Who is pregnant? Defining real-world data-based pregnancy episodes in the National COVID Cohort Collaborative (N3C)

Objectives

To define pregnancy episodes and estimate gestational age within electronic health record (EHR) data from the National COVID Cohort Collaborative (N3C).

Materials and Methods

We developed a comprehensive approach, named Hierarchy and rule-based pregnancy episode Inference integrated with Pregnancy Progression Signatures (HIPPS), and applied it to EHR data in the N3C (January 1, 2018-April 7, 2022). HIPPS combines: (1) an extension of a previously published pregnancy episode algorithm, (2) a novel algorithm to detect gestational age-specific signatures of a progressing pregnancy for further episode support, and (3) pregnancy start date inference. Clinicians performed validation of HIPPS on a subset of episodes. We then generated pregnancy cohorts based on gestational age precision and pregnancy outcomes for assessment of accuracy and comparison of COVID-19 and other characteristics.

Results

We identified 628 165 pregnant persons with 816 471 pregnancy episodes, of which 52.3% were live births, 24.4% were other outcomes (stillbirth, ectopic pregnancy, abortions), and 23.3% had unknown outcomes. Clinician validation agreed 98.8% with HIPPS-identified episodes. We were able to estimate start dates within 1 week of precision for 475 433 (58.2%) episodes. 62 540 (7.7%) episodes had incident COVID-19 during pregnancy.

Discussion

HIPPS provides measures of support for pregnancy-related variables such as gestational age and pregnancy outcomes based on N3C data. Gestational age precision allows researchers to find time to events with reasonable confidence.

Conclusion

We have developed a novel and robust approach for inferring pregnancy episodes and gestational age that addresses data inconsistency and missingness in EHR data.

Real-World Treatment Patterns and Outcomes of First-Line Immunotherapy Among Patients With Advanced Nonsquamous NSCLC Harboring BRAF, MET, or HER2 Alterations

Introduction

Data on utilization and clinical outcomes of programmed cell death protein or programmed death-ligand 1 (PD-[L]1) inhibitors in NSCLC with uncommon oncogenic alterations is limited.

Methods

This retrospective study used a deidentified U.S. nationwide clinicogenomic database to select patients with advanced nonsquamous NSCLC without EGFR, ALK, or ROS1 alterations, diagnosed from January 1, 2016 to September 30, 2020, who initiated first-line therapy. Our objectives were to summarize characteristics and treatment patterns for patients with four little-studied genomic alterations or driver-negative NSCLC. We estimated Kaplan-Meier real-world time on treatment (rwTOT) and time to next treatment for patients receiving PD-(L)1 inhibitors. The data cutoff was September 30, 2021.

Results

Of the 3971 eligible patients, 84 (2%) had NSCLC with BRAF V600E mutation, 117 (3%) had MET exon 14 skipping mutation, 130 (3%) had MET amplification, 91 (2%) had ERBB2 activation mutation, and 691 patients (17%) had driver-negative NSCLC. Patient characteristics differed among cohorts as expected. The most common first-line regimen in each cohort was a PD-(L)1 inhibitor as monotherapy or in combination with chemotherapy. The median rwTOT with anti-PD-(L)1 monotherapy was 4.6 months in the driver-negative cohort and ranged from 2.9 months (ERBB2 mutation) to 7.6 months (BRAF V600E mutation). The median rwTOT with anti-PD-(L)1-chemotherapy combination was 5.2 months in the driver-negative cohort and 6 months in all but the BRAF V600E cohort (17.5 mo). The patterns of real-world time to next treatment results were similar.

Conclusions

Substantial use of anti-PD-(L)1 therapy and associated clinical outcomes are consistent with previous real-world findings and suggest no detriment from PD-(L)1 inhibitors for advanced nonsquamous NSCLC harboring one of these four genomic alterations relative to driver-negative NSCLC.

Late preterm antenatal corticosteroids in singleton and twin gestations: a retrospective cohort study

BACKGROUND

In 2016, the American College of Obstetricians and Gynecologists recommended antenatal corticosteroids in the late preterm period for women at risk for preterm delivery. Limited real-world evidence exists on neonatal outcomes, particularly for twin gestations, following the guideline change. The study objective is to determine the association of antenatal corticosteroids in late preterm singleton and twin pregnancies with respiratory complications and hypoglycemia in a real-world clinical setting.

METHODS

This is a retrospective cohort study comprising late preterm deliveries (4,341 mother-child pairs) within the Mount Sinai Health System, 2012-2018. The exposure of interest is antenatal corticosteroid administration of betamethasone during pregnancy between 34 0/7 and 36 6/7 weeks. Our primary outcomes are neonatal respiratory complications and hypoglycemia. Multivariable logistic regression was used to estimate the association between antenatal corticosteroid exposure and these two outcomes. We stratified the study population by singleton gestations and twins to minimize the potential confounding from different obstetric management between the two groups.

RESULTS

Among a total of 4,341 mother-child pairs (3,309 singleton and 1,032 twin mother-child pairs), 745 mothers received betamethasone, of which 40.94% (305/745) received the full course. Relative to no treatment, a full course of betamethasone was associated with reduced odds of respiratory complications (OR = 0.53, 95% CI:[0.31-0.85], p < 0.01) and increased odds of hypoglycemia (OR = 1.86, 95%CI:[1.34-2.56], p < 0.01) in singletons; however, the association with respiratory complications was not significant in twins (OR = 0.42, 95% CI:[0.11-1.23], p = 0.16), but was associated with increased odds of hypoglycemia (OR = 2.18, 95% CI:[1.12-4.10], p = 0.02). A partial course of betamethasone (relative to no treatment) was not significantly associated with any of the outcomes, other than respiratory complications in twins (OR = 0.34, 95% CI:[0.12-0.82], p = 0.02).

CONCLUSIONS

Exposure to antenatal corticosteroids in singletons and twins is associated with increased odds of hypoglycemia. Among singletons, exposure to the full dosage (i.e. two doses) was associated with decreased odds of respiratory complications but this was only the case for partial dose among twins. Twin gestations were not studied by the Antenatal Late Preterm Steroids trial. Therefore, our study findings will contribute to the paucity of evidence on the benefit of antenatal corticosteroids in this group. Health systems should systematically monitor guideline implementations to improve patient outcomes.

Who is pregnant? defining real-world data-based pregnancy episodes in the National COVID Cohort Collaborative (N3C)

Objective

To define pregnancy episodes and estimate gestational aging within electronic health record (EHR) data from the National COVID Cohort Collaborative (N3C).

Materials and Methods

We developed a comprehensive approach, named H ierarchy and rule-based pregnancy episode I nference integrated with P regnancy P rogression S ignatures (HIPPS) and applied it to EHR data in the N3C from 1 January 2018 to 7 April 2022. HIPPS combines: 1) an extension of a previously published pregnancy episode algorithm, 2) a novel algorithm to detect gestational aging-specific signatures of a progressing pregnancy for further episode support, and 3) pregnancy start date inference. Clinicians performed validation of HIPPS on a subset of episodes. We then generated three types of pregnancy cohorts based on the level of precision for gestational aging and pregnancy outcomes for comparison of COVID-19 and other characteristics.

Results

We identified 628,165 pregnant persons with 816,471 pregnancy episodes, of which 52.3% were live births, 24.4% were other outcomes (stillbirth, ectopic pregnancy, spontaneous abortions), and 23.3% had unknown outcomes. We were able to estimate start dates within one week of precision for 431,173 (52.8%) episodes. 66,019 (8.1%) episodes had incident COVID-19 during pregnancy. Across varying COVID-19 cohorts, patient characteristics were generally similar though pregnancy outcomes differed.

Discussion

HIPPS provides support for pregnancy-related variables based on EHR data for researchers to define pregnancy cohorts. Our approach performed well based on clinician validation.

Conclusion

We have developed a novel and robust approach for inferring pregnancy episodes and gestational aging that addresses data inconsistency and missingness in EHR data.

[The Effect of High Humidity Environments on Very Low Birth Weight Preterm Infants: A Systematic Review]

BACKGROUND

The scholarly evidence on the timing and practice of interventional care administered to preterm infants in high-humidity environments is unclear. This makes evaluating the prognosis of preterm infants with comorbidities difficult and means that clinical medical staff lack clear guidelines for care.

PURPOSE

This systematic review was designed to explore the prognostic effects of interventions for comorbidities performed on very low birthweight preterm infants in high humidity environments to provide an empirical basis for developing related clinical-care guidelines.

METHODS

An electronic database was searched for all relevant documents published between 1930 and September 2021. The keywords used were "premature infants" OR "very low weight premature infants" OR "very low weight premature infants" AND "humidity", and the target groups were premature infants weighing ≤ 1,500 grams or delivered at ≤ 34 weeks of gestation. The timing and practice of interventions in high humidity environments and the occurrence and prognosis of related comorbidities were explored. The main findings cover the issues of body weight, total water intake, electrolytes, urine output, insensitivity water loss, infection, common complications, and mortality in preterm infants. After reviewing the methods, quality, and efficacy of the research in the identified studies, 9 articles were selected for integrated synthesis.

RESULTS

Recommendations for the use of high humidity with infants delivered at ≤ 30 weeks of gestation or at birth weights ≤ 1,000 grams were integrated. An environment with a relative humidity of 70%-80% should be used during the first postpartum week and 50%-60% during the second postpartum week. The recommended total duration of use of a high-humidity environment is two weeks to avoid delaying the development of the stratum corneum. Physiological indicators shown to exhibit significant improvement under this regimen include reduced total water intake, increased urine output, and a lower incidence of hypernatremia.

CONCLUSIONS / IMPLICATIONS FOR PRACTICE

The appropriate timing and practice of high humidity intervention were integrated in this study. It is hoped that this review provides an evidence-based clinical practice guideline for preterm infant care.

Improving preeclampsia risk prediction by modeling pregnancy trajectories from routinely collected electronic medical record data

Preeclampsia is a heterogeneous and complex disease associated with rising morbidity and mortality in pregnant women and newborns in the US. Early recognition of patients at risk is a pressing clinical need to reduce the risk of adverse outcomes. We assessed whether information routinely collected in electronic medical records (EMR) could enhance the prediction of preeclampsia risk beyond what is achieved in standard of care assessments. We developed a digital phenotyping algorithm to curate 108,557 pregnancies from EMRs across the Mount Sinai Health System, accurately reconstructing pregnancy journeys and normalizing these journeys across different hospital EMR systems. We then applied machine learning approaches to a training dataset (N = 60,879) to construct predictive models of preeclampsia across three major pregnancy time periods (ante-, intra-, and postpartum). The resulting models predicted preeclampsia with high accuracy across the different pregnancy periods, with areas under the receiver operating characteristic curves (AUC) of 0.92, 0.82, and 0.89 at 37 gestational weeks, intrapartum and postpartum, respectively. We observed comparable performance in two independent patient cohorts. While our machine learning approach identified known risk factors of preeclampsia (such as blood pressure, weight, and maternal age), it also identified other potential risk factors, such as complete blood count related characteristics for the antepartum period. Our model not only has utility for earlier identification of patients at risk for preeclampsia, but given the prediction accuracy exceeds what is currently achieved in clinical practice, our model provides a path for promoting personalized precision therapeutic strategies for patients at risk.

Inpatient Administration of Alpha-1-Adrenergic Receptor Blocking Agents Reduces Mortality in Male COVID-19 Patients

Apha-1-adrenergic receptor antagonists (α₁-blockers) can suppress pro-inflammatory cytokines, thereby potentially improving outcomes among patients with COVID-19. Accordingly, we evaluated the association between α₁-blocker exposure (before or during hospitalization) and COVID-19 in-hospital mortality. We identified 2,627 men aged 45 or older who were admitted to Mount Sinai hospitals with COVID-19 between February 24 and May 31, 2020, in New York. Men exposed to α₁-blockers (N = 436) were older (median age 73 vs. 64 years, P < 0.001) and more likely to have comorbidities than unexposed men (N = 2,191). Overall, 777 (29.6%) patients died in hospital, and 1,850 (70.4%) were discharged. Notably, we found that α₁-blocker exposure was independently associated with improved in-hospital mortality in a multivariable logistic analysis (OR 0.699; 95% CI, 0.498-0.982; P = 0.039) after adjusting for patient demographics, comorbidities, and baseline vitals and labs. The protective effect of α₁-blockers was stronger among patients with documented inpatient exposure to α₁-blockers (OR 0.624; 95% CI 0.431-0.903; P = 0.012). Finally, age-stratified analyses suggested variable benefit from inpatient α₁-blocker across age groups: Age 45-65 OR 0.483, 95% CI 0.216-1.081 (P = 0.077); Age 55-75 OR 0.535, 95% CI 0.323-0.885 (P = 0.015); Age 65-89 OR 0.727, 95% CI 0.484-1.092 (P = 0.124). Taken together, clinical trials to assess the therapeutic value of α₁-blockers for COVID-19 complications are warranted.

A comprehensive digital phenotype for postpartum hemorrhage

OBJECTIVE

We aimed to establish a comprehensive digital phenotype for postpartum hemorrhage (PPH). Current guidelines rely primarily on estimates of blood loss, which can be inaccurate and biased and ignore complementary information readily available in electronic medical records (EMR). Inaccurate and incomplete phenotyping contributes to ongoing challenges in tracking PPH outcomes, developing more accurate risk assessments, and identifying novel interventions.

MATERIALS AND METHODS

We constructed a cohort of 71 944 deliveries from the Mount Sinai Health System. Estimates of postpartum blood loss, shifts in hematocrit, administration of uterotonics, surgical interventions, and diagnostic codes were combined to identify PPH, retrospectively. Clinical features were extracted from EMRs and mapped to common data models for maximum interoperability across hospitals. Blinded chart review was done by a physician on a subset of PPH and non-PPH patients and performance was compared to alternate PPH phenotypes. PPH was defined as clinical diagnosis of postpartum hemorrhage documented in the patient's chart upon chart review.

RESULTS

We identified 6639 PPH deliveries (9% prevalence) using our phenotype-more than 3 times as many as using blood loss alone (N = 1,747), supporting the need to incorporate other diagnostic and intervention data. Chart review revealed our phenotype had 89% accuracy and an F1-score of 0.92. Alternate phenotypes were less accurate, including a common blood loss-based definition (67%) and a previously published digital phenotype (74%).

CONCLUSION

We have developed a scalable, accurate, and valid digital phenotype that may be of significant use for tracking outcomes and ongoing clinical research to deliver better preventative interventions for PPH.

[Improving the Completeness of Facilitated Tucking for Preterm Infants in the Neonatal Intensive Care Unit]

BACKGROUND & PROBLEMS

Facilitated tucking (containment) is a strategy that has been demonstrated to improve insufficient muscle tone, reduce procedural pain, and stabilize vital signs in premature infants.

PURPOSE

The aim of this study was to improve the accuracy and implementation rate of nursing staffs` facilitated tucking.

METHODS

Formulate and standardize nursing care to reduce the burden on nursing staff and make staff implementation consistent. Decomposition diagrams of the production steps were posted in patient units, on-the-job education courses were held, and a short video was used to provide care guidelines to nursing staff.

RESULTS

Compared to pretest levels, the rate of facilitated tucking implementation in the early, middle, and late invasive medical treatment periods, respectively, increased from 0% to 53.5%, 1.2% to 50%, and 6% to 48.8%, while the accuracy rate of facilitated tucking cognition increased from 61.1% to 91.9%.

CONCLUSIONS

This project effectively promoted the standardization of facilitated tucking in our hospital, provided preterm infants with better care and neurological development, and improved mother-infant attachment.

In-hospital use of ACE inhibitors/angiotensin receptor blockers associates with COVID-19 outcomes in African American patients

BACKGROUNDThe angiotensin-converting enzyme (ACE) D allele is more prevalent among African Americans compared with other races and ethnicities and has previously been associated with severe coronavirus disease 2019 (COVID-19) pathogenesis through excessive ACE1 activity. ACE inhibitors/angiotensin receptor blockers (ACE-I/ARB) may counteract this mechanism, but their association with COVID-19 outcomes has not been specifically tested in the African American population.METHODSWe identified 6218 patients who were admitted into Mount Sinai hospitals with COVID-19 between February 24 and May 31, 2020, in New York City. We evaluated whether the outpatient and in-hospital use of ACE-I/ARB is associated with COVID-19 in-hospital mortality in an African American compared with non-African American population.RESULTSOf the 6218 patients with COVID-19, 1138 (18.3%) were ACE-I/ARB users. In a multivariate logistic regression model, ACE-I/ARB use was independently associated with a reduced risk of in-hospital mortality in the entire population (OR, 0.655; 95% CI, 0.505-0.850; P = 0.001), African American population (OR, 0.44; 95% CI, 0.249-0.779; P = 0.005), and non-African American population (OR, 0.748, 95% CI, 0.553-1.012, P = 0.06). In the African American population, in-hospital use of ACE-I/ARB was associated with improved mortality (OR, 0.378; 95% CI, 0.188-0.766; P = 0.006), whereas outpatient use was not (OR, 0.889; 95% CI, 0.375-2.158; P = 0.812). When analyzing each medication class separately, ARB in-hospital use was significantly associated with reduced in-hospital mortality in the African American population (OR, 0.196; 95% CI, 0.074-0.516; P = 0.001), whereas ACE-I use was not associated with impact on mortality in any population.CONCLUSIONIn-hospital use of ARB was associated with a significant reduction in in-hospital mortality among COVID-19-positive African American patients.FUNDINGNone.

Hospitalised COVID-19 patients of the Mount Sinai Health System: a retrospective observational study using the electronic medical records

OBJECTIVE

To assess association of clinical features on COVID-19 patient outcomes.

DESIGN

Retrospective observational study using electronic medical record data.

SETTING

Five member hospitals from the Mount Sinai Health System in New York City (NYC).

PARTICIPANTS

28 336 patients tested for SARS-CoV-2 from 24 February 2020 to 15 April 2020, including 6158 laboratory-confirmed COVID-19 cases.

MAIN OUTCOMES AND MEASURES

Positive test rates and in-hospital mortality were assessed for different racial groups. Among positive cases admitted to the hospital (N=3273), we estimated HR for both discharge and death across various explanatory variables, including patient demographics, hospital site and unit, smoking status, vital signs, lab results and comorbidities.

RESULTS

Hispanics (29%) and African Americans (25%) had disproportionately high positive case rates relative to their representation in the overall NYC population (p<0.05); however, no differences in mortality rates were observed in hospitalised patients based on race. Outcomes differed significantly between hospitals (Gray's T=248.9; p<0.05), reflecting differences in average baseline age and underlying comorbidities. Significant risk factors for mortality included age (HR 1.05, 95% CI 1.04 to 1.06; p=1.15e-32), oxygen saturation (HR 0.985, 95% CI 0.982 to 0.988; p=1.57e-17), care in intensive care unit areas (HR 1.58, 95% CI 1.29 to 1.92; p=7.81e-6) and elevated creatinine (HR 1.75, 95% CI 1.47 to 2.10; p=7.48e-10), white cell count (HR 1.02, 95% CI 1.01 to 1.04; p=8.4e-3) and body mass index (BMI) (HR 1.02, 95% CI 1.00 to 1.03; p=1.09e-2). Deceased patients were more likely to have elevated markers of inflammation.

CONCLUSIONS

While race was associated with higher risk of infection, we did not find racial disparities in inpatient mortality suggesting that outcomes in a single tertiary care health system are comparable across races. In addition, we identified key clinical features associated with reduced mortality and discharge. These findings could help to identify which COVID-19 patients are at greatest risk of a severe infection response and predict survival.

Using social media for smoking cessation interventions: a systematic review

Background:

Previous studies have shown that smoking tobacco significantly increases both incidence and mortality rates for many diseases. Social media has become one of the most influential platforms for various smoking cessation interventions. However, results from smoking cessation interventions have differed from study to study. Limited studies have summarised cessation outcomes from social media–based interventions. Therefore, the objective of this review is to explore the effectiveness of using social media for smoking cessation.

Methods:

We searched PubMed, MEDLINE, PsycINFO, and CINAHL for articles between June 2008 and June 2018, and also assessed the references of selected articles. We included studies that used social media as intervention platforms, provided a baseline assessment before the intervention, and provided smoking cessation outcomes after the intervention.

Results:

We identified 13 original studies that enrolled between 16 and 1698 participants; 7-day Point Prevalence Abstinence (PPA) rate was the most frequently used measure of abstinence, with a range of 7%–75%, regardless of the measurement time, study design, and analysis methods. Social media–based smoking cessation interventions were effective, because (1) smokers reported higher 7-day PPA rates after intervention compared to baseline and (2) smokers reported higher 7-day PPA rates in intervention groups than in control groups. Moreover, at each time point, approximately half of all smokers in studies reporting abstinence were found to be biochemically abstinent. There were no significant differences in the effectiveness of smoking cessation outcomes between those that used existing popular social networking platforms (e.g. Pechmann et al’s studies) and those that used individually designed interactive platforms (e.g. MyLastDip, iQuit system, Quitxt system).

Conclusions:

This review highlights the effectiveness of social media–based smoking cessation intervention studies. Due to the widespread use of social media, as well as its low cost, we suggest embedding smoking cessation interventions within existing popular social media platforms.

Potential Industrial Production of a Well-Soluble, Alkaline-Stable, and Anti-Inflammatory Isoflavone Glucoside from 8-Hydroxydaidzein Glucosylated by Recombinant Amylosucrase of Deinococcus geothermalis

8-Hydroxydaidzein (8-OHDe), an ortho-hydroxylation derivative of soy isoflavone daidzein isolated from some fermented soybean foods, has been demonstrated to possess potent anti-inflammatory activity. However, the isoflavone aglycone is poorly soluble and unstable in alkaline solutions. To improve the aqueous solubility and stability of the functional isoflavone, 8-OHDe was glucosylated with recombinant amylosucrase of Deinococcus geothermalis (DgAS) with industrial sucrose, instead of expensive uridine diphosphate-glucose (UDP-glucose). One major product was produced from the biotransformation, and identified as 8-OHDe-7-α-glucoside, based on mass and nuclear magnetic resonance spectral analyses. The aqueous solubility and stability of the isoflavone glucoside were determined, and the results showed that the isoflavone glucoside was almost 4-fold more soluble and more than six-fold higher alkaline-stable than 8-OHDe. In addition, the anti-inflammatory activity of 8-OHDe-7-α-glucoside was also determined by the inhibition of lipopolysaccharide-induced nitric oxide production in RAW 264.7 cells. The results showed that 8-OHDe-7-α-glucoside exhibited significant and dose-dependent inhibition on the production of nitric oxide, with an IC₅₀ value of 173.2 µM, which remained 20% of the anti-inflammatory activity of 8-OHDe. In conclusion, the well-soluble and alkaline-stable 8-OHDe-7-α-glucoside produced by recombinant DgAS with a cheap substrate, sucrose, as a sugar donor retains moderate anti-inflammatory activity, and could be used in industrial applications in the future.

Effect of benign prostatic hyperplasia on the development of spine, hip, and wrist fractures

Benign prostatic hyperplasia is one of the most common diseases in the elderly male population. The urinary tract symptoms may increase the risk of falls and fractures. The results indicated that patients with benign prostatic hyperplasia could increase the risk of vertebral compression fractures in both the thoracic and lumbar spine and also hip fractures, but did not increase the risk of wrist fracture.

INTRODUCTION

The relationship between benign prostatic hyperplasia and the development of fall-related fractures, especially vertebral compression fractures, has been seldom mentioned in the literature. This study aimed to evaluate the risk of developing vertebral compression fracture, hip fracture, and wrist fracture in patients with benign prostatic hyperplasia.

METHODS

This study obtained claims data retrospectively from the National Health Insurance Research Database of Taiwan and identified 48,114 patients who were diagnosed as having benign prostatic hyperplasia. Subjects of the control cohort were individually matched at a ratio of 4:1 with those in the benign prostatic hyperplasia cohort according to age and the index day. Comorbidities were classified as those existing before the index day and included a previous fracture history, osteoporosis, myocardial infarction, congestive heart failure, diabetes mellitus, hypertension, cerebrovascular accident, etc. The end of the follow-up period of the analyses was the day when the patient developed new vertebral compression fractures, hip fractures, or wrist fractures, terminated enrollment from the National Health Insurance, or died or until the end of 2012. The study used the Cox proportion hazard model to determine the hazard ratio for developing new hip fractures.

RESULTS

Patients with benign prostatic hyperplasia were significantly more likely than those in the control cohort to develop new vertebral compression fractures in the thoracic spine (0.43% vs. 0.40%, adjusted hazard ratio 3.03, confidence interval 2.12-4.31) and lumbar spine (1.26% vs. 1.23%, adjusted hazard ratio 4.12, confidence interval 3.39-5.01), and hip fracture (1.47% vs. 2.09%, adjusted hazard ratio 1.22, confidence interval 1.10-1.36), but does not increase the risk of wrist fracture (0.61% vs. 0.67%, adjusted hazard ratio 1.07, confidence interval 0.85-1.34).

CONCLUSIONS

Patients with benign prostatic hyperplasia exhibited an increased risk of developing vertebral compression fractures in both the thoracic and lumbar spine and also hip fractures, but did not increase the risk of wrist fracture. However, more research is needed to confirm this trend in the clinical setting.

Practical unidentifiability of a simple vector-borne disease model: Implications for parameter estimation and intervention assessment

Mathematical modeling has an extensive history in vector-borne disease epidemiology, and is increasingly used for prediction, intervention design, and understanding mechanisms. Many studies rely on parameter estimation to link models and data, and to tailor predictions and counterfactuals to specific settings. However, few studies have formally evaluated whether vector-borne disease models can properly estimate the parameters of interest given the constraints of a particular dataset. Identifiability analysis allows us to examine whether model parameters can be estimated uniquely-a lack of consideration of such issues can result in misleading or incorrect parameter estimates and model predictions. Here, we evaluate both structural (theoretical) and practical identifiability of a commonly used compartmental model of mosquito-borne disease, using the 2010 dengue epidemic in Taiwan as a case study. We show that while the model is structurally identifiable, it is practically unidentifiable under a range of human and mosquito time series measurement scenarios. In particular, the transmission parameters form a practically identifiable combination and thus cannot be estimated separately, potentially leading to incorrect predictions of the effects of interventions. However, in spite of the unidentifiability of the individual parameters, the basic reproduction number was successfully estimated across the unidentifiable parameter ranges. These identifiability issues can be resolved by directly measuring several additional human and mosquito life-cycle parameters both experimentally and in the field. While we only consider the simplest case for the model, we show that a commonly used model of vector-borne disease is unidentifiable from human and mosquito incidence data, making it difficult or impossible to estimate parameters or assess intervention strategies. This work illustrates the importance of examining identifiability when linking models with data to make predictions and inferences, and particularly highlights the importance of combining laboratory, field, and case data if we are to successfully estimate epidemiological and ecological parameters using models.

Adenosine Augmentation Evoked by an ENT1 Inhibitor Improves Memory Impairment and Neuronal Plasticity in the APP/PS1 Mouse Model of Alzheimer's Disease

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by cognitive impairment and synaptic dysfunction. Adenosine is an important homeostatic modulator that controls the bioenergetic network in the brain through regulating receptor-evoked signaling pathways, bioenergetic machineries, and epigenetic-mediated gene regulation. Equilibrative nucleoside transporter 1 (ENT1) is a major adenosine transporter that recycles adenosine from the extracellular space. In the present study, we report that a small adenosine analogue (designated J4) that inhibited ENT1 prevented the decline in spatial memory in an AD mouse model (APP/PS1). Electrophysiological and biochemical analyses further demonstrated that chronic treatment with J4 normalized the impaired basal synaptic transmission and long-term potentiation (LTP) at Schaffer collateral synapses as well as the aberrant expression of synaptic proteins (e.g., NR2A and NR2B), abnormal neuronal plasticity-related signaling pathways (e.g., PKA and GSK3β), and detrimental elevation in astrocytic A_2AR expression in the hippocampus and cortex of APP/PS1 mice. In conclusion, our findings suggest that modulation of adenosine homeostasis by J4 is beneficial in a mouse model of AD. Our study provides a potential therapeutic strategy to delay the progression of AD.

Isolated Clavicle Fracture with Secondary Pneumothorax: A Case Report

Clavicle fractures complicated by pneumothorax are rare. This case report describes a young man who developed pneumothorax secondary to an isolated clavicle fracture following blunt trauma to his right shoulder in an assault. The pneumothorax was diagnosed on a shoulder X-ray, and required the insertion of a chest drain. It may be prudent to specifically exclude a pneumothorax in clavicle fractures if the fractured segment is directed towards the lung.

Targeting ENT1 and adenosine tone for the treatment of Huntington's disease

Huntington's disease (HD) is caused by an abnormal CAG expansion in the exon 1 of huntingtin gene. The treatment of HD is an unmet medical need. Given the important role of adenosine in modulating brain activity, in this study, levels of adenosine and adenine nucleotides in the cerebral spinal fluid of patients with HD and in the brain of two mouse models of HD (R6/2 and Hdh150Q) were analysed. The expression and activity of ENT1 in the striatum of mice with HD were measured. Targeting adenosine tone for treating HD was examined in R6/2 mice by genetic removal of ENT1 and by giving an ENT1 inhibitor, respectively. The results showed that the adenosine homeostasis is dysregulated in the brain of patients and mice with HD. In patients, the ratio of adenosine/ATP in the cerebral spinal fluid was negatively correlated with the disease duration, and tended to have a positive correlation with independence scale and functional capacity. In comparison to controls, mRNA level of ENT1 was higher in the striatum of R6/2 and Hdh150Q mice. Intrastriatal administration of ENT1 inhibitors increased extracellular level of adenosine in the striatum of R6/2 mice to a much higher level than controls. Chronic inhibition of ENT1 or by genetic removal of ENT1 enhanced the survival of R6/2 mice. Collectively, adenosine homeostasis and ENT1 expression are altered in HD. The inhibition of ENT1 can enhance extracellular adenosine level and be a potential therapeutic approach for treating HD.

Identification of the chitinase genes from the diamondback moth, Plutella xylostella

Chitinases have an indispensable function in chitin metabolism and are well characterized in numerous insect species. Although the diamondback moth (DBM) Plutella xylostella, which has a high reproductive potential, short generation time, and characteristic adaptation to adverse environments, has become one of the most serious pests of cruciferous plants worldwide, the information on the chitinases of the moth is presently limited. In the present study, using degenerated polymerase chain reaction (PCR) and rapid amplification of cDNA ends-PCR strategies, four chitinase genes of P. xylostella were cloned, and an exhaustive search was conducted for chitinase-like sequences from the P. xylostella genome and transcriptomic database. Based on the domain analysis of the deduced amino acid sequences and the phylogenetic analysis of the catalytic domain sequences, we identified 15 chitinase genes from P. xylostella. Two of the gut-specific chitinases did not cluster with any of the known phylogenetic groups of chitinases and might be in a new group of the chitinase family. Moreover, in our study, group VIII chitinase was not identified. The structures, classifications and expression patterns of the chitinases of P. xylostella were further delineated, and with this information, further investigations on the functions of chitinase genes in DBM could be facilitated.

Regulation of P-glycoprotein expression in brain capillaries in Huntington's disease and its impact on brain availability of antipsychotic agents risperidone and paliperidone

Huntington's disease (HD) is a neurodegenerative disease marked by an expanded polyglutamine (polyQ) tract on the huntingtin (HTT) protein that may cause transcriptional dysfunction. This study aimed to investigate the regulation and function of P-glycoprotein, an important efflux transporter, in brain capillaries in HD. The results showed that, compared with the littermate controls, R6/2 HD transgenic mice with the human mutant HTT gene had higher levels of P-glycoprotein mRNA and protein and enhanced NF-κB activity in their brain capillaries. Higher P-glycoprotein expression was also observed in the brain capillaries of human HD patients. Consistent with this enhanced P-glycoprotein expression, brain extracellular levels and brain-to-plasma ratios of the antipsychotic agents risperidone and paliperidone were significantly lower in R6/2 mice than in their littermate controls. Exogenous expression of human mutant HTT protein with expanded polyQ (mHTT-109Q) in HEK293T cells enhanced the levels of P-glycoprotein transcripts and NF-κB activity compared with cells expressing normal HTT-25Q. Treatment with the IKK inhibitor, BMS-345541, decreased P-glycoprotein mRNA level in cells transfected with mHTT-109Q or normal HTT-25Q In conclusion, mutant HTT altered the expression of P-glycoprotein through the NF-κB pathway in brain capillaries in HD and markedly affected the availability of P-glycoprotein substrates in the brain.

Yttrium-90 internal pair production imaging using first generation PET/CT provides high-resolution images for qualitative diagnostic purposes

Yttrium-90 ((90)Y) internal pair production can be imaged by positron emission tomography (PET)/CT and is superior to bremsstrahlung single-photon emission CT/CT for evaluating hepatic (90)Y microsphere biodistribution. We illustrate a case of (90)Y imaging using first generation PET/CT technology, producing high-quality images for qualitative diagnostic purposes.

Positron emission tomography findings in patients with lymphoma-associated haemophagocytic syndrome

Lymphomas that manifest initially with haemophagocytic syndrome (HPS) often pose a diagnostic challenge, as the majority of cases have no significant lymphadenopathy for early histological diagnosis. There is paucity of data on specific features of fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography with integrated computed tomography (PET/CT) in patients with lymphoma-associated HPS (LHPS). We describe three cases of LHPS and their characteristic PET imaging features. These three patients had pyrexia and pancytopenia. Their PET/CT images showed extensive and diffuse FDG uptakes in the bone marrow of the axial skeleton, with little involvement in the lymph nodes. They also faced a common initial diagnostic difficulty; the lack of nodal involvement on clinical examination or CT contributed to the delay in the diagnosis of lymphoma. The PET/CT images, however, revealed extensive and distinctive FDG uptakes in the axial skeletal marrow compartment, thus leading to a greater appreciation of the full extent of the disease.

Induction of indoleamine 2,3-dioxygenase in livers following hepatectomy prolongs survival of allogeneic hepatocytes after transplantation

OBJECTIVES

Indoleamine 2,3-dioxygenase (IDO), which catalyzes the breakdown of tryptophan into kyneurenine, has immunologic significance for the induction of maternal tolerance and liver allograft tolerance by inhibiting T-cell activation. In the present study, we compared survival of syngeneic or allogeneic hepatocytes in livers with or without hepatectomy. Subsequently, we investigated gene expression and localization of IDO in the recipient liver.

METHODS

DA and Fisher 344 rats were used in the following experimental groups: group 1, DA hepatocytes transplanted into hepatectomized Fisher 344 rats; group 2, Fisher 344 hepatocytes transplanted into hepatectomized Fisher 344 rats; group 3, DA hepatocytes transplanted into nonhepatectomized Fisher 344 rats; and group 4, Fisher 344 hepatocytes transplanted into nonhepatectomized Fisher 344 rats. After transplantation, the surviving cells were evaluated on day 5. The IDO signal of the recipient liver was detected by reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry.

RESULTS

In the hepatectomized groups subjected to allogeneic or syngeneic hepatocyte transplantation, the number of surviving hepatocytes was greater than in the nonhepatectomized group after transplantation. The IDO signals (RT-PCR) in the hepatectomized groups were stronger than those in the nonhepatectomized groups. Immunohistochemistry demonstrated that the IDO signal is located in liver antigen-presenting cells, such as Kupffer cells or dendritic cells, and not expressed in hepatocytes.

CONCLUSIONS

Our results demonstrated that IDO is induced in antigen-presenting cells of hepatectomized livers by which subsequently transplanted cells may be protected from rejection by inhibiting indirect or direct recognition of donor antigen and further T-cell activation.

The role of a nuclear protein, histone H1, on signalling pathways for the maturation of dendritic cells

We have demonstrated previously that liver allograft tolerance is associated with the immunosuppressive activity of anti-histone H1 autoreactive antibodies induced in the serum of liver transplantation. Furthermore, we and others have shown that nuclear proteins such as histone H1 and high mobility group box 1 play an important role in maturation of dendritic cells (DCs), although the precise mechanisms are still unknown. In the present study, we focus upon the significance of histone H1 on DCs in terms of the intracellular signalling pathway of DCs. Our immunostaining and immunoblot studies demonstrated that histone H1 was detected in cytoplasm and culture supernatants upon the activation of DCs. Histone H1 blockage by anti-histone H1 antibody down-regulated the intracellular activation of mitogen-activated protein kinases (MAPKs) (p38) and IkappaBalpha of DCs, and inhibited DC activity in the proliferation of CD4+ T cells. On the other hand, the addition of histone H1 without endotoxin stimulation up-regulated major histocompatibility complex class II, the CD80 and CD86 surface markers of DCs and the activation of MAPKs (p38 and extracellular-regulated kinase 1/2) and IkappaBalpha. These results suggest that the translocation of histone H1 from nuclei to cytoplasm and the release of their own histone H1 are necessary for the maturation of DCs and the activation for T lymphocytes.

The role of dose distribution gradient in the observed ferric ion diffusion time scale in MRI-Fricke-infused gel dosimetry

Ferric ion diffusion is a detrimental factor in MRI-Fricke-infused gel dosimetry. In this study, a novel approach involving MR image subtraction and a fast image-based dosimetry technique to study ferric ion diffusion effects is presented. The fast image-based approach allows studying dose profile degradation within minutes post-irradiation. The relationship between the rate of dose profile deterioration and dose distribution gradients can be elucidated with the improved imaging temporal resolution also. Our results showed that for a dose distribution with gradient 4 Gy/mm or higher, ferric ion diffusion causes apparent dose profile degradation in 0.5-1 h post-irradiation. For a gradual dose gradient change of 2.1 Gy/mm or smaller, dose profile degradation appears insignificant for a two-hour elapsed diffusion time. These observations agree well with the theoretical analysis of a square dependence between dose profile degradation and dose distribution gradient. Because all stereotactic radiosurgery procedures produce steep dose distributions and because the ideal "snapshot" of MR scanning cannot be achieved, knowledge of the ferric ion diffusion time scale is important in experimental designs in order to avoid potential measurement errors in MRI-Fricke-agarose gel dosimetry.

The effect of combined 5-fluorouracil and dexamethasone on cultured human retinal pigment epithelial cells

This study was designed to investigate the inhibitory effect of 5-fluorouracil (5-FU) and dexamethasone (DEX) on the proliferation of human retinal pigment epithelial (RPE) cells in vitro. The human RPE cells (R-50 cell line) were cultured and exposed to various concentrations of combined 5-FU (0, 250, 500, 1000, 2000 ng/ml) and DEX (0, 1, 10, 100, 200 micrograms/ml). The cells were incubated for 96 hr and the medium was changed every 48 hr to replenish the drug action. Cell viability was assessed using cell counting and trypan blue exclusion method. Tetrazolium salt, which can be metabolized by mitochondrial dehydrogenase to form a formazan dye, was used to assay cell proliferation. Treatment with 5-FU alone inhibited cell proliferation in a dose-dependent manner. The concentration of 5-FU that inhibited growth by 50% (IC50) was found to be 704.12 ng/ml. There was a bimodal effect of DEX on RPE cells--stimulation at low concentrations (1, 10 micrograms/ml) and inhibition at high concentrations (100, 200 micrograms/ml). When the two drugs were combined, there was additive inhibition in the concentration of 200 micrograms/ml of DEX. These results indicate that a combination of 5-FU and DEX is no more effective in the inhibition of human RPE cells, except in combination with high concentrations of DEX (> or = 200 micrograms/ml).

Characterization of filter extractables by proton NMR spectroscopy: studies on intact filters with process buffers

Studies were conducted to characterize potential extractables from sterilizing grade filters. The focus of this report is the 0.22 micron Durapore (hydrophilic modified PVDF) filter which is used throughout our recovery processes. The objectives of this study are (1) to identify potential filter extractables from the hydrophilic PVDF filters; (2) to show that NMR spectroscopy may be used to detect filter extractables in the presence of product and excipients; and (3) to establish levels of filter extractables obtained by extraction with a variety of buffers. The data show that the primary source of filter extractables is the hydrophilic modification of the PVDF membrane surface. Extractables from the modified hydrophilic PVDF filter include propylene glycol (PG) and soluble oligomers of the hydroxypropyl acrylate and cross-linker. Propylene glycol, arising from the hydrolysis of the hydroxypropyl acrylate, appears to be the primary extractable in buffers above pH 11. Since the 1H-NMR method can easily detect the methyl proton signals of PG, an NMR assay was developed to detect PG in the presence of buffer excipients and final product. Propylene glycol can be used as a marker for the extractables from Durapore hydrophilic PVDF filters. Although numerous buffers were used to generate extractables from the PVDF filter, significant extractables (PG and soluble oligomers) were found only in high pH extraction buffers. As a result of this finding, only a limited number of new buffers or new PVDF filters will require testing for future validation studies. Process validation studies have shown that neither PG nor soluble oligomers are at levels that impact the quality or safety of the product.

Growth suppression of hamster flank organs by topical application of catechins, alizarin, curcumin, and myristoleic acid

Hamster flank organ growth, as measured by an increase in the area of the pigmented macule, is androgen-dependent. When flank organs of a castrated hamster are treated topically with testosterone, the flank organ becomes larger and darker. Since this growth is known to be dependent on the intracellular active androgen, 5alpha-dihydrotestosterone (DHT), inhibitors of 5alpha-reductase which converts testosterone to DHT can inhibit the growth of the flank organ. Certain unsaturated aliphatic fatty acids, such as gamma-linolenic acid and myristoleic acid, as well as other natural compounds, including alizarin and curcumin, are 5alpha-reductase inhibitors and inhibited flank organ growth. Green tea catechins, including (-)-epicatechin-3-gallate, and (-)-epigallo-catechin-3-gallate (EGCG) are also 5alpha-reductase inhibitors and inhibited flank organ growth. However, (-)-epicatechin and (-)-epigallocatechin, which are not 5alpha-reductase inhibitors, also inhibited flank organ growth. EGCG also inhibited DHT-dependent growth of flank organs. These catechins, therefore, may act by a mechanism other than inhibition of 5alpha-reductase. The effect of EGCG and other compounds was localized at the site of application; they did not affect the growth of the contralateral flank organ in the same animal. Since these compounds do not appear to exhibit systemic effects, they may be potentially useful for treatment of androgen-dependent skin disorders.

Prenatal exposure to morphine alters kinetic properties of NMDA receptor-mediated synaptic currents in the hippocampus of rat offspring

Whole-cell patch-clamp recordings of pharmacologically isolated N-methyl-D-asparate (NMDA) receptor-mediated evoked excitatory postsynaptic currents (EPSCs) were made, to study whether prenatal exposure to morphine affected functional properties of synaptic NMDA receptors in hippocampal slices of 2-week-old rat offspring from morphine-addicted mothers. The saturated amplitude of synaptic NMDA receptor-mediated EPSCs from morphine-treated offspring was about twofold larger than that from vehicle-control offspring. The apparent dissociation constant (Kd) values of NMDA receptors for Mg2+ at 0 mV were 7.5 +/- 1.4 and 7.9 +/- 1.3 mM in slices from vehicle-control and morphine-treated offspring, respectively. In addition, no distinguishable changes in the voltage-dependent nature and the reversal potential of NMDA receptors occurred in morphine-treated offspring, suggesting no alterations of Mg2+ blockade and ion selectivity to NMDA receptors. The 10-90% rise times of NMDA receptor-mediated EPSCs in morphine-treated offspring became longer than those in vehicle-control offspring. The decay of NMDA receptor-mediated EPSCs in both morphine-treated and vehicle-control offspring could be described by the sum of a fast and a slow exponential function. The slow, but not fast, decay times of synaptic NMDA receptor-mediated currents in morphine-treated offspring became slower than those in vehicle-control offspring. Collectively, these results suggest that prenatal exposure to morphine altered kinetic properties of synaptic NMDA receptors in hippocampal CA1 pyramidal neurons of rat offspring during early life. The extended duration of synaptic NMDA receptor-mediated currents presumably provided more Ca2+ entry through NMDA receptors in morphine-treated offspring, and its further prolongation by depolarization in such young offspring strengthened NMDA receptor-dependent functions. Thus, in light of pathophysiological implications within the central nervous system of morphine-treated offspring during early life, the present study may provide important insights and serve as a basis for therapeutic intervention in conditions under which NMDA receptors become abnormal.

Studies of impurities in magnetic semiconductors: an example of important XAFS applications

The x-ray absorption fine structure (XAFS) technique has been employed to investigate the local structure and valency about Mn and Fe ions in the III-V diluted magnetic semiconductors In(1-x)Mn(x)As and Ga(1-x)Fe(x)As, prepared by molecular-beam-epitaxy under various growth conditions. These new systems are promising magnetic materials of considerable current interest and with important technical applications including photo-carrier induced magnetism and spin-polarized current devices. The local structure around the magnetic ions can play a pivotal role in affecting the magnetic properties of these semiconductors. Local structure information obtained from XAFS has provided the first direct evidence that the magnetic impurities can indeed substitute for the cation host atoms in samples prepared under appropriate conditions.

MR perfusion studies of brain for patients with unilateral carotid stenosis or occlusion: evaluation of maps of "time to peak" and "percentage of baseline at peak"

Maps of "time to peak" (TTP) and "percentage of baseline at peak" (PBP) were compared with maps of conventional brain perfusion parameters, namely, mean transit time (MTT) and relative cerebral blood volume (rCBV). We performed MR perfusion studies in 11 patients. All of them had occlusion or high-grade stenosis of the unilateral carotid artery. Three areas of old infarct, 4 areas of new infarct, and 10 areas of brain without infarct were evaluated specifically. In all these cases, the TTP maps appeared similar to the MTT maps. They showed increases, normal values, or decreases at the same time in all areas evaluated. Most areas of abnormally decreased CBV had increased signal in PBP maps. In conclusion, the TTP map provided the same qualitative information as MTT. PBP seemed correlated inversely to CBV and was less sensitive in demonstrating abnormality.

Relationship between outcome of proliferative vitreoretinopathy and results of tissue culture of excised preretinal membranes

The purpose of this study was to explore the relationship between clinical post-surgery outcome of proliferative vitreoretinopathy (PVR) and the laboratory results of tissue culture, the specimens of which were excised of pre- or subretinal membranes from PVR patients. Surgically excised membranes from 25 PVR patients were microdissected into small pieces and plated into culture dishes with F12 medium supplemented with 30% fetal bovine serum. After primary culture became confluent, cells were passaged in subculture with F12 medium (10% fetal bovine serum). PVR patients were followed-up after surgery for an average of 21 months. The clinical outcome was compared, according to the growth pattern of the cells derived from the explanted membranes. In 25 PVR patients, 16 cases showed cell migration in the membrane, and cells grew rapidly to confluence in the primary culture in 7 cases. All active growing cells were identified as retinal pigment epithelial (RPE) cells by immunocytochemistry. In 7 cases with active cell growth, all had recurrent retinal detachment. In 18 cases without active cell growth, only 4 cases had the same outcomes. Statistical study showed that the difference between these two groups was significant (P < 0.01). These results indicate that the growth capacity of cultured RPE derived from excised membranes of PVR patients strongly influenced the prognosis for surgery.

Salt effects on ionization equilibria of histidines in myoglobin

The salt dependence of histidine pK(a) values in sperm whale and horse myoglobin and in histidine-containing peptides was measured by (1)H-NMR spectroscopy. Structure-based pK(a) calculations were performed with continuum methods to test their ability to capture the effects of solution conditions on pK(a) values. The measured pK(a) of most histidines, whether in the protein or in model compounds, increased by 0.3 pH units or more between 0.02 M and 1.5 M NaCl. In myoglobin two histidines (His(48) and His(36)) exhibited a shallower dependence than the average, and one (His(113)) showed a steeper dependence. The (1)H-NMR data suggested that the salt dependence of histidine pK(a) values in the protein was determined primarily by the preferential stabilization of the charged form of histidine with increasing salt concentrations rather than by screening of electrostatic interactions. The magnitude and salt dependence of interactions between ionizable groups were exaggerated in pK(a) calculations with the finite-difference Poisson-Boltzmann method applied to a static structure, even when the protein interior was treated with arbitrarily high dielectric constants. Improvements in continuum methods for calculating salt effects on pK(a) values will require explicit consideration of the salt dependence of model compound pK(a) values used for reference in the calculations.

Correction of MR kappa-space data corrupted by spike noise

Magnetic resonance images are reconstructed from digitized raw data, which are collected in the spatial-frequency domain (also called kappa-space). Occasionally, single or multiple data points in the k-space data are corrupted by spike noise, causing striation artifacts in images. Thresholding methods for detecting corrupted data points can fail because of small alterations, especially for data points in the low spatial frequency area where the k-space variation is large. Restoration of corrupted data points using interpolations of neighboring pixels can give incorrect results. We propose a Fourier transform method for detecting and restoring corrupted data points using a window filter derived from the striation-artifact structure in an image or an intermediate domain. The method provides an analytical solution for the alteration at each corrupted data point. It can effectively restore corrupted kappa-space data, removing striation artifacts in images, provided that the following three conditions are satisfied. First, a region of known signal distribution (for example, air background) is visible in either the image or the intermediate domain so that it can be selected using a window filter. Second, multiple spikes are separated by the full-width at half-maximum of the point spread function for the window filter. Third, the magnitude of a spike is larger than the minimum detectable value determined by the window filter and the standard deviation of kappa-space random noise.

Modulation of endocrine systems and food intake by green tea epigallocatechin gallate

Green tea polyphenols, especially the catechin, (-)-epigallocatechin gallate (EGCG), have been proposed as a cancer chemopreventative based on a variety of laboratory studies. For clear assessment of the possible physiological effects of green tea consumption, we injected pure green tea catechins ip into rats and studied their acute effects on endocrine systems. We found that EGCG, but not related catechins, significantly reduced food intake; body weight; blood levels of testosterone, estradiol, leptin, insulin, insulin-like growth factor I, LH, glucose, cholesterol, and triglyceride; as well as growth of the prostate, uterus, and ovary. Similar effects were observed in lean and obese male Zucker rats, suggesting that the effect of EGCG was independent of an intact leptin receptor. EGCG may interact specifically with a component of a leptin-independent appetite control pathway. Endocrine changes induced by parenteral administration of EGCG may relate to the observed growth inhibition and regression of human prostate and breast tumors in athymic mice treated with EGCG as well as play a role in the mechanism by which EGCG inhibits cancer initiation and promotion in various animal models of cancer.

A post-processing technique for displaying vessels from routine fast-spin-echo images: MRI-derived angiography

Fast-spin-echo magnetic resonance (MR) images are routine components of a standard MR brain examination. On these images, blood vessels are visible as black flow void. We report that by applying an enhancement filter to a stack of routine fast-spin-echo MR images, projected angiographic images can be generated. The vascular detail in the projected image is similar to that observed in a phase-contrast image. In addition to its advantage in obtaining vessel information from routine images, the proposed post-processing technique is fast, easy to implement and completely automatic. These images provide additional vessel information that is useful when MR angiography is unavailable or as an aid in planning dedicated MR angiographic studies.

Activation of gonadotropin-releasing hormone receptors produces neuronal excitation in the rat hippocampus

Whole-cell patch-clamp recordings of evoked action potentials were made in CA1 and CA3 pyramidal neurons of rat hippocampal slices. Previously we have demonstrated that activation of gonadotropin-releasing hormone (GnRH) receptors induces a long-lasting enhancement of synaptic transmission mediated by ionotropic glutamate receptors in CA1 pyramidal neurons of rat hippocampal slices. Here, we further studied whether activation of GnRH receptors could modulate intrinsic neuronal excitability in CA1 and CA3 pyramidal neurons of rat hippocampal slices. The use of a specific GnRH analog, leuprolide (10(-8) M), elicited a relatively long-term increase in evoked action potentials in CA1 and CA3 pyramidal neurons, respectively. The GnRH receptor-induced increase in evoked action potentials in both CA1 and CA3 pyramidal neurons could be abolished by a potent GnRH receptor antagonist, [acetyl-3,4-dehydro-Pro1,D-p-F-Phe2,D-Trp(3,6)]-LHRH (10(-8) M). The present study suggests that activation of GnRH receptors can lead to an increase of intrinsic neuronal excitability of both CA1 and CA3 pyramidal neurons in the rat hippocampus, an important integrative region for reproductive process, both endocrinologically and behaviorally.

The effect of O-fucosylation on the first EGF-like domain from human blood coagulation factor VII

The first epidermal growth factor-like domain (EGF-1) from blood coagulation factor VII (FVII) contains two unusual O-linked glycosylation sites at Ser-52 and Ser-60. We report here a detailed study of the effect of O-fucosylation at Ser-60 on the structure of FVII EGF-1, its Ca2+-binding affinity, and its interaction with tissue factor (TF). The in vitro fucosylation of the nonglycosylated FVII EGF-1 was achieved by using O-fucosyltransferase purified from Chinese hamster ovary cells. Distance and dihedral constraints derived from NMR data were used to determine the solution structures of both nonglycosylated and fucosylated FVII EGF-1 in the presence of CaCl2. The overall structure of fucosylated FVII EGF-1 is very similar to the nonfucosylated form even for the residues near the fucosylation site. The Ca2+ dissociation constants (Kd) for the nonfucosylated and fucosylated FVII EGF-1 were found to be 16.4 +/- 1.8 and 8.6 +/- 1.4 mM, respectively. The FVII EGF-1 domain binds to the extracellular part of TF with a low affinity (Kd approximately 0. 6 mM), and the addition of fucose appears to have no effect on this affinity. These results indicate that the FVII EGF-1 alone cannot form a tight complex with TF and suggest that the high binding affinity of FVIIa for TF requires cooperative interaction among the four domains in FVII with TF. Although the fucose has no significant effect on the interaction between TF and the individual FVII EGF-1 domain, it may affect the interaction of full-length FVIIa with TF by influencing its Ca2+-binding affinity.

Effects of somatostatin on lipid metabolism of larvae and metamorphosing landlocked sea lamprey, Petromyzon marinus

This study was designed to examine the role of somatostatin in regulating changes in lipid metabolism of larvae and metamorphosing landlocked sea lamprey, Petromyzon marinus. Larvae and animals in late metamorphosis (stage 6 on a 7-stage scale) were injected intraperitoneally once per day for 2 days with either saline (0.6%) or somatostatin-14 (SS-14; 500 ng/g body wt). Injection of SS-14 into larval and stage 6 metamorphosing animals resulted in elevated plasma fatty acids levels. In larvae, SS-14-induced hyperlipidemia was supported by enhanced lipolysis, as indicated by increased triacylglycerol lipase (TGL) activity in the liver and kidney. Mobilization of larval renal lipid was accompanied by reduced TG synthesis, as indicated by decreased diacylglycerol acyltransferase (DGAT) activity. In stage 6 metamorphosing lamprey, SS-14 did not significantly affect TGL activity; however, SS-14 significantly reduced fatty acid synthesis, as measured by acetyl-CoA carboxylase activity, in kidney, liver, and muscle, as well as muscular TG synthesis. SS-14-stimulated lipid depletion is reminiscent of the pattern of lipid metabolism displayed by P. marinus during their spontaneous metamorphosis-an observation which suggests that somatostatin may play a role in metamorphosis-associated changes in lipid metabolism in this species.