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Biomedical subjects

M L Rhodes

Publications and source records attributed to M L Rhodes.

35 records · Page 2Linked to original sources

Transbronchial biopsy via flexible fiberoptic bronchoscope; results in 164 patients.

The diagnostic accuracy and complication rate of transbronchial forceps lung biopsy combined with bronchial brushing were analyzed in 164 consecutive patients, of whom 95 had nonmalignant disease and 51 had malignant disease. Eighteen patients with abnormal chest radiographs had normal transbronchial forceps lung biopsies and no established diagnosis. Satisfactory specimens were obtained in 153 patients (93 per cent), with diagnositc accuracies of 62, 64, and 67 per cent, respectively, in infectious, interstitial, and malignant lung disease. The over-all diagnostic accuracy was 57 per cent. Seven patients were diagnosed as having metastatic carcinoma to the lung by transbronchial forceps lung biopsy, but brush biopsy was psoitive in only 3. Of the 23 patients with primary lung carcinoma diagnosed by transbronchial forceps lung biopsy, 21 had positive brush biopsies. An additional 3 patients with bronchogenic carcinoma, however, were diagnosed only by brush biopsy. Fluoroscopy was essential for accurate positioning of the biopsy instrument. Increased risk factors were present in 83 patients (51 per cent), among whom the immunosuppressed group presented special problems. Significant bleeding in 15 patients (9 per cent) was controlled by conservative management. Pneumothorax occurred in 7 patients (4 per cent). There were no deaths. Transbronchial forceps lung biopsy in experienced hands is safe and well tolerated. The physician, nevertheless, must be prepared to handle major complications, especially bleeding. The procedure has a resonable diagnostic yield in high-risk patients who have a variety of lung lesions.

Adolescent↗

Hypoxic protection in paraquat poisoning.

Ingestion or injection of the herbicide paraquat (1,1'-dimethyl-4,4'-dipyridylium dichloride) has caused more than 120 deaths in humans. Most have been due to respiratory failure caused by pulmonary edema, hemorrhage, and atelectasis, or subsequent pulmonary fibrosis. Paraquat is concentrated in lung tissue and is believed to cause superoxide radical formation in the presence of oxygen and suitable electron donors. Exposure to increased concentrations of oxygen has been reported to accelerate the toxicity of paraquat. The therapeutic efficacy of a reduced oxygen environment was investigated by exposing paraquat-poisoned mice to 10% oxygen after stepwise drops from 14% oxygen. Sixty-one mice were given intraperitoneal injections of 27 mg. per kg. of paraquat. The 25 mice in hypoxia for 7 days had a 32% mortality rate versus a 78% mortality rate for the remainder of the mice in room air, p less than 0.01. After a dose of 20 mg. per kg. of paraquat administered intraperitoneally, 24 mice in hypoxia had a 25% mortality rate versus 51% for 35 animals in room air. Brief exposures of the hypoxic group to "normoxia" (room air) led to pulmonary edema and death. The continuous exposure of paraquat-poisoned animals to hypoxic environments was protective. This approach may be useful in other oxidant lung injuries.

Animals↗

Light and immunofluorescent study of the Arthus reaction in the rabbit lung.

A localized Arthus reaction was produced in the lung of sensitized rabbits by delivery of antigen into a lower lobe bronchus using a method of selective bronchial catheterization under fluoroscopy. The rabbits were sensitized with bovine immunoglobulin G (B-IgG) in incomplete Freund's adjuvant (IFA) to produce precipitating antibody without classic delayed hypersensitivity. Pulmonary histopathology was studied at intervals following antigen challenge, using light and immunofluorescent microscopy. Gross lesions peripheral to the lower lobe bronchus receiving antigen were found within 12 hr. Subsequent necrosis resulted in a dense scar by 6 wk. Microscopically, early lesions were typified by localized bronchitis, bronchiolitis, alveolitis, and vasculitis with exuberant exudates containing predominantly polymorphonuclear leukocytes. Extensive focal necrosis was present by 72 hr. Immunofluorescent studies revealed the presence of B-IgG, rabbit IgG, and complement (C3) in and around bronchi, bronchioles, alveoli, and vessels. No granulomatous lesions were found, and proliferation of alveolar lining cells was not detected in these studies. Thus, the lung can participate in an acute Arthus reaction following local antigen challenge in systemically sensitized animals. The pathology more closely resembles a necrotizing bacterial pneumonia than an interstitial or hypersensitivity pneumonitis under the conditions of this experimental system. Implications for human disease are speculative.

Animals↗

The Graduate Record Examination as an admission requirement for the graduate nursing program.

The use of the Graduate Record Examination (GRE) as an admission criterion for the master's degree program was evaluated using data from student records of the population that graduated or dropped out of the State University of New York at Buffalo program between 1983 and 1992. The GRE correlated with first-year and overall graduate grade point averages, but it was a weaker predictor of performance than was the undergraduate grade point average. These findings are discussed in light of the negative consequences of using the GRE related to the recruitment of minority students, women, and older students.

Adult↗

Foreign body removal: a new role for the fiberoptic bronchoscope.

Artificial and animal lung models initially were used to investigate the removal of foreign bodies from the tracheobronchial tree with the flexible fiberoptic bronchoscope. Different extraction instruments (claw, basket, forceps, and balloon catheter) were passed separately through the channel of the bronchofiberscope, and tested for usefulness prior to human application. The Fogarty balloon catheter served as a valuable aid in dislodging impacted objects so that the operator could then grasp them with the claw, basket or forceps. The wire claw recovered many of the metallic and organic objects, the wire basket was successful in retrieving only the bulky objects and the forceps (ACMI) was effective in capturing all of the metallic foreign bodies. These techniques, developed in our laboratory, are now being used to augment rigid bronchoscopy in the removal of foreign bodies from adults and older children. At the present time fiberoptic foreign body removal is not recommended for pediatric cases because of the small diameter of the trachea and glottis in infants and young children.

Adult↗