Optical Density Units Research Articles

Removal Torque and Biofilm Accumulation at Two Dental Implant-Abutment Joints After Fatigue.

The aim of this study was to evaluate the removal torque and in vitro biofilm penetration at Morse taper and hexagonal implant-abutment joints after fatigue tests. Sixty dental implants were divided into two groups: (1) Morse taper and (2) external hexagon implant-abutment systems. Fatigue tests on the implant-abutment assemblies were performed at a normal force (FN) of 50 N at 1.2 Hz for 500,000 cycles in growth medium containing human saliva for 72 hours. Removal torque mean values (n = 10) were measured after fatigue tests. Abutments were then immersed in 1% protease solution in order to detach the biofilms for optical density and colony-forming unit (CFU/cm²) analyses. Groups of implant-abutment assemblies (n = 8) were cross-sectioned at 90 degrees relative to the plane of the implant-abutment joints for the microgap measurement by field-emission guns scanning electron microscopy. Mean values of removal torque on abutments were significantly lower for both Morse taper (22.1 ± 0.5 μm) and external hexagon (21.1 ± 0.7 μm) abutments after fatigue tests than those recorded without fatigue tests (respectively, 24 ± 0.5 μm and 24.8 ± 0.6 μm) in biofilm medium for 72 hours (P = .04). Mean values of microgap size for the Morse taper joints were statistically signicantly lower without fatigue tests (1.7 ± 0.4 μm) than those recorded after fatigue tests (3.2 ± 0.8 μm). Also, mean values of microgap size for external hexagon joints free of fatigue were statistically signicantly lower (1.5 ± 0.4 μm) than those recorded after fatigue tests (8.1 ± 1.7 μm) (P < .05). The optical density of biofilms and CFU mean values were lower on Morse taper abutments (Abs630nm at 0.06 and 2.9 × 10⁴ CFU/cm²) than that on external hexagon abutments (Abs630nm at 0.08 and 4.5 × 10⁴ CFU/cm²) (P = .01). The mean values of removal torque, microgap size, and biofilm density recorded at Morse taper joints were lower in comparison to those recorded at external hexagon implant-abutment joints after fatigue tests in a simulated oral environment for 72 hours.

Quantification of MCT1 and CD147 in Red Blood Cells of Arabian and Quarter Horses

During anaerobic glycolysis for energy production, lactate and H+ ions accumulate in muscle fibers and pass into the blood stream. The monocarboxylate transporter isoform 1 (MCT1) and its ancillary protein cluster of differentiation 147 (CD147) transport H+ and lactate ions from the plasma into red blood cells (RBCs), thereby maintaining acid/base homeostasis and retarding systemic acidosis and fatigue. The aim of this study was to compare the levels of MCT1 and CD147 protein in the RBC membranes of Arabian and Quarter Horses with different levels of athletic ability. Blood samples were collected from 40 Arabian and 40 Quarter Horses, both males and females, ranging from 3 to 16 years and 2 to 23 years, respectively. The horses were divided into two groups: 20 animals of low performance and 20 animals of high performance for each breed. The amount of MCT1 and CD147 in the plasma membranes of their RBCs was determined by Western blotting analysis with arbitrary optical density (OD) units, using a human-specific anti-MCT1 and anti-CD147 antibodies that were previously validated for horses. The means ± standard errors were analyzed by repeated measures analysis of variance using the PROC MIXED procedure of SAS software. The effect of age was included as covariate and sex as a class effect in the model. The correlations were analyzed by Pearson correlation test at P < .05. Monocarboxylate transporter isoform 1 with a molecular mass of approximately 52 and 49 kDa was found in the RBC membranes of all the Arabian and Quarter Horses, respectively. Cluster of differentiation 147 also was observed in all Arabian and Quarter Horses at approximately 52 and 48 kDa, respectively. A positive correlation was observed between the total amount of MCT1 and CD147 (r = 0.932, P < .001) in the RBC. The amount of MCT1 was significantly (P < .0001) higher in Quarter Horses (3.03 ± 0.37 OD) than in Arabians (1.02 ± 0.07 OD). Quarter Horses (3.23 ± 0.39 OD) also showed increased contents of CD147 than Arabians (0.89 ± 0.06 OD). However, there was no statistical difference in the amount of the protein between the low- and high-performance groups in either breed. Results indicate that the levels of MCT1 and CD147 are different between Arabian and Quarter Horses and the most probable explanation is that different pathways are used for the production of energy for each breed.

Skin Carotenoids as Biomarker for Vegetable and Fruit Intake: Validation of the Reflection‐Spectroscopy Based “Veggie Meter”

Skin is a relatively stable storage medium for carotenoids; non‐invasive optical measurements of carotenoids in this tissue via Resonance Raman spectroscopy (RRS) serve as a non‐invasive biomarker for fruit and vegetable (F/V) intake. The RRS method has been validated with HPLC‐based measurements of carotenoid concentrations in serum and excised skin tissue samples and has been shown in feeding studies to respond to changes in F/V intake.An attractive alternative to RRS is based on reflection spectroscopy (RS), which requires less complex instrumentation and has an advantage in also measuring skin melanin and hemoglobin absorptions. Using a suitable algorithm, the latter can be taken into account in the RS‐based derivation of skin carotenoid levels. Furthermore, these levels can be quantified in optical density units, which directly correlate with the carotenoid concentrations encountered in the measured tissue volume. The objective of this study was to validate the RS method via comparison with the RRS method.We compared RS and RRS measurements in 5 diverse human subject cohorts of different age groups and ethnicities in community and clinical settings. These measurements included inter‐subject comparisons of carotenoid levels in 146 adults and children, tracking of carotenoid changes in response to dietary interventions in 29 adults, and an ongoing exploration of a potential correlation between skin and retinal carotenoid levels in adult patients with vision disorders. Depending on the particular study, correlation coefficients varied between R ~ 0.80 and 0.96, showing that the RS method provides a valid substitute for RRS in skin carotenoid measurements of all age groups. A compact, portable instrument configuration will be presented, which permits rapid non‐invasive measurement and tracking of F/V derived carotenoid levels. In its capacity as “Veggie Meter” it should be attractive for screening of large populations and the assessment of the effectiveness of F/V intake interventions.Support or Funding InformationSupport for this research was provided in part by the Paso del Norte Health Foundation and the USDA‐ARS.

Antibacterial activity of Syzygium aromaticum seed: Studies on oxidative stress biomarkers and membrane permeability

Oxidative stress and membrane permeability as mode of antibacterial activity of aqueous extract of Syzygium aromaticum seeds against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus was investigated. The concentration of phytochemical constituents of Syzygium aromaticum was determined using gas chromatography. Syzygium aromaticum seeds contain eugenol acetate > β-carophyllene > eugenin > eugenol > methyl salicylate > β-humulene > rhamnatin > fernesol > α-copeane > β-ylangene > kaempferol > cinnamic acid > oleanolic acid > benzaldehyde > α-humulene > vanillin > α-cubebene > carvicol > benzoic acid. Syzygium aromaticum showed antimicrobial activity with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values as 0.06 and 0.10 mg/mL respectively. Time kill susceptibility by Syzygium aromaticum at MBC values showed significant decrease in the optical density and colony-forming unit (CFU) of Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. Superoxide anion radical content of the bacterial cells increased significantly following exposure to the extract. In a similar vein, superoxide dismutase and catalase activities increased significantly, while the level of reduced glutathione reduced, malondialdehyde increased significantly in bacterial cells exposed to the extract. The extract at MBC also enhanced the leakage of 260 nm absorbing materials and outer membrane permeability. It is evident from the data generated from this study that aqueous extract of Syzygium aromaticum seeds enhanced membrane permeability and oxidative stress in Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus.

Mechanical prophylaxis is a heparin-independent risk for anti–platelet factor 4/heparin antibody formation after orthopedic surgery

AbstractPlatelet-activating antibodies, which recognize platelet factor 4 (PF4)/heparin complexes, induce spontaneous heparin-induced thrombocytopenia (HIT) syndrome or fondaparinux-associated HIT without exposure to unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH). This condition mostly occurs after major orthopedic surgery, implying that surgery itself could trigger this immune response, although the mechanism is unclear. To investigate how surgery may do so, we performed a multicenter, prospective study of 2069 patients who underwent total knee arthroplasty (TKA) or hip arthroplasty. Approximately half of the patients received postoperative thromboprophylaxis with UFH, LMWH, or fondaparinux. The other half received only mechanical thromboprophylaxis, including dynamic (intermittent plantar or pneumatic compression device), static (graduated compression stockings [GCSs]), or both. We measured anti-PF4/heparin immunoglobulins G, A, and M before and 10 days after surgery using an immunoassay. Multivariate analysis revealed that dynamic mechanical thromboprophylaxis (DMT) was an independent risk factor for seroconversion (odds ratio [OR], 2.01; 95% confidence interval [CI], 1.34-3.02; P = .001), which was confirmed with propensity-score matching (OR, 1.99; 95% CI, 1.17-3.37; P = .018). For TKA, the seroconversion rates in patients treated with DMT but no anticoagulation and in patients treated with UFH or LMWH without DMT were similar, but significantly higher than in patients treated with only GCSs. The proportion of patients with ≥1.4 optical density units appeared to be higher among those treated with any anticoagulant plus DMT than among those not treated with DMT. Our study suggests that DMT increases risk of an anti-PF4/heparin immune response, even without heparin exposure. This trial was registered to www.umin.ac.jp/ctr as #UMIN000001366.

Inappropriate Listing of Heparin As an Allergy in the Electronic Medical Record Due to Misdiagnosis of Heparin-Induced Thrombocytopenia: Frequency and Consequences

Introduction Heparin-induced thrombocytopenia (HIT) is a prothrombotic complication of heparin therapy. Treatment involves discontinuation of heparin and initiation of an alternative anticoagulant. Misdiagnosis is common and may result in unnecessary exposure of thrombocytopenic patients to costly direct thrombin inhibitors and their approximate 1% daily risk of major hemorrhage. Another potential and previously unstudied consequence of misdiagnosis is the inappropriate listing of heparin as an allergy in the electronic medical record (EMR). We hypothesized that inappropriate listing of heparin as an allergy due to misdiagnosis of HIT is relatively common, often persists beyond the index hospitalization, and is associated with unnecessary avoidance of heparin as well as increased bleeding and costs. Methods We conducted a retrospective cohort study of patients with an inappropriate heparin allergy listed in the EMR due to misdiagnosis of HIT. We searched the EMR of a tertiary care center and a community hospital in our health system for patients with a new heparin allergy documented between 2004 and 2011. Patients were eligible for the study if the reason for allergy listing was suspicion for acute HIT and laboratory testing for HIT had been performed within 60 days of the allergy listing. We excluded patients that were listed as having a heparin allergy due to a remote history of suspected HIT, an adverse reaction to heparin other than HIT, or if the allergy was listed for an unknown reason. Charts of eligible subjects were reviewed and demographic, clinical, and laboratory data were extracted using a standardized data collection form. Subjects were defined as "negative for HIT" if they had a 4T score ≤3 or negative laboratory testing for HIT (ELISA &lt;1.0 optical density units and negative serotonin release assay). All other subjects were considered to have "possible HIT." Results Among 903 patients with a new allergy to heparin documented during the time period of interest, 239 were eligible for inclusion in the study. Of these 239 subjects, 100 (42%) met the prespecified definition of "negative for HIT" (15 had a 4T score ≤3, 49 had negative laboratory testing, and 36 had both a 4T score ≤3 and negative laboratory testing) . Sixty-eight of the subjects who were negative for HIT (68%) received an alternative parenteral anticoagulant during the index admission: 52 received argatroban, 18 lepirudin, 2 both argatroban and lepirudin. No patients were treated with fondaparinux or bivalirudin. Median length of time on an alternative parenteral anticoagulant was 10.5 days. Among the 68 patients who received unnecessary argatroban and/or lepirudin, 45 (66%) met ISTH criteria for major bleeding. The majority of these subjects met criteria for a major bleed based on a decrease in hemoglobin of at least 2.0 g/dL (n=40, 58.8%) and/or transfusion of at least 2 units of packed red blood cells (n=33, 48.5%). There were 2 subjects who had a symptomatic bleed in a critical area or organ. No subjects had a fatal hemorrhage. Seventy-five (75%) of the 100 subjects that were negative for HIT had an inappropriate allergy to heparin listed in the EMR at the time of discharge from the index hospitalization, and 68 (68%) had an inappropriate allergy to heparin that remained in effect as of August 2015. These 68 patients have had 68 subsequent hospitalizations within our health system after the index admission. Conclusions We found that a substantial percentage (42%) of patients with a heparin allergy documented in the EMR due to suspected HIT were clearly negative for HIT based on review of clinical and laboratory data. Many of these patients were unnecessarily treated with a direct thrombin inhibitor (68%) and experienced major bleeding (66%). Inappropriate heparin allergy listing persisted in the EMR in most patients (75%) beyond the index hospitalization, suggesting that heparin may be unnecessarily avoided and alternative parenteral anticoagulants used in subsequent admissions. Disclosures Cuker: Bracco: Consultancy; CSL Behring: Consultancy; Genzyme: Consultancy; T2 Biosystems: Research Funding.

Involvement of oxidative stress in bactericidal activity of 2-(2-nitrovinyl) furan against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus

The involvement of reactive oxygen species and oxidative stress in 2-(2-nitrovinyl) furan mediated bacterial cell death was investigated in Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. Time kill assay resulted in significant decrease in the optical density and colony-forming unit (CFU) of E. coli, P. aeruginosa and S. aureus. The level of superoxide anion radical and nitric oxide increased significantly in concentration dependent when compared with dimethyl sulfoxide (DMSO) treated bacteria. Similar concentration dependent increase in the activity of superoxide dismutase and catalase were recorded. The non-enzymatic antioxidant glutathione decreased significantly with a concomitant increase in glutathione disulfide. The level of malondialdehyde and fragmented DNA increased significantly in the bacterial cells treated with 2-(2-nitrovinyl) furan when compared with DMSO treated cells. The CFU of E. coli, P. aeruginosa and S. aureus following exposure to 2-(2-nitrovinyl) furan increased significantly (p < 0.05) in the presence of 2,2′ bipyridyl, an Fe chelator, significantly when compared with only 2-(2-nitrovinyl) furan suggesting the involvement of hydroxyl radical in the cell death. The available data from this study showed that 2-(2-nitrovinyl) furan induced oxidative stress in E. coli, P. aeruginosa and S. aureus as evident from elevated levels of superoxide anion radical nitric oxides and antioxidant enzymes.

Short Communication: Low False Recent Rate of Limiting-Antigen Avidity Assay Among Long-Term Infected Subjects from Guangxi, China.

Assays used for HIV cross-sectional incidence testing can misclassify some individuals with nonrecent HIV infection as recently infected, overestimating HIV incidence. We analyzed the frequency and factors associated with false-recent misclassification on subjects from Quangxi, China known to have long-term infection using the limited antigen-avidity assay (LAg-Avidity). Stored samples from treatment-naive individuals from Guangxi, China were tested using the LAg-Avidity. A total of 362 samples from individuals known to be infected 2 to 13.5 years were tested and the false-recent rate (FRR), the frequency of samples with a positive result, was determined at different cutoff values of the assay. Additionally, factors associated with misclassification were determined. The FRR of the LAg-Avidity was 1.1% (4/362) using a cutoff of 1.5 normalized optical density units (OD-n). All four samples had viral loads >1,000 copies/ml. Using a cutoff of 3.0 OD-n the FRR was 5.5% (20/362), with four samples having viral loads <1,000 copies/ml. Factors associated with a higher odds of misclassification were female gender (OR 7.7, 95% CI 1.0-56.4) and being a female sex worker (OR 31.3, 95% CI 4.0-242). At the higher cutoff, being of Zhuang decent, relative to Han, had higher odds of misclassification (OR 6.2, 95% CI 1.99-19.0). The LAg-Avidity assay had a low FRR in this Chinese population. Further investigations of the higher frequency of low LAg-Avidity results seen in female sex workers and individuals of Zhuang descent should be explored in a larger study.

Expression of vascular cell adhesion molecule-1 in the aortic tissues of atherosclerotic patients and the associated clinical implications.

The aim of this study was to investigate the expression level of vascular cell adhesion molecule-1 (VCAM-1) in the aortic tissues of atherosclerotic patients and to explore the associated clinical implications. Full-thickness aortic wall tissue samples were collected from atherosclerotic patients. Biochemical analysis was used for the detection of the serum levels of triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), lipoprotein (a) [Lp (a)], apolipoprotein (Apo) AI and Apo-B. Coronary angiography and SYNTAX scoring were used to determine the extent and severity of the disease. Immunohistochemistry was employed for the detection of the VCAM-1 protein expression levels in the arterial tissues. Significant differences were observed in the blood lipid levels between atherosclerotic patients and control subjects. Immunohistochemistry indicated that the aortic VCAM-1 expression level in atherosclerotic patients was 0.23±0.06 optical density (OD) units, which was significantly higher than that in the control subjects (0.08±0.03 OD units). In the atherosclerotic patients, the aortic VCAM-1 expression was positively correlated with the serum levels of TG (r=0.347), TC (r=0.469), LDL-C (r=0.463), Lp (a) (r=0.507) and Apo-B (r=0.384), while VCAM-1 and HDL-C were negatively correlated (r=-0.319). Furthermore, a higher SYNTAX score was accompanied by a higher VCAM-1 expression level (r=0.532), and an elevated aortic VCAM-1 expression was associated with certain cardiovascular risk factors. In conclusion, aortic VCAM-1 expression is associated with the severity of atherosclerosis and cardiovascular risk factors, indicating that VCAM-1 plays a role in the pathogenesis of atherosclerosis.

Effect of Clozapine and Other Antipsychotics on the Level of Platelet-Associated Autoantibodies in Children with Schizophrenia: A Longitudinal Follow-Up Study

Background: Previous studies have demonstrated significantly higher blood titers of platelet-associated autoantibodies (PAA) in adult schizophrenia patients compared to normal healthy subjects. In addition, young adult schizophrenia patients at their early stages of the disorder displayed higher PAA titers than older patients with longer duration of the disorder. Aim: To assess longitudinally the blood titers of PAA in inpatients with childhood-onset schizophrenia at admission, after short- and long-term follow-up, and the correlation of these titers with the response to clozapine and other antipsychotic treatments. Methods: Thirty children, age range of 6-12 (mean ± SD: 9.6 ± 1.5 years), with DSM-IV TR schizophrenia in active psychotic state were assessed 3 times: at baseline, after short-term (8-17 weeks; n = 26) and after long-term follow-up (33-170 weeks; n = 19). The blood titers of PAA were analyzed using ELISA and expressed by a linear optical density (OD) scale. A test recording >1.4 OD units was predefined as the positive cutoff value. Results: On long-term follow-up, 9 out of the 17 children who were PAA-positive at baseline became PAA-negative: 7 already after 2 months of clozapine treatment and 2 following 3 years of risperidone treatment. Eight children remained PAA-positive during the entire study period. There was no significant correlation between the clinical improvement (as assessed by change in the Positive and Negative Syndrome Scale score) and the alteration in PAA levels (n = 19, r = -0.4, p = 0.088). Conclusions: High rates of positive PAA in COS patients may indicate an active autoimmune process in early-onset schizophrenia. It is concluded that PAA may serve as a biomarker for the diagnosis of COS, but does not predict the response to treatment. A transition to a PAA-negative status does not indicate an improvement in psychosis.

New toxicity mechanism of silver nanoparticles: promoting apoptosis and inhibiting proliferation.

Silver nanoparticles are increasingly recognized for their utility in biological applications, especially antibacterial effects. Herein, we confirmed the antibacterial effect of silver nanoparticles on Escherichia coli using the conventional optical density (OD) and colony-forming units (CFU) method and used flow cytometry (FC), TEM and BrdU ELISA to investigate the mechanisms of this effect. From the results, we conclude that AgNPs can simultaneously induce apoptosis and inhibit new DNA synthesis in the cells in a positive concentration-dependent manner. This study presents the first induction of apoptosis in these bacteria by AgNPs in this field. Our findings may provide a new strategy for the use of silver nanoparticles in antibacterial applications.

DIAGNOSTIC CAPABILITIES OF DIGITAL FLUOROGRAPHY IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE

The purpose of the study – to examine the capabilities of the method of digital chest fluorography in diagnosis of chronic obstructive pulmonary disease (COPD) of different stages. By chest digital fluorography 247 patients with clinically diagnosed COPD stage I–III were examined. The average age of the patients was (55.3  1.7) years (16 to 88 years), forced expiration volume for the first second (FEV1) was (59.17  16.28) %. It was shown that for patients with COPD stage I most characteristic radiographic symptom was emphysema of the lung in the upper regions (26 (48%) of 54 patients); the mean values of the inspiratory lung optical density (ILOD) ranged from (703.48  2.15) to (807.47  5.61) optical density units (ODU), the expiratory lung optical density (ELOD) – from (786.05  6.15) to (830.23  4.71) ODU. For patients with COPD stage II the most common radiographic sign was the presence of amplification and deformation pulmonary pattern (95 (89%) of 107 patients); the mean values of ILOD ranged from (646.20  4.94) to (791.38  2.81) ODU, ELOD – from (677.34  9.91) to (813.91  3.29) ODU. Patients with COPD stage III were characterized by a combination of amplification and deformation pulmonary pattern (77 (90%) of 86 patients) with lung emphysema (51 (59%) of 86 patients); the mean values of the inspiratory lung optical density ranged from (765.93  16.4) to (863.37  15.83) ODU, expiratory lung optical density – from (826.80  11.64) to (881.37  4.29) ODU. Thus, we concluded that the method of digital chest fluorography, possessing low dose burden to the patient, can detect the characteristic radiological symptoms and determine the stage of the disease up to the values of the lung optical density in patients with COPD.

Evaluation of filtering blebs exhibiting transconjunctival oozing using anterior segment optical coherence tomography.

To explore the features of filtering blebs exhibiting transconjunctival oozing via three-dimensional anterior segment optical coherence tomography (3D AS-OCT). In this cross-sectional study, 131 eyes of 131 patients exhibiting filtering blebs were examined. Of those, 20 eyes were excluded as flat-shaped, non-functioning bleb. Transconjunctival oozing was defined as transconjunctival aqueous egress evident on the bleb surface, in the absence of any point leak observable using a slit-lamp, as confirmed by application of digital pressure. Total bleb height, the height of the fluid-filled cavity, and bleb wall thickness and density were measured using 3D AS-OCT. Patient age, the etiology of glaucoma, postoperative follow-up period, number of glaucoma medication classes prescribed, intraocular pressure (IOP), grade of bleb vascularity, and bleb parameters were compared in eyes with and without bleb oozing. Sixty (54.0 %) of 111 eyes excluding non-functioning flat blebs exhibited oozing; mean IOP value (11.7 ± 4.5 vs. 14.8 ± 4.0 mmHg) and bleb vascularity grade (1.5 ± 0.7 vs. 2.4 ± 1.0) were lower than those of eyes without oozing. Total bleb height (1.1 ± 0.4 vs. 0.9 ± 0.4 mm), bleb wall thickness (0.7 ± 0.4 vs. 0.5 ± 0.3 mm), and bleb wall density (131.3 ± 45.7 vs. 180.9 ± 39.8 optical density units) differed significantly between the two groups (oozing vs. non-oozing). Transconjunctival oozing after trabeculectomy with MMC was associated with a low IOP, low-level bleb vascularity, an elevated total bleb height, a thicker bleb wall, and low bleb wall density.

Comparison of antibody responses to HIV infection in Ugandan women infected with HIV subtypes A and D.

We compared the serologic response to HIV infection in Ugandan women with HIV subtype A (N=82) and D (N=32) infection using a limiting antigen avidity assay (LAg-Avidity assay); 2,614 samples were analyzed. Study participants were followed a median of 6.6 years after HIV seroconversion. Samples were classified as assay positive if they had a LAg-Avidity assay result <1.5 normalized optical density units (OD-n). Women with subtype D infection were more likely to have delayed antibody maturation. During the first 2 years after seroconversion, the mean time that women had an assay-positive result (mean duration of recent infection, MDRI) was longer for women with subtype D infection than women with subtype A infection (267.9 days, 95% CI: 231.2-308.2 vs. 167.3 days, 95% CI: 151.8-185.9 days, p<0.01). The MDRI was also longer for women with subtype D infection after excluding low viral load samples and samples from women on antiretroviral therapy (ART). Women infected for >2 years were also more likely to be misclassified as recently infected in they had subtype D infection. Women with subtype D infection were also more likely to have antibody waning compared to women with subtype A infection. These findings may be related to the higher pathogenicity of subtype D HIV infection and are relevant to use of the LAg-Avidity assay for cross-sectional HIV incidence estimation in populations where subtype D infection is prevalent.

Increased Anti-Flagellin and Anti-Lipopolysaccharide Immunoglobulins in Pediatric Intestinal Failure: Associations With Fever and Central Line-Associated Bloodstream Infections.

Central line-associated bloodstream infections (CLABSIs) pose a significant challenge in the lives of patients with intestinal failure (IF). We hypothesized that plasma immunoglobulins against flagellin (FLiC) and lipopolysaccharide (LPS) would be able to differentiate CLABSIs from nonbacterial febrile episodes and that levels would increase with infection and decline following appropriate antibiotic treatment. Patients with IF, due to short bowel syndrome, between the ages of 3 months and 4 years of age, were recruited at Cincinnati Children's Hospital Medical Center. Anti-FLiC and anti-LPS plasma antibody levels were measured in 13 children with IF at baseline, during febrile events, and also following treatment with antibiotics. These were also measured in 11 healthy children without IF who were recruited as controls. Plasma anti-FLiC IgA levels increased during febrile episodes in all patients with IF (baseline mean of 1.10 vs febrile episode mean of 1.32 optical density units, respectively; P = .046). Neither plasma anti-FLiC nor anti-LPS IgA or IgG levels distinguished CLABSI from nonbacterial febrile episodes compared with baseline levels. Compared with controls, patients with IF had significantly higher plasma levels of anti-FLiC and anti-LPS IgA at baseline. Plasma anti-FLiC IgA antibody levels rise during febrile episodes but do not differentiate between nonbacterial febrile illnesses and CLABSIs in pediatric IF. However, the upregulation of these antibodies in IF suggests the baseline systemic presence of Gram-negative bacterial products.

Preliminary Results on CD147 Expression in Red Blood Cells of Arabian Horses

IntroductionDuring anaerobic glycolysis for energy production, lactate and H+ ions accumulate in muscle fibers and pass into the bloodstream. Monocarboxylate transporter type 1 and its ancillary protein CD147 transport H+ and lactate ions from the plasma into red blood cells, thereby maintaining acid/base homeostasis and retarding systemic acidosis and fatigue. The aim of this study was to compare the levels of CD147 protein in the red blood cells of Arabian horses with different levels of athletic ability.MethodsBlood samples were taken from 12 Arabian horses before exercise. The horses were divided into two groups: untrained horses (UH, n = 6) and 160‐km endurance horses (FEI, n = 6). The amount of CD147 in the plasma membranes of their red blood cells was determined by Western blotting analysis using a human‐specific anti‐CD147 antibody previously validated for horses. The medians were compared by Mann‐Whitney Rank Sum test at 5%.ResultsCD147 protein with a molecular mass of approximately 45 kDa was found in the red blood cell membranes of the studied horses. The CD147 expression levels of the two groups were not different (P = 0.065). The observed median values (min–max) were 0.50 (0.37–1.26) and 0.27 (0.09–0.69) arbitrary optical density units for the FEI and UH group respectively.ConclusionsStudies must be performed with more horses to determine if a different level of CD147 expression exists in FEI horses related to their intensive training programs or to the genetic traits of each horse.Ethical Animal ResearchAll procedures were approved by the institutional animal care and use committee of the university (CEUA, Process: 019314/13). Explicit owner informed consent for participation in this study is not stated. Sources of funding: FAPESP ‐ Fundação de Amparo à Pesquisa do Estado de São Paulo. Process: 2012/24193‐0. Competing interests: none.

An ELISA method to compute endpoint titers to Epstein–Barr virus and cytomegalovirus: Application to population-based studies

Indirect fluorescence analysis (IFA), the gold standard for determining herpesvirus antibody titers, is labor-intensive and poorly suited for large population-based studies. The enzyme-linked immunosorbent assay (ELISA) is used widely for measuring antiviral antibodies but also suffers drawbacks such as reduced specificity and the qualitative nature of the results due to limited interpretation of the optical density (OD) units. This paper describes a method to titer herpesvirus antibodies using microplates coated with virally-infected cells in which a standard curve, derived from IFA-scored samples, allowed OD units to be converted into titers. A LOOKUP function was created in order to report the data as traditional IFA-based (i.e., 2-fold) titers. The modified ELISA correlated significantly with IFA and was subsequently used to compute endpoint antibody titers to Epstein–Barr virus (EBV)-virus capsid antigen (VCA) and cytomegalovirus (CMV) in blood samples taken from 398 pregnant Hispanic women. Four women were EBV negative (1%), while 58 women were CMV negative (14.6%). EBV VCA antibody titers were significantly higher than CMV antibody titers (p<0.001). This method allows titering of herpesvirus antibodies by ELISA suitable for large population-based studies. In addition, the LOOKUP table enables conversion from OD-derived titers into 2-fold titers for comparison of results with other studies.

The association between dark adaptation and macular pigment optical density in healthy subjects

To investigate whether macular pigment optical density (MPOD) is related to dark adaptation in healthy subjects. Dark adaptation was measured after a minimum 30 % pigment bleach in 33 subjects (aged 15-68), using a white 1° stimulus presented 11° below fixation on a cathode ray tube monitor. The luminance range of the monitor was extended using neutral density filters. A heterochromatic flicker photometry based instrument (MPS 9000) was used to measure MPOD. The average MPOD for the whole group was 0.37 ± 0.21 optical density units. Subjects with lighter irides had on average 40 % lower MPOD compared to those with darker irides (0.3 ± 0.20 vs 0.5 ± 0.19). Group mean MPOD was weakly associated with second (r = 0.32, p = 0.07) and third rod-mediated recovery rates (r = 0.31, p = 0.08) and with the rod threshold (r = -0.24, p = 0.18) 30 min after the onset of bleach. MPOD was unrelated to cone time constant (r = -0.02, p = 0.91), cone threshold (r = -0.01, p = 0.96), rod-cone break (r = 0.13, p = 0.45) or the rod-rod break (r = 0.11, p = 0.52). The second rod-mediated recovery rate (S2) for the lower 10th percentile of MPOD (n = 4) was 0.18 log cd.m(-2).min(-1) and 0.24 log cd.m(-2).min(-1) for the upper 10th percentile (n = 4). The two groups were significantly different (t = -2.67, p = 0.037). We report a statistically significant difference between subjects falling in the 10th percentile extremes of MPOD and rod-mediated but not cone-mediated sensitivity recovery. Further investigation into the relationship between MPOD and rod function is warranted, particularly extending the work to encompass those with low MPOD and poor night vision.

Outcome Of Patients with Positive Heparin-Platelet Factor 4 Antibodies: A Retrospective Observational Study

▪ IntroductionHeparin-induced thrombocytopenia (HIT) is a rare but potentially serious complication of heparin use. Immunoassay (EIA) can detect the presence of antibodies directed toward heparin-platelet factor 4 (H-PF4) complexes, but provide no information about their ability to activate platelets and have only modest specificity. Significance of positive H-PF4 antibodies without clinical HIT is not known. This study evaluates the outcomes of patients with positive H-PF4 antibodies expressed in optical density (OD) units. ObjectivesTo examine the correlation between positive H-PF4 antibodies, mortality and thrombotic events in hospitalized patients with suspected HIT. MethodsA retrospective electronic medical record review was conducted in two institutions. Patients with H-PF4 antibodies detected by commercial ELISA during 2006 - 2010 were identified. We compared 30-day, 90-day and 1-year mortality in patients with negative, equivocal, and positive H-PF4 test and evaluated the relationship between H-PF4 status and rate of thrombosis. One-way ANOVA and Chi square tests were used testing continuous and categorical variables respectively. A multivariate logistic regression model was fitted to estimate relationships between patient characteristics, laboratory findings, and H-PF4 antibody test status. The Kaplan-Meier method and log-rank tests were used to compare survival between groups. ResultsA total of 417 patients were included in the study, of which 44 patients had equivocal (OD value 0.4-0.9) and 21 had positive (OD value ≥1) H-PF4 antibody test result. 30-day, 90-day and 1-year mortalities were 13.6% (48/352), 33.2% (117/352), 46.3% (163/352) respectively for H-PF4 negative patients, 4.5% (2/44), 45.4 % (20/44), 56.8% (25/44) respectively for patients with equivocal H-PF4 status and 14.3% (3/21). 33.3% (7/21), 42.8% (9/21) respectively for H-PF4 positive patients. There were no statistically significant differences in mortality between patients with negative, equivocal, and positive results at all 3 time points (p-value 0.222, 0.273, 0.385, respectively); even after excluding patients with thrombosis (p-value 0.222, 0.248, 0.310 respectively). Age and Charlson score were associated with increased in-hospital, three-months and 1 year mortality; odds ratios were 1.018 and 1.170 (p-value >0.05) for in-hospital mortality, 1.034 and 1.247 (p-value <0.05) for three-months mortality, 1.04 and 1.289 for 1 year mortality (p-value <0.05). Multiple regression analysis showed that age, gender and Charlson score had no statistically significant effect on the occurrence of thrombosis in negative, equivocal, or positive groups. There was a significant correlation between the occurrence of thrombosis and H-PF4 result. Using logistic regression analysis odds ratio of having thrombosis was 2.476 for equivocal vs. negative and positive vs. equivocal results (p <0.0001) (Table 2). ConclusionOur results suggest no association between H-PF4 status positivity and mortality, as well as no difference in survival over one year between the positive and negative groups. H-PF4 positivity however showed positive correlation with thrombosis risk. Disclosures:No relevant conflicts of interest to declare.

Effects of tramadol hydrochloride preconditioning on the activation of nuclear factor-ΚB induced by norepinephrine in cultured neonatal rat cardiomyocytes

To investigate the effects of tramadol hydrochloride preconditioning on activation of nuclear factor-ΚB (NF-ΚB) induced by norepinephrine (NE) in cultured neonatal rat cardiomyocytes. 1 to 3-day old Sprague-Dawley (SD) rats were raised, and their cardiomyocytes were cultured for 4 to 5 days. Sixteen wells of cultured cardiomyocytes were randomly divided into four groups (n=4): blank control group, NE1 group in which the cells were incubated with 1×10(-6) mmol/L of NE, NE2 group in which cells were incubated with 1×10(-7) mmol/L of NE, and NE3 group in which cells were incubated with 1×10(-8) mmol/L of NE. Another 12 wells of cultured cardiomyocytes were randomly divided into three groups (n=4): blank control group, NE3 group in which cells were incubated with 1×10(-8) mmol/L of NE, tramadol plus NE group (T + NE group) in which cells were incubated with 1×10(-5) mmol/L of tramadol hydrochloride plus 1×10(-8) mmol/L of NE. Tramadol hydrochloride was added 30 minutes before the use of NE in T + NE group. After exposure to NE for 24 hours, the expression and activation of NF-ΚB in the cultured cardiomyocytes were determined by immunocytochemistry and flow cytometry (FCM). The results of immunocytochemistry showed that the expression of NF-ΚB (including average optical density and positive units) in NE3 group was significantly increased as compared with that in the blank control group (A average optical density: 0.30±0.03 vs. 0.12±0.04, t=7.200, P=0.008; positive units: 39±14 vs. 22±6, t=4.610, P=0.020). The results of FCM showed that the levels of cytoplasm NF-ΚB in cultured cardiomyocytes were decreased significantly in NE1 group, NE2 group and NE3 group compared with blank control group [(45.8±1.9)%, (38.3±1.8)%, (20.9±1.6)% vs. (54.6±0.6)%, all P<0.05], and the level in NE3 group was significantly lower than that in NE1 and NE2 groups (both P<0.05). The level of the cardiomyocytes cytoplasm NF-ΚB in T + NE group was higher than that in NE3 group [(57.8±0.4)% vs. (20.9±1.6)%, t=57.524, P=0.001]. Tramadol hydrochloride preconditioning can inhibit the activation of NF-ΚB induced by NE in cultured rat cardiomyocytes. It plays a protective role in ischemia myocardium at cell level.