Radiation effects on the lung: clinical features, pathology, and imaging findings.
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Diagnosis, Differential↗
Biomedical subjects
S D Davis
Publications and source records attributed to S D Davis.
Radiology of congenital abnormalities of the chest.
Radiologic imaging plays a critical role in the management of congenital abnormalities affecting the tracheobronchial tree, lung parenchyma, pulmonary vessels, and the mediastinum. Although procedures such as bronchoscopy, bronchography, and angiography may at times still be required, diagnosis is now usually established noninvasively using ultrasound, CT, MR imaging, or radionuclide imaging techniques. Earlier diagnosis, even in the antenatal period, is possible, thus allowing more prompt and effective treatment. Patients with congenital abnormalities that were previously fatal in infancy and childhood are surviving into adulthood. Clinicians and radiologists alike must now be able to recognize congenital disorders in patients who may have minimal or absent symptoms.
Bronchi↗
Effects of steroid administration on pituitary luteinizing hormone and follicle-stimulating hormone in ovariectomized pony mares in the early spring: pituitary responsiveness to gonadotropin-releasing hormone and pituitary gonadotropin content.
These experiments tested the hypothesis that administration of steroid hormones to ovariectomized (OVX) mares during the vernal transition to the breeding season would influence LH and FSH secretion. Circulating gonadotropin concentrations, response to exogenous GnRH, and pituitary gonadotropin content were monitored. Experiments 1 and 2 were conducted, beginning 10 March, and 3 February, respectively, utilizing a total of 30 long-term OVX pony mares. In experiment 1, mares were administered vehicle (n = 5) or estradiol-17 beta (E2, n = 5, 5 mg/3 ml sesame oil), twice daily for 16 days. Blood samples were collected daily for assessment of circulating LH and FSH concentrations. On Day 10 of treatment, 400 micrograms GnRH were administered to all mares. LH increased significantly over days of treatment in the estradiol-treated group, but pituitary response to GnRH tended to be less than in control mares. Circulating FSH tended to decline over days of treatment in estradiol-treated mares, and the pituitary response to GnRH was significantly reduced. Pituitary LH, but not FSH, was increased on Day 16 of treatment with estradiol. In experiment 2, 20 OVX mares received, twice daily, vehicle (n = 5), E2, n = 5; 5 mg), progesterone (P4, n = 5; 100 mg), or progesterone plus estradiol (P4/E2, n = 5; 100 + 5 mg). Treatment continued for 14 days. GnRH (100 micrograms) challenges were administered on Days 6 and 13 of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
Anestrus↗
CT evaluation for pulmonary metastases in patients with extrathoracic malignancy.
Computed tomography (CT) is clearly more sensitive than chest radiography or conventional linear tomography in the detection of pulmonary metastases. Routine chest CT scans may reveal peripheral nodules as small as 2-3 mm, and high-resolution CT may demonstrate lymphangitic carcinomatosis. Specificity remains a problem, but attention to clinical factors, such as the type of extrathoracic malignancy (ETM), epidemiology, patient age, and prior treatment, should be of assistance. CT is useful in the evaluation of an apparent solitary pulmonary nodule or an equivocal radiographic finding. For single or multiple nodules, CT is essential for planning invasive procedures such as biopsy or surgical resection. Routine CT scanning to screen for occult metastases is indicated only for patients with ETMs that have a high propensity for metastasizing to the lungs and for which detection of pulmonary metastases would influence therapy--bone and soft-tissue sarcomas, most pediatric tumors, choriocarcinoma, nonseminomatous testicular carcinoma, and possibly advanced melanoma. Future large prospective studies evaluating individual malignancies are needed to assess the impact on long-term survival of early detection of pulmonary metastases with CT.
Humans↗
Effect of constant light exposure on circulating gonadotrophin levels and hypothalamic gonadotrophin-releasing hormone (GnRH) content in the ovariectomized pony mare.
Melatonin is thought to play a role in relaying photic information to the central nervous system as part of the seasonal reproductive cycle of the mare. However, the mechanisms by which melatonin may act are unknown. Therefore, this study was designed to determine whether exposure to constant light would, by reducing circulating melatonin concentrations, have any effect on hypothalamic gonadotrophin-releasing hormone (GnRH) content and circulating levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Blood samples were collected for 12 h at 15-min intervals from 8 ovariectomized (OVX) pony mares under ambient light conditions (12 h light, 12 h dark, October 6). Animals were then placed under representative ambient light (12 h light, 12 h dark; control, n = 4) or constant light (24 h light, 0 h dark; treatment, n = 4) in light-controlled rooms. Blood samples were collected daily and on experimental Days 14, 21 and 28 samples were collected at 15-min intervals for 12 h for analysis of circulating LH and melatonin (Bleed 2, 3 and 4, respectively). All animals were killed on Day 28 (following Bleed 4) and the hypothalami were collected. Mares exposed to constant light had significantly higher (P less than 0.05) LH concentrations in daily blood samples and showed significantly (P less than 0.05) higher LH concentrations during frequent sampling periods on Days 14 and 21 (Bleeds 2 and 3) compared with control mares. FSH did not differ significantly among groups in the daily samples. GnRH content was 1.5994 +/- 0.325 and 0.9457 +/- 0.193 pg/mg protein (treatment and control respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Intra-follicular and peripheral steroid characteristics during vernal transition in the pony mare.
This experiment investigated steroid production by ovarian tissues, in vitro, of pony mares during vernal transition from anoestrus to the breeding season. Follicular dynamics were monitored to detect the first, second, third or fourth transition follicle, greater than or equal to 30 mm diameter or the first large post luteal follicle of the breeding season. Twenty-four hours after a large follicle was detected, theca (T) and granulosa (G) tissues were harvested. Separate and co-incubations of these tissues were conducted to determine steroid production in early transition (ET), late transition (LT) and pre-ovulatory (OV) follicles. Peripheral plasma and follicular fluid steroids and gonadotrophins also were assayed. Peripheral plasma oestradiol concentrations increased from ET to LT and again from LT to OV in parallel with tissue production and follicular fluid content. Androgen production increased from LT to OV whereas progesterone production showed no change, thereby indicating a possible failure of 17-alpha steroid hydroxylase in ET follicles. Examination of tissue steroid secretion rates revealed that granulosa was the major site of oestrogen production, whereas theca secreted greater amounts of androgen.
Androstenedione↗
Interleukin-2 therapy for advanced renal cell carcinoma: radiographic evaluation of response and complications.
To evaluate the radiographic manifestations of the response of intrathoracic metastases to and the toxicity of interleukin-2 (IL-2) therapy, the chest radiographs and computed tomographic scans of 43 patients receiving 103 cycles of IL-2 treatment and lymphokine-activated killer cells for advanced renal cell carcinoma were reviewed. Among these 43 patients, 31 could be assessed for response of metastatic disease: Complete response was seen in one (3%), partial response in 11 (36%), mixed response in nine (29%), progressive disease in five (16%), and stable disease in five (16%). In 103 treatment cycles radiographic evidence of toxicity included pleural effusions (45.6%), pulmonary edema (21.4%), increased cardiothoracic ratio (16.5%), increased azygos vein diameter (9.7%), pericardial effusion (5.8%), and hilar lymphadenopathy (1.0%). These toxic effects could be distinguished from metastatic disease by a temporal relationship to treatment cycles. A favorable response to IL-2 therapy was significantly correlated (P less than .001) with the presence of pleural effusions.
Adult↗
Septic pulmonary embolism complicating a central venous catheter.
Bacteremia is a recognized complication in patients with indwelling central venous catheters. More recently pulmonary embolism in such patients has also been described. Despite abundant clinical experience with these devices, to our knowledge, septic pulmonary embolism has not been reported in adult patients. This case illustrates such a complication.
Adolescent↗
Peripheral carcinoid tumor of the lung: CT diagnosis.
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Adult↗
Spontaneous regression of pulmonary metastases from renal cell carcinoma.
One year after nephrectomy for renal cell carcinoma in a seventy-year-old man pulmonary nodules developed which proved to be metastases by needle biopsy. Chest radiographs thirteen and eighteen months later revealed complete spontaneous regression of the nodules without therapy.
Aged↗
Anatomy of the minor fissure: evaluation with thin-section CT.
The minor fissure was studied with thin computed tomographic (CT) sections in 40 patients. It was absent in eight (20%) and seen in 32 (80%) patients; of these 32 the fissure was complete in seven (22%), incomplete in 23 (72%), and of indeterminate completeness in two (6%). Appearance of the minor fissure on CT scans can be categorized into two major configurations, which are determined by variation in contour of the middle lobe upper surface. The location of the highest point along this surface is either medial (type I configuration) or lateral (type II configuration). The lowest tributary of the vein draining the anterior segment of the upper lobe was seen in 75% of the patients. This vessel was a reliable landmark in delineating boundaries between upper and middle lobes, even when the fissure was radiologically incomplete or absent. In the authors' experience, familiarity with these configurations of the minor fissure has been useful in localization of a lesion in a lobe or determination of its possible extension beyond the fissure into the neighboring lobe.
Adult↗
Right phrenic nerve: anatomy, CT appearance, and differentiation from the pulmonary ligament.
The pulmonary ligament appears on computed tomographic (CT) sections as a thin, high-attenuation line, frequently seen above or at the level of the diaphragm and usually extending from the region of the esophagus. However, another line coursing laterally from the midportion of the inferior vena cava has also been identified as the pulmonary ligament. The authors examined sections from eight cadavers and 80 chest CT examinations to more clearly delineate the pulmonary ligament from this second structure. Anatomic and CT correlation proves that the line seen at the midportion of the inferior vena cava represents the right phrenic nerve and that the right pulmonary ligament is located posterior to it.
Humans↗
Torsion of the upper lobe in pneumothorax.
A rounded density is occasionally seen hanging down from the hilus in the presence of a large pneumothorax. To find an explanation for this appearance, the authors obtained a right-sided bronchogram on a baboon, after which they induced pneumothorax on the same side. This experiment demonstrated that the rounded density is formed by a twisted and atelectatic upper lobe.
Animals↗
Peripheral bronchial involvement in relapsing polychondritis: demonstration by thin-section CT.
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Bronchi↗
Pleural effusions: pathogenesis, radiologic evaluation, and therapy.
The imaging of pleural effusions by plain radiography, sonography, computed tomography (CT), and magnetic resonance imaging (MRI) has greatly facilitated the planning of both initial diagnostic thoracentesis and subsequent therapeutic management. The normal anatomy and physiology of the pleura, the pathogenesis of effusions, and the clinical criteria for classifying effusions are briefly summarized. The usefulness of each imaging modality is then discussed, particularly with regard to the problems of detecting small effusions, identifying loculation of fluid, distinguishing pleural from intraparenchymal disease, and assessing the extent to which a pleural process has become organized.
Diagnostic Imaging↗
The pathogenesis, radiologic evaluation, and therapy of pleural effusions.
Radiology has played a pivotal role in the management of patients with pleural effusions. By confirming the presence of an effusion and providing information regarding the size and distribution of fluid, chest radiography greatly facilitates initial diagnostic thoracentesis. Identification of even small effusions is important because these commonly occur and may have clinical significance. The development of improved antibiotics and a wider range of interventional techniques has increased the reliance on the radiologic imaging of pleural disease in order to plan appropriate therapy. The newer imaging modalities of CT and sonography have proved to be particularly valuable in detecting small effusions and demonstrating single or multiple loculations. Additional features, such as the degree to which a pleural process has become organized and whether there is adjacent lung parenchymal disease, are well assessed on CT. Experience with MR has been limited, but preliminary data suggest that it may be a valuable addition and/or alternative to CT.
Animals↗
Fortified antibiotic ointment in bacterial keratitis.
We conducted experiments to determine the effectiveness of fortified antibiotic ointment in the treatment of Pseudomonas keratitis in rabbits. We evaluated gentamicin ointment (3, 10, 20, and 40 mg/g), gentamicin solution (3 and 10 mg/ml), and placebo, each given every 30 minutes. We also examined the effectiveness of fortified ointment given in extended treatment intervals. In short-term trials, commercial-strength gentamicin solution (3 mg/ml) was therapeutically superior (P less than .001) to commercial-strength gentamicin ointment (3 mg/g) in reducing corneal bacterial colony counts. No significant difference in antimicrobial effect was noted between fortified gentamicin ointment and fortified gentamicin solution at 30-minute treatment intervals. Fortified gentamicin ointment reduced colony counts even at extended treatment intervals of up to four hours in a severe keratitis model.
Animals↗