Loci controlling lymphocyte production of interferon γ after alloantigen stimulation in vitro and their co-localization with genes controlling lymphocyte infiltration of tumors and tumor susceptibility

Low infiltration of lymphocytes into cancers is associated with poor prognosis, but the reasons why some patients exhibit a low and others a high infiltration of tumors are unknown. Previously we mapped four loci (Lynf1–Lynf4) controlling lymphocyte infiltration of mouse lung tumors. These loci do not encode any of the molecules that are involved in traffic of lymphocytes. Here we report a genetic relationship between these loci and the control of production of IFNγ in allogeneic mixed lymphocyte cultures (MLC). We found that IFNγ production by lymphocytes of O20/A mice is lower than by lymphocytes of OcB-9/Dem mice (both H2 ^pz ) stimulated in MLC by irradiated splenocytes of C57BL/10SnPh (H2 ^b ) or BALB/cHeA (H2 ^d ) mice, or by ConA. IFNγ production in MLCs of individual (O20 × OcB-9)F₂ mice stimulated by irradiated C57BL/10 splenocytes and genotyped for microsatellite markers revealed four IFNγ-controlling loci (Cypr4-Cypr7), each of which is closely linked with one of the four Lynf loci and with a cluster of susceptibility genes for different tumors. This suggests that inherited differences in certain lymphocyte responses may modify their propensity to infiltrate tumors and their capacity to affect tumor growth.     

Phospholipid oxidation catalyzed by cytochrome c in liposomes

Oxidation of liposome phospholipids has been studied in the presence of cytochrome c. Sonicated vesicles of soya bean or egg-yolk lipids, or purified phospholipid preparations, were treated with oxidized cytochrome c at a 10:4 lipid/protein ratio (w/w). Lipid peroxidation was examined by oxygen polarography, gas-liquid chromatography (GLC) and the thiobarbituric acid test. Oxidized, but not reduced, cytochrome effectively catalyzes lipid oxidation under these conditions. Oxygen consumption and disappearance of unsaturated fatty acids follow closely similar patterns, the O2 consumption rate showing a maximum (1.53 mol O2/min per mol heme) shortly before fatty acid loss reaches its peak. GLC and O2 consumption data suggest that monohydroperoxides are the most abundant oxidized species in the system. The thiobarbituric acid reaction, however, appears only to be of qualitative value in peroxidation studies. In order to test the mechanism through which oxidation occurs in our system, the effect of liposome composition and the presence of antioxidants was tested, both on cytochrome c binding to bilayers and on O2 consumption. Oxidized and reduced cytochrome c bind the lipid bilayers with similar affinity, but only the oxidized form is active in autoxidation. Antioxidants do not modify either cytochrome c binding to sonicated liposomes. Lipid composition does influence considerably cytochrome binding, and O2 consumption is correspondingly altered. Studies with various antioxidants and inhibitors suggest that both free radicals and singlet oxygen may be involved in the process under study.     

Indo-Pacific and Atlantic spurs and grooves revisited: the possible effects of different Holocene sea-level history,exposure, and reef accretion rate in the shallow fore reef

Shallow fore-reef areas worldwide are usually characterized by spurs and grooves. A comparison of examples from the three world oceans suggests that Indo-Pacific spurs and grooves are shaped predominantly by erosion, whereas western Atlantic spur and groove systems are largely a product of constructive processes. I propose that this difference is caused by regional differences in Holocene sea-level change, which controlled exposure to waves and currents, and reef-accretion rates. The transgressive–regressive sea-level curve in the Indo-Pacific realm, i.e., the Mid-to-Late Holocene sea-level fall in these areas has maintained high-energy conditions in the shallow fore reef. Higher exposure to waves and currents favors erosion and leads to a dominance of crustose coralline algae that have relatively slow growth rates. In the western Atlantic, the transgressive Holocene sea level has caused Mid-to-Late Holocene deepening and has maintained accommodation space for reef accretion. Fast-growing acroporid corals thrive under lower exposure and are more common than coralline algae. The fossil record of the spur and groove system is rather poor, which is probably a consequence of the need of excellent, three-dimensional outcrops for identification.     

Tropical Vine Growth and the Effects on Forest Succession: A Review of the Ecology and Management of Tropical Climbing Plants

The climbing habit has evolved independently in many plant taxa, offering vines the ability to compete with non-climbing vegetation for resources such as light, nutrients, and water. This review examines the structural and functional characteristics that allow climbing plants to (1) achieve widespread dispersal, (2) transport large amounts of water throughout vessels, (3) maintain high photosynthesis levels through a large leaf area to biomass ratio, (4) achieve rapid vertical and horizontal expansion by fast growth rates and various climbing mechanisms and (5) survive and recover from disturbances. Due to the competitive effects of vines on trees, management of vine growth is used to preserve tropical timber plantations, combat invasive weeds, and promote rainforest recovery. In order to sustainably manage the vines into the future, it is necessary to understand the mechanisms by which they can alter tropical forest succession and the impacts of various management techniques.     

Glycosyl conjugates of biotinylated diaminopyridine applied for study of carbohydrate-to-carbohydrate interaction

Previous studies by us and others established that cell-cell adhesion is mediated by specific carbohydrate-to-carbohydrate interaction (CCI). Those previous studies were based on various biochemical and biophysical approaches, including the use of labeled glycosyl epitopes with fluorescent tag. However, these methods ideally require that the glycosyl epitope must be fixed to a solid phase molecule, preferably with multivalency. The purpose of the present study is to establish a CCI process using specific glycosyl residues conjugated to biotinylated diaminopyridine (BAP), and to observe: (i) clear occurrence of homotypic CCI between “Os Fr.B” having 5–6 GlcNAc termini, vs. absence of such homotypic CCI between “Os Fr.1” having 2 GlcNAc termini; (ii) occurrence of heterotypic CCI between GM3 ganglioside and Os Fr.B, vs. absence of such heterotypic CCI between GM3 and Os Fr.1. Interaction between Os Fr.B-BAP conjugate and Os Fr.B-ceramide mimetic (Os Fr.B-mCer) was demonstrated based on two experiments: (i) dose-dependent binding of Os Fr.B-BAP conjugate to polystyrene plates coated with Os Fr.B-mCer was observed in the presence of bivalent cation, a prerequisite for all CCI processes, and such binding was abolished by EDTA; (ii) binding between equal nanomolar Os Fr.B-BAP and Os Fr.B-mCer was inhibited by mM concentration Os Fr.B without conjugate, in dose-dependent manner. Thus, cell adhesion processes based on homotypic CCI between N-linked glycans having multiple GlcNAc termini, and heterotypic CCI between GM3 and such glycans, were clearly observed using BAP conjugates of glycosyl epitopes.     

Using diffusion distances for flexible molecular shape comparison

Background  

Many molecules are flexible and undergo significant shape deformation as part of their function, and yet most existing molecular shape comparison (MSC) methods treat them as rigid bodies, which may lead to incorrect shape recognition.     

Factors associated with whole carcass condemnation rates in provincially-inspected abattoirs in Ontario 2001-2007: implications for food animal syndromic surveillance

Background  

Ontario provincial abattoirs have the potential to be important sources of syndromic surveillance data for emerging diseases of concern to animal health, public health and food safety. The objectives of this study were to: (1) describe provincially inspected abattoirs processing cattle in Ontario in terms of the number of abattoirs, the number of weeks abattoirs process cattle, geographical distribution, types of whole carcass condemnations reported, and the distance animals are shipped for slaughter; and (2) identify various seasonal, secular, disease and non-disease factors that might bias the results of quantitative methods, such as cluster detection methods, used for food animal syndromic surveillance.     

Estimation of transport distance of fine particulate organic matter in relation to channel morphology in tailwaters of the Lake Biwa and reservoir dams

Knowledge on transport and deposition of fine particulate organic matter (FPOM) from reservoir dams is increasingly required for habitat management and restoration of dam tailwater ecosystems. Variations in the transport distance of FPOM, however, have never been studied well, particularly in relation to channel morphology, due to channel size restrictions of artificial tracers such as corn pollen when applied to larger river channels. This study aims to show the relations between FPOM retention efficiency and channel morphology in dam tailwaters using lentic plankters as tracers. We estimated the mean transport distance, S _p, by calculating downstream reduction ratios of lentic tracer plankters and calculated the deposition velocity, v _dep. Suspended FPOM samples were collected in tailwaters of two river channels below reservoir dams and two artificial canals below Lake Biwa in the Yodo River system. The longest S _p (19.2 km) and the shortest one (2.2 km) were recorded in the deep canal and shallow canal, respectively, showing a positive correlation with channel hydraulic radius. The values of v _dep were 4.7–6.4 times higher in river channels than in artificial canals. These results indicate that increasing complexity of bed morphology can minimize S _p, whereas bed degradation and armored bed materials may lead to increased S _p. Advantages of lentic plankters as tracers for estimating distance ranges of reservoir dam impact on river ecosystems are also discussed.     

Viral and Bacterial Pathogens in Bovine Respiratory Disease in Finland

Pathogens causing bovine respiratory tract disease in Finland were investigated. Eighteen cattle herds with bovine respiratory disease were included. Five diseased calves from each farm were chosen for closer examination and tracheobronchial lavage. Blood samples were taken from the calves at the time of the investigation and from 86 calves 3–4 weeks later. In addition, 6–10 blood samples from animals of different ages were collected from each herd, resulting in 169 samples. Serum samples were tested for antibodies to bovine parainfluenza virus-3 (PIV-3), bovine respiratory syncytial virus (BRSV), bovine coronavirus (BCV), bovine adenovirus-3 (BAV-3) and bovine adenovirus-7 (BAV-7). About one third of the samples were also tested for antibodies to bovine virus diarrhoea virus (BVDV) with negative results. Bacteria were cultured from lavage fluid and in vitro susceptibility to selected antimicrobials was tested. According to serological findings, PIV-3, BAV-7, BAV-3, BCV and BRSV are common pathogens in Finnish cattle with respiratory problems. A titre rise especially for BAV-7 and BAV-3, the dual growth of Mycoplasma dispar and Pasteurella multocida, were typical findings in diseased calves. Pasteurella sp. strains showed no resistance to tested antimicrobials. Mycoplasma bovis and Mannheimia haemolytica were not found.