Rapid implementation of triaging system for assessment of breast referrals from primary care centres during the COVID-19 pandemic.

OBJECTIVE: The aim of this study was to establish a triaging system for assessment of breast referrals from primary care to ensure safe and effective breast services without compromising breast cancer management. BACKGROUND: COVID-19 was officially declared a global pandemic on 11 March 2020, and with no effective treatment available, preventing spread has been paramount. Previously, all referrals from primary care were seen in the rapid-access breast clinic (RABC). Clinic appointments exposed patients and healthcare professionals to risk. METHOD: Initial triage during the lockdown was in line with national governing body guidance, rejected low risk referrals and streamed remaining patients through a telephone consultation to RABC or discharge. A modified triage pathway streamed all patients through virtual triage to RABC, telephone clinic or discharge with advice and guidance categories. Demographics, reasons for referral and outcomes data were collected and presented as median with range and frequency with percentages. RESULTS: Initial triage (23 March-23 April 2020) found fewer referrals with a higher percentage of breast cancer diagnoses. Modified triage (22 June-17 July 2020) resulted in a 35.1% (99/282) reduction in RABC attendance. Overall cancer detection rate remained similar at 4.2% of all referrals pre-COVID (18/429) and 4.3% (12/282) during modified triage. After six months follow-up of patients not seen in RABC during the modified triage pathway, 18 patients were re-referred to RABC and none were diagnosed with cancer. CONCLUSION: A modified triage pathway has the potential to improve triage efficiency and prevent unnecessary visits during the COVID-19 pandemic. Further refinement of pathway is feasible in collaboration with primary care.

Corin Overexpression Reduces Myocardial Infarct Size and Modulates Cardiomyocyte Apoptotic Cell Death.

Altered expression of corin, a cardiac transmembrane serine protease, has been linked to dilated and ischemic cardiomyopathy. However, the potential role of corin in myocardial infarction (MI) is lacking. This study examined the outcomes of MI in wild-type vs. cardiac-specific overexpressed corin transgenic (Corin-Tg) mice during pre-MI, early phase (3, 24, 72 h), and late phase (1, 4 weeks) post-MI. Corin overexpression significantly reduced cardiac cell apoptosis (p < 0.001), infarct size (p < 0.001), and inhibited cleavage of procaspases 3, 9, and 8 (p < 0.05 to p < 0.01), as well as altered the expression of Bcl2 family proteins, Bcl-xl, Bcl2 and Bak (p < 0.05 to p < 0.001) at 24 h post-MI. Overexpressed cardiac corin also significantly modulated heart function (ejection fraction, p < 0.0001), lung congestion (lung weight to body weight ratio, p < 0.0001), and systemic extracellular water (edema, p < 0.05) during late phase post-MI. Overall, cardiac corin overexpression significantly reduced apoptosis, infarct size, and modulated cardiac expression of key members of the apoptotic pathway in early phase post-MI; and led to significant improvement in heart function and reduced congestion in late phase post-MI. These findings suggest that corin may be a useful target to protect the heart from ischemic injury and subsequent post-infarction remodeling.

Standard of care vs reduced-dose chemoradiation after induction chemotherapy in HPV+ oropharyngeal carcinoma patients: The Quarterback trial.

BACKGROUND: Human Papillomavirus oropharyngeal carcinoma (HPVOPC) has better progression free (PFS) and overall survival (OS) than non-HPVOPC. Standard-dose chemoradiotherapy (sdCRT) results in significant acute toxicity and late morbidity. We hypothesized that after induction chemotherapy (IC), reduced dose chemoradiation (rdCRT) would result in equivalent PFS and OS compared to sdCRT plus IC in HPVOPC and would reduce toxicity. METHODS: Patients with p16+, previously untreated, locally advanced HPVOPC and ≤20 pack years smoking history received 3 cycles of IC with docetaxel, cisplatin and fluorouracil (TPF). Clinical responders who were HPV positive by type-specific PCR were randomized 1:2 to sdCRT (7000 cGy) or rdCRT (5600 cGy) with weekly carboplatin. The endpoints of the study were 3 year PFS and OS. RESULTS: 23 patients were enrolled, 22 were evaluable for TPF toxicity and 20 were randomized, 8 to sdCRT and 12 to rdCRT. Sixteen (80%) were HPV 16+ and 4 (20%) were other high risk (HR) variants. Fourteen (70%) had high risk features: T4, N2c, or N3. Median follow up was 56 months (range 42-70). Three-year PFS/OS for sdCRT and rdCRT are 87.5% vs 83.3% (log-rank test p = 0.85), respectively. All 3 failures are locoregional within 4 months of completion of CRT; 2 were in HR variants (50%). CONCLUSIONS: rdCRT after IC resulted in similar PFS/OS compared sdCRT. These data support Phase 3 clinical trials of radiation dose reduction after IC as a treatment strategy in HPVOPC. Molecular HPV with variant testing and smoking history are necessary for de-escalation trials.

Correction: RCP induces Slug expression and cancer cell invasion by stabilizing ß1 integrin.

Following the publication of this article the authors noted that images were inadvertently duplicated in Fig. 1b. The corrected Fig. 1 can be found in the associated Correction. The conclusions of this paper are not affected. The authors sincerely apologize for this error. This error has not been corrected in the HTML or PDF of the original Article.

Meta-Analysis of the Relative Efficacy and Safety of Oral P2Y12 Inhibitors in Patients With Acute Coronary Syndrome.

A cornerstone of medical therapy for patients with acute coronary syndrome (ACS) is dual antiplatelet therapy, which includes aspirin and a P2Y12 inhibitor. Randomized controlled trials (RCTs) have shown that prasugrel and ticagrelor are superior to clopidogrel, but none directly compared these 3 commonly used oral P2Y12 inhibitors for safety and efficacy. Therefore, we performed a Bayesian network meta-analysis of RCTs to compare the efficacies and safeties of 3 commonly used oral P2Y12 inhibitors in patients with ACS. Scientific databases and websites were searched for relevant RCTs. We included data from 9 RCTs that enrolled 106,288 patients. Clopidogrel decreased the rates of major adverse cardiac event, recurrent myocardial infarction, and all-cause mortality compared with placebo. Both ticagrelor and prasugrel decreased the rates for major adverse cardiac event and recurrent myocardial infarction compared with clopidogrel, but there was no difference between the 2. Both also decreased the stent thrombosis rate compared with clopidogrel, but prasugrel was more effective than ticagrelor. Ticagrelor use was also associated with improved all-cause and CV mortalities compared with clopidogrel. There was no difference in CV mortality or all-cause mortality between clopidogrel and prasugrel. Prasugrel use was also associated with significantly increased risk of major bleeding compared with clopidogrel but showed a nonsignificant trend toward increasing the risk of bleeding compared with ticagrelor. In treatment ranking, ticagrelor was the most efficacious, and prasugrel was the least safe. In conclusion, this meta-analysis shows that in patients with ACS, adding P2Y12 inhibitors to aspirin and other standard treatments reduces ischemic events and all-cause mortality. Among the commonly used oral P2Y12 inhibitors, ticagrelor has the best net efficacy and safety profile.

RCP induces Slug expression and cancer cell invasion by stabilizing ß1 integrin.

Rab coupling protein (RCP)-induced tumor cell migration has been implicated in tumor pathophysiology and patient outcomes. In the present study, we demonstrate that RCP stabilizes ß1 integrin leading to increased ß1 integrin levels and activation of a signaling cascade culminating in Slug induction, epithelial-to-mesenchymal transition and increased invasion. Ectopic expression of RCP induced Slug expression. Silencing ß1 integrin efficiently inhibited RCP-induced Slug expression and subsequent cancer cell invasion. Conversely, ectopic expression of ß1 integrin was sufficient to induce Slug expression. Pharmacological inhibition of integrin linked kinase (ILK), EGFR and NF-κB, as well as transfection of a dominant-negative mutant of Ras (RasN17), significantly inhibited RCP-induced Slug expression and cancer cell invasion. Strikingly, ectopic expression of RCP was sufficient to enhance metastasis of ovarian cancer cells to the lung. Collectively, we demonstrate a mechanism by which RCP promotes cancer cell aggressiveness through sequential ß1 integrin stabilization, activation of an ILK/EGFR/Ras/NF-κB signaling cascade and subsequent Slug expression.

Epac2a-null mice exhibit obesity-prone nature more susceptible to leptin resistance.

BACKGROUND: The exchange protein directly activated by cAMP (Epac), which is primarily involved in cAMP signaling, has been known to be essential for controlling body energy metabolism. Epac has two isoforms: Epac1 and Epac2. The function of Epac1 on obesity was unveiled using Epac1 knockout (KO) mice. However, the role of Epac2 in obesity remains unclear. METHODS: To evaluate the role of Epac2 in obesity, we used Epac2a KO mice, which is dominantly expressed in neurons and endocrine tissues. Physiological factors related to obesity were analyzed: body weight, fat mass, food intake, plasma leptin and adiponectin levels, energy expenditure, glucose tolerance, and insulin and leptin resistance. To determine the mechanism of Epac2a, mice received exogenous leptin and then hypothalamic leptin signaling was analyzed. RESULTS: Epac2a KO mice appeared to have normal glucose tolerance and insulin sensitivity until 12 weeks of age, but an early onset increase of plasma leptin levels and decrease of plasma adiponectin levels compared with wild-type mice. Acute leptin injection revealed impaired hypothalamic leptin signaling in KO mice. Consistently, KO mice fed a high-fat diet (HFD) were significantly obese, presenting greater food intake and lower energy expenditure. HFD-fed KO mice were also characterized by greater impairment of hypothalamic leptin signaling and by weaker leptin-induced decrease in food consumption compared with HFD-fed wild-type mice. In wild-type mice, acute exogenous leptin injection or chronic HFD feeding tended to induce hypothalamic Epac2a expression. CONCLUSIONS: Considering that HFD is an inducer of hypothalamic leptin resistance and that Epac2a functions in pancreatic beta cells during demands of greater work load, hypothalamic Epac2a may have a role in facilitating leptin signaling, at least in response to higher metabolic demands. Thus, our data indicate that Epac2a is critical for preventing obesity and thus Epac2a activators may be used to manage obesity and obesity-mediated metabolic disorders.

Renin-Angiotensin Activation and Oxidative Stress in Early Heart Failure with Preserved Ejection Fraction.

Animal models have suggested a role of renin-angiotensin system (RAS) activation and subsequent cardiac oxidation in heart failure with preserved ejection fraction (HFpEF). Nevertheless, RAS blockade has failed to show efficacy in treatment of HFpEF. We evaluated the role of RAS activation and subsequent systemic oxidation in HFpEF. Oxidative stress markers were compared in 50 subjects with and without early HFpEF. Derivatives of reactive oxidative metabolites (DROMs), F2-isoprostanes (IsoPs), and ratios of oxidized to reduced glutathione (E h GSH) and cysteine (E h CyS) were measured. Angiotensin converting enzyme (ACE) levels and activity were measured. On univariate analysis, HFpEF was associated with male sex (p = 0.04), higher body mass index (BMI) (p = 0.003), less oxidized E h CyS (p = 0.001), lower DROMs (p = 0.02), and lower IsoP (p = 0.03). Higher BMI (OR: 1.3; 95% CI: 1.1-1.6) and less oxidized E h CyS (OR: 1.2; 95% CI: 1.1-1.4) maintained associations with HFpEF on multivariate analysis. Though ACE levels were higher in early HFpEF (OR: 1.09; 95% CI: 1.01-1.05), ACE activity was similar to that in controls. HFpEF is not associated with significant systemic RAS activation or oxidative stress. This may explain the failure of RAS inhibitors to alter outcomes in HFpEF.

Effect of Perioperative Terlipressin on Postoperative Renal Function in Patients Who Have Undergone Living Donor Liver Transplantation: A Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Recent studies have shown the efficacy of terlipressin on postoperative renal function in patients who have undergone living donor liver transplantation (LDLT). OBJECTIVES: To evaluate the effect of perioperative terlipressin on postoperative renal function in patients who have undergone LDLT and to analyze the hemodynamic data during transplantation surgery. STUDY DESIGN: A meta-analysis. METHODS: We assessed the postoperative peak serum creatinine level and changes in the hemodynamic data (e.g. the mean arterial pressure, heart rate, and systemic vascular resistance). We collected randomized controlled trials from PubMed, EMBASE Drugs and Pharmacology, Cochrane Controlled Trials Register, and Cochrane Database on Systematic Reviews. Analysis was conducted using RevMan 5.2. Data from each trial were pooled and weighted by their mean differences and corresponding 95% confidence intervals (CI). A heterogeneity assessment was performed. RESULTS: Three trials (151 patients) were included. The difference in the mean (95% CI) peak serum creatinine (mg/dL) levels postoperatively was not significant between the intervention and control groups (weighted mean difference [WMD]: -0.27; CI: -0.55-0.01; P = .06). Terlipressin significantly decreased heart rate during the anhepatic phase (WMD: -6.58; 95% CI: -8.85 to -4.31; P < .00001) with a low heterogeneity (I(2) = 41%) and significantly decreased heart rate during the neohepatic phase (WMD: -9.82; 95% CI: -11.96 to -7.68; P < .00001), although the heterogeneity was high (I(2) > 50%). CONCLUSIONS: An intravenous infusion of terlipressin perioperatively for LDLT has no effect on the creatinine values postoperatively. Larger randomized controlled trials on terlipressin infusions during liver transplantation are needed.

Medication profile and polypharmacy in adults with pediatric-onset spinal cord injury.

STUDY DESIGN: Cross-sectional survey. OBJECTIVES: To describe the medications taken by individuals who had sustained a spinal cord injury (SCI) in childhood or adolescence (age <19 years) and to report the prevalence of polypharmacy and its association with demographic, injury-related and psychosocial factors. SETTING: Community. METHODS: Structured interviews of adults with pediatric-onset SCI. Routine medications and secondary health conditions (SHCs) experienced were recorded. Polypharmacy was defined as the concomitant use of five or more different types of medications. Bivariate analyses and multiple regression models were conducted to determine associations between polypharmacy and demographic factors, injury-related factors, number of SHCs and psychosocial outcomes (FIM, SF-12v2 Health Survey, CHART, PHQ-9). RESULTS: A total of 159 participants (male, 63%; tetraplegia, 59%) with mean age 35.0±6.2 years (range, 26.7-50.9 years) were included. Most common routine medications were muscle relaxants (50.3%), bladder medications (48.5%), bowel agents (41.5%), analgesics (26.4%) and antidepressants (16.9%). Polypharmacy was present in 30.8% (n, 49) and was more prevalent in those with tetraplegia (40.2% vs 17.9%; P=0.003). Participants with polypharmacy were older, had lower FIM, CHART and SF-12v2 scores, and higher PHQ-9 scores. Regression models indicate the total number of SHCs, time since injury and tetraplegia to be significant positive predictors of polypharmacy. CONCLUSION: Duration of SCI and SHCs are risk factors for polypharmacy in this population of adults with SCI. Measures should be taken to prevent the occurrence of SHCs throughout adulthood so as to prevent the potentially adverse physiological effects and psychosocial outcomes associated with polypharmacy.

An 81-year-old man with an abnormal right-sided heart shadow on chest radiograph.

An 81-year-old man presented with a 1-week history of dry cough. He also complained of mild dyspnea, wheezing, and low-grade fever. He denied hemoptysis, fever, rashes, or chest pain. The patient's medical history included coronary artery bypass surgery, hypertension, gastroesophageal reflux disease, and COPD. The patient was a retired welder and an ex-smoker.

Candidate tumor suppressor B-cell translocation gene 3 impedes neoplastic progression by suppression of AKT.

BTG3 (B-cell translocation gene 3) is a p53 target that also binds and inhibits E2F1. Although it connects two major growth-regulatory pathways functionally and is downregulated in human cancers, whether and how BTG3 acts as a tumor suppressor remain largely uncharacterized. Here we present evidence that BTG3 binds and suppresses AKT, a kinase frequently deregulated in cancers. BTG3 ablation results in increased AKT activity that phosphorylates and inhibits glycogen synthase kinase 3ß. Consequently, we also observed elevated ß-catenin/T-cell factor activity, upregulation of mesenchymal markers, and enhanced cell migration. Consistent with these findings, BTG3 overexpression suppressed tumor growth in mouse xenografts, and was associated with diminished AKT phosphorylation and reduced ß-catenin in tissue specimens. Significantly, a short BTG3-derived peptide was identified, which recapitulates these effects in vitro and in cells. Thus, our study provides mechanistic insights into a previously unreported AKT inhibitory pathway downstream of p53. The identification of an AKT inhibitory peptide also unveils a new avenue for cancer therapeutics development.

Widespread correction of central nervous system disease after intracranial gene therapy in a feline model of Sandhoff disease.

Sandhoff disease (SD) is caused by deficiency of N-acetyl-ß-hexosaminidase (Hex) resulting in pathological accumulation of GM2 ganglioside in lysosomes of the central nervous system (CNS) and progressive neurodegeneration. Currently, there is no treatment for SD, which often results in death by the age of five years. Adeno-associated virus (AAV) gene therapy achieved global CNS Hex restoration and widespread normalization of storage in the SD mouse model. Using a similar treatment approach, we sought to translate the outcome in mice to the feline SD model as an important step toward human clinical trials. Sixteen weeks after four intracranial injections of AAVrh8 vectors, Hex activity was restored to above normal levels throughout the entire CNS and in cerebrospinal fluid, despite a humoral immune response to the vector. In accordance with significant normalization of a secondary lysosomal biomarker, ganglioside storage was substantially improved, but not completely cleared. At the study endpoint, 5-month-old AAV-treated SD cats had preserved neurological function and gait compared with untreated animals (humane endpoint, 4.4±0.6 months) demonstrating clinical benefit from AAV treatment. Translation of widespread biochemical disease correction from the mouse to the feline SD model provides optimism for treatment of the larger human CNS with minimal modification of approach.

The anticancer gene ORCTL3 targets stearoyl-CoA desaturase-1 for tumour-specific apoptosis.

ORCTL3 is a member of a group of genes, the so-called anticancer genes, that cause tumour-specific cell death. We show that this activity is triggered in isogenic renal cells upon their transformation independently of the cells' proliferation status. For its cell death effect ORCTL3 targets the enzyme stearoyl-CoA desaturase-1 (SCD1) in fatty acid metabolism. This is caused by transmembrane domains 3 and 4, which are more efficacious in vitro than a low molecular weight drug against SCD1, and critically depend on their expression level. SCD1 is found upregulated upon renal cell transformation indicating that its activity, while not impacting proliferation, represents a critical bottleneck for tumourigenesis. An adenovirus expressing ORCTL3 leads to growth inhibition of renal tumours in vivo and to substantial destruction of patients' kidney tumour cells ex vivo. Our results indicate fatty acid metabolism as a target for tumour-specific apoptosis in renal tumours and suggest ORCTL3 as a means to accomplish this.

Estimated long-term dietary exposure to lead, cadmium, and mercury in young Korean children.

BACKGROUND: Controlling for day-to-day variation is a key issue in estimating long-term dietary exposure to heavy metals using 24-hour recall (24HR) data from a relatively small number of days. OBJECTIVES: This study was conducted to estimate long-term dietary exposure to lead, cadmium and mercury among Korean children using the Iowa State University (ISU) method and to assess the contributions of different food groups to heavy metal intake. METHODS: We analyzed 2 days of 24HR data from 457 children between 0 and 6 years of age in 2010. Using bootstrapped concentration data for 118 representative foods, 93.5% of total intake was included in the exposure estimates in this study. Using the 2-day exposure data, we estimated long-term exposure by controlling for within-individual variation using the ISU method. RESULTS: The long-term dietary exposure estimates (mean±standard deviation) for lead, cadmium, and mercury were 0.47±0.14, 0.38±0.20, and 0.22±0.08 µg/kg bw/day, respectively. For lead and cadmium, the percentages of children whose exposure was greater than the reference value were 35 and 42%, respectively. Fruits were an important source of lead exposure, and cereal and fish and shellfish made the greatest contributions to the total cadmium and mercury exposure. CONCLUSIONS: Our findings also suggest that the long-term exposure to lead and cadmium was somewhat greater than the reference values, whereas mercury exposure was well below than the reference value in this population. Further studies may be necessary to evaluate the food items contributing to heavy metal exposure, and continuous monitoring is needed to ensure the safety of food intake and dietary patterns among vulnerable groups in Korea.

Impact of bowel cancer screening on the management of colorectal cancer.

AIM: The National Bowel Cancer Screening Programme (NBCSP) was introduced in the West Midlands in 2006. Studies, including the UK Bowel Cancer Screening Pilot, have reported an 18% reduction in mortality. This regional study assesses the impact of screening on elective and emergency colorectal cancer (CRC) surgery. METHOD: Data were extracted from the West Midlands cancer registration database for CRC diagnosed in residents of the West Midlands between 1998 and 2010. Screen-detected cancers were identified by matching to the NBCSP database. Mode of admission and intervention was obtained by matching to Hospital Episode Statistics and the classification of Interventions and Procedures code. RESULTS: Of 42,082 patients diagnosed with CRC, 30,309 received surgical treatment. From 1998 to 2005, the number of patients who underwent emergency surgery increased from 4362 to 18,357, with the proportion each year remaining constant (23.85 ± 0.95% each year). In the screening age group (60-69 years) over the same period, emergency surgery was performed in 918 of 4831 patients (19.15 ± 1.65% each year). Following the introduction of screening, the emergency surgery rate decreased each year, reaching 16% (406/2520) in all patients and 12% (101/829) in the screening age group in 2010 (P < 0.001). These changes in emergency surgery were mirrored by increases in elective surgery. CONCLUSION: The NBCSP has had a positive impact on elective and emergency surgery for CRC in the West Midlands.

Metastatic breast cancer in patients with schizophrenia.

Breast cancer is a major health problem worldwide. The median survival duration for patients with metastatic breast cancer is two to three years. Approximately 1% of populations worldwide have schizophrenia. The manner in which schizophrenic patients fare when diagnosed with metastatic breast carcinoma (MBC) was evaluated. We queried the National Department of Veterans Affairs (DVA) datasets using computer codes for a pre-existing diagnosis of schizophrenia and a later diagnosis of breast carcinoma. Chart-based data concerning the identified subjects were then requested. Previously determined inclusion and exclusion criteria were applied to select evaluable patients from the medical records, prior to extracting demographic details and data concerning the treatment course in each subject. Ten patients had distant metastases at initial diagnosis, while seven developed MBC following prior curative-intent treatment. Two patients refused therapy. Ten did not comply with recommended management. Five harmed or threatened physicians, other caregivers or themselves. Schizophrenic patients with MBC often fail to understand the nature of their illnesses. Often they do not accept palliative treatment, while a number of them do not comply with therapy, once initiated. They often exhibit behaviors that are detrimental to themselves or others. Formal psychiatric consultation is therefore necessary in patients. Several detrimental behaviors may be predicted reliably by history alone.

Substance use in young adults with pediatric-onset spinal cord injury.

STUDY DESIGN: Cross-sectional survey. OBJECTIVES: To assess the prevalence of substance use in young adults with pediatric-onset spinal cord injury (SCI) and its relationship with demographic factors, and medical and psychosocial outcomes. SETTING: Young adults living in the United States who received pediatric SCI care at one of three SCI programs at the Shriners Hospitals for Children. METHODS: Individuals aged 21-25 years who had sustained SCI before the age of 19 were interviewed with a structured questionnaire including standardized outcome measures: FIM, satisfaction with life scale (SWLS), short-form 12 health survey (SF-12), patient health questionnaire-9 (PHQ-9) depression scale, and Craig handicap assessment and recording technique (CHART). RESULTS: Sample included 215 individuals with a mean age at interview of 23.3 (s.d.=0.9) years and mean age at injury of 13.2 (s.d.=4.9) years. In all, 24% had a college degree, 36% were employed and 12% were married. Regular substance use was reported by 28% for tobacco, 55% for alcohol and 11% for marijuana. Tobacco use was associated with depressive symptoms and unemployment; alcohol use was associated with having a college degree, single status and independent mobility; and marijuana use was associated with not having a college degree. There were no significant associations between substance use and injury-related factors or life satisfaction. CONCLUSION: Substance use in young adults with pediatric-onset SCI was associated with factors such as education, employment, marital status and depressive symptoms. Clinicians caring for youth with SCI should counsel patients and caregivers regarding the use of substances and potential associations with outcomes in adulthood.

Inflammatory responses to Mycoplasma hyopneumoniae in murine alveolar macrophage cell lines.

AIM: To investigate the mechanism by which Mycoplasma hyopneumoniae induces inflammatory responses in murine alveolar macrophage (MH-S) cells. METHODS: A pathogenic strain of M. hyopneumoniae cultured in modified Friis medium was used to investigate the inflammatory response in MH-S cell lines. The effect of stimulation by M. hyopneumoniae on the production of nitric oxide (NO) and cytokines in MH-S cells and inhibition of their production, using specific inhibitors of signalling pathways, was investigated using the Griess reaction and ELISA respectively. A Western blot assay was used to confirm activation of the nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways. Nuclear translocation of NF-κB was further confirmed using transient transfection and luciferase gene reporter assay. RESULTS: The results revealed dose-dependent production of NO in MH-S cells stimulated by M. hyopneumoniae. Increased concentrations of the cytokines tumour necrosis factor (TNF)-α and interleukin (IL)-1ß and IL-6 were also observed (p<0.05). Using immunoblot analysis, involvement of three MAPK pathways, extracellular signal-regulated kinase I/II (ERK1/2), p38 and Jun N-terminal kinases/stress-activated protein kinases (JNK/SAPK) was confirmed. Specific inhibitors of signal pathways also demonstrated their effect on the NO and cytokine responses of MH-S cells. Degradation and phosphorylation of inhibitory kappa B (IκB)-alpha was observed, while the luciferase gene reporter assays revealed activation of NF-κB after stimulation by M. hyopneumoniae. Inhibition of NF-κB by pyrrolidine dithiocarbamate decreased M. hyopneumoniae-induced production of NO and IL-1ß (p<0.05), whereas no inhibitory effect was observed on concentrations of TNF-α, and IL-6. CONCLUSION: These findings indicate that M. hyopneumoniae induces NO and pro-inflammatory cytokines, and NF-κB and the three MAPK pathways are involved in the process.