The relationship between thyroid function,serum monokine induced by interferon gamma and soluble interleukin‐2 receptor in thyroid autoimmune diseases

Interactions between cytokines play an important role in the development of thyroid autoimmunity. Using enzyme-linked immunosorbent assay we investigated serum concentrations of soluble interleukin-2 receptor (sIL-2R), interferon-gamma, tumour necrosis factor (TNF)-α, interleukin (IL)-10, CD30, monokine induced by interferon-gamma (MIG), cytotoxic T lymphocyte antigen-4 and markers of apoptosis decoy receptor 3 and Bcl-2 in 28 patients with hyperthyroid Graves'' disease (GD), 24 patients with untreated Hashimoto''s thyroiditis (HT) and 15 healthy controls. TNF-α, IL-10 and sIL-2R were higher in GD compared with HT and controls (TNF-α: 8·79 in GD versus 2·54 pg/ml in HT, P = 0·01; IL-10: 10·00 versus 3·10 versus 3·10 pg/ml, P₁ < 0·001, P₂ = 0·005; sIL-2R: 1·26 versus 0·64 versus 0·46 ng/ml, P < 0·001). MIG and CD30 were higher in HT compared with controls (649·22 ± 262·55 versus 312·95 ± 143·35 pg/ml, P = 0·037, 6·57 ± 2·35 versus 3·03 ± 1·04 U/ml, P = 0·036 respectively). In GD sIL-2R decreased when the euthyroid state was achieved (1·31 ± 0·64 versus 0·260 ± 0·11, n = 12, P < 0·001). sIL-2R correlated positively with free thyroxine (FT4) (R = 0·521, P = 0·000) and negatively with thyroid stimulating hormone (TSH) (R = −0·472, P = 0·00132). MIG correlated negatively with FT4 (R = −0·573, P = 0·00234) and positively with TSH (R = 0·462, P = 0·0179). The results suggest that serum concentrations of sIL-2R and MIG are related to thyroid function rather than to activation of autoimmunity.     

Alterations in immune cell subsets and their cytokine secretion profile in childhood idiopathic thrombocytopenic purpura (ITP)

Immune thrombocytopenic purpura (ITP) is acquired autoimmune disease in children characterized by the breakdown of immune tolerance. This work is designed to explore the contribution of different lymphocyte subsets in acute and chronic ITP children. Imbalance in the T helper type 1 (Th1)/Th2 cytokine secretion profile was investigated. The frequency of T (CD3⁺, CD4⁺, CD8⁺) and B (CD19⁺) lymphocytes, natural killer (NK) (CD16⁺56⁺) and regulatory T (T_reg) [CD4⁺CD25^+highforkhead box protein 3 (FoxP3)⁺] cells was investigated by flow cytometry in 35 ITP children (15 acute and 20 chronic) and 10 healthy controls. Plasma levels of Th1 cytokines [interferon (IFN-γ) and tumour necrosis factor (TNF-α)] and Th2 [interleukin (IL)-4, IL-6 and IL-10)] cytokines were measured using enzyme-linked immunosorbent assay (ELISA). The percentage of T_reg (P < 0·001) and natural killer (NK) (P < 0·001) cells were significantly decreased in ITP patients compared to healthy controls. A negative correlation was reported between the percentage of T_reg cells and development of acute (r = −0·737; P < 0·01) and chronic (r = −0·515; P < 0·01) disease. All evaluated cytokines (IFN-γ, TNF-α, IL-4, IL-6 and IL-10) were elevated significantly in ITP patients (P < 0·001, P < 0·05, P < 0·05, P < 0·05 and P < 0·001, respectively) compared to controls. In conclusion, our data shed some light on the fundamental role of immune cells and their related cytokines in ITP patients. The loss of tolerance in ITP may contribute to the dysfunction of T_regs. Understanding the role of T cell subsets will permit a better control of autoimmunity through manipulation of their cytokine network.     

Beta-arrestin 2 negatively regulates sepsis-induced inflammation

β-arrestins 1 and 2 are ubiquitously expressed proteins that alter signalling by G-protein-coupled receptors. β-arrestin 2 plays an important role as a signalling adaptor and scaffold in regulating cellular inflammatory responses. We hypothesized that β-arrestin 2 is a critical modulator of inflammatory response in experimental sepsis. β-arrestin 2(−/−) and wild-type (WT) mice were subjected to caecal ligation and puncture (CLP). The survival rate was significantly decreased (P < 0·05) in β-arrestin 2(−/−) mice (13% survival) compared with WT mice (53% survival). A second group of mice were killed 18 hr after CLP for blood, peritoneal lavage and tissue sample collection. CLP-induced plasma interleukin (IL)-6 was significantly increased 25 ± 12 fold and caecal myeloperoxidase (MPO) activity was increased 2·4 ± 0·3 fold in β-arrestin 2(−/−) compared with WT mice. β-arrestin 2(−/−) mice exhibited more severe lung damage and higher bacterial loads compared with WT mice post CLP challenge as measured by histopathology and colony-forming unit count. In subsequent experiments, splenocytes, peritoneal macrophages and bone marrow-derived macrophages (BMDMs) were isolated and cultured from β-arrestin 2(−/−) and WT mice and stimulated in vitro with lipopolysaccharide (LPS). Tumour necrosis factor (TNF)-α, IL-6 and IL-10 production induced by LPS was significantly augmented (2·2 ± 0·2 fold, 1·8 ± 0·1 fold, and 2·2 ± 0·4 fold, respectively; P < 0·05) in splenocytes from β-arrestin 2(−/−) mice compared with WT mice. The splenocyte response was different from that of peritoneal macrophages or BMDMs, which exhibited no difference in TNF-α and IL-6 production upon LPS stimulation between WT and β-arrestin 2(−/−) mice. Our data demonstrate that β-arrestin 2 functions to negatively regulate the inflammatory response in polymicrobial sepsis.     

Serum titres of anti-glutamic acid decarboxylase-65 and anti-IA-2 autoantibodies are associated with different immunoregulatory milieu in newly diagnosed type 1 diabetes patients

Several studies correlated genetic background and pancreatic islet-cell autoantibody status (type and number) in type 1A diabetes mellitus (T1AD), but there are no data evaluating the relationship among these markers with serum cytokines, regulatory T cells and β cell function. This characterization has a potential importance with regard to T1AD patients'' stratification and follow-up in therapeutic prevention. In this study we showed that peripheral sera cytokines [interleukin (IL)-12, IL-6, II-1β, tumour necrosis factor (TNF)-α, IL-10] and chemokines (CXCL10, CXCL8, CXCL9, CCL2) measured were significantly higher in newly diagnosed T1AD patients when compared to healthy controls (P < 0·001). Among T1AD, we found a positive correlation between CXCL10 and CCL-2 (r = 0·80; P = 0·000), IL-8 and TNF-α (r = 0·60; P = 0·000); IL-8 and IL-12 (r = 0·57; P = 0·001) and TNF-α and IL-12 (r = 0·93; P = 0·000). Glutamic acid decarboxylase-65 (GAD-65) autoantibodies (GADA) were associated negatively with CXCL10 (r = −0·45; P = 0·011) and CCL2 (r = −0·65; P = 0·000), while IA-2A showed a negative correlation with IL-10 (r = −0·38; P = 0·027). Human leucocyte antigen (HLA) DR3, DR4 or DR3/DR4 and PTPN22 polymorphism did not show any association with pancreatic islet cell antibodies or cytokines studied. In summary, our results revealed that T1AD have a proinflammatory cytokine profile compared to healthy controls and that IA-2A sera titres seem to be associated with a more inflammatory peripheral cytokine/chemokine profile than GADA. A confirmation of these data in the pre-T1AD phase could help to explain the mechanistic of the well-known role of IA-2A as a more specific marker of beta-cell damage than GADA during the natural history of T1AD.     

Tumour necrosis factor‐α plus interleukin‐10 low producer phenotype predicts acute kidney injury and death in intensive care unit patients

Genetic polymorphism studies of cytokines may provide an insight into the understanding of acute kidney injury (AKI) and death in intensive care unit (ICU) patients. The aim of this study was to investigate whether the genetic polymorphisms of −308 G < A tumour necrosis factor (TNF)-α, −174 G > C interleukin (IL)-6 and −1082 G > A IL-10 may predispose ICU patients to the development of AKI and/or death. In a prospective nested case–control study, 303 ICU patients and 244 healthy individuals were evaluated. The study group included ICU patients who developed AKI (n = 139) and 164 ICU patients without AKI. The GG genotype of TNF-α (low producer phenotype) was significantly lower in the with AKI than without AKI groups and healthy individuals (55 versus 62 versus 73%, respectively; P = 0·01). When genotypes were stratified into four categories of TNF-α/IL-10 combinations, it was observed that low TNF-α plus low IL-10 producer phenotypes were more prevalent in patients with AKI, renal replacement therapy and death (P < 0·05). In logistic regression analysis, low TNF-α producer plus low IL-10 producer phenotypes remained as independent risk factors for AKI and/or death [odds ratio (OR) = 2·37, 95% confidence interval (CI): 1·16–4·84; P = 0·02] and for renal replacement therapy (RRT) and/or death (OR = 3·82, 95% CI: 1·19–12·23; P = 0·02). In this study, the combination of low TNF-α plus low IL-10 producer phenotypes was an independent risk factor to AKI and/or death and RRT and/or death in critically ill patients. Our results should be validated in a larger prospective study with long-term follow-up to emphasize the combination of these genotypes as potential risk factors to AKI in critically ill patients.     

Cooling Capacity of Transpulmonary Cooling and Cold-Water Immersion After Exercise-Induced Hyperthermia

ContextCold-water immersion (CWI) may not be feasible in some remote settings, prompting the identification of alternative cooling methods as adjunct treatment modalities for exertional heat stroke (EHS).ObjectiveTo determine the differences in cooling capacities between CWI and the inhalation of cooled air.DesignRandomized controlled clinical trial.SettingLaboratory.Patients or Other ParticipantsA total of 12 recreationally active participants (7 men, 5 women; age = 26 ± 4 years, height = 170.6 ± 10.1 cm, mass = 76.0 ± 18.0 kg, body fat = 18.5% ± 9.7%, peak oxygen uptake = 42.7 ± 8.9 mL·kg⁻¹·min⁻¹).Intervention(s)After exercise in a hot environment (40°C and 40% relative humidity), participants were randomized to 3 cooling conditions: cooling during passive rest (PASS; control), CWI, and the Polar Breeze thermal rehabilitation machine (PB) with which participants inspired cooled air (22.2°C ± 1.0°C).Main Outcome Measure(s)Rectal temperature (T_REC) and heart rate were continuously measured throughout cooling until T_REC reached 38.25°C.ResultsCooling rates during CWI (0.18°C·min⁻¹ ± 0.06°C·min⁻¹) were greater than those during PASS (mean difference [95% CI] of 0.16°C·min⁻¹ [0.13°C·min⁻¹, 0.19°C·min⁻¹]; P < .001) and PB (0.15°C·min⁻¹ [0.12°C·min⁻¹, 0.16°C·min⁻¹]; P < .001). Elapsed time to reach a T_REC of 38.25°C was also faster with CWI (9.71 ± 3.30 minutes) than PASS (−58.1 minutes [−77.1, −39.9 minutes]; P < .001) and PB (−46.8 minutes [−65.5, −28.2 minutes]; P < .001). Differences in cooling rates and time to reach a T_REC of 38.25°C between PASS and PB were not different (P > .05).ConclusionsTranspulmonary cooling via cooled-air inhalation did not promote an optimal cooling rate (>0.15°C·min⁻¹) for the successful treatment of EHS. In remote settings where EHS is a risk, access and use of treatment methods via CWI or cold-water dousing are imperative to ensuring survival.Trial RegistryClinicalTrials.gov (NCT0419026).     

Gastric emptying after pickle-juice ingestion in rested, euhydrated humans

Context:

Small volumes of pickle juice (PJ) relieve muscle cramps within 85 seconds of ingestion without significantly affecting plasma variables. This effect may be neurologic rather than metabolic. Understanding PJ''s gastric emptying would help to strengthen this theory.

Objective:

To compare gastric emptying and plasma variables after PJ and deionized water (DIW) ingestion.

Design:

Crossover study.

Setting:

Laboratory.

Patients or Other Participants:

Ten men (age  =  25.4 ± 0.7 years, height  =  177.1 ± 1.6 cm, mass  =  78.1 ± 3.6 kg).

Intervention(s):

Rested, euhydrated, and eunatremic participants ingested 7 mL·kg⁻¹ body mass of PJ or DIW on separate days.

Main Outcome Measure(s):

Gastric volume was measured at 0, 5, 10, 20, and 30 minutes postingestion (using the phenol red dilution technique). Percentage changes in plasma volume and plasma sodium concentration were measured preingestion (−45 minutes) and at 5, 10, 20, and 30 minutes postingestion.

Results:

Initial gastric volume was 624.5 ± 27.4 mL for PJ and 659.5 ± 43.8 mL for DIW (P > .05). Both fluids began to empty within the first 5 minutes (volume emptied: PJ  =  219.2 ± 39.1 mL, DIW  =  305.0 ± 40.5 mL, P < .05). Participants who ingested PJ did not empty further after the first 5 minutes (P > .05), whereas in those who ingested DIW, gastric volume decreased to 111.6 ± 39.9 mL by 30 minutes (P < .05). The DIW group emptied faster than the PJ group between 20 and 30 minutes postingestion (P < .05). Within 5 minutes of PJ ingestion, plasma volume decreased 4.8% ± 1.6%, whereas plasma sodium concentration increased 1.6 ± 0.5 mmol·L⁻¹ (P < .05). Similar changes occurred after DIW ingestion. Calculated plasma sodium content was unchanged for both fluids (P > .05).

Conclusions:

The initial decrease in gastric volume with both fluids is likely attributable to gastric distension. Failure of the PJ group to empty afterward is likely due to PJ''s osmolality and acidity. Cardiovascular reflexes resulting from gastric distension are likely responsible for the plasma volume shift and rise in plasma sodium concentration despite nonsignificant changes in plasma sodium content. These data support our theory that PJ does not relieve cramps via a metabolic mechanism.     

Cooling the neck region during exercise in the heat

Context:

Cooling the neck region can improve the ability to exercise in a hot environment. It might improve performance by dampening the perceived level of thermal strain, allowing individuals to override inhibitory signals.

Objective:

To investigate whether the enhanced ability to exercise in a hot environment observed when cooling the neck region occurs because of dampening the perceived level of thermal strain experienced and the subsequent overriding of inhibitory signals.

Design:

Crossover study.

Setting:

Walk-in environmental chamber.

Patients or Other Participants:

Eight endurance-trained, nonacclimated men (age  =  26 ± 2 years, height  =  1.79 ± 0.04 m, mass  =  77.0 ± 6.2 kg, maximal oxygen uptake [V̇O_2max]  =  56.2 ± 9.2 mL·kg⁻¹·min⁻¹) participated.

Intervention(s):

Participants completed 4 running tests at approximately 70% V̇O_2max to volitional exhaustion: 2 familiarization trials followed by 2 experimental trials (cooling collar [CC] and no collar [NC]). Trials were separated by 7 days. Familiarization and NC trials were performed without a collar and used to assess the test variability.

Main Outcome Measure(s):

Time to volitional exhaustion, heart rate, rectal temperature, neck skin temperature, rating of perceived exertion, thermal sensation, and feeling scale (pleasure/displeasure) were measured.

Results:

Time to volitional exhaustion was increased by 13.5% ± 3.8% (CC  =  43.15 ± 12.82 minutes, NC  =  38.20 ± 11.70 minutes; t₇  =  9.923, P < .001) with the CC, which reduced mean neck skin temperature throughout the test (P < .001). Participants terminated exercise at identical levels of perceived exertion, thermal sensation, and feeling scale, but the CC enabled participants to tolerate higher rectal temperatures (CC  =  39.61°C ± 0.45°C, NC  =  39.18°C ± 0.7°C; t₇  =  −3.217, P  =  .02) and heart rates (CC  =  181 ± 6 beats/min, NC  =  178 ± 9 beats/min; t₇  =  −2.664, P  =  .03) at the point of termination.

Conclusions:

Cooling the neck increased the time taken to reach volitional exhaustion by dampening the perceived levels of thermal strain.     

The augmented neutrophil respiratory burst in response to Escherichia coli is reduced in liver cirrhosis during infection

Several functional abnormalities in phagocytes from patients with liver cirrhosis contribute to an increased risk of infection. An increased resting respiratory burst has been observed in neutrophils from cirrhotic patients. We investigated whether an infection in cirrhosis affects the respiratory burst capacity of neutrophils and monocytes in response to Escherichia coli. This study included 45 hospitalized patients with liver cirrhosis and clinical signs of infection, 39 patients with liver cirrhosis in the absence of infection and 29 healthy subjects. Respiratory burst, lipopolysaccharide-binding protein (LBP), and immunoglobulin (Ig)G-autoantibodies against oxidized low-density lipoproteins (ab-oxLDL) were measured. The fraction of neutrophils spontaneously producing reactive oxygen species (ROS) was elevated in liver cirrhosis (P < 0·01). The neutrophil resting burst increased with Child–Pugh stage (P = 0·02) and correlated with augmented ROS release in response to opsonized E. coli (P < 0·05). Although LBP was increased in patients with cirrhosis (P < 0·01), higher LBP levels correlated with a lower resting burst in neutrophils (r_s = –0·395; P < 0·01). In the presence of infection, the resting burst was unaltered. However, neutrophil ROS release in response to E. coli was reduced markedly (P = 0·01), and it decreased as serum C-reactive protein (CRP) concentration rose (r_s = −0·437; P < 0·01), indicating the development of a sepsis-like immune paralysis. A positive correlation between ab-oxLDL and ROS release was observed (P < 0·01). In conclusion, the respiratory burst increases with severity of liver cirrhosis but is restrained by increasing LBP levels. Augmented ROS release in response to E. coli is accompanied by elevated markers of oxidative damage and becomes exhausted in the presence of infection.     

Nitric oxide production by polymorphonuclear leucocytes in infected cystic fibrosis sputum consumes oxygen

Chronic Pseudomonas aeruginosa lung infection in cystic fibrosis (CF) patients is characterized by persisting mucoid biofilms in hypoxic endobronchial mucus. These biofilms are surrounded by numerous polymorphonuclear leucocytes (PMNs), which consume a major part of present molecular oxygen (O₂) due to production of superoxide (O₂⁻). In this study, we show that the PMNs also consume O₂ for production of nitric oxide (NO) by the nitric oxide synthases (NOS) in the infected endobronchial mucus. Fresh expectorated sputum samples (n = 28) from chronically infected CF patients (n = 22) were analysed by quantifying and visualizing the NO production. NO production was detected by optode measurements combined with fluorescence microscopy, flow cytometry and spectrophotometry. Inhibition of nitric oxide synthases (NOS) with N^G-monomethyl-L-arginine (L-NMMA) resulted in reduced O₂ consumption (P < 0·0008, n = 8) and a lower fraction of cells with fluorescence from the NO-indicator 4-amino-5-methylamino-2′,7′-difluorofluorescein diacetate (DAF-FM) (P < 0·002, n = 8). PMNs stained with DAF-FM and the superoxide indicator hydroethidine (HE) and host cells with inducible NOS (iNOS) were identified in the sputum. In addition, the production of the stable end-products of NO in CF sputum was correlated with the concentration of PMNs; NO₃⁻ (P < 0·04, r = 0·66, n = 10) and NO₂⁻ (P< 0·006, r = 0·78, n = 11). The present study suggests that besides consumption of O₂ for production of reactive oxygen species, the PMNs in CF sputum also consume O₂ for production of NO.     

Curcumin alleviates immune‐complex‐mediated glomerulonephritis in factor‐H‐deficient mice

Complement factor H (Cfh) is a key regulator of the complement cascade and protects C57BL/6 mice from immune complex-mediated complement-dependent glomerulonephritis. In chronic serum sickness (CSS) there are increased deposits of immune complexes in the glomeruli with inflammation and a scarring phenotype. As cucurmin is an effective anti-inflammatory agent and reduces complement activation, we hypothesized that it should alleviate renal disease in this setting. To determine the effectiveness of curcumin, an apoferritin-induced CSS model in Cfh-deficient (Cfh^−/−) mice was used. Curcumin treatment (30 mg/kg) given every day in parallel with apoferritin reduced glomerulonephritis and enhanced kidney function (blood urea nitrogen, 45·4 ± 7·5 versus 35·6 ± 5·1; albuminuria, 50·1 ± 7·1 versus 15·7 ± 7·1; glomerulonephritis, 2·62 + 0·25 versus 2 + 0·3, P < 0·05). In line with reduced IgG deposits in mice with CSS given curcumin, C9 deposits were reduced indicating reduced complement activation. Mice treated with curcumin had a significant reduction in the number of splenic CD19⁺ B cells and the ratio of CD19 : CD3 cells (P < 0·05) with no change in the T-cell population. Myeloperoxidase assay showed reduced macrophages in the kidney. However, a significant reduction in the M2 subset of splenic macrophages by apoferritin was prevented by curcumin, suggesting a protective function. Curcumin treatment reduced mRNA expression of inflammatory proteins monocyte chemoattractant protein-1 and transforming growth factor-β and matrix proteins, fibronectin, laminin and collagen. Our results clearly illustrate that curcumin reduces glomerulosclerosis, improves kidney function and could serve as a therapeutic agent during serum sickness.     

Increase in tumour‐infiltrating lymphocytes with regulatory T cell immunophenotypes and reduced ζ‐chain expression in nasopharyngeal carcinoma patients

The pathological significance of the mechanisms of tumour immune-evasion and/or immunosuppression, such as loss of T cell signalling and increase in regulatory T cells (T_regs), has not been well established in the nasopharyngeal carcinoma (NPC) microenvironment. To evaluate the T_reg immunophenotypes in tumour-infiltrating lymphocytes (TILs), we performed a double-enzymatic immunostaining for detection of forkhead box P3 (FoxP3) and other markers including CD4, CD8, and CD25 on 64 NPC and 36 non-malignant nasopharyngeal (NP) paraffin-embedded tissues. Expression of CD3ζ and CD3ε was also determined. The prevalence of CD4⁺FoxP3⁺ cells in CD4⁺ T cells and the ratio of FoxP3⁺/CD8⁺ were increased significantly in NPC compared with those in NP tissues (P < 0·001 and P = 0·025 respectively). Moreover, the ratio of FoxP3⁺/CD25⁺FoxP3⁻ in NPC was significantly lower than that in NP tissues (P = 0·005), suggesting an imbalance favouring activated phenotype of T cells in NPC. A significant negative correlation between the abundance of FoxP3⁺ and CD25⁺FoxP3⁻ cells (P < 0·001) was also identified. When histological types of NPC were considered, a lower ratio of FoxP3⁺/CD25⁺FoxP3⁻ was found in non-keratinizing and undifferentiated carcinomas. Increased CD4⁺FoxP3⁺/CD4⁺ proportion and FoxP3⁺/CD8⁺ ratio were associated with keratinizing squamous cell carcinoma. A reduced expression of CD3ζ in TILs was found in 20·6% of the NPC tissues but none of the NP tissues. These data provide evidence for the imbalances of T_reg and effector T cell phenotypes and down-regulation of signal-transducing molecules in TILs, supporting their role in suppression of immune response and immune evasion of NPC.     

Combined Env- and Gag-specific T cell responses in relation to programmed death-1 receptor and CD4+ T cell loss rates in human immunodeficiency virus-1 infection

Additional progression markers for human immunodeficiency virus (HIV) infection are warranted. In this study we related antigen-specific responses in CD4⁺ and CD8⁺ T cells to CD38, reflecting chronic immune activation, and to CD4⁺ T cell loss rates. Clones transiently expressing CD107a (CD8⁺) or CD154 (CD4⁺) in response to Gag, Env and Nef overlapping peptide pools were identified, along with their expression of the inhibitory programmed death-1 receptor (PD-1) in fresh peripheral blood mononuclear cells (PBMC) from 31 patients off antiretroviral treatment (ART). HIV-specific CD8⁺ T cell responses dominated over CD4⁺ T cell responses, and among CD8⁺ responses, Gag and Nef responses were higher than Env-responses (P < 0·01). PD-1 on CD8⁺ HIV-specific subsets was higher than CMV-specific CD8⁺ cells (P < 0·01), whereas PD-1 on HIV-specific CD4⁺ cells was similar to PD-1 on CMV-specific CD4⁺ cells. Gag and Env CD8⁺ responses correlated oppositely to the CD4 loss rate. Env/Gag CD8⁺ response ratios, independently of PD-1 levels, correlated more strongly to CD4 change rates (r = −0·50 to −0·77, P < 0·01) than the total number of Gag-specific CD8⁺ cells (r = 0·44–0·85, P ≤ 0·02). The Env/Gag ratio performed better than CD38 and HIV-RNA in logistic regression analysis predicting CD4 change rate as a measure of progression. In conclusion, HIV-specific CD8⁺CD107a⁺ Env/Gag response ratio was a stronger predictor for progression than CD38 and HIV-RNA. The Env/Gag ratio may reflect the balance between possibly beneficial (Gag) and detrimental (Env) CD8⁺ T cell responses and should be explored further as a progression marker.     

The uncertainty (validity and reliability) of three electrothermometers in therapeutic modality research

Context: Data from electrothermometers are used to determine therapeutic modality usage, but the value of experimental results is only as good as the data collected.Objective: To determine the reliability and validity of 3 electrothermometers from 2 manufacturers.Design: A 3 × 4 × 17 factorial with repeated measures on 2 factors. Independent variables were trial (1, 2, 3), thermometer (mercury thermometer, Iso-Thermex calibrated from −50°C to 50°C, Iso-Thermex calibrated from −20°C to 80°C, and Datalogger), and time (17).Setting: Human Performance Research Center.Intervention(s): Eighteen thermocouples were inserted through the wall of a foamed polystyrene cooler, and 6 were connected to each of the 3 electrothermometers. The cooler was positioned on a stir plate and filled with room-temperature water (18.4°C). A mercury thermometer was immersed into the water bath. Measurements of the water bath were taken every 10 seconds for three 3-minute trials.Main Outcome Measure(s): The temperature variability of 3 electrothermometers was taken from a calibrated mercury thermometer.Results: The Iso-Thermex electrothermometers did not differ statistically from each other in uncertainty (validity error ± reliability error = 0.06°C ± 0.03°C ± 0.03°C ± 0.02°C, P < .05), but both differed from the Datalogger (0.64°C ± 0.20°C, P < .05). The Datalogger temperature was consistently higher than the mercury thermometer temperature.Conclusions: The Iso-Thermex electrothermometers were more stable than the Datalogger, and values were within the published uncertainty (±0.1°C) when used with PT-6 thermocouples. The Datalogger we used had an uncertainty of measurement greater than that indicated in the user''s manual (∼±0.52°C). Uncertainty of ±0.84°C can significantly influence the interpretation of results when intramuscular temperature changes are usually less than 5°C.     

Cold-Water Immersion and the Treatment of Hyperthermia: Using 38.6��C as a Safe Rectal Temperature Cooling Limit

Context:

Cold-water immersion is recommended for the immediate field treatment of exertional heat stroke. However, concerns exist over potential overcooling of hyperthermic individuals during cold-water immersion.

Objective:

To evaluate the recommendation that removing previously hyperthermic individuals from a cold-water bath at a rectal temperature (T_re) of 38.6°C would attenuate overcooling.

Design:

Controlled laboratory study.

Setting:

University research laboratory.

Patients or Other Participants:

Participants included 6 men and 4 women (age  =  22 ± 3 years, height  =  172 ± 10 cm, mass  =  67.8 ± 10.7 kg, body fat percentage  =  17.1% ± 4.5%, maximum oxygen consumption  =  59.3 ± 8.7 mL·kg⁻¹·min⁻¹).

Intervention(s):

After exercising at an ambient temperature of 40.0°C for 38.5 ± 9.4 minutes, until T_re reached 39.5°C, participants were immersed in a 2.0°C circulated water bath until T_re decreased to either 37.5°C or 38.6°C. Subsequently, participants were removed from the water bath and recovered for 20 minutes at an ambient temperature of 25°C.

Main Outcome Measure(s):

Rectal and esophageal temperatures were measured continuously during the immersion and recovery periods.

Results:

Because of the experimental design, the overall time of immersion was greater during the 37.5°C trial (16.6 ± 5.7 minutes) than the 38.6°C trial (8.8 ± 2.6 minutes) (t₉  =  −4.740, P  =  .001). During the recovery period after cold-water immersion, both rectal (F_1,9  =  50.540, P < .001) and esophageal (F_1,6  =  20.365, P  =  .007) temperatures remained greater in the 38.6°C trial than in the 37.5°C trial. This was evidenced by low points of 36.47°C ± 0.70°C and 37.19°C ± 0.71°C for rectal temperature (t₉  =  2.975, P  =  .016) and of 35.67°C ± 1.27°C and 36.72°C ± 0.95°C for esophageal temperature (t₆  =  3.963, P  =  .007) during the recovery period of the 37.5°C and 38.6°C trials, respectively.

Conclusions:

Immersion for approximately 9 minutes to a rectal temperature cooling limit of 38.6°C negated any risk associated with overcooling hyperthermic individuals when they were immersed in 2°C water.     

Response of Thermocouples Interfaced to Electrothermometers When Immersed in 5 Water Bath Temperatures

Context:

Thermocouples and electrothermometers are used in therapeutic modality research. Until recently, researchers assumed that these instruments were valid and reliable.

Objective:

To examine 3 different thermocouple types in 5°C, 15°C, 18.4°C, 25°C, and 35°C water baths.

Design:

Randomized controlled trial.

Setting:

Therapeutic modality laboratory.

Intervention(s):

Eighteen thermocouple leads were inserted through the wall of a foamed polystyrene cooler. The cooler was filled with water. Six thermocouples (2 of each model) were plugged into the 6 channels of the Datalogger and 6 randomly selected channels in the 2 Iso-Thermexes. A mercury thermometer was immersed into the water and was read every 10 seconds for 4 minutes during each of 6 trials. The entire process was repeated for each of 5 water bath temperatures (5°C, 15°C, 18.4°C, 25°C, 35°C).

Main Outcome Measure(s):

Temperature and absolute temperature differences among 3 thermocouple types (IT-21, IT-18, PT-6) and 3 electrothermometers (Datalogger, Iso-Thermex calibrated from −50°C to 50°C, Iso-Thermex calibrated from −20°C to 80°C).

Results:

Validity and reliability were dependent on thermocouple type, electrothermometer, and water bath temperature (P < .001; modified Levene P < .05). Statistically, the IT-18 and PT-6 thermocouples were not reliable in each electrothermometer; however, these differences were not practically different from each other. The PT-6 thermocouples were more valid than the IT-18s, and both thermocouple types were more valid than the IT-21s, regardless of water bath temperature (P < .001).

Conclusions:

The validity and reliability of thermocouples interfaced to an electrothermometer under experimental conditions should be tested before data collection. We also recommend that investigators report the validity, the reliability, and the calculated uncertainty (validity + reliability) of their temperature measurements for therapeutic modalities research. With this information, investigators and clinicians will be better able to interpret and compare results and conclusions.     

Low expression of CD39+/CD45RA+ on regulatory T cells (Treg) cells in type 1 diabetic children in contrast to high expression of CD101+/CD129+ on Treg cells in children with coeliac disease

Type 1 diabetes (T1D) and coeliac disease are both characterized by an autoimmune feature. As T1D and coeliac disease share the same risk genes, patients risk subsequently developing the other disease. This study aimed to investigate the expression of T helper (Th), T cytotoxic (Tc) and regulatory T cells (T_reg) in T1D and/or coeliac disease children in comparison to healthy children. Subgroups of T cells (Th : CD4⁺ or Tc : CD8⁺); naive (CD27⁺CD28⁺CD45RA⁺CCR7⁺), central memory (CD27⁺CD28⁺CD45RA⁻CCR7⁺), effector memory (early differentiated; CD27⁺CD28⁺CD45RA⁻CCR7⁻ and late differentiated; CD27⁻CD28⁻CD45RA⁻CCR7⁻), terminally differentiated effector cells (TEMRA; CD27⁻CD28⁻CD45RA⁺CCR7⁻) and T_reg (CD4⁺CD25⁺FOXP3⁺CD127⁻) cells, and their expression of CD39, CD45RA, CD101 and CD129, were studied by flow cytometry in T1D and/or coeliac disease children or without any of these diseases (reference group). Children diagnosed with both T1D and coeliac disease showed a higher percentage of TEMRA CD4⁺ cells (P < 0·05), but lower percentages of both early and late effector memory CD8⁺ cells (P < 0·05) compared to references. Children with exclusively T1D had lower median fluorescence intensity (MFI) of forkhead box protein 3 (FoxP3) (P < 0·05) and also a lower percentage of CD39⁺ and CD45RA⁺ within the T_reg population (CD4⁺CD25⁺FOXP3⁺CD127⁻) (P < 0·05). Children with exclusively coeliac disease had a higher MFI of CD101 (P < 0·01), as well as a higher percentage of CD129⁺ (P < 0·05), in the CD4⁺CD25^hi lymphocyte population, compared to references. In conclusion, children with combined T1D and coeliac disease have a higher percentage of differentiated CD4⁺ cells compared to CD8⁺ cells. T1D children show signs of low CD39⁺/CD45RA⁺ T_reg cells that may indicate loss of suppressive function. Conversely, children with coeliac disease show signs of CD101⁺/CD129⁺ T_reg cells that may indicate suppressor activity.     

Heparin‐coated cardiopulmonary bypass circuits selectively deplete the pattern recognition molecule ficolin‐2 of the lectin complement pathway in vivo

The complement system can be activated via the lectin pathway by the recognition molecules mannose-binding lectin (MBL) and the ficolins. Ficolin-2 exhibits binding against a broad range of ligands, including biomaterials in vitro, and low ficolin-2 levels are associated with increased risk of infections. Thus, we investigated the biocompatibility of the recognition molecules of the lectin pathway in two different types of cardiopulmonary bypass circuits. Bloods were drawn at five time-points before, during and postoperatively from 30 patients undergoing elective cardiac surgery. Patients were randomized into two groups using different coatings of cardiopulmonary bypass circuits, Phisio® (phosphorylcholine polymer coating) and Bioline® (albumin-heparin coating). Concentrations of MBL, ficolin-1, −2 and −3 and soluble C3a and terminal complement complex (TCC) in plasma samples were measured. Ficolin-3-mediated complement activation potential was evaluated with C4, C3 and TCC as output. There was no significant difference between the two circuit materials regarding MBL, ficolin-1 and −3. In the Bioline® group the ficolin-2 levels decreased significantly after initiation of surgery (P < 0·0001) and remained reduced throughout the sampling period. This was not seen for Phisio®-coated circuits. Ficolin-3-mediated complement activation potential was reduced significantly in both groups after start of operation (P < 0·0001), whereas soluble C3a and TCC in the samples were increased (P < 0·0001). Ficolin-2 was depleted from plasma during cardiac surgery when using heparin-coated bypass circuits and did not reach baseline level 24 h postoperation. These findings may have implications for the postoperative susceptibility to infections in patients undergoing extracorporeal circulation procedures.     

Increased aortic intimal proliferation due to MasR deletion in vitro

A growing body of evidence suggests that the vascular actions of Ang-(1-7) appear to involve increased production of nitric oxide (NO), an important vasodilator, through the activation of MasR, thus indicating the involvement of the MasR in preventing endothelial dysfunction. However, it is unknown whether the MasR could be involved in the progression of the next step in atherosclerosis, neo-intimal formation. To determine whether the deletion of the MasR is involved in the development of intimal thickening in an in vitro model. Mice [three background controls (C57Bl/6) and 3 MasR (−/−)] were killed and the aortas excised and cleaned of connective tissue and cut into 3 mm rings. Rings were placed in an organ culture medium for 5 weeks, embedded in paraffin, cut at 5 μm and stained with haematoxylin and eosin and Masson’s trichrome. In addition, aortic reactivity was measured in organ baths. After 5 weeks of culture, the intima:media ratio increased in the aortas from MasR (−/−) mice compared to the control group by 4.5-fold (P < 0.01). However, no significant difference in nuclei area count (cell proliferation) between the MasR (−/−) mice and control group was observed (0.87 ± 0.29% vs. 0.94 ± 0.18%, respectively, P = ns). Functional studies showed only a minor vasoconstrictive and full vasodilative response. This study shows that the deletion of the MasR causes marked increase in the aortic intima:media ratio, which is not due to generalized cellular proliferation. These results provide a functional role for the MasR in atherogenesis.