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Biomedical subjects

W T Miller

Publications and source records attributed to W T Miller.

At least 127 records · Page 7Linked to original sources
PubMed1990

Supplemental emergent chest computed tomography in the management of blunt torso trauma.

The efficacy of conventional chest X-ray (CXR) in comparison to chest computed tomography (CCT) in acutely injured blunt trauma patients was examined. Over a 21-month period, 50 patients underwent CXR and CCT according to a standard protocol, and their films and records were reviewed retrospectively. Hemo- and/or pneumothorax (HPTX) was noted in 12 patients (five by CXR, 12 by CCT). Pulmonary contusion (PC) was identified in ten patients (four by CXR, ten by CCT). Three additional false positive PC were diagnosed by CXR. Therapy changes based upon CCT findings occurred in seven of seven HPTX and five of six PC. The two imaging techniques were complementary in detecting fractures. Atelectasis was a common CCT finding (58% incidence). Chest X-ray is less sensitive than chest computed tomography in the detection of HPTX (42% vs. 100%) and PC (40% vs. 100%). Emergent chest computed tomography is recommended in stable patients with: 1) blunt high-energy torso trauma, 2) "cross-body" injury pattern, and/or 3) a mechanism of injury suggestive of chest trauma.

Adult↗
PubMed1990

Cryptococcal pulmonary infection in patients with AIDS: radiographic appearance.

The clinical, laboratory, and radiographic findings in seven patients with acquired immunodeficiency syndrome (AIDS) and cryptococcal pulmonary infections were reviewed. The infection was most commonly seen on radiographs as lymphadenopathy, interstitial infiltrates, or both. Interstitial infiltrates were commonly nodular. Large nodules or alveolar infiltrates, the most common findings at presentation in both immunocompetent patients and immunocompromised patients without AIDS, were not present in our series. Isolated pleural effusion was seen as the only radiographic finding in one case. Meningitis was present in six of seven cases and was neurologically silent in five of six cases. Cryptococcal pneumonia in AIDS patients should prompt a search for neurologically silent cryptococcal meningitis.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Purification of recombinant pp60v-src protein tyrosine kinase and phosphorylation of peptides with different secondary structure preference.

The expression of the transforming gene product of Rous sarcoma virus (pp60v-src) in Saccharomyces cerevisiae has recently been reported (Kornbluth et al., 1987; Brugge et al., 1987). To carry out biochemical and structural studies of this enzyme, a facile purification was developed. The purification was accomplished in four chromatographic steps: Q-Sepharose, Affi-Gel Blue, phosphoagarose, and hydroxylapatite chromatography. The tyrosine kinase was isolated in milligram quantities as two highly active proteolytic fragments (52 and 54 kDa). Three model tyrosine kinase substrates with propensities to adopt helical or omega-loop conformations were synthesized and characterized. The peptides were based on the sites of phosphorylation of pp60v-src, lipocortin I, and lipocortin II. Circular dichroism spectroscopy was used to study the conformation of the helix-forming peptides in 50 mM Tris and in 50% trifluoroethanol/Tris. Peptide 1, which was designed to form an amphiphilic alpha-helix, displayed 24.2% helicity in buffer and 40.2% helicity in 50% TFE/buffer. Similar experiments for peptide 3, the other helix former, showed a lower helicity (8.1% helical and 26.0% helical in buffer and in 50% TFE/buffer, respectively). All three peptides were shown to be substrates for the recombinant tyrosine kinase. Kinetic measurements using high-voltage paper electrophoresis indicated that the helix-forming peptides exhibited low KM values (approximately 450 microM) for the purified src gene product, consistent with the notion that elements of secondary structure may be important in substrate recognition by tyrosine kinases.

Amino Acid Sequence↗
PubMed1989

Whole-lung tomography in urologic malignancy.

The place of whole-lung tomography in urologic malignancy has not been established. We reviewed 88 cases of known or suspected urologic malignancy in which tomography was used. Most patients had renal, bladder, or testicular tumors. Of the 68 patients with negative screening chest roentgenograms, all but 2 had negative tomograms. One of these 2 patients had a normal chest film (the other had extrapulmonary metastasis), and he did not have the renal carcinoma initially suspected. Tomography discovered no metastases from urologic malignancy that was not already known about from the screening x-ray film. In 20 cases with a positive screening x-ray film, tomography was of limited value. It cleared two suspicious chest films and added information on extent of metastatic involvement in three. We conclude that whole-lung tomography adds little information not available by chest roentgenogram in our selected population, and with a negative screening chest film no additional chest study is needed.

Costs and Cost Analysis↗
PubMed1989

Bowler-hat sign: a simple principle for differentiating polyps from diverticula.

The bowler-hat sign has been described both with colonic polyps and with diverticula. The authors describe a simple principle for evaluating a bowler-hat sign in order to determine whether it is caused by a polyp or a diverticulum. If the bowler hat points toward the center of the long axis of the bowel, it represents an intraluminal structure (ie, a polyp). If, however, it points away from the center of the long axis of the bowel, it represents an extraluminal structure (ie, a diverticulum). Only if the bowler hat is located in the midline or is directly parallel to the long axis of the bowel is it impossible to classify the abnormality as a polyp or a diverticulum. The value of this principle was confirmed with both a radiographic model and a blinded review of radiographs from 37 cases demonstrating the bowler-hat sign. When a bowler hat is present on a double-contrast barium enema examination, use of this principle provides a simple and objective means of differentiating a polyp from a diverticulum.

Barium Sulfate↗
PubMed1989

Pulmonary edema as a complication of interleukin-2 therapy.

Eight patients underwent IV bolus therapy with recombinant interleukin-2 (Cetus Corporation, Emeryville, CA) for treatment of metastatic melanoma or renal cell carcinoma. The patients were randomized to receive interleukin-2 alone or interleukin-2 in combination with lymphokine-activated killer cells. Radiographs showed pulmonary edema in five of the eight patients. The changes ranged from mild interstitial edema (two patients) to frank pulmonary edema (three patients). The edema generally resolved within 4 days after the termination of therapy (four patients), however, one patient developed edema and arrhythmias approximately 7 days after interleukin-2 therapy ended. Seven of the eight patients had either cardiac arrythmias or angina. The mechanisms that contribute to the pathogenesis of these cardiac complications with interleukin-2 therapy remain unclear. The development of pulmonary edema is thought to be caused by capillary leakage and cardiac pulmonary edema due to cardiac toxicity of the drug. The radiologic appearances of these types of pulmonary edema were indistinguishable from one another and from other causes of pulmonary edema. Our study shows that interleukin-2 can cause pulmonary edema, cardiac arrhythmias, and unstable angina. The severity of these conditions is unrelated to dose.

Adult↗
PubMed1988

Probing the peptide binding site of the cAMP-dependent protein kinase by using a peptide-based photoaffinity label.

A peptide-based photoaffinity label for the catalytic subunit of the cAMP-dependent protein kinase was prepared from the amino acid p-benzoyl-L-phenylalanine [L-Phe(pBz)]. By using solid-phase peptide synthesis methodology, DL-Phe(pBz) was incorporated into the cAMP-dependent protein kinase substrate Leu-Arg-Arg-Ala-Ser-Leu-Gly in place of the phosphorylatable serine. The diastereomeric peptides were separated by reverse-phase HPLC. The peptide substrate analog containing L-Phe(pBz) had a Ki of approximately 110 microM at pH 7.5. When photolyzed at 350 nm in the presence of the enzyme, this peptide caused time- and concentration-dependent inactivation. Radioactive acetylated L-Phe(pBz) peptide was used to establish the binding stoichiometry of peptide to enzyme; these results, together with protection experiments, showed the photoaffinity labeling to be specific (approximately 1:1). To identify the residues that were modified on the catalytic subunit, the photoinactivated enzyme was cleaved with CNBr and V8 protease (Staphylococcus aureus). The resulting peptide fragments were purified by HPLC and were sequenced; these experiments identified the modified residues as Gly-125 and Met-127. This region of the cAMP-dependent protein kinase catalytic subunit contains many residues that are conserved in serine- and tyrosine-protein kinases.

Affinity Labels↗
PubMed1988

Chronic traumatic diaphragmatic hernia: the significance of pleural effusion.

Five patients with chronic traumatic diaphragmatic hernia presented with symptoms of acute intestinal obstruction and unilateral pleural effusion. In each case, infarcted herniated abdominal structures were found at surgery. The presence of an ipsilateral pleural effusion is an important radiographic sign, which may indicate strangulation in patients with chronic traumatic diaphragmatic hernia.

Adult↗
PubMed1988

Pulmonary sarcoidosis in the older patient: conventional radiographic features.

The clinical and radiographic findings in 29 patients presenting with pulmonary sarcoidosis after the age of 50 years were reviewed. Fifty-nine percent (17 patients) had atypical findings at presentation. The atypical patterns at radiography included mediastinal adenopathy alone or in combination with unilateral hilar adenopathy (n = 8), solitary or multiple pulmonary masses (n = 3), and atelectasis (n = 3). Five patients had extrathoracic tumors at the time that the diagnosis of pulmonary sarcoidosis was made, which confused the diagnosis at radiography. An enhanced awareness of the atypical patterns of sarcoidosis in the older patient may facilitate the diagnostic process.

Age Factors↗
PubMed1988

Clinical evaluation of a medical image management system for chest images.

The clinical efficacy and physicians' assessment of a medical image management system (MIMS) for chest images that involved the medical intensive care unit (MICU) and the radiology department were evaluated. A token-passing fiber-optic network was implemented to connect display stations in the MICU and in the chest reading area in the radiology department with a laser film digitizer and an archiving system. To study the clinical efficacy of this system, blocks of 8 weeks during which portable chest images were digitized and immediately made available in the MICU were alternated with blocks of 8 weeks during which film images only were available. Approximately 3000 portable chest examinations were tracked; patients were entered into the study at a rate of 65 per month. Data on time intervals associated with the examination process were collected from MICU physicians, radiologists, radiographers, and film librarians. The time from the completion of an examination to the time an action was taken that was based on radiographic findings showed significant reductions during the digital periods for certain actions. For example, the time to begin drug therapy decreased from a mean of 4.7 hr when films were viewed to a mean of 3.3 hr when digital images were viewed. In conclusion, if prompt action by the MICU physician improves a patient's outcome, a positive effect on patient care will result from the immediate availability of radiographic images.

Computer Systems↗