A Friction Testing-Bioreactor Device for Study of Synovial Joint Biomechanics, Mechanobiology, and Physical Regulation.

In primary osteoarthritis (OA), normal 'wear and tear' associated with aging inhibits the ability of cartilage to sustain its load-bearing and lubrication functions, fostering a deleterious physical environment. The frictional interactions of articular cartilage and synovium may influence joint homeostasis through tissue level wear and cellular mechanotransduction. To study these mechanical and mechanobiological processes, a device capable of replicating the motion of the joint is described. The friction testing device controls the delivery of reciprocal translating motion and normal load to two contacting biological counterfaces. This study adopts a synovium-on-cartilage configuration, and friction coefficient measurements are presented for tests performed in a phosphate-buffered saline (PBS) or synovial fluid (SF) bath. The testing was performed for a range of contact stresses, highlighting the lubricating properties of SF under high loads. This friction testing device can be used as a biomimetic bioreactor for studying the physical regulation of living joint tissues in response to applied physiologic loading associated with diarthrodial joint articulation.

The retinal pigment epithelium in Sorsby Fundus Dystrophy shows increased sensitivity to oxidative stress-induced degeneration.

Sorsby Fundus Dystrophy (SFD) is a rare inherited autosomal dominant macular degeneration caused by specific mutations in TIMP3. Patients with SFD present with pathophysiology similar to the more common Age-related Macular Degeneration (AMD) and loss of vision due to both choroidal neovascularization and geographic atrophy. Previously, it has been shown that RPE degeneration in AMD is due in part to oxidative stress. We hypothesized that similar mechanisms may be at play in SFD. The objective of this study was to evaluate whether mice carrying the S179C-Timp3 mutation, a variant commonly observed in SFD, showed increased sensitivity to oxidative stress. Antioxidant genes are increased at baseline in the RPE in SFD mouse models, but not in the retina. This suggests the presence of a pro-oxidant environment in the RPE in the presence of Timp3 mutations. To determine if the RPE of Timp3 mutant mice is more susceptible to degeneration when exposed to low levels of oxidative stress, mice were injected with low doses of sodium iodate. The RPE and photoreceptors in Timp3 mutant mice degenerated at low doses of sodium iodate, which had no effect in wildtype control mice. These studies suggest that TIMP3 mutations may result in a dysregulation of pro-oxidant-antioxidant homeostasis in the RPE, leading to RPE degeneration in SFD.

Immature bovine cartilage wear by fatigue failure and delamination.

This study investigated wear damage of immature bovine articular cartilage using reciprocal sliding of tibial cartilage strips against glass or cartilage. Experiments were conducted in physiological buffered saline (PBS) or mature bovine synovial fluid (SF). A total of 63 samples were tested, of which 47 exhibited wear damage due to delamination of the cartilage surface initiated in the middle zone, with no evidence of abrasive wear. There was no difference between the friction coefficient of damaged and undamaged samples, showing that delamination wear occurs even when friction remains low under a migrating contact area configuration. No difference was observed in the onset of damage or in the friction coefficient between samples tested in PBS or SF. The onset of damage occurred earlier when testing cartilage against glass versus cartilage against cartilage, supporting the hypothesis that delamination occurs due to fatigue failure of the collagen in the middle zone, since stiffer glass produces higher strains and tensile stresses under comparable loads. The findings of this study are novel because they establish that delamination of the articular surface, starting in the middle zone, may represent a primary mechanism of failure. Based on preliminary data, it is reasonable to hypothesize that delamination wear via subsurface fatigue failure is similarly the primary mechanism of human cartilage wear under normal loading conditions, albeit requiring far more cycles of loading than in immature bovine cartilage.

Reversible Loss of Hippocampal Function in a Mouse Model of Demyelination/Remyelination.

Demyelination of axons in the central nervous system (CNS) is a hallmark of multiple sclerosis (MS) and other demyelinating diseases. Cycles of demyelination, followed by remyelination, appear in the majority of MS patients and are associated with the onset and quiescence of disease-related symptoms, respectively. Previous studies in human patients and animal models have shown that vast demyelination is accompanied by wide-scale changes to brain activity, but details of this process are poorly understood. We used electrophysiological recordings and non-linear fluorescence imaging from genetically encoded calcium indicators to monitor the activity of hippocampal neurons during demyelination and remyelination over a period of 100 days. We found that synaptic transmission in CA1 neurons was diminished in vitro, and that neuronal firing rates in CA1 and the dentate gyrus (DG) were substantially reduced during demyelination in vivo, which partially recovered after a short remyelination period. This new approach allows monitoring how changes in synaptic transmission induced by cuprizone diet affect neuronal activity, and it can potentially be used to study the effects of therapeutic interventions in protecting the functionality of CNS neurons.

Cancer Antigen 72-4 for the Monitoring of Advanced Tumors of the Gastrointestinal Tract, Lung, Breast and Ovaries.

BACKGROUND: Cancer antigen CA72-4 is a tumor marker found to be elevated in a variety of human adenocarcinomas. Using the DRG TM-CA72-4, we quantified the elevation of CA72-4 compared to current United States Food And Drug Administration-approved tumor markers in various cancer types. MATERIALS AND METHODS: We conducted a prospective, single-center study enrolling 96 patients between March 2013 and August 2016 with different locally advanced, unresectable or metastatic cancer known to express CA72-4. Quantification of CA72-4 was performed according to the manufacturer's instructions using the DRG TM-CA72-4 enzyme-linked immunosorbent assay kit and the positivity rates were calculated. RESULTS: CA72-4 expression varied with tumoral site of origin, with the highest positivity rates found in pancreatic and ovarian malignancies. Correlation with clinical activity was also noted in some patients. CONCLUSION: CA72-4 may have a potential role as an adjunct to conventional biomarkers in disease monitoring of pancreatic, ovarian and colorectal carcinomas.

Adherence to thromboprophylaxis guidelines in elderly patients with hospital acquired venous thromboembolism: a case control study.

Venous thromboembolism (VTE) remains the number one preventable cause of hospital acquired mortality and morbidity. Each year, more than 12 million patients are at risk for VTE. The delivery of appropriate and timely VTE prophylaxis is still suboptimal in many healthcare institutions and can lead to increased readmissions, morbidity, as well as costs. To clarify this issue further, we performed a retrospective case control study at our institution to determine if poor adherence to the VTE prophylaxis guidelines could lead to an increase in VTE events. This was a retrospective case control study conducted at Winthrop-University Hospital from January 2007 to December 2011. Exclusion criteria were age < 18 and concurrent use of anticoagulant agents. Out of 322 cases of hospital acquired VTE or readmission with VTE within 30 days of discharge, 289 cases were selected for final analysis and paired with age and sex matched controls. Patients with a hospital acquired VTE or a readmission for VTE within 30 days of discharge had a significantly reduced rate of VTE prophylaxis when compared to the control group (54.0 vs. 79.2 %, p < 0.0001). The VTE risk assessment rate was also lower in the VTE group (77.2 vs. 85.5 %, p = 0.035). No difference was noted in the time to prophylaxis administration between the two groups (34.8 vs. 33.1 h, p = 0.34). Lastly, sequential compression device (SCD) documentation rate was not different: 68/116 (58.6 %) vs. 44/87 (50.6 %), p = 0.32, between the two arms. Low adherence to the American College of Chest Physician (ACCP) guidelines for VTE prophylaxis correlated with an increase in hospital acquired VTE. The decreased adherence may be linked to a lower VTE risk assessment rate, and other barriers including incorrect identification of contraindications to pharmacologic prophylaxis, and poor documentation of mechanical prophylaxis. There was no difference in SCD documentation rate and timeliness to administration of initial thromboprophylaxis between the two groups. Future studies are needed to reassess adherence and documentation rates after system-wide improvements.

Coronary Calcium Scanning in Patients after Adjuvant Radiation for Early Breast Cancer and Ductal Carcinoma In situ.

BACKGROUND AND OBJECTIVE: Radiation therapy (RT) is part of standard adjuvant treatment for breast cancer. Earlier studies demonstrated increased cardiac morbidity and mortality from this. Coronary Calcium scanning utilizing Multidetector Computed Tomography (MDCT) can detect early atherosclerosis in coronary arteries by identifying the amount of calcifications. In our study we employed these tools to detect occult atherosclerosis at least 5 years following breast RT. METHODS: We evaluated 20 asymptomatic patients, <60 years old, treated with RT at least 5 years prior to enrollment. Nine received RT to the left and 11 to the right chest wall. The median interval between RT and calcium scan was 8 years. All patients were treated with external beam RT using tangential technique. All patients underwent MDCT to compute volumetric and Agatston calcium scores of the coronary arteries and the aorta. RESULTS: Eleven patients had RT to the right chest wall, and eight had a calcium score of 0, while two had minimally elevated scores and one patient had a significantly elevated score. Meanwhile nine patients had RT to the left chest wall, and seven had a calcium score of 0. None had significantly elevated scores. In the aorta, 11 of 20 patients had a score of 0, while 8 of 20 had minimally elevated scores. CONCLUSION: In contrast to studies demonstrating increased cardiovascular morbidity, our pilot study did not detect significant occult atherosclerosis using MDCT of the coronaries and aorta of patients assessed five or more years following radiation for treatment of breast cancer.

Phase III, randomized, double-blind, placebo-controlled study of long-acting methylphenidate for cancer-related fatigue: North Central Cancer Treatment Group NCCTG-N05C7 trial.

PURPOSE: Fatigue is one of the most common symptoms experienced by patients with cancer. This trial was developed to evaluate the efficacy of long-acting methylphenidate for improving cancer-related fatigue and to assess its toxicities. PATIENTS AND METHODS: Adults with cancer were randomly assigned in a double-blinded manner to receive methylphenidate (target dose, 54 mg/d) or placebo for 4 weeks. The Brief Fatigue Inventory was the primary outcome measure, while secondary outcome measures included a Symptom Experience Diary (SED), the Short Form-36 (SF-36) Vitality Subscale, a linear analog self-assessment, the Pittsburgh Sleep Quality Index, and the Subject Global Impression of Change. RESULTS: In total, 148 patients were enrolled. Using an area under the serum concentration-time curve analysis, there was no evidence that methylphenidate, as compared with placebo, improved the primary end point of cancer-related fatigue in this patient population (P = .35). Comparisons of secondary end points, including clinically significant changes in quality-of-life variables and cancer-related fatigue change from baseline, were similarly negative. However, a subset analysis suggested that patients with more severe fatigue and/or with more advanced disease did have some fatigue improvement with methylphenidate (eg, in patients with stage III or IV disease, the mean improvement in usual fatigue was 19.7 with methylphenidate v 2.1 with placebo; P = .02). There was a significant difference in self-reported toxicities (SED), with increased levels of nervousness and appetite loss in the methylphenidate arm. CONCLUSION: This clinical trial was unable to support the primary prestudy hypothesis that the chosen long-acting methylphenidate product would decrease cancer-related fatigue.

A ketogenic diet as a potential novel therapeutic intervention in amyotrophic lateral sclerosis.

BACKGROUND: The cause of neuronal death in amyotrophic lateral sclerosis (ALS) is uncertain but mitochondrial dysfunction may play an important role. Ketones promote mitochondrial energy production and membrane stabilization. RESULTS: SOD1-G93A transgenic ALS mice were fed a ketogenic diet (KD) based on known formulations for humans. Motor performance, longevity, and motor neuron counts were measured in treated and disease controls. Because mitochondrial dysfunction plays a central role in neuronal cell death in ALS, we also studied the effect that the principal ketone body, D-beta-3 hydroxybutyrate (DBH), has on mitochondrial ATP generation and neuroprotection. Blood ketones were > 3.5 times higher in KD fed animals compared to controls. KD fed mice lost 50% of baseline motor performance 25 days later than disease controls. KD animals weighed 4.6 g more than disease control animals at study endpoint; the interaction between diet and change in weight was significant (p = 0.047). In spinal cord sections obtained at the study endpoint, there were more motor neurons in KD fed animals (p = 0.030). DBH prevented rotenone mediated inhibition of mitochondrial complex I but not malonate inhibition of complex II. Rotenone neurotoxicity in SMI-32 immunopositive motor neurons was also inhibited by DBH. CONCLUSION: This is the first study showing that diet, specifically a KD, alters the progression of the clinical and biological manifestations of the G93A SOD1 transgenic mouse model of ALS. These effects may be due to the ability of ketone bodies to promote ATP synthesis and bypass inhibition of complex I in the mitochondrial respiratory chain.

Cyclooxygenase (COX)-2 and COX-1 potentiate beta-amyloid peptide generation through mechanisms that involve gamma-secretase activity.

In previous studies we found that overexpression of the inducible form of cyclooxygenase, COX-2, in the brain exacerbated beta-amyloid (A beta) neuropathology in a transgenic mouse model of Alzheimer's disease. To explore the mechanism through which COX may influence A beta amyloidosis, we used an adenoviral gene transfer system to study the effects of human (h)COX-1 and hCOX-2 isoform expression on A beta peptide generation. We found that expression of hCOXs in human amyloid precursor protein (APP)-overexpressing (Chinese hamster ovary (CHO)-APPswe) cells or human neuroglioma (H4-APP751) cells resulting in 10-25 nM prostaglandin (PG)-E2 concentration in the conditioned medium coincided with an approximately 1.8-fold elevation of A beta-(1-40) and A beta-(1-42) peptide generation and an approximately 1.8-fold induction of the C-terminal fragment (CTF)-gamma cleavage product of the APP, an index of gamma-secretase activity. Treatment of APP-overexpressing cells with the non-selective COX inhibitor ibuprofen (1 microM, 48 h) or with the specific gamma-secretase inhibitor L-685,458 significantly attenuated hCOX-1- and hCOX-2-mediated induction of A beta peptide generation and CTF-gamma cleavage product formation. Based on this evidence, we next tested the hypothesis that COX expression might promote A beta peptide generation via a PG-E2-mediated mechanism. We found that exposure of CHO-APPswe or human embryonic kidney (HEK-APPswe) cells to PG-E2 (11-deoxy-PG-E2) at a concentration (10 nM) within the range of PG-E2 found in hCOX-expressing cells similarly promoted (approximately 1.8-fold) the generation of the CTF-gamma cleavage product of APP and commensurate A beta-(1-40) and A beta-(1-42) peptide elevation. The study suggests that expression of COXs may influence A beta peptide generation through mechanisms that involve PG-E2-mediated potentiation of gamma-secretase activity, further supporting a role for COX-2 and COX-1 in Alzheimer's disease neuropathology.