[Hemoglobin alpha chain isoelectric point modification under the action of urea, sodium cyanate, succinic anhydride or diethylene triamine pentaacetic acid anhydride]. / Modifications du point isoélectrique de la chaine-alpha de l'hémoglobine sous l'action de l'urée, du cyanate de sodium, de l'anhydride succinique ou de l'anhydride diéthylène triamine pentaacétique.

A monomeric protein, the hemoglobin alpha chain, was used to compare four protocols for conjugation with diethylene triamine pentaacetic (DTPA) anhydride. Carbamylation and succinylation were also performed. The isoelectric point (pI) was 7.7 for the native protein versus only 5.5 to 7.3 for the five carbamylated derivatives and 4.0 to 7.0 for the six succinylated derivatives. With carbamylation or succinylation, increasing the molar ratio (agent/protein) was associated with a gradual downward pI shift producing trains of bands. This phenomenon did not occur with DTPA conjugation, whose results varied with the method used; only one derivate (pI 6.7) was produced by all four methods, and multiple fine bands with pH values in the vicinity of 3.6 were seen. For the protein, the pI shift varied with the number of groups inserted on the primary amine residues. Also, the shift was larger if the inserted groups carried electrically-charged moieties.

Effects of L-thyroxine on brain monoamines during parr-smolt transformation of Atlantic salmon (Salmo salar L.).

During spring, seaward migrating juvenile Atlantic salmon (Salmo salar) undergo parr-smolt transformation (PST) which involves changes in physiology, including one or two peaks in plasma thyroxine (T4). To investigate if changes in plasma T4 influence neural function, we measured levels of dopamine (DA) and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), and also measured serotonin (5-hydroxytryptamine, 5-HT) and its metabolite, 5-hydroxyindoleacetic acid (5-HIAA) in brain regions of two groups of Atlantic salmon parr on an 8:16 h light/dark photoperiod. One group was treated with ambient T4 to simulate the natural smolt peak in plasma T4. T4 treatment depressed DOPAC levels as well as DOPAC/DA and 5-HIAA/5-HT ratios in the olfactory system but with no changes in the optic tectum. We conclude that during PST monoaminergic functions in specific brain regions of juvenile Atlantic salmon are affected by T4 treatment.

T4 depresses olfactory responses to L-alanine and plasma T3 and T3 production in smoltifying Atlantic salmon.

During natural or induced smoltification, Atlantic salmon exhibit spring elevations in olfactory activity and plasma L-thyroxine (T4). To determine whether T4 influences olfactory activity, we administered T4 to late parr in early April and measured olfactory bulb electroencephalogram and olfactory epithelium electroolfactorogram responses to L-alanine nasal stimulation, plasma T4 and 3,5,3'-triiodo-L-thyronine (T3) levels, and hepatic and brain monodeiodination. T4 treatment raised plasma T4 to 15 ng/ml, simulating the smolt T4 surge, and depressed plasma T3 and electroencephalogram responses, without modifying electroolfactorogram responses. Decreased plasma T3 may be explained by inhibition of hepatic T4 outer-ring deiodination, generating T3, and stimulation of inner-ring deiodination, degrading T4 and T3. Brain T4 outer-ring deiodination was also strongly inhibited. In conclusion, creation of a high plasma T4 concentration simulating the natural smolt peak depressed olfactory bulb responses to L-alanine due to the high T4 concentration or the depressed T3 availability in brain induced by T4. T4 may terminate the period of heightened olfactory responsiveness during smoltification.

Reliability of low-frequency auditory stimulation studies associated with technetium-99m hexamethylpropylene amine oxime single-photon emission tomography.

Development of auditory stimulation tests associated with single-photon emission tomography (SPET) shows evidence of variations in perfusion related to the stimuli. Three brain SPET examinations with technetium-99m hexamethylpropylene amine oxime were performed on eight right-handed adults with normal hearing, the first one without stimulation and the other two associated with a 500-Hz/30-dB stimulation of the right ear. Temporal regions of interest covering auditory areas, as well as parietal ones (internal control), were drawn on three successive coronal slices. A cortico-cerebellar index R was calculated, and the variation in activity was defined for each subject using the ratio R poststimulation--R prestimulation/R prestimulation. A significant increase in the temporal cortex count occurred in all subjects. This increase was bilateral, except for one subject in whom it was not significant on the right side. This result recurred during the second stimulation study. Overall the response of the left temporal cortex was stronger, although the asymmetry was not significant. The asymmetry repeated itself after each stimulation. The perfusion response is globally reliable in our study. We must ascertain how sensitive this test is with regard to deaf adults and adults with normal hearing before extending its use to children.

Thyroid hormone deiodination in brain, liver, gill, heart and muscle of Atlantic salmon (Salmo salar) during photoperiodically-induced parr-smolt transformation. I. Outer- and inner-ring thyroxine deiodination.

Outer-ring deiodinase (ORD) and inner-ring deiodinase (IRD) pathways for L-thyroxine (T4) were examined in the microsomes of tissues of 20-month-old Atlantic salmon induced to undergo parr-smolt transformation (PST) in late February and March by imposing a 16-hr photoperiod. Smolt external characteristics, decline in condition factor, increases in brain-somatic index, cardiac-somatic index, gill-somatic index, gill Na+/K+ ATPase activity, and food consumption developed progressively during the 5-week study. Plasma T4 (4.1 ng/ml, Week 1) rose to 13.5 and 12.5 ng/ml (Weeks 3 and 4) and fell to 7.5 ng/ml (Week 5). Plasma T3 rose from 2.1 ng/ml (Week 1) to 3.8 ng/ml (Week 2) and fell to 2.4 ng/ml (Week 5). T4ORD activity occurred in liver, heart, gill, brain, and skeletal muscle, increasing in liver and heart between Weeks 1 and 2, and in brain between Weeks 4 and 5. Only liver T4ORD activity was correlated (r = +0.946) with plasma T3 concentrations, suggesting that hepatic T4ORD may determine the plasma T3 concentration. For hepatic T4ORD the mean Km was 0.42 nM and the mean Vmax 1.2 pmols T4 converted.hr-1.mg microsomal protein-1. HPLC analysis revealed 3,3',5-T3(rT3) and 3,3'-diiodo-L-thyronine, as evidence of T4IRD activity, but only in liver and brain. The lower bound estimates of T4IRD activities to generate rT3 were 28% (liver) and 50% (brain) of the respective T4ORD activities. Brain T4IRD increased progressively during PST. In post-smolts in later October, plasma T3 concentrations and both hepatic and brain T4ORD and T4IRD activities were low, but some rT3 was produced. We conclude that during induced PST in Atlantic salmon (i) T4ORD activity increases in liver, heart, and brain, but not in gill or skeletal muscles; (ii) the hepatic T4ORD is highly correlated with plasma T3 and may therefore determine plasma T3; and (iii) there are changes in T4ORD and T4IRD in brain, which may reflect regulation of intracellular thyroid hormone metabolism in that tissue. However, it remains to be determined how changes in deiodinase activity relate to the surge in plasma T4 and the role of thyroid hormones during PST.

Thyroid hormone deiodination in brain, liver, gill, heart and muscle of Atlantic salmon (Salmo salar) during photoperiodically-induced parr-smolt transformation. II. Outer- and inner-ring 3,5,3'-triiodo-L-thyronine and 3,3',5'-triiodo-L-thyronine (reverse T3) deiodination.

Outer-ring deiodinase (ORD) and inner-ring deiodinase (IRD) pathways for 3,5,3'-triiodo-L-thyronine (T3) and 3,3',5'-T3 (reverse T3, rT3) were examined in microsomal fractions of liver, heart, gill, brain, and skeletal muscle of 20-month-old Atlantic salmon induced to undergo parr-smolt transformation (PST) in late February and March by imposing a 16-hr photoperiod. All tissues showed negligible T3ORD activity. T3IRD activity was detected in both the liver (Km = 0.65 nM; Vmax = 15.5 pmol T3 deiodinated.hr-1.mg microsomal protein-1) and brain of smolts, but not in gill, heart, or skeletal muscle. rT3ORD was detected in liver, brain, and muscle, and at very low levels in gill and heart. rT3IRD activity occurred to some extent in all tissues except brain. T3IRD activity changed in brain during PST, and was low in brain and liver of post-smolts examined in late October. We conclude that (i) deiodination of T3 proceeds exclusively through an IRD pathway, which may permit regulation of T3 degradation independently of the ORD pathway responsible for T3 formation; (ii) deiodination of rT3 proceeds mainly through an ORD pathway but rT3IRD activity does occur in some tissues; and (iii) the altered brain T3IRD activity during PST suggests regulation of T3 turnover in the brain at this time.

[Changes in isoelectric points of the monoclonal antibody OC 125 during indium 111 radiolabeling]. / Modifications des points isoélectriques de l'anticorps monoclonal OC 125 lors de son radiomarquage par l'indium 111.

Isoelectrofocusing analysis of the murine monoclonal antibody OC 125 (IgG1) revealed four bands at pI (6.6-7.2). After pepsin digestion, f(ab')2 pIs were increased by 0.6 pH units and two additional bands were visible. DTPA conjugation decreased pI (by up to -2 units) and increased heterogeneity (10 bands or more). With In3+ at saturation level, the conjugate was slightly modified. Autoradiography revealed pI heterogeneity of OC 125-f(ab')2-DTPA-In-111. These data show that isoelectrofocusing enables accurate monitoring of monoclonal antibody changes during In-111 labeling.

[Urinary iodide determination by X-ray fluorescence]. / Dosage des iodures urinaires par fluorescence X.

Urinary iodide measurement has been carried out by X-ray-fluorescence, either directly on urinary solution, or after matrix concentration. Proportionality between emitted XK alpha rays of iodine and iodide mass in standards has been observed on a large scale, ranging up to 400 micrograms. With an exciting-1.11 GBq (241(95) Am)-radioactive source, 0.44 microgram are detected for solid matrix, and 0.9 microgram/ml for iodide in solution for 10 mn measuring time. So direct measurement on solution can be applied only to high excreted iodide. For normal range iodide determination is performed after anionic resin concentration (on 100 ml or 200 ml). For tracing, Na I131 is employed. The binding ratio is strongly depending on flow, resin weight, and associate urinary anionic components. On 20 healthy subjects, normal range value is 53 +/- 22 micrograms/l (m +/- s.d.). Comparative study with an electrochemical method showed fluorescence iodide values are lower than the former. The proposed method is very simple, one or two steps (function of iodide content). As no interfered Rx has been observed in the Rx iodide region, the authors can ascertain that accurate values are observed by X-ray fluorescence. In case of high iodide content, this methods allows to distinguish urinary iodide versus total urinary iodine, when performing solution and matrix concentration studies on the urinary batch.

[Radioisotope and ultrasonic diagnosis of a localized form of infarction of the right ventricle]. / Diagnostic radio-isotopique et échographique d'une forme localisée d'infarctus du ventricule droit.

We are reporting the case of a localized form of right ventricle infarction. The right catheterization, on which the diagnosis usually rests, is completely normal. Cardiac gamma-angiography and bi-dimensional sonography demonstrate, on the contrary, a localized dyskinesis of the inferior wall of the right ventricle which is not dilated and retains its ejection fraction. The failure of right catheterization in the diagnosis of infarction of the right ventricle is usually attributed to hypovolemia or a delay in the performance of the catheterization, which is not the case here. Therefore, this case demonstrates the existence of infarction of the right ventricle without total diastolic or systolic dysfunction, the diagnosis of which may be made with isotopic and sonographic methods.

Computer-automated method to study cardiac conditioning to a chemical cue in young salmon.

An apparatus was designed in which young Atlantic salmon (Salmo salar) are rapidly conditioned to reduce heart rate using a chemical-electric shock conditioning procedure. A chemical calibration system permitting efficient stimulus control is described as well as the electronic systems and computer software used to control all events of an experimental session and to quantify cardiac and chemical data. Efficient stimulus control and computer-automated recording techniques minimize inter-trial intervals and the time required for the measurement and analysis of cardiac responses. Data are presented showing that 15-month-old Atlantic salmon can be trained to reduce by 20% their heart rate to the synthetic chemical morpholine within 5 training trials whereas 10-month-old fish did not do so until 15 training trials.

[Metallic trace elements--A1, Cd, Cu, Fe--in solutions of 111InCl3: determination by flameless atomic absorption and results in 111In-radiolabeling of monoclonal antibodies]. / Traces métalliques--A1, Cd, Cu, Fe--dans les solutions de 111InCl3: dosage par absorption atomique sans flamme et conséquences pour le radiomarquage par 111In des anticorps monoclonaux.

Determination of trace elements in 111InCl3 solution have been carried out by flameless atomic absorption spectrometry. Five successive batches from three European companies have been analysed. The means of measured values range from 4560 to 6930 micrograms L-1 for aluminium, 131 to 874 for cadmium, 49 to 300 for copper, 387 to 698 for iron. Using two molar ration indexes, trivalent metallic traces have been compared to theoretical 111In content. The trace elements largely exceed radioactive material. As Fe and In have similar chemical properties, it results in low specific activity of radioactive complex when labeling monoclonal antibodies by 111In. Using a mathematical model, a detrimental effect of Fe trace levels has been studied.

[Effect of pH and the binding anion on In3+-transferrin interaction: spectroscopic study of the perturbed angular correlation of 172-245 keV gamma rays of indium 111]. / Influence du pH et de l'anion de liaison sur l'interaction In3+-transferrine: étude spectroscopique de la corrélation angulaire perturbée des raies gamma 172-245 keV de l'indium 111.

The formation of ternary complexes, transferrin-anion-In111 has been investigated by means of gamma-gamma coincidence spectrometry of the 172-245 keV rays. The angular correlation between the two gamma-rays emitted in cascade depends on the magnetic and electric fields gradients, consequently the chemical structure of metal holder. Any modification of this structure causes the variation of angular correlation. The study of G22 (infinity) as function of pH (G22(infinity): integrated perturbed angular correlation coefficient) has been performed to turn out the hydrolysis of In111 in aqueous solution, metal complex formation in presence of chelating agents (citric acid and sodium bicarbonate) and the formation of protein-metal complexes. The presence of complexing agents limits the domain of In111 colloid existence and allows fast transfer of ionised indium on the transferrin. Two types of metal-protein interactions has been turn out. The first in the weakly acidic range of pH is characterized by an affinity constant near to this of citric acid. The second lying in neutral and basic range of pH, where the formation rate of transferrin-In111 complex is fast (t less than 500 s). In citrate medium, for pH 6-7,5 the rate of metal transfer on the protein, studied by means of G22 (infinity) = f(t), is function of pH. The binding anion appears as an indispensable element for the formation of protein-metal complexes. The In111 previously chelated by 8-Hydroxyquinoline is fixed by the protein if only exits a binding anion in the solution. This mays bring in the formation of an intermediate active state, indispensable step for the ternary complex formation transferrin-anion-In111.

[Significance of antinuclear anti-histone antibodies]. / Signification des anticorps anti-nucléaires dirigés contre les histones.

The results of routine antihistone antibody (AHA) assay in a preliminary series of 189 sera are presented. There were 23 positive tests (systemic lupus erythematosus, 8 cases; drug induced SLE, 4 cases; rheumatoid arthritis 7 cases; and multiple sclerosis, 1 case; chronic active hepatitis, 1 case; systemic sclerosis, 1 case and primary biliary cirrhosis 1 case). The results of routine assay in 5 other patients groups are reported: 30 spontaneous SLE (9 positive AHA), 63 rheumatoid arthritis (2 positive AHA), 19 Sjögren syndrome (no AHA), 11 primary biliary cirrhosis (1 positive AHA) and 7 mixed connective tissue disease (no AHA).

Folic acid deficiency and neutrophil dysfunction.

Polymorphonuclear leukocyte functions were studied in 92 patients with protein-calorie malnutrition. Serum folic acid levels were higher than 3 ng/ml in 38 patients and 3 ng/ml or less in 54 patients. Significant differences were found between these two groups of patients with regard to phagocytosis (81.5 +/- 1.9 versus 69.2 +/- 2.0 percent, p less than 0.001) and bactericidal ability (90.6 +/- 1.1 versus 84.5 +/- 2.3 percent, p less than 0.05). Correction of folic acid deficiency in 22 patients was associated with recovery of normal phagocytosis (p less than 0.001) but not bactericidal function. Adding folic acid to the serum of eight patients also restored normal phagocytic function (p less than 0.001). A correlation was found in vivo and in vitro between changes over time in folic acid levels and in phagocytosis.