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PubMed1984

Characterization of prototypical opioid antagonists, agonist-antagonists, and agonists in the morphine-dependent rhesus monkey.

In non-withdrawn maximally-dependent rhesus monkeys, both naloxone (NOX) and nalorphine (NAL) precipitated withdrawal when given 2 h after morphine (M). When these drugs were given 15 h after M, at which time the animals were in severe withdrawal and M blood levels were much lower, they promptly exacerbated withdrawal. Thus, mu antagonists may act competitively in non-withdrawn addicts and noncompetitively in withdrawn subjects. Buprenorphine (BRN), the partial mu agonist, precipitated withdrawal in stable addicts and partly suppressed withdrawal signs in abstinent addicts. Finally, ethyl-ketocyclazocine (EKC), the purported kappa agonist, did not precipitate but partly suppressed withdrawal at doses producing severe side effects. Perhaps this suppression is associated with kappa activity.

Animals↗
PubMed1989

Interleukin 2: prototype for a new generation of immunoactive pharmaceuticals.

Molecular biological techniques have revealed the interleukin-2 receptor to be a dimer composed of one alpha-subunit and one beta-subunit which interact noncovalently in a cooperative manner. Site-directed mutagenesis, in conjunction with structural analysis, is beginning to clarify the relationship between structural components of the receptor and their function, and Thomas Ciardelli and Kendall Smith explain why this is bringing drug developers closer to the design of IL-2 agonists and antagonists.

Adjuvants, Immunologic↗
PubMed1985

Feline calicivirus subunit vaccine--a prototype.

A vaccine was prepared from a subunit component, antigenically similar to the whole feline calicivirus (FCV) particles. Despite the limited number of animals available for this study we were able to demonstrate that the vaccine protected cats when challenged with a virulent strain of the virus while the non-vaccinates kept as controls developed clinical and histopathological symptoms of the calicivirus disease.

Animals↗
PubMed1993

Automatic bioprocess control. 4. A prototype batch of Saccharomyces cerevisiae.

The recent investigations in our high performance bioreactors have shown that living cells can be extremely sensitive to physical-chemical environmental conditions and their changes. Consequently, the relationship bioreactor-living cell must thoroughly be investigated in order to discuss both: whether bioreactor characteristics are limiting/dominating during cultivation and to what extent controlled changes of the cellular environment can lead the cells to a desired physiological state. For these investigations, a generally accepted biological test organism would be helpful, of which the requirements and reactions under certain conditions are well known. Saccharomyces cerevisiae is a well known, very robust but nevertheless sensitive organism, eligible for this purpose. In this article a typical batch cultivation on glucose is presented, collected from approx. 300 experiments. Regarding metabolite production and consumption, seven different phases are distinguished on the basis of approx. 20 sensor signals and their metabolic background is discussed. Prerequisite, however, was an exhaustive knowledge upon extracellular conditions, a task which could successfully be fulfilled with the highly automated equipment introduced in the preceding articles of this series.

Acetates↗
PubMed1993

Equine influenza virus from the 1991 Swedish epizootic shows major genetic and antigenic divergence from the prototype virus.

The antigenic properties of H3N8 equine influenza virus from the Swedish epizootic of 1991 differ from those of A/eq 2/Fontainebleau/79 (representative of the Swedish vaccine strain) in hemagglutination inhibition tests. The amino acid sequence of the hemagglutinin (HA) of an isolate from the 1991 outbreak was deduced from the nucleotide sequence and comparison was made to the A/eq 2/Fontainebleau/79 strain. Twenty-three amino acid substitutions were found, 10 mapping onto areas of the HA known to bind antibodies in human H3 influenza viruses. The amino acid changes together with the serological data suggest that a major antigenic drift has taken place in equine H3N8 viruses in Sweden and we conclude that recent strains of the virus must be incorporated into vaccines on a regular basis if epizootics of equine influenza are to be controlled in the future.

Amino Acid Sequence↗
PubMed1994

The human parainfluenza virus type-1 prototypic strain contains a heat-labile hemagglutinin-neuraminidase protein.

The virus yield of human parainfluenza virus type-1 (hPIV-1) in cultured cells at 38 degrees C is reduced more than 100-fold compared to 34 degrees C, while the virus yield of Sendai virus (SV, Enders strain), a murine parainfluenza virus type-1 with high homology to hPIV-1 was almost equal at both temperatures. To understand the basis for the differences in the temperature growth characteristics of the two viruses, we examined the heat-stability of hPIV-1 and SV glycoproteins expressed from cDNAs by pulse-chase experiments. The hemagglutinin-neuraminidase (HN) protein of hPIV-1 was stable after a 6-h chase at 34 degrees C, while at 38 degrees C prominent protein degradation was observed starting at 3 h chase and by 6 h HN was reduced by 65%. In contrast, SV HN protein was stable at both 34 and 38 degrees C. The other hPIV-1 glycoprotein, the fusion (F) protein was stable at both temperatures. To identify the amino acids which are responsible for the heat-lability of hPIV-1 HN, mutant HN proteins were constructed by site-directed mutagenesis. Mutant hPIV-1 HN which had substitutions at positions 461 and 462 became heat-stable at 38 degrees C. These data indicate amino acids around 461 are responsible for the heat-lability of the wild type hPIV-1 HN protein and the reduced yield of the virus at 38 degrees C.

Amino Acid Sequence↗
PubMed1994

European prototype for integrated care (EPIC).

The EPIC project has devised a means by which care workers can share client information between different professions and different locations through the use of a common domain information model for the client dossier, the client reference dossier and the EPIC message. This approach will be tested by its application to the assessment, planning and delivery of care to individual elderly clients in the community with the intention of extending and applying it to other aspects of the business of the community care service and other client groups in the future.

Community Health Services↗
PubMed1986

RNA fingerprinting of South American prototype aphthovirus strains.

Aphthovirus strains used in South America for vaccine production or as reference for diagnostic purposes were analysed by RNA fingerprinting (RNase T1 maps, one- and two-dimensional gels). The results obtained constitute the basis for a data bank containing available information about the genome structure of strains of aphthovirus prevalent in this continent and can be used as an adjunct to serological and immunological information. These data are currently being used in South American countries to assess the genetic stability of strains during vaccine production; to establish possible vaccine origin of field outbreaks and to monitor the origin, behaviour and fate of new strains in the field.

Animals↗
PubMed1992

Comparative analysis of the immunostimulatory properties of different adjuvants on the immunogenicity of a prototype parainfluenza virus type 3 subunit vaccine.

The immunogenicity of a parainfluenza virus type 3 (PIV-3) subunit vaccine consisting of affinity-purified haemagglutinin-neuraminidase (HN) and fusion (F) surface glycoproteins was tested in guinea-pigs and hamsters. The ability of several different immunopotentiating agents to enhance the antibody response of animals to the PIV-3 surface glycoproteins was evaluated. The immunity induced by HN and F alone was compared with the response elicited by purified proteins combined with Freund's complete adjuvant, aluminium phosphate, Syntex's threonyl-muramyl dipeptide (MDP) SAF-MF formulation, or Ribi's adjuvant formulation containing BCG cell wall skeleton (CWS), trehalose dimycolate (TDM) and monophosphoryl lipid A (MPL) in a 2% squalene-in-water emulsion. Purified proteins were also incorporated into three different liposome formulations prepared by the detergent dialysis procedure. Immunization of guinea-pigs and hamsters with two 15 micrograms doses of the PIV-3 surface glycoproteins administered in the absence of adjuvant elicited high haemagglutination inhibition, neutralization and anti-fusion titres. The liposome preparations failed to enhance the antibody titres. Ribi's adjuvant formulation was effective at inducing a good secondary response to the purified proteins while the immunostimulatory effects of aluminium phosphate, Syntex and Freund's adjuvants were clearly demonstrated in both primary and secondary responses. When administered without adjuvant, a 15 microgram dose of the HN and F mixture was capable of protecting hamsters against live virus challenge. The immunoprotective dose of the purified proteins could be reduced to at least 0.1 microgram by the addition of aluminium phosphate, Syntex or Freund's adjuvants.

Adjuvants, Immunologic↗
PubMed1995

The antibody response to a prototype liposome vaccine containing Neisseria meningitidis outer membrane protein P1 produced in Bacillus subtilis.

Monoclonal antibodies to the class 1 outer membrane protein P1 of Neisseria meningitidis B:15:P1.7,16 have been shown to be bactericidal and protective in an infant rat meningitis model. We have produced the P1 protein in Bacillus subtilis as inclusion bodies. When the purified and denatured protein (BacP1) was reconstituted with phosphatidylcholine into liposomes, native antigenic epitopes were formed. Such liposomes were reproducibly immunogenic in mice and guinea pigs at a low dose (1-10 micrograms of BacP1 protein) and without any other adjuvant. The resulting antisera contained high titers (enzyme immunoassay) of antibodies directed to native P1 epitopes exposed on the surface of meningococcal cells. The sera were also active with live N. meningitidis in bactericidal assays and protective in the infant rat meningitis model; all these activities were specific to the serosubtype of the P1 protein.

Animals↗
PubMed1995

Evaluating the effects of elevated levels of atmospheric trace gases on herbs and shrubs: a prototype dual array field exposure system.

In the context of global climate change, an understanding of the long-term effects of increasing concentrations of atmospheric trace gases (carbon dioxide, CO(2), ozone, O(3), oxides of nitrogen, NO(x) etc.) on both cultivated and native vegetation is of utmost importance. Over the years, under field conditions, various trace gas-vegetation exposure methodologies with differing advantages and disadvantages have been used. Because of these variable criteria, with elevated O(3) or CO(2) levels, at the present time the approach of free-air experimental-release of the gas into study plots is attracting much attention. However, in the case of CO(2), this approach (using 15 m diameter study plot with a single circular array of vent pipes) has proven to be cost prohibitive (about 59000-98000 dollars/year/replicate) due to the consumption of significant quantities of the gas to perform the experiment (CO(2) level elevated to 400 ppm above the ambient). Therefore, in this paper, we present a new approach consisting of a dual, concentric exposure array of vertical risers or vent pipes. The purpose of the outer array (17 m diameter) is to vent ambient air outward and toward the incoming wind, thus providing an air curtain to reduce the velocity of that incoming wind to simulate the mode or the most frequently occurring wind speed at the study site. The inner array (15 m diameter) vents the required elevated levels of trace gases (CO(2), O(3), etc.) into the study plot. This dual array system is designed to provide spatial homogeneity (shown through diffusion modeling) of the desired trace-gas levels within the study plot and to also reduce its consumption. As an example, while in the single-array free-air CO(2)-release system the consumption of CO(2) to elevate its ambient concentration by 400 ppm is calculated to be about 980 tons/year/replicate, it is estimated that in the dual array system it would be approximately 590 tons/year/replicate. Thus, the dual array system may provide substantial cost savings (24000-39000 dollars/year/replicate) in the CO(2) consumption (60-100 dollars/ton of CO(2)) alone. Similarly, benefits in the requirements of other trace gases (O(3), NO(x), etc.) are expected, in future multivariate studies on global climate change.

Journal Article↗
PubMed1992

Biosphere 2 Test Module: a ground-based sunlight-driven prototype of a closed ecological life support system.

Constructed in 1986, the Biosphere 2 Test Module has been used since the end of that year for closed ecological systems experiments. It is the largest closed ecological facility ever built, with a sealed variable volume of some 480 cubic meters. It is built with a skin of steel spaceframes with double-laminated glass panels admitting about 65 percent Photosynthetically Active Radiation (PAR). The floor is of welded steel and there is an underground atmospheric connection via an air duct to a variable volume chamber ("lung") permitting expansion and contraction of the Test Module's air volume caused by changes in temperature and barometric pressure, which causes a slight positive pressure from inside the closed system to the outside thereby insuring that the very small leakage rate is outward. Several series of closed ecological system investigations have been carried out in this facility. One series of experiments investigated the dynamics of higher plants and associated soils with the atmosphere under varying light and temperature conditions. Another series of experiments included one human in the closed system for three, five and twenty-one days. During these experiments the Test Module had subsystems which completely recycled its water and atmosphere; all the human dietary needs were produced within the facility, and all wastes were recycled using a marsh plant/microbe system. Other experiments have examined the capability of individual component systems used, such as the soil bed reactors, to eliminate experimentally introduced trace gases. Analytic systems developed for these experiments include continuous monitors of eleven atmospheric gases in addition to the complete gas chromatography mass spectrometry (GCMS) examinations of potable, waste system and irrigation water quality.

Air Conditioning↗
PubMed1992

Effect of prototypic polychlorinated biphenyls on hepatic and renal vitamin contents and on drug-metabolizing enzymes in rats fed diets containing low or high levels of retinyl palmitate.

Two groups of weanling male Sprague-Dawley rats fed a diet supplemented with either 0.6 or 6 retinol equivalents/g diet were each separated into three further groups receiving 300 mumol 2,2',4,4',5,5'-hexachlorobiphenyl/kg body weight, 300 mumol 3,3',4,4'-tetrachlorobiphenyl kg/body weight or vehicle only (corn oil). Only the coplanar (3,4)2Cl congener caused a slight reduction in food intake, thymic atrophy and led to a significant decrease in the liver vitamin A storage. The vitamin A lost by the liver was approximately the same in both dietary groups; however an increased renal accumulation of vitamin A was observed in the high vitamin A group. Serum retinol was reduced by (3,4)2Cl treatment but remained unchanged by (2,4,5)2Cl exposure. Total amounts of ascorbic acid and its oxidation products were increased in the liver and in the kidney by both xenobiotics while niacin and thiamine concentrations were lowered by (3,4)2Cl only. Microsomes from vitamin A-deficient rats exhibited a marked decrease in the anisotropy parameter. After (2,4,5)2Cl exposure, an increase in membrane fluidity was observed linked to a decrease in cholesterol/phospholipid (C/P) ratio. Treatment with (3,4)2Cl caused a significant decrease in the index of fluorescence polarization only in the low vitamin A group even if the C/P ratio was enhanced in both dietary groups. This study shows that the polychlorinated biphenyl with the 3-methylcholanthrene-type pattern of induction of cytochrome P-450 has more profound effects on B group vitamins and particularly vitamin A homeostasis than does the phenobarbital-type inducer. Moreover, this situation, which has been found to be similar to that in vitamin A deficiency, is not ameliorated by a high dietary vitamin A intake.

Animals↗
PubMed1987

A time-course investigation of vitamin A levels and drug metabolizing enzyme activities in rats following a single treatment with prototypic polychlorinated biphenyls and DDT.

Xenobiotics previously characterized as selective inducers of drug-metabolizing enzymes were chosen to probe possible relationships between enzyme induction and vitamin A metabolism. Liver, kidney and serum retinol and retinyl palmitate levels were investigated in male Sprague--Dawley rats receiving a single i.p. injection of the polychlorinated biphenyls (PCBs), 2,2',5,5'-tetrachlorobiphenyl, 3,3',4,4'-tetrachlorobiphenyl or 2,2',4,4',5,5'-hexachlorobiphenyl (300 mumol/kg) or 1,1,1-trichloro-2,2-bis-(4-chlorophenyl)-ethane (DDT) (150 mumol/kg). While 2,2',5,5'-tetrachlorobiphenyl, a weak or non-inducer, and 2,2',4,4',5,5'-hexaclorobiphenyl and DDT, phenobarbital-type inducers of cytochrome P-450, led to no reduction in total vitamin A content of liver or kidney during the 7 day time-course, administration of 3,3',4,4'-tetrachlorobiphenyl, a toxic PCB and a potent 3-methylcholanthrene-type inducer of cytochrome P-450, resulted in progressively lowered liver vitamin A levels (to 40% of control values by day 7). During this time, kidney total vitamin A content increased 3-fold. The increase in kidney vitamin A (due primarily to increased retinol content) was only equal to 1/40 of total vitamin A which had disappeared from the liver. Although 3,3',4,4'-tetrachlorobiphenyl specifically induced certain drug-metabolizing enzyme activities, e.g. aryl hydrocarbon hydroxylase and UDP-glucuronosyltransferase (toward 4-nitrophenol), no highly significant correlations were found among the vitamin A levels and drug-metabolizing enzyme activities in the liver (aminopyrine N-demethylase, aryl hydrocarbon hydroxylase, aldrin epoxidase, microsomal epoxide hydrolase, UDP-glucuronosyltransferase toward 4-nitrophenol, glutathione transferase toward 1-chloro-2,4-dinitrobenzene and cytochrome P-450 content) as determined by multiple linear regression analysis.

Animals↗
PubMed1981

Toward a "bio-energy supplement" -- a prototype for functional orthomolecular supplementation.

A broad-spectrum approach to the nutritional optimization of bioenergetics is discussed as a specific example of the principle of functional orthomolecular supplementation. Experimental and clinical studies with "metavitamins" such as lipoic acid, carnitine, coenzyme Q, and creatine, and with mitochondrial antioxidants, indicate that many nutritional agents involved in bioenergetics are often functionally sub-saturated. Numerous therapeutic applications for a well-designed "bio-energy supplement" can be postulated.

Animals↗