Survival of Clostridioides difficile spores in thermal and chemo-thermal laundering processes and influence of the exosporium on their adherence to cotton bed sheets.

Clostridioides difficile spores were previously demonstrated to survive industrial laundering. Understanding interactions between heat, disinfectants and soiling (e.g. bodily fluids) affecting C. difficile spore survival could inform the optimization of healthcare laundry processes. Reducing spore attachment to linen could also enhance laundering efficacy. This study aimed to compare the sensitivity of C. difficile spores to heat and detergent, with and without soiling and to investigate adherence to cotton. Survival of C. difficile spores exposed to industrial laundering temperatures (71-90°C), reference detergent and industrial detergent was quantified with and without soiling. The adherence to cotton after 0 and 24 h air drying was determined with the exosporium of C. difficile spores partially or fully removed. Clostridioides difficile spores were stable at 71°C for 20 min (≤0·37 log10 reduction) while 90°C was sporicidal (3 log10 reduction); soiling exerted a protective effect. Industrial detergent was more effective at 71°C compared to 25°C (2·81 vs 0·84 log10 reductions), however, specifications for sporicidal activity (>3 log10 reduction) were not met. Clostridioides difficile spores increasingly adhered to cotton over time, with 49% adherence after 24 h. Removal of the exosporium increased adherence by 19-23% compared to untreated spores. Further understanding of the role of the exosporium in attachment to cotton could enhance spore removal and aid decontamination of linen.

Residual neuromuscular blockade in the ICU: a prospective observational study and national survey.

Residual neuromuscular blockade is associated with significant morbidity. It has been widely studied in anaesthesia; however, the incidence of residual neuromuscular blockade in patients managed in the ICU is unknown. We conducted a prospective observational study in a tertiary ICU to determine the incidence of residual neuromuscular blockade using quantitative accelerographic monitoring. We tested for residual neuromuscular blockade (defined as a train-of-four ratio < 0.9) before cessation of sedation in anticipation of tracheal extubation. We also surveyed 16 other ICUs in New Zealand to determine their use of neuromuscular monitoring. A total of 191 patients were included in the final analysis. The incidence (95%CI) of residual neuromuscular blockade was 43% (36-50%), with a similar incidence observed in non-postoperative and postoperative patients. There was a lower risk of residual neuromuscular blockade with atracurium than rocuronium (risk ratio (95%CI) of 0.39 (0.12-0.78)) and a higher risk with pancuronium than rocuronium (1.59 (1.06-2.49)). Our survey shows that, in New Zealand ICUs, monitoring of neuromuscular function is rarely carried out before tracheal extubation. When neuromuscular monitoring is undertaken, it is based on individual clinician suspicion and performed using qualitative measurements. No ICU reported using a quantitative monitor or a clinical guideline. The results demonstrate a high incidence of residual neuromuscular blockade in our ICU patients and identify the type of neuromuscular blocking drug as a possible risk factor. Monitoring neuromuscular function before tracheal extubation is not currently the standard of care in New Zealand ICUs. These data suggest that residual neuromuscular blockade may be an under-recognised problem in ICU practice.

Activation of RyR2 by class I kinase inhibitors.

BACKGROUND AND PURPOSE: Kinase inhibitors are a common treatment for cancer. Class I kinase inhibitors that target the ATP-binding pocket are particularly prevalent. Many of these compounds are cardiotoxic and can cause arrhythmias. Spontaneous release of Ca2+ via cardiac ryanodine receptors (RyR2), through a process termed store overload-induced Ca2+ release (SOICR), is a common mechanism underlying arrhythmia. We explored whether class I kinase inhibitors could modify the activity of RyR2 and trigger SOICR to determine if this contributes to the cardiotoxic nature of these compounds. EXPERIMENTAL APPROACH: The impact of class I and II kinase inhibitors on SOICR was studied in HEK293 cells and ventricular myocytes using single-cell Ca2+ imaging. A specific effect on RyR2 was confirmed using single channel recordings. Ventricular myocytes were also used to determine if drug-induced changes in SOICR could be reversed using anti-SOICR agents. KEY RESULTS: Class I kinase inhibitors increased the propensity of SOICR. Single channel recording showed that this was due to a specific effect on RyR2. Class II kinase inhibitors decreased the activity of RyR2 at the single channel level but had little effect on SOICR. The promotion of SOICR mediated by class I kinase inhibitors could be reversed using the anti-SOICR agent VK-II-86. CONCLUSIONS AND IMPLICATIONS: Part of the cardiotoxicity of class I kinase inhibitors can be assigned to their effect on RyR2 and increase in SOICR. Compounds with anti-SOICR activity may represent an improved treatment option for patients.

In Vitro Maturation and In Vivo Integration and Function of an Engineered Cell-Seeded Disc-like Angle Ply Structure (DAPS) for Total Disc Arthroplasty.

Total disc replacement with an engineered substitute is a promising avenue for treating advanced intervertebral disc disease. Toward this goal, we developed cell-seeded disc-like angle ply structures (DAPS) and showed through in vitro studies that these constructs mature to match native disc composition, structure, and function with long-term culture. We then evaluated DAPS performance in an in vivo rat model of total disc replacement; over 5 weeks in vivo, DAPS maintained their structure, prevented intervertebral bony fusion, and matched native disc mechanical function at physiologic loads in situ. However, DAPS rapidly lost proteoglycan post-implantation and did not integrate into adjacent vertebrae. To address this, we modified the design to include polymer endplates to interface the DAPS with adjacent vertebrae, and showed that this modification mitigated in vivo proteoglycan loss while maintaining mechanical function and promoting integration. Together, these data demonstrate that cell-seeded engineered discs can replicate many characteristics of the native disc and are a viable option for total disc arthroplasty.

Opportunity for interprofessional collaborative care-findings from a sample of federally qualified health center patients in the Midwest.

OBJECTIVES: Federally qualified health centers (FQHCs) frequently serve more socio-economically disadvantaged populations; existing literature suggests that underserved groups are more likely to experience various chronic physical and mental health conditions. FQHC patients may have significant needs for various specialty services that are beyond common FQHC providers. This study examines chronic condition prevalence, healthcare satisfaction, and use of multiprovider services in a Midwest FQHC patient population. We also evaluated the potential of interprofessional collaborative practices in FQHC settings. STUDY DESIGN: Cross-sectional study. METHODS: A total of 232 participants were recruited prior to or immediately after their scheduled clinic visit within an FQHC located on the fringes of an urban area. Respondents were invited to complete a brief questionnaire and grant access to their electronic medical records. RESULTS: Nearly half of participants were covered by Medicaid, private insurance carriers (19.4%), or Medicare (17.7%). The most prevalent chronic conditions included diabetes, depression, anxiety, and chronic pain. Almost half (46.6%) of participants were seen by two or three providers; 20% had 7+ office visits in the last year. While 35.3% reported health dissatisfaction, 30.6% reported health satisfaction. When asked if they were satisfied with their health care, nearly 70% reported satisfaction with health care, while only 4.7% reported healthcare dissatisfaction. CONCLUSIONS: The authors of this study recommend an interprofessional collaborate healthcare model be explored to address the complex and multifaceted healthcare needs of this population. Future research in this area should prospectively examine the utility of monitoring patient satisfaction in a collaborative practice setting.

Comparison of bacterial attachment to platelet bags with and without preconditioning with plasma.

BACKGROUND AND OBJECTIVES: Canadian Blood Services produces apheresis and buffy coat pooled platelet concentrates (PCs) stored in bags produced by two different manufacturers (A and B, respectively), both made of polyvinyl chloride-butyryl trihexyl citrate. This study was aimed at comparing Staphylococcus epidermidis adhesion to the inner surface of both bag types in the presence or absence of plasma factors. MATERIALS AND METHODS: Sets (N = 2-6) of bags type A and B were left non-coated (control) or preconditioned with platelet-rich, platelet-poor or defibrinated plasma (PRP, PPP and DefibPPP, respectively). Each bag was inoculated with a 200-ml S. epidermidis culture adjusted to 0·5 colony-forming units/ml. Bags were incubated under platelet storage conditions for 7 days. After culture removal, bacteria attached to the plastic surface were either dislodged by sonication for bacterial quantification or examined in situ by scanning electron microscopy (SEM). RESULTS: Higher bacterial adhesion was observed to preconditioned PC bags than control containers for both bag types (P < 0·0001). Bacterial attachment to preconditioned bags was confirmed by SEM. Bacteria adhered equally to both types of containers in the presence of PRP, PPP and DefibPPP residues (P > 0·05). By contrast, a significant increase in bacterial adherence was observed to type A bags compared with type B bags in the absence of plasma (P < 0·05) [Correction added on 16 June 2017, after first online publication: this sentence has been corrected]. CONCLUSION: The ability of S. epidermidis to adhere to preconditioned platelet collection bags depends on the presence of plasma factors. Future efforts should be focused on reducing plasma proteins' attachment to platelet storage containers to decrease subsequent bacterial adhesion.

PAI-1 gain-of-function genotype, factors increasing PAI-1 levels, and airway obstruction: The GALA II Cohort.

BACKGROUND: PAI-1 gain-of-function variants promote airway fibrosis and are associated with asthma and with worse lung function in subjects with asthma. OBJECTIVE: We sought to determine whether the association of a gain-of-function polymorphism in plasminogen activator inhibitor-1 (PAI-1) with airway obstruction is modified by asthma status, and whether any genotype effect persists after accounting for common exposures that increase PAI-1 level. METHODS: We studied 2070 Latino children (8-21y) with genotypic and pulmonary function data from the GALA II cohort. We estimated the relationship of the PAI-1 risk allele with FEV1/FVC by multivariate linear regression, stratified by asthma status. We examined the association of the polymorphism with asthma and airway obstruction within asthmatics via multivariate logistic regression. We replicated associations in the SAPPHIRE cohort of African Americans (n=1056). Secondary analysis included the effect of the at-risk polymorphism on postbronchodilator lung function. RESULTS: There was an interaction between asthma status and the PAI-1 polymorphism on FEV1 /FVC (P=.03). The gain-of-function variants, genotypes (AA/AG), were associated with lower FEV1 /FVC in subjects with asthma (ß=-1.25, CI: -2.14,-0.35, P=.006), but not in controls. Subjects with asthma and the AA/AG genotypes had a 5% decrease in FEV1 /FVC (P<.001). In asthmatics, the risk genotype (AA/AG) was associated with a 39% increase in risk of clinically relevant airway obstruction (OR=1.39, CI: 1.01, 1.92, P=.04). These associations persisted after exclusion of factors that increase PAI-1 including tobacco exposure and obesity. CONCLUSIONS AND CLINICAL RELEVANCE: The decrease in the FEV1 /FVC ratio associated with the risk genotype was modified by asthma status. The genotype increased the odds of airway obstruction by 75% within asthmatics only. As exposures known to increase PAI-1 levels did not mitigate this association, PAI-1 may contribute to airway obstruction in the context of chronic asthmatic airway inflammation.

A large animal model that recapitulates the spectrum of human intervertebral disc degeneration.

OBJECTIVE: The objective of this study was to establish a large animal model that recapitulates the spectrum of intervertebral disc degeneration that occurs in humans and which is suitable for pre-clinical evaluation of a wide range of experimental therapeutics. DESIGN: Degeneration was induced in the lumbar intervertebral discs of large frame goats by either intradiscal injection of chondroitinase ABC (ChABC) over a range of dosages (0.1U, 1U or 5U) or subtotal nucleotomy. Radiographs were used to assess disc height changes over 12 weeks. Degenerative changes to the discs and endplates were assessed via magnetic resonance imaging (MRI), semi-quantitative histological grading, microcomputed tomography (µCT), and measurement of disc biomechanical properties. RESULTS: Degenerative changes were observed for all interventions that ranged from mild (0.1U ChABC) to moderate (1U ChABC and nucleotomy) to severe (5U ChABC). All groups showed progressive reductions in disc height over 12 weeks. Histological scores were significantly increased in the 1U and 5U ChABC groups. Reductions in T2 and T1ρ, and increased Pfirrmann grade were observed on MRI. Resorption and remodeling of the cortical boney endplate adjacent to ChABC-injected discs also occurred. Spine segment range of motion (ROM) was greater and compressive modulus was lower in 1U ChABC and nucleotomy discs compared to intact. CONCLUSIONS: A large animal model of disc degeneration was established that recapitulates the spectrum of structural, compositional and biomechanical features of human disc degeneration. This model may serve as a robust platform for evaluating the efficacy of therapeutics targeted towards varying degrees of disc degeneration.

Thrombolysis by chemically modified coagulation factor Xa.

UNLABELLED: Essentials Factor Xa (FXa) acquires cleavage-mediated tissue plasminogen activator (tPA) cofactor activity. Recombinant (r) tPA is the predominant thrombolytic drug, but it may cause systemic side effects. Chemically modified, non-enzymatic FXa was produced (Xai-K), which rapidly lysed thrombi in mice. Unlike rtPA, Xai-K had no systemic fibrinolysis activation markers, indicating improved safety. SUMMARY: Background Enzymatic thrombolysis carries the risk of hemorrhage and re-occlusion must be evaded by co-administration with an anticoagulant. Toward further improving these shortcomings, we report a novel dual-functioning molecule, Xai-K, which is both a non-enzymatic thrombolytic agent and an anticoagulant. Xai-K is based on clotting factor Xa, whose sequential plasmin-mediated fragments, FXaß and Xa33/13, accelerate the principal thrombolytic agent, tissue plasminogen activator (tPA), but only when localized to anionic phospholipid. Methods The effect of Xai-K on fibrinolysis was measured in vitro by turbidity, thromboelastography and chromogenic assays, and measured in a murine model of occlusive carotid thrombosis by Doppler ultrasound. The anticoagulant properties of Xai-K were evaluated by normal plasma clotting assays, and in murine liver laceration and tail amputation hemostatic models. Results Xa33/13, which participates in fibrinolysis of purified fibrin, was rapidly inhibited in plasma. Cleavage was blocked at FXaß by modifying residues at the active site. The resultant Xai-K (1 nm) enhanced plasma clot dissolution by ~7-fold in vitro and was dependent on tPA. Xai-K alone (2.0 µg g(-1) body weight) achieved therapeutic patency in mice. The minimum primary dose of the tPA variant, Tenecteplase (TNK; 17 µg g(-1) ), could be reduced by > 30-fold to restore blood flow with adjunctive Xai-K (0.5 µg g(-1) ). TNK-induced systemic markers of fibrinolysis were not detected with Xai-K (2.0 µg g(-1) ). Xai-K had anticoagulant activity that was somewhat attenuated compared with a previously reported analogue. Conclusion These results suggest that Xai-K may ameliorate the safety profile of therapeutic thrombolysis, either as a primary or tPA/TNK-adjunctive agent.

Radiographic, computed tomographic and surgical anatomy of the equine sphenopalatine sinus in normal and diseased horses.

REASONS FOR PERFORMING STUDY: Knowledge of imaging anatomy, surgical anatomy and disorders affecting the sphenopalatine sinus are currently lacking. OBJECTIVES: To describe the computed tomographic (CT) and surgical anatomy of the sphenopalatine sinus and diagnosis, treatment and outcome in clinical cases with sphenopalatine sinus disease. STUDY DESIGN: Cadaver observational study and retrospective case series. METHODS: The sphenopalatine sinuses of 10 normal cadaver heads were examined with digital radiography, CT and sinoscopic examination prior to anatomical sectioning. Sphenopalatine sinus anatomy was described and compared between cadaver specimens across the imaging modalities. Medical records (January 2004-2014) of cases diagnosed with sphenopalatine sinus disease were reviewed. RESULTS: The anatomy of the sphenopalatine sinus was variable. The borders of the sphenopalatine sinus were not identifiable on plain radiographs, whereas CT provided useful anatomical information. The palatine portion of the sphenopalatine sinus was consistently accessible sinoscopically and the sphenoidal portion was accessible in 6/10 cadaver heads. Fourteen cases of sphenopalatine sinus disease were identified, presenting with one or more clinical signs of exophthalmos, blindness, unilateral epistaxis or unilateral nasal discharge. Diagnoses included neoplasia (7), progressive ethmoidal haematoma (4), sinus cyst (2) and empyema (1). Computed tomography provided diagnostic information but could not differentiate the nature of soft tissue masses. Standing sinoscopic access to the palatine portion of the sphenopalatine sinus was possible for evaluation, biopsy and resection of abnormal soft tissues. Surgical access to the sphenoidal portion was limited. Eight horses were alive at 1 year after diagnosis, with a worse outcome associated with CT evidence of bone loss and a diagnosis of neoplasia. CONCLUSIONS: Sphenopalatine sinus disease should be considered a rare cause of the clinical signs described. Knowledge of the anatomical variation of the sphenopalatine sinus is vital for interpreting CT images. A combination of CT and sinoscopy provides the most comprehensive approach for diagnosis and treatment of sphenopalatine sinus disease.

Sedative and echocardiographic effects of dexmedetomidine combined with butorphanol in healthy dogs.

OBJECTIVES: To evaluate the echocardiographic variables and sedation after two dosages of dexmedetomidine combined with butorphanol in healthy dogs. ANIMALS: Fourteen healthy dogs. METHODS: The dogs received dexmedetomidine 5 mcg/kg IM and butorphanol 0.4 mg/kg (low dose (LD), n = 6) or dexmedetomidine 10 mcg/kg IM and butorphanol 0.4 mg/kg (recommended dose (RD), n = 8). Sedation scoring, noninvasive blood pressure measurement, and echocardiography were performed before sedation at baseline, at 20 minutes (T20), and 60 minutes (T60) after drug administration. RESULTS: The median sedation scores were increased at both T20 and T60 in the RD group, and at T60 in the LD group, compared with baseline (p < 0.0001, p = 0.012). At T60, the RD dogs were more sedated than the LD dogs (p = 0.0093). The median cardiac output (CO) decreased at both T20 (63%) and T60 (65%) in the RD group and at T60 (42%) in the LD group, compared with baseline (p = 0.0011, p = 0.0055). The median heart rate (HR) was decreased at both T20 and T60 in the RD group and at T60 in the LD group, compared with baseline (p = 0.0009, p = 0.0001). In both RD and LD dogs, valvular regurgitation developed and was identified by color Doppler imaging. CONCLUSIONS: There were significant hemodynamic changes, mainly related to HR and indices of systolic function, following administration of dexmedetomidine in these healthy dogs. The changes also included decreases in systolic function and CO, as well as appearance of 'new' valvular regurgitation. Caution should be used when considering dexmedetomidine for sedation in dogs with, or being screened for, cardiovascular disease.

Functional consequences of glucose and oxygen deprivation on engineered mesenchymal stem cell-based cartilage constructs.

OBJECTIVE: Tissue engineering approaches for cartilage repair have focused on the use of mesenchymal stem cells (MSCs). For clinical success, MSCs must survive and produce extracellular matrix in the physiological context of the synovial joint, where low nutrient conditions engendered by avascularity, nutrient utilization, and waste production prevail. This study sought to delineate the role of microenvironmental stressors on MSC viability and functional capacity in three dimensional (3D) culture. DESIGN: We evaluated the impact of glucose and oxygen deprivation on the functional maturation of 3D MSC-laden agarose constructs. Since MSC isolation procedures result in a heterogeneous cell population, we also utilized micro-pellet culture to investigate whether clonal subpopulations respond to these microenvironmental stressors in a distinct fashion. RESULTS: MSC health and the functional maturation of 3D constructs were compromised by both glucose and oxygen deprivation. Importantly, glucose deprivation severely limited viability, and so compromised the functional maturation of 3D constructs to the greatest extent. The observation that not all cells died suggested there exists heterogeneity in the response of MSC populations to metabolic stressors. Population heterogeneity was confirmed through a series of studies utilizing clonally derived subpopulations, with a spectrum of matrix production and cell survival observed under conditions of metabolic stress. CONCLUSIONS: Our findings show that glucose deprivation has a significant impact on functional maturation, and that some MSC subpopulations are more resilient to metabolic challenge than others. These findings suggest that pre-selection of subpopulations that are resilient to metabolic challenge may improve in vivo outcomes.

APC promoter 1B deletion in seven American families with familial adenomatous polyposis.

Familial adenomatous polyposis (FAP) is a colorectal cancer predisposition syndrome caused by mutations in the adenomatous polyposis coli (APC) gene. Clinical genetic testing fails to identify disease causing mutations in up to 20% of clinically apparent FAP cases. Following the inclusion of multiplex ligation-dependent probe amplification (MLPA) probes specific for APC promoter 1B, seven probands were identified with a deletion of promoter 1B. Using haplotype analysis spanning the APC locus, the seven families appear to be identical by descent from a common founder. The clinical phenotype of 19 mutation carriers is classical FAP with colectomy at an average age of 24. The majority of cases had a large number of duodenal and gastric polyps. Measurements of allele-specific expression of APC mRNA using TaqMan assay confirmed that relative expression in the allele containing the promoter 1B deletion was reduced 42-98%, depending on tissue type. This study confirms the importance of APC promoter deletions as a cause of FAP and identifies a founder mutation in FAP patients from the United States.

A plasmin-activatable thrombin inhibitor reduces experimental thrombosis and assists experimental thrombolysis in murine models.

The leech protein hirudin is a potent natural thrombin inhibitor. Its potential as an antithrombotic agent is limited by its promotion of bleeding. We attempted to modify this profile by positioning albumin and a plasmin cleavage site on its N-terminus, in recombinant protein HSACHV3 [comprising hirudin variant 3 (HV3) fused to the C-terminus of human serum albumin (HSA) via a plasmin cleavage site (C)], Previously we showed that HSACHV3 inhibited thrombin in a plasmin-dependent manner, and that, unlike HV3, it did not increase bleeding in vivo when administered to mice. Here we tested HSACHV3 for the ability to reduce thrombosis and assist enzymatic thrombolysis in animal models. Intravenous administration of HSACHV3, but not a control protein lacking the plasmin cleavage site (HSAHV3), reduced thrombus weight by 2.1-fold in the ferric chloride-injured mouse vena cava. Similarly, thrombi formed in a rabbit jugular vein stasis model were 1.7-fold lighter in animals treated with HSACHV3 compared to those receiving HSAHV3. Administration of 60 mg/kg body weight HSACHV3 prolonged the time to occlusion in the ferric chloride-injured mouse carotid artery by threefold compared to vehicle controls, while equimolar HSAHV3 had no effect. HSACHV3 had no ability to restore flow to the murine carotid arteries occluded by ferric chloride treatment, but combining HSACHV3 (60 mg/kg) with recombinant mutant tissue plasminogen activator (TNKase) significantly reduced the time to restore patency to the artery compared to TNKase alone. Unlike unfused HV3, HSACHV3 did not increase bleeding in a mouse liver laceration model. Our results show that HSACHV3 acts as an antithrombotic agent that does not promote bleeding and which speeds the time to flow restoration when used as an adjunct to pharmacological thrombolysis in animal models.

γT -S195A thrombin reduces the anticoagulant effects of dabigatran in vitro and in vivo.

BACKGROUND: Dabigatran etexilate (DE) is an oral direct thrombin inhibitor used to prevent strokes in patients with atrial fibrillation. No licensed DE antidote is currently available. We hypothesized that active site-mutated S195A thrombin (S195A-IIa) and/or its trypsinized derivative (γT -S195A-IIa) would sequester dabigatran, the active form of DE, and reduce its anticoagulant effects. OBJECTIVE: To assess active site-mutated S195A or γT -S195A-IIa as dabigatran reversal agents in vitro and in vivo. METHODS: Diluted thrombin time (dTT) assays were performed using human or murine plasma containing dabigatran, combined with S195A-IIa, γT -S195A-IIa or FPR-chloromethyl ketone-treated thrombin (FPR-IIa). Bleeding times were determined in anesthetized DE-treated mice also receiving γT -S195A-IIa or vehicle 15 min prior to tail transection. The time to occlusion of carotid arteries of DE-treated mice also receiving S195A-IIa, γT -S195A-IIa, prothrombin complex concentrate (PCC) or vehicle, 15 min prior to topical FeCl3 , was determined using Doppler ultrasound. RESULTS: γT-S195A-IIa reduced dTT values of dabigatran-containing human and murine plasma more effectively than S195-IIa; FPR-IIa had no effect. A dose of 13 mg kg(-1) DE abrogated occlusive thrombus formation in the carotid arteries of FeCl3 -treated mice; γT -S195A-IIa (6 mg kg(-1) ) or PCC (14.3 IU kg(-1) ), but not saline vehicle or S195A-IIa (6 mg kg(-1) ), was equally effective in restoring thrombus formation. Bleeding times of mice treated with 60 mg kg(-1) DE and γT -S195A-IIa (6 mg kg(-1) ) or saline vehicle did not differ. CONCLUSIONS: Our data suggest that γT -S195A-IIa decreases the anticoagulant effects of dabigatran in vitro and is partially effective at restoring hemostasis-related thrombus formation in DE-treated mice in vivo.

Prothrombin complex concentrates reduce blood loss in murine coagulopathy induced by warfarin, but not in that induced by dabigatran etexilate.

BACKGROUND: Both established oral anticoagulants such as warfarin and newer agents such as dabigatran etexilate (DE) effectively prevent thromboembolic disease, but may provoke bleeding. Limited clinical data exist linking oral anticoagulant reversal and bleeding tendency, as opposed to surrogate laboratory markers. OBJECTIVE: To quantify bleeding in warfarin-anticoagulated and DE-anticoagulated mice by tail transection with or without pretreatment with potential reversal agents: prothrombin complex concentrate (PCC); activated PCC (APCC); recombinant factor VIIa (rFVIIa); or murine fresh-frozen plasma (FFP). METHODS: CD1 mice were given warfarin or DE by gavage, and the effects on in vitro coagulation assays, volume of blood loss and the bleeding time following tail transection injury were evaluated with different reversal agents. RESULTS: PCC (14.3 IU kg(-1) ), but not rFVIIa (3 mg kg(-1) ) or FFP (12 mL kg(-1) ), normalized blood loss and bleeding time in mice with warfarin-induced elevations of mean prothrombin time at two intensities (prothrombin time ratios of either 4.3 or 24). Neither separate nor combined PCC and/or rFVIIa treatment nor APCC (100 U kg(-1) ) treatment significantly reduced blood loss in mice anticoagulated with 60 mg kg(-1) DE 75 min prior to tail transection. Both combined PCC plus rFVIIa treatment and APCC treatment significantly reduced bleeding time in the DE-treated mice. CONCLUSIONS: Our data suggest that PCC treatment prevents excess bleeding much more effectively in warfarin-induced coagulopathy than in DE-induced coagulopathy.

Inhibition of p53 expression by peptide-conjugated phosphorodiamidate morpholino oligomers sensitizes human cancer cells to chemotherapeutic drugs.

The p53 tumor suppressor gene encodes a transcription factor that is commonly mutated in cancer. Tumors arise when premalignant cells are unable to undergo p53-dependent apoptosis, cell cycle arrest or DNA repair. The p53-signaling pathway affects not only tumor development, but also the response of tumors to chemotherapeutic drugs. In this study, we use cell penetrating peptide conjugates of phosphorodiamidate morpholino oligomers (PPMOs) to inhibit p53 expression. We examine the functional properties of endogenous p53 isoforms that are produced upon PPMO-mediated inhibition of p53 translation and splicing, and report that loss of N-terminal or C-terminal sequences interferes with the transcriptional activity of p53. Importantly, we report that PPMO-mediated inhibition of p53 expression sensitizes human cancer cells with wild-type p53 to chemotherapeutic drugs.

Relationship between prenatal lead exposure and infant blood lead levels.

Recent literature has shown that analyzing newborn dried blood spots (DBS) may be effective in assessing some prenatal environmental exposures, such as exposure to lead. The purpose of this study was to evaluate the relationship between prenatal exposure to lead (as measured by newborn DBS results) and blood lead levels (BLLs) in infants 6 months of age or younger, using public health registry data for infants born in Texas from July 2002 through July 2006. The Texas Child Lead Registry (TCLR) was used to identify infants with documented elevated BLLs of 10 µg/dL or higher as well as infants with documented low BLLs. BLLs for these children were compared to their corresponding newborn DBS results using Pearson correlation coefficients and exact logistic regression models. Overall, a significant but weak positive correlation was found between infant BLLs and corresponding newborn DBS lead levels (r = 0.48). However, the odds of an infant with an elevated newborn DBS lead level having an elevated BLL at 6 months of age or younger were much greater than for an infant with a low newborn DBS lead level of <5 µg/dL (adjusted odds ratio 27.95, 95% CI: 5.52-277.28). Although an association was observed between newborn DBS lead levels and BLLs in infants tested between 0 to 6 months of age, our findings suggest that prenatal exposure may not be the only significant source of lead exposure for infants ≤6 months of age.

Lung spirometry parameters and diffusion capacity are decreased in patients with Type 2 diabetes.

AIMS: In cohort studies, Type 2 diabetes mellitus has been associated with decreased forced 1 s expiratory volume and forced vital capacity. We examined if forced vital capacity, forced 1 s expiratory volume and diffusion lung capacity correlate with diabetes mellitus across different races in a clinical setting. METHODS: We examined the medical records of 19,882 adults 18-97 years of age in our centre from 1 January 2000 to 1 May 2009. After excluding patients with diseases causing abnormal lung function, 4164 subjects were available for analysis. We used multiple linear regressions to examine cross-sectional differences in forced vital capacity, forced 1 s expiratory volume and carbon monoxide diffusing capacity between patients with and without diabetes mellitus, after adjustment for age, sex, race, height, smoking, BMI and heart failure. RESULTS: Patients with diabetes (n = 560) were older (62 ± 12 vs. 55 ± 16 years), more likely to be men (56 vs. 43%), overweight (BMI 31.7 ± 8.5 vs. 27.3 ± 6.7 kg/m2 ), have heart failure (33 vs. 14%) and less likely to be Caucasians (65 vs. 76%) and never smokers (66 vs. 72%) compared with patients without diabetes (n = 3604). The mean unadjusted values in patients with diabetes vs. those without were: forced vital capacity 2.78 ± 0.91 vs. 3.19 ± 1.03 l; forced 1 s expiratory volume 2.17 ± 0.74 vs. 2.49 ± 0.0.83; and carbon monoxide diffusing capacity 16.67 ± 5.53 vs. 19.18 ± 6.72 ml(-1) min(-1) mmHg, all P < 0.0001. These differences remained significant after adjustment for covariates. After race stratification, only Caucasians with diabetes had a significant decrease in all lung function measures. CONCLUSIONS: Patients with diabetes have decreased lung function compared with those without diabetes. Caucasians with diabetes have more global lung function impairment compared with African-Americans and Hispanics.