Nasal Lipopolysaccharide Challenge and Cytokine Measurement Reflects Innate Mucosal Immune Responsiveness

<div><p>Background</p><p><b>P</b>ractical methods of monitoring innate immune mucosal responsiveness are lacking. Lipopolysaccharide (LPS) is a component of the cell wall of Gram negative bacteria and a potent activator of Toll-like receptor (TLR)-4. To measure LPS responsiveness of the nasal mucosa, we administered LPS as a nasal spray and quantified chemokine and cytokine levels in mucosal lining fluid (MLF).</p><p>Methods</p><p>We performed a 5-way cross-over, single blind, placebo-controlled study in 15 healthy non-atopic subjects (n = 14 <i>per protocol</i>). Doses of ultrapure LPS (1, 10, 30 or 100μg/100μl) or placebo were administered by a single nasal spray to each nostril. Using the recently developed method of nasosorption with synthetic adsorptive matrices (SAM), a series of samples were taken. A panel of seven cytokines/chemokines were measured by multiplex immunoassay in MLF. mRNA for intercellular cell adhesion molecule-1 (ICAM-1) was quantified from nasal epithelial curettage samples taken before and after challenge.</p><p>Results</p><p>Topical nasal LPS was well tolerated, causing no symptoms and no visible changes to the nasal mucosa. LPS induced dose-related increases in MLF levels of IL-1β, IL-6, CXCL8 (IL-8) and CCL3 (MIP-1α) (AUC at 0.5 to 10h, compared to placebo, p<0.05 at 30 and 100μg LPS). At 100μg LPS, IL-10, IFN-α and TNF-α were also increased (p<0.05). Dose-related changes in mucosal ICAM-1 mRNA were also seen after challenge, and neutrophils appeared to peak in MLF at 8h. However, 2 subjects with high baseline cytokine levels showed prominent cytokine and chemokine responses to relatively low LPS doses (10μg and 30μg LPS).</p><p>Conclusions</p><p>Topical nasal LPS causes dose-dependent increases in cytokines, chemokines, mRNA and cells. However, responsiveness can show unpredictable variations, possibly because baseline innate tone is affected by environmental factors. We believe that this new technique will have wide application in the study of the innate immune responses of the respiratory mucosa.</p><p>Key Messages</p><p>Ultrapure LPS was used as innate immune stimulus in a human nasal challenge model, with serial sampling of nasal mucosal lining fluid (MLF) by nasosorption using a synthetic absorptive matrix (SAM), and nasal curettage of mucosal cells. A dose response could be demonstrated in terms of levels of IL-1β, IL-6, CXCL8 and CCL3 in MLF, as well as ICAM-1 mRNA in nasal curettage specimens, and levels of neutrophils in nasal lavage. Depending on higher baseline levels of inflammation, there were occasional magnified innate inflammatory responses to LPS.</p><p>Trial Registration</p><p>Clinical Trials.gov <a href="https://clinicaltrials.gov/ct2/show/NCT02284074?term=nasal+lipopolysaccharide&rank=1" target="_blank">NCT02284074</a></p></div

Somatic Symptom Disorder, Conversion Disorder, and Chronic Pain: Pediatric Clinician Perspectives

Objectives: The appropriateness and relevance of somatic symptom disorder and conversion disorder (American Psychiatric Association, 2013) diagnoses are in question as they relate to pediatric chronic pain. This survey-based study on pediatric chronic pain explores how these psychiatric diagnoses are made and perceived and how treatment of patients is approached by Canadian health care professionals working in pediatric chronic pain clinics. Method: Health care professionals (N = 50) completed the survey, which contained both qualitative and quantitative items. Results: Of participants, 88% reported moderate/advanced training in pain, whereas only 26% reported moderate/advanced training in somatic symptom disorder and conversion disorder. Somatic symptom disorder and conversion disorder were reportedly diagnosed in approximately 17% and 5% of young people with chronic pain, respectively; however, overall, the participants were not confident or only slightly confident when diagnosing these disorders. There were no major differences in the reported interventions used to treat pain, somatic symptom disorder, or conversion disorder. Conclusions: These results highlight the need for standardized training in pain and psychiatric assessment, diagnosis, and treatment; diagnostic guidelines; and how to best provide this training to health care staff who work with young people with chronic pain

Impact of metal/ceramic interactions on interfacial shear strength: Study of Cr/TiN using a new modified embedded-atom potential

The effect of misfit dislocation networks (MDNs) on the stability and shear strength of Cr/TiN was investigated using a newly developed modified embedded atom model parameterized to pure Cr, CrTi, CrN, and Cr/TiN interfacial properties. The interfacial energy was lowest when the MDN was located in the Cr layer adjacent to the chemical interface, which also had the largest dislocation core widths. This was consistent with generalized stacking fault energies, which had lower energy barriers between the first and second Cr layers next to the chemical interface. As the MDN moved away from the interface, dislocation core widths consistently decreased along with the interfacial energy. For all positions of MDNs, shear failure occurred in the ceramic, between the first and second TiN layers next to the chemical interface. The lowest shear strength was found for the system with the MDN in the first Cr layer with respect to the chemical interface. Only for this particular configuration was there a significant plastic deformation present

Urban Malaria Scheme - Past, Present & Future

Urban Malaria, as a specific problem in India, was first recognized in 1969, after an in- depth review of the situation of malaria in India was done by Madhok Committee. However, main malaria vector in urban areas of India is An. stephensi, which was first recognized in early part of the 20th century. Many of the local bodies carrying out anti- larval operations earlier failed to continue the same due to paucity of funds. During that time, malaria in urban areas was not considered as a major problem because the epidemics recorded earlier in Bombay, Delhi, Lucknow etc. could immediately be contained. Based on recommendations of Madhok Committee to control malaria in urban areas, the Urban Malaria Scheme (UMS) was launched in the country in 1971–7 2. A large scale migration of population, creation of slum clusters, construction activities and water storage practices have contributed in the establishment of malaria foci. Urban malaria control is therefore based on source reduction, larviciding, minor engineering interventions, legislative measures, building bye laws and limited spraying of indoor residual spray in peri- urban and jhuggies. Initially 131 towns with a population of > 40,000 and reporting > 2 API were included in the UMS. Later in 1978, due to merger of National Filaria control programme, 206 towns were also brought under vector control support and the preventive measures against malaria vector breeding in clean water as well as filaria vector breeding in polluted water were integrated. Though there has been a well structured separate programme for prevention and control of malaria in urban areas since 1971, the priority attached to it and its implementation has been an issue primarily because it is the responsibility of the local body. Moreover, in recent past, upsurge in cases of Dengue and Chikungunya in urban areas has diverted attention on both disease surveillance and vector control. Coincidently, the vectors of malaria and dengue/ Chikungunya in urban areas breed in clean water and control strategies are same but surveillance with limited resources has affected in assessing the actual magnitude of problem. This has resulted in upsurge in cases and deaths due to malaria in Mumbai during 2010. Historical background and future vision of Urban Malaria Scheme has been discussed in present article

Evaluation of Direct Rapid Immunohistochemistry Test (DRIT) for Postmortem Diagnosis of Rabies

Direct fluorescent antibody test (DFAT) is considered as the gold standard for diagnosis of rabies in infected mammals as it has high sensitivity and specificity. However, high cost and technical demand limits its utilization, particularly in developing countries including India. Therefore, in this study we evaluated recently developed direct rapid immunohistochemistry test (DRIT) for diagnosis of rabies in comparison with the DFAT. A total of 109 brain samples received during the period of 6 years from different regions of India were tested following standard protocol. The results showed 100% correlation between the two tests.

Association of acute toxic encephalopathy with litchi consumption in an outbreak in Muzaffarpur, India, 2014: a case-control study

Background Outbreaks of unexplained illness frequently remain under-investigated. In India, outbreaks of an acute neurological illness with high mortality among children occur annually in Muzaffarpur, the country’s largest litchi cultivation region. In 2014, we aimed to investigate the cause and risk factors for this illness. Methods In this hospital-based surveillance and nested age-matched case-control study, we did laboratory investigations to assess potential infectious and non-infectious causes of this acute neurological illness. Cases were children aged 15 years or younger who were admitted to two hospitals in Muzaffarpur with new-onset seizures or altered sensorium. Age-matched controls were residents of Muzaffarpur who were admitted to the same two hospitals for a non-neurologic illness within seven days of the date of admission of the case. Clinical specimens (blood, cerebrospinal fluid, and urine) and environmental specimens (litchis) were tested for evidence of infectious pathogens, pesticides, toxic metals, and other non-infectious causes, including presence of hypoglycin A or methylenecyclopropylglycine (MCPG), naturally-occurring fruit-based toxins that cause hypoglycaemia and metabolic derangement. Matched and unmatched (controlling for age) bivariate analyses were done and risk factors for illness were expressed as matched odds ratios and odds ratios (unmatched analyses). Findings Between May 26, and July 17, 2014, 390 patients meeting the case definition were admitted to the two referral hospitals in Muzaffarpur, of whom 122 (31%) died. On admission, 204 (62%) of 327 had blood glucose concentration of 70 mg/dL or less. 104 cases were compared with 104 age-matched hospital controls. Litchi consumption (matched odds ratio [mOR] 9·6 [95% CI 3·6 – 24]) and absence of an evening meal (2·2 [1·2–4·3]) in the 24 h preceding illness onset were associated with illness. The absence of an evening meal significantly modified the effect of eating litchis on illness (odds ratio [OR] 7·8 [95% CI 3·3–18·8], without evening meal; OR 3·6 [1·1–11·1] with an evening meal). Tests for infectious agents and pesticides were negative. Metabolites of hypoglycin A, MCPG, or both were detected in 48 [66%] of 73 urine specimens from case-patients and none from 15 controls; 72 (90%) of 80 case-patient specimens had abnormal plasma acylcarnitine profiles, consistent with severe disruption of fatty acid metabolism. In 36 litchi arils tested from Muzaffarpur, hypoglycin A concentrations ranged from 12·4 μg/g to 152·0 μg/g and MCPG ranged from 44·9 μg/g to 220·0 μg/g. Interpretation Our investigation suggests an outbreak of acute encephalopathy in Muzaffarpur associated with both hypoglycin A and MCPG toxicity. To prevent illness and reduce mortality in the region, we recommended minimising litchi consumption, ensuring receipt of an evening meal and implementing rapid glucose correction for suspected illness. A comprehensive investigative approach in Muzaffarpur led to timely public health recommendations, underscoring the importance of using systematic methods in other unexplained illness outbreaks