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Biomedical subjects

L Reed

Publications and source records attributed to L Reed.

52 records · Page 3Linked to original sources
PubMed1989

Prophylactic antibiotics in trauma: the hazards of underdosing.

Prophylactic antibiotic regimens in trauma patients may be significantly altered by large fluid shifts and hyperdynamic physiologic responses. We prospectively studied prophylactic amikacin and clindamycin in 150 abdominal trauma patients requiring laparotomy, analyzing the effects of duration of coverage, dosing interval, and dose. No difference in infection rates was noted when 72-hour coverage was compared with 24-hour coverage (19% vs. 21%). Clindamycin dosed at 1,200 mg every 12 hours achieved acceptable serum concentrations; infection rates were not significantly higher than seen with 600 mg every 6 hours (21% vs. 12%, p greater than 0.05). High-dose (11 mg/kg) amikacin reduced infection rates in patients with high blood loss (p less than 0.025), high Injury Severity Scores (p less than 0.025), and no colon penetration (p less than 0.005). These data suggest that high doses are more effective than long courses of antibiotics in reducing infections in trauma patients undergoing laparotomy.

Abdominal Injuries↗
PubMed1986

Glucagon: endocrine effects and calcium involvement in cardiovascular actions in dogs.

Although the cardiovascular effects of glucagon are understood, its mechanism(s) of action remains unclear. We studied the effects of increasing doses of glucagon (0.001, 0.01, 0.1 mg/kg) on cardiovascular responses in dogs relative to concurrent measurements of circulating glucagon, cyclic AMP, glucose, norepinephrine, epinephrine, triiodothyronine, thyroxine, and cortisol levels. Glucagon-induced increases in plasma cyclic AMP, glucose, and catecholamine concentrations paralleled the heart rate response to glucagon administration. Further studies were conducted to evaluate the role of beta-adrenergic function as well as calcium in mediating glucagon's actions. The tachycardic effects of glucagon (0.01 mg/kg) were unaltered by prior beta-adrenergic receptor blockade with propranolol (3.5 mg/kg total dose). The calcium antagonist verapamil (0.2 mg/kg bolus then 7.5 micrograms/kg/min/infusion) prevented glucagon-induced increases in heart rate. However, the coadministration of glucagon (0.01 mg/kg) with calcium (1.0, 5.0, 10.0, or 50.0 mg/kg) did not alter glucagon's cardiovascular effects. These data indicate that glucagon is a potent tachycardiac agent that also elevates circulating endocrine-related substances. The antagonism of glucagon's tachycardiac effects by verapamil suggests that glucagon's action may be via glucagon-induced calcium movement through calcium channels, although extracellular calcium changes do not alter glucagon's effect. Furthermore, the persistence of glucagon's cardiovascular actions following beta-adrenergic blockade indicates the potential clinical utility of glucagon in reversing the adverse effects of beta-blocker overdoses, and its potential usefulness in treating circulatory shock in "beta-blocked" patients.

Animals↗
PubMed1985

Bacteriology and ultrastructure of the bladder in patients with urinary tract infections.

Tissue obtained by biopsy of the bladder from 33 patients with various urinary tract symptoms was studied by conventional bacteriological techniques and by scanning electron microscopy (SEM). All the patients had recurrent urinary tract symptoms which had not completely responded to antibiotic therapy. Eleven of the patients had greater than or equal to 10(8) colony-forming units (CFU) of bacteria/1 urine; six had between 10(6) and 10(7) CFU/1, and 16 were abacteruric. Bacteria were isolated, however, from the tissue obtained by biopsy from eight of the 16 patients with sterile urine and bacteria were seen on the uro-epithelium in 14 of these patients. By comparison, in all samples of tissue obtained from the 11 patients with greater than or equal to 10(8) CFU/1 of urine bacteria were seen on the uro-epithelium and from nine of these, bacteria were subsequently grown. Fastidious organisms were not isolated from any of the patients. The uro-epithelium of all those studied was also shown to be grossly disrupted with increased disturbance and loss of the epithelial cells when compared with tissue obtained from uninfected patients. The degree of uro-epithelial disturbance was greatest in patients with histories of urinary tract infections lasting more than 4 months. The findings suggest that bacteriological examination of the urine does not always reflect bacterial infection on the bladder surface nor disruption of the uro-epithelium. The changes on the bladder surface may explain the patients' symptoms. In view of the results, a scheme is proposed that explains the development of symptoms in patients with urinary tract and bladder infections.

Adult↗
PubMed1976

The grammatic closure subtest of the ITPA: a comparative study of black and white children.

This study investigated the performance of black children and white children on the grammatic closure subtest of the Illinois Test of Psycholinguistic Abilities. Ninety-six children, who were attending kindergarten, second, and fourth grades, were examined. They were equally divided for sex, race, and grade placement. Results indicated that kindergarten children, regardless of race and sex, performed similarly; however, black children of both sexes did significantly poorer than white children in higher grades. When allowances were made for some black English responses, however, all children in each age-group performed similarly. Implications for diagnostic applications are discussed.

Black or African American↗
PubMedDate not supplied

Successful therapy of a human lung cancer xenograft using MAb RS7 labeled with residualizing radioiodine.

We have recently reported that a radioiodinated, DTPA-appended peptide, designated IMP-R1, is a residualizing iodine label that overcomes many of the limitations that have impeded the development of residualizing iodine for clinical use. In this study the potential of 131I-IMP-R1-RS7, an internalizing anti-EGP-1 monoclonal antibody, was evaluated by performing preclinical therapy studies in nude mice bearing Calu-3 human non-small cell carcinoma of the lung xenografis. Elimination of 6 of 9 established tumors (mean tumor volume=0.3 cm(3)) was observed using a single dose of 350 microCi/mouse of 131I-IMP-R1-RS7, with all animals tolerating the dose. At the same dose and specific activity of 131I-RS7, labeled using the conventional chloramine-T method, there were four deaths, and one complete remission in nine treated mice. At the maximum tolerated dose of conventionally 131I-labeled RS7, 275 microCi, mean stable disease for approximately 5 weeks was observed, with no complete responses. Specificity of the therapeutic effect was shown in an isotype-matched control experiment, where 131I-IMP-R1-RS7 was markedly more effective than the (131)I-IMP-R1-labeled control antibody. These studies demonstrate that (131)I-IMP-R1-RS7 provides a therapeutic advantage in comparison to conventional 131I-labeled RS7, as predicted by the increased tumor accretion observed previously in targeting studies. A direct comparison of the maximum tolerated doses of (131)I-IMP-R1-RS7 (350 microCi) and 90Y-DOTA-RS7 (105 microCi) was performed in this tumor model using large established tumors (mean tumor volume=0.85 cm(3)). Anti-tumor efficacy and toxicity of the two treatments were comparable.

Animals↗
PubMedDate not supplied

Epidemic Serratia marcescens in a neonatal intensive care unit: importance of the gastrointestinal tract as a reservoir.

Between a March and December of 1979, and outbreak of infections due to multiply antibiotic resistant Serratia marcescens took place in a 50-bed neonatal intensive care unit. Fifteen neonates suffered major infections (sepsis, meningitis and pneumonia) with one death, and 20 suffered minor infections (conjunctivitis, cystitis, wound infections). Epidemiologic investigation failed to reveal a common source; S. marcescens, however, ws isolated from an employee's hand, emollient skin cleanser, suction tubing, and three in-use manual infant resuscitation bags. The skin cleanser and equipment-cleaning agents were ineffective against S. marcescens. Asymptomatic, colonized infants were the major reservoir of S marcescens. These infants were identified by daily cultures of the nose, umbilicus and rectum. The rectal swab most commonly (76%) yielded first-positive cultures in previously uncolonized infants, and was ultimately positive in 92% of colonized infants. A control program was begun by: 1) removing all inanimate sources of S. marcescens; and 2) cohorting patients and staff into a S. marcescens-exposed group and a new patient group. The new patient group of infants was surveyed by daily triple-site cultures for colonization and subsequent transfer to the S. marcescens-exposed group. After four months, the epidemic was controlled and the organism eradicated from the neonatal intensive care unit.

Cross Infection↗
PubMedDate not supplied

Nurse staffing and patient outcomes.

BACKGROUND: Nursing studies have shown that nursing care delivery changes affect staff and organizational outcomes, but the effects on client outcomes have not been studied sufficiently. OBJECTIVE: To describe, at the level of the nursing care unit, the relationships among total hours of nursing care, registered nurse (RN) skill mix, and adverse patient outcomes. METHODS: The adverse outcomes included unit rates of medication errors, patient falls, skin breakdown, patient and family complaints, infections, and deaths. The correlations among staffing variables and outcome variables were determined, and multivariate analyses, controlling for patient acuity, were completed. RESULTS: Units with higher average patient acuity had lower rates of medication errors and patient falls but higher rates of the other adverse outcomes. With average patient acuity on the unit controlled, the proportion of hours of care delivered by RNs was inversely related to the unit rates of medication errors, decubiti, and patient complaints. Total hours of care from all nursing personnel were associated directly with the rates of decubiti, complaints, and mortality. An unexpected finding was that the relationship between RN proportion of care was curvilinear; as the RN proportion increased, rates of adverse outcomes decreased up to 87.5%. Above that level, as RN proportion increased, the adverse outcome rates also increased. CONCLUSIONS: The higher the RN skill mix, the lower the incidence of adverse occurrences on inpatient care units.

Accidental Falls↗
PubMedDate not supplied

Assessment of lead toxicity to the marine bacterium, Vibrio fischeri, and to a heterogeneous population of microorganisms derived from the Pearl River in Jackson, Mississippi, USA.

Microorganisms are known to be excellent test organisms because of the relative ease for handling and suitability for analysis related to their small size, large number and convenient growing conditions. In this research, we tested the toxic effects of lead against a marine bacterium (Vibrio fischeri), and a heterogeneous population of bacteria derived from the Pearl River in Jackson, Mississippi. Using the level of bioluminescence in the Microtox Assay (V. fischeri), and the kinetics of dissolved oxygen uptake and growth (mixed bacterial population) as measures of toxicity, lead concentrations effecting a 50% reduction in these parameters (EC50) were determined as the toxic end-points. The activity quotients were also computed to determine the degrees of toxicity. Optical density (measure of growth) and oxygen uptake were measured over an extended period of time (20 h). EC50 values of 0.34 +/- 0.03, 3.10 +/- 0.01, and 3.80 +/- 0.02 mg/L were recorded for bioluminescence, growth, and oxygen uptake, respectively. As expected, the results indicated that the sensitivity to lead toxicity of V. fischeri was about one order of magnitude (10 times) greater than that of the mixed population of Pearl River microorganisms. Reductions in bioluminescence, growth, and oxygen uptake were directly correlated to lead concentrations, with toxic levels ranging from slightly toxic in lower concentrations to extremely toxic in higher concentrations. Upon 20 h of exposure, the times required to produce 50% reduction in dissolved oxygen uptake were (TD50S) 8.01 +/- 0.44, 9.60 +/- 0.46, 11.29 +/- 0.46, 13.03 +/- 0.57, 17.32 +/- 0.95, and 20.00 +/- 0.00 h in 0, 1, 2, 3, 4, 5, and 6 mg/L of lead, respectively, indicating a time-response relationship with respect to lead toxicity.

Fresh Water↗
PubMedDate not supplied

Visual characteristics of aspirates from feeding tubes as a method for predicting tube location.

A sample of 880 feeding tube aspirates were classified as being primarily clear or cloudy and as having one of six colors. Gastric aspirates were most frequently cloudy and green, tan or off-white, or bloody or brown. Intestinal fluids were primarily clear and yellow to bile-colored. In the absence of blood, pleural fluid was usually pale yellow and serous, and tracheobronchial secretions were usually tan or off-white mucus. However, respiratory aspirates often contained blood and therefore failed to have the expected characteristics of respiratory fluid. Staff nurses were shown photographs of a sample of 106 aspirates and asked to predict tube position. Their ability to identify 50 gastric aspirates improved significantly after reading a list of suggested characteristics of feeding tube aspirates (81.33% to 90.47%, p < .0001). Similarly, their ability to identify 50 intestinal aspirates improved from 64.07% to 71.53% after reading the list of criteria. However, nurses were often unable to identify respiratory aspirates; the accuracy of their predictions decreased after reading the list of suggested characteristics (from 56.67% to 46.11%). The appearance of aspirates is often helpful in distinguishing between gastric and intestinal placement, but is of little value in ruling out respiratory placement.

Adult↗
PubMedDate not supplied

Effectiveness of pH measurements in predicting feeding tube placement: an update.

This paper reports further findings from an ongoing clinical study designed to evaluate the extent to which pH values of aspirates from feeding tubes can be used to differentiate between gastric and intestinal tube placement and gastric and respiratory tube placement. The sample consisted of 405 aspirates from small-bore nasogastric tubes and 389 aspirates from nasointestinal tubes, which were obtained from 605 subjects ranging in age from 18 to 94 years. Data were collected at the time of initial placement and again, when possible, after feedings were initiated. A total of 794 pH-meter readings were made concurrently with X-rays to determine feeding tube position. Gastric placement was successfully distinguished from intestinal placement of the feeding tubes on the basis of pH-meter readings (p < .0001). Approximately 85% of the 405 pH-meter readings from gastric fluid were between 0 and 6.0, while over 87% of the 389 pH-meter measurements performed on intestinal aspirates were greater than 6.0. Four aspirates from feeding tubes inadvertently placed in the respiratory tract (two in the pleural space and two in the tracheobronchial tree) were tested with a pH-meter, all had pH values greater than 6.5.

Adolescent↗