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PubMed2004

Atmospheric pollen season in Zagreb (Croatia) and its relationship with temperature and precipitation.

The number of individuals allergic to plant pollen has recently been on a constant increase, especially in large cities and industrial areas. Therefore, monitoring of airborne pollen types and concentrations during the pollen season is of the utmost medical importance. The research reported in this paper aims to determine the beginning, course and end of the pollen season for the plants in the City of Zagreb, to identify allergenic plants, and to assess the variation in airborne pollen concentration as a function of temperature and precipitation changes for the year 2002. A volumetric Hirst sampler was used for airborne pollen sampling. Qualitative and quantitative pollen analysis was performed under a light microscope (magnification x400). In the Zagreb area, 12 groups of highly allergenic plants (alder, hazel, cypress, birch, ash, hornbeam, grasses, elder, nettles, sweet chestnut, artemisia and ambrosia) were identified. Birch pollen predominated in spring, the highest concentrations being recorded in February and March. Grass pollen prevailed in May and June, and pollen of herbaceous plants of the genus Urtica (nettle) and of ambrosia in July, August and September. Air temperature was mostly higher or considerably higher than the annual average in those months, which resulted in a many days with high and very high airborne pollen concentrations. The exception was April, when these concentrations were lower because of high levels of precipitation. This also held for the first half of August and the second half of September. Pollen-sensitive individuals were at high risk from February till October because of the high airborne pollen concentrations, which only showed a transient decrease when the temperature fell or there was precipitation.

Allergens↗
PubMed2004

Evaporation of intercepted precipitation from fruit litter of Liquidambar styraciflua L. (sweetgum) in a clearing as a function of meteorological conditions.

Interception of precipitation by fruit litter is a poorly understood component of the hydrologic cycle in forested ecosystems. Even less well understood is the effect of meteorological conditions on the evaporation of precipitation intercepted by forest litter. This study sought to examine the influence of meteorological conditions on the evaporation of intercepted precipitation by fruit litter from Liquidambar styraciflua L. (sweetgum) by deriving and calibrating a regression model to estimate evaporation from the fruit litter that may be of potential use to forest and watershed managers. Data on evaporative losses from the fruit litter used to derive and calibrate the statistical model were acquired through a larger field experiment conducted from mid November 2002 through April 2003. Results from the forward stepwise least squares multiple regression model demonstrated that evaporative losses from the fruit litter were estimated with a high degree of accuracy based on the amount of water stored, solar radiation inputs, and vapor pressure deficit (adjusted R(2)=0.836, F=82.28, P<0.00001). The amount of water stored in the fruit litter explained the highest proportion of variance in the regression model. Storm to storm comparisons also highlighted the importance of solar radiation and wind speed in determining evaporation from the fruit litter. The regression model potentially may be used in conjunction with a canopy interception model to predict interception losses from L. styraciflua dominated forests and plantations.

Ecosystem↗
PubMed2005

Precipitants to psychiatric patient assaults on staff: review of empirical findings, 1990-2003, and risk management implications.

Psychiatric patient assaults on staff are a serious and continuing problem in health care settings. Over thirty years of empirical research have documented the characteristics of both patient assailants and staff victims. Notably absent from this literature have been similar empirical studies on the nature of patient precipitants to these assaults. This paper reviewed empirical studies of patient assault precipitants from 1990-2003. Six studies from three countries were reviewed. Common precipitants included staff restrictions on patient behaviors, denial of services, excessive sensory overload, and provocation by others. The clinical, methodological, and risk management implications are examined.

Empiricism↗
PubMed1987

Protein precipitation assay for quantitation of tannins: determination of protein in tannin-protein complex.

A protein precipitation method for the determination of tannins has been developed. The protein in the tannin-protein complexes was measured using the ninhydrin assay of amino acids released by alkaline hydrolysis of the complex. Standard protein and the complex were hydrolyzed with 13.5 N NaOH at 120 degrees C for 20 min and the amino acids released were measured with ninhydrin. Tannins did not interfere in the determination of protein by ninhydrin assay. The bovine serum albumin (BSA) precipitated (y; mg) increased linearly with increase in tannic acid (x) from 0.2 to 0.9 mg (y = 2.598x - 0.258). The protein precipitation capacities (mg BSA precipitated/g dry wt) measured by the method for young and mature leaves of oaks were Quercus incana (young, 42.21; mature, 79.51), Q. ilex (young, 1.86; mature, 1.86), and Q. semecarpifolia (young, 733.54; mature, 304.32). The method can provide valuable information on the mechanisms of protein-tannin interactions and nutritional and physiological significances of tannins.

Animals↗
PubMed1988

Densitometric assay of nanogram quantities of proteoglycans precipitated on nitrocellulose membrane with Safranin O.

Proteoglycan (PG) and glycosaminoglycan (GAG) samples corresponding to a minimum of 10 ng of uronic acid were reliably quantified as precipitates with the cationic dye Safranin O, collected by vacuum-aided filtration onto a cellulose acetate/nitrate membrane in a standard 96-well dot assay apparatus. The reflectances of the precipitation dots were measured by automatic densitometric scanning of the membrane sheets. Standard GAGs produced reflectance values which were related to the number of anionic groups per unit disaccharide; hyaluronate and keratan sulfate gave lower values while heparin yielded values higher than those of chondroitin sulfates. The presence of 8 M urea, 1% Triton X-100, 30% sucrose, 0.02% NaN3, or mixtures of proteinase inhibitors and various buffers did not markedly influence the reflectances, while 4 M guanidinium chloride and 3 M CsCl reduced the sensitivity of the assay to 30-50 ng. Samples containing sodium dodecyl sulfate (SDS) were not applicable because SDS precipitated with Safranin O. Proteins showed virtually no response, while nucleic acids gave significant although smaller reflectances than GAGs. Owing to its marked sensitivity and convenience the method is particularly suitable for the detection of PGs during their preparative purification and fractionation as well as in various analytical assays.

Chondroitin Sulfates↗
PubMed1975

Precipitation and carbohydrate-binding specificity studies on wheat germ agglutinin.

The ability of wheat germ agglutinin to form precipitates with a series of synthetic carbohydrate-protein conjugates and with carcinoembryonic antigen and its Smith degradation products was investigated. The precipitation reaction between wheat germ agglutinin and p-azophenyl 2-acetamido-2-deoxy-beta-D-glucopyranoside-bovine serum albumin was selected to examine the capacity of a large number of sugar haptens to inhibit this system. Our results indicate that the wheat germ agglutinin binding site is complementary to a sequence of three beta-(1 leads to 4)-linked N-acetyl-D-glucosamine units (N,N'N"-triacetyl chitotriose). The internal carbohydrate portion of carcinoembryonic antigen probably contains two such units and wheat germ agglutinin precipitates with untreated as well as sequentially Smith degraded carcinoembryonic antigen. Compared with other reports certain discrepancies in the relative binding affinities of per N-acetylated chitodextrins and N-acetyl-D-glucosamine were found. These differences are discussed in terms of the methods used and the proposed subsite hypothesis of Allen, A.K., Neuberger, A. and Sharon, N. (1973) Biochem. J. 131, 155-162.

Binding Sites, Antibody↗
PubMed1994

Precipitating events, locations and reactions associated with initial unexpected panic attacks.

This study examined the phenomenology of the initial panic attack in 85 panic disorder patients with or without agoraphobia. Patients were divided into minimal and extensive avoiders and three domains were assessed: precipitating factors, location of initial panic, and reaction to the panic. No apparent precipitating factor could be identified in approx 40% of the patients. The most common precipitants were injury/illness and interpersonal conflict. Extensive avoiders were more likely to have experienced the initial panic in classic agoraphobic situations. Public transportation was the most common location for the total sample. In reaction to the panic, minimal avoiders were more likely to have gone to a hospital emergency room (ER) whereas extensive avoiders were more likely to have done nothing in terms of help-seeking. Many patients with either minimal or extensive avoidance avoided the locations where the initial panic occurred, suggesting that circumscribed avoidance does not always generalize.

Adult↗
PubMed1989

In the absence of antibody IgGsorb precipitates human placenta phosphotyrosine-containing proteins.

Lectin-purified human placenta plasma membrane proteins were phosphorylated in vitro. Mixing the reaction mixture with IgGsorb and incubation of the resultant pellet with p-nitrophenyl phosphate demonstrated the presence of phosphorylated-insulin receptor beta-subunit and a phosphorylated-180 kDa protein in acrylamide gel electrophoresis. The same two proteins were detected in the electrophoretic analyses of anti-phosphotyrosine immunoprecipitated phosphorylation reaction mixtures. In the absence of antibody, the amount of phosphorprotein in the IgGsorb pellet was dependent on the amount of IgGsorb added. IgGsorb did not precipitate 125I-labeled lectin-purified human placenta protein. Further, 10 mM O-phosphotyrosine completely inhibited the precipitation of phosphorylated human placenta proteins. These data suggest that IgGsorb specifically bound and precipitated phosphotyrosine-containing proteins in soluble human placenta plasma membranes.

Cell Membrane↗
PubMed1987

Are 'precipitated LDL' really low density lipoproteins?

Cholesterol, phospholipid and Apo B levels were determined in low density lipoproteins (LDL) precipitated by amphipathic polymers (Biomérieux kit, Marcy-l'Etoile, France) and compared to those of ultracentrifuged LDL. For 113 sera (triglyceride level less than 4.5 mmol/l, absence of very low density lipoproteins-remnants) LDL-cholesterol values were significantly higher (p less than 0.001), and those of LDL-phospholipids (p less than 0.001) and LDL-Apo B (p less than 0.005) significantly lower. The correlations between the 3 constituents studied gave statistically different regression coefficients for the two methods. It is likely that discrepancy in results is due to the effect of ultracentrifugation and precipitation removing from the lipoprotein spectrum different sections which nonetheless have some common physicochemical or immunological properties. It would seem that the term 'LDL' is inappropriate to designate these precipitated lipoproteins.

Apolipoproteins B↗
PubMed1995

Intracisternal administration of interleukin-1 beta attenuates naloxone-precipitated withdrawal in morphine-dependent mice.

The effect of central administration of interleukin-1 beta on naloxone-precipitated withdrawal in morphine-dependent mice was studied. The degree of physical dependence on morphine was estimated by counting the number of jumps precipitated by naloxone, one of the typical withdrawal signs. Intracisternal (i.c.) administration of interleukin-1 beta (0.01-1 ng/5 microliters per mouse) to morphine-dependent mice 30 min prior to the injection of naloxone (10 mg/kg i.p.) decreased the number of jumps in a dose-dependent manner. The effect of interleukin-1 beta (1 ng) was significantly antagonized when it was co-administered with interleukin-1 receptor antagonist (1 microgram/mouse). These results suggest that centrally administered interleukin-1 beta could attenuate naloxone-precipitated withdrawal in morphine-dependent mice via interleukin-1 receptors in the brain. Co-administration of alpha-melanocyte-stimulating hormone (300 ng/mouse) or alpha-helical corticotropin-releasing factor (CRF)-(9-41), a CRF receptor antagonist (300 ng/mouse), with interleukin-1 beta also antagonized the inhibitory effect of interleukin-1 beta (1 ng). Moreover, i.c. administration of CRF (200 ng/mouse) significantly decreased the number of jumps.

Animals↗
PubMed1989

Determination of epitope specificities and affinities of monoclonal antibodies in solution phase using biotin-labeled carcinoembryonic antigen and avidin as precipitating agent.

A generally applicable method for the selective precipitation of antigens from solution phase is presented. The method is based on the rapid and quantitative binding of avidin to biotin-labeled antigen in the presence of biotinylated carrier protein. Using carcinoembryonic antigen (CEA) as a model antigen biotin-labeled CEA was precipitated to greater than 97% at amounts of up to 5000 ng/tube. The method was applied to the determination of epitope specificities and affinities of monoclonal anti-CEA antibodies in solution phase. Non-specific precipitation did not exceed 2% for radiolabeled Fab fragments and 6% for radiolabeled IgG. Because antigen-antibody binding takes place in solution, artifacts introduced by the immobilization of reactants to solid supports are omitted.

Animals↗
PubMed1987

Cerebrospinal fluid from morphine-dependent rats precipitates opiate abstinence syndrome.

Cerebrospinal fluid (CSF) was withdrawn from opiate-dependent rats following six hours of abstinence. It was infused into the third ventricle of opiate-dependent rats, precipitating immediate abstinence signs. The effect was similar to that of infusing the opiate antagonist naloxone, suggesting that opiate-dependent organisms may secrete an endogenous opiate antagonist substance. CSF withdrawn from non-dependent rats failed to precipitate an abstinence syndrome in morphine-dependent recipients. Conversely, CSF withdrawn from opiate-dependent rats following six hours of abstinence failed to precipitate an abstinence syndrome in non-dependent recipients. The active factor in the CSF is probably a peptide since it is filterable through a 10,000 MW filter and its activity is destroyed by three different proteolytic enzymes.

Animals↗
PubMed1994

Naloxone-precipitated morphine withdrawal increases pontine glutamate levels in the rat.

Extracellular fluid (ECF) levels of glutamate (Glu) and aspartate (Asp) were measured in the locus coeruleus (LC) during morphine withdrawal by using microdialysis in conscious morphine-dependent Sprague-Dawley rats. Guide cannulae were implanted chronically and rats were given intracerebroventricular (i.c.v.) infusions of morphine (26 nmol/1 microliters/hr) or saline (1 microliters/hr) for 3 days. Microdialysis probes (2 mm tip) were inserted into the LC 24 hr before precipitation of withdrawal by i.c.v. injection of naloxone (12 or 48 nmol/5 microliters). Behavioral evidence of withdrawal (teeth-chattering, wet-dog shakes, etc.) was detected following naloxone challenge in morphine, but not in saline-infused rats. Increases (P < 0.01) in ECF levels of Glu (and Asp, to a lesser degree) were noted after naloxone-precipitated withdrawal only in the morphine group. The ECF Glu levels in the LC increased from 9.6 +/- 2.7 to 15.5 +/- 5.0 microM following 12 nmol/5 microliters naloxone, and from 9.5 +/- 1.9 to 20.5 +/- 3.3 microM following 48 nmol/5 microliters naloxone, before and in the first 15 min sample after the precipitation of withdrawal in the morphine-dependent rats, respectively. These results provide direct evidence to support the role of excitatory amino acids within the LC in morphine withdrawal.

Animals↗
PubMed1994

Acid precipitation--effects on trace elements and human health.

Environmental pollution by acid precipitation increases the solubilization and mobilization of toxic metals. Through the food chain, this may alter the intake of toxic and essential elements in man. Potential adverse health effects could follow after increased human exposure. For the general population, the exposure pattern and health effects caused by aluminium, cadmium, lead and mercury are of particular concern. Although there are several indications that the exposure to toxic elements (e.g. aluminium, cadmium, lead and methylmercury), as well as the intake of essential elements (e.g. selenium), may be affected by acid precipitation, there is presently no firm evidence of adverse health effects in man. However, the present data clearly indicate that the safety margins are small. Thus, the ongoing acidification in many areas must be stopped before such effects become evident. The effects on trace element status and human health by acid precipitation were discussed at the ISTERH (International Society for Trace Element Research in Humans) Conference in Stockholm, May, 1992. The main findings are briefly summarized here.

Acid Rain↗
PubMed1994

Context-specific sensitization to naloxone-precipitated withdrawal in hamsters: effect of pimozide.

Three experiments were conducted to investigate the development of context-specific sensitization to naloxone-precipitated withdrawal in hamsters. In Experiment 1, animals in group M/S were given morphine (15 mg/kg) injections in a distinctive environment and saline in the home cage. Animals in group S/M were given saline in the distinctive environment and morphine in the home cage, and animals in group S/S were given saline in both environments. All groups were challenged subsequently with naloxone (0.4 mg/kg) in the distinctive environment and then observed for signs of opiate withdrawal. The results showed that group M/S gave more naloxone-precipitated withdrawal signs than each of the other groups, which did not differ from one another. Experiment 2 was designed to test the effect of pimozide on context-specific sensitization to naloxone-precipitated withdrawal. The design was similar to that of Experiment 1 but group P/M/S, which received an injection of pimozide (0.5 mg/kg) 4 h prior to morphine, was added. The results indicated that context-specific sensitization developed as in Experiment 1, except among animals treated with pimozide. Experiment 3 was designed to determine whether pimozide interferes with the development or the expression of context-specific sensitization. Six groups, differing in the frequency and timing of the pimozide injection, were employed. The results indicated that pimozide interfered with context-specific sensitization, whenever it was given. It is concluded that pimozide interferes with the expression of context-specific sensitization, although a separate effect on the development of sensitization is not ruled out.

Animals↗
PubMed1996

Nicotine abstinence syndrome precipitated by an analog of neuropeptide FF.

In a recently introduced rodent model of nicotine abstinence syndrome the observed behavioral signs closely resembled those typical of rat opiate abstinence syndrome. Nicotine-induced release of endogenous opioids may contribute to nicotine dependence; morphine potently reverses nicotine abstinence signs, while naloxone precipitates abstinence signs and prevents nicotine from alleviating them. Considerable evidence suggests that neuropeptide FF, an endogenous antiopiate peptide, contributes to opiate dependence. Third ventricle injection of neuropeptide FF precipitates abstinence syndrome in morphine-dependent rats, as does SC injection of its lipophilic analogs, dansyl-PQRFamide and dansyl-RFamide. Might NPFF also play a role in nicotine dependence? In the present study, SC injection of 15 or 25 mg/kg dansyl-RFamide or vehicle alone dose dependently precipitated an abstinence syndrome in nicotine-dependent rats. There was a significant, p < 0.01, positive linear trend of abstinence signs as a function of dose. Categories of abstinence signs had the same rank ordering by frequency as observed in spontaneous nicotine abstinence. Injection of 25 mg/kg dansyl-RFamide SC had no significant effect in nondependent rats.

Amino Acid Sequence↗
PubMed1978

Comparisons of alum-precipitated and unprecipitated aqueous ragweed pollen extracts in the treatment of hay fever.

In 1969 and 1970, groups of patients with ragweed hay fever never before treated were started on preseasonal course of immunization with an alum precipitate of aqueous ragweed extract. A comparison between these two groups of patients and a similar group of patients treated with unprecipitated aqueous extract in 1968 shows that treatment with alum precipitate was safely initiated with fever injections even though a higher dose was administered. The larger cumulative dose appeared to give better IgG antibody responses and greater relief of symptoms. A repeat preseasonal course the next year again required fewer injections of the alum-precipitated extract than a repeat course of aqueous extract.

Antibody Formation↗
PubMed1990

The effect of antibody isotype on the activation of C3 and C4 by immune complexes formed in the presence of serum: correlation with the prevention of immune precipitation.

Radioimmunoassays for C3a and C4a have been used to measure the activation of complement during the formation of immune complexes in human serum by the interaction of DNP-BSA and each of 11 mouse anti-DNP monoclonal antibodies of varied isotype and affinity. Those containing IgG2 or IgM were potent activators of C4, whilst IgG1 containing complexes were less efficient. C3 activation in normal serum was similar for complexes containing IgG1, IgG2a, IgG2b or IgM. IgA complexes did not activate C3 or C4. All complexes except those containing IgA precipitated more slowly in serum than in buffer. IgG2 antibodies were potent activators despite being very slow to precipitate in buffer. In serum containing EGTA activation of C4 was abolished and precipitation of complexes occurred at the same rate as in buffer. Nevertheless, C3 activation still occurred by the alternative pathway for all IgG and IgM complexes. Antibodies of the same isotype did not necessarily activate complement to the same extent. The ranking of the ability to activate complement was the same as that observed when performed complexes containing the same antibodies were added to serum. The levels of C4a generated were similar under both conditions but for most antibodies more C3a was generated by preformed complexes.

Antibodies, Monoclonal↗