Biomedical subjects

S M Homan

Publications and source records attributed to S M Homan.

7 recordsLinked to original sources

PubMed1992

When do alcoholics first discuss drinking problems?

Data from a sample of 338 alcoholics who were identified from medical record reviews and diagnosed as alcohol dependent according to DSM-III criteria by means of a structured psychiatric interview were analyzed to determine when in the course of alcohol disorder development first discussion with a health professional about their drinking problems had occurred. The data support an image of alcoholics as experiencing many drinking problems before seeking professional help and, particularly, before attending AA. These data point to early identification as a possible fruitful strategy to alleviate some of the social costs of drinking problems.

Adult↗

PubMed1991

Overexpression of sigma receptors in nonneural human tumors.

Previous data indicated that opioid receptors occur in both neural and nonneural human tumors. However, it has recently been shown that some of the putative opioid binding may be attributable to sigma sites. In this study the occurrence of sigma and opioid receptors in nonneural human tumors was assessed. The neoplasms included renal and colon carcinomas and a sarcoma. [3H]1,3-di-o-tolylguanidine was used to assay sigma receptors by homologous competition binding assays, which when analyzed provided dissociation constant and receptor density values. Opioid binding was measured with [3H]-(-)-ethylketocyclazocine, a ligand which interacts with mu, delta, and kappa subtypes. Fresh surgical specimens were obtained from 9 human neoplasms, selected for their large size, and compared with nonmalignant tissues. All 9 tumors contained sigma sites, and dissociation constant values were within the range of 27-83 nM. Occasionally, two-site fit the data better than one-site binding, suggesting the presence of multiple sigma sites. Opioid binding was not detected. Intratumoral variability was evaluated by sampling several locations on the periphery of the mass and one in the center. Each of the samples was bisected, with a portion reserved for histological examination to correlate morphological features with receptor data. Changes in sigma binding were not associated with the extent of fibrosis, viability, or necrosis. Receptor density values displayed moderate intra- and intertumoral variation (coefficients of variation, 8-39 and 27-49%, respectively). More important, sigma binding in tumors was found to be greater than or equal to 2-fold higher than that of control nonmalignant tissue.

Binding, Competitive↗

PubMed1991

In vitro reappraisal of the pulmonary artery catheter balloon volume-pressure relationship: comparison of four different catheters.

The most serious risk of the use of the flow-directed pulmonary artery (PA) catheter is PA rupture due to high balloon inflation pressure of the catheter. Previously reported measurements of PA catheter intra-balloon pressure and volume during balloon inflation were performed mostly in a static fashion, that is, measurements were performed after a certain volume of air had been injected into the balloon. In this study, simultaneous measurements of pressure and volume, in addition to a static study, were performed in vitro using four PA catheters (Abbott Opticath, Arrow Hands-Off, Baxter Edwards and Spectramed). The peak intra-balloon pressure was recorded immediately before loss of resistance was felt in the inflating syringe. Contrary to previously reported studies, the peak intra-balloon pressure was not the pressure exerted on the pulmonary artery wall unless the tip of the catheter was already in the peripheral pulmonary artery. The loss of resistance volume which was constant for each catheter could be used reliably as an indicator of instantaneous balloon inflation. The slower the rate of injection, the lower were the peak pressure and the injection volume at the peak pressure. The Abbott, Edwards and Spectramed catheters had similar characteristics of inflation volume and intra-balloon pressure. The Arrow catheter had higher balloon opening and plateau pressures, and a smaller balloon volume compared with the other three catheters.

Analysis of Variance↗

PubMed1990

Relation of silent myocardial ischemia after coronary artery bypass grafting to angiographic completeness of revascularization and long-term prognosis.

The prevalence and characteristics of silent myocardial ischemia as detected by 24-hour ambulatory electrocardiography ST-segment depression were prospectively assessed in 94 patients examined early (1 to 3 months) and 184 patients examined late (12 months) after coronary artery bypass grafting (CABG), and followed for a mean of 48 +/- 11 (range 4 to 62) months. The relation of ambulatory electrocardiographic silent ischemia to evidence of completeness of revascularization as defined by cardiac angiography performed 1 and 12 months after CABG, and to prognosis by follow-up of adverse clinical events was analyzed. Silent ischemia was detected early in 20% (19 of 94) and late in 27% (50 of 184) of patients, and showed a mean frequency of episodes ranging from 6 to 10 episodes/24 hours with a mean duration ranging from 15 to 23 minutes. The circadian distribution of episodes disclosed a significant peak of ischemic activity during the period of 6 A.M. to noon and a secondary peak between 6 P.M. and midnight (p less than 0.01 and p less than 0.001, respectively). Silent ischemia was not found by univariate analysis to be associated with graft or anastomotic site occlusions, low graft flow rates, grafted arteries with significant distal residual stenoses or ungrafted stenotic native coronary arteries. Kaplan-Meier analysis of time to cardiac event showed that silent ischemia was not predictive of an adverse clinical event in the early years after CABG. Cox regression analysis of 30 covariates only disclosed age (relative risk 1.06 [95% confidence interval, 1.01 to 2.94]) as having an effect on time to adverse clinical event.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography↗

PubMed1990

Measurement of blood cyanide with a microdiffusion method and an ion-specific electrode.

The use of a cyanide ion-specific electrode in combination with the Conway microdiffusion method was modified for the measurement of cyanide concentration in human red blood cells and plasma. With our modified method, the optimal pH of cyanide isolation from red blood cells and plasma was investigated. Cyanide recovery from red blood cells increased with decreasing pH. The maximal recovery of 96.9 +/- 2.6% was obtained at a pH of less than 1. Cyanide recovery from plasma, however, peaked at a pH between 7 and 8, and further changes in pH reduced the recovery rate. The maximal recovery rate from plasma was 74.1 +/- 1.5%. In previous studies, cyanide isolations from both plasma and red blood cells were carried out at a pH of less than 1. This study shows that cyanide isolation from plasma should be performed at a pH between 7 and 8.

Blood Chemical Analysis↗

PubMed1990

The effects of monitoring and feedback on compliance.

A two-group randomized experimental design was employed to assess the effects of monitoring and feedback on the compliance of 93 psychiatric outpatients treated with lithium. Compliance in both groups was measured using self-report, lithium level, appointment-keeping, and medication refill frequency. The experimental group was also monitored using a unique electronic device that records the time and day pills are removed. At the midpoint of the study, the experimental group received feedback about serum lithium levels and patterns of removing medications from the monitoring device while the control group received feedback about serum lithium levels only. The study demonstrated no sustained effect of the monitoring and feedback interventions on compliance.

Adult↗

PubMedDate not supplied

Intraoperative autologous blood salvage with cardiac surgery: an analysis of five years' experience in more than 3,000 patients.

STUDY OBJECTIVE: To analyze intraoperative autologous salvage of shed mediastinal blood and subsequent transfusion in cardiac surgery. DESIGN: Retrospective statistical analysis. SETTING: University hospital. PATIENTS: Three thousand twenty two patients undergoing cardiac surgery from 1984 to 1988. INTERVENTIONS: A review of anesthesia and transfusion records of all patients who underwent intraoperative salvage of shed blood and autologous transfusion using the Sorenson Receptal Auto Transfusion System (ATS) with saline wash prior to reinfusion in cardiac surgery. MEASUREMENTS AND MAIN RESULTS: The salvaged blood volume ranged from 36 to 2,795 ml, with a mean of 321 +/- 222 ml (SD). Eighteen percent of patients did not receive any homologous blood products during their hospitalization. Patients who received only salvaged autologous transfusion were younger, had higher preoperative hemoglobin and hematocrit values, had a larger body surface area, and had shorter surgeries compared with patients who received only homologous blood or both autologous and homologous blood. More blood products were given to patients who received salvaged autologous blood compared with those who did not. Patients who underwent normovolemic hemodilution prior to extracorporeal circulation with subsequent reinfusion received significantly fewer blood products. Ten preoperative and four intraoperative variables significantly influenced the salvaged volume. Previous cardiac surgery was the most significant preoperative variable, and repair of ventricular septal defect produced by myocardial ischemia was the most significant intraoperative variable. CONCLUSION: Considering the average salvaged volume and its current autologous transfusion-related expense, autologous blood salvage is potentially an economic benefit. Perioperative blood conservation requires a considerable commitment from surgeons, anesthesiologists, perfusionists, and intensive care physicians to be effective.

Blood Substitutes↗