Whole-genome sequencing reveals clinically relevant insights into the aetiology of familial breast cancers.

BACKGROUND: Whole-genome sequencing (WGS) is a powerful method for revealing the diversity and complexity of the somatic mutation burden of tumours. Here, we investigated the utility of tumour and matched germline WGS for understanding aetiology and treatment opportunities for high-risk individuals with familial breast cancer. PATIENTS AND METHODS: We carried out WGS on 78 paired germline and tumour DNA samples from individuals carrying pathogenic variants in BRCA1 (n = 26) or BRCA2 (n = 22) or from non-carriers (non-BRCA1/2; n = 30). RESULTS: Matched germline/tumour WGS and somatic mutational signature analysis revealed patients with unreported, dual pathogenic germline variants in cancer risk genes (BRCA1/BRCA2; BRCA1/MUTYH). The strategy identified that 100% of tumours from BRCA1 carriers and 91% of tumours from BRCA2 carriers exhibited biallelic inactivation of the respective gene, together with somatic mutational signatures suggestive of a functional deficiency in homologous recombination. A set of non-BRCA1/2 tumours also had somatic signatures indicative of BRCA-deficiency, including tumours with BRCA1 promoter methylation, and tumours from carriers of a PALB2 pathogenic germline variant and a BRCA2 variant of uncertain significance. A subset of 13 non-BRCA1/2 tumours from early onset cases were BRCA-proficient, yet displayed complex clustered structural rearrangements associated with the amplification of oncogenes and pathogenic germline variants in TP53, ATM and CHEK2. CONCLUSIONS: Our study highlights the role that WGS of matched germline/tumour DNA and the somatic mutational signatures can play in the discovery of pathogenic germline variants and for providing supporting evidence for variant pathogenicity. WGS-derived signatures were more robust than germline status and other genomic predictors of homologous recombination deficiency, thus impacting the selection of platinum-based or PARP inhibitor therapy. In this first examination of non-BRCA1/2 tumours by WGS, we illustrate the considerable heterogeneity of these tumour genomes and highlight that complex genomic rearrangements may drive tumourigenesis in a subset of cases.

The effect of a pill inserter on vaginal misoprostol dosing.

OBJECTIVE: To determine whether the method of placing a 25-microg misoprostol chip into the posterior fornix to achieve cervical ripening affects the drug's efficacy. METHODS: A pill inserter was used to place a misoprostol chip into the posterior fornix for the purpose of cervical ripening prior to induction of labor. Data from a control group were obtained by retrospective chart review. RESULTS: The control and study groups contained 49 patients each. Compared to placing the misoprostol chip with a lubricated finger, the use of the pill inserter resulted in statistically significantly more patients receiving only one dose. This occurred either because a Bishop score of 8 or greater was achieved or because repeat dosing was disallowed secondary to the onset of uterine contractions. Although the total number of patients subsequently requiring oxytocin was significantly increased, there was no difference in the use of oxytocin for either induction or augmentation of labor. The lengths of the latent and active phases of labor did not differ between the two groups. CONCLUSION: The number of doses of a 25-microg misoprostol chip for cervical ripening that result in uterine contractions, with or without a change in the Bishop score, is affected by the method used to place it in the vagina.

Family suite: an innovative method to provide inexpensive postpartum care.

The postpartum hospital stay has been decreasing in the United States in recent decades. Early discharge to achieve cost savings has been criticized by many inside and outside the health care community as sometimes being detrimental to the mother and infant. This article describes the efforts of the administration, nursing staff, and medical staff of a large public urban hospital to develop an alternative to the forced early discharge of mothers and infants.

The effects of Betamethasone on white blood cells during pregnancy with PPROM.

OBJECTIVE: To determine the effects of Betamethasone injections on maternal white blood cell counts. STUDY DESIGN: Thirteen pregnant women without fever or clinical infection and with premature rupture of the membranes at less than 34 weeks gestation were studied. No subject had labor during the week of study. Daily complete blood counts were done before and on days one and two after two 12 mg intramuscular injections of Betamethasone given 24 hours apart. RESULTS: The steroid injections produced a significant increase in total white counts from 9.8 +/- 5.0 to 14.2 +/- 0.7 x 10(3) cells/cc. There was a significant increase in polymorphonucleocytes and a decrease in lymphocytes and monocytes. CONCLUSION: The use of Betamethasone injections to mature fetal lungs results in a leukocytosis, but total white cell counts remain less than 20 x 10(3) cells/cc.

Comparison of the in vivo activity of different oxytocin antagonists in the pregnant baboon.

OBJECTIVE: To ascertain the relative activity of five oxytocin antagonists (OTAs) in vivo in a tethered pregnant baboon model and compare these results to previously reported affinities in human and rat oxytocin receptor assays and median effective dose in rat uterotonic bioassays. METHODS: Pregnant tethered baboons between days 130 and 160 of pregnancy were given an oxytocin challenge test 1 minute after infusion of 1 mg of one of five randomly selected OTAs: ANTAG I, ANTAG II, ANTAG III, L366948, and Atosiban. Once the uterine response to oxytocin returned to normal (1-8 days) the OCT was repeated with one of the remaining, untested OTAs during the 130-160 day period. Uterine activity, the time until the first significant response, and the dose of oxytocin needed to induce this response were all factored into one expression, the antagonist-response interval (ARI). RESULTS: When expressed as ratio to ANTAG I the relative ARI for the OTAs were 0, .5, 1.0, 2.4 and 59.2 for L366948, Atosiban, ANTAG I, ANTAG II, and ANTAG III, respectively. ANTAG III and L366948 were significantly different from each other and the three other OTAs (P < .05). The log10 ARI for the 4 active OTAs when correlated with the log10 of the human and rat oxytocin receptor affinities and the rat uterotonic bioassay were all highly correlated (r = .99; P < .05). CONCLUSION: ANTAG III is a potent, long-acting OTA in vivo in the pregnant baboon and has the potential as a tocolytic in humans.

Morphine inhibits nocturnal oxytocin secretion and uterine contractions in the pregnant baboon.

Morphine is a potent inhibitor of nocturnal uterine contractions (UCs) in the pregnant baboon, and these contractions are known to be induced by oxytocin (OT). The purpose of this study was to determine the mode of action of morphine in inhibiting nocturnal UCs by examining the effect of morphine on OT secretion, OT clearance, and uterine responsiveness to OT. A tethered pregnant baboon model during the last third of gestation was used for these experiments. In study 1, the effects of morphine or control saline on OT release and on spontaneous nocturnal UCs were examined. Study 2 determined the effects of morphine or control saline on the pharmacokinetics of OT after a bolus injection of OT. To exclude/include direct opiate effects on UCs, study 3 examined the responsiveness of the uterus to exogenous OT after morphine or control saline administration. Plasma OT levels were analyzed by RIA after extraction. UCs were assessed by frequency, amplitude, duration, and area under the curve. During nocturnal UCs, morphine, but not saline, administration resulted in the precipitous suppression of integrated OT levels (p < 0.05) to 42% of pretreatment values at 0-15 min postinjection and 17% at 30-45 min. Simultaneously, UCs were significantly suppressed (p < 0.05) by 75% at the 30- to 45-min interval. By 1 h, 5 of 7 animals showed no UCs. In study 2, morphine consistently increased the metabolic clearance rate (MCR) of OT in all trials (p < 0.05), although the magnitude of this effect was small (median 9%). Finally, study 3 demonstrated that myometrial responsiveness to the challenge of exogenous OT was not depressed by opiate administration (p > 0.05). To summarize, the decrease in nocturnal UCs after morphine is primarily due to an inhibition of OT release, and perhaps, but to a much lesser extent, an increase in OT MCR. There was no evidence of a direct tocolytic effect of morphine on the uterus. In conclusion, opioids such as morphine are potent inhibitors of nocturnal UCs and act by suppressing OT release in the pregnant baboon.

Amniotomy to induce labor.

Amniotomy to induce labor is used frequently. The potential risks compared with potential benefits of artificial rupture of membranes have caused the popularity of amniotomy to vary in the last two centuries. Although there are little data available from prospective randomized studies regarding the effectiveness of amniotomy alone to induce labor, several series have showed success in its use. In addition, no well-accepted, prospectively randomized study is available comparing the effectiveness of amniotomy to oxytocin for induction of labor. The most effective combination of amniotomy with uterotonic agents to induce labor is still a fertile area for investigation.

Laparoscopic cholecystectomy in pregnancy. A case report.

Laparoscopic cholecystectomy was performed on a pregnant woman at 18 weeks of gestation without complications. Considering the risk/benefit ratio, laparoscopic cholecystectomy in pregnant women is preferable to conventional cholecystectomy.

Oxytocin antagonist inhibitory effect on the rat and baboon uterus may be overcome by prostaglandins.

OBJECTIVE: A potent, long-acting oxytocin antagonist produced in our laboratory (ANTAG-III) can inhibit uterine response to oxytocin in the rat and baboon for hours and even days. The purpose of this study was to evaluate uterine response to prostaglandins subsequent to the administration of ANTAG-III. STUDY DESIGN: For the rat study one cannula was inserted in the jugular vein, and another cannula to measure uterine activity was inserted in the uterus. In study 1 saline solution or 5 micrograms of ANTAG-III was administered to five rats each, followed by 100 mU of oxytocin at 0.1, 1, and 2 hours. In study 2 six rats each were infused with saline solution of 5 micrograms of ANTAG-III, followed 1 hour later by 5 micrograms of 15-methyl-prostaglandin F2 alpha and uterine activity monitored. After baseline activity returned to normal 100 mU of oxytocin was infused and the uterine response reassessed. For the baboon study ANTAG-III was administered into the aorta of tethered pregnant baboons (n = 2). An oxytocin challenge test was performed starting with 10 mU/min and going up to 400 mU/min. After a significant uterine contractile response was established and activity returned to baseline, a 15-methyl-prostaglandin F2 alpha challenge test was performed. RESULTS: During the period in which the response to oxytocin was inhibited the uterine response to 15-methyl-prostaglandin F2 alpha of the estrous rat and pregnant baboon was maintained. CONCLUSIONS: The inhibition of the estrous rat and pregnant baboon uterus to oxytocin caused by ANTAG-III may be prolonged. During this period uterine response to prostaglandins is not altered.

The benefits of using the loop ligature (Endoloop) laparoscopic sterilization procedure in a residency program.

This study was conducted to determine the impact of the addition of the loop ligation (Endoloop) technique on choice of sterilization surgery in our residency teaching program and to investigate significant differences between this technique and other methods performed at our hospital. A retrospective study of all patients undergoing interval tubal sterilization at Tampa General Hospital in 1989 and 1991 was undertaken. Data were analyzed to determine the frequency of sterilization methods and differences between the loop ligation method and the other procedures performed; p values of less than 0.05 were considered significant. Sixty-one patients in 1989 and 75 in 1991 qualified for the study. Five methods of interval sterilization were performed: loop ligation, minilaparotomy, colpotomy, laparoscopic bipolar fulguration, and Silastic ring application. The frequency of the loop ligature technique increased from 0% in 1989 to 40% in 1991. There were no significant differences in operative time and complication rate among the loop method and other procedures. The loop ligature (Endoloop) method of laparoscopic sterilization does not significantly change the length of surgery, blood loss, or complication rate compared to the other laparoscopic techniques used in our residency program. This method provides a definitive tissue diagnosis, eliminates the risk of thermal injury, theoretically provides an opportunity of later tubal reanastomosis, and subjectively helps develop laparoscopic skills.

Preterm premature rupture of membranes: a randomized study of home versus hospital management.

OBJECTIVE: To compare length of latency period, gestational age at delivery, and safety in a carefully selected group of patients with preterm premature rupture of the membranes (PROM) randomized to home versus hospital management. METHODS: After meeting strict inclusion criteria, 67 patients with preterm PROM were randomized by sealed envelope to home versus hospital expectant management. The groups were managed similarly with pelvic and bed rest. Management included recording of temperature and pulse every 6 hours, daily charting of fetal movements, twice-weekly nonstress test and complete blood count, and weekly ultrasound and visual examination of the cervix. RESULTS: There was no significant difference in clinical characteristics or perinatal outcome between the groups. There was, however, a significant decrease in both the days of maternal hospitalization and maternal hospital expenses in the home group. CONCLUSION: Only a very small proportion of cases of preterm PROM (18%) could meet the strict safety criteria for inclusion used in the study. In the home-management group, length of the latency period and gestational age at delivery were not significantly different than in hospitalized patients.

Forward shift in the initiation of the nocturnal estradiol surge in the pregnant baboon: is this the genesis of labor?

Daily (9 AM and 6 PM) blood samples were obtained from the inferior vena cava during the last trimester of pregnancy in a tethered baboon model. In addition, three 24-hour (hourly blood sampling) studies were performed at days 143 to 147, 158 to 162, and 172 to 177 of pregnancy. Dramatic 24-hour rhythms in progesterone and estradiol were detected, with both steroids surging nocturnally. Early in the third trimester the estradiol surge followed the progesterone surge. However, approximately 10 to 12 days before delivery, the initiation of the nocturnal estradiol surge shifted forward, thus preceding the progesterone surge. This forward shift in the estradiol surge created a daily (3 to 5 hours) window of elevated estradiol-to-progesterone ratio and appears to coincide with the initiation of nocturnal uterine contractions. The nocturnal uterine contractions can be inhibited by an oxytocin antagonist. We hypothesize that this forward shift in the initiation of the estradiol surge induces nocturnal uterine contractions by oxytocin release and/or increase in uterine oxytocin receptors and generates molecular messages that are the genesis for labor and delivery in the baboon.

Human fetal response to vibroacoustic stimulation as a function of stimulus duration.

The effect of stimulus duration on the initial fetal heart rate (FHR) acceleration response was evaluated by assessing its amplitude and span following a single vibroacoustic stimulation with durations of 0 (sham), 1, 3, or 5 seconds. Statistically significant differences were observed in the mean amplitude and duration of acceleration in groups 3 and 5 when compared with groups 0 and 1 (P less than .05). In addition, groups 3 and 5 demonstrated significantly greater fetal reactivity than group 0 and a decrease in testing time over groups 0 and 1 (P less than .05). Our results suggest that the magnitude of the FHR acceleration response is dependent on the duration of the stimulus. Furthermore, a 3-second sound stimulus appears to be adequate for a shift to the fetal behavioral "awake" state.

Inhibition of oxytocin-induced uterine contractions by an oxytocin antagonist in the pregnant baboon.

Uterine contractions were induced with oxytocin in anesthetized pregnant baboons (Papio anubis) at three stages of pregnancy (days 140, 156, and 169; normal gestation length, 184 days). After the contractile activity was greater than two to three contractions every 10 minutes, beta-mercapto-beta, beta-cyclopentamethylenepropionic acid1-[D-Trp2,Phe3,Ile4,Arg8]-oxytocin, a novel oxytocin antagonist produced in our laboratories, was given simultaneously with the oxytocin for 90 minutes. Contractile force (frequency x mean amplitude) was determined for 30 minutes before and for three 30-minute intervals after the oxytocin antagonist was administered. Animals at 140 days' gestation showed a significant (p less than 0.05) decrease in contractile force in the first 30-minute interval after oxytocin antagonist infusion was initiated, whereas those at days 156 and 169 showed decreases (p less than 0.05) at the second 30-minute interval. In addition, in late gestation a higher dose of oxytocin antagonist per unit of oxytocin was required to prevent uterine contractions. In conclusion, these results suggest (1) that an oxytocin antagonist can inhibit oxytocin-induced uterine contractions in the pregnant baboon and (2) that the interval from oxytocin antagonist administration to significant inhibition of uterine contractions appears to increase with advancing gestational age.

Fetal head molding. Diagnosis by ultrasound and a review of the literature.

Head molding refers to changes in cranial bone relationships that occur in response to external compression force. In the normal term labor with vertex presentation, the suboccipito-bregmatic diameter shortens and the mentovertical diameter lengthens. This is accomplished partially through the unbending or straightening of the parietal bones rather than the frequently taught mechanism of overlapping sutures. The occipital and frontal bones may also contribute by an inward movement of their apex, using their basal portions as a hinge. A locking mechanism may occur in protracted labors as the free edges of the cranial bones are forced into one another, preventing further molding and providing more protection for the fetal brain. The preterm skull has weaker material properties and wider sutures. Thus, more molding at lower pressures is possible and the protective effect of "locking" may not be operational. A case of extreme antenatal preterm fetal head molding discovered at ultrasound is presented as an introduction to review the literature regarding molding.

Peritoneal closure or non-closure at cesarean.

The value of peritoneal closure at the time of cesarean birth was evaluated prospectively. Two hundred forty-eight women undergoing low transverse cesarean through a Pfannenstiel skin incision were assigned to one of two groups: peritoneum open (N = 127) or peritoneum closed (N = 121). The mean (+/- SEM) surgical time in the open group (48.1 +/- 1.2 minutes) was significantly less than for the closed group (53.2 +/- 1.4 minutes) (P less than .005). There were no postoperative differences between the groups in the incidence of wound infection, dehiscence, endometritis, ileus, and length of hospital stay. Our study suggests that leaving the parietal peritoneum unsutured is an acceptable way to manage patients at cesarean delivery.

Inhibition of spontaneous uterine contractions during the last trimester in pregnant baboons by an oxytocin antagonist.

The effect of a potent oxytocin antagonist, produced in our laboratories, on spontaneous uterine contractions in the pregnant baboon was examined. Three types of uterine contractions were studied: immediately after operation, during the nocturnal period, and near or at labor. Bolus intravenous injections of oxytocin antagonist were given and uterine activity was examined +/- 1 hour after the injection. The oxytocin antagonist caused a precipitate decrease (approximately 70%) in contractile force (mean amplitude x frequency) in the first 15 minutes after injection (p less than 0.05); this force diminished to approximately 90% at the end of 1 hour for both nocturnal and labor contractions. In contrast, uterine contractions immediately after operation were diminished by only 60% within 60 minutes after the oxytocin antagonist. These results indicate that the oxytocin antagonist is a potent inhibitor and suggest that oxytocin is a primary regulator of spontaneous nocturnal and labor uterine contractions in the pregnant baboon.

Cocaine use and its effect on umbilical artery prostacyclin production.

Cocaine's association with adverse perinatal outcome has been attributed to its inhibition of norepinephrine uptake. This study examined the effect of cocaine on umbilical artery prostacyclin (PGI2) production. Umbilical arteries from pregnant cocaine users and controls were incubated in vitro and PGI2 levels in the media determined by measuring its stable metabolite, 6-keto-PGF1 alpha, by RIA. Cocaine users showed a significant decrease (p less than .05) in PGI2 production from their umbilical arteries when compared to controls. This appears to be through a direct effect of cocaine, as it decreases PGI2 production when added in vitro to umbilical arteries from controls. In addition, in vitro phospholipase A2 activity is inhibited by cocaine in a dose-dependent manner. These results suggest that the adverse perinatal outcome associated with cocaine use may be due in part to reduced vascular PGI2 production in the fetus.

A new tocolytic agent: development of an oxytocin antagonist for inhibiting uterine contractions.

A potent oxytocin antagonist has been developed and tested on both the rat and human uterus. In the rat the oxytocin antagonist: (1) inhibited in vitro and in vivo uterine contractions in the nonpregnant animal in response to exogenous oxytocin, (2) inhibited milk letdown, and (3) disrupted the progress of labor. In addition, the oxytocin antagonist inhibited the in vitro contractile response to exogenous oxytocin of human myometrial tissue obtained by cesarean section at term. The results of these studies suggest that the oxytocin antagonist can be used to study the role of oxytocin in labor and has the potential of inhibiting preterm labor in humans.

Pregnancy outcomes in short women.

The pregnancy outcomes in 3,059 women who were 122-152 cm (48-60 in) tall with singleton pregnancies were compared to those of 7,414 women who were 160 cm (63 in) tall. The short women were of lower weight at delivery and had slightly higher parity. There were fewer whites in the short group. The higher parity was associated with a slightly higher occurrence of placenta previa. The pregnancies in the short women were characterized by smaller infants and more frequent delivery by cesarean section, depending on race. For whites the cesarean section rate was 43% in the very-short group (122-136 cm, or 48-53 in), 35% in the short group (137-151 cm, or 54-59 in) and 23% in the control group. The results suggest that women less than 152 cm (60 in) tall are a high-risk group.