Disseminated intravascular coagulation or extended intravascular coagulation in massive pulmonary embolism

See also Leitner JM, Jilma B, Spiel AO, Sterz F, Laggner AN, Janata KM. Massive pulmonary embolism leading to cardiac arrest is associated with consumptive coagulopathy presenting as disseminated intravascular coagulation. This issue, pp 1477–82; Thachil J. DIC score predicts mortality in massive clot coagulopathy as a result of extensive pulmonary embolism: a rebuttal. This issue, pp 1657–8; Leitner JM, Janata-Schwatzek K, Spiel AO, Sterz F, Laggner AN, Jilma B. DIC score predicts mortality in massive clot coagulopathy as a result of extensive pulmonary embolism: reply to a rebuttal. This issue, pp 1658–9.

Platelet-vessel wall interaction in health and disease

Upon vessel wall injury platelets rapidly adhere to the exposed subendothelial matrix which is mediated by several cellular receptors present on platelets or endothelial cells and various adhesive proteins such as von Willebrand factor, collagen and fibrinogen. Subsequent platelet activation results in the recruitment of additional platelets and the generation of platelet aggregates forming a stable platelet plug. In addition, activated platelets form a strong link between primary and secondary haemostasis as they provide the phospholipid surface that is necessary for the assembly of activated coagulation factor complexes required for thrombin generation. Other than the physiological function acting as a first line of defence against bleeding, platelets may also contribute to pathological thrombus formation. Platelets play an important role in thromboembolic diseases and may contribute to the formation of occlusive thrombi which can lead to severe complications such as stroke or myocardial infarction. Improved understanding of the respective roles of the various cellular receptors, adhesive proteins and regulatory proteins involved in platelet-vessel wall interaction and subsequent thrombus formation, both under physiological and pathological conditions, has led to the development and investigation of a broad range of antiplatelet drugs. This review provides an overview of the current knowledge on the mechanisms involved in the interaction between platelets and vascular endothelium and discusses recent advancements in the development of drugs interfering with platelet-vessel wall interaction at various stages of thrombus formation.

Factor V Leiden mutation does not affect coagulopathy or outcome in lethal H1N1 influenza

Influenza A is a major cause of mortality. Knowledge on coagulation activation in influenza infection is limited. The factor V Leiden (FVL) mutation is possibly subject to positive selection pressure. It is unknown whether this mutation impacts on the outcome of severe influenza. In the present study, the effect of lethal influenza on pulmonary and systemic coagulation activation and whether or not FVL mutation alters coagulation activation in and the course of lethal influenza, was determined. Wild-type mice, and mice heterozygous or homozygous for FVL were infected intranasally with a lethal dose of H1N1 (haemagglutinin 1 and neuraminidase 1) influenza A. Mice were sacrificed after 48 or 96 h for determination of coagulation activation, histopathology, pulmonary inflammatory parameters and viral load, or were observed in a survival study. Extensive local and systemic coagulation activation during lethal influenza was demonstrated by increased lung and plasma levels of thrombin-antithrombin complexes and fibrin degradation products, and by pulmonary fibrin deposition. FVL mutation did not influence the procoagulant response, lung histopathology or survival. FVL mice demonstrated elevated viral loads 48 h after infection. In conclusion, coagulation is activated locally and systemically during lethal murine influenza A infection. The FVL mutation does not influence coagulation activation, lung inflammation or survival in lethal influenza A.

Nucleic acid testing (NAT) of organ donors: is the 'best' test the right test? A consensus conference report

Nucleic acid testing (NAT) for HIV, HBV and HCV shortens the time between infection and detection by available testing. A group of experts was selected to develop recommendations for the use of NAT in the HIV/HBV/HCV screening of potential organ donors. The rapid turnaround times needed for donor testing and the risk of death while awaiting transplantation make organ donor screening different from screening blood-or tissue donors. In donors with no identified risk factors, there is insufficient evidence to recommend routine NAT, as the benefits of NAT may not outweigh the disadvantages of NAT especially when false-positive results can lead to loss of donor organs. For donors with identified behavioral risk factors, NAT should be considered to reduce the risk of transmission and increase organ utilization. Informed consent balancing the risks of donor-derived infection against the risk of remaining on the waiting list should be obtained at the time of candidate listing and again at the time of organ offer. In conclusion, there is insufficient evidence to recommend universal prospective screening of organ donors for HIV, HCV and HBV using current NAT platforms. Further study of viral screening modalities may reduce disease transmission risk without excessive donor loss.

The role of Fyn kinase in the release from metaphase in mammalian oocytes

Meiosis in mammalian oocytes starts during embryonic life and arrests for the first time before birth, at prophase of the first meiotic division. The second meiotic arrest occurs after spindle formation at metaphase of the second meiotic division (MII) in selected oocytes designated for ovulation. The fertilizing spermatozoon induces the release from MII arrest only after the oocyte's spindle assembly checkpoint (SAC) was deactivated. Src family kinases (SFKs) are nine non-receptor protein tyrosine kinases that regulate many key cellular functions. Fyn is an SFK expressed in many cell types, including oocytes. Recent studies, including ours, imply a role for Fyn in exit from meiotic and mitotic metaphases. Other studies demonstrate that SFKs, particularly Fyn, are required for regulation of microtubules polymerization and spindle stabilization. Altogether, Fyn is suggested to play an essential role in signaling events that implicate SAC pathway and hence in regulating the exit from metaphase in oocytes and zygote.

The coagulant response in sepsis and inflammation

Critically ill patients often have systemic activation of both inflammation and coagulation. Increasing evidence points to an extensive cross-talk between these two systems, whereby inflammation not only leads to activation of coagulation, but coagulation also considerably affects inflammatory activity. The intricate relationship between inflammation and coagulation may have major consequences for the pathogenesis of microvascular failure and subsequent multiple organ failure, as a result of severe infection and the associated systemic inflammatory response. Molecular pathways that contribute to inflammation-induced activation of coagulation have been precisely identified. Activation of the coagulation system and ensuing thrombin generation is dependent on an interleukin-6-induced expression of tissue factor on activated mononuclear cells and endothelial cells and is insufficiently counteracted by tissue factor pathway inhibitor. Simultaneously, endothelial-bound anticoagulant mechanisms, in particular the protein C system and the antithrombin system, are shut-off by pro-inflammatory cytokines. Modulation of inflammatory activity by activation of coagulation also occurs by various mechanisms. Activated coagulation proteases, such as the tissue factor-factor VIIa complex, factor Xa and thrombin can bind to protease-activated receptors on various cells and the ensuing intracellular signaling leads to increased production of pro-inflammatory cytokines and chemokines. Physiological anticoagulants can modulate inflammatory activity as well. Increasing knowledge on the various mechanisms underlying activation of inflammation and coagulation may lead to better (adjunctive) management strategies in critically ill patients.

Epidemiology and management of bleeding in patients using vitamin K antagonists

Vitamin K antagonists are effective in the prevention and treatment of a variety of arterial and venous thrombotic disorders, but are associated with an increased risk of serious bleeding complications. According to well documented studies of patients using vitamin K antagonists, the incidence of major bleeding is 0.5% per year and the incidence of intracranial bleeding is 0.2% per year, however, in real life practice this incidence may be even higher. Risk factors for bleeding are the intensity of anticoagulation, the management strategy to keep the INR in the desired range, and patient characteristics. In case of serious bleeding complications in a patient who uses vitamin K antagonists, this anticoagulant treatment can be quickly reversed by administration of vitamin K or coagulation factor concentrates.

Design, fabrication, and characterization of a composite scaffold for bone tissue engineering

Poly(lactide-co-glycolide) (PLGA) scaffolds have been successfully used in bone tissue engineering, with or without hydroxyapatite (HA) and with a macroporosity given either by simple PLGA sphere packaging and/or by leaching out NaCl. The objective of this work was the optimization of the design parameters for bone tissue engineering scaffolds made by sintering microspheres of PLGA, HA nanocrystals for matrix reinforcement and osteoconduction, and salt crystals for macroporosity and control of matrix pore size. Microsphere fabrication by a single-emulsion and solvent evaporation technique was first optimized to obtain a high yield of PLGA microspheres with a diameter between 80 and 300 microm. The influence of the sintering process and matrix composition on the scaffold structure was then evaluated morphologically and mechanically. Three scaffold types were tested for biocompatibility by culturing with human fibroblasts for up to 14 days. The most important parameters to obtain microspheres with the selected diameter range were the viscosity ratio of the dispersed phase to the continuous phase and the relative volume fraction of the 2 phases. The Young's modulus and the ultimate strength of the sintered matrices ranged between 168-265 MPa and 6-17 MPa, respectively, within the range for trabecular bone. Biocompatibility was demonstrated by fibroblast adhesion, proliferation, and spreading throughout the matrix. This work builds upon previous work of the PLGA/HA sintering technique to give design criteria for fabricating a bone tissue engineered matrix with optimized morphological, functional, and biological properties to fit the requirements of bone replacements.

Use of recombinant factor VIIa in the perioperative period

Recombinant activated factor VII (rFVIIa) is a pro-haemostatic agent that can be used for patients with haemophilia and inhibiting antibodies towards a coagulation factor. Recombinant factor VIIa is, however, increasingly used for several other indications, including patients who experience serious and life-threatening bleeding. In addition, rFVIIa has been evaluated for the prevention of major blood loss in patients undergoing surgical procedures that are known to be associated with major blood loss. In this manuscript we review the data on efficacy and safety of rFVIIa in the prevention of excessive blood loss and transfusion requirements in the perioperative period. We conclude that recombinant factor VIIa is a promising agent for perioperative prevention of major blood loss but that its efficacy will probably vary between specific clinical settings. Its exact place in surgery warrants further clinical trials in various situations that will also more precisely determine the safety of this intervention.

Ventilator-induced coagulopathy in experimental Streptococcus pneumoniae pneumonia

Pneumonia, the main cause of acute lung injury, is characterised by a local pro-inflammatory response and coagulopathy. Mechanical ventilation (MV) is often required. However, MV can lead to additional injury: so-called ventilator-induced lung injury (VILI). Therefore, the current authors investigated the effect of VILI on alveolar fibrin turnover in Streptococcus pneumoniae pneumonia. Pneumonia was induced in rats, followed 48 h later by either lung-protective MV (lower tidal volumes (LV(T)) and positive end-expiratory pressure (PEEP)) or MV causing VILI (high tidal volumes (HV(T)) and zero end-expiratory pressure (ZEEP)) for 3 h. Nonventilated pneumonia rats and healthy rats served as controls. Thrombin-antithrombin complexes (TATc), as a measure for coagulation, and plasminogen activator activity, as a measure of fibrinolysis, were determined in bronchoalveolar lavage fluid (BALF) and serum. Pneumonia was characterised by local (BALF) activation of coagulation, resulting in elevated TATc levels and attenuation of fibrinolysis compared with healthy controls. LV(T)-PEEP did not influence alveolar coagulation or fibrinolysis. HV(T)-ZEEP did intensify the local procoagulant response: TATc levels rose significantly and levels of the main inhibitor of fibrinolysis, plasminogen activator inhibitor-1, increased significantly. HV(T)-ZEEP also resulted in systemic elevation of TATc compared with LV(T)-PEEP. Mechanical ventilation causing ventilator-induced lung injury increases pulmonary coagulopathy in an animal model of Streptococcus pneumoniae pneumonia and results in systemic coagulopathy.

Catastrophic antiphospholipid syndrome mimicking a malignant pancreatic tumour – a case report

Abstract

The catastrophic antiphospholipid syndrome is characterised by rapid onset thromboses, often resistant to conventional anticoagulant treatment, and resulting in life threatening multiple organ dysfunction. The diagnosis of catastrophic antiphospholipid syndrome may be difficult, predominantly due to its frequently atypical presentation. We report a case of a 35-year-old female who presented with a pancreatic tumour and extensive thromboses. Following a storm of ischemic events due to thrombotic occlusions in spite of therapeutic heparin dose, the suspicion of catastrophic antiphospholipid syndrome emerged. The patient was successfully treated with anticoagulants, immunuglobulins, plasmapheresis and rituximab. The present report shows that the use of the diluted Russell’s viper venom time can be helpful in providing additional information on the lupus anticoagulans antibody status, allowing careful monitoring of lupus anticoagulans conversion and hence response to therapy.

Absence of Pneumocystis jiroveci pneumonia in liver transplantation recipients receiving short-term (3-month) prophylaxis

Pneumocystis jiroveci (formerly known as Pneumocystis carinii) is a fungal pathogen that causes pneumonia (PCP) in liver transplant recipients. Consequently, prophylaxis with trimethoprim-sulfamethoxazole (TMP/SMZ) is typically administered for at least 1 year at most liver transplant programs. At our center we have utilized a short-term (3-month) prophylactic regimen with TMP/SMZ for the past decade and report our experience and speculate on the potential widespread application of this approach.

METHODS

For patients transplanted at our center between January 1997 and January 2007, we recorded all documented PCP infections by review of our liver transplant database and hospital-based electronic medical records system, both of which record all infections and culture results.

RESULTS

We recorded no cases of PCP in any of the liver transplant recipients at our center during the study period.

CONCLUSIONS

We report the absence of PCP in a large cohort of liver transplant recipients receiving a short-term (3-month) prophylaxis with TMP/SMZ. These findings provide a rational basis to consider short-term (3-month) PCP prophylaxis or avoidance of prophylaxis altogether in selected low-risk patients.

Estrogen downregulates the proximal tubule type IIa sodium phosphate cotransporter causing phosphate wasting and hypophosphatemia

Estrogen treatment causes significant hypophosphatemia in patients. To determine the mechanisms responsible for this effect, we injected ovariectomized rats with either 17beta-estradiol or vehicle for three days. Significant renal phosphate wasting and hypophosphatemia occurred in estrogen-treated rats despite a decrease in their food intake. The mRNA and protein levels of the renal proximal tubule sodium phosphate cotransporter (NaPi-IIa) were significantly decreased in estradiol-treated ad-libitum or pair-fed groups. Estrogen did not affect NaPi-III or NaPi-IIc expression. In ovariectomized and parathyroidectomized rats, 17beta-estradiol caused a significant decrease in NaPi-IIa mRNA and protein expression compared to vehicle. Estrogen receptor alpha isoform blocker significantly blunted the anorexic effect of 17beta-estradiol but did not affect the downregulation of NaPi-IIa. Our studies show that renal phosphate wasting and hypophosphatemia induced by estrogen are secondary to downregulation of NaPi-IIa in the proximal tubule. These effects are independent of food intake or parathyroid hormone levels and likely not mediated through the activation of estrogen receptor alpha subtype.

Transgenic tissue-type plasminogen activator expression improves host defense during Klebsiella pneumonia

BACKGROUND

Severe pneumonia is associated with a local inhibition of fibrinolysis in the lung as reflected by strongly reduced pulmonary plasminogen activator activity.

OBJECTIVES

To study the effect of elevation of local plasminogen activator activity during pneumonia caused by the common respiratory pathogen Klebsiella pneumoniae.

METHODS

Female C57Bl/6 mice were inoculated intranasally with a replication-defective adenoviral vector expressing human tissue-type plasminogen activator or a control vector 24 h before intranasal infection with K. pneumoniae.

RESULTS

Mice infected with Klebsiella via the airways developed overt pneumonia, which was accompanied by a downregulation of pulmonary tissue-type plasminogen activator levels at protein and mRNA levels. Pulmonary overexpression of human tissue-type plasminogen activator resulted in increased fibrinolytic activity in the lungs during pneumonia, as indicated by higher D-dimer levels and reduced fibrin deposition. Interestingly, overexpression of tissue-type plasminogen activator markedly improved host defense against pneumonia: mice treated with the tissue-type plasminogen activator vector displayed less bacterial growth and dissemination, attenuated distant organ injury and a reduced mortality.

CONCLUSIONS

These data demonstrate that local elevation of plasminogen activator activity in the lungs improves host defense against severe gram-negative pneumonia and sepsis.

Structure, wettability and thermal degradation of new fluoro-oligomer modified nanoclays

Quaternary ammonium salts based on monofunctionalized Perfluoropolyether (PFPE) oligomers were synthesized and used for the cation exchange process of sodium Montmorillonite nanoclays. The new fluoromodified nanoclays were characterized through X-rays diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), termogravimetric analysis (TGA), differential scanning calorimetry (DSC), electronic microscopy (SEM-EDS), and contact angle measurements (CA). In particular XRD showed rather complex patterns (presence of higher order reflections) which allowed the calculation of basal spacings, regularly increasing with the molecular weight of the fluorinated macrocation. Both IR and SEM confirmed the presence of fluorinated segments at clays interface, while TGA showed a limited thermal stability with an onset of degradation temperature which seems not dependent on the molecular weight of the macrocation. CA measurements showed a peculiar behaviour, with evident dynamic hysteresis phenomena and surface tension components quite different from those of commercially available, organomodified clays.

[Thromboprophylaxis for cerebrovascular disorders: acetylsalicylic acid remains the cornerstone]

Antithrombotic medication plays a key role in the treatmentand secondary prophylaxis of atherothrombotic conditions. Numerous studies have found that acetylsalicylic acid is effective in reducing the incidence of (recurrent) acute vascular events, such as myocardial infarction or ischaemic stroke. For coronary atherothrombosis, anticoagulation with vitamin K antagonists was shown to be slightly superior to acetylsalicylic acid in high-risk patients. Two major trials, the 'Stroke prevention in reversible ischemia trial' (SPIRIT) and the 'European/Australasian stroke prevention in reversible ischaemia trial' (ESPRIT), showed that vitamin K antagonists were more effective than placebo in the prevention of ischaemic stroke, but the favourable effect was completely offset by a higher incidence of major bleeding (including intracerebral bleeding) in patients using vitamin K antagonists. In the ESPRIT trial, the combination of acetylsalicylic acid and dipyridamole provided a modest benefit over acetylsalicylic acid alone in the prevention of (recurrent) ischaemic stroke.

The involvement of Src family kinases (SFKs) in the events leading to resumption of meiosis

Ovulated mammalian eggs remain arrested at the second meiotic metaphase (MII) until fertilization. The fertilizing spermatozoon initiates a sequence of biochemical events, collectively referred to as 'egg activation', which overcome this arrest. The initial observable change within the activated egg is a transient rise in intracellular Ca2+ concentration ([Ca2+]i) followed by cortical granule exocytosis (CGE) and resumption of the second meiotic division (RMII). To date, the mechanism by which the fertilizing spermatozoon activates the signaling pathways upstream to the Ca2+ release and the manner by which the signals downstream to Ca2+ release evoke RMII are not well documented. Protein tyrosine kinases (PTKs) were suggested as possible inducers of some aspects of egg activation. Src family kinases (SFKs) constitute a large family of evolutionarily conserved PTKs that mediate crucial biological functions. At present, the theory that one or more SFKs are necessary and sufficient for Ca2+ regulation at fertilization is documented in eggs of marine invertebrates. The mechanism leading to Ca2+ release during fertilization is less established in mammalian eggs. A controversy still exists as to whether SFKs within the mammalian egg are sufficient and/or necessary for Ca2+ release, or whether they play a role during egg activation via other signaling pathways. This article summarizes the possible signaling pathways involved upstream to Ca2+ release but focuses mainly on the involvement of SFKs downstream to Ca2+ release toward RMII, in invertebrate and vertebrate eggs.

Activation of coagulation with concurrent impairment of anticoagulant mechanisms correlates with a poor outcome in severe melioidosis

BACKGROUND

Melioidosis, which is caused by infection with the Gram-negative bacterium Burkholderia pseudomallei, is an important cause of sepsis in South-East Asia with a mortality of up to 40%. Knowledge of the involvement of coagulation and fibrinolysis in the pathogenesis of melioidosis is highly limited.

OBJECTIVE

To define the involvement of the coagulation and fibrinolytic systems in patients with severe melioidosis.

METHODS

Parameters of coagulation and fibrinolysis were measured in 34 patients with culture proven septic melioidosis and 32 healthy controls.

RESULTS

Patients demonstrated strong activation of the coagulation system, as reflected by high plasma levels of soluble tissue factor, the prothrombin fragment F(1+2) and thrombin-antithrombin complexes (TATc), and consumption of coagulation factors resulting in a prolonged prothrombin time and activated partial thromboplastin time. Concurrently, anticoagulant pathways were downregulated in patients: protein C, protein S, and antithrombin levels were all decreased when compared to controls. Patients also demonstrated evidence of activation and inhibition of fibrinolysis, as reflected by elevated concentrations of tissue-type plasminogen activator (tPA), plasminogen activator inhibitor type 1, plasmin-alpha2-antiplasmin complexes (PAPc) and D-dimer. High TATc/PAPc ratios in patients pointed to a predominance of the prothrombotic pathway in melioidosis. Furthermore, soluble thrombomodulin levels were increased. The extent of coagulation activation correlated with mortality; patients who went on to die had higher TATc, F(1+2), tPA and PAPc and lower protein C and antithrombin levels on admission than patients who survived.

CONCLUSIONS

The coagulation system is strongly activated during melioidosis. A high degree of activation of the coagulation system is an indicator of poor outcome in patients with melioidosis.

Novel blocked functionality copolymers as surface coatings in DNA microarray technology

New copolymers made of 2-(dimethyl amino) ethyl methacrylate (DMAEM) and isocyanate ethyl methacrylate blocked with methyl ethyl ketoxime (IEMB) was synthesized in various composition ratios in order to obtain water reducible copolymers after acidification. They were characterized by infrared spectroscopy, chemical titration for the determination of amine equivalent weight, and by differential scanning calorimetry (DSC). Calorimetric analysis showed the presence of a former broad endothermal peak followed by a latter, stronger exothermal one, which can be respectively attributed to the deblocking of isocyanate groups and to their subsequent reactions. Some copolymer compositions were dip coated onto microscope glass slides and surfaces were characterized by static and dynamic contact angles, revealing a clear effect of the salifying agent and a likely surface rearrangement of polar groups while in contact with water. Finally, oligonucleotides surface immobilization and molecular recognition capability of the coated glass slides were positively assessed by hybridization tests with fluorescently labelled complementary probes.

Self-Assembly of Methacrylic Nanostructured Copolymers Containing Polyhedral Oligomeric Silsesquioxanes

Two hybrid copolymer series obtained by free-radical copolymerization of methacrylcyclohexyl Polyhedral oligomeric silsesquioxane (POSS) with butyl methacrylate or 2-ethylhexylmethacrylate were characterized by 1H-NMR spectroscopy, gel permeation chromatography (GPC), X-rays Diffraction (XRD), differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TGA). Reactivity ratios were calculated by low yield composition data suggesting the formation of random copolymers with low probability of poly-POSS sequences. XRD studies showed the crystallization behaviour of the inorganic phase independently on the POSS content; however sample processing by solvent casting effectively hindered the copolymer self-assembling ability. DSC suggests the formation of polyphasic structures with Tg increasing with POSS content, and with endothermal peaks occurring at higher temperature. Finally TGA shows an improved thermal stability of hybrid copolymers with char yield correlated to the level of inorganic phase.

Tissue factor-dependent blood coagulation is enhanced following delivery irrespective of the mode of delivery

BACKGROUND

The risk of thrombosis is clearly increased in the postpartum period. Mice with a targeted deletion of the transmembrane domain of tissue factor (TF) develop serious activation of blood coagulation and widespread thrombosis after delivery.

OBJECTIVE AND METHODS

We hypothesized that TF, abundantly present in placental tissue, is released during delivery, resulting in the activation of blood coagulation. We measured sensitive markers for TF-dependent activation of coagulation before and after induction of labor in two groups: a vaginal delivery (VAG) group and a cesarean section (CS) group.

RESULTS

One hour after delivery, soluble TF (sTF) significantly increased in both groups [VAG group (mean +/- SD) 226 +/- 42 to 380 +/- 42 pg mL(-1) and CS group 193 +/- 17 to 355 +/- 44 pg mL(-1)]. The day after delivery, sTF was somewhat less increased. Both groups also showed an increase in factor VIIa, indicating activation of the TF pathway of coagulation. Indeed, after delivery, TF-dependent coagulation, as measured by the TF clotting time assay, was significantly enhanced. Increased plasma levels of prothrombin fragment 1 + 2 and thrombin-antithrombin complexes demonstrated thrombin generation following delivery. TF pathway-dependent activation of coagulation upon delivery was not blocked by TF pathway inhibitor and was not dependent on the mode of delivery.

CONCLUSION

The postdelivery increase in TF-dependent activation of coagulation is likely to be a natural mechanism to prevent excessive blood loss during and after delivery, and may also indicate a novel mechanism by which puerperal women have an increased risk of venous thromboembolism.

Interactions of the growth-related, type IIc renal sodium/phosphate cotransporter with PDZ proteins

Despite similar molecular structures, the growth-related sodium/phosphate cotransporter NaPiIIc is regulated differently than the main NaPiIIa phosphate transporter. Using two-hybrid systems and immunoprecipitation, we identified several proteins that interact with NaPiIIc that might account for this differential regulation. NaPiIIc interacted with the PDZ domain-containing sodium-hydrogen exchange-regulating factor (NHERF) 1 and NHERF3 through novel binding motifs in its C terminus. NaPiIIc from brush-border membranes coprecipitated with both NHERF1 and NHERF3, with more NHERF3 co-precipitated in rats fed a low-phosphorus diet. NaPiIIc colocalizes with both NHERF1 and NHERF3 in brush-border membranes of rats fed either a low- or high-phosphorus diet. When mouse NaPiIIc was transfected into opossum kidney cells, it was localized mainly in apical microvilli and the trans-Golgi. Both confocal and total internal reflection microscopy show that NaPiIIc colocalizes with NHERF1 and NHERF3 in the apical microvilli, and this was not altered by truncation of the last three amino acids of NaPiIIc. Interactions of NaPiIIc with NHERF1 and NHERF3 were modulated by the membrane-associated 17 kDa protein (MAP17) similarly to NaPiIIa, but only the MAP17-NaPiIIc-NHERF3 complexes were internalized to the trans-Golgi. Our study shows that NaPiIIc interacts with a limited number of PDZ domain proteins, and the mechanisms and consequences of such interactions differ from those of NaPiIIa.

[Co-morbidity in acutely hospitalised older patients as a risk factor for death in hospital or within 3 months after discharge]

OBJECTIVE

To study the presence of co-morbidity and delirium and to determine whether these factors are predictors of hospital and shortterm mortality in elderly patients acutely admitted to a department of internal medicine.

DESIGN

Prospective cohort study.

METHOD

Social and demographic data as well as data on their physical and cognitive limitations were collected from consecutive patients of 65 years and older who were hospitalised in the period from I December 2002 to 30 June 2005 in the Academic Medical Centre in Amsterdam, the Netherlands. Co-morbidity and ICD diagnosis were determined on discharge from the hospital. Three months after discharge the patients' circumstances were assessed.

RESULTS

A total of 461 patients, 195 men and 266 women with an average age of 78.2 years (SD: 7.8), were included. Of these patients, 132 (28.6%) had cognitive impairment and the mean number of limitations with regard to the activities of daily living (ADL) was 5.48 (10.4%) patients died in hospital and another 74 patients (16.1%) had died 3 months after discharge. The only independent predictor of hospital mortality was delirium at admission (OR: 2.28; 95% CI: 1.23-4.21). Independent risk factors for mortality within 3 months after discharge were: delirium at admission (OR: 2.20; 95% CI: 1.12-4.31), pre-admission ADL limitations (OR: 1.11; 95% CI: 1.02-1.21), a diagnosed malignancy (OR: 5.96; 95% CI: 2.45-14-52), and a higher Charlson co-morbidity index (OR: 1.19; 95% CI: 1.04-1-34).

CONCLUSION

At discharge from the hospital, the risk of death within 3 months after discharge in acutely hospitalised patients of 65 years and older was determined by a combination of delirium at admission, pre-admission ADL limitations, a malignancy, and co-morbidity. These results can be used to identify elderly patients who might benefit from comprehensive geriatric assessment during hospitalisation and from a well-prepared discharge planning that takes their co-morbidity into consideration.

Application of the voluntary step execution test to identify elderly fallers

OBJECTIVES

To assess the use of the Voluntary Step Execution Test to identify fallers.

DESIGN

Cross-sectional retrospective.

SETTING

Two self-care, residential facilities.

PARTICIPANTS

a total of 100 healthy old volunteers (mean age = 78.4 +/- 5.7).

MEASUREMENTS

The study investigated the use of the Voluntary Step Execution Test to identify fallers under single and dual-task conditions. Berg Balance Test (BBS) and Timed Get Up and Go (TUG) were used to assess balance and gait function.

RESULTS

There were no significant differences found between fallers and non-fallers in BBS and TUG (50.5 +/- 4.6 versus 52.5 +/- 3.4 and 9.4 +/- 3.4 versus 7.98 +/- 2.3 respectively). There were no statistically significant differences between non-fallers and fallers across all step execution parameters under the single-task condition. However, adding cognitive load to the Voluntary Step Execution Test revealed statistically significant increases in duration of the preparatory phase, swing time and the time to foot-contact (P = 0.035;P = 0.033 and P = 0.037, respectively). Based on the coefficients of the logistic regression model participants with dual-task step execution times of > or =1,100 ms had five times the risk of falling than participants with execution times of <1,100 ms.

CONCLUSIONS

The study provides evidence that a simple, safe measure of step execution under dual-task conditions can identify elderly individuals at risk for falls.

Systemic inflammation as a risk factor for atherothrombosis

Several chronic inflammatory disorders, such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), and chronic infections that are associated with a chronic inflammatory state, such as human immunodeficiency virus (HIV) infection, are associated with an increased incidence of cardiovascular disease (CVD). Cardiovascular mortality is a major cause of death in patients with these disorders. Direct effects and indirect sequelae of systemic inflammation promote atherothrombotic vascular disease. Pathophysiological processes promoting atherogenesis can initiate years before the diagnosis of a chronic inflammatory disease is made, and since exposure to risk factors in this pre-clinical phase is widespread, early cardiovascular protection in these patients seems warranted.

[A patient with repeated, life-threatening gastro-intestinal haemorrhages treated by means of medication, open surgery, endoscopic surgery, intervention radiology and conservative methods]

A 56-year-old man with Henoch Schönlein purpura vasculitis suffered from repeated and multiple life-threatening gastrointestinal haemorrhages. Over recent years a number of interventions for the treatment of gastrointestinal haemorrhaging have become available; choosing which option to use can present difficulties. The available interventions are carried out by different disciplines and include haemostatic drugs, endoscopic intervention, intervention radiology, and surgery. In this patient, following a severe drop in haemoglobin levels, CT and angiography revealed active bleeding in the distal jejunum. Transarterial embolization by means of a coiling procedure halted the bleeding. The patient was also given tranexamic acid, a fibrinolysis inhibitor. More episodes of bleeding subsequently followed which necessitated further coiling procedures, two bowel resections, the endoscopic clipping of a bleeding artery, treatment with the recombinant activated factor VII (rFVIIa) at a dosage of 90 microg/kg, as well as conservative treatment with multiple transfusions of filtered erythrocytes and fresh plasma. The patient eventually recovered.