RESUMEN
A clinical evaluation of the Amplicor polymerase chain reaction (PCR) assay for the detection of Chlamydia trachomatis in endocervical swabs (Roche Molecular Systems, Branchburg, N.J.) is described. This new clinical system used one-step sample preparation, amplification with biotinylated cryptic plasmid primer pairs (CP24-CP27), uracil-N-glycosylase (AmpErase), and a microtiter format for amplicon capture and detection. Culture with McCoy cells in duplicate 1-dram (3.697-ml) vials with fluorescent immunostaining was the reference system. Endocervical swab samples from 945 women provided 74 culture-positive specimens, of which PCR detected 71. The initial PCR result was positive for 12 additional specimens. Arbitration of the PCR-positive, culture-negative samples by PCR with major outer membrane protein primers, duplicate culture, elementary body direct fluorescent-antibody staining, and DNA extraction PCR showed that all 12 samples were positive for chlamydia, raising the number of truly positive samples from 74 to 86. After arbitration the true sensitivities of PCR and culture were 96.5 and 86%, respectively (P = 0.02). Specificities for both were 100%. For PCR, the positive and negative predictive values were 100 and 99.7%, respectively. Total test efficiency was 99.7%. A high-test-volume (121 samples) timing study with all items included in the College of American Pathologists work load method indicated that this PCR format took approximately 3 min per sample. Because of the high sensitivity, specificity, and improved ease of handling, we found PCR to be a good alternative to culture for detection of C. trachomatis.
Asunto(s)
Cuello del Útero/microbiología , Chlamydia trachomatis/aislamiento & purificación , Reacción en Cadena de la Polimerasa/métodos , Chlamydia trachomatis/genética , Medios de Cultivo , ADN Bacteriano/análisis , Femenino , Humanos , Técnicas para InmunoenzimasRESUMEN
The temperature changes associated with total care nursing procedures were studied on 249 occasions during the first week of life in 25 preterm infants weighing less than 1500 g, 16 of whom weighed less than 1100 g. Large drops in both central and peripheral temperature occurred, with widening of the central-peripheral temperature gap. Recovery of the temperature after the total care procedure took up to two hours. These routine nursing procedures are carried out every four to six hours. They cause an important alteration in the environmental temperature with consequent thermal stress to the infants that may influence ultimate outcome.
Asunto(s)
Regulación de la Temperatura Corporal/fisiología , Recién Nacido de Bajo Peso/fisiología , Recien Nacido Prematuro/fisiología , Cuidado Intensivo Neonatal/métodos , Atención de Enfermería , Humanos , Incubadoras para Lactantes , Recién Nacido , LondresRESUMEN
We determined the oncotic and cardiovascular effects of a standardised infusion of human albumin (1.2 g/kg over 2 h as a 20% solution) in 12 premature infants on 18 occasions when hypovolaemia was suspected on clinical grounds. Blood volume increased by a median value of 15.5%, and fell to preinfusion values by 3 h post infusion in all but four cases. Albumin concentration and colloid osmotic pressure rose during infusion and remained raised even when blood volume had fallen to preinfusion levels. Blood pressure rose in 3 cases only and heart rate fell by greater than 5 beats/min in 6 cases. Indices of long- and short-term heart rate variability were unchanged, but blood pressure variability fell in the second hour of infusion (P = 0.03), an effect which was independent of changes in lung inflation. No changes in blood gases or oxygenation occurred during infusion and no evidence of pulmonary oedema was found. There were wide variations in oncotic and cardiovascular responses to the standardised infusion both between and within subjects. When human albumin is infused in this manner some protection against respiration-induced variability in blood pressure can result, but the circulatory response may prove difficult to predict in the individual.
Asunto(s)
Presión Sanguínea/efectos de los fármacos , Volumen Sanguíneo/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Recien Nacido Prematuro/fisiología , Albúmina Sérica/farmacología , Humanos , Recién Nacido , Infusiones Intravenosas , Presión Osmótica/efectos de los fármacos , Albúmina Sérica/administración & dosificaciónRESUMEN
We studied temperature stability in 22 infants of birthweight less than 1500 g in the first four days of life. Infants were nursed in incubators using either air mode control or skin temperature servo control. Data were collected continuously using a computer linked monitoring system. Skin temperature control resulted in a less stable thermal environment than air mode control. Increased thermal stability in the incubator on air mode control may well be beneficial, particularly to sick, very low birthweight infants.