Investigating the Efficacy of HPV Vaccines in Preventing Cervical Cancer from 2006 to 2018 in the US: A SEER Data Set Analysis.

BACKGROUND: Human papillomavirus (HPV) is the most common sexually transmitted infection in the US.The first HPV vaccine was introduced in 2006. There are three different HPV vaccines that commonly target high-risk HPV types. OBJECTIVE: This study compares HPV vaccine efficacy based on alternative endpoints with the most recently available cervical cancer incidence data from the Surveillance, Epidemiology and End Results (SEER) program and SEER*Stat statistical software. METHODS: The incidence of cervical cancer, mined from the most recent April 2021 SEER data set, was stratified according to age and racial groups. Trend analysis reporting cervical cancer incidence percentage change (PC) and annual percentage change (APC) was calculated by SEER*Stat statistical software. RESULTS: A total of 46,583 cases of cervical cancer were reported, with an average of about 3,580 incidents of cervical cancer per year, with an overall decrement of about 60 cases over the period of 12 years. The percentage change according to age and race groups varied between -15.9 among 40- 44 years old (yo) and +13.8 among 30-34 yo, and from -12 among non-Hispanic White women to +13 among Hispanic women. Statistically significant APC was observed for five of the nine age groups and four of the five racial groups. CONCLUSION: There seems to be little if any, correlation between cervical cancer incidence and the HPV vaccine program in the US. HPV vaccine efficacy based on alternative endpoints, such as nucleic acid testing and cytological, surgical, and seropositivity endpoints, is fair. Therefore, it is important to emphasize such alternative testing and surrogate endpoints.

Predictors of success on the MCAT among post-baccalaureate pre-medicine students.

Post-baccalaureate pre-medicine programs (PBPMP) provide prerequisite coursework for non-life science majors who aspire to become physicians. Students entering these programs generally do not have previous college-level exposure to the natural sciences. This pilot study was conducted to determine characteristics of scientifically naive, career changer, pre-medical students that may be used by PBPMP admissions committees. Statistical analyses were performed between Medical College Admission Test (MCAT) scores and student gender, Scholastic Aptitude Test (SAT) scores, undergraduate field of study, and undergraduate Grade Point Average (GPA). While relationships between certain subscores on the SAT and MCAT were found, data suggest that other non-quantitative metrics be considered as predictors of performance among PBPMP students.

Statistical approach for optimization of external quality assurance (EQA) studies of molecular and serological viral diagnostics.

Management of viral diagnostic quality is based on external quality assurance (EQA), where laboratories involved in diagnostics of a targeted virus are offered to analyze a panel of blinded samples. The utility of EQAs is compromised because of the absence of an approach to EQA design which upfront defines acceptance criteria and associated statistical analysis ensuring fair and consistent interpretation. We offer a rigorous statistically based approach for EQA planning. Instead of a conventional performance characteristic (the score) which is calculated as the sum of the points for correctly identified samples in a blinded test panel, Youden index is used as the performance measure. Unlike the score, Youden index requires an estimate of sensitivity and specificity and incorporates the relationship of these performance parameters. Based on the assumption that the coordinator is a reputable expert of viral diagnostics, the performance of the coordinator's laboratory is defined as a proficiency standard for performance evaluation. The immediate goal of EQA is defined as to obtain a statistically reliable estimation for every laboratory whether its performance meets the proficiency standard, while the overall goal is to match every laboratory to its specific performance level. Dependence of informational capacities of test panel from the panel size and content is quantitatively analyzed and the optimal design and informational capacities of both idealized panels (whose size is not restricted by financial factors) and currently feasible panels are considered. Our approach provides the basis both for rational design of currently feasible EQA test panels and for an increased panel size.

Outer membrane vesicles alter inflammation and coagulation mediators.

INTRODUCTION: Outer membrane vesicles (OMVs) were previously shown to be capable of initiating the inflammatory response seen in the transition of an infection to sepsis. However, another tenet of sepsis is the development of a hypercoagulable state and the role of OMVs in the development of this hypercoagulability has not been evaluated. The objective of this study was to evaluate the ability of OMVs to elicit endothelial mediators of coagulation and inflammation and induce platelet activation. METHODS: Human umbilical vein endothelial cells (HUVECs) were incubated with OMVs and were analyzed for the expression of tissue factor (TF), thrombomodulin, and the adhesion molecules P-selectin and E-selectin. Supernatants of OMV-treated HUVECs were mixed with whole blood and assessed for prothrombotic monocyte-platelet aggregates (MPA). RESULTS: OMVs induce significantly increased expression of TF, E-selectin, and P-selectin, whereas, the expression of thrombomodulin by HUVECs is significantly decreased (P < 0.05). The lipopolysaccharide inhibitor clearly inhibited the expression of E-selectin following incubation with OMVs, although its impact on TF and thrombomodulin expression was nominal. Incubation of whole blood with supernatant from HUVECs exposed to OVMs resulted in increased MPAs. CONCLUSIONS: This study demonstrates that, at the cellular level, OMVs from pathogenic bacteria play a complex role in endothelial activation. Although OMV-bound lipopolysaccharide modulates inflammatory proteins, including E-selectin, it has a negligible effect on the tested coagulation mediators. Additionally, endothelial activation by OMVs facilitates platelet activation as indicated by increased MPAs. By influencing the inflammatory and coagulation cascades, OMVs may contribute to the hypercoagulable response seen in sepsis.

Bariatric surgery decreases monocyte-platelet aggregates in blood: a pilot study.

Morbid obesity is accompanied by platelet hyperactivity, leading to thrombotic events including myocardial infarction and stroke. Bariatric surgery is an effective intervention to reduce cardiovascular risk in obesity. However, the effect of bariatric surgery on platelet function is largely unknown. This study investigated the effects of laparoscopic Roux-en-Y gastric bypass (RYGB) and laparoscopic adjustable gastric banding (LAGB) on prothrombotic monocyte-platelet aggregates (MPAs), markers of platelet activation in vivo. MPA were measured in whole blood by flow cytometry before surgery and 1 and 3 months after surgery. In non-obese healthy controls, MPA level is 13 ± 2 %. MPAs are elevated in morbidly obese subjects. RYGB (n = 12 patients) decreases MPAs 1 month after surgery by a weight-independent mechanism (56 ± 6 % presurgically vs 26 ± 8 % at 1 month, p <0.01). LAGB (n = 5 patients) has a smaller weight-dependent effect (49 ± 8 % presurgically vs 32 ± 6 % at 1 month, p > 0.05). Bariatric surgery may reduce thrombotic events by alleviation of platelet overactivity.

Tamoxifen promotes superoxide production in platelets by activation of PI3-kinase and NADPH oxidase pathways.

BACKGROUND: Tamoxifen is a selective estrogen receptor antagonist that is widely used for treatment and prevention of breast cancer. However, tamoxifen use can lead to an increased incidence of thrombotic events. The reason for this adverse event remains unknown. Previous studies showed that tamoxifen and its active metabolite Z-4-hydroxytamoxifen rapidly increased intracellular free calcium ([Ca(2+)](i)) in human platelets by a non-genomic mechanism that involved the activation of phospholipase C. Platelets play a pivotal role in thrombosis and Ca(2+) elevation is a central event in platelet activation. Therefore the mechanism by which tamoxifen activated Ca(2+) entry into platelets was investigated. METHODS: [Ca(2+)](i) was measured using the fluorescent indicator fura-2 and reactive oxygen species were measured using lucigenin in isolated human platelets. RESULTS: Tamoxifen analogs E-4-hydroxytamoxifen, with weak activity at the nuclear estrogen receptor and Z-4-hydroxytamoxifen, with strong activity at nuclear estrogen receptor, were equally active at increasing [Ca(2+)](i) and synergizing with ADP and thrombin to increase [Ca(2+)](i) in platelets. This result suggests that the effects of tamoxifen and E- and Z-4-hydroxytamoxifen to increase [Ca(2+)](i) are not mediated by the classical genomic estrogen receptor. The effects of tamoxifen to increase [Ca(2+)](i) were strongly inhibited by apocynin and apocynin dimer. This suggests that tamoxifen activates NADPH oxidase which leads to superoxide generation and in turn caused an increase in [Ca(2+)](i). Free radical scavengers TEMPO and TEMPOL also inhibited tamoxifen-induced [Ca(2+)](i) elevation. Inhibition of phosphoinositide-3-kinase (PI3-kinase), an upstream effector of NADPH oxidase with wortmannin and LY-294,002 also caused substantial inhibition of tamoxifen-induced elevation of [Ca(2+)](i). CONCLUSION: Tamoxifen increases [Ca(2+)](i) in human platelets by a non-genomic mechanism. Tamoxifen activates phospholipase Cγ as well as PI3-kinase and NADPH oxidase pathway to generate superoxide which causes the release of Ca(2+) from the endoplasmic reticulum, and promotes Ca(2+) influx into the platelets.

Diethylstilbestrol and other nonsteroidal estrogens: novel class of store-operated calcium channel modulators.

BACKGROUND: Compounds with the stilbene pharmacophore and other nonsteroidal estrogens have previously been shown to inhibit thrombin-induced elevation of intracellular free calcium ([Ca]i) in human platelets. Thrombin elevates [Ca]i in platelets predominantly by activating a store-operated Ca entry (SOCE) mechanism, probably involving STIM1 and Orai1 although other components may be involved. METHODS: Human platelets were loaded with the Ca sensitive indicator fura-2, various concentrations of stilbene compounds and other nonsteroidal estrogens were added to the platelets, and thrombin was added to elevate [Ca]i. The degree of inhibition by each compound was determined at the peak increase in [Ca]i induced by thrombin. RESULTS: The additional compounds that were examined in the present study were analogs of diethylstilbestrol (DES), namely trans-resveratrol, hexestrol, tetrahydrochrysene (THC), indenestrol, isoflavones, flavones, and flavanones. DES, indenestrols, and substituted THC diols had the highest inhibitory activity. Dietary polyphenols were less active, and isoflavones were more active than flavones. Glycosides of flavones, flavanones, and isoflavones were inactive. Equol (a product of isoflavone metabolism) had low activity. Among the compounds with a stilbene moiety the presence of unsubstituted phenyl hydroxyls in the para- position were required for activity. Esterification of hydroxyls and bulky substituents at a hydroxyl group diminished or abolished activity. Presence of the ethyl side chains enhanced activity, and shortening or removal of these side chains was detrimental to activity. Presence of the conjugated double bound was necessary for activity. Reduction of the double bond (in fused rings such as equol, dihydrogenistein, indanestrol, or in open chain stilbene derivatives) or repositioning of this double bond outside the stilbene moiety was detrimental to activity, because phenyl rings are not co-planar and have to be at a certain angle to each other. CONCLUSION: DES likely represents the pharmacophore of this group of nonsteroidal estrogens as an inhibitor of SOCE in platelets.

Phenolphthalein as a prototype drug for a group of structurally related calcium channel blockers in human platelets.

Thrombin increases intracellular free Ca ([Ca]i) in human platelets by 2 mechanisms: internal mobilization and the influx of Ca via store-operated Ca entry (SOCE). 2-Aminoethoxydiphenyl borate (2-APB) is an inhibitor of SOCE. In search for nonboron analogues of 2-APB, we identified a well-known compound, phenolphthalein, structurally related to 2-APB. Many phenolphthalein analogues inhibited the ability of thrombin and thapsigargin (a specific activator of SOCE) to increase [Ca]i. Phenolphthalein has an IC50 approximately 10 microM to inhibit thrombin-induced [Ca]i elevation, its active analogues have a similar potency. Several phenolphthalein analogues also inhibited thrombin-induced intracellular Ca mobilization, which indicates action on inositol 1,4,5-trisphosphate receptors. We identified structural features among active and inactive phenolphthalein analogues that are responsible for the activity. Opening of the 5-membered lactone ring of phenolphthalein resulted in a total loss of activity. If the diphenyl rings possessed primary amine, dimethyl amine, or a cyano group, there was no activity. Modifications to the diphenyl groups that were tolerated include phosphate, sulfate, iodine, bromine, methyl, nitrite, and methoxy. Inhibition of thrombin-induced [Ca]i increase by phenolphthalein was not mediated by an increase in cyclic adenosine monophosphate because the inhibitor of cyclic adenosine monophosphate-dependent protein kinase A, 4-cyano-3-methylisoquinoline, did not affect the inhibitory action of phenolphthalein. The inhibitory effect of phenolphthalein was not mediated by an increase in NO/cyclic guanosine monophosphate (cGMP) because the inhibitors of NO-sensitive soluble guanylyl cyclase, methylene blue, and ODQ did not affect the inhibition. Phytohemagglutinin and thapsigargin-induced SOCE in Jurkat cells was also inhibited by phenolphthalein and 2-APB to the same extent as seen in platelets. Therefore, phenolphthalein and its derivatives structurally similar to 2-APB inhibit SOCE in platelets and other cells.

Tamoxifen stimulates calcium entry into human platelets.

The anti-estrogenic drug tamoxifen, which is used therapeutically for treatment and prevention of breast cancer, can lead to the development of thrombosis. We found that tamoxifen rapidly increased intracellular free calcium [Ca2+]i in human platelets from both male and female donors. Thus 10 microM tamoxifen increased [Ca2+]i above the resting level by 197 +/- 19%. Tamoxifen acted synergistically with thrombin, ADP, and vasopressin to increase [Ca2+]i. The anti-estrogen ICI 182780 did not attenuate the effects of tamoxifen to increase [Ca2+]i; however, phospholipase C inhibitor U-73122 blocked this effect. 4-hydroxytamoxifen, a major metabolite of tamoxifen, also increased [Ca2+]i, but other tamoxifen metabolites and synthetic derivatives did not. Three hydroxylated derivatives of triphenylethylene (corresponding to the hydrophobic core of tamoxifen) which are transitional structures between tamoxifen (Ca agonist) and diethylstilbestrol (Ca antagonist) increased [Ca2+]i slightly (6% to 24%) and partially inhibited thrombin-induced [Ca2+]i elevation (68% to 79%). Therefore the dimethylaminoethyl moiety is responsible for tamoxifen being a Ca agonist rather than antagonist. 4-Hydroxytamoxifen and polymer-conjugated derivatives of 4-hydroxytamoxifen increased [Ca2+]i, with similar efficacy. The ability of tamoxifen to increase [Ca2+]i in platelets, leading to platelet activation, and its ability to act synergistically with other platelet agonists may contribute to development of tamoxifen-induced thrombosis.

2-aminoethoxydiphenyl borate as a prototype drug for a group of structurally related calcium channel blockers in human platelets.

We have synthesized a series of 2-aminoethoxydiphenyl borate (2-APB, 2,2-diphenyl-1,3,2-oxazaborolidine) analogs and tested their ability to inhibit thrombin-induced Ca(2+) influx in human platelets. The analogs were either synthesized by adding various substituents to the oxazaborolidine ring (methyl, dimethyl, tert-butyl, phenyl, methyl phenyl, and pyridyl) or increasing the size of the oxazaborolidine ring to seven- and nine-membered rings. NMR analysis of the boron-containing analogs suggests that each of them exist as a ring structure through the formation of an N-->B coordinate bond (except for the hexyl analog). The possibility that these boron-containing compounds formed dimers was also considered. All compounds dose-dependently inhibited thrombin-induced Ca(2+) influx in human platelets, with the 2,2-diphenyl-1,3,2-oxazaborolidine-5-one derivative having the weakest activity at 100 microM, whereas the (S)-4-benzyl and (R)-4-benzyl derivatives of 2-APB were approximately 10 times more potent than the parent 2-APB. Two nonboron analogs (3-methyl and 3-tert-butyl 2,2-diphenyl-1,3-oxazolidine) were synthesized; they had approximately the same activity as 2-APB, and this implies that the presence of boron was not necessary for inhibitory activity. All of the compounds tested were also able to inhibit thrombin-induced calcium release. We concluded that extensive modifications of the oxazaborolidine ring in 2-APB can be made, and Ca(2+)-blocking activity was maintained.

Diethylstilbestrol is a potent inhibitor of store-operated channels and capacitative Ca(2+) influx.

We have recently found that diethylstilbestrol (DES), a synthetic estrogen agonist, inhibits thrombin-induced Ca(2+) influx in human platelets, but it remains unclear to what extend this effect might be related to the store-operated Ca(2+) influx pathway. To study the effect of DES on store-operated channels and capacitative Ca(2+) influx, we used rat basophilic leukemia (RBL) cells, vascular smooth muscle cells (SMC), and human platelets, and recorded whole-cell Ca(2+) release-activated Ca(2+) (CRAC) currents and thapsigargin (TG)-induced capacitative Ca(2+) influx. In this study, we demonstrate that extracellular DES produces a dose-dependent and reversible inhibition of CRAC currents in RBL cells (IC(50), approximately 0.5 microM), whereas intracellular DES (25 microM) has no effect. Extracellular DES (up to 30 microM) inhibited only CRAC but did not affect a whole-cell monovalent cation current mediated by TRPM7 channels. DES effectively inhibited TG-induced capacitative Ca(2+) influx in a dose-dependent manner with an IC(50) values of approximately 0.1 microM in RBL cells, <0.1 microM in SMC, and approximately 1 microM in human platelets. It is noteworthy that trans-stilbene, a close structural analog of DES that lacks hydroxyl and ethyl groups, had no effect on CRAC current and on store-operated Ca(2+) influx. Thus, we found DES to be a very effective inhibitor of store-operated channels and Ca(2+) influx in a variety of cell types.

Diethylstilbestrol and tetrahydrochrysenes are calcium channel blockers in human platelets: relationship to the stilbene pharmacophore.

The effects of compounds with the stilbene pharmacophore [diethylstilbestrol (DES), DES derivatives, tetrahydrochrysene (THC), and THC derivatives] were examined for their ability to inhibit thrombin-induced Ca(2+) influx in human platelets. DES derivatives (DES dimethyl ether, DES dipropionate, dienestrol, and hexestrol) had lower inhibitory activity than DES. Esterification of DES with the bulky monobenzyl group eliminated inhibitory activity. Unsubstituted THC diol had the lowest inhibitory activity in the series of the THC derivatives bearing substituents in the 5,11 positions. These derivatives, either diethyl or dipropyl, cis or trans, were potent inhibitors of thrombin-induced [Ca(2+)](i) elevation (near 100% inhibition at 10 microM). Therefore, stilbene pharmacophore having bulk out of the plane of the double bond (from the twisting of the two aromatic rings or from addition of all substituents) seems to be requirement for the inhibitory activity. Free hydroxyl groups are also required for inhibitory activity, most likely for hydrogen bonding, since trans-diethyl tetrahydrochrysene dimethyl ether was inactive. Compounds bearing ethyl substituents (DES and THC derivatives) inhibited thrombin-induced release of calcium from the endoplasmic reticulum. These compounds also inhibited thapsigargin-induced Ca(2+) influx. This result implies that these compounds also block store-operated Ca(2+) influx directly, as well as internal Ca(2+) release. Compounds without ethyl substituents (trans-resveratrol, genistein, daidzein, and THC diol) only inhibited calcium influx into platelets.

Dietary phytoestrogens and their synthetic structural analogues as calcium channel blockers in human platelets.

Phytoestrogens have been shown to inhibit platelet activation by blocking platelet calcium channels. This study examined the effect of several synthetic derivatives of trans-resveratrol, genistein, and daidzein on platelet free intracellular calcium ([Ca2+]i) elevation in thrombin-activated platelets and the possible mechanisms of this inhibitory effect. Studies were conducted on fresh human platelets from healthy volunteers. The fluorescent dye fura-2 was used to monitor [Ca2+]i in platelets. At 10 microM-resveratrol, triacetyl-trans-resveratrol, and trimethoxy-trans-resveratrol produced, respectively, 57 +/- 4%, 40 +/- 4%, and 21 +/- 1% inhibition; genistein, acetylgenistein, and dihydrogenistein produced 51 +/- 10%, 26 +/- 7%, and 16 +/- 2% inhibition, respectively; daidzein and diacetyldaidzein produced 56 +/- 5% and 45 +/- 10% inhibition of thrombin-induced [Ca2+]i elevation. The inhibitory effect was immediate and appeared to directly affect the calcium influx channels. Phytoestrogen action on [Ca2+]i did not cause alteration in nitric oxide signaling. Tyrosine phosphorylation was not involved in the inhibition of [Ca2+]i elevation by phytoestrogens, because the percent inhibition produced by the tyrosine kinase inhibitor genistein and its inactive analogue daidzein on thrombin-induced and thapsigargin-induced [Ca2+]i elevation was not significantly different for either compound at any concentration tested. Structure-activity relationship studies on this limited set of compounds reveal the requirements for the stilbene pharmacophore for the calcium-blocking activity.