Role of the C-C chemokine receptor-2 in a murine model of injury-induced osteoarthritis.

OBJECTIVE: We previously found in our embryonic studies that proper regulation of the chemokine CCL12 through its sole receptor CCR2, is critical for joint and growth plate development. In the present study, we examined the role of CCR2 in injury-induced-osteoarthritis (OA). METHOD: We used a murine model of injury-induced-OA (destabilization of medial meniscus, DMM), and systemically blocked CCR2 using a specific antagonist (RS504393) at different times during disease progression. We examined joint degeneration by assessing cartilage (cartilage loss, chondrocyte hypertrophy, MMP-13 expression) and bone lesions (bone sclerosis, osteophytes formation) with or without the CCR2 antagonist. We also performed pain behavioral studies by assessing the weight distribution between the normal and arthritic hind paws using the IITS incapacitance meter. RESULTS: Testing early vs delayed administration of the CCR2 antagonist demonstrated differential effects on joint damage. We found that OA changes in articular cartilage and bone were ameliorated by pharmacological CCR2 blockade, if given early in OA development: specifically, pharmacological targeting of CCR2 during the first 4 weeks (wks) following injury, reduced OA cartilage and bone damage, with less effectiveness with later treatments. Importantly, our pain-related behavioral studies showed that blockade of CCR2 signaling during early, 1-4 wks post-surgery or moderate, 4-8 wks post-surgery, OA was sufficient to decrease pain measures, with sustained improvement at later stages, after treatment was stopped. CONCLUSIONS: Our data highlight the potential efficacy of antagonizing CCR2 at early stages to slow the progression of post-injury OA and, in addition, improve pain symptoms.

Environmental stress-corrosion cracking of fiberglass: lessons learned from failures in the chemical industry.

Fiberglass reinforced plastic (FRP) composite materials are often used to construct tanks, piping, scrubbers, beams, grating, and other components for use in corrosive environments. While FRP typically offers superior and cost effective corrosion resistance relative to other construction materials, the glass fibers traditionally used to provide the structural strength of the FRP can be susceptible to attack by the corrosive environment. The structural integrity of traditional FRP components in corrosive environments is usually dependent on the integrity of a corrosion-resistant barrier, such as a resin-rich layer containing corrosion resistant glass fibers. Without adequate protection, FRP components can fail under loads well below their design by an environmental stress-corrosion cracking (ESCC) mechanism when simultaneously exposed to mechanical stress and a corrosive chemical environment. Failure of these components can result in significant releases of hazardous substances into plants and the environment. In this paper, we present two case studies where fiberglass components failed due to ESCC at small chemical manufacturing facilities. As is often typical, the small chemical manufacturing facilities relied largely on FRP component suppliers to determine materials appropriate for the specific process environment and to repair damaged in-service components. We discuss the lessons learned from these incidents and precautions companies should take when interfacing with suppliers and other parties during the specification, design, construction, and repair of FRP components in order to prevent similar failures and chemical releases from occurring in the future.

Polycythemia vera and mesenteric arterial thrombosis. A disease association resulting from decreased platelet sensitivity to aspirin.

Recurrent mesenteric arterial thrombosis developed in a 56-year-old man with polycythemia vera (PV) despite therapy with heparin sodium, warfarin sodium, and standard doses of aspirin and dipyridamole. Platelet aggregation studies disclosed a normal response to aggregating agents in the presence of blood levels of aspirin that usually inhibit in vitro platelet aggregation. Increasing the in vivo dose of aspirin was associated with inhibition of in vitro platelet aggregation and, thereafter, arterial thrombosis did not recur. This case demonstrates that some patients with PV and arterial thrombosis may be refractory to standard doses of anticoagulants and platelet antiaggregating agents.

Glucose metabolism in abdominally obese hypertensive and normotensive subjects.

To determine whether the combination of obesity and hypertension results in additive defects in oxidative and nonoxidative glucose metabolism and the association of these changes with altered hemodynamic actions of insulin, we studied 11 abdominally obese hypertensive, 6 abdominally obese normotensive, and 7 lean normotensive nondiabetic subjects. Endogenous glucose production and glucose metabolized were calculated from a euglycemic clamp at 72 and 287 pmol insulin/m2 per minute. Glucose metabolized divided by insulin was lower at 72 pmol/m2 per minute in both obese groups than in lean normotensive subjects, at 148 +/- 14, 144 +/- 33, and 373 +/- 69 (mumol/m2 per minute)/(pmol/L), respectively (P < .01). Similar results were obtained during the higher insulin dose. Nonoxidative and oxidative glucose disposals by indirect calorimetry were lower in both abdominally obese groups (P < .05). Hepatic glucose production was completely suppressed in lean subjects at the lower insulin dose and in all three groups at the higher insulin dose. Hemodynamic responses during the clamp were not significantly different among the three groups. Abdominal obesity is associated with defects in insulin-regulated oxidative and nonoxidative glucose disposal as well as in insulin suppression of hepatic glucose production. Mild hypertension does not exacerbate these defects. Whereas the global impairment in glucose metabolism suggests the presence of an early defect or defects, including reduced tissue perfusion, systemic and regional hemodynamic responses to insulin were not altered. These findings do not support a direct role for insulin resistance in the pathogenesis of the hypertension associated with abdominal obesity.

Left internal thoracic artery graft occlusion following mediastinal radiation therapy.

Premature coronary artery disease is a late consequence of mediastinal radiation therapy. Many of these patients have been successfully treated with coronary bypass surgery. A 51-year-old man underwent bypass surgery for severe multivessel coronary disease 18 years following radiation therapy for a posterior mediastinal tumor. Recurrent angina 1 year later occurred following closure of the left internal thoracic artery graft. We suspect that this occurred as a consequence of injury sustained during mediastinal irradiation. Patients who have undergone prior mediastinal radiation therapy may not be assured the excellent long-term patency of the internal thoracic artery graft which has been reported for the general population. Saphenous vein grafts probably should be considered instead.

Hemolytic anemia associated with heterograft replacement of the mitral valve.

The first case of overt hemolytic anemia following mitral valve replacement with a porcine heterograft is reported. Cardiac catheterization failed to reveal a paravalvular leak or valvular incompetence to account for the hemolysis. Red cell traumatization by the Dacron-covered Stellite ring and stent is suggested as the cause of hemolysis with the porcine heterograft.

Humoral and cellular studies of eosinophils in reactive and myeloproliferative syndromes with marked eosinophilia.

In five patients with eosinophilia and myeloproliferative disorders, the IgE levels were normal, and immune complexes were not detected. In contrast, in six patients with reactive eosinophilia accompanying immunologic diseases, the IgE levels were elevated in five, and immune complexes were elevated in two. Five of six patients within the reactive group had positive rheumatoid factor titers by latex agglutination, while only one of five in the myeloproliferative group showed this finding. Purified eosinophils from patients with myeloproliferative diseases showed enhanced oxygen consumption responses during the ingestion of latex beads, relative to reactive eosinophils. The stimulated oxidative response of reactive eosinophils during phagocytosis of bacteria opsonized with antibody and complement was reduced, relative to myeloproliferative eosinophils. In vitro incubation of eosinophils with immune complexes reduced, by more than two-thirds, the increased oxidative responses of myeloproliferative eosinophils. Our findings suggest that eosinophilia seen in myeloproliferative diseases is an intrinsic part of the myeloproliferative process, which is not mediated or enhanced by allergic or immunologic reactions. The measurements reported here have potential value for differentiating reactive eosinophilic states from the eosinophilia accompanying myeloproliferative diseases.

Left ventricular assist system as a bridge to myocardial recovery.

BACKGROUND: Despite recent advances in medical therapy, heart transplantation, and mechanical circulatory support, the mortality of patients with congestive heart failure remains high. METHODS: Retrospective data on 5 patients were obtained from our hospital's medical records. Each patient was supported by a left ventricular assist system (LVAS) because of severe congestive heart failure. The duration of LVAS support averaged 229 days (range, 46 to 447 days). In 3 patients, the LVAS was removed electively after the patient showed recovery of myocardial function. In the other 2, it was removed because of a malfunction. RESULTS: In response to LVAS support, hemodynamic variables were significantly improved. The mean cardiac index increased from 1.45 to 2.69 L x min(-1) x m(-2) (p < 0.001) and the mean left ventricular ejection fraction increased from 0.144 to 0.288 (p < 0.025). All patients were in New York Heart Association functional class IV at LVAS implantation and class I at its explantation. One patient died of noncardiac-related causes 10 days after LVAS removal. The remaining 4 patients are alive and well 35, 33, 14, and 2 months after LVAS removal. CONCLUSIONS: In select patients with severe congestive heart failure, mechanical unloading with an LVAS can result in recovery of myocardial function. These patients can return to a normal physical status, thereby avoiding heart transplantation. More research is required to determine optimal modes of LVAS support, to predict which patients are likely to recover, and to assess long-term outcomes.

Myocardial tumor necrosis factor-alpha expression does not correlate with clinical indices of heart failure in patients on left ventricular assist device support.

BACKGROUND: Mechanical unloading with a left ventricular assist device (LVAD) can improve clinical indices of heart failure and alter myocardial tumor necrosis factor-alpha (TNFalpha) expression, but a correlation between clinical and molecular indices has not been established. METHODS: We enrolled 14 patients with end-stage heart failure treated with drugs and mechanical unloading in a protocol including the collection of myocardial tissue samples at LVAD implantation and explantation. Ten nonfailing donor hearts served as controls. TNFalpha expression was measured by quantitative reverse transcription polymerase chain reaction. Clinical indices of heart failure were retrospectively analyzed and correlated with myocardial TNFalpha expression. RESULTS: Left ventricular end-diastolic dimension decreased (p < 0.01) and cardiac index (p < 0.001) increased with unloading. Abnormal values of serum sodium, creatinine, blood urea nitrogen, glutamic-oxaloacetic transaminase, glutamic-pyruvic transaminase, and albumin showed a trend toward normalization with mechanical unloading. TNFalpha expression was increased in 5 of 14 patients and decreased with mechanical unloading in 4 of them. Surprisingly, there was no correlation between mRNA levels of TNFalpha and any of the clinical indices studied. CONCLUSIONS: Although clinical indices of heart failure improve and elevated levels of myocardial TNFalpha expression decrease with mechanical unloading, there is no correlation between the two. Thus, clinical and molecular indices of heart failure in LVAD-supported patients do not always correlate.

Improved survival after extended bridge to cardiac transplantation.

In the past, left ventricular assist device (LVAD) support was frequently plagued by complications; thus, bridge to transplantation times were kept short. Increasing evidence suggests that extended bridging provides greater benefit due to improved end-organ perfusion and, thus, generally improved physical condition. To assess whether extended bridging translates into improved long-term survival after transplantation, we reviewed our experience with the HeartMate 1000 IP LVAD (Thermo Cardiosystems, Inc, Woburn, MA). Since January 1988, 19 patients (mean age, 45 +/- 9 years) have undergone extended bridging (mean time, 106 +/- 57 days). Their mean weight was 82 +/- 16 kg, and their mean body surface area was 2.0 +/- 0.2 m2. We define "extended" as the length of support necessary for systemic organ recovery after prolonged heart failure. During support, average pump flow indices ranged from 2.3 to 3.3 L.min-1.m-2, and all patients underwent physical rehabilitation. Between the time of LVAD implantation and explantation, the mean serum creatinine value decreased from 1.63 +/- 0.6 to 1.25 +/- 0.6 mg/dL (p = not significant), and the mean serum total bilirubin value decreased from 2.8 +/- 2.0 to 0.63 +/- 0.11 mg/dL (p < 0.05). All but 1 patient improved from New York Heart Association class IV to class I. Device-related complications were minimal. Twelve control patients ("de facto randomized") who did not receive the LVAD also were evaluated: actuarial survival at 1 year was 0% (p < 0.05); 3 (25%) underwent transplantation and died within 2 months; 9 (75%) died before transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Research and development of an implantable, axial-flow left ventricular assist device: the Jarvik 2000 Heart.

Advances in technology and increased clinical need have led to the development of a new type of blood pump. The Jarvik 2000 Heart is an electrically powered, axial-flow left ventricular assist device that has been developed during the past 13 years. Unlike first-generation left ventricular assist devices, which were developed in the 1970s and were designed to totally capture the cardiac output, the Jarvik 2000 is designed to normalize the cardiac output by augmenting the function of the chronically failed heart for extended periods. Design iterations have been tested in 67 animals, and clinical trials have recently begun. Three patients have received the Jarvik 2000 as a bridge to transplantation, and 1 patient is being supported permanently outside the hospital. All 4 patients have improved from New York Heart Association functional class IV to class I, and 2 of them have been discharged from the hospital after heart transplantation. The experimental and clinical results indicate that the Jarvik 2000 can provide physiologic support with minimal complications and is reliable, biocompatible, and easy to implant.

A novel reconstruction algorithm to extend the CT scan field-of-view.

For various reasons, a projection dataset acquired on a computed tomography (CT) scanner can be truncated. That is, a portion of the scanned object is positioned outside the scan field-of-view (SFOV) and the line integrals corresponding to those regions are not measured. A projection truncation problem causes imaging artifacts that lead to suboptimal image quality. In this paper, we propose a reconstruction algorithm that enables an adequate estimation of the projection outside the SFOV. We make use of the fact that the total attenuation of each ideal projection in a parallel sampling geometry remains constant over views. We use the magnitudes and slopes of the projection samples at the location of truncation to estimate water cylinders that can best fit to the projection data outside the SFOV. To improve the robustness of the algorithm, continuity constraints are placed on the fitting parameters. Extensive phantom and patient experiments were conducted to test the robustness and accuracy of the proposed algorithm.

Natural killer cell activity of chicken intraepithelial leukocytes against rotavirus-infected target cells.

Intraepithelial leukocytes (IEL) and splenocytes collected from uninfected and rotavirus-infected chickens were evaluated for cytotoxic activity against a natural killer (NK) cell-susceptible lymphoblastoid cell line (LSCC-RP9) and against rotavirus-infected chick kidney cells in 4-h chromium-release assays. Both splenocytes and IELs from uninfected and rotavirus-infected chickens were cytotoxic for LSCC-RP9, and the levels of this NK cell activity were not altered by infection of the host with rotavirus. IELs but not splenocytes from uninfected and rotavirus-infected chickens were cytotoxic for rotavirus-infected but not for uninfected chick kidney cell targets. Because this cytotoxic activity was not induced nor altered by rotavirus infection of the host, and was not major histocompatibility complex-restricted, it was considered to be due to NK cell activity. The cytotoxicity of IELs against rotavirus-infected target cells was dose-dependent; however, there was some suppression of cytotoxic activity at high effector to target cell ratios. There were no differences in the cytotoxic activities of IELs collected from the duodenum versus the jejunum. The in vitro cytotoxic activity of IELs against rotavirus-infected target cells suggested that NK cell activity may be an important immune response to rotavirus infections in vivo. The absence of cytotoxic activity by splenocytes against rotavirus-infected target cells indicated that there may be different subpopulations of NK cells in the spleen and intestinal epithelium of chickens.

Partial purification and characterization of chicken interleukin-2.

Chicken interleukin 2 (IL-2) activity was partially purified from conditioned medium produced by culturing chicken splenic lymphocytes in the presence of concanavalin A. The purification procedure included sequential steps of gel filtration chromatography, reverse-phase high-pressure liquid chromatography, and phenyl-sepharose chromatography. Two peaks of IL-2 activity with apparent mol. wt. ranges of 36-39 kD and 17.5-25 kD were eluted from the Sephadex G100 gel filtration column. An increase in IL-2 spec. act. from 14 U mg-1 to between 2000 and 20,000 U mg-1 was obtained for the Sephadex G100 column peaks when subjected to the subsequent steps of the purification procedure. Alkylative reduction of the higher mol. wt. Sephadex G100 column peak (followed by re-chromatography with Sephadex G100), resulted in generation of the lower (17.5 kD) mol. wt. peak, indicating that chicken IL-2 is capable of either dimerizing or forming aggregates with other proteins. Elution of the lower mol. wt. IL-2 activity from a non-reducing sodium dodecyl sulfate-polyacrylamide gel demonstrated an apparent mol. wt. for chicken IL-2 of 20 kD, which confirmed the range of 17.5-25 kD seen with gel filtration.

Tensile strength of spinal ligaments.

Spinal ligaments from 41 fresh human male cadavers were tested. The ligaments were tested in situ by sectioning all elements except the one under study. The force deflection curves demonstrated a sigmoidal shape, and the point at which an increase in deflection was obtained with decreasing force was taken as failure. The force and deformation at failure are shown for each ligament as a function of spinal level.

Pure red cell aplasia and the syndrome of multiple endocrine gland insufficiency.

A 26-year-old female with the syndrome of multiple endocrine gland insufficiency developed pure red cell aplasia. A clinical remission of the pure red cell aplasia was induced with prednisone and cyclophosphamide therapy. The occurrence of these two disorders in a single patient allows speculation on a possible defect in immune surveillance leading to multisystemic immune dysfunction in this patient.

Propagation of avian rotavirus in primary chick kidney cell and MA104 cell cultures.

The Ch2 strain of avian rotavirus was propagated in primary chick kidney cell (CKC) and MA104 cell cultures in the presence of trypsin. Cultures were evaluated for the presence of rotavirus by an indirect fluorescent antibody (IFA) assay and by an indirect enzyme-linked immunosorbent assay (ELISA). After two passages, the viral titer was significantly higher in CKC than MA104 cell cultures. Also, the IFA assay was more sensitive than the indirect ELISA for detecting rotavirus-positive cultures.

Development of immunoglobulin class-specific enzyme-linked immunosorbent assays for measuring antibodies against avian rotavirus.

Immunoglobulin class-specific enzyme-linked immunosorbent assays were developed for detecting antibodies against avian rotavirus in serum, intestinal contents, and bile from experimentally infected specific-pathogen-free (SPF) chickens. Both indirect and antibody-capture (AbC) assays were developed based on monoclonal antibodies specific for chicken IgG, IgM, and IgA. Treatment of purified rotavirus with sodium thiocyanate before coating the plate improved the rotavirus-specific reading in the indirect assay. Use of Immunolon 2 plates facilitated attachment of monoclonal antibodies to the plate in the AbC assay. Addition of 5% powdered skim milk to the diluent buffer reduced nonspecific background readings. The indirect assay was superior for detecting rotavirus-specific IgG, whereas the AbC assay was better for detecting rotavirus-specific IgM and IgA. The presence of intestinal contents in the assay wells did not reduce the measurable titers of IgG, IgM, or IgA. These assays showed that SPF chickens produced systemic and mucosal antibodies against avian rotavirus.

USDA options for regulatory changes to enhance the prevention and control of avian influenza.

During the past decade, several examples of the ability of H5 and H7 low-pathogenicity avian influenza (LPAI) viruses to mutate to high-pathogenicity (HP) viruses have been documented worldwide. During this time, the introduction and persistence of an H7N2 LPAI virus in the northeast live-bird marketing system in the United States has raised concern on how to prevent the possibility of such a mutation occurring in this country. The United States has periodically experienced trade restrictions based on the occasional introduction of H5 and H7 LPAI viruses into commercial poultry and based on AI-related changes in the import requirements for poultry and poultry products of several of our trading partners. Consequently, the U.S. Department of Agriculture (USDA) is exploring options for how our regulatory response to H5 and H7 LPAI viruses might be revised to better protect our domestic poultry flocks from HPAI and to ensure that any interruptions in trade are scientifically supportable. The options under consideration include mandatory and voluntary measures to improve the surveillance for and control of H5 and H7 LPAI virus infections.

Epidemiologic and surveillance studies on avian influenza in live-bird markets in New York and New Jersey, 2001.

In 2001, all 109 retail live-bird markets (LBMs) in New York and New Jersey were surveyed for the presence of avian influenza virus (AIV) by a real time reverse transcriptase/polymer chain reaction assay (RRT/PCR) and results compared to virus isolation (VI) in embryonating chicken eggs. The RRT/PCR had a 91.9% sensitivity and 97.9% specificity in detecting presence of AIV at the market level. However, the sensitivity at the sample level is 65.87%. The RRT/PCR is a reliable method to identify AIV at the market level. In addition, a cross-sectional epidemiologic study of the LBMs showed that, during the past 12 months, markets that were open 7 days per week and those that also sold rabbits had the highest risk for being positive for AIV. Markets that were closed one or more days per week and those that performed daily cleaning and disinfecting had the lowest risk for being AIV positive.