Development of a patient specific cartilage graft using magnetic resonance imaging and 3D printing

OBJECTIVES

The goal of this project was to develop and validate a patient-specific, anatomically correct graft for cartilage restoration using magnetic resonance imaging (MRI) data and 3-dimensional (3D) printing technology. The specific aim was to test the accuracy of a novel method for 3D printing and implanting individualized, anatomically shaped bio-scaffolds to treat cartilage defects in a human cadaveric model. We hypothesized that an individualized, anatomic 3D-printed scaffold designed from MRI data would provide a more optimal fill for a large cartilage defect compared to a generic flat scaffold.

METHODS

Four focal cartilage defects (FCDs) were created in paired human cadaver knees, age <40 years, in the weight-bearing surfaces of the medial femoral condyle (MFC), lateral femoral condyle (LFC), patella, and trochlea of each knee. MRIs were obtained, anatomic grafts were designed and 3D printed for the left knee as an experimental group, and generic flat grafts for the right knee as a control group. Grafts were implanted into corresponding defects and fixed using tissue adhesive. Repeat post-implant MRIs were obtained. Graft step-off was measured as the distance in mm between the surface of the graft and the native cartilage surface in a direction perpendicular to the subchondral bone. Graft contour was measured as the gap between the undersurface of the graft and the subchondral bone in a direction perpendicular to the joint surface.

RESULTS

Graft step-off was statistically significantly better for the anatomic grafts compared to the generic grafts in the MFC (0.0 ​± ​0.2 ​mm vs. 0.7 ​± ​0.5 ​mm, p ​< ​0.001), LFC (0.1 ​± ​0.3 ​mm vs. 1.0 ​± ​0.2 ​mm, p ​< ​0.001), patella (-0.2 ​± ​0.3 ​mm vs. -1.2 ​± ​0.4 ​mm, p ​< ​0.001), and trochlea (-0.4 ​± ​0.3 vs. 0.4 ​± ​0.7, p ​= ​0.003). Graft contour was statistically significantly better for the anatomic grafts in the LFC (0.0 ​± ​0.0 ​mm vs. 0.2 ​± ​0.4 ​mm, p ​= ​0.022) and trochlea (0.0 ​± ​0.0 ​mm vs. 1.4 ​± ​0.7 ​mm, p ​< ​0.001). The anatomic grafts had an observed maximum step-off of -0.9 ​mm and a maximum contour mismatch of 0.8 ​mm.

CONCLUSION

This study validates a process designed to fabricate anatomically accurate cartilage grafts using MRI and 3D printing technology. Anatomic grafts demonstrated superior fit compared to generic flat grafts.

LEVEL OF EVIDENCE

Level IV.

Quantification of inter-brain coupling: A review of current methods used in haemodynamic and electrophysiological hyperscanning studies

Hyperscanning is a form of neuroimaging experiment where the brains of two or more participants are imaged simultaneously whilst they interact. Within the domain of social neuroscience, hyperscanning is increasingly used to measure inter-brain coupling (IBC) and explore how brain responses change in tandem during social interaction. In addition to cognitive research, some have suggested that quantification of the interplay between interacting participants can be used as a biomarker for a variety of cognitive mechanisms aswell as to investigate mental health and developmental conditions including schizophrenia, social anxiety and autism. However, many different methods have been used to quantify brain coupling and this can lead to questions about comparability across studies and reduce research reproducibility. Here, we review methods for quantifying IBC, and suggest some ways moving forward. Following the PRISMA guidelines, we reviewed 215 hyperscanning studies, across four different brain imaging modalities: functional near-infrared spectroscopy (fNIRS), functional magnetic resonance (fMRI), electroencephalography (EEG) and magnetoencephalography (MEG). Overall, the review identified a total of 27 different methods used to compute IBC. The most common hyperscanning modality is fNIRS, used by 119 studies, 89 of which adopted wavelet coherence. Based on the results of this literature survey, we first report summary statistics of the hyperscanning field, followed by a brief overview of each signal that is obtained from each neuroimaging modality used in hyperscanning. We then discuss the rationale, assumptions and suitability of each method to different modalities which can be used to investigate IBC. Finally, we discuss issues surrounding the interpretation of each method.

The effectiveness of a telemedical program for COVID-19 positive high-risk patients in domestic isolation

Background

For almost two years, the Covid-19 pandemic has posed an enormous challenge to healthcare systems. Recurrent waves of disease brought the health systems to the limit of their resilience.

Purpose

The Tele-Covid telemedicine care program was installed in December 2020 to monitor high-risk patients in home isolation. Close monitoring allows early detection of disease deterioration and timely intensification of therapy, ideally avoiding intensive care. Conversely, if the course of the disease is stable, unnecessary hospitalisation can be avoided, thus reducing the burden on the healthcare system.

Methods

Patient acquisition was performed in collaboration with the local public health service and primary care physicians. Covid-19 positive high-risk patients (age >65 years and/or severe comorbidities) from the greater Innsbruck area were fitted with an ear sensor-based home monitoring system. The ear sensor measures SpO2, respiratory rate, body temperature and heart rate. The monitoring team (25 medical students supervised by 6 physicians) provided continuous monitoring of vital signs (24/7).

After validation of the measurements, the collected parameters were evaluated using a specially developed risk score. If a defined risk score was exceeded, the patient was contacted by telephone. The combination of the clinical condition and the risk score determined the further course of action: (a) wait and see, (b) notify the primary care physician, or (c) refer for inpatient admission.

The program was active from December 2020 to March 2022. In Summer 2021, the program was temporarily paused due to the epidemiological situation.

Results

A total of 132 patients (59.8% women) were monitored. The median age was 74 years (IQR: [67.3–80.8]). 91 patients (68.9%) had at least one relevant comorbidity. During the monitoring period, hospitalisation was required in 20 patients (15.2%), 3 of whom were transferred to the intensive care unit. Of the hospitalised patients, 3 (15%) patients died. During the same monitoring period, the Austrian Ministry of Health reported a mortality rate of 20.5% of all hospitalised patients in Austria aged 70–79 years. Subjectively, the patients felt safe due to close monitoring.

Conclusion

The Tele-Covid program is the successful implementation of a remote monitoring system in a pandemic situation. In the future, a broad application of the program is feasible.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Funded by the Region of the Tyrol

Anatomical Differences Between Human and Pig Hearts and Their Relevance for Cardiac Xenotransplantation Surgical Technique

Cardiac xenotransplantation has been proposed to bridge the gap between supply and demand for patients with end-stage heart failure requiring transplantation. However, differences in pig anatomy compared with human anatomy require modification of the surgical approach. In addition, careful consideration should be given to size matching before transplantation. (Level of Difficulty: Advanced.)

POS1484-HPR THE ASSOCIATION OF STIGMA WITH DISEASE VARIABLES IN PATIENTS WITH FIBROMYALGIA (FM)

Background:

Stigma, defined as social devaluation of an individual, can be an important stressor for chronic pain patients [1]. Not every condition is stigmatized. A relevant factor for illness stigmatization seems to be whether the cause is mental-behavioural or physical. Chronic pain is often regarded as an imaginary illness or caused by psychological problems [2]. Sources of stigma for chronic pain patients are perceived negative attitudes from family members, the general public, and physicians [1]..

Objectives:

To assess perceived stigma and the associations with disease variables in a cohort of patients with FM.

Methods:

We invited 18 FM self-help groups in Germany to participate anonymously in our survey, and we sent the survey battery to 192 potential participants via postal mail. To measure perceived stigma, we used the Chronic Pain Stigma Scale (CPSS) developed by Reed [3], which has 30 items and 3 subscales (public, physicians, family). We also assessed sociodemographic characteristics, disease related variables (e.g., pain, stress, depression, anxiety), and other health-related factors, including health related quality of life [Healthy Days Core Module (CDC HDQOL-4)], disease specific impact (FIQ), fear avoidance belief questionnaire (physical activity subscale) (FABQ-PA), pain catastrophizing scale (PCS) and pain self-efficacy questionnaire (PSEQ).

Results:

In total 162 FM patients participated (=84% response rate). Their mean age was 58 years (SD=10), 84% (N=135) were female. Highest level of education was: Elementary School 29%, Junior High School 35%, High School 15%, College 12%, and other 10%. Duration of chronic pain was 18.2 years (SD=12.0). There was no significant gender difference in the stigma subscales, nor was there an association with duration of chronic pain. Table 1 presents the significant Pearson correlations.

Table 1.

Correlations of CPSS stigma subscales with health variables. *<.05; **<.01; ns=not significant.

CPSS-publicCPSS-physicianCPSS-familyRegional pain scalens.19*.20*VAS pain todaynsnsNsFIQ.20*.16*.22**HADS-anxiety.37*.20*.24*HADS-depression.41**.16*.25**CDC-HDQOL-4 General health.19*.18*.22** Physical health.19*nsns Mental health.20*ns.21* Impairment.24*nsnsPerceived stress scale.44**.24**.37**FABQ-PAns-.17*nsPCS.21*nsnsPSEQ.19*ns.18*

Conclusion:

Perceived stigma in our FM patient cohort has an important impact on a variety of different disease variables including mental and general health, physical functioning, and on pain coping. Stigmatizing attitudes perceived from the general public exhibited the greatest association with most variables in our chronic pain patients. Perceived stigma from physicians and the family were also related to negative disease consequences in our FM patients. To conclude, we assert that assessing and addressing multi-source perceived stigmatization in routine clinical care may improve the management and wellbeing of patients with FM.

References:

[1]Waugh OC, Byrne DG, Nicholas MK. Internalized stigma in people living with chronic pain. J Pain 2014;15(5):550 e1-10.

[2]Werner A, Isaksen LW, Malterud K. ‘I am not the kind of woman who complains of everything’: illness stories on self and shame in women with chronic pain. Soc Sci Med 2004;59(5): 1035-45

[3]Reed P. Chronic pain stigma: developement of the Chronic Pain Stigma Scale. 2005.

Disclosure of Interests:

None declared

AB0889-HPR PERCEIVED SATISFACTION WITH CHRONIC PAIN CARE IN GERMAN PATIENTS WITH FIBROMYALGIA (FM)

Background:

In chronic pain care a multidimensional perspective with attention to patients’ cognitions, emotions, and their ability to cope is needed (1). Previous studies are also pointing to the role of experiencing meaningfulness in life in the adjustment to disability.Therefore care should additionally focus on the existential domain of patients’ lives to live up to a holistic care approach (2). However, there are only a few studies on how FM patients are satisfied with practitioners’ attention to multiple aspects of life with a chronic pain condition.

Objectives:

To assess perceived satisfaction with chronic pain care and its associations with health variables in a cohort of patients with FM.

Methods:

We invited 18 FM self-help groups in Germany to participate anonymously in our survey and sent them in total 192 paper-and-pencil surveys. Sociodemographics, disease related variables (e.g. pain, general health) and psychological variables [e.g. depression, anxiety, hope, stress] were assessed with standardized instruments, including 5 items (answer format 1=very unsatisfied – 10=very satisfied) assessing subjective satisfaction with medical care in different domains with the following questions: How satisfied are you with the attention of your treatment team/physician at home for physiological aspects of your pain (Physio)/ the consequences of the pain on your physical functioning (Physical)/ on your psychological well-being (Mental)/ on your social life (Social)/ on your meaning in life (Meaning).

Results:

In total 162 FM patients participated (=84% response rate). Their mean age was 58 years (SD=10), 84% (N=135) were female. Highest level of education was: Elementary School 29%, Junior High School 35%, High School 15%, College 12%, and other 10%. Duration of chronic pain was 18.2 years (SD=12.0). The satisfaction with care scale showed good internal consistency and measured one factor. The means of the subscale were: Physio 5.7 (SD=2.5)/ Physical 5.5 (SD=2.5)/ Mental 5.5 (SD=2.6)/ Social 5.0 (SD=2.5)/ Meaning 5.3 (SD=2.6). Correlations of the subscales are depicted in Table 1. There were no associations between pain variables and satisfaction with care, but satisfaction with care was associated with mental health, but not physical health, outcomes.

Table 1.

Correlations of satisfaction of care with different health variables. Subscales physiological and physical aspects and HADS-anxiety were not significantly correlated. *<.05; **<.01; ns=not significant.

PhysioPhysicalMentalSocialMeaningHADS-depression-.10 (ns)-.12 (ns)-.19*-.16*-.14 (ns)General Health .02 (ns) .14 (ns) .13 (ns) .18* .12 (ns)Stress-.15 (ns)-.14 (ns)-.17*-.17*-.13 (ns)Hope .18 (ns) .18 (ns) .26** .26* .22*

Conclusion:

In this cohort of German FM patients the average satisfaction with care overall, as well as the specific aspects of care, was only moderate. Interestingly we found associations between satisfaction with care in mental, social and meaning in life aspects with psychological well-being pointing to the fact that care for chronic pain patients should also include those aspects in addition to just addressing biomedical aspects.

References:

[1]Flor H and Turk D. Chronic pain: an integrated approach. Seattle, WA: IASP Press, 2011.

[2]Dezutter J, Casalin S, Wacholtz A, et al. Meaning in life: An important factor for the psychological well-being of chronically ill patients? Rehabilitat Psychol 2013; 58:334–341.

Disclosure of Interests:

None declared

Racial disparities in pre-operative pain, function and disease activity for patients with rheumatoid arthritis undergoing Total knee or Total hip Arthroplasty: a New York based study

Background

Black and Hispanic patients with osteoarthritis have more pain and worse function than Whites at the time of arthroplasty. Whether this is true for patients with rheumatoid arthritis (RA) is unknown.

Methods

This cross-sectional study used data on RA patients acquired between October 2013 and November 2018 prior to elective total knee (TKA) or hip arthroplasty (THA). Pain, function, and disease activity were assessed using the visual analogue scale (VAS), the Multidimensional Health Assessment Questionnaire (MDHAQ), and the Disease Activity Score (DAS28-ESR). We linked the cases to census tracts using geocoding to determine the community poverty level. Race, education, income, insurance and medications were collected via self-report. Using multivariable linear and logistic models we examined whether minority status predicted pain, function and RA disease activity at the time of arthroplasty.

Results

Thirty seven (23%) of the 164 patients were Black or Hispanic (minorities). The MDHAQ and DAS28-ESR were not significantly worse while VAS pain score was significantly worse in minority patients (p = 0.03). There was no significant difference in education between the groups. Insurance varied significantly; 29% of minority patients had Medicaid vs. 0% of Whites (p < 0.0001). In the multivariable analyses minority status was not significantly associated with DAS28-ESR [p = 0.66], MDHAQ [p = 0.26], or VAS pain [p = 0.18].

Conclusions

For Black and/or Hispanic patients with RA undergoing THA or TKA at a high-volume specialty hospital, unlike Black or Hispanic patients with osteoarthritis (OA), there was no association with worse pain, function, or RA disease activity at the time of elective arthroplasty.

3D Printing Prototypes for Healthcare Professionals: Creating a Reciprocating Syringe

3D printing (additive manufacturing) has been around since 1984, but interest in the technology has increased exponentially as it has become both accessible and inexpensive. The applications of the technology in healthcare are still being explored; however, initial forays have been encouraging. It has the potential to revolutionize the process of prototyping for healthcare professionals by democratizing the process and enhancing collaboration, making it cheaper to do iterative prototyping with little or no engineering experience. This case report details the creation of a multi-lumen reciprocating syringe with 3D printing. The product has been created and tested using a variety of publicly available resources. It provides a detailed overview of the approach and the framework required to create such a medical device. However, the implications of this report are much larger than this one product, and the fundamental ideas discussed here could be used for creating customized solutions for many healthcare problems.

New and emerging patient-centered CT imaging and image-guided treatment paradigms for maxillofacial trauma

This article reviews the conceptual framework, available evidence, and practical considerations pertaining to nascent and emerging advances in patient-centered CT-imaging and CT-guided surgery for maxillofacial trauma. These include cinematic rendering-a novel method for advanced 3D visualization, incorporation of quantitative CT imaging into the assessment of orbital fractures, low-dose CT imaging protocols made possible with contemporary scanners and reconstruction techniques, the rapidly growing use of cone-beam CT, virtual fracture reduction with design software for surgical pre-planning, the use of 3D printing for fabricating models and implants, and new avenues in CT-guided computer-aided surgery.

A Perinatal Database Management System

Obstetric services have long recognized the need for ongoing evaluation of their experiences. Manual »departmental statistics« systems sufficed, but with the advent of more sophisticated care, perinatal re-gionalization and increased research activity, the potential usefulness of computer technology became obvious. At Cleveland Metropolitan General Hospital, a laboratory computer based patient information file system was designed and implemented beginning in 1974. Over the succeeding six years, data have been collected and stored for all delivered pregnancies. There are now over 61,000 files for more than 20,000 consecutively delivered patients. The system provides over 40,000 clinical reports per year. However, the use of a file-oriented system has limited our ability to respond to specific research queries. The application of a relational database management system, INGRES, for perinatal information is reported here. Examples of its use for efficiently »answering questions« are presented, as are guidelines for the development and implementation of computer-based perinatal record systems.

Difficulties in screening for peripheral neuropathies in children with diabetes

AIMS

To assess the diagnostic utility of a novel abbreviated monofilament test in comparison with the tuning fork test to detect diabetic peripheral neuropathy in children.

METHODS

A total of 88 children with Type 1 diabetes mellitus were screened for diabetic peripheral neuropathy using the monofilament test and the tuning fork. Nerve conduction studies were performed according to the 'gold standard' for neuropathy. We assessed the diagnostic utility and inter-rater agreement of the two screening methods.

RESULTS

A total of 43 (49%) children (aged 6-18 years) had at least one abnormal nerve conduction study result. Diagnostic utility and inter-rater agreement were very low for both screening methods. The monofilament test yielded a sensitivity of 18% and a specificity of 80%. The tuning fork yielded a sensitivity of 0% and a specificity of 98%.

CONCLUSION

The present study found that an abbreviated monofilament test has low diagnostic utility for the detection of early diabetic peripheral neuropathy because of its low reliability. The problem of reliability needs to be more thoroughly addressed in order to improve the screening procedures in diabetes management in childhood and adolescence.

Impact of intraoperative hypotension and blood pressure fluctuations on early postoperative delirium after non-cardiac surgery

INTRODUCTION

Postoperative delirium is common in older patients. Despite its prognostic significance, the pathophysiology is incompletely understood. Although many risk factors have been identified, no reversible factors, particularly ones potentially modifiable by anaesthetic management, have been identified. The goal of this prospective cohort study was to investigate whether intraoperative hypotension was associated with postoperative delirium in older patients undergoing major non-cardiac surgery.

METHODS

Study subjects were patients >65 years of age, undergoing major non-cardiac surgery, who were enrolled in an ongoing prospective observational study of the pathophysiology of postoperative delirium. Intraoperative blood pressure was measured and predefined criteria were used to define hypotension. Delirium was measured by the Confusion Assessment Method on the first two postoperative days. Data were analysed using t-tests, two-sample proportion tests and ordered logistic regression multivariable models, including correction for multiple comparisons.

RESULTS

Data from 594 patients with a mean age of 73.6 years (sd 6.2) were studied. Of these 178 (30%) developed delirium on day 1 and 176 (30%) on day 2. Patients developing delirium were older, more often female, had lower preoperative cognitive scores, and underwent longer operations. Relative hypotension (decreases by 20, 30, or 40%) or absolute hypotension [mean arterial pressure (MAP)<50 mm Hg] were not significantly associated with postoperative delirium, nor was the duration of hypotension (MAP<50 mm Hg). Conversely, intraoperative blood pressure variance was significantly associated with postoperative delirium.

DISCUSSION

These results showed that increased blood pressure fluctuation, not absolute or relative hypotension, was predictive of postoperative delirium.

Qualitative and quantitative evaluation of rigid and deformable motion correction algorithms using dual-energy CT images in view of application to CT perfusion measurements in abdominal organs affected by breathing motion

OBJECTIVE

To compare six different scenarios for correcting for breathing motion in abdominal dual-energy CT (DECT) perfusion measurements.

METHODS

Rigid [RRComm(80 kVp)] and non-rigid [NRComm(80 kVp)] registration of commercially available CT perfusion software, custom non-rigid registration [NRCustom(80 kVp], demons algorithm) and a control group [CG(80 kVp)] without motion correction were evaluated using 80 kVp images. Additionally, NRCustom was applied to dual-energy (DE)-blended [NRCustom(DE)] and virtual non-contrast [NRCustom(VNC)] images, yielding six evaluated scenarios. After motion correction, perfusion maps were calculated using a combined maximum slope/Patlak model. For qualitative evaluation, three blinded radiologists independently rated motion correction quality and resulting perfusion maps on a four-point scale (4 = best, 1 = worst). For quantitative evaluation, relative changes in metric values, R(2) and residuals of perfusion model fits were calculated.

RESULTS

For motion-corrected images, mean ratings differed significantly [NRCustom(80 kVp) and NRCustom(DE), 3.3; NRComm(80 kVp), 3.1; NRCustom(VNC), 2.9; RRComm(80 kVp), 2.7; CG(80 kVp), 2.7; all p < 0.05], except when comparing NRCustom(80 kVp) with NRCustom(DE) and RRComm(80 kVp) with CG(80 kVp). NRCustom(80 kVp) and NRCustom(DE) achieved the highest reduction in metric values [NRCustom(80 kVp), 48.5%; NRCustom(DE), 45.6%; NRComm(80 kVp), 29.2%; NRCustom(VNC), 22.8%; RRComm(80 kVp), 0.6%; CG(80 kVp), 0%]. Regarding perfusion maps, NRCustom(80 kVp) and NRCustom(DE) were rated highest [NRCustom(80 kVp), 3.1; NRCustom(DE), 3.0; NRComm(80 kVp), 2.8; NRCustom(VNC), 2.6; CG(80 kVp), 2.5; RRComm(80 kVp), 2.4] and had significantly higher R(2) and lower residuals. Correlation between qualitative and quantitative evaluation was low to moderate.

CONCLUSION

Non-rigid motion correction improves spatial alignment of the target region and fit of CT perfusion models. Using DE-blended and DE-VNC images for deformable registration offers no significant improvement.

ADVANCES IN KNOWLEDGE

Non-rigid algorithms improve the quality of abdominal CT perfusion measurements but do not benefit from DECT post processing.

De novo membranous nephropathy in renal allograft associated with antibody-mediated rejection and review of the literature

A 71-year-old woman with unknown renal failure etiology received living donor transplantation had normal graft function for many years. At 11 years from transplantation, she developed nephrotic syndrome. Allograft biopsy showed membranous nephropathy (MN) and C4d positivity in the peritubular capillaries, suggestive of antibody-mediated rejection. At the time of nephrosis onset, she had new donor-specific antibody positivity. The case is unusual in that the diagnosis of de novo MN is based on evidence that she had antibody-mediated rejection. De novo MN remains relatively uncommon; we have reviewed the literature on this diagnosis.

Vacuolar H+-ATPase is down-regulated by the angiogenesis-inhibitory pigment epithelium-derived factor in metastatic prostate cancer cells

The Vacuolar H+-ATPases (V-ATPases), a multi-subunits nanomotor present in all eukaryotic cells resides in the endomembranes of exocytotic and endocytotic pathways. Plasmalemmal V-ATPases have been shown to be involved in tumor cell metastasis. Pigment epithelium-derived factor (PEDF), a potent endogenous inhibitor of angiogenesis, is down-regulated in prostate cancer cells. We hypothesized that the transduction of PEDF in prostate cancer cells will down-regulate V-ATPase function; that in turn will decrease the expression of the V-ATPase accessory protein ATP6ap2 and a-subunit isoforms that target V-ATPase to the cell surface. To test these hypotheses, we used the human androgen-sensitive prostate cancer cells LNCaP, and its castration-refractory-derivative CL1 that were engineered to stably co-express the DsRed Express Fluorescent Protein with or without PEDF. To determine if PEDF down-regulates the function of V-ATPase, we measured the rate of proton fluxes (JH+) of the cytosolic and endosome/lysosome compartments. The mRNA levels for subunit-a isoforms and the ATP6ap2 were measured using quantitative reverse transcription-PCR. The results showed that PEDF expression decreased the rate of JH+ in metastatic CL1 cells without affecting JH+ in non-metastatic LNCaP cells, when studying pH(cyt). Interestingly, PEDF did not affect JH+ in endosomes/lysosomes either in metastatic cells or in non-metastatic cells. We also showed that PEDF significantly decreases the levels of a4 isoform and ATP6ap2 in metastatic CL1 cells, without affecting the levels of a4 isoform in the non-metastatic LNCaP cells. These data identify PEDF as a novel regulator of V-ATPase suggesting a new way by which PEDF may inhibit prostate tumor growth.

Pigment epithelium-derived factor expression prolongs survival and enhances the cytotoxicity of low-dose chemotherapy in castration-refractory prostate cancer

There is currently no cure for advanced castration-refractory prostate cancer (CRPC) despite the recent approval of several new therapeutic agents. We report here the anti-tumor effect of the angio-inhibitory pigment epithelium-derived factor (PEDF) in the metastatic LNCaP-derivative CRPC CL1 model and explore PEDF anti-neoplasic efficacy in combination with low-dose chemotherapy. Androgen-sensitive LNCaP and CRPC PC3 cell lines were examined as comparison. Using a retroviral expression system, we showed that PEDF limited the proliferation of all prostatic cell lines tested; an effect attributed to interleukin 8 (IL8)-CXCR1/IL8RA inhibition. PEDF also reduced the number and size of 3D tumor spheroids in vitro, but only induced cell differentiation in CRPC spheroids. Similarly, PEDF inhibited the migration of CRPC cells suggesting both anti-proliferative and anti-migratory functions. In vivo, PEDF decreased by 85% and 65% the growth of subcutaneous (s.c.) PC3 and CL1 tumors, respectively. In the CL1 orthotopic model, tumor intake with lethal metastases was found in all animals; nevertheless, PEDF prolonged the median survival of tumor-bearing mice (95% confidence interval: 53±0.001 to 57±1 days). Accordingly, PEDF delayed the emergence of skeletal-related event in intra-tibial xenografts. Next, we evaluated low-dose docetaxel (DTX; 5, 1, 0.5 mg/kg) or cyclophosphamide (CTX; 10–20 mg/kg) on established s.c. PC3 tumors that conditionally express PEDF anti-tumoral epitope/NT3. Although NT3–DTX-5 mg/kg combination was inefficient, NT3–DTX-1 mg/kg and -0.5 mg/kg inhibited by 95% and 87.8%, respectively, tumor growth compared with control and induced tumor stasis. Both NT3–CTX combinations were advantageous. Inversely, PEDF–DTX-5 mg/kg and PEDF–CTX-10 mg/kg delayed the most CL1 tumor growth (15, 11 and 5 days for PEDF–DTX-5 mg/kg, PEDF–CTX-10 mg/kg and single treatments, respectively) with elevated apoptosis and serum thrombospondin-1 as possible mechanism and marker, respectively. As well, both PEDF–CTX-10 mg/kg and PEDF–DTX-5 mg/kg prolonged significantly the survival of tumor-bearing mice compared with single treatments. Metastases were reduced in PEDF–DTX-5 mg/kg compared with other treatments, suggesting that PEDF–DTX delayed metastases formation. Our results advocate that PEDF/low-dose chemotherapy may represent a new therapeutic alternative for CRPC.

[Metaanalysis to estimate the expected drop out-rates reported in clinical trials on cataract surgery]

BACKGROUND

A realistic sample size calculation is crucial to achieve significant results in clinical trials. As an expected drop out-rate has to be included in the sample size calculation, current practice consists in the presumption of drop out-rates published in previous similar investigations. This approach may, however, result in severely over- or under-estimated sample sizes. Therefore this meta-analysis sought to aggregate the drop out-rates from published clinical trial reports on cataract surgery to derive a quantitative suggestion for the planning of future clinical trials.

METHODS

The data collection was a complete review of all prospective and retrospective studies in five journals of the years 2002-2012; trial-wise recall rates of subjects at follow-up 3, 6, 12, and 24 months after recruitment were documented. The primary endpoint of the meta-analysis was the reported drop out-rates after 6 months. 95 % confidence intervals were calculated for each trial, respectively; a median drop out-rate was estimated including its 95 % confidence interval. The drop-out-rate estimates were furthermore stratified by design characteristics of the reported studies.

RESULTS

For randomised clinical trials on cataract surgery, the median drop out-rate increased during the follow-up period of 24 months from 4 % at three months to 17 % at 24 months after recruitment; for the six-month drop out-rate a median drop-out rate of 3 % (95 % CI 0 %; 14 %) was estimated.

CONCLUSION

Drop out-rates in sample size calculations for clinical trials on cataract surgery were found to be over-estimated in general, ending up in the calculation of overly large patient numbers and thereby in both ethical and economic consequences. For randomised clinical trials on cataract surgery the median drop out-rate can be expected to be 5 % during a six-month follow-up and may rise up to 15 % during a 12-month trial period.

[Men with type 2 diabetes and erectile dysfunction are a particular risk group for LUTS - results of the Witten Diabetes Survey]

INTRODUCTION

According to our data on 4 071 patients with type 2 diabetes, 65.5% of the men and 70.4% of the women complain of lower urinary tract symptoms (LUTS). That is twice as much as the normal population for the same age group. The most common symptom was overactive bladder (OAB). In patients with a diabetes-related complication such as retinopathy or nephropathy, the incidence for LUTS was about 20% higher than that in patients without complications, whereas in men with diabetes mellitus type 2 and erectile dysfunction (ED) the incidence for LUTS was 31.9% higher than without ED. We wanted to compare the incidence of LUTS in patients with type 2 diabetes and ED against patients without ED as well as women with type 2 diabetes.

RESULTS

Men with ED had a statistically significant longer history of diabetes, a higher HbA1c and increased serum creatinine compared to men without ED (p value <0.0001). The length of diabetes history was not statistically relevant compared to women with type 2 diabetes. However the HbA1c and serum creatinine were higher than those of the women from the data bank (p value <0.0001). Diabetic men with ED complained more often of urinary incontinence, urge incontinence and made more often use of incontinence pads (p value <0.0001). As for pollakisuria and nocturia the difference was not significant. 42.3% of type 2 diabetic patients with ED were diagnosed with OAB by their urologist or GP. That was significantly more than type 2 diabetic patients without ED and type 2 diabetic women (see graph). The same was true of stress incontinence, overflow incontinence and non-classified incontinence with the exception of faecal incontinence. Patients with type 2 diabetes and ED had to take drugs more often than type 2 diabetic men without ED and women with diabetes.

CONCLUSION

Amongst patients with type 2 diabetes, ED increases the risk of developing lower urinary tract disorders. Moreover it is connected with a higher HbA1c and a higher risk for LUTS, especially for OAB. The regular use of incontinence pads in every fourth patient with type 2 diabetes and erectile dysfunction demonstrates a high number of under-treated patients. Patients with type 2 diabetes and especially patients with type 2 diabetes AND erectile dysfunction represent a risk group that needs special attention and a special management plan from urologists and GPs.

Relation between changes in neural responsivity and reductions in desire to eat high-calorie foods following gastric bypass surgery

Reductions in reward-related (e.g. striatal) neural activation have been noted following obesity surgery. It has been speculated that these postoperative neural changes may be related to documented postoperative changes in food preferences; however, this relation has not been previously established. In this study, functional magnetic resonance imaging and rating scales were used to assess neural responsivity, desire to eat (i.e. wanting), and liking for high- and low-calorie food cues in 14 females one month pre- and one month post-Roux-en-Y gastric bypass (RYGB) surgery. Pre- to post-RYGB changes in all variables were assessed, and postoperative changes in neural responsivity were regressed on postoperative changes in desire to eat and liking of foods. Results revealed significant postoperative reductions in mesolimbic (e.g. striatal) neural responsivity, desire to eat (wanting), and liking for high- relative to low-calorie food cues. Postoperative reductions in mesolimbic responsivity were associated with postoperative reductions in wanting, but not liking, for high- versus low-calorie foods. Interestingly, reductions in food wanting were also related to reductions in inhibitory (e.g. dorsolateral prefrontal cortex) activation following RYGB. Results are consistent with the hypothesized delineation between wanting and liking, supporting the notion that wanting, but not liking, is processed through the dopaminergic reward pathway. Concurrent reductions in both reward-related and inhibitory activation-predicted reductions in desire to eat might suggest that less dietary inhibition was elicited to resist potential overconsumption as the anticipated reward value of high-calorie foods decreased following RYGB.