Shirley L. Kauffman

Lengthening of the generation cycle during embryonic differentiation of the mouse neural tube

Abstract A comparative autoradiographic study of the generation cycle in the 10-and 11-day embryonic mouse neural tube showed an increase in mean generation time of 2 h over the period studied. This was caused by an increase in the time spent in DNA synthesis (S), post-synthetic (G2) and pre-synthetic interphase (G1) with no alteration in mitotic time.

An autoradiographic study of the generation cycle in the ten-day mouse embryo neural tube☆

Abstract An autoradiographic study of the generation cycle in the 10-day-old mouse embryo neural tube shows a total generation time of 8.5 hr, and a DNA synthetic period of approximately 4.0 hr. Though growth appears to be almost exponential over the early part of the time studied, increasing migration and differentiation of labeled cells becomes evident towards the end of the observation period. Between day 10 and day 11, the mean Ts increases by approximately 1 hr. This increase in the S period appears to correlate with the transition between the phase of predominate cell proliferation in the 10 day neural tube and accelerated migration and differentiation of the 11 day neural tube.

Persistent venous valves, maldevelopment of the right heart, and coronary artery-ventricular communications

Abstract An unusual malformation of the heart in a newborn infant is described, consisting of persistent venous valves in the right atrium, hypoplasia of the tricuspid valve, pulmonary atresia, and multiple coronary artery-ventricular communications with the right ventricle. Coronary flow to the right heart was shunted through the right ventricle, and focal necrosis was seen in the right ventricular myocardium. The pertinent literature is reviewed and the pathogenesis of the malformation is discussed.

The fine structure of the embryonic mouse neural tube with special reference to cytoplasmic microtubules

Abstract The fine structure of undifferentiated interphase and mitotic cells of the 10-day mouse embryo neural tube has been described. Cytoplasmic microtubules (270 A) were seen in the interphase cells, often connected to the Golgi vesicles near the nucleus and ending in an apical vesicle or parabasal body adjacent to the central canal. Similar microtubules forming spindle fibers and connected with chromosomes were prominent in mitotic cells. The possible role of cytoplasmic microtubules in maintenance of cell shape, nuclear migration, and cerebrospinal fluid secretion is discussed.

Idiopathic infantile cardiomyopathy with involvement of the conduction system

Abstract A 2 year old girl died of heart failure after recurrent episodes of ventricular tachycardia. At autopsy, portions of the subendocardium of the left ventricular septum, bundle of His, left bundle branch and trabecular muscles were replaced or compressed by masses of lipid-filled cells. Five additional reported cases, all with similar clinical and pathologic features, are reviewed.

Mycotic Aneurysms of the Intrapulmonary Arteries

In the case presented, multiple aneurysms of the peripheral pulmonary arteries occurred in a child with secondary pulmonary hypertension complicated by bacterial endocarditis. Study of other reported cases suggests that pulmonary hypertension may be significantly associated with the development of mycotic aneurysms. As surgical resection of aneurysms has been at least temporarily successful, increased attention may be given to control of infection in these patients and to the appreciation of the frequency of aneurysms of the main pulmonary artery as well as peripheral pulmonary arteries in patients with congenital heart disease and pulmonary hypertension complicated by bacterial endocarditis.

AUTORADIOGRAPHIC STUDY OF TYPE II-CELL HYPERPLASIA IN LUNGS OF MICE CHRONICALL EXPOSED TO URETHANE

Hyperplasia of pulmonary alveolar epithelium was induced by exposure of adult mice to 0–1% urethane in drinking water, and their lungs were analysed using combined autoradiographic and morphometric methods. The response of pulmonary epithelium showed three phases: an initial one of 3 weeks in which the number of type II cells was consistently low and, after a transient decrease in 3H‐thymidine labeling index, the latter steadily increased. Degenerating or dead type II cells were found, consequently this period was considered one in which cell death was disproportionately increased over cell production. Between the 3rd and 6th weeks the number of type II cells doubled, and thereafter increased at a slower rate. The 3H‐thymidine labeling index reached its peak at 6 weeks. The third phase was marked by a decline in labeling index which returned to near‐normal levels by the 16th week. The number of type II cells declined slowly after the 10th week and was still elevated at the end of the observation period. Tumors consisting of type II cells continued to arise even during the period of declining labeling index.

Teflon Embolization to Pulmonary Arteries

A previously unreported complication of cardiac surgery, embolization to the lungs from Teflon pledgets, is presented. The pathological changes found in the pulmonary arteries postmortem are described and their possible clinical significance is discussed. Properties inherent in Teflon are implication in the origin of the embolization.

Malignant Clara cell line derived from ethylnitrosourea-induced murine lung adenomas

Lung adenoma induced in Swiss-Webster mice by transplacental exposure to ethylnitrosourea were minced, cultured and carried as cell lines for up to 2 years. The evolution of cell lines was followed every 3 months by ability to grow in nude mice and by morphological and ultrastructural examination of the tumors. Four cell lines, each originating from a single cell inoculum, were cloned. One of these produced mainly papillary tumors in nude mice and ultrastructurally had the morphology of Clara cells.

Origin of the right pulmonary artery from the aorta. A clinical-pathologic study of two types based on caliber of the pulmonary artery.

Abstract A case of isolated origin of the right pulmonary artery from the aorta is presented. Fifteen reported autopsy cases in infants and children are reviewed and classified into two groups. In Group 1 the right pulmonary artery originated from or adjacent to the innominate artery, and there was usually stenosis or atresia of the right pulmonary artery. The lung on the right side was poorly developed and the media of the pulmonary arteries normal to atrophic, with evidence of pulmonary hypertension on the left side. In Group 2 the right pulmonary artery arose from the ascending aorta, usually from the right or posterior aspect. Here, a wide communication was maintained between the pulmonary-artery and aorta. In these cases there was bilateral medial hypertrophy of the intrapulmonary arteries. Certain features (x-ray, electrocardiographic and pathologic) that may permit separation of the two groups are discussed.