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Biomedical subjects

R E Ryan

Publications and source records attributed to R E Ryan.

At least 19 recordsLinked to original sources
PubMed1989

Cluster headaches.

The patient with cluster headaches will be afflicted with the most severe type of pain that one will encounter. If the physician can do something to help this patient either by symptomatic or, more importantly, prophylactic treatment, he or she will have a most thankful patient. This type of headache is seen most frequently in men, and occurs in a cyclic manner. During an acute cycle, the patient will experience a daily type of pain that may occur many times per day. The pain is usually unilateral and may be accompanied by unilateral lacrimation, conjunctivitis, and clear rhinorrhea. Prednisone is the first treatment we employ. Patients are seen for follow-up approximately twice a week, and their medication is lowered in an appropriate manner, depending on their response to the treatment. Regulation of dosage has to be individualized, and when one reaches the lower dose such as 5 to 10 mg per day, the drug may have to be tapered more slowly, or even maintained at that level for a period of time to prevent further recurrence of symptoms. We frequently will use an intravenous histamine desensitization technique to prevent further attacks. We will give the patient an ergotamine preparation to use for symptomatic relief. As these patients often have headaches during the middle of the night, we will place the patient on a 2-mg ergotamine preparation to take prior to going to bed in the evening. This often works in a prophylactic nature, and prevents the nighttime occurrence of a headache. We believe that following these principles to make the accurate diagnosis and institute the proper therapy will help the practicing otolaryngologist recognize and treat patients suffering from this severe pain.

Calcium Channel Blockers↗
PubMed1987

Properties of a plasma membrane-associated cathepsin B-like cysteine proteinase in metastatic B16 melanoma variants.

Activities of a cathepsin B-like cysteine proteinase have previously been observed to correlate with the malignancy of several animal and human tumors. Plasma membrane fractions of some of these tumors have been found to be enriched in cathepsin B-like activity. We have determined the subcellular distribution of this enzyme and three additional lysosomal hydrolases (cathepsin H, beta-hexosaminidase, and beta-glucuronidase) in normal murine liver and six metastatic variants of the B16 melanoma. The tissues were fractionated initially by differential centrifugation followed by Percoll density gradient centrifugation of the light mitochondrial fraction. Two fractions were obtained: an L-2 fraction enriched in all four lysosomal hydrolases; and an L-1 fraction enriched in a marker enzyme for the plasma membrane. Cathepsin B-like and beta-hexosaminidase activities, but not the other hydrolase activities, were also found to be enriched in the L-1 fractions of the metastatic B16 tumors. We explored the nature of the association of the cathepsin B-like activity with the plasma membrane using fractions from the spontaneously metastatic B16 amelanotic melanoma. Activity could not be dissociated from the plasma membrane fraction by washing with a physiological salt solution suggesting that it was not adsorbed to this fraction nonspecifically, nor could it be displaced by mannose 6-phosphate or other sugars which compete for binding to the known lysosomal receptors. High salt concentrations, low concentrations of the mild detergent saponin, mild acidification, or phosphatidylinositol-specific phospholipase C did not elute the cathepsin B-like activity. However, activity was eluted by exposure to 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate, a detergent used in the purification of integral membrane proteins. The B16 amelanotic melanoma plasma membrane-associated cathepsin B-like activity had a slightly higher pH optimum and was resistant to inactivation by neutral pH and to inhibition by three low molecular weight inhibitors of cysteine proteinases. The Ki values for inhibition by leupeptin and stefin A were 20-fold higher. The presence of a cathepsin B-like cysteine proteinase at the surface of metastatic tumor cells, particularly in a form which can retain activity at physiological pH and retain activity in the presence of extracellular proteinase inhibitors, may contribute to the focal dissolution of the extracellular matrix observed at sites of contact with invading tumor cells.

Animals↗
PubMed1985

Cathepsin B-like activity in viable tumor cells isolated from rodent tumors.

The cathepsin B-like cysteine proteinase activity which has been implicated in tumor malignancy has been attributed to several cellular sources, including viable tumor cells, necrotic tumor cells, and host-inflammatory cells. We have isolated subpopulations of cells from eight rodent tumors of five histological types, using centrifugal elutriation, and verified the cellular composition of the subpopulations cytologically. Ninety-two % or greater of the cathepsin B-like activity was associated with the isolated fractions containing greater than or equal to 95% tumor cells of 86 +/- 2% (SE) viability (beta fractions). The isolated fractions consisting of necrotic tumor cells and inflammatory cells (alpha fraction) apparently contain a cysteine proteinase inhibitor, since both cathepsin B-like and cathepsin H activities in the beta fraction of B16 amelanotic melanomas could be inhibited by addition of the alpha fraction.

Animals↗
PubMed1979

Antral-choanal polyps.

The series involves 38 patients who had antral-choanal polyps removed at the Mayo Clinic during the 10 year period between 1965 and 1974. In contrast to common nasal polyps, antral-choanal polyps often are solitary and unilateral and usually are not associated with an allergic diathesis. These polyps recur frequently if they are simply avulsed; permanent ablation of the polyps requires thorough curettage of the antrum.

Adolescent↗
PubMed1978

Cellular mixed tumors of the salivary glands.

Mixed tumors are unusual in that they possess both epithelial and mesenchymal elements. The proportions of the two elements vary greatly; the lesions with a pronounced preponderance of epithelial tissue have been called cellular mixed tumors. This increase in epithelial cellularity often results in misdiagnosis or in concern that the tumor may be more aggressive than the ordinary mixed tumor--possibly even malignant. We have reviewed 1,095 consecutive parotid tumors that were removed at the Mayo Clinic, Rochester, Minn, from 1950 through 1970. Ninety-three of the lesions were diagnosed initially as cellular mixed tumors, and slides were available for review. Of these 93, 43 fulfilled our criteria of having greater than 80% of each tumor composed of the packed epithelial cells. All tumors had a corresponding reduction in the mesenchymal portion. The records of the 43 patients were studied to determine the clinical behavior of these neoplasms, particularly with regard to recurrence, metastasis, and malignant transformation. Our findings confirmed our clinical suspicions that some of these cellular mixed tumors, notably those that showed histopathologic evidence of an increased rate of mitotic activity, can and do act in a more aggressive manner.

Adenoma, Pleomorphic↗
PubMed1977

Verrucous carcinoma of the larynx.

Verrucous carcinoma, because of its oftentimes unusual clinical appearance, may be misdiagnosed if there is not good communication between the surgeon and the pathologist. We have reviewed our series of 20 cases of verrucous carcinoma from 1964 through 1974 and have analyzed the results of our therapy. We have concluded that verrucous carcinoma is a slow-growing, locally invasive lesion that does not metastasize to the cervical lymph nodes. Radiation therapy does not seem to be an effective method of treatment; the recurrence rate is high. Conservative laryngeal surgery is the preferred method of treatment in these patients and should prevent loss of life and spare laryngeal function.

Adult↗
PubMed1975

Symposium. ENT for nonspecialists. Supraglottic.

Because supraglottic cancer usually is diagnosed late and metastasizes early, the cure rate is poorer than for glottic cancer. Supraglottic lesions can spread in any direction. The main method of diagnosis is either indirect or direct laryngoscopy, and the main symptoms are vague throat pain, otalgia, hemoptysis, hoarseness, and enlarged cervical lymph nodes. Roentgenographic examination is useful only as a supplement to other diagnostic measures. Staging of the disease is important in determining the most effective therapy and in predicting the results of treatment. Treatment should be individualized for each patient and should be selected on the basis of lesion size and site, the presence or absence of regional metastasis, the general health of the patient, and the likelihood of faithful follow-up.

Female↗