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Biomedical subjects

J D Armstrong

Publications and source records attributed to J D Armstrong.

At least 109 records · Page 6Linked to original sources
PubMed1977

Bilateral venography of the lower extremities.

The authors describe a simplified method of venography of the lower extremity which gives improved visualization of the proximal deep venous system. The technique involves high volumes of contrast material, no tourniquets, a relatively vertical, non-weight-bearing position, and passive elevation of the legs.

Humans↗
PubMed1977

Rebreathing pulmonary capillary and tissue volume in normals after saline infusion.

A rebreathing technique was utilized to assess changes in diffusing capacity (DCO), pulmonary capillary blood volume (Vc), pulmonary parenchymal tissue volume (Vt), and cardiac output (Qc), after infusion of 2 liters of 0.9% saline intravenously in 13-25 min in five healthy subjects. Blood hemoglobin concentration decreased an average of 17%. Vc increased strikingly in all five subjects. No significant changes in Vt, or in Vt per unit lung volume were observed. Radiographic evidence of interstitial pulmonary edema was present in four of the five subjects. Radiographic total lung capacity was reduced significantly in four of the five subjects. Significant reductions in forced vital capacity (FVC), forced expiratory volume in 1.0 and 3.0 s, and mean forced expiratory flow during the middle half of the FVC occurred in three of the five subjects. No dyspnea, cough, or physical examination abnormalities of lungs or heart occurred. This noninvasive, ventilation-limited, rebreathing technique appears capable of detecting early changes in pulmonary congestion, at a time when definitive radiographic changes and changes in the physical examination are absent. It appears capable of detecting the increase in Vc associated with hypervolemia in man.

Adult↗
PubMed1977

Diffuse pulmonary disease after therapy with nitrogen mustard, vincristine, procarbazine, and prednisone.

Pulmonary reactions may follow therapy with nitrogen mustard, vincristine, procarbazine, and prednisone. Two patients with Hodgkin's disease are described who were treated with nitrogen mustard, vincristine, procarbazine, and prednisone and developed diffuse lung disease. Their disease processes were evaluated with serial pulmonary function studies, chest radiography, and open lung biopsy. Hypersensitivity reactions appeared to be responsible, and treatment with corticosteroids was successful. Procarbazine may have been the responsible agent.

Adult↗
PubMed1976

Noninvasive diagnosis of deep venous thrombosis.

Eighty-five patients suspected of having lower-extremity deep venous thrombosis (DVT) participated in a prospective study to test the diagnostic accuracy of four noninvasive techniques: Doppler ultrasonic flow study, electrical impedance plethysmography, the serial dilution protamine sulfate test, and an extensive physical examination. Ascending radiocontrast phlebography was the diagnostic standard of reference. We found that (1) when both Doppler and impedance examinations were positive, the diagnosis of DVT could be considered virtually certain; (2) impedance and Doppler examinations, when used in combination, were reliable screening tests capable of establishing or excluding the presence of thigh DVT; (3) physical examination and the serial dilution protamine sulfate test were unreliable screening techniques for DVT; (4) techniques other than the noninvasive methods investigated were needed to reliably detect or to exclude popliteal and call DVT.

Diagnostic Errors↗
PubMedDate not supplied

Metamorphosis of the mushroom bodies; large-scale rearrangements of the neural substrates for associative learning and memory in Drosophila.

Paired brain centers known as mushroom bodies are key features of the circuitry for insect associative learning, especially when evoked by olfactory cues. Mushroom bodies have an embryonic origin, and unlike most other brain structures they exhibit developmental continuity, being prominent components of both the larval and the adult CNS. Here, we use cell-type-specific markers, provided by the P[GAL4] enhancer trap system, to follow specific subsets of mushroom body intrinsic and extrinsic neurons from the larval to the adult stage. We find marked structural differences between the larval and adult mushroom bodies, arising as the consequence of large-scale reorganization during metamorphosis. Extensive, though incomplete, degradation of the larval structure is followed by establishment of adult specific alpha and beta lobes. Kenyon cells of embryonic origin, by contrast, were found to project selectively to the adult gamma lobe. We propose that the gamma lobe stores information of relevance to both developmental stages, whereas the alpha and beta lobes have uniquely adult roles.

Animals↗