TNF-alpha-dependent ICAM-1- and VCAM-1-mediated inflammatory responses are delayed in neonatal mice infected with Pneumocystis carinii

Neonatal mice have a delayed CD4-mediated inflammatory response to Pneumocystis carinii (PC) infection in the lungs that corresponds to a delayed TNF-alpha response and a delayed clearance of the organisms compared with adult mice. Since TNF-alpha is known to drive the up-regulation of adhesion molecules, we examined the expression and function of adhesion molecules in the lungs of neonatal mice. The expression of both ICAM-1 and VCAM-1 was significantly lower in the lungs of PC-infected neonatal mice compared with adults. Additionally, migration of neonatal T cells across endothelial cells expressing VCAM-1 and monocyte chemotactic protein-1 was aberrant compared with that in adult T cells, although alpha(4)beta(1) integrin-mediated adhesion of neonatal lymphocytes was comparable to that of adult lymphocytes. Treatment of neonatal mice with exogenous TNF-alpha resulted in increased expression of ICAM-1 and VCAM-1 as well as increased expression of chemokines, resulting in infiltration of CD4(+) cells into the lungs. Treatment with exogenous TNF-alpha resulted in a trend (although not statistically significant) toward a reduction of PC organisms from the lungs. These data indicate that neonatal lung endothelial cells do not up-regulate ICAM-1 and VCAM-1 in response to PC infection, probably due to depressed TNF-alpha production. Additionally, neonatal T cells are defective in the ability to migrate across endothelial cells.     

Investment into Human Risks in Railways and Decision Optimization

ABSTRACT

The Life Quality Index (LQI) is a rational way to establish a relationship among the resources utilized to improve human safety and the expected fatalities that can be avoided by safety improvement. This article uses the LQI approach to quantify the social benefits of a number of safety management plans for a railway facility such as level crossing (LC). We apply influence diagrams (IDs), which are the extensions of Bayesian Networks, to model and assess the life safety risks. In IDs, problems of probabilistic inference, economics-based utility values, and decision alternatives are combined and optimized. The optimal decision, which maximizes total benefits to society, is obtained for the LC. As low as reasonably practicable (ALARP) case, and is a widely accepted risk acceptance criteria in the railway industry. According to the ALARP, there exists a so-called tolerable region between the regions of intolerable and negligible risks. In the tolerable region, risk is undertaken only if a benefit is desired. To quantify socioeconomic benefits, one needs to have an additional risk acceptance criterion such as LQI. In this article we apply and discuss the advantages of the LQI and the IDs for a number of safety management plans for railway LCs.     

Genetic diversity in tilapia populations in a freshwater reservoir assayed by randomly amplified polymorphic DNA markers

Genetic variation in fish stocks decreasing due to water pollution in the freshwater rivers, streams and canals. The objective of this study was to determine the genetic diversity and polymorphism in Oreochromis niloticus collected from the Wadi Hanefah Riyadh, Saudi Arabia by using RAPD-PCR. Total thirty fish specimens were harvested from each of four pre-determined locations of the reservoir which were designated as H1, H2, H3, and H4. Five random decamer primers were used to assess the diversity in the stock of O. niloticus. In this fish stock 48 bands were polymorphic and 12 were monomorphic. The maximum polymorphism (100%) was recorded in the fish samples procured from H4, followed by 88.75, 87.33 and 76.12% of the tilapia collected from H3, H2, and H4, respectively. Nei’s genetic distance value was ranged as 0.0005 to 0.1006. Maximum and minimum genetic distance was recorded as 0.1006 and 0.005 in tilapia harvested from H1 and H2 locations. Average heterozygosity was ranged from 0.3009 to 0.3744. This information about the genetic polymorphism of O. niloticus may be used by the concerned authorities to evolve strategies to conserve the diversity of tilapia in the country.     

Leaf anatomical characters in relation to the C3 and C4 photosynthetic pathway in Cyperus (Cyperaceae)

Leaf anatomical characters of twelve species from the genus Cyperus, a genus known to contain species with both C₃ and C₄ plants, have been investigated. We investigated and established the usefulness of all‐inclusive functional leaf anatomical characters for identifying the photosynthetic pathways of these species. The species investigated were C. articulatus L., C. compressus L., C. difformis L., C. dilatatus Schum. & Thonn., C. distans L., C. esculentus L., C. haspan L., C. imbricatus Retz., C. iria L., C. rotundus L., C. sphacelatus Rottb. and C. tenuiculmis (Boeck.) Hooper, collected from locations in southwestern Nigeria. Standard anatomical procedures for examining epidermal and cross sections of leaves were employed. Our data suggested that a combination of characters, such as the occurrence of Kranz tissue, maximum cell distant count, maximum lateral cell count, interveinal distance, and to some extent leaf and mesophyll thickness, provide a reliable basis for the assessment of the photosynthetic pathways of the investigated species as compared to the isolated characters used previously. The study indicate that C. difformis and C. haspan are C₃ species while the rest follow the C₄ photosynthetic pathway. A salient feature of this study is the identification of C. dilatatus as belonging to the C₄ group.     

Kinetics of propylene glycol elimination and metabolism in rat

The kinetics of 1,2-propanediol (PD) metabolism in vivo have been determined by employing the Michaelis-Menten rate equation; it was found that maximum metabolizing capacity was 8.33 mmole PD/kg/hr in the rat, which is equivalent to 1.06 kg/day for an average 70-kg human. The rate equation could be suitably used for optimizing the dosage schedule of a drug from the linear elimination pattern; in the present case this gave a Km value of 17.86 mmole/kg on the basis of the elimination rate of PD. The competitive inhibition of PD elimination by preadministration of pyrazole (Ki = 44 mumole/kg) demonstrated that the first step of the biotransformation of PD catalyzed by the NAD-dependent dehydrogenase might be the rate-limiting step for its in vivo metabolism. The low threshold level of the compound and significant rate of metabolism suggested that the CNS toxicity reported in clinical studies might be due to some of its metabolites such as lactaldehyde and other oxo compounds. Thus, PD could not be considered as an inert and innocuous substance.     

Differential effect of Cryptococcus neoformans on the production of IL-12p40 and IL-10 by murine macrophages stimulated with lipopolysaccharide and gamma interferon

In the present study, we examined the in vitro effect of Cryptococcus neoformans on the production of interleukin-12 (IL-12) and IL-10 by murine macrophages. At a dose of 1 x 10(5), 1 x 10(6) or 1 x 10(7) ml-1, a highly virulent strain of C. neoformans (strain YC-11) suppressed the production of IL-12p40 by a murine macrophage cell line, J774.1 stimulated with lipopolysaccharide (LPS) and interferon (IFN)-gamma, while the production of IL-10 was not inhibited, but rather slightly augmented. The suppression of IL-12p40 production did not change by neutralizing anti-IL-10 mAb. A direct contact of C. neoformans with macrophages was largely involved in this inhibitory effect, since placement of a 0.45 micron pore membrane between the organism and macrophages prevented such effect. On the other hand, the culture supernatant of YC-11 did not inhibit macrophage IL-12p40 production when used at a lower dose, which contained an equivalent amount of capsular polysaccharide to that in the supernatant of YC-11 cultured at 1 x 10(5) or 1 x 10(6) ml-1, although it showed a small suppression at higher doses. Our results suggest that C. neoformans may suppress the induction of Th1 responses by inhibiting macrophage IL-12 production predominantly through a direct contact-dependent mechanism and to a lesser extent by a certain soluble factor(s) released from this microorganism.     

Identification and biochemical characterisation of α-amylase in the alimentary tract of Mediterranean fruit fly,Ceratitis capitata (Wiedemann) (Diptera: Tephritidae)

Mediterranean fruit fly (Medfly), Ceratitis capitata, is an important pest of many fruit crops in temperate and subtropical regions worldwide. α-Amylases are hydrolytic enzymes involved in carbohydrate metabolism in insects. There is no report about α-amylase activity in C. capitata in literature. So, the aim of the current study was biochemical characterisation of α-amylase in the alimentary canal of the pest to gain a better understanding of digestive physiology of the insect. α-Amylase of Medfly was extracted and characterised using starch as the substrate. The results showed the presence of α-amylase activity in the gut of the insect for carbohydrate digestion. Optimum activity of the enzyme occurs at pH 8.0 and 40?°C. The most effective activator of the enzyme was determined in treatment with 20?mM CaCl₂. Na⁺, K⁺ and Mg²⁺ ions also activated the enzyme. Native PAGE of α-amylase showed two isoenzymes suggesting the importance of α-amylase in the carbohydrate digestion in the insect. Understanding of the digestive physiology and α-amylase activity of Medfly is important when new management strategies for this economically important pest are devised.     

Onset of hepatic erythropoiesis after malarial infection in mice

Plasmodium yoelii-infected erythrocytes were injected into mice with or without 6.5 Gy irradiation. This irradiation suppressed erythropoiesis and induced severe immunosuppression. However, these mice showed a rather delayed infection, suggesting that fresh erythrocytes may become malarial targets. In other words, malarial infection did not persist without newly generated erythrocytes in mice. We then examined erythropoiesis in the liver and bone marrow of mice with malaria. Surprisingly, erythropoiesis began in the liver. At this time, the serum level of erythropoietin (EPO) was prominently elevated and the EPO mRNA also became detectable in the kidney. Many clusters of red blood cells appeared de novo in the parenchymal space of the liver. These results revealed that malarial infection had a potential to induce the onset of hepatic erythropoiesis in mice.     

Gamma radiation induced mutagenesis in <Emphasis Type="Italic">Aspergillus niger</Emphasis> to enhance its microbial fermentation activity for industrial enzyme production

α- and β-Galactosidases find application in food processing, health and nutrition. Aspergillus niger is one of the potent producer of these enzymes and was genotypically improved using gamma-ray induced mutagenesis. The mutant-derivative produced two-fold higher α- and β-galactosidases. For testing genetic variability and its relationship with phenotypic properties of the two organisms, DNA samples of the mutant and parental strains of A. niger were amplified with 28 deca-nucleotide synthetic primers. RAPD analysis showed significantly different pattern between parental and mutant cultures. The mutant derivative yielded homogeneous while parental strain formed heterogeneous amplification patterns. Seven primers identified 42.9% polymorphism in the amplification products, indicating that these primers determined some genetic variability between the two strains. Thus RAPD was found to be an efficient technique to determine genetic variability in the mutant and wild organisms. Both wild and mutant strains were analyzed for their potential to produce galactosidases. Comparison of different carbon sources on enzyme yield revealed that wheat bran is significant (P < 0.01) effective producer and economical source followed by rice bran, rice polishing and lactose. The mutant was significantly better enzyme producer and could be considered for its prospective application in food, nutrition and health and that RAPD can be effectively used to differentiate mutant strain from the parental strain based on the RAPD patterns.     

A diazen-1-ium-1,2-diolated nitric oxide donor ester prodrug of 3-(4-hydroxymethylphenyl)-4-(4-methanesulfonylphenyl)-5H-furan-2-one: synthesis, biological evaluation and nitric oxide release studies

A novel hybrid nitric oxide-releasing anti-inflammatory (AI) ester prodrug (NONO-coxib 14) wherein an O²-acetoxymethyl 1-(2-carboxypyrrolidin-1-yl)diazen-1-ium-1,2-diolate (O²-acetoxymethyl PROLI/NO) NO-donor moiety was covalently coupled to the CH₂OH group of 3-(4-hydroxymethylphenyl)-4-(4-methylsulfonylphenyl)-5H-furan-2-one (12), was synthesized. The prodrug 14 released a low amount of NO (4.2%) upon incubation with phosphate buffer (PBS) at pH 7.4 which was significantly higher (34.8% of the theoretical maximal release of two molecules of NO/molecule of the parent hybrid ester prodrug) upon incubation in the presence of rat serum. These incubation studies suggest that both NO and the parent compound 12 would be released from the prodrug 14 upon in vivo cleavage by non-specific serum esterases. The prodrug ester 14 is a selective COX-2 inhibitor that exhibited AI activity (ED₅₀ = 72.2 mmol/kg po) between that of the reference drugs celecoxib (ED₅₀ = 30.9 μmol/kg po) and ibuprofen (ED₅₀ = 327 μmol/kg po). The NO donor compound 14 exhibited enhanced inhibition of phenylephrine-induced vasoconstriction of isolated mesenteric arteries compared with that observed under control conditions. These studies indicate hybrid ester AI/NO donor prodrugs (NONO-coxibs) constitutes a plausible drug design concept targeted toward the development of selective COX-2 inhibitory AI drugs that are devoid of adverse cardiovascular effects.