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Biomedical subjects

D A Miller

Publications and source records attributed to D A Miller.

At least 55 records · Page 3Linked to original sources
PubMed1997

Predictive value of several signs of infection as surrogate markers for mortality in a neutropenic guinea pig model of Pseudomonas aeruginosa sepsis.

Infected, neutropenic animals are used as experimental models to evaluate the relative efficacies of antimicrobial agents and host-pathogen-antibiotic interactions. In the past, these models used death as the study end point. Because of the concern about use of death as an end point, we evaluated the accuracy with which various signs of infection predicted mortality in a neutropenic guinea pig model of treated and untreated Pseudomonas aeruginosa sepsis. The potential surrogate markers studied included ruffled fur, respiratory distress, diarrhea, hunched posture, lethargy, abnormal neurologic movements (twitching, paralysis of a limb), inappetence for > 48 h, the inability to ambulate, and the inability of a supine animal to stand. In addition, we evaluated whether percentage of weight loss or change in daily food and water consumption were predictive of mortality. Animals were inspected for these signs at least every 4 h during the day and every 8 h in the evening. In treated and untreated animals, 100% of subjects that were unable to ambulate or to rise from the supine position died (positive predictive value for death was 100% for either sign). Guinea pigs that could not rise from a supine position expired between 1 and 8 h after this sign was observed. Those that could not ambulate died between 4 and 40 h after that sign was observed. In treated and untreated animals, none of the survivors manifested either sign of disease (100% specificity for each sign). However, 59% of untreated and 69% of treated animals that were ambulatory were found dead at the next observation period, underscoring the rapidity with which this infection progresses to death when it enters its final stage. No other signs of infection distinguished animals that survived or died. Thus, the inability of neutropenic, infected guinea pigs to rise from a supine position and the inability to ambulate were the only signs that accurately predicted death and, therefore, are the only signs that can be used as surrogates for death in this experimental model of P. aeruginosa sepsis.

Animals↗
PubMed1996

Vaginal birth after cesarean section in twin gestation.

OBJECTIVE: We report a 10-year experience with vaginal birth after cesarean section in women with twins. STUDY DESIGN: Data were gathered from labor and delivery records and maternal and neonatal hospital charts. Women with a vertical uterine scar, a previous uterine rupture, an unrepaired dehiscence, or obstetric contraindications to labor were excluded from a trial of labor. Full-thickness uterine defects requiring intervention were classified as ruptures; all others were classified as dehiscences. RESULTS: Between Jan. 1, 1985, and Dec. 31, 1994, at Los Angeles County/University of Southern California Women's Hospital, 210 women with previous cesarean births were delivered of twins. One hundred eighteen (56%) underwent repeat cesarean delivery without a trial of labor. Ninety-two (44%) undertook a trial of labor with no uterine ruptures and no increase in maternal or perinatal morbidity or mortality. CONCLUSIONS: In women with twins a trial of labor after a previous cesarean section is a safe and effective alternative to routine repeat cesarean delivery.

Adult↗
PubMed1996

The modified biophysical profile: antepartum testing in the 1990s.

OBJECTIVE: Our goal was to determine the false-negative and false-positive rates of antepartum testing by use of the modified biophysical profile. STUDY DESIGN: From Jan. 1, 1990, through Dec. 31, 1994, antepartum testing results were gathered prospectively and tabulated monthly. For 1 year, 1991, detailed intrapartum and neonatal data were collected from all women admitted and delivered as a result of an abnormal antepartum test result. RESULTS: The false-negative rate of the antepartum testing protocol was 0.8 per 1000 women tested. Sixty percent of those delivered because of an abnormal antepartum test had no evidence of short-term or long-term fetal compromise. False-positive test results led to preterm delivery in 1.5% of those tested before term. CONCLUSION: The false-negative rate of the modified biophysical profile is lower than that of the nonstress test and compares favorably with the false-negative rates of the contraction stress test and the complete biophysical profile. Iatrogenic prematurity resulting from intervention for false positive test results occurred in 1.5% of women tested before 37 weeks.

Adult↗
PubMed1996

Amnioinfusion in women with previous cesarean births: a preliminary report.

OBJECTIVE: Our purpose was to evaluate the use of intrapartum amnioinfusion in women undergoing a trial of labor after a previous cesarean delivery. STUDY DESIGN: Labor and delivery records of women undergoing intrapartum amnioinfusion over a 1-year period were reviewed retrospectively. Neonatal data were obtained by chart review. RESULTS: During the study period 936 women underwent intrapartum amnioinfusion for the following indications: oligohydramnios (76.6%), meconium-stained amniotic fluid (12.8%),and variable decelerations (7.5%). Among these, 122 (13%) had previous cesarean births. Seventy-one (58.2%) women were delivered vaginally; the remaining 51 (41.8%) were delivered by repeat cesarean. Among women undergoing intrapartum amnioinfusion there were no statistically significant differences (p<0.05) between those with previous cesarean births and those with unscarred uteri with respect to the following: cesarean section for fetal distress (1.6% vs 1.4%), meconium aspiration (0% vs 0.9%), or low 5-minute Apgar scores (2.5% vs 0.9%). There were no perinatal or maternal deaths in either group. One uterine rupture occurred in a woman with one previous cesarean birth. CONCLUSIONS: Amnioinfusion appears to be an acceptable procedure in women with previous cesarean births. The incidence of uterine rupture (0.8%) noted was similar to the 10-year institutional rate at Los Angeles County-University of Southern California Women's Hospital (0.7%).

Adult↗
PubMed1996

Pediatric exercise-induced laryngomalacia.

Laryngomalacia is a well-recognized cause of airway obstruction and inspiratory stridor in infants. As children grow and become more active, laryngomalacia may manifest in different, unexpected ways. Otherwise healthy athletes may generate enough inspiratory force to draw the aryepiglottic folds into the endolarynx, causing a subtotal glottic obstruction. This problem may be overlooked or attributed to asthma, lack of fitness, or functional abnormalities. The purpose of this report is to review the prevalence, diagnosis, and treatment of exercise-induced laryngomalacia (EIL) in children and young adults. To study the incidence and diagnosis of this disorder, we examined 10 healthy volunteers. Fiberoptic laryngoscopy was used to videotape each subject's larynx during active exercise on a stationary bicycle. All volunteers demonstrated altered laryngeal dynamics with exercise, and 1 of the 10 volunteers developed laryngomalacia. Anatomically, it appears that the aryepiglottic fold serves as the critical point of obstruction. When symptomatic, laryngomalacia may be treated with supraglottoplasty. We have had experience with 2 EIL patients in the last 12 months who have undergone carbon dioxide laser microlaryngoscopy. Both patients benefited significantly from surgery. We conclude that EIL is underdiagnosed but responds well to treatment.

Adolescent↗
PubMed1996

Severe rhinorrhea and respiratory distress in a neonate exposed to fluphenazine hydrochloride prenatally.

OBJECTIVE: To report a case of respiratory distress with severe rhinorrhea in a newborn exposed prenatally to fluphenazine hydrochloride. CASE SUMMARY: The safety of phenothiazines during pregnancy and the effect on the fetus and newborn are not well known. We describe a newborn who had severe rhinorrhea, vomiting, and respiratory distress after being exposed in utero to fluphenazine hydrochloride. Sepsis, choanal atresia, and congenital syphilis were excluded as causative factors for rhinorrhea. The rhinorrhea and upper airway obstruction responded to treatment with pseudoephedrine. CONCLUSIONS: Severe rhinorrhea, vomiting, and respiratory distress that occurred in this infant have not been reported previously following prenatal fluphenazine hydrochloride exposure. Awareness of this problem would be helpful to clinicians and should be considered in the differential diagnosis of rhinorrhea in newborns.

Antipsychotic Agents↗
PubMed1995

Production of brefeldin-A.

Fermentation conditions are described for the production of the antitumor antibiotic 7-(S)-brefeldin-A (brefeldin-A) in liquid culture by Eupenicillium brefeldianum, (B.Dodge) Stolk and Scott, ATCC 58665. An analytical hplc method was developed which allowed rapid quantitation of the compound during fermentation. A kilogram of brefeldin-A was isolated from a fermentation at the 6800-liter scale.

Antibiotics, Antineoplastic↗