Identification of Novel Carbocyclic Pyrimidine Cyclic Dinucleotide STING Agonists for Antitumor Immunotherapy Using Systemic Intravenous Route

Stimulator of Interferon Genes (STING) plays an important role in innate immunity by inducing type I interferon production upon infection with intracellular pathogens. STING activation can promote increased T-cell activation and inflammation in the tumor microenvironment, resulting in antitumor immunity. Natural and synthetic cyclic dinucleotides (CDNs) are known to activate STING, and several synthetic CDN molecules are being investigated in the clinic using an intratumoral administration route. Here, we describe the identification of STING agonist 15a, a cyclic dinucleotide structurally diversified from natural ligands with optimized properties for systemic intravenous (iv) administration. Our studies have shown that STING activation by 15a leads to an acute innate immune response as measured by cytokine secretion and adaptive immune response via activation of CD8+ cytotoxic T-cells, which ultimately provides robust antitumor efficacy.

Analysis of the K+ current profile of mature rat oligodendrocytes in situ

Previous studies have reported that mature oligodendrocytes (OLGs) in vitro display various voltage-dependent K+ currents while in situ OLGs show only voltage-independent K+ currents. Given this discrepancy and the lack of information on myelinating OLG ion channel expression in situ, we characterized mature OLG currents in myelinating corpus callosum slices from 17 to 36-day old rats. OLGs were recorded in cell-attached and whole-cell patch-clamp configurations, displayed morphology typical of mature OLGs, and stained positive for myelin basic protein. OLGs displayed large voltage-independent currents that decayed during the voltage pulse and small voltage-activated outward currents. The latter were blocked by TEA, activated between -40 and -50 mV, and decayed slowly. The former were composed of large voltage-independent, time-dependent Ba2+ (1 mM)-sensitive currents, and voltage-dependent Cs+ (5 mM) and Ba2+ (100 mM)-sensitive currents that reversed near the K+ equilibrium potential and inactivated at hyperpolarized potentials, identifying them as inwardly rectifying K+ currents. Inwardly rectifying single-channel K+currents could be recorded in the cell-attached configuration. The estimated single-channel slope conductance was 30 pS. The steady-state open probability was voltage-dependent and declined from 0.9 to 0.5 between -80 and -150 mV. Overall, mature OLGs in situ possess time- and also voltage-dependent K+ currents, which may facilitate clearance of K+ released during axonal firing.

Use of cervical ultrasonography in prediction of spontaneous preterm birth in triplet gestations

OBJECTIVE

The aim of this study was to assess the role of cervical ultrasonography in the prediction of spontaneous preterm birth in triplet gestations and to compare various ultrasonographic cervical parameters with respect to predictive ability.

STUDY DESIGN

This prospective cohort study included 51 triplet gestations longitudinally evaluated between 15 and 28 weeks' gestation on 274 occasions with transvaginal cervical ultrasonography and transfundal pressure. The cervical parameters obtained were funnel width and length, cervical length, percentage of funneling, and cervical index.

RESULTS

Receiver operating characteristic curve analyses showed that cervical lengths of < or =2.5 cm and < or =2.0 cm between 15 and 24 weeks' gestation and between 25 and 28 weeks' gestation, respectively, were at least as good as other ultrasonographic cervical parameters for the prediction of spontaneous preterm birth. A cervical length of < or =2.5 cm between 15 and 20 weeks' gestation had both a specificity and a positive predictive value of 100% for delivery at <28 weeks' gestation, and the sensitivities and negative predictive values ranged from 25% to 50% and from 72% to 91%, respectively, for deliveries at <28, <30, and <32 weeks' gestation. A cervical length of < or =2.5 cm between 21 and 24 weeks' gestation had an 86% sensitivity for prediction of spontaneous delivery at <28 weeks' gestation. A cervical length of < or =2.0 cm between 25 and 28 weeks' gestation had both a sensitivity and a negative predictive value of 100% for delivery at both <28 and <30 weeks' gestation.

CONCLUSIONS

In triplet gestations cervical lengths of < or =2.5 cm between 15 and 24 weeks' gestation and < or =2.0 cm between 25 and 28 weeks' gestation were at least as good as other ultrasonographic cervical parameters for the prediction of spontaneous preterm birth.

Backscattering enhancements from Rayleigh waves on the flat face of a tilted solid cylinder in water

When the face of a finite solid elastic cylinder is ensonified by an acoustic wave, a variety of backscattering contributions associated with acoustic wave coupling into elastic waves are observed. A significant backscattering enhancement is observed for tilts such that the acoustic wave is incident on the face of the cylinder in the vicinity of the coupling angle for launching Rayleigh waves across the face. The observed backscattering indicates that the Rayleigh waves are reflected at the edge of the face and subsequently radiate acoustic waves in the backscattering direction. The measured backscattering is compared to an approximate theoretical prediction. Approximating the focusing of the Rayleigh wave after reflection at the (circular) edge by a Gaussian beam pressure distribution on the cylinder's face yields simple expressions for the amplitude which are consistent with the measurements. In the vicinity of end-on incidence, other backscattering contributions due to the reflection of waves traveling down the length of the cylinder are observed. There is also evidence of a face-traversing longitudinal wave for slightly tilted cylinders.

Pregnancy outcomes in women treated with elective versus ultrasound-indicated cervical cerclage

OBJECTIVE

To compare pregnancy outcomes in women at risk for pregnancy loss treated with elective versus ultrasound-indicated placement of cerclage.

METHODS

A retrospective cohort study was performed on two groups of patients with singleton gestations. The first group consisted of women at risk for pregnancy loss who were treated with an elective cerclage, while the second group was managed conservatively and followed with serial transvaginal cervical sonography and transfundal pressure. An emergency cerclage was placed in women in the second group when the endocervical canal length shortened to < 20 mm, either spontaneously or in response to transfundal pressure. The two groups were compared with respect to maternal demographics, obstetric and gynecological history, and gestational age, both at time of cerclage placement and delivery.

RESULTS

A total of 138 patients were identified. Eighty-one patients were treated with an elective cerclage and 57 with an ultrasound-indicated cerclage. Patients treated with elective cerclages were older (32 versus 27 years, p = 0.0003), more commonly white (56.8% versus 38.6%, p = 0.0380), less commonly nulliparous (23.5% versus 43.9%, p = 0.0063), and more often private patients (92.6% versus 28.1%, p < 0.0001). A history of previous treatment with cerclage (45.7% versus 10.5%, odds ratio (OR) 0.2, 95% confidence interval (CI) 0.1-0.4) and one prior midtrimester loss (53.1% versus 33.3%, OR 0.4, 95% CI 0.2-0.9) were also more common in the elective versus ultrasound-indicated cerclage group. However, there was no difference in the rates of previous preterm delivery, two midtrimester losses, two terminations of pregnancy, in utero diethylstilbestrol exposure, uterine anomalies, history of cone biopsy or parity. As expected, gestational age at placement of cerclage was significantly earlier in the elective group (13.0 versus 20.0 weeks, p < 0.0001). The median (range) gestational age at delivery (37 (15-41) versus 37 (17-41) weeks, p = 0.90), the number of early (< 25 weeks) losses (9.9% versus 8.8%, OR 1.6, 95% CI 0.3-7.9), and preterm deliveries (< 37 weeks) (35.8% versus 36.8%, OR 1.1, 95% CI 0.4-3.2) were similar in the elective and ultrasound-indicated cerclage patients, respectively.

CONCLUSION

In patients at risk for pregnancy loss, placement of cervical cerclages in response to ultrasonographically detected shortening of the endocervical canal length is a medically acceptable alternative to the use of elective cerclage.

Relationship between endocervical canal length between 15-24 weeks gestation and obstetric history

The object was to determine whether there is a correlation between the obstetric history and the ultrasonographically determined endocervical canal length between 15 and 24 weeks gestation. A retrospective cohort study was performed in singleton pregnancies of multigravidas with normal and abnormal obstetric histories. They underwent sonographic evaluation for the determination of the endocervical canal length between 15 and 24 weeks gestation. The shortest endocervical canal length measurements between 15 and 20 weeks and also between 21 and 24 weeks of gestation were recorded. An ultrasound diagnosis of cervical incompetence was defined as progressive shortening of the endocervical canal length to <2 cm or a single endocervical canal length measurement <2 cm. A multivariable general linear regression model was used to correlate the relationship between endocervical canal lengths at 15-20 weeks and 21-24 weeks gestation in the current pregnancy with the earliest gestational age at delivery of prior pregnancies. Chi-square test was used to determine the relationship between the development of an ultrasound diagnosis of cervical incompetence and the earliest gestational age at delivery of prior pregnancies. A total of 155 pregnancies were studied. The number of women according to the obstetric history categories were: 57 had delivered <24 weeks, 12 between 24 and 26 weeks, 16 between 27 and 32 weeks, 16 between 33 and 36 weeks, and 54 delivered > or =37 weeks. There was a significant correlation between the endocervical canal length measurements between 15-20 (P < 0.0001) weeks and 21-24 weeks (P < 0.0001) in the studied pregnancy and the earliest gestational age at delivery of prior pregnancies. A significant relationship between the ultrasound diagnosis of cervical incompetence and the obstetric history category (P = 0.0026) was observed. There were 36 cases of ultrasound diagnosed cervical incompetence with 91.7% (33/36) occurring in women who had a prior <27 weeks' gestation delivery. These data provide further evidence that cervical incompetence is a relative condition and not an "all or none" phenomenon. In addition, women with a prior delivery <30 weeks gestation should be followed with second trimester serial cervical sonography to rule out cervical incompetence.

Longitudinal assessment of endocervical canal length between 15 and 24 weeks' gestation in women at risk for pregnancy loss or preterm birth

OBJECTIVE

To determine the weekly cervical shortening rates of the endocervical canal between 15 and 24 weeks' gestation in women at risk for pregnancy loss or spontaneous preterm birth.

METHODS

We performed a retrospective cohort study of transvaginal sonographic measurements of the endocervical canal length done at least twice between 15 and 24 weeks' gestation in women at risk for pregnancy loss and spontaneous preterm birth. The ultrasound diagnosis of cervical incompetence was defined as progressive shortening of the endocervical canal length to 2 cm or less either spontaneously or after application of transfundal pressure. Multivariable linear regression models were developed to determine the weekly crude rate of endocervical canal length shortening rates in cases of competent cervices and incompetent cervices, with incompetent cervices further stratified as those diagnosed at 15-19 weeks' and 20-24 weeks' gestation. Comparisons of the models for weekly rate of endocervical canal length shortening were performed.

RESULTS

The endocervical canal lengths were measured in 61 women (180 measurements) who did not develop ultrasound evidence of cervical incompetence and 28 women (103 measurements) who had ultrasound evidence of cervical incompetence. Between 15 and 24 weeks' gestation, competent cervices had a nonsignificant rate of endocervical canal length shortening (-0.03 cm/week). During this period in gestation, incompetent cervices had significantly greater endocervical canal length shortening (-0.41 cm/week, P < .001). The rate of endocervical canal length shortening of incompetent cervices diagnosed between 15 and 19 weeks' gestation was -0.52 cm/week (P < .001). The rate of endocervical canal length shortening in incompetent cervices diagnosed between 20 and 24 weeks' gestation was significant and varied from -0.49 cm/week to -0.80 cm/week at 20 and 24 weeks' gestation, respectively (P < .001). The models describing the rate of cervical shortening in the two groups of incompetent cervices were significantly different (P < .001). The sonographic detection of endocervical canal length shortening in the 28 cases of cervical incompetence was identified at a median (range) gestational age of 20 (16-24) weeks.

CONCLUSION

Weekly rates of endocervical canal length shortening were established, which may be useful for detecting and managing cervical incompetence in high-risk women examined with cervical sonography.