Search PubMed⌕ Search

Biomedical subjects

M D Miller

Publications and source records attributed to M D Miller.

At least 199 records · Page 11Linked to original sources
PubMed1983

Diphenhydramine blocks the leukotriene-C4 enhanced mucus secretion in canine trachea in vivo.

Leukotrienes (C4, D4) have been shown to enhance mucus secretion in both isolated human airway tissue and intact canine trachea in vivo. They also have been implicated as putative mediators in several airways diseases. In previous canine studies the mucus enhancing effect of leukotriene-C4 was blocked by atropine, FLP 55,712, and hexamethonium but not by cutting the superior laryngeal and vagus nerves. We anesthetized mongrel dogs with chloralose (100 mg/kg) and urethane (500 mg/kg) and ventilated them on a pump. To visualize the secretions from submucosal glands, we exposed the mucosa of the upper trachea and coated its surface with powdered tantalum. Secretions from the glands formed elevation in the tantalum layer (hillocks) with time: the number of tracheal hillocks (an index of mucus secretion) was measured at one or more of the four time points on six dogs after each treatment of the treatment sequence: no LTC4, LTC4, no LTC4 + blocker, and LTC4 + blocker. The potential blocker was diphenhydramine, an H1 antagonist for histamine. LTC4 was injected into the cranial thyroid artery which directly feeds the tracheal segment. We observed hillocks through a dissecting microscope, and the number of hillocks per 1.2 cm2 were counted for a 1-4 min interval. In 6 dogs with 12 responses, LTC4 (10 micrograms) gave a positive response that was significantly different from control (p less than 0.01-0.05) at 2-4 min. Diphenhydramine (n = 6), 0.5 mg/kg, a dose which blocked a histamine challenge without blocking an acetylcholine challenge of secretion, gave a statistically significant (p less than 0.01-0.05) reduction in mucus secretion at 1-4 min. These results support the conclusion that leukotriene C4 induces mucus secretion in dogs that is blocked by prior diphenhydramine administration. This would indicate histamine has a role, but as yet an unknown mechanism in the action of leukotriene-C4 in enhancing mucus.

Animals↗
PubMed1983

Developing a model for clinical and basic science teaching skills.

This report describes a model for identifying sets of teaching abilities considered to be effective for medical school teaching staff, based on roles teachers assume and functions they are expected to perform as instructors. The specification of these teaching abilities was the first step in the development of a comprehensive course on Medical Instruction at the Basic Institute of Medical and Agricultural Biology of the State University of Sao Paulo, Botucatu, Brazil, where the senior author is employed. The work was based on the assumption that medical school teachers are expected to assume a variety of teaching roles and that identification and specification of the abilities that define their roles can result in more effective and efficient teaching.

Brazil↗
PubMed1983

Leukotriene C4 and dimethylphenylpiperazinium-induced responses in canine airway tracheal muscle contraction and fluid secretion.

Leukotrienes have been implicated as putative mediators in several air way diseases. In previous canine studies it was shown that leukotriene C4 (LTC4) enhanced fluid secretion over baseline values and this enhancement could be blocked by hexamethonium. This indicates that leukotrienes have as one of their actions, stimulation of ganglionic motor neurons. In the present study, we determined that LTC4 acts at a similar site as the specific nicotinic receptor agonist dimethylphenylpiperazinium (DMPP). Both LTC4 and DMPP when given alone enhanced mucus secretion and induced tracheal muscle contraction over control baseline (p less than 0.05). When added to DMPP, LTC4 enhanced the DMPP effect of muscle contraction at 5 and 8 micrograms by a synergistic amount, while the secretion was only additive. The slopes of the dose-response curves for DMPP + LTC4 did not differ by a statistically significant amount. LTC4 and DMPP act on a similar, if not the same, ganglionic receptor.

Animals↗
PubMed1982

Evaluation of heart sounds and murmurs in children.

Auscultation is the core of pediatric cardiovascular evaluation and should be performed according to a routine. The four heart sounds should be sought in order at their usual locations, with particular attention to the second sound because of its important diagnostic role in congenital cyanotic heart disease. The next sounds to listen for are clicks, which can be systolic, pulmonary, aortic, or midsystolic. Finally, murmurs should be sought in systole and then diastole. Besides being identified as systolic, diastolic, or continuous, murmurs should be characterized according to their relationship with the first and second heart sounds, intensity, frequency, and maximum location and radiation.

Adolescent↗
PubMed1982

Differential diagnosis of heart murmurs in children.

When a heart murmur turns up on routine examination of an otherwise health child, a thorough cardiovascular evaluation should be carried out according to the guidelines presented in the first two articles in this series (June, page 235, and July, page 151). The information gained by inspection, palpation, and auscultation is then coordinated and analyzed to arrive at the most likely diagnosis, as described in this concluding presentation.

Aortic Coarctation↗
PubMed1982

Ratings of medical journals by family physician educators.

A survey asking respondents to rank journals related to medicine and to medical education was sent to a sample of members of the Society of Teachers of Family Medicine to determine the prestige value of those journals. The participants were asked to rank from a list of more than 75 different medical and nonmedical journals those they considered to be among the top ten. The results indicate that a relatively small number of journals were ranked by the respondents. Six journals were designated as most prestigious by members of the Society of Teachers of Family Medicine: The Journal of Family Practice, The New England Journal of Medicine, American Family Physician, The Journal of the American Medical Association, Annals of Internal Medicine, and the Journal of Medical Education. There was general agreement as to the value of certain journals regardless o participant's work area or major academic interest.

Attitude of Health Personnel↗
PubMed1981

Hemodynamic and ECG responses to exercise in children with sickle cell anemia.

To determine whether exercise responses are different from normal in children with sickle cell anemia (SCA), we performed dynamic cycle ergometer exercise testing in 47 patients with SCA, aged 5 to 18 years, and 170 healthy, black age-matched control subjects. Seven (15%) of the patients with SCA had definitely ischemic, 16 (34%) had equivocally ischemic, and 24 (51%) had nonischemic ECG responses. Resting heart rate in the three groups of patients with SCA was higher than control values. Maximum exercise heart rate attained was lowest in the definitely ischemic group. All patients with SCA had decreased blood pressure responses and maximum working capacity when compared with control subjects. Hemoglobin concentration was lowest in the definitely ischemic group and correlated with maximum workload. Long-term myocardial ischemia may lead to fibrosis and the decreased myocardial contractility seen in adult patients with SCA.

Adolescent↗
PubMed1979

Inhibition of histamine release and ionophore-induced calcium flux in rat mast cells by lidocaine and chlorpromazine.

We studied the effects of lidocaine (L) and chlorromazine (C), two compounds known to affect the binding of calcium to cell membranes, on histamine release and calcium uptake by purified mast cells upon challenge with the ionophore A23,187 or with compound 48/80. At low concentrations L and C inhibited the Ca++ flux as well as histamine release while higher concentration caused enhancement in this function. Evidence was obtained that L 10(-4) M may displace Ca++ from the cell membranes.

Animals↗
PubMed1979

Cervical spine trauma: the common combined conditions.

The two most common groups of combined traumatic conditions of the cervical spine are hyperextension and hyperflexion fracture-dislocations. In a series of 400 patients with fractures and/or dislocations of the cervical spine, 25% had hyperextension and 19% hyperflexion fracture-dislocations. A computer analysis of the cases revealed that there are five distinct types of hyperextension and four types of hyperflexion fracture-dislocations. Each of the types is considered as to incidence, causes, mechanism of injury, and roentgen and differential diagnosis.

Cervical Vertebrae↗
PubMed1979

Vessel occlusion with transcatheter electrocoagulation: initial clinical experience.

Transcatheter electrocoagulation (TCEC) was used for vessel occlusion in combination with embolization by Gelfoam and/or Ivalon in six patients in whom other interventional or surgical techniques were considered dangerous or unfeasible. The technique was effective in decreasing or obliterating the blood supply to variously located lesions in all cases. The only complications were small skin burns in one patient and a small ulceration of the upper lip in another.

Adult↗
PubMed1979

Traumatic anterior atlanto-occipital dislocation.

The five cases of atlanto-occipital dislocation reported in the world literature are reviewed, and four additional cases are presented, including two survivors. The pathological anatomy of this potentially catastrophic injury and its management are briefly discussed. Because immediate recognition of the atlanto-occipital dislocation is critical to proper treatment and because the neurological findings are extremely varied, a new radiographic criterion for its identification has been developed.

Adult↗
PubMed1979

Health care.

Explore the source record for details and available documents.

Economics, Medical↗