The anterolateral ligament is a distinct ligamentous structure: A histological explanation

Background

The aim was to determine whether the anterolateral ligament (ALL) had a histological structure that defined it as a real ligament.

Existence of a differentiation blockage at the stage of a megakaryocyte precursor in the thrombocytopenia and absent radii (TAR) syndrome

The thrombocytopenia and absent radii (TAR) syndrome is a rare disease associating bilateral radial agenesis and congenital thrombocytopenia. Here, we investigated in vitro megakaryocyte (MK) differentiation and expression of c-mpl in 6 patients. Using blood or marrow CD34(+) cells, the colony-forming unit (CFU)-MK number was markedly reduced. CD34(+) cells were also cultured in liquid medium in the presence of a combination of 3 cytokines (stem cell factor, interleukin-3, and interleukin-6) or megakaryocyte growth and development factor (PEG-rHuMGDF) with or without SCF. In the presence of PEG-rHuMGDF, the majority of mature megakaryocytes (CD41 high, CD42 high) underwent apoptosis. This phenomenon was also observed in cultures stimulated by three cytokines. However, this last combination of cytokines allowed a more complete terminal MK differentiation. Surprisingly, a homogeneous population of CD34(-)CD41(+)CD42(-) cells accumulated during the cultures. This population was unable to differentiate along the myeloid pathways. This result suggests that a fraction of MK cells is unable to differentiate in the TAR syndrome. We subsequently investigated whether this could be related to an abnormality in c-mpl. No mutation or rearrangement in the c-mpl gene was found by Southern blots or by sequencing of the c-mpl coding region and its promoter in any of the patients. Using Western blot analysis, a decreased level of Mpl was found in patient platelets. A decreased level of c-mpl messenger RNA in TAR platelets was also detected with a lower c-mpl-P to c-mpl-K ratio in comparison to adult platelets. Altogether, these results demonstrate that the thrombocytopenia of the TAR syndrome is associated with a dysmegakaryocytopoiesis characterized by cells blocked at an early stage of differentiation. (Blood. 2000;95:1633-1641)     

Inhibition of mitochondrial permeability transition prevents sepsis-induced myocardial dysfunction and mortality.

OBJECTIVES: The purpose of this study was to test whether mitochondrial dysfunction is causative of sepsis sequelae, a mouse model of peritonitis sepsis induced by cecal ligation and perforation. Inhibition of mitochondrial permeability transition was achieved by means of pharmacological drugs and overexpression of the antiapoptotic protein B-cell leukemia (Bcl)-2. BACKGROUND: Sepsis is the leading cause of death in critically ill patients and the predominant cause of multiple organ failure. Although precise mechanisms by which sepsis leads to multiple organ dysfunction are unknown, growing evidence suggests that perturbations of key mitochondrial functions, including adenosine triphosphate production, Ca2+ homeostasis, oxygen-derived free radical production, and permeability transition, might be involved in sepsis pathophysiology. METHODS: Heart and lung functions were evaluated respectively by means of isolated heart preparation, bronchoalveolar lavage fluid protein concentration, lung wet/dry weight ratio, lung homogenate myeloperoxidase activity, and histopathologic grading. Respiratory fluxes, calcium uptake, and membrane potential were evaluated in isolated heart mitochondria. RESULTS: Peritonitis sepsis induced multiple organ dysfunction, mitochondrial abnormalities, and increased mortality rate, which were reduced by pharmacological inhibition of mitochondrial transition by cyclosporine derivatives and mitochondrial Bcl-2 overexpression. CONCLUSIONS: Our study provides strong evidence that mitochondrial permeability transition plays a critical role in septic organ dysfunction. These studies demonstrate that mitochondrial dysfunction in sepsis is causative rather than epiphenomenal and relevant in terms of vital organ function and outcome. Regarding the critical role of heart failure in the pathophysiology of septic shock, our study also indicates a potentially new therapeutic approach for treatment of sepsis syndrome.     

Ultraflex precision colonic stent placement as a bridge to surgery in patients with malignant colon obstruction

BACKGROUND: Emergency surgery for malignant colon obstruction entails relatively high morbidity and mortality rates and typically necessitates a 2-step resection. These problems might be potentially mitigated by placement of a self-expanding metal stent (SEMS) as a bridge to surgery. A nitinol colorectal SEMS may offer several advantages, but available evidence on the utility of this SEMS type remains highly limited. OBJECTIVE: Our purpose was to evaluate the effectiveness and safety as a bridge to surgery of a nitinol SEMS designed for colorectal use. DESIGN: Prospective and retrospective multicenter clinical study. SETTING: Sixteen European study centers. PATIENTS: Thirty-six patients with malignant colonic obstruction. INTERVENTIONS: Nitinol colorectal SEMS placement. MAIN OUTCOME MEASURES: Technical success in accurate SEMS placement with coverage of the entire stricture length, clinical success in alleviating colonic obstructive symptoms, and bridging to elective surgery. RESULTS: Technical success was achieved in 97% of patients with a 95% CI of 85% to 100% and clinical success in 81% (95% CI, 64%-92%). Elective surgery was performed in 94% (95% CI, 81%-99%) of patients at a median of 11 days (95% CI, 7-15 days) after SEMS placement. SEMS-related perforation occurred in 3 patients. LIMITATIONS: No control group was included in this nonrandomized cohort study. CONCLUSIONS: In this first comparatively large clinical study of a nitinol colorectal SEMS as a bridge to surgery, a high proportion of patients successfully proceeded to elective surgery after prior decompression by SEMS placement.     

Serum uric acid levels are associated with lupus nephritis in patients with normal renal function

Uric acid has been recognised as a potential marker of endothelial dysfunction and kidney disease but there are scarce data about its importance in systemic lupus erythematosus (SLE) nephritis. This study aimed to evaluate serum uric acid (UA) levels in lupus nephritis (LN), by comparing SLE patients with normal renal function, with and without nephritis. Forty-six female SLE patients were consecutively selected and divided in two groups according to renal activity at the evaluation: presence of a recently diagnosed lupus nephritis (LN+, n?=?18) and absence of lupus nephritis (LN?, n?=?28). Age-matched healthy women were selected (CONTROL, n?=?28). Patients with gout, creatinine clearance lower than 80 ml/min and use of drugs that interfere in UA were excluded. Laboratory and clinical data were analysed by appropriate tests. A multivariate analysis was performed, and a receiver operating characteristic (ROC) curve was plotted, and the area under the curve was calculated to assess the diagnostic strength of UA in LN. The mean age was similar among LN+, LN? and CONTROL groups (32.44?±?6.09 vs. 30.68?±?5.36 vs. 30.86?±?5.00 years, p?=?0.52). UA was significantly higher in LN+ compared to LN? (5.54?±?1.67 vs. 3.65?±?1.090 mg/dL, p?<?0.001) and CONTROL (5.54?±?1.67 vs. 3.92?±?0.95 mg/dL p?<?0.001). Multivariate analysis confirmed that high UA was an independent variable related to LN (p?<?0.001). The cut-off value for UA using the ROC curve was 4.47 mg/dL (AUC 0.86, p?=?0.00004, CI 95% 0.75–0.96). Lupus nephritis was associated with higher UA. Hyperuricemia as a predictor of renal damage in SLE needs to be evaluated in further studies.     

Takayasu arteritis developing during treatment of ulcerative colitis with infliximab

A 22-year-old female with ulcerative colitis that was successfully treated with infliximab (IFX), and remained stable following tapered discontinuation of prednisolone, developed anterior neck pain and elevation of C-reactive protein following her fourth administration of IFX. She was diagnosed with Takayasu arteritis (TA) based on neck ultrasound and computed tomography angiography. This is the first report describing the development of TA during treatment of UC with IFX.     

Therapeutic Concentrations of Mitoxantrone Elicit Energetic Imbalance in H9c2 Cells as an Earlier Event

Mitoxantrone (MTX) is a chemotherapeutic agent that emerged as an alternative to anthracycline therapy. However, MTX also causes late cardiotoxicity, being oxidative stress and mitochondrial-impaired function proposed as possible mechanisms. This work aimed to investigate the relevance of these mechanisms to the MTX toxicity in H9c2 cells, using therapeutic concentrations. The observed cytotoxicity of MTX was time and concentration dependent in both lactate dehydrogenase leakage assay and MTT reduction assay. Two therapeutic concentrations (100 nM and 1 μM) and three time points were selected (24, 48, and 96 h) for further studies. Both MTX concentrations caused a significant increase in caspase-3 activity, which was not prevented by inhibiting MTX CYP450-metabolism. Significant decreases were observed in the total and reduced glutathione levels only in MTX 100 nM at 96 h; however, neither alterations in oxidized glutathione nor increases in the malondialdehyde levels were observed at any time or concentrations tested. On the other hand, changes in the intracellular ATP levels, mitochondrial membrane potential, and intracellular calcium levels were observed in both concentrations and all time tested. Noteworthy, decreased levels of ATP-synthase expression and activity and increases in the reactive species generation were observed at 96 h in both working concentrations. However, the radical scavenger N-acetylcysteine or the mitochondrial function enhancer L-carnitine did not prevent MTX cytotoxicity. Thus, this work evidenced the early MTX-induced energetic crisis as a possible key factor in the cell injury.     

Effects of PHEX antisense in human osteoblast cells.

X-linked hypophosphatemia (XLH) is an X-linked dominant disorder that is characterized by rachitic bone disease and hypophosphatemia due to renal phosphate transport defect. The candidate gene for XLH, PHEX, has recently been identified and found to share high homology with endopeptidases. PHEX is expressed in various tissues, including bones, and the available evidence today indicates that bones can release abnormal humoral factors that affect bone mineralization and proximal tubule phosphate transport in XLH. It was, therefore, hypothesized that the inactivating mutations of PHEX in bone may lead to the release of humoral factors and contribute to the phenotypic expression of the disease. To test this possibility, clones of MG-63 cells, a human osteoblast cell line, were produced and stably transfected with PHEX-antisense vectors, resulting in a decrease in PHEX expression at mRNA and protein levels. It was found that these antisense-transfected cells had impaired mineralization, with a decrease in 45Ca incorporation and calcification nodule formation. It was also found that the conditioned culture media collected from these antisense-transfected cells exhibited inhibitory activities on 45Ca incorporation by the nontransfected MG-63 cells and 32P uptake by the opossum kidney proximal tubular cells. The results of the study, therefore, provide strong evidence that supports the link between PHEX mutations and the pathogenesis of XLH.