Richard H. Mandl

Methods for the qualitative, semiquantitative and quantitative determination of iodoamino acids and of inorganic iodide in iodoprotein digests and in human serum.

Abstract 1. 1. Iodo compounds in a proteolytic digest of iodoproteins are concentrated by extraction with n -butanol (yield of iodine ca . 98%). The extract is further purified by chromatography on cellulose (yield of iodine ca . 97%). 2. 2. Free and protein-bound iodo compounds of serum are concentrated by the method described previously. 3. 3. The iodo compounds are separated by paper chromatography and estimated by three procedures: 3.1. (a) Visual comparison employing ceric sulfate-arsenious acid followed by counter-staining with methylene blue. The sensitivity of this procedure is approximately 0.1 μg. organic iodine. 3.2. (b) Manual colorimetry using the ceric sulfate-arsenious acid reaction after elution of the chromatogram. This method has a sensitivity of approximately 0.005 μg. of organic iodine and a reproducibility of 25% or better. 3.3. (c) Automatic colorimetry using the ceric sulfate-arsenious acid reaction after elution of the chromatogram. This procedure also has a sensitivity of approximately 0.005 μg. of organic iodine and a reproducibility of 10%. 4. 4. The data indicate that there is sufficient 3,5,3′-triiodothyronine in the “thyroxine” fraction of digests of thyroglobulin to account for the observed discrepancies between the biological activity of thyroid preparations and the quantity of thyroxine found in these preparations by the Blau method.

The curative action of iodine on soybean goiter and the changes in the distribution of iodoamino acids in the serum and in thyroid gland digests.

Abstract Rats were fed iodine-deficient rations (0.7–2.3 μg. iodine /100 g. diet) based upon raw soybeans, solvent-extracted soy Hour, isolated soy proteins, or soybean infant formulas with or without added iodide. Significant enlargement of the thyroid gland occurred on the iodine-deficient rations in 1 or 2 weeks. The addition of 160 μg. iodine as KI /100 g. diet caused the hypertrophied gland to return to normal size in 2 or 3 weeks. Although the lack of iodine is the principal cause of soybean goiter, raw soybeans, which contain more iodine than either solvent -extracted soy flour or glycinin, produce greater thyroid hypertrophy. This observation suggests that raw soybeans have a goitrogenic activity (goitrogen?) which is removed or destroyed during processing. The methodology used to estimate the iodoamino acids in serum and in thyroid digests is discussed. Evidence is presented that neither thiouracil nor propylthiouracil, added as a preservative to serum, is responsible for the reported presence of appreciable quantities of iodotyrosines in rat and human sera. The quantities and distribution of the iodoamino acids in the sera and in digests of the thyroid glands were used as additional criteria to study the changes produced by soybean, goiter and its prevention by the inclusion of KI in the iodine-deficient regimens. Besides the very marked decrease in organic iodine in the serum and in the thyroid glands of the animals on the iodine-deficient rations, the ratios of iodotyrosines to iodothyronines differed from those found in rats receiving soybean diets with added KI or from those on the usual laboratory foods. Thus the ratio of iodotyrosines to iodothyronines in the sera of animals on iodine-deficient diets is approximately 1:1, while it is in the range of 1:2 or 1:4 in the sera of animals containing an adequate, quantity of KI. The situation with respect to the distribution of iodoamino acids in digests of the glands is reversed from that of the serum. In this case, the ratio of iodotyrosines to iodothyronines is much higher in thyroid glands of euthyroid rats than in the glands from iodine-deficient animals. Tentative explanations of these changes in the distribution of iodoamino acids are offered.

Effects of hydrogen flouride and sulphur dioxide alone and in combination on several species of plants

Abstract Bean, barley and sweet corn were exposed separately to charcoal-filtered air, hydrogen fluoride (HF), sulphur dioxide (SO 2 ), and a combination of the two pollutants. In two experiments, plants were exposed to 0·0005–0·0007 mg F/m 3 (0·0006–0·0009 ppm), to 0·15 or 0·30 ppm (-·40 or 0·79 mg/m 3 ) SO 2 , and to the combined pollutants for 7 days. Lower concentrations of SO 2 were used in two other experiments, viz. 0·06 to 0·08 ppm (0·16–0·21 mg/m 3 ) and exposures were made for 27 days. When high concentrations of SO 2 were used, severe injury occurred on corn and barley leaves, and the combination of SO 2 and HF did not alter foliar symptom production. Beans were not injured by any of the the treatments. With lower concentrations of SO 2 , the foliar response of barley and corn was accentuated by the combination of SO 2 and HF. On both of the corn cultivars tested, symptoms consisted of elliptical lesions on the distal half of older leaves. In one experiment, foliar accumulation of fluoride was reduced by the combination of SO 2 and HF as compared with HF alone. Fresh and dry weight yields of plant tops were not affected by treatment in any experiment.

Field tests of a linear gradient system for exposure of row crops to S02 and HF

An exposure system for exposing plants to gradients of gaseous air pollutants in the field was tested using sulfur dioxide SO2 and hydrogen fluoride (HF). Well defined linear gradients of SO2 concentration and HF flux were easily produced and were repeatable from exposure to exposure. The gradients were altered by wind speed and direction, but in tightly closed canopies, the alterations were minor. This system has many advantages: a graded series of exposures can be conducted in a small area, plants may be grown using accepted cultural practices, the cost of the apparatus is low, and more than one pollutant can be used, either concurrently or countercurrently. Disadvantages include the requirement for an intensive air monitoring network and an unnatural vertical pollutant profile in the canopy. The gradient system should be used as a supplement to open-top chambers, and not as a replacement for them.

Automatic analysis of iodoamino acids and of iodide in digests of iodinated proteins.

When a test dose of NaI131 is administered to a man or other animal, approximately 90 per cent of the protein-bound iodine (PBI; SPI ) is present as radioactive thyroxine ( T4I3l ) and triiodothyronine (T3l3I) (Pitt-Rivers and Tata, 1959). This observation, together with the unproved assumption that the administered 1131 comes into equilibrium quickly with the circulating P 7 , forms the basis for the widely employed PBI method as a diagnostic tool (Werner, 1955). Experimental results, published during the past few years, have thrown considerable doubt on the assumption that the PBI is truly representative of circulating thyroid hormones in the great majority of individuals (Block et al., 1960; Werner and Block, 1959). If a considerable, though variable, quantity of the PBI is composed of monoand diiodotyrosine ( MIT; DIT ) , the interpretation of the results obtained using the conventional PBI (or butanol-extractable iodine) methods must be re-evaluated. In view of the reported discrepancy between the results obtained with IIZ7 and 1131 (Block et al., 1960; Stolc, 1961), it would be most desirable to quantitate the distribution of the iodoamino acids not only in the blood but also in the thyroid gland itself by a more accurate and technically simpler method than those used previously (Mandl and Block, 1959; Block et al., 1961; Stolc, 1961). The recent advances in methods of obtaining small quantities of tissue by needle biopsy strengthen the desirability of diagnosis of thyroid pathology by direct examination of the glandular tissue. The technique described in this paper permits the quantitative determination of iodide (I-) , DIT, MIT, Tq, T3, and 3,5-diiodothyronine (T2) in enzymatic digests of less than 1 mg. of iodoproteins by a fully automatic method. Unidentified iodocompounds in the digests are also revealed.

The binding of mixtures of iodoamino acids and of inorganic iodide by various serum proteins.

Abstract 1. 1. Human serum was treated with a thyroid digest prepared from rat thyroids 72 hr. after the animals received a dose of NaI 131 . 2. 2. The dialyzed I 131 -containing serum proteins were fractionated by diethylaminoethylcellulose ion-exchange chromatography. 3. 3. The composition of the protein fractions was characterized by means of paper electrophoresis. 4. 4. The protein-bound iodo compounds were removed from the proteins and tentatively identified by means of paper chromatography. 5. 5. Thyroxine (T 4 ), triiodothyronine (T 3 ), diiodothyronine (T 2 ), iodide (I − ), diiodotyrosine (DIT), monoiodotyrosine (MIT), and diiodohistidine (DIH) were found to be bound to the serum proteins. 6. 6. These iodo compounds were present in many or all of the 16 fractions obtained; however, specific binding sites for T 4 occurred in the α 1 -globulins, for T 2 and T 3 in the α 1 -globulins and albumins, for iodide in the α-globulins and albumins, for DIT in the fast-moving γ-globulins, for MIT in the basic, slow-moving γ-globulins, and for DIH in the proteins most strongly retained by the cellulose exchanger.

Studies on the Measurement of Fluoride in Air and Plant Tissues By the Willard-Winter and Semiautomated Methods

Determinations of F in plant tissues by the Willard-Winter and semiautomated methods have been studied for the presence of determinate and indeterminate errors by multiple linear regression analysis. The results have provided a better understanding of the magnitude of differences between tissue samples required for statistical significance and have suggested that the errors involved are much greater both in number and magnitude than usually assumed. The results have also established that the semiautomated method is a satisfactory alternative to the Willard-Winter method for determining the F content of plant tissues. Investigations of the sources of error in F determinations by the semi-automated method were carried out, and the results indicated a number of ways of reducing errors. Determinations of the F content of air by three methods were compared and studied to estimate the magnitude and locate the sources of error. Here, too, the results indicated that present estimates of the reliability of determi...

Studies on the effects of saline aerosols of cooling tower origin on plants

A research program was undertaken to develop information that could be used to estimate the risk of adverse effects of saline cooling tower drift on native and cultivated flora in the Indian Point, New York area. Eleven species of woody plants were exposed at 85 % relative humidity to a saline mist with 95% of the particles between 50 and 150 nm in diameter. Three biological factors—stage of development, species, and phenotype—determined the susceptibility of plants to saline aerosols when the occurrence of any lesion on the foliage was used as a measure of response. The effects of stage of development on the incidence and severity of foliar lesions depended upon the kind of plant. In deciduous woody species, the youngest leaves were most susceptible, but in conifers, the year-old needles were most susceptible. Canadian hemlock was the most susceptible species and witch hazel was the least susceptible. Median effective doses for these two species, although undetermined, could be more than 100-fold differe...

SEMI-AUTOMATED ANALYSIS OF FLUORIDE IN BIOLOGICAL MATERIALS.

A semi-automated method for determination of fluorine in biological materials has been developed incorporating the Technicon AutoAnalyzer. One-half gram of dried, ground plant material is ashed, alkali-fused, diluted with water, and the suspension is pumped, along with H2SO4, at controlled rates, into the hot revolving glass helix of a digestor unit. As the acid-digest mixture passes through the heated coil, volatile fluoride and water vapor are evolved. The volatile fluoride and water vapor are pulled from the helix under reduced pressure through a tube which projects into the helix. The tube, in turn, is connected to a water-jacketed condenser and then to an impinger where the sample is continuously mixed. An aliquot of the impinger liquid is being constantly withdrawn. This sample is then air-segmented and mixed with a reagent containing alizarin complexone, pH 4 acetate buffer, lanthanum nitrate, acetone, and water. The sample-reagent combination passes through 4 full-length mixing coils where color d...

A weighing lysimeter for determining water loss in red spruce saplings (Picea rubens Sarg.)

Abstract A relatively simple, economical, and sensitive load cell weighing lysimeter system was developed for determining water use by 1–1.5 m tall red spruce ( Picea rubens Sarg.) trees exposed in the field to ozone and simulated acidic precipitation in open-top chambers. The lysimeters have been operating successfully in the field for the past two growing seasons. They are used to measure moisture losses by evapotranspiration and deposition of simulated acidic precipitation to tree and soil. The lysimeter was constructed of materials that are sturdy, corrosion resistant, and readily available from commercial sources. Each lysimeter has a total capacity of 681 kg (1500 lbs) based on a rated load cell capacity of 227 kg (500 lbs); however, an increased capacity is attainable if load cells are overloaded within the manufacturers safe rated limits. The completed system has a maximum sensitivity of 18 g, which corresponds to 0.023 mm water based on a soil surface area of 7854 cm 2 ; however practical use limits the system to an accuracy of about 100 g, which corresponds to 0.13 mm equivalent water depth.