Fetal fraction-based risk algorithm for non-invasive prenatal testing: screening for trisomies 13 and 18 and triploidy in women with low cell-free fetal DNA

OBJECTIVE

To identify pregnancies at increased risk for trisomy 13, trisomy 18 or triploidy attributable to low fetal fraction (FF).

METHODS

A FF-based risk (FFBR) model was built using data from more than 165 000 singleton pregnancies referred for single-nucleotide polymorphism (SNP)-based non-invasive prenatal testing (NIPT). Based on maternal weight and gestational age (GA), FF distributions for normal, trisomy 13, trisomy 18 and triploid pregnancies were constructed and used to adjust prior risks for these abnormalities. A risk cut-off of ≥ 1% was chosen to define pregnancies at high risk for trisomy 13, trisomy 18 or triploidy (high FFBR score). The model was evaluated on an independent blinded set of pregnancies for which SNP-based NIPT did not return a result, and for which pregnancy outcome information was gathered retrospectively.

RESULTS

The evaluation cohort comprised 1148 cases, of which approximately half received a high FFBR score. Compared with rates expected based on maternal age (MA) and GA, cases with a high FFBR score had a significantly increased rate of trisomy 13, trisomy 18 or triploidy combined (5.7% vs 0.7%; P < 0.001) and also of unexplained pregnancy loss (14.7% vs 10.4%; P < 0.001). For cases that did not receive a high FFBR score, the incidence of a chromosomal abnormality or pregnancy loss was not significantly different from that expected based on MA and GA. In this study cohort, the sensitivity of the FFBR model for detection of trisomy 13, trisomy 18 or triploidy was 91.4% (95% CI, 76.9-98.2%) with a positive predictive value of 5.7% (32/564; 95% CI, 3.9-7.9%).

CONCLUSIONS

For pregnancies with a FF too low to receive a result on standard NIPT, the FFBR algorithm identified a subset of cases at increased risk for trisomy 13, trisomy 18 or triploidy. For the remainder of cases, the risk of a fetal chromosomal abnormality was unchanged from that expected based on MA and GA. © 2018 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Two-dimensional and 3-dimensional optical coherence tomographic imaging of the airway, lung, and pleura

BACKGROUND

Methods for obtaining real-time in vivo histologic resolution by means of noninvasive endoscopic optical imaging would be a major advance for thoracic surgical diagnostics and treatment. Optical coherence tomography is a rapidly evolving technology based on near-infrared interferometry that might provide these capabilities. The purpose of this study is to investigate the feasibility of real-time 2- and 3-dimensional optical coherence tomographic imaging of airway, pleural, and subpleural lung tissues in normal, inflammatory, and malignant animal models and patients with known or suspected airway malignancy.

METHODS

Freshly excised lungs and pleural tissue obtained from rabbits with inhalation lung injury and induced empyema, metastatic sarcomas, and pleural sarcomas and from patients with airway disease were imaged by using 2- and 3-dimensional optical coherence tomography with a prototype superluminescent diode optical coherence tomographic system constructed in our laboratory. Lungs and pleural tissue were subsequently processed for standard hematoxylin and eosin histology for comparison with optical coherence tomography.

RESULTS

Optical coherence tomographic imaging achieved an ex vivo resolution of 10 microm and an in vivo resolution of about 30 microm with a depth penetration of 1 to 2 mm with 2- and 3- dimensional reconstruction capabilities. Tumors as small as 500 microm were detectable with optical coherence tomography. The acquired images closely matched histologic images, demonstrating details at the level of mucosal layers, glands, alveoli, and respiratory bronchioles.

CONCLUSIONS

Optical coherence tomography with near-infrared interferometric methods enables near real-time in vivo near-histologic resolution optical imaging. With further advances, optical coherence tomography has the potential for real-time accurate and early pleural and subpleural diagnostics by using small-diameter flexible fiberoptic endoscopic probes for a wide range of thoracic surgical applications.

In vitro and in vivo cytotoxicity of an anti-osteosarcoma immunotoxin containing pokeweed antiviral protein

Successful treatment of many patients with osteosarcoma requires more effective chemotherapy. Since new agents are needed, we have developed an immunotoxin using TP-3, an IgG2b mAb which recognizes human and canine osteosarcomas and budding capillaries of tumors. The plant hemitoxin, pokeweed antiviral protein (PAP), was conjugated to TP-3 to produce an immunotoxin highly active against osteosarcoma. After 48 h no viable human OHS osteosarcoma cells were present in cultures containing TP-3-PAP as demonstrated by the absence of [3H]thymidine uptake into DNA. Furthermore, clonogenic assays indicated > 3.9 log kill of OHS at 18 h. The IC50 of TP-3-PAP against OHS was 3.5 +/- 1.0 (SD) x 10(-12) M. TP-3 mAb without PAP had no effect on OHS proliferation; PAP alone had no effect on OHS growth unless concentrations > 1000 pM were used. When TP-3-PAP (1.25 micrograms-10.0 micrograms) was given i.p. q.d. on days 3-5 after tumor inoculation, a dose-dependent reduction of the number of lung metastases was observed (P < 0.001). These results indicate that the TP-3-PAP immunotoxin may be useful in the treatment of osteosarcoma and some soft tissue sarcomas.

Corticotrophin releasing hormone levels in human plasma and amniotic fluid during gestation

OBJECTIVE

Corticotrophin releasing hormone, a hypothalamic neuropeptide also made in placenta, may regulate fetal maturation in a stress-responsive manner. The objectives of this study were: (1) to determine if levels of corticotrophin releasing hormone in the amniotic fluid correlate with fetal lung maturation; (2) to confirm that third trimester plasma levels of corticotrophin releasing hormone are increased in patients with pregnancy-induced hypertension compared to normotensives, and (3) to increase the recovery of extracted corticotrophin releasing hormone from plasma and amniotic fluid.

DESIGN

(1) Levels of corticotrophin releasing hormone in amniotic fluid during the third trimester were compared with those of saturated phosphatidyl choline. (2) Corticotrophin releasing hormone levels were measured in a group of normotensive pregnant women during the entire gestation period. Corticotrophin releasing hormone levels during the third trimester were compared in normotensives and patients with pregnancy-induced hypertension.

PATIENTS

Twenty-one non-pregnant normal volunteers and 63 pregnant women.

MEASUREMENTS

Blood pressure, corticotrophin releasing hormone in plasma and amniotic fluid, and saturated phosphatidyl choline in amniotic fluid.

RESULTS

Corticotrophin releasing hormone levels in amniotic fluid samples during the third trimester ranged from 12 to 98 pmol/l and positively correlated with the saturated phosphatidyl choline levels, but not with gestational age. A significant difference existed in plasma corticotrophin releasing hormone concentration between gestational age-matched third trimester normotensive and hypertensive gravids: corticotrophin releasing hormone levels were significantly lower in normotensives (223 +/- 65 pmol/l) than in patients with pregnancy-induced hypertension (544 +/- 106 pmol/l, P = 0.001). Plasma corticotrophin releasing hormone increased with gestational age from 51 pmol/l (range 8.4-85) at 25-32 weeks to 375 pmol/l (range 35-1386) at 33-40 weeks. During the third trimester the rise in plasma corticotrophin releasing hormone conformed to an exponential mathematical model of a positive feedback loop between placental corticotrophin releasing hormone and fetal adrenal cortisol.

CONCLUSIONS

During the third trimester of pregnancy there is a positive correlation between the level of amniotic fluid corticotrophin releasing hormone and that of saturated phosphatidyl choline. The positive correlation between amniotic fluid corticotrophin releasing hormone and saturated phosphatidyl choline, but not between amniotic fluid corticotrophin releasing hormone and gestational age, suggests that a factor(s), such as stress, may affect both amniotic fluid corticotrophin releasing hormone and saturated phosphatidyl choline in parallel. Furthermore, our data are consistent with the hypothesis that the rise in placental corticotrophin releasing hormone is coupled to an increase in fetal glucocorticoid and lung maturation, and that stresses such as pregnancy-induced hypertension may accelerate this process.

The microvasculature in skeletal muscle. VI. Adrenergic innervation of arterioles in normotensive and spontaneously hypertensive rats

A microanatomical study of the adrenergic nerve plexus on the arterioles in the spinotrapezius muscle of normotensive and spontaneously hypertensive rats was carried out. The spinotrapezius muscle was selected since its microvasculature has been reconstructed in previous studies of this series. A modified glyoxylic acid amine densification technique was used to visualize the major portion of the microvascular nerve plexus. The nerve plexus density was quantified in the form of fiber length per unit area of vascular smooth muscle media. The adrenergic innervation was found to be limited to the arterial/arteriolar side of the microcirculation and positioned in close vicinity to vascular smooth muscle, in line with previous reports. Substantial variations of the nerve plexus density could be detected along the arterioles. Arcade arterioles show a significant reduction of the adrenergic innervation compared to that of the thoracodorsal supply artery. There was a significant elevation of the nerve plexus density at the origin of the transverse arterioles at the arcade arterioles, a site that in the past has been shown to exhibit the highest microvascular tonus in all arterioles of this organ. Distal to this site, transverse arterioles exhibit a progressive reduction of adrenergic plexus density toward their capillary endings, in line with the termination of vascular smooth muscle in these small branches. Sporadic fiber extensions were encountered leading from some of the transverse arterioles into the capillary network per se, but no regular innervation was detected in capillaries or in venules. These results suggest that the transverse arterioles may play a central role in nervous control of blood flow to the capillaries of muscle. Compared with the Wistar and Wistar-Kyoto strain, the spontaneously hypertensive rats exhibit qualitatively a similar pattern, but show quantitatively a significantly higher plexus density in the thoracodorsal artery and the arcade arterioles, a factor that may contribute to the elevated arteriolar tone.

Effects of subsequent pregnancy on left ventricular function in peripartum cardiomyopathy

Pregnancy has been discouraged in patients with peripartum cardiomyopathy (PPCM) to avoid the risk of precipitating recurrent or progressive left ventricular dysfunction. We assessed left ventricular size and contractile function using echocardiography in four PPCM patients prior to pregnancy, during the third trimester, and a mean of 6 weeks postpartum. Left ventricular mean diameters at end diastole and at end systole prior to pregnancy (5.2 +/- 0.3 and 3.0 +/- 0.2 cm, respectively) did not change during pregnancy (5.2 +/- 0.3 and 3.1 +/- 0.2 cm). Similarly, left ventricular fractional shortening did not alter significantly during pregnancy or postpartum. Furthermore, no patient developed any symptoms or signs of left ventricular failure. All patients had normal babies, including one who had twins. We conclude that PPCM patients whose left ventricular function returns to normal may undertake further pregnancy with a normal fetal outcome and a low risk of recurrent left ventricular dysfunction.

Peripheral venous monitoring with acute blood volume alteration: cuff-occluded rate of rise of peripheral venous pressure

We investigated the use of a new peripheral hemodynamic monitoring technique, the cuff-occluded rate of rise of peripheral venous pressure (CORRP), in the assessment of volume status in fluid overload. Seven adult mongrel dogs were given a general anesthetic, and monitoring lines were inserted. The animals were then subjected to an incremental volume overload of approximately 13% of estimated initial blood volume at 5-min intervals until a total volume infusion nearly equal to the animal's initial blood volume was reached. Comparison of the various monitoring techniques (e.g., cardiac output, CVP, systemic BP, pulmonary wedge pressure) demonstrated that the peripheral measurement of CORRP had better correlation with known administered volume (r = .96) than any of the other variables. The sensitivity of each of the variables in assessing small amounts of volume overload was also studied. The volume of crystalloid infusion necessary to cause a clinically significant change (defined as greater than 2 SD above the baseline mean) was compared for each of the monitoring variables. CORRP was equivalent to the other variables in sensing early volume overload. In summary, in the anesthetized animal model CORRP appears to be a sensitive, minimally invasive method of assessing volume status in acute volume overload. The efficacy of CORRP in a canine hemorrhagic shock and reperfusion model had previously been demonstrated. This technique could be clinically applicable in situations such as trauma with hemorrhagic shock, intraoperative volume changes, and in the assessment of intravascular volume after resuscitation.

Longitudinal changes in left ventricular architecture and function in peripartum cardiomyopathy

Left ventricular (LV) function was quantitated in 14 patients with peripartum cardiomyopathy, in 10 using 2-dimensional (2-D) echocardiography and in 4 radionuclide ventriculography, and values were compared with those in 11 normal women in the immediate postpartum period. LV end-diastolic and end-systolic volume indexes, LV wall mass index and ejection fraction were calculated during the acute phase of the illness and serially through long-term follow-up (mean 24 months). During the acute phase of illness there was marked LV dilatation: mean end-diastolic volume index was 95 +/- 22 ml/m2, vs 67 +/- 9 ml/m2 in control subjects (p less than 0.005), and mean end-systolic volume index was 66 +/- 18 ml/m2, compared to 27 +/- 5 ml/m2 in control subjects (p less than 0.001). Mean heart rates and mean systolic pressures in the patients with peripartum cardiomyopathy and the control subjects were similar, 91 +/- 24 vs 79 +/- 14 beats/min and 120 +/- 14 vs 117 +/- 10 mm Hg, respectively. LV wall mass index was higher, 139 +/- 38 vs 96 +/- 8 g/m2 (p less than 0.005), and ejection fraction much lower, 29 +/- 5% vs 67 +/- 5% (p less than 0.001), in control subjects. Five patients underwent endomyocardial biopsy during the acute illness, which showed interstitial fibrosis but no evidence of active inflammation. There was rapid and early improvement in LV function in 13 of 14 patients. Changes in LV volume, mass and ejection fraction all followed an exponential time course during LV remodeling.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of the subcutaneous heparin pump during pregnancy

Six patients requiring anticoagulation during pregnancy were managed with a continuous-infusion subcutaneous heparin pump. There were no cases of recurrent thrombosis; however, five of the six patients had major or minor bleeding complications despite therapeutic partial thromboplastin time levels.

Elevated beta-human chorionic gonadotropin and testosterone in cord serum of male infants of diabetic mothers

Leydig cell hyperplasia is a common histological finding in male infants of diabetic mothers. The functional correlates of this histological finding were investigated by measuring beta hCG, testosterone, androstenedione, dihydrotestosterone, and progesterone in mixed cord serum of male and female infants of diabetic mothers (n = 40) and normal mothers (n = 40) at term. Male and female infants of diabetic mothers had significantly higher cord serum beta hCG levels than male and female controls. Male infants of diabetic mothers had significantly higher cord serum testosterone concentrations than male controls, female controls, and female infants of diabetic mothers. Cord serum testosterone concentrations were similar in female infants of diabetic mothers and female controls. In the male infants of diabetic mothers, there was a significant positive correlation between beta hCG and testosterone (r = 0.64; P less than 0.01). There was no significant correlation between beta hCG and testosterone in the male controls (r = -0.15; P = NS). There was no significant difference in cord serum dihydrotestosterone in any group tested. Cord serum progesterone was significantly higher in the males than in the females. Cord serum androstenedione was lower in the infants of diabetic mothers than in the controls. This study suggests that the Leydig cell hyperplasia found in male infants of diabetic mothers is due, in part, to elevated concentrations of hCG and is accompanied by elevated testosterone concentrations in the fetal compartment.

Pneumomediastinum in pregnancy: two case reports and a review of the literature, pathophysiology, and management

Pneumomediastinum, free air trapped in the mediastinal connective tissue, is a rare complication of pregnancy, occurring most frequently in the second stage of labor. Symptoms are often not noted until after delivery. Occurrence before and in the first stage of labor, as seen in the two cases reported here, is more uncommon. One case history is the first report of the coexistence of pneumomediastinum and pneumothorax in pregnancy. The prognosis for spontaneous pneumomediastinum in pregnancy is favorable. Pathophysiologic mechanisms, diagnosis, and management are discussed, and a review of the literature is presented.

Possible relationship of primary hyperparathyroidism and fibrous dysplasia: report of case

This report has considered the possibility that the described patient had a maxillary and possibly a mandibular fibrous dysplasia concomitant with a parathyroid abnormality. It has attempted to arouse the diagnostician's suspicion of possible interrelations of fibrous dysplasia and endocrine abnormalities, and to strengthen the hypothesis of others that association of fibrous dysplasia and hyperparathyroidism is not coincidental. Clinical, radiographic, and laboratory examinations more than a year postoperatively further substantiate our hypothesis that the patient had a facial fibrous dysplasia concomitant with primary hyperparathyroidism. The maxilla and mandible continued to enlarge clinically. Systemic manifestations of hyperparathyroidism had resolved. Calcium phosphorus, and parathyroid hormone levels returned to normal limits. Radiographically, there had been remodeling and recalcification of all involved bones except the maxilla and mandible which continued to expand. A possible explanation is that the maxillofacial lesions represent the polyostotic fibrous dysplasia component of the Albright syndrome. The endocrine abnormality could be manifested by the hyperparathyroidism. The third component of Albright syndrome, café au lait lesions, has not been identified. The potential interrelation of fibrous dysplasia with endocrine abnormalities is obviously important from a diagnostic and therapeutic standpoint. If there is more than a coincidental relationship-hereditary, hormonal, neurological, developmental, or any as-yet-unknown factor-only further research and studies will confirm or disprove it.