Beneficial versus Detrimental Effects of Complement-Microglial Interactions in Alzheimer's Disease.

Research indicates that brain-region-specific synapse loss and dysfunction are early hallmarks and stronger neurobiological correlates of cognitive decline in Alzheimer's disease (AD) than amyloid plaque and neurofibrillary tangle counts or neuronal loss. Even though the precise mechanisms underlying increased synaptic pruning in AD are still unknown, it has been confirmed that dysregulation of the balance between complement activation and inhibition is a crucial driver of its pathology. The complement includes three distinct activation mechanisms, with the activation products C3a and C5a, potent inflammatory effectors, and a membrane attack complex (MAC) leading to cell lysis. Besides pro-inflammatory cytokines, the dysregulated complement proteins released by activated microglia bind to amyloid ß at the synaptic regions and cause the microglia to engulf the synapses. Additionally, research indicating that microglia-removed synapses are not always degenerating and that suppression of synaptic engulfment can repair cognitive deficits points to an essential opportunity for intervention that can prevent the loss of intact synapses. In this study, we focus on the latest research on the role and mechanisms of complement-mediated microglial synaptic pruning at different stages of AD to find the right targets that could interfere with complement dysregulation and be relevant for therapeutic intervention at the early stages of the disease.

Role of HbA1c in diagnosis of gestational diabetes mellitus.

OBJECTIVE: To evaluate glycated haemoglobin as a biomarker for diagnosing gestational diabetes mellitus while keeping the oral glucose tolerance test as the gold standard. METHODS: The cross-sectional study was conducted from Januray, 2016, to January, 2018, at PNS Hafeez Hospital, Islamabad, Pakistan and comprised of pregnant subjects who were first subjected to 2-hour oral glucose tolerance test along with the first evaluation of glycated haemoglobin. Clinical evaluation, including history and measurements of anthropometric indices and blood pressure, were also done. On the basis of the results, the subjects were grouped as those having gestational diabetes mellitus (group A) and those without it (group B). Data was analysed using SPSS 15. RESULTS: Of the 280 subjects, gestational diabetes mellitus was found in 50(17.85%). Differences in glycated haemoglobin between the groups was significant (p<0.002). Glycated haemoglobin test provided sensitivity of 70% and specificity of 84.78%. CONCLUSIONS: With due adjustments, glycated haemoglobin testing can help in reducing the frequency of oral glucose tolerance test.

Impact of COVID-19 on percutaneous coronary intervention for ST-elevation myocardial infarction.

BACKGROUND: The objective of the study was to identify any changes in primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI) in England by analysing procedural numbers, clinical characteristics and patient outcomes during the COVID-19 pandemic. METHODS: We conducted a retrospective cohort study of patients who underwent PCI in England between January 2017 and April 2020 in the British Cardiovascular Intervention Society-National Institute of Cardiovascular Outcomes Research database. Analysis was restricted to 44 hospitals that reported contemporaneous activity on PCI. Only patients with primary PCI for STEMI were included in the analysis. RESULTS: A total of 34 127 patients with STEMI (primary PCI 33 938, facilitated PCI 108, rescue PCI 81) were included in the study. There was a decline in the number of procedures by 43% (n=497) in April 2020 compared with the average monthly procedures between 2017 and 2019 (n=865). For all patients, the median time from symptom to hospital showed increased after the lockdown (150 (99-270) vs 135 (89-250) min, p=0.004) and a longer door-to-balloon time after the lockdown (48 (21-112) vs 37 (16-94) min, p<0.001). The in-hospital mortality rate was 4.8% before the lockdown and 3.5% after the lockdown (p=0.12). Following adjustment for baseline characteristics, no differences were observed for in-hospital death (OR 0.87, 95% CI 0.45 to 1.68, p=0.67) and major adverse cardiovascular events (OR 0.71, 95% CI 0.39 to 1.32, p=0.28). CONCLUSIONS: Following the lockdown in England, we observed a decline in primary PCI procedures for STEMI and increases in overall symptom-to-hospital and door-to-balloon time for patients with STEMI. Restructuring health services during COVID-19 has not adversely influenced in-hospital outcomes.

Comparison of Reproductive Hormonal Profile and Sexual Performance Satisfaction among Type-2 Diabetes Mellitus and Controls.

OBJECTIVE: To evaluate reproductive hormonal profile among three groups with varying sexual performance satisfaction (erectile dysfunction) with or without type-2 diabetes (T2DM). STUDY DESIGN: Comparative cross-sectional analysis. PLACE AND DURATION OF STUDY: Department of Pathology, PNS Hafeez Hospital, Islamabad, from January to December, 2018. METHODOLOGY: One hundred and twenty-one subjects including T2DM and age-matched controls were segregated into three groups based upon their sexual performance satisfaction. These groups were evaluated by one-way ANOVA for various anthropometric, glycemic indices and reproductive hormones and free androgen indices (FAI). A general linear model (GLM) was utilised using HbA1c and FAI as dependent variable with sexual performance satisfaction as fixed and quantitative CRP and urinary albumin creatinine ratio (UACR) as random variables to evaluate diabetes complication and inflammation on sexual performance. RESULTS: Comparison between three groups suggested a rising trend for FAI as: FAI: {Non-satisfied (n=43):41.78 (95%CI:36.67-46.90)}, {Just satisfied (n=38):48.81(95%CI: 42.96-54.66)}, {Satisfied (n=40):51.86 (95%CI:45.27-58.44)}, [p=0.041]. GLM model evaluation suggestion that for any particular degree of reported ED, HbA1c demonstrated a higher trend from non-satisfied subjects to satisfied subjects with inflammation following a rise with HbA1c levels, identifying inflammation as more related with worsening diabetes than with sexual performance satisfaction. FAI levels were higher among subjects who showed no erectile dysfunction than subjects with less satisfied groups with both inflammation (qCRP) and nephropathy (UACR) causing across the group decline for FAI among all ED groups. CONCLUSION: Sexual performance satisfaction and FAI decline with rise in HbA1c. Moreover, subjects having nephropathy or higher inflammation (qCRP) were found to have lower FAI and ED, both in controls and T2DM.

Comparison of Various Abdominal Obesity Measures for Predicting Metabolic Syndrome, Diabetes, Nephropathy, and Dyslipidemia.

OBJECTIVE: To evaluate abdominal volume index (AVI), body roundness index (BRI), body adiposity index (BAI), a body shape index (ABSI) and conicity index (C-Index) for differences in subjects with or without metabolic syndrome, diabetes, nephropathy, and dyslipidemia; and secondly, to evaluate the diagnostic performance through measuring area under curve (AUC) by ROC curve analysis for new and conventional obesity measures in diagnosing metabolic syndrome. STUDY DESIGN: Cross-sectional analytical study. PLACE AND DURATION OF STUDY: PNS Hafeez Hospital, Islamabad, from January 2016 to December 2018. METHODOLOGY: Baseline anthropometric measures including BMI, WHpR, WHtR, AVI, BRI, BAI, ABSI and C-Index were measured for 232 subjects along with measurement of various biochemical parameters. Differences among subjects with and without metabolic syndrome, diabetes, nephropathy, and groups based upon insulin resistance were noted. ROC curve analysis was utilised to measure AUC for all anthropometric measures for diagnosing metabolic syndrome. RESULTS: Pearson's correlation between obesity measures and lipid indices suggested highest correlation for AVI for most lipid indices followed by WHpR and WHtR. Mean AUC for obesity measures were greater than 0.80 for WHtR and AVI, followed by other parameters. The least AUC i.e. 0.320, was observed for ABSI. The differences between various anthropometric measures for groups based upon metabolic syndrome, diabetes, nephropathy, and insulin resistance remain variable indicating that each anthropometric index may depict a different aspect of the metabolic risk. CONCLUSION: WHtR and AVI showed the highest AUC to diagnose metabolic syndrome and were better associated with metabolic diseases.

Comparison of various steady state surrogate insulin resistance indices in diagnosing metabolic syndrome.

BACKGROUND: Insulin resistance is core cause of metabolic syndrome. Determining insulin resistance is one of the foremost requirements imperative to understanding the pathophysiology of disease. The gold standard "Euglycaemic clamp test" is cumbersome, long and non-feasible in routine clinical setups to diagnose metabolic syndrome. Various continuous and steady state insulin resistance indices are now available in literature. We plan to evaluate commonly utilized steady state insulin resistance indices directly and Homeostasis Model Assessment for Insulin Resistance (HOMAIR) with added triglyceride (HOMA-TG index). METHODS: The cross-sectional study was carried from Jan-2016 to Dec-2018 at PNS HAFEEZ and department of chemical pathology, AFIP with following objectives: (1) To evaluate steady state insulin resistance markers for diagnosing metabolic syndrome as per IDF defined criteria by ROC curve analysis, (2) to measure Kendal Concordance between various insulin resistance indices and (3) to correlate steady state insulin resistance markers with anthropometric and lipid indices. After several exclusions we selected 224 subjects based upon "non-probability convenience sampling" for inclusion in study. Clinical history, anthropometric measures were calculated and sampling was done for insulin, glucose and other biochemical parameters. Metabolic syndrome was diagnosed as per IDF criteria, while HbA1c was utilized to diagnose diabetes mellitus. Pearson correlation was used to correlate various steady state insulin resistance indices including HOMAIR, HOMA2 index, QUICKI, G/I ratio, HOMA-TG index and serum insulin. AUC was calculated by ROC analysis for all surrogate insulin measures in diagnosis of metabolic syndrome. RESULTS: "HOMA-TG index" has shown the highest AUC for diagnosing metabolic syndrome along with higher correlation with lipid markers and anthropometric indices in comparison to other steady-state insulin resistance markers. Furthermore, QUICKI and G/I ratio showed the lowest AUC for detection of metabolic syndrome. CONCLUSION: "HOMA-TG index" has shown highest AUC for metabolic syndrome diagnosis. However, QUICKI and G/I ration showed the lowest AUC for detection of metabolic syndrome. It is hoped that the potential "HOMA-TG index" may provide better diagnostic efficiency for diagnosing metabolic syndrome.

Friedewald's equation for calculating LDL-cholesterol: Is it the time to say "Goodbye" and adopt direct LDL cholesterol methods?

OBJECTIVES: To measure correlation and concordance between measured LDL cholesterol (mLDLc) and Friedewald's calculated LDL cholesterol (cLDLc). To compare the mLDLc and cLDLc values for various anthropometric measures and biochemical indices including insulin resistance, nephropathy, glycated hemoglobin and triglycerides. METHODS: Two hundred thirty two subjects were included in this cross-sectional analysis from Jan-2016 to July-2017 from a target population visiting PNS HAFEEZ hospital. Mean age of the subjects was 46.56(±11.95) years (n=232). These subjects underwent clinical evaluation including measurement of anthropometric measurements, biochemical testing for fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), lipid profile, urine albumin creatinine ratio (UACR), and insulin. Correlation and concordance between mLDLc and Friedewald's cLDLc were measured. Finally, Comparison of risk evaluation for mLDLc and cLDLc between groups formulated based upon UACR (Based upon a cut off of 2.5 mg/g) and fasting triglycerides (Group-1 :< 1.0 mmol/L, Group-2: 1.0-1.99 mmol/L and Group-3 :> 1.99 mmol/) was carried out. RESULTS: There was significant positive linear correlation between mLDLc and cLDLc [r=0.468, <0.001]. Kendall's Coefficient of concordance between mLDLc and cLDLc was 0.055 (p<0.001). Differences evaluated by one way ANOVA analysis for mLDLc between various triglycerides groups were only significant between group-1 and group-2 [{Group-1:Mean=2.40, (2.19-2.61), n=43}, {Group-2:Mean=2.81, (2.69-2.92), n=136}, [{Group-3:Mean=2.59,(2.37-2.81), n=53}],(p=0.004) in comparison to cLDLc [{Group-1:Mean=2.63, (2.43-2.84), n=43}, {Group-2:Mean=2.85, (2.76-2.93), n=136}, [{Group-3:Mean=2.75, (2.60-2.90), n=53}]. Calculated method for LDLc showed higher UACR than mLDLc. (p=0.021). CONCLUSION: cLDLc over estimates LDL-cholesterol in comparison to mLDLc. The correlation between cLDLc and mLDLc was only moderate. However, cLDLc provided better degree of risk prediction for nephropathy and glycated hemoglobin than mLDLc.

Glucose Tolerance versus HbA1c Results as Depictive of Gestational Diabetes Mellitus.

OBJECTIVE: To evaluate glucose tolerance patterns in pregnant ladies undergoing 2-hour oral glucose tolerance test (OGTT) for comparing fasting, 1-hour, 2-hour post-glucose load results, HbA1c, sum of all glucose readings with and without gestational diabetes mellitus (GDM) using International Association of the Diabetes and Pregnancy Study Group (IADPSG) diagnostic criteria. STUDY DESIGN: Cross-sectional analysis. PLACE AND DURATION OF STUDY: PNS Hafeez, Naval Hospital, Islamabad, from January 2016 to July 2017. METHODOLOGY: For 280 evaluated subjects reporting in mid-pregnancy for OGTT, results were segregated into four groups based upon comparison of 2-hour glucose result with 1-hour glucose. Group-1 2-hour results drop being >2.0 mmol/L than1-hour results, group-2 with 2-hour result between <2.0 to >0.5 mmol/L than peak at 1-hour, and group-3 with either 2-hour glucose drop being <0.5mmol/L or >1-hour results. Further, the ROC curve analysis was performed to compare the AUC for fasting plasma glucose, 1-hour post OGTT result, 2-hour post-OGTT result, factor additive of all OGTT readings and HbA1c. RESULTS: There was a progressive rise in HbA1c from group-1 to group-3 (p<0.001). Area under curve (AUC) for various diagnostic parameters for diagnosing GDM for additive value of all glucose results was 0.962 (95% CI: 0.935-0.988), 0.881 (95% CI: 0.818-0944) for plasma glucose at 2-hour, for plasma glucose at 1-hour 0.898 (95% CI: 0.0.842-0.954), 0.831 (95% CI: 0.0.762-0.901) for fasting plasma glucose and 0.668 (95% CI: 0.0.578-0.759) for HbA1c (p<0.001). CONCLUSION: Pregnant ladies demonstrating poor tolerance to glucose at 2-hour were observed to have higher HbA1c levels.

Metabolic clustering of risk factors: evaluation of Triglyceride-glucose index (TyG index) for evaluation of insulin resistance.

BACKGROUND: Metabolic syndrome over the years have structured definitions to classify an individual with the disease. Literature review suggests insulin résistance is hallmark of these metabolic clustering. While measuring insulin resistance directly or indirectly remains technically difficult in general practice, along with multiple stability issues for insulin, various indirect measures have been suggested by authorities. Fasting triglycerides-glucose (TyG) index is one such marker, which is recently been suggested as a useful diagnostic marker to predict metabolic syndrome. However, limited data is available on the subject with almost no literature from our region on the subject. OBJECTIVE: 1. To correlate TyG index with insulin resistance, anthropometric indices, small dense LDLc, HbA1c and nephropathy. 2. To evaluate TyG index as a marker to diagnose metabolic syndrome in comparison to other available markers. DESIGN-CROSS-SECTIONAL ANALYSIS: Place and duration of study-From Jun-2016 to July-2017 at PSS HAFEEZ hospital Islamabad. SUBJECTS AND METHODS: From a finally selected sample size of 227 male and female subjects we evaluated their anthropometric data, HbA1c, lipid profile including calculated sdLDLc, urine albumin creatinine raito(UACR) and insulin resistance (HOMAIR). TyG index was calculated using formula of Simental-Mendía LE et al. Aforementioned parameters were correlated with TyG index, differences between subjects with and without metabolic syndrome were calculated using Independent sample t-test. Finally ROC curve analysis was carried out to measure AUC for candidate parameters including TyG Index for comparison. RESULTS: TyG index in comparison to other markers like fasting triglycerides, HOMAIR, HDLc and non-HDLc demonstrated higher positive linear correlation with BMI, atherogenic dyslipidemia (sdLDLc), nephropathy (UACR), HbA1c and insulin resistance. TyG index showed significant differences between various markers among subjects with and without metabolic syndrome as per IDF criteria. AUC (Area Under Curve) demonstrated highest AUC for TyG as [(0.764, 95% CI 0.700-0.828, p-value ≤ 0.001)] followed by fasting triglycerides [(0.724, 95% CI 0.656-0.791, p-value ≤ 0.001)], sdLDLc [(0.695, 95% CI 0.626-0.763, p-value ≤ 0.001)], fasting plasma glucose [(0.686, 95% CI 0.616-0.756, p-value ≤ 0.001)], Non-HDLc [(0.640, 95% CI 0.626-0.763, p-value ≤ 0.001)] and HOMAIR [(0.619, 95% CI 0.545-0.694, p-value ≤ 0.001)]. CONCLUSION: TyG index, having the highest AUC in comparison to fasting glucose, triglycerides, sdLDLc, non-HDLc and HOMAIR can act as better marker for diagnosing metabolic syndrome.

Association of metabolic risks with subclinical hypothyroidism: A cross-sectional analysis.

OBJECTIVE: To compare lipid parameters, HbA1c, uric acid and albumin creatinine ratio (UACR) among subjects having euthyroidism, Sub-Clinical Hypothyroidism (SCH) and overt hypothyroidism. METHODS: This comparative cross-sectional analysis was carried out from Dec-2015 to Oct-2016 in collaboration between PNS HAFEEZ hospital and department of chemical pathology and endocrinology, Armed Forces Institute of Pathology, Rawalpindi. Biochemical parameters including lipid indices, HbA1c and UACR were compared between euthyroidism (TSH: 0.5 to 4.0 mIU/L, n=163), subclinical hypothyroidism (TSH: 4.0 to 10 mIU/L, n=16) and overt hypothyroidism (TSH:≥ 10.0 mIU/L, n=9). RESULTS: LDL-cholesterol, non-HDL-cholesterol and UACR results were as: [(Euthyroid: 2.66 ± 0.73), (SCH: 2.68 ± 0.51) and (Overt hypothyroidism: 3.23 ± 0.59), p-value=0.063], [(Euthyroid: 3.49 ± 0.64), (SCH: 3.35 ± 0.59) and (Overt hypothyroidism: 4.01 ± 0.30), p-value=0.033] and [{Euthyroid: 2.48 (95% CI: 1.63-3.33)}, {SCH: 2.27 (95% CI: 0.37-4.90)} and {Overt hypothyroidism: 14.95 (95% CI: 10.71-19.14){, (p-value< 0.001)] Results for total cholesterol, triglycerides and HDL-cholesterol though increased in overt hypothyroid group were not found to be statistically significant. CONCLUSION: LDL-cholesterol, non-HDL-cholesterol and UACR increased from euthyroid subjects to overt hypothyroidism group. However, these changes were found to be more subtle in the subclinical hypothyroid subjects than cases with overt hypothyroidism.

Status of non-HDL-cholesterol and LDL-cholesterol among subjects with and without metabolic syndrome.

OBJECTIVE: To to compare non-high-density lipoprotein and low-density lipoprotein cholesterol among subjects with or without metabolic syndrome, glycation status and nephropathic changes. METHODS: The comparative cross-sectional study was carried out from Dec 21, 2015, to Nov 15, 2016, at the department of pathology and medicine PNS HAFEEZ and department of chemical pathology and clinical endocrinology (AFIP), and comprised patients of either gender visiting the out-patient department for routine screening. They were evaluated for anthropometric indices, blood pressure and sampled for lipid profile, fasting plasma glucose, glycated haemoglobin, insulin, and urine albumin-to-creatinine ratio. Subjects were segregated based upon presence (Group1) or absence (Group2) of metabolic syndrome based upon criteria of National Cholesterol Education Programme and the International Diabetes Federation. Differences in high and low density lipoprotein cholesterols were calculated between the groups. RESULTS: Of the 229 subjects, 120(52.4%) were women and 109(47.6%) were men. Overall, there were 107(46.7%) subjects in Group 1, and 122(53.3%) in Group 2. Non-high-density lipoprotein cholesterol was significantly different between subjects with and without metabolic syndrome as per both the study criteria (p<0.05 each). . CONCLUSIONS: Non-high-density lipoprotein cholesterol levels were higher in subjects with metabolic syndrome.

Insulin Resistance and Glucose Levels in Subjects with Subclinical Hypothyroidism.

OBJECTIVE: To compare insulin resistance and glycemic indicators among subjects with euthyroidism and subclinical hypothyroidism. STUDY DESIGN: Comparative cross-sectional study. PLACE AND DURATION OF STUDY: Department of Pathology and Medicine, PNS Hafeez, Islamabad, in collaboration with the Department of Chemical Pathology and Endocrinology at the Armed Forces Institute of Pathology (AFIP), Rawalpindi, from December 2015 to September 2016. METHODOLOGY: Subjects referred for executive screening of apparently healthy population (without any known history of diabetes, hypertension, heart disease or other chronic ailments), were included. Subjects were grouped as euthyroidism and subclinical hypothyroidism. RESULTS: Median (IQR) insulin resistance indices including fasting insulin and Homeostasis Model Assessment for Insulin Resistance in subjects with group-1 (n=176, 87%, Thyroid Stimulating Hormone: 0.5 - 3.5 mIU/L) and group-2 (n=26, 13%, Thyroid Stimulating Hormone: 3.51 - 15 mIU/L) were 7.6 (6.70) vs. 11.4 (13.72, p=0.040) and 1.77 (1.79) vs. 2.8 (3.07, p=0.071). The median differences for fasting plasma glucose were 5.0 (1.0) in group-1 vs. 5.0 (1.47) for Group-2 [p=0.618], and glycated hemoglobin was 5.60 (1.1) vs. 5.60 (1.7, p=0.824). Homeostasis Model Assessment for beta sensitivity index in paradox showed slightly higher values for group-2 [median (IQR) 86.67 (92.94)] than group-1 [111.6 (189.64, p= 0.040)]. CONCLUSION: Measures of insulin resistance including Homeostasis Model Assessment for Insulin Resistance and fasting insulin levels were significantly different between subjects with euthyroidism and having subclinical hypothyroidism.

Correlation between Cholesterol, Triglycerides, Calculated, and Measured Lipoproteins: Whether Calculated Small Density Lipoprotein Fraction Predicts Cardiovascular Risks.

BACKGROUND: Recent literature in lipidology has identified LDL-fractions to be more atherogenic. In this regard, small density LDL-cholesterol (sdLDLc) has been considered to possess more atherogenicity than other LDL-fractions like large buoyant LDL-cholesterol (lbLDLc). Recently, Srisawasdi et al. have developed a method for calculating sdLDLc and lbLDLc based upon a regression equation. Using that in developing world may provide us with a valuable tool for ASCVD risk prediction. OBJECTIVE: (1) To correlate directly measured and calculated lipid indices with insulin resistance, UACR, glycated hemoglobin, anthropometric indices, and blood pressure. (2) To evaluate these lipid parameters in subjects with or without metabolic syndrome, nephropathy, and hypertension and among various groups based upon glycated hemoglobin results. DESIGN: Cross-sectional study. Place and Duration of Study. From Jan 2016 to 15 April 2017. SUBJECTS AND METHODS: Finally enrolled subjects (male: 110, female: 122) were evaluated for differences in various lipid parameters, including measured LDL-cholesterol (mLDLc), HDLc and calculated LDL-cholesterol (cLDLc), non-HDLc, sdLDLC, lbLDLC, and their ratio among subjects with or without metabolic syndrome, nephropathy, glycation index, anthropometric indices, and hypertension. RESULTS: Significant but weak correlation was mainly observed between anthropometric indices, insulin resistance, blood pressure, and nephropathy for non-HDLc, sdLDLc, and sdLDLc/lbLDLc. Generally lipid indices were higher among subjects with metabolic syndrome [{sdLDLc: 0.92 + 0.33 versus 0.70 + 0.29 (p < 0.001)}, {sdLDLc/lbLDLc: 0.55 + 0.51 versus 0.40 + 0.38 (p = 0.010)}, {non-HDLc: 3,63 + 0.60 versus 3.36 + 0.65 (p = 0.002)}]. The fact that the sdLDLc levels provided were insignificant in Kruskall Wallis Test indicated a sharp increase in subjects with HbA1c > 7.0%. Subjects having nephropathy (UACR > 2.4 mg/g) had higher concentration of non-HDLc levels in comparison to sdLDLc [{non-HDLc: 3.68 + 0.59 versus 3.36 + 0.43} (p = 0.007), {sdLDLc: 0.83 + 0.27 versus 0.75 + 0.35 (p = NS)}]. CONCLUSION: Lipid markers including cLDLc and mLDLc are less associated with traditional ASCVD markers than non-HDLc, sdLDLc, and sdLDLc/lbLDLc in predicting metabolic syndrome, nephropathy, glycation status, and hypertension.

Evidence for simvastatin anti-inflammatory actions based on quantitative analyses of NETosis and other inflammation/oxidation markers.

Simvastatin (SMV) has been shown to exhibit promising anti-inflammatory properties alongside its classic cholesterol lowering action. We tested these emerging effects in a major thermal injury mouse model (3rd degree scald, ~20% TBSA) with previously documented, inflammation-mediated intestinal defects. Neutrophil extracellular traps (NETs) inflammation measurement methods were used alongside classic gut mucosa inflammation and leakiness measurements with exogenous melatonin treatment as a positive control. Our hypothesis is that simvastatin has protective therapeutic effects against early postburn gut mucosa inflammation and leakiness. To test this hypothesis, we compared untreated thermal injury (TI) adult male mice with TI littermates treated with simvastatin (0.2 mg/kg i.p., TI + SMV) immediately following burn injury and two hours before being sacrificed the day after; melatonin-treated (Mel) (1.86 mg/kg i.p., TI + Mel) mice were compared as a positive control. Mice were assessed for the following: (1) tissue oxidation and neutrophil infiltration in terminal ileum mucosa using classic carbonyl, Gr-1, and myeloperoxidase immunohistochemical or biochemical assays, (2) NETosis in terminal ileum and colon mucosa homogenates and peritoneal and fluid blood samples utilizing flow cytometric analyses of the surrogate NETosis biomarkers, picogreen and Gr-1, and (3) transepithelial gut leakiness as measured in terminal ileum and colon with FITC-dextran and transepithelial electrical resistance (TEER). Our results reveal that simvastatin and melatonin exhibit consistently comparable therapeutic protective effects against the following: (1) gut mucosa oxidative stress as revealed in the terminal ileum by markers of protein carbonylation as well as myeloperoxidase (MPO) and Gr-1 infiltration, (2) NETosis as revealed in the gut milieu, peritoneal lavage and plasma utilizing picogreen and Gr-1 flow cytometry and microscopy, and (3) transepithelial gut leakiness as assessed in the ileum and colon by FITC-dextran leakiness and TEER. Thus, simvastatin exhibits strong acute anti-inflammatory actions associated with marked decreases in gut tissue and systemic NETosis and decreased gut mucosa leakiness.

OX62+OX6+OX35+ rat dendritic cells are unable to prime CD4+ T cells for an effective immune response following acute burn injury.

Co-stimulatory molecules expressed on Dendritic Cells (DCs) function to coordinate an efficient immune response by T cells in the peripheral lymph nodes. We hypothesized that CD4+ T cell-mediated immune suppression following burn injury may be related to dysfunctional DCs residing in gut associated lymphoid tissues (GALT), such as Mesenteric Lymph Nodes (MLN). Therefore, we studied co-stimulatory molecules expressed on burn rat MLN DCs as an index of functional DCs that would mount an effective normal CD4+ T cell immune response. In a rat model of 30% Total Body Surface Area (TBSA) scald burn, OX62+OX6+OX35+ DCs and CD4+ T cells were isolated from MLN of day 3 post-burn and sham control rats. DCs were tested for their expression of co-stimulatory molecules, and prime CD4+ T cell (DC:CD4+T cell co-culture assays) to determine an effector immune response such as CD4+ T cell proliferation. The surface receptor expressions of MLN DCs co-stimulatory molecules, i.e., MHC-II, CD40, CD80 (B7-1), and CD86 (B7-2) were determined by Flow cytometry (quantitatively) and confocal microscopy (qualitatively). Tritiated thymidine and CFDA-SE determined CD4+ T cell proliferation following co-incubation with DCs. Cytokine milieu of MLN (IL-12 and IL-10) was assessed by mRNA determination by RT-PCR. The results showed down-regulated expressions of co-stimulatory markers (CD80, CD86, CD40 and MHC-II) of MLN DCs obtained from burn-injured rats, as well as lack of ability of these burn-induced DCs to stimulate CD4+ T cell proliferation in co-culture assays, as compared to the sham rats. Moreover, anti-CD40 stimulation of affected burn MLN DCs did not reverse this alteration. Furthermore, a marked up-regulation of mRNA IL-10 and down-regulation of mRNA IL-12 in burn MLN as compared to sham animals was also observed. To surmise, the data indicated that dysfunctional OX62+OX6+OX35+ rat MLN DCs may contribute to CD4+ T-cell-mediated immune suppression observed following acute burn injury.

Burn-injury affects gut-associated lymphoid tissues derived CD4+ T cells.

After scald burn-injury, the intestinal immune system responds to maintain immune balance. In this regard CD4+T cells in Gut-Associated Lymphoid Tissues (GALT), like mesenteric lymph nodes (MLN) and Peyer's patches (PP) respond to avoid immune suppression following major injury such as burn. Therefore, we hypothesized that the gut CD4+T cells become dysfunctional and turn the immune homeostasis towards depression of CD4+ T cell-mediated adaptive immune responses. In the current study we show down regulation of mucosal CD4+ T cell proliferation, IL-2 production and cell surface marker expression of mucosal CD4+ T cells moving towards suppressive-type. Acute burn-injury lead to up-regulation of regulatory marker (CD25+), down regulation of adhesion (CD62L, CD11a) and homing receptor (CD49d) expression, and up-regulation of negative co-stimulatory (CTLA-4) molecule. Moreover, CD4+CD25+ T cells of intestinal origin showed resistance to spontaneous as well as induced apoptosis that may contribute to suppression of effector CD4+ T cells. Furthermore, gut CD4+CD25+ T cells obtained from burn-injured animals were able to down-regulate naïve CD4+ T cell proliferation following adoptive transfer of burn-injured CD4+CD25+ T cells into sham control animals, without any significant effect on cell surface activation markers. Together, these data demonstrate that the intestinal CD4+ T cells evolve a strategy to promote suppressive CD4+ T cell effector responses, as evidenced by enhanced CD4+CD25+ T cells, up-regulated CTLA-4 expression, reduced IL-2 production, tendency towards diminished apoptosis of suppressive CD4+ T cells, and thus lose their natural ability to regulate immune homeostasis following acute burn-injury and prevent immune paralysis.

Differential effector responses by circulating/blood and tissue/peritoneal neutrophils following burn combined with Enterococcus faecalis infection.

Recently we found that superimposition of Enterococcus faecalis infection on burn injury caused an eruption of host mortality not seen with either individual challenge. We hypothesized that the Enterococcus bacteria, and/or factors related to these organisms, aggravate burn-induced modulations in host defense by neutrophils. Our study focuses on alterations in neutrophils' oxidative, proteolytic, and adhesive functions and transendothelial migration of neutrophils in burn rats inoculated with E. faecalis. Rats were subjected to burn (30% total body surface area) and then intra-abdominally inoculated with E. faecalis (10(4)CFU kg(-1) b.w). Polymorphonuclear neutrophils (PMNs) were harvested from circulating/blood and tissue/peritoneal cavity at day-2 post injury. Extracellular release of O(-)(2) anion production was determined by luminometry, and intracellular production of reactive oxygen species was measured by digital imaging technique. Fluoroscan analysis and confocal microscopy determined intracellular elastase production. The expression of adhesion molecule CD11b/CD18 was performed by flow cytometry. Calcein AM-labeled PMNs were co-cultured with TNF-α-stimulated rat lung microvascular endothelial cells, and their ability to adhere was assessed by fluorometry and digital imaging and finally, chemotaxis was measured by neutrophil transmigration assays. The results showed differential effector responses by circulatory and/or tissue PMNs. Tissue/peritoneal PMNs produced more O(-)(2), less intracellular elastase, and increased expression of CD11b/CD18 accompanied with increased adhesivity of MIP-2-stimulated PMNs to endothelial cells as compared to circulatory/blood PMNs. This differential effect was more pronounced following burn plus E. faecalis infection, indicating that the combined injury changed neutrophil functions.

Melatonin plays a protective role in postburn rodent gut pathophysiology.

Melatonin is a possible protective agent in postburn gut pathophysiological dynamics. We investigated the role of endogenously-produced versus exogenously-administered melatonin in a major thermal injury rat model with well-characterized gut inflammatory complications. Our rationale is that understanding in vivo melatonin mechanisms in control and inflamed tissues will improve our understanding of its potential as a safe anti-inflammatory/antioxidant therapeutic alternative. Towards this end, we tested the hypothesis that the gut is both a source and a target for melatonin and that mesenteric melatonin plays an anti-inflammatory role following major thermal injury in rats with 3rd degree hot water scald over 30% TBSA. Our methods for assessing the gut as a source of melatonin included plasma melatonin ELISA measurements in systemic and mesenteric circulation as well as rtPCR measurement of jejunum and terminal ileum expression of the melatonin synthesizing enzymes arylalkylamine N-acetyltransferase (AA-NAT) and 5-hydroxyindole-O-methyltransferase (HIOMT) in sham versus day-3 postburn rats. Our melatonin ELISA results revealed that mesenteric circulation has much higher melatonin than systemic circulation and that both mesenteric and systemic melatonin levels are increased three days following major thermal injury. Our rtPCR results complemented the ELISA data in showing that the melatonin synthesizing enzymes AA-NAT and HIOMT are expressed in the ileum and jejunum and that this expression is increased three days following major thermal injury. Interestingly, the rtPCR data also revealed negative feedback by melatonin as exogenous melatonin supplementation at a dose of 7.43 mg (32 micromole/kg), but not 1.86 mg/kg (8 micromole/kg) drastically suppressed AA-NAT mRNA expression. Our methods also included an assessment of the gut as a target for melatonin utilizing computerized immunohistochemical measurements to quantify the effects of exogenous melatonin supplementation on postburn gut mucosa barrier inflammatory profiles. Here, our results revealed that daily postburn intraperitoneal melatonin administration at a dose of 1.86 mg/kg (8 micromole/kg) significantly suppressed both neutrophil infiltration and tyrosine nitrosylation as revealed by Gr-1 and nitrotyrosine immunohistochemistry, respectively. In conclusion, our results provide support for high mesenteric melatonin levels and dynamic de novo gut melatonin production, both of which increase endogenously in response to major thermal injury, but appear to fall short of abrogating the excessive postburn hyper-inflammation. Moreover, supplementation by exogenous melatonin significantly suppresses gut inflammation, thus confirming that melatonin is protective against postburn inflammation.

Anaesthetic risks in children with obstructive sleep apnea syndrome undergoing adenotonsillectomy.

OBJECTIVE: To determine the frequency of anaesthetic risks in children having Obstructive Sleep Apnea Syndrome (OSAS), undergoing adenotonsillectomy. STUDY DESIGN: A case-control study. PLACE AND DURATION OF STUDY: Department of Anaesthesiology, Armed Forces Hospital, Najran, Saudi Arabia from November 2006 to January 2008. METHODOLOGY: The study was carried out in 60 children scheduled to undergo adenotonsillectomy and divided into two equal groups of 30 each. Group-1 had obstructive sleep apnoea syndrome and group-2 had children without it. Both groups were given a standard general anaesthesia and frequency and rate of complications and medical interventions taken in such children were studied. P-value and odds ratio were determined. RESULTS: The age ranged from 3 to 10 years. The frequency of difficult intubation was higher in the group-1 than in the control group (16.6 vs. 3.3%, odds ratio 5.8). At the time of induction of anaesthesia desaturation was higher in group-1 (33.3 vs. 6.6%, p=0.021, odds ratio 7). At the time of extubation, desaturation was significantly higher in group-1 (43.3 vs. 6.6%, p=0.002, odds ratio 10.70). The complications at extubation, for example cough, laryngospasm and postoperative nausea and vomiting were higher in group-1 but not statistically significant. In the postanaesthesia care unit, the frequency of complications and medical interventions were also higher in group-1. More patients of group-1 required oxygen (63.3 vs. 10%, p < 0.001, odds ratio 15.54) and insertion of an oropharyngeal airway (20% vs. nil, p=0.023) respectively. CONCLUSION: Children with OSAS, operated for adenotonsillectomy, are at significant risk of certain life-threatening perioperative anaesthetic complications. These results may be used as a guideline for safe and successful anaesthetic management of these children.

Thermal injury-plus-sepsis contributes to a substantial deletion of intestinal mesenteric lymph node CD4 T cell via apoptosis.

Thermal injury (TI) with septic complications continues to be a serious clinical problem. One of the main concerns in such patients is immunosuppression related to functional derangements in intestinal CD4+ T lymphocytes. Extensive previous studies in thermal injury/septic patients and animal models of thermal injury/sepsis have shown decreased responsiveness of intestinal CD4+ T cells to antigen/mitogen. This hyporesponsiveness could significantly contribute to increase injured host susceptibility to pathogens including those translocating from host's gut lumen. Our previous studies indicated that while thermal injury or sepsis alone lead to suppressed proliferation and IL-2 production of intestinal CD4+ T cells, this study showed a substantial deletion via apoptosis of the Mesenteric Lymph Nodes (MLN) CD4+ T cells. Hence, thermal injury-plus-sepsis contributes not only to suppressed CD4+ T proliferation/IL-2 production but also to a substantial modulation of CD4+ T cell survivability. These findings allow us to conclude that while thermal injury alone can produce attenuated cell mediated responses without an overt change in CD4+ T cell survival, thermal injury with septic complications causes CD4+ T cell death and an irreversible loss of cell-mediated responses. The latter happening could be responsible for high morbidity and mortality in the injured host afflicted with thermal injury plus a critical infection.