A Central Bioactive Region of LTBP-2 Stimulates the Expression of TGF-ß1 in Fibroblasts via Akt and p38 Signalling Pathways.

Latent transforming growth factor-ß-1 binding protein-2 (LTBP-2) belongs to the LTBP-fibrillin superfamily of extracellular proteins. Unlike other LTBPs, LTBP-2 does not covalently bind transforming growth factor-ß1 (TGF-ß1) but appears to be implicated in the regulation of TGF-ß1 bioactivity, although the mechanisms are largely unknown. In experiments originally designed to study the displacement of latent TGF-ß1 complexes from matrix storage, we found that the addition of exogenous LTBP-2 to cultured human MSU-1.1 fibroblasts caused an increase in TGF-ß1 levels in the medium. However, the TGF-ß1 increase was due to an upregulation of TGF-ß1 expression and secretion rather than a displacement of matrix-stored TGF-ß1. The secreted TGF-ß1 was mainly in an inactive form, and its concentration peaked around 15 h after addition of LTBP-2. Using a series of recombinant LTBP-2 fragments, the bioactivity was identified to a small region of LTBP-2 consisting of an 8-Cys motif flanked by four epidermal growth factor (EGF)-like repeats. The LTBP-2 stimulation of TGF-ß expression involved the phosphorylation of both Akt and p38 mitogen-activated protein kinase (MAPK) signalling proteins, and specific inactivation of each protein individually blocked TGF-ß1 increase. The search for the cell surface receptor mediating this LTBP-2 activity proved inconclusive. Inhibitory antibodies to integrins ß1 and αVß5 showed no reduction of LTBP-2 stimulation of TGF-ß1. However, TGF-ß1 upregulation was partially inhibited by anti-αVß3 integrin antibodies, suggestive of a direct or indirect role for this integrin. Overall, the study indicates that LTBP-2 can directly upregulate cellular TGF-ß1 expression and secretion by interaction with cells via a short central bioactive region. This may be significant in connective tissue disorders involving aberrant TGF-ß1 signalling.

Novel Staged Free-Fall Reactor for the (Catalytic) Pyrolysis of Lignocellulosic Biomass and Waste Plastics.

Pyrolysis of lignocellulosic biomass and waste plastics has been intensely studied in the last few decades to obtain renewable fuels and chemicals. Various pyrolysis devices have been developed for use in a laboratory setting, operated either in batch or continuously at scales ranging from milligrams per hour to tenths of g per hour. We report here the design and operation of a novel staged free-fall (catalytic) pyrolysis unit and demonstrate that the concept works very well for the (catalytic) pyrolysis of pinewood sawdust, paper sludge, and polypropylene as representative feeds. The unit consists of a vertical tube with a pretreatment section, a pyrolysis section, a solid residue collection section, a gas-liquid separation/collection section, and a catalytic reaction section to optionally perform ex situ catalytic upgrading of the pyrolysis vapor. The sample is placed in a tube, which is transported by gravity through various sections of the unit. It allows for rapid testing with semicontinuous feeding (e.g., 50 g h-1) and the opportunity to perform reactions under an (inert) gas (e.g., N2) at atmospheric as well as elevated pressure (e.g., 50 bar). Liquid yields for noncatalytic sawdust pyrolysis at optimized conditions (475 °C and atmospheric pressure) were 63 wt % on biomass intake. A lower yield of 51 wt % (on a biomass basis) was obtained for the noncatalytic pyrolysis of paper sludge, likely due to the presence of minerals (e.g., CaCO3) in the feed. The possibility of using the unit for ex situ catalytic pyrolysis (pyrolysis at 475 °C and catalytic upgrading at 550 °C) was also successfully demonstrated using paper sludge as the feed and H-ZSM-5 as the catalyst (21 wt % catalyst on biomass). This resulted in a biphasic liquid product with 25.6 wt % of an aqueous phase and 11 wt % of an oil phase. The yield of benzene, toluene, and xylenes was 1.9 wt % (on a biomass basis). Finally, the concept was also proven for a representative polyolefin (polypropylene), both noncatalytic as well as in situ catalytic pyrolysis using H-ZSM-5 as the catalyst at 500 °C. The liquid yield of thermal, noncatalytic plastic pyrolysis was as high as 77 wt % on plastic intake, while in situ catalytic pyrolysis gave a combined 7.8 wt % yield of benzene, toluene, and xylenes on plastic intake.

The response of the heart and pulmonary arteries to hypoxia, pressure, and volume. A short review.

The pulmonary arterioles react to hypoxia by contraction and to increased pressure and volume by hypertrophy of the muscular wall, referred to as pulmonary vascular remodeling, both of which increase vascular resistance and result in increased pulmonary arterial pressure. Heart muscle reacts to increased pressure by hypertrophy of cardiac myocytes and thickening of the muscular wall. The heart responds to increased volume by dilation of the chamber that may result in physiologic or pathologic hypertrophy of the muscle wall. Heart muscle cells are very sensitive to hypoxia or other insults, and this may result in death of individual cardiac myocytes with lengthening and thinning of the remaining heart muscle cells and dilation of the chamber in a process called dilated cardiomyopathy.

Molecular characterization and analysis of the acrB gene of Aspergillus nidulans: a gene identified by genetic interaction as a component of the regulatory network that includes the CreB deubiquitination enzyme.

Mutations in the acrB gene, which were originally selected through their resistance to acriflavine, also result in reduced growth on a range of sole carbon sources, including fructose, cellobiose, raffinose, and starch, and reduced utilization of omega-amino acids, including GABA and beta-alanine, as sole carbon and nitrogen sources. The acrB2 mutation suppresses the phenotypic effects of mutations in the creB gene that encodes a regulatory deubiquitinating enzyme, and in the creC gene that encodes a WD40-repeat-containing protein. Thus AcrB interacts with a regulatory network controlling carbon source utilization that involves ubiquitination and deubiquitination. The acrB gene was cloned and physically analyzed, and it encodes a novel protein that contains three putative transmembrane domains and a coiled-coil region. AcrB may play a role in the ubiquitination aspect of this regulatory network.

LTBP-2 Has a Single High-Affinity Binding Site for FGF-2 and Blocks FGF-2-Induced Cell Proliferation.

Latent transforming growth factor-beta-1 binding protein-2 (LTBP-2) belongs to the fibrillin-LTBP superfamily of extracellular matrix proteins. LTBPs and fibrillins are involved in the sequestration and storage of latent growth factors, particularly transforming growth factor ß (TGF-ß), in tissues. Unlike other LTBPs, LTBP-2 does not covalently bind TGF-ß, and its molecular functions remain unclear. We are screening LTBP-2 for binding to other growth factors and have found very strong saturable binding to fibroblast growth factor-2 (FGF-2) (Kd = 1.1 nM). Using a series of recombinant LTBP-2 fragments a single binding site for FGF-2 was identified in a central region of LTBP-2 consisting of six tandem epidermal growth factor-like (EGF-like) motifs (EGFs 9-14). This region was also shown to contain a heparin/heparan sulphate-binding site. FGF-2 stimulation of fibroblast proliferation was completely negated by the addition of 5-fold molar excess of LTBP-2 to the assay. Confocal microscopy showed strong co-localisation of LTBP-2 and FGF-2 in fibrotic keloid tissue suggesting that the two proteins may interact in vivo. Overall the study indicates that LTBP-2 is a potent inhibitor of FGF-2 that may influence FGF-2 bioactivity during wound repair particularly in fibrotic tissues.

Targeting Pim kinases for cancer treatment: opportunities and challenges.

Pim oncogenes are highly expressed in many types of hematological and solid cancers. Pim kinases regulate the network of signaling pathways that are critical for tumorigenesis and development, making Pim kinases the attractive drug targets. Currently, two approaches have been employed in designing Pim kinase inhibitors: ATP-mimetics and non-ATP mimetics; but all target the ATP-binding pocket and are ATP-competitive. In this review, we summarize the current progress in understanding the Pim-related structure and biology, and provide insights into the binding modes of some prototypical Pim-1 inhibitors. The challenges as well as opportunities are highlighted for development of Pim kinase inhibitors as potential anticancer agents.

Physiological, management and environmental triggers of the ascites syndrome: a review.

In meat-type chickens, an inadequacy of vascular capacity for blood flow through the lung to provide the tissues with the oxygen needed for rapid growth is the primary cause of pulmonary hypertensioninduced ascites. There are a variety of other factors that can trigger the ascites syndrome. These factors may cause increased blood flow because of a higher metabolic rate (cold, heat, certain nutrients, chemicals, etc.) or they may cause pulmonary hypertension-induced ascites in rapidly growing chickens because of greater resistance to blood flow in the lung by: (i) increased blood viscosity or red blood cell rigidity; or (ii) reduced vascular capacity in the lung. Some secondary factors, such as high sodium from salt in feed or water, may cause both increased flow and increased resistance to flow. Measures to reduce the ascites syndrome must address the primary genetic cause of insufficient vascular flow capacity in the lung and oxygen delivery to tissues, and the secondary factors that increase oxygen requirement, blood flow and the resistance to blood flow in the lung.

Tendon avulsion as a cause of lameness in turkeys.

Avulsion of the lateral intertarsal tendon is a common cause of hock deformity and lameness in turkeys. The clinical and pathological features of this condition are described.

Lung volume of meat-type chickens.

Lung volume (LV) in meat-type chickens was measured by water displacement and was computed as a percentage of body weight (BW). The percentage of LV/BW declined from 2.02 +/- 0.190% at day 1 to 1.38 +/- 0.163% at day 144. Pulmonary hypertension caused by insufficient lung capillary capacity or oxygen exchange area results in right ventricular failure and ascites in meat-type chickens. Insufficient LV in very fast-growing broilers may contribute to this problem. Selection procedures in meat-type chickens should include a method for estimating LV.

Osteochondrosis, dyschondroplasia, and osteomyelitis causing femoral head necrosis in turkeys.

Femoral head necrosis is a term that has been used, frequently inappropriately, to describe a variety of lesions in the head and proximal femur of poultry. In a survey of causes of lameness in a group of 18,000 tom turkeys, examination of femurs from lame 16-to-30-week-old heavy male turkeys with femoral head necrosis revealed that the lesions could be placed in one of three categories: degeneration of articular or growth plate cartilage and bone, with separation usually between the growth plate and metaphysial bone; avascular necrosis with sequestration and degeneration of an abnormal mass of prehypertrophying cartilage (dyschondroplastic cartilage), with spontaneous fracture and collapse of the femoral head or fracture through the metaphyses or neck of the femur; and osteomyelitis, with necrosis usually beneath the growth plate in the metaphyses. The second and third categories of lesion were frequently found in the proximal tibia as well, so the term long-bone necrosis would be a more suitable morphologic description than femoral head necrosis.

Reduced erythrocyte deformability as a possible contributing factor to pulmonary hypertension and ascites in broiler chickens.

Deformability of erythrocytes and hematological parameters in white leghorn and broiler chickens were measured at age 7, 14, 21, 28, and 35 days. For deformability testing, a simple vertical apparatus containing a polycarbonate membrane with 5-microns pores was used. This technique assesses erythrocyte deformability by measuring the filtration time of an erythrocyte suspension through the pores. There was a significant difference in filtration time between the leghorns and broilers at all sampling times. These results indicate that reduced erythrocyte deformability in broilers may be one of the predisposing factors that increase resistance to blood flow and alter the rheology of blood in the microcirculation in the lung. Increased resistance to flow may result in pulmonary hypertension, heart failure, and ascites in broiler chickens.

Blood oxygen concentration of fast-growing and slow-growing broiler chickens, and chickens with ascites from right ventricular failure.

Percent hemoglobin oxygen saturation was measured with a pulse oximeter in 6-week-old slow-growing (light) and fast-growing (heavy) male broiler chickens and those with ascites from right ventricular failure (RVF). Pulse rate and percent oxygen saturation were read from the ulnar artery just proximal to the carpus. Percent oxygen saturation was significantly (P less than or equal to 0.0001) higher in light chickens (mean 91.6%) than in heavy chickens (mean 86.0%), and the percent oxygen saturation was significantly (P less than or equal to 0.0001) higher in both groups with normal hearts than in the group with RVF from valvular insufficiency (mean 62.1%). All RVF chickens and those with normal hearts were confirmed at necropsy. Light chickens were males with leg deformity or stunting and were 20-50% lighter than the heavy chickens.

Pen oxygen concentration and pulmonary hypertension-induced right ventricular failure and ascites in meat-type chickens at low altitude.

Percentage O2 and CO2 were measured in the air in environmentally controlled commercial poultry pens (altitude approximately 300 m) containing broiler or roaster chickens 14 to 56 days of age. Outside air (mean of 10 samples) measured 20.85% O2 and 0.041% CO2. Air in the pens had significantly lower O2 and higher CO2 than outside air; however, air in 25 pens with a high incidence of ascites (mean 20.50% O2, 0.264% CO2) was not different from the air in 25 pens with a low incidence of ascites (mean 20.49% O2, 0.319% CO2). The lowest pen O2 was 20.20%, which would not cause reduced hemoglobin saturation (percent oxygen) of the arterial blood of normal chickens.

Necrotic enteritis in turkeys.

Three flocks of turkey hens (16,000 each) between 7 and 12 weeks of age experienced outbreaks of necrotic enteritis. Necropsy revealed a dilated duodenum and jejunum with mucosal surfaces covered with a diphtheritic membrane. Intestinal scrapings showed very few oocysts of Eimeria sp. Histopathological findings were compatible with necrotic enteritis but with deeper, more severe lesions than in broiler chickens. Clostridium perfringens was isolated by anaerobic culture from the intestinal contents. Mortality returned to normal after ampicillin or tetracycline was added to the drinking water.

Cartilage lesions associated with shaky-leg lameness in turkeys.

Shaky-leg lameness is a poorly defined, mild to very severe, painful lameness occurring mainly in 10-to-18-week-old fast-growing male turkeys. Since there are no significant gross or microscopic lesions in early or uncomplicated cases, the cause of the lameness is likely soft-tissue (muscle or tendon) pain. A case history of a flock problem of shaky-leg lameness is described, and it is suggested that stiffness and inactivity secondary to footpad dermatitis in these turkeys was responsible for the severe shaky-leg lameness in the flock. The cartilage lesion described is an avascular lesion and appeared to be the result of inactivity rather than the cause of lameness in these turkeys.

Hepatic lipidosis in turkeys.

Two flocks of 14,000 twenty-week-old turkey hens each experienced increased mortality due to hepatic lipidosis. Some hens showed signs of dyspnea and cyanosis before death. Necropsy revealed dark muscles and enlarged livers with pale areas and numerous hemorrhages. Petechial and ecchymotic hemorrhages were also found on the abdominal fat and epicardium. Lung congestion and edema were prominent. In the heart and blood vessels, the blood was uncoagulated. Mortality was elevated for 12 days and resulted in the death of 0.7% of the turkey hens in one flock and 1.7% in the other. Vitamin E administered in water at a dose of 25 IU per hen appeared to reduce mortality. The nutritional and environmental factors that may contribute to the development of hepatic lipidosis in turkeys are discussed.

Right ventricular failure and ascites in broiler chickens caused by phosphorus-deficient diets.

Phosphorus-deficient diets fed to broiler chicks from day 1 to day 21 induced rickets. Some chicks were stunted, but most grew well, though they had increased respiratory rates, high arterial carbon dioxide partial pressure, and low oxygen partial pressure and were polycythemic. Most of the broilers that died showed signs of pulmocardiovascular abnormalities, some died from hypoxia, and some died from right ventricular failure with or without ascites. Many broilers had mild to marked right ventricular hypertrophy and dilation with or without ascites when examined at 21 days. It is suggested that right ventricular hypertrophy and dilation was a response to pulmonary arterial hypertension caused by chronic hypoxia, which resulted from inability to breathe normally because of poor rib strength and infolding. When right ventricular failure occurred, it was secondary to right ventricular hypertrophy and dilation.

Colonization of the intestine of turkey embryos exposed to Mycoplasma iowae.

Eight-day-old turkey embryos were inoculated into the yolk sac with 3 X 10(5) colony-forming units of Mycoplasma iowae strain D112 in order to study the growth-depressing effect, the histopathological changes, and colonization of the intestinal tract. The embryo: egg weight ratio was significantly lower in the inoculated eggs than in controls. Histologically, there were infiltrations in parenchymatous organs and chorioallantoic membranes with heterophilic granulocytes. M. Iowae was demonstrated on the intestinal mucosa by antibody fluorescent microscopy and by transmission electron microscopy. Attaching mycoplasmas had a distinct morphology; the segment in contact with enterocytes was cone-shaped and had finely granulated cytoplasma which was abruptly separated from the distal coarsely granulated area. We conclude that M. iowae has a predilection for the intestinal tract of avian hosts.

Single and combined infections of specific-pathogen-free chickens with infectious bursal disease virus and an intestinal isolate of reovirus.

The susceptibility of 1-day-old and 7-day-old specific-pathogen-free chickens to infection with a virulent strain of infectious bursal disease virus (IBDV) or an intestinal isolate of avian reovirus, or a combination of the two, was investigated. Chickens infected with IBDV and reovirus had more severe pathological lesions than chickens infected with either virus alone, and prior infection with IBDV enhanced the pathogenicity of enteric reovirus. Virus recovery was attempted from bursa, spleen, thymus, liver, intestine, pancreas, cecal tonsils, heart, and tarso-metatarsal tendons. Viruses were recovered from all tissues sampled for either IBDV or reovirus isolation, and indications were that infection with IBDV before infection with reovirus led to longer persistence of reovirus in some tissues. Antibodies to IBDV or reovirus were measured by the virus neutralization test and enzyme-linked immunosorbent assay. Chickens infected with IBDV had lower (P less than 0.05) antibody responses to reovirus than chickens infected with reovirus alone.

Experimental Escherichia coli respiratory infection in broilers.

This study determined optimal conditions for experimental reproduction of colibacillosis by aerosol administration of avian pathogenic Escherichia coli to 2-to-4-wk-old broiler chickens. The basic model for reproducing disease was intranasal administration of approximately 10(4) mean embryo infectious dose of infectious bronchitis virus (IBV) followed by aerosol administration of an 02 or an 078 strain of E. coli in a Horsfall unit (100 ml of a suspension of 10(9) colony-forming units/ml over 40 min). Scores were assigned to groups of infected chickens on the basis of deaths; frequency and severity of lesions in the air sacs, liver and heart; and recovery of the challenge E. coli 6 days post-E. coli infection. An interval of 4 days between the IBV and E. coli challenges was best whether the chickens received the IBV at 8 or 20 days of age. Typically, 50%-80% of the chickens developed airsacculitis and 0 to 29% of the chickens developed pericarditis or perihepatitis, with little or no mortality. Escherichia coli alone resulted in no deaths and 0 to 20% airsacculitis, but these percentages increased to 0 to 5% and 52%-60% when the E. coli aerosol was administered through a cone-shaped chamber. Administration of IBV alone failed to induce lesions. Recovery of the challenge E. coli from chickens did not correlate well with lesions. On the basis of these data, administration of IBV to 20-day-old chickens followed 4 days later by exposure to an avian pathogenic E. coli reproduces avian colibacillosis with the low mortality, high percentage of airsacculitis, and low percentage of septicemic lesions characteristic of the conditions seen in the natural disease.