Biomedical subjects
H Roach
Publications and source records attributed to H Roach.
An abnormal venous clot.
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Apoptotic cell nuclei favour aggregation and fluorescence quenching of DNA dyes.
Apoptotic cell nuclei are known to stain hyperchromatically with absorption dyes and dimly with many DNA fluorochromes. We hypothesised that both optical phenomena have the same cause--the ability of apoptotic chromatin to aggregate cationic dyes. This hypothesis was tested using prednisolone-primed rat thymus, which is known to contain apoptotic cells. The apoptotic cells were classified as early and late, based on their morphology, in thin and semithin sections and in thymus imprints on slides. Direct reaction for DNA strand breaks (TUNEL) indicated the presence of breaks in both categories of cells, with more intense labelling in late apoptosis. The chromatin ultrastructure of early apoptotic cells initially retained the supranucleosomal order of packaging which characterises control cells, whereas the dense chromatin of late apoptotic cells possessed the degraded structure. Absorption spectra of the toluidine blue-stained early apoptotic cell chromatin revealed a metachromatic shift, indicating a change of DNA conformation and polymerisation of the dye. When the staining was performed by acridine orange (preceded by a short acid treatment), a paradoxical several-fold increase of fluorescence intensity at a several-fold dilution of the dye was found. The simultaneous reduction of the ratio of red to green components of fluorescence confirmed that the concentration-dependent fluorescence quenching was due to aggregation of the dye. The results suggest that the enhanced affinity of the chromatin of early apoptotic cells for cationic dyes is associated with conformational relaxation rather than degradation of DNA. In late apoptotic cells, the very dense packaging of degraded DNA promotes further aggregation of dyes. The results suggest alternative methods for detection and discrimination of early and late apoptotic cells.
Cesarean section for suspected fetal distress. Does the decision-incision time make a difference?
OBJECTIVE: To compare perinatal outcomes in patients at term (37 weeks) in whom the decision-incision time for cesarean delivery was due to suspected fetal distress. STUDY DESIGN: All parturients who underwent cesarean delivery primarily for possible fetal distress during a three-year period were identified retrospectively. Student's t test and the chi 2 test were utilized, and P < .05 was considered significant. A regression analysis of decision-incision time and umbilical arterial pH was performed. RESULTS: From 1991 to 1993, 1.3% (117/9,137) of term laboring patients underwent emergency cesarean delivery for the primary indication of possible fetal distress. In 61 patients (52%) the decision-incision time was 30 minutes, while it exceeded 30 minutes in the remaining 56 women. The two patient groups were similar in maternal demographics, antepartum complications, oxytocin usage, thick meconium, type of abnormal fetal heart rate tracing prompting surgery, use of amnioinfusion (41% vs. 36%), general anesthesia (97% vs. 93%), mean birth weight and Apgar score < 7 at five minutes. Three adverse outcomes were observed more frequently in association with decision-incision time > 30 minutes: (1) lower mean (+/-SD) umbilical arterial pH (7.16 +/- 0.15 vs. 7.26 +/- 0.06, P = .001), (2) pH < 7.00 (8/61 vs. 0/56, P = .005), and (3) admission to the neonatal intensive care unit (P = .008). When the incision was made longer than 30 minutes after the decision, there was no apparent adverse neonatal or infant outcome. CONCLUSION: Although a cesarean decision-incision time < or = 30 minutes is a desirable goal for the fetus possibly in distress, failure to achieve this goal is not associated with a measurable negative impact on newborn outcome.
A pilot study of intravenous ondansetron for hyperemesis gravidarum.
OBJECTIVE: We attempted to determine whether the antiemetic ondansetron would be more effective than promethazine in treating hyperemesis gravidarum. STUDY DESIGN: Patients with hyperemesis gravidarum who required hospital admission were randomized to receive either intravenous ondansetron (n = 15) or intravenous promethazine (n = 15) in a double-blind manner. Severity of disease was determined by electrolyte status, weight loss, ketonuria, and prior use of outpatient antiemetics. Outcome variables included degree of nausea, weight gain during treatment, days of hospitalization, and number of medication doses. RESULTS: In this preliminary investigation ondansetron offered no advantage when compared with promethazine in the relief of nausea, weight gain, days of hospitalization (4.5 +/- 2.3 vs 4.5 +/- 1.5), and total doses of medication per hospitalization (2.1 +/- 1.2 vs 1.9 +/- 1.3). CONCLUSION: This preliminary trial of ondansetron demonstrated no benefit over promethazine in patients hospitalized for hyperemesis gravidarum.
Combining medical and mechanical methods of cervical ripening. Does it increase the likelihood of successful induction of labor?
OBJECTIVE: To determine if combining two commonly used methods or cervical ripening (intracervical prostaglandin E2 [Pge2] gel and Foley balloon catheter) would result in a higher number of successful inductions and fewer cesarean sections when compared to PGE2 gel alone. STUDY DESIGN: Seventy-eight patients with unfavorable cervixes eligible for induction of labor were prospectively randomized to receive either one dose (0.5 mg) of PGE2 gel followed by insertion of a 24-French Foley catheter (group 1, 41 patients) or two doses of 0.5 mg of intracervical gel (group 2, 37 patients). Outcome parameters included change in Bishop score, number of failed inductions, rate of cesarean section, rate of uterine hyperstimulation and postpartum infection. RESULTS: Patients in group 1 had a significant increase in posttreatment Bishop scores (7.26 +/- 2.0 SD vs. 4.82 +/- 1.8 P = .0001) and fewer failed inductions (0 vs. 6, P = .009) when compared to patients in group 2. Abdominal delivery rates, uterine hyperstimulation and infections complications were not different between the two groups. CONCLUSION: The combination of the Foley balloon and prostaglandin gel significantly improved the Bishop score and led to fewer failed inductions, although it did not increase the vaginal delivery rate.
Delivery of the nonvertex second twin: breech extraction versus external cephalic version.
OBJECTIVE: Our purpose was to compare the maternal and perinatal outcomes of twin gestations in which the nonvertex second twin was delivered by total breech extraction versus those delivered by external cephalic version. STUDY DESIGN: The intrapartum courses of 284 consecutive twin gestations were analyzed retrospectively. Once those with actual birth weight < 600 gm, unrecognized multifetal pregnancy, multiple congenital anomalies, cesarean delivery, and/or antepartum intrauterine fetal death were excluded, 23 mothers were delivered by total breech extraction and 21 underwent external cephalic version. RESULTS: The two groups were similar for mean (+/- SD) maternal age, gravidity, parity, gestational age at delivery, ultrasonographic estimate of birth weight for twin B, incidence of breech or transverse presentation for the second fetus, and actual birth weight of the first or second newborn. Suspected fetal distress that led to cesarean delivery occurred significantly more often in parturients who underwent attempted external version (4/21) than total breech extraction (0/23, p = 0.04). The incidence of eventual abdominal delivery was also significantly higher in patients who underwent attempted external cephalic version (10/21) rather than breech extraction (1/23, p = 0.001). For twin B the occurrence of low Apgar scores at 1 minute was significantly higher for infants after attempted external version (7/21) rather than breech extraction (1/23, p = 0.02), but the mean pH, number with Apgar scores < 7 at 5 minutes, and number of neonatal intensive care unit admissions were similar. No perinatal traumatic injury occurred in either group. CONCLUSION: On the basis of our experience, total breech extraction of the nonvertex second twin is preferable to external cephalic version because it appears to be associated with a significantly lower incidence of fetal distress and abdominal delivery with comparable neonatal outcome.
Trial of labor after cesarean delivery with a lower-segment, vertical uterine incision: is it safe?
OBJECTIVE: Our purpose was to assess maternal and perinatal outcomes associated with a trial of labor and attempted vaginal birth after prior low-segment vertical cesarean delivery. STUDY DESIGN: During a 10-year period in a single tertiary hospital, all patients with a prior low-segment uterine incision (whether vertical or transverse) were considered candidates for a trial of labor in the absence of other contraindications or patient refusal. Among the 1137 women who underwent low-segment vertical cesarean delivery, 262 were subsequently delivered of 322 live-born infants, and 174 (54%) of them were identified retrospectively as having attempted vaginal birth. The maternal and perinatal outcomes of patients who did or did not undergo a trial of labor were analyzed and compared. RESULTS: No significant differences between the two patient groups were observed regarding demographic characteristics, antepartum complications, gestational age at delivery (mean 37.4 weeks), birth weight, and cord pH at delivery. Vaginal delivery was accomplished successfully in 144 of 174 (83%) patients who underwent a trial of labor. Abdominal delivery was necessary for 17 mothers with labor disorders and 13 with suspected fetal distress. Postpartum hemorrhage occurred more often in the trial of labor group (7/174 [4.0%] vs 2/148 [1.4%], p not significant), but endometritis developed significantly more often in patients with elective repeat cesarean delivery (16.9% vs 6.3%, p = 0.006). Rupture of the low-segment vertical cesarean scar occurred in 2 patients during a trial of labor (1.1%) versus none in the elective repeat cesarean group. Neither mother experienced fetal extrusion or adverse maternal or fetal sequelae. Frequency of serious neonatal complications (8.1% vs 10%) and neonatal mortality (1.7% vs 2.0%) were similar between groups. All neonatal deaths were a result of extreme prematurity or congenital anomalies. CONCLUSIONS: Our experience indicates that a mother with a prior low-segment vertical cesarean delivery can undertake a trial of labor with relative maternal-perinatal safety. The likelihood of successful outcome and the incidence of complications are comparable to those of published experience with a trial of labor after a previous low-segment transverse incision.
Differentiation and programmed cell death in Sa-45 tumour treated with bone inducer.
The relationship between differentiation and concerted cell death was studied using ultrastructural, histochemical and immunochemical methods in solid rat fibrosarcoma Sa-45 grown in the presence of demineralized bone matrix. The control tumour consisted mostly of undifferentiated cells with few poorly or moderately differentiated cells. In the presence of the inducer, cells with a more differentiated pattern appeared in the surrounding area. The proliferative activity in the presence of the inducer was 3 to 5 times lower but the apoptotic index was higher than in the controls. However, complete differentiation was induced only in stromal cells, whereas the parenchymal cells showed signs of enhanced but incomplete differentiation. The ultrastructural signs of programmed cell death progressed in them faster than the corresponding features of maturation, thus leaving differentiation incomplete.
Parturitional factors associated with membrane stripping.
OBJECTIVE: Our purpose was to determine what factors occurring after digital separation of the chorionic membranes from the lower uterine segment (membrane stripping) are involved in observed clinical changes compared with patients not so treated. STUDY DESIGN: Thirty patients were randomly divided among a study population and two control groups to assess uterine contractions and microbiologic, histologic, and biochemical markers associated with parturitional events over a 7-hour time frame. RESULTS: Clinically, an increased frequency of uterine contractile activity was observed among patients in the membrane-stripped group (p < 0.03). There was a significant increase in plasma 13,14-dihydro-15-keto-prostaglandin F2 alpha (p < 0.001) and endocervical phospholipase A2 activity (p < 0.04) among those who underwent membrane stripping. Blood leukocyte counts, sedimentation rates, prostaglandin E2 metabolite concentrations, and fibronectin levels revealed no significant change during the 7-hour study session. CONCLUSION: Membrane stripping was associated with increases in phospholipase A2 activity and prostaglandin F2 alpha concentrations, indicating a possible correlation with initiation of the cascade of parturitional events.
Intrapartum assessment by house staff of birth weight among twins.
OBJECTIVE: To determine among twins in labor: 1) the relative accuracy of an intrapartum sonographic estimate of the birth weight for both fetuses using biparietal diameter and abdominal circumference, 2) the accuracy of detecting discordant growth (difference in actual birth weights greater than or equal to 15%), and 3) the estimate of fetal weight for nonvertex twin B that would reliably avoid breech extraction of infants less than 1500 g. METHODS: Retrospectively, we identified and analyzed parturients with twins who had an intrapartum sonogram performed by a house officer assigned to the labor and delivery suite. RESULTS: The mean birth weight (+/- standard deviation) for the twin A group was 1910 +/- 628 g and for twin B was 1869 +/- 668 g. The mean standardized absolute errors for the twin A group (121 +/- 118 g/kg) and the twin B group (92 +/- 67 g/kg) were not significantly different (P = .06). Analysis of variance revealed that regardless of the presentation of the fetuses, the mean standardized absolute error was not significantly different (P = .10). Using a difference in the estimates of birth weight of 15% or greater, the positive and negative predictive values of detecting discordant growth within a twin pair were 53 and 83%, respectively. Among 30 vertex-nonvertex twin pairs, 12 of the second fetuses had actual birth weights of 1500 g or less, and all were estimated to weigh less than 1700 g. CONCLUSIONS: The intrapartum sonographic estimate of fetal weight in twin pregnancy by house staff appears reliable, and the accuracy of prediction is similar regardless of presentation, discordance, or actual birth weight greater or less than 1500 g. To avoid vaginal delivery of a persistent nonvertex twin B with a birth weight of 1500 g or less, a sonographic estimate of 1700 g for the second fetus may be adequate.
Uterine activity among a diverse group of patients at high risk for preterm delivery.
In this study, 98 patients with early premature rupture of membranes (PROM), postoperative recuperation, placenta previa, or blunt abdominal trauma were assessed for uterine contractions with an ambulatory uterine activity monitor. Uterine irritability manifested by low-amplitude, high-frequency contractions of 30 seconds' duration or less was prevalent in all groups but decreased as the patients were stabilized and diminished or disappeared in those who did not develop preterm labor. In the 18 women who developed preterm labor, daily uterine activity monitoring detected contractions 24-48 hours before clinical symptoms of preterm labor and/or vaginal bleeding occurred. A number of patients with early PROM and placenta previa had low-amplitude, high-frequency contractions, and the majority occurred in those who subsequently developed preterm labor.
Use of the designation "M.D." by foreign medical graduates.
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Intravenous site care practices in critical care: a national survey.
OBJECTIVE: To collect and compare written procedures for central line intravenous site care. DESIGN: Descriptive, stratified, random sample survey. SETTING: Adult medical-surgical critical care units among hospitals throughout the United States. SAMPLE: One hundred fifty-two returned surveys. RESULTS: A 24.6% response rate with underrepresentation from smaller institutions and hospitals in the Mid-Atlantic and West South Central regions of the country. There were wide variations in procedures for intravenous site care related to type of dressing used and frequency of dressing changes. CONCLUSIONS: Standardization of catheter care is needed to ensure consistent quality of intravenous site care. Lack of standardization may be due to lack of a research data base linking various components of care to outcomes such as infection, patient comfort, or catheter retention.
Intravascular site care: are critical care nurses practicing according to written protocols?
OBJECTIVE: To observe and describe site care for intravascular devices, to identify internurse variations in site care, and to compare written protocols for site care with actual practice in one geographic area. DESIGN: Observational, descriptive study. SETTING: Adult critical care units in one community, and one university teaching hospital in the Washington, D.C., metropolitan area. SAMPLE: Direct observation of 86 central and 30 peripheral site care episodes. RESULTS: A total of 116 site care episodes were observed on five critical care units. There were wide variations between units from the same hospital in gloving practices and use of aseptic technique. Significant differences across both hospitals, as well as between individual units, were noted for a number of other practices including: time since last site care, use of ointment and skin adhesive, type of dressing used, and duration of care. In both hospitals, compliance with all steps of the written protocol was similar-23.2% and 23.3%. Compliance with documentation requirements ranged from 53.3% to 85.7%, and was significantly different between the two hospitals with regard to recording the dressing change and whether the dressing label and chart agreed. CONCLUSIONS: Intravascular site care varies significantly among critical care units within the same institution, as well as between different hospitals, and varies from written protocol. Standardized, well-defined site care protocols and education of staff, along with quality improvement surveillance systems are needed to ensure consistent quality intravascular site care.
Effect of intravascular surveillance and education program on rates of nosocomial bloodstream infections.
BACKGROUND: Because of high proportions of central line-related bloodstream infections (BSIs), an intravascular surveillance and education program (IVSP) was instituted in the study institution in 1987. METHODS: A 6 1/2-year historical prospective study was conducted to evaluate the effects of the IVSP on incidence of nosocomial BSIs. With use of Centers for Disease Control and Prevention criteria, concurrent data on nosocomial BSIs were collected by two infection control professionals before, during, and for 3 years after the IVSP. RESULTS: Hospital-wide BSIs during the 3-year IVSP and for 3 years after were 0.9% and 0.9% (p = 0.58) or 1.4 and 1.2/1000 patient-days (p = 0.24). Central line-related BSIs represented 29%, 24%, and 29% of the total BSIs 6 months before, 3 years during, and 6 months after the intervention, respectively (p = 0.62). CONCLUSIONS: The IVSP resulted neither in a reduction in the total intravascular catheter-related BSIs nor in a change in the proportion of potentially preventable central line-related BSIs. To be successful, an intervention must include the authority to mandate practice changes; education and feedback without such authority were inadequate.
Treatment for hyperemesis gravidarum in the home: an alternative to hospitalization.
Our objective was to determine whether medical therapy in the home for patients with hyperemesis gravidarum is safe, efficacious, and cost effective compared with hospitalization. In this retrospective, matched control study 50 women with hyperemesis were treated in the home and were matched for gravidity, gestational age, and weight loss from prepregnancy weight with 47 patients who were hospitalized for traditional treatment. Both groups had similar intravenous fluid and medical support until they could tolerate adequate oral intake. Women in the home had 9.7 +/- 8.0 days of intravenous therapy compared with 9.5 +/- 6.2 days in hospitalized patients (not significant). The mean percent of weight loss at initiation of therapy was similar in both groups (4.6% +/- 5.7% vs 4.5% +/- 6.1%, not significant). The mean weight change during therapy in the home group was + 1.0 +/- 4.3 pounds compared with +1.2 +/- 8.6 pounds in the hospitalized group (not significant). The only complication was infiltration of the intravenous site, the occurrence of which was similar in the two groups (40% vs 57%, not significant). At discontinuation of therapy 90% of the home patients no longer required any supportive therapy; 10% (n = 5) required hospitalization because of relapse. The cost of therapy was significantly lower for patients in the home group ($708 +/- $533 vs $2701 +/- $1717, p < 0.001). These data show that management of hyperemesis in the home is both safe and efficacious. Furthermore, successful therapy can be achieved in the home at a significantly reduced cost.