Comparison of the toxicity of cinnamaldehyde when administered by microencapsulation in feed or by corn oil gavage

The toxicity of cinnamaldehyde (CNMA) was compared after administration by gavage and in dosed feed. Rats and mice of both sexes received CNMA by daily corn oil gavage (for 2 wk), or in microencapsulated form in feed (2 wk for rats, 3 wk for mice). Feed formulations contained 0-10% CNMA microcapsules, equivalent to approximate daily doses of 0-3000 mg CNMA/kg body weight for rats and 0-10,000 mg CNMA/kg body weight for mice. Concentrations were chosen to deliver CNMA doses approximately equal to doses in the gavage study. Gavage doses of 2620 mg/kg/day and above in mice and 940 mg/kg/day and above in rats produced nearly 100% mortality; there were no deaths in animals receiving microencapsulated CNMA. Rats and mice receiving CNMA in feed showed a dose-related decrease in body weight gain, which was accompanied in rats by hypoplastic changes in reproductive organs and accessory sex glands. CNMA administration by either route caused hyperplasia of the forestomach mucosa. These results demonstrate that microencapsulation in feed can present a useful alternative to gavage dosing for repeated-dose or prolonged-exposure studies, in that (1) the toxic effects of CNMA were similar after gavage dosing and after administration in microencapsulated form in feed, (2) ingestion of chemical in the feed more closely approximates human exposures, and (3) microencapsulation allows the delivery of higher net doses of chemical, while avoiding the acutely toxic effects of a bolus dose.

Analysis of collagens solubilized from cartilage of normal and spontaneously osteoarthritic rhesus monkeys

Osteoarthritis (OA) is a disorder which results in the destruction of the articular cartilage and the remodeling of the subchondral bone in synovial joints. We have analyzed the cartilage collagen from normal and osteoarthritic free-ranging rhesus monkeys from the Cayo Santiago colony. The cartilage samples were assigned a severity score based on histological staging system and were divided into four groups (normals, mild OA, moderate OA and severe OA). After a 4.0 M guanidinium chloride (GuCl) extraction, the remainder of the cartilage was digested with pepsin and the collagen was salt precipitated at 2.5 M and 4.3 M NaCl. The GuCl solubility of the osteoarthritic cartilage increased compared to normals. Collagen extractability by GuCl also increased with the severity of disease. Pepsin digestion followed by salt precipitation shows that collagen from rhesus osteoarthritis cartilage is more easily extracted than from normal cartilage. With an anti-type I collagen antibody we have detected the presence of type I collagen in the severe OA cartilage samples but not in the milder OA groups or in normal cartilage. Total collagen content decreases with severity of OA, which is not due to changes in propyl hydroxylation because examination of collagen hydroxylation, based on hydroxyproline analysis, shows no difference between OA and normal cartilage.

SecA homolog in protein transport within chloroplasts: evidence for endosymbiont-derived sorting

The SecA protein is an essential, azide-sensitive component of the bacterial protein translocation machinery. A SecA protein homolog (CPSecA) now identified in pea chloroplasts was purified to homogeneity. CPSecA supported protein transport into thylakoids, the chloroplast internal membrane network, in an azide-sensitive fashion. Only one of three pathways for protein transport into thylakoids uses the CPSecA mechanism. The use of a bacteria-homologous mechanism in intrachloroplast protein transport provides evidence for conservative sorting of proteins within chloroplasts.

Toxicokinetics of oxazepam in rats and mice

The comparative toxicokinetics of oxazepam were studied in F344 rats, B6C3F1 mice, and Swiss-Webster mice of both sexes after an i.v. dose of 20 mg/kg and oral gavage doses of 50, 200, and 400 mg/kg. In addition, the toxicokinetics of oxazepam in a 3-week dosed-feed study of male B6C3F1 mice at 125 and 2500 ppm were also investigated. Results indicated that the elimination of oxazepam from plasma after i.v. injection in both rats and mice were first-order and could be best described by a two-compartment model with a terminal elimination half-life of 4-5 h for rats and 5-7 h for mice. After oral gavage dosing the peak oxazepam plasma concentrations in most rodents were reached within 2-3.5 h. At all doses studied, female rodents had significantly higher plasma concentrations than males. Absorption of oxazepam was significantly extended at higher oral doses of 200 and 400 mg/kg. At 50 mg/kg, the bioavailability of oxazepam in rats (< 50%) was lower than in Swiss-Webster mice (> 80%). The bioavailability of oxazepam in both B6C3F1 and Swiss-Webster mice decreased with increasing dose. A dose proportionality of Cmax was not observed in rats and mice after gavage doses of 50, 200, and 400 mg/kg. Plasma concentrations of oxazepam in the dosed-feed study increased with the concentration of oxazepam in the feed, a quasi-steady-state of plasma concentrations of oxazepam was reached after approximately 4 days ad libitum exposure. In B6C3F1 mice, the estimated relative bioavailability of oxazepam from dosed feed (relative to gavage study at 50 mg/kg) was about 43%.

Changes in composition and distribution of LDL subspecies in hypertriglyceridemic and hypercholesterolemic patients during gemfibrozil therapy

The effect of gemfibrozil (GEM) on composition and distribution of LDL subspecies in 10 hypertriglyceridemic (HTG) patients with triglyceride (TG) levels of 300-750 mg/dl and low density lipoprotein cholesterol (LDL-C) < 160 mg/dl, and 8 hypercholesterolemic (HC) patients with LDL-C > or = 190 mg/dl and TG < 200 mg/dl was investigated. Patients were randomized in a double-blind, crossover design to 12 week periods of placebo and 1200 mg/day GEM with an intervening washout period. All 7 LDL subspecies in the density range of 1.029 to 1.063 g/ml in the HTG group contained more TG (P < 0.01) and less free cholesterol (P < 0.05), while the proportion of cholesterol ester was lower only in LDL subspecies 1 to 3 (P < 0.05) as compared to the HC group. In HTG patients, GEM increased the proportion of cholesterol ester (P < 0.05) in all subfractions, while the proportion of free cholesterol was increased and TG was decreased in LDL subspecies 1 to 4 only (P < 0.05). GEM decreased the LDL subspecies score from 4.8 +/- 0.7 to 4.2 +/- 0.5, and the major LDL subclass density from 1.048 +/- 0.006 to 1.043 +/- 0.002 g/ml (P < 0.01) in HTG patients. GEM decreased TG levels to mean of 228 +/- 52 mg/dl in HTG patients, but there was no change in LDL phenotype. No significant changes in composition and distribution of LDL subspecies were noted in HC patients with GEM. We conclude that GEM significantly altered the composition and distribution of LDL subspecies with a shift from small dense LDL particles to large, less dense particles in HTG patients.

Ich-1, an Ice/ced-3-related gene, encodes both positive and negative regulators of programmed cell death

We report here the isolation and characterization of Ich-1, a gene related to the C. elegans cell death gene ced-3 and the mammalian homolog of ced-3, interleukin-1 beta-converting enzyme (ICE). Alternative splicing results in two distinct Ich-1 mRNA species. One mRNA species encodes a protein product of 435 amino acids (ICH-1L) that is homologous to both the P20 and P10 subunits of ICE (27% identity) and the entire CED-3 protein (28% identity). The other mRNA encodes a 312 amino acid truncated version of ICH-1L protein (ICH-1S). Overexpression of IchL induces programmed cell death, suggesting that Ich-1 is also a mammalian programmed cell death gene. More interestingly, overexpression of the Ich-1S suppresses Rat-1 cell death induced by serum deprivation. These observations suggest that Ich-1 plays an important role in both positive and negative regulation of programmed cell death in vertebrate animals.

Expression of a specific marker of avian programmed cell death in both apoptosis and necrosis

Apoptosis and necrosis are two types of cell death with different morphologic features. We report here the isolation of a monoclonal antibody, BV2, that specifically recognizes cells undergoing developmental programmed cell death in different tissues of the chicken and zebra-finch embryos. The antigen recognized by BV2 monoclonal antibody is detected in vitro in primary chicken embryonic fibroblasts induced to die by actinomycin D, as well as fibroblasts induced to die by chemical anoxia. The expression of this specific antigen during necrosis appears to require active protein synthesis. These findings provide evidence that cells from different embryonic tissues undergoing programmed cell death during vertebrate development express similar antigens and indicate that apoptosis and necrosis may share similar biochemical features.

Stimulation of the human intercellular adhesion molecule-1 promoter by interleukin-6 and interferon-gamma involves binding of distinct factors to a palindromic response element

Intercellular adhesion molecule-1 (ICAM-1) is a transmembrane glycoprotein that promotes adhesion in immunological and inflammatory reactions. ICAM-1 is expressed on cells of many lineages and is induced by interleukin-6 (IL-6) and interferon-gamma (IFN-gamma). Functional analysis of ICAM-1 promoter-luciferase constructs in HepG2 cells enabled us to identify a region between -110 and -37 mediating IL-6 and IFN-gamma responsiveness and containing a palindromic IL-6/IFN-gamma response element (pIRE). Site-directed mutagenesis of key nucleotides in the ICAM-1 pIRE abolished the effect of both IL-6 and IFN-gamma stimulation, while this pIRE element was sufficient to confer IL-6 and IFN-gamma responsiveness to a heterologous promoter. We further show by gel retardation analysis that distinct nuclear factors induced by both IL-6 or IFN-gamma specifically bind to this pIRE. Furthermore, treatment with IL-6 results in the formation of multiple complexes while IFN-gamma induces a single binding complex, both in HepG2 and monocytic U937 cells. Differentiation of U937 cells by exposure to 12-O-tetradecanoyl phorbol-13-acetate abolishes response to IL-6 but not IFN-gamma. Supershift data utilizing the ICAM-1 pIRE revealed that IFN-gamma and IL-6 both induce a factor antigenically related to IFN-gamma activation factor. We further provide data suggesting that IL-6 additionally activates an ICAM-1 pIRE binding factor related to the previously described acute-phase response factor in disparate cell types. We therefore conclude that the activation of these related nuclear factors by IL-6 and IFN-gamma is important in the regulation of ICAM-1 gene expression.

Impact of annual screening and chemotherapy with praziquantel on schistosomiasis japonica on Jishan Island, People's Republic of China

The impact of annual screening and treatment with praziquantel on schistosomiasis japonica was examined on Jishan Island in Po Yang Lake, Jiangxi Province. China. Prevalence of infection in the community decreased from 39% in year 1 to 33% in year 3 with a corresponding decrease in the geometric mean egg count from 51 eggs per gram of stool (epg) to 31 epg. The most dramatic changes in infection status and intensity of infection were observed in younger individuals (0-19 years of age). The prevalence of hepatosplenomegaly also significantly decreased, again primarily in younger individuals. No change in the community prevalence of schistosome-induced hepatic fibrosis was observed as determined by ultrasonography. Longitudinal cohort analysis, however, demonstrated significant improvement in treated individuals with advanced hepatic fibrosis. These data indicate that annual screening and treatment had a significant impact on infection status and morbidity and suggest that community therapy may be an effective approach to control schistosomiasis japonica in lake regions and marshlands in China. Further studies are necessary to determine the optimal and most cost-effective approach for drug delivery.

Plastocyanin and the 33-kDa subunit of the oxygen-evolving complex are transported into thylakoids with similar requirements as predicted from pathway specificity

Plastocyanin and the 33-kDa subunit of the oxygen-evolving complex (OE33) are two of several thylakoid lumen-located proteins that are made in the cytosol, imported into chloroplasts, and subsequently transported into thylakoids. Recently, competition studies showed that there are two pathways for protein transport into the thylakoid lumen and that plastocyanin and OE33 are on the same pathway (Cline, K., Henry, R., Li, C., and Yuan, J. (1993) EMBO J. 12, 4105-4114). Our expectation is that transport requirements reflect the steps of the process and that proteins on the same pathway share similar requirements. Unfortunately, the transport requirements for plastocyanin and OE33 are not well established. Here, we investigated transport in a reconstituted system with isolated thylakoids. Efficient transport of OE33 and plastocyanin was only obtained when stromal extract was included in the assay. Heat or protease treatment of stromal extract eliminated its ability to stimulate transport. Transport was abolished by treatments designed to deplete ATP or to prevent its formation and was greatly reduced in the presence of ionophores that dissipate the trans-thylakoidal proton gradient. These results show that transport of OE33 and plastocyanin requires ATP and is stimulated by stromal protein(s) and the trans-thylakoidal proton gradient. Taken together, these and previous results suggest that there are two mechanistically distinct pathways for protein transport into the thylakoid lumen.

Defective assembly of membrane proteins in erythroid precursors of beta-thalassemic mice

beta-Thalassemic mice provide a useful model for studying the pathophysiology of human beta-thalassemia in that one can perform experiments that are difficult to perform in humans. The ease of access to beta-thalassemic mouse marrow provided the opportunity to explore the cause of the ineffective erythropoiesis that characterizes severe beta-thalassemia in mouse and man. We hypothesized that the accumulation of excess alpha-globin might interfere with the normal assembly of red blood cell (RBC) membrane proteins, thus contributing to the severe intramedullary lysis. Femoral marrow was obtained from normal and beta-thalassemic mice, and RBC precursors were purified (> 90%) by panning and harvesting CD45- cells. The assembly of RBC membrane proteins was assessed by observing immunofluorescence patterns obtained on fixed permeabilized precursors using rabbit polyclonal antibodies directed against human spectrin, and band 4.1, and murine band 3. The distribution of the proteins was shown with a fluorescein-tagged goat antirabbit antibody. In contrast to normal mice, about 30% of intermediate and late stage erythroblasts in beta-thalassemic mice appear abnormal. Neither spectrin nor band 4.1 formed crisp rim fluorescence in these erythroid precursors of thalassemic mice, whereas assembly of band 3 appeared normal. Therefore, the assembly of membrane skeletal proteins is abnormal in murine beta-thalassemic erythroid precursors perhaps because of the deposition of unmatched alpha-globin chains.

"Oh, no, not another hand-washing in-service!"

The need for in-service education is constant in the 1990s. To meet the mandates of federal and accreditation bodies, organizations must be prepared to conduct required education. In an environment where healthcare organizations are being asked to do more with less, education dollars are at a premium. There is also the need to be creative to heighten the interest of the staff in what might otherwise be considered a boring topic. Our annual in-service program on hand-washing and infection control was scheduled to present the required information, but this time we had fun and the participants paid attention. The message was received and the home health agency met its requirements and those imposed by outside regulatory and accrediting organizations.

[Site-directed mutagenesis of Lac Z gene in Escherichia coli and the kinetic properties of the mutated enzymes]

Glutamic acid at position of 537 of beta-D-galactosidase coded by Lac Z gene was substituted with Aspartic acid, Glutamine and Valine using synthetic oligonucleotide probes. Compared to native enzyme, the kcat values for substrate ONPG were 0.13%, 0.0006% and 0.0035% for Asp-537, Gln-537 and Val-537 mutated enzymes respectively. The Km values were of the same order of magnitude, either native or mutated enzymes. The substrate analog, IPTG was a strong inhibitor of each of the substituted enzymes, as in the case of native enzyme. The transition state analogs, 2-NH2-galactose and L-ribose were almost the same effects for the mutated enzymes as for the normal enzyme. The nucleophili, Azide, did not activate the mutated enzymes as in the case of Glu-461 substituted in beta-D-galactosidase. The effect of methanol on the mutated enzymes was less than on native enzyme. The order of the thermal stability was native enzyme > Asp-537 > Gln-537 > Val-537 enzymes. Overall, the evidence strongly supports the suggestion that Glu-537 is an essential residue of beta-D-galactosidase.

Anti-apogens and anti-engulfens: monoclonal antibodies reveal specific antigens on apoptotic and engulfment cells during chicken embryonic development

We have isolated a group of monoclonal antibodies that specifically recognize either apoptotic or engulfment cells in the interdigit areas of chicken hind limb foot plates, and throughout the embryo. Ten of these antibodies (anti-apogens) detect epitopes on dying cells that colocalize to areas of programmed cell death, characterized by the presence of apoptotic cells and bodies with typical cellular and nuclear morphology. Our results indicate that cells destined to die, or that are in the process of dying, express specific antigens that are not detectable in or on the surface of living cells. The detection of these apoptotic cell antigens in other areas of programmed cell death throughout the chick embryo indicates that different cell types, which form specific tissues and organs, may utilize similar cell death mechanisms. Six of the monoclonal antibodies (antiengulfens) define a class of engulfment cells which contain various numbers of apoptotic cells and/or apoptotic bodies in areas of programmed cell death. The immunostaining pattern of the anti-engulfen R15F is similar to that of an antibody against a common leukocyte antigen, suggesting the participation of cells from the immune system in the removal of apoptotic cell debris. These novel monoclonal antibody markers for apoptotic and engulfment cells will provide new tools to assist the further understanding of developmental programmed cell death in vertebrates.

The interleukin-6-activated acute-phase response factor is antigenically and functionally related to members of the signal transducer and activator of transcription (STAT) family

Interleukin-6 (IL-6), leukemia inhibitory factor, oncostatin M, IL-11, and ciliary neurotropic factor are a family of cytokines and neuronal differentiation factors which bind to composite plasma membrane receptors sharing the signal transducing subunit gp130. We have shown recently that IL-6 and leukemia inhibitory factor rapidly activate a latent cytoplasmic transcription factor, acute-phase response factor (APRF), by tyrosine phosphorylation, which then binds to IL-6 response elements of various IL-6 target genes. Here we demonstrate that APRF is activated by all cytokines acting through gp130 and is detected in a wide variety of cell types, indicating a central role of this transcription factor in gp130-mediated signaling. APRF activation is also observed in vitro upon addition of IL-6 to cell homogenates. Protein tyrosine kinase inhibitors block both the tyrosine phosphorylation and DNA binding of APRF. The factor was purified to homogeneity from rat liver and shown to consist of a single 87-kDa polypeptide, while two forms (89 and 87 kDa) are isolated from human hepatoma cells. As reported earlier, the binding sequence specificity of APRF is shared by gamma interferon (IFN-gamma) activation factor, which is formed by the Stat91 protein. Partial amino acid sequence obtained from purified rat APRF demonstrated that it is likely to be related to Stat91. In fact, an antiserum raised against the amino-terminal portion of Stat91 cross-reacted with APRF, suggesting the relatedness of APRF and Stat91. Altogether, these data indicate that APRF belongs to a growing family of Stat-related proteins and that IFN-gamma and IL-6 use similar signaling pathways to activate IFN-gamma activation factor and APRF, respectively.

Dexfenfluramine and serotonin neurotoxicity: further preclinical evidence that clinical caution is indicated

Dexfenfluramine, a drug used as an appetite suppressant in Europe, is currently under evaluation for approval in the United States. Studies in animals indicate that dexfenfluramine damages brain serotonin neurons, but have been challenged by some because of questions regarding their relevance to humans. The present studies were designed to address the three most salient questions regarding the applicability of preclinical dexfenfluramine neurotoxicity data to humans. Specifically, the present studies sought to determine: 1) whether dexfenfluramine's effects on brain serotonin neurons are transient and related to its therapeutic actions; 2) whether the p.o. route of administration affords protection against dexfenfluramine neurotoxicity; and 3) whether the mouse, an animal thought to best approximate the human with regard to dexfenfluramine metabolism, is sensitive to dexfenfluramine's neurotoxic action. Results from the present study indicate that monkeys continue to show large serotonergic deficits as long as 12 to 17 months after dexfenfluramine treatment, suggesting that dexfenfluramine's effects in nonhuman primates are persistent and unlikely to be related to its therapeutic actions. Furthermore, the present results indicate that the p.o. route of administration affords little or no protection against dexfenfluramine neurotoxicity. Finally, mice, like all other animals tested to date, were found to be susceptible to dexfenfluramine neurotoxicity. Taken together, these findings indicate that concern over possible dexfenfluramine neurotoxicity in humans is warranted, and that physicians and patients alike need to be aware of dexfenfluramine's toxic potential toward brain serotonin neurons.

Substitutions for Glu-537 of beta-galactosidase from Escherichia coli cause large decreases in catalytic activity

Glu-537 of beta-galactosidase (EC 3.2.1.23) was replaced by Asp, Gln and Val using synthetic oligonucleotides. The kcat values of the purified enzyme mixtures were reduced by about 100-fold for the Asp mutant, 30,000-60,000-fold for the Val mutant and 160,000-300,000-fold for the Gln mutant. The greatest differences in properties from the wild-type enzyme were found for the Asp-substituted enzyme: the Km values increased (from 0.12 to 0.42 mM for o-nitrophenyl beta-D-galactopyranoside), and from 0.04 to 0.37 mM for p-nitrophenyl beta-D-galactopyranoside), the Ki value for isopropyl beta-D-galactopyranoside increased (from 0.11 to 0.30 mM), the stability to heat decreased and methanol did not act as an acceptor. The enzymes with the other two substitutions had properties similar to those of the wild-type. For all three substituted enzymes, the inhibitory effects of the transition-state analogues (2-deoxy-2-amino-D-galactose and L-ribose) and the Mg2+ effects were similar to those of the normal enzyme. As all of the properties (except the kcat values) of the Gln- and Val-substituted enzyme preparations were similar to those of the wild-type enzyme, the activities in those preparations were probably due to the presence of a few wild-type enzyme molecules (formed from misreads) among the substituted enzymes. The enzymes with Gln and Val substitutions appear to be totally inactive. The results obtained support a recent suggestion that Glu-537 is an important catalytic residue of beta-galactosidase.

Multi-target PCR analysis by capillary electrophoresis and laser-induced fluorescence

Quantitative analysis of polymerase chain reaction (PCR) amplified HIV-1 DNA or cDNA fragments is attained using an automated system that combines capillary-gel electrophoresis (CGE) for high-efficiency separation and laser-induced fluorescence (LIF) for high-sensitivity detection. This system enables the detection of PCR-amplified multiple target DNA or cDNA in the same tube by a single injection with high precision.

The signalling pathways of interleukin-6 and gamma interferon converge by the activation of different transcription factors which bind to common responsive DNA elements

Interleukin-6 (IL-6) and gamma interferon (IFN-gamma) induce a partially overlapping set of genes, including the genes for interferon regulatory factor 1 (IRF-1), intercellular adhesion molecule 1 (ICAM-1), and the acute-phase protein alpha 2-macroglobulin. We report here that the rat alpha 2-macroglobulin promoter is activated by IFN-gamma in human hepatoma (HepG2) cells and that the IFN-gamma response element maps to the same site previously defined as the acute-phase response element (APRE), which binds the IL-6-activated transcription factor APRF (acute-phase response factor). As was reported for fibroblasts, the IFN-gamma-regulated transcription factor GAF is phosphorylated at tyrosine after IFN-gamma treatment of HepG2 cells. IFN-gamma posttranslationally activates a protein which specifically binds to the alpha 2-macroglobulin APRE. This protein is shown to be identical or closely related to GAF. Although APRF and GAF are shown to represent different proteins, their binding sequence specificities are very similar. APRF and GAF bind equally well to the APRE sequences of various acute-phase protein genes as well as to the IFN-gamma response elements of the IRF-1, ICAM-1, and other IFN-gamma-inducible genes. Transient transfection analysis revealed that the IFN-gamma response elements of the IRF-1 and ICAM-1 promoters are able to confer responsiveness to both IFN-gamma and IL-6 onto a heterologous promoter. Therefore, APRF and GAF are likely to be involved in the transcriptional induction of these immediate-early genes by IL-6 and IFN-gamma, respectively. Taken together, these results demonstrate that two functionally distinct hormones, IL-6 and IFN-gamma, act through common regulatory elements to which different transcription factors sharing almost the same sequence specificity bind.

Prevention of vertebrate neuronal death by the crmA gene

Interleukin-1 beta converting enzyme (ICE) is a mammalian homolog of CED-3, a protein required for programmed cell death in the nematode Caenorhabditis elegans. The activity of ICE can be specifically inhibited by the product of crmA, a cytokine response modifier gene encoded by cowpox virus. Microinjection of the crmA gene into chicken dorsal root ganglion neurons was found to prevent cell death induced by deprivation of nerve growth factor. Thus, ICE is likely to participate in neuronal death in vertebrates.

Association of transcription factor APRF and protein kinase Jak1 with the interleukin-6 signal transducer gp130

Interleukin-6 (IL-6), leukemia inhibitory factor, oncostatin M, interleukin-11, and ciliary neurotrophic factor bind to receptor complexes that share the signal transducer gp130. Upon binding, the ligands rapidly activate DNA binding of acute-phase response factor (APRF), a protein antigenically related to the p91 subunit of the interferon-stimulated gene factor-3 alpha (ISGF-3 alpha). These cytokines caused tyrosine phosphorylation of APRF and ISGF-3 alpha p91. Protein kinases of the Jak family were also rapidly tyrosine phosphorylated, and both APRF and Jak1 associated with gp130. These data indicate that Jak family protein kinases may participate in IL-6 signaling and that APRF may be activated in a complex with gp130.

Model-based quality control of the baker's yeast Saccharomyces cerevisiae

This paper deals with the optimal control of storage stability for compressed baker's yeast by minimizing the fraction of budding cells (FBC) based on a metabolic and cell cyclic model system for Saccharomyces cerevisiae. Three experiments of quality control were successfully carried out. The experimental data revealed that under optimal operation conditions, the final FBC-values approached the theoretical minimum and that storage stability was enhanced.

Codeine toxicokinetics in rats during a two-year dosed feed study

Codeine toxicokinetics in F344 rats of both sexes were determined during a 2-year chronic toxicology study using dosed feed as the exposure route with a 12-hr light/dark cycle starting at 7:00 a.m. Rats were allowed to access to dosed feed formulations ad libitum with codeine concentrations at 0, 400, 800, and 1600 ppm. Blood samples were collected from individual rat on days 7, 21, and 90 at 7:00 p.m., 11:00 p.m., 3:00 a.m., and 7:00 a.m. Additional samples were collected at 16 and 24 months between 6:00-8:00 a.m. Plasma concentrations of codeine and morphine were determined directly by radioimmunoassay. Concentrations of their conjugates were determined indirectly by measuring the total amount of free codeine and morphine released after samples were treated with beta-glucuronidase. Results indicated that plasma concentrations of both codeine and morphine steadily decreased from day 7 to 16 months and then rebounded at 24 months. Results also indicated that plasma concentrations of both codeine and morphine correlated well with the amounts of codeine added to the feed. Bioavailability of codeine using the dosed feed route increased with dose, varying from 10% to 25%, which was somewhat higher than the previously reported approximately 8% bioavailability using the gavage route. Concentrations of conjugated codeine were very low, whereas concentrations of conjugated morphine were very high. These results suggested that demethylation of codeine to morphine in rats is the main metabolic pathway and was maintained over the course of the study.