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Biomedical subjects

F J Miller

Publications and source records attributed to F J Miller.

At least 163 records · Page 9Linked to original sources
PubMed1979

Influence of exposure mode on the toxicity of NO2.

Pollutant gases are subject to a variety of physical and chemical interactions within the atmosphere due to cyclic production and various meteorological influences. In consequence there is generally a diurnal concentration profile for NO2 which consists of peaks of short duration and irregular occurrence superimposed on a low background. Since this variation could play an important role in the toxic effect of NO2, the influences of various exposure modes was studied. Continuous and intermittent exposure studies were used to determine the relationship between biological response and length of exposure to various concentrations of NO2. As the concentration decreased, the slope of the regression line decreased. After adjusting for total differences in the product concentration x time, the response for the two exposure modes was essentially the same. When a constant concentration x time level was employed, a short-term exposure to a high concentration produced a greater effect than exposure to a lower concentration administered over a longer period. Using these curves, the relationship between level of effect, concentration, and time can be determined. Results of these studies indicated that the frequency and amplitude of short-term peaks are of significance even though the exposure is interrupted with periods of zero concentration of NO2.

Animals↗
PubMed1979

Need for chest radiographs during and after lymphography.

Retrospective review of 100 lymphograms showed that routine chest radiography after injection of the lymphographic contrast medium and follow-up films 24-48 hr later yielded no clinically useful information. It was concluded that routine postlymphography chest radiography is not necessary and should be reserved for patients in whom complications are suspected.

Humans↗
PubMed1979

Uncontrollable postpartum bleeding: a new approach to hemostasis through angiographic arterial embolization.

A case of severe postpartum hemorrhage is reported. Three separate surgical procedures failed to reveal the source of bleeding, and standard surgical techniques, including bilateral ligation of the hypogastric arteries, were unsuccessful in producing hemostasis. However, angiography successfully identified the specific bleeding vessel, and transcatheter embolization with Gelfoam fragments quickly and effectively stopped the hemorrhage. The authors consider angiographic embolization to be an effective alternative approach to the control of pelvic hemorrhage and recommend that the technique be considered prior to surgical intervention.

Adult↗
PubMed1978

Similarity between man and laboratory animals in regional pulmonary deposition of ozone.

Predicted pulmonary ozone (O3) dose curves obtained by model analysis of the transport and removal of O3 in the lungs of guinea pigs, rabbits, and man indicate that a general similarity exists among these species in the shapes of the dose curves. An overview of the major features of the lower airway mathematical model used is presented. This model predicts that the respiratory bronchioles receive the maximum O3 dose. For exposures corresponding to tracheal O3 concentrations greater than 100 micrograms/m3 (0.05 ppm), the predicted respiratory bronchiolar dose for rabbits was found to be twice that for guinea pigs and 80% of that for man. Sensitivity analyses are presented for model parameters relating to the treatment of the chemical reactions of O3 with the mucous layer. The role of tidal volume in the determination of pulmonary uptake of O3 in man is examined. The consistency and similarity of the dose curves for the three species lend strong support to the validity of extrapolating to man the results obtained on animals exposed to O3.

Animals↗
PubMed1978

Experimental internal iliac artery embolization: evaluation of low viscosity silicone rubber, isobutyl 2-cyanoacrylate, and carbon microspheres.

The angiographic, morphologic, and histologic effects of carbon microspheres, isobutyl 2-cyanoacrylate (IBC), and low viscosity silicone rubber (LVSR) were compared. Carbon spheres did not effectively occlude the internal iliac artery, but resulted in small vessel occlusions leading to the most frequent complications. IBC was effective in causing occlusion but resulted in significant inflammatory changes within the thrombus and vessel wall. LVSR gave satisfactory occlusion without inciting vessel wass inflammatory reaction. Two of 4 animals developed a hind extremity paralysis. None of these materials is approved for general intravascular usage.

Animals↗
PubMed1978

Cytotoxic effects of nickel on ciliated epithelium.

Studies were conducted to measure the effect of graded concentrations of nickel on ciliary activity in an in vitro model system using isolated hamster tracheal rings, and to compare the in vitro findings with in vivo exposures using an organ culture system. Dose-response experiments were conducted for various Ni concentrations and for various lengths of exposure. In the in vitro model, significant decreases in ciliary activity occurred at concentrations as low as 0.011 mM nickel (0.65 microgram of nickel per ml). A dose-response relationship between the concentration of nickel and ciliary action was demonstrated. A range of effects from a significant decrease of 26 beats per min (0.65 microgram of nickel per ml) to complete ciliostasis (65 microgram of nickel per ml)) was observed after 24 hours of exposure. Validation of the in vitro results occurred when hamsters were exposed to a nickel chloride aerosol at concentrations of 100 to 275 microgram of nickel per m3. Immediately after the cessation of a 2-hour in vivo exposure, a decrease in ciliary activity of 60 and 140 beats per min was observed for animals exposed to 100 and 275 microgram of nickel per m3, respectively. The length of time required for recovery from the in vivo exposure to nickel aerosol was determined. Histologic examination of the epithelial cells also showed dose-related effects. It is apparent that nickel, either administered to the whole animal or to the tracheal epithelium directly, can significantly decrease the ciliary beating frequency and interfere with the normal functioning of respiratory defense mechanisms, thereby increasing the risk of the host to respiratory infections.

Aerosols↗
PubMed1978

Gastrointestinal angiographic findings in systemic amyloidosis.

Amyloidosis is a multisystem disease process of unknown cause in which characteristically staining protein-polysaccharide material is deposited in body tissues. Although gastrointestinal involvement is usually asymptomatic, amyloid infiltration of mesenteric and submucosal vessel walls may be associated with acute or recurrent gastrointestinal hemorrhage in patients with the diagnosis of amyloidosis. Angiography in such cases may demonstrate arterial and venous changes as a result of these vascular wall deposits. Two patients with proven amyloidosis and gastrointestinal hemorrhage are presented, and their angiographic findings are discussed with the pathologic correlations.

Amyloidosis↗
PubMed1977

Clinical and radiographic findings of focally infected polycystic kidneys.

Three patients with localized polycystic kidney infections are presented with the pertinent clinical, laboratory, and radiographic findings. Gallium-67 citrate and angiography play an important role in evaluation of these patients. Angiography in particular is valuable in the diagnosis and the exact localization of the inflammatory disease. Localization is extremely important in planning surgical treatment should conservative therapy fail.

Adult↗
PubMed1977

Clinical vascular laboratory diagnosis of deep venous thrombosis.

The accuracy of our clinical vascualr laboratory was evaluated. Sixty-nine limbs (55 patients) were examined clinically for thrombophlebitis. All of these patients were then evaluated using segmental plethysmography and Doppler ultrasound techniques. Each limb was then studied with venography. In 57 of the 69 (82.6%) limbs evaluated, measurement of the maximum venous outflow accurately reflected the venographic findings. Doppler augmented venous sounds were correct when compared to venography in 77.6% of limbs. In the 59 limbs that exhibited clinical signs of deep venous thrombosis, only 35.6% had venographic confirmation of the diagnosis. The clinical vascular laboratory provides an accuracy of diagnosis of deep venous thrombosis not achieved by clinical examination. If both segmental plethysmography and Doppler ultrasound were negative, it was very unlikely that deep venous thrombosis had occurred.

Doppler Effect↗
PubMed1976

Clinical and roentgenographic findings in splenic abscess.

A splenic abscess developed in a 16-year-old boy following a supposed viral illness and left lower thoracic trauma. Preoperative diagnosis was at first obscured, but a spleen scan suggested fractured spleen and a splenic arteriogram showed a "subcapsular hematoma" and an aneurysm of the left hepatic artery. A 1,800-gm spleen containing one large abscess and one small one was removed. Splenic abscess is rare and, before modern methods of spleen scan and arteriography, rarely diagnosed.

Abscess↗