Formyl peptide receptor 2 orchestrates mucosal protection against Citrobacter rodentium infection.

Citrobacter rodentium is an attaching and effacing intestinal murine pathogen which shares similar virulence strategies with the human pathogens enteropathogenic- and enterohemorrhagic Escherichia coli to infect their host. C. rodentium is spontaneously cleared by healthy wild-type (WT) mice whereas mice lacking Muc2 or specific immune regulatory genes demonstrate an impaired ability to combat the pathogen. Here we demonstrate that apical formyl peptide receptor 2 (Fpr2) expression increases in colonic epithelial cells during C. rodentium infection. Using a conventional inoculum dose of C. rodentium, both WT and Fpr2-/- mice were infected and displayed similar signs of disease, although Fpr2-/- mice recovered more slowly than WT mice. However, Fpr2-/- mice exhibited increased susceptibility to C. rodentium colonization in response to low dose infection: 100% of the Fpr2-/- and 30% of the WT mice became colonized and Fpr2-/- mice developed more severe colitis and more C. rodentium were in contact with the colonic epithelial cells. In line with the larger amount of C. rodentium detected in the spleen in Fpr2-/- mice, more C. rodentium and enteropathogenic Escherichia coli translocated across an in vitro mucosal surface to the basolateral compartment following FPR2 inhibitor treatment. Fpr2-/- mice also lacked the striated inner mucus layer that was present in WT mice. Fpr2-/- mice had decreased mucus production and different mucin O-glycosylation in the colon compared to WT mice, which may contribute to their defect inner mucus layer. Thus, Fpr2 contributes to protection against infection and influence mucus production, secretion and organization.

Interleukin 4 induces rapid mucin transport, increases mucus thickness and quality and decreases colitis and Citrobacter rodentium in contact with epithelial cells.

Citrobacter rodentium infection is a murine model for pathogenic intestinal Escherichia coli infection. C. rodentium infection causes an initial decrease in mucus layer thickness, followed by an increase during clearance. We aimed to identify the cause of these changes and to utilize this naturally occurring mucus stimulus to decrease pathogen impact and inflammation. We identified that mucin production and speed of transport from Golgi to secretory vesicles at the apical surface increased concomitantly with increased mucus thickness. Of the cytokines differentially expressed during increased mucus thickness, IFN-γ and TNF-α decreased the mucin production and transport speed, whereas IL-4, IL-13, C. rodentium and E. coli enhanced these aspects. IFN-γ and TNF-α treatment in combination with C. rodentium and pathogenic E. coli infection negatively affected mucus parameters in vitro, which was relieved by IL-4 treatment. The effect of IL-4 was more pronounced than that of IL-13, and in wild type mice, only IL-4 was present. Increased expression of Il-4, Il-4-receptor α, Stat6 and Spdef during clearance indicate that this pathway contributes to the increase in mucin production. In vivo IL-4 administration initiated 10 days after infection increased mucus thickness and quality and decreased colitis and pathogen contact with the epithelium. Thus, during clearance of infection, the concomitant increase in IL-4 protects and maintains goblet cell function against the increasing levels of TNF-α and IFN-γ. Furthermore, IL-4 affects intestinal mucus production, pathogen contact with the epithelium and colitis. IL-4 treatment may thus have therapeutic benefits for mucosal healing.

Brainstem anesthesia presenting as contralateral third nerve palsy following peribulbar anesthesia for cataract surgery.

Brainstem anesthesia is a serious complication that has been reported to occur more commonly with retrobulbar anesthesia compared to peribulbar anesthesia. We herein report a case of contralateral third nerve palsy following administration of peribulbar anesthesia for cataract surgery. Two hours after the surgery, the patient recovered completely without any residual neurological deficit. The importance of immediate recognition of clinical signs and symptoms of central spread of the local anesthetic and the mechanical factors of the block that could have contributed to this complication are discussed in this report.

Hepatoprotective activity of methanolic extract of Syzygium jambos (Linn.) leaf against paracetamol intoxicated Wistar albino rats.

Hepatoprotective activity of methanolic extract of Syzygium jambos (Alston) (Linn.) leaves against Paracetamol-induced hepatic damage in Wistar albino rats was observed at two different doses, 100 and 200 mg/kg body weight. The healthy control, disease control, and standard drug Silymarin-treated groups were also maintained for the comparison. The liver marker enzymes SGOT, SGPT, ALKP, Serum Bilirubin and other metabolic parameters like total cholesterol, HDL-cholesterol were evaluated in all the experimental groups. The changes in liver function parameters were significant in comparison to disease control group and the observed efficacy was comparable to standard drug. The efficacy of the extract was found to be dose dependent. The histopathology study of liver also supports the presence of hepatoprotective activity in S. jambos by showing improved cytoarchitecture of liver cells in the treated groups. The results obtained in this study indicate necessity for further research on isolation and characterization of functional molecules from the extract.

Antioxidant and tumor cell suppression potential of premna serratifolia linn leaf.

Herbal and natural products have been used in folk medicine for centuries throughout the world. There has been renewed interest in screening higher plants for novel biologically active compounds, particularly those that effectively intervene in human ailments in the field of chronic diseases. The present study has been taken up to evaluate the free radical scavenging activity and tumor cell suppression potential of Premna serratifolia leaf in various in vitro model systems. The methanolic extract of P. serratifolia leaf was obtained by soxhlet extraction method. The superoxide radical scavenging activity, nitric oxide radical, hydroxyl radical, DPPH radical and ABTS radical scavenging activity and lipid peroxidation were determined. The tumor cell suppression cell potential was determined in three different cancer cell lines MCF7 (breast cancer), HepG2 (liver cancer) and A549 (lung cancer) by SRB assay. The study showed that the methanolic extract of P. serratifolia was having free radical scavenging activity against superoxide radical, nitric oxide radical, hydroxyl radical, DPPH radical, ABTS radical and inhibition of lipid peroxidation. The IC50 value showed the efficacy was dose dependent. The test extract showed cytotoxic activity against MCF7, HepG2 and A549 cells. The GI50, TGI and LC50 values were determined against each cell line and compared with standard drug Adriamycin. The present study proved the free radical scavenging activity and tumor cell suppression potential of P. serratifolia leaf in the selective in vitro model systems. The further study has to be carried out in the aspects of isolation of functional molecules of the extract.

Withanolide induces apoptosis in HL-60 leukemia cells via mitochondria mediated cytochrome c release and caspase activation.

The present study is on the growth inhibitory effect of Withania somnifera methanolic leaf extract and its active component, withanolide on HL-60 promyelocytic leukemia cells. The decrease in survival rate of HL-60 cells was noted to be associated with a time dependent decrease in the Bcl-2/Bax ratio, leading to up regulation of Bax. Both the crude leaf extract and the active component activated the apoptotic cascade through the cytochrome c release from mitochondria. The activation of caspase 9, caspase 8 and caspase 3 revealed that caspase was a key mediator in the apoptotic pathway. DNA fragmentation analysis revealed typical ladders as early as 12h indicative of caspase 3 role in the apoptotic pathway. Flow cytometry data demonstrated an increase of sub-G1 peak upon treatment by 51% at 24h, suggesting the induction of apoptotic cell death in HL-60 cells.

Determination of the radiation dose from administered apolipoprotein tracers in humans.

Radioactive tracers are routinely used in investigation of the metabolism of apolipoprotein kinetics. Here, metabolic studies of apolipoprotein tracers labeled with radioiodine were analyzed to determine the absorbed radiation dose received by the subject. This analysis used compartmental modeling techniques to evaluate the radiation dose to various organs and the total body resulting from radioiodinated tracer injection. In this approach, we combined the published kinetic models of iodine and those of specific apolipoproteins. From the solution of the integrated compartmental models, residence times of the radiation in various source organs, in particular the thyroid, whole body, bladder, and red bone marrow, have been determined for the apolipoproteins apoA-I, apoA-II, very-low-density lipoprotein (VLDL)-apoB, and low-density lipoprotein (LDL)-apoB, each labeled with iodine 123, 133, 124, 131, 126, and 125. These tabulated values were used to calculate radiation doses to the different target organs. The thyroid is the organ that receives the largest dose of delivered radiation, and the importance of the duration of administration of iodine salts in blocking radiation to the thyroid is demonstrated. Optimal block times of 28 days for 131I and 42 days for 125I-labeled apolipoprotein tracers are proposed. When such a protocol is followed, the radiation dose to the thyroid and other organs is small by comparison to radiation doses allowed for workers whose occupation exposes them to radiation. The importance of frequent voiding to reduce the radiation dose to the bladder has also been demonstrated.

The 3H-leucine tracer: its use in kinetic studies of plasma lipoproteins.

3H-leucine administered as a bolus has been widely used as a tracer in kinetic investigations of protein synthesis and secretion. After intravenous injection, plasma specific radioactivity decays over several orders of magnitude during the first half-day, followed by a slow decay lasting a number of weeks that results from recycling of the leucine tracer as proteins are degraded and 3H-leucine reenters the plasma pool. In studies in which kinetic data are analyzed by mathematical compartmental modeling, plasma leucine activity is generally used as a forcing function to drive the input of 3H-leucine into the protein synthesis pathway. 3H-leucine is an excellent tracer during the initial hours of rapidly decreasing plasma activity; thereafter, reincorporation of recycled tracer into new protein synthesis obscures the tracer data from proteins with slower turnover rates. Thus, for proteins such as plasma albumin and apolipoprotein (apo) A-I, this tracer is unsatisfactory for measuring fractional catabolic (FCR) and turnover rates. By contrast, the kinetics of plasma very-low-density lipoprotein (VLDL)-apoB, a protein with a residence time of approximately 5 hours, are readily measured, since kinetic parameters of this protein can be determined by the time plasma leucine recycling becomes established. However, measurement of VLDL-apoB specific radioactivity extending up to 2 weeks provides further data on the kinetic tail of VLDL-apoB. Were plasma leucine a direct precursor for the leucine in VLDL-apoB, the kinetics of the plasma tracer should determine the kinetics of the protein. However, this is not the case, and the deviations from linearity are interpreted in terms of (1) the dilution of plasma leucine in the liver by unlabeled dietary leucine; (2) the recycling of hepatocellular leucine from proteins within the liver, where recycled cellular leucine does not equilibrate with plasma leucine; and (3) a "hump" in the kinetic data of VLDL-apoB, which we interpret to reflect recycling or retention of a portion of the apoB protein within the hepatocyte, with its subsequent secretion. Because hepatocellular tRNA is the immediate precursor for synthesis of these secretory proteins, its kinetics should be used as the forcing function to drive the modeling of this system. The VLDL-apoB tail contains the information needed to modify the plasma leucine data, to provide an appropriate forcing function when using 3H-leucine as a tracer of apolipoprotein metabolism. This correction is essential when using 3H-leucine as a tracer for measuring low-density lipoprotein (LDL)-apoB kinetics. The 3H-leucine tracer also highlights the importance of recognizing the difference between plasma and system residence times, the latter including the time the tracer resides within exchanging extravascular pools. The inability to determine these fractional exchange coefficients for apoA-I and albumin explains the failure of this tracer in kinetic studies of these proteins. For apoB-containing lipoproteins, plasma residence times are generally determined, and these measurements can be made satisfactorily with 3H-leucine.

Kinetic evidence for both a fast and a slow secretory pathway for apolipoprotein A-I in humans.

The kinetics of apolipoproteins A-I and A-II were examined in human subjects using leucine tracers administered intravenously. High density lipoproteins were separated and apoA-I and A-II were isolated. The specific activity or enrichment data for these apolipoprotein were analyzed by mathematical compartmental modeling. In 11 of 14 subjects studied with a bolus-injected [3H]leucine tracer, in 3 subjects studied similarly with [3H]leucine, and in one subject studied by primed dose, constant infusion of [3H]leucine, a rapidly turning-over apoA-I fraction was resolved. A similar component was observed in 7 of 10 studies of apoA-II. The apoA-I data were analyzed using a compartmental model (Zech, L.A. et al. 1983. J. Lipid Res. 24: 60-71) modified to incorporate plasma leucine as a precursor for apoprotein synthesis. The data permitted resolution of two apoA-I pools, one, C(2), turned-over with a residence time of less than 1 day, the other, C(1), a slowly turning-over pool, appeared in plasma after a delay of less than half a day. C(1) comprised the predominant mass of apoA-I and was also the primary determinant of the residence time of apoA-I. Although the mass of the fast pool, C(2), was considerably less than that of C(1), because of its rapid turnover, the quantities of apoA-I transported through this fast pathway were 2- to 4-fold greater. These kinetic studies indicate that apoA-I is secreted into both fast and slowly turning-over plasma pools. The latter is predominantly measured with radioiodinated apoA-I tracers. The data can be analyzed by postulating either separate input pathways to each of the pools or by assuming the fast pool is the precursor to the slow pool. Thus, apoA-I could be initially secreted as a family of particles that are rapidly cleared from plasma, and a portion of this apoprotein then reappears in a slowly turning-over pool that constitutes the major mass of apoA-I. The physiologic identity of these kinetically distinct apoA-I species is unknown; however, the fast pool of apoA-I demonstrated in these studies is strikingly similar to that seen in subjects with Tangier disease who lack the slow pool.

Serendibite, a complicated, new, inorganic crystal structure.

Serendibite with very similar analyses is known from Ceylon and New York. The triclinic cell of symmetry P[unk] and volume 670.9 A(3) contains 2Ca(1.64)Mg(2.64)Fe(0.27) (II)Al(4.64)B(1.66)Si(3)O(20), with 14 metal atoms and 20 oxygen atoms in the asymmetric unit. It was solved by the "direct" method of transforming the ordinary three-dimensional Patterson function into an approximation of the electron density by using conjugate peaks and minimum functions, followed by successive Fourier syntheses and least-squares refinement to R = 7.1%. This new structure is composed of interrupted brucite-type layers which form an octahedral framework, and winged single chains of tetrahedra. The structure has units of similar, but not identical, geometry to those of the minerals sapphirine and aenigmatite, and these similar units are assembled in a different way.