Oscar J. Balchum

Diffuse Interstitial Lung Disease in Systemic Lupus Erythematosus

Abstract The clinical and physiological features of 18 patients with systemic lupus erythematosus and diffuse interstitial lung infiltrations, along with the histopathologic studies in 4 of these s...

Ozone and Vitamin E

Vitamin E deficiency in rats is associated with a greater susceptibility to lethal levels of ozone. Exposure of rats to sublethal ozone concentrations produces an accelerated decline in serum vitamin E levels. These findings are consistent with the possibility that lipid peroxidation is a mechanism of ozone toxicity.

Electron Paramagnetic Resonance Spectroscopy

The air pollutant ozone Is believed to exert its deleterious biological effects by the formation of free radicals. However these free radicals have not been directly measured. It has also been suggested that peroxidation of cell membrane unsaturated fatty acids is an important mechanism In ozone toxicity. Utilizing electron paramagnetic resonance technique, direct ozonization of linoleic acid produced measurable free radicals after a two-hour induction period.

Effect of Ozone on Lipid Peroxidation in the Red Blood Cell.

Summary In vitro exposure of erythrocytes to ozone resulted in an increased osmotic fragility associated with the formation of TBA reactants. This suggests that lipid peroxidation may be involved in the mechanism of ozone toxicity.

Fluorescence bronchoscopy for localization of carcinoma in situ.

A fluorescence bronchoscope system has been developed for imaging lung tumors by fluorescence of a previously injected, tumor-specific agent hematoporphyrin derivative. Carcinoma in situ has been localized, but there are too many false positives and negatives. A new system has been implemented which allows rapid switching between viewing of fluorescence, and viewing of the same area under white light illumination as in conventional bronchoscopy. The excitation source is a violet krypton ion laser coupled to a fused quartz fiber light conductor, with a diverging microlens to spread the light uniformly. A third-generation, microchannel plate image intensifier amplifies the weak fluorescence for viewing and video display, recording, and analysis. A movable mirror and periscope bypasses the intensifier for normal color viewing and video display and recording, with the laser shutter closed and the white light shutter open. This facilitates accurate localization, comparison of the color and fluorescence images, and precise sampling during biopsy. The improved system should reduce the false positive rate due to biopsy sampling error, and together with the video analyzer should reduce indeterminate results.

Skin photosensitivity: duration and intensity following intravenous hematoporphyrin derivates, HpD and DHE.

Abstract In this pilot study, the duration and degree of skin photosensitivity after intravenous injection of HpD or DHE was tested sequentially once a week, using a solar simulator delivering 19.5 ± 1.5 J cm−2 to an area of skin 1.4 cm diameter. The longest duration of skin photosensitivity was 7 weeks amongst the 12 patients studied. In 180 other patients, the incidence of sunburn following PDT was less than 10% over a period of 7 y. Sunburn was always minimal (mild redness and swelling–no blisters), and required no systemic therapy or hospitalization. The reaction subsided within 2‐3 days. The low incidence was attributed to good verbal and written instructions in methods of prevention delivered to not only patients, but spouse, family members and friends by the investigator.

Digital background subtraction for fluorescence imaging

A method of enhancing contrast in fluorescence imaging has been devised, based on real-time digital subtraction of a background video image from a signal-plus-background video image. Color filters are used to differentiate signal from background. The technique has been applied to detection of small tumors labeled with the tumor specific fluorescent drug hematoporphyrin derivative.

Fluorescence Diagnosis of Cancer

The fluorescence of hematoporphyrin-derivative (HpD) or dihematoporphyrin ether (DHE), together with the property of attaining a higher concentration in malignant tumors than in most normal tissues, form a basis for diagnosis of cancer. Malignant tumors exhibit greater fluorescence than the surrounding nonmalignant tissue when excited by light of appropriate wavelength, and the tumor can be detected by a suitable imaging or nonimaging system. This paper discusses the fluorescent agent and background fluorescence, excitation systems, imaging methods, and nonimaging methods for diagnosis of cancer.

Ozone and Unsaturated Fatty Acids

The earliest manifestation of the toxicity of ozone in an in vitro system utilizing human erythrocytes had been previously suggested to be due to the breakdown of unsaturated fatty acids in the cell membrane. To confirm that destruction of unsaturated fatty acids does occur in biological membranes exposed to ozone, red cell fatty acids were extracted, methylated, and quantitated by gas-liquid chromatography. After ozone exposure there was a relative decrease in unsaturated fatty acids as compared to saturated fatty acids, and the more unsaturated the fatty acid, the greater the loss. These findings are interpreted as additional evidence supporting the concept that the peroxidation or ozonization of unsaturated fatty acids in biological membranes is a primary mechanism of the deleterious effects of ozone.

Fluorescence Bronchoscopy for Localizing Early Bronchial Cancer and Carcinoma in Situ

The detection, diagnosis, and aggressive treatment of lung cancer in its intrabronchial or preinvasive phase has been shown to result in 5-year survival rates of over 70%–80% [16, 19, 29]. In the case of carcinoma in situ, resection may result in prolonged survival and possibly cure [4]. In contrast, stage I lung cancer is of the invasive type and includes lesions that have already extended to the ipsilateral hilar lymph nodes; the 5-year survival at this stage is at best about 40%–50%. In small peripheral lung cancers (less than 3.0 cm in diameter), visible on chest X-ray but without hilar lymph node involvement, 5-year survival can be up to 60% [18]. The goal of physicians, therefore, must be the diagnosis of preinvasive lung cancer in patients at high risk. High risk patients include heavy cigarette smokers who have smoked one package per day or more for 20 years or longer, particularly those over age 45 years. Patients at particularly high risk are heavy smokers who also have symptoms or signs related to lung cancer and especially include smokers who have also been occupationally exposed to asbestos, uranium mining, coke oven emissions, nickel, and chromates, which are known industrial carcinogens.