Charles E. Tobin

Arteriovenous Shunts in the Human Lung.

Summary Arteriovenous shunts, many times the accepted diameter of capillaries, were demonstrated in isolated human lungs with little or no pulmonary pathology, by the passage of glass spheres from the pulmonary artery to or through the pulmonary veins. Injection of these vessels with liquid latex or vinyl acetate indicates that the shunts are located at the apex of and within the lobular divisions of the lungs.

Visualization of arterio-venous shunts by cinefluorography in the lungs of normal dogs.

Summary A shunt between the pulmonary artery and vein was demonstrated in 3 of 4 dogs by injecting Thorotrast into a catheter inserted tightly into the pulmonary artery and following the circulation by cinefluorography. In one of these dogs the passage of glass spheres 200 ± 25 μ in diameter: through a cannula in the pulmonary artery, to and through a cannula in the aorta, together with the location of the shunt from plastic casts of the pulmonary vessels, help to confirm the presence of the shunt.

Arteriovenous shunts in the myometrium

Abstract Arteriovenous shunts were found in the muscular portion of 16 of 25 surgically removed uteri. These shunts were demonstrated by plastic casts of the vessels obtained by injecting arteries and veins with vinyl acetate of different colors. Glass spheres with a diameter many times that of capillaries passed from arteries into veins with the plastic. In several myomatous uteri large venous sinusoids containing plastic from both arteries and veins were found around the periphery of the tumors, indicating that shunts were present. Shunts were demonstrated in 4 pregnant uteri, but there was no perfect correlation of shunts with any other physiological or pathological condition. The possible significance of these findings is discussed.

Reaction of the Subcutaneous Tissue of Rats to Injected Air.

Summary Single discrete gas pockets were formed by injection of air into the dorsal subcutaneous tissue of rats. The presence of the gas caused a local morphological reorganization which was complete in 2 weeks. A wall, consisting mainly of modified fibroblasts and collagen fibers, developed around the gas and local vasculature increased in proportion to the wall thickness. After removal of the gas, opposing surfaces of the wall fused together and the collagen fibers with their associated cells were resorbed. Enlarged blood vessels remained after the other modified structures were no longer present in the pocket wall.

Survival of Litters from Adrenalectomized Rats Treated with Cortico-Adrenal Substitutes

Conclusions These experiments indicate that NaCl drinking solutions, crystalline progesterone, crude progestin, testosterone propionate, and Antuitrin S, in the dosages used as cortico-adrenal substitutes, will not enhance lactation as determined by the survival of the litters from adrenalectomized females. As compared with the survival of untreated adrenalectomized controls, crude progestin reduced the survival time of the females, whereas the other substitutes prolonged the survival time of the females.

Radioactive pulmonary emboli in rats

Abstract Blood clots were made from rats blood, mixed with rat fibrinogen, labeled with radioactive iodine (I 131 ), and clotted in polyethylene tubing to produce clots of uniform diameter. Varying lengths of these clots, when injected into the jugular or femoral veins or the inferior vena cava, were located most often in the more cauded parts of the lungs. In this respect, the cauded parts of the rat lung are comparable to the inferior lobes of human lungs. Rats have a lysing agent for fibrin in their blood, which lyses most of the clot during the first two days after the clot is injected. The lysing activity varies with age, pregnancy, and the physical environment in which the animals are kept. A prepared lysing agent (Thrombolysin) ® accelerated the lysis of the clots in the majority of the animals tested. Pulmonary infarcts were not found after injecting various sized clots into normal animals, or into animals with pulmonary circulation slowed by: the inhalation or injection of nitrites, hypothermia, pulmonary edema from injected alpha-naphthyl-thiourea, cr cardiac damage due to repeated cardiac puncture.

Some Effects of Thyrotropic Hormone on the Pregnant Rat

Conclusion Rats injected with thyrotropic hormone, between the 10th and 16th days of pregnancy, showed a high percentage of dead embryos, stimulation of the maternal-thyroid and luteinization of unruptured Graafian follicles. The embryonic deaths are attributed to secretion from the stimulated maternal-thyroid. Injections of crystalline thyroxin produced no such effects.

Some Effects of Subcutaneous Tocopherols in Normal and Tocopherol-Deficient Mice

Summary and Conclusions 1. Pellets of crystalline tocopherol esters (d-alpha-tocopheryl palmitate, phosphate, or succinate and d-delta-tocopheryl phosphate) were implanted into the subcutaneous tissue over the dorsal shoulder region of male and female mice. A solution of mixed natural tocopherols was injected into the same region in other animals. 2. All the tocopherol preparations produced local tissue changes resembling a foreign body reaction. Qualitatively, alpha-tocopheryl palmitate and mixed natural tocopherol concentrate produced slight local reaction, The reaction to alpha-tocopheryl succinate and delta-tocopheryl phosphate was greater, and that to alpha-tocopheryl phosphate the most pronounced. 3. All the tocopherol preparations maintained gestation in tocopherol-deficient mice. 4. Two of the alpha-tocopheryl succinate and the alpha-tocopheryl palmitate preparations produced intermittent or continuous vaginal cornification.

Effect of a High Salt Diet on Survival of Adrenalectomized Rats

That NaCl is beneficial in the treatment of experimental adrenal insufficiency was established by the earlier work of Stewart and Rogoff, 1 Banting and Gairns, 2 Marine and Baumann, 3 and Corey; 4 and the recent work of Loeb et al, 5 , 6 Harrop et al, 7 Swingle et al, 8 Zwemer, 9 and Rubin and Krick. 10 A consensus of the findings is that NaCl feeding in dogs and cats will prolong, but not indefinitely maintain, life after total adrenal ablation. Rubin and Krick found, however, that in 8 rats a drinking solution of 0.0329% CaCl2, 0.015% MgCl, 0.07% NaCl and 0.035% KCl given upon the appearance of adrenal insufficiency symptoms, would maintain life for 4 months or more in animals which normally would not live longer than 10 days. At the time of their publication these authors had apparently not determined, by discontinuing treatment, whether accessory adrenals had assumed a functional condition. From their work it would appear that the rat, unlike the cat and dog, will live indefinitely if fed a high salt diet after adrenalectomy. At the time of Rubin and Kricks publication we were studying the effects of adding salt to the diets of adrenalectomized rats. In addition to this we adopted their technique of adding salt to the drinking water, a method probably more effective. In previous experience with our rat colony we found that approximately 95% do not survive adrenalectomy. 11 In the latest adult control series 4 out of 24 survived longer than 30 days, 2 longer than SO days. In the present experiments, 1.5% NaCl was added to the stock diet∗ in part of the cases, 2.5% in the others. Either the Rubin-Krick salt solution or 0.9% NaCl solution was given the animals to drink. As far as we could tell one of these feeding-drinking combinations was no more effective than another, so further distinctions between them are not made here.