Anatomic femorotibial changes associated with tibial plateau leveling osteotomy.

This prospective study evaluated anatomic femorotibial changes utilizing the relationship between the intercondylar notch and the intercondylar eminence following tibial plateau leveling osteotomy (TPLO). We hypothesized that TPLO results in anatomic alteration of the femorotibial joint. Pre- and post-operative computed tomography (CT) scans of cranial cruciate deficient stifle joints treated with TPLO were performed on 25 client-owned dogs. Computed tomography scans were performed at 3 different stifle angles: extension, 135° walking angle, and 90° of flexion. Tibial plateau leveling osteotomy did not result in a significant medial or lateral shift of the intercondylar eminence relative to the intercondylar notch. There was a significant cranial shift of the intercondylar eminence with the stifle in extension following TPLO. In addition, TPLO resulted in a significantly narrowed femorotibial joint space. The biomechanical effects of TPLO and medial meniscal release need to be further defined.

Changements fémoro-tibiaux anatomiques associés à une ostéotomie de nivellement du plateau tibial. Cette étude prospective a évalué les changements fémoro-tibiaux anatomiques en utilisant le lien entre l'échancrure intercondylienne et l'éminence intercondylienne après une ostéotomie de nivellement du plateau tibial (ONPT). Nous avons formulé l'hypothèse que l'ONPT produit une altération anatomique de l'articulation fémoro-tibiale. Des tomodensitogrammes des articulations déficientes du grasset du ligament cruciforme traitées à l'aide de l'ONPT ont été réalisés sur 25 chiens appartenant à des propriétaires. Les tomodensitogrammes ont été réalisés à 3 angles différents : extension, angle ambulatoire à 135° et flexion de 90°. L'ostéotomie de nivellement du plateau tibial n'a pas produit un mouvement médial ou latéral significatif de l'éminence intercondylienne en rapport avec l'échancrure intercondylienne. Il y avait un mouvement crânial significatif de l'éminence intercondylienne du grasset dans l'extension après l'ONPT. De plus, l'ONPT a produit une réduction importante de l'espace fémoro-tibial. Les effets biomécaniques de l'ONPT et du déclenchement du ménisque médial doivent être définis de manière plus précise.(Traduit par Isabelle Vallières).

Clinical assessment following tibial tuberosity advancement in 28 stifles at 6 months and 1 year after surgery.

This prospective study evaluated the effect of tibial tuberosity advancement (TTA) on lameness, thigh circumference, range of motion (ROM), and radiographic osteoarthritis (OA) scores at 6 wk, 6 mo, and 1 y after surgery in 24 client-owned dogs with cranial cruciate ligament (CrCL) deficiency. Complications associated with TTA were also assessed. A significant improvement in lameness score and thigh circumference was observed in CrCL deficient limbs that received TTA, but no significant overall change in range of motion occurred in the affected limbs over the course of the study. Post-operative complications were identified in 33.3% of the dogs. This study demonstrates that TTA results in significant clinical improvement in patients up to 1 y after surgery. However, 21% of the dogs had post-operative recurrent lameness.

Évaluation clinique après l'avancement de la tubérosité tibiale dans 28 grassets 6 mois et 1 an près la chirurgie. Cette étude prospective a évalué l'effet de l'avancement de la tubérosité tibiale (ATT) sur la boiterie, la circonférence de la cuisse, l'amplitude articulaire (AA) et les cotations radiographiques d'ostéo-arthrite 6 semaines, 6 mois et 1 an après la chirurgie chez 24 chiens, qui appartenaient à des clients, atteints d'une dysfonction du ligament croisé crânial (LCCr). Les complications associées à l'ATT ont aussi été évaluées. Une amélioration importante de la cotation de la boiterie et de la circonférence des cuisses a été observée dans les membres atteints d'une dysfonction du LCCr qui avaient reçu l'ATT, mais aucun changement général important ne s'est produit au niveau de l'amplitude articulaire des membres touchés pendant l'étude. Des complications post-opératoires ont été identifiées chez 33,3 % des chiens. Cette étude a démontré que l'ATT produit une amélioration clinique importante chez les patients jusqu'à 1 an après la chirurgie. Cependant, 21 % des chiens présentaient une boiterie post-opératoire récurrente.(Traduit par Isabelle Vallières).

A bedside communication tool did not improve the alignment of a multidisciplinary team's goals for intensive care unit patients.

PURPOSE: Establishing well-understood daily patient care goals should improve healthcare team (HCT) communication, reduce errors, and improve patient outcomes. The purpose of this study was to test the hypothesis that implementation of a daily goals "Door Communication Card" (DCC) would improve goal alignment between members of the HCT. METHODS: As part of a process improvement project, HCT members listed their top care goals for a patient on a given day. After initial data collection, DCCs were placed on patients' doors. Anyone was allowed to write on the card, but the "official" daily goals were recorded during multidisciplinary rounds. One month after introduction of the DCC, HCT members were re-queried about their patients' care goals. Three reviewers independently compared goals and assessed their alignment before and after implementation of the DCC. We collected goals over a 4-month period and selected 5 random days before and after intervention for assessment. RESULTS: The goal alignment among HCT members was low before and did not improve after intervention (Attending-to-Nurse 55% vs 38%, P = .02; Attending-to-Resident 60% vs 54%, P = .43; Attending-to-Primary 35% vs 28%, P = .45; Nurse-to-Attending 52% vs 36%, P = .03; Nurse-to-Resident 55% vs 38%, P = .04; Nurse-to-Primary 37% vs 27%, P = .36; Resident-to-Attending 59% vs 54%, P = .4; Resident-to-Nurse 56% vs 40%, P = .05; Resident-to-Primary 36% vs 24%, P = .16; Primary-to-Attending 34% vs 42%, P = .44; Primary-to-Nurse 42% vs 35%, P = .6; Primary-to-Resident 32% vs 34%, P = .8). CONCLUSIONS: Alignment of daily patient care goals among HCT members is low overall and did not improve after implementing a DCC available to all team members. Further study to elucidate the mechanism by which daily goals forms improve patient care is required.

Checklists change communication about key elements of patient care.

BACKGROUND: Combat casualty care is distributed across professions and echelons of care. Communication within it is fragmented, inconsistent, and prone to failure. Daily checklists used during intensive care unit (ICU) rounds have been shown to improve compliance with evidence-based practices, enhance communication, promote consistency of care, and improve outcomes. Checklists are criticized because it is difficult to establish a causal link between them and their effect on outcomes. We investigated how checklists used during ICU rounds affect communication. METHODS: We conducted this project in two military ICUs (burn and surgical/trauma). Checklists contained up to 21 questions grouped according to patient population. We recorded which checklist items were discussed during rounds before and after implementation of a "must address" checklist and compared the frequency of discussing items before checklist prompting. RESULTS: Patient discussions addressed more checklist items before prompting at the end of the 2-week evaluation compared with the 2-week preimplementation period (surgical trauma ICU, 36% vs. 77%, p < 0.0001; burn ICU, 47% vs. 72 %, p < 0.001). Most items were addressed more frequently in both ICUs after implementation. Key items such as central line removal, reduction of laboratory testing, medication reconciliation, medication interactions, bowel movements, sedation holidays, breathing trials, and lung protective ventilation showed significant improvements. CONCLUSION: Checklists modify communication patterns. Improved communication facilitated by checklists may be one mechanism behind their effectiveness. Checklists are powerful tools that can rapidly alter patient care delivery. Implementing checklists could facilitate the rapid dissemination of clinical practice changes, improve communication between echelons of care and between individuals involved in patient care, and reduce missed information.

Clinician satisfaction with computer decision support in the intensive care unit.

The purpose of this study was to determine baseline user satisfaction for 2 computer decision support systems (DSSs) with demonstrated improvement in patient outcome used in a burn intensive care unit. We conducted a survey of staff members of a 16-bed burn intensive care unit (n = 82) using a written, anonymous questionnaire to determine satisfaction for 2 DSSs: a commercial glycemic management system and software program to guide initial burn fluid resuscitation. Staff members are not yet convinced of a positive correlation between DSS technology and patient outcomes. We suggest user satisfaction may be generally improved for DSS with concentration in the areas of interface, information, and communication.

Dexamethasone ameliorates renal ischemia-reperfusion injury.

In the setting of renal ischemia-reperfusion injury (IRI), the effect and mechanism of action of glucocorticoids are not well understood. In rat renal IRI, a single dose of dexamethasone administered before ischemia, or at the onset of reperfusion, ameliorated biochemical and histologic acute kidney injury after 24 h. Dexamethasone upregulated Bcl-xL, downregulated ischemia-induced Bax, inhibited caspase-9 and caspase-3 activation, and reduced apoptosis and necrosis of proximal tubular cells. In addition, dexamethasone decreased the number of infiltrating neutrophils and ICAM-1. We observed the protective effect of dexamethasone in neutrophil-depleted mice, suggesting a neutrophil-independent mechanism. In vitro, dexamethasone protected human kidney proximal tubular (HK-2) cells during serum starvation and IRI-induced apoptosis, but inhibition of MEK 1/2 abolished its anti-apoptotic effects in these conditions. Dexamethasone stimulated rapid and transient phosphorylation of ERK 1/2, which required the presence of the glucocorticoid receptor and was independent of transcriptional activity. In summary, in the setting of renal ischemia-reperfusion injury, dexamethasone directly protects against kidney injury by a receptor-dependent, nongenomic mechanism.

Inhibiting glycogen synthase kinase 3beta in sepsis.

The serine-threonine protein kinase glycogen synthase kinase (GSK)-3 is involved in the regulation of many cell functions, but its role in the regulation of the inflammatory response is unknown. Here we investigate the effects of GSK-3beta inhibition on organ injury/dysfunction caused by endotoxaemia or severe inflammation in the rat. Rats received either intravenous Escherichia coli lipopolysaccharide (LPS) (6 mg/kg) or LPS (1mg/kg) plus Staphylococcus aureus peptidoglycan (PepG) (0.3mg/kg) or their vehicle (saline). The GSK-3p1 inhibitors TDZD-8, SB415286 (both 1mg/kg, i.v.), and SB216763 (0.6 mg/kg i.v.), or vehicle (10% dimethyl sulfoxide) were administered 30 min before LPS or LPS/PepG. Both endotoxaemia and co-administration of LPS/PepG resulted in multiple organ injury and dysfunction. The GSK-3beta inhibitors attenuated the organ injury/dysfunction caused by LPS or LPS/PepG. GSK-3beta inhibition reduced the Ser536 phosphorylation of nuclear factor (NF)-kappaB subunit p65 and the mRNA expression of NF-kappaB-dependent pro-inflammatory mediators, but had no effect on the NF-kappaB/DNA binding activity in the lung. GSK-3beta inhibition reduced the increase in NF-kappaB p65 activity caused by interleukin (IL)1 in human e mbryonic kidney cells in vitro. We propose that GSK-3beta inhibition may be useful in the therapy of sepsis, shock and other diseases associated with local or systemic inflammation.

Insulin reduces the multiple organ injury and dysfunction caused by coadministration of lipopolysaccharide and peptidoglycan independently of blood glucose: role of glycogen synthase kinase-3beta inhibition.

OBJECTIVE: Insulin reduces morbidity and mortality among critically ill patients, but the molecular mechanisms of its effect remain unknown. Insulin is a well-known inhibitor of glycogen synthase kinase-3, which may play an important role in systemic inflammation and shock. Here we investigate the role of blood glucose and glycogen synthase kinase-3beta inhibition in the protective effect of insulin on the organ injury/dysfunction associated with excessive systemic inflammation. DESIGN: Prospective, randomized study. SETTING: University-based research laboratory. SUBJECTS: Eighty-five anesthetized Wistar rats. INTERVENTIONS: Rats received Escherichia coli lipopolysaccharide (1 mg/kg) and Staphylococcus aureus peptidoglycan (0.3 mg/kg) or vehicle intravenously. Insulin (1.4 units/kg intravenously) was administered in the absence or presence of continuous glucose administration (4.5 mg/kg/hr intravenously) either prophylactically or therapeutically. The potent and selective glycogen synthase kinase-3beta inhibitor TDZD-8 (1 mg/kg intravenously) or vehicle (10% dimethyl sulfoxide) was administered either prophylactically or therapeutically. MEASUREMENTS AND MAIN RESULTS: Coadministration of lipopolysaccharide and peptidoglycan resulted in increases in the serum levels of creatinine (indicator of renal dysfunction), alanine aminotransferase, and aspartate aminotransferase (indicators of liver injury) at 6 hrs. Insulin or TDZD-8 similarly attenuated the organ injury/dysfunction caused by lipopolysaccharide and peptidoglycan when given either prophylactically or therapeutically. Continuous glucose administration had no effect on blood glucose levels or organ injury/dysfunction at 6 hrs. Treatment with insulin or TDZD-8 reduced the plasma levels of the proinflammatory cytokine interleukin-1beta. In vitro, insulin or TDZD-8 caused similar reductions in the nuclear factor-kappaB p65 activity and similar increases in the phosphorylation of Ser9 of glycogen synthase kinase-3beta. CONCLUSIONS: Therapy with insulin or the potent and selective glycogen synthase kinase-3beta inhibitor TDZD-8 reduced the organ injury/dysfunction caused by lipopolysaccharide and peptidoglycan in the rat. We propose that the inhibitory effect of insulin on the activity of glycogen synthase kinase-3beta contributes to the protective effect of insulin against the organ injury/dysfunction caused by excessive systemic inflammation independently of any effects on blood glucose.

Caspase and calpain function in cell death: bridging the gap between apoptosis and necrosis.

Calpain and caspase are families of cysteine proteases that have important roles in the initiation, regulation and execution of cell death. The function of both groups of proteases in the progression of apoptotic and necrotic pathways is presented here in the context of a concise overview of regulated cell death. Many of the morphological differences between apoptotic and necrotic processes are thought to be as a consequence of the action of cysteine proteases. Recent studies suggest that caspase and calpain cascades are tightly interrelated and an appreciation of how these proteases cross-talk should enable a greater understanding of how the boundaries between apoptotic and necrotic cell death have become blurred. Furthermore, an assessment of the contribution that caspase and calpain make to human physiology and pathology is provided, with a description of how these proteases can be detected and quantified. Lastly, an evaluation is made of how caspase and calpain activation might be exploited diagnostically.

GSK-3beta inhibitors attenuate the organ injury/dysfunction caused by endotoxemia in the rat.

OBJECTIVE: Serine-threonine protein kinase glycogen synthase kinase (GSK)-3 is involved in regulation of many cell functions, but its role in regulation of inflammatory response is unknown. Here we investigate the effects of GSK-3beta inhibition on organ injury/dysfunction caused by lipopolysaccharide or coadministration of lipopolysaccharide and peptidoglycan in the rat. DESIGN: Prospective, randomized study. SETTING: University-based research laboratory. SUBJECTS: Ninety-nine anesthetized male Wistar rats. INTERVENTIONS: Study 1: Rats received either intravenous Escherichia coli lipopolysaccharide (6 mg/kg) or vehicle (1 mL/kg; saline). Study 2: Rats received either intravenous E. coli lipopolysaccharide (1 mg/kg) and Staphylococcus aureus peptidoglycan (0.3 mg/kg) or vehicle. The potent and selective GSK-3beta inhibitors TDZD-8 (1 mg/kg intravenously), SB216763 (0.6 mg/kg intravenously), and SB415286 (1 mg/kg intravenously) or vehicle (10% dimethyl sulfoxide) was administered 30 mins before lipopolysaccharide or lipopolysaccharide and peptidoglycan. MEASUREMENTS AND MAIN RESULTS: Endotoxemia resulted in increases in the serum levels of creatinine (indicator of renal dysfunction), aspartate aminotransferase, alanine aminotransferase (markers for hepatocellular injury), lipase (indicator of pancreatic injury), and creatine kinase (indicator of neuromuscular injury). Coadministration of lipopolysaccharide and peptidoglycan resulted in hepatocellular injury and renal dysfunction. All GSK-3beta inhibitors attenuated the organ injury/dysfunction caused by lipopolysaccharide or lipopolysaccharide and peptidoglycan. GSK-3beta inhibition reduced the Ser536 phosphorylation of nuclear factor-kappaB subunit p65 and the messenger RNA expression of nuclear factor-kappaB-dependent proinflammatory mediators but had no effect on the nuclear factor-kappaB/DNA binding activity in the lung. GSK-3beta inhibition reduced the increase in nuclear factor-kappaB p65 activity caused by interleukin-1 in human embryonic kidney cells in vitro. CONCLUSIONS: The potent and selective GSK-3beta inhibitors TDZD-8, SB216763, and SB415286 reduced the organ injury/dysfunction caused by lipopolysaccharide or lipopolysaccharide and peptidoglycan in the rat. We propose that GSK-3beta inhibition may be useful in the therapy of the organ injury/dysfunction associated with sepsis, shock, and other diseases associated with local or systemic inflammation.

Mechanisms of high glucose-induced apoptosis and its relationship to diabetic complications.

Cellular responses to high glucose are numerous and varied but ultimately result in functional changes and, often, cell death. High glucose induces oxidative and nitrosative stress in many cell types causing the generation of species such as superoxide, nitric oxide and peroxynitrite and their derivatives. The role of these species in high glucose-mediated apoptotic cell death is relevant to the complications of diabetes such as neuropathy, nephropathy and cardiovascular disease. High glucose causes activation of several proteins involved in apoptotic cell death, including members of the caspase and Bcl-2 families. These events and the relationship between high glucose-induced oxidative stress and apoptosis are discussed here with reference to additional regulators of apoptosis such as the mitogen-activated protein kinases (MAPKs) and cell-cycle regulators.

Albumin stimulates cell growth, l-arginine transport, and metabolism to polyamines in human proximal tubular cells.

BACKGROUND: Pure albumin stimulates proximal tubular epithelial cell (PTEC) proliferation, and may have a role in homeostasis in health, as well as in disrupted PTEC turnover in proteinuric nephropathies. We investigated a role for arginine and its metabolites, the polyamines, in this process, given the ability of polyamines to trigger proliferation in other mammalian cells. METHODS: [(3)H]-L-arginine uptake was examined after incubation with 20 mg/mL recombinant human serum albumin (rHSA) in HK-2 PTEC monolayers. Nitric oxide synthase (NOS) and arginase activity was measured; NOS, arginase, and ornithine decarboxylase (ODC) expression was identified by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). Polyamine synthesis and intracellular amino acid concentrations were compared using high-performance liquid chromatography, and cell growth measured by [(3)H]-thymidine incorporation. RESULTS: In HK-2 PTEC exposed to 20 mg/mL rHSA for 24 hours, cell proliferation as determined by [(3)H]-thymidine incorporation was increased. In parallel, L-arginine transport capacity was increased in a dose- and time-dependent manner. This effect was specific to rHSA, and was not seen with transferrin or immunoglobulin G. The intracellular concentration of L-arginine remained unchanged, although L-ornithine was increased with rHSA incubation. rHSA up-regulated type II arginase mRNA, and increased arginase activity, although no difference in nitric oxide synthase expression or activity was seen. ODC mRNA was increased, as were intracellular polyamine concentrations. alpha-Difluoromethylornithine (DFMO), an ODC inhibitor, reduced intracellular polyamine concentrations and rHSA-induced cell proliferation to control levels. CONCLUSION: The arginine-ornithine-polyamine pathway appears enhanced in PTEC incubated with rHSA and is involved in cellular proliferation; this may offer novel approaches to understanding progressive proteinuric nephropathies.

High glucose-induced oxidative stress causes apoptosis in proximal tubular epithelial cells and is mediated by multiple caspases.

Diabetic nephropathy is the leading cause of end-stage renal disease in the Western world. Poor glycemic control contributes to the development of diabetic nephropathy, but the mechanisms underlying high glucose-induced tissue injury are not fully understood. In the present study, the effect of high glucose on a proximal tubular epithelial cell (PTEC) line was investigated. Reactive oxygen species (ROS) were detected using the fluorescent probes dichlorofluorescein diacetate, dihydrorhodamine 123, and 2,3-diaminonapthalene. Peroxynitrite (ONOO-) generation and nitrite concentrations were increased after 24 h of high glucose treatment (P<0.05). LLC-PK1 cells exposed to high D-glucose (25 mM) for up to 48 h had increased DNA fragmentation (P<0.01), caspase-3 activity (P<0.001), and annexin-V staining (P<0.05) as well as decreased expression of XIAP when compared with controls (5 mM D-glucose). The ONOO- scavenger ebselen reduced DNA fragmentation and caspase-3 activity as well as the high glucose-induced nitrite production and DCF fluorescence. High glucose-induced DNA fragmentation was completely prevented by an inhibitor of caspase-3 (P<0.01) and a pan-caspase inhibitor (P<0.001). Caspase inhibition did not affect ROS generation. This study, in a PTEC line, demonstrates that high glucose causes the generation of ONOO-, leading to caspase-mediated apoptosis. Ebselen and a caspase-3 inhibitor provided significant protection against high glucose-mediated apoptosis, implicating ONOO- as a proapoptotic ROS in early diabetic nephropathy.

Calpain is a mediator of myocardial injury in experimental uremia: is it activated by endogenous ouabain?

BACKGROUND: Incidence of cardiovascular disease is more than 20-fold higher in patients with chronic renal failure than in aged-matched individuals with normal renal function. Little is understood about the causes or the mechanism of uremia-induced cardiovascular injury, but the involvement of calpain as a possible mediator has recently been under investigation. Mean calpain activity was found to be 3.4-fold higher in the hearts of uremic rats than in control or spontaneously hypertensive (SHR) rats. In addition, calpain activity was found to be stimulated in myoblasts (Girardi) treated with media enriched with uremic serum compared with cells treated with serum from healthy volunteers. In this study, we assessed the impact of calpain activation in uremia and explored the possibility that calpain might be activated in uremia by endogenous ouabain. Ouabain is known to be elevated in uremia and is strongly associated with left ventricular hypertrophy in essential hypertension. METHODS: Calpain activity was measured in situ in human-derived myoblasts treated with low doses of ouabain similar to those concentrations found in uremic patients. RESULTS: Low concentrations of ouabain (10 nmol/L) caused a highly significant increase in calpain activity, which could be completely inhibited by the simultaneous chelation of intracellular and extracellular Ca2+, and by the chelation of extracellular Ca2+ alone. CONCLUSIONS: Calpain activity can be stimulated by nanomolar concentrations of ouabain due to an influx of extracellular Ca2+. As circulating ouabain is known to be elevated in uremia and strongly associated with LVH remodeling, we hypothesize that endogenous ouabain might be one of the factors that facilitates the remodeling of the left ventricle in patients with renal failure.

Calpain is activated in experimental uremia: is calpain a mediator of uremia-induced myocardial injury?

BACKGROUND: The cysteine proteases calpain and caspase-3 are known mediators of cell death. The aim of this study was to assess their contribution to the tissue damage found in experimental uremia. METHODS: Calpain and caspase-3 activities were measured in the hearts of rats that were sham-operated (control), sham-operated and spontaneously hypertensive (SHR), and those rendered uremic by 5/6 nephrectomy (uremic). In an in vitro study, heart myoblasts (Girardi) were incubated with human serum from healthy subjects (control serum conditioned media, CSCM) or uremic patients (uremic serum conditioned media, USCM), in the presence and absence of calpain and caspase-3 inhibitors. After 48 hours the activity of calpain and caspase-3 was measured, and cell injury determined by DNA fragmentation (ELISA) and lactate dehydrogenase (LDH) release. An in situ assay was designed to study how USCM affects calpain activity over time. RESULTS: In the in vivo study, mean calpain activities were almost identical in the control and SHR groups, but calpain and caspase-3 activities were much elevated in the uremic group (P < 0.01 and 0.001 respectively vs. control). The SHR group had significantly higher mean arterial blood pressure (P < 0.001 vs. control, 0.01 vs. uremic). In the in vitro study calpain activity and DNA fragmentation were markedly higher in USCM treated cells compared to CSCM (both P<0.05). Both were reduced in USCM cells containing calpain inhibitors (E64d, calpastatin, or PD 150606). LDH release was raised also in USCM treated cultures (P < 0.05), which only the E64d treatment could significantly reduce (P < 0.02). Caspase-3 activities were similar in USCM and CSCM groups. The in situ assay showed significant increases in calpain activity in USCM treated cells compared to CSCM after just 3.5 hours (P<0.01). CONCLUSIONS: In vivo results suggest that the increases in calpain and caspase-3 activity in uremic rat hearts were primarily due to uremia and not to hypertension. In vitro data demonstrate that uremia-induced cell injury can be attenuated by calpain inhibition. Therefore, it is likely that calpain is a mediator of uremia-induced myocardial injury.