The use of radioactive iodine in the treatment of Graves disease

Fifty patients with uncomplicated Graves' disease were treated with radioactive iodine (I(131)). Twenty-six patients who were followed for one year or longer are the basis of this report. Twenty-five are now euthyroid; only one is not completely well. The total dose of radioiodine administered varied from 0.5 to 10 millicuries. The average length of time necessary for return to a euthyroid state was from three to four months. Hypometabolism developed in three patients, and in one the signs and symptoms of myxedema developed. No other complications ensued. One patient who apparently relapsed had complete return to normal after further iodine administration. The determination of the uptake of radioactive iodine by the thyroid gland is a useful diagnostic procedure in differentiating conditions simulating hyperthyroidism.Following treatment with radioactive iodine, the thyroid gland becomes smaller, the uptake of iodine by the gland is reduced, and the level of organic iodine in the plasma becomes normal. In acute thyroiditis, in spite of a high basal metabolic rate, high content of organic iodine in the plasma and other evidences of "hyperthyroidism," the uptake of I(131) has been very low.     

Increased tolerance of Staphylococcus aureus to vancomycin in viscous media

The increased viscosity observed in biofilms, adherent communities of bacterial cells embedded in a polymeric matrix, was hypothesized to induce increased tolerance of bacteria to antibiotics. To test this concept, planktonic Staphylococcus aureus cells were grown and exposed to vancomycin in media brought to specific viscosities in order to mimic the biofilm extracellular polymeric matrix. A viscous environment was observed to decrease the vancomycin susceptibility of planktonic S. aureus to levels seen for biofilms. Both planktonic S. aureus at a viscosity of 100 mPa s and staphylococcal biofilms were able to survive at >500 times the levels of the antibiotic effective against planktonic populations in standard medium. Time-dependent and dose-dependent viability curves revealed that more than one mechanism was involved in high S. aureus tolerance to vancomycin in viscous media. Increased viscosity affects antibiotic susceptibility by reducing diffusion and the mass transfer rate; this mechanism alone, however, cannot explain the increased tolerance demonstrated by S. aureus in viscous media, suggesting that viscosity may also alter the phenotype of the planktonic bacteria to one more resistant to antimicrobials, as seen in biofilms. However, these latter changes are not yet understood and will require further study.     

Enzymatic synthesis of water-soluble derivatives of salicylic acid in organic media

A novel enzymatic method for preparing water-soluble derivatives of salicylic acid catalyzed by immobilized lipase was described. This study is the first to describe the enzymatic transesterification of methyl salicylate in organic solvents with different hydroxyl donors. The acyl-transfer between methyl salicylate and sorbitol was best supported by solvents of log P values –0.33 to 1.4. With Candida antarctica lipase in tert-amyl alcohol, a sorbitol conversion yield of 98% can be obtained by transesterification with sorbitol and methyl salicylate in one step.     

The use of hormone-supplemented serum-free media in primary cultures.

Recent advances in tissue culture and endocrinology have made possible the growth of established cell lines in hormone-supplemented serum-free media. The hormone requirements differ for different cell types but are similar or identical for the same cell types. The hormone supplements derived for four different cell types, a melanoma, GH3 pituitary tumor, and testicular cell lines TM3 and TM4 are used in preparing primary cultures for organs to detect melanoma metastasis, and grow normal pituitary and normal Leydig and Sertoli cells, respectively. This hormone supplementation and the concomitant elimination or reduction of the serum requirement is shown to have several advantages in the preparation of primary cultures including prolonged viability and function, partial or total selection of the desired cell type and inhibition of fibroblast overgrowth.It is felt that such culture systems will significantly expand the range of problems which can be approached using primary culture systems.     

The use of a water-soluble carbodiimide to cross-link cytochrome c to plastocyanin

Canine cardiac sarcoplasmic reticulum is phosphorylated by adenosine 3',5'-monophosphate (cAMP)-dependent and by Ca2+-calmodulin-dependent protein kinases on an Mr 22 000 protein called phospholamban. Both types of phosphorylation are associated with an increase in the initial rate of Ca2+ transport. Thus, phospholamban appears to be a regulator for the calcium pump in cardiac sarcoplasmic reticulum. However, there is conflicting evidence as to the degree of association of the Ca2+-ATPase with its regulator, phospholamban. In this study, we report that phospholamban does not copurify with a Ca2+-ATPase preparation of high specific activity. Although 32P-labeled phospholamban is solubilized in the same fraction as the Ca2+-ATPase from cardiac sarcoplasmic reticulum, it dissociates from the Ca2+ pump during subsequent purification steps. Our isolation procedure results in an increase of over 4-fold in the specific activity of the Ca2+-ATPase, but a decrease of 2.5-fold in the specific activity of 32Pi-phosphoester bonds (pmol Pi/mg). Furthermore, the purified Ca2+-ATPase enzyme preparation is not a substrate for protein kinase in vitro to any significant extent. These data indicate that phospholamban does not copurify with the Ca2+-ATPase from cardiac sarcoplasmic reticulum. Isolation of a Ca2+-ATPase preparation essentially free of phospholamban will aid in future kinetic studies designed to elucidate similarities and differences in the Ca2+-ATPase parameters from cardiac and skeletal muscle (which is known not to contain phospholamban).     

Therapeutic studies in hyperthyroidism; use of radioactive iodine

Of 112 patients with hyperthyroidism who were treated with radioactive iodine, 110 were relieved of the disease. Nine had transient hypothyroidism. Twelve had permanent hypothyroidism. No other adverse effects that could be attributed to radioactive iodine were noted.     

Double contrast retrograde urethrography using viscous and gaseous contrast media in men

The authors present the literature and their own data on the use of a double contrast study of the urethra in 38 male patients with dysuria of various etiology. The investigations were performed with roentgeno-television control using viscid contrast substances (propyliodone) and gel-like triiodinated liquid contrast media (verografin, urografin, triombrast, etc.). A high informative value of the method in the detection of pathological changes in the urethra and the neck of the urinary bladder, lesser risk of the development and lesser severity of urethro-venous refluxes were noted.     

Photopolymerized water-soluble chitosan-based hydrogel as potential use in tissue engineering

Novel biodegradable hydrogels by photocrosslinking macromers based on chitosan derivative are reported. Photocrosslinkable macromers, a water-soluble (methacryloyloxy) ethyl carboxyethyl chitosan were prepared by Michael-addition reaction between chitosan and ethylene glycol acrylate methacrylate. The macromers were characterized by Fourier transform infrared spectroscopy, (1)H NMR and (13)C NMR. Hydrogels were fabricated by exposing aqueous solutions of macromers with 0.1% (w/v) photoinitiator to UV light irradiation, and their swelling kinetics as well as degradation behaviors was evaluated. The results demonstrated that the degradation rates were affected strongly by crosslinking density. The hydrogel was compatible to Vero cells, not exhibiting significant cytotoxicity. Cell culture assay also demonstrated that the hydrogels were good in promoting the cell attachment and proliferation, showing their potential as tissue engineering scaffolds.