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Biomedical subjects

L R Brown

Publications and source records attributed to L R Brown.

At least 145 records · Page 8Linked to original sources
PubMed1978

Pulmonary processes of mature-appearing lymphocytes: pseudolymphoma, well-differentiated lymphocytic lymphoma, and lymphocytic interstitial pneumonitis.

Patients with pseudolymphoma, well-differentiated lymphocytic lymphoma, and lymphocytic interstitial pneumonitis were studied. Diagnoses were confirmed by recently developed immunochemical staining techniques. Radiographic findings in pseudolymphoma were different from those in well-differentiated lymphocytic lymphoma, and clinical findings in lymphocytic interstitial pneumonitis were different from those in the other two types of lesions. The interstitial infiltrate of lymphocytic interstitial pneumonitis had two patterns: basilar with an alveolar component and diffuse with associated honeycombing. Pseudolymphoma and lymphocytic interstitial pneumonitis are being polyclonal inflammatory processes without malignant potential. Well-differentiated lymphocytic lymphoma, a monoclonal neoplasm, often has an indolent course.

Humans↗
PubMed1978

Computed tomography of the mediastinum.

Findings from the first 430 CT examinations of the thorax performed at the Mayo Clinic were compared with results of film studies and the most certain later diagnoses in the same cases. Results were analyzed by disease and by mediastinal compartment. CT was superior in staging bronchogenic carcinoma, detecting abnormal masses, and in demonstrating mediastinal normally when plain films were equivocal. It generally gave clear delineations of lesions and distinguished them better from normal structures, and, in correlation with clinical data, it was more accurate in suggesting whether they were benign or malignant.

Adenocarcinoma↗
PubMed1978

Comparison of whole lung tomography and computed tomography for detecting pulmonary nodules.

Detecting pulmonary metastasis is important when planning surgical therapy, radiotherapy, or chemotherapy in patients with known malignancy. A series of 91 patients was studied by both whole lung tomography and computed tomography (CT) of the lungs. More pulmonary nodules were detected with CT than with whole lung tomography in 32 (35%) of the patients. Of the 91 patients in the study, 31 had resection of some or all of the pulmonary nodules. In 27 patients, the nodules were primary or metastatic malignant lesions. Bilateral pulmonary nodules were detected with CT in 13 patients when whole lung tomography had demonstrated nodules in only one lung. CT has replaced whole lung tomography as the method preferred by the authors for detecting pulmonary nodules in selected patients at risk to develop pulmonary metastasis.

Adolescent↗
PubMed1978

Lymphocytic interstitial pneumonitis. Review of 13 cases.

Thirteen patients with lymphocytic interstitial pneumonitis were seen at the Mayo Clinic from 1966 through 1976. The group included nine women and four men, with a mean age of 50.7 years. Their primary complaints were cough, dyspnea, and loss of weight. Chest roentgenographic features were predominantly basilar, coarse interstitial-alveolar infiltrations. Pulmonary function studies showed restrictive ventilatory impairments with a low CO diffusing capacity in all 13 patients. Lung biopsies in all cases showed diffuse interstitial infiltrations, consisting of mature lymphocytes and plasma cells. Ten of the 13 patients had an associated dysproteinemia, including two patients with hypogammaglobulinemia. Three patients had coexistent Sjögren's syndrome, including two with localized amyloidosis. Although lymphocytic interstitial pneumonitis is a histologically distinct pulmonary lesions, it occurs with a variety of immune disorders.

Adolescent↗
PubMed1977

Nuclear-magnetic-resonance-spectroscopic studies of the amino groups of insulin.

The amino groups of insulin have been studied by 1H and 13C nuclear magnetic resonance spectroscopy in insulin, zinc-free insulin and methylated insulin. By difference spectroscopy it is possible to follow the shift with pH of the epsilon-CH2 and delta-CH2 proton resonances of lysine-B29 in insulin. In methylated insulin the dimethyl proton resonances of glycine-A1, phenylalanine-B1 and lysine-B29 can be followed as a function of pH. In native insulin pKapp values of 6.7 and 8.0 are obtained for phenylalanine-B1 and glycine-A1 (the assignment is tentative) and 11.2 for lysine-B29. Separate resonances have been observed from the lysine-B29 Nepsilon-(CH3)2 group for the monomeric and dimeric forms of methylated insulin, which indicates a small change in the environment of lysine-B29 on dimerisation. The nuclear magnetic resonance spectral characteristics of these groups are, in general, consistent with the overall structure of the crystal form of the 2-zinc insulin hexamer.

Amines↗
PubMed1977

A spin label study of lipid oxidation catalyzed by heme proteins.

Rapid loss of the electron spin resonance signal from a variety of spin labels is observed when ferricytochrome c or metmyoglobin are combined with lipids. Evidence is presented that this loss of signal can be used as a sensitive method to study lipid oxidation catalyzed by heme proteins. Under aerobic conditions and with lipids which bind the heme protein, the kinetics of the oxidation process as observed by the spin label method are identical to the kinetics previously observed by measurements of oxygen uptake. Use of pre-oxidized lipids under anaerobic conditions indicates that cytochrome c reacts with a product of lipid oxidation. Kinetic studies of the anaerobic reaction indicate that cytochrome c reacts rapidly with lipid oxidation products in membrane areas far larger than the area occupied by cytochrome c, implying rapid transport of reactive species within the membrane interior in directions parallel to the membrane surface. Under anaerobic conditions, reaction of cytochrome c with lipid oxidation products appears to produce a relatively long lived (hours) species located in the hydrophobic portion of the membrane, which is capable of subsequent reaction with lipid-soluble spin labels.

Animals↗
PubMed1977

Oral complications of cancer radiotherapy.

Injury to surrounding tissues during radiotherapy for oral cancer can have devastating physical and psychologic consequences for the patient. Oral complications include xerostomia, dental decay, mucositis, taste loss, osteoradionecrosis, infection, and trismus. In many instances, these problems can be eradicated or controlled with appropriate treatment.

Adult↗
PubMed1977

Prevention of xerostomia-related dental caries in irradiated cancer patients.

Three caries preventative regimens: oral hygiene; oral hygiene and topical fluoride; and oral hygiene, typical fluoride, and sucrose restriction were evaluated in patients with cancer given xerostomia-producing radiotherapy. The oral hygiene-fluoride gel combination was remarkably effective in protecting these high risk patients from caries, regardless of the cariogenicity of the diet.

Adolescent↗
PubMed1977

The effect of Skylab on the chemical composition of saliva.

The levels of specific proteins and electrolytes in stimulated whole saliva were monitored in Skylab crew members before and after each mission. With few exceptions, mission-associated compositional changes in saliva were relatively minimal. There were no changes in(formula see text), Cl-, albumin, or IgG concentrations. There were slight decreases in total protein coinciding with moderate saliva flow rate increases immediately before and after each flight. Other changes included diminutions in Na+ and lysozyme, and elevations in Mg++ and IgA. The IgA increase was the most pronounced mission-associated change observed.

Adult↗
PubMed1977

Detection of pulmonary nodules by computed tomography.

In 11 of 23 patients, computed tomography of the chest detected pulmonary nodules that were not detected by conventional chest radiography or whole lung tomography. CT is recommended for patients suspected of having pulmonary metastasis and those with a solitary pulmonary nodule.

Carcinoma, Small Cell↗
PubMed1977

Use of computed tomography in the detection of pulmonary nodules.

The ability of computed tomography of the lungs to detect pulmonary nodules was compared with that of conventional chest roentgenography and whole-lung tomography. Computed tomography detected more pulmonary nodules in 10 of 29 patients studied with both computed tomography and whole-lung tomography. Computed tomography of the lungs is the most accurate noninvasive method available for detecting pulmonary nodules.

Adenocarcinoma↗
PubMed1976

A study of the lysyl residues in the basic pancreatic trypsin inhibitor using 1H nuclear magnetic resonance at 360 Mhz.

Fourier transform 1H nuclear magnetic resonance (NMR) experiments at 360 MHz using convolution difference techniques to improve the spectral resolution were employed to investigate the resonances of the lysyl residues in bovine pancreatic trypsin inhibitor. The observations in both native protein and in chemically modified protein containing Nepsilon-dimethyllsysine show that three of the four lysines extend predominantly freely into the solvent, whereas lysine-41 is involved in an intramolecular interaction with tyrosine-10. Since in the single crystal structure tyrosine-10 is involved in an intermolecular interaction with arginine-42 of the neighboring protein molecule, the NMR data thus reveal a local conformation difference for bovine pancreatic trypsin inhibitor in solution and in the crystalline form which appears to result primarily from intermolecular interaction in the crystal lattice.

Hydrogen-Ion Concentration↗
PubMed1976

Radiation-induced xerostomia in cancer patients. Effect on salivary and serum electrolytes.

Saliva and serum electrolyte concentrations were monitored in 30 patients given a course of xerostomia-producing cancer radiotherapy. The mean flow rate of stimulated whole saliva decreased 83.3% during a 6-week treatment period. The striking reduction in saliva output was accompanied by significant increases in saliva Na+, Cl-, Ca++, Mg++ and Prot.- concentrations and by a decrease in saliva HCO3- content. The xerostomic saliva was more concentrated and had a greater salinity than the pretreatment saliva in each instance. In contrast, none of the serum electrolytes measured was significantly altered by the subtotal salivary shutdown.

Adolescent↗
PubMed1976

The effect of radiation-induced xerostomia on saliva and serum lysozyme and immunoglobulin levels.

Saliva and serum lysozyme, immunoglobulin, albumin, and total protein levels were monitored in thirty patients with cancer of the head or neck before, during, and after radiotherapy and compared with those of a group of non-irradiated noncancer control subjects. The mean volume-based saliva lysozyme and total protein concentrations were significantly higher in the cancer patients before radiotherapy than in the control group. During radiotherapy, the mean volume-based concentrations of all protein components assayed increased as the saliva flow rate decreased. Protein-based ratios of saliva albumin, IgG, and lysozyme and the ratio of IgG/IgA increased as the xerostomia intensified. Ratios of saliva total protein and IgA to flow rate paralleled the flow rate decrease. Such increased concentrations in saliva immunoproteins were offset, however, by a greater than 93 per cent reduction in total saliva output. This reduced saliva output, therefore, resulted in an immunoprotein deficit. There were no significant differences between the mean serum lysozyme levels of the cancer and control groups at any point of comparison. The mean serum immunoglobulin concentrations in the cancer patients before radiotherapy were significantly higher than those in the control group. During radiotherapy, there was a decrease in the mean serum total protein, albumin, and immunoglobulin levels which reverted toward the pretreatment values during the postirradiation period.

Adult↗