Effect of hypochlorous acid solution on the eradication and prevention of Pseudomonas aeruginosa infection,serum biochemical variables,and cecum microbiota in rats

In this study, hypochlorous acid solution, a weak acid, provided as drinking water to rats, was evaluated for its ability to eradicate and prevent Pseudomonas aeruginosa infection, while monitoring its simultaneous effect on serum biochemical variables and microbiota in the rat cecum. The results suggest that the solution could not eliminate the bacteria in the experimentally infected rats; however, the administration of a 10-parts-per-million (ppm) hypochlorous acid solution as drinking water was effective in inhibiting horizontal spread of P. aeruginosa infection among cage mates. Additionally, exposure to hypochlorous solution did not have any effect on serum biochemical variables of the rat including levels of total cholesterol, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), albumin, total bilirubin, lipase, amylase, urea nitrogen, total protein, calcium (Ca), phosphorus (P), sodium (Na), chlorine (Cl), except for potassium (K) levels. The most frequently isolated bacteria in the rat cecum included species belonging to Bacteroidales, Lactobacillus, Clostridiales, Erysipelotrichaceae, Akkermansia, Coriobacteriales, and Firmicutes. The ratio of the terminal restriction fragment length polymorphism (T-RFLP) peaks did not differ across rats administered with 5 and 10 ppm weak acid solution as compared to the control group for any of the bacteria, except for Erysipelotrichaceae and Firmicutes, where the ratio of T-RFLP peaks was higher in the 5 ppm group for Erysipelotrichaceae and in the 10 ppm group for Firmicutes than that in the control group (P<0.01). The results suggest that the weak acid hypochlorous solution could not eradicate P. aeruginosa completely from rats. The solution was effective in preventing infection without affecting serum biochemical variables; however, some of bacterial microbiota may have changed due to administration of the solution.     

The Effect of Oxygen on Melanin Precursors Released from Retinal Pigment Epithelial Cells In Vitro

The autoxidation of dopa to melanin in culture media causes toxicity to retinal pigment epithelial (RPE) cells and endothelial cells. The damage is specific to cell type and to the ambient oxygen concentration. To determine whether RPE cells influence the oxidation of dopa to media, we compared light absorbing dopa derivatives in the media exposed to cells with those found in the media incubated without cells. Dopa was extensively oxidized in the presence of RPE cells, and more light absorbing substances were generated with higher dopa and oxygen concentrations. However, an increase in ambient oxygen concentration decreased the quantity of several dopa derivatives which had been formed. The data provided evidence that RPE modulated dopa metabolism. Quinolic derivatives produced from a tyrosinase reaction and dopa-melanin formation moved the peak absorbance wavelength of dopa into the visible range. The spectrum between the dopa-derived compounds in the media has an absorbance at 240–275 nm and a maximum around 300 nm wth a shoulder near 375 nm. Gaussian analysis (peak separation) resolved these spectra into five components: a sharp band at 248 nm, a band at 295 nm, a large band at 359 nm, and two broad bands at 459 and 585 nm.     

Leaf Anatomy and Carbon Discrimination in NAD-malic Enzyme Panicum Species and their Hybrids Differing in Bundle Sheath Cell Ultrastructure

The relationship between leaf anatomy, ultrastructure and carbondiscrimination was investigated in leaves of two F₁hybrids (F₁-1and F₁-2) between two different types of the grassPanicum [anNAD-malic enzyme (ME) C₄species], which differ in bundle sheathultrastructure. The female parent was Kabulabula grass, whichhas centrifugal chloroplasts in bundle sheath cells and is designatedan NAD-ME(F) species, while the male parent was Makarikari grass,which has centripetal chloroplasts in the bundle sheath cellsand is designated an NAD-ME(P) species. Suberin lamellae arepresent in Kabulabula grass but are lacking in Makarikari grass.Both F₁hybrids had the same chromosome number (2n =36) as theparents but exhibited both univalent (about 45%) and bivalent(about 55%) chromosome pairing which was the major basis forthe identification of F₁hybrids. In F₁-1, elongated bundle sheathcell chloroplasts are arranged mainly in a centripetal position,similar to those in the male parent, Makarikari grass. In contrast,most of the bundle sheath cells in F₁-2 are packed with starch-containingchloroplasts, although in some cells chloroplasts tended tobe centripetally arranged. In both F₁hybrids, suberin lamellaewere found in the bundle sheath cell walls, similar to the femaleparent, Kabulabula grass. The ¹³C values of both F₁hybrids were-11.4 to -11.7, almost the same as those of Kabulabula grass(-11.4), but significantly higher than those of Makarikari grass(-12.7). These results indicate that the chloroplast orientationin the bundle sheath cells and the presence of suberin lamellaeare not obligatorily linked in their expression and suggestthat suberin lamellae may play an important role in discriminationagainst¹³C. Panicum ; NAD-malic enzyme species; hybrid; chloroplast position; ¹³C discrimination; suberin lamellae     

Distribution and Evolution of C4 Syndrome in Eleocharis, a Sedge Group Inhabiting Wet and Aquatic Environments, Based on Culm Anatomy and Carbon Isotope Ratios

In order to clarify the occurrence of the C₄ syndrome in Eleocharis,a group of bladeless sedges inhabiting wet and aquatic environments,the anatomical characteristics and carbon isotope ratios ofculms were investigated in 118 species. Among these, only sixspecies of the series Tenuissimae showed the Kranz type of anatomyand     

Environmental regulation of photosynthetic metabolism in the amphibious sedge Eleocharis baldwinii and comparisons with related species

The amphibious leafless sedge, Eleocharis baldwinii, expresses C₄ characteristics in the terrestrial form and intermediate characteristics between C₃ and C₄ photosynthesis in the submerged form. This study examined the immunocytochemical localization of C₃ and C₄ enzymes in culms of the two forms to elucidate the regulatory mechanism of photosynthetic metabolism and compared the activities and amounts of C₃ and C₄ enzymes with those in other Eleocharis species, E. vivipara and E. retroflexa, which show C₄ characteristics on land but C₃ and C₄ characteristics under water. The terrestrial form of E. baldwinii exhibited a C₄‐like pattern of enzyme localization. The submerged form exhibited a modified anatomy with well‐developed mesophyll cells and small Kranz cells. The C₄ enzyme levels declined conspicuously in outer mesophyll cells adjacent to the epidermis, whereas Rubisco levels increased throughout the mesophyll in the submerged form. These results suggest that intermediate photosynthesis between C₃ and C₄ photosynthesis in the submerged form results from the predominant operation of the C₃ pathway in the outer mesophyll cells and the C₄ pathway in both the inner mesophyll and Kranz cells. Differences in the degree of C₄ expression in terrestrial forms of Eleocharis species may cause the differences in the expression of photosynthetic modes under water.