Selective activation of prodrugs in breast cancer using metabolic glycoengineering and the tetrazine ligation bioorthogonal reaction.

Increasing the selectivity of chemotherapies by converting them into prodrugs that can be activated at the tumour site decreases their side effects and allows discrimination between cancerous and non-cancerous cells. Herein, the use of metabolic glycoengineering (MGE) to selectively label MCF-7 breast cancer cells with tetrazine (Tz) activators for subsequent activation of prodrugs containing the trans-cyclooctene (TCO) moiety by a bioorthogonal reaction is demonstrated. Three novel Tz-modified monosaccharides, Ac4ManNTz 7, Ac4GalNTz 8, and Ac4SiaTz 16, were used for expression of the Tz activator within sialic-acid rich breast cancer cells' surface glycans through MGE. Tz expression on breast cancer cells (MCF-7) was evaluated versus the non-cancerous L929 fibroblasts showing a concentration-dependant effect and excellent selectivity with ≥35-fold Tz expression on the MCF-7 cells versus the non-cancerous L929 fibroblasts. Next, a novel TCO-N-mustard prodrug and a TCO-doxorubicin prodrug were analyzed in vitro on the Tz-bioengineered cells to probe our hypothesis that these could be activated via a bioorthogonal reaction. Selective prodrug activation and restoration of cytotoxicity were demonstrated for the MCF-7 breast cancer cells versus the non-cancerous L929 cells. Restoration of the parent drug's cytotoxicity was shown to be dependent on the level of Tz expression where the Ac4ManNTz 7 and Ac4GalNTz 8 derivatives (20 µM) lead to the highest Tz expression and full restoration of the parent drug's cytotoxicity. This work suggests the feasibility of combining MGE and tetrazine ligation for selective prodrug activation in breast cancer.

Bioorthogonal activation of prodrugs, for the potential treatment of breast cancer, using the Staudinger reaction.

Selective prodrug activation at a tumor site is crucial to maximise the efficiency of chemotherapy approaches and minimise side effects due to off-site activation. In this paper, a new prodrug activation strategy is reported based on the bioorthogonal Staudinger reaction. The feasibility of this prodrug activation strategy was initially demonstrated using 9-azido sialic acid 4 as a trigger and two novel triphenylphosphine-modified N-mustard-PRO 10 and doxorubicin-PRO 12 prodrugs in an HPLC-monitored release study. Then, the azide reporter group was introduced on cancer cells' surfaces through metabolic glycoengineering of sialic acid-rich surface glycans using azide-modified monosaccharides (9-azido sialic acid 4, tetra-O-acetylated-9-azido sialic acid 5 and tetra-O-acetyl azidomannosamine). Next, the N-mustard-PRO 10 and doxorubicin-PRO 12 prodrugs were employed in vitro with the bioengineered cells, and activation of the prodrugs, which allowed selective release of the cytotoxic moiety at the tumour cell, was assessed. Release of the parent drugs from the prodrugs was shown to be dependent on the level of metabolic labelling, where tetra-O-acetyl azidomannosamine allowed the highest level of azide reporter generation in tumor cells and led to full recovery of the parent cytotoxic drug's potency. The selectivity of azide expression on breast cancer MCF-7 cells versus normal fibroblast L929 cells was also probed, with the 9-azido sialic acid and tetra-O-acetylated-9-azido sialic acid showing ∼17-fold higher azide expression on the former. Taken together, these data demonstrate the feasibility of the Staudinger reaction for selective activation of prodrugs targeted to the MCF-7 breast cancer cells.

COVID-19 Severity Shifts the Cytokine Milieu Toward a Proinflammatory State in Egyptian Patients: A Cross-Sectional Study.

Despite extensive research to decipher the immunological basis of coronavirus disease (COVID-19), limited evidence on immunological correlates of COVID-19 severity from MENA region and Egypt was reported. In a single-center cross-sectional study, we have analyzed 25 cytokines that are related to immunopathologic lung injury, cytokine storm, and coagulopathy in plasma samples from 78 hospitalized Egyptian COVID-19 patients in Tanta University Quarantine Hospital and 21 healthy control volunteers between April 2020 and September 2020. The enrolled patients were divided into 4 categories based on disease severity, namely mild, moderate, severe, and critically ill. Interestingly, interleukin (IL)-1-α, IL-2Rα, IL-6, IL-8, IL-18, tumor necrosis factor-alpha (TNF-α), FGF1, CCL2, and CXC10 levels were significantly altered in severe and/or critically ill patients. Moreover, principal component analysis (PCA) demonstrated that severe and critically ill COVID-19 patients cluster based on specific cytokine signatures that distinguish them from mild and moderate COVID-19 patients. Specifically, levels of IL-2Rα, IL-6, IL-10, IL-18, TNF-α, FGF1, and CXCL10 largely contribute to the observed differences between early and late stages of COVID-19 disease. Our PCA showed that the described immunological markers positively correlate with high D-dimer and C-reactive protein levels and inversely correlate with lymphocyte counts in severe and critically ill patients. These data suggest a disordered immune regulation, particularly in severe and critically ill Egyptian COVID-19 patients, manifested as overactivated innate immune and dysregulated T-helper1 responses. Additionally, our study emphasizes the importance of cytokine profiling to identify potentially predictive immunological signatures of COVID-19 disease severity.

In Vivo Applications of Bioorthogonal Reactions: Chemistry and Targeting Mechanisms.

Bioorthogonal chemistry involves selective biocompatible reactions between functional groups that are not normally present in biology. It has been used to probe biomolecules in living systems, and has advanced biomedical strategies such as diagnostics and therapeutics. In this review, the challenges and opportunities encountered when translating in vitro bioorthogonal approaches to in vivo settings are presented, with a focus on methods to deliver the bioorthogonal reaction components. These methods include metabolic bioengineering, active targeting, passive targeting, and simultaneously used strategies. The suitability of bioorthogonal ligation reactions and bond cleavage reactions for in vivo applications is critically appraised, and practical considerations such as the optimum scheduling regimen in pretargeting approaches are discussed. Finally, we present our own perspectives for this area and identify what, in our view, are the key challenges that must be overcome to maximise the impact of these approaches.

Additive manufactured polymeric shock absorbers for automotive applications.

This paper deals with the use of shock absorbers, placed in the upper roof of vehicles, able to increase the safety of passengers during an impact event. Numerical impact analyses have been introduced to demonstrate the effectiveness of these shock absorbers by assessing the deformations, stress and energy dissipation capabilities in the different structural components of a vehicle, somehow related to the safety of passengers. Indeed, shock absorbers have been found to play an important role in relation to passengers' safety. The homologation limitations of the reference regulation have been taken into account: FMVSS No. 201U "internal head impact - passenger compartment". This regulation, actually, provides a fundamental parameter, known as HIC(d) - "Head Injury Criteria", which is strictly related to the injuries of the passenger head under impact conditions alongside the rigid components inside the vehicle. The HIC(d) threshold value, if exceeded, affects the final conformity test of a vehicle. Hence, to fall within the range of reliable values of the HIC(d), shock absorbers need to be adopted. In order to increase these shock absorbers efficiency, in terms of passenger safety, in compliance with the regulations, the possibility of production of such devices by additive manufacturing techniques has been assessed.

Validation of a lateral flow immunoassay for the detection of immunoglobulin G/immunoglobulin M antibodies to severe acute respiratory syndrome coronavirus 2-COVID-19 among symptomatic and asymptomatic high-risk OBGYN patients in selected hospitals in Olongapo city and Zambales – A multicenter prospective study / Philippine Journal of Obstetrics and Gynecology

Background/Introduction@#As the world face health-system shocks from COVID-19, Obstetrician-Gynecologists become perplexed by the uncertainties these bring to the vulnerable pregnant and gynecologic population. The country's capacity for diagnosis via RTPCR consists of only a tiny proportion of the population. With the intent of coming up with a less expensive fast point of care test kits, antibody-based lateral flow assays were developed. @*Aims and Objectives@#Determine the diagnostic accuracy of a lateral flow immunoassay for the detection IgM/IgG antibodies to SARS-CoV2 using RT-PCR as gold standard among symptomatic and asymptomatic high risk OBGYN population. @*Materials and Methods@#This is a multicenter cross-sectional prospective study performed on 147 asymptomatic and symptomatic high risk OBGYN patients who underwent both RTPCR and RAT. Test results were entered using a two by two table to compute for the sensitivity (Sn), specificity (Sp), positive and negative predictive value (PPV/NPV), likelihood ratios (LR) comparing RT-PCR with IgM/IgG using Medcalc statistical software. @*Results@#The RAT for IgG/IgM was not found to be sensitive in both groups. It was able to identify only one of the five patients who had COVID-19 based on RT-PCR. Moreover, the (PPV) was found to be only 20% since only one patient tested positive in the RAT for IgM/IgG that was also positive in the RT-PCR. The (LR+ and LR-) for the symptomatic group was close to 1 implying a slightly higher probability of a true positive compared to that of a false positive test and a negative test result given the absence of the disease respectively. (Sp) and (NPV) of the RAT for IgM/IgG is high for both groups. This means that RAT for IgM/IgG does well in identifying patients who truly do not have COVID-19. @*Conclusion@#With a very low sensitivity of 5% in this study, RAT for COVID-19 cannot be used for screening purposes.

Aliskiren and captopril improve cognitive deficits in poorly controlled STZ-induced diabetic rats via amelioration of the hippocampal P-ERK, GSK3ß, P-GSK3ß pathway.

Learning and memory deficits are obvious symptoms that develop over time in patients with poorly controlled diabetes. Hyperactivity of the renin-angiotensin system (RAS) is directly associated with ß-cell dysfunction and diabetic complications, including cognitive impairment. Here, we investigated the protective and molecular effects of two RAS modifiers, aliskiren; renin inhibitor and captopril; angiotensin converting enzyme inhibitor, on cognitive deficits in the rat hippocampus. Injection of low dose streptozotocin for 4 days resulted in type 1 diabetes. Then, poorly controlled diabetes was mimicked with ineffective daily doses of insulin for 4 weeks. The hyperglycaemia and pancreatic atrophy caused memory disturbance that were identifiable in behavioural tests, hippocampal neurodegeneration, and the following significant changes in the hippocampus, increases in the inflammatory marker interleukin 1ß, cholinesterase, the oxidative stress marker malondialdehyde and protein expression of phosphorylated extracellular-signal-regulated kinase and glycogen synthase kinase-3 beta versus decrease in the antioxidant reduced glutathione and protein expression of phosphorylated glycogen synthase kinase-3 beta. Blocking RAS with either drugs along with insulin amended all previously mentioned parameters. Aliskiren stabilized the blood glucose level and restored normal pancreatic integrity and hippocampal malondialdehyde level. Aliskiren showed superior protection against the hippocampal degeneration displayed in the earlier behavioural modification in the passive avoidance test, and the aliskiren group outperformed the control group in the novel object recognition test. We therefore conclude that aliskiren and captopril reversed the diabetic state and cognitive deficits in rats with poorly controlled STZ-induced diabetes through reducing oxidative stress and inflammation and modulating protein expression.

Curcumin dietary supplementation ameliorates disease phenotype in an animal model of Huntington's disease.

Huntington's disease (HD) has traditionally been described as a disorder purely of the brain; however, evidence indicates that peripheral abnormalities are also commonly seen. Among others, severe unintended body weight loss represents a prevalent and often debilitating feature of HD pathology, with no therapies available. It correlates with disease progression and significantly affects the quality of life of HD patients. Curcumin, a naturally occurring polyphenol with multiple therapeutic properties, has been validated to exert important beneficial effects under health conditions as well as in different pathological settings, including neurodegenerative and gastrointestinal (GI) disorders. Here, we investigated the potential therapeutic action that curcumin-supplemented diet may exert on central and peripheral dysfunctions in R6/2 mice, a well-characterized HD animal model which recapitulates some features of human pathology. Maintenance of normal motor function, protection from neuropathology and from GI dysfunction and preservation of GI emptying and conserved intestinal contractility, proved the beneficial role of life-long dietary curcumin in HD and corroborated the potential of the compound to be exploited to alleviate very debilitating symptoms associated with the disease.

Leucine partially protects muscle mass and function during bed rest in middle-aged adults.

BACKGROUND: Physical inactivity triggers a rapid loss of muscle mass and function in older adults. Middle-aged adults show few phenotypic signs of aging yet may be more susceptible to inactivity than younger adults. OBJECTIVE: The aim was to determine whether leucine, a stimulator of translation initiation and skeletal muscle protein synthesis (MPS), can protect skeletal muscle health during bed rest. DESIGN: We used a randomized, double-blind, placebo-controlled trial to assess changes in skeletal MPS, cellular signaling, body composition, and skeletal muscle function in middle-aged adults (n = 19; age ± SEM: 52 ± 1 y) in response to leucine supplementation (LEU group: 0.06 g ∙ kg(-1) ∙ meal(-1)) or an alanine control (CON group) during 14 d of bed rest. RESULTS: Bed rest decreased postabsorptive MPS by 30% ± 9% (CON group) and by 10% ± 10% (LEU group) (main effect for time, P < 0.05), but no differences between groups with respect to pre-post changes (group × time interactions) were detected for MPS or cell signaling. Leucine protected knee extensor peak torque (CON compared with LEU group: -15% ± 2% and -7% ± 3%; group × time interaction, P < 0.05) and endurance (CON compared with LEU: -14% ± 3% and -2% ± 4%; group × time interaction, P < 0.05), prevented an increase in body fat percentage (group × time interaction, P < 0.05), and reduced whole-body lean mass loss after 7 d (CON compared with LEU: -1.5 ± 0.3 and -0.8 ± 0.3 kg; group × time interaction, P < 0.05) but not 14 d (CON compared with LEU: -1.5 ± 0.3 and -1.0 ± 0.3 kg) of bed rest. Leucine also maintained muscle quality (peak torque/kg leg lean mass) after 14 d of bed-rest inactivity (CON compared with LEU: -9% ± 2% and +1% ± 3%; group × time interaction, P < 0.05). CONCLUSIONS: Bed rest has a profoundly negative effect on muscle metabolism, mass, and function in middle-aged adults. Leucine supplementation may partially protect muscle health during relatively brief periods of physical inactivity. This trial was registered at clinicaltrials.gov as NCT00968344.

Understanding the role of Notch in osteosarcoma.

The Notch pathway has been described as an oncogene in osteosarcoma, but the myriad functions of all the members of this complex signaling pathway, both in malignant cells and nonmalignant components of tumors, make it more difficult to define Notch as simply an oncogene or a tumor suppressor. The cell-autonomous behaviors caused by Notch pathway manipulation may vary between cell lines but can include changes in proliferation, migration, invasiveness, oxidative stress resistance, and expression of markers associated with stemness or tumor-initiating cells. Beyond these roles, Notch signaling also plays a vital role in regulating tumor angiogenesis and vasculogenesis, which are vital aspects of osteosarcoma growth and behavior in vivo. Further, osteosarcoma cells themselves express relatively low levels of Notch ligand, making it likely that nonmalignant cells, especially endothelial cells and pericytes, are the major source of Notch activation in osteosarcoma tumors in vivo and in patients. As a result, Notch pathway expression is not expected to be uniform across a tumor but likely to be highest in those areas immediately adjacent to blood vessels. Therapeutic targeting of the Notch pathway is likewise expected to be complicated. Most pharmacologic approaches thus far have focused on inhibition of gamma secretase, a protease of the presenilin complex. This enzyme, however, has numerous other target proteins that would be expected to affect osteosarcoma behavior, including CD44, the WNT/ß-catenin pathway, and Her-4. In addition, Notch plays a vital role in tissue and organ homeostasis in numerous systems, and toxicities, especially GI intolerance, have limited the effectiveness of gamma secretase inhibitors. New approaches are in development, and the downstream targets of Notch pathway signaling also may turn out to be good targets for therapy. In summary, a full understanding of the complex functions of Notch in osteosarcoma is only now unfolding, and this deeper knowledge will help position the field to better utilize novel therapies as they are developed.

Dietary protein distribution positively influences 24-h muscle protein synthesis in healthy adults.

The RDA for protein describes the quantity that should be consumed daily to meet population needs and to prevent deficiency. Protein consumption in many countries exceeds the RDA; however, intake is often skewed toward the evening meal, whereas breakfast is typically carbohydrate rich and low in protein. We examined the effects of protein distribution on 24-h skeletal muscle protein synthesis in healthy adult men and women (n = 8; age: 36.9 ± 3.1 y; BMI: 25.7 ± 0.8 kg/m2). By using a 7-d crossover feeding design with a 30-d washout period, we measured changes in muscle protein synthesis in response to isoenergetic and isonitrogenous diets with protein at breakfast, lunch, and dinner distributed evenly (EVEN; 31.5 ± 1.3, 29.9 ± 1.6, and 32.7 ± 1.6 g protein, respectively) or skewed (SKEW; 10.7 ± 0.8, 16.0 ± 0.5, and 63.4 ± 3.7 g protein, respectively). Over 24-h periods on days 1 and 7, venous blood samples and vastus lateralis muscle biopsy samples were obtained during primed (2.0 µmol/kg) constant infusion [0.06 µmol/(kg⋅min)] of l-[ring-(13)C6]phenylalanine. The 24-h mixed muscle protein fractional synthesis rate was 25% higher in the EVEN (0.075 ± 0.006%/h) vs. the SKEW (0.056 ± 0.006%/h) protein distribution groups (P = 0.003). This pattern was maintained after 7 d of habituation to each diet (EVEN vs. SKEW: 0.077 ± 0.006 vs. 0.056 ± 0.006%/h; P = 0.001). The consumption of a moderate amount of protein at each meal stimulated 24-h muscle protein synthesis more effectively than skewing protein intake toward the evening meal.

Factors associated with a diabetes diagnosis and late diabetes diagnosis for males and females.

AIMS: To examine the factors associated with diabetes, a late diabetes diagnosis, and whether these factors are different for males and females. METHODS: Cross-sectional study including 7101 individuals aged ≥25 years in Newfoundland and Labrador, Canada (466 with diabetes; 332 diagnosed late). Logistic regression analysis was used to determine the factors associated with a diabetes diagnosis and late diabetes diagnosis. RESULTS: For males, overweight/obesity (HR, 1.35; 95% CI, 1.06-1.72) was positively associated with diabetes while being a regular/occasional drinker (HR, 0.53; 95% CI, 0.32-0.88) was inversely associated with diabetes. Living in a rural area (HR, 1.47; 95% CI, 1.01-2.15), receiving social assistance (HR, 2.80; 95% CI, 1.52-5.15), having poor self perceived health (HR, 2.06; 95% CI, 1.32-3.21), and considering most days stressful (HR, 1.45; 95% CI, 1.01-2.10) were positively associated with diabetes for females. No factors were significantly associated with a late diabetes diagnosis for males. Having a low education (OR, 0.33; 95% CI, 0.11-0.99) was inversely associated with a late diabetes diagnosis for females. CONCLUSIONS: Different factors are associated with diabetes for males and females. Disadvantaged females appear to be at the greatest risk. The factors associated with a late diabetes diagnosis were also different for males and females. Females with lower education levels are diagnosed with diabetes earlier than females with higher education levels. Certain risk factors appear to impact males and females differently and more research is needed on how males and females develop diabetes and when they are diagnosed.

Understanding the Biology of Bone Sarcoma from Early Initiating Events through Late Events in Metastasis and Disease Progression.

The two most common primary bone malignancies, osteosarcoma (OS), and Ewing sarcoma (ES), are both aggressive, highly metastatic cancers that most often strike teens, though both can be found in younger children and adults. Despite distinct origins and pathogenesis, both diseases share several mechanisms of progression and metastasis, including neovascularization, invasion, anoikis resistance, chemoresistance, and evasion of the immune response. Some of these processes are well-studies in more common carcinoma models, and the observation from adult diseases may be readily applied to pediatric bone sarcomas. Neovascularization, which includes angiogenesis and vasculogenesis, is a clear example of a process that is likely to be similar between carcinomas and sarcomas, since the responding cells are the same in each case. Chemoresistance mechanisms also may be similar between other cancers and the bone sarcomas. Since OS and ES are mesenchymal in origin, the process of epithelial-to-mesenchymal transition is largely absent in bone sarcomas, necessitating different approaches to study progression and metastasis in these diseases. One process that is less well-studied in bone sarcomas is dormancy, which allows micrometastatic disease to remain viable but not growing in distant sites - typically the lungs - for months or years before renewing growth to become overt metastatic disease. By understanding the basic biology of these processes, novel therapeutic strategies may be developed that could improve survival in children with OS or ES.

Differential effect of long-term drug selection with doxorubicin and vorinostat on neuroblastoma cells with cancer stem cell characteristics.

Numerous studies have confirmed that cancer stem cells (CSCs) are more resistant to chemotherapy; however, there is a paucity of data exploring the effect of long-term drug treatment on the CSC sub-population. The purpose of this study was to investigate whether long-term doxorubicin treatment could expand the neuroblastoma cells with CSC characteristics and histone acetylation could affect stemness gene expression during the development of drug resistance. Using n-myc amplified SK-N-Be(2)C and non-n-myc amplified SK-N-SH human neuroblastoma cells, our laboratory generated doxorubicin-resistant cell lines in parallel over 1 year; one cell line intermittently treated with the histone deacetylase inhibitor (HDACi) vorinostat and the other without exposure to HDACi. Cells' sensitivity to chemotherapeutic drugs, the ability to form tumorspheres, and capacity for in vitro invasion were examined. Cell-surface markers and side populations (SPs) were analyzed using flow cytometry. Differentially expressed stemness genes were identified through whole genome analysis and confirmed with real-time PCR. Our results indicated that vorinostat increased the sensitivity of only SK-N-Be(2)C-resistant cells to chemotherapy, made cells lose the ability to form tumorspheres, and reduced in vitro invasion and the SP percentage. CD133 was not enriched in doxorubicin-resistant or vorinostat-treated doxorubicin-resistant cells. Nine stemness-linked genes (ABCB1, ABCC4, LMO2, SOX2, ERCC5, S100A10, IGFBP3, TCF3, and VIM) were downregulated in vorinostat-treated doxorubicin-resistant SK-N-Be(2)C cells relative to doxorubicin-resistant cells. A sub-population of cells with CSC characteristics is enriched during prolonged drug selection of n-myc amplified SK-N-Be(2)C neuroblastoma cells. Vorinostat treatment affects the reversal of drug resistance in SK-N-Be(2)C cells and may be associated with downregulation of stemness gene expression. This work may be valuable for clinicians to design treatment protocols specific for different neuroblastoma patients.

Sex differences in all-cause and cardiovascular mortality, hospitalization for individuals with and without diabetes, and patients with diabetes diagnosed early and late.

OBJECTIVE: To compare risk of all-cause mortality, cardiovascular disease (CVD) mortality, acute myocardial infarction (AMI) mortality, stroke mortality, and hospitalizations for males and females with and without diabetes and those with diabetes diagnosed early and late. RESEARCH DESIGN AND METHODS: We conducted a population-based retrospective cohort study including 73,783 individuals aged 25 years or older in Newfoundland and Labrador, Canada (15,152 with diabetes; 9,517 with late diagnoses). RESULTS: Males and females with diabetes had an increased risk of all-cause mortality, CVD mortality, AMI mortality, and CVD hospitalizations compared with individuals without diabetes, and the risk was stronger in females than in males. For females, risks of all-cause mortality (hazard ratio [HR] 1.85 [95% CI 1.74-1.96]) and CVD hospitalizations (2.57 [2.24-2.94]) were significantly higher compared with their male counterparts (1.59 [1.51-1.69] and 1.92 [1.72-2.14]). Females with diabetes diagnosed late had an increased risk of CVD mortality (6.54 [4.80-8.91]) and CVD hospitalizations (5.22 [4.31-6.33]) compared with females without diabetes, and both were significantly higher compared with their male counterparts (3.44 [2.47-4.79]) and (3.33 [2.80-3.95]). CONCLUSIONS: Females with diabetes have a greater risk of mortality than males with diabetes. CVD has a greater impact on females with diabetes than males, especially when diagnosed at a later stage. Different management strategies should be considered for males and females and those with early and late diagnoses of diabetes.

Longitudinal evaluation of mouse hind limb bone loss after spinal cord injury using novel, in vivo, methodology.

Spinal cord injury (SCI) is often accompanied by osteoporosis in the sublesional regions of the pelvis and lower extremities, leading to a higher frequency of fractures. As these fractures often occur in regions that have lost normal sensory function, the patient is at a greater risk of fracture-dependent pathologies, including death. SCI-dependent loss in both bone mineral density (BMD, grams/cm2) and bone mineral content (BMC, grams) has been attributed to mechanical disuse, aberrant neuronal signaling and hormonal changes. The use of rodent models of SCI-induced osteoporosis can provide invaluable information regarding the mechanisms underlying the development of osteoporosis following SCI as well as a test environment for the generation of new therapies. Mouse models of SCI are of great interest as they permit a reductionist approach to mechanism-based assessment through the use of null and transgenic mice. While such models have provided important data, there is still a need for minimally-invasive, reliable, reproducible, and quantifiable methods in determining the extent of bone loss following SCI, particularly over time and within the same cohort of experimental animals, to improve diagnosis, treatment methods, and/or prevention of SCI-induced osteoporosis. An ideal method for measuring bone density in rodents would allow multiple, sequential (over time) exposures to low-levels of X-ray radiation. This study describes the use of a new whole-animal scanner, the IVIS Lumina XR (Caliper Instruments) that can be used to provide low-energy (1-3 milligray (mGy)) high-resolution, high-magnification X-ray images of mouse hind limb bones over time following SCI. Significant bone density loss was seen in the tibiae of mice by 10 days post-spinal transection when compared to uninjured, age-matched control (naïve) mice (13% decrease, p < 0.0005). Loss of bone density in the distal femur was also detectable by day 10 post-SCI, while a loss of density in the proximal femur was not detectable until 40 days post injury (7% decrease, p < 0.05). SCI-dependent loss of mouse femur density was confirmed post-mortem through the use of Dual-energy X-ray Absorptiometry (DXA), the current "gold standard" for bone density measurements. We detect a 12% loss of BMC in the femurs of mice at 40 days post-SCI using the IVIS Lumina XR. This compares favorably with a previously reported BMC loss of 13.5% by Picard and colleagues who used DXA analysis on mouse femurs post-mortem 30 days post-SCI (9). Our results suggest that the IVIS Lumina XR provides a novel, high-resolution/high-magnification method for performing long-term, longitudinal measurements of hind limb bone density in the mouse following SCI.

Does higher continuity of family physician care reduce hospitalizations in elderly people with diabetes?

The objective of this study was to investigate the relationship between continuity of family physician (FP) care and inpatient hospitalizations in elderly people with diabetes who have universally-insured health care. We constructed a population-based retrospective cohort study using a sample of 1143 people aged 65 years or older with newly diagnosed diabetes who were selected from a longitudinal surveillance database in the province of Newfoundland and Labrador (NL), Canada. Continuity of FP care was estimated by 3 chronological indices (Continuity of Care [COC], Usual Provider Continuity [UPC], and Sequential Continuity [SECON]) using administrative physician claims data. Age, sex, number of chronic conditions, and income were used as control variables. People with high continuity had lower crude rates of hospitalization than those with lower continuity. Log-linear regression analysis showed that higher continuity was associated with decreased rates of hospitalization in an unadjusted model [rate ratio (95% confidence interval)]; COC: 0.73 (0.61-0.86); UPC: 0.71 (0.59-0.86); SECON: 0.64 (0.52-0.78), and after adjusting for control variables; COC: 0.82 (0.69-0.97); UPC: 0.82 (0.68-0.98); SECON: 0.75 (0.61-0.91). Other significant predictors of reduced hospitalizations were female sex, fewer chronic conditions, and higher income. The findings suggest that high levels of continuity of FP care are associated with reduced hospitalizations in elderly people with diabetes within a universally-insured health care system.

A resilience intervention in African American adults with type 2 diabetes: a pilot study of efficacy.

PURPOSE: The purpose of this pilot study was to determine the feasibility of offering the authors' Diabetes Coaching Program (DCP), adapted for African Americans, in a sample of African American adults with type 2 diabetes. METHODS: The study used a 1-group, pretest-posttest design to test the acceptance and potential effectiveness of the DCP. Subjects were a convenience sample of 16 African Americans (8 women, 8 men) with type 2 diabetes; 12 subjects (6 women, 6 men) completed the program. The DCP included 4 weekly class sessions devoted to resilience education and diabetes self-management, followed by 8 biweekly support group meetings. Psychosocial process variables (resilience, coping strategies, diabetes empowerment) and proximal (perceived stress, depressive symptoms, diabetes self-management) and distal outcomes (body mass index [BMI], fasting blood glucose, HbA1C, lipidemia, blood pressure) were assessed at baseline and at 6 months after study entry. Qualitative data were collected at 8 months via a focus group conducted to examine the acceptability of the DCP. RESULTS: Preliminary paired t tests indicated statistically significant improvements in diabetes empowerment, diabetes self-management, BMI, HbA1c, total cholesterol, low-density lipoprotein cholesterol, and systolic and diastolic blood pressure. Medium to large effect sizes were reported. Resilience, perceived stress, fasting blood glucose, and high-density lipoprotein cholesterol improved, but changes were not statistically significant. Focus group data confirmed that participants held positive opinions regarding the DCP and follow-up support group sessions, although they suggested an increase in program length from 4 to 8 weeks. CONCLUSIONS: The pilot study documented the feasibility and potential effectiveness of the DCP to enhance diabetes empowerment, diabetes self-management, and reductions in the progression of obesity, type 2 diabetes, and cardiovascular disease in the African American community. Randomized experimental designs are needed to confirm these findings.

Quantification methods in contrast echocardiography.

New technologies and the availability of new echo-contrast agents have resulted in advances of diagnostic and prognostic indications of left ventricular opacification (LVO) and myocardial perfusion. The clinical diagnostic value of ultrasound contrast media for LVO and its impact on the clinical decision-making process has been demonstrated in several studies. Recent research aims at developing new quantitative software to improve the delineation of the endocardial border, to assess 3D myocardial perfusion for more accurate regional/global LV function measurements, and to evaluate 4D intra-cardiac flow dynamics. Furthermore, a general consensus has been reached on the incremental value of myocardial contrast echocardiography (MCE) for obtaining additional information in both chronic and acute coronary artery disease (CAD) patients and on the possibility to make quantitative measurements of microvascular damage. Q-contrast is a new software system which provides quantitative measurements to generate parametric images of microcirculatory flow. In a research project including 120 patients, Q-contrast software has been tested to assess the role of contrast in AMI (Acute Myocardial Infarction Contrast Imaging (A.M.I.C.I. Study); good agreement between parametric MCE and SPECT has been found. Preliminary results further confirm that quantitative MCE may provide additional clinical value over qualitative information for the assessment of LV function and of the effects of coronary artery disease on the myocardial microcirculation (viability, ischemia or infarct).

Prenatal environmental tobacco smoke exposure promotes adult atherogenesis and mitochondrial damage in apolipoprotein E-/- mice fed a chow diet.

BACKGROUND: Environmental tobacco smoke (ETS) exposure is recognized as a cardiovascular disease risk factor; however, the impact of prenatal ETS exposure on adult atherogenesis has not been examined. We hypothesized that in utero ETS exposure promotes adult atherosclerotic lesion formation and mitochondrial damage. METHODS AND RESULTS: Atherosclerotic lesion formation, mitochondrial DNA damage, antioxidant activity, and oxidant load were determined in cardiovascular tissues from adult apolipoprotein E-/- mice exposed to either filtered air or ETS in utero and fed a standard chow diet (4.5% fat) from weaning until euthanasia. All parameters were significantly altered in male mice exposed in utero to ETS. CONCLUSIONS: These data support the hypothesis that prenatal ETS exposure is sufficient to promote adult cardiovascular disease development.