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PubMed1977

Changes in striatal dopamine metabolism during precipitated morphine withdrawal.

Precipitation of withdrawal in morphine tolerant/dependent rats by either naloxone or the partial agonist ZK 48491 caused a significant increase in the contration of striatal DA, which persisted for at least 1 h. During the same time the probenecid-induced accumulation of HVA and DOPAC was reduced in the striatum in relation to probenecid-treated tolerant/dependent controls. 20 min after precipitation of withdrawal by naloxone, the striatal concentration of 3-methoxytyramine was decreased by about 40%, while the activity of the DA metabolizing enzymes, MAO and COMT, remained unchanged. Naloxone-precipitated withdrawal was, further, found to delay the depletion of striatal DA caused by inhibition of synthesis 90 min after alpha-methyl-p-tyrosine treatment. All these results provide evidence for a decreased release of DA from the striatum during precipitated morphine withdrawal.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1988

Solubilization of immune precipitates by complement in the absence of properdin or factor D.

Various experiments have demonstrated that immune precipitates (IPs) are not solubilized by complement in the absence of alternative pathway function. To determine whether the characteristics of the IPs were responsible for these observations, we studied the solubilization (Sol) of IPs formed by bovine serum albumin (BSA)-rabbit antiBSA and tetanus toxoid (TT)-human antiTT. Sera deficient in properdin solubilized a fraction of BSA-antiBSA precipitates, although only when the IPs were formed in antibody excess. The same sera solubilized TT-antiTT precipitates with some delay but almost as efficiently as normal serum. Factor D-depleted serum solubilized a fraction of TT-antiTT precipitates too, indicating that Sol may proceed through activation of the classical pathway only. Thus, the requirements for complement-mediated Sol depend on the characteristics of the IPs and do not necessarily include alternative pathway function.

Antibodies↗
PubMed1991

An intercultural assessment of the type, intensity and number of crisis precipitating factors in three cultures: United States, Brazil and Taiwan.

The precipitating factors of crisis have cultural interpretations that make diagnostic criteria and intervention methods ethnologically different. The crisis precipitating factors of individuals seeking intervention in the Republic of China (Taiwan), Brazil and the United States (U.S.) were investigated toward the end of isolating correlates and discrepancies of ethnic-related precipitants of crisis. The primary objective of the study was to influence crisis intervention in the profession of nursing from the almost universally utilized Western Model, to one that takes cultural uniqueness into account. Stressors and stressor intensities which lead to help-seeking behavior of clients in selected crisis intervention facilities in the three countries were identified. A 60 question instrument ranked client responses according to Axis 4 of the Diagnostic and Statistical Manual-III of the American Psychiatric Association (APA, 1980; 1986). Each item also reflected one of four Human Response Patterns of the North American Nursing Diagnostic Association (NANDA) taxonomy, which was utilized as a clustering device in data analysis. Somatization versus psychologization of crisis precipitating factors was also measured through the NANDA categories. A convenience sample of 30 subjects were queried in each country by nurse interviewers. Data analysis through ANOVA showed cultural uniqueness and mutuality.

Adolescent↗
PubMed1983

Precipitability and composition of HBsAg-anti-HBs immune complexes formed in the presence of complement. A model of circulating immune complex analysis.

Immune complexes (IC) of partially purified HBsAg and human anti-HBs were prepared at different antigen/antibody ratios in the presence of complement in normal human serum (NHS), and under conditions not allowing complement activation in buffers or in NHS containing 10 mM EDTA (NHS-EDTA). Commercial preparations of the radiolabelled antigen and antibody were used. IC formed in NHS were not significantly precipitated even after incubation for 24 h at 4 degrees C, whereas a typical precipitation curve was observed with complexes formed in the absence of complement. Thus, complement activation was found to markedly and permanently inhibit precipitability of HBsAg-anti-HBs immune complexes (HBsAg-IC). HBsAg-IC were precipitated from sera with 3.5% polyethylene glycol (PEG), boiled in sodium dodecyl sulphate (SDS)-urea buffer, and analysed by SDS-polyacrylamide slab gel electrophoresis (SDS-PAGE). With complexes formed in the presence of complement, about one-sixth of the antibody activity was found in high molecular weight fractions corresponding in size to IgG oligomers. By contrast, with complexes formed without complement, no significant amount of antibody was found in these fractions. With blotting technique and radiolabelled anti-human-C3 antibody, it was demonstrated that anti-HBs was covalently bound to C3b fragments in IC formed in the presence of complement and was in the high molecular weight fractions.

Animals↗
PubMed1990

The detection of anti-Ro/SS-A and anti-La/SS-B antibodies. A comparison of counterimmunoelectrophoresis with immunoblot, ELISA, and RNA-precipitation assays.

The presence in serum of anti-Ro/SS-A and/or anti-La/SS-B autoantibodies is a characteristic of autoimmune diseases such as Sjögren's syndrome and systemic lupus erythematosus. To evaluate different assays currently available for the detection of these antibodies 50 sera were tested using the four different assay methods: counterimmunoelectrophoresis (CIE), RNA precipitation assay, immunoblotting technique and ELISA. The RNA-precipitation assay showed the highest sensitivity and specificity. The CIE for the detection of anti-Ro/SS-A antibodies gave comparable results whereas the Ro/SS-A ELISA and Ro/SS-A or HeLa immunoblot showed lower sensitivities (96% and 80% respectively). Sensitivity was even lower (66%) when only reactivity towards the 60 kDa Ro/SS-A protein was considered. The ELISA for the detection of anti-La/SS-B antibodies showed a sensitivity of 98%, the immunoblotting technique of 86% and the CIE only 67%. The high sensitivity of the La/SS-B ELISA went together with a low specificity of 14%. We conclude from these data that for the detection of anti-Ro/SS-A and anti-La/SS-B antibodies the RNA precipitation assay shows the highest sensitivity and highest specificity. For routine screening purposes the CIE is the most convenient and reliable assay to detect anti-Ro/SS-A antibodies. For the detection of anti-La/SS-B antibodies the immunoblot corresponds most closely to the RNA precipitation assay.

Antibodies, Antinuclear↗
PubMed1993

Inhibition of naloxone-precipitated withdrawal jumping by i.c.v. and i.t. administration of saline in morphine-dependent mice.

In morphine-dependent mice, s.c. and i.t. administered naloxone produced withdrawal jumping (ED50 values were i.t. = s.c.) but i.c.v. administered naloxone failed to produce dose-dependent jumping. Peak times of jumping were earliest after i.t. administration of naloxone among the three administration routes. These results suggested that the spinal site was more sensitive to naloxone than the supraspinal site. Concomitant administration of naloxone i.c.v. and i.t. did not precipitate jumping. It was found that i.c.v. and i.t. injections of saline inhibited withdrawal jumping precipitated by s.c. administered naloxone and that the i.c.v. effect was more profound than the i.t. effect. I.c.v. injection of saline also delayed the peak time of withdrawal jumping precipitated by s.c. administered naloxone. These inhibitory effects of the injection procedures may explain the difficulty of i.c.v. administered naloxone and concomitant i.c.v. + i.t. administered naloxone to precipitate jumping, and may explain the difference in the ED50 values of naloxone and the time courses of jumping.

Animals↗
PubMed1984

Does qualitatively altered fibrinogen contribute to the increased heparin precipitable fraction (HPF) in acute myocardial infarction (AMI)?

The amount and protein composition of heparin precipitable fraction (HPF), and the plasma concentrations of fibrinogen, fibronectin, alpha 1-acid glycoprotein, alpha 1-antitrypsin, haptoglobin and C-reactive protein (CRP) were determined in healthy subjects as well as during the course of acute myocardial infarction (AMI). In all samples tested, HPF consisted nearly exclusively of fibrinogen and fibronectin. In the small precipitates from healthy subjects, approximately equal amounts of these two proteins were recovered. During the first days of AMI, plasma fibrinogen increased 2-3 fold. At the same time, however, the amount of HPF increased 5-10 fold. This increase was associated with increased precipitation of fibrinogen, whereas no simultaneous increase in fibronectin was found. In fact, a slight drop in plasma as well as HPF-fibronectin was regularly observed during this period. During the following week HPF returned to normal values, whereas the plasma fibrinogen remained elevated. No satisfactory explanation for this discrepancy can be offered at present. Thus, no evidence could be provided that other acute phase proteins than fibrinogen itself were involved. Some experiments, however, indicated qualitative changes in the fibrinogen participating in the HPF precipitation. Further studies are necessary to clarify this point. Such studies are in progress.

Acute-Phase Proteins↗
PubMed1983

Cold-precipitable immune complexes in collagen diseases: evidence for the coexistence of multiple types of circulating complexes in the same serum.

In patients with systemic lupus erythematosus, mixed cryoglobulinemia, and rheumatoid arthritis, the presence of cold-precipitable immune complexes (IC) was investigated by means of two different methods, i.e., the Clq-binding activity (ClqBA) and a competitive enzyme immunoassay, based on solid-phase bovine conglutinin (K). Cold precipitability of IC ranged between 0 and 100% with K and between 0 and 71% with ClqBA. No correlation existed either between the levels or the cold precipitability of the IC measured by the two systems in the same sera. On the whole, cold-precipitable IC were better determined by the K method than by ClqBA and in mixed cryoglobulinemia cryocrit levels correlated with IC levels determined with K, but not ClqBA. These data provide direct evidence of the coexistence of several types of circulating IC in the same serum and that the two methods recognize, at least in part, different IC in the same specimen. It might be hypothesized that different IC present in a serum may have a distinct biological significance.

Antigen-Antibody Complex↗
PubMed1992

Blocking naloxone-precipitated withdrawal in rats and hamsters.

Three experiments studied the effects of putative antagonists of opiate withdrawal in hamsters and rats. In Experiment 1, the calcium channel antagonists verapamil (20 mg/kg) and nifedipine (20 mg/kg) failed to antagonize naloxone (1 mg/kg)-precipitated withdrawal in hamsters implanted with two 75-mg morphine pellets, whereas clonidine (0.4 mg/kg), the alpha 2-adrenergic agonist, blocked most withdrawal signs. In Experiment 2, clonidine (0.4 mg/kg) and verapamil (20 mg/kg) were tested against naloxone-precipitated withdrawal in hamsters made acutely dependent by a single injection of morphine (15 mg/kg). As in Experiment 1, clonidine but not verapamil was effective. In Experiment 3, the effects of verapamil on naloxone-precipitated withdrawal were studied in morphine-pelleted rats and hamsters. In rats implanted with two morphine pellets, verapamil (20 mg/kg) reversed naloxone-precipitated withdrawal. By contrast, in hamsters implanted with either one or two morphine pellets neither of two doses of verapamil (20 and 30 mg/kg) was effective. These results are discussed in terms of species' differences in sensitivity to calcium channel blockers.

Animals↗
PubMed1987

Mixed precipitation in gel: a new method of identification and characterization of monoclonal antibodies.

A mixed precipitation in the gel (MPG) technique is suggested for detection and characterization of monoclonal antibodies (MAbs). The MPG is based on the formation of a mixed precipitate composed of an antigen, the corresponding MAb and precipitating polyclonal antiserum. MAb incorporated into the precipitate is revealed by Fab'-peroxidase conjugate added to polyclonal antiserum. The MPG technique was applied to hybridoma screening as well as for the antigen and epitope specificity analysis of different MAbs. The MPG is a one-step, simple, inexpensive technique and valuable for the study of any antigen which could be revealed by immunodiffusion.

Agar↗
PubMed1988

Jacalin: isolation, characterization, and influence of various factors on its interaction with human IgA1, as assessed by precipitation and latex agglutination.

An IgA1-specific lectin, Jacalin, was isolated from dried seeds of the jackfruit, Artocarpus integrifolia, by affinity binding to IgA1-Sepharose and elution with D-galactose. Jacalin is a glycoprotein with two non-covalently bound subunits (15 and 18 K). Interactions between Jacalin and human Igs were studied by precipitation in gel and in solution, and by agglutination of IgA1-coated latex by Jacalin. Jacalin precipitated only with IgA1-containing samples, including monomers, polymers, monoclonal, polyclonal and secretory IgA1, but not IgA2 of both A2m(1) and A2m(2) allotypes, nor with IgG1, 2, 3 and 4, IgM, IgD, and IgE; after neuraminidase treatment, only IgA1 and IgD were precipitated. Jacalin had a relatively broad pH range of activity in both precipitation and agglutination of IgA1-latex. Bivalent metal cations (Ca, Mg, Mn, Cu, Zn, Co, Cd), EDTA, Triton X-100, Tween-20, Na deoxycholate and ionic strength did not influence these reactions. Na dodecylsulphate, guanidine and urea inhibited the reactions whereas NP-40 rather enhanced them. Among 39 types of sugar tested, 10 displayed inhibitory activity, decreasing in the following order: p-nitrophenyl-alpha-D-galactopyranoside, 1-O-methyl-alpha-D-galactopyranoside, D-melibiose, p-nitrophenyl-beta-D-galactopyranoside, GalNAc, stachyose, 1-O-methyl-alpha-D-mannopyranoside, D-galactose, D-galactosamine and 1-O-methyl-alpha-D-glucopyranoside. IgA1, treated with neuraminidase or not, but not the other human Igs, was also an excellent inhibitor of agglutination, being more powerful than the best sugars studied. Only neuraminidase-treated IgD was also inhibitory, but less so than IgA1. Jacalin preferentially bound to alpha-linked non-reducing D-galactose. The configuration of OH-groups at C-2, C-4 and C-6 of D-galactose was important for the reaction. Jacalin recognizes terminal Gal beta 1-3GalNac-, as in the IgA1-hinge, and/or GalNAc-, but not Gal beta 1-4GlcNAc-, nor Gal beta 1-6GlcNAc-, nor their sialylayted extensions. Latex agglutination and its inhibition assay are particularly well suited for the study of these lectin-glycoprotein interactions.

Agglutination↗
PubMed1990

The role of calcium precipitation in the sulfoglycolithocholate-induced cholestasis of the bile fistula hamster.

Sulfate glycolithocholic acid (SGLC) has been shown to be highly cholestatic in the rat. This study was performed in order to gain understanding of the mechanisms of SGLC-induced cholestasis and the aim of the investigation was to explore the hypothesis that SGLC could cause a precipitation of calcium in bile. We studied the effects of intravenously administrated SGLC on bile flow, biliary lipids secretion and calcium excretion in the female bile fistula hamster. We also performed in-vitro studies with a Ca2(+)-selective electrode in order to measure the calcium binding capacity of SGLC. The results showed that after 1 h of infusion of 8 mumol/100 g body weight [14C]SGLC bile flow dropped to zero. During the infusion period a fine white sludge was visible in the test tube used for bile collection. TLC and HPLC analysis of both the supernatant and the precipitate showed that unchanged SGLC was excreted into bile. Up to 20% of biliary SGLC and more than 50% of the total Ca2+ present in bile was precipitated. The SGLC/Ca2+ molar ratio in the precipitate was 1.12 +/- 0.3 (mean +/- S.D. of four experiments). Light and electron microscopy of the liver did not show any specific abnormalities. The Ca2+ binding activity of SGLC in vitro, was highest among the bile acids tested at a concentration of 0.1 mM, when almost 100% of bile acids are in the monomeric (non-micellar) form. This suggests that among the bile acids, SGLC exerts the strongest binding activity on free calcium ions.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Hydrogen behaviour and ion concentrations in precipitation of Europe and the United States.

Hydrogen ions in precipitation vary primarily with (SO4 + NO3) concentration. However the slope of the H: (SO4 + NO3) relation for high concentrations (0.60 and 0.61) is twice that at low concentrations (0.32 and 0.22) in European and US samples respectively. Sulphuric and nitric acid dominate precipitation in the US. Precipitation in Europe, although nearly equally acid, is dominated by NH4+, Ca2+, and Mg2+ salts at total ionic concentrations 2 and 3 times higher. Ion concentrations in precipitation, other than H, are proportional to their respective emission fluxes.

Journal Article↗
PubMed1992

Fluxes of ions in precipitation, throughfall and stemflow in an urban forest in Kuala Lumpur, Malaysia.

A study was carried out to determine the chemical composition of bulk precipitation, throughfall and stemflow in an urban forest in Kuala Lumpur, Malaysia. The mean weekly rainfall recorded during the period of study was 63.2 mm. Throughfall, stemflow and canopy interception of incident precipitation were 77.1%, 1.2% and 21.7% respectively. Bulk precipitation, througfall and stemflow were acidic, the pH recorded being 4.37, 4.71 and 4.15 respectively. In all cases the dominant ions were NO3, SO4, Cl, NH4, K, Ca and Na. Of the ions studied Ca, K, Cl, SO4, Mg and Mn showed net increases in passing through the forest canopy, while NH4, Na, NO3, Zn, H and Fe showed net retention. This study shows that the urban environment of Kuala Lumpur contributes considerable amounts of materials to the atmosphere, as reflected by the high ionic contents in bulk precipitation, throughfall and stemflow.

Journal Article↗
PubMed1986

Methysergide-induced precipitated withdrawal syndrome in phencyclidine-dependent rats.

Chronic phencyclidine (PCP) administration has been shown to produce tolerance to a number of its pharmacological actions. We have suggested that PCP interacts with the 5-HT2 receptors since it inhibits [3H]spiperone binding to 5-HT2 receptors in vitro. In the present study, we investigated whether methysergide (a 5-HT2 receptor blocker) induces the precipitated withdrawal syndrome in PCP-tolerant rats. The body weight of the rats in the abrupt and precipitated withdrawal groups was significantly lower 5 days and 1-5 days after withdrawal, respectively, than that in the control group. Furthermore, other typical precipitated abstinence syndrome characteristics such as jumping, wet-dog shake and ptosis were also observed in the precipitated withdrawal group. These results suggest that PCP produces its behavioral effects via an agonistic interaction with 5-HT2 receptor sites and that our method may be very useful for the development of a rat model for studying physical dependence on PCP.

Animals↗
PubMed1990

Identification of precipitable Ca2+ by electron spectroscopic imaging and electron energy loss spectroscopy in the organ of Corti of the guinea pig.

Ca2+ cations were precipitated with potassium antimonate in the cochlea of the guinea pig, and the formed precipitates were localized by electron microscopy using either elastically or inelastically scattered electrons. The elemental composition of the precipitates was determined by electron spectroscopic imaging (ESI) and electron energy loss spectroscopy (EELS). It was found that calcium, antimony and oxygen were the dominating elements in the precipitates formed in different cell types in the inner ear.

Animals↗
PubMed1990

Clonidine attenuates increased brain glucose metabolism during naloxone-precipitated morphine withdrawal.

The effect of two doses of clonidine on regional cerebral metabolic rates for glucose were measured during morphine withdrawal in rats. In the first study, 0 or 200 micrograms/kg clonidine was administered to rats subjected to naloxone-precipitated morphine withdrawal (naloxone, 0.5 mg/kg, s.c.), and to non-dependent control rats. In a second study of similar design, 0 or 20 micrograms/kg clonidine were administered. Withdrawal signs in rats subjected to naloxone-precipitated morphine withdrawal and receiving 0, 20 or 200 micrograms/kg clonidine were also assessed. Naloxone-precipitated morphine withdrawal stimulated regional cerebral metabolic rates for glucose (59 of 83 regions in study no. 1; 73 of 83 regions in study no. 2). At 200 micrograms/kg, clonidine attenuated this effect (33 of 59 regions). Although 200 micrograms/kg clonidine directly suppressed regional cerebral metabolic rates for glucose in many regions (significant main effect of clonidine), it attenuated the naloxone-precipitated morphine withdrawal effect specifically in the lateral septal nucleus, medial habenula, subiculum and gracile nucleus (significant interactions between clonidine and morphine withdrawal). The 20 micrograms/kg dose of clonidine had no statistically significant effect. In behavioral experiments, both doses of clonidine diminished withdrawal in that there was no diarrhea, fewer wet-dog shakes and less abnormal posturing. However, locomotion, grooming and jumping were increased by clonidine. Most of these effects were statistically significant only with the 200 micrograms/kg dose. The results of these studies show that clonidine reduces morphine withdrawal-induced increases in regional cerebral metabolic rates for glucose in many brain regions, irrespective of the distribution of alpha 2-adrenoceptors. Although clonidine has been thought to ameliorate morphine withdrawal by actions primarily at the locus coeruleus and central amygdala, it may play a major role in other regions as well.

Animals↗
PubMed1993

Noninvasive subthreshold auricular electrical stimulation reduces the severity of precipitated and abrupt opiate withdrawal.

The objective of this study was to use noninvasive, subthreshold auricular electrical stimulation (AES) as a treatment to reduce the severity of precipitated and of abrupt opiate withdrawal. Sixty-four male Sprague-Dawley rats were divided into six groups. The first three groups were used to study the effects of AES on naloxone-precipitated withdrawal; the other three groups were used to examine the influence of AES on abrupt withdrawal. Morphine dependence was induced by multiple injections of the drug on an incremental staircase dosage regimen for 6 days. The results obtained from first three groups show that AES reduced the severity of the withdrawal signs precipitated by naloxone injection (0.5 mg/kg SC) by more than 75% (p < 0.01). The observations obtained from the other three groups show that AES reduced the severity of abrupt withdrawal for at least 4 h as assessed by measuring the locomotor behavior of the animals. This study demonstrates that noninvasive subthreshold AES is effective in reducing the severity of precipitated and of abrupt opiate withdrawal.

Animals↗