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Biomedical subjects

H I Miller

Publications and source records attributed to H I Miller.

At least 37 records · Page 2Linked to original sources
PubMed1999

Priming of Peyer's patch lymphoid cells by hemorrhagic shock and resuscitation to produce superoxide radical.

Hemorrhagic shock (HS) can cause whole body ischemia including the gastrointestinal tract. We investigated whether cells from small intestine Peyer's patches (PP) were capable of producing superoxide radical when animals underwent HS or HS followed by resuscitation (HS/RS). HS was initiated by removing 60% of the blood volume of surgically prepared guinea pigs. PP lymphoid cells were purified and stimulated with phorbol 12-myristate 13-acetate in the presence of spin trap 5-diethoxyphosphoryl-5-methyl-1-pyrroline-N-oxide (DEPMPO). Electron paramagnetic resonance spectra of PP lymphoid cells from sham-treated control, HS, and HS/RS animals produced DEPMPO radical adducts characterized as the adducts of superoxide (DEPMPO/*OOH) and hydroxyl (DEPMPO/*OH) radicals. The formation of both radical adducts was totally inhibited by superoxide dismutase or a nicotinamide adenine dinucleotide phosphate (reduced form) oxidase inhibitor, diphenyleneiodonium chloride. HS/RS increased radical adduct formation, expressed as a percentage control, by 160% and 225% for DEPMPO/*OOH, and DEPMPO/*OH, respectively. When animals were allowed to recover for 24 h post-HS/RS treatment, PP cells decreased the superoxide generation to the same level as controls. Thus, RS following HS may prime PP lymphoid cells for increased nicotinamide adenine dinucleotide phosphate (reduced form) oxidase-dependent superoxide generation, and this process may have cytotoxic and/or immunomodulatory effects on the host.

Animals↗
PubMed1998

FDA "reform"?

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Drug Approval↗
PubMed1998

Ultrasound inhibits the adhesion and migration of smooth muscle cells in vitro.

This study investigated in vitro the effect of therapeutic ultrasound (ULS) on smooth muscle cell (SMC) function as adhesion, migration and proliferation. Experiments were conducted on aortic SMC in culture. The LD50 was established (1.5 W for 15 s at a frequency of 20 kHz) and used as standard dose in all experiments. Control SMC and viable sonicated SMC were compared in each experiment. Migratory capacity decreased 2.4-fold after sonication and stayed reduced for up to 24 h. Adhesion capacity decreased 5.5-fold after ULS. The proliferative capacity was similar to that of nonsonicated SMC. Sonication was accompanied by the disorganization of alpha-SM actin fibers and diminished distribution of vinculin; tyrosinated alpha tubulin and vimentin appeared unaffected. These changes might be responsible for the observed inhibition of SMC adhesion and migration. Sonicated cells exhibited less lamellipodia, membrane collapse and bleb formation. The signal transduction cascade, which involves activation of the phospholipase-C pathway, was unaffected by ULS.

Animals↗
PubMed1997

Analysis of coronary ultrasound thrombolysis endpoints in acute myocardial infarction (ACUTE trial). Results of the feasibility phase.

BACKGROUND: It has been demonstrated that therapeutic ultrasound effects ultrasound thrombolysis by selectively disrupting the fibrin matrix of the thrombus. This study was conducted to evaluate the clinical feasibility of percutaneous transluminal coronary ultrasound thrombolysis in acute myocardial infarction (AMI). METHODS AND RESULTS: Consecutive patients (n = 15) with evidence of anterior AMI and Thrombolysis in Myocardial Infarction (TIMI) grade 0 or 1 flow in the left anterior descending artery underwent coronary ultrasound thrombolysis. Angiographic follow-up was performed after 10 minutes and 12 to 24 hours. Ultrasound induced successful reperfusion (TIMI grade 3 flow) in 87% of the patients. Adjunct percutaneous transluminal coronary angioplasty (PTCA) after ultrasound thrombolysis produced a final residual stenosis of 20 +/- 12% as determined by quantitative coronary angiographic analysis. There were no adverse angiographic signs or clinical effects during the procedure. There was no change in the degree of flow in any of the patients at the 12- to 24-hour angiograms. During hospitalization, 1 patient had recurrent ischemia on the fifth day after the procedure, and emergent catheterization revealed occlusion at the treatment site. The patient was successfully treated with PTCA. CONCLUSIONS: These results suggest that ultrasound thrombolysis has the potential to be a safe and effective catheter-based therapeutic modality in reperfusion therapy for patients with AMI and other clinical conditions associated with intracoronary thrombosis.

Adult↗
PubMed1997

Changes in hemostatic function at times of cyclic variation in occupational stress.

In this study we demonstrated, in the same healthy subjects, a significant elevation in coagulation factors VII and VIII, fibrinogen, thrombocyte count, and thrombin and adenosine diphosphate-induced platelet aggregation during a period of increased workload compared with a calm work period. These findings may add to the understanding of the mechanism that links mental stress to coronary disease.

Adult↗
PubMed1997

Delayed development of a pseudoaneurysm in the left circumflex artery following angioplasty and stent placement, treated with intravascular ultrasound-guided stenting.

Three months following satisfactory angioplasty and stent placement, a patient developed restenosis and a pseudoaneurysm of a coronary artery segment proximal to the previously stented area. The restenosis and the pseudoaneurysm were successfully treated with intravascular ultrasound-guided primary stenting. The delay in the appearance of the pseudoaneurysm attests to the chronic nature of the lesion.

Adult↗
PubMed1997

High-dose isosorbide dinitrate for myocardial revascularization with composite arterial grafts.

BACKGROUND: Composite arterial grafting for myocardial revascularization is a surgical technique in which free arterial conduits are proximally attached to an in situ internal mammary artery. METHODS: Composite arterial grafting was performed in 78 patients with internal mammary artery (n = 24), inferior epigastric artery (n = 21), or radial artery (n = 33) connected to the internal mammary artery. Overall, 254 distal anastomoses were performed (average number, 3.3 per patient), 225 of which were arterial. All patients were treated postoperatively with high-dose isosorbide dinitrate (4 to 20 mg/h for 24 hours). RESULTS: The in-hospital mortality rate was 2.6% (2 patients). Early recatheterization studies performed 3 weeks (range, 1 to 20 weeks) after operation in 30 patients demonstrated patency rates of 100%, 93%, and 100% for the composite internal mammary artery, inferior epigastric artery, and radial artery groups, respectively. In addition, two inferior epigastric artery conduits had major intraluminal constriction. At a mean follow-up of 20 months (range, 1 to 42 months) all patients are alive, and all but 2 in the inferior epigastric group (97%) are angina free. CONCLUSIONS: This surgical technique can be safely used. On the basis of our experience, the right internal mammary artery and the radial artery are the most suitable conduits for this procedure. High-dose nitrates given perioperatively prevent spasm and ensure early patency rates.

Adult↗