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Biomedical subjects

O J Balchum

Publications and source records attributed to O J Balchum.

At least 19 recordsLinked to original sources

Fluorescence spectra in lung with porphyrin injection.

The fluorescence emission spectra from human bronchial mucosa and tumors, before and after injection of dihematoporphyrin ether/ester, have been measured with an optical multichannel analyzer from 500 to 750 nm. Fluorescence was excited with a violet krypton ion laser (average wavelength 410 nm). The autofluorescence spectra decrease monotonically with increasing wavelength except for a small broad peak near 600 nm. The spectra from tumor sites, after injection of the fluorescent porphyrin, exhibit the characteristic fluorescence emission at 630 and 690 nm, added to the autofluorescence spectrum. The spectra from control or nontumor sites are similar but the magnitude of the component due to the injected porphyrin is smaller than at a tumor site. The magnitude ratio of tumor to control site fluorescence depends on concentration of the porphyrin, tumor thickness, and time after injection. Autofluorescence degrades contrast and thus makes very thin tumors difficult to image. Subtraction of the autofluorescence background is desirable.

Humans↗

Photoradiation therapy of endobronchial lung cancer. Large obstructing tumors, nonobstructing tumors, and early-stage bronchial cancer lesions.

Photoradiation (photodynamic) therapy of endobronchial primary and metastatic lung cancers uniformly results in a complete response--that is, the opening up of totally or partially obstructed bronchi to their walls. The method, employing hematoporphyrin derivative and red laser light from an argon-pumped dye laser, is safe, efficient, and effective. The safety and lack on any complications rest upon the use of light-diffusing cylinder tips, and upon clean-up bronchoscopy to remove tumor debris promptly. The trachea and main and lobar bronchi, as well as segmental and subsegmental bronchi, can be entirely freed of tumor and completely opened up.

Adult↗

Photoradiation therapy of endobronchial lung cancers employing the photodynamic action of hematoporphyrin derivative.

Thirty-five patients with tumors within the tracheobronchial tree were treated with photoradiation therapy (PRT) employing the photodynamic action of hematoporphyrin derivative (HPD). An effective protocol has been developed consisting of 3.0 mg/kg HPD given intravenously 72 hours prior to the bronchoscopic illumination of the endobronchial tumor sites with red light (630 nm) from an argon pumped dye laser. Light applicators were developed that provided surface (area) and insertion (volume) illumination of tumor masses. Average light dosages of 100 J/cm2 and 200 J/cm were used for surface and insertion illumination, respectively. Delivery rates were 200 mW/cm2 and 400 mW/cm. There was no immediate visible effect such as coagulation or charring noted. All malignant endobronchial tumors responded. Tumors included primary and metastatic lesions of various histologic types. Response was complete for tumor within the bronchus after one treatment in 80% of instances. The remaining cases required two treatments to obtain a complete response due to the extensive length of bronchus involved or because multiple sites were present. A complete response, that is, the full opening up of the lumen to the bronchial wall, was accomplished in all but one instance. Atelectatic lungs or lobes were re-expanded and reaerated. Dyspnea and cough became significantly less. The follow-up achieved to date indicates improvement in symptoms, activity level, and the return to work in a significant number of cases.

Adenocarcinoma↗

Fluorescing cells in sputum after parenteral HpD.

Cells exfoliated into sputum were examined for fluorescence after the intravenous injection of HpD. Malignant and non-malignant cells were seen to fluoresce up to 9 days post injection of HpD. Not all exfoliated squamous cell cancer cells or non-malignant cells fluoresced. Implications are discussed relative to imaging diagnostic fluorescence bronchoscopy and photoradiation therapy of obstructing endobronchial cancers and bronchial carcinoma in situ.

Bronchial Neoplasms↗

HpD photodynamic therapy for obstructing lung cancer.

Twenty-two patients with endobronchial cancer of the lungs have been treated with photoradiation therapy (PRT) employing a set protocol of 3.0 mg/kg hematoporphyrin derivative (HpD) administered intravenously 72 hours prior to red light (630 nm) illumination via a bronchoscope. Twenty patients showed a complete response. Of these, nineteen had large obstructing endobronchial tumors; one had a small mucosal lesion. Only one patient with an obstructing tumor showed a partial response. The one showing no response had an endobronchial mass that consisted of fibrous tissue, not tumor, as shown on three separate bronchoscopic biopsies.

Adult↗

Imaging fluorescence bronchoscopy for localizing early bronchial cancer and carcinoma in situ.

A system of imaging fluorescence bronchoscopy instrumentation and methods has been devised that has succeeded in localizing very small (1 X 2 mm) areas of bronchial mucosal cancer, in individuals with radiologically occult lung cancer (positive sputum cytology for malignant cells and a negative chest X-ray). These areas were located solely by their fluorescence, and were visibly normal on white-light examination. The detection of lung cancer in individuals with radiologically occult lung cancer depends upon adequate methods of sputum collection and processing. Proving that fluorescing areas show "true positive" fluorescence depends upon accurate brush and forceps biopsies, providing adequate cytological and biopsy material. The entire system of the diagnosis and localization of early or pre-invasive lung cancer (while still confined to a bronchus) rests on skilled cytopathology methods and interpretation, not only skilled fluorescence bronchoscopic examination and adequate instrumentation.

Aged↗

Unsuspected pulmonary emboli in well persons: the incomplete pulmonary infarction syndrome.

Pulmonary embolization from occult venous thrombosis in the lower extremities occurs in previously well individuals of all ages. Incomplete or hemorrhagic pulmonary infarction may result. The incomplete pulmonary infarction syndrome (IPIS) is characterized by sudden onset of pain in the lower chest, knife-like and stabbing in quality and accentuated by breathing, with pathognomonic abnormalities on chest x-rays. The physician should hospitalize the patient, begin heparinization and confirm the diagnosis with daily chest x-rays in multiple views. Failure to promptly diagnose and treat IPIS may lead to catastrophic, massive pulmonary embolism and death, or to recurrent embolism with pulmonary hypertension and chronic cor pulmonale, resulting in incapacitating dyspnea on exertion, and disability.

Adolescent↗

Chronic obstructive airway diseases. Current concepts in diagnosis and comprehensive care.

Physicians and paramedical personnel often find the early diagnosis and differentiation of obstructive airway diseases to be a challenging problem. The history and physical examination are often not enough to allow the physician to detect either the presence of, or determine the type of, disease present. Patterns of pulmonary function abnormality to determine the presence of obstructive or restrictive defects are discussed. Guidelines useful in the differentiation of obstructive airway diseases are presented. Once a patient with COAD is assessed, the physician needs to outline a therapeutic program after establishing goals with the patient. These goals include (1) improved ability for the patient to achieve relief from symptoms and (2) improved capacity to carry out the activities of daily living. The therapeutic modalities available for the comprehensive care of patients with COAD are discussed. These include general factors such as patient and family education, avoidance of smoking and other inhaled irritants, avoidance of infection, a minimum stress environment, high fluid intake, and proper nutrition. The appropriate use of the medications most commonly employed in the teatment of these patients, eg, bronchodilators, expectorants, antimicrobials, corticosteroids, cromolyn, digitalis, and diuretics, are individually discussed. The use of such respiratory therapy techniques as aerosol therapy, intermittent positive pressure breathing, and oxygen therapy are considered. Application of the specialty of rehabilitation medicine to patients with obstructive airway disease is described. This includes physical therapy with breathing retraining, clapping and postural drainage, and exercise reconditioning, occupational therapy with attention to energy conservation in activities of daily living, psychological considerations, and vocational rehabilitation. Definite benefits that can be demonstrated if the physician employs this type of systematic respiratory care program include a decrease in the frequency and duration of hospital admissions, socioeconomic gains from reduced hospitalizations, a reduction in anxiety, depression and somatic concern, the return of patients to positions of employment and the establishment of a better quality of life. Persistence in making sure the patient continues in a systematic program, including both pharmacological and nonpharmacological modalities, may be the means of assuring maintenance or even improvement in his health. The day-to-day treatment for the majority of patients should remain in the hands of the primary physician. However, community resources must be established to allow the primary physician to provide these patients with adequate comprehensive respiratory care. Development of three levels of care (the primary physician, community respiratory rehabilitation units, and the regional respiratory center) should make superior respiratory care available to every patient with obstructive airway disease.

Adrenal Cortex Hormones↗