Search PubMed⌕ Search

Biomedical subjects

R F Wilson

Publications and source records attributed to R F Wilson.

At least 199 records · Page 11Linked to original sources
PubMed1988

The effect of coronary angioplasty on coronary flow reserve.

To determine the effects of coronary angioplasty on coronary flow reserve (CFR), we studied 32 patients before and immediately after single-vessel coronary angioplasty and 31 patients evaluated late after angioplasty (7.5 +/- 1.2 months, mean +/- SEM). The geometry (percent area stenosis and minimal cross-sectional area) of each lesion was determined by quantitative coronary angiography (Brown/Dodge method) and the integrated optical density was measured by videodensitometry. CFR was measured with a No. 3F coronary Doppler catheter placed immediately proximal to the lesion and a maximally vasodilating dose of intracoronary papaverine. The translesional pressure gradient was obtained in all lesions before and immediately after angioplasty and in 18 of 31 vessels late after angioplasty. CFR immediately after angioplasty returned to normal levels (greater than 3.5 peak/resting velocity ratio) in 14 of 31 patients and was improved, although not normalized, in the remaining 17 patients. CFR immediately after dilation was not significantly correlated with any of the angiographic variables of arterial stenosis nor the resting pressure gradient. Moreover, the pressure gradient and absolute distal coronary pressure at peak hyperemia were not significantly different in vessels with normal and those with abnormal flow reserve immediately after dilation, suggesting that the residual stenosis did not significantly limit hyperemia. Late after angioplasty, however, a significant relationship emerged between CFR and all four indexes of residual arterial stenosis (percent area stenosis r = .70, p less than .01; minimum arterial cross-sectional area r = .70, p less than .01; integrated optical density r = .60, p less than .01; and translesional pressure gradient r = .77, p less than .01). Furthermore, in the absence of restenosis, CFR eventually normalized in all patients. These findings demonstrate that in one-half of patients there is a transient reduction in coronary flow reserve immediately after angioplasty. In the absence of restenosis, coronary flow reserve later normalizes. Consequently, measurements of coronary flow reserve immediately after angioplasty may not reflect the eventual success of the procedure in removing physiologic obstruction to coronary blood flow.

Angiography↗
PubMed1988

Coronary vasodilator reserve after human orthotopic cardiac transplantation.

Cardiac transplantation is frequently associated with accelerated coronary atherosclerosis and immune-mediated microvascular injury. To determine if orthotopic cardiac transplantation impairs the capacity of the coronary vasculature to vasodilate and conduct hyperemic blood flow, maximal coronary vasodilator reserve was measured in 25 cardiac allograft recipients with no evidence of rejection 6-57 months after transplantation and in 20 normal subjects. Left ventricular wall thickness was assessed echocardiographically, and epicardial coronary anatomy was evaluated by quantitative coronary angiography. Coronary vasodilator reserve (CVDR) was measured in all patients with a coronary Doppler catheter and a maximally vasodilating dose of intracoronary papaverine. CVDR measured in the transplant recipients with normal coronary arteries, left ventricular function, and wall thickness (5.0 +/- 0.3 [mean +/- SEM] peak/resting velocity; range, 3.8-7.3; n = 16) was not different from that of normal subjects (4.8 +/- 0.2; range, 3.7-8.3). CVDR in the five cardiac allograft recipients with diffuse coronary atherosclerosis producing 30 +/- 5% narrowing (range, 25-38%) of epicardial vessel diameter also was normal (5.1 +/- 0.3; range, 4.3-6.2; n = 5). The CVDR was reduced, however, in two of the four cardiac allograft recipients with left ventricular hypertrophy. In the only transplant recipient in whom a regional wall motion abnormality was present, CVDR was abnormal in the vascular distribution of the hypokinetic wall segment (1.8) but was normal in the artery that supplied normally functioning myocardium (4.0). These findings demonstrate that in the absence of allograft rejection, acquired left ventricular hypertrophy, and regional wall motion abnormalities, coronary vasodilator reserve is normal after orthotopic human cardiac transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1988

The effects of experimental variations in dietary sugar intake and oral hygiene on the biochemical composition and pH of free smooth-surface and approximal plaque.

The biochemical compositions of free smooth-surface and approximal plaque were compared after 48 hours in the presence and absence of twice-daily toothbrushing and during ingestion of either high- or low-sugar diets in ten young adults. In addition, the effect of a single sugar intake on the pH of both types of plaque was investigated. The results confirmed previously reported differences in biochemical composition between free smooth-surface and approximal plaque, the concentrations of inorganic ions and carbohydrate fractions being generally lower in the approximal sample after all experimental regimens. The concentrations of calcium and phosphorus were doubled on the low-sugar diet compared with the high-sugar diet in both types of plaque. A significant decrease in carbohydrate concentrations was observed in free smooth-surface plaque in subjects on the low-sugar diet, but not in approximal plaque. Little variation was observed in the biochemical composition which could be attributed to the presence or absence of toothbrushing. The pH in free smooth-surface plaque was lower than that in approximal plaque five minutes after a sugar intake, but the situation was reversed two hours later. The results indicate that differences in composition and pH between free smooth-surface and approximal plaque are associated with reduced access to salivary and dietary influences due to diffusion limitation in the deeper layers of plaque.

Carbohydrates↗
PubMed1988

Central lung injuries: a need for early vascular control.

During a 7-year period (1980-1987), 161 patients underwent emergency thoracotomy for penetrating lung injuries. Of these, 25 (15%) had injuries involving central pulmonary (hilar) vascular structures. Anterolateral thoracotomies were performed in 14 patients because of unstable vital signs (ten) or cardiac arrest (four), and only two (14%) of these patients survived. In seven of these patients the incision was extended into a bilateral thoracotomy to provide better exposure for continued severe bleeding, and all seven died. Of 11 relatively stable patients having a posterolateral incision (ten) or a median sternotomy (one), only two (18%) died. Of 18 patients in whom the initial procedure was hilar clamping, ten (63%) survived. In seven patients an attempt was made to control the bleeding before hilar clamping and only one (14%) survived. In six patients, resection of a lobe (five) or a segment (one) was used to achieve hemostasis with five (83%) survivors. Eight of the 14 deaths were clearly due to blood loss, which was treated with an average of 19.5 units of blood. However, in six of the earlier deaths with much less blood loss, air emboli may have been a factor, but was unproven. Early vascular control at the hilum for central lung injuries seems to be needed not only to stop the bleeding but also to prevent systemic air emboli.

Adult↗
PubMed1988

Treatment of penetrating abdominal trauma and gynecologic infections.

Both penetrating abdominal trauma and gynecologic infections are polymicrobial and require antibiotics with broad-spectrum activity against both aerobic and anaerobic pathogens. In an open study, ticarcillin disodium/clavulanate potassium was used to treat patients with penetrating abdominal trauma, intraabdominal infection or gynecologic infection. Ticarcillin disodium/clavulanate potassium was administered at a dose of 3.1 g every four or every six hours, and therapy lasted for a minimum of three days. Among 20 patients with intraabdominal infections that involved abdominal organ perforation, ticarcillin disodium/clavulanate potassium was effective in 16. Eighteen of 19 aerobic isolates were susceptible to ticarcillin disodium/clavulanate potassium, as were all of 21 anaerobic isolates. Fifteen of 21 evaluable patients with gynecologic infections were cured. Among the infections were pelvic inflammatory disease, salpingitis, salpingitis with tuboovarian abscess, pelvic inflammatory disease with tuboovarian abscess, salpingitis/pelvic inflammatory disease and peritonitis, endomyometritis, cervicitis and pelvic inflammatory disease with peritonitis. A total of 32 aerobic and 15 anaerobic organisms were isolated, and 14 of the patients had more than one organism isolated.

Abdominal Injuries↗
PubMed1988

Inferior vena cava injuries--the challenge continues.

The records of 67 patients with inferior vena cava (IVC) injuries seen from 1980-1986 were reviewed. The mortality rate (MR) overall was 57 per cent, and for specific portions of the IVC it was: retrohepatic - 60 per cent (9/15); suprarenal 59 per cent (16/27); pararenal - 45 per cent (5/11); and infrarenal - 57 per cent (8/14). Several prognostic factors were identified. Of 44 patients who presented to the emergency department (ED) with a BP less than 70 mm Hg, 33 (75%) died. Of 28 patients who experienced greater than 30 minutes of shock, 15 (83%) died. Of 26 patients presenting to the OR with a systolic blood pressure less than 70 mm Hg, 22 (85%) died. Of 40 patients who received greater than 10 units of blood in the ED and OR, 31 (78%) died. Of 19 patients who had a prelaparotomy thoracotomy with cross-clamping of the thoracic aorta for persistent severe shock (BP less than 70), nine responded rapidly with a sustained increase in systolic BP to greater than 90 mm Hg with four (44%) survivors. All ten patients who did not respond to prelaparotomy aortic cross-clamping died in the OR. Of seven patients with persistent shock (BP less than 70) without a prelaparotomy thoracotomy, there were no survivors. Six patients with retrohepatic IVC injuries underwent atrio-caval shunting with no survivors; of nine others with similar injuries treated without a shunt, six (67%) survived. Of 18 patients who received more than ten units of blood and survived the surgery, ten (56%) developed septic complications, and four of these patients died. Of 17 patients who received less than ten units of blood and survived the surgery, none became septic. Thus, early control of shock and bleeding is essential, not only to reduce mortality rate, but also later septic complications.

Adolescent↗
PubMed1987

Primary adenocarcinoma of the esophagus.

Of 163 patients with carcinomas of the esophagus seen between 1975 and 1982, 11 (6.7%) had a primary adenocarcinoma. Although the high ratio of men to women (10:1) was similar to that seen in patients with squamous cell carcinoma of the esophagus, the mean age of those with adenocarcinoma was younger (57 years). In contrast to squamous cell carcinomas, which predominantly involve blacks, esophageal adenocarcinomas in these patients involved only Caucasians. The great majority of lesions were found in the lower third of the esophagus. Only 3 (27%) of the patients with adenocarcinomas gave a history of a large daily alcohol consumption and only 2 (18%) had a Barrett's esophagus. Although various combinations of surgery, chemotherapy, and radiotherapy could control the primary tumor rather well, the final results were poor. All patients have now expired; median survival time was 16 months.

Adenocarcinoma↗
PubMed1987

Outcome of massive transfusion exceeding two blood volumes in trauma and emergency surgery.

Our experience with 56 patients who sustained massive transfusion exceeding two times their estimated blood volume is reviewed. Survival was 39% for the entire group, which included six cases of blunt multiple trauma and seven nontraumatic surgical emergencies, and 51% for the subgroup who sustained penetrating trauma. Six patients arrived without detectable vital signs, but half of them left the hospital alive. Three subgroups sustained 100% mortality: cirrhotics, nontraumatic surgical emergencies, and victims of blunt trauma. Thirty-eight per cent of the noncirrhotics developed a post-transfusion bleeding disorder, but the specific patients who would develop coagulopathy could not be predicted on the basis of any clinical parameter scrutinized, including lowest measured platelet count. Pulmonary morbidity was rare among penetrating trauma patients in spite of an average of 35 units of blood transfusion. Acute respiratory failure developed in a subgroup with penetrating trauma who received an average of 59 units of blood; blunt trauma patients developed acute respiratory failure at an average transfusion volume of 35 units. The 77% mortality among patients who developed coagulopathy, and our inability to predict in advance which patients will develop serious clinical bleeding, argue strongly in favor of an aggressive approach toward prophylaxis in these patients in spite of the theoretical risk of disease transmission from the additional units of platelets and frozen plasma required.

Blood Coagulation Disorders↗
PubMed1987

Insulin production following injury and sepsis.

It is known that alterations in insulin metabolism following injury and infection result in depression of insulin levels and the development of insulin resistance. In order to further study insulin during septic and traumatic stress, we estimated insulin production in control (Group 1, n = 6), postoperative (Group 2, n = 5), and postoperative-septic (Group 3, n = 8) human subjects by measuring the 24-hour urinary C-peptide excretion. In addition, basal and peak glucose and insulin levels in response to a standard (0.5 gm/kg) intravenous glucose stimulus were measured immediately thereafter to determine if insulin levels reflected insulin production. Basal insulin for Groups 1, 2, and 3 (16 +/- 8.4, 10 +/- 3.4, 9.5 +/- 4.4 microU/ml +/- SD, respectively) were not substantially different. Peak insulin response to glucose infusion declined from Groups 1 to 3 (51 +/- 14, 42.4 +/- 31, 20.4 +/- 6.8 microU/ml, respectively) with Group 3 exhibiting a significantly decreased mean peak level compared to the other groups. Corresponding C-peptide excretion rates increased from Groups 1 to 3 (28.3 +/- 15.3, 63.7 +/- 27.6, 121.3 +/- 95.2 micrograms/day, respectively) with Group 3 exhibiting a significantly (p less than 0.05) higher level than Group 1. These data suggest that low insulin levels which may be evident in injured or septic patients not in shock reflect increased clearance and not decreased production.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

Hemoptysis in trauma.

In an attempt to more clearly delineate the importance and pathophysiology of moderate-severe hemoptysis, a clinical and experimental study was performed. The clinical portion consisted of a retrospective review of 344 patients undergoing thoracotomy for penetrating trauma. There were 138 patients with injuries to the trachea, mainstem bronchi or lungs. Six with GSW to the chest had severe hemoptysis in the Emergency Department (ED) and had a cardiac arrest just after endotracheal intubation. At thoracotomy, all six had air in their coronary arteries and could not be resuscitated, Of 14 patients with posterolateral OR thoracotomies, three had significant (20-30 mm Hg) drops in systolic pressure plus increased aspiration of blood into the dependent lung when turned onto their sides. Of 12 patients surviving surgery, six with continued aspiration of blood required prolonged ventilatory support. In an experimental study, minimally heparinized (0.07 units/ml) blood was infused into the lower trachea of 17 anesthetized normovolemic supine dogs at 0.15 ml/kg/min. The PaO2 fell from 100 +/- 11 to 65 +/- 16 mm Hg after infusion of 4.5 ml/kg of blood. At the same time peak ventilator pressure rose only minimally (8.5 +/- 1.7 to 11.2 +/- 3.1 mm Hg). The PCO2, mean PA pressure, PAWP, CVP, and cardiac output were essentially unchanged. In a second study of 18 dogs, reducing the systolic BP by one third reduced cardiac output by almost 48% and oxygen transport by 58%. After 4.5 ml/kg blood were infused into the trachea, the PaO2 fell from 84 +/- 19 to 52 +/- 9 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Plant Morphological and Biochemical Responses to Field Water Deficits : II. Responses of Leaf Glycerolipid Composition in Cotton.

The effects of water deficits on leaf glycerolipid composition were analyzed in two photoperiodic strains of field grown cotton (Gossypium kirsutum L.) that differ in sensitivity to drought. Leaves from plants grown under dryland conditions exhibited increased dry weight and specific leaf weight. The average midday leaf water potential in the dryland treatment decreased to -1.9 and -2.4 megapascals, respectively, for the T25 and T185 genotypes. Total leaf lipid content of plants exposed to dryland conditions was 5.9 and 7.5% of leaf dry weight for strain T25 and T185, respectively. The difference in leaf lipid content between these genotypes was caused by water deficits and was attributed to loss of both phospholipids and glycolipids in strain T25. There was no apparent loss of phospholipids due to water deficits in the T185 genotype; however, a significant loss of glycolipids was partially compensated by a 2-fold increase in triacylglycerol. No change in triacylglycerol was found between treatments in T25 leaves. Water deficit caused a significant decline in the relative degree of acylunsaturation in phospholipids and glycolipids from both genotypes; however, the double bond index for triacylglycerol increased in both genotypes. It is believed that the observed responses of leaf lipid composition to dryland conditions may be an additional criterion for characterization and selection of new drought-tolerant cotton genotypes.

Journal Article↗
PubMed1987

Studies on genetic male-sterile soybeans : v. Effects of male-sterility on the function and glycerolipid composition of chloroplast thylakoids.

Soybean (Glycine max L. Merr.) germplasm, isogenic except for loci controlling male sterility (ms(1)), was utilized to study the effects of reproductive development on certain aspects of photosynthesis. Plants were sampled at various times between flowering (77 days after transplanting) and maturity (147 days after transplanting). During that period photosynthetic rates declined more rapidly in the male-sterile genotypes than male-fertile genotypes; and after 105 days, the sterile genotypes maintained low but relatively constant carbon exchange rates. The decline of leaf photosynthesis in the male-sterile genotype occurred concomitantly with an inhibition of the photosynthetic electron transport chain associated with photosystem II. Changes in photosystem I activities, cytochrome f levels, and chlorophyll a/b ratios per se were not responsible for the decline in whole leaf photosynthesis. These conditions were independent of the source of nitrogen nutrition. Lipid analyses of the thylakoids revealed that a loss of phosphatidylglycerol was highly correlated with the inhibition of photosystem II activity. These results suggested a relation between the decline in leaf carbon exchange and the decline in photosynthetic electron transport activity.

Journal Article↗
PubMed1987

Prediction of the physiologic significance of coronary arterial lesions by quantitative lesion geometry in patients with limited coronary artery disease.

Studies in animals with normal coronary arteries have shown that coronary flow reserve can be predicted by angiographic measurements of arterial stenosis. Studies in man, however, suggest that even quantitative analysis of coronary angiograms cannot predict the physiologic significance of individual coronary lesions. These studies, however, were carried out in patients with either widespread, diffuse coronary artery disease or by measurement techniques that tend to underestimate maximal coronary flow reserve. To determine the relationship between coronary arterial stenosis and coronary flow reserve (CFR) in patients with discrete limited coronary atherosclerosis, we studied 50 patients with a single discrete coronary stenosis in only one or two vessels. The minimum coronary arterial cross-sectional area (mCSA), percent area stenosis (%AS), and percent diameter stenosis in the left and right anterior oblique projections were determined by the Brown/Dodge method of quantitative coronary angiography. A No. 3F coronary Doppler catheter was placed immediately proximal to the lesion. Measurements of CFR were obtained by intracoronary administration of papaverine in doses sufficient to provide maximal arteriolar vasodilation. In 25 patients, a translesional pressure gradient was obtained with an angioplasty catheter. CFR measured in patients with coronary artery disease was compared with that in 13 patients with normal coronary vessels. In normal patients, CFR averaged 5.0 +/- 0.6 (peak/resting velocity ratio; mean +/- SEM, range 3.7 to 8.2). In patients with limited coronary artery disease, CFR was closely correlated with %AS (r = .85), mCSA (r = .79), and the translesional pressure gradient (r = .83). Additionally, the most severe percent diameter stenosis in either the left or right anterior oblique view was also highly correlated with CFR (r = .82). Importantly, all arteries with lesions producing less than 70% area stenosis and less than 50% diameter stenosis, or with greater than 2.5 mm2 mCSA had CFR of over 3.5. These results suggest that, in contrast to the poor correlation of percent area and percent diameter stenosis to CFR measured in patients with multivessel coronary artery disease, CFR measured at angiography in patients with discrete, limited coronary artery disease correlates closely with luminal stenosis determined precisely with quantitative coronary angiography. Differences in the extent of diffuse arterial narrowing may account for these discrepancies.

Blood Pressure↗
PubMed1987

Methods of measurement of myocardial blood flow in patients: a critical review.

During the past decade, major progress has been made in the evolution of technology directed toward the accurate measurement of regional myocardial perfusion in patients. The deficiencies of some of the older methods (thermodilution and gas clearance) are better appreciated and improved approaches (Doppler catheters, positron-emission tomography, and digital subtraction angiography) have been developed. The new approaches should play a major role in research and for most applications the older methods will gradually be replaced. Efforts to bring these new methods to community hospitals and practicing cardiologists should be stimulated. Doppler catheters, positron-emission tomography, and digital-subtraction angiography are commercially available and Doppler catheters and digital-subtraction angiography could be easily incorporated into routine cardiac catheterization procedures. The Doppler catheter is the most inexpensive and probably the simplest to apply. In our opinion, routine measurements of coronary flow reserve will significantly improve the care of patients with coronary obstructive disease and other diseases that impair myocardial perfusion. If coronary reserve measurements are used frequently, patient selection for coronary angioplasty and bypass surgery will no longer depend entirely on visual assessment of percent diameter stenosis, a very poor criterion in many situations. Also, patients with chest pain syndromes, normal coronary vessels, and impaired coronary reserve will be identified and perhaps some effective treatment for this condition will be devised.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMed1987

Does coronary artery bypass surgery restore normal maximal coronary flow reserve? The effect of diffuse atherosclerosis and focal obstructive lesions.

Aortocoronary vein bypass surgery might not restore normal maximal coronary flow reserve to bypassed coronary vessels because residual diffuse coronary atherosclerosis might limit maximal hyperemia. To investigate the effect of diffuse atherosclerosis and a focal stenosis at the graft-coronary anastomosis, we measured coronary flow reserve with an extensively validated subselective Doppler catheter in 24 patients with 35 bypass grafts perfusing angiographically normal coronary vessels. The Doppler catheter was positioned in the midportion of the graft, and coronary flow reserve was measured as the peak/resting velocity ratio after selective graft injection of a maximally vasodilating dose of papaverine. Luminal dimensions of the bypass graft, graft-coronary insertion, and bypassed coronary vessel were measured by quantitative coronary angiography (Brown/Dodge method). Measurements of coronary flow reserve and coronary dimensions of vein bypass grafts were compared with similar measurements obtained from 13 patients with normal coronary vessels and normal myocardium. Seventeen of the 35 bypass grafts perfused unobstructed coronary-vein graft anastomoses (less than 50% area stenosis) and normal myocardium. The coronary flow reserve of these 17 bypass grafts was normal (5.0 +/- 0.4, mean +/- SEM) and not significantly different from that measured in normal arteries (5.1 +/- 0.6), even though the cross-sectional area of the native coronary artery just distal to the bypass insertion was 40% smaller than in matched normal vessels. Bypass grafts perfusing hypertrophied (n = 2) or infarcted (n = 6) myocardium had significantly reduced coronary flow reserve compared with normal vessels (2.7 +/- 0.3; p less than .01), even when the infarcted wall had only minimal hypokinesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography↗