An altered heparan sulfate structure in the articular cartilage protects against osteoarthritis.

OBJECTIVE: Osteoarthritis (OA) is a progressive degenerative disease of the articular cartilage caused by an unbalanced activity of proteases, cytokines and other secreted proteins. Since heparan sulfate (HS) determines the activity of many extracellular factors, we investigated its role in OA progression. METHODS: To analyze the role of the HS level, OA was induced by anterior cruciate ligament transection (ACLT) in transgenic mice carrying a loss-of-function allele of Ext1 in clones of chondrocytes (Col2-rtTA-Cre;Ext1e2fl/e2fl). To study the impact of the HS sulfation pattern, OA was surgically induced in mice with a heterozygous (Ndst1+/-) or chondrocyte-specific (Col2-Cre;Ndst1fl/fl) loss-of-function allele of the sulfotransferase Ndst1. OA progression was evaluated using the OARSI scoring system. To investigate expression and activity of cartilage degrading proteases, femoral head explants of Ndst1+/- mutants were analyzed by qRT-PCR, Western Blot and gelatin zymography. RESULTS: All investigated mouse strains showed reduced OA scores (Col2-rtTA-Cre;Ext1e2fl/e2fl: 0.83; 95% HDI 0.72-0.96; Ndst1+/-: 0.83, 95% HDI 0.74-0.9; Col2-Cre;Ndst1fl/fl: 0.87, 95% HDI 0.76-1). Using cartilage explant cultures of Ndst1 animals, we detected higher amounts of aggrecan degradation products in wildtype samples (NITEGE 4.24-fold, 95% HDI 1.05-18.55; VDIPEN 1.54-fold, 95% HDI 1.54-2.34). Accordingly, gelatin zymography revealed lower Mmp2 activity in mutant samples upon RA-treatment (0.77-fold, 95% HDI: 0.60-0.96). As expression of major proteases and their inhibitors was not altered, HS seems to regulate cartilage degeneration by affecting protease activity. CONCLUSION: A decreased HS content or a reduced sulfation level protect against OA progression by regulating protease activity rather than expression.

Prediction of Shigellosis outcomes in Israel using machine learning classifiers.

Shigellosis causes significant morbidity and mortality in developing and developed countries, mostly among infants and young children. The World Health Organization estimates that more than one million people die from Shigellosis every year. In order to evaluate trends in Shigellosis in Israel in the years 2002-2015, we analysed national notifiable disease reporting data. Shigella sonnei was the most commonly identified Shigella species in Israel. Hospitalisation rates due to Shigella flexenri were higher in comparison with other Shigella species. Shigella morbidity was higher among infants and young children (age 0-5 years old). Incidence of Shigella species differed among various ethnic groups, with significantly high rates of S. flexenri among Muslims, in comparison with Jews, Druze and Christians. In order to improve the current Shigellosis clinical diagnosis, we developed machine learning algorithms to predict the Shigella species and whether a patient will be hospitalised or not, based on available demographic and clinical data. The algorithms' performances yielded an accuracy of 93.2% (Shigella species) and 94.9% (hospitalisation) and may consequently improve the diagnosis and treatment of the disease.

[Isolated true aneurysm of the deep femoral artery]. / Un anévrisme isolé de l'artère fémorale profonde.

Aneurysms of the deep femoral artery, accounting for 5% of all femoral aneurysms, are uncommon. There is a serious risk of rupture. We report the case of an 83-year-old patient with a painless pulsatile mass in the right groin due to an aneurysm of the deep femoral artery. History taking revealed no cardiovascular risk factors and no other aneurysms at other localizations. The etiology remained unclear because no recent history of local trauma or puncture was found. ACT angiography was performed, revealing a true isolated aneurysm of the deep femoral artery with a diameter of 90mm, beginning 1cm after its origin. There were no signs of rupture or distal emboli. Due to unsuitable anatomy for an endovascular approach, the patient underwent open surgery, with exclusion of the aneurysm and interposition of an 8-mm Dacron graft to preserve deep femoral artery flow. Due to their localization, the diagnosis and the management of aneurysms of the deep femoral artery can be difficult. Options are surgical exclusion or an endovascular approach in the absence of symptoms or as a bridging therapy. If possible, blood flow to the distal deep femoral artery should be maintained, the decision depending also on the patency of the superficial femoral artery. In case of large size, aneurysms of the deep femoral artery should be treated without any delay.

Angiojet Thrombo-aspiration Guided by Trans-Oesophageal Ultrasound.

INTRODUCTION: A 59 year old woman presented with acute right leg ischemia. On the computed tomography scan, thrombi were seen in the brachiocephalic trunk, in the descending aorta, in the infrarenal aorta, in the right deep femoral artery, and in the right crural arteries. TECHNIQUE: To remove the risk of cerebral emboli, thrombo-aspiration of the brachiocephalic trunk was planned, with associated thrombectomy of the infrarenal aorta, the right deep femoral artery, and the right crural arteries. Because the brachiocephalic thrombus could not be visualized with angiography, the anesthetists, who were performing a trans-oesophageal ultrasound of the heart, were asked to locate the thrombus, which was easily seen on the trans-oesophageal ultrasound. The aspiration catheter Angiojet (Boston Scientific, Marlborough, MA, USA) could be positioned under ultrasound guidance. Complete aspiration of the thrombus was then confirmed with the ultrasound (see video). The thrombectomy of the infrarenal aorta and right leg was then performed by open surgery. The patient's recovery was uneventful. Despite extensive investigations no etiology was found for the thrombi. DISCUSSION: Pre-operative trans-oesophageal ultrasound is routinely performed by anesthetists in patients with acute ischemia, to search for a cardiac source of emboli. In this case it had the added advantage of helping to locate and aspirate a thrombus in the brachiocephalic trunk.

Systemic mastocytosis in an African fat-tail gecko (Hemitheconyx caudicinctus).

A 3-year-old African fat-tail gecko (Hemitheconyx caudicinctus) suddenly became lethargic and died 2 days later. Necropsy examination revealed a submandibular mass and discolouration of the liver, kidneys and skeletal muscles of the tail. Microscopical evaluation revealed neoplastic mast cells in the skin, liver, kidneys, skeletal muscles, bones, spleen, uterus, ovaries and lungs. Exfoliative cytological, histopathological and ultrastructural features were consistent with systemic mastocytosis. Neoplastic proliferative disorders of mast cells are rare in reptiles and this is the first report of mast cell neoplasia in geckos.

Diagnosis of renal allograft rejection and acute tubular necrosis by 99mTc-mononuclear leukocyte imaging.

One hundred kidney transplant recipients were evaluated on the first and fifth days after transplantation by Tc-99m mononuclear cell scintigraphy. We have developed a quantitative method to diagnose rejection and acute tubular necrosis (ATN) by comparing regions of interest drawn on allograft scintigraphs at different times after endovenous administration of the labeled cells. We suggest that the use of Tc-99m-WBC may be useful for the early diagnosis of rejection and the differential diagnosis of ATN.

11C-methionine PET for differential diagnosis of low-grade gliomas.

Management of low-grade gliomas continues to be a challenging task, because CT and MRI do not always differentiate from nontumoral lesions. Furthermore, tumor extent and aggressiveness often remain unclear because of a lack of contrast enhancement. Previous studies indicated that large neutral amino acid tracers accumulate in most brain tumors, including low-grade gliomas, probably because of changes of endothelial and blood-brain barrier function. We describe 11C-methionine uptake measured with PET in a series of 196 consecutive patients, most of whom were studied because of suspected low-grade gliomas. Uptake in the most active lesion area, relative to contralateral side, was significantly different among high-grade gliomas, low-grade gliomas, and chronic or subacute nontumoral lesions, and this difference was independent from contrast enhancement in CT or MRI. Corticosteroids had no significant effect on methionine uptake in low-grade gliomas but reduced uptake moderately in high-grade gliomas. Differentiation between gliomas and nontumoral lesions by a simple threshold was correct in 79%. Recurrent or residual tumors had a higher uptake than primary gliomas. In conclusion, the high sensitivity of 11C-methionine uptake for functional endothelial or blood-brain barrier changes suggests that this tracer is particularly useful for evaluation and follow-up of low-grade gliomas.

11C-methionine and 18F-2-fluorodeoxyglucose positron emission tomography: a tool for diagnosis of cerebral glioma and monitoring after brachytherapy with 125I seeds.

Forty-six patients with suspected brain tumors were investigated by positron emission tomography (PET). Using 11C-methionine PET, the spatial extent of increased uptake in gliomas was larger than that of contrast enhancement on CT/MR images in 67% or the same in 33%. Ten of 46 patients treated with brachytherapy for low-grade gliomas were also investigated with 18F-2-fluorodeoxyglucose (FDG)-PET. One year after seed implantation, the glucose metabolism had not changed, but the decline of methionine uptake was significant. In conclusion, 11C-methionine PET may improve tumor delineation and, following brachytherapy, provides more information on the therapeutic effects than FDG.

Diagnosis of acute hepatitis E infection utilizing enzyme immunoassay.

Acute hepatitis E infection was diagnosed in a Pakistani immigrant admitted to the University of Illinois Hospital. Utilizing enzyme immunoassay (EIA) tests, specific IgG and IgM class antibodies to three different epitopes of hepatitis E virus (HEV) were detected 12 weeks after the onset of illness and in the early convalescent stage. Sixteen months after the onset of hepatitis, IgM anti-HEV was no longer detectable. Low levels of IgG class anti-HEV antibodies continued to be detected. We demonstrate the utility of the EIA HEV assay to diagnose prospectively acute HEV infection.

Hepatitis C infection in potential recipients with normal liver biochemistry does not preclude renal transplantation.

The hepatitis C virus (HCV) may be an important cause of chronic liver disease in renal transplant recipients. We investigated retrospectively the incidence and outcome of HCV infection in long-term renal transplant recipients and patients on hemodialysis. Stored, pretransplant sera of transplant recipients with normal liver biochemistry at surgery were tested for hepatitis C by a second-generation enzyme immunoassay. Hemodialysis patients were tested by a first-generation enzyme-linked immunosorbent assay (ELISA) against c100-3. We studied 252 renal transplant recipients and 58 hemodialysis patients followed for 65 +/- 10 months and 26 +/- 6 months, respectively. Fifteen percent (38/252) of the transplant recipients were HCV positive as were 3/58 (5%) of the hemodialysis patients. Overt liver disease occurred in 22/252 (8.7%) transplant recipients and none in the hemodialysis group. Thirty-six percent (8/22) of transplant recipients with overt liver disease were HCV positive. No HCV-positive patients died of liver failure. Of six biopsies in the HCV-positive transplant group, two had histological evidence of CAH. CAH was seen in six of eight biopsies in the HCV-negative transplants and two of these latter patients progressed to cirrhosis. No hemodialysis patients had clinical or histological evidence of chronic liver disease. Two HCV-negative transplant patients died of liver failure, while no deaths related to liver disease occurred in hemodialysis patients regardless of HCV status. We conclude that hepatitis C may cause chronic hepatitis in renal transplant patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Frequency of cells positive for HIV-1 p24 antigen assessed by flow cytometry.

OBJECTIVE: Markers of HIV disease progression such as soluble p24 antigen detection and CD4 lymphocyte depletion are most useful in the later stages of HIV disease and are relatively insensitive as therapeutic monitors. Flow cytometric detection of HIV-1 replication in CD4 lymphocytes was evaluated for use as a marker in predicting disease progression earlier in the course of HIV disease. DESIGN: To determine whether the number of HIV-1-infected CD4 cells, as measured by p24 antigen detection, can be correlated with disease progression, we used flow cytometry to detect intracellular HIV-1 p24 in CD4 lymphocytes from HIV-1-seropositive subjects at all stages of HIV disease. METHODS: Mononuclear cells from HIV-1-seropositive subjects and uninfected control subjects were permeabilized and stained with anti-HIV-1 p24 monoclonal antibodies. The cells were then stained with a fluorescein isothiocyanate-conjugated goat antimurine immunoglobulin G followed by a phycoerythrin-conjugated monoclonal anti-CD4 antibody. The percentage of p24-positive CD4 lymphocytes was compared with absolute CD4 counts, soluble p24 detection and Walter Reed classification. RESULTS: CD4 lymphocyte absolute counts and the percentage of CD4 lymphocytes declined as the Walter Reed classification indicated disease progression. The mean percentage of p24 antigen-positive CD4 lymphocytes increased with disease progression. Only 30% of Walter Reed stage 6 subjects were soluble p24 antigen-positive, whereas 68% were cellular p24 antigen-positive. CONCLUSION: The percentage of p24 antigen-positive CD4 lymphocytes increased as HIV disease progressed. Flow cytometric quantitation of p24 antigen-positive CD4 cells is a useful method of monitoring in vivo HIV replication and disease progression.

FDG-PET as a prognostic indicator in radiochemotherapy of glioblastoma.

OBJECTIVE: We performed a prospective cohort study in a homogeneous patient group with proven glioblastoma who received uniform therapy to determine the prognostic value and clinical correlates of [18F]fluorodeoxyglucose (FDG) PET at different stages of the disease. MATERIALS AND METHODS: Fifteen newly diagnosed patients with glioblastoma, aged 52 +/- 9 years and with Karnofsky performance score (KPS) of at least 50, were treated with surgical resection, chemotherapy (nimustine), and radiotherapy. They were followed prospectively for 2 years. Clinical data (e.g., tumor progression, performance status, and survival) were recorded and glucose metabolism was measured with PET and FDG before and during radiochemotherapy. RESULTS: Median survival of all patients was 13 months and four patients were alive 24 months after surgery. All tumors were hypermetabolic compared with normal white matter. A metabolic index was calculated as the ratio of maximum residual tumor metabolism to contralateral normal brain metabolism. It was of prognostic value for patient survival and tumor recurrence already in the first postoperative and all following PET studies and was correlated with the KPS. Reduction of contralateral brain metabolism was more closely related to prognosis than the tumor metabolism proper. CONCLUSION: These results underscore the prognostic relevance of metabolically active residual tumor tissue after surgical resection.

Human neutrophil oxidative response and phagocytic killing of clinical and laboratory strains of Enterococcus faecalis.

Many clinical isolates of Enterococcus faecalis produce a hemolysin/bacteriocin that is plasmid mediated. Recent human epidemiologic studies and animal research suggest that this hemolysin/bacteriocin may enhance the pathogenicity of hemolysin-producing enterococci compared with non-hemolysin-producing strains. These studies determined that clinical strains that produce hemolysin/bacteriocin differed from non-hemolysin-producing clinical and laboratory strains in their ability to induce the production of reactive oxygen intermediates in human peripheral blood neutrophils and in their susceptibility to phagocytic killing in vitro. The induction of superoxide anion generation by neutrophils was demonstrated to be directly proportional to the presence of the hemolysin/bacteriocin plasmid and was transferable to a non-hemolysin-producing laboratory strain by transconjugation. The presence of the plasmid, however, did not effect killing by phagocytic cells in vitro. It is proposed that hemolysin/bacteriocin-producing strains of enterococcus may be more pathogenic due to reactive oxygen product-induced tissue injury in vitro.

Antiviral phospholipids. Anti-HIV drugs conjugated to the glycerobackbone of phospholipids.

Heteroatom fatty acid analogs of myristic acid containing oxygen or sulfur substituted for the alkyl methylene groups inhibit replication of the human immunodeficiency virus (HIV) in infected cells by acting as alternative substrates during the viral protein myristoylation event. In this class of compounds, 12-methoxydodecanoic acid is the most potent compound but is approximately 10(3)-fold less active than azidothymidine. The antiviral activity of 12-methoxydodecanoic acid can be enhanced > 40-fold by preparing L-alpha-phosphatidylethanolamine containing 12-methoxydodecanoic acid in both alkyl chains. In addition, the diacylated L-alpha-phosphatidylcholine analog containing 12-methoxydodecanoic acid in both alkyl chains (i) has a 15-fold better antiviral selectivity, (ii) is 7-fold more potent, and (iii) is 10-100-fold more synergistic with azidothymidine than 12-methoxydodecanoic acid. Because of potent synergism, the antiviral selectivity of the diacylated L-alpha-phosphatidylcholine analog is > 10(4) when coadministered with azidothymidine. Phospholipid conjugates are chiral at the C-2 carbon of the glycerol backbone and most interesting is the observation that both the D- and L-isomers of phosphatidylcholine, phosphatidylglycerol, phosphatidic acid, and phosphatidylserine have approximately equal antiviral activity. Phospholipase A2 stereospecifically hydrolyzes only the L isomer of phospholipids and similar activity for both the D- and L- phospholipid isomers suggests that phospholipase A2 is not the rate-limiting enzyme for release of the drugs in vivo.

Evaluation of a flow cytometric model for monitoring HIV antigen expression in vitro.

Using flow cytometry, monoclonal antibodies to the HIV proteins p24, gp41 and p17 were evaluated for their ability to detect HIV antigens associated with HIV-infected T cells. Mixtures containing varying ratios of HIV-infected and uninfected cells were subjected to analysis with these monoclonal antibodies. In most cases, the monoclonal antibodies identified the correct ratio of HIV-infected cells to uninfected cells in the mixtures tested. An HIV anti-p24 monoclonal antibody was selected for further studies. Flow cytometric analysis was performed on various populations of cells including uninfected, acutely infected and chronically infected cells. Based on cell population fluorescence intensity three distinct regions were identified. In the first region were cells having low level fluorescence that were considered negative for HIV antigens, a profile detected in uninfected cells, and in the majority of cells in the first days following acute HIV infection. In the second region were those cells exhibiting strong fluorescence such as chronically infected cells or acutely infected cells several days after infection. A third region was identified containing cells that were intermediate in fluorescence intensity. Cells exhibiting intermediate intensity fluorescence appeared to have low concentrations of HIV p24 antigen associated with them either through viral adsorption and uptake or through low level virus expression. These intermediate region cells appeared in the early stages following acute infection, and also when chronically infected cells and uninfected cells were permeabilized together, suggesting a 'leaching' of HIV proteins from highly infected cells to uninfected cells. This leaching type of phenomenon could present problems in determining gating parameters for positive cells since uninfected cells that have associated HIV antigens exhibit higher fluorescence intensity than uninfected cells.

Altered lymphocyte phenotypes and proliferative responses in chimpanzees infected with hepatitis C virus.

Peripheral blood mononuclear cells (MNC) from three chimpanzees infected with hepatitis C virus (HCV) and from two uninfected animals were analyzed by monoclonal antibody phenotyping using flow cytometry. Significant differences in numbers of MNC's expressing cluster designation (CD) phenotypes CD4, CD14, CD19, and CD45RA were found. Additionally, significant differences in MNC proliferation in response to mitogens were also found. This altered proliferative capacity and cellular phenotype profile may be important markers in studying the pathogenesis of chronic HCV disease.