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Altered mechanical stress and strain in cardiac myocytes induce modifications in gene expression that affects cardiac remodeling and myocyte contractile function. To study the mechanisms of mechanotransduction in cardiomyocytes, probing alterations in mechanics and gene expression has been an effective strategy. However, previous studies are self-limited due to the general use of isolated neonatal rodent myocytes or intact animals. The main goal of this study was to develop a novel tissue culture chamber system for mouse myocardium that facilitates loading of cardiac tissue, while measuring tissue stress and deformation within a physiological environment. Intact mouse right ventricular papillary muscles were cultured in controlled conditions with superfusate at 95% O2/ 5% CO2, and 34 degrees C, such that cell to extracellular matrix adhesions as well as cell to cell adhesions were undisturbed and both passive and active mechanical properties were maintained without significant changes. The system was able to measure the induction of hypertrophic markers (BNP, ANP) in tissue after 2 hrs and 5 hrs of stretch. ANP induction was highly correlated with the diastolic load of the muscle but not with developed systolic load. Load induced ANP expression was blunted in muscles from muscle-LIM protein knockout mice, in which defective mechanotransduction pathways have been predicted.

Serum protein-bound iodine (PBI), total blood thyrotoxin (T4), triiodthyronine (T3), coefficient of thyrotoxin efficacy (CTE), serum thyrotoxin-binding capacity (TBC) or some of these indices were determined in 44 patients with nodular toxic goiter with thyrotoxemia. An increase in T3 level was revealed in 27 of 35 of the patients; T3-thyrotoxicosis was diagnosed in 18 of these in whom an increase of the T3 level was combined with normal T4 or normal CTE content and an unchanged TBC. The symptoms of T3-thyrotoxicosis displayed no significant differences from the symptoms of thyrotoxicosis caused by the excess of thyroxin. In many of the patients T3-thyrotoxicosis coursed for a long time with but a few symptoms. Loss of weight in this form of thyrotoxicosis was much less frequent than in "thyrotoxin'' thyrotoxicosis. PBI was elevated in 12 of 44 patients, and total T4 and CTE -- in 10 of 35. These methods do not permit to diagnose hyperthyroidism in many of the patients with nodular toxic goiter in which T3-thyrotoxicosis is of frequent occurrence.

According to well documented histories a group of experts-endocrinologists determined the presence of one or another disease in 109 patients with different thyroid pathology. Two examinations were performed according to the clinical findings and on the basis of the same indices, added by results of the radioiodine test. Diagnostic informativity of different indices of the radioiodine test was evaluated according to the correlation (by means of calculation of the correlations) between the radiological parameter and the disease probability. It was concluded that the parameters of the routine research methods (131I absorption within 2, 4, 24 and 48 hours) are more informative than the values of more complicated variants of the radioiodine test. Informativity of the whole radiological and non-radiological findings was estimated, using a diagnostic coefficient method. It was shown that the role of radiological indices in making a correct diagnosis averages 17% and in cases of hypothyrosis and toxic forms of goiter this value increases up to 30%.