Joseph T. Wearn

The nature of the vascular communications between the coronary arteries and the chambers of the heart

Abstract By the employment of injection methods, it has been possible to demonstrate vascular communications between the coronary arteries and the chambers of the heart. Serial sections and wax-plate reconstructions of these communicating vessels revealed two types which have not been described previously. The first of these communicating vessels are small branches of arteries or arterioles lying near the endocardium. They run a short course and empty directly into the lumen of the heart and, for this reason, they have been referred to as “arterio-luminal” vessels. The second type of vessel arises as a branch of an artery or arteriole and soon breaks up into sinusoids which lie between the muscle bundles and at times between the individual muscle fibers. These vessels have been referred to as “arterio-sinusoidal” vessels, and the sinusoids have been designated as “myocardial sinusoids.” The histological structure of the “myocardial sinusoids” would indicate that they play a role in the nourishment of the heart muscle.

Two cases of complete occlusion of both coronary orifices

Abstract Two cases of essential closure of both coronary orifices are reported. The lesions indicate a slowly progressive process which has probably taken months at least to reach the point of essentially complete closure. No evidences of fatty change, myocarditis or repair were found in the heart muscle. The only adequate explanation of the ability of these patients to live and work rests upon a belief that the Thebesian veins have supplied the compensatory circulation necessary for the functioning of the heart muscle.

The incidence of blood vessels in human heart valves

Abstract 1. 1. In one hundred hearts from patients without history or clinical evidence of endocarditis, blood vessels were demonstrated in the valves of eighty-six. 2. 2. Twelve of the hearts showed evidence of active or healed valvulitis on one or more valves. 3. 3. Active or healed valvulitis occurred in the absence of blood vessels, and blood vessels were found in valves without evidence of active or healed valvulitis. 4. 4. Of the eighty-eight hearts without evidence of previous inflammation, blood vessels were found in one or more of the valves in 84 per cent. 5. 5. The incidence of blood vessels in a given heart valve was not in keeping with the incidence of rheumatic valvulitis in that valve. 6. 6. A method of injecting the blood vessels in heart valves is described.

Measurement of Mean Blood Flow in Arteries and Veins by Means of the Rotameter.

Summary and Conclusions The rotameter has been used to measure cardiac input and mean blood flow in the arteries and veins of the anesthetized dog. Typical records are shown. Tests indicate that in routine use the instrument will give reliable blood flow values with an error of less than 10%. Its use enables the experimenter to determine at a glance the moment to moment flow during the time that flow is actually being measured, an advantage not possessed by any other known method. The rotameter is so simple in operation that it should also serve a very useful purpose for the measurement of blood flows in student experiments in the classroom for which as yet no simple and reliable method has been available.

The Capillary-Muscle Ratio in Normal and Hypertrophied Human Hearts.∗

In this investigation, the quantitative study of capillaries as initiated by Krogh 1 and by Wearn and collaborators 1 , 2 , 3 has been applied to normal and hypertrophied human hearts. The methods of injection and sectioning were essentially the same as those used on rabbit hearts in an earlier study from this laboratory. 4 Counts were made in 5 areas of each ventricle of the number of capillaries and fibers per square millimeter. Measurements were made to determine also the average diameter of the individual muscle fibers. In this preliminary report we are able to compare the results of such a study in 10 normal and 10 hypertrophied human hearts. As compared with the normal hearts, the hypertrophied hearts show: (1) A marked increase in the average heart weight/body weight ratio and in the average heart weight, (2) a definite increase correspondingly in the average fiber diameter, and (3) a very evident decrease in the number of capillaries per square millimeter. At the same time, there is, (4) no change in the ratio of capillaries and fibers; that is, the capillaries do not multiply to accompany the increase in muscle mass. From this study on human material, which is in accord with the experimental study of Shipley, Shipley and Wearn 4 on normal and hypertrophied rabbit hearts, it is evident that there is an increase in the distance from the center of a given myocardial capillary to the periphery of its region of supply, which is approximately proportional to the degree of cardiac hypertrophy. At the present time the oxygen utilization of normal and hypertrophied hearts is being investigated to determine whether or not the diminished anatomical vascularization of hypertrophied hearts results in a physiological impairment to the exchange of metabolic substances.

Proliferation of Myeloid and Lymphoid Cells Induced by Extracts of Urine from Leucemic Patients.

Summary Myeloid metaplasia in liver, spleen, adrenal, and other organs, as well as myeloid white cell hyperplasia of the bone marrow, was produced in 33 guinea pigs by injections with extracts of urines obtained from patients with chronic myeloid leucemia. One animal, similarly treated, showed no change. Twenty-eight guinea pigs, injected with extracts of the urine from normal individuals and individuals with diseases other than myeloid leucemia, showed no myeloid change. The animals which received the extracts of urine from patients with chronic lymphoid leucemia and multiple myeloma showed lymphoid hyperplasia. Two animals showed hyperplasia which has not been classified.

A Characterization of a Urinary Fraction Capable of Producing Myeloid Metaplasia in Guinea Pigs

Heinle, Wearn, Weir, and Rose1 reported myeloid hyperplasia and metaplasia in guinea pigs following the injection of extracts and adsorbates of human urine. The majority of potent preparations had been obtained from patients with chronic myeloid leukemia.