Prevention of preterm birth in multiples

PURPOSE OF REVIEW

Multifetal pregnancy carries increased risk of preterm delivery, and consensus on management options to prevent early birth in this population has not been reached. This review serves to summarize the most contemporary findings on this controversial topic.

RECENT FINDINGS

Examination-indicated cerclage is effective in reducing preterm birth in twin pregnancies, whereas cerclages for other indications are less convincing. Cervical pessary may be beneficial for patients with a short cervix and in those who have had threatened preterm labor. Progesterone supplementation for multifetal gestation alone is not beneficial, but it can be considered in those with a history of prior singleton preterm birth.

SUMMARY

Interventions for preterm birth prevention in multiple gestations remain under investigation, and further data is required in order to reach consensus for this high-risk population.

Intrapartum Management of Sickle Cell Anemia With Rare Antibody and Minimal Blood Availability

Sickle cell disease (SCD) can pose serious maternal and fetal risk in pregnancy. Transfusion, both during and outside of pregnancy, can improve patient morbidity and mortality but carries risk of alloimmunization, complicating future management. This case describes a 29-year-old gravida 1, para 0 woman with sickle cell anemia and rare red blood cell alloantibody (anti-Rh46) who presented with severe vaso-occlusive crisis at 29 weeks with hemoglobin of 7.6 g/dL. Only one unit of compatible blood existed in the country. Planning for transfusion with least-incompatible blood was made. She ultimately underwent cesarean section at 31 weeks and 2 days for abnormal fetal testing. This case highlights that blood products should be utilized judiciously because their adverse effects, like alloimmunization, can increase patient morbidity and mortality.

Abstract 1678: Bioavailability and anti-tumor activity of capsaicin in human small cell lung cancer

The nutritional compound capsaicin has been shown to display anti-neoplastic activity in breast, prostate and colon tumors xenografted in nude mice. Based on these data from other research laboratories, we wanted to determine the bioavailability of capsaicin in nude mice in vivo. We found that capsaicin was rapidly metabolized primarily in the liver. The bioavailability of intact capsaicin was highest in the lung. Therefore, we hypothesized that capsaicin should suppress the growth of lung tumors. We found that capsaicin induced robust apoptosis in human SCLC cell lines. Capsaicin decreased the growth rates of human SCLC tumors in two in vivo models, namely the CAM model and the nude mouse model. HPLC studies showed intact capsaicin in the tumors excised from nude mice. The heat-sensation activity of capsaicin is mediated by the transient receptor potential vanilloid (TRPV) family of proteins. Capsaicin functions as an agonist of the TRPV1 receptor. The apoptotic activity of capsaicin was found to be mediated by TRPV6 and not TRPV1. Preliminary data shows that capsaicin increases the expression of the TRPV6 receptor, causing apoptosis in human SCLCs.

Citation Format: John D. Hurley, William D. Rollyson, Cody A. Stover, Kathleen C. Brown, Haley E. Perry, Cathryn D. Stevenson, Clayton M. Crabtree, Aaron M. Dom, Jamie K. Lau, Theodore R. Witte, W E. Hardman, Piyali Dasgupta. Bioavailability and anti-tumor activity of capsaicin in human small cell lung cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1678. doi:10.1158/1538-7445.AM2015-1678

Abstract 5229: Disruption of the acetylcholine signaling pathway suppresses the growth and angiogenesis of human lung cancers

Cigarette smoking bears a strong association with the development of lung cancer. Nicotine is the addictive component of cigarettes. Several convergent studies show that nicotine facilitates the growth and angiogenesis of human lung cancers. The biological activity of nicotine is mediated by nicotinic acetylcholine receptors (nAChRs). The endogenous ligand of nAChRs is acetylcholine (ACh). Data from our laboratory and other research groups show that lung cancers express all of the genes for synthesis, transport and degradation of ACh. These include nAChRs, choline acetyltransferase (ChAT), vesicular acetylcholine transporter (VAChT), choline transporter (ChT1) and acetylcholinesterase (AChE). Nicotine upregulates the ACh-signaling loop in human lung cancer cells. Therefore, we conjectured that disruption of ACh-signaling pathway should suppress the growth of human cancers. We show that alpha7-nAChR antagonists robustly suppress angiogenesis in human lung and retinal microvascular endothelial cells. The anti-angiogenic activity of alpha7-nAChR antagonists was also observed in chicken chorioallantoic membrane (CAM) and nude mouse models. Similarly, vesamicol, a small molecule antagonist of VAChT, decreases nicotine-induced tumor growth in human NSCLCs. Our studies suggest that the acetylcholine signaling pathway may be have potential applications in the therapy of human lung cancers. Our results are also relevant to lung cancer patients who are exposed to nicotine via secondhand smoke, nicotine patches, gums or electronic cigarettes.

Citation Format: Piyali Dasgupta, Kathleen C. Brown, Jamie K. Lau, Aaron M. Dom, Brent A. Thornhill, Clayton M. Crabtree, Theodore R. Witte, W E. Hardman, Cody A. Stover, A B. Carpenter, Yi C. Chen. Disruption of the acetylcholine signaling pathway suppresses the growth and angiogenesis of human lung cancers. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5229. doi:10.1158/1538-7445.AM2015-5229

Capsaicin induces apoptosis in human small cell lung cancer via the TRPV6 receptor and the calpain pathway

Capsaicin, the pungent ingredient of chili peppers, displays potent anti-neoplastic activity in a wide array of human cancer cells. The present manuscript examines the signaling pathways underlying the apoptotic activity of capsaicin in human small cell lung cancer (SCLC) in vitro and in vivo. Studies in neuronal cells show that capsaicin exerts its biological activity via the transient receptor potential vanilloid (TRPV) superfamily of cation-channel receptors. The TRPV family is comprised of six members (TRPV1-6). Capsaicin is a known agonist of the TRPV1 receptor. We observed that capsaicin-induced apoptosis in human SCLC cells was mediated via the TRPV receptor family; however it was independent of TRPV1. Surprisingly, the apoptotic activity of capsaicin required the TRPV6 receptor. Depletion of TRPV6 receptor by siRNA methodology abolished the apoptotic activity of capsaicin in SCLC cells. Immunostaining and ELISA showed that TRPV6 receptor was robustly expressed on human SCLC tissues (from patients) and SCLC cell lines but almost absent in normal lung tissues. This correlates with our results that capsaicin induced very little apoptosis in normal lung epithelial cells. The pro-apoptotic activity of capsaicin was mediated by the intracellular calcium and calpain pathway. The treatment of human SCLC cells with capsaicin increased the activity of calpain 1 and 2 by threefold relative to untreated SCLC cells. Such calpain activation, in response to capsaicin, was downstream of the TRPV6 receptor. Taken together, our data provide insights into the mechanism underlying the apoptotic activity of capsaicin in human SCLCs.

Independent learning modules enhance student performance and understanding of anatomy

Didactic lessons are only one part of the multimodal teaching strategies used in gross anatomy courses today. Increased emphasis is placed on providing more opportunities for students to develop lifelong learning and critical thinking skills during medical training. In a pilot program designed to promote more engaged and independent learning in anatomy, self-study modules were introduced to supplement human gross anatomy instruction at Joan C. Edwards School of Medicine at Marshall University. Modules use three-dimensional constructs to help students understand complex anatomical regions. Resources are self-contained in portable bins and are accessible at any time. Students use modules individually or in groups in a structured self-study format that augments material presented in lecture and laboratory. Pilot outcome data, measured by feedback surveys and examination performance statistics, suggest that the activity may be improving learning in gross anatomy. Positive feedback on both pre- and post-examination surveys showed that students felt the activity helped to increase their understanding of the topic. In concordance with student perception, average examination scores on module-related laboratory and lecture questions were higher in the two years of the pilot program compared with the year before its initiation. Modules can be fabricated on a modest budget using minimal resources, making implementation practical for smaller institutions. Upper level medical students assist in module design and upkeep, enabling continuous opportunities for vertical integration across the curriculum. This resource offers a feasible mechanism for enhancing independent and lifelong learning competencies, which could be a valuable complement to any gross anatomy curriculum.

Inhibition of cholinergic signaling causes apoptosis in human bronchioalveolar carcinoma

Recent case-controlled clinical studies show that bronchioalveolar carcinomas (BAC) are correlated with smoking. Nicotine, the addictive component of cigarettes, accelerates cell proliferation through nicotinic acetylcholine receptors (nAChR). In this study, we show that human BACs produce acetylcholine (ACh) and contain several cholinergic factors including acetylcholinesterase (AChE), choline acetyltransferase (ChAT), choline transporter 1 (CHT1, SLC5A7), vesicular acetylcholine transporter (VAChT, SLC18A3), and nACh receptors (AChRs, CHRNAs). Nicotine increased the production of ACh in human BACs, and ACh acts as a growth factor for these cells. Nicotine-induced ACh production was mediated by α7-, α3β2-, and β3-nAChRs, ChAT and VAChT pathways. We observed that nicotine upregulated ChAT and VAChT. Therefore, we conjectured that VAChT antagonists, such as vesamicol, may suppress the growth of human BACs. Vesamicol induced potent apoptosis of human BACs in cell culture and nude mice models. Vesamicol did not have any effect on EGF or insulin-like growth factor-II-induced growth of human BACs. siRNA-mediated attenuation of VAChT reversed the apoptotic activity of vesamicol. We also observed that vesamicol inhibited Akt phosphorylation during cell death and that overexpression of constitutively active Akt reversed the apoptotic activity of vesamicol. Taken together, our results suggested that disruption of nicotine-induced cholinergic signaling by agents such as vesamicol may have applications in BAC therapy.

MG624, an α7-nAChR antagonist, inhibits angiogenesis via the Egr-1/FGF2 pathway

Small cell lung cancer (SCLC) demonstrates a strong etiological association with smoking. Although cigarette smoke is a mixture of about 4,000 compounds, nicotine is the addictive component of cigarette smoke. Several convergent studies have shown that nicotine promotes angiogenesis in lung cancers via the α7-nicotinic acetylcholine receptor (α7-nAChR) on endothelial cells. Therefore, we conjectured that α7-nAChR antagonists may attenuate nicotine-induced angiogenesis and be useful for the treatment of human SCLC. For the first time, our study explores the anti-angiogenic activity of MG624, a small-molecule α7-nAChR antagonist, in several experimental models of angiogenesis. We observed that MG624 potently suppressed the proliferation of primary human microvascular endothelial cells of the lung (HMEC-Ls). Furthermore, MG624 displayed robust anti-angiogenic activity in the Matrigel, rat aortic ring and rat retinal explant assays. The anti-angiogenic activity of MG624 was assessed by two in vivo models, namely the chicken chorioallantoic membrane model and the nude mice model. In both of these experimental models, MG624 inhibited angiogenesis of human SCLC tumors. Most importantly, the administration of MG624 was not associated with any toxic side effects, lethargy or discomfort in the mice. The anti-angiogenic activity of MG624 was mediated via the suppression of nicotine-induced FGF2 levels in HMEC-Ls. MG624 decreased nicotine-induced early growth response gene 1 (Egr-1) levels in HMEC-Ls, and reduced the levels of Egr-1 on the FGF2 promoter. Consequently, this process decreased FGF2 levels and angiogenesis. Our findings suggest that the anti-angiogenic effects of MG624 could be useful in anti-angiogenic therapy of human SCLCs.

The α7-nicotinic acetylcholine receptor and MMP-2/-9 pathway mediate the proangiogenic effect of nicotine in human retinal endothelial cells

PURPOSE

Nicotine, the active component of cigarette smoke, has been found to stimulate angiogenesis in several experimental systems. In this study, the Matrigel duplex assay (Matrigel; BD Biosciences, Franklin Lakes, NJ) and the rat retinal explant assay were used to explore the molecular mechanisms underlying the proangiogenic effects of nicotine in endothelial cells.

METHODS

Western blot analysis was performed to determine the nicotinic acetylcholine receptor (nAChR) subtypes expressed on primary human retinal microvascular endothelial cells (HRMECs). The angiogenic effect of nicotine in the retina was evaluated with the duplex assay. The results obtained from the assay were confirmed by the rat retinal explant angiogenesis assay. ELISAs were used to measure MMP-2, -9, and -13 levels in HRMEC culture supernatants. The role of α7-nAChRs in nicotine-induced angiogenesis was examined by siRNA techniques.

RESULTS

Nicotine-induced angiogenesis required nAChR function and was associated with the upregulation of MMP-2 and -9 in HRMECs. Specifically, α7-nAChRs mediated the stimulatory effects of nicotine on retinal angiogenesis and MMP levels. Treatment of HRMECs with α7-nAChR antagonists ablated nicotine-induced angiogenesis. The inhibitory actions of α7-nAChR antagonists correlated with the suppression of MMP-2 and -9 levels in HRMECs.

CONCLUSIONS

The α7-nAChR is vital for the proangiogenic activity of nicotine. The α7-nAChRs expressed on HRMECs upregulate levels of MMP-2 and -9, which stimulate retinal angiogenesis. The data also suggest that α7-nAChR antagonists could be useful agents for the therapy of angiogenesis-related retinal diseases.