The use of surfactant-filled mesoporous silica as an immobilising medium for a fluorescence lifetime pH indicator, providing long-term calibration stability.

Surfactant filled mesoporous silica is applied as a matrix for immobilizing the fluorescence lifetime pH-indicator acridine. We demonstrate that this type of encapsulation provides a stable and uniform chemical environment for the indicator and has good proton transport properties leading to rapid pH response times. Furthermore, the immobilising medium effectively prevents leaching of the indicator, facilitates high long-term stability and does not influence the pH sensing-range of the indicator.

Lactate, lactate clearance and outcome after cardiac arrest: A post-hoc analysis of the TTM-Trial.

BACKGROUND: Admission lactate and lactate clearance are implemented for risk stratification in sepsis and trauma. In out-of-hospital cardiac arrest, results regarding outcome and lactate are conflicting. METHODS: This is a post-hoc analysis of the Target Temperature Management trial in which 950 unconscious patents after out-of-hospital cardiac arrest were randomized to a temperature intervention of 33°C or 36°C. Serial lactate samples during the first 36 hours were collected. Admission lactate, 12-hour lactate, and the clearance of lactate within 12 hours after admission were analyzed and the association with 30-day mortality assessed. RESULTS: Samples from 877 patients were analyzed. In univariate logistic regression analysis, the odds ratio for death by day 30 for each mmol/L was 1.12 (1.08-1.16) for admission lactate, P < .01, 1.21 (1.12-1.31) for 12-hour lactate, P < .01, and 1.003 (1.00-1.01) for each percentage point increase in 12-hour lactate clearance, P = .03. Only admission lactate and 12-hour lactate levels remained significant after adjusting for known predictors of outcome. The area under the receiver operating characteristic curve was 0.65 (0.61-0.69), P < .001, 0.61 (0.57-0.65), P < .001, and 0.53 (0.49-0.57), P = .15 for admission lactate, 12-hour lactate, and 12-hour lactate clearance, respectively. CONCLUSIONS: Admission lactate and 12-hour lactate values were independently associated with 30-day mortality after out-of-hospital cardiac arrest while 12-hour lactate clearance was not. The clinical value of lactate as the sole predictor of outcome after out-of-hospital cardiac arrest is, however, limited.

Paratracheal placement of orotracheal tube: a complication when aborting percutaneous tracheotomy.

Percutaneous dilatational tracheotomies (PT) are commonly performed in the ICU. The procedure carries the risk of complications, among them severe events as loss of airway or pneumothorax. In this case report we describe complications related to a PT procedure in the ICU. The procedure was performed with a single dilator kit, and by visual guidance of a bronchoscope. Because of difficulties with the insertion of the tracheal cannula, the procedure was aborted, and the endotracheal tube (ET) reinserted. After placement of the ET, subcutaneous emphysema emerged. Upon digital exploration in the tracheotomy incision the tube was found to exit from the trachea, the tube-tip being situated para-tracheally. The tube position was corrected using a finger in the incision, and the patient could again be ventilated. Poor visual conditions may occur during PT because of bleeding. Importantly, there is a risk for the ET to exit an incision in the trachea when reintubating during a PT procedure, or after decannulation. This can be prevented using digital occlusion of the tracheal opening.

Outcome, timing and adverse events in therapeutic hypothermia after out-of-hospital cardiac arrest.

BACKGROUND: Therapeutic hypothermia (TH) after cardiac arrest protects from neurological sequels and death and is recommended in guidelines. The Hypothermia Registry was founded to the monitor outcome, performance and complications of TH. METHODS: Data on out-of-hospital cardiac arrest (OHCA) patients admitted to intensive care for TH were registered. Hospital survival and long-term outcome (6-12 months) were documented using the Cerebral Performance Category (CPC) scale, CPC 1-2 representing a good outcome and 3-5 a bad outcome. RESULTS: From October 2004 to October 2008, 986 TH-treated OHCA patients of all causes were included in the registry. Long-term outcome was reported in 975 patients. The median time from arrest to initiation of TH was 90 min (interquartile range, 60-165 min) and time to achieving the target temperature (< or =34 degrees C) was 260 min (178-400 min). Half of the patients underwent coronary angiography and one-third underwent percutaneous coronary intervention (PCI). Higher age, longer time to return of spontaneous circulation, lower Glasgow Coma Scale at admission, unwitnessed arrest and initial rhythm asystole were all predictors of bad outcome, whereas time to initiation of TH and time to reach the goal temperature had no significant association. Bleeding requiring transfusion occurred in 4% of patients, with a significantly higher risk if angiography/PCI was performed (2.8% vs. 6.2%P=0.02). CONCLUSIONS: Half of the patients survived, with >90% having a good neurological function at long-term follow-up. Factors related to the timing of TH had no apparent association to outcome. The incidence of adverse events was acceptable but the risk of bleeding was increased if angiography/PCI was performed.

Therapeutic hypothermia after out-of-hospital cardiac arrest: experiences with patients treated with percutaneous coronary intervention and cardiogenic shock.

BACKGROUND: Therapeutic hypothermia has been shown to increase survival after out-of-hospital cardiac arrest (OHCA). The trials documenting such benefit excluded patients with cardiogenic shock and only a few patients were treated with percutaneous coronary intervention prior to admission to an intensive care unit (ICU). We use therapeutic hypothermia whenever cardiac arrest patients do not wake up immediately after return of spontaneous circulation. METHODS: This paper reports the outcome of 50 OHCA patients with ventricular fibrillation admitted to a tertiary referral hospital for immediate coronary angiography and percutaneous coronary intervention when indicated. Patients were treated with intra-aortic balloon counterpulsation (IABP) (23 of 50 patients) if indicated. All patients who were still comatose were treated with therapeutic hypothermia at 32-34 degrees C for 24 h before rewarming. The end-points were survival and cerebral performance category (CPC: 1, best; 5, dead) after 6 months. RESULTS: Forty-one patients (82%) survived until 6 months. Thirty-four patients (68%) were in CPC 1 or 2, and seven (14%) were in CPC 3. Of the 23 patients treated with IABP, 14 (61%) survived with CPC 1 or 2. In patients not treated with IABP, 20 patients (74%) survived with CPC 1 or 2. Forty patients (80%) developed myocardial infarction. Percutaneous coronary intervention was performed in 36 patients (72%). CONCLUSION: In OHCA survivors who reached our hospital, the survival rate was high and the neurological outcome acceptable. Our results indicate that the use of therapeutic hypothermia is justified even in haemodynamically unstable patients and those treated with percutaneous coronary intervention.

[Transfusion-associated graft-versus-host disease. Increased risk when using HLA matched donors]. / Transfusjonsassosiert transplantat-mot-vert-sykdom. Okt risiko ved bruk av HLA-forlikelige givere.

For 30 years it has been known that immunodeficient patients can have a fatal reaction to transfused blood components containing viable lymphocytes. This risk of a transfusion-associated graft-versus-host reaction can be totally eliminated by irradiation of the blood prior to transfusion. Immunocompetent individuals can have this potentially fatal reaction if the blood donor is homozygous for one of the HLA-haplotypes of the recipient. The probability of this coincidence is low when donor and recipient are unrelated, but considerably higher when they are genetically related. When HLA-matched blood platelets are indicated for transfusing patients refractory to random platelets, the platelets must always be irradiated with minimum 25 Gy, since a large proportion of the donors will be homozygous with one of the HLA-haplotypes of the recipient.

Hereditary porcine membranoproliferative glomerulonephritis type II is caused by factor H deficiency.

We have recently described hereditary membranoproliferative glomerulonephritis type II in the pig. All affected animals had excessive complement activation, revealed as low plasma C3, elevated plasma terminal complement complex, and massive deposits of complement in the renal glomeruli, and eventually died of renal failure within 11 wk of birth. The aim of the present study was to investigate the cause of complement activation in this disease. Transfusion of normal porcine plasma to affected piglets inhibited complement activation and increased survival. Plasma was successively fractionated and the complement inhibitory effect of each fraction tested in vivo. A single chain 150-kD protein which showed the same complement inhibitory effect as whole plasma was finally isolated. Immunologic cross-reactivity, functional properties, and NH2-terminal sequence identified the protein as factor H. By Western blotting and enzyme immunoassay, membranoproliferative glomerulonephritis-affected piglets were demonstrated to be subtotally deficient in factor H. At 1 wk of age, median (range) factor H concentration was 1.6 mg/liter (1.1-2.3) in deficient animals (n = 13) and 51 mg/liter (26-98) in healthy littermates (n = 52). Our data show that hereditary porcine membrano-proliferative glomerulonephritis type II is caused by factor H deficiency.

A study of the effect of rheumatoid synovial fluid on proliferation and IL-2 production by total mononuclear cells and purified CD4+ cells of synovial fluid and peripheral blood.

T cells from synovial fluid (SF) of rheumatoid arthritis (RA) patients have previously been shown to proliferate less after mitogenic stimulation and produce less interleukin 2 (IL-2) than normal T cells. To test whether SF is responsible for the reduced T-cell responses, we studied the effect of inflammatory SF on peripheral blood (PB) RA and normal mononuclear cells (MNC) and CD4+ T cells and on RA SF MNC and CD4+ cells in vitro. Most rheumatoid SF present in concentrations of 50% and 5% during in vitro stimulation increased mitogen-induced IL-2 production and proliferative response by normal PB and RA MNC and CD4+ cells. Other rheumatoid SF samples did not influence the T cell responses, while only a few samples had an inhibitory effect. The results indicate that SF contain both stimulatory and inhibitory factors and that the resultant effect on T cells may depend on the net effect of these. The results do not support the hypothesis that the apparently impaired function of SF T cells is due to contact with SF.

IL-6 in synovial fluids, plasma and supernatants from cultured cells of patients with rheumatoid arthritis and other inflammatory arthritides.

The purpose of this investigation was to measure interleukin 6 (IL-6) levels in synovial fluid (SF) and plasma from patients with rheumatoid arthritis (RA) and other inflammatory arthritides (non-RA) and to examine the in vitro production of IL-6 by T cells and monocytes from SF and peripheral blood (PB). All patients had high levels of IL-6 in SF. Although the median level was higher in the group of non-RA arthritides, the difference was not statistically significant. Supernatants from both unstimulated and stimulated highly purified CD4+ and CD8+ cells from SF and PB did not contain IL-6, while high levels of IL-6 were detectable in supernatants of mononuclear cells (MNC) and plastic adherent cells without any specific in vitro stimulant. Since IL-6 is so readily produced by normal mononuclear cells in vitro without any specific stimulant, spontaneous in vitro production by SF MNC cannot be considered as evidence for in vivo production by the same cells.

Mitogen-induced interleukin 2 and gamma interferon production by CD4+ and CD8+ cells of patients with inflammatory arthritides. A comparison between cells from synovial fluid and peripheral blood.

The purpose of this study was to investigate interleukin 2 (IL-2) and gamma interferon (IFN-gamma) production by purified CD4+ and CD8+ cells isolated from peripheral blood (PB) and synovial fluid (SF) of patients with rheumatoid arthritis (RA) and other inflammatory arthritides (non-RA). CD4+ and CD8+ cells were selected positively by immunomagnetic separation. Supernatants of unstimulated CD4+ and CD8+ cells from both compartments did not contain any detectable IL-2 or IFN-gamma, while supernatants of CD4+ and CD8+ cells stimulated with phytohaemagglutinin and irradiated Raji cells mostly contained both cytokines. In vitro stimulated SF CD4+ cells gave supernatants with significantly less IL-2 than supernatants from PB CD4+ cells, while in vitro stimulated SF CD4+-cell supernatants contained significantly more IFN-gamma. SF CD4+-cell supernatants contained significantly more IL-2 than the parallel CD8+ supernatants, while there was no significant difference with regard to IFN-gamma content. The pattern of differences between SF- and PB-derived T cells was the same for the two groups of patients, but the SF CD4+ cells from RA patients produced significantly less IL-2 than the corresponding cells from the non-RA group. The difference between SF and PB T cells with regard to lymphokine production is probably related to various degrees of in vivo pre-activation. The results do not indicate a major T-cell deficiency in relation to lymphokine production in RA.

Expression of activation markers on CD4+ and CD8+ cells from synovial fluid, synovial tissue, and peripheral blood of patients with inflammatory arthritides.

We studied the expression of the Tac antigen, the transferrin receptor (Tfr-R), HLA class II antigens (DR, DQ, DP), CD30, and Act 1 on purified CD4+ and CD8+ cells isolated from synovial fluid (SF), synovial tissue (ST), and peripheral blood (PB) of patients with rheumatoid arthritis (RA) and with non-RA inflammatory arthritides (not ST). Subfractionated T cells of PB from healthy individuals served as controls. SF CD4+ cells from RA and non-RA arthritides expressed the Tac antigen much more frequently than corresponding CD8+ cells (54 and 58% versus 16 and 17%). In contrast, SF CD8+ cells of both patient groups expressed the HLA class II antigens rather more frequently than the corresponding CD4+ cells (88 and 68% versus 72 and 40%). Tfr-R expression was low on CD4+ and CD8+ SF T cells from both patient groups. SF T cells did not express CD30, and their expression of Act 1 did not differ from that of normal PB T cells. The RA ST findings were similar to those of RA SF. The overall expression of activation markers on PB T cells of patients was slightly higher than on those of normal controls, and the RA group was slightly higher than the non-RA group. The results show that intra-articular T cells in arthritis are activated and that CD4+ and CD8+ subsets differ in their expression of Tac antigen and HLA class II antigens. There were also similar patterns of activation markers on both CD4+ and CD8+ SF cells from RA and non-RA arthritis patients, suggesting that several types of arthritis display a similar immunopathogenesis in the joints.

A functional study of purified CD4+ and CD8+ cells isolated from synovial fluid of patients with rheumatoid arthritis and other arthritides.

The purpose of this investigation was to study purified synovial fluid (SF) CD4+ and CD8+ cells from patients with rheumatoid arthritis (RA) and other inflammatory joint diseases (non-RA) with respect to the proliferative response to mitogens and recombinant interleukin 2 (rIL-2). Highly purified cell subsets were isolated by an immunomagnetic technique, and spontaneous proliferation as well as proliferative reSponses to rIL-2 and a combination of phytohaemagglutinin (PHA) and phorbol myristate acetate (PMA) (to substitute for accessory cells) were measured. Some patients had SF CD4+ and/or CD8+ cells with moderately increased spontaneous proliferation, but only the CD4+ cells of the two patient groups differed significantly from the peripheral blood (PB) T-cell subsets of healthy individuals who served as controls. The response to rIL-2 was variable but generally low, although about 50% of the CD4+ and 20% of the SF CD8+ cells of both patient groups expressed the Tac antigen. The response to PHA/PMA was significantly lower for RA SF CD4+ cells than for non-RA SF CD4+ cells, which again was lower than for normal PB CD4+ cells. SF CD8+ response to PMA/PHA by both groups of patients was somewhat decreased, but not significantly lower than in the controls. Thus, the CD4+ cells seemed functionally more deviant than the CD8+ cells in both patient groups, but the abnormality was most pronounced in the RA group. The results demonstrate that the previously reported diminished response to mitogens by SF mononuclear cells is present even when SF CD4+ cells are cultured alone. This indicates that these T cells have a reduced response, probably because of prior activation.

B-cell growth-promoting activity in supernatants from CD4+ cells from synovial fluid and peripheral blood of patients with rheumatoid arthritis and other inflammatory arthritides.

The purpose of this study was to compare CD4+ cells from peripheral blood (PB) and synovial fluid (SF) of patients with rheumatoid arthritis with regard to mitogen-induced production of B-cell growth-promoting activity. CD4+ cells were isolated by a direct immunomagnetic technique and supernatants from both unstimulated and mitogen-stimulated CD4+ cells were studied. B-cell growth-promoting activity was assayed using highly purified B cells obtained from peripheral blood of healthy individuals. The indicator B cells were isolated by an indirect immunomagnetic technique and solid-phase anti-mu was used for activation of the B cells. Supernatants of unstimulated CD4+ cells from SF and PB did not contain B-cell growth-promoting activity, while usually high levels of B-cell growth-promoting activity were detected in the supernatants from mitogen-stimulated cultures. There was no significant difference in the B-cell growth-promoting activity level between supernatants from SF CD4+ and patient PB CD4+ cells, nor was there any significant difference between SF CD4+ and control PB CD4+ supernatants. The results indicate that the CD4+ cells in the SF have a normal potential for producing B-cell growth-promoting activity.

Immunoregulatory lymphokines in rheumatoid joints. III. B cell growth promoting activity of cells eluted from rheumatoid synovial tissue.

Synovial fluid (SF) from rheumatoid arthritis patients (RA) and culture-supernatants of synovial tissue (ST) cells from RA patients and juvenile rheumatoid arthritis (JRA) patients were examined for their ability to promote B cell growth. SF was not suitable for studying B cell growth promotion because with the anti-mu driven assay system employed, all 15 samples strongly inhibited B cell proliferation. Supernatants of in vitro unstimulated ST cells from RA and JRA patients affected B cell growth in different ways, ranging from strong inhibition to moderate stimulation. Supernatants of unstimulated peripheral blood mononuclear cells (MNC) from healthy donors did not influence B cell proliferation. After phytohaemagglutinin (PHA) stimulation of the ST cells and normal MNC, culture supernatants of RA ST cells and normal MNC all stimulated B-cell growth, while culture supernatants of PHA-stimulated JRA ST cells displayed a variable picture. The differences between PHA-supernatants from RA, JRA and normal MNC were not statistically significant. These results indicate that the inflamed synovia of JRA and RA patients contain cells that can produce soluble factors with B cell growth promoting activity. Some of the data in the study suggest that these factors are produced in vivo and thus might be responsible for the observed B-cell activation in joints of these patients.

Immunoregulatory lymphokines in rheumatoid joints. II. Production by and responsiveness to interleukin-2 of eluted synovial tissue cells.

Since the role of interleukin-2 (IL-2) in rheumatoid synovial joints has been debated, we examined IL-2 production by, and IL-2 responsiveness of, cells eluted from synovial tissue (ST) of patients with rheumatoid arthritis (RA) and juvenile rheumatoid arthritis (JRA). IL-2 was not detected in unstimulated cell-culture supernatants from any of the four RA patients tested, but it was present in small amounts in supernatants of unstimulated cultures derived from three of seven JRA patients studied. After PHA stimulation, IL-2 was detected in corresponding supernatants from all RA and JRA patients and from normal mononuclear cells (MNC). There was no significant difference in IL-2 activity between supernatants of normal MNC and supernatants from either RA or JRA patients. The eluted cells showed a proliferative response to recombinant IL-2. Rheumatoid ST cells are thus able to produce and respond to IL-2. Since non-T cells present in the eluates might interfere with IL-2 metabolism, one cannot yet say whether T cells of rheumatoid ST themselves produce and respond to IL-2 in a normal or abnormal way.