tecsi

OBJECTIVE: Titanium dioxide (TiO2 ) pigments (pure) or with a hydrophobic coating of triethoxycaprylylsilane (TECSi) used in cosmetics. Using different methods we studied properties of commercially available pure and coated pigment. We determined the elemental composition of pigments that differ in their behavior in a cosmetic formulation. The significant differences in the coating composition was revealed. METHODS: UV-Vis absorption spectroscopy allowed us to investigate the pigment purity and determined the polymorph form in pigments...

Two pathways can be used by gluconeogenesis in plants: one employs phosphoenolpyruvate carboxykinase (PEPCK) and the other pyruvate orthophosphate dikinase (PPDK). The occurrence-location of these enzymes was determined in developing kernels of maize. PPDK was much more abundant than PEPCK in extracts of whole kernels. However, their location within the kernel was different. PPDK was particularly abundant in the peripheral endosperm (in which alanine is abundant), whereas PEPCK was localised in the pedicel and basal endosperm transfer cells (where asparagine is metabolised)...

Glycolysis from sugars is necessary at all stages of development of grape pericarp, and this raises the question as to why gluconeogenesis from malate occurs. Phosphoenolpyruvate carboxykinase (PEPCK) is required for gluconeogenesis in grape pericarp. In this study we determined the abundance of PEPCK protein and activity in different parts of grape pericarp during its development. Both PEPCK protein and activity were present throughout development, however, in both the skin and the flesh their abundance increased greatly at the start of ripening...

A 34-year-old multiparous woman with a breech presentation, intrauterine growth restriction and premature rupture of membranes was transferred to our referral unit at 33 weeks of gestation. She was diagnosed with Alagille syndrome soon after birth because of cholestasis and pruritus. Her condition was later complicated by esophageal varices, treated with propranolol, thrombocytopenia, and insulin-dependent diabetes. She had characteristic facies, posterior embryotoxon, "butterfly" vertebrae but had no cardiac or renal abnormalities...

In cucumber ( Cucumis sativus L.), phosphoenolpyruvate carboxykinase (PEPCK) was shown by activity measurements and immunoblots to be present in leaves, stems, roots, flowers, fruit and seed. However, immunolocalisation showed that it was present only in certain cell types. PEPCK was present in the companion cells of the adaxial phloem of minor veins, the adaxial and abaxial phloem of larger veins, the internal and external phloem of vascular bundles in petioles and stems, the phloem in roots and the extra-fascicular phloem in leaves, cotyledons, petioles and stems...

PURPOSE: Early feeding is well tolerated after Cesarean delivery. However, patient wellbeing and nurses' attitudes toward implementation of early feeding have rarely been investigated. METHODS: A quality-assurance program of 18 months duration was implemented because evaluation of traditional practice demonstrated significant deficiencies (phase I). Drinking was then allowed within one hour and feeding within six to eight hours after delivery. Gradual dietary expansion followed according to a detailed program...

Changes in host primary metabolism associated with the compatible interaction between cucumber mosaic virus and cotyledons of the marrow plant (Cucurbita pepo L.) have been localized, first by measuring activities of key enzymes in infected and uninfected regions of the cotyledon, and second by histochemical techniques applied to tissue prints of the infected region. A series of progressive metabolic changes occurs within the expanding infected lesion. Virus replication and the synthesis of viral protein at the periphery creates a strong sink demand associated with increased activities of anaplerotic enzymes, increased photosynthesis, and starch accumulation...

To understand many aspects of the metabolism of complex plant structures such as leaves, fruit and roots it is important to understand how metabolic processes are compartmentalized between tissues. The aim of this article is to show how immunohistochemistry, in conjunction with biochemical and physiological studies, is useful in understanding both the function of an enzyme in a tissue and metabolic processes occurring in plant tissues. This is illustrated by two examples. Firstly, the use of immunohistochemisty in the localization of amino acids in plant tissues is described...

The aim of this study was to investigate whether gluconeogenesis catalysed by phosphoenolpyruvate carboxykinase (PEPCK) occurs during leaf senescence. This was addressed by determining changes in the abundance and intercellular location of enzymes necessary for gluconeogenesis during the senescence of barley leaves and cucumber cotyledons. PEPCK was never present in barley leaves, despite the presence of large amounts of isocitrate lyase (ICL), a key enzyme of the glyoxylate cycle, and of its product, glyoxylate...

The compartmentation of key processes in sugar, organic acid and amino acid metabolism was studied during the development of the flesh and seeds of grape (Vitis vinifera L.) berries. Antibodies specific for enzymes involved in sugar (cell wall and vacuolar invertases, pyrophosphate: fructose 6-phosphate phosphotransferase, aldolase, NADP-glyceraldehyde-P dehydrogenase, cytosolic fructose 1,6-bisphosphatase), photosynthesis (Rubisco, fructose 1,6-bisphosphatase, sedoheptulose 1,7-bisphosphatase), amino acid metabolism (cytosolic and mitochondrial aspartate aminotransferases, alanine aminotransferase, glutamate dehydrogenase, glutamine synthetase), organic acid metabolism (phosphoenolpyruvate carboxylase, NAD- and NADP-dependent malic enzyme, ascorbate peroxidase), and lipid metabolism (acetyl CoA carboxylase, isocitrate lyase) were used to determine how their abundance changed during development...

Phosphoenolpyruvate carboxykinase (PEPCK) was shown to be present in a range of developing seeds by measurement of its activity and by immunoblotting. Its function was investigated during grape (Vitis vinifera L.) seed development. The maximum abundance of PEPCK coincided with the deposition of storage reserves. At this stage of development, immunohistochemistry showed that PEPCK was very abundant in a layer of cells located at the boundary of developing storage tissues and in the chalaza (close to the termination of the vascular supply to the seed) and was also present in the palisade layer of the seed coat (the inner layer of the outer integument)...

We recently showed that maize (Zea mays L.) leaves contain appreciable amounts of phosphoenolpyruvate carboxykinase (PEPCK; R.P. Walker, R.M. Acheson, L.I. Tecsi, R.C. Leegood [1997] Aust J Plant Physiol 24: 459-468). In the present study, we investigated the role of PEPCK in C4 photosynthesis in maize. PEPCK activity and protein were enriched in extracts from bundle-sheath (BS) strands compared with whole-leaf extracts. Decarboxylation of [4-14C]aspartate (Asp) by BS strands was dependent on the presence of 2-oxoglutarate and Mn2+, was stimulated by ATP, was inhibited by the PEPCK-specific inhibitor 3-mercaptopicolinic acid, and was independent of illumination...