Impact of valvular regurgitation and ventricular dysfunction on long-term survival in patients with chest pain

Doppler echocardiography is often used in evaluating patients with chest pain, but information on prognostic value of this testing and data to help guide selective use are limited. We prospectively studied 448 patients admitted from the emergency department for acute chest pain to assess the utility of qualitative echocardiographic data in predicting long-term survival and the incremental value of this information over routine clinical and electrocardiographic data. Doppler echocardiograms, recorded an average of 21 hours after presentation, were analyzed independently by 2 echocardiographers for global left and right ventricular function and valvular disease. Regional function was assessed by wall motion index. Data on long-term survival were collected with an average follow-up of 35.0 +/- 12.1 months. In univariate Cox regression analysis, left ventricular function and size, wall motion index, right ventricular function, and aortic, mitral, and tricuspid insufficiency were significant predictors of total and cardiovascular mortality. In multivariate analysis, moderate or severe left ventricular dysfunction (mortality rate ratio 3.2, 95% confidence intervals 1.8 to 5.8] and more than mild valvular regurgitation (mortality rate ratio 2.0, 95% confidence interval 1.1 to 3.6) were independent predictors of mortality in a model adjusted for clinical and electrocardiographic data. These factors were more common in patients aged >60 years, in those with prior acute myocardial infarction or angina, and in those with rales on physical examination. In the absence of these clinical characteristics, only 8 of 124 patients (7%) had moderate or severe left ventricular dysfunction or valvular regurgitation. In patients with moderate or severe regurgitation, a murmur was noted on the admission physical examination in 41 of 69 cases (59%). We conclude that echocardiographic evidence of moderate or severe left ventricular dysfunction or valvular regurgitation identifies a high-risk group for overall and cardiovascular mortality in patients with chest pain, and this evidence may not be detected clinically.

Expression of interleukin-5 and granulocyte-macrophage colony-stimulating factor in aspirin-sensitive and non-aspirin-sensitive asthmatic airways

Increased numbers of eosinophils and mast cells in the bronchial mucosa are characteristic features in subjects with aspirin-sensitive asthma. Interleukin-5 (IL-5) and granulocyte-macrophage colony-stimulating factor (GM-CSF) are involved in the activation, maturation, and perpetuation of survival of eosinophils. Immunohistochemical techniques were therefore used to study the expression of IL-5 and GM-CSF on frozen bronchial biopsies from 13 aspirin-sensitive asthmatic (ASA) and 8 non-ASA (NASA) subjects. Aspirin sensitivity was diagnosed by lysine-aspirin inhalation provocation. ASA airways demonstrated a significant 2-fold increase in the total number of submucosal inflammatory cells expressing IL-5 (p = 0.03) and approximate 4- and 2-fold increases in the numbers of mast cells expressing IL-5 and GM-CSF (p = 0.02 and p = 0.04, respectively). There was also a 4-fold increase in the number of eosinophils expressing IL-5 (p = 0.004). These results suggest a central role for the mast cell and eosinophil in regulation of the inflammatory cell infiltrate of ASA airways by secretion of the hemopoietic cytokines IL-5 and GM-CSF.

Enhanced expression of cyclo-oxygenase isoenzyme 2 (COX-2) in asthmatic airways and its cellular distribution in aspirin-sensitive asthma

BACKGROUND

There are two isoforms of cyclo-oxygenase (COX), namely COX-1 and COX-2. COX-1 is constitutively expressed in most tissues and in blood platelets. The metabolites derived from COX-1 are probably involved in cellular housekeeping functions. COX-2 is expressed only following cellular activation by inflammatory stimuli and is thought to be involved in inflammation.

METHODS

The expression of COX-1 and COX-2 isoenzymes has been studied in the bronchial mucosa of 10 normal and 18 asthmatic subjects, 11 of whom had aspirin-sensitive asthma (ASA) and seven had non-aspirin-sensitive asthma (NASA) RESULTS: There was a significant fourfold and 14-fold increase, respectively, in the epithelial and submucosal cellular expression of COX-2, but not of COX-1, in asthmatic patients. There was no significant difference in the total number of cells staining for either COX-1 or COX-2 between subjects with ASA and NASA, but the number and percentage of mast cells that expressed COX-2 was significantly increased sixfold and twofold, respectively, in individuals with ASA. There was a mean fourfold increase in the percentage of COX-2 expressing cells that were mast cells in subjects with ASA and the number of eosinophils expressing COX-2 was increased 2.5-fold in these subjects.

CONCLUSION

COX-2-derived metabolites may play an essential part in the inflammatory processes present in asthmatic airways and development of drugs targeted at this isoenzyme may have therapeutic potential in the treatment of asthma. Mast cells and eosinophils may also have a central role in the pathology of aspirin-sensitive asthma.

Health-related quality of life after elective surgery: measurement of longitudinal changes

OBJECTIVE

To examine the responsiveness of the 36-Item Short Form Health Survey (SF-36) to clinical changes in three surgical groups and to study how health-related quality of life (HRQL) changes with time among patients who undergo total hip arthroplasty, thoracic surgery for treatment of non-small-cell lung cancer, or abdominal aortic aneurysm (AAA) repair.

DESIGN

Prospective cohort study with serial evaluations of HRQL preoperatively and at 1, 6, and 12 months after surgery.

SETTING

University tertiary care hospital.

PATIENTS

Of 528 patients, more than 50 years of age, who were admitted for these elective procedures, 454 (86%) provided preoperative health status data and are members of the study cohort. At 12 months after surgery, 439 (93%) of the cohort was successfully contacted and 390 (90%) provided follow-up interviews.

MEASUREMENTS AND MAIN RESULTS

The Medical Outcomes Study SF-36, the Specific Activity Scale, five validated health transition questions, and a 0 to 100 scale measure of global health were used to assess changes in health status at 1, 6, and 12 months after surgery. Change in health status as measured by the SF-36 demonstrated that physical function and role limitations due to physical health problems were worse 1 month after these three surgeries. However, by 6 months after surgery, most patients experienced significant gains in the majority of the dimensions of health, and these gains were sustained at 12 months after surgery. Longitudinal changes in the SF-36 were positively associated with responses to the five health transition questions, to changes on the Specific Activity Scale and global health rating question, and to clinical parameters for persons who had AAA repair. These findings indicate that the SF-36 has evidence of validity and is responsive to expected changes in HRQL after elective surgery for these procedures.

CONCLUSIONS

For the total hip arthroplasty patients, responsiveness was greatest for the SF-36 scales that measure physical constructs. However, for the two other procedures and at various points of recovery, significant changes were observed for all eight subscales, suggesting that responsiveness was dependent on the type of surgery and the timing of follow-up, and that multidimensional measures are needed to fully capture changes in HRQL after surgery.

Codon optimization for high-level expression of human erythropoietin (EPO) in mammalian cells

Codon bias has been observed in many species. The usage of selective codons in a given gene is positively correlated with its expression efficiency. As an experimental approach to study codon-usage effects on heterologous gene expression in mammalian cells, we designed two human erythropoietin (EPO) genes, one in which native codons were systematically substituted with codons frequently found in highly expressed human genes and the other with codons prevalent in yeast genes. Relative performances of the re-engineered EPO genes were evaluated with various combinations of promoters and signal leader sequences. Under the comparable set of combinations, mature EPO gene with human high-frequency codons gave a considerably higher level of expression than that with yeast high-frequency codons. However, the levels of EPO expression varied, depending on the alternate combinations. Since the promoters and the signal leader sequences that we used are known to be equally efficient in gene expression, we hypothesized that the varied expression levels were due to the linear sequence between the promoter and the coding gene sequence. To test this possibility, we designed the EPO gene with hybrid codon usage in which the 5'-proximal region of the EPO gene was synthesized with yeast-biased codons and the rest with human-biased codons. This codon-usage hybrid EPO gene substantially enhanced the level of EPO transcripts and proteins up to 2.9-fold and 13.8-fold, respectively, when compared to the level reached by the original counterpart. Our results suggest that the linear sequence between the promoter and the 5'-proximal region of a gene plays an important role in achieving high-level expression in mammalian cells.

Polymorphic sequence of Korean Native goat lactoferrin exhibiting greater antibacterial activity

Lactoferrin, which exhibits antibacterial activity to protect infants from infectious disease, is a major component of colostrum and milk. Lactoferrin was purified from the colostrum of Korean Native goat, and the cDNA from the mammary gland mRNA of the animal was cloned and sequenced. The nucleotide sequence of the lactoferrin gene of Korean Native goat was found to differ in 15 sites from that of the goat lactoferrin gene reported earlier. This difference in nucleotide sequence resulted in six amino acid substitutions: five in the N-lobe and one in the C-lobe. The antibacterial activity of Korean Native goat lactoferrin was found to be greater than that of Sannen goat lactoferrin.

GM-CSF increases the ability of cultured macrophages to support autologous CD4+ T-cell proliferation in response to Dermatophagoides pteronyssinus and PPD antigen

Previous studies have demonstrated an infiltration of monocytes and increased levels of granulocyte-macrophage colony-stimulating factor (GM-CSF) in the asthmatic lung. To study the possible effects of this cytokine upon the differentiation and function of these newly recruited monocytes, we have developed a model in which monocytes isolated from human peripheral blood were differentiated into macrophages in serum in the presence or absence of GM-CSF. After 7 days, the macrophages increased in size and granularity, had increased phagocytic activity, and expressed various adhesion molecules, CD14 and major histocompatibility complex (MHC) class II. The effects of GM-CSF on antigen presentation by cultured macrophages on the antigen-specific proliferative response of CD4+ T cells to Dermatophagoides pteronyssinus or purified protein derivative of tuberculin and the mitogen phytohaemagglutinin was determined. CD4+ T-cell proliferation was reduced when either antigen was presented by macrophages cultured in serum alone, compared with the values obtained with freshly isolated monocytes. However, CD4+ cell proliferation was comparable to that observed with monocytes when antigen was presented by macrophages which had been pre-cultured with 50 U/ml GM-CSF. CD4+ T-cell proliferation to phytohaemagglutinin was similar when all three populations were used as accessory cells. High numbers of macrophages partially suppressed CD4+ T-cell proliferation in response to antigen presented by monocytes, but there was no significant difference between macrophages cultured in the presence or absence of GM-CSF. This data suggests that GM-CSF directs monocyte differentiation into macrophages with an antigen-presenting, rather than a suppressive, phenotype. Elevated levels of GM-CSF in the asthmatic lung may therefore maintain recently recruited monocytes in an inflammatory and T-cell activating state.

Development of sporulation/immobilization method and its application for the continuous production of cyclosporin A by Tolypocladium inflatum

An efficient sporulation/immobilization procedure for immobilized fungal cell culture was developed by modifying an existing immobilized technique to shorten the time and number of steps for sporulation. This method was applied to an immobilized-cell perfusion bioprocess (IPB) for continuous production of CyA, an intracellular secondary metabolite produced by a filamentous fungus, Tolypocladium inflatum. In the IPB, the fungal cells were immobilized in the pores of celite beads (100-500 microm) and a top-driven stirred tank fermentor was used for the culture. The IPB showed good process benefits as demonstrated by the high density of immobilized cells continuously producing CyA-containing free cells. The productivity of cyA-containing free cells in the effluent was very high, ca. 1.0g/(L/h) at a dilution rate of 0.1 h-1, due to the high density of immobilized cells in the fermentor. The CyA productivity was 4.0-6.0 mg/(L/h) which was about 6-10-fold higher than that of batch suspended cell culture. Such an efficient IPB was possible since a decantor was developed in this study, which could effectively separate cell-immobilized beads from the effluent although bead loss slightly increased as the cell loading increased in the latter part of culture. Furthermore, long-term operation of IPB was carried out successfully by employing an in-situ immobilization strategy. It was found that a large number of spores in the fermentation broth in the reactor were entrapped in-situ into the newly supplemented celite beads and then germinated, thus forming new immobilized cells.

Recruitment of engrafted donor cells postnatally into the blood with cytokines after in utero transplantation in mice

BACKGROUND

We have previously shown that MHC-mismatched fetal liver cells can durably engraft in 45% of nondefective fetal mice, although male donor cells were found in the blood in only 8% of female recipients. We postulated that adult bone marrow stem cells would engraft similarly to fetal liver cells and that postnatal administration of cytokines would recruit donor cells into the peripheral circulation.

METHODS

Bone marrow from C57BL/6 adult male mice was injected into allogeneic BALB/c or congenic C57BL/6 fetal recipients that were 11-13 days old. Engraftment was tested by quantitative polymerase chain reaction for the Y chromosome in female recipients (0.0001% sensitivity). Recipients were injected at 1-2 years of age with rat stem cell factor (SCF) and human granulocyte colony-stimulating factor (G-CSF) for 7 days and tested for donor cells in the blood.

RESULTS

The overall engraftment rate (in the blood, spleen, or liver) was 44% in both female allogeneic and congenic bone marrow recipients. Of 49 recipients of bone marrow or fetal liver cells with no evidence of donor cells in the blood before injection, 29 (59%) developed circulating donor cells at some time after cytokine injection for up to 2 months. Twenty-seven of 49 animals were negative in the blood, liver, and spleen before cytokine therapy; 14 of 27 (52%) became positive in the blood after stem cell factor/granulocyte colony-stimulating factor injection. Tolerance to donor skin grafts was not altered by the mobilization of donor cells into the circulation.

CONCLUSIONS

Adult bone marrow durably engrafts in nondefective mice at a rate similar to that previously obtained with fetal liver. Engrafted donor cells can be mobilized with cytokines into the circulation for up to 2 months even in animals with no evidence of donor cells in the blood, liver, or spleen. Based on these results we estimate that 70-75% of hematopoietically nondefective fetal mice engraft with MHC-mismatched fetal liver or adult bone marrow stem cells.

Risk of initiating antiarrhythmic drug therapy for atrial fibrillation in patients admitted to a university hospital

BACKGROUND

The risks of antiarrhythmic therapy are increasingly recognized, but the risks associated with the initiation of antiarrhythmic therapy in patients hospitalized for atrial fibrillation are poorly defined.

OBJECTIVE

To determine the incidence, time course, and predictors of adverse cardiac events that require intervention during initiation of antiarrhythmic drug therapy for atrial fibrillation.

DESIGN

Retrospective chart review.

SETTING

University hospital.

PARTICIPANTS

417 consecutive patients who underwent a total of 597 drug trials during a total of 550 hospitalizations for atrial fibrillation.

INTERVENTION

Initiation of therapy with antiarrhythmic drugs: procainamide (189 trials), quinidine (179 trials), disopyramide (20 trials), propafenone (110 trials), flecainide (2 trials), sotalol (72 trials), and amiodarone (25 trials). Electrical conversion was performed during 247 trials.

MEASUREMENTS

Incidence of adverse events and daily hazard rate were measured. Logistic regression was done to identify risk factors.

RESULTS

During the 597 drug trials, 80 (13.4%) cardiac adverse events occurred in 73 patients. The risk was greatest during the first 24 hours of therapy. Bradyarrhythmias were the most common adverse event, occurring in 47 trials (7.9%); prolongation of the QT interval warranting discontinuation of drug therapy (9 trials; 1.5%) and ventricular arrhythmias (8 trials; 1.3%) were less frequent. In multivariate analysis, previous myocardial infarction was associated with increased risk (odds ratio, 1.90 [95% CI, 1.05 to 3.43]) and the association between older age and increased risk (odds ratio, 1.29 per decade [CI, 0.97 to 1.72]) was of borderline statistical significance.

CONCLUSIONS

A significant risk for cardiac adverse events exists during initiation of antiarrhythmic therapy in patients hospitalized for atrial fibrillation. Observation with electrocardiographic monitoring seems advisable for 24 to 48 hours during initiation of antiarrhythmic therapy, particularly for elderly patients and patients who have previously had myocardial infarction.

Interaction of the UV-damaged DNA-binding protein with hepatitis B virus X protein is conserved among mammalian hepadnaviruses and restricted to transactivation-proficient X-insertion mutants

We carried out a comparative analysis of several proposed host protein partners of the human hepatitis B virus X protein (HBx) using both the GAL4- and the LexA-based yeast two-hybrid system. We showed that the interaction of HBx with the UV-damaged DNA-binding protein (UVDDB) is positive in both yeast systems, detectable in cotransfected human cells, conserved by rodent hepadnavirus X proteins (known to transactivate in human cells), and tightly correlated with the transactivation proficiency of X-insertion mutants. Taken together, our results strongly suggest that UVDDB is involved in X-mediated transactivation.

Immune memory in CD4+ CD45RA+ T cells

This study addresses the question of whether human peripheral CD4+ CD45RA+ T cells possess antigen-specific immune memory. CD4+ CD45RA+ T cells were isolated by a combination of positive and negative selection. Putative CD4+ CD45RA+ cells expressed CD45RA (98.9%) and contained < 0.1% CD4+ CD45RO+ and < 0.5% CD4+ CD45RA+ CD45RO+ cells. Putative CD45RO+ cells expressed CD45RO (90%) and contained 9% CD45RA+ CD45RO+ and < 0.1% CD4+ CD45RA+ cells. The responder frequency of Dermatophagoides pteronyssinus-stimulated CD4+ CD45RA+ and CD4+ CD45RO+ T cells was determined in two atopic donors and found to be 1:11,314 and 1:8031 for CD4+ CD45RA+ and 1:1463 and 1:1408 for CD4+ CD45RO+ T cells. The responder frequencies of CD4+ CD45RA+ and CD4+ CD45RO+ T cells from two non-atopic, but exposed, donors were 1:78031 and 1:176,903 for CD4+ CD45RA+ and 1:9136 and 1:13,136 for CD4+ CD45RO+ T cells. T cells specific for D. pteronyssinus were cloned at limiting dilution following 10 days of bulk culture with D. pteronyssinus antigen. Sixty-eight clones were obtained from CD4+ CD45RO+ and 24 from CD4+ CD45RA+ T cells. All clones were CD3+ CD4+ CD45RO+ and proliferated in response to D. pteronyssinus antigens. Of 40 clones tested, none responded to Tubercule bacillus purified protein derivative (PPD). No difference was seen in the pattern of interleukin-4 (IL-4) or interferon-gamma (IFN-gamma) producing clones derived from CD4+ CD45RA+ and CD4+ CD45RO+ precursors, although freshly isolated and polyclonally activated CD4+ CD45RA+ T cells produced 20-30-fold lower levels of IL-4 and IFN-gamma than their CD4+ CD45RO+ counterparts. Sixty per cent of the clones used the same pool of V beta genes. These data support the hypothesis that immune memory resides in CD4+ CD45RA+ as well as CD4+ CD45RO+ T cells during the chronic immune response to inhaled antigen.

The effect of R 15.7/HO, an anti-CD18 antibody, on the late airway response and airway hyperresponsiveness in an allergic rabbit model

1. The effects of a mouse (IgG1 fraction) anti-CD 18 neutralizing antibody (R15.7) on allergen-induced late airway response (LAR), airway hyperresponsiveness (AHR) and cellular recruitment were investigated in an allergic rabbit model. 2. Litter-matched NZW rabbits immunized within 24 h of birth with Alternaria tenuis (i.p.) and subsequently exposed to the allergen (i.p.) for the first 3 months of life were challenged with inhaled allergen as adult rabbits. Lung function in terms of dynamic compliance (Cdyn; ml cmH2O-1) and total lung resistance (RL; cmH2O-1 s-1) was monitored for 6 h following the allergen challenge. On day 16, separate groups of rabbits were pretreated with either control antibody (a non-binding mouse IgG1, 1 mg kg-1, i.v.) or R15.7 (1 mg kg-1, i.v.) and 1 h later all were challenged with Alternaria tenuis and lung function monitored thereafter. Airway responsiveness to inhaled histamine was assessed by measuring RL and Cdyn 24 h before and after allergen challenge and bronchoalveolar lavage (BAL) was also performed 24 h before and after allergen challenge. 3. Pretreatment of rabbits with the control antibody had no effect on the LAR as measured by AUC (Cdyn, 0-6 h). However, the magnitude of the LAR following treatment with R15.7 was significantly reduced when compared to LAR demonstrated on 1st challenge (P < 0.001) or to that of the control group on both challenges (P < 0.01). 4. In control antibody pretreated rabbits allergen induced a significant 3.4 fold reduction in the PC50 response to inhaled histamine in terms of RL changes (P < 0.05) and a significant 2.1 fold reduction in PC35 response to inhaled histamine in terms of Cdyn changes (P < 0.05). However, in anti-CD 18 antibody pretreated rabbits there was no significant change in responsiveness to histamine 24 h following allergen, as assessed by either RL PC50 or Cdyn PC35. 5. Allergen challenge induced a significant increase in eosinophil and neutrophil numbers (P < 0.05) in rabbits pre-treated with control antibody, whereas treatment with R15.7 significantly inhibited this increase in the numbers of both cell types. 6. This study demonstrates that the neutralization of CD-18 molecules reduces allergen-induced infiltration of both eosinophils and neutrophils into the airways and abolishes the accompanying LAR and AHR. These results provide evidence to support a role for CD-18 adhesion molecules in the transmigration of inflammatory cells into airways.

Human lung mast cells release small amounts of interleukin-4 and tumour necrosis factor-alpha in response to stimulation by anti-IgE and stem cell factor

Recent reports have suggested that mast cells are capable of producing and releasing a number of pro-inflammatory cytokines. However, these studies have mainly been carried out using murine tissue culture derived mast cells and it is known that these cells differ markedly in their functional properties from isolated human mast cells. It was therefore essential to study the release of cytokines from the latter cell type. On immunological stimulation with anti-immunoglobulin E (anti-IgE) or stem cell factor (SCF), purified human lung mast cells released, within 2-10 min, small amounts of tumour necrosis factor-alpha (10.5 +/- 2.9 pg/10(6) mast cells and 17.9 +/- 7.9 pg/10(6) mast cells, respectively) and interleukin-4 (5.3 +/- 2.5 pg/10(6) mast cells and 8.0 +/- 3.2 pg/10(6) mast cells, respectively). After longer periods of activation (30 min-4 h). the amounts of cytokines released from stimulated cells decreased to levels which were below those of the unstimulated cells. This possible degradation of cytokines by mast cells could not be prevented by the addition of protease inhibitors.

Effect of inhaled glucocorticoids on IL-1 beta and IL-1 receptor antagonist (IL-1 ra) expression in asthmatic bronchial epithelium

BACKGROUND

Accumulating evidence suggests that the cytokine network is central to the immunopathology of bronchial asthma and the existence of naturally occurring cytokine antagonists has added to this complexity. Upregulation of both interleukin 1 beta (IL-1 beta) and its naturally occurring receptor antagonist, interleukin 1 receptor antagonist (IL-1ra), has previously been observed on asthmatic bronchial epithelium compared with normal airways.

METHODS

The effect of inhaled beclomethasone dipropionate (BDP) on asthmatic bronchial epithelial expression of IL-1 beta and IL-1ra was studied. Frozen bronchial biopsy specimens from nine asthmatic subjects receiving 1000 micrograms BDP daily for eight weeks and from six asthmatic subjects receiving matching placebo were stained with anti-IL-1 beta and anti-IL-1ra antibodies. Hue-saturation-intensity (HSI) colour image analysis was used to quantify the brown immunoperoxidase reaction colour present on the bronchial epithelium.

RESULTS

There was a significant twofold decrease in the epithelial expression of IL-1 beta after treatment with BDP but no significant change was seen in IL-1ra (P = 0.175).

CONCLUSION

The selective inhibition of IL-1 beta, without effect on IL-1ra, provides a novel mechanism for the anti-inflammatory action of glucocorticosteroids.

Mechanisms of corticosteroid resistance in asthmatic patients

Corticosteroid-resistant (CR) asthma is associated with disease chronicity, a more frequent family history of asthma and impaired in vitro and in vivo responsiveness of peripheral blood mononuclear cells to the suppressive effects of glucocorticoids. CR asthma is associated with normal suppression of the hypothalamic-pituitary-adrenal axis and of biochemical indices of bone turnover by dexamethasone, indicating that the phenomenon of glucocorticoid resistance is specific to inflammatory leukocytes and that these patients are equally at risk of developing 'cushingoid' side effects. We have been unable to detect altered bioavailability of administered glucocorticoid, impaired ligand binding or nuclear translocation of the activated glucocorticoid receptor (GR) complex or structural abnormalities of the GR cDNA in our population of CR asthmatics. We have recently demonstrated that CR asthma is associated with decreased GR and increased AP-1 (Fos; Jun) DNA binding in peripheral blood mononuclear cells as compared to corticosteroid-sensitive asthma. These results highlight the central role of the AP-1/GR interactions in glucocorticoid action in CR asthma.

Prognostic value of cardiac troponin T after noncardiac surgery: 6-month follow-up data

OBJECTIVES

We sought to evaluate the prognostic significance of cardiac troponin T (TnT) serum levels after noncardiac surgery.

BACKGROUND

Cardiac TnT has been found to be marker for myocardial injury, but elevations of TnT are common in patients undergoing noncardiac surgery without clinical evidence of severe ischemia.

METHODS

We studied 772 patients who underwent major noncardiac procedures and did not have major cardiovascular complications during their inpatient course. Total serum creatine kinase (CK) and cardiac TnT were measured according to a protocol that included sampling in the recovery room and during the next 2 days. A 6-month follow-up interview was performed for 722 (94%) of the patients.

RESULTS

Elevated cardiac TnT and CK-MB results were detected for 92 (12%) and 211 (27%) patients, respectively. During the follow-up period, there were 19 (2.5%) major cardiac complications, including 14 cardiac deaths, 3 nonfatal myocardial infarctions and 2 admissions for unstable angina. Compared with patients with cardiac TnT values < 0.1 ng/ml, patients with elevated TnT had a relative risk for cardiac events of 5.4 (95% confidence interval: 2.2 to 13, p = 0.001), whereas CK-MB was not correlated with postdischarge cardiac events. In multivariate logistic regression analysis adjusting for preoperative clinical and CK-MB data, a cardiac TnT value > 0.1 ng/ml was in independent correlate of cardiac events (adjusted odds ratio 4.6, p < 0.05). This correlation was a function of the relation of elevated TnT levels with postoperative in-hospital congestive heart failure and new sustained arrhythmias, suggesting that elevated postoperative TnT levels detected myocardial ischemia during these clinical events.

CONCLUSIONS

We conclude that an abnormal TnT level in patients undergoing noncardiac surgery may be a useful marker of ischemic disease and a predictor of 6-month prognosis.

2',5'-Dihydroxychalcone as a potent chemical mediator and cyclooxygenase inhibitor

Eleven chalcone derivatives have been tested for their inhibitory effects on platelet aggregation in rabbit platelet suspension and the activation of mast cells and neutrophils. Arachidonic acid-induced platelet aggregation was potently inhibited by almost all the compounds and some also had a potent inhibitory effect on collagen-induced platelet aggregation and cyclooxygenase. Some hydroxychalcone derivatives showed strong inhibitory effects on the release of beta-glucuronidase and lysozyme, and on superoxide formation by rat neutrophils stimulated with the peptide fMet-Leu-Phe (fMLP). We found that the anti-inflammatory effect of 2',5'-dihydroxychalcone was greater than that of trifluoperazine. 2'5'-Dihydroxy and 2',3,4,5'-tetrahydroxyl chalcones, even at low concentration (50 microM), tested in platelet-rich plasma from man almost completely inhibited secondary aggregation induced by adrenaline. These results suggest that the anti-platelet effects of the chalcones are mainly a result of inhibition of thromboxane formation.

The effect of a novel orally active selective PDE4 isoenzyme inhibitor (CDP840) on allergen-induced responses in asthmatic subjects

Recent studies have suggested that theophylline, a nonspecific phospho-diesterase inhibitor, has useful anti-inflammatory actions in asthma. Phosphodiesterase 4 (PDE4) represents the predominant PDE isoenzyme present in inflammatory cells. PDE4 inhibitors might, therefore, have beneficial effects in asthma. Side-effects, specifically nausea, have limited the use of existing agents. CDP840 is an orally active, potent and selective PDE4 inhibitor. We have examined the effect of CDP840 on the allergen-induced asthmatic response, its possible modes of action, and its tolerability at therapeutic doses. A total of 54 patients were recruited to three double-blind, placebo-controlled studies. The first study examined the effect of CDP840 (15 mg b.i.d. for 9.5 days) on the allergen-induced asthmatic response in patients with known dual response to allergen. A second study examined the effect of CDP840 (15 mg b.i.d. for 9.5 days) on airway responsiveness to histamine. A third study examined whether single dose CDP840 (15 and 30 mg) had significant bronchodilatory effects. In all studies, CDP840 was well-tolerated, with no patients reporting nausea. CDP840 did not lead to changes in baseline forced expiratory volume in one second (FEV1) as compared to placebo. The late asthmatic response (LAR) to allergen, expressed as area under the curve at 3-8 h (AUC3-8h), was inhibited by 30% (p=0.016), an effect which persisted to the end of the observation period. The early asthmatic response (EAR) was unaffected, and there was no bronchodilatory effect at the doses used. Treatment with CDP840 did not affect bronchial hyperresponsiveness to histamine. In conclusion, CDP840 significantly attenuated the late asthmatic response to allergen challenge in the absence of any bronchodilatory or histamine antagonist effect. This suggests that CDP840 may exert its effects via an anti-inflammatory mechanism.

Conformational stability of a type II' beta-turn motif in human growth hormone [6-13] peptide analogues at hydrophobic surfaces

The interactive properties of several peptides related to human growth hormone (hGH) [6-13] containing a type II' beta-turn motif have been investigated using reversed-phase high-performance liquid chromatography (RP-HPLC). Various chromatographic parameters related to the hydrophobic interactive surface area and binding affinity were measured over the range of temperatures between 5 and 85 degrees C. Variations in these parameters were consistent with significant differences in the relative stability of the type II' beta-turn structures of these peptidomimetics. The effect of changes in peptide conformation were also investigated through the analysis of band-broadening behaviour during the chromatographic process. Significant variations in bandwidth observed at discrete temperatures were related to the rate of interconversion between the type II' beta-turn and more extended conformers. These investigations further document the potential of RP-HPLC for monitoring subtle changes in peptide secondary structure at hydrophobic interfaces.