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Biomedical subjects

A Miller

Publications and source records attributed to A Miller.

At least 865 records · Page 48Linked to original sources
PubMedDate not supplied

Effects of surrounding tissue on the sound spectrum of arterial bruits in vivo.

Turbulent flow distal to arterial stenoses producers bruits with a characteristic sound spectrum, analysis of which has permitted accurate non-invasive assessment of the residual lumen diameter of the stenosis in the case of the human carotid artery. In contrast, investigators working with in vitro elastic models of arteries or with excised vessels have reported finding mainly resonant spectra of bruits recorded distal to stenoses. We have studied the effects of turbulent flow on the sound spectrum produced at the arterial wall and the influence of surrounding tissue on this spectrum. Aortic, carotid, and femoral stenoses were produced in dogs by external banding of the arteries with 5mm wide Teflon bands. Recordings of bruits made directly on the vessel wall had a sound spectrum made up of 2 components, one due to turbulent flow, and the second to a superimposed resonant spectrum from arterial wall vibration. This was true of 3 kinds of vessels studied. The effects of surrounding tissue on the sound spectrum of arterial bruits was shown by comparing the spectra o bruits recorded directly on the vessel wall, on the freshly closed wound and on the healed wound. The sound properties of the artery in situ are very different from those of exposed or excised vessels or elastic tubes. Although intravascular turbulence may be accurately appreciated at the skin surface, arterial wall resonance in the intact animal is extensively damped by the normal coupling of the artery to its surrounding tissue.

Animals↗
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Simultaneous therapy with antiplatelet and anticoagulant drugs in symptomatic cardiovascular disease.

Twenty of approximately 1000 patients attending the arteriosclerosis clinic at MIT during a 13 year period were treated simultaneously with aspirin and warfarin for symptomatic atherosclerotic (19) or rheumatic (1) heart or vascular disease. The average duration of therapy was 5.8 years. Thirteen patients suffered from familial hyperlipoproteinemia; only one patient had none of the major risk factors for arteriosclerosis. Refractory symptoms were related to the central nervous system in 13, peripheral vascular system in 5 and the heart in 2. All twenty patients became asymptomatic or showed marked clinical improvement on aspirin plus warfarin therapy. While on this therapy, complications, both thrombotic and hemorrhagic, occurred in 7 of the 20 patients (graft embolus in 1, and bleeding in 6; with one death as a result of intracranial bleeding) and sudden death, probably from acute myocardial ischemia, in a further 2 patients. We conclude that when alternative therapies are impossible or have proven to be of no avail in patients suffering from the complications of advanced atherosclerosis, the simultaneous administration of aspirin and warfarin may be a therapeutic alternative, although very close and careful followup of the patients' prothrombin times and clinical status is essential.

Adult↗
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Flexible bronchoscopy in nonvisualized carcinoma of the lung.

Of 1,000 consecutive patients undergoing fiberoptic bronchoscopy, 331 eventually were proven to have primary lung cancer. Of the 331 carcinomas, 253 were beyond the visual range of the flexible bronchoscope. However, under fluoroscopic guidance, the diagnosis of carcinoma was established in 194 (76.7%) of these nonvisualized tumors. Cytologic analysis of brush specimens was more often positive for malignancy than specimens obtained by forceps biopsy. An expert cytologist and experienced bronchoscopy team are esential for a high percentage of reliable positive diagnoses in bronchogenic carcinoma.

Biopsy↗
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Baclofen-induced bronchoconstriction.

OBJECTIVE: To report the occurrence of acute bronchospasm in one asthmatic patient and increased bronchial reactivity in another following the administration of a single dose of oral baclofen. CASE SUMMARY: On two separate occasions, a 46-year-old asymptomatic asthmatic man developed dyspnea and chest tightness one hour after the ingestion of baclofen 40 mg. Pulmonary function studies revealed a significant decrease in airflow relative to baseline. A 33-year-old asymptomatic woman with a history of exercise-induced dyspnea and wheezing displayed bronchial hyperresponsiveness to inhaled metacholine 2 hours after ingesting 40 mg of baclofen. The patient had had a negative methacholine challenge test 72 hours earlier. DISCUSSION: The gamma-aminobutyric acid-agonist baclofen has been shown to reduce airway responsiveness to various bronchoconstricting agents in animal studies. The etiology of this seemingly paradoxical response in two patients is unclear, but may offer insight into the neurally mediated airway constriction that occurs in asthma. CONCLUSIONS: Clinicians should be aware of the possibility of baclofen-induced bronchospasm, especially in asthmatic patients.

Adult↗
PubMedDate not supplied

Glucocorticoid receptor characteristics in healthy childrens' leukocytes: correlation with gender, weight, age and plasma cortisol.

This study evaluated the glucocorticoid receptor (GR) binding capacity of mononuclear leukocytes (MNL) in male and female, obese and non-obese children and adolescents. Fifteen male and eleven female subjects, ages 6.3 to 21 years, approximately equally divided between obese and non-obese were included. The age distribution was equivalent among groups. Average GR binding capacity and apparent dissociation constant (Kd) did not differ significantly between the obese and non-obese groups. However, females averaged 7280 +/- 1440 GR sites/MNL, significantly more than males with 5720 +/- 1132 sites/MNL (p = 0.005). There was no significant difference in average Kd between the groups nor was there a difference in the GR characteristics with respect to subjects' age, plasma cortisol concentrations, or degree of adiposity. While in the group studied, there were no differences in MNL GR characteristics based on subjects' weight, age or plasma cortisol, female subjects' MNL averaged 27% greater GR binding capacity than males. This difference appears to be concentrated in the pubertal subgroup.

Adolescent↗
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Merging with for-profits: flawed strategy. Such affiliations benefit neither the Catholic hospital nor society.

Some Catholic healthcare organizations, seeking new sources of capital, are eyeing mergers with for-profit systems. However, such mergers raise questions about their effects on both the mission of particular Catholic institutions and the well-being of society at large. For-profit organizations are driven by the pursuit of profit. They market ¿products.¿ This pursuit naturally shapes their decision-making rationales, employee relations, and business priorities. Not for-profits, on the other hand, provide ¿public goods¿--goods that for-profits either will not provide or will not provide adequately--and this mission shapes their priorities, decision making, and employee relations differently. What is more, economic power is unequal between the two kinds of organization. Since not-for profits are seeking capital when they merge with for profits, they usually do so from a position of relative disadvantage. When conflicts arise, the for-profit partner generally prevails. The not-for-profit partner then finds itself, not merged with, but acquired by the for-profit. Throughout U.S. history, not-for-profits have performed a function neglected by both government and private companies. Now, in the 1990s, the whole social welfare framework of our society is under attack. A moral-political crisis questions the very concept of the voluntary sector. If Catholic healthcare organizations allow themselves to be swallowed by for-profits, who will care for the voiceless and the vulnerable?

Catholicism↗
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Reversal of acute fulminant lymphocytic myocarditis with combined technology of OKT3 monoclonal antibody and mechanical circulatory support.

Reported is a case of acute fulminant lymphocytic myocarditis with profound circulatory compromise that was successfully reversed by treatment with OKT3 monoclonal antibody. The patient was supported with biventricular assist devices while being treated with the monoclonal antibody. The patient had remarkable recovery of ventricular function, which allowed for the removal of the device after 8 days of support. This case shows the success of combined technologies of monoclonal antibody and mechanical circulatory support to treat a potentially fatal disease process.

Adult↗
PubMedDate not supplied

Surgical treatment of left ventricular aneurysms.

An analysis of 37 patients surgically treated for left ventricular aneurysms provides preoperative clinical information regarding surgical risk. Operative mortality can be correlated with clinical and cardiac functional data as well as with the extent of coronary artery disease. Review of operative mortality in relation to the surgical procedure and the functional status of survivors indicates that aorto-coronary bypass grafting, complementary to aneurysmectomy, not only relieves angina pectoris, but also improves the functional status of the residual myocardium.

Adult↗