Microwave-field sensing via electromagnetically induced absorption of Rb irradiated by three-color infrared lasers.

A microwave electric field sensing has been set up based on a three-color electromagnetically induced absorption in rubidium vapor cell via cascading transitions. All transitions are irradiated by infrared lasers: a 780 nm laser servers as probe to monitor the optical transmittancy via transition 5S1/2→P3/2;, a 776 nm laser and a 1260 nm laser are used to couple the states 5P3/2 and 5D5/2 and states 5D5/2 and 44F7/2, respectively. We find that a frequency detuning ∼2π × ( - 40) MHz of the 776 nm dressing beam prefers to a better signal-to-noise ratio for the probe beam. The off-resonance greatly depresses the double resonance pumping effect. A demonstration measurement for the electric field of microwave 1.18988 GHz, corresponding to the coupling resonance between two adjacent Rydberg states 44F7/2 and 44F9/2, gives a sensitivity of 55.79(23)nVcm-1/Hz and a smallest discernible electric field of 78.9(33) nVcm-1 in time scale of 500 ms.

MGMT Promoter Methylation Status in Initial and Recurrent Glioblastoma: Correlation Study with DWI and DSC PWI Features.

BACKGROUND AND PURPOSE: O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status in primary and recurrent glioblastoma may change during treatment. The purpose of this study was to correlate MGMT promoter methylation status changes with DWI and DSC PWI features in patients with recurrent glioblastoma after standard treatment. MATERIALS AND METHODS: Between January 2008 and November 2016, forty patients with histologically confirmed recurrent glioblastoma were enrolled. Patients were divided into 3 groups according to the MGMT promoter methylation status for the initial and recurrent tumors: 2 groups whose MGMT promoter methylation status remained, group methylated (n = 13) or group unmethylated (n = 18), and 1 group whose MGMT promoter methylation status changed from methylated to unmethylated (n = 9). Normalized ADC and normalized relative CBV values were obtained from both the enhancing and nonenhancing regions, from which histogram parameters were calculated. The ANOVA and the Kruskal-Wallis test followed by post hoc tests were performed to compare histogram parameters among the 3 groups. The t test and Mann-Whitney U test were used to compare parameters between group methylated and group methylated to unmethylated. Receiver operating characteristic curve analysis was used to measure the predictive performance of the normalized relative CBV values between the 2 groups. RESULTS: Group methylated to unmethylated showed significantly higher means and 90th and 95th percentiles of the cumulative normalized relative CBV values of the nonenhancing region of the initial tumor than group methylated and group unmethylated (all P < .05). The mean normalized relative CBV value of the nonenhancing region of the initial tumor was the best predictor of methylation status change (P < .001), with a sensitivity of 77.78% and specificity of 92.31% at a cutoff value of 2.594. CONCLUSIONS: MGMT promoter methylation status might change in recurrent glioblastoma after standard treatment. The normalized relative CBV values of the nonenhancing region at the first preoperative MR imaging were higher in the MGMT promoter methylation change group from methylation to unmethylation in recurrent glioblastoma.

Feasibility of modulated electro-hyperthermia in preoperative treatment for locally advanced rectal cancer: Early phase 2 clinical results.

Despite advances in the multimodal approach for rectal cancer, treatment-related side effects remain an important issue. From this perspective, a prospective trial was performed to investigate the feasibility of modulated electro-hyperthermia (mEHT) as a concomitant boost to preoperative chemoradiation in locally advanced rectal cancer. Seventy-six patients with cT3-4 or cT2N+ rectal cancer were enrolled consecutively. Whole pelvic radiotherapy of 40 Gy was delivered with a 2-Gy daily fraction. mEHT with 13.56 MHz frequency was boosted on a twice-weekly schedule concurrently with intravenous 5-fluorouracil or oral capecitabine. Surgical resection was planned 6-8 weeks after radiotherapy. The primary endpoint was the non-inferior treatment response rate assessed by pathologic downstaging and tumor regression. The secondary endpoint was acceptable toxicity during the preoperative treatment period. Sixty patients completed the planned treatment schedule. T- and N-downstaging was demonstrated in 40 patients (66.7%) and 53 patients (88.3%), respectively. Pathologic complete response was noted in 15.0% (9 patients) and 76.7% (46 patients) for T-stage and N-stage, respectively. Total or near total tumor regression was observed in 20 patients (33.3%). Grade ≥3 toxicity occurred only in hematologic assessment; one case (1.7%) of leukopenia and one case (1.7%) of anemia. Sixteen patients (26.7%) developed thermal toxicity, which was mostly Grade 1 (15 patients, 93.8%). The relatively low dose of 40 Gy radiation showed comparable pathologic treatment outcomes and tolerable toxicity profiles with the addition of mEHT, which may potentially replace part of the radiation dose in neoadjuvant treatment for rectal cancer.

Artificial modulation-free Pound-Drever-Hall method for laser frequency stabilization.

We have proposed an artificial modulation-free Pound-Drever-Hall (PDH) method for laser frequency stabilization and demonstrated it via two-color polarization spectroscopy of Rydberg electromagnetically induced transparency (EIT) resonance in a room-temperature rubidium vapor. Due to the unique error signal profile, the conventional PDH method owns a large capture range in laser frequency locking. Here we manually construct a PDH error signal via a linear combination of polarization spectroscopies of the Rydberg EIT resonances without and with a magnetic field applied. The artificial modulation-free PDH error signal owns a subnatural linewidth dispersion curve as well as a large capture range with which we successfully stabilize the laser to an absolute atomic frequency reference in a long running time, immune to environmental fluctuation and even manmade impulse perturbation. This method can provide an absolute frequency reference based on atomic transition while keeping similar locking ability to provide corrections for frequency fluctuations over a broad bandwidth as the conventional PDH.

MR Imaging for Differentiating Contrast Staining from Hemorrhagic Transformation after Endovascular Thrombectomy in Acute Ischemic Stroke: Phantom and Patient Study.

BACKGROUND AND PURPOSE: Early differentiation of contrast staining from hemorrhagic transformation in patients with acute ischemic stroke who have undergone endovascular treatment is critical in preventing the delayed administration of antiplatelet agents. We aimed to demonstrate the usefulness of an immediate postinterventional DWI protocol including B0 and gradient recalled-echo sequences to discriminate those 2 conditions through phantom and preliminary retrospective patient studies. MATERIALS AND METHODS: On 3T MR imaging, the signal intensities of the phantom models consisting of iodinated contrast agents diluted with normal saline and arterial blood were compared using T1WI, T2WI, and gradient recalled-echo sequences. A total 17 patients (8 with hemorrhagic transformation and 9 with contrast staining; 8 men and 9 women; mean age, 72.00 ± 10.91 years; range, 52-90 years) who underwent mechanical thrombectomy for acute ischemic stroke and showed newly appearing hyperdense lesions on immediate (<24 hours) postinterventional nonenhanced CT scans were included in this study. Immediate postinterventional DWI of patients were compared. RESULTS: In the phantom study, iodinated contrast agents diluted with normal saline showed minimal signal drop, while those diluted with arterial blood demonstrated dark signal intensity in the T2WI and gradient recalled-echo sequences. In the patient study, all hemorrhagic transformations and none of the contrast staining demonstrated dark or low signal (

Can Arterial Spin-Labeling with Multiple Postlabeling Delays Predict Cerebrovascular Reserve?

BACKGROUND AND PURPOSE: The effect of delayed transit time is the main source of error in the quantitative measurement of CBF in arterial spin-labeling. In the present study, we evaluated the usefulness of the transit time-corrected CBF and arterial transit time delay from multiple postlabeling delays arterial spin-labeling compared with basal/acetazolamide stress technetium Tc99m-hexamethylpropylene amineoxime (Tc99m-HMPAO) SPECT in predicting impairment in the cerebrovascular reserve. MATERIALS AND METHODS: Transit time-corrected CBF maps and arterial transit time maps were acquired in 30 consecutive patients with unilateral ICA or MCA steno-occlusive disease (severe stenosis or occlusion). Internal carotid artery territory-based ROIs were applied to both perfusion maps. Additionally, impairment in the cerebrovascular reserve was evaluated according to both qualitative and quantitative analyses of the ROIs on basal/acetazolamide stress Tc99m-HMPAO SPECT using a previously described method. The area under the receiver operating characteristic curve was used to evaluate the diagnostic accuracy of arterial spin-labeling in depicting impairment of the cerebrovascular reserve. The correlation between arterial spin-labeling and cerebrovascular reserve was evaluated. RESULTS: The affected hemisphere had a decreased transit time-corrected CBF and increased arterial transit time compared with the corresponding values of the contralateral normal hemisphere, which were statistically significant (P < .001). The percentage change of transit time-corrected CBF and the percentage change of arterial transit time were independently differentiating variables (P < .001) for predicting cerebrovascular reserve impairment. The correlation coefficient between the arterial transit time and cerebrovascular reserve index ratio was -0.511. CONCLUSIONS: Our results demonstrate that the transit time-corrected CBF and arterial transit time based on arterial spin-labeling perfusion MR imaging can predict cerebrovascular reserve impairment.

Added Value of Arterial Spin-Labeling MR Imaging for the Differentiation of Cerebellar Hemangioblastoma from Metastasis.

BACKGROUND AND PURPOSE: In adults with only cerebellar masses, hemangioblastoma and metastasis are the 2 most important differential diagnoses. Our aim was to investigate the added value of arterial spin-labeling MR imaging for differentiating hemangioblastoma from metastasis in patients with only cerebellar masses. MATERIALS AND METHODS: This retrospective study included a homogeneous cohort comprising patients with only cerebellar masses, including 16 hemangioblastomas and 14 metastases. All patients underwent enhanced MR imaging, including arterial spin-labeling. First, the presence or absence of a hyperperfused mass was determined. Next, in the hyperperfused mass, relative tumor blood flow (mean blood flow in the tumor divided by blood flow measured in normal-appearing cerebellar tissue) and the size ratio (size in the arterial spin-labeling images divided by size in the postcontrast T1WI) were measured. To validate the arterial spin-labeling findings, 2 observers independently evaluated the conventional MR images and the combined set of arterial spin-labeling images. RESULTS: All patients with hemangioblastomas and half of the patients with metastases presented with a hyperperfused mass (P < .001). The size ratio and relative tumor blood flow were significantly larger for hemangioblastomas than for metastases (P < .001 and P = .039, respectively). The size ratio revealed excellent diagnostic power (area under the curve = 0.991), and the relative tumor blood flow demonstrated moderate diagnostic power (area under the curve = 0.777). The diagnostic accuracy of both observers was significantly improved after the addition of arterial spin-labeling; the area under the curve improved from 0.574 to 0.969 (P < .001) for observer 2 and from 0.683 to 1 (P < .001) for observer 2. CONCLUSIONS: Arterial spin-labeling imaging can aid in distinguishing hemangioblastoma from metastasis in patients with only cerebellar masses.

[Comparison study of subcutaneous immunotherapy and sublingual immunotherapy in patients with allergic rhinitis].

Objective: To observe the compliance, efficacy and safety of subcutaneous immunotherapy(SLIT) and sublingual immunotherapy(SCIT) in patients with allergic rhinitis(AR).Method:One hundred and fifteen patients sensitized to house dust mites were recruited in this study. The standardized extract of house dust mites was used for SLIT in 64 cases, and the standardized extract of dual house dust mites was used for SCIT in the other 51 cases. The compliance, nasal symptom scores, the medication scores, the quality of life and the adverse reaction were evaluated before and 2 years after immunotherapy. SPSS 19.0 was used for data analysis. Result:Forty patients out of 64 completed the 2 years-SLIT, and the compliance rate was 62.50%. Forty three patients out of 51 completed the 2 years-SCIT and the compliance rate was 84.31%.The compliance rate of SLIT was significantly lower than that of SCIT(P <0.05). The nasal symptom scores, the anti-allergic medication, the scores in quality of life decreased significantly after receiving SLIT or SCIT for 2 years（P <0.05）. However, the changed values of scores between the two groups had no significant differences（P >0.05）. There was no moderate or severe adverse reactions occurred in SLIT group but a total of 6 moderate or severe adverse reactions occurred in SCIT group.Conclusion:SLIT has same effect compared with SCIT with a lower compliance rate but a significantly higher safety.

Assessing coughing-induced influenza droplet transmission and implications for infection risk control.

Indoor transmission of respiratory droplets bearing influenza within humans poses high risks to respiratory function deterioration and death. Therefore, we aimed to develop a framework for quantifying the influenza infection risk based on the relationships between inhaled/exhaled respiratory droplets and airborne transmission dynamics in a ventilated airspace. An experiment was conducted to measure the size distribution of influenza-containing droplets produced by coughing for a better understanding of potential influenza spread. Here we integrated influenza population transmission dynamics, a human respiratory tract model, and a control measure approach to examine the indoor environment-virus-host interactions. A probabilistic risk model was implemented to assess size-specific infection risk for potentially transmissible influenza droplets indoors. Our results found that there was a 50% probability of the basic reproduction number (R0) exceeding 1 for small-size influenza droplets of 0·3-0·4 µm, implicating a potentially high indoor infection risk to humans. However, a combination of public health interventions with enhanced ventilation could substantially contain indoor influenza infection. Moreover, the present dynamic simulation and control measure assessment provide insights into why indoor transmissible influenza droplet-induced infection is occurring not only in upper lung regions but also in the lower respiratory tract, not normally considered at infection risk.

Behavioural response in educated young adults towards influenza A(H1N1)pdm09.

The purpose of this paper was to determine how contact behaviour change influences the indoor transmission of influenza A(H1N1)pdm09 among school children. We incorporated transmission rate matrices constructed from questionnaire responses into an epidemiological model to simulate contact behaviour change during an influenza epidemic. We constructed a dose-response model describing the relationships between contact rate, viral load, and respiratory symptom scores using published experimental human infection data for A(H1N1)pdm09. Findings showed that that mean numbers of contacts were 5.66 ± 6.23 and 1.96 ± 2.76 d-1 in the 13-19 and 40-59 years age groups, respectively. We found that the basic reproduction number (R 0) was <1 during weekends in pandemic periods, implying that school closures or class suspensions are probably an effective social distancing policy to control pandemic influenza transmission. We conclude that human contact behaviour change is a potentially influential factor on influenza infection rates. For substantiation of this effect, we recommend a future study with more comprehensive control measures.

Network information analysis reveals risk perception transmission in a behaviour-influenza dynamics system.

Influenza poses a significant public health burden worldwide. Understanding how and to what extent people would change their behaviour in response to influenza outbreaks is critical for formulating public health policies. We incorporated the information-theoretic framework into a behaviour-influenza (BI) transmission dynamics system in order to understand the effects of individual behavioural change on influenza epidemics. We showed that information transmission of risk perception played a crucial role in the spread of health-seeking behaviour throughout influenza epidemics. Here a network BI model provides a new approach for understanding the risk perception spread and human behavioural change during disease outbreaks. Our study allows simultaneous consideration of epidemiological, psychological, and social factors as predictors of individual perception rates in behaviour-disease transmission systems. We suggest that a monitoring system with precise information on risk perception should be constructed to effectively promote health behaviours in preparation for emerging disease outbreaks.

Using experimental human influenza infections to validate a viral dynamic model and the implications for prediction.

The aim of this work was to use experimental infection data of human influenza to assess a simple viral dynamics model in epithelial cells and better understand the underlying complex factors governing the infection process. The developed study model expands on previous reports of a target cell-limited model with delayed virus production. Data from 10 published experimental infection studies of human influenza was used to validate the model. Our results elucidate, mechanistically, the associations between epithelial cells, human immune responses, and viral titres and were supported by the experimental infection data. We report that the maximum total number of free virions following infection is 10(3)-fold higher than the initial introduced titre. Our results indicated that the infection rates of unprotected epithelial cells probably play an important role in affecting viral dynamics. By simulating an advanced model of viral dynamics and applying it to experimental infection data of human influenza, we obtained important estimates of the infection rate. This work provides epidemiologically meaningful results, meriting further efforts to understand the causes and consequences of influenza A infection.

The growth and characterization of ZnO/ZnTe core-shell nanowires and the electrical properties of ZnO/ZnTe core-shell nanowire field effect transistor.

Vertically aligned ZnO/ZnTe core-shell nanowires were grown on a-plane sapphire substrate by using chemical vapor deposition with gold as catalyst for the growth of ZnO core and then followed by growing ZnTe shell using metal-organic chemical vapor deposition (MOCVD). Transmission electron microscope (TEM) and Raman scattering indicate that the core-shell nanostructures have good crystalline quality. Three-dimensional fluorescence images obtained by using laser scanning confocal microscope demonstrate that the nanowires have good optical properties. The core-shell nanowire was then fabricated into single nanowire field effect transistor by standard e-beam photolithography. Electrical measurements reveals that the p-type ZnO/ZnTe FET device has a turn on voltage of -1.65 V and the hole mobility is 13.3 cm2/V s.

Characteristic features of unruptured intracranial aneurysms: predictive risk factors for aneurysm rupture.

BACKGROUND AND PURPOSE: The purpose of this study was to identify the risk factors predisposing to aneurysm rupture and to provide a reliable estimation for likelihood of rupture in unruptured intracranial aneurysms. METHODS: The authors performed a nested case-control study of 290 aneurysms (123 unruptured aneurysms and 167 ruptured aneurysms) occurring during a prospective cohort study in 1493 consecutive patients with newly diagnosed intracranial aneurysm and were treated in a single institute between January 1995 and December 2006. Controls were matched for age, treatment group, number of lesion, sex, region and study period in which the incidence of ruptured and unruptured intracranial aneurysm was equivalently balanced. The authors assessed the predictive risk factors associated with aneurysmal rupture based on the clinical and angiographic findings reported in the patients' medical records. RESULTS: Between January 1997 and December 2002, 167 patients with ruptured intracranial aneurysms were assigned to group 1, and 123 patients with unruptured intracranial aneurysms during the same period were assigned to group 2. Aspect ratio (OR 3.76), maximum diameter of neck (N(max)) < or =3 mm (OR 2.56) and family history of cerebrovascular disease (OR 5.63) were strongly correlated with aneurysm rupture (p<0.05). CONCLUSIONS: There are differences between the clinical and intrinsic characteristics of patients with unruptured and ruptured intracranial aneurysm. It will be helpful to make rational decisions regarding the optimal therapeutic strategy for unruptured intracranial aneurysm.

Expression of livin in gastric cancer and induction of apoptosis in SGC-7901 cells by shRNA-mediated silencing of livin gene.

BACKGROUND: Because of increased resistance to apoptosis in tumor cells, inhibition of specific anti-apoptotic factors may provide a rational approach for the development of novel therapeutic strategies. Livin, a novel inhibitor of apoptosis protein family, has been found to be expressed in various malignancies and is suggested to have poorly prognostic significance. However, no data are available concerning the significance of livin in gastric cancer. In this study, we detected the expression of livin in human gastric carcinoma and investigated the apoptotic susceptibility of SGC - 7901 cell by shRNA-mediated silencing of the livin gene. METHODS: The mRNA and protein expression of livin were analyzed by RT-PCR and western blot assay. The relationship between livin expression and clinical pathologic parameters was investigated. The small interfering RNA eukaryotic expression vector specific to livin was constructed by gene recombination, and the nucleic acid was sequenced. Then it was transfected into SGC-7901 cells by Lipofectamin 2000. RT-PCR and Western blot assay were used to validate gene-silencing efficiency of livin in SGC-7901 cells. Stable clones were obtained by G418 screening. The cell apoptosis was assessed by flow cytometry (FCM). Cell growth state and 50 % inhibition concentration (IC50) of 5-FU and cisplatin was determined by MTT method. RESULTS: The expression of livin mRNA and protein were detected in 19 of 40 gastric carcinoma cases (47.5%) and SGC-7901 cells. No expression of livin was detected in tumor adjacent tissues and benign gastric lesion. The positive correlation was found between livin expression and poor differentiation of tumors as well as lymph node metastases (P<0.05). Four small interfering RNA eukaryotic expression vector specific to livin were constructed by gene recombination. And one of them can efficiently decrease the expression of livin, the inhibition of the gene was not less than 70% (P<0.01). The recombinated plasmids were extracted and transfected gastric cancer cells. The stable clones were obtained by G418 screening, and were amplified and cultured. When livin gene was silenced, the reproductive activity of the gastric cancer cells was significantly lower than the control groups(P<0.05). The study also showed that IC50 of 5-Fu and cisplatin on gastric cancer cells treated by shRNA was decreased and the cells were more susceptible to proapoptotic stimuli (5-Fu and cisplatin) (P<0.01). CONCLUSIONS: Livin is overexpressed in gastric carcinoma with a relationship to tumor differentiation and lymph node metastases, which is suggested to be one of the molecular prognostic factors for some cases of gastric cancer. ShRNA can inhibit livin expression in SGC-7901 cells and induce cell apoptosis. Livin may serve as a new target for apoptosis-inducing therapy of gastric cancer.

Effects of Bacillus subtilis var. natto and Saccharomyces cerevisiae mixed fermented feed on the enhanced growth performance of broilers.

Bacillus subtilis var. natto N21 (Bac; for greater proteolytic capacity) and Saccharomyces cerevisiae Y10 (Sac; for greater acidic capacity) were applied to produce a 2-stage combined fermentation feed. This study investigated whether the enhancement of Bac+Sac fermented feed on broiler growth performance was due to the probiotics per se or due to the fermentation process. Trial 1 included 1-d-old broiler chicks (n=144) randomly assigned to control, water added (same as in the fermentation feed, 23%), and Bac+Sac fermented feed (FBac+Sac) treatments with 4 replicates. Trial 2 included 21-d-old broiler chickens (n=12) assigned into control and FBac+Sac groups for a metabolic trial for nutrient availability. Trial 3 included 1-d-old male broiler chicks (n=216) randomly assigned into 6 treatments with 3 replicates. Treatments included a control, Sac fermented feed (FSac), FBac+Sac, Bac powder (PBac), Sac powder (PSac), and Bac+Sac powder (PBac+Sac). The results from trial 1 showed that FBac+Sac increased BW and feed intake (P<0.05) in 21- and 39-d-old chickens. The water-added group showed decreased BW, weight gain, and feed intake (P<0.05). Trial 2 showed that FBac+ Sac increased gross energy availability (P<0.05). Trial 3 showed that FBac+Sac increased 21- and 39-d-old BW and weight gain (P<0.05). Diets supplemented with probiotic powder or fermented with Sac did not improve broiler growth performance (P>0.05). The growth performance improvement of the FBac+Sac treatment was probably not due to the added water, probiotic powder inclusion, or through single-strain fermentation, but due to the 2-stage fermentation process using Bac and Sac strains.

Longitudinal fMRI study for locomotor recovery in patients with stroke.

The authors investigated bihemispheric motor network reorganization supporting locomotor recovery after stroke over time. They determined longitudinal changes in locomotor function and fMRI in 10 stroke patients at the subacute stage and the chronic stage. The results suggest that the bihemispheric reorganization mechanism underlying locomotor recovery evolved from the ipsilateral (contralesional) primary sensorimotor cortex (SM1) activation at the subacute stage to the contralateral (ipsilesional) SM1 activation at the chronic stage.

Primary endobronchial leiomyosarcoma. Diagnosis following expectoration of tumor fragment.

A case is presented with spontaneous expectoration of a small piece of solid tissue. Pathologic examination of the expectorated tissue was found to be consistent with leiomyosarcoma. After further work-up, there was no evidence of another primary site of leiomyosarcoma except for the right lower lobe. Right lower lobectomy was performed. The surgical specimen showed a tumor that was histologically identical to the patient's previous expectorated tissue. To the authors' knowledge, this is the first report of partial expectoration of a primary endobronchial leiomyosarcoma.

Involvement of JAK/STAT (Janus kinase/signal transducer and activator of transcription) in the thyrotropin signaling pathway.

TSH is an important physiological regulator of growth and function in thyroid gland. The mechanism of action of TSH depends on interaction with its receptor coupled to heterotrimeric G proteins. We show here that TSH induces the phosphorylation of tyrosine in the intracellular kinases Janus kinase 1 (JAK1) and -2 (JAK2) in rat thyroid cells and in Chinese hamster ovary (CHO) cells transfected with human TSH receptor (TSHR). The JAK family substrates STAT3 (signal transducers and activators of transcription) are rapidly tyrosine phosphorylated in response to TSH. We also find that JAK1, JAK2, and STAT3 coprecipitate with the TSHR, indicating that the TSHR may be able to signal through the intracellular phosphorylation pathway used by the JAK-STAT cascade. TSH increases STAT3-mediated promoter activity and also induces endogenous SOCS-1 (suppressor of cytokine signaling-1) gene expression, a known target gene of STAT3. The expression of a dominant negative form of STAT3 completely inhibited TSH-mediated SOCS-1 expression. These findings suggest that the TSHR is able to signal through JAK/STAT3 pathways.

Hormone-dependent regulation of intercellular adhesion molecule-1 gene expression: cloning and analysis of 5'-regulatory region of rat intercellular adhesion molecule-1 gene in FRTL-5 rat thyroid cells.

Intercellular adhesion molecule-1 (ICAM-1) has been suggested to play an important role in the perpetuation of autoimmune thyroid disease. To clarify the regulation of ICAM-1 gene in thyroid cells, we investigated ICAM-1 expression in the FRTL-5 thyroid cell model and defined several elements in the 5'-regulatory region that are important for transcriptional regulation of the rat ICAM-1 gene. Cells maintained in medium with 5% serum but without hydrocortisone, insulin, and thyrotropin (TSH) express the highest levels of ICAM-1 RNA. TSH/forskolin downregulate ICAM-1 RNA levels independent of the presence or absence of hydrocortisone or insulin. Moreover, TSH/forskolin decrease ICAM-1 RNA levels that are maximally induced by two cytokines: 100 ng/mL tumor necrosis factor-alpha (TNF-alpha) or 100 U/ml interferon-gamma (IFN-gamma). The effect of TSH/forskolin, as well as TNF-alpha and IFN-gamma, on ICAM-1 RNA levels is transcriptional. Thus, we cloned a 1.8-kb fragment of the 5'-flanking region of the rat ICAM-1 gene, upstream of the translational start site, and showed that TNF-alpha or IFN-gamma caused a 3.5- and greater than 12-fold increase respectively, in its promoter activity, when linked to a luciferase reporter gene and stably transfected into FRTL-5 cells. TSH or forskolin, in contrast, halved the activity of the full length chimera within 24 hours and significantly suppressed the TNF-alpha and IFN-gamma-induced increase (>50%; p < 0.02). Using 5'-deletion mutants, we located the element important for the TNF-alpha effect between -431 and -175 bp; we additionally show that deletion of a NF-kappaB core element within this region, TTGGAAATTC (-240 to -230 bp), causes the loss of TNF-alpha inducibility. The effect of IFN-gamma could be localized between -175 bp and -97 bp from the start of translation. This region contains 2 regulatory elements known to be involved in IFN-gamma action in other eukaryotic cells, an IFN-gamma activated site (GAS), -138 to -128 bp, and Spl site, -112 to -108 bp. Deletion of the 10 bp GAS sequence resulted in the complete loss of IFN-gamma induction of pCAM-175 promoter activity. TSH and forskolin action was also mapped between -175 bp and -97 bp from the start of translation. The mutant construct, pCAM-175delGAS mutl, which has no GAS sequence, exhibited no TSH-mediated suppression of promoter activity. We thus show that TSH/cAMP can downregulate ICAM-1 gene expression and inhibit the activity of cytokines (TNF-alpha and IFN-gamma) to increase ICAM-1 gene expression in FRTL-5 thyroid cells. We also localized elements on the 5'-flanking region of ICAM-1 important for these actions. We propose that this TSH/cyclic adenosine monophosphate (cAMP) action is a component of the mechanism to preserve self-tolerance of the thyroid during hormone-induced growth and function of the gland, and it may attenuate cytokine action during inflammatory reactions.