Decreased antithrombin activity in the early phase of trauma is strongly associated with extravascular leakage,but not with antithrombin consumption: a prospective observational study

Background

We conducted a prospective observational study for investigating coagulofibrinolytic changes and mechanisms of antithrombin (AT) alternations in trauma.

Methods

Trauma patients hospitalized for more than seven days were analyzed for coagulofibrinolytic biomarkers. The patients were stratified into two groups according to AT activity level on admission (day 0), comprising normal AT and low AT patients.

Results

Thirty-nine patients (median Injury Severity Score 20) exhibited initial coagulatory activation and triphasic fibrinolytic changes. AT activity did not show a negative linear correlation with levels of thrombin-antithrombin complex (TAT), a marker of coagulation activity and AT consumption, but was strongly correlated with levels of albumin (Alb), an index of vascular permeability, on day 0 (r?=?0.702, p?<? 0.001). Furthermore, Alb was one of the independent predictors for AT on day 0. IL-6 on day 0 and thrombomodulin (TM) levels during the study period, reflecting systemic inflammation and endothelial cell injury, respectively, were significantly higher in the lower AT group (n?=?10) than in the normal group (n?=?29) (IL-6, p?=?0.004; TM, p?=?0.017). On days 2 and 4, TAT levels in the lower AT group were significantly higher than in the normal group.

Conclusions

Trauma caused clear triphasic coagulofibrinolytic changes. Decreased AT in the later phase might lead to a prolonged hypercoagulation. AT reduction in the initial phase of trauma is strongly associated with extravascular leakage as suggested by the association of Alb depletion with IL-6 and TM elevation, but not with AT consumption.

     

Vasodilator prostanoids, but not nitric oxide, may account for skeletal muscle hyperaemia in Type I diabetes mellitus

We and others have previously documented increased resting and exercise-induced skeletal muscle blood flow in young subjects with Type I (insulin-dependent) diabetes mellitus compared with healthy controls. Both NO and prostanoids are important regulators of vascular tone and may therefore contribute to this hyperaemia. The aim of the present study was to determine the contribution of NO and vasodilator prostanoids to this skeletal muscle hyperaemia in diabetes. We assessed the effects of infusion into the intrabrachial artery of the cyclo-oxygenase inhibitor acetylsalicylic acid (ASA; aspirin) and of the L-arginine analogue N(G)-monomethyl-L-arginine (L-NMMA) on skeLetal muscle blood flow in subjects with Type I diabetes mellitus (DM subjects) and control subjects. Blood flow was measured by venous occlusion plethysmography. Isotonic forearm exercise involved 2 min of wrist flexion and extension. Resting flow (forearm blood flow; FBF) was augmented in DM subjects, as was peak exercise-related blood flow (PFBF) and the volume repaid to the forearm 5 min after exercise (AUC 5, where AUC is area under the flow-time curve) (P<0.05), even when accounting for differences in basal flow. Infusion of L-NMMA reduced resting flow by 48% in controls (P<0.005) and by 12% in DM subjects (not significant). L-NMMA reduced PFBF and AUC 5 by 29% (P<0.05) and 39% (P<0.0005) respectively in controls, but had no significant effect on these parameters in DM subjects. Infusion of ASA reduced FBF, PFBF and AUC 5 in both DM (P<0.05) and control (P<0.05) subjects, but the magnitude of this reduction was greater in DM than in control subjects (ANOVA, P<0.05), even when differences in resting FBF were accounted for. Indeed, ASA eliminated the differences in FBF, PFBF and AUC 5 between DM and control subjects. Thus increased release of vasodilator prostanoids, rather than of NO, appears to account for skeletal muscle hyperaemia in Type I diabetes.     

A sensitive colorimetric assay for thrombin, prothrombin and antithrombin III in human plasma using a new synthetic substrate

Benzoyl-L-leucyl-L-alanyl-L-arginine-alpha-naphthylester (Bz-Leu-Ala-Arg-NE) was synthesized as a new substrate for use in the assay of thrombin. In the assay alpha-naphthol released by the enzyme reaction was measured colorimetrically. With Bz-Leu-Ala-Arg-NE as substrate, the minimum detectable concentration of human thrombin was 0.0025 U. This assay using Bz-Leu-Ala-Arg-NE is a highly sensitive method for detecting prothrombin, thrombin and antithrombin III in human plasma. Prothrombin could be determined with 0.2 microliter of human plasma using Echis carinatus venom (ECV) as activator. Antithrombin III activity could be determined with 2 microliter of human plasma using human thrombin and heparin as cofactor. A zymogram of human prothrombin was prepared with Bz-Leu-Ala-Arg-NE as substrate. The preparation gave one band (pI 4.9) on polyacrylamide disc gel isoelectrophoresis.     

Essential role of IRAK-4 protein and its kinase activity in Toll-like receptor-mediated immune responses but not in TCR signaling

Interleukin-1 receptor-associated kinase 4 (IRAK-4) was reported to be essential for the Toll-like receptor (TLR)- and T cell receptor (TCR)-mediated signaling leading to the activation of nuclear factor kappaB (NF-kappaB). However, the importance of kinase activity of IRAK family members is unclear. In this study, we investigated the functional role of IRAK-4 activity in vivo by generating mice carrying a knockin mutation (KK213AA) that abrogates its kinase activity. IRAK-4(KN/KN) mice were highly resistant to TLR-induced shock response. The cytokine production in response to TLR ligands was severely impaired in IRAK-4(KN/KN) as well as IRAK-4(-/-) macrophages. The IRAK-4 activity was essential for the activation of signaling pathways leading to mitogen-activated protein kinases. TLR-induced IRAK-4/IRAK-1-dependent and -independent pathways were involved in early induction of NF-kappaB-regulated genes in response to TLR ligands such as tumor necrosis factor alpha and IkappaBzeta. In contrast to a previous paper (Suzuki, N., S. Suzuki, D.G. Millar, M. Unno, H. Hara, T. Calzascia, S. Yamasaki, T. Yokosuka, N.J. Chen, A.R. Elford, et al. 2006. Science. 311:1927-1932), the TCR signaling was not impaired in IRAK-4(-/-) and IRAK-4(KN/KN) mice. Thus, the kinase activity of IRAK-4 is essential for the regulation of TLR-mediated innate immune responses.     

Demonstration of the insulin receptor in vivo in rabbits and its possible role as a reservoir for the plasma hormone.

Based on studies of the interaction of insulin with its receptors in vitro, we calculated that a receptor compartment should be measurable directly in vivo. For this purpose, rabbits were injected intravenously with a labeled insulin that has low affinity for receptors in combination with a radioiodinated insulin that has high affinity for receptors. Plasma concentrations of labeled insulins were measured at selected intervals after injection. Apparent volumes of distribution were calculated by extrapolation of plasma distribution were calculated by extrapolation of plasma disappearance curves; high affinity insulins consistently distributed into spaces that were two-three times greater than those of the low affinity insulins. Injections of unlabeled pork insulin before tracer insulins decreased the distribution space of the high affinity insulin in a dose-dependent manner while having little or no effect on the distribution space of the low affinity labeled insulin. When unlabeled insulin was injected after the tracer insulins, there was an immediate rise in the plasma concentration of the high affinity insulin with only a slight change in the plasma concentration of the low affinity insulin. These results demonstrate that high affinity insulins distribute into a body compartment which has many properties of the insulin receptor previously studied in vitro. This receptor compartment: (a) recognizes insulins based on their biological potencies; (b) is saturated by elevated concentrations of insulin; and (c) insulin bound to receptors is in equilibrium with free hormone in plasma. Further, the bound to free ratios for hormone, calculated from these data, suggest that in vivo greater than 50% of the extrapancreatic insulin is bound to receptors during normal physiological states.     

Norepinephrine-sensitive, phenoxybenzamine-resistant receptor sites associated with contraction in rabbit arterial but not venous smooth muscle: possible role in adrenergic neurotransmission

The possibility that not all contractions of rabbit blood vessels to norepinephrine (NE) are mediated through alpha adrenoceptors sensitive to phenoxybenzamine (PBZ) was investigated. Dose-response curves (DRCs) to NE were made in the absence and presence of PBZ pretreatment which minimized the contribution of alpha adrenoceptors. In all arteries studied (saphenous, renal, femoral and central ear arteries), after PBZ-treatment, NE produced biphasic DRCs. The initial component of these DRCs corresponded to doses of NE which in the absence of PBZ were supramaximal. Under conditions of our experimentation the plateau-phase usually occurred at between 5 and 40% of the pre-PBZ maximal response to NE. The second phase occurred with further additions of NE, and achieved a mean of 72 (+/- 4)% of the pre-PBZ maximal contraction to NE. The latter component presumably represented contractions mediated through low-affinity sites for NE which were insensitive to doses of PBZ sufficient to alkylate alpha adrenoceptors. In veins (saphenous and inferior vena cava), we found no evidence for such sites. Our results are discussed in light of current ideas of adrenergic neurotransmission in vascular smooth muscle as proposed by Hirst and Neild (1980a) and others who suggest that response to high concentrations of neuronally released NE occur through PBZ-resistant receptors termed gamma adrenoceptors located exclusively at the postsynaptic membrane. We were able to demonstrate PBZ-resistant, low-affinity sites for NE contractions in the femoral artery, a vessel with very sparse adrenergic innervation, and conclude that such sites for NE are present in a number of arteries (and not veins) irrespective of their innervation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Increased plasma glycosidase and protease activity in uraemia: possible role in the aetiology of the anaemia of chronic renal failure

We have measured plasma N-acetyl-beta-D-glucosaminidase (EC 3.2.1.30) and neuraminidase (EC 3.2.1.18) activities as markers of glycosidase activity and immunoreactive trypsin (EC 3.4.21.4) levels as a marker of proteolytic potential in the plasma of normal and uraemic subjects. The levels of all of these enzymes are significantly elevated in the plasma of uraemic subjects when compared to normal. We have postulated that the combined attack of glycosidases and proteases on erythropoietin will lead to fragmentation of this glycoprotein hormone with loss of activity. This may be a major contributory cause to the anaemia of chronic renal failure.     

Klotho gene polymorphism may be a genetic risk factor for atherosclerotic coronary artery disease but not for vasospastic angina in Japanese

BACKGROUND: The klotho gene, originally identified by insertional mutagenesis in mice, suppresses multiple aging phenotypes, including atherosclerosis. We tested the hypothesis that the G-395A polymorphism of the klotho gene is associated with increased risk for 2 types of ischemic heart disease in Japanese. METHODS: The study population consisted of 197 patients with coronary heart disease (CAD) who had >75% luminal diameter narrowing, 77 patients with vasospastic angina (VSA) without significant fixed coronary artery disease, and 331 healthy control subjects. RESULTS: The frequency of the A allele carriers of the klotho gene was significantly higher in the CAD group than in the control group (29.9% vs. 19.0%). The unadjusted odds ratio for CAD in the A allele carriers compared with the control group was 1.82 (p=0.004) and a traditional risk-adjusted logistic regression model revealed that the A allele was an independent predictor of CAD (odds ratio, 1.76; p=0.03). In contrast, the frequency of the A allele carriers was not significantly different in the VSA group (23.4%; adjusted odds ratio, 1.18. CONCLUSIONS: The -395A polymorphism of the human klotho gene may be a genetic risk factor for IHD and not for VSA.     

Consumption of Lactobacillus acidophilus and Bifidobacterium longum does not alter phytoestrogen metabolism and plasma hormones in men: a pilot study

OBJECTIVE: The aim of this study was to determine whether equol excretion status and plasma hormone and leptin concentrations can be influenced by consumption of a probiotic supplement. A secondary focus was to investigate whether male equol excretors have a hormone profile consistent with reduced prostate cancer risk. DESIGN: The design was a randomized, single-blinded, placebo-controlled, parallel-arm trial. SUBJECTS: Thirty-one (31) of the initially enrolled 39 subjects, 18 to 37 years old, completed all study requirements. INTERVENTION: Subjects consumed either probiotic capsules (containing Lactobacillus acidophilus and Bifidobacterium longum) or placebo capsules for 2 months. Fasting plasma concentrations of testosterone (T), dihydrotestosterone (DHT), androstanediol glucuronide (AAG), androstenedione (A), dehydroepiandrosterone sulfate (DHEAS), sex hormone-binding globulin (SHBG), and leptin were measured on days 1 and 57. Urinary excretion of genistein, glycitein, daidzein, O-desmethylangolensin (O-Dma), and equol was measured on days 4 and 61 following a 4-day soy challenge. RESULTS: Probiotic consumption did not significantly alter equol excretor status, plasma hormone, or leptin concentrations in these subjects. At baseline, there were no differences in plasma hormone concentrations between equol excretors and nonexcretors; however, the low number of equol excretors included in this study limits the strength of this finding. CONCLUSIONS: The 2-month intervention with probiotic capsules did not significantly alter equol excretion, plasma hormone, or leptin concentrations in these subjects. A secondary finding was that male equol excretors in this study did not exhibit a hormone profile consistent with reduced prostate cancer risk, although this result should be interpreted with caution.     

Hyperoxic lung injury in mice: a possible protective role for prostacyclin

Arachidonic acid metabolites have biologic properties that can mimic the pulmonary changes produced by hyperoxic exposure, but little information is available regarding their importance in this setting. The role of prostacyclin (PGI2) and thromboxane (Tx) A2 in oxygen-induced lung injury was evaluated by exposing mice to 100% oxygen for up to 4 days and measuring plasma and bronchoalveolar lavage (BAL) fluid concentrations of 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha), a metabolite of PGI2, and TxB2, a metabolite of TxA2. To determine whether a relationship exists between changes in these arachidonic acid metabolites and the severity of the lung injury, we also measured mortality, BAL protein concentration, BAL angiotensin-converting enzyme (ACE) activity, and plasma lactate dehydrogenase activity, and we examined lung sections by light and electron microscopy. After 3 days of exposure to 100% oxygen, microscopic and biochemical changes consistent with mild lung damage were found, but there was no increase in either plasma or BAL 6-keto-PGF1 alpha concentration. On day 4, severe lung damage was present. and BAL 6-keto-PGF 1 alpha level increased threefold (P less than 0.001). The level of TxB2 in BAL fluid did not change on any day. Twice-daily administration of either a high (5 mg/kg) or a low (1 mg/kg) dose of indomethacin reduced BAL concentrations of 6-keto-PGF1 alpha, and it resulted in increased mortality and higher BAL protein concentration and BAL ACE activity. These data suggest that TxA2 has little if any role in the pathogenesis of oxygen-induced lung injury, whereas prostacyclin may play a protective role.     

Grade-IV inferior glenohumeral mobilization does not immediately alter shoulder and scapular muscle activity: a repeated-measures study in asymptomatic individuals

Objectives: To assess: (1) the presence of any carry-over effect between interventions; (2) the immediate effects of inferior shoulder mobilization on shoulder and scapular muscle activity; and (3) to compare muscle activity response between the control and mobilization conditions. Repeated measures, cross-over, pre-post intervention study with sample of convenience.

Methods: Twenty-two asymptomatic individuals performed 10 repetitions of shoulder abduction before and after the control and mobilization, with a dosage of three sets of 30-s duration, with grade-IV. The order of intervention was randomized. Surface electromyography was used for recording activity of upper and lower trapezius; anterior, middle and posterior deltoids; supraspinatus; infraspinatus; and serratus anterior. Repeated measures mixed-model analysis of variance was used to assess immediate changes in muscle activity levels following inferior shoulder mobilization. Statistical parametric mapping (SPM) was used for comparing muscle activity waveforms between control and mobilization conditions throughout the range of motion.

Results: No systematic changes in muscle activity levels were found between: (1) baseline and follow-up for each condition, at the concentric and eccentric phases of shoulder abduction; (2) control and mobilization conditions during the concentric and eccentric phases of shoulder abduction. SPM results suggested no differences in muscle activity pattern between conditions.

Conclusions: Inferior shoulder mobilization did not produce immediate effects on shoulder and scapular muscle activity. It is possible that the dose used was insufficient to generate an immediate neuromuscular response to the mobilization.     

Vanadium: a review of its potential role in the fight against diabetes.

The potential role of vanadium in human health is described as a building material of bones and teeth. However, another very interesting and promising application for vanadium in human health emerges from recent studies that evaluated the role of vanadium in the management of diabetes. Vanadium is present in a variety of foods that we commonly eat. Skim milk, lobster, vegetable oils, many vegetables, grains and cereals are rich source of vanadium (>1 ppm). Fruits, meats, fish, butter, cheese, and beverages are relatively poor sources of vanadium. The daily dietary intake in humans has been estimated to vary from 10 microg to 2 mg of elemental vanadium, depending on the environmental sources of this mineral in the air, water, and food of the particular region tested. In animals, vanadium has been shown essential (1-10 microg vanadium per gram of diet). There is only circumstantial evidence that vanadium is essential for humans. However, in doses ranging from 0.083 mmol/d to 0.42 mmol/d, vanadium has shown therapeutic potential in clinical studies with patients of both insulin-dependent diabetes mellitus (IDDM) and noninsulin-dependent diabetes mellitus (NIDDM) type. Although vanadium has a significant biological potential, it has a poor therapeutic index, and attempts have been made to reduce the dose of vanadium required for therapeutic effectiveness. Organic forms of vanadium, as opposed to the inorganic sulfate salt of vanadium, are recognized as safer, more absorbable, and able to deliver a therapeutic effect up to 50% greater than the inorganic forms. The goal is to provide vanadium with better gastrointestinal absorption, and in a form that is best able to produce the desired biological effects. As a result, numerous organic complexes of vanadium have been developed including bis(maltolato)oxovanadium (BMOV), bis(cysteinamide N-octyl)oxovanadium known as Naglivan, bis(pyrrolidine-N-carbodithioato)oxovanadium, vanadyl-cysteine methyl ester, and bis-glycinato oxovanadium (BGOV). The health benefits of vanadium and the safety and efficacy of the available vanadium supplements are discussed in this review.     

Increasing research evidence in practice: a possible role for the consultant nurse

AIMS: To determine the extent to which clinical nursing practice has adopted research evidence. To identify barriers to the application of research findings in practice and to propose ways of overcoming these barriers. BACKGROUND: Way back in 1976, nursing and midwifery practice started adopting research evidence. By 1990s, there was some transparency of research evidence in practice, but more could have been done to widen its adoption. Many barriers were identified which could hinder implementation of the evidence in practice, and the effort to remove these remains weak. EVALUATION: 25 research articles from across Europe and America were selected, and scrutinized, and recommendations analysed. FINDINGS: Many clinical practitioners report a lack of time, ability and motivation to appraise research reports and adopt findings in practice. The clinical environment was not seen as research friendly as there were a general lack of research activities and facilities locally. There was a clear lack of research leadership in practice. IMPLICATION FOR NURSING MANAGEMENT: This paper reviewed the research evidence from several published research papers and provides consultant nurses with practical suggestions on how to enhance research evidence application in their practice. It recommends how consultant nurses can make their practice more research transparent by providing the required leadership, creating a research-friendly organization, developing a clear research agenda and facilitating staff develop a local research framework for reading research and implementing research evidence in their practice.     

Screening for primary aldosteronism in essential hypertension: diagnostic accuracy of the ratio of plasma aldosterone concentration to plasma renin activity

BACKGROUND: The ratio of plasma aldosterone concentration to plasma renin activity (PRA) is considered the screening test of choice for primary aldosteronism. Uncertainty exists, however, regarding its diagnostic accuracy and the effects of antihypertensive drugs and dietary sodium balance on test characteristics. METHODS: We measured PRA and aldosterone in 118 white adults [71 men and 47 women; mean (SD) age, 51 (7) years] with previously diagnosed essential hypertension. Measurements were made while individuals were on antihypertensive drug therapy, after a 2-week drug-free period, after 4 days of dietary sodium loading, and after acute furosemide diuresis. We measured 24-h urine aldosterone excretion and PRA on the 4th day of dietary sodium loading to establish the diagnosis of primary aldosteronism. ROC curves were constructed for ratios measured under each clinical condition, and likelihood ratios were determined for individuals on or off antihypertensive drug therapy. RESULTS: Fifteen patients [13%; 95% confidence interval (CI), 7-20%] met the reference standard for primary aldosteronism. The mean (SD) areas under the ROC curves did not differ significantly across conditions of measurement [range, 0.80 (0.10) to 0.85 (0.04); P = 0.72]. When measured on and off antihypertensive drug therapy, the 95% CIs for the optimum cutpoint for the ratio overlapped. Point estimates of sensitivity on and off therapy were 73% (95% CI, 50-96%) and 87% (70-100%), respectively, and specificities were 74% (65-83%) and 75% (66-84%). Under either condition, increased ratios were associated with 2.4- to 13-fold increases of posttest odds above pretest odds. CONCLUSIONS: The aldosterone:PRA ratio provides only fair diagnostic accuracy in screening for primary aldosteronism, but concomitant antihypertensive drug therapy or acute variation in dietary sodium balance does not adversely affect test accuracy. Reporting of likelihood ratios associated with ranges of values of the aldosterone:PRA ratio, rather than use of a single "optimum" cutpoint, may enhance the usefulness of the test.     

Quantitative study of starving platelets in a minimal medium: maintenance by acetate or plasma but not by glucose

Summary. The requirement of donor platelets for fuels, plasma and calcium were studied using platelets washed, filtered to remove leucocytes and resuspended in a new glucose-free minimal platelet storage medium with low citrate (3 mmol/1), low buffer capacity and no calcium. This is the first study of platelets stored without plasma, glucose or calcium and it was shown that platelets continued to aggregate with collagen plus adrenaline for 48 h and showed only a 50% fall in 'swirl index', an objective morphology score, after 3 days, showing that by these criteria human platelets do not require glucose. Sodium acetate extended the storage time by between 2 and 4 days, depending on the index parameter. This is the first evidence showing that failure of platelets in these conditions is at least partly due to exhaustion of fuel, and the first evidence that acetate prolongs in vitro survival. As little as 10% low-glucose plasma extended the storage time, but it was no better than acetate. New observations using this system included a very rapid fall in pH during resuspension of the washed platelet pellet, a rising pH in the absence of added fuel and an increased pH with added acetate.