Search PubMed⌕ Search

Biomedical subjects

S Peterson

Publications and source records attributed to S Peterson.

At least 19 recordsLinked to original sources
PubMed1991

Aspergillus flavus and aflatoxins B1, B2, and M1 in corn associated with equine death.

Corn from an Arkansas farm, where three horses died and others became sick, was investigated for causative principles. Necropsy of the three horses revealed what appeared to be severe hepatic necrosis. Histopathological examination indicated a pattern of hepatic lesions that was suggestive of aflatoxin contamination of the feed. Mycological examination of the corn by dilution plating revealed 95% of the colonies as Aspergillus flavus. Chemical analysis of the corn for mycotoxins was positive for aflatoxin B1, B2, and M1 at concentrations of 114, 10, and 6 micrograms/Kg, respectively. Cyclopiazonic acid, sterigmatocystin, and the Fusarium toxins, vomitoxin (deoxynivalenol), T-2 toxin, and diacetoxyscirpenol, were not detected. The presence of aflatoxin metabolites in the moldy corn and the presence of appropriate lesions were compatible with the diagnosis, equine aflatoxicosis.

Aflatoxins↗
PubMed1991

Selective decontamination of the digestive tract in cardiac surgical patients.

OBJECTIVE: To test the hypothesis that selective decontamination of the digestive tract improves outcome in cardiac surgical patients. DESIGN: Prospective, consecutive, controlled trial over two 4-month periods. SETTING: Eight-bed, open-plan postcardiac surgery ICU. PATIENTS: All patients undergoing cardiac bypass surgery were eligible. Patients requiring endotracheal intubation for greater than 4 days were included in the analysis. In the initial 4 months, 12 (8.5%) of 141 patients required greater than 4 days of intubation. These 12 patients were not treated with selective decontamination of the digestive tract. We therefore used these patients as the control group. In the second 4-month period, 12 (6.6%) of 180 patients were treated with selective decontamination of the digestive tract and formed the study group. MAIN OUTCOME MEASURES: The primary measure was mortality. Secondary measures included oropharyngeal decontamination and the presence of lower airway infection. INTERVENTIONS: Cephradine prophylaxis. The study group received every 6 hrs 4 mL orally and 20 mL intragastrically a suspension of antimicrobial agents (tobramycin 80 mg, polymyxin E 100 mg, amphotericin B 500 mg), starting on postoperative day 1. The control group did not receive any oral antimicrobial agents. RESULTS: Mortality rate was significantly (p less than .05) reduced from eight (66%) of 12 patients in the control group to two (16.7%) of 12 patients in the selective decontamination of the digestive tract group. No differences in oropharyngeal decontamination or lower airway infection rates between the two groups were found. CONCLUSIONS: There is a reduced mortality rate in patients receiving selective decontamination of the digestive tract. However, the reader should recognize the small sample size studied. A simple suspension of the antimicrobial agents failed to rid the oropharynx of bacteria.

Administration, Oral↗
PubMed1989

A combined primary care residency in internal medicine and pediatrics.

The authors describe the development and evaluation of a primary care residency program encompassing both internal medicine and pediatrics. The combined residency is a four-year program of alternating six-month rotations in the two disciplines. One-fourth of the program is ambulatory medicine and includes training in a clinic for children and adults. Patient demographics are maintained for each resident, and an ambulatory-medicine-focused curriculum consisting of weekly conferences and self-directed independent study is used. The program is routinely evaluated and is highly rated by patients and residents. Factors critical to its success include emphasizing goals and experiences in outpatient versus inpatient care, developing an ambulatory practice to help support resident salaries, adequately preparing residents to take the board examinations in both disciplines, and providing a comprehensive primary care curriculum.

Ambulatory Care↗
PubMed1988

Homologous blood use and conservation techniques for cardiac surgery in the United Kingdom.

The transfusion laboratories of 32 cardiothoracic surgical centres for adults were surveyed to determine the donor blood requirement for open heart surgery in the United Kingdom. Details of the transfusion practice and the use of blood conservation techniques were sought from a representative senior cardiac anaesthetist at each centre. Suitable data were received from 24 transfusion laboratories (75%) and 29 anaesthetists (90%). The mean (SD) blood use was 5.07 (1.53) units per operation. Seven centres routinely transfused fresh frozen plasma to all patients postoperatively. Experience with autologous deposit (three centres), "cell separators" (four centres), and the reinfusion of shed mediastinal blood (four centres) was limited. Prebypass phlebotomy for postbypass reinfusion (14 centres) and the infusion of residual oxygenator blood (27 centres) were the conservation techniques most commonly applied. In only nine centres was a postoperative normovolaemic anaemia to a haemoglobin concentration of less than 100 g/l accepted. Applying blood conservation techniques more widely would help to maintain blood supplies and reduce morbidity and mortality related to transfusion.

Anemia↗
PubMed1988

Resolution of quantitative traits into Mendelian factors by using a complete linkage map of restriction fragment length polymorphisms.

The conflict between the Mendelian theory of particulate inheritance and the observation of continuous variation for most traits in nature was resolved in the early 1900s by the concept that quantitative traits can result from segregation of multiple genes, modified by environmental effects. Although pioneering experiments showed that linkage could occasionally be detected to such quantitative trait loci (QTLs), accurate and systematic mapping of QTLs has not been possible because the inheritance of an entire genome could not be studied with genetic markers. The use of restriction fragment length polymorphisms (RFLPs) has made such investigations possible, at least in principle. Here, we report the first use of a complete RFLP linkage map to resolve quantitative traits into discrete Mendelian factors, in an interspecific back-cross of tomato. Applying new analytical methods, we mapped at least six QTLs controlling fruit mass, four QTLs for the concentration of soluble solids and five QTLs for fruit pH. This approach is broadly applicable to the genetic dissection of quantitative inheritance of physiological, morphological and behavioural traits in any higher plant or animal.

Chromosome Mapping↗
PubMed1988

Pathophysiology of increased urinary N-acetyl-beta-D-glucosaminidase activity in human hypertension: effect of cilazapril therapy.

To investigate the pathophysiology of elevated urinary N-acetyl-beta-D-glucosaminidase (NAG) activity in human hypertension, total and fractional urinary NAG activities were correlated with Li clearance, a measure of proximal renal tubular Na reabsorption, in 15 white hypertensive subjects, aged 56 years, and in 13 normotensive control subjects. In 11 hypertensive subjects, the measurements were repeated after 2 months of antihypertensive therapy with the converting enzyme inhibitor cilazapril (2.5 or 5.0 mg daily). Urinary NAG activity was increased in hypertensives and correlated directly with Li clearance in both hypertensive and normotensive subjects. Li clearance and urinary NAG activity were reduced by antihypertensive therapy. The findings indicate an inverse correlation between urinary NAG activity and proximal renal tubular Na reabsorption, suggesting that NAG is reabsorbed in the proximal renal tubules with Na and other proteins. High Li clearance and urinary NAG activity in hypertension are in part functional and, therefore, reversible disturbances of renal function.

Acetylglucosaminidase↗
PubMed1988

Risk, cost, and benefit of transporting ICU patients for special studies.

Prospective evaluation of 103 consecutive transports for diagnostic studies of 56 patients out of the Shock Trauma Unit over a 3-month period was done to document physiologic changes, the cost of each transport, and to assess whether the information gained was utilized to change patient management. Of the 56 patients, 36 (65%) were males and 20 (35%) were females with an age range of 14-82 years (mean, 48 years). The Apache II score ranged from 3-49 (mean, 19.4). There were seven types of diagnostic studies: CT of the head (28), CT of abdomen (35), CT of chest (four), angiography (nine), ventilation/perfusion scan (three), tomography (seven) and miscellaneous studies (15). The average trip time was 81 minutes, a range of 15-210, requiring an average of 3.3 personnel per trip. Ninety-four transported patients had ventilatory support, 26 had PA lines, and 26 transports required three or more IV infusion pumps. Sixty-eight per cent of all transports experienced serious physiologic changes of 5 minutes' duration defined as BP systolic or diastolic +/- 20 mm Hg (40%), pulse +/- 20 beats/minute (21%), ventilatory rate +/- 5/minute (20%), O2 saturation decrease by 5% or more (17%). There was a total of 113 serious changes requiring an increase in support of the patient during the transport. There were no significant differences when comparing diagnosis of patient or types of studies to the number of changes in the physiologic parameters, nor were there significant differences within a physiologic parameter when comparing patient types or diagnostic studies.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Serotonin, norepinephrine, and histamine mediation of endothelial cell barrier function in vitro.

The effects of serotonin (5-hydroxytryptamine, 5-HT), norepinephrine (NE), and histamine on endothelial cell barrier function were examined in vitro. Bovine aortic endothelial (BAE) cells grown to confluence on microcarriers formed a measurable barrier to the passage of a trypan blue dye-bovine serum albumin conjugate (TB-BSA) from the culture medium into the microcarrier matrix. Vascular smooth muscle (VSM) cells or Swiss 3T3 fibroblasts impeded TB-BSA diffusion only 42% and 56%, respectively, relative to BAE cells. These results suggest that barrier formation may be an endothelial cell-specific phenomenon. Treatment of BAE cells with histamine was associated with 2- to 3-fold increases in the rate of TB-BSA diffusion. In contrast, treatment with 5-HT or NE at concentrations ranging from normal to pathophysiological circulating plasma levels significantly impeded TB-BSA diffusion by up to 43% and 33%, respectively, relative to untreated controls. The barrier-modulating effects of the vasoactive amines were dose-dependent, cell-specific, and in some cases appear to be receptor-mediated. These results are consistent with previous reports that histamine increases vascular permeability in part by affecting diffusion between endothelial cells; they support the hypothesis that 5-HT and NE contribute to the maintenance of the endothelial barrier in vivo.

Animals↗
PubMed1985

Serotonin, histamine, and norepinephrine mediation of endothelial and vascular smooth muscle cell movement.

The effects of serotonin (5-HT), histamine (H), and norepinephrine (NE) on bovine aortic endothelial cell (BAE) and vascular smooth muscle cell (VSM) movement were quantitated using a phagokinetic tracking assay. BAE movement was significantly reduced by 5-HT (31%), H (48%), and NE (62%) at concentrations ranging from 10(-10) to 10(-4) M (P less than 0.01). VSM motility was significantly enhanced by 5-HT (17%) and H (25%) at concentrations of 10(-8) and 10(-4)M, respectively (P less than 0.01). NE (10(-4)M) reduced VSM motility by 63% (P less than 0.01). Ketanserin (1 microM) reduced the 5-HT-associated inhibition of BAE movement by 75% (P less than 0.01). Diphenhydramine (1 microM) reduced the H-associated inhibition of BAE movement by 66% (P less than 0.01). Propranolol (1 microM) reduced NE-associated inhibition of BAE movement by 50% (P less than 0.01) and 5-HT-associated inhibition by 45% (P less than 0.05), but phenoxybenzamine had no significant effect. The results suggest 1) BAE and VSM are affected qualitatively in opposite ways by 5-HT and H; 2) the H-associated inhibition of BAE movement appears to be at least partially mediated by H1 receptors; 3) the 5-HT-associated inhibition of BAE movement may be mediated directly by a 5-HT binding component but indirectly by beta-adrenergic receptors; and 4) the NE-associated inhibition of BAE movement appears to be mediated by beta-adrenergic receptors.

Animals↗
PubMed1985

Caries resistance in children with chronic renal failure: plaque pH, salivary pH, and salivary composition.

We studied properties of saliva and of dental plaque which affect the caries process in an effort to understand the low prevalence of caries in patients with chronic renal failure. Plaque pH, before and following carbohydrate exposure, saliva pH, and saliva composition were evaluated in children and adolescents with chronic renal failure (n = 10) and successful renal transplantation (n = 11), and in two comparison groups of healthy children with few caries (n = 15) and numerous caries (n = 15). Salivary urea nitrogen concentration was elevated in all subjects with elevated serum urea nitrogen concentration. Chronic renal failure subjects had significantly higher salivary urea nitrogen concentration than transplanted subjects. Plaque pH correlated directly with salivary urea nitrogen concentration and was significantly more alkaline in chronic renal failure than transplant or comparison groups. Salivary urea nitrogen concentration accounted for the majority of variability in plaque pH; salivary pH and salivary phosphorous contributed negligibly. Absolute pH drop following carbohydrate exposure did not differ among groups, but because baseline plaque pH was elevated for chronic renal failure subjects, minimum pH did not attain cariogenic levels. Our data support the hypothesis that the relative paucity of caries in patients with chronic renal failure results from alteration of plaque by metabolic end products of urea metabolism. Our data further suggest that transplanted patients whose renal function is normal may be at increased risk of caries, especially if enamel hypoplasia is present and oral hygiene is poor.

Adolescent↗
PubMed1979

A study of faculty attitudes toward Ohio State's three-year medical program.

Three-year curricula, once a proliferating innovation in medical education, are now rapidly waning with the fading of capitation support and the easing of physician manpower shortages. In this article the authors examine faculty opinion of a three-year medical program at the Ohio State University. Using a Likert attitude-scaling technique, the authors developed a questionnaire and administered it to full-time faculty members. Five issues upon which faculty opinion was found to be most diverse include: adequacy of content in a three-year program, time available for faculty to do research, work demands on faculty, basic medical knowledge of three-year students, and quality of post-M.D. positions obtained by three-year graduates. Overall, three general deficiencies in the three-year curriculum, as perceived by faculty, emerged: students have limited instruction in basic medical knowledge and skills; unnecessary emotional, physical, and economic demands are imposed; and neither student learning nor quality of teaching is enhanced.

Attitude↗