Impact of Saliva Collection and Processing Methods on Aspartate Aminotransferase, Creatin Kinase and Lactate Dehydrogenase Activities

We aimed to investigate the impact of saliva collection and processing methods on AST, CK and LDH. Saliva was collected from 17 healthy participants by a passive drool. Each saliva sample was distributed into 3 aliquots: not treated, centrifuged, and passed through cotton. Centrifugation improved the precision of assays and produced lower values of AST and CK. The use of cotton resulted in decreased levels of LDH. This data stress the importance of the standardization of sample processing to measure enzymes in saliva.

Anabolic status and functional impairment in men with mild chronic heart failure

The purpose of this study was to establish the role of hormonal anabolic deficiencies in exercise intolerance in patients with chronic heart failure One hundred four consecutive men (mean age 53.1 ± 10.6 years) with established diagnoses of chronic heart failure were included. At enrollment, blood samples were taken, and echocardiography and cardiopulmonary exercise testing were carried out. Exercise capacity was expressed as peak oxygen consumption (Vo₂), predicted peak Vo₂, and the ventilatory response to exercise (VE/Vco₂) slope. The mean left ventricular ejection fraction was 29.7 ± 11.9%, and most patients (86%) were in New York Heart Association class I or II, with a mean peak Vo₂ of 18 ml/min/kg. According to the age-adjusted reference values, hormonal deficiencies were present in 29% for total testosterone, 39% for estimated free testosterone, 34% for insulin-like growth factor-1, and 61% for dehydroepiandrosterone sulfate. Dehydroepiandrosterone sulfate showed a significant correlation with peak Vo₂ (r = 0.29, p = 0.007), predicted peak Vo₂ (r = 0.28, p = 0.006), and VE/Vco₂ slope (r = -0.39, p <0.001), whereas total testosterone, estimated free testosterone, and insulin-like growth factor-1 were not significantly correlated. After adjusting in a multivariable model, dehydroepiandrosterone sulfate remained an independent predictor of each exercise parameter. In conclusion, in a cohort of patients with mild chronic heart failure, exercise capacity objectively measured using cardiopulmonary exercise testing was related to anabolic impairment of the adrenal rather than the somatotropic or peripheral axis.

Sex hormone-binding globulin: a new marker of disease severity and prognosis in men with chronic heart failure

INTRODUCTION AND OBJECTIVES

Sex hormone-binding globulin (SHBG) is a key regulator of the actions of anabolic steroids. Chronic heart failure (HF) has been associated with anabolic steroid deficiency, but its relationship with SHBG is not known.

METHODS

The study involved 104 men (53+/-11 years) with HF (i.e. left ventricular ejection fraction [LVEF] <40%) attending a specialist clinic on optimum treatment and in a stable condition. At enrolment, the median and interquartile range (IQR) SHBG level was determined, associated hormone levels were measured, and known risk factors were recorded. The study end-point was cardiac death within 3 years.

RESULTS

At enrolment, the SHBG level (median 34.5 nmol/L, IQR 27-50 nmol/L) was correlated with the N-terminal probrain natriuretic peptide level (r=0.271, P=.005), LVEF (r=-0.263, P=.007), body mass index (r=-0.199, P=.020) and total testosterone level (r=0.332, P=.001). The median SHBG level was higher in the 16 patients (15.4%) who died, at 48.5 nmol/L (IQR 36-69.5 nmol/L) vs. 33 nmol/L (IQR 25.3-48.7 nmol/L; P=.001), and a high level was associated with an increased risk of death (hazard ratio [HR]=1.045, 95% confidence interval [CI] 1.021-1.069; P< .001). The association remained significant after adjustment in Cox multivariate regression modeling, at HR=1.049 (95% CI 1.020-1.079; P=.001). Analysis by SHBG tertiles showed mortality was 30% in the third tertile, 14% in the second, and 4% in the first (log rank 0.007; HR=3.25, 95% CI 1.43-7.34; P=.004).

CONCLUSIONS

The SHBG level correlated with measures of HF severity and was associated with a higher risk of cardiac death. Further studies are needed to clarify whether SHBG plays a role in HF pathophysiology.

Preoperative Statin Therapy and Troponin T Predict Early Complications of Coronary Artery Surgery

BACKGROUND

Pretreatment with statins reduces early ischemic events after percutaneous coronary interventions, primarily in patients with a high level of inflammation markers. We sought to examine the association between preoperative statin therapy, systemic inflammation, and myocardial ischemia with the occurrence of early cardiac complications after coronary artery bypass grafting surgery.

METHODS

One hundred forty-one consecutive patients who underwent coronary artery bypass grafting surgery from two university tertiary hospitals were stratified according to their preoperative status of statin therapy (87 treated and 54 nontreated). Preoperative blood samples were collected for measurement of lipid parameters, C-reactive protein, interleukin-6, and troponin T. The evaluated primary endpoint was a composite of death and myocardial infarction at 30 days.

RESULTS

Patients undergoing preoperative statin therapy showed a reduced incidence of death (2.3% versus 13.0%, p = 0.012), myocardial infarction (5.7% versus 18.5%, p = 0.017), and primary combined endpoint (8.0% versus 22.2%, p = 0.017). In the multivariate model, preoperative troponin T greater than 0.01 ng/mL (odds ratio 6.85, p = 0.001) and nonstatin therapy (odds ratio 4.2, p = 0.01) predicted a higher risk of primary endpoint. Statins showed a significant interaction with troponin T status and benefited primarily those patients with positive troponin T. Among 19 patients with troponin T greater than 0.01 ng/mL, the primary endpoint occurred in all 6 nonstatin-treated patients, but it occurred in only 1 of 13 statin-treated patients (p < 0.001). Neither C-reactive protein nor interleukin-6 predicted early complications, nor did they interact with statin therapy (p = not significant).

CONCLUSIONS

Preoperative statin therapy reduces early complications and offers additional protection in patients with positive troponin T status, regardless of inflammatory markers.

Inhibition of poly(ADP-ribose) polymerase attenuates the severity of acute pancreatitis and associated lung injury

The severity of acute pancreatitis results from the transmigration and activation of leukocytes within the pancreas and the local synthesis and release of proinflammatory-soluble mediators that transform a local injury into a systemic inflammatory response. Poly(ADP-ribose)polymerase-1 (PARP-1) is a nuclear DNA-binding protein that has been shown to play a relevant role in cell necrosis and organ failure in various diseases associated with inflammation. Therefore, we set out to investigate whether the genetic deletion of PARP-1 or PARP-2 (a new member of the PARP family) genes, or pharmacological inhibition of PARP activity might affect the development and severity of acute pancreatitis and pancreatitis-associated lung injury. Secretagogue-induced acute pancreatitis was achieved by 12 hourly intraperitoneal injections of cerulein in mice deficient in PARP-1 or PARP-2 genes, and wild-type (WT) littermate mice untreated or treated with PARP activity inhibitors. The severity of pancreatitis was assessed by measurements of serum amylase, lipase, interleukin-1beta and IL-6, pancreatic water content, histologic grading and pancreas myeloperoxidase (MPO) activity. Lung injury was evaluated by quantifying MPO activity and morphological changes. We found that the severity of acute pancreatitis and pancreatitis-associated lung injury was significantly attenuated in mice lacking PARP-1, but not PARP-2, compared with WT mice. Interestingly, administration of PARP inhibitors, 3-aminobenzamide or PJ34 (N-(6-oxo-5,6-dihydro-phenanthridin-2-yl)-N,N-dimethyacetamide HCl), in WT mice markedly decreased acute pancreatitis severity and pulmonary-associated injury in a larger extension than genetic deletion of PARP-1. Our results support the potential therapeutic application of PARP inhibitors in the development and severity of acute pancreatitis and associated lung injury.

Evaluation of the turnaround time of an integrated preanalytical and analytical automated modular system in a medium-sized laboratory

OBJECTIVES

Evaluation of an integrated Modular Preanalytics (MPA) and Modular Analytics SWA (MA) system (Roche Diagnostics) during continuous batch processing.

DESIGN AND METHODS

A total of 1000 blood specimen tubes was processed and tested in a batch-wise fashion, according to two different specimen input conditions (Study 1 and Study 2). The resulting turnaround time of the system was assessed.

RESULTS

Study 1 tubes were centrifuged in the MPA. The preanalytical time rose steadily from 14 to 28 min, and after sample 315, it showed minimal variation. The analytical time remained almost constant. In Study 2, tubes were centrifuged before being processed in the MPA. The preanalytical time increased from 4 to 19 min, and the analytical time increased similarly. The turnaround time in Study 1 was 132 min and in Study 2 was 108 min.

CONCLUSION

Centrifugation in the MPA slightly increased the turnaround time. Nevertheless, the labor associated with specimen processing was reduced and the efficiency of the laboratory was improved.

Copper metabolism and biliary secretion in patients receiving orthotopic liver transplantation

BACKGROUND

The quantitative aspects of biliary copper excretion in health and disease have not been fully defined yet. The aim of the study was to evaluate copper metabolism and biliary excretion of patients who have received an orthotopic liver transplant (OLT) during the immediate postoperative period.

METHODS

We have studied retrospectively 16 patients undergoing primary OLT and eight undergoing cholecystectomy, and measured serum concentration of copper and its secretion in bile and urine by flame atomic absorption spectrometry (FAAS).

RESULTS

We found a progressive increase of biliary copper secretion rates and a corresponding lowering of urinary copper during the postoperative period. Thus, in OLT patients, the mean of biliary copper secretion on day 1 is 0.7+/-0.2 micromol/day compared with 2.3+/-1.1 micromol/day on day 7 (p<0.01) and 6.1+/-2.5 micromol/day on day 15 (p<0.0001). The rate of copper output on day 5 after surgery is about one sixth of the value reported for patients who had undergone cholecystectomy. In patients suffering an acute rejection episode, there was an abrupt fall in bile flow (<15 ml/day) and excretion of biliary copper (<1 micromol/day), accompanied by an increase of urine copper excretion (>3 micromol/day), and both were recovered when the rejection episode was solved. We found an inverse relationship between the serum bilirubin (Bt), alkaline phosphatase (ALP) and the biliary copper excretion (p<0.01), and a direct relationship with urinary copper excretion (p<0.01).

CONCLUSIONS

The copper measurements in urine and bile are non-invasive techniques, of low cost, rapid and easy to accomplish, and available in hospitals accredited for hepatic transplantation. These characteristics make these methods helpful in the monitoring of patients submitted to OLT for assessment of graft quality and subsequent outcome.

Serum ionized magnesium monitoring during orthotopic liver transplantation

During orthotopic liver transplantation (OLT) citrate accumulates and magnesium can be chelated, which can lead to ionized hypomagnesemia and cardiovascular dysfunction. Our aim was to study the serum ionized magnesium (Me2+) evolution and establish its relation to serum total Mg and citrate levels during OLT. We studied 58 adult patients undergoing OLT. The serum Me2+ level dropped significantly at the end of the preanhepatic phase, and remained low until the end of the procedure. Furthermore, the Me2+ levels remained below the range of reference from the beginning of the anhepatic phase onward. There was an inverse correlation between Me2+ and citrate for all patients. Me2+, like ionized calcium (Ca2+), is chelated by citrate and its evolution is a mirror image of that of citrate. In our patients, we did not observe any significant dysrhythmias that could be directly attributed to ionized hypomagnesemia. In conclusion, low preoperative levels, together with the massive transfusion of blood products and the increase in renal losses, cause progressive ionized hypomagnesemia in OLT patients. We propose that it he routinely monitored and treated accordingly, as is already done with Ca2+.

The value of polymorphonuclear elastase in adult respiratory distress syndrome

The clinical usefulness of quantitative plasma polymorphonuclear elastase (PMN-elastase) determinations as prognostic markers of adult respiratory distress syndrome (ARDS) in polytraumatized patients was analyzed. PMN-elastase and C-reactive protein (CRP) levels were determined in 55 polytraumatized patients admitted into the Intensive Care Unit. Eight patients developed ARDS and 47 patients did not. These parameters were also analyzed in a control group (n = 34). PMN-elastase levels in ARDS cases reached significantly higher values than in patients who did not develop this syndrome (P < 0.01). We conclude that the increase in plasma PMN-elastase levels can be useful in predicting the development of ARDS in polytraumatized patients, in instituting prophylactic actions and monitoring the course of the disease in these high risk patients. This test is easily adaptable to the routine of any hospital laboratory.

Amphiphilic and hydrophilic forms of acetyl- and butyrylcholinesterase in human brain

Human brain acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) were sequentially extracted, first with a Tris-saline buffer (S1) and then with 1% (w/v) Triton X-100 (S2). About 20 and 30% of the AChE and BuChE activities were recovered in S1 and most of the remaining enzymes in S2. Main molecular forms of about 10.5 S and 12.0 S, G4 forms of AChE and BuChE, and smaller amounts of 4.5 S and 5.5 S forms, G1 species of AChE and BuChE, were measured in S1. Application of Triton X-114 phase partitioning and affinity chromatography on phenyl-agarose to S1 revealed that 25% of the AChE and none of the BuChE molecules displayed amphiphilic properties. Analysis of the enzyme activity retained by the phenyl-agarose showed that G1 AChE constituted the bulk of the amphiphilic molecules released without detergent. Main G4 forms of AChE and BuChE were found in the S2 extract. Eighty and 45% of the AChE and BuChE activities in S2 were measured in the detergent-rich phase by Triton X-114 phase partitioning. Thus, most of the AChE and about half of the BuChE molecules in S2 displayed amphiphilic properties. The main peak of BuChE, a 12.0 S form in gradients made with Triton X-100, splits into two peaks of 9.5 S and 12.5 S in Brij 96-containing gradients. This suggests that hydrophilic G4 BuChE forms are predominant in S1 and that hydrophilic and amphiphilic isoforms coexist in S2.

Ricinus communis agglutinin I reacting and non-reacting butyrylcholinesterase in human cerebrospinal fluid

Differences in glycosylation of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) in human brain, plasma and cerebrospinal fluid (CSF) have been investigated by means of their interaction with agarose-immobilized lectins. Most of the AChE in brain and CSF was associated to concanavalin A (Con A), Lens culinaris (LCA) and Triticum vulgaris (WGA) agglutinins, but little activity was adsorbed to Ricinus communis agglutinin I (RCAI). Brain, plasma and CSF BuChE was almost fully bound to Con A, LCA and WGA-agarose. Brain BuChE was unable to react with RCA (RCA-BuChE), the plasma enzyme was completely bound to the lectin (RCA+BuChE) and BuChE from CSF of normal children was partially fixed to RCA (RCA +/- BuChE). BuChE in CSF of children with meningitis fully reacts with the lectin. The data suggest that the proportion of RCA+BuChE in CSF of children with meningitis is increased, this enzyme probably coming from plasma.