Effects of interferon-alpha on serum hepatitis C virus in patients with chronic hepatitis C

Interferon is beneficial in some patients with chronic hepatitis C. To assess the efficacy of interferon, we used the polymerase chain reaction (PCR) to measure HCV RNA in serial serum samples from 13 chronic hepatitis C patients who were treated with interferon-alpha. Serum alanine aminotransferase (ALT) values normalized in association with the disappearance of serum HCV RNA in nine cases during the therapy. Serum HCV remained negative after the therapy in the three patients who had no relapse, while serum HCV RNA reappeared in the six patients with elevation of ALT values. The persistence of normal ALT levels appears to be correlated with the clearance of the serum HCV. There were two patients whose ALT became normal immediately after the cessation of interferon. Serum HCV was detectable at the end of treatment when serum ALT was elevated, and thereafter serum HCV disappeared. This result suggests an immunomodulatory effect of interferon in the clearance of HCV in some cases. Furthermore, the semiquantitative PCR assay showed that all five patients in whom ALT values were normal at the end of follow-up without detectable serum HCV genome had lower HCV titers in the pretreatment sera than the other eight patients. The detection of HCV RNA by the PCR assay is useful in determining the efficacy of interferon and its mechanisms.     

Effects of ketamine-nitrous oxide anesthesia and surgical procedure serum levels of thyroxine and triiodothyronine]

503 samplings of palmitic acid in amniotic fluid are correlated with gestational age during labor or not. In nine cases of R.D.S. determinations during labor were of very low values, but not in those before labor started. Results are discussed, indicating that values over 2 mg./100 ml. show adequate pulmonary maturity. Inferior values would only be valuable if samples are obtained during labor.     

Ellipsometry of the passivation film on iron in neutral solution

Ellipsometric and electrochemical measurements have been made of the passivation film on iron during its potentiostatic anodic formation and galvanostatic cathodic reduction in boric-acid-sodium-borate buffer solution.     

Ubiquitin in cerebrospinal fluid: a rapid competitive enzyme-linked immunoflow assay

The aims of this study were to develop a rapid immunoassay to determine the levels of ubiquitin in cerebrospinal fluid and to establish the ubiquitin levels in the spinal fluid of normal aged individuals. A competitive enzyme-linked immunoflow assay was developed. In this assay, ubiquitin is bound to nitrocellulose membrane, after which the primary antibody-test sample mixture and the enzyme-labeled secondary antibody under vacuum are applied sequentially. The final reaction product is collected in a microtiter plate by suction. This competitive assay requires only approximately 4 h and is potentially useful for determining in biological fluids the levels of any antigen or its antibodies that might be present. Employing this immunoassay, cerebrospinal fluid ubiquitin levels were found to be 147.5 +/- 5.2 ng ml-1 in non-neurological aged cases.     

Acute mastoiditis in infants: penicillin-resistant Streptococcus pneumoniae and its therapy

Earlier studies in our laboratory showed that hydroxylated metabolites of polychlorinated biphenyls (PCBs), dibenzo-p-dioxins (PCDDs), and dibenzofurans (PCDFs) competitively inhibit thyroxine (T4) binding to transthyretin (TTR) and type I deiodinase (D1) activity. In this study, we investigated the possible inhibitory effects of hydroxylated metabolites of polyhalogenated aromatic hydrocarbons (PHAHs) on iodothyronine sulfotransferase activity. Rat liver cytosol was used as a source of sulfotransferase enzyme in an in vitro assay with 125I-labeled 3,3'-diiodothyronine (T2) as a model substrate. Increasing amounts of hydroxylated PCBs, PCDDs, or PCDFs or extracts from incubation mixtures of PHAHs and induced liver microsomes were added as potential inhibitors of T2 sulfotransferase activity. Hydroxylated metabolites of PCBs, PCDDs, and PCDFs were found to be potent inhibitors of T2 sulfotransferase activity in vitro with IC50 values in the low micromolar range (0.2-3.8 microM). The most potent inhibitor of T2 sulfotransferase activity in our experiments was the PCB metabolite 3-hydroxy-2,3',4, 4',5-pentachlorobiphenyl with an IC50 value of 0.2 microM. A hydroxyl group in the para or meta position appeared to be an important structural requirement for T2 sulfotransferase inhibition by PCB metabolites. Ortho hydroxy PCBs were much less potent, and none of the parent PHAHs was capable of inhibiting T2 sulfotransferase activity. In addition, the formation of T2 sulfotransferase-inhibiting metabolites of individual brominated diphenyl ethers and nitrofen as well as from some commercial PHAH mixtures (e.g., Bromkal, Clophen A50, and Aroclor 1254) was also demonstrated. These results indicate that hydroxylated PHAHs are potent inhibitors of thyroid hormone sulfation. Since thyroid hormone sulfation may play an important role in regulating free hormone levels in the fetus, and PCB metabolites are known to accumulate in fetal tissues after maternal exposure to PCBs, these observations may have implications for fetal thyroid hormone homeostasis and development.     

Cloning and characterization of the azurin iso-1 gene, concerned with the electron transport chain involved in methylamine/methanol oxidation in the obligate methylotroph Methylomonas sp. strain J

Two azurin-type blue copper proteins, which is concerned with the electron transport chain involved in methylamine/methanol oxidation, have been found in the obligate methylotroph Methylomonas sp. strain J. The azurin iso-1 gene was cloned and sequenced to analyze the role in the electron transport chain. PCR products synthesized with primers based on the N- and C-terminal amino acid sequences of azurin iso-1 were used as probes for cloning. One complete open reading frame (the azurin iso-1 gene) and one partial orf (orf1) were found in a cloned Eco105I-HindIII fragment, pMAZ3, with a total of 1066 bp. The gene encoded 148 amino acid residues. The amino acid sequence after Ala-21, deduced from the nucleotide sequence, was identical to that of the azurin iso-1 protein. The gene was in a region separate from the mau gene cluster in the chromosome. Escherichia coli expressed azurin iso-1. The results of northern blotting analysis suggested that expression of the azurin iso-1 gene is regulated by a complex regulatory network controlling oxidation of methylamine or methanol in this strain; for example, copper ions affected the expression of the azurin iso-1 gene.     

On-line neuro-expert monitoring system for Borssele Nuclear Power Plant

A new method for an on-line monitoring system for the nuclear power plants has been developed utilizing the neural networks and the expert system. The integration of them is expected to enhance a substantial potential of the functionality as operators support.

The recurrent neural network and the feed-forward neural network with adaptive learning are selected for the plant modeling and anomaly detection because of the high capability of modeling for dynamic behavior. The expert system is used as a decision agent, which works on the information space of both the neural networks and the human operators. The information of other sensory signals is also fed to the expert system, together with the outputs that the neural networks generate from the measured plant signals. The expert system can treat almost all known correlation between plant status patterns and operation modes as a priori set of rules.

From the off-line test at Borssele Nuclear Power Plant (PWR 480 MWe) in the Netherlands, it was shown that the neuro-expert system successfully monitored the plant status. The expert system worked satisfactorily in diagnosing the system status by using the outputs of the neural networks and a priori knowledge base from the PWR simulator. The electric power coefficient is simultaneously monitored from the measured reactive and active electric power signals.     

Human placental amino acid transporter genes: expression and function

Recent findings on amino acid transporter genes are reviewed with particular focus on matching previously described transport systems to individual genes. Functional studies using cloned and expressed transporters are considered as the critical tool allowing identification of the functional properties of individual genes. Specifically, these experiments allow identification of the transported substrate amino acids and of the transport mechanism. We focus on the very recent discovery and properties of the heterodimeric family of amino acid transport proteins where two subunits encoded in different genes are required. For these transporters, co-expression of both subunits is mandatory for functional studies. The field of placental amino acid transport is further complicated by complexities arising from both gestational age-specific and species-specific gene expression. The function of the transporter also depends on its cellular localization in the trophoblast. In addition, for transporters that are coupled to ion gradients, both membrane potential and ion pumping will contribute to the rate of amino acid delivery to the fetus. Regulation of function is important not only for fetal nutrition but also for specific additional aspects of placental biology.