Integrative traditional Chinese medicine treatment for children with obstructive sleep apnea

Purpose

Obstructive sleep apnea (OSA) is a chronic disease that affects 1%-6% of children. Our study aims to explore the effectiveness and clinical characteristics of integrative Traditional Chinese Medicine (ITCM) for pediatric OSA.

Materials and methods

In this retrospective cohort study, we assessed differences of polysomnography (PSG) parameters and clinical characteristics between 2009 and 2020. Children <12 years old diagnosed with OSA (n = 508) were included and were categorized into ITCM cohort, western medicine (WM) cohort ,and surgery cohort. Outcomes were apnea-hypopnea index (AHI), respiratory disturbance index (RDI), and body mass index (BMI).

Results

There were 56 (11%), 324 (63.8%), and 128 (25.2%) patients in the ITCM, WM, and surgery cohorts. Among 17, 26, and 33 patients in the ITCM, WM, and surgery cohorts underwent follow-up PSG studies, respectively. In the ITCM follow-up cohort, AHI were significantly reduced (9.59 to 5.71, p < 0.05). BMI significantly increased in the WM follow-up cohort (19.46 to 20.50, p < 0.05) and the surgery follow-up cohort (18.04 to 18.85, p < 0.01). Comparing ITCM to WM cohort, a significant difference was found between the changes in RDI (ITCM: -6.78, WM: 0.51, p < 0.05) after treatment. Among ITCM follow-up cohort, the most prescribed TCM formula was Forsythia and Laminaria Combination. The most prescribed TCM herb was Ephedrae Herba.

Conclusions

ITCM therapy can significantly reduce RDI and control BMI. We identified potential TCM treatments for pediatric OSA. Further study of the pharmacological mechanisms and clinical efficacy is warranted.

Value of monocyte distribution width for predicting severe cholecystitis: a retrospective cohort study

OBJECTIVES

Acute cholecystitis is a gallbladder inflammation, and the Tokyo Guidelines 2018 (TG18) can be used to predict its presence and severity with high sensitivity and specificity. However, TG18 grading require the collection of excessive parameters. Monocyte distribution width (MDW) is a parameter used to detect sepsis early. Therefore, we investigated the correlation between MDW and cholecystitis severity.

METHODS

We conducted a retrospective study of patients with cholecystitis admitted to our hospital from November 1, 2020, to August 31, 2021. The primary outcome was severe cholecystitis analyzed as a composite of intensive care unit (ICU) admission and mortality. The secondary outcomes were length of hospital stay, ICU stay, and TG18 grade.

RESULTS

A total of 331 patients with cholecystitis were enrolled in this study. The average MDWs for TG18 grades 1, 2, and 3 were 20.21 ± 3.99, 20.34 ± 3.68, and 25.77 ± 6.61, respectively. For patients with severe cholecystitis, the average MDW was 25.42 ± 6.83. Using the Youden J statistic, we set a cutoff MDW of 21.6. Multivariate logistic regression revealed that patients with an MDW≥21.6 had a higher risk of severe cholecystitis (odds ratio=4.94; 95 % CI, 1.71-14.21; p=0.003). The Cox model revealed that patients with an MDW≥21.6 were more likely to have a prolonged hospital stay.

CONCLUSIONS

MDW is a reliable indicator of severe cholecystitis and prolonged length of stay. Additional MDW testing and a complete blood count may provide simple information for predicting severe cholecystitis early.

The effect of exercise on the risk of metabolic syndrome associated with sleep insufficiency: a cross-sectional study

Introduction

Sleep disturbance and insufficient sleep have been linked to metabolic syndrome, increasing cardiovascular disease and mortality risk. However, few studies investigate the joint effect of sleep and exercise on metabolic syndrome. We hypothesized that regular exercise can mitigate the exacerbation of metabolic syndrome by sleep insufficiency.

Objective

The aim of this study was to investigate whether exercise can attenuate or eliminate the relationship between sleep insufficiency and metabolic syndrome.

Method

A total of 6,289 adults (mean age = 33.96 years; women: 74.81%) were included in the study, a cross-sectional study conducted based on the results of employee health screening questionnaires and databases from a large healthcare system in central Taiwan. Participants reported sleep insufficiency or not. Self-reported exercise habits were classified into 3 levels: no exercise, exercise <150 min/week, and exercise ≧150 min/week. Multiple logistic regression and sensitivity analyses were conducted to understand the joint associations of sleep patterns and exercise with metabolic syndrome with exposure variables combining sleep duration/disturbances and PA.

Results

Compared with the reference group (sufficient sleep), individuals with sleep insufficiency had a higher risk for metabolic syndrome [adjusted odds ratio (AOR) = 1.40, 95% confidence interval (95% CI): 1.01-1.94, p < 0.05] in females aged 40-64 years, but not in other populations. Sleep insufficiency was not associated with the risk of metabolic syndrome among individuals achieving an exercise level of <150 min/week, and in particular among those achieving ≧150 min/week in all populations in our study.

Conclusion

Sleep insufficiency was related to a higher risk of metabolic syndrome in female healthcare staff aged 40-64 years. Being physically active with exercise habits in these individuals, the risk of metabolic syndrome was no longer significant.

Comparison of In-Hospital Major Adverse Cardiovascular Events in Patients with Acute Myocardial Infarction Treated with Ticagrelor or Clopidogrel in the Emergency Department: A Propensity Score Matched Retrospective Cohort Study

BACKGROUND

Dual antiplatelet therapy (DAPT) is a standard treatment option for acute myocardial infarction (AMI). The difference between the efficacy of ticagrelor and clopidogrel in the emergency department (ED) before percutaneous coronary intervention (PCI) remains unknown. The present study compared the in-hospital major adverse cardiovascular event (MACE) rates between patients with AMI treated with clopidogrel and those treated with ticagrelor in the ED before PCI.

METHODS

We retrospectively collected the data of patients diagnosed as having AMI in the ED. Patients were only included if they had successfully received complete DAPT with aspirin and ticagrelor/clopidogrel in the ED and had undergone PCI. The patients were divided into two groups according to their DAPT regimen. The primary outcome was the rate of in-hospital MACEs. The secondary outcomes included an unexpected return to the ED within 72 h, readmission within 14 d, and revascularization.

RESULTS

A total of 1836 patients were enrolled. Patients in the ticagrelor group had a lower in-hospital MACE rate (3.01% versus 7.51%, p < 0.001) and in-hospital mortality rate (2.15% versus 5.70%, p < 0.001) than those in the clopidogrel group. Multivariate logistic regression analysis revealed ticagrelor was independently associated with a lower risk of in-hospital MACEs (odds ratio [OR]: 0.53, 95% CI: 0.32-0.88, p = 0.013). After propensity score matching, the risk of in-hospital MACEs remained significantly lower in the ticagrelor group (OR 0.42, 95% CI: 0.21-0.85, p = 0.016).

CONCLUSION

DAPT with ticagrelor and aspirin in the ED before PCI is associated with a lower in-hospital MACE rate among patients with AMI.

Utility of monocyte distribution width in the differential diagnosis between simple and complicated diverticulitis: a retrospective cohort study

BACKGROUND

Colonic diverticulitis is a leading cause of abdominal pain. The monocyte distribution width (MDW) is a novel inflammatory biomarker with prognostic significance for coronavirus disease and pancreatitis; however, no study has assessed its correlation with the severity of colonic diverticulitis.

METHODS

This single-center retrospective cohort study included patients older than 18 years who presented to the emergency department between November 1, 2020, and May 31, 2021, and received a diagnosis of acute colonic diverticulitis after abdominal computed tomography. The characteristics and laboratory parameters of patients with simple versus complicated diverticulitis were compared. The significance of categorical data was assessed using the chi-square or Fisher's exact test. The Mann-Whitney U test was used for continuous variables. Multivariable regression analysis was performed to identify predictors of complicated colonic diverticulitis. Receiver operator characteristic (ROC) curves were used to test the efficacy of inflammatory biomarkers in distinguishing simple from complicated cases.

RESULTS

Of the 160 patients enrolled, 21 (13.125%) had complicated diverticulitis. Although right-sided was more prevalent than left-sided colonic diverticulitis (70% versus 30%), complicated diverticulitis was more common in those with left-sided colonic diverticulitis (61.905%, p = 0.001). Age, white blood cell (WBC) count, neutrophil count, C-reactive protein (CRP) level, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and MDW were significantly higher in the complicated diverticulitis group (p < 0.05). Logistic regression analysis indicated that the left-sided location and the MDW were significant and independent predictors of complicated diverticulitis. The area under the ROC curve (AUC) was as follows: MDW, 0.870 (95% confidence interval [CI], 0.784-0.956); CRP, 0.800 (95% CI, 0.707-0.892); NLR, 0.724 (95% CI, 0.616-0.832); PLR, 0.662 (95% CI, 0.525-0.798); and WBC, 0.679 (95% CI, 0.563-0.795). When the MDW cutoff was 20.38, the sensitivity and specificity were maximized to 90.5% and 80.6%, respectively.

CONCLUSIONS

A large MDW was a significant and independent predictor of complicated diverticulitis. The optimal cutoff value for MDW is 20.38 as it exhibits maximum sensitivity and specificity for distinguishing between simple and complicated diverticulitis The MDW may aid in planning antibiotic therapy for patients with colonic diverticulitis in the emergency department.

Prognostic value of early and late spontaneous conversion into a shockable rhythm for patients with out-of-hospital cardiac arrest

BACKGROUND

The prognostic significance of conversion into a shockable rhythm in patients who experienced out-of-hospital cardiac arrest (OHCA) with an initially nonshockable rhythm is controversial, perhaps due to the timing of rhythm conversion not being considered previously. We aimed to compare the different prognoses of patients with OHCA and early and late conversion of their rhythm into a shockable rhythm.

METHODS

This was a single-centre retrospective cohort study. We enrolled patients with OHCA who were sent to a medical centre in central Taiwan from 2016 to 2020. Patients <18 years old, those with cardiac arrest due to trauma or a circumstantial cause, and those for whom resuscitation was not attempted were excluded. Patients were divided into two groups in accordance with presentation with an initially shockable rhythm. Those with an initially nonshockable rhythm were divided into three subgroups: early-conversion, late-conversion, and nonconversion groups. The primary outcome was the neurological functional status upon discharge from hospital.

RESULTS

A total of 1645 patients with OHCA were included: initially shockable rhythm group, 339; early conversion group, 68; late-conversion group, 166; and nonconversion group, 1072. After adjustment, multivariate logistic regression revealed that a favourable neurological outcome was more common in the early conversion group than the nonconversion group (odds ratio [OR] 2.4; 95% confidence interval [CI], 1.1-5.3; p = 0.035), whereas the late-conversion group did not significantly differ from the nonconversion group (OR 0.5; 95% CI, 0.1-1.5; p = 0.211). The proportions of sustained return of spontaneous circulation and survival to discharge were also higher in the early conversion group than the late-conversion group (OR 2.9 95% CI 1.6-5.5, p = 0.001 and OR 4.5, 1.8-11.0, p = 0.001, respectively).

CONCLUSION

In patients who experience OHCA and have an initially nonshockable rhythm, early conversion into a shockable rhythm resulted in a better prognosis, whereas late conversion was not significantly different from nonconversion.

Risk factors for sudden cardiac arrest in patients with ST-segment elevation myocardial infarction: a retrospective cohort study

Background

Sudden cardiac arrest (SCA) is a critical complication of acute myocardial infarction, especially ST-segment elevation myocardial infarction (STEMI). This study identified the risk factors for SCA in patients with STEMI before receiving catheterization.

Methods

We retrospectively analyzed the data of patients with STEMI and cardiac arrest who presented to a tertiary care center in Taiwan between January 1, 2016, and December 31, 2019. Only patients with coronary artery disease (CAD) confirmed by coronary angiography were included in this study. We collected the patients’ demographic and clinical data, such as age, sex, medical history, estimated glomerular filtration rate (eGFR), and coronary angiographic findings. The primary outcome of this study was SCA in patients with STEMI. Continuous and nominal variables were compared using the two-sample Student's t-test and chi-squared test, respectively. The results of logistic regression were subjected to multivariate analysis with adjustment for possible confounders.

Results

A total of 920 patients with STEMI and coronary angiography–documented CAD and 108 patients with SCA who presented between January 1, 2016, and December 31, 2019, were included. The bivariate logistic regression analysis of patients’ demographic data revealed that patients with STEMI and SCA were slightly younger, were more likely to have diabetes mellitus, and had a lower eGFR than did the patients without SCA. The coronary angiographic findings indicated a higher prevalence of left main CAD and three-vessel disease in patients with SCA than in patients without SCA. Multivariate logistic regression revealed that left main CAD (odds ratio [OR]: 3.77; 95% confidence interval [CI], 1.84 to 7.72), a lower eGFR (OR: 0.97; 95% CI, 0.96 to 0.98), and younger age (OR: 0.98; 95% CI, 0.96 to 0.99) were the risk factors for SCA in patients with STEMI.

Conclusions

Left main CAD, lower eGFR, and younger age are the risk factors for cardiac arrest in patients with acute myocardial infarction.

Validation of the traditional Chinese version of the Sinus and Nasal Quality of Life Survey (SN-5) for children

BACKGROUND

Persistent sinonasal symptoms are common in children with chronic rhinosinusitis. The Sinus and Nasal Quality of Life (QoL) Survey (SN-5) was the first validated questionnaire measuring sinonasal-related QoL in populations aged 2-12 years. No norm has been established for Chinese-speaking countries. We translated the SN-5 into traditional Chinese and evaluated validity and reliability.

METHODS

From December 2016 to December 2017, healthy volunteers and children with persistent sinonasal symptoms were enrolled. Guardians of the participants completed the SN-5, a visual analog scale (VAS) of nasal symptoms, and the Obstructive Sleep Apnea-18 (OSA-18); the responses were used to assess internal consistency, discriminant validity, and treatment responsiveness. A nontreatment group was administered the SN-5 1 week later to assess test-retest reliability.

RESULTS

We recruited 31 healthy volunteers and 85 children with rhinosinusitis, 50 and 35 in the treatment and nontreatment groups, respectively. The SN-5 demonstrated good internal consistency (Cronbach's α = 0.86) and test-retest reliability (0.74, p < 0.01). It exhibited good discriminant validity between the healthy and rhinosinusitis groups (p < 0.001). The SN-5 scores were correlated with the VAS scores (0.63, p < 0.001). The effect size of the SN-5 scores was 0.51. The total SN-5 and OSA-18 scores changed significantly after 4-week treatment (p < 0.05) and demonstrated good responsiveness. The SN-5 and OSA-18 scores were significantly and positively correlated (r² = 0.53, p < 0.001).

CONCLUSION

Our traditional Chinese version of the SN-5 is reliable and valid for measuring sinonasal-related QoL in children in Chinese-speaking countries.

TRIAL REGISTRATION NUMBER

NCT04836403.

Impact of the COVID-19 pandemic on emergency medical service response to out-of-hospital cardiac arrests in Taiwan: a retrospective observational study

Background

Emergency medical service (EMS) personnel have high COVID-19 risk during resuscitation. The resuscitation protocol for patients with out-of-hospital cardiac arrest (OHCA) was modified in response to the COVID-19 pandemic. However, how the adjustments in the EMS system affected patients with OHCA remains unclear.

Methods

We analysed data from the Taichung OHCA registry system. We compared OHCA outcomes and rescue records for 622 cases during the COVID-19 outbreak period (1 February to 30 April 2020) with those recorded for 570 cases during the same period in 2019.

Results

The two periods did not differ significantly with respect to patient age, patient sex, the presence of witnesses or OHCA location. Bystander cardiopulmonary resuscitation and defibrillation with automated external defibrillators were more common in 2020 (52.81% vs 65.76%, p<0.001%, and 23.51% vs 31.67%, p=0.001, respectively). The EMS response time was longer during the COVID-19 pandemic (445.8±210.2 s in 2020 vs 389.7±201.8 s in 2019, p<0.001). The rate of prehospital return of spontaneous circulation was lower in 2020 (6.49% vs 2.57%, p=0.001); 2019 and 2020 had similar rates of survival discharge (5.96% vs 4.98%). However, significantly fewer cases had favourable neurological function in 2020 (4.21% vs 2.09%, p=0.035).

Conclusion

EMS response time for patients with OHCA was prolonged during the COVID-19 pandemic. Early advanced life support by EMS personnel remains crucial for patients with OHCA.

Early blood pH as an independent predictor of neurological outcome in patients with out-of-hospital cardiac arrest: A retrospective observational study

ABSTRACT

Metabolic acidosis is observed in 98% of patients with out-of-hospital cardiac arrest (OHCA). The longer the no-flow or low-flow duration, the more severe is the acidosis in these patients. This study explored whether blood pH in early stages of advanced life support (ALS) was an independent predictor of neurological prognosis in patients with OHCA.We retrospectively enrolled patients with OHCA from January 2012 to June 2018 in a single-medical tertiary hospital in Taiwan. Patients with OHCA whose blood gas analyses within 5 minutes after receiving ALS at the emergency department (ED) were enrolled. Patients younger than 20 years old, with cardiac arrest resulting from traumatic or circumstantial causes, with return of spontaneous circulation (ROSC) before ED arrival, lacking record of initial blood gas analysis, and with do-not-resuscitate orders were excluded. The primary outcome of this study was neurological status at hospital discharge.In total, 2034 patients with OHCA were enrolled. The majority were male (61.89%), and the average age was 67.8 ± 17.0 years. Witnessed OHCA was noted in 571 cases, cardiopulmonary resuscitation was performed before paramedic arrival in 512 (25.2%) cases, and a shockable rhythm was observed in 269 (13.2%). Blood pH from initial blood gas analysis remained an independent predictor of neurological outcome after multivariate regression.Blood pH at early stages of ALS was an independent prognostic factor of post-OHCA neurological outcome. Blood gas analysis on arrival at the ED may provide additional information about the prognosis of patients with OHCA.

Derivation and Validation of the SWAP Score for Very Early Prediction of Neurologic Outcome in Patients With Out-of-Hospital Cardiac Arrest

STUDY OBJECTIVE

For patients with out-of-hospital cardiac arrest who receive cardiopulmonary resuscitation in an emergency department (ED), the early evaluation of their neurologic prognosis is essential for emergency physicians. The aim of this study is to establish a simple and useful assessment tool for rapidly estimating the prognosis of patients with out-of-hospital cardiac arrest after their arrival at an ED.

METHODS

A total of 852 patients admitted from January 1, 2015, to June 30, 2017, were prospectively registered and enrolled in the derivation cohort. Multivariate logistic regression on this cohort identified 4 independent factors associated with unfavorable outcomes: initial nonshockable rhythm (odds ratio [OR] 3.40; 95% confidence interval [CI] 1.58 to 7.32), no witness of collapse (OR 3.19; 95% CI 1.51 to 6.75), older than 60 years (OR 3.65; 95% CI 1.64 to 8.09), and pH less than or equal to 7.00 (OR 3.27; 95% CI 1.42 to 7.54). The shockable rhythm-witness-age-pH (SWAP) score was developed and 1 point was assigned to each predictor.

RESULTS

For a SWAP score of 4, the specificity was 97.14% (95% CI 91.62% to 100%) for unfavorable outcomes in the derivation cohort. For validation, we retrospectively collected data for 859 patients with out-of-hospital cardiac arrest from January 1, 2012, to December 31, 2014. A SWAP score of 4 was 100% specific (95% CI 99.9% to 100%) for unfavorable outcomes in the validation cohort.

CONCLUSION

The SWAP score is a simple and useful predictive model that may provide information for the very early estimation of prognosis for patients with out-of-hospital cardiac arrest. Further research is required to integrate ultrasonographic findings and validate the SWAP score's application in other populations.

TERT promoter mutations and monoallelic activation of TERT in cancer

Here we report that promoter mutations in telomerase (TERT), the most common noncoding mutations in cancer, give rise to monoallelic expression of TERT. Through deep RNA sequencing, we find that TERT activation in human cancer cell lines can occur in either mono- or biallelic manner. Without exception, hotspot TERT promoter mutations lead to the re-expression of only one allele, accounting for approximately half of the observed cases of monoallelic TERT expression. Furthermore, we show that monoallelic TERT expression is highly prevalent in certain tumor types and widespread across a broad spectrum of cancers. Taken together, these observations provide insights into the mechanisms of TERT activation and the ramifications of noncoding mutations in cancer.

Mn-doped GaN as photoelectrodes for the photoelectrolysis of water under visible light

Hydrogen generation through direct photoelectrolysis of water was studied using photoelectrochemical (PEC) cells made of Mn-doped GaN photoelectrodes. In addition to its absorption of the ultraviolet spectrum, Mn-doped GaN photoelectrodes could absorb photons in the visible spectrum. The photocurrents measured from PEC cells made of Mn-doped GaN were at least one order higher than those measured from PEC cells made of undoped GaN-working electrodes. Under the visible light illumination and a bias voltage below 1.2 V, the Mn-doped GaN photoelectrodes could drive the water splitting reaction for hydrogen generation. However, hydrogen generation could not be achieved under the same condition wherein undoped GaN photoelectrodes were used. According to the results of the spectral responses and transmission spectra obtained from the experimental photoelectrodes, the enhanced photocurrent in the Mn-doped GaN photoelectrodes, compared with the undoped GaN photoelectrodes, was attributable to the Mn-related intermediate band within the band gap of GaN that resulted in further photon absorption.

Immersed finger-type indium tin oxide ohmic contacts on p-GaN photoelectrodes for photoelectrochemical hydrogen generation

In this study, we demonstrated photoelectrochemical (PEC) hydrogen generation using p-GaN photoelectrodes associated with immersed finger-type indium tin oxide (IF-ITO) ohmic contacts. The IF-ITO/p-GaN photoelectrode scheme exhibits higher photocurrent and gas generation rate compared with p-GaN photoelectrodes without IF-ITO ohmic contacts. In addition, the critical external bias for detectable hydrogen generation can be effectively reduced by the use of IF-ITO ohmic contacts. This finding can be attributed to the greatly uniform distribution of the IF-ITO/p-GaN photoelectrode applied fields over the whole working area. As a result, the collection efficiency of photo-generated holes by electrode contacts is higher than that of p-GaN photoelectrodes without IF-ITO contacts. Microscopy revealed a tiny change on the p-GaN surfaces before and after hydrogen generation. In contrast, photoelectrodes composed of n-GaN have a short lifetime due to n-GaN corrosion during hydrogen generation. Findings of this study indicate that the ITO finger contacts on p-GaN layer is a potential candidate as photoelectrodes for PEC hydrogen generation.

Hydrogen gas generation using n-GaN photoelectrodes with immersed Indium Tin Oxide ohmic contacts

An n-GaN photoelectrochemical (PEC) cell with immersed finger-type indium tin oxide (ITO) ohmic contacts was demonstrated in the present study to enhance the hydrogen generation rate. The finger-type ITO ohmic contacts were covered with SiO₂ layers to prevent the PEC cell from generating leakage current. Using a 1M NaCl electrolyte and external biases, the typical photocurrent density and gas generation rate of the n-GaN working electrodes with ITO finger contacts were found to be higher than those with Cr/Au finger contacts. The enhancement in photocurrent density or gas generation rate can be attributed to the transparent ITO contacts which allowed the introduction of relatively more photons into the GaN layer. No significant corrosion was observed in the ITO layer after the PEC process compared with the Cr/Au finger contacts which were significantly peeled from the GaN layer. These results indicate that the use of n-GaN working electrodes with finger-type ITO ohmic contacts is a promising approach for PEC cells.

High-performance GaN metal-insulator-semiconductor ultraviolet photodetectors using gallium oxide as gate layer

In this study, gallium nitride (GaN)-based metal-insulator-semiconductor (MIS) ultraviolet (UV) photodetectors (PDs) with a gallium oxide (GaO(x)) gate layer formed by alternating current bias-assisted photoelectrochemical oxidation of n-GaN are presented. By introducing the GaO(x) gate layer to the GaN MIS UV PDs, the leakage current is reduced and a much larger UV-to-visible rejection ratio (R(UV/vis)) of spectral responsivity is achieved. In addition, a bias-dependent spectral response results in marked increase of the R(UV/vis) with bias voltage up to ~10(5). The bias-dependent responsivity suggests the possible existence of internal gain in of the GaN MIS PDs.

Mechanism for a transcriptional activator that works at the isomerization step

Transcriptional activators in prokaryotes have been shown to stimulate different steps in the initiation process including the initial binding of RNA polymerase (RNAP) to the promoter and a postbinding step known as the isomerization step. Evidence suggests that activators that affect initial binding can work by a cooperative binding mechanism by making energetically favorable contacts with RNAP, but the mechanism by which activators affect the isomerization step is unclear. A well-studied example of an activator that normally exerts its effect exclusively on the isomerization step is the bacteriophage lambda cI protein (lambdacI), which has been shown genetically to interact with the C-terminal region of the final sigma(70) subunit of RNAP. We show here that the interaction between lambdacI and final sigma can stimulate transcription even when the relevant portion of final sigma is transplanted to another subunit of RNAP. This activation depends on the ability of lambdacI to stabilize the binding of the transplanted final sigma moiety to an ectopic -35 element. Based on these and previous findings, we discuss a simple model that explains how an activator's ability to stabilize the binding of an RNAP subdomain to the DNA can account for its effect on either the initial binding of RNAP to a promoter or the isomerization step.

Amyloid beta-peptide possesses a transforming growth factor-beta activity

Amyloid beta-peptide (Abeta) of 39-42 amino acid residues is a major constituent of Alzheimer's disease neurite plaques. Abeta aggregates (fibrils) are believed to be responsible for neuronal damage and dysfunction, as well as microglia and astrocyte activation in disease lesions by multiple mechanisms. Since Abeta aggregates possess the multiple valencies of an FAED motif (20th to 23rd amino acid residues), which resembles the putative transforming growth factor-beta (TGF-beta) active site motif, we hypothesize that Abeta monomers and Abeta aggregates may function as TGF-beta antagonists and partial agonists, analogous to previously described monovalent and multivalent TGF-beta peptide antagonists and agonists (Huang, S. S., Liu, Q., Johnson, F. E., Konish, Y., and Huang, J. S. (1997) J. Biol. Chem. 272, 27155-27159). Here, we report that the Abeta monomer, Abeta-(1-40) and its fragment, containing the motif inhibit radiolabeled TGF-beta binding to cell-surface TGF-beta receptors in mink lung epithelial cells (Mv1Lu cells). Abeta-(1-40)-bovine serum albumin conjugate (Abeta-(1-40)-BSA), a multivalent synthetic analogue of Abeta aggregates, exhibited cytotoxicity toward bovine cerebral endothelial cells and rat post-mitotic differentiated hippocampal neuronal cells (H19-7 cells) and inhibitory activities of radiolabeled TGF-beta binding to TGF-beta receptors and TGF-beta-induced plasminogen activator inhibitor-1 expression, that were approximately 100-670 times more potent than those of Abeta-(1-40) monomers. At less than micromolar concentrations, Abeta-(1-40)-BSA but not Abeta-(1-40) monomers inhibited proliferation of Mv1Lu cells. Since TGF-beta is an organizer of responses to neurodegeneration and is also found in neurite plaques, the TGF-beta antagonist and partial agonist activities of Abeta monomers and aggregates may play an important role in the pathogenesis of the disease.

Activated thyroglobulin possesses a transforming growth factor-beta activity

Thyroglobulin (Tg), the thyroid hormone precursor, is a major protein component in the thyroid gland and may have other important functions. Here, we show that bovine Tg inhibited 125I-labeled transforming growth factor-beta1 (125I-TGF-beta1) binding to cell-surface TGF-beta receptors in mink lung epithelial cells with an IC50 of approximately 300 nM. After disuccinimidyl suberate (DSS) modification, reduction/alkylation, treatment with 8 M urea, 0. 1% SDS, or acidic pH (pH 4-5), Tg exhibited a approximately 5-10-fold increase of 125I-TGF-beta1 binding inhibitory activity with IC50 of approximately 30-60 nM. This inhibitory activity was an intrinsic property of the Tg and could not be segregated from Tg protein by 5% SDS-polyacrylamide gel electrophoresis or by immunoprecipitation using antiserum to Tg. Untreated Tg did not affect DNA synthesis but blocked the TGF-beta-induced inhibition of DNA synthesis in mink lung epithelial cells. After DSS activation, Tg possessed TGF-beta agonist activity and inhibited DNA synthesis of mink lung epithelial cells and rat thyroid cells. The activated Tg also exerted a small but significant TGF-beta agonist activity in transcriptional activation of plasminogen activator inhibitor-1. These results suggest that Tg possesses an authentic TGF-beta activity which can be induced by chemical modifications and treatments with denaturing agents and acidic pH.