Fibroblast growth factor enhances the interleukin-1-mediated chondrocytic protease release

The unfractionated macrophage-conditioned medium stimulates the chondrocytes to produce high levels of proteases. Purified IL-1 preparations exhibit significantly lower activity towards chondrocytes. This IL-1 mediated effect can be enhanced in presence of fibroblast growth factor, suggesting that other factors may collaborate with IL-1, in events leading to the cartilage destruction in vivo.     

Fluidity,permeability and antioxidant behaviour of model membranes incorporated with α-tocopherol and vitamin E acetate

Magnetic resonance studies reveal a marked difference between the binding of α-tocopherol and that of the corresponding acetate (vitamin E acetate) with dipalmitoylphosphatidylcholine (DPPC) vesicles. This is reflected in differences in the phase-transition curves of the DPPC vesicles incorporated with the two compounds, as well as in the ¹³C relaxation times and line widths. A model for the incorporation of these molecules in lipid bilayers has been suggested. α-Tocopherol binds strongly with the lipids, possibly through a hydrogen bond formation between the hydroxyl group of the former and one of the oxygen atoms of the latter. The possibility of such a hydrogen bond formation is excluded in vitamin E acetate, which binds loosely through the normal hydrophobic interaction. The model for lipid-vitamin interaction explains the in vitro decomposition of H₂O₂ by α-tocopherol. α-Tocopherol in conjuction with H₂O₂ can also act as a free-radical scavenger in the lipid phase. The incorporation of α-tocopherol and vitamin E acetate in DPPC vesicles enhances the permeability of lipid bilayers for small molecules such as sodium ascorbate.     

Glucose oxidase immobilized electrode for potentiometric estimation of glucose

Glucose oxidase has been immobilized onto a thin platinum strip, by co-crosslinking with bovine serum albumin and glutaraldehyde. The retention of redox characteristics of glucose oxidase has been verified by cyclic voltammetry. The activity of the immobilized enzyme reduces to a quarter of its value when the enzyme is in solution but improves when coimmobilized with 1 urea. The potentiometric response builds up and remains stable after 100 s. It is sensitive to the thickness of the immobilizing matrix, pH and temperature. An improvement in the performance of the electrode has been achieved by coimmobilizing 2 urea and metal ions such as Mg²⁺ and Mn²⁺. The presence of Cu has been proved to be detrimental. The electrode has been calibrated in the 0.1–5.0 mM glucose concentration range. It gives a stable response for more than 50 independent assays and can be stored for 60 days without significant loss of function.     

Characteristics of cellular immune responses to collagen type I or collagen type II

We have examined the murine cell-mediated immune (CMI) response to collagens type I (CI) and type II (CII) as measured by in vivo delayed-type hypersensitivity responses. We have verified the histopathology and kinetics of the cell-mediated immune responses. Predominant cell-mediated responses were obtained 7, 10, or 14 days following immunization. A presumed antibody-mediated reaction was observed at later times (e.g., greater than 21 days following immunization). The CMI responses to the collagens show a strain-dependent relationship. For CI, the CMI response profile shows H-2b greater than or equal to H-2k = H-2q much greater than H-2d. For bovine CII, the response profile is H-2d greater than H-2b = H-2k = H-2q; the chick CII response profile is H-2q = H-2k greater than H-2b = H-2d, and in limited testing, only the H-2q strain could generate murine CII-specific cell-mediated immune responses. The CII-specific CMI response is cross-reactive with CII from several species of animals, but not with CI. Further, the collagen-specific CMI response can be elicited with certain cyanogen-bromide fragments of bovine CII. Finally, our study also demonstrates that there is a non-H-2-linked locus(i) involved in the development of CII-induced arthritis.     

Risk factors of peripheral arterial disease: a case control study in Sri Lanka

Background

Peripheral artery disease (PAD) is an important global health problem and contributes to notable proportion of morbidity and mortality. This particular manifestation of systemic atherosclerosis is largely under diagnosed and undertreated. For sustainable preventive strategies in a country, it is mandatory to identify country-specific risk factors. We intended to assess the risk factors of PAD among adults aged 40–74 years.

Methods

This case control study was conducted in 2012–2013 in Sri Lanka. Seventy-nine cases and 158 controls in the age group of 40–74 years were selected for the study in order to have case to control ratio 1:2. The criterion for selecting cases and control was based on Ankle brachial pressure index (ABPI). Cases were selected from those who had ABPI 0.85 or less (ABPI ≤0.85) in either lower limb. Controls were selected from those ABPI score between 1.18 and 1.28 in both lower limbs. Only newly identified individuals with PAD were selected as cases. Controls were selected from the same geographical location and within the 5 year age group as cases.

Results

The history of diabetes mellitus more than 10 years (OR 5.8, 95% CI 2.2–14.2), history of dyslipidemia for more than 10 years (OR 4.9, 95% CI 2.1–16.2), history of hypertension for more than 10 years (OR 3.8, 95% CI 1.8–12.7) and smoking (OR 2.9, 95% CI 1.2–6.9), elevated HsCRP (OR 3.7, 95% CI 1.2–12.0) and hyperhomocysteinemia (OR 3.0, 95% CI 1.1–8.1) were revealed as country specific significant risk factor of PAD.

Conclusions

Diabetes mellitus, hypertension, dyslipidemia, smoking as well as elevated homocysteine and HsCRP found as risk factors of PAD. Longer the duration or higher level exposure to these risk factors has increased the risk of PAD. These findings emphasis the need for routine screening of PAD among patients with the identified risk factors.

     

The role of fish-poultry integration on fish growth performance,yields and economic benefits among smallholder farmers in sub-Saharan Africa,Tanzania

Aquaculture practices from sub-Saharan Africa are characterised by low production, owing to improper technology. Production can be increased through integrating fish farming with other existing on-farm activities, particularly livestock husbandry. We assessed the role of fish-poultry integration on all male Nile tilapia, Oreochromis niloticus growth performance, yields and economic benefits among smallholder farmers in sub-Saharan Africa, Tanzania. The study also compared phytoplankton species composition, abundance and biomass between the fish-poultry integration and non-integrated system. After 180 days of the experiment, all male O. niloticus cultured under fish-poultry integration exhibited significantly higher growth rates than those in the non-integrated system (p < 0.05). Gross fish yield (GFY), net fish yield (NFY) and net annual yields (NAY) obtained from fish-poultry integration were significantly higher than those from non-integrated system (p < 0.05). Partial enterprise budget analysis revealed that fish-poultry integration was more profitable than the non-integrated system. Moreover, fish-poultry integrated system produced significantly higher phytoplankton abundance and biomass than those from the non-integrated system. Results demonstrate that rural smallholder farmers can achieve higher growth rate, farm net yields and income by integrating all male O. niloticus with other on-farm activities than practising a stand-alone fish culture system.     

A novel steroidal spin label for membrane structure studies: synthesis and applications

2,2,6,6-Tetramethyl piperidine-N-oxyl nitroxyls are known to partition between aqueous and lipid phases, thus serving as probes to study membrane dynamics. The synthesis of a novel steroidal spin label, 3alpha-hydroxycholan-24-yl-(2",2",6",6"-tetramethyl-N-oxyl)p iperidyl butan-1',4'-dioate, containing 2,2,6,6-tetramethylpiperidine-N-oxyl moiety covalently bonded to the side chain in 3,24-caprostan-diol has been described. The localization of this spin label in model biomembranes has been studied by using electron spin resonance, differential scanning calorimetry, and 1H and 31P NMR spectroscopic techniques. Its applicability in studying the phase transition properties of model membrane L-alpha-dipalmitoyl phosphatidyl choline in the presence and absence of drugs has been described by using electron spin resonance. The label has also been used to study the permeability of epinephrine into membrane. The results have shown the applicability of the spin label as a potential spin probe in the study of biomembranes.     

Proteomic screening and identification of differentially distributed membrane proteins in Escherichia coli

Bacteria show asymmetric subcellular distribution of many proteins involved in diverse cellular processes such as chemotaxis, motility, actin polymerization, chromosome partitioning and cell division. In many cases, the specific subcellular localization of these proteins is critical for proper regulation and function. Although cellular organization of the bacterial cell clearly plays an important role in cell physiology, systematic studies to uncover asymmetrically distributed proteins have not been reported previously. In this study, we undertook a proteomics approach to uncover polar membrane proteins in Escherichia coli. We identified membrane proteins enriched in E. coli minicells using a combination of two-dimensional electrophoresis and mass spectrometry. Among a total of 173 membrane protein spots that were consistently detected, 36 spots were enriched in minicell membranes, whereas 15 spots were more abundant in rod cell membranes. The minicell-enriched proteins included the inner membrane proteins MCPs, AtpA, AtpB, YiaF and AcrA, the membrane-associated FtsZ protein and the outer membrane proteins YbhC, OmpW, Tsx, Pal, FadL, OmpT and BtuB. We immunolocalized two of the minicell-enriched proteins, OmpW and YiaF, and showed that OmpW is a bona fide polar protein whereas YiaF displays a patchy membrane distribution with a polar and septal bias.