The principal supply of carbon precursors for fatty acid synthesis in leaf tissue has been a much debated topic, with some experiments suggesting a direct supply from the C3 products of photosynthetic carbon fixation and colleagues suggesting the utilization of free acetate (for which concentrations in leaves in the range of 0.05-1.4 mM have been reported).
View Article and Find Full Text PDFTo examine the involvement of different ionotropic glutamate receptors in the mediation of responses evoked by noxious cutaneous stimulation, single unit recordings were made from 31 neurons in the primary somatosensory (SI) cortex of rats anesthetized with urethane. To compare synaptic receptor pharmacology across somatosensory submodalities, 13 of the neurons were also tested with an innocuous, cutaneous air jet stimulus. Mechanical (HT) responses, evoked by a 5-s noxious pinch, decayed gradually upon termination of the stimulus and lasted on average for 15.
View Article and Find Full Text PDFSusceptibility of Noble strain rats to induced cancers in the accessory sex glands was determined. Following an IV inoculation of methylnitrosourea plus three successive SC implants of testosterone propionate, early stage adenocarcinomas were observed in the seminal vesicles and anterior prostates, but not in the dorsolateral nor in the ventral lobes.
View Article and Find Full Text PDFWax synthase (WS, fatty acyl-coenzyme A [coA]: fatty alcohol acyltransferase) catalyzes the final step in the synthesis of linear esters (waxes) that accumulate in seeds of jojoba (Simmondsia chinensis). We have characterized and partially purified this enzyme from developing jojoba embryos. A protein whose presence correlated with WS activity during chromatographic fractionation was identified and a cDNA encoding that protein was cloned.
View Article and Find Full Text PDFThe jojoba (Simmondsia chinensis) plant produces esters of long-chain alcohols and fatty acids (waxes) as a seed lipid energy reserve. This is in contrast to the triglycerides found in seeds of other plants. We purified an alcohol-forming fatty acyl-coenzyme A reductase (FAR) from developing embryos and cloned the cDNA encoding the enzyme.
View Article and Find Full Text PDFIn Vitro Cell Dev Biol Anim
January 2000
Prostate tumors were induced in Lobund-Wistar rats by treatment with N-methyl-N-nitrosourea (MNU) and testosterone propionate (TP). Androgen receptor (AR) expression was confirmed in 16 (100%) of the primary prostate cancers, with strong uniform staining in well-differentiated tumors and more variable AR immunoreactivity in poorly differentiated tumors. Epithelial cell lines were established from nine of the tumors.
View Article and Find Full Text PDFOxygen-18 labeling has been applied to the study of plant lipid biosynthesis for the first time. [(13)C(2)(18)O(2)]Acetate was incubated with spinach (Spinacia oleracea) leaves and the (18)O content in fatty acid methyl esters isolated from different lipid classes measured by gas chromatography-mass spectometry. Fatty acids isolated from lipids synthesized within the plastid, such as monogalactosyldiacylglycerol, show an (18)O content consistent with the exogenous acetate undergoing a single activation step and with the direct utilization of acyl-acyl carrier protein by the acyl transferases of the chloroplast.
View Article and Find Full Text PDFThis is the first case report detailing the musculoskeletal pathology and treatment ramifications associated with velocardiofacial syndrome. Orthopaedic manifestations include scoliosis, clubfoot, Sprengel's deformity, generalized ligamentous laxity that is especially problematic about the knee, and epiphyseal dysplasia that is most notable in the lateral humeral condyle, lateral femoral condyle, and femoral head.
View Article and Find Full Text PDFBackground: Since prostate cancer (PC) development involves a combination of genetic predisposition and promotional mechanisms, especially the metabolic conversion of testosterone to 5alpha dihydrotestosterone (DHT) by 5alpha reductase, how do mechanisms in man relate to prostate-seminal vesicle (P-SV) tumor development in Lobund-Wistar (L-W) rats? The disease in man and in L-W rats shares developmental mechanisms and characteristics to the extent that prevention of P-SV tumors in L-W rats could be predictive of similar results in man. The epidemiology of PC in man and P-SV tumors in L-W rats indicates that both are hormone-related diseases based on genetic predisposition, high production of androgens (which are activated to DHT by 5alpha reductase), and early development of androgen-dependent and metastasizing late androgen-independent stages of adenocarcinomas, all after long latency periods.
Methods: L-W rats at risk of developing spontaneous or induced P-SV tumors were subjected to putative antitumor agents or procedures.
By stimulating afferent nerve endings in skeletal muscle, heart, kidney and the carotid body, adenosine infusion evokes a receptor-specific sympatho-excitatory reflex in humans that overrides its direct negative chronotropic effect. We tested the hypothesis that adenosine increases heart rate by suppressing parasympathetic and augmenting sympathetic components of heart rate variability. High-frequency (PH; 0.
View Article and Find Full Text PDFThe concept that spectral analysis of heart rate variability (HRV) can estimate cardiac sympathetic nerve traffic in subjects with both normal and impaired left ventricular systolic function has not been validated against muscle sympathetic nerve activity (MSNA). We used coarse-graining spectral analysis to quantify the harmonic and non-harmonic, or fractal, components of HRV and to determine low-frequency (0.0-0.
View Article and Find Full Text PDFTwo commercially available enzyme-linked immunosorbent assays (ELISA) for total polycyclic aromatic hydrocarbon (PAH) and carcinogenic PAH (C-PAH) were evaluated. The testing procedures were refined for application to screening PAH and C-PAH in house dust and soil samples for human exposure studies. The overall method precision expressed as percent relative standard deviation (%RSD) of triplicate real world dust and soil samples was within +/- 29% (12-29%) for PAH ELISA and +/- 21% (5.
View Article and Find Full Text PDFJ Gerontol B Psychol Sci Soc Sci
November 1998
Objectives: This article examines the availability, exchange, and receipt of informal support for unmarried childless elderly persons. These individuals may be at particular risk of lacking social support because they lack the two most important sources: spouses and children.
Methods: Using data drawn from the 1991 Canadian Survey on Aging and Independence (N = 1,078), ordered-response logistic regression models were employed to assess the availability and exchange of social support.
Purpose: This study was performed to determine the prevalence of dental disease in British school children with asthma.
Methods: A convenience sample of 100 asthmatic children (aged 4-16 years) was examined for dental caries, periodontal condition, and tooth surface loss. School children, equated for age, sex, race, and socioeconomic status were chosen for comparison.
Plant Physiol
September 1998
The prevailing hypothesis on the biosynthesis of erucic acid in developing seeds is that oleic acid, produced in the plastid, is activated to oleoyl-coenzyme A (CoA) for malonyl-CoA-dependent elongation to erucic acid in the cytosol. Several in vivo-labeling experiments designed to probe and extend this hypothesis are reported here. To examine whether newly synthesized oleic acid is directly elongated to erucic acid in developing seeds of Brassica rapa L.
View Article and Find Full Text PDFBackground: Gene-regulated mechanisms govern tumor development, but the actual development of tumors can be suppressed or promoted by epigenetic factors. Lobund-Wistar (L-W) rats are genetically predisposed to development of spontaneous and induced metastasizing moderately differentiated adenocarcinomas in the prostate-seminal vesicle (P-SV) complex. In L-W rats with one slow-release subcutaneous implant of dihydrotestosterone (DHT) (5alpha-Androstan-17beta-ol-3-one), the development of induced P-SV tumors 14 months later was significantly suppressed, with involution of testes, aspermia, and absence of detectable serum testosterone.
View Article and Find Full Text PDFThe structure of many proteins entering the secretory pathway is dependent on stabilization by disulfide bonds. To support disulfide-linked folding, the endoplasmic reticulum (ER) must maintain a strongly oxidizing environment compared to the highly reduced environment of the cytosol. We report here the identification and characterization of Ero1p, a novel and essential ER-resident protein.
View Article and Find Full Text PDFBackground: Angiogenesis and antiangiogenesis, as applied to oncology, are phenomena in which (1) tumors acquire a new blood vascular system from the host that is needed for their growth progression and metastasis; and (2) factors are produced that interfere with neovascularization, thereby inhibiting growth and metastasis of the tumor. Linomide, a chemical antiangiogenesis agent, inhibited the growth of transplanted tumors in mice and rats and inhibited the early development of metastasizing tumors induced in the prostate-seminal vesicle (P-SV) complex of genetically susceptible Lobund-Wistar (L-W) rats.
Methods: L-W rats with small induced P-SV tumors were treated with a recommended dosage of linomide (100 mg/kg BW/day) by the intraperitoneal and oral routes.
Marrow stromal cells from wild-type mice were infused into transgenic mice that had a phenotype of fragile bones resembling osteogenesis imperfecta because they expressed a human minigene for type I collagen. In mice that were irradiated with potentially lethal levels (700 cGy) or sublethal levels (350 cGy), DNA from the donor marrow stromal cells was detected consistently in marrow, bone, cartilage, and lung either 1 or 2.5 mo after the infusions.
View Article and Find Full Text PDFDGHs are faced with a choice between restricting their focus to intensive surgical and medical services or building up alliances with other agencies, including GPs. Their best hope for survival lies in robust relationships with GPs, local authorities, support groups and consumer organisations. Hospitals must pay more attention to discharge procedures.
View Article and Find Full Text PDFThe level of care for children over the past 5 years has become bimodal, with most children with low levels of dental caries having good maintenance care, but those with moderate to high caries receiving significantly poorer care. Capitation has led to supervised neglect for many children who develop dental decay. This is not at all unexpected considering the general lack of concern by the government and public dental services and the fact that the level of payment of GDPs is such that they cannot afford to treat children.
View Article and Find Full Text PDF