Delivery outcomes in the subsequent pregnancy following the conservative management of placenta accreta spectrum disorder: a systematic review and meta-analysis

OBJECTIVE

Cesarean hysterectomy is generally presumed to decrease maternal morbidity and mortality secondary to placenta accreta spectrum disorder. Recently, uterine-sparing techniques have been introduced in conservative management of placenta accreta spectrum disorder to preserve fertility and potentially reduce surgical complications. However, despite patients often expressing the intention for future conception, few data are available regarding the subsequent pregnancy outcomes after conservative management of placenta accreta spectrum disorder. Thus, we aimed to perform a systematic review and meta-analysis to assess these outcomes.

DATA SOURCES

PubMed, Scopus, and Web of Science databases were searched from inception to September 2022.

STUDY ELIGIBILITY CRITERIA

We included all studies, with the exception of case studies, that reported the first subsequent pregnancy outcomes in individuals with a history of placenta accreta spectrum disorder who underwent any type of conservative management.

METHODS

The R programming language with the "meta" package was used. The random-effects model and inverse variance method were used to pool the proportion of pregnancy outcomes.

RESULTS

We identified 5 studies involving 1458 participants that were eligible for quantitative synthesis. The type of conservative management included placenta left in situ (n=1) and resection surgery (n=1), and was not reported in 3 studies. The rate of placenta accreta spectrum disorder recurrence in the subsequent pregnancy was 11.8% (95% confidence interval, 1.1-60.3; I2=86.4%), and 1.9% (95% confidence interval, 0.0-34.1; I2=82.4%) of participants underwent cesarean hysterectomy. Postpartum hemorrhage occurred in 10.3% (95% confidence interval, 0.3-81.4; I2=96.7%). A composite adverse maternal outcome was reported in 22.7% of participants (95% confidence interval, 0.0-99.4; I2=56.3%).

CONCLUSION

Favorable pregnancy outcome is possible following successful conservation of the uterus in a placenta accreta spectrum disorder pregnancy. Approximately 1 out of 4 subsequent pregnancies following conservative management of placenta accreta spectrum disorder had considerable adverse maternal outcomes. Given such high incidence of adverse outcomes and morbidity, patient and provider preparation is vital when managing this population.

Surgical Techniques for the Management of Placenta Accreta Spectrum

The surgical management of placenta accreta spectrum (PAS) is often challenging. There are a variety of techniques and management options described in the literature ranging from uterine sparing to cesarean hysterectomy. Following the inaugural meeting of the Pan-American Society for Placenta Accreta Spectrum a multidisciplinary group collaborated to describe collective recommendations for the surgical management of PAS. In this manuscript, we outline individual components of the procedure and provide suggested direction at key points of a cesarean hysterectomy in the setting of PAS. KEY POINTS: · The surgical management of PAS requires careful planning and expertise.. · Multidisciplinary team care for pregnancies complicated by PAS can decrease morbidity and mortality.. · Careful surgical techniques can minimize risk of significant hemorrhage by avoiding pitfalls..

A comparison of MRI appearance and surgical detethering rates between intrauterine and postnatal myelomeningocele closures: a single-center pilot matched cohort study

INTRODUCTION

Intrauterine myelomeningocele repair (IUMR) and postnatal myelomeningocele repair (PNMR) differ in terms of both setting and surgical technique. A simplified technique in IUMR, in which a dural onlay is used followed by skin closure, has been adopted at our institution. The goal of this study was to compare the rates of clinical tethering in IUMR and PNMR patients, as well as to evaluate the appearance on MRI.

METHODS

We conducted a retrospective review of 36 patients with MMC repaired at our institution, with 2:1 PNMR to IUMR matching based on lesion level. A pediatric neuroradiologist blinded to the clinical details reviewed the patients' lumbar spine MRIs for the distance from neural tissue to skin and the presence or absence of a syrinx. An EMR review was then done to evaluate for detethering procedures and need for CSF diversion.

RESULTS

Mean age at MRI was 4.0 years and mean age at last follow-up was 6.1 years, with no significant difference between the PNMR and IUMR groups. There was no significant difference between groups in the distance from neural tissue to skin (PNMR 13.5 mm vs IUMR 17.6 mm; p = 0.5). There was no difference in need for detethering operations between groups (PNMR 12.5% vs IUMR 16.7%; RR 0.75; CI 0.1-5.1).

CONCLUSIONS

There was no significant difference between postnatal- and intrauterine-repaired myelomeningocele on MRI or in need for detethering operations. These results imply that a more straightforward and time-efficient IUMR closure technique does not lead to an increased rate of tethering when compared to the multilayered PNMR.

Intrauterine closure of myelomeningocele defects with primary linear repair versus bipedicle fasciocutaneous flaps: a post-MOMS cohort study with long-term follow-up

OBJECTIVE

The objective of this study was to determine the effects of in utero bipedicle flaps on maternal-fetal morbidity/mortality, the need for CSF diversion, and long-term functional outcomes.

METHODS

Eighty-six patients who underwent fetal myelomeningocele repair from 2011 to 2021 at a single institution were reviewed. Primary outcomes included intrauterine fetal demise, postnatal death, postnatal myelomeningocele repair dehiscence, and CSF diversion by final follow-up.

RESULTS

The cohorts were no different with regard to race, ethnicity, maternal age at fetal surgery, body mass index, gravidity, parity, gestational age at fetal surgery, estimated fetal weight at fetal surgery, or fetal lesion level. Of the 86 patients, 64 underwent primary linear repair and 22 underwent bipedicle flap repair. There were no significant differences in rates of intrauterine fetal demise, postnatal mortality, midline repair site dehiscence, or the need for CSF diversion by final follow-up. Operative times were longer (32.5 vs 18.7 minutes, p < 0.001) and gestational age at delivery was lower (232 vs 241 days, p = 0.01) in the bipedicle flap cohort, but long-term functional outcomes were not different.

CONCLUSIONS

Analysis of the total cohort affirms the long-term benefits of fetal myelomeningocele repair. In utero bipedicle flaps are safe and can be used for high-tension lesions without increasing perioperative risks to the mother or fetus. In utero flaps preserve the long-term benefits seen with primary linear repair and may expand inclusion criteria for fetal repair, providing life-changing care for more patients.

Evaluating suitability of saliva to measure steroid concentrations in grey seal pups

Measurement of steroids in wild pinnipeds can facilitate assessment of breeding, nutritional and stress status, and is useful in understanding behavioral responses. Even in young animals, sex steroids may be important in behavioral interactions and immune modulation. Use of saliva can avoid the large fluctuations seen in some steroids in plasma, and can negate the need for venipuncture, making it a potentially useful matrix in the wildlife. However, its utility in estimating steroid levels in wild young pinnipeds has not been evaluated. Here, we investigated the suitability of saliva for steroid hormone analysis in wild grey seal pups during their suckling and post-weaning fast periods. We collected saliva (n = 38) and plasma (n = 71) samples during the breeding season on the Isle of May, Scotland, 2012. We investigated success of sample collection, ease of preparation, accuracy and precision of analysis, and, where possible, comparability of measurements (n = 27) from saliva and plasma. Plasma sampling was rapid, whereas sampling saliva took up to five times longer. Analytical performance criteria (parallelism, accuracy, and precision (intra and inter assay co-efficient of variation (% CV)) of commercial ELISA kits to measure estradiol, testosterone and cortisol in both matrices were assessed. Estradiol and cortisol assays performed well and can be used in plasma and saliva. However, we could not confidently validate testosterone for either matrix. Saliva estradiol correlated with levels in plasma. Saliva sample preparation was faster and simpler than plasma preparation because it did not require extraction. However, given the additional time taken to obtain saliva in the wild, the possibility of blood contamination from oral damage and the lower success rate in obtaining sufficient sample for analysis, we recommend that this matrix only be used as an alternative to plasma sampling measurement in pinnipeds when animals are anaesthetized, tolerate mouth swabbing, or have been trained to accept saliva sampling in captivity.

Placental Location in Maternal-Fetal Surgery for Myelomeningocele

INTRODUCTION

Uterine incision based on placental location in open maternal-fetal surgery (OMFS) has never been evaluated in regards to maternal or fetal outcomes.

OBJECTIVE

To investigate whether an anterior placenta was associated with increased rates of intraoperative, perioperative, antepartum, obstetric, or neonatal complications in mothers and babies who underwent OMFS for myelomeningocele (fMMC) closure.

METHODS

Data from the international multi-center prospective registry of patients who underwent OMFS for fMMC closure (fMMC Consortium Registry, 12/15/2010-7/31/2019) was used to compare fetal and maternal outcomes between anterior and posterior placental locations.

RESULTS

Placental location for 623 patients was evenly distributed between anterior (51%) or posterior (49%). Intraoperative fetal bradycardia (8.3% vs 3.0%, p=0.005) and performance of fetal resuscitation (3.6% vs 1.0%, p=0.034) occurred more frequently in cases with an anterior placenta when compared to those with a posterior placenta. Obstetric outcomes including membrane separation, placental abruption, and spontaneous rupture of membranes were not different among the two groups. However, thinning of the hysterotomy site (27.7% vs 17.7%, p=0.008) occurred more frequently in cases of anterior placenta. Gestational age at delivery (p=0.583) and length of stay in the neonatal intensive care unit (p=0.655) were similar between the two groups. Fetal incision dehiscence and wound revision were not significantly different between groups. Critical clinical outcomes including fetal demise, perinatal death, and neonatal death were all infrequent occurrences and not associated with placental location.

CONCLUSIONS

Anterior placental location is associated with increased risk of intraoperative fetal resuscitation and increased thinning at the hysterotomy closure site. Individual institutional experiences may have varied but the aggregate data from the fMMC Consortium did not show a significant impact on the gestational age at delivery or maternal or fetal clinical outcomes.

Brine-driven destruction of clay minerals in Gale crater, Mars

Mars' sedimentary rock record preserves information on geological (and potential astrobiological) processes that occurred on the planet billions of years ago. The Curiosity rover is exploring the lower reaches of Mount Sharp, in Gale crater on Mars. A traverse from Vera Rubin ridge to Glen Torridon has allowed Curiosity to examine a lateral transect of rock strata laid down in a martian lake ~3.5 billion years ago. We report spatial differences in the mineralogy of time-equivalent sedimentary rocks <400 meters apart. These differences indicate localized infiltration of silica-poor brines, generated during deposition of overlying magnesium sulfate-bearing strata. We propose that destabilization of silicate minerals driven by silica-poor brines (rarely observed on Earth) was widespread on ancient Mars, because sulfate deposits are globally distributed.

Outcomes following a clinical algorithm allowing for delayed hysterectomy in the management of severe placenta accreta spectrum

BACKGROUND

The incidence of placenta accreta spectrum is rising. Management is most commonly with cesarean hysterectomy. These deliveries often are complicated by massive hemorrhage, urinary tract injury, and admission to the intensive care unit. Up to 60% of patients require transfusion of ≥4 units of packed red blood cells. There is also a significant risk of death of up to 7%.

OBJECTIVE

The purpose of this study was to assess the outcomes of patients with antenatal diagnosis of placenta percreta that was managed with delayed hysterectomy as compared with those patients who underwent immediate cesarean hysterectomy.

STUDY DESIGN

We performed a retrospective study of all patients with an antepartum diagnosis of placenta percreta at our large academic institution from January 1, 2012, to May 30, 2018. Patients were treated according to standard clinical practice that included scheduled cesarean delivery at 34-35 weeks gestation and intraoperative multidisciplinary decision-making regarding immediate vs delayed hysterectomy. In cases of delayed hysterectomy, the hysterotomy for cesarean birth used a fetal surgery technique to minimize blood loss, with a plan for hysterectomy 4-6 weeks after delivery. We collected data regarding demographics, maternal comorbidities, time to interval hysterectomy, blood loss, need for transfusion, occurrence of urinary tract injury and other maternal complications, and maternal and fetal mortality rates. Descriptive statistics were performed, and Wilcoxon rank-sum and chi-square tests were used as appropriate.

RESULTS

We identified 49 patients with an antepartum diagnosis of placenta percreta who were treated at Vanderbilt University Medical Center during the specified period. Of these patients, 34 were confirmed to have severe placenta accreta spectrum, defined as increta or percreta at the time of delivery. Delayed hysterectomy was performed in 14 patients: 9 as scheduled and 5 before the scheduled date. Immediate cesarean hysterectomy was completed in 20 patients: 16 because of intraoperative assessment of resectability and 4 because of preoperative or intraoperative bleeding. The median (interquartile range) estimated blood loss at delayed hysterectomy of 750 mL (650-1450 mL) and the sum total for delivery and delayed hysterectomy of 1300 mL (70 -2150 mL) were significantly lower than the estimated blood loss at immediate hysterectomy of 3000 mL (2375-4250 mL; P<.01 and P=.037, respectively). The median (interquartile range) units of packed red blood cells that were transfused at delayed hysterectomy was 0 (0-2 units), which was significantly lower than units transfused at immediate cesarean hysterectomy (4 units [2-8.25 units]; P<.01). Nine of 20 patients (45%) required transfusion of ≥4 units of red blood cells at immediate cesarean hysterectomy, whereas only 2 of 14 patients (14.2%) required transfusion of ≥4 units of red blood cells at the time of delayed hysterectomy (P=.016). There was 1 maternal death in each group, which were incidences of 7% and 5% in the delayed and immediate hysterectomy patients, respectively.

CONCLUSION

Delayed hysterectomy may represent a strategy for minimizing the degree of hemorrhage and need for massive blood transfusion in patients with an antenatal diagnosis of placenta percreta by allowing time for uterine blood flow to decrease and for the placenta to regress from surrounding structures.

Intrauterine closure of myelomeningocele is associated with superior long-term quality of life than postnatal closure: a single-center study

OBJECTIVE

The Management of Myelomeningocele Study (MOMS) established several important benefits of myelomeningocele fetal closure, including decreased need for shunting at 30 months. However, the effects of fetal closure on long-term quality of life (QOL) have not been studied. In this study, the authors aimed to analyze the differences in long-term QOL between children treated with intrauterine repair and those treated with postnatal repair.

METHODS

Caregivers of children treated with either intrauterine or postnatal closure at a tertiary acute care hospital between 1997 and 2003 were contacted to participate. The Pediatric Quality of Life Inventory (PedsQL 4.0) and a surgical history questionnaire were administered over the phone. Responses to the QOL survey were reverse scored and linearly transformed to a 0-100 scale, with a higher score indicating better QOL. The Mann-Whitney U-test was used to analyze differences in means.

RESULTS

Seventy-four children had MMC repair between 1997 and 2003. Twenty-three (31%) of the patients' families responded to the PedsQL 4.0 questionnaire. Of these 23 children, 11 had intrauterine closure and 12 had postnatal closure. The intrauterine group did not differ in age (median [IQR] 17 years [14-17 years] vs 15 years [14-19 years], p = 0.926), sex (27.3% vs 41.7% male, p = 0.469), or lesion level (p = 0.199) from the postnatal group. Fewer patients in the intrauterine group underwent neurosurgical procedures than those in the postnatal group (55.6% vs 100%, p = 0.018). However, of the children receiving neurosurgical procedures, there was no difference in the number of procedures between the intrauterine and postnatal groups (median [IQR] 4 [2-10.5] vs 2.5 [1.75-6.25], p = 0.458). There was no difference in the percentage of children receiving nonneurosurgical procedures between the two groups (100% vs 100%, p > 0.99). Children who underwent intrauterine closure had significantly higher psychosocial health (median [IQR] 70.0 [56.7-83.3] vs 55.0 [42.1-60.0], p = 0.015) as well as total QOL (median [IQR] 56.5 [55.4-81.5] vs 49.5 [32.9-59.0], p = 0.019) than children with postnatal closure. Physical health was not significantly different between the two groups (median [IQR] 62.5 [37.5-78.1] vs 39.1 [18.8-59.4], p = 0.108).

CONCLUSIONS

Relative to postnatal closure, children who underwent intrauterine closure of MMC demonstrated better long-term QOL as measured by psychosocial and overall QOL metrics. Given that not all medical and socioeconomic confounders were adjusted for due to the low sample size, validation of these results in a larger population and across multiple centers is needed.

Subsequent pregnancy outcomes after open maternal-fetal surgery for myelomeningocele

BACKGROUND

Open maternal-fetal surgery for fetal myelomeningocele results in reduction in neonatal morbidity related to spina bifida but may be associated with fetal, neonatal, and maternal complications in subsequent pregnancies.

OBJECTIVE

The objective of this study was to ascertain obstetric risk in subsequent pregnancies after open maternal-fetal surgery for fetal myelomeningocele closure.

STUDY DESIGN

An international multicenter prospective observational registry created to track and report maternal, obstetric, fetal/neonatal, and subsequent pregnancy outcomes following open maternal-fetal surgery for fetal myelomeningocele was evaluated for subsequent pregnancy outcome variables. Institutional Review Board approval was obtained for the registry.

RESULTS

From 693 cases of open maternal-fetal surgery for fetal myelomeningocele closure entered into the registry, 77 subsequent pregnancies in 60 women were identified. The overall live birth rate was 96.2%, with 52 pregnancies delivering beyond 20 weeks gestational age and median gestational age at delivery of 37 (36.3-37.1) weeks. The uterine rupture rate was 9.6% (n = 5), resulting in 2 fetal deaths. Maternal transfusion was required in 4 patients (7.7%).

CONCLUSION

The risk of uterine rupture or dehiscence in subsequent pregnancies with associated fetal morbidity after open maternal-fetal surgery is significant, but is similar to that reported for subsequent pregnancies after classical cesarean deliveries. Future pregnancy considerations should be included in initial counseling for women contemplating open maternal-fetal surgery.

Development of a visually guided Raman spectroscopy probe for cervical assessment during pregnancy

Preterm birth (PTB) is the leading cause of neonatal death, however, accurate prediction methods do not exist. Detection of early changes in the cervix, an organ that biochemically remodels to deliver the fetus, has potential to predict PTB risk. Researchers have employed light-based methods to monitor biochemical changes in the cervix during pregnancy, however, these approaches required patients to undergo a speculum examination which many patients find uncomfortable and is not standard practice during prenatal care. Herein, a visually guided optical probe is presented that measures the cervix via introduction by bimanual examination, a procedure that is commonly performed during prenatal visits and labor for tactile monitoring of the cervix. The device incorporates a Raman spectroscopy probe for biochemical monitoring and a camera for visualizing measurement location to ensure it is void of cervical mucus and blood. This probe was tested in 15 patients receiving obstetric and gynecological care, and results acquired with and without a speculum revealed similar spectra, demonstrating that the visually guided probe conserved data quality. Additionally, the majority of patients reported reduced discomfort from the device. In summary, the visual guidance probe successfully measured the cervix while integrating with standard prenatal care, reducing a barrier in clinical translation.

Applying a physiologic partograph to Consortium on Safe Labor data to identify opportunities for safely decreasing cesarean births among nulliparous women

BACKGROUND

The timing of hospital admission for women with spontaneous labor onset and the criteria used to assess active labor progress and diagnose labor dystocia may significantly influence women's risk for primary cesarean birth. Our aims were to assess associations of labor status at admission (i.e., preactive or active) and active labor progress (i.e., dystocic or physiologic) with oxytocin augmentation, cesarean birth, and adverse neonatal outcome rates.

METHODS

A sample of low-risk, nulliparous women admitted to hospitals for spontaneous labor onset was extracted from the Consortium on Safe Labor (n = 27 077). Binomial logistic regression was used to assess associations between labor classifications and outcomes.

RESULTS

At admission, 68.0% of women were in preactive labor and 32.0% were in active labor. Cesarean rates for these groups were 18.0% and 7.2%, respectively (adjusted odds ratio [AOR] 2.69; 95% CI 2.45-2.96). Oxytocin augmentation and adverse neonatal outcomes were more likely for women admitted in preactive labor. Among women admitted in active labor, 9.3% experienced labor dystocia and 90.7% progressed physiologically. Cesarean rates for these groups were 20.4% and 5.9%, respectively (AOR 3.02; 95% CI 2.45-3.73). Nearly half of the cesareans performed for dystocia among women admitted in active labor occurred when cervical dilation was physiologic. Oxytocin augmentation and adverse neonatal outcomes were more likely when active labor was dystocic.

CONCLUSIONS

Adoption of evidence-based, standardized approaches for diagnosing active labor onset, assessing labor progress, and diagnosing dystocia may safely decrease oxytocin augmentation and cesarean birth rates in the United States.

Consumer health-related needs of pregnant women and their caregivers

Objectives

To build effective applications, technology designers must understand consumer health needs. Pregnancy is a common health condition, and expectant families have unanswered questions. This study examined consumer health-related needs in pregnant women and caregivers and determined the types of needs that were not met.

Materials and Methods

We enrolled pregnant women <36 weeks’ gestational age and caregivers from advanced maternal–fetal and group prenatal care settings. Participant characteristics were collected through surveys, and health-related needs were elicited in semi-structured interviews. Researchers categorized needs by semantic type and whether they were met (ie, met, partially met, or unmet). Inter-rater reliability was measured by Cohen’s kappa.

Results

Seventy-one pregnant women and 29 caregivers participated and reported 1054 needs, 28% unmet, and 49% partially met. Need types were 66.2% informational, 15.9% logistical, 8.9% social, 8.6% medical, and 0.3% other. Inter-rater reliability was near perfect (κ=0.95, P < 0.001).

Discussion

Common topics of unmet needs were prognosis, life management, and need for emotional support. For pregnant women, these unmet needs focused around being healthy, childbirth, infant care, and being a good mother; caregivers’ needs involved caring for the mother, the natural course of pregnancy, and life after pregnancy.

Conclusion

Pregnant women and caregivers have a rich set of health-related needs with many not fully met. Caregivers’ needs differed from those of pregnant women and may not be adequately addressed by resources designed for mothers. Many unmet needs involved stress and life management. Knowledge about consumer health needs can inform the design of better technologies for pregnancy.

In vivo Raman spectroscopy for biochemical monitoring of the human cervix throughout pregnancy

BACKGROUND

The cervix must undergo significant biochemical remodeling to allow for successful parturition. This process is not fully understood, especially in instances of spontaneous preterm birth. In vivo Raman spectroscopy is an optical technique that can be used to investigate the biochemical composition of tissue longitudinally and noninvasively in human beings, and has been utilized to measure physiology and disease states in a variety of medical applications.

OBJECTIVE

The purpose of this study is to measure in vivo Raman spectra of the cervix throughout pregnancy in women, and to identify biochemical markers that change with the preparation for delivery and postpartum repair.

STUDY DESIGN

In all, 68 healthy pregnant women were recruited. Raman spectra were measured from the cervix of each patient monthly in the first and second trimesters, weekly in the third trimester, and at the 6-week postpartum visit. Raman spectra were measured using an in vivo Raman system with an optical fiber probe to excite the tissue with 785 nm light. A spectral model was developed to highlight spectral regions that undergo the most changes throughout pregnancy, which were subsequently used for identifying Raman peaks for further analysis. These peaks were analyzed longitudinally to determine if they underwent significant changes over the course of pregnancy (P < .05). Finally, 6 individual components that comprise key biochemical constituents of the human cervix were measured to extract their contributions in spectral changes throughout pregnancy using a linear combination method. Patient factors including body mass index and parity were included as variables in these analyses.

RESULTS

Raman peaks indicative of extracellular matrix proteins (1248 and 1254 cm^-1) significantly decreased (P < .05), while peaks corresponding to blood (1233 and 1563 cm^-1) significantly increased (P < .0005) in a linear manner throughout pregnancy. In the postpartum cervix, significant increases in peaks corresponding to actin (1003, 1339, and 1657 cm^-1) and cholesterol (1447 cm^-1) were observed when compared to late gestation, while signatures from blood significantly decreased. Postpartum actin signals were significantly higher than early pregnancy, whereas extracellular matrix proteins and water signals were significantly lower than early weeks of gestation. Parity had a significant effect on blood and extracellular matrix protein signals, with nulliparous patients having significant increases in blood signals throughout pregnancy, and higher extracellular matrix protein signals in early pregnancy compared to patients with prior pregnancies. Body mass index significantly affected actin signal contribution, with low body mass index patients showing decreasing actin contribution throughout pregnancy and high body mass index patients demonstrating increasing actin signals.

CONCLUSION

Raman spectroscopy was successfully used to biochemically monitor cervical remodeling in pregnant women during prenatal visits. This foundational study has demonstrated sensitivity to known biochemical dynamics that occur during cervical remodeling, and identified patient variables that have significant effects on Raman spectra throughout pregnancy. Raman spectroscopy has the potential to improve our understanding of cervical maturation, and be used as a noninvasive preterm birth risk assessment tool to reduce the incidence, morbidity, and mortality caused by preterm birth.

Shipping noise in a dynamic sea: a case study of grey seals in the Celtic Sea

Shipping noise is a threat to marine wildlife. Grey seals are benthic foragers, and thus experience acoustic noise throughout the water column, which makes them a good model species for a case study of the potential impacts of shipping noise. We used ship track data from the Celtic Sea, seal track data and a coupled ocean-acoustic modelling system to assess the noise exposure of grey seals along their tracks. It was found that the animals experience step changes in sound levels up to ~20dB at a frequency of 125Hz, and ~10dB on average over 10-1000Hz when they dive through the thermocline, particularly during summer. Our results showed large seasonal differences in the noise level experienced by the seals. These results reveal the actual noise exposure by the animals and could help in marine spatial planning.

The Management of Myelomeningocele Study: obstetrical outcomes and risk factors for obstetrical complications following prenatal surgery

BACKGROUND

The Management of Myelomeningocele Study was a multicenter randomized trial to compare prenatal and standard postnatal closure of myelomeningocele. The trial was stopped early at recommendation of the data and safety monitoring committee and outcome data for 158 of the 183 randomized women published.

OBJECTIVE

In this report, pregnancy outcomes for the complete trial cohort are presented. We also sought to analyze risk factors for adverse pregnancy outcome among those women who underwent prenatal myelomeningocele repair.

STUDY DESIGN

Pregnancy outcomes were compared between the 2 surgery groups. For women who underwent prenatal surgery, antecedent demographic, surgical, and pregnancy complication risk factors were evaluated for the following outcomes: premature spontaneous membrane rupture ≤34 weeks 0 days (preterm premature rupture of membranes), spontaneous membrane rupture at any gestational age, preterm delivery at ≤34 weeks 0 days, nonintact hysterotomy (minimal uterine wall tissue between fetal membranes and uterine serosa, or partial or complete dehiscence at delivery), and chorioamniotic membrane separation. Risk factors were evaluated using χ² and Wilcoxon tests and multivariable logistic regression.

RESULTS

A total of 183 women were randomized: 91 to prenatal and 92 to postnatal surgery groups. Analysis of the complete cohort confirmed initial findings: that prenatal surgery was associated with an increased risk for membrane separation, oligohydramnios, spontaneous membrane rupture, spontaneous onset of labor, and earlier gestational age at birth. In multivariable logistic regression of the prenatal surgery group adjusting for clinical center, earlier gestational age at surgery and chorioamniotic membrane separation were associated with increased risk of spontaneous membrane rupture (odds ratio, 1.49; 95% confidence interval, 1.01-2.22; and odds ratio, 2.96, 95% confidence interval, 1.05-8.35, respectively). Oligohydramnios was associated with an increased risk of subsequent preterm delivery (odds ratio, 9.21; 95% confidence interval, 2.19-38.78). Nulliparity was a risk factor for nonintact hysterotomy (odds ratio, 3.68; 95% confidence interval, 1.35-10.05).

CONCLUSION

Despite the confirmed benefits of prenatal surgery, considerable maternal and fetal risk exists compared with postnatal repair. Early gestational age at surgery and development of chorioamniotic membrane separation are risk factors for ruptured membranes. Oligohydramnios is a risk factor for preterm delivery and nulliparity is a risk factor for nonintact hysterotomy at delivery.

Adiponectin and Insulin in Gray Seals during Suckling and Fasting: Relationship with Nutritional State and Body Mass during Nursing in Mothers and Pups

Animals that fast during breeding and/or development, such as phocids, must regulate energy balance carefully to maximize reproductive fitness and survival probability. Adiponectin, produced by adipose tissue, contributes to metabolic regulation by modulating sensitivity to insulin, increasing fatty acid oxidation by liver and muscle, and promoting adipogenesis and lipid storage in fat tissue. We tested the hypotheses that (1) circulating adiponectin, insulin, or relative adiponectin gene expression is related to nutritional state, body mass, and mass gain in wild gray seal pups; (2) plasma adiponectin or insulin is related to maternal lactation duration, body mass, percentage milk fat, or free fatty acid (FFA) concentration; and (3) plasma adiponectin and insulin are correlated with circulating FFA in females and pups. In pups, plasma adiponectin decreased during suckling (linear mixed-effects model [LME]: T = 4.49; P < 0.001) and the early postweaning fast (LME: T = 3.39; P = 0.004). In contrast, their blubber adiponectin gene expression was higher during the early postweaning fast than early in suckling (LME: T = 2.11; P = 0.046). Insulin levels were significantly higher in early (LME: T = 3.52; P = 0.004) and late (LME: T = 6.99; P < 0.001) suckling than in fasting and, given the effect of nutritional state, were also positively related to body mass (LME: T = 3.58; P = 0.004). Adiponectin and insulin levels did not change during lactation and were unrelated to milk FFA or percentage milk fat in adult females. Our data suggest that adiponectin, in conjunction with insulin, may facilitate fat storage in seals and is likely to be particularly important in the development of blubber reserves in pups.

Reducing perinatal complications and preterm delivery for patients undergoing in utero closure of fetal myelomeningocele: further modifications to the multidisciplinary surgical technique

OBJECT.: As more pediatric neurosurgeons become involved with fetal myelomeningocele closure efforts, examining refined techniques in the overall surgical approach that could maximize beneficial outcomes becomes critical. The authors compared outcomes for patients who had undergone a modified technique with those for patients who had undergone fetal repair as part of the earlier Management of Myelomeningocele Study (MOMS).

METHODS

Demographic and outcomes data were collected for a series of 43 delivered patients who had undergone in utero myelomeningocele closure at the Fetal Center at Vanderbilt from March 2011 through January 2013 (the study cohort) and were compared with data for 78 patients who had undergone fetal repair as part of MOMS (the MOMS cohort). For the study cohort, no uterine trocar was used, and uterine entry, manipulation, and closure were modified to minimize separation of the amniotic membrane. Weekly ultrasound reports were obtained from primary maternal-fetal medicine providers and reviewed. A test for normality revealed that distribution for the study cohort was normal; therefore, parametric statistics were used for comparisons.

RESULTS

The incidence of premature rupture of membranes (22% vs 46%, p = 0.011) and chorioamnion separation (0% vs 26%, p < 0.001) were lower for the study cohort than for the MOMS cohort. Incidence of oligohydramnios did not differ between the cohorts. The mean (± SD) gestational age of 34.4 (± 6.6) weeks for the study cohort was similar to that for the MOMS cohort (34.1 ± 3.1 weeks). However, the proportion of infants born at term (37 weeks or greater) was significantly higher for the study cohort (16 of 41; 39%) than for the MOMS cohort (16 of 78; 21%) (p = 0.030). Compared with 10 (13%) of 78 patients in the MOMS cohort, only 2 (4%) of 41 infants in the study cohort were delivered earlier than 30 weeks of gestation (p = 0.084, approaching significance). For the study cohort, 2 fetal deaths were attributed to the intervention, and both were believed to be associated with placental disruption; one of these mothers had previously unidentified thrombophilia. Mortality rates did not statistically differ between the cohorts.

CONCLUSIONS

These early results suggest that careful attention to uterine entry, manipulation, and closure by the surgical team can result in a decreased rate of premature rupture of membranes and chorioamnion separation and can reduce early preterm delivery. Although these results are promising, their confirmation will require further study of a larger series of patients.

Raman spectroscopy provides a noninvasive approach for determining biochemical composition of the pregnant cervix in vivo

The molecular changes that occur with cervical remodelling during pregnancy are not completely understood. This study reviews Raman spectroscopy, an optical technique for detecting changes in the pregnant cervix, and reports preliminary studies on cervical remodelling in mice that suggest that the technique provides advantages over other methods.

CONCLUSION

Raman spectroscopy is sensitive to biochemical changes in the pregnant cervix and has high potential as a tool for detecting premature cervical remodelling in pregnant women.

Liver glucose-6-phosphatase proteins in suckling and weaned grey seal pups: structural similarities to other mammals and relationship to nutrition, insulin signalling and metabolite levels

Phocid seals have been proposed as models for diabetes because they exhibit limited insulin response to glucose, high blood glucose and increasing insulin resistance when fasting. Liver glucose-6-phosphatase (G6Pase) catalyses the final step in glucose production and is central to glucose regulation in other animals. G6Pase comprises a translocase (SLC37A4) and a catalytic subunit (G6PC). G6PC and SLC37A4 expression and activity are normally regulated by nutritional state and glucostatic hormones, particularly insulin, and are elevated in diabetes. We tested the hypotheses that (1) grey seal G6PC and SLC37A4 cDNA and predicted protein sequences differ from other species' at functional sites, (2) relative G6Pase protein abundances are lower during feeding than fasting and (3) relative G6Pase protein abundances are related to insulin, insulin receptor phosphorylation and key metabolite levels. We show that G6PC and partial SLC37A4 cDNA sequences encode proteins sharing 82-95 % identity with other mammals. Seal G6PC contained no differences in sites responsible for activity, stability or subcellular location. Several substitutions in seal SLC37A4 were predicted to be tolerated with low probability, which could affect glucose production. Suckling pups had higher relative abundance of both subunits than healthy, postweaned fasting pups. Furthermore, relative G6PC abundance was negatively related to glucose levels. These findings contrast markedly with the response of relative hepatic G6Pase abundance to feeding, fasting, insulin, insulin sensitivity and key metabolites in other animals, and highlight the need to understand the regulation of enzymes involved in glucose control in phocids if these animals are to be informative models of diabetes.

Is preterm delivery indicated in fetuses with gastroschisis and antenatally detected bowel dilation?

INTRODUCTION

Due to the controversy surrounding diagnostic ultrasound evaluations and elective preterm delivery of fetuses with gastroschisis, we sought to calculate the predictive value of bowel dilation in fetuses with gastroschisis and evaluate the effect of preterm delivery on neonatal outcomes.

MATERIALS AND METHODS

Ultrasounds and medical records of 103 mother-infant pairs with fetal gastroschisis were reviewed. Eighty-nine pairs met the criteria. Intestinal complications, gestational age at delivery, birth weight, and number of abdominal surgeries were documented.

RESULTS

Forty-eight fetuses (54%) had bowel dilation and 41 (46%) did not. The positive predictive value of bowel dilation for complicated gastroschisis was 21%. There were 50 (56%) preterm and 39 (44%) term deliveries. The mean birth weight was 2,114 g (SD = 507) and 2,659 g (SD = 687), p = 0.001. For infants delivered preterm, the mean number of postnatal abdominal surgeries was 2.1 (SD = 1.1) as compared to 1.3 (SD = 0.5) surgical procedures for those infants delivered at term gestation. This was not statistically significant. With respect to hospital stay for each group, the mean length of neonatal intensive care unit admission was 48 days (SD = 33) in the preterm group and 35 days (SD = 50) in the term group, which was not statistically significant.

DISCUSSION

Ultrasound-detected bowel dilation was not predictive of important intestinal complications. Our data did not substantiate any benefit for elective preterm delivery of neonates with gastroschisis.

Predictors of successful labor induction with oral or vaginal misoprostol

OBJECTIVE

To identify independent predictors of successful labor induction with oral or vaginal misoprostol.

METHODS

Women enrolled in four previous randomized trials involving oral or vaginal misoprostol for cervical ripening and labor induction were included in the present cohort study, with dosing of 25-50 microg every 4 to 6 h vaginally (n = 574) or 50 microg every 4 h orally (n = 207). Multiple logistic regression was performed to identify factors independently associated with successful labor induction -- defined as vaginal delivery within 12 h, vaginal delivery within 24 h and spontaneous vaginal delivery. Predictors of Cesarean birth and the need for only one dose of misoprostol were also identified. Variables included in the models were maternal age, weight, height, parity, gravidity, membrane status, route of misoprostol, gestational age, birth weight, and Bishop score and its individual components.

RESULTS

Maternal age, height, weight, parity, birth weight, dilatation, effacement and cervical station were associated with vaginal delivery within 24 h of induction. Maternal age, height, weight, nulliparity, birth weight and route of misoprostol were associated with Cesarean birth, with oral misoprostol being associated with a lower rate of Cesarean birth. The need for only one dose of misoprostol was predicted by maternal height, weight, parity, gestational age, Bishop score and route of misoprostol.

CONCLUSION

Characteristics of the woman (height, weight, parity), the fetus (birth weight) and some of the individual components of the Bishop score, were associated with successful labor induction, with oral misoprostol being associated with a lower rate of Cesarean birth.

First trimester ultrasound screening is effective in reducing postterm labor induction rates: a randomized controlled trial

OBJECTIVE

This study was designed to test the null hypothesis that first trimester ultrasound crown-rump length measurement for gestational age determination will result in no difference in the rate of induction of labor for postterm pregnancy, compared with second trimester biometry alone.

STUDY DESIGN

Two hundred eighteen women were randomly assigned to receive either first trimester ultrasound screening or second trimester ultrasound screening to establish the expected date of confinement. Sample size was calculated by using a 2-tailed alpha=.05 and power (1-beta)=80%. Data were analyzed with chi(2) and Fisher exact tests.

RESULTS

Of 104 women randomly assigned to the first trimester screening group, 41.3% had their gestational age adjusted on the basis of the crown-rump length measurement. Of 92 women randomly assigned to the second trimester screening group, 10.9% were corrected as a result of biometry (P <.001, relative risk=0.26, 95% CI=0.15-0.46). Five women in the first trimester screening group and 12 women in the second trimester screening group had labor induced for postterm pregnancy (P=0.04, relative risk=0.37, 95% CI=0.14-0.96).

CONCLUSION

The application of a program of first trimester ultrasound screening to a low-risk obstetric population results in a significant reduction in the rate of labor induction for postterm pregnancy.

Excessive uterine activity accompanying induced labor

OBJECTIVE

To estimate the incidence and timing of excessive uterine activity accompanying induction of labor with misoprostol using different routes (oral or vaginal) and forms (intact tablet or crushed) and to compare these with dinoprostone gel, oxytocin, and spontaneous labor.

METHODS

This retrospective cohort study included 519 women at term who had labor induced and 86 women at term in spontaneous labor. Induction agents included misoprostol, dinoprostone, or oxytocin. Fetal heart rate and uterine activity tracings were analyzed independently by three maternal-fetal medicine physicians. The diagnosis of tachysystole or hyperstimulation required the agreement of two or more reviewers.

RESULTS

The incidence of tachysystole was highest with misoprostol administered by vaginal tablet (misoprostol vaginal tablet 50 microg every 4 hours, 48.6%; vaginal tablet crushed 50 microg and suspended in hydroxyethyl gel every 4 hours, 30.7%, P =.009; oral tablet 50 microg every 4 hours, 22.2%, P =.001; oral tablet crushed 50 microg every 4 hours, 15.5%, P <.001; dinoprostone gel, 33.0%, P =.022; intravenous oxytocin, 30.2%, P =.027; and spontaneous onset of labor, 23.3%, P <.001). Hyperstimulation occurred more often with dinoprostone gel (16.5%) than with other forms of induction or spontaneous labor. Hyperstimulation occurred significantly more often with vaginal misoprostol crushed tablet (7.9%) and vaginal misoprostol intact tablet (7.6%) than with crushed oral misoprostol (1.0%) (P =.016 and.018, respectively). There was a shorter time to tachysystole with increasing doses of vaginal misoprostol tablet (P =.01).

CONCLUSION

The incidence of tachysystole and hyperstimulation, and time to tachysystole, varied depending on the route and form of misoprostol given.

Pregnancy with cytochrome oxidase-deficient mitochondrial myopathy

BACKGROUND

Cytochrome oxidase-deficient mitochondrial myopathies represent a heterogeneous group of muscle disorders. Physical stress can cause life-threatening risks related to rhabdomyolysis or respiratory compromise.

CASE

A 21-year-old primigravida with cytochrome C oxidase-deficient mitochondrial myopathy who presented for obstetric care at 8 weeks' gestation complained of muscle fatigue and spasm after exertion. The increased metabolic demands of pregnancy led to worsening pain, muscle fatigue, and ultimately complete immobility.

CONCLUSION

Cytochrome oxidase-deficient mitochondrial myopathies are rare but serious complications of pregnancy.

Diurnal and seasonal variations in the duration and depth of the longest dives in southern elephant seals (Mirounga leonina): possible physiological and behavioural constraints

This study seeks to understand how the physiological constraints of diving may change on a daily and seasonal basis. Dive data were obtained from southern elephant seals (Mirounga leonina) from South Georgia using satellite relay data loggers. We analysed the longest (95th percentile) dive durations as proxies for physiological dive limits. A strong, significant relationship existed between the duration of these dives and the time of day and week of year in which they were performed. The depth of the deepest dives also showed a significant, but far less consistent, relationship with local time of day and season. Changes in the duration of the longest dives occurred irrespective of their depth. Dives were longest in the morning (04:00-12:00 h) and shortest in the evening (16:00-00:00 h). The size of the fluctuation varied among animals from 4.0 to 20.0 min. The daily pattern in dive depth was phase-shifted in relation to the diurnal rhythm in dive duration. Dives were deeper at midday and shallower around midnight. Greater daily changes in duration occurred in seals feeding in the open ocean than in those foraging on the continental shelf. The seasonal peak in the duration of the longest dives coincided with austral midwinter. The size of the increase in dive duration from autumn/spring to winter ranged from 11.5 to 30.0 min. Changes in depth of the longest dives were not consistently associated with particular times of year. The substantial diurnal and seasonal fluctuations in maximum dive duration may be a result of changes in the physiological capacity to remain submerged, in addition to temporal changes in the ecological constraints on dive behaviour. We speculate about the role of melatonin as a hormonal mediator of diving capability.

A META-ANALYSIS OF CONTROLLED-RELEASE PROSTAGLANDIN FOR CERVICAL RIPENING AND LABOUR INDUCTION

OBJECTIVES: to examine the effectiveness and safety of controlled-release prostaglandin for cervical ripening. DATA SOURCES: we conducted a computerized search of Medline using the keywords "Cervidil"; or "Propess"; or "prostaglandin/dinoprostone" and "pessary"; or "prostaglandin/dinoprostone" and "controlled" and "release"; or "prostaglandin/dinoprostone" and "vaginal" and "insert"; identifying studies in the English literature published between January 1980 and December 1999. STUDY SELECTION: we included all randomized trials that compared controlled-release vaginal prostaglandin with a retrieval string with any other method of cervical ripening or with a placebo. Nine studies were identified.TABULATION, INTERACTION, AND RESULTS: the two coauthors independently abstracted the data and evaluated the studies for methodologic quality, blinded to each other's results. Homogeneity of results was evaluated, and if present, the summary odds ratio and 95 percent confidence intervals were determined. Compared with placebo, controlled-release prostaglandin resulted in cervical change (summary odds ratio [OR] = 3.99, 95% confidence interval [CI] = 2.71-5.86), a higher rate of vaginal delivery in 12 hours (OR = 29.01, 95% CI = 7.08-118.87), less need for oxytocin (OR = 0.14, 95% CI = 0.06-0.32), but a higher incidence of excessive uterine activity (P<0.0001) and hyperstimulation (P = 0.004). When compared with Prepidil, there was a higher rate of excessive uterine activity with controlled-release prostaglandin (P = 0.03), but less need for oxytocin (OR = 0.09, 95% CI = 0.01-0.53). When compared with Prepidil/immediate oxytocin, there was a lower rate of active labour in 12 hours with controlled-release prostaglandin (OR = 0.27, 95% CI = 0.10-0.72). There was a lower rate of vaginal delivery in 12 hours and higher incidence of oxytocin use with controlled-release prostaglandin as compared with misoprostol (OR = 0.53, 95% CI = 0.34-0.83 and OR = 1.58, 95% CI = 1.08-2.32 respectively). The induction to delivery interval was shorter with controlled-release prostaglandin than with placebo or Prepidil, but longer than with Prepidil/immediate oxytocin, or misoprostol. Although no differences were seen with maternal morbidity (such as Caesarean delivery) or neonatal outcomes, the sample size was not adequate to evaluate these outcomes. CONCLUSION: controlled-release prostaglandin appears to be an effective cervical ripening agent as compared with Prepidil, but may result in an increased incidence of excessive uterine activity. Controlled-release prostaglandin may not be as effective as misoprostol or Prepidil/immediate oxytocin. Further randomized trials with larger sample sizes are needed to evaluate maternal morbidity and neonatal outcomes.

Sexuality and sexual activity in pregnancy

OBJECTIVES

To evaluate women's sexual experience in pregnancy, and to describe their sources of information regarding sexuality during this period.

DESIGN

Cross-sectional study.

SETTING

The offices of obstetricians providing obstetric care in a tertiary care university hospital in St. John's, Newfoundland, Canada.

POPULATION

One hundred and forty-one pregnant women.

METHODS

Pregnant women anonymously completed self-administered questionnaires regarding sexuality and sexual activity during pregnancy. Responses were summarised using descriptive statistics, and comparisons were made between the trimesters of pregnancy. Multiple logistic regression was performed to assess the influences of a variety of factors on sexual activity.

RESULTS

Vaginal intercourse and sexual activity overall decreased throughout pregnancy (P = 0.004 and 0.05, respectively) with the trimester of pregnancy being the only independent predictor. Most women reported a decrease in sexual desire (58%). Overall, 49% of women worried that sexual intercourse may harm the pregnancy. Concerns regarding sexual activity leading to preterm labour or premature rupture of membranes increased as the pregnancy progressed (P < 0-001 and P = 0-001, respectively). Only 29% of women discussed sexual activity in pregnancy with their doctor and 49% of these women raised the issue first, with 34% feeling uncomfortable in bringing up the topic themselves. Most women (76%) who had not discussed these issues with their doctor felt they should be discussed.

CONCLUSIONS

A reduction in sexual activity, vaginal intercourse and sexual desire occurs in many women as pregnancy progresses. Both the woman and her partner have concerns regarding complications in the pregnancy as a result of sexual intercourse. The majority of women wish to discuss these issues with their doctor, but are not always comfortable raising the topic themselves.

Randomized comparison of oral misoprostol and oxytocin for labor induction in term prelabor membrane rupture

OBJECTIVES

To compare labor induction intervals between oral misoprostol and intravenous oxytocin in women who present at term with premature rupture of membranes.

METHODS

One hundred eight women were randomly assigned to misoprostol 50 microg orally every 4 hours as needed or intravenous oxytocin. The primary outcome measure was time from induction to vaginal delivery. Sample size was calculated using a two-tailed alpha of 0.05 and power of 80%.

RESULTS

Baseline demographic data, including maternal age, gestation, parity, Bishop score, birth weight, and group B streptococcal status, were similar. The mean time +/-standard deviation to vaginal birth with oral misoprostol was 720+/-382 minutes compared with 501+/-389 minutes with oxytocin (P = .007). The durations of the first, second, and third stages of labor were similar. There were no differences in maternal secondary outcomes, including cesarean birth (eight and seven, respectively), infection, maternal satisfaction with labor, epidural use, perineal trauma, manual placental removal, or gastrointestinal side effects. Neonatal outcomes including cord pH, Apgar scores, infection, and admission to neonatal intensive care unit were not different.

CONCLUSION

Although labor induction with oral misoprostol was effective, oxytocin resulted in a shorter induction-to-delivery interval. Active labor intervals and other maternal and neonatal outcomes were similar.

A masked randomized comparison of oral and vaginal administration of misoprostol for labor induction

OBJECTIVE

To test the null hypothesis that administering misoprostol orally or vaginally will result in no difference in time to vaginal birth, and to determine whether different frequencies of tachysystole and hyperstimulation are associated with route of administration.

METHODS

Two hundred six women after 37 completed weeks' gestation who presented with an indication for induction were randomly assigned to receive misoprostol (50 microg) either orally or vaginally every 4 hours as needed to induce labor. Placebo use and allocation concealment accomplished blinding until data analysis was completed. Sample size was calculated to allow a two-tailed alpha of .05 and power (1-beta) of 80%. All fetal heart rate and uterine activity graphs were classified according to Curtis' criteria before induction groups were unmasked.

RESULTS

Analysis involved 104 women in the oral group and 102 in the vaginal group. The mean time (+/-standard deviation) to vaginal birth with oral misoprostol was 1072 (+/-593) minutes compared with 846 (+/-385) minutes with the vaginal protocol (P=.004). There were no significant differences in cesarean rate, epidural use, or neonatal outcomes. More frequent tachysystole for 20 minutes (P < .01) and hyperstimulation (P < .04) were observed with vaginal misoprostol. No neonatal asphyxia occurred in either group.

CONCLUSION

Misoprostol effectively induces labor, given orally or vaginally. There is a shorter interval to vaginal birth with vaginal application; however, the more frequent occurrence of fetal heart rate graph abnormalities in this group suggests that, until the optimal dosing interval for vaginal use is determined, the preferred route of misoprostol administration might be oral.

Direct genetic selection of two classes of R17/MS2 coat proteins with altered capsid assembly properties and expanded RNA-binding activities

RNA challenge phages are derivatives of bacteriophage P22 that enable direct genetic selection for a specific RNA-protein interaction. The bacteriophage P22 R17 encodes a wild-type R17 operator site and undergoes lysogenic development following infection of susceptible bacterial strains that express the R17/MS2 coat protein. A P22 R17 derivative with an OcRNA site (P22 R17 [A(-10)U]) develops lytically following infection of these strains. RNA challenge phages can be used to isolate second-site coat protein suppressors that recognize an OcRNA sequence by selecting for lysogens with a P22 R17 [Oc] phage derivative. The bacteriophage derivative P22 R17 [A(-10)U] was used in one such scheme to isolate two classes of genes that encode R17 coat proteins with altered capsid assembly properties and expanded RNA-binding characteristics. These mutations map outside the RNA-binding surface and include amino acid substitutions that interfere with interactions between coat protein dimers in the formation of the stable phage capsid. One class of mutants encodes substitutions at the highly conserved first and second positions of the mature coat protein. N-terminal sequence analysis of these mutants reveals that coat proteins with substitutions only at position 1 are defective in post-translational processing of the initiator methionine. All selected proteins possess expanded RNA-binding properties since they direct efficient lysogen formation for P22 R17 and P22 R17 [A(-10)U]; however, bacterial strains that express the protein mutants remain sensitive to lytic infection by other P22 R17 [Oc] bacteriophages. The described selection strategy provides a novel genetic approach to dissecting protein structure within RNA-binding proteins.

The influence of fixed rotational deformities of the femur on the patellofemoral contact pressures in human cadaver knees

Patellofemoral contact pressures resulting from fixed rotational deformities of the femur were studied in human cadaver knees. The increase in the degree of fixed rotational deformities of the femur results in a nonlinear increase in patellofemoral contact pressures on the contralateral facets of the patella (i.e., external rotational deformity resulted in a contact pressure increase on the medial facet, and internal rotational deformity resulted in a contact pressure increase on the lateral facet of the patella). With the initial isometric tension of 200 N in the quadriceps tendon for 30 degrees, 60 degrees, 90 degrees, and 120 degrees knee flexion, the peak contact pressure showed no significant differences between the medial and lateral facets of the patella in its anatomic position. At 20 degrees of rotational deformity of the femur, only a slight increase was noted for the tension in the quadriceps tendon and the patellofemoral contact pressures on the contralateral facets of the patella. However, at 30 degrees rotational deformity of the femur, both the external and internal rotational deformity of the femur showed a significant increase in the tension of the quadriceps tendon and the patellofemoral contact pressures on contralateral facets of the patella. The greatest increase in patellofemoral contact pressures was observed at 30 degrees and 60 degrees knee flexion for both the external and internal rotational deformity of the femur. The external rotational deformity of the femur for all knee flexion angles showed significantly higher peak patellofemoral contact pressure increases on the medial facet of the patella as compared with the lateral patellofemoral contact pressure increase resulting from internal rotational deformity of the femur.

Acute effects of parenteral beta-blockade on regional ventricular function of infarct and noninfarct zones after reperfusion therapy in humans

Although the mechanism is unknown, clinical trials have suggested that intravenous beta-adrenergic blockade may prevent early cardiac rupture after myocardial infarction. Previous studies have examined effects of beta-blockers on global left ventricular function after myocardial infarction; however, few data exist regarding their immediate effects on regional function or in patients after successful reperfusion. Therefore, 65 patients in whom thrombolysis with or without coronary angioplasty achieved reperfusion at 4.6 +/- 1.7 h from symptom onset were studied. Low osmolarity contrast ventriculograms were obtained immediately before and after administration of 15 mg of intravenous metoprolol (n = 54) or placebo (n = 11). Intravenous metoprolol immediately decreased heart rate (from 92 to 76 beats/min, p less than 0.0001), increased left ventricular diastolic volume (from 150 to 163 ml, p less than 0.001) and systolic volume (from 72 to 77 ml, p less than 0.0005) but did not change systolic and diastolic pressures. Although there was no difference in ejection fraction after metoprolol, centerline chord analysis revealed reduced noninfarct zone motion (from 0.41 to 0.12 SD/chord, p less than 0.05), improved infarct zone motion (from -3.1 to -2.9 SD/chord, p less than 0.01) and smaller circumferential extent of hypokinesia (from 30 to 27 chords, p less than 0.05). Patients with dyskinesia of the infarct zone had the most striking improvement in infarct zone wall motion. Because these changes occurred immediately after beta-blockade, they could not be attributed to myocardial salvage. No significant changes in heart rate, left ventricular volumes or regional wall motion were apparent in the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Determination of sex from arm bone measurements

Discriminant function analysis has been applied to numerous dimensions of the cranial and postcranial skeleton for sex determination of U.S. blacks and whites and is extended here to five measurements of the arm and wrist. These include maximum lengths of the long arm bones in addition to two measurements that reflect wrist breadth. Our results indicate that whites are more accurately classified than blacks, but seven of the 31 possible measurement combinations common to both groups yield functions with sex prediction accuracies comparable to most, but not all, functions based on other parts of the skeleton.

Mechanism of acute myocardial infarction in patients with prior coronary artery bypass grafting and therapeutic implications

Although acute myocardial infarction (AMI) is usually due to thrombotic occlusion when involving a native coronary artery, the mechanism responsible for AMI in patients with previous coronary artery bypass grafting (CABG) is not well understood. Since knowledge of pathophysiology of AMI may alter subsequent management, angiograms obtained between 1 hour and 7 days of AMI (median 1 day) were reviewed in 50 patients greater than 1 year after CABG. The culprit vessel was identified by the presence of residual stenosis and/or thrombus in the vessel supplying the infarct zone or by reviewing previous angiograms. The infarct vessel was identified as a vein graft in 38 (76%) patients, the native vessel in 8 patients (16%) and could not be accurately determined in 4 patients (8%). Among the 38 vein grafts suspected as the infarct vessel, unequivocal angiographic evidence of residual thrombus (filling defect/persistent staining) was present in 31 (82%) and was greater than 2 cm in length in 15 patients. Successful reperfusion occurred in only 2 of 8 (25%) grafts after intravenous thrombolytic therapy. Intragraft thrombolysis with or without additional angioplasty was successful at restoring flow in 8 of 10 (80%) grafts. Data indicate that in patients who have undergone previous CABG, AMI is usually caused by thrombotic occlusion of a saphenous vein graft and that conventional intravenous thrombolytic therapy may be inadequate to restore flow. The large mass of thrombus and absent flow in the graft may require subselective drug infusion, a higher thrombolytic dose or a mechanical means of recanalization.

A new thrombolytic regimen for acute myocardial infarction using combination half dose tissue-type plasminogen activator with full dose streptokinase: a pilot study. KAMIT Study Group

Because a previous study utilizing a combination of recombinant tissue-type plasminogen activator (rt-PA) and urokinase demonstrated reduced reocclusion rates compared with rates obtained with rt-PA alone, this study was conducted to determine whether the combination of rt-PA and streptokinase might achieve similar results at reduced cost. Forty patients with acute myocardial infarction were treated with a 1 h infusion of rt-PA (50 mg) and streptokinase (1.5 million U) administered within 6 h (mean 3.6 +/- 1.2) of symptom onset. Emergency coronary arteriography revealed patency of the infarct-related artery in 30 (75%) of 40 patients. With the addition of coronary angioplasty in those who had unsuccessful thrombolytic reperfusion, the early patency rate was increased to 98%. In-hospital mortality rate (2.5%) and the incidence of significant bleeding requiring transfusion (15%) were low. Angiographically documented reocclusion of the infarct vessel occurred in 3 (8%) of 37 patients by day 7. Regional wall motion of the infarct zone improved by 0.9 +/- 0.9 SD/chord (p less than 0.0005), and ejection fraction increased 3.6 +/- 8% units (p less than 0.05) between immediate and day 7 studies. In contrast to the price of full dose rt-PA ($2,300) or rt-PA with urokinase ($3,500), the cost of this regimen was $1,230. This pilot study demonstrates that at half the cost, a combination of half dose rt-PA with full dose streptokinase offers high infarct vessel patency, recovery of ventricular function, a low rate of reocclusion and few bleeding complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Fluctuating asymmetry in fetuses of diabetic rhesus macaques

This study examines dental fluctuating asymmetry (FA) in two samples of fetal rhesus monkeys, one composed of 19 fetuses from diabetic mothers (FDM) and the other of 20 fetuses from nondiabetic mothers. Seventeen measurements were taken on the deciduous dentition of right and left mandibles. The degree of FA was assessed by comparing FDM to fetuses of normal mothers by correlation between right and left sides, and analysis of variation differences between right and left sides. Significant FA was found for three traits based on the correlation between right and left sides and for seven traits by the between-treatment ratio of variance between sides. Distal teeth, both within and outside of a morphologic field, exhibit significantly greater FA than mesial teeth. Our results support the hypothesis that developmental instability is detectable by dental FA.