Liraglutide 3.0 mg in the treatment of adults with obesity and prediabetes using real-world UK data: A clinical evaluation of a multi-ethnic population

UK guidelines recommend liraglutide 3.0 mg in adults treated within specialist weight management services with BMI ≥35 kg/m2, prediabetes and high cardiovascular disease risk. We aimed to clinically evaluate liraglutide 3.0 mg in specialist weight management services. We evaluated liraglutide 3.0 mg in weight management services at Guys and St Thomas' NHS Foundation Trust. Objective body weight (BW) was measured at baseline and 4 months, allowing classification as 'responders' (≥5% BW reduction) and 'non-responders' (<5% BW reduction). One hundred and twenty-one patients were evaluated. At 4 months, 76.0% attended follow-up (82.6% responders, 17.4% non-responders); BW (-8.6 kg, 95%CI:-9.8, -7.4 kg), BMI (-3.2 kg/m2, 95%CI: -3.6, -2.8) and %-BW (-6.6%, IQR: -8.8%, -5.2%) significantly reduced. In responders, HbA1c reduced by -5.0 mmol/mol (IQR: -7.0. -4.0 mmol/mol). In responders BW continued to reduce up to 12 months (4 m: -10.2 kg, p < .0001; 6 m: -15.6 kg, p < .0001; 9 m: -16.5 kg, p < .0001; 12 m: -16.7 kg, p < .01). Those of Black African and Caribbean ethnicity experienced less BW loss than those of white ethnicity (4.12 kg, p = .017) and had a greater attrition rate. In adults with obesity and prediabetes who are treated within specialist weight management services, liraglutide 3.0 mg reduces BW and HbA1c. Those of Black African and Caribbean ethnicity experienced less BW reduction and greater attrition at 4 months. Further evaluation of the ethnic differences in response to obesity pharmacotherapy is required.

Significant enhancement in the cold emission characteristics of chemically synthesized super-hydrophobic zinc oxide rods by nickel doping

The current article presents a huge enhancement in the field emission characteristics of zinc oxide (ZnO) micro/nanorods by nickel doping. The synthesis of pure and nickel-doped zinc oxide (ZnO) micro/nanorods was done by a simple low-temperature chemical method. Both the as-prepared pure and doped samples were analyzed by X-ray diffraction and electron microscopy to confirm the proper phase formation and the developed microstructure. UV-vis transmittance spectra helped in determining the band gap of the samples. Fourier-Transform Infrared Spectroscopy (FTIR) spectra showed the different bonds present in the sample, whereas X-ray Photoelectron Spectroscopy (XPS) confirmed the presence of nickel in the doped sample. Photoluminescence (PL) spectra showed that after doping, the band-to-band transition was affected, whereas defect-induced transition had increased significantly. After the nickel doping, contact angle measurement revealed a significant decrease in the sample's surface energy, leading to a remarkably high water contact angle (within the superhydrophobic region). Simulation through ANSYS suggested that the doped sample has the potential to function as an efficient cold emitter, which was also verified experimentally. The cold emission characteristics of the doped sample showed a significant improvement, with the turn-on field (corresponding to J = 1 μA cm-2) reduced from 5.34 to 2.84 V μm-1. The enhancement factor for the doped sample reached 3426, approximately 1.5 times higher compared to pure ZnO. Efforts have been made to explain the results, given the favorable band bending as well as the increased number of effective emission sites.

POS0205 AMELIORATION OF ENDOTHELIAL DYSFUNCTION WITH JAK INHIBITION IN RHEUMATOID ARTHRITIS: JAK CV-RISK REDUCTION STUDY

Background:

Cardiovascular (CV) disease is the leading cause of premature mortality and sudden death in Rheumatoid Arthritis (RA). Conventional CV risk factors and disease specific risk factors are responsible for endothelial dysfunction (ED) in RA. ED is the barometer of CV health and key initial event in atherosclerosis. Tofacitinib, a JAK inhibitor, is in clinical use since 2012 and has had the most extensive development program in RA, but its impact on ED has not yet been explored in humans.

Objectives:

To investigate the impact of tofacitinib on endothelial dysfunction in RA

Methods:

40 RA patients fulfilling the 2010 Rheumatoid Arthritis classification criteria with active disease (DAS28>3.2) were randomized to receive 24 weeks of treatment with Tofacitinib (5mg bd, n=20) and placebo (n=20) as an adjunct to existing stable antirheumatic drugs. Primary endpoints included endothelial dysfunction assessed by FMD using Angiodefender and lipids were estimated at baseline and after 12 weeks of treatment. The secondary end points included: DAS28, ESR, CRP, HAQ-DI and cardiovascular risk using SCORE chart assessed at week 0 and 12.

Results:

At baseline, endothelial function was impaired and levels of inflammatory measures were elevated in both groups. CV risk SCORE was high and HAQ-DI was impaired at baseline. After treatment, FMD improved significantly in the tofacitinib group from (8.16±1.38% to 10.98±2.33%, p≤0.05) as compared to placebo (7.12±0.25% to 8.04±0.30%, p=0.35) (Fig. 1A). DAS28 (Fig. 1B), ESR and CRP (Fig. 1C) levels improved significantly in tofacitinib group as compared to placebo (p≤0.05). Tofacitinib significantly decreased HAQ-DI and SCORE (Fig. 1D) values as compared to placebo. There was significant increase in HDL (p≤0.05) after treatment with tofacitinib as compared to placebo. After 12 weeks of treatment, FMD and HDL increased by 34.55% and 13.58% respectively where as DAS28, ESR and CRP decreased by 37.40%, 36.10% and 76.59% respectively in the tofacitinib group. Significant negative correlation was observed between FMD and DAS28 (r= -0.50, p≤0.05) and CRP (r= -52, p≤0.05) after treatment with tofacitinib where as no such correlation was found in placebo group.

Figure 1.

Impact of Tofacitinib on FMD, DAS 28, CRP & SCORE

Conclusion:

First study to show that tofacitinib, apart from its anti inflammatory activity, improves endothelial dysfunction and cardiovascular risk in RA. Thus, JAK inhibition with tofacitinib has vasculoprotective and cardioprotective effect mediated through anti-inflammatory and probably other mechanisms. This study would stimulate further research in exploring the vasculoprotective and cardioprotective potential of tofacitinib in RA.

References:

[1]Tofacitinib reversed endothelial dysfunction in rheumatoid arthritis: mechanistic insights from the rat adjuvant-induced arthritis model. http://dx.doi.org/10.1136/annrheumdis-2020-eular.2747

Disclosure of Interests:

None declared

Market assessment of tuberculosis diagnostics in India in 2013

BACKGROUND

India represents a significant potential market for new tests. We assessed India's market for tuberculosis (TB) diagnostics in 2013.

METHODS

Test volumes and unit costs were assessed for tuberculin tests, interferon-gamma release assays, sputum smear microscopy, serology, culture, speciation testing, nucleic-acid amplification tests (i.e., in-house polymerase chain reaction, Xpert(®) MTB/RIF, line-probe assays) and drug susceptibility testing. Data from the public sector were collected from the Revised National TB Control Programme reports. Private sector data were collected through a survey of private laboratories and practitioners. Data were also collected from manufacturers.

RESULTS

In 2013, India's public sector performed 19.2 million tests, with a market value of US$22.9 million. The private sector performed 13.6 million tests, with a market value of US$60.4 million when prices charged to the patient were applied. The overall market was US$70.8 million when unit costs from the ingredient approach were used for the 32.8 million TB tests performed in the entire country. Smear microscopy was the most common test performed, accounting for 25% of the overall market value.

CONCLUSION

India's estimated market value for TB diagnostics in 2013 was US$70.8 million. These data should be of relevance to test developers, donors and implementers.

Coliform detection in cheese is associated with specific cheese characteristics, but no association was found with pathogen detection

Coliform detection in finished products, including cheese, has traditionally been used to indicate whether a given product has been manufactured under unsanitary conditions. As our understanding of the diversity of coliforms has improved, it is necessary to assess whether coliforms are a good indicator organism and whether coliform detection in cheese is associated with the presence of pathogens. The objective of this study was (1) to evaluate cheese available on the market for presence of coliforms and key pathogens, and (2) to characterize the coliforms present to assess their likely sources and public health relevance. A total of 273 cheese samples were tested for presence of coliforms and for Salmonella, Staphylococcus aureus, Shiga toxin-producing Escherichia coli, Listeria monocytogenes, and other Listeria species. Among all tested cheese samples, 27% (75/273) tested positive for coliforms in concentrations >10cfu/g. Pasteurization, pH, water activity, milk type, and rind type were factors significantly associated with detection of coliforms in cheese; for example, a higher coliform prevalence was detected in raw milk cheeses (42% with >10cfu/g) compared with pasteurized milk cheese (21%). For cheese samples contaminated with coliforms, only water activity was significantly associated with coliform concentration. Coliforms isolated from cheese samples were classified into 13 different genera, including the environmental coliform genera Hafnia, Raoultella, and Serratia, which represent the 3 genera most frequently isolated across all cheeses. Escherichia, Hafnia, and Enterobacter were significantly more common among raw milk cheeses. Based on sequencing of the housekeeping gene clpX, most Escherichia isolates were confirmed as members of fecal commensal clades of E. coli. All cheese samples tested negative for Salmonella, Staph. aureus, and Shiga toxin-producing E. coli. Listeria spp. were found in 12 cheese samples, including 5 samples positive for L. monocytogenes. Although no association was found between coliform and Listeria spp. detection, Listeria spp. were significantly more likely to be detected in cheese with the washed type of rind. Our data provide information on specific risk factors for pathogen detection in cheese, which will facilitate development of risk-based strategies to control microbial food safety hazards in cheese, and suggest that generic coliform testing cannot be used to assess the safety of natural cheese.

Self-similarity in the inertial region of wall turbulence

The inverse of the von Kármán constant κ is the leading coefficient in the equation describing the logarithmic mean velocity profile in wall bounded turbulent flows. Klewicki [J. Fluid Mech. 718, 596 (2013)] connects the asymptotic value of κ with an emerging condition of dynamic self-similarity on an interior inertial domain that contains a geometrically self-similar hierarchy of scaling layers. A number of properties associated with the asymptotic value of κ are revealed. This is accomplished using a framework that retains connection to invariance properties admitted by the mean statement of dynamics. The development leads toward, but terminates short of, analytically determining a value for κ. It is shown that if adjacent layers on the hierarchy (or their adjacent positions) adhere to the same self-similarity that is analytically shown to exist between any given layer and its position, then κ≡Φ(-2)=0.381966..., where Φ=(1+√5)/2 is the golden ratio. A number of measures, derived specifically from an analysis of the mean momentum equation, are subsequently used to empirically explore the veracity and implications of κ=Φ(-2). Consistent with the differential transformations underlying an invariant form admitted by the governing mean equation, it is demonstrated that the value of κ arises from two geometric features associated with the inertial turbulent motions responsible for momentum transport. One nominally pertains to the shape of the relevant motions as quantified by their area coverage in any given wall-parallel plane, and the other pertains to the changing size of these motions in the wall-normal direction. In accord with self-similar mean dynamics, these two features remain invariant across the inertial domain. Data from direct numerical simulations and higher Reynolds number experiments are presented and discussed relative to the self-similar geometric structure indicated by the analysis, and in particular the special form of self-similarity shown to correspond to κ=Φ(-2).

Vancomycin-resistant Enterococcus faecium: report of two cases

Vancomycin-resistant Enterococci (VRE), especially Enterococcus faecium has emerged as an important nososcomial pathogen and represents a serious threat to patients with impaired host defense. Early detection of patients colonised or infected with VRE is an essential component of any hospital program designed to prevent nosocomial transmission of this organism. The authors report two cases of VRE isolated from blood and surgical site pus of two neonates admitted in the same neonatal unit, highlighting that early detection, prompt and appropriate infection control measures were keys to successful containment of this dreaded pathogen.

Comparison of molecular markers to detect fresh sewage in environmental waters

Human-specific Bacteroides HF183 (HS-HF183), human-specific Enterococci faecium esp (HS-esp), human-specific adenoviruses (HS-AVs) and human-specific polyomaviruses (HS-PVs) assays were evaluated in freshwater, seawater and distilled water to detect fresh sewage. The sewage spiked water samples were also tested for the concentrations of traditional fecal indicators (i.e., Escherichia coli, enterococci and Clostridium perfringens) and enteric viruses such as enteroviruses (EVs), sapoviruses (SVs), and torquetenoviruses (TVs). The overall host-specificity of the HS-HF183 marker to differentiate between humans and other animals was 98%. However, the HS-esp, HS-AVs and HS-PVs showed 100% host-specificity. All the human-specific markers showed >97% sensitivity to detect human fecal pollution. E. coli, enterococci and, C. perfringens were detected up to dilutions of sewage 10(-5), 10(-4) and 10(-3) respectively. HS-esp, HS-AVs, HS-PVs, SVs and TVs were detected up to dilution of sewage 10(-4) whilst EVs were detected up to dilution 10(-5). The ability of the HS-HF183 marker to detect fresh sewage was 3-4 orders of magnitude higher than that of the HS-esp and viral markers. The ability to detect fresh sewage in freshwater, seawater and distilled water matrices was similar for human-specific bacterial and viral marker. Based on our data, it appears that human-specific molecular markers are sensitive measures of fresh sewage pollution, and the HS-HF183 marker appears to be the most sensitive among these markers in terms of detecting fresh sewage. However, the presence of the HS-HF183 marker in environmental waters may not necessarily indicate the presence of enteric viruses due to their high abundance in sewage compared to enteric viruses. More research is required on the persistency of these markers in environmental water samples in relation to traditional fecal indicators and enteric pathogens.

Role of the Penrose drain in the management of VLBW infants with perforated necrotising enterocolitis

We studied the effectiveness of the Penrose drain in very low birth weight infants with BW < 1500g with perforated necrotizing Enterocolitis. We reviewed the infants with perforated NEC over the 9 years between 1995-2004. The inclusive criteria was free intraperitoneal air in VLBW infants < 1500g. A total 22 infants were studied. Gestational age ranged from 23 to 33 weeks. Perforated NEC was diagnosed on PFA. In all infants a Penrose drain was inserted in either the right or left lower abdominal quadrants. Most of the infants fell in the BW range 800g to 980g with median age of 16 days. The incidence of Perforated NEC was very high in females (81.8%) as compared to males (18.2%). A Penrose drain was inserted on the same day when the pneumoperitoneum was diagnosed. A total of 22 infants had a Penrose drain inserted. Two (9%) showed improvement, 20(91%) were taken to theatre for laparotomy. Thirteen (59%) had an ileostomy performed. Seven (31.8%) had extensive bowel necrosis and subsequently died. A total 15(68.2%) out of 22 survived with initial management of Penrose drain insertion and subsequent laparotomy. Penrose drain insertion is an effective first line treatment in the pre-term infant BW < 1500g, with perforated NEC.

Medical Negligence in Military Hospitals

BACKGROUND

Bringing the doctors under the ambit of Consumer Protection Act has made an impact on doctor-patient relationship. There has been an increase in legal cases of medical negligence in the recent past. This article provides practical information on medical negligence.

METHODS

Complaints received at Army Headquarters were studied to understand the factors involved in medical negligence.

RESULT

Various aspects of medical negligence including doctor-patient relationship in the military set up have been discussed. Preliminary measures to be taken to avoid cases of negligence are enumerated.

CONCLUSION

Good communication skills to build a rapport with the patient is the key to avoid majority of the complaints. The doctor must pay due courtesy, respect and care to the patient besides maintaining medical records scrupulously.

Laparoscopic appendectomy versus open appendectomy in children

This study compares the benefits, advantages and complications of laparoscopic Appendicectomy (LA) versus Open Appendectomy (OA) in children's in Dublin Ireland. Total 200 patients were studied. Hundred of LA and 100 for OA. Out of 100 LA 58 were male, 42 were female aged between 4-15 yr. and out of 100 OA 58 were male, 42 were female aged between 4-14 yr. The mean operative time of LA was 35.8 minutes and the Anaesthetic time was 46.6 minutes. Patients having LA had less post-op pain with early start of feed at 16.7 hrs, and had significantly less post-op hospital stay of 1.6 days. Post op complications rate was 3%. The patient started the normal life activities at 10.8th post op day. Wound infection rate was 3% with Re-admission rate of 2%. The mean operative time of OA was 45.66 minutes and the Anaesthetic time was 56.75 minutes. Patients having OA had post-op pain hospital stay of 2.55 days with start of feed at 24.7 hrs. Post op complications rate was 2%. The patient started the normal life activities at 15.78th post op day. Wound infection rate was 3% with Re-admission rate of 1%. Laparoscopic appendectomy is safe alternative to conventional open appendectomy, leading to early ambulation, decreased hospital stay, and better exploration of abdominal cavity.

Raised visual detection thresholds depend on the level of complexity of cognitive foveal loading

The objective of the study was to measure the interactions between visual thresholds for a simple light (the secondary task) presented peripherally and a simultaneously performed cognitive task (the primary task) presented foveally The primary task was highly visible but varied according to its cognitive complexity. Interactions between the tasks were determined by measuring detection thresholds for the peripheral task and accuracy of performance of the foveal task. Effects were measured for 5, 10, 20, and 30 deg eccentricity of the peripherally presented light and for three levels of cognitive complexity. Mesopic conditions (0.5 lx) were used. As expected, the concurrent presentation of the foveal cognitive task reduced peripheral sensitivity. Moreover, performance of the foveal task was adversely affected when conducting the peripheral task. Performance on both tasks was reduced as the level of complexity of the cognitive task increased. There were qualitative differences in task interactions between the central 10 deg and at greater eccentricities. Within 10 deg there was a disproportionate effect of eccentricity, previously interpreted as the 'tunnel-vision' model of visual field narrowing. Interactions outside 10 deg were less affected by eccentricity. These results are discussed in terms of the known neurophysiological characteristics of the primary visual pathway.

Hypoxia stimulates the synthesis of cytochrome P450-derived inflammatory eicosanoids in rabbit corneal epithelium

The corneal epithelium metabolizes arachidonic acid by a cytochrome P450-(CYP) mediated pathway to 12(R)hydroxy-5,8,10,14-eicosatrienoic acid [12(R)-HETE] and 12(R)hydroxy-5,8,14-eicosatrienoic acid [12(R)-HETrE]. Both metabolites possess potent inflammatory properties with 12(R)-HETrE being a powerful angiogenic factor and assume the role of inflammatory mediators in hypoxia- and chemical-induced injury in the cornea, in vivo. We developed an in vitro model of corneal organ culture to characterize the biochemical and molecular events involved in the increased synthesis of these metabolites. These cultured corneas exhibit epithelial cytochrome P450 CYP-dependent 12(R)-HETE and 12(R)-HETrE synthesis as indicated by chiral analysis and by the ability of CYP enzyme inhibitors to repress their synthesis. Hypoxia greatly and selectively stimulated the synthesis of 12(R)-HETE (7-fold over control normoxic conditions) and 12(R)-HETrE. The bacterial endotoxin, lipopolysaccharide, also increased the synthesis of these eicosanoids, substantiating the notion that this activity may function as an inflammatory pathway. These metabolites were detected in the culture medium by gas chromatography/mass spectroscopy (GC/MS) analysis and their levels significantly increased in hypoxia-treated corneas, further indicating their endogenous formation in response to injury. This in vitro model provides an excellent preparation for studying factors regulating the synthesis of these inflammatory eicosanoids and for isolating, identifying and characterizing the CYP protein responsible for their synthesis.

Involvement of a 43-kilodalton outer membrane protein in beta-lactam resistance of Shigella dysenteriae

A beta-lactam-sensitive strain (C152) of Shigella dysenteriae showed two major outer membrane proteins (OMPs) with M(r)s of 43,000 and 38,000, while the clinical isolate M2 lacked the 43,000-Mr OMP, which acted as a channel for beta-lactam antibiotics. Permeability of beta-lactams across the outer membrane (OM) of M2 was lower than that across the OM of C152. Mutants deficient in the 43-kDa OMP could be selected in vitro from strain C152 in the presence of cefoxitin. All beta-lactam-resistant strains were sensitive to imipenem.

Accommodation and acuity under night-driving illumination levels

Laboratory experiments are described in which the monocular changes in the refractive error and acuity of six young, normal, adult subjects were measured as the field luminance was reduced from approximately 100 to 10(-3) cd/m2. It was found that, at luminance levels equal to those recommended for road lighting (about 1 cd/m2), acuity fell from its photopic value of > or = 6/6 to about 6/9, with little change in the measured refraction. Marked changes in refraction, i.e. night myopia, only started to become manifest when the luminance was further reduced to below about 0.03 cd/m2, much less than that applying under normal night-driving conditions. Direct experiments under street-lighting conditions confirmed the absence of any significant night myopia. It is concluded, therefore, that neural changes, rather than night myopia, normally are responsible for the acuity loss suffered by drivers at night.

Accommodation responses to flickering stimuli

It has been suggested that accommodation to visual display unit (VDU) symbols or to stimuli lit by fluorescent tubes or similar temporally modulated light sources may be less accurate due to flicker. Furthermore, if the microfluctuations of accommodation play a part in the control of steady-state accommodation, the effects of stimulus flicker might affect the quality of this control. Experiments are described in which monocular accommodation stimulus-response curves for sinusoidal grating stimuli (1.0, 5.3 and 8.9 c/deg) were measured under the following conditions of temporal modulation: (1) square-wave on-off modulation to give spatial modulation varying between 0 and 37%; (2) sinusoidal modulation to give spatial modulation varying between 0 and 37%; (3) sinusoidal modulation to give spatial modulation varying between 16 and 32%; and (4) on-off modulation with varying mark/space ratio. Temporal modulation frequencies were between 0.5 and 7.8 Hz and above the critical fusion frequency (CFF) i.e., > or = 40 Hz. In general, the results suggest that while lower-frequency flicker may adversely affect the accuracy and stability of the accommodation response, the latter are very little affected by flicker at frequencies > or = 40 Hz. Thus flicker from fluorescent lamps or VDUs is unlikely to cause systematic accommodation difficulties. The possible relevance of the results to theories which ascribe a role for the higher-frequency (> 0.5 Hz) accommodative microfluctuations in the control of the response is considered.

Single figure indices for the steady-state accommodative response

The slope of the regression line fit is often used to characterize an accommodation response-stimulus curve. It is argued that comparisons based on this parameter alone may be misleading, as also may be those using the intercept or correlation coefficient of the regression line. It is suggested that it would be more useful to compare curves on the basis of a combination of all three regression line parameters, together with the stimulus interval over which the fit is derived. A new parameter, the accommodative error index which is effectively the mean of the magnitude of the response error divided by the correlation coefficient, is proposed to achieve this.

Effects of oxo and dihydro metabolites of 12-hydroxy-5,8,10,14-eicosatetraenoic acid on chemotaxis and cytosolic calcium levels in human neutrophils

One of the pathways of metabolism of leukotriene B4 (LTB4) and 12-hydroxy-5,8,10,14-eicosatetraenoic acid (12-HETE) in leukocytes is oxidation of the 12-hydroxyl group, followed by reduction of the 10,11-double bond. In the case of 12R-HETE and 12S-HETE, this results in the formation of 12-oxo-ETE, 10,11-dihydro-12-oxo-ETE, and the 12R and 12S isomers of 10,11-dihydro-12-HETE (i.e., 12R-HETrE and 12S-HETrE). We investigated the effects of metabolites of 12-HETE formed by this pathway on cytosolic calcium levels and chemotaxis in human neutrophils. Of the above series of metabolites, 12S-HETrE (which has the same absolute stereochemistry at C-12 as 12R-HETE) was the most potent in stimulating both cytosolic calcium levels and chemotaxis. It was slightly less potent than 12R-HETE, consistent with the concept that reduction of the 10,11-double bond results in a loss of biological activity on neutrophils. The effect of 12S-HETrE on calcium levels was blocked by preincubation of these cells with LTB4, suggesting that it acted by stimulating the LTB4 receptor. 12R-HETrE was about 20 times less potent than its 12S isomer in stimulating cytosolic calcium in neutrophils and was also less active as a chemotactic agent. Oxidation of the 12-hydroxyl group to an oxo group resulted in a further loss of biological activity. 12-Oxo-ETE, 8-trans-12-oxo-ETE, and 12-oxo-ETrE had only modest effects on cytosolic calcium levels at concentrations as high as 10 microM and did not display detectable chemotactic activity. However, 12-oxo-ETE and its 8-trans isomer inhibited calcium responses to LTB4 by about 40%. It is concluded that reduction of the 10,11-double bond of 12-HETE results in a slight loss of biological activity on neutrophils, whereas oxidation of the 12-hydroxyl group results in a considerably greater loss of activity.

Enhancement of delayed hypersensitivity inflammatory reactions in guinea pig skin by 12(R)-hydroxy-5,8,14-eicosatrienoic acid

Delayed-type hypersensitivity (DTH) reactions are initiated by sensitized T cells. Their progression is dependent upon the local release of various autacoids, including cytokines and eicosanoids, by T cells, infiltrating inflammatory cells, and resident tissue cells. 12(R)-hydroxy-5,8,14-eicosatrienoic acid [12(R)-HETrE], an eicosanoid produced by skin and cornea, possesses potent proinflammatory properties at picomolar concentrations including vasodilation, increase in membrane permeability, neutrophil chemotaxis, and angiogenesis. Because DTH reactions are associated with many of these same phenomena, we examined the effect of 12(R)-HETrE and related 12-hydroxyeicosanoids on the expression of DTH to purified protein derivative of tuberculin in sensitized guinea pigs. In the absence of purified protein derivative of tuberculin, none of the eicosanoids evoked erythema or edema after intradermal injection at doses up to 100 pmol. When injected together with purified protein derivative of tuberculin, 12(R)-hydroxy-5,8,10,14-eicosatetraenoic acid [12(R)-HETE], but not its enantiomer 12(S)-HETE, significantly inhibited macroscopic expression of delayed reactivity (erythema) only at the highest dose tested, 10 pmol. In contrast, 12(R)-HETrE significantly enhanced expression of DTH at doses between 1 fmol and 1 pmol (50% and 30% increases above control, respectively). Its stereoisomer, 12(S)-HETrE, did not enhance DTH at any tested dose, but was able to block the activity of 12(R)-HETrE when injected simultaneously. Enhancement or inhibition of visible skin responses was not associated with qualitative or quantitative changes in cellular infiltrates at the reaction site. 12(R)-HETrE had no effect on the nonimmunologic inflammatory skin reaction induced by phorbol myristate acetate, suggesting selectivity toward DTH. We conclude that 12(R)-HETrE enhances DTH via a yet to be determined mechanism and that its stereoisomer, 12(S)-HETrE, may be a useful antagonist for studying the inflammatory actions of this eicosanoid.

Anti-CD36 antibodies in patients with lupus anticoagulant and thrombotic complications

Six patients with lupus anticoagulant with thrombotic complications, but not exhibiting systemic lupus erythematosus, demonstrated the presence in their plasma of antibodies directed against platelet antigens which were not detectable in two patients presenting with lupus anticoagulant but without thrombotic complications. Protein blotting of separated normal platelet proteins against patient plasma gave up to 18 bands of varying intensity indicative of multiple antiplatelet antibodies; one of these antibodies recognized a component with a mobility identical with CD36 (GPIV; m.w. 88,000) in 4/6 cases. Antibodies to CD36 and one or two other components were identified in 5/6 cases by immunoprecipitation from 125I-labelled control platelets and 6/6 by dot blots against purified CD36. These results suggest that antiplatelet antibodies and, specifically, anti CD36 antibodies, occur frequently in the plasma of patients presenting with lupus anticoagulant and thrombotic complications.

Activation of nuclear factor kappa B and oncogene expression by 12(R)-hydroxyeicosatrienoic acid, an angiogenic factor in microvessel endothelial cells

12(R)-Hydroxy-5,8,14(Z,Z,Z)-eicosatrienoic acid (12(R)-HETrE) is an arachidonic acid metabolite formed by the corneal epithelium of several species, porcine leukocytes, and human and rat epidermal cells. It is a potent, stereospecific proinflammatory and angiogenic factor and its synthesis is increased manyfold in inflamed tissues, e.g. cornea and skin. It is possible that the angiogenic activity of 12(R)-HETrE is due to a direct mitogenic effect on microvessel endothelial cells via yet to be elucidated cellular and molecular mechanisms. In the present study, we demonstrated the ability of 12(R)-HETrE to stimulate the growth of quiescent endothelial cells in a time- and concentration-dependent manner with a maximal effect at 0.1 nM. This effect was highly stereospecific since its enantiomer, 12(S)-HETrE, had no effect within the same concentration range. Northern blot analysis and transient transfection experiments with chloramphenicol acetyltransferase constructs of oncogene promoter regions demonstrated significant increases over control (0.5% fetal calf serum) in c-myc-, c-jun, and c-fos mRNA levels and expression in cells treated with 0.1 nM 12(R)-HETrE. Electrophoretic mobility shift assay of nuclear protein extracts from cells treated with 12(R)-HETrE with specific radiolabeled oligonucleotides corresponding to known transcriptional binding sites, including AP-1, AP-2, SP1, TRE, NF kappa B, TFIID, OKT1, CREB, CTF/NF1, and GRE demonstrated a markedly rapid and specific increase in the binding activity of NF kappa B and to a lesser extent, AP-1. No significant increase was observed in the binding of other transcription factors assayed as compared to control (untreated) cells. Since the protooncogenes (c-fos, c-jun, and c-myc) are immediate early response genes that are implicated in the process of cell proliferation and differentiation, and activation of certain transcription factors, in particular NF kappa B, is associated with the immediate response of the cell to an injury, we propose that 12(R)HETrE's mitogenic and angiogenic activities are mediated, in part, via the activation of NF kappa B and expression of these protooncogenes.

Oxidation and keto reduction of 12-hydroxy-5,8,10,14-eicosatetraenoic acids in bovine corneal epithelial microsomes

The R and S enantiomers of 12-hydroxyeicosatetraenoic acid (12-HETE) exhibit different biological activities. Although they appear to be produced by different enzymatic pathways, cytochrome P-450 monooxygenase and lipoxygenase, respectively, they display similar metabolism in both corneal epithelium and neutrophils. In corneal epithelial microsomes, both enantiomers are subject to oxidation and keto reduction reactions to form the dihydro metabolite, 12-hydroxy-5,8,14-eicosatrienoic acid (12-HETrE), via a keto intermediate. The apparent Km for the formation of 12-HETrE was 17.9 and 20 microM for 12(R)-HETE and 12(S)-HETE, respectively, and the apparent Vmax of the reaction was 17.4 and 8.2 pmol/mg per min, respectively. Chiral analysis of the dihydro metabolite demonstrated a product enantiospecificity. Arachidonic acid, 12(R)-HETE, 12(S)-HETE and the intermediate of this reaction, 12-oxo-ETrE, were metabolized predominantly to 12(R)-HETrE in a ratio [12(R)-HETrE: 12(S)-HETrE] of 7.3:1, 4.3:1, 1.5:1 and 2.3:1, respectively. 12(R)-HETrE is a potent vasodilator, chemotactic and angiogenic factor whose synthesis is induced in inflamed tissues; 12(S)HETrE is devoid of these properties. 12(R)-HETE, derived from NADPH-dependent cytochrome P-450 monooxygenases, and 12(S)-HETE, derived from 12-lipoxygenase, may both play an important role in regulating the inflammatory response by serving as substrates for the local synthesis of 12(R)-HETrE.

Time-averaged accommodation response to flickering stimuli

Experiments are described in which the steady-state accommodation response versus stimulus curve was measured with an infrared autorefractor for high-contrast stimuli having a 100% square-wave temporal modulation of luminance in the frequency band 1-200 Hz. Slightly more accurate responses were found at frequencies approximately 50-100 Hz, i.e. above flicker fusion. The relevance of the results to practical situations in which flicker may be experienced is discussed.

20-Hydroxyeicosatetraenoic acid is excreted as a glucuronide conjugate in human urine

20-hydroxyeicosatetraenoic acid, a major renal P-450 metabolite of arachidonic acid, has been quantified in human urine using capillary gas chromatography/electron capture negative ion chemical ionization mass spectrometry. The urinary excretion of 20-hydroxyeicosatetraenoic acid was in the low pg/ml range. However, treatment of urine with beta-glucuronidase resulted in a 13- to 28-fold increase in its concentration. This suggests 20-hydroxyeicosatetraenoic acid differs from other eicosanoids in that it is excreted primarily as a glucuronide conjugate.

A collaborative study on the suitability of commercial, assayed plasmas for one-stage factor VIII assays

A collaborative study was carried out to determine the suitability of commercial assayed plasmas for one-stage factor VIII assays. Activated partial thromboplastin times were performed on successive days on serially diluted paired freeze-dried reference plasmas (one sample buffered with HEPES), a freeze-dried test plasma and local laboratory standards-commercial assayed plasmas and in-house frozen pooled plasmas calibrated against commercial plasmas. The factor VIII activity levels of the study reference plasmas relative to average normal plasma were arrived at cumulatively by assaying them against a large number of individual fresh normal plasmas. Estimates of the activity of the test plasma relative to the claimed activity of local standards showed significant discrepancies from the expected value. However the estimates were more precise when the activity was assessed relative to the activity of the local standards derived by calibration against the reference plasmas. The study also showed that a HEPES buffered reference plasma may not contribute to inter-laboratory variability of one-stage factor VIII assays.

Reliability of "standard" plasmas used by clinical laboratories for one-stage factor VIII assays

The reliability of "standard" plasmas used by clinical laboratories to assay factor VIII concentrations of patients' plasmas was studied by assessing the credibility of their reference values. Two of three commercial reference plasmas were considered to be unreliable. The third commercial reference plasma appeared to be suitable when assayed against frozen pools of fresh normal plasma with an assigned value of 100% activity. However, assays using fresh pools of normal plasma suggested that the reference value may lack credibility. This study also showed that assignment of 100% activity to frozen pools of fresh normal plasma prepared locally in laboratories may be fallacious.