Increased sialylation and defucosylation of plasma proteins are early events in the acute phase response

Within hours of turpentine injection to stimulate the acute phase (AP) response in rats, the N-acetylneuraminic acid content of plasma proteins increases and that of fucose decreases, each by about 60%. The two changes are inversely related (r = -0.97). The NeuAc/Gal ratio increases from the normal 0.75 to 1.0 on day 2 of the AP. Whereas 50% of the isolated oligosaccharides of normal plasma proteins are retarded on immobilized Ricinus communis agglutinin, those from day 2 AP plasma fail to do so. This indicates that NeuAc caps the normally Gal-terminated chains. alpha1-Acid glycoprotein (a positive AP protein), alpha1-macroglobulin (a non-AP protein), and alpha1-inhibitor3 (a negative AP protein) also show similar alterations in NeuAc/Gal ratio and decreases in Fuc. alpha2-Macroglobulin, which arises only during the AP, does not contain significant amounts of Fuc. Sambucus nigra agglutinin (alpha2,6-linked NeuAc-specific) binds a majority of plasma proteins, and binding is increased during the AP response. Maackia amurensis lectin (alpha2,3-linked NeuAc-specific) binds only three proteins in normal plasma and three additional proteins in AP plasma. The Fuc-specific Aleuria aurantia agglutinin and Lens culinaris agglutinin each detect five proteins in normal plasma. Their binding decreases during the AP response. These results show that: (1) sialylation and defucosylation of preexisting plasma proteins occur rapidly in the AP response; (2) sialylation caps the preexisting Gal-terminating oligosaccharides; and (3) the oligosaccharides of even the non-AP and negative AP proteins are modified. These changes are distinct from the elevation in the levels of protein-bound monosaccharides and the altered concanavalin A-binding profile the oligosaccharides of AP proteins acquire in diseases.     

On the status of the smut genus liroa cif.

Summary This paper embodies the results obtained through a critical examination of the taxonomic position of the gall-forming smut genusLiroa Cif. On the basis of these studies it is proposed to conserve the nameLiroa Cif. for this gallforming smut fungus. The formation of inverted lunate type of sori is a distinctive character of the genus separating it from the other smut genera. The chlamydospore formation in a centripetal fashion is characteristic of the family Ustilaginaceae and not Graphiolaceae.Part of the work submitted to the Poona University in fulfilment of Ph. D. degree, 1959, by the junior author.     

Tocotrienols from palm oil as effective inhibitors of protein oxidation and lipid peroxidation in rat liver microsomes

Tocotrienols from palm oil showed significant ability to inhibit oxidative damage induced by ascorbate-Fe2+ and photosensitization, involving different mechanisms, in rat liver microsomes. The tocotrienol-rich fraction from palm oil (TRF), being tried as a more economical and efficient substitute for -tocopherol, showed time- and concentration-dependent inhibition of protein oxidation as well as lipid peroxidation. It was more effective against protein oxidation. The extent of inhibition by TRF varied with different peroxidation products such as conjugated dienes, lipid hydroperoxides and thiobarbituric acid reactive substances (TBARS). Among the constituents of TRF, -tocotrienol was the most effective followed by its - and -isomers. In general, at a low concentration of 5 M, TRF was able to prevent oxidative damage to significant extent (37% inhibition of protein oxidation and 27–30% of lipid peroxidation at 1 h of incubation). The protective ability of TRF (30.1% at 5 M with TBARS formation) was significantly higher than that of the dominant form of vitamin E, -tocopherol (16.5% under same conditions). Hence our studies indicate that this fraction from palm oil can be considered as an effective natural antioxidant supplement capable of protecting cellular membranes against oxidative damage.     

Biocatalytic synthesis of acrylates in organic solvents and supercritical fluids: III. Does carbon dioxide covalently modify enzymes?

We have previously demonstrated that the activity of the lipase (Candida cylindracea) catalyzed transesterification reaction between methylmethacrylate and 2-ethylhexanol in supercritical carbon dioxide is comparatively low. In this article, we have investigated the same reaction in supercritical carbon dioxide with a special emphasis on determining the extent of any interaction between the enzyme and carbon dioxide. Transesterification reaction rates in hexane and supercritical carbon dioxide are compared at different temperatures. In supercritical carbon dioxide, temperature was found to have no significant effect on reaction rate in the range of 40 degrees to 55 degrees C. Above 55 degrees C, however, the reaction rate increased significantly as a function of temperature. It appears that carbon dioxide forms reversible complexes with the free amine groups on the surface of the enzyme. Direct evidence of modification was obtained using mass spectroscopy to detect the extent of modification of a pure protein. The kinetics of the reaction have been studied in hexane, and they obey a ping-pong bi-bi mechanism with inhibition by 2-ethylhexanol. The effect of bubbling carbon dioxide and/or fluoroform on the reaction rate in hexane at different temperatures suggests that the enzyme undergoes shear inactivation in hexane. (c) 1995 John Wiley & Sons, Inc.     

Postpartum depression and infant feeding practices in a low income urban settlement in Nairobi-Kenya

Background

Postpartum depression can compromise caregiving activities, including infant feeding practices, resulting in child malnutrition. The purpose of this study was to examine the effects of postpartum depression on infant feeding practices and malnutrition among women in an urban low income settlement in Nairobi-Kenya. We conducted a cross-sectional study based in Kariobangi North Health Centre in Nairobi County. The study sample included 200 mother-infant pairs visiting the Maternal and Child Health clinics for infant immunization at 6–14 weeks postpartum. We assessed postpartum depression using the Edinburgh Postpartum Depression Scale. Infant feeding practices were assessed based on World Health Organization infant and young child feeding guidelines. Nutritional status (weight for age) was ascertained using infants’ growth monitoring card (percentiles and z-score). We conducted logistic regression analyses to determine the relative odds of non-exclusive breast feeding and infant underweight among mothers with postpartum depression.

Results

The prevalence of PPD was 13.0% (95% CI 8.3–17.7%). Taking into account differences in socioeconomic status of depressed and non-depressed mothers, non-depressed mothers had a 6.14 (95% CI 2.45–13.36) times higher odds of practicing exclusive breastfeeding than mothers who were depressed. Mothers with PPD had a 4.40 (95% CI 1.91–11.93) time higher odds of having an underweight infant than mothers without depression.

Conclusions

This study contributes towards filling the knowledge gap regarding the adverse effects of postpartum depression on infant health in sub-Saharan Africa. We recommend more research on PPD using longitudinal designs to establish temporal ordering of these important public health problems and development of community-based interventions to address post-partum depression.

     

Age-dependent loss of hepatic SIRT1 enhances NLRP3 inflammasome signaling and impairs capacity for liver fibrosis resolution

Our studies indicate that the longevity factor SIRT1 is implicated in metabolic disease; however, whether and how hepatocyte-specific SIRT1 signaling is involved in liver fibrosis remains undefined. We characterized a functional link of age-mediated defects in SIRT1 to the NLRP3 inflammasome during age-related liver fibrosis. In multiple experimental murine models of liver fibrosis, we compared the development of liver fibrosis in young and old mice, as well as in liver-specific SIRT1 knockout (SIRT1 LKO) mice and wild-type (WT) mice. Liver injury, fibrosis, and inflammation were assessed histologically and quantified by real-time PCR analysis. In a model of hepatotoxin-induced liver fibrosis, old mice displayed more severe and persistent liver fibrosis than young mice during liver injury and after injury cessation, as characterized by inhibition of SIRT1, induction of NLRP3, infiltration of macrophages and neutrophils, activation of hepatic stellate cells (HSCs), and excessive deposition and remodeling of the extracellular matrix. Mechanistically, deletion of SIRT1 in hepatocytes resulted in NLRP3 and IL-1β induction, pro-inflammatory response, and severe liver fibrosis in young mice, mimicking the ability of aging to impair the resolution of established fibrosis. In an aging mouse model, chronic-plus-binge alcohol feeding-induced liver fibrosis was attenuated by treatment with MCC950, a selective NLRP3 inhibitor. NLRP3 inhibition ameliorated alcoholic liver fibrosis in old mice by repressing inflammation and reducing hepatocyte-derived danger signaling—ASK1 and HMGB1. In conclusion, age-dependent SIRT1 defects lead to NLRP3 activation and inflammation, which in turn impairs the capacity to resolve fibrosis during aging.     

Tet2 Rescues Age-Related Regenerative Decline and Enhances Cognitive Function in the Adult Mouse Brain

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Isolation of wildXanthomonas strains from agricultural produce, their characterization and potential related to polysaccharide production

One hundred fifty wild strains ofXanthomonas were isolated on five selective and nonselective media. The comparative effectivity of the five media has been discussed. Fifteen polysaccharide-producing strains shortlisted were identified up to species level. These were studied for polysaccharide production in shake flasks using YM media. The highest final yield of 21.3 g/L of the amount of carbon source supplied has been obtained in the optimum medium in shake-flask experiments fromXanthomonas campestris ICa-125 strain isolated from cabbage. Rheological properties of the exocellular polysaccharide (EPS) have been compared with standard xanthan. EPS fromX. campestris ICa-125 was found to be superior with respect to heat stability and effect of electrolytes as compared to standard xanthan.