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PubMed1986

Formation of HCN and its chlorination to ClCN by stimulated human neutrophils--2. Oxidation of thiocyanate as a source of HCN.

Leucocytes challenged by Staphylococcus epidermidis or stimulated by phorbol myristate acetate (PMA) produce cyanide from thiocyanate. The amount of H14CN formed depends on KS14CN concentration and is enhanced by pretreatment of phagocytosed bacteria with penicillin or by adding amine-taurine to the medium of PMA-stimulated neutrophils. The reaction of taurine chloramine or chlorinated Staphylococcus epidermidis (containing N-Cl groups) with thiocyanate results in HCN formation. At higher concentration of chloramine cyanogen chloride is formed. Cyanide is chlorinated by PMA-stimulated neutrophils and this process is significantly enhanced by exogenous taurine and inhibited by 3-amino 1,2,4-triazole. It is conceivable that oxidation of thiocyanate to HCN and chlorination of HCN to ClCN is mediated by the chlorinating species (taurine chloramine) produced by stimulated neutrophils.

Carbon Radioisotopes↗
PubMed2003

The fate of chlorine and organic materials in swimming pools.

The fate of organic nitrogen and carbon introduced into a swimming pool by pool users has been studied using a 2.2 m(3) model pool. The study made use of a body fluid analogue (BFA), containing the primary endogenous organic amino compounds, and a soiling analogue represented by humic acid (HA). The system was used to examine the effect of organic loading and organic carbon (OC) sources (i.e. amino or HA) on the levels and speciation of the key chlorinated disinfection by-products of trihalomethanes (THMs) and chloramines under operating conditions representative of those employed on a full-scale pool. Results revealed OC, chloramines and THMs to all attain steady-state levels after 200-500 h of operation, reflecting mineralisation of the dosed OC. Steady-state levels of OC were roughly linearly dependent on dose rate over the range of operational conditions investigated and, as with the chloramine levels recorded, were in reasonable agreement with those reported for full-scale pools. THM levels recorded were somewhat lower than those found in real pools, and were dependent on both on pH carbon source: the THM formation propensity for the soling analogue was around eight times than of the BFA. Of the assayed by-products, only nitrate was found to accumulate, accounting for 4-28% of the dosed amino nitrogen. Contrary to previous postulations based on the application of Henry's Law, only insignificant amounts of the volatile by-products were found to be lost to the atmosphere.

Chlorine Compounds↗
PubMed1978

Surface-specific iodination of membrane proteins of viruses and eucaryotic cells using 1,3,4,6-tetrachloro-3alpha,6alpha-diphenylglycoluril.

The use of the iodinating reagent 1,3,4,6-tetrachloro-3alpha,6alpha-diphenylglycouril (chloroglycoluril) to selectively label membrane surface proteins was investigated with the following systems: enveloped viruses (Sendai and Newcastle disease viruses), human erythrocytes, and nucleated cells propagated both in suspension (EL-4) and in monolayer culture (BHK-21). Conditions are described for specifically iodinating surface proteins while maintaining full virus integrity or cell viability. Comparison of the chloroglycoluril method with the lactoperoxidase and chloramine-T methods for labeling surface membrane proteins shows that the chloroglycoluril method has a number of advantages: It routinely produces a 3- to 17-fold greater specific radioactivity without sacrificing viral or cellular integrity, it is technically simpler to use, it does not require the addition of extraneous protein to initiate the reaction nor a strong reducing reagent to terminate it. Chloroglycoluril also proved to be an effective substitute for chloramine-T in the nonvectorial labeling of viral and cellular proteins. Membrane protein samples were solubilized with the detergent sodium dodecyl sulfate before iodination or labeled in the presence of high iodide concentrations without prior solubilization. The resulting specific radioactivities generated by the use of chloroglycoluril were equal to or greater than those generated by the chloramine-T method. The effectiveness, simplicity of use, and versatility of chloroglycoluril recommend it as an iodinating reagent for both surface-specific and nonvectorial labeling of membrane systems.

Cell Line↗
PubMed2004

Characterization and fate of N-nitrosodimethylamine precursors in municipal wastewater treatment plants.

The potent carcinogen, N-nitrosodimethylamine (NDMA), is produced during disinfection of municipal wastewater effluent from the reaction of monochloramine and organic nitrogen-containing precursors. To delineate the sources and fate of NDMA precursors during municipal wastewater treatment, NDMA formation was measured after extended chloramination of both model precursors and samples from conventional and advanced wastewater treatment plants. Of the model precursors, only dimethylamine, tertiary amines with dimethylamine functional groups, and dimethylamides formed significant NDMA concentrations upon chloramination. In samples from municipal wastewater treatment plants, dissolved NDMA precursors always were present in primary and secondary effluents. Biological treatment effectively removed the known NDMA precursor dimethylamine, lowering its concentration to levels that could not produce significant quantities of NDMA upon chlorine disinfection. However, biological treatment was less effective at removing other dissolved NDMA precursors, even after extended biological treatment. Significant concentrations of particle-associated NDMA precursors only were detected in secondary effluent at treatment plants that recycled water from sludge thickening operations in which dimethylamine-based synthetic polymers were used. Effective strategies for the prevention of NDMA formation during wastewater chlorination include ammonia removal by nitrification to preclude chloramine formation during chlorine disinfection, elimination of dimethylamine-based polymers, and use of filtration and reverse osmosis to remove particle-associated precursors and dissolved precursors, respectively.

Bioreactors↗
PubMed2006

Occurrence of a new generation of disinfection byproducts.

A survey of disinfection byproduct (DBP) occurrence in the United States was conducted at 12 drinking water treatment plants. In addition to currently regulated DBPs, more than 50 DBPs that rated a high priority for potential toxicity were studied. These priority DBPs included iodinated trihalomethanes (THMs), other halomethanes, a nonregulated haloacid, haloacetonitriles, haloketones, halonitromethanes, haloaldehydes, halogenated furanones, haloamides, and nonhalogenated carbonyls. The purpose of this study was to obtain quantitative occurrence information for new DBPs (beyond those currently regulated and/or studied) for prioritizing future health effects studies. An effort was made to select plants treating water that was high in total organic carbon and/or bromide to enable the detection of priority DBPs that contained bromine and/or iodine. THMs and haloacetic acids (HAAs) represented the two major classes of halogenated DBPs formed on a weight basis. Haloacetaldehydes represented the third major class formed in many of the waters. In addition to obtaining quantitative occurrence data, important new information was discovered or confirmed at full-scale plants on the formation and control of DBPs with alternative disinfectants to chlorine. Although the use of alternative disinfectants (ozone, chlorine dioxide, and chloramines) minimized the formation of the four regulated THMs, trihalogenated HAAs, and total organic halogen (TOX), several priority DBPs were formed at higher levels with the alternative disinfectants as compared with chlorine. For example, the highest levels of iodinated THMs-which are not part of the four regulated THMs-were found at a plant that used chloramination with no prechlorination. The highest concentration of dichloroacetaldehyde was at a plant that used chloramines and ozone; however, this disinfection scheme reduced the formation of trichloroacetaldehyde. Preozonation was found to increase the formation of trihalonitromethanes. In addition to the chlorinated furanones that have been measured previously, brominated furanones-which have seldom been analyzed-were detected, especially in high-bromide waters. The presence of bromide resulted in a shift to the formation of other bromine-containing DBPs not normally measured (e.g., brominated ketones, acetaldehydes, nitromethanes, acetamides). Collectively, -30 and 39% of the TOX and total organic bromine, respectively, were accounted for (on a median basis) bythe sum of the measured halogenated DBPs. In addition, 28 new, previously unidentified DBPs were detected. These included brominated and iodinated haloacids, a brominated ketone, and chlorinated and iodinated aldehydes.

Chromatography, Gas↗
PubMed2005

Myeloperoxidase generates 5-chlorouracil in human atherosclerotic tissue: a potential pathway for somatic mutagenesis by macrophages.

Somatic mutations induced by oxidative damage of DNA might play important roles in atherogenesis. However, the underlying mechanisms remain poorly understood. Myeloperoxidase, a heme protein expressed by select populations of artery wall macrophages, initiates one potentially mutagenic pathway by generating hypochlorous acid. This potent chlorinating agent reacts rapidly with primary amines to yield long-lived, selectively reactive N-chloramines. In the current studies, we demonstrate that myeloperoxidase produced by human macrophages differentiated in the presence of granulocyte macrophage colony-stimulating factor generates 5-chlorouracil, a mutagenic thymine analog. The primary amine taurine fails to block the reaction, suggesting that N-haloamines produced by macrophages might oxidize uracil. Model system studies demonstrated that N-chloramines convert uracil to 5-chlorouracil. Interestingly, the tertiary amine nicotine dramatically enhances uracil chlorination, suggesting that cigarette smoke might promote nucleobase oxidation by N-chloramines. To look for evidence that myeloperoxidase promotes uracil oxidation in vivo, we measured 5-chlorouracil levels in human aortic tissue, using isotope dilution gas chromatography-mass spectrometry. The level of 5-chlorouracil was 10-fold higher in atherosclerotic aortic tissue obtained during vascular surgery than in normal aortic tissue, suggesting that halogenated nucleobases produced by macrophages might contribute to atherogenesis. Because 5-chlorouracil can be incorporated into nuclear DNA, our observations raise the possibility that halogenation reactions initiated by phagocytes provide one pathway for mutagenesis, phenotypic modulation, and cytotoxicity during atherogenesis.

Antioxidants↗
PubMed1976

Preparation of 125I-labeled synthetic porcine secretin for radioimmunoassay.

Synthetic porcine secretion was labelled by the conjugation-labelling method of Bolton & Hunter, the lactoperoxidase method, the gaseous diffusion method, and the chloramine-T method. The chloramine-T technique was adapted as routine method. Ten mug (3.27 nmol) peptide was reacted with 5 mCi of Na125I at a concentration of chloramine-T of 1.3 mmol/l. Synthetic secretin was suitable for labelling for at least eight months when stored as dry matter in nitrogen-filled glass ampoules. Purification and separation of labelled from unlabelled hormone was carried out by gel-permeation chromatography on Sephadex G-50 superfine. The labelled preparation had a specific radioactivity of 405 +/- 33 muCi/nmol (mean +/- SEM., n = 9) and was unable for six days. 6-tyrosyl-secretin took more iodine compared to porcine synthetic secretin but had lower immunoreactivity with all antisera tested.

Animals↗
PubMed1996

Full-scale studies of factors related to coliform regrowth in drinking water.

An 18-month survey of 31 water systems in North America was conducted to determine the factors that contribute to the occurrence of coliform bacteria in drinking water. The survey included analysis of assimilable organic carbon (AOC), coliforms, disinfectant residuals, and operational parameters. Coliform bacteria were detected in 27.8% of the 2-week sampling periods and were associated with the following factors: filtration, temperature, disinfectant type and disinfectant level, AOC level, corrosion control, and operational characteristics. Four systems in the study that used unfiltered surface water accounted for 26.6% of the total number of bacterial samples collected but 64.3% (1,013 of 1,576) of the positive coliform samples. The occurrence of coliform bacteria was significantly higher when water temperatures were > 15 degrees C. For filtered systems that used free chlorine, 0.97% of 33,196 samples contained coliform bacteria, while 0.51% of 35,159 samples from chloraminated systems contained coliform bacteria. The average density of coliform bacteria was 35 times higher in free-chlorinated systems than in chloraminated water (0.60 CFU/100 ml for free-chlorinated water compared with 0.017 CFU/100 ml for chloraminated water). Systems that maintained dead-end free chlorine levels of < 0.2 mg/liter or monochloramine levels of < 0.5 mg/liter had substantially more coliform occurrences than systems that maintained higher disinfectant residuals. Free-chlorinated systems with AOC levels greater than 100 micrograms/liter had 82% more coliform-positive samples and 19 times higher coliform levels than free-chlorinated systems with average AOC levels less than 99 micrograms/liter. Systems that maintained a phosphate-based corrosion inhibitor and limited the amount of unlined cast iron pipe had fewer coliform bacteria. Several operational characteristics of the treatment process or the distribution system were also associated with increased rates of coliform occurrence. The study concludes that the occurrence of coliform bacteria within a distribution system is dependent upon a complex interaction of chemical, physical, operational, and engineering parameters. No one factor could account for all of the coliform occurrences, and one must consider all of the parameters described above in devising a solution to the regrowth problem.

Data Collection↗
PubMedDate not supplied

Neutrophil oxidants inactivate alpha-1-protease inhibitor and promote PMN-mediated detachment of cultured endothelium. Protection by free methionine.

Activated granulocytes have been implicated in mediating pulmonary endothelial damage in the Adult Respiratory Distress Syndrome. In another lung disease, emphysema, pulmonary granulocytes (PMNs) are thought to be doubly responsible for lung dissolution: they release potent proteolytic enzymes including elastase, and they generate reactive oxygen species that oxidize a reactive site methionine group in alpha-1-protease inhibitor (alpha-1-PI) rendering it, in turn, impotent as an anti-elastase. This suggested an analogous scenario for pulmonary vascular damage: namely, undefended PMN elastase might also mediate endothelial injury. Our strategy to prove this notion used 51chromium-labeled human endothelial cells exposed to intact PMN or to enucleate "neutroplasts." The latter are elastase-free cytoplasmic blebs derived from PMN. When activated, both PMN and neutroplasts generate similar amounts of toxic oxygen species; yet neutroplasts caused insignificant endothelial damage, measured as 51Cr "lift-off"from anchoring matrix (PMN = 24.3% +/- 1.8% vs neutroplast = 1.2% +/- 0.4%; p less than 0.001). Adding pure elastase back to neutroplasts increased endothelial cell lift-off (7% +/- 0.2%). Although the prototypic serine protease inhibitor phenyl methylsulfonylfluoride (PMSF) protected endothelium from PMNs, pure alpha-1-PI (also a potent anti-elastase) when added in physiologic amounts did not protect endothelial cells from PMN assault, suggesting that PMN oxidants might inactivate it. By adding exogenous myeloperoxidase (MPO) to MPO-deficient neutroplasts, we demonstrated that MPO-dependent oxidants, probably N-chloramines, are critical inactivators of alpha-1-PI. This was further confirmed since added free methionine, a scavenger of chloramine, protected alpha-1-PI from inactivation by reagent chloramine or that produced by rearmed neutroplasts or PMN.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Proteins↗
PubMed2000

The antithrombotic factor singlet oxygen/light (1O2/h nu).

Activated phagocytes (especially polymorphonuclear granulocytes (PMNs)) by respiratory oxidative/photonic burst (activation of NADPH-oxidase and myeloper-oxidase) generate large amounts of oxidants of the hypochlorite-/chloramine-type, which are physiologic sources for singlet oxygen (1O2), a nonradical-excited (photon (h nu) emitting) oxygen species [Weiss SJ, NEJM 1989;320:365-376]. In vitro experiments show that 1O2 (1) inhibits coagulation by inactivation of thrombocytes, fibrinogen, factor V, factor VIII, and factor X and (2) activates fibrinolysis by inactivation of the main fibrinolysis inhibitors plasminogen activator inhibitor (PAI)-1 and alpha-2-antiplasmin, and by activation of single-chain urokinase by plasmin and oxidized fibrin. Additionally, this work suggests that 1O2/h nu acts antithrombotically, inducing selective thrombolysis in vivo (i.e., thrombolysis induced by 0.1 to 0.5 mmol/l chloramine within 30 to 60 minutes without changes of the plasmatic hemostasis system). 1O2 might activate flowing to (on the endothelium) rolling PMN, increasing their chance to get in contact with fibrin/platelet aggregates deposited on the endothelial layer. Via 1O2 generation, the thrombus-activated phagocytes might call for (acute, physiologic) inflammation/fibrinolysis amplification, resulting in the "moving front" of PMN, which infiltrates and destroys the thrombus. 1O2 seems to (partially) participate in the reactivity of nitric oxide, another prooxidative agent. The inhibition of physiologic amounts of 1O2 by blood cholesterol might be involved in the pathogenesis of atherothrombosis. Consequently, it is suggested that activated PMNs modulate hemostasis, shifting it into an antithrombotic state; this cellular part of fibrinolysis seems to be of greater physiologic importance than the plasmatic one. Impaired PMN function (e.g., as occurring in patients with antineutrophil cytoplasmic antibodies or under cytostatic treatments) often results in serious thrombotic complications. Light is the only signal whose origin can be immediately recognized by a fast moving cell in the (dark) blood stream. The cell signal action of 1O2/h nu (e.g., released by chloramines such as taurine-chloramine or vancomycin, by fiberoptic, by photodynamic therapy, or by so-called redox-cycling drugs such as quinones or tetracyclines) might be a new and physiologic principle for pharmacologic intervention in atherothrombosis.

Animals↗
PubMed2005

Functional determination of plasmin in arginine-stabilized plasma.

Reliable data on plasmin activities in blood of patients during fibrinolytic treatment are lacking. This is due to continuing plasminogen activation by plasminogen activators after blood withdrawal. The purpose of this study was to establish a new method for stabilization of blood and to detect plasmin activity in stabilized plasma. For optimization of plasma stabilization by arginine, 50 microL pooled normal citrated plasma was incubated with 50 microL of 0 to 1500 mM arginine, pH 8.7, and 25 microL 100 IU/mL u-PA, 1250 IU/mL t-PA, 10000 U/mL reteplase, 400 U/mL plasminogen-streptokinase-activator complex, 10 microg/mL tenecteplase in 6% BSA-PBS or 25 microL 25 microg/mL plasmin in 20% glycerol. Twenty-five microliters 3 mM HD-Val-Leu-Lys-pNA were added immediately (1 step) or after 90 minutes (room temperature [RT]). The same experiment was performed with pooled normal citrated plasma supplemented with 3.2 mg/mL EDTA, preoxidized with 0 mM or 20 mM chloramine-T for 10 minutes (37 degrees C). For optimization of plasmin activity, the oxidation time of the arginine-stabilized plasma sample containing 0.5 U/mL active plasmin and the chloramine-T amount was varied. Citrated plasma is stabilized against the in vitro action of all six plasminogen activators tested if the final arginine concentration is greater than 500 mM. Neither the addition of EDTA nor the addition of chloramine-T changes this plasma-stabilizing power of arginine. The optimized functional plasmin assay consists of incubation of 10 microL arginine-stabilized plasma with 10 microL 1.5 M arginine, pH 8.7, and 10 microL 100 mM CT in PBS. After 30 minutes (37 degrees C), 75 microL 1.2 M KCl, 1.6 M Arg, 0.75 mM Val-Leu-Lys-pNA (Stop-CS Reagent), and 175 microL 6% BSA-PBS are added and the absorbance increase (DeltaA) at 405 nm is determined. With the present arginine stabilization procedure of plasma and the determination of plasmin activity in arginine-stabilized plasma as described, it is feasible to determine the activity of plasmin in blood of patients receiving fibrinolytic treatment without artefactual in vitro changes in the samples.

Arginine↗
PubMed1976

[Purification of subunits from human chorionic gonadotropin and radioimmunoassay].

A crude hCG with an activity of about 3,000 IU per mg was purifed to 10,000--15,000 IU per mg of dry weight using Amberlite CG-50 chromatography combined with DEAE-Sephadex A-50 and Sephadex G-75. The alpha and beta subunits of hCG were prepared by urea-treatment of the hormone and isolated by DEAE-Sephadex A-50 chromatography. Further purification of the subunits was achieved by gel filtration on a Sephadex G-76 column. For radioimmunoassay hCG was iodinated by the DMSO-chloramine T method. Iodination of hCG with non-radioactive iodine revealed that the addition of DMSO to the iodination mixture seemed to reduce the iodination damage to the antigenic activity of the hormone. Non-radioactive iodine substituted hCG accomplished by the DMSO-chloramine T method showed 1.5 times more immunoreactive in the hCG radioimmunoassay than hCG iodinated by the usual chloramine T method. The radioimmunoassay of the hCG-beta subunit developed in our laboratory was satisfactory with respect to specificity; hLH, hFSH, hTSH and hCG-alpha subunit tested were cross-reacted very poorly in our assay system. Desialylated-hCG and subunits, whose biologic potency was almost zero, exhibited also decreased immunoreactivity, about 30% of the native hormones with grossly unimpaired parallelism in their respective homologous radioimmunoassays. The concentrations of hCG and the subunits were determined on human sera from pregnant patients during the course of pregnancy. The hCG levels reached to the peak at the first trimester of the pregnancy, however, the hCG-beta subunits varied in their concentrations poorly throughout the pregnancy periods. The hCG-alpha levels, on the other hand, depicted two distinct peaks, at the early period and the term of pregnancy.

Animals↗
PubMed1988

Inactivation of serine proteinase inhibitors (serpins) in human plasma by reactive oxidants.

Activated polymorphonuclear neutrophils (PMN) and macrophages generate oxidizing agents similar to or identical with N-chloroamines. Mimicking this oxidation in normal human plasma by usage of chloramine T (CT), we observed an oxidant concentration-dependent inactivating effect on plasma alpha 2-plasmin inhibitor (alpha 2-PI), antithrombin III (AT III), and alpha 1-proteinase inhibitor (alpha 1-PI). 20-50 mumol CT/ml plasma are necessary for almost complete inactivation of alpha 2-PI and AT III-activity, i.e. about 2-5 times the dose necessary for inactivation of alpha 1-PI which has already been classified as "oxidant sensitive". The inactivation of alpha 1-PI, alpha 2-PI and AT III in plasma by oxidants is the result of a specific oxidative damage since C1-inhibitor, serine proteinases and complexes of plasmin and alpha 2-PI were chloramine resistant under the conditions used. According to our results, the amount of chloramines released by 1 x 10(6) activated PMN, namely ca. 10 nmol (see Weiss et al. Science 222 625-628, 1983) would be sufficient to destroy alpha 1-PI and alpha 2-PI activity of 1.5 and 0.4 microliter of human plasma, respectively. Consequently, activated leukocytes may be able to create a microenvironment in which elastase as well as plasmin and thrombin can display their proteolytic activity unchecked by their regulator proteins. Oxidation may provide a general basis for altering enzyme/inhibitor balances.

Animals↗
PubMed1998

Sirius red and acid fuchsin staining mechanisms.

The purpose of the study was to investigate the staining mechanism of acid fuchsin and Sirius red. Acid (poly-glutamic acid), neutral (poly-hydroxyproline) and basic (poly-arginine, poly-histidine, poly-lysine) poly-amino acids, collagen types I, II and III, and arginine- and lysine-containing histones were used as test substances applied to nitrocellulose membranes as dot blots. Five micrometer sections of granulation tissue on slides were tested in parallel. Some dots and sections were treated with chloramine-T before staining with acid fuchsin and Sirius red and some with 1 M NaOH after staining. The acid and neutral poly-amino acids were not stained, but the basic amino acids polylysine and poly-arginine, poly-amino acids containing these basic amino acids and the histones and the collagens exhibited intense staining. Oxidative deamination by chloramine-T abolished the staining and 1 M NaOH removed the staining except in the case of poly-arginine. Tissue sections treated in the same way showed a considerable decrease in staining after oxidative deamination with chloramine-T; in particular, the staining of the smaller fibers was abolished. The staining was totally removed by destaining with 1 M NaOH. Therefore, acid fuchsin and Sirius red are not selectively bound to collagen; they are also bound to other proteins containing basic amino acids, and staining to a large extent is influenced by electrostatic forces. The staining seems not to be selective for collagen, and one must account for this when quantitative conclusions are drawn from collagen methods using these stains.

Animals↗
PubMed1990

Site-specifically radioiodinated antibody for targeting tumors.

Labeling of an antibody site specifically through its carbohydrate regions preserves its antigen-binding activity (Rodwell et al., Proc. Natl. Acad. Sci., 83: 2632, 1986). Previously site-specific labeling studies have conjugated antibodies with metallic radioisotopes or drugs. We now report site-specific labeling with a new radioiodinated compound, 2-hydroxy-5-iodo-3-methylbenzoyl hydrazide, whose synthesis we described earlier (Belinka et al., Biochemistry, 27: 3084, 1988). The compound is reacted with aldehyde groups produced by specific oxidation of the carbohydrate portion of the antibody with sodium m-periodate. Optimized conjugation conditions give good recovery of active antibody containing 10 groups per molecule. The conjugate is stable in solution for at least several weeks at both 4 and -70 degrees C. When injected into nude mice bearing LS174T human cancer xenografts, the conjugate of B72.3 antibody localizes well to tumor tissue, with low uptake by other organs. This biodistribution is similar to that of conjugate prepared by using solid-phase chloramine-T (Iodohead). There are only two significant differences. First, the carbohydrate conjugate is much less susceptible to dehalogenation, and thus shows much less thyroid uptake. Secondly, the biological half-life of the carbohydrate conjugate was about half that of the chloramine-T one. This could be due primarily to lysis of the hydrazine bond through which the antibody is attached to the compound, which would then be excreted rapidly by itself. The new reagent will be especially useful for antibodies which either cannot be labeled by chloramine-T methods, or whose activity is impaired by them.

Animals↗
PubMed1977

[Agents and methods for the disinfection of the integument of animals before slaughter].

Experiments were carried out to test the disinfection effect of some agents, such as chloramine B, chloramine B+ surface active substances, vofasteril (peracetic acid), perfumaric acid, and bradofen on a dry skin or when applied immediately after washing--in buffaloes, cattle, and swine. Parallel trials were conducted under conditions of the practice as well. Escherichia coli and Staphylococcus aureus were used as model organisms. Results showed that best disinfection effect have 1.5 percent chloramine B and 0.5 per cent peracetic acid (for dry skins), and 3.0 and 0.8 per cent of the same agents when applied on wet skins (immediately after washing). The animals should be slaughtered not earlier than 10 min and not later than 30 min following disinfection. The effect of disinfection is read best on impression preparations of agar (in aluminum folio).

Abattoirs↗
PubMed1984

[Coagulation of 125I bovine fibrinogen].

Bovine fibrinogen was labelled with 125I using the chloramine T method or the iodogen method and the clottability of the preparations was studied in vitro and in vivo. Three days after radioiodination the in vitro clottability was 82.3% (chloramine T) and 80.4% (iodogen), respectively. When the solutions were allowed to stand at 4 degrees C for 13 days, the in vitro clottability decreased to 70% or 60%, respectively; either preparation was practically unclottable after 25 days. The preparations were administered to rats three days following radioiodination. They showed the same elimination rate and, on thrombin infusion, the same clottability. 125I-labelled (chloramine T) bovine fibrinogen stored in solution at -20 degrees C for 38 days showed a clottability of 76%, the in vivo clottability was unchanged.

Animals↗
PubMed1981

Preparation of biologically active mono-125I-insulin of high specific activity.

Pork insulin was labeled by the chloramine T technique (phosphate buffer 0.25 M; pH 7.5; EDTA 0.001 M; chloramine T: 0.2625 mg/ml; sodium metabisulfite 2.4 mg/ml) in a reaction volume of 50 microliters, adding chloramine T every 30 seconds twice (2.1 micrograms in 1 minute) and halting the reaction with 5 microliters metabisulfite. Three fractions were separated in preparative starch gel: F1 (mono-125I-insulin contaminated with cold insulin), F2 (mono-125I-insulin free from cold insulin), and F3 (di-125I-insulin). Insulins with low and high specific activity (iodine/insulin ratios 0.1/1 and 1/1 respectively) were prepared for study purposes, and quality was assessed by means of dose-response curves with antibodies and with liver cells. Specific activity of F2 as obtained from dose-response curves utilizing Scatchard's plot was 323 and 382 mCi/mg. Specific activity of F1 varied according to the extent of contamination with cold insulin. A reduction in the F2 B/F ratio was observed upon iodination with iodine/insulin ratios of 1/1 or in the neighborhood. The mass and immunoreactivity of F3, as well as its B/F ratios were constant, regardless of specific activity. The behavior with antibodies was ratified upon observations on uptake by liver cells and glucose consumption by isolated fat cells. In conclusion, F2 labeled with 0.1/1 iodine/insulin ratios was separated from cold insulin in preparative starch gel, thus increasing its specific activity (360 mCi/mg approximately) without alteration of its immunologic or biologic properties.

Animals↗