoses, improves pathologist's accuracy and efficiency and, in overall terms, is cost-effective. In addition, it is possible to structure these tests within the routine of a diagnostic service with little impact on the overall capacity of the laboratory.

A129 CYP2C19 PHARMACOGENETIC TESTING IN PAEDIATRIC PATIENTS WITH EOSINOPHILIC ESOPHAGITIS INFLUENCES DOSING OF PROTON-PUMP-INHIBITORS AND RESPONSE TO THERAPY

Background

Eosinophilic esophagitis (EoE) is a chronic inflammatory disorder that can be treated with a proton pump inhibitor (PPI). Pharmacogenetics (PGx) is the study of how variations in an individual’s genome influences drug response. Genetic variation in the metabolism gene CYP2C19 can produce differences in enzyme activity which is known to be a contributing factor for therapeutic failure with PPI treatment. Use of 2^nd generation PPI (rabeprazole) can be beneficial in some as this PPI is less effected by CYP2C19 metabolism. PGx has been studied in PPI therapy for peptic ulcer disease but has not been demonstrated in patients with EoE.

Aims

To describe the CYP2C19 metabolism in patients with EoE on PPI and to estimate the clinical utility of PGx testing in directing subsequent changes in therapy with improvement in remission rates.

Methods

Interim analyses of a single centre, non-interventional, ongoing descriptive pilot study investigating CYP2C19 metabolism in patients with EoE, as part of a larger PGx pilot study and EoE- AHEAD Registry Study at SickKids. Patients with EoE that were newly diagnosed and started PPI or those not in remission on current non-PPI therapy or not in remission on dose PPI (2 mg/kg/day, max 30 mg lansoprazole BID) were included. Active disease was defined as a peak eosinophil count >15/hpf.

Results

37 patients met the inclusion criteria with completed PGx test; mean age was 13 years, 29(78%) were male, and 13(35%) had concurrent atopic disease. PGx testing showed that 12(32%) and 4(11%) were rapid (RM) and ultrarapid metabolizers (URM) respectively (Fig.1), which is significantly higher than the population average. Of this subgroup, 9 started rabeprazole, 3 had a lansoprazole dose increase, and 4 had no changes. Overall, changes in therapy based on PGx testing were made in 29(78%) patients, 8 are awaiting follow-up (Fig 2). Currently, the patients with available repeat biopsy results after PGx test-guided therapy changes is limited due COVID-19 related delays in endoscopies.

Conclusions

The preliminary findings of our study using PGx to guide PPI dosing in pediatric patients with EoE demonstrate that PGx test results lead to a change in clinical management in most patients. In RM and URM, PGx results trigger an adjustment of PPI dose or type could lead to earlier disease remission in PPI-responsive patients, thereby optimizing PPI efficacy. PGx may support dose reduction in poor metabolizers aiming to avoid long-term adverse events.

Further correlation with endoscopy and histology findings of patients after PGx-guided therapy changes will follow. Furthermore, it is important to examine if CYP2C19 variant information available before PPI therapy further streamlines an initial phase of the treatment.

Funding Agencies

Dr. Marcon: J Garfield Campbell Fund, Dr. Hulst: Start-up Funds from the Department of Pediatrics at SickKids

A128 PATIENT CHARACTERIZATION AND ASSESSMENT OF REMISSION RATES IN CHILDREN WITH EOSINOPHILIC ESOPHAGITIS AFTER INITIAL TREATMENT AND 1-YEAR POST-DIAGNOSIS

Background

Eosinophilic esophagitis (EoE) is a chronic immune- or antigen-mediated esophageal disorder characterized by symptoms of esophageal dysfunction and eosinophil-predominant inflammation. With incidence rates rapidly increasing, EoE is the leading cause of food bolus impaction and the second leading cause of chronic esophagitis. The treatment of EoE includes both induction and maintenance therapy to prevent complications including esophageal fibrosis and strictures. Despite significant advances in the diagnosis and treatment of EoE, the natural history and long-term management of the disease remains poorly understood.

Aims

To describe the clinical characterization of children with EoE, and to assess remission rates after initial treatment and 1-year post-diagnosis.

Methods

In this ongoing, single-center retrospective study, the electronic medical charts of children newly diagnosed with EoE between January 2017-March 2021 participating in the EoE-AHEAD Registry study were reviewed. Children aged 6 months-18 years with a confirmed diagnosis of EoE based on consensus guidelines and receiving outpatient care at the SickKids EoE clinic were included.

Results

A total of 37 children with a median age of 11 years (IQR: 4.5, 12.5) were included, the majority of which were male (86.5%). Demographic and clinical characteristics are shown in Table 1. On initial treatment, 2.7% of children were on an elemental diet, 18.9% on a food elimination diet, 40.5% on proton-pump inhibitor (PPI) therapy, 16.2% on topical steroids, 8.1% on systemic steroids, and 13.5% on a combination therapy. Of the 30 children with a second endoscopy (mean interval since diagnosis of 6.1 months (3.9)), 30% achieved histological remission after the initial treatment (see Figure 1). Of the 14 children with a one-year follow-up endoscopy, 14.2% were in remission, 3 of which had relapsed. No significant differences in treatment modality were found between those who achieved remission and those who did not.

Conclusions

This is the first Canadian registry study to examine the longitudinal outcomes of EoE in a pediatric setting. Our preliminary results show that only 30% of children achieved histological remission following first-line treatment. The choice of initial therapy varied, although the majority of patients (62.2%) were prescribed a PPI and/or a topical steroid. Our findings highlight the importance of identifying different disease phenotypes to develop personalized therapeutic approaches for the management of EoE.

Funding Agencies

SickKids start-up funds (JM Hulst) and the Comprehensive Research Experience for Medical Students (CREMS) Program

Focal HIFU therapy for anterior compared to posterior prostate cancer lesions

Objective

To compare cancer control in anterior compared to posterior prostate cancer lesions treated with a focal HIFU therapy approach.

Materials and methods

In a prospectively maintained national database, 598 patients underwent focal HIFU (Sonablate^®500) (March/2007–November/2016). Follow-up occurred with 3-monthly clinic visits and PSA testing in the first year with PSA, every 6–12 months with mpMRI with biopsy for MRI-suspicion of recurrence. Treatment failure was any secondary treatment (ADT/chemotherapy, cryotherapy, EBRT, RRP, or re-HIFU), tumour recurrence with Gleason ≥ 3 + 4 on prostate biopsy without further treatment or metastases/prostate cancer-related mortality. Cases with anterior cancer were compared to those with posterior disease.

Results

267 patients were analysed following eligibility criteria. 45 had an anterior focal-HIFU and 222 had a posterior focal-HIFU. Median age was 64 years and 66 years, respectively, with similar PSA level of 7.5 ng/ml and 6.92 ng/ml. 84% and 82%, respectively, had Gleason 3 + 4, 16% in both groups had Gleason 4 + 3, 0% and 2% had Gleason 4 + 4. Prostate volume was similar (33 ml vs. 36 ml, p = 0.315); median number of positive cores in biopsies was different in anterior and posterior tumours (7 vs. 5, p = 0.009), while medium cancer core length, and maximal cancer percentage of core were comparable. 17/45 (37.8%) anterior focal-HIFU patients compared to 45/222 (20.3%) posterior focal-HIFU patients required further treatment (p = 0.019).

Conclusion

Treating anterior prostate cancer lesions with focal HIFU may be less effective compared to posterior tumours.

Oncological outcomes of 356 patients undergoing salvage focal ablative HIFU or cryotherapy following radiation failure

5582

Background: Patients that have previously failed radiotherapy for prostate cancer is usually limited to systemic therapy due to morbidity from salvage prostatectomy. We reviewed the outcomes following focal salvage ablative therapy with HIFU or cryotherapy within the UK’s HEAT and ICE registries. Methods: 356 consecutive patients underwent focal ablative treatment after initial radiation treatment failure (28/1/2004-1/10/2019, 194 (54.5%) underwent HIFU (posterior recurrence) and 162 (45.5%) underwent cryotherapy (mostly anterior or T3b). Primary outcome was failure-free survival (FFS) defined as no systemic therapy, whole-gland treatment, metastases or prostate cancer-specific death. Secondary outcomes were adverse events and overall survival. Results: Median (IQR) age was 69years (65-73) and PSA (IQR) was 4.0ng/ml (1-7-7.2). Overall median (IQR) follow-up was 41.3 months (21.4-58.5). Quadrant ablation was performed in 128 (36.0%), hemi-ablation performed in 64 (18.0%), hockey-stick in 5 (1.4%) and 159 (43.8%) had unknown ablative patterns. Due to histological or MRI proven recurrence/residual disease, 31 (8.7%) underwent further focal salvage re-treatment. FFS (95%CI) at 3 and 6 years were 81% (76-87%) and 75% (68-83%) respectively. Median (IQR) time to failure was 15.5 months (19.7). Overall survival (95%CI) at 3 and 6 years were 97% (95-100%) and 88% (81-96%) respectively. Prostate-specific mortality was 2.8%. Overall 3 (0.8%) patients were managed for fistula formation, 16 (4.5%) were treated for UTIs. Conclusions: Salvage focal ablative therapy for radio-recurrent prostate cancer is safe and provides good short to medium-term oncological control. The FORECAST study is awaited to further determine oncological outcomes in this cohort.

Effect of Structure Modifying Agents on the Structural, Morphological and Optical Features of Hydrothermally Grown ZnO

Morphology of Zinc Oxide (ZnO) is an important parameter to enhance the efficiency of optoelectronic devices. Morphology also plays a significant role in gas sensing properties of ZnO. In this research work, different morphologies of Zinc Oxide including nanorods, disks and flakes were obtained using Zinc Acetate, Sodium Dodecyl Sulphate and Trisodium Citrate as additives to a parent solution of Zinc nitrate hexahydrate (Zn(NO₃)₂·6H₂O) and Hexamethylenetetramine (HMTA, (CH₂)₆N₄) for hydrothermal growth. Use of Zinc Acetate as an additive has been rarely reported. This work presents the ability of Zinc Acetate to transform the morphology of ZnO nanorods to nanoneedles. Furthermore, in this study addition of Sodium Dodecyl Sulphate and Trisodium Citrate to the parent solution has shown potential for growing continuous granular films by the low cost and low temperature hydrothermal technique. Variation in crystallite size and band gap values with increasing concentration of Zinc Acetate, Sodium Dodecyl Sulphate and Trisodium Sulphate has been studied. Films with crystallite sizes of 7.48 nm and 6.77 nm were achieved with 5 mM Sodium Dodecyl Sulphate and 5 mM Trisodium Citrate respectively. The band gap of films produced with 5 mM Sodium Dodecyl Sulphate and with 5 mM Trisodium Citrate were 3.43 eV and 3.45 eV respectively. Therefore hydrothermal growth with Sodium Dodecyl Sulphate or Trisodium Citrate is a potential technique for obtaining granular ZnO films.

An Exploratory Study of Dose Escalation vs Standard Focal High-Intensity Focused Ultrasound for Treating Nonmetastatic Prostate Cancer

Objective: Analysis of treatment success regarding oncological recurrence rate between standard and dose escalation focal high-intensity focused ultrasound (HIFU) of prostate cancer. Materials and Methods: In this analysis of our prospectively maintained HIFU (Sonablate^® 500) database, 598 patients were identified who underwent a focal HIFU (Sonablate 500) between March 2007 and November 2016. Follow-up occurred with 3-monthly clinic visits and prostate specific antigen (PSA) testing in the first year. Thereafter, PSA was measured 6-monthly or annually at least. Routine and for-cause multiparametric MRI (mpMRI) was conducted with biopsy for MRI suspicion of recurrence. Treatments were delivered in a quadrant or hemiablation fashion depending on the gland volume as well as tumor volume and location. Before mid-2015, standard focal HIFU was used (two HIFU blocks); after this date, some urologists conducted dose escalation focal HIFU (three overlapping HIFU blocks). Propensity matching was used to ensure two matched groups, leading to 162 cases for this analysis. Treatment failure was defined by any secondary treatment (systemic therapy, cryotherapy, radiotherapy, prostatectomy, or further HIFU), metastasis from prostate cancer without further treatment, tumor recurrence with Gleason score ≥7 (≥3 + 4) on prostate biopsy without further treatment, or prostate cancer-related mortality. Complications and side-effects were also compared. Results: Median age was 64.5 years (interquartile range [IQR] 60-73.5) in the standard focal-HIFU group and 64.5 years (IQR 60-69) in the dose-escalation group. Median prostate volume was 37 mL (IQR 17-103) in the standard group and 47.5 mL (IQR 19-121) in the dose-escalation group. As tumor volume on mpMRI and Gleason score were major matching criteria, these were identical with 0.43 mL (IQR 0.05-2.5) and Gleason 3 + 3 = 6 in 1 out of 32 (3%), 3 + 4 = 7 in 27 out of 32 (84%), and 4 + 3 = 7 in 4 out of 32 (13%). Recurrence in treated areas was found in 10 out of 32 (31%) when standard treatment zones were applied, and in 6 out of 32 (19%) of dose-escalation focal HIFU (p = 0.007). Conclusion: This exploratory study shows that dose escalation focal HIFU may achieve higher rates of disease control compared with standard focal HIFU. Further prospective comparative studies are needed.

Evaluation of functional outcomes after a second focal high-intensity focused ultrasonography (HIFU) procedure in men with primary localized, non-metastatic prostate cancer: results from the HIFU Evaluation and Assessment of Treatment (HEAT) registry

OBJECTIVES

To assess change in functional outcomes after a second focal high-intensity focused ultrasonography (HIFU) treatment compared with outcomes after one focal HIFU treatment.

PATIENTS AND METHODS

In this multicentre study (2005-2016), 821 men underwent focal HIFU for localized non-metastatic prostate cancer. The patient-reported outcome measures of International Prostate Symptom Score (IPSS), pad usage and erectile function (EF) score were prospectively collected for up to 3 years. To be included in the study, completion of at least one follow-up questionnaire was required. The primary outcome was comparison of change in functional outcomes between baseline and follow-up after one focal HIFU procedure vs after a second focal HIFU procedure, using IPSS, Expanded Prostate Cancer Index Composite (EPIC) and International Index of Erectile Function (IIEF) questionnaires.

RESULTS

Of 821 men, 654 underwent one focal HIFU procedure and 167 underwent a second focal HIFU procedure. A total of 355 (54.3%) men undergoing one focal HIFU procedure and 65 (38.9%) with a second focal HIFU procedure returned follow-up questionnaires, respectively. The mean age and prostate-specific antigen level were 66.4 and 65.6 years, and 7.9 and 8.4 ng/mL, respectively. After one focal HIFU treatment, the mean change in IPSS was -0.03 (P = 0.02) and in IIEF (EF score) it was -0.4 (P = 0.02) at 1-2 years, with no subsequent decline. Absolute rates of erectile dysfunction increased from 9.9% to 20.8% (P = 0.08), leak-free continence decreased from 77.9% to 72.8% (P = 0.06) and pad-free continence from 98.6% to 94.8% (P = 0.07) at 1-2 years, respectively. IPSS prior to second focal HIFU treatment compared to baseline IPSS prior to first focal HIFU treatment was lower by -1.3 (P = 0.02), but mean IPSS change was +1.4 at 1-2 years (P = 0.03) and +1.2 at 2-3 years (P = 0.003) after the second focal HIFU treatment. The mean change in EF score after the second focal HIFU treatment was -0.2 at 1-2 years (P = 0.60) and -0.5 at 2-3 years (P = 0.10), with 17.8% and 6.2% of men with new erectile dysfunction. The rate of new pad use was 1.8% at 1-2 years and 2.6% at 2-3 years.

CONCLUSION

A second focal HIFU procedure causes minor detrimental effects on urinary function and EF. These data can be used to counsel patients with non-metastatic prostate cancer prior to considering HIFU therapy.

Association of Ankle-Brachial Indices With Limb Revascularization or Amputation in Patients With Peripheral Artery Disease

IMPORTANCE

The prevalence and morbidity of peripheral artery disease (PAD) are high, with limb outcomes including revascularization and amputation. In community-dwelling patients with PAD, the role of noninvasive evaluation for risk assessment and rates of limb outcomes have not been established to date.

OBJECTIVE

To evaluate whether ankle-brachial indices are associated with limb outcomes in community-dwelling patients with PAD.

DESIGN, SETTING, AND PARTICIPANTS

A population-based, observational, test-based cohort study of patients was performed from January 1, 1998, to December 31, 2014. Data analysis was conducted from July 15 to December 15, 2017. Participants included a community-based cohort of 1413 patients with PAD from Olmsted County, Minnesota, identified by validated algorithms deployed to electronic health records. Automated algorithms identified limb outcomes used to build Cox proportional hazards regression models. Ankle-brachial indices and presence of poorly compressible arteries were electronically identified from digital data sets. Guideline-recommended management strategies within 6 months of diagnosis were also electronically retrieved, including therapy with statins, antiplatelet agents, angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers, and smoking abstention.

MAIN OUTCOMES AND MEASURES

Ankle-brachial index (index ≤0.9 indicates PAD; <.05, severe PAD; and ≥1.40, poorly compressible arteries) and limb revascularization or amputation.

RESULTS

Of 1413 patients, 633 (44.8%) were women; mean (SD) age was 70.8 (13.3) years. A total of 283 patients (20.0%) had severe PAD (ankle-brachial indices <0.5) and 350 (24.8%) had poorly compressible arteries (ankle-brachial indices ≥1.4); 780 (55.2%) individuals with less than severe disease formed the reference group. Only 32 of 283 patients (11.3%) with severe disease and 68 of 350 patients (19.4%) with poorly compressible arteries were receiving 4 guideline-recommended management strategies. In the severe disease subgroup, the 1-year event rate for revascularization was 32.4% (90 events); in individuals with poorly compressible arteries, the 1-year amputation rate was 13.9% (47 events). In models adjusted for age, sex, and critical limb ischemia, poorly compressible arteries were associated with amputation (hazard ratio [HR], 3.12; 95% CI, 2.16-4.50; P < .001) but not revascularization (HR, 0.91; 95% CI, 0.69-1.20; P = .49). In contrast, severe disease was associated with revascularization (HR, 2.69; 95% CI, 2.15-3.37; P < .001) but not amputation (HR, 1.30; 95% CI, 0.82-2.07; P = .27).

CONCLUSIONS AND RELEVANCE

Community-dwelling patients with severe PAD or poorly compressible arteries have high rates of revascularization or limb loss, respectively. Guideline-recommended management strategies for secondary risk prevention are underused in the community.

Leveraging the Electronic Health Record to Create an Automated Real-Time Prognostic Tool for Peripheral Arterial Disease

Background Automated individualized risk prediction tools linked to electronic health records ( EHR s) are not available for management of patients with peripheral arterial disease. The goal of this study was to create a prognostic tool for patients with peripheral arterial disease using data elements automatically extracted from an EHR to enable real-time and individualized risk prediction at the point of care. Methods and Results A previously validated phenotyping algorithm was deployed to an EHR linked to the Rochester Epidemiology Project to identify peripheral arterial disease cases from Olmsted County, MN, for the years 1998 to 2011. The study cohort was composed of 1676 patients: 593 patients died over 5-year follow-up. The c-statistic for survival in the overall data set was 0.76 (95% confidence interval [CI], 0.74-0.78), and the c-statistic across 10 cross-validation data sets was 0.75 (95% CI, 0.73-0.77). Stratification of cases demonstrated increasing mortality risk by subgroup (low: hazard ratio, 0.35 [95% CI, 0.21-0.58]; intermediate-high: hazard ratio, 2.98 [95% CI, 2.37-3.74]; high: hazard ratio, 8.44 [95% CI, 6.66-10.70], all P<0.0001 versus the reference subgroup). An equation for risk calculation was derived from Cox model parameters and β estimates. Big data infrastructure enabled deployment of the real-time risk calculator to the point of care via the EHR . Conclusions This study demonstrates that electronic tools can be deployed to EHR s to create automated real-time risk calculators to predict survival of patients with peripheral arterial disease. Moreover, the prognostic model developed may be translated to patient care as an automated and individualized real-time risk calculator deployed at the point of care.

A comparison of word embeddings for the biomedical natural language processing

BACKGROUND

Word embeddings have been prevalently used in biomedical Natural Language Processing (NLP) applications due to the ability of the vector representations being able to capture useful semantic properties and linguistic relationships between words. Different textual resources (e.g., Wikipedia and biomedical literature corpus) have been utilized in biomedical NLP to train word embeddings and these word embeddings have been commonly leveraged as feature input to downstream machine learning models. However, there has been little work on evaluating the word embeddings trained from different textual resources.

METHODS

In this study, we empirically evaluated word embeddings trained from four different corpora, namely clinical notes, biomedical publications, Wikipedia, and news. For the former two resources, we trained word embeddings using unstructured electronic health record (EHR) data available at Mayo Clinic and articles (MedLit) from PubMed Central, respectively. For the latter two resources, we used publicly available pre-trained word embeddings, GloVe and Google News. The evaluation was done qualitatively and quantitatively. For the qualitative evaluation, we randomly selected medical terms from three categories (i.e., disorder, symptom, and drug), and manually inspected the five most similar words computed by embeddings for each term. We also analyzed the word embeddings through a 2-dimensional visualization plot of 377 medical terms. For the quantitative evaluation, we conducted both intrinsic and extrinsic evaluation. For the intrinsic evaluation, we evaluated the word embeddings' ability to capture medical semantics by measruing the semantic similarity between medical terms using four published datasets: Pedersen's dataset, Hliaoutakis's dataset, MayoSRS, and UMNSRS. For the extrinsic evaluation, we applied word embeddings to multiple downstream biomedical NLP applications, including clinical information extraction (IE), biomedical information retrieval (IR), and relation extraction (RE), with data from shared tasks.

RESULTS

The qualitative evaluation shows that the word embeddings trained from EHR and MedLit can find more similar medical terms than those trained from GloVe and Google News. The intrinsic quantitative evaluation verifies that the semantic similarity captured by the word embeddings trained from EHR is closer to human experts' judgments on all four tested datasets. The extrinsic quantitative evaluation shows that the word embeddings trained on EHR achieved the best F1 score of 0.900 for the clinical IE task; no word embeddings improved the performance for the biomedical IR task; and the word embeddings trained on Google News had the best overall F1 score of 0.790 for the RE task.

CONCLUSION

Based on the evaluation results, we can draw the following conclusions. First, the word embeddings trained from EHR and MedLit can capture the semantics of medical terms better, and find semantically relevant medical terms closer to human experts' judgments than those trained from GloVe and Google News. Second, there does not exist a consistent global ranking of word embeddings for all downstream biomedical NLP applications. However, adding word embeddings as extra features will improve results on most downstream tasks. Finally, the word embeddings trained from the biomedical domain corpora do not necessarily have better performance than those trained from the general domain corpora for any downstream biomedical NLP task.

Postoperative bleeding risk prediction for patients undergoing colorectal surgery

BACKGROUND

There is limited consensus regarding risk factors for postoperative bleeding. The objective of this work was to investigate the capability of machine learning techniques in combination with practice-based longitudinal electronic medical record data for identifying potential new risk factors for postoperative bleeding and predicting patients at high risk of postoperative bleeding.

METHODS

A retrospective study was conducted for patients who underwent colorectal surgery 1998-2015 at a single tertiary referral center. Various predictors were extracted from electronic medical record. The outcome of interest was the occurrence of postoperative bleeding within 7 days of surgery. Logistic regression and gradient boosting machine models were trained. Area under the receiver operating curve and area under the precision recall curve were used to evaluate the performance to different models.

RESULTS

Of 13,399 cases undergoing colorectal resection, 1,680 (12.5%) experienced postoperative bleeding. A total of 299 variables were evaluated. Logistic regression and gradient boosting machine models returned an area under the receiver operating curve of 0.735 and 0.822 and area under the precision recall curve of 0.287 and 0.423, respectively. In addition to well-known risk factors for postoperative bleeding, nutrition (ranked third), weakness (ranked fifth), patient mobility (ranked sixth), and activity level (ranked eighth) were found to be novel predictors in the gradient boosting machine model based on permutation importance.

CONCLUSION

The study identified measures of functional capacity of patient as novel predictors of postoperative bleeding. The study found that risk of postoperative bleeding can be assessed, allowing for better use of human resources in addressing this important adverse event after surgery.

A Multicentre Study of 5-year Outcomes Following Focal Therapy in Treating Clinically Significant Nonmetastatic Prostate Cancer

Background

Clinically significant nonmetastatic prostate cancer (PCa) is currently treated using whole-gland therapy. This approach is effective but can have urinary, sexual, and rectal side effects.

Objective

To report on 5-yr PCa control following focal high-intensity focused ultrasound (HIFU) therapy to treat individual areas of cancer within the prostate.

Design, setting, and participants

This was a prospective study of 625 consecutive patients with nonmetastatic clinically significant PCa undergoing focal HIFU therapy (Sonablate) in secondary care centres between January 1, 2006 and December 31, 2015. A minimum of 6-mo follow-up was available for599 patients. Intermediate- or high-risk PCa was found in 505 patients (84%).

Intervention

Disease was localised using multiparametric magnetic resonance imaging (mpMRI) combined with targeted and systematic biopsies, or transperineal mapping biopsies. Areas of significant disease were treated. Follow-up included prostate-specific antigen (PSA) measurement, mpMRI, and biopsies.

Outcome measurements and statistical analysis

The primary endpoint, failure-free survival (FFS), was defined as freedom from radical or systemic therapy, metastases, and cancer-specific mortality.

Results and limitations

The median follow-up was 56 mo (interquartile range [IQR] 35–70). The median age was 65 yr (IQR 61–71) and median preoperative PSA was 7.2 ng/ml (IQR 5.2–10.0). FFS was 99% (95% confidence interval [CI] 98–100%) at 1 yr, 92% (95% CI 90–95%) at 3 yr, and 88% (95% 85–91%) at 5 yr. For the whole patient cohort, metastasis-free, cancer-specific, and overall survival at 5 yr was 98% (95% CI 97–99%), 100%, and 99% (95% CI 97–100%), respectively. Among patients who returned validated questionnaires, 241/247 (98%) achieved complete pad-free urinary continence and none required more than 1 pad/d. Limitations include the lack of long-term follow-up.

Conclusions

Focal therapy for select patients with clinically significant nonmetastatic prostate cancer is effective in the medium term and has a low probability of side effects.

Patient summary

In this multicentre study of 625 patients undergoing focal therapy using high-intensity focused ultrasound (HIFU), failure-free survival, metastasis-free survival, cancer-specific survival, and overall survival were 88%, 98%, 100%, and 99%, respectively. Urinary incontinence (any pad use) was 2%. Focal HIFU therapy for patients with clinically significant prostate cancer that has not spread has a low probability of side effects and is effective at 5 yr.

Innovative Informatics Approaches for Peripheral Artery Disease: Current State and Provider Survey of Strategies for Improving Guideline-Based Care

OBJECTIVE

To quantify compliance with guideline recommendations for secondary prevention in peripheral artery disease (PAD) using natural language processing (NLP) tools deployed to an electronic health record (EHR) and investigate provider opinions regarding clinical decision support (CDS) to promote improved implementation of these strategies.

PATIENTS AND METHODS

Natural language processing was used for automated identification of moderate to severe PAD cases from narrative clinical notes of an EHR of patients seen in consultation from May 13, 2015, to July 27, 2015. Guideline-recommended strategies assessed within 6 months of PAD diagnosis included therapy with statins, antiplatelet agents, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, and smoking abstention. Subsequently, a provider survey was used to assess provider knowledge regarding PAD clinical practice guidelines, comfort in recommending secondary prevention strategies, and potential role for CDS.

RESULTS

Among 73 moderate to severe PAD cases identified by NLP, only 12 (16%) were on 4 guideline-recommended strategies. A total of 207 of 760 (27%) providers responded to the survey; of these 141 (68%) were generalists and 66 (32%) were specialists. Although 183 providers (88%) managed patients with PAD, 51 (25%) indicated they were uncomfortable doing so; 138 providers (67%) favored the development of a CDS system tailored for their practice and 146 (71%) agreed that an automated EHR-derived mortality risk score calculator for patients with PAD would be helpful.

CONCLUSION

Natural language processing tools can identify cases from EHRs to support quality metric studies. Findings of this pilot study demonstrate gaps in application of guideline-recommended strategies for secondary risk prevention for patients with moderate to severe PAD. Providers strongly support the development of CDS systems tailored to assist them in providing evidence-based care to patients with PAD at the point of care.

Leveraging Collaborative Filtering to Accelerate Rare Disease Diagnosis

In the USA, rare diseases are defined as those affecting fewer than 200,000 patients at any given time. Patients with rare diseases are frequently misdiagnosed or undiagnosed which may due to the lack of knowledge and experience of care providers. We hypothesize that patients' phenotypic information available in electronic medical records (EMR) can be leveraged to accelerate disease diagnosis based on the intuition that providers need to document associated phenotypic information to support the diagnosis decision, especially for rare diseases. In this study, we proposed a collaborative filtering system enriched with natural language processing and semantic techniques to assist rare disease diagnosis based on phenotypic characterization. Specifically, we leveraged four similarity measurements with two neighborhood algorithms on 2010-2015 Mayo Clinic unstructured large patient cohort and evaluated different approaches. Preliminary results demonstrated that the use of collaborative filtering with phenotypic information is able to stratify patients with relatively similar rare diseases.

Clinical information extraction applications: A literature review

BACKGROUND

With the rapid adoption of electronic health records (EHRs), it is desirable to harvest information and knowledge from EHRs to support automated systems at the point of care and to enable secondary use of EHRs for clinical and translational research. One critical component used to facilitate the secondary use of EHR data is the information extraction (IE) task, which automatically extracts and encodes clinical information from text.

OBJECTIVES

In this literature review, we present a review of recent published research on clinical information extraction (IE) applications.

METHODS

A literature search was conducted for articles published from January 2009 to September 2016 based on Ovid MEDLINE In-Process & Other Non-Indexed Citations, Ovid MEDLINE, Ovid EMBASE, Scopus, Web of Science, and ACM Digital Library.

RESULTS

A total of 1917 publications were identified for title and abstract screening. Of these publications, 263 articles were selected and discussed in this review in terms of publication venues and data sources, clinical IE tools, methods, and applications in the areas of disease- and drug-related studies, and clinical workflow optimizations.

CONCLUSIONS

Clinical IE has been used for a wide range of applications, however, there is a considerable gap between clinical studies using EHR data and studies using clinical IE. This study enabled us to gain a more concrete understanding of the gap and to provide potential solutions to bridge this gap.

Burden of hospitalization in clinically diagnosed peripheral artery disease: A community-based study

The burden and predictors of hospitalization over time in community-based patients with peripheral artery disease (PAD) have not been established. This study evaluates the frequency, reasons and predictors of hospitalization over time in community-based patients with PAD. We assembled an inception cohort of 1798 PAD cases from Olmsted County, MN, USA (mean age 71.2 years, 44% female) from 1 January 1998 through 31 December 2011 who were followed until 2014. Two age- and sex-matched controls ( n = 3596) were identified for each case. ICD-9 codes were used to ascertain the primary reasons for hospitalization. Patients were censored at death or last follow-up. The most frequent reasons for hospitalization were non-cardiovascular: 68% of 8706 hospitalizations in cases and 78% of 8005 hospitalizations in controls. A total of 1533 (85%) cases and 2286 (64%) controls ( p < 0.001) were hospitalized at least once; 1262 (70%) cases and 1588 (44%) controls ( p < 0.001) ≥ two times. In adjusted models, age, prior hospitalization and comorbid conditions were independently associated with increased risk of recurrent hospitalizations in both groups. In cases, severe PAD (ankle-brachial index < 0.5) (HR: 1.25; 95% CI: 1.15, 1.36) and poorly compressible arteries (HR: 1.26; 95% CI: 1.16, 1.38) were each associated with increased risk for recurrent hospitalization. We demonstrate an increased rate of hospitalization in community-based patients with PAD and identify predictors of recurrent hospitalizations. These observations may inform strategies to reduce the burden of hospitalization of PAD patients.

Surveillance of Peripheral Arterial Disease Cases Using Natural Language Processing of Clinical Notes

Peripheral arterial disease (PAD) is a chronic disease that affects millions of people worldwide and yet remains underdiagnosed and undertreated. Early detection is important, because PAD is strongly associated with an increased risk of mortality and morbidity. In this study, we built a PAD surveillance system using natural language processing (NLP) for early detection of PAD from narrative clinical notes. Our NLP algorithm had excellent positive predictive value (0.93) and identified 41% of PAD cases before the initial ankle-brachial index (ABI) test date while in 12% of cases the NLP algorithm detected PAD on the same date as the ABI (the gold standard for comparison). Hence, our system ascertains PAD patients in a timely and accurate manner. In conclusion, our PAD surveillance NLP algorithm has the potential for translation to clinical practice for use in reminding clinicians to order ABI tests in patients with suspected PAD and to reinforce the implementation of guideline recommended risk modification strategies in patients diagnosed with PAD.

Mining peripheral arterial disease cases from narrative clinical notes using natural language processing

OBJECTIVE

Lower extremity peripheral arterial disease (PAD) is highly prevalent and affects millions of individuals worldwide. We developed a natural language processing (NLP) system for automated ascertainment of PAD cases from clinical narrative notes and compared the performance of the NLP algorithm with billing code algorithms, using ankle-brachial index test results as the gold standard.

METHODS

We compared the performance of the NLP algorithm to (1) results of gold standard ankle-brachial index; (2) previously validated algorithms based on relevant International Classification of Diseases, Ninth Revision diagnostic codes (simple model); and (3) a combination of International Classification of Diseases, Ninth Revision codes with procedural codes (full model). A dataset of 1569 patients with PAD and controls was randomly divided into training (n = 935) and testing (n = 634) subsets.

RESULTS

We iteratively refined the NLP algorithm in the training set including narrative note sections, note types, and service types, to maximize its accuracy. In the testing dataset, when compared with both simple and full models, the NLP algorithm had better accuracy (NLP, 91.8%; full model, 81.8%; simple model, 83%; P < .001), positive predictive value (NLP, 92.9%; full model, 74.3%; simple model, 79.9%; P < .001), and specificity (NLP, 92.5%; full model, 64.2%; simple model, 75.9%; P < .001).

CONCLUSIONS

A knowledge-driven NLP algorithm for automatic ascertainment of PAD cases from clinical notes had greater accuracy than billing code algorithms. Our findings highlight the potential of NLP tools for rapid and efficient ascertainment of PAD cases from electronic health records to facilitate clinical investigation and eventually improve care by clinical decision support.

Medium-term Outcomes after Whole-gland High-intensity Focused Ultrasound for the Treatment of Nonmetastatic Prostate Cancer from a Multicentre Registry Cohort

BACKGROUND

High-intensity focused ultrasound (HIFU) is a minimally-invasive treatment for nonmetastatic prostate cancer.

OBJECTIVE

To report medium-term outcomes in men receiving primary whole-gland HIFU from a national multi-centre registry cohort.

DESIGN, SETTING, AND PARTICIPANTS

Five-hundred and sixty-nine patients at eight hospitals were entered into an academic registry.

INTERVENTION

Whole-gland HIFU (Sonablate 500) for primary nonmetastatic prostate cancer. Redo-HIFU was permitted as part of the intervention.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Our primary failure-free survival outcome incorporated no transition to any of the following: (1) local salvage therapy (surgery or radiotherapy), (2) systemic therapy, (3) metastases, or (4) prostate cancer-specific mortality. Secondary outcomes included adverse events and genitourinary function.

RESULTS AND LIMITATIONS

Mean age was 65 yr (47-87 yr). Median prostate-specific antigen was 7.0 ng/ml (interquartile range 4.4-10.2). National Comprehensive Cancer Network low-, intermediate-, and high-risk disease was 161 (28%), 321 (56%), and 81 (14%), respectively. One hundred and sixty three of 569 (29%) required a total of 185 redo-HIFU procedures. Median follow-up was 46 (interquartile range 23-61) mo. Failure-free survival at 5 yr after first HIFU was 70% (95% confidence interval [CI]: 64-74). This was 87% (95% CI: 78-93), 63% (95% CI: 56-70), and 58% (95% CI: 32-77) for National Comprehensive Cancer Network low-, intermediate-, and high-risk groups, respectively. Fifty eight of 754 (7.7%) had one urinary tract infection, 22/574 (2.9%) a recurrent urinary tract infection, 22/754 (3%) epididymo-orchitis, 227/754 (30%) endoscopic interventions, 1/754 (0.13%) recto-urethral fistula, and 1/754 (0.13%) osteitis pubis. Of 206 known to be pad-free pre-HIFU, 183/206 (88%) remained pad free, and of 236 with good baseline erectile function, 91/236 (39%) maintained good function. The main limitation is lack of long-term data.

CONCLUSIONS

Whole-gland HIFU is a repeatable day-case treatment that confers low rates of urinary incontinence. Disease control at a median of just under 5 yr of follow-up demonstrates its potential as a treatment for nonmetastatic prostate cancer. Endoscopic interventions and erectile dysfunction rates are similar to other whole-gland treatments.

PATIENT SUMMARY

In this report we looked at the 5-yr outcomes following whole-gland high-intensity focused ultrasound treatment for prostate cancer and found that cancer control was acceptable with a low risk of urine leakage. However, risk of erectile dysfunction and further operations was similar to other whole-gland treatments like surgery and radiotherapy.

Identifying Peripheral Arterial Disease Cases Using Natural Language Processing of Clinical Notes

Peripheral arterial disease (PAD) is a chronic disease that affects millions of people worldwide. Ascertaining PAD status from clinical notes by manual chart review is labor intensive and time consuming. In this paper, we describe a natural language processing (NLP) algorithm for automated ascertainment of PAD status from clinical notes using predetermined criteria. We developed and evaluated our system against a gold standard that was created by medical experts based on manual chart review. Our system ascertained PAD status from clinical notes with high sensitivity (0.96), positive predictive value (0.92), negative predictive value (0.99) and specificity (0.98). NLP approaches can be used for rapid, efficient and automated ascertainment of PAD cases with implications for patient care and epidemiologic research.

Topical application of mitomycin-C in oesophageal strictures

BACKGROUND

Benign oesophageal strictures may occur as a complication of caustic ingestion or severe gastro-oesophageal reflux or as a sequela of oesophageal surgery and other fibrosing conditions. The traditional initial treatment of oesophageal strictures is intraluminal dilation; however, even if frequent, this occasionally may not provide adequate oesophageal lumen capacity or give significant symptom-free intervals, and restricturing after dilation is difficult and challenging. Topical postdilation application of an antifibrotic agent, mitomycin-C, in the treatment of an oesophageal stricture has been described.

PATIENTS AND METHODS

Eight centres participated, with a total of 16 patients (4 girls), median age 48 (range 0-276) months. The causes of stricture were as follows: caustic (10), post-trachea-oesophageal fistula repair (2), peptic (2), Crohn disease (1), and dystrophic epidermolysis bullosa (1). The median (range) length and diameter of the strictures were as follows: 22 mm (8-50 mm) and 1.5 mm (1-6 mm). Of the 16 patients, 15 had undergone repeated dilations varying from 3 to more than 1000 (daily self-bouginage) before mitomycin-C, and the median interval between dilations was 4 weeks. Mitomycin-C 0.1 mg/mL was applied after dilation for a median time of 3.5 minutes and a median of 3 (1-12) times.

RESULTS

Major success, both endoscopic and clinical improvement or cure, occurred in 10 of 16 patients. In 3 of 16 patients the interval period between dilations increased dramatically. Failure of therapy was considered in 3 of 16. All of the patients remained symptom free for a follow-up time of as long as 5 years.

CONCLUSIONS

Postdilation application of topical mitomycin-C resulted in major success in 62.5% of patients and partial success in 19%, and it may be a useful strategy in oesophageal strictures of differing causes that are refractory to repeated perendoscopic dilation.

Endoluminal gastroplication in children with significant gastro-oesophageal reflux disease

AIMS

To describe paediatric experience, and to assess complications and therapeutic effectiveness of the use of endoluminal gastroplication in children with gastro-oesophageal reflux disease (GORD) refractory to, or dependent on, proton pump inhibitors.

METHODS

Seventeen (five male) consecutive children/adolescents (median (range) age 12.4 (6.1-15.9) years, median (range) weight 46.0 (16.5-87.5) kg) with GORD either dependent for more than 12 months on proton pump inhibitors or non-responsive to medical treatment underwent endoscopic gastroplication using a flexible endoscopic sewing device (EndoCinch). Three plications were placed in gastric tissue below the lower oesophageal sphincter. Drug dose requirement, pH measurements, daily symptom severity and frequency, and validated reflux (QOLRAD) and general gastrointestinal (GSRS) quality of life scores were compared before and after endoscopic gastroplication.

RESULTS

All patients showed post-treatment improvement in symptom severity, frequency, and quality of life scores (p<0.0001). Three patients with recurrent symptomatic GORD had a repeat procedure within six weeks and did well subsequently. At up to 33 months of follow up (median 23), 14/17 patients remained off all antireflux medications, and 14/17 had maintained their symptomatic improvement. All pH parameters improved and had returned to normal values in 14/16 patients post-treatment and in 6/9 after one year of follow-up: in particular the reflux index had decreased from a median of 16.6% (0.9-67%) to 2.5% (0.7-15.7%) (p<0.0001) six weeks and 4.3% (2.2-20.6) (p<0.02) 12 months post-procedure. The only complication observed was gastric bleeding in one patient due to previously undiagnosed coagulopathy, which spontaneously resolved.

CONCLUSIONS

Endoluminal gastroplication is an effective and safe procedure in children/adolescents with significant GORD refractory to, or dependent on, medical anti-GORD therapy.

Cortisol response to a cognitive stress challenge in posttraumatic stress disorder (PTSD) related to childhood abuse

Preclinical studies show that animals with a history of chronic stress exposure have increased hypothalamic-pituitary-adrenal (HPA) axis reactivity following reexposure to stress. Patients with posttraumatic stress disorder (PTSD) have been found to have normal or decreased function of the HPA axis, however no studies have looked at the HPA response to stress in PTSD. The purpose of this study was to assess cortisol responsivity to a stressful cognitive challenge in patients with PTSD related to childhood abuse. Salivary cortisol levels, as well as heart rate and blood pressure, were measured before and after a stressful cognitive challenge in patients with abuse-related PTSD (N=23) and healthy comparison subjects (N=18). PTSD patients had 61% higher group mean cortisol levels in the time period leading up to the cognitive challenge, and 46% higher cortisol levels during the time period of the cognitive challenge, compared to controls. Both PTSD patients and controls had a similar 66-68% increase in cortisol levels from their own baseline with the cognitive challenge. Following the cognitive challenge, cortisol levels fell in both groups and were similar in PTSD and control groups. PTSD patients appeared to have an increased cortisol response in anticipation of a cognitive challenge relative to controls. Although cortisol has been found to be low at baseline, there does not appear to be an impairment in cortisol response to stressors in PTSD.

Portal Vein Thrombosis and Pancreatic Failure

We report a case of a child with portal vein thrombosis presenting with protein losing enteropathy. Helater developed exocrine and endocrine pancreatic failure. This association has not been reported before.

Effect of urinary tract infection on ureteropelvic junction obstruction in a rat model

OBJECTIVES

When a partially obstructed kidney becomes infected, more rapid and extreme renal parenchymal damage appears to occur than might result from either infection or obstruction alone. Previously, we showed that either bacteriuria or partial obstruction in congenital unilateral hydronephrosis causes elevated renal pelvic pressures in a rat model. In this same model, we examined the combined effects of partial upper tract obstruction and bacteriuria on renal pelvic and bladder pressures.

METHODS

Female rats from an inbred colony in which more than one half are born with unilateral obstructive hydronephrosis were studied. Type 1 piliated Escherichia coli was instilled into the bladder. Two to 6 days later, the bladder and renal pelvic pressures were measured during varying urinary flows (less than 2 to more than 30 mL/kg/hr). All animals were killed and the kidneys and bladder grossly and histologically assessed. Hydronephrosis was determined at pathologic examination.

RESULTS

Eight rats had congenital unilateral hydronephrosis; five were normal. Acute inflammation was found in all bladder and renal specimens. In hydronephrotic, infected kidneys, the renal pelvic pressures exceeded those in nonhydronephrotic, infected kidneys at all urinary flow rates. Bladder capacity and pressures did not differ between the two groups.

CONCLUSIONS

This model demonstrates that the combination of infection and obstructive hydronephrosis in this model causes renal pelvic pressure elevation that is higher than that associated with either infection or obstructive hydronephrosis alone. These data demonstrate the compound effect that infection and obstruction may have on the kidney and offers an explanation for why this clinical situation is more likely to be associated with greater renal parenchymal injury than either alone.

Is preoperative donation of autologous blood rational for radical retropubic prostatectomy?

PURPOSE

We investigated differences in the rate of homologous blood transfusion and the degree of anemia to determine whether it is rational to have patients donate autologous blood before radical prostatectomy.

MATERIALS AND METHODS

We retrospectively reviewed the charts of 221 consecutive men who underwent radical retropubic prostatectomy performed by 1 surgeon in a 14-month period. About half of the patients donated autologous blood preoperatively. We evaluated perioperative hemoglobin, and the rate of autologous and homologous transfusion.

RESULTS

The groups did not significantly differ in terms of demographic data, co-morbid conditions, clinical variables or hospitalization. Preoperatively mean hemoglobin plus or minus standard deviation was 13.4 +/- 1 and 14.7 +/- 1 gm./dl. in patients who did and did not donate blood, while homologous transfusion was required in 1 (1%) and 4 (3.5%), respectively (p = 0. 18). At hospital discharge anemia was more prevalent in nondonors. Of the men who did versus did not donate blood hemoglobin was less than 10 and less than 9 gm./dl. in 8.4% versus 34% (p <0.0001), and 12.5% versus 0% (p <0.0004), respectively.

CONCLUSIONS

Our retrospective review of a cohort of patients who underwent radical retropubic prostatectomy showed no difference in homologous blood transfusion based on preoperative autologous donation status. Autologous donors had lower hemoglobin preoperatively, a higher rate of transfused units and higher hemoglobin at hospital discharge. Preoperative donation of autologous blood may not decrease the need for homologous transfusion in healthy patients undergoing radical retropubic prostatectomy.

Molecular analysis of a null mutant for pea (Pisum sativum L.) seed lipoxygenase-2

A mutant line of Pisum fulvum was identified that lacked seed lipoxygenase-2 (LOX-2). The mutant phenotype was introgressed into a standard Pisum sativum cv. Birte to provide near-isogenic lines with or without seed LOX-2. Genetic analyses showed the mutation to behave as a single, recessive Mendelian gene. Northern and dot-blot analyses showed a large reduction in LOX-2 mRNA from developing seeds of the LOX-2-null mutant. A restriction fragment length polymorphism associated with the 5' end of the LOX-2 gene(s) co-segregated with the null phenotype, indicating that the reduction of LOX-2 mRNA was neither a consequence of deletion of the LOX genes nor a consequence of the action of a genetically distant regulatory gene. Analysis of the 5'-flanking sequences of LOX-2 genes from Birte and the near-isogenic LOX-2-null mutant revealed a number of insertions, deletions and substitutions within the promoter from the LOX-2-null mutant that could be responsible for the null phenotype. Incubation of crude seed LOX preparations from Birte and the LOX-2-null mutant showed that the latter generated relatively less 13-hydroperoxides and also produced relatively more hydroxy- and ketoacid compounds that have implications for the fresh-frozen pea industry.

Correlation of transrectal ultrasound measurements of prostate and transition zone size with symptom score, bother score, urinary flow rate, and post-void residual volume

OBJECTIVES

To assess the correlation of total prostatic size and prostate transition zone dimensions with various measurements of the severity of bladder outlet obstruction secondary to benign prostatic hyperplasia.

METHODS

Prostate-specific antigen, creatinine, American Urological Association symptom score, bother score, urinary history, uroflowmetry, and post-void residual urine volume determination was followed by measurement of the prostate gland and transition zone on transrectal ultrasound images in 136 men undergoing systematic prostate biopsies. Patients were divided into five groups based on past urinary tract treatment history and the presence of prostate cancer on the biopsies. The total prostate and transition zone dimensions, as well as calculated prostate and transition zone volumes, were compared by Pearson correlation with both the subjective and objective voiding parameters in each patient group.

RESULTS

The transition zone dimensions correlated positively with American Urological Association symptom score, bother score, and post-void residual urine volume and correlated negatively with maximum and mean flow rates, particularly in patients with no history of prostate surgery, alpha-blocker administration, urinary infections, irritative voiding symptoms, or prostate cancer.

CONCLUSIONS

Transrectal ultrasound measurements of transition zone dimensions correlate better than total prostatic dimensions or calculated prostatic or transition zone volumes with the severity of benign prostatic hyperplasia. Of these, the transverse transition zone dimension demonstrated the best correlation; however, this correlation is probably not adequate for clinical utility.

Identification of changes in cardiac phospholipase C activity in congestive heart failure

Although phosphoinositide-specific phospholipase C (PLC) is involved in signal transduction mechanisms of the myocardial cell. very little is known about its status in congestive heart failure (CHF). We have examined the PLC activity in sarcolemmal and cytosolic fractions isolated from the viable left ventricle of rats at 8 weeks (moderate stage of CHF) and 16 weeks (severe stage of CHF) after occlusion of the left anterior descending coronary artery; the hypertrophied right ventricle was used for comparison. At 8 weeks, the hydrolysis of phosphatidylinositol 4,5-bisphosphate by sarcolemmal PLC was reduced by 37% of sham control values only in the left ventricle, whereas at 16 weeks, PLC-mediated hydrolysis was depressed in both left and right ventricles by 25% and 30%, respectively. The hydrolysis of phosphatidylinositol 4-monophosphate (PIP) was reduced by 25% of control value only in the severely failing left ventricle, while the phosphatidylinositol (PI) hydrolysis remained unaltered. Kinetic studies of PLC activity in the left ventricle showed a depression of V(max) at moderate and severe failure stages, whereas the affinity for the substrate was increased in the left ventricle at 8 weeks and decreased in the right ventricle at 16 weeks. The only difference observed between experimental and control groups at the cytosolic level, was a significant enhancement of PLC activity in the severely failing left ventricle when PIP was given as a substrate, and in the corresponding right ventricle when PI was the substrate. The results of this study identify time-related defects in sarcolemmal PLC in right and left ventricles during the development of CHF due to myocardial infarction.

Decreased expression of cardiac sarcoplasmic reticulum Ca(2+)-pump ATPase in congestive heart failure due to myocardial infarction

Myocardial infarction in rats induced by occluding the left coronary artery for 4, 8 and 16 weeks has been shown to result in congestive heart failure (CHF) characterized by hypertrophy of the viable ventricular myocardial tissue. We have previously demonstrated a decreased calcium transport activity in the sarcoplasmic reticulum (SR) of post-myocardial infarction failing rat hearts. In this study we have measured the steady state levels of the cardiac SR Ca(2+)-pump ATPase (SERCA2) mRNA using Northern blot and slot blot analyses. The relative amounts of SERCA2 mRNA were decreased with respect to GAPDH mRNA and 28 S rRNA in experimental failing hearts at 4 and 8 weeks post myocardial infarction by about 20% whereas those at 16 weeks declined by about 35% of control values. The results obtained by Western blot analysis, revealed that the immunodetectable levels of SERCA2 protein in 8 and 16 weeks postinfarcted animals were decreased by about 20% and 30%, respectively. The left ventricular SR Ca(2+)-pump ATPase specific activity was depressed in the SR preparations of failing hearts as early as 4 weeks post myocardial infarction and declined by about 65% at 16 weeks compared to control. These results indicate that the depressed SR Ca(2+)-pump ATPase activity in CHF may partly be due to decreased steady state amounts of SERCA2 mRNA and SERCA2 protein in the failing myocardium.