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Biomedical subjects

E L Effmann

Publications and source records attributed to E L Effmann.

66 records · Page 4Linked to original sources
PubMed1976

Duplication of the urethra.

Ten patients with patent urethral duplication are presented. Nine patients had two independent patient channels originating from the bladder or the posterior urethra. Both voiding cystourethro and retrograde urethrography are necessary to completely evaluate this anomaly. In each instance the ventral channel, regardless of the position of its meatus, proved to be the more functional urethra. In those patients whose dorsal channel was in an epispadiac position, the symphysis pubis was abnormally wide. A functionally and anatomically accurate classification is proposed, and the embryology of these anomalies is discussed.

Child↗
PubMed1975

Tracheal agenesis.

Tracheal agenesis is a rare anomaly that produces neonatal respiratory distress and has been uniformly lethal to date. In this malformation the entire trachea is usually absent, air reaching the bronchi through a communication with the esophagus, and the lungs are normally formed. The diagnosis should be suspected in any infant in whom improved ventilation is obtained despite difficult intubation and abnormal tracheal tube placement. Coexistent cardiac, gastrointestinal, and genitourinary anomalies are common. The growth of the tracheoesophageal septum and the elongation of the dividing foregut are crucial phases in the morphogenesis of this malformation.

Abnormalities, Multiple↗
PubMedDate not supplied

MR microscopy of chick embryo vasculature.

Six-day-old chick embryos were examined with magnetic resonance microscopy after vascular perfusion fixation and perfusion with gadolinium-doped gelatin to high-light the developing vascular anatomy. Gadolinium gelatin, with its short T1, provided a source of signal contrast within the vessels. The entire embryo was embedded in gelatin to minimize susceptibility artifacts that are prevalent at the high field strength (7.0 T) used. A series of single-section spin-echo images were acquired with various TRs to determine the optimal imaging sequence for a three-dimensional (3D) acquisition. The combination of gadolinium gelatin in the vascular spaces, gelatin embedding of the specimen, and optimal acquisition parameters yielded a 3D stack of high-resolution images that was readily reconstructed and rendered to effectively demonstrate the developing thoracic vessels in the embryo.

Animals↗
PubMedDate not supplied

A computed tomographic study of the dog lung during hemorrhagic shock and after resuscitation.

A shock model was used to explore the capability of computed tomography (CT) to detect changes in lung density during hypovolemia and after resuscitation. The same level of the lower thorax was scanned repeatedly during base-line, shock (aortic pressure 60 mmHg), and after resuscitation with shed blood. The average baseline CT number (+/- SEM) for 5 areas of interest for four prone dogs was -754 +/- 16 (air = -1000, water = 0). This decreased 7.4% to -810 +/- 15 (P less than .05) during shock. After resuscitation CT density was -773 +/- 17 or 2.5% less than baseline (P greater than .1). A dorsal to ventral gradient of increasing CT density during baseline was maintained in all five areas during shock and post-resuscitation. From baseline to shock there were also significant changes in heart rate, mean aortic pressure, cardiac output, and vascular volume. Extravascular lung volume after resuscitation was equal to baseline volume. We conclude that CT is sufficiently sensitive to detect rapid physiological changes leading to increased or decreased lung density.

Animals↗
PubMedDate not supplied

Analysis of the density of pleural fluid analogs by computed tomography.

A noninvasive method for differentiating transudative and exudative pleural effusions could make thoracentesis unnecessary in many cases. Since computed tomography (CT) can be used to measure tissue densities, it has a potential use in assessing density of intrathoracic fluid. This study was performed to test this possibility. Plastic syringes containing water, saline, and three saline-albumin solutions with densities up to 1.021 g/cc were scanned individually in air, in a chest phantom, and in a dog thorax during apnea. We found significant positive correlations between specific gravity and CT density; coefficients ranged from 0.85 to 0.99. Regression lines for the different test conditions were not statistically different. However, CT number variability, as indicated by the average standard deviation (SD), did differ for the test conditions: 1) Syringes alone, average SD was 3.8 HU; 2) chest phantom, average SD was 5.5 HU adjacent to rib and 5.8 HU anterior to vertebral column; 3) dog chest average SD was 19.2 HU with heart motion and 9.4 HU without heart motion. These results suggest that heart motion is a major factor in CT number variability in vivo, and that differentiation of transudates from exudates is not possible with current CT methods.

Animals↗
PubMedDate not supplied

Hydrostatic pulmonary edema. An analysis of lung density changes by computed tomography.

The computed tomographic (CT) appearance of pulmonary edema induced by elevated left atrial (LA) pressure was examined. Dogs, in the prone position, were scanned during suspended ventilation at functional residual capacity. A surgically implanted LA balloon was inflated to elevate LA pressure for 30 to 140 minutes to a mean pressure of 29.8 mm Hg. Lung water, measured gravimetrically, averaged 14.7 ml/kg body weight compared with 5.7 ml/kg in nonedema control dogs. Lung density in dogs with edema was 69.5% higher than base-line density, while in the control group final lung density was only 4% higher than base line. Analysis of regional density indicated that there were greater increases in density in more central and dependent (ventral) zones of the lung and relatively smaller increases in nondependent (dorsal) peripheral zones. These results are in contrast to the previously reported pattern of density change seen with oleic acid injury in which density increases were primarily in peripheral zones of the lung.

Animals↗
PubMedDate not supplied

Morphology of oleic acid-induced lung injury. Observations from computed tomography, specimen radiography, and histology.

Previously, we reported that oleic acid infusion in dogs produced a patchy and predominantly peripheral increase in lung density. The present study examines in more detail the morphology of the early stages of development of the oleic acid lesion using computed tomography (CT), specimen radiography, and conventional histology. Dogs were sacrificed 10, 30, 60, and 240 minutes after infusion of oleic acid (.05 ml/kg). After freezing in dry-ice, the thorax was scanned and cut into 1-cm thick sections. Frozen sections were then contact radiographed and sampled for histology. Within 10 minutes of infusion, subtle increases in peripheral lung density were visible on the contact radiographs. Patchy areas of peripheral density, resembling secondary lobules, were especially prominent 60 and 240 minutes after infusion. These lesions were often clearly associated with the distal bronchovascular structures. Histologic signs of edema were present in all animals sacrificed 30 or more minutes after receiving oleic acid. These correlative studies provide additional insight into the early subgross development of oleic acid-induced injury by showing the relationship between the developing edema and the bronchovascular structure of the lung.

Animals↗
PubMedDate not supplied

MR "microscopy" of the rat thorax.

High resolution images can be obtained from anywhere in the body of small animals with magnetic resonance combined with cardiac gating and scan synchronous ventilation. We used these methods to examine the intrathoracic anatomy of the rat. Anesthetized rats were intubated and ventilated in synchrony with imaging acquisition. Images were obtained in a 1 m bore, 1.5 T system fitted with a 28 cm diameter high field gradient coil and a 5 cm radio-frequency coil. We used cardiac gated, three-dimensional spin warp acquisitions. Eight contiguous slices (2.5 mm thick) were obtained simultaneously. In addition to visualizing major vessels and cardiac chambers, cardiac valves and papillary muscles were clearly demonstrated. Major pulmonary vessels and peripheral parenchyma were also seen. These results demonstrate MR "microscopy" can be used to image all major cardiopulmonary structures in the rat with respect to selected times of the cardiac cycle. This capability for noninvasive "microscopy" opens new avenues for cardiopulmonary research using well characterized rodent models.

Animals↗
PubMedDate not supplied

Development of the right and left pulmonary arteries. A microangiographic study in the mouse.

The developing aortic arches and pulmonary vasculature of 200 mouse embryos (gestational age 11.5-18 days) were directly imaged by stereomicroradiography after perfusion fixation, endothelial staining, and critical point drying. At 11.5-days gestational age, symmetric third, fourth, and sixth aortic arches and proximal portions of the right and left pulmonary arteries were noted. At 12 days, rudimentary pulmonary arteries extended dorsocaudally from the middle portion of the left sixth arch, and there was loss of the dorsal component of the right sixth arch. Semilunar valve anlagen were noted at 12 days, and cusps formed during days 13 and 14. With continued growth, the lungs and pulmonary arteries enlarged and came to occupy a more cephalad position relative to the heart. Stereomicroradiographic techniques permit direct imaging of developing vascular systems in the mouse embryo. Information gained from these whole specimen studies serve to complement serial section and reconstruction studies and offer the potential for evaluating normal and abnormal vascular development.

Animals↗