Assessment of In Vitro Airway Smooth Muscle Relaxant Activity of Rhus coriaria L. Fruit Ethanolic Extract and Its Possible Mechanisms.

Rhus coriaria L. (Anacardiaceae), also known as Sumac, is commonly used as a spice, flavoring agent, and as a traditional medicinal herb. This includes also the traditional use for treating asthma, catarrh, and common colds. The accumulating evidence supports its cardioprotective, antidiabetic, neuroprotective, anticancer, gastroprotective, antibacterial, anti-inflammatory, antiviral, antioxidant, and respiratory effects. However, there are no previous studies that have shown its effects and mechanism in the airway smooth muscle tone, and therefore, the aim of our study was to investigate the in vitro pharmacological action of R. coriaria L. extract (RCE) on the rat isolated tracheal and bronchial preparations by exploring its relaxant activity and mechanism of action. The direct relaxant effect of RCE (0.1-0.7 mg/mL) was tested in the rat bronchi and trachea rings precontracted by carbachol (CCh). In addition, the pretreatment with RCE (1 mg/mL) was tested on the bronchial and tracheal reactivity induced by CCh, potassium chloride (KCl), or CaCl2. In addition, the cyclooxygenase inhibitor indomethacin and the nitric oxide synthase inhibitor N(G)-nitro-l-arginine methyl ester (L-NAME), respectively, were used for exploring the mechanisms of RCE-induced relaxation and reduction of reactivity. Our findings demonstrated that RCE induced a concentration-dependent relaxation and a significant reduction of reactivity, significantly reduced with either indomethacin or L-NAME. In addition, RCE decreased the responsiveness to KCl and affected the extracellular Ca2+-induced contraction in the tissues with added CCh or KCl in Ca2+-free Krebs-Henseleit solution. In summary, we have shown that RCE displayed relaxant activities in the in vitro airway smooth muscles, and the possible mechanisms seems to involve the prostaglandin, nitric oxide, and Ca2+ pathways. Taken together, our findings indicate the potential role of RCE in the treatment of respiratory diseases with limited airflow, or obstructive respiratory diseases, and could justify its traditional use in the respiratory diseases.

Comparative Assessment of Short-Term Tendon-Scleral Postoperative Inflammation and α-Smooth Muscle Actin Expression following Oral and Topical Diclofenac Administration for Strabismus Surgery in Rabbits.

PURPOSE: Wound healing and fibrosis modulation are considered pivotal for the long-term outcome of strabismus surgery. Nonsteroidal anti-inflammatory drugs, including diclofenac sodium, are inflammation suppressive drugs that may modulate wound healing, including postoperative inflammation. This study aimed to compare the effect of oral and 0.1% topical diclofenac sodium on short-term inflammation and α-smooth muscle actin (α-SMA) expression at the tendon-scleral attachment site following strabismus surgery in an experimental rabbit model. METHODS: Superior rectus recession was performed in 12 eyes of six New Zealand rabbits. Rabbits were divided into three groups: oral diclofenac 2 × 5 mg/kg for three days (group A), 0.1% diclofenac sodium eye drops 3 times/day for three days (group B), and controls (group C). On postoperative day 14, enucleation was performed. Macroscopic adhesion score, microscopic adhesion score, percentage of postoperative inflammation area (Masson's trichrome staining), and α-SMA (immunohistochemistry staining) were assessed. Data analysis was performed using a semi-quantitative and quantitative assessment with ImageJ. All groups were compared with reciprocal staining intensity (RSI) values to measure α-SMA expression. RESULTS: All groups showed no difference in macroscopic (p = 0.13) and microscopic adhesion scores (p = 0.28). The percentage of postoperative inflammation area in group B (12.44% (8.63-18.29)) was significantly lower than group A (26.76% (21.38-37.56) p = 0.03) and group C (27.80% (16.42-36.28), p = 0.04). Comparative RSI analysis found that group B had a significantly lower α-SMA expression than group C (174.08 ± 21.78 vs 212.58 ± 12.06, p = 0.04). CONCLUSION: The results suggest that compared to oral, the administration of topical diclofenac showed a more significant reduction of short-term postoperative inflammation and α-SMA expression at the tendon-scleral attachment site following strabismus surgery.

In vivo biomechanical assessment of iridial deformations and muscle contractions in human eyes.

The iris is a muscular organ whose deformations can cause primary angle-closure glaucoma (PACG), a leading cause of blindness. PACG risk assessment does not consider iridial biomechanical factors, despite their expected influence on iris deformations. Here, we exploited an existing biometric dataset consisting of near-infrared movies acquired during the pupillary light reflex (PLR) as a unique resource to study iris biomechanics. The PLR caused significant (greater than 100%) and essentially spatially uniform radial strains in the iris in vivo, consistent with previous findings. Inverse finite-element modelling showed that sphincter muscle tractions were ca fivefold greater than iridial stroma stiffness (range 4- to 13-fold, depending on sphincter muscle size). This muscle traction is greater than has been previously estimated, which may be due to methodological differences and/or to different patient populations in our study (European descent) versus previous studies (Asian); the latter possibility is of particular interest due to differential incidence rates of PACG in these populations. Our methodology is fast and inexpensive and may be a useful tool in understanding biomechanical factors contributing to PACG.

X-ray micro-computed tomography in the assessment of penile cavernous fibrosis in a rabbit castration model.

BACKGROUND: Current assessment methods of penile cavernous fibrosis in animal models have limitations due to the inability to provide complex and volume analysis of fibrotic alterations. OBJECTIVE: The aim was to evaluate micro-computed tomography for assessment of cavernous fibrosis and compare it with histological, histochemical, immunohistochemical, and RT-PCR analysis. MATERIALS AND METHODS: A controlled trial was performed involving 25 New Zealand male rabbits with induced testosterone deficiency by orchidectomy. Penile samples were obtained before and after 7, 14, 21, and 84 days from orchidectomy. We consistently performed (a) gray value analysis of corpora cavernosa 3D models reconstructed after micro-computed tomography, (b) morphometry of smooth muscles/connective tissue ratio, collagen type I/III ratio, and area of TGF-beta-1 expression in corpora cavernosa, and (c) RT-PCR of TGF-beta-1 expression. RESULTS: Micro-computed tomography allowed visualization of penile structures at a resolution comparable to light microscopy. Gray values of corpora cavernosa decreased from 1673 (1512-1773) on the initial day to 1184 (1089-1232) on the 21st day (p < 0.005). However, on the 84th day, it increased to 1610 (1551-1768). On 21st and 84th days, there was observed a significant decrease in smooth muscle/connective tissue ratio and a significant increase in collagen type I/III ratio (p < 0.05). TGF-beta1 expression increased on the 84th day according to immunohistochemistry (p < 0.005). RT-PCR was impossible to conduct due to the absence of RNA in obtained samples after micro-CT. DISCUSSION AND CONCLUSIONS: Micro-computed tomography provided 3D visualization of entire corpora cavernosa and assessment of radiodensity alterations by gray value analysis in fibrosis progression. We speculate that gray value changes at early and late fibrosis stages could be related to tissue reorganization. RT-PCR is impossible to conduct on tissue samples studied by micro-CT due to RNA destruction. We also suggest that micro-computed tomography could negatively affect the immunohistochemical outcome, as a significant increase of TGF-beta-1 expression occurs later than histological fibrotic signs.

Post-void residual urine ratio: A novel clinical approach to the post-void residual urine in the assessment of males with lower urinary tract symptoms.

PURPOSE: To assess the correlation between post-void residual urine ratio (PVR-R) and pathological bladder emptying diagnosed by pressure-flow studies (PFS) in males with lower urinary tract symptoms (LUTS). MATERIALS AND METHODS: PVR-R and PVR urine were evaluated in 410 males underwent PFS for LUTS. PVR-R was the percentage of PVR to bladder volume (voided volume+PVR). Schafer and International Continence Society (ICS) nomograms, Bladder Contractility Index (BCI) were used to diagnose bladder outlet obstruction (BOO) and detrusor underactivity (DUA). We subdivided the cohort in 4 groups: Group I, BOO+/DUA+; Group II, BOO-/DUA+; Group III, BOO+/DUA-; Group IV, BOO-/DUA- (control group). We subdivided the 4 groups according to PVR-R strata: (1) 0%-20%; (2) 21%-40%; (3) 41%-60%; (4) 61%-80%; (5) 81%-100%. RESULTS: Group I had a greater median PVR-R (50%) with a >40% in 61.4% of the cohort. Median PVR-R was 16.6% in Group II, 24% in Group III, and 0% in the control Group. According to ICS nomograms and BCI, median PVR-R and PVR were significantly higher (p<0.001) in obstructed and underactive males. PVR-R threshold of 20% allowed to recognize males with voiding disorders with high sensibility, specificity, PPV, and NPV. A PVR-R cut-off of 40% identified males with associated BOO and DUA and more severe voiding dysfunction. CONCLUSIONS: A higher PVR-R is related to a more severe pathological bladder emptying, and to the association of BOO and DUA. PVR-R may have a clinical role in first assessment of males with LUTS and severe voiding dysfunction.

In vivo assessment of changes to canine airway smooth muscle following bronchial thermoplasty with OR-OCT.

The inability to assess and measure changes to the airway smooth muscle (ASM) in vivo is a major challenge to evaluating asthma and its clinical outcomes. Bronchial thermoplasty (BT) is a therapy for asthma that aims to reduce the severity of excessive bronchoconstriction by ablating ASM. Although multiple long-term clinical studies of BT have produced encouraging results, the outcomes of BT treatment in practice have been variable, and questions remain regarding the selection of patients. Previously, we have demonstrated an imaging platform called orientation-resolved optical coherence tomography that can assess ASM endoscopically using an imaging catheter compatible with bronchoscopy. In this work, we present results obtained from a longitudinal BT study performed using a canine model (n = 8) and with the goal of investigating the use of orientation-resolved optical coherence tomography (OR-OCT) for measuring the effects of BT on ASM. We demonstrate that we are capable of accurately assessing ASM both before and in the weeks following the BT procedure using blinded matching to histological samples stained with Masson's trichrome (P < 0.0001, r2 = 0.79). Analysis of volumetric ASM distributions revealed significant decreases in ASM in treated airways (average cross-sectional ASM area: 0.245 ± 0.145 mm2 pre-BT and 0.166 ± 0.112 mm2 6 wk following BT). These results demonstrate that OR-OCT can provide clinicians with the feedback necessary to better evaluate ASM and its response to BT, and may potentially play an important role in phenotyping asthma and predicting which patients are most likely to respond to BT treatment.NEW & NOTEWORTHY The inability to assess ASM in vivo is a significant hurdle in advancing our understanding of airway diseases such as asthma, as well as evaluating potential treatments and therapies. In this study, we demonstrate that endoscopic OR-OCT can be used to accurately measure changes to ASM structure following BT. Our results demonstrate how this technology could occupy an important role in asthma treatments targeting ASM.

Are there age-related changes in the measurements of the urethral sphincter complex in nulliparous women? A three-dimensional ultrasound assessment.

INTRODUCTION AND HYPOTHESIS: The objective was to determine age-related changes in measurements of urethral sphincter complex components in asymptomatic nulliparous women. METHODS: Eighty nulliparous women ≥18 years underwent 3D ultrasound of the anterior pelvic compartment in a cross-sectional study. Measurements of the urethral sphincter components (smooth muscle sphincter [SMS] and striated urinary sphincter [SUS]) and urethra including area, length, width, and distance of the SUS and SMS from the urethrovesical junction were obtained. The women were grouped into four age groups: < 30 years (group A), 30 to < 45 (group B), 45 to < 60 (group C), and ≥ 60 years (group D). Age-related differences in the measurements were determined. Inter-rater and intra-rater agreement were performed for 20 nulliparous women. RESULTS: There were 24, 18, 26, and 12 women in groups A, B, C, and D respectively. None of the urethral sphincter complex measurements was significantly associated with age (p > 0.05). No differences were found between the groups for any measurements using one-way ANOVA and multiple comparison pairwise comparison (p > 0.05) other than width of SMS (C > A), urethral length (C > A), and distance of SUS from urethrovesical junction (C > D). Inter-rater and intra-rater agreement were moderate for area, length, and width of SUS (intraclass correlation 0.6) and good (intraclass correlation above 0.8) for the remaining measurements. CONCLUSION: Other than width of SMS, urethral length, and distance of SUS from urethrovesical junction, the dimensions of urethral sphincter complex components, as visualized by 3D endovaginal ultrasound, do not vary with age.

Assessment of Polygonum odoratum Lour. Leaf Extract on Rat's Ileum Contraction and the Mechanisms Involved.

Vietnamese coriander (Polygonum odoratum Lour.) is a plant native to northern Thailand. The biological activities of P. odoratum Lour. extract (POE) include antibacterial, antiviral, and expectorant. However, the effect of POE on intestinal smooth muscle motility is unclear. The aim of this study was to evaluate the relaxant effects of POE on isolated rat ileum. Propranolol (1 µM), calcium chloride (1-20 mM), and Nω-nitro-l-arginine methylester (l-NAME, 100 µM) were used to investigate the mechanisms of action. The results showed that POE (0.01-5 mg/mL) reduced KCl-induced contraction. In addition, POE (1 mg/mL) reduced the contraction by propranolol and l-NAME and attenuated CaCl2-induced contractions. Our results indicate that the relaxation effect of POE on ileum contractions seems to involve nitric oxide and ß-adrenergic pathways, and blockade of calcium influx. These findings provide a pharmacological basis for the traditional use of POE to treat gastrointestinal disorders such as irritable bowel syndrome or diarrhea.

Risk assessment of neuromuscular stimulation by energy-based transurethral resection devices: an ex vivo test standard.

BACKGROUND: During transurethral resection of bladder tumours (TURB), radio-frequency (RF) currents can lead to adverse neuromuscular stimulation (NMS). Here we present a novel ex vivo method to determine the risk of RF generators and their bipolar TURB modes to cause NMS. We aimed to develop an experimental platform for safety evaluation of new RF generators and their modes with a newly established test standard, suitable for replacement or reduction of animal testing. METHODS: We tested four contemporary RF generators with their bipolar modes for TURB in saline. A two-stage ex vivo approach was pursued: First, we recorded voltages at possible positions of the obturator nerve behind a porcine bladder wall in a TURB model using 18 RF applications per generator. Second, these voltage records were used as stimuli to evoke nerve compound action potentials (CAPs) in isolated porcine axillary nerves. The NMS potential was defined as the ratio between the observed area under the CAPs and the theoretical CAP area at maximum response and a firing rate of 250 Hz, which would reliably induce tetanic muscle responses in most human subjects. The measurement protocol was tailored to optimise reproducibility of the obtained NMS potentials and longevity of the nerve specimens. RESULTS: As prerequisite for the clinical translation of our results, the robustness of our test method and reproducibility of the NMS potential are demonstrated with an excellent correlation (r = 0.93) between two sets of identical stimuli (n = 72 each) obtained from 16 nerve segments with similar diameters (4.2 ± 0.37 mm) in the nerve model. The RF generators differed significantly (p < 0.0001) regarding NMS potential (medians: 0-3%). CONCLUSIONS: Our test method is suitable for quantifying the NMS potential of different electrosurgical systems ex vivo with high selectivity at a reasonable degree of standardization and with justifiable effort. Our results suggest that the clinical incidence of NMS is considerably influenced by the type of RF generator. Future generations of RF generators take advantage from the proposed test standard through higher safety and less animal testing. Health professionals and treated patients will benefit most from improved RF surgery using generators with a low NMS risk.

Increasing use of positron emission tomography among medicare beneficiaries undergoing radical cystectomy.

OBJECTIVE: To examine factors associated with PET scan use in the pre-operative evaluation of patients diagnosed with bladder cancer. METHODS: Using SEER-Medicare data, we identified bladder cancer patients who underwent radical cystectomy from 2006 to 2011 (n = 4,138). The primary outcome was PET scan use within 6 months before surgery. To examine predictors of PET scan use, we fit a mixed logit model with health service area as a random effect to account for patients nested within health service areas. We also calculated the adjusted probability of use over time and examined variation among the highest volume surgeons. RESULTS: Among the 4,138 patients, 406 (10%) received a pre-operative PET scan. The adjusted probability of a patient undergoing a PET scan increased from 0.04 in 2004 to 0.10 in 2011 (p < .001). Among the 78 highest volume surgeons, there was significant variation in PET scan use (p < .001). Patients with non-urothelial histology, measurement of alkaline phosphatase levels, and receipt of neoadjuvant chemotherapy were more likely to receive PET scan (all p < .05). CONCLUSION: Use of PET prior to radical cystectomy doubled over a 5-year period, suggesting its increased use in patients with muscle-invasive bladder cancer, particularly those with high-risk disease. Whether its use is warranted and improves patient outcomes is not clear and requires further studies.

Assessment of Inhibitory Effects of Hypnotics on Acetylcholine-Induced Contractions in Isolated Rat Urinary Bladder Smooth Muscle.

The present study aimed to investigate the potential inhibitory effects of 21 clinically available hypnotics on acetylcholine (ACh)-induced contractions in rat urinary bladder smooth muscle (UBSM) in order to predict whether these hypnotics could induce voiding impairment. ACh-induced contraction in rat UBSM was inhibited only by diphenhydramine (a histamine H1 receptor antagonist) at a concentration that was clinically relevant. ACh-induced contraction was also significantly inhibited by flurazepam (a benzodiazepine hypnotic) and suvorexant (an orexin receptor antagonist), albeit at concentrations that substantially exceeded clinically achievable blood levels. These three drugs (at 10-5 M) also inhibited high-KCl (80 mM) Locke-Ringer solution-induced contractions. In contrast to the effects of the abovementioned hypnotics, ACh-induced contractions were not significantly affected by triazolam, etizolam, brotizolam, lormetazepam, estazolam, flunitrazepam, nitrazepam (benzodiazepine hypnotics), thiopental, thiamylal, pentobarbital, amobarbital, secobarbital, phenobarbital (barbiturate hypnotics), zolpidem (an imidazopyridine hypnotic), zopiclone (a cyclopyrrolone hypnotic), ramelteon (a melatonin receptor agonist), bromovalerylurea, and chloral hydrate. These findings suggest that most clinically used hypnotics are not likely to result in anticholinergic-induced dysuria within their clinically achievable blood concentration ranges. Diphenhydramine may, however, induce voiding impairment, an action attributable to diminished UBSM contractility within its clinical dose range.

Anorectal manometry assessment of sphincter relaxation after local-regional anesthesia with posterior perineal block.

INTRODUCTION: Since the 1970s, in the USA, we witnessed a progressive increase of one-day surgical procedures. This attitude soon gained ground in Europe as well. In proctology, this kind of clinical approach has always been limited by the acute sensitivity of the anal- perineal area and by difficulties in attaining a complete sphincter relaxation with local anesthesia. Posterior perineal block seems to be associated with both a good pain control and an effective sphincter relaxation. MATERIAL AND METHODS: Between January 2017 and January 2018, we enrolled in our study 33 patients suffering from hemorrhoidal disease. They were all subjected to posterior perineal block. We measured anal resting pressure and squeeze pressure before and after anesthesia. Measurements where taken 5 minutes before and 15 minutes after the administration of local. RESULTS: We registered an average decrease of 39,2% of resting pressure and of 45,4% of squeeze pressure. CONCLUSIONS: We may state that perineal posterior block, while reducing striated muscle contractile activity, also causes a relevant reduction of anal basal tone. During surgical procedures done under regional anesthesia, we experienced a good sphincter relaxation, which was comparable, if not equal, to that induced by general anesthesia. In fact, 10 to 15 minutes after performing the block you could observe the elevation of the inferior margin of the exterior sphincter and the concomitant descent of the inferior margin of the internal sphincter (coaxial dislocation). KEY WORDS: Anorectal manometry, Anesthesia, Local-regional, Perineal block.

Recent advances in intestinal smooth muscle research: from muscle strips and single cells, via ICC networks to whole organ physiology and assessment of human gut motor dysfunction.

Gastrointestinal smooth muscle research has evolved from studies on muscle strips to spatiotemporal mapping of whole organ motor and electrical activities. Decades of research on single muscle cells and small sections of isolated musculature from animal models has given us the groundwork for interpretation of human in vivo studies. Human gut motility studies have dramatically improved by high-resolution manometry and high-resolution electrophysiology. The details that emerge from spatiotemporal mapping of high-resolution data are now of such quality that hypotheses can be generated as to the physiology (in healthy subjects) and pathophysiology (in patients) of gastrointestinal (dys) motility. Such interpretation demands understanding of the musculature as a super-network of excitable cells (neurons, smooth muscle cells, other accessory cells) and oscillatory cells (the pacemaker interstitial cells of Cajal), for which mathematical modeling becomes essential. The developing deeper understanding of gastrointestinal motility will bring us soon to a level of precision in diagnosis of dysfunction that is far beyond what is currently available.

Cost-effectiveness of surveillance schedules in older adults with non-muscle-invasive bladder cancer.

OBJECTIVE: To estimate the cost-effectiveness of surveillance schedules for non-muscle-invasive bladder cancer (NMIBC) amongst older adults. PATIENTS AND METHODS: We developed a MIcrosimulation SCreening ANalysis (MISCAN) microsimulation model to compare the cost-effectiveness of various surveillance schedules (every 3 months to every 24 months, for 2, 5 or 10 years or lifetime) for older adults (aged 65-85 years) with NMIBC. For each surveillance schedule we calculated total costs per patient and the number of quality adjusted life-years (QALYs) gained. Incremental cost-effectiveness ratios (ICERs), as incremental costs per QALY gained, were calculated using a 3% discount. RESULTS: As age increased, the number of QALYs gained per patient decreased substantially. Surveillance of patients aged 65 years resulted in 2-7 QALYs gained, whereas surveillance at age 85 years led to <1 QALY gained. The total costs of the surveillance schedules also decreased as age increased. The ICER of 6-monthly surveillance at age 65 years for lifetime was $4999 (American dollars)/QALY gained. Amongst patients aged >75 years, the incremental yield of QALY gains for any increase in surveillance frequency and/or duration was quite modest (<2 QALYs gained). CONCLUSION: With increasing age, surveillance for recurrences leads to substantially fewer QALYs gained. These data support age-specific surveillance recommendations for patients treated for NMIBC.

Health-related quality of life after BCG or MMC induction for non-muscle invasive bladder cancer.

INTRODUCTION: To evaluate health-related quality of life (HRQoL) in patients with non-muscle invasive bladder cancer (NMIBC) during the induction phase of intravesical instillations with BCG or MMC. MATERIALS AND METHODS: HRQoL was measured by two questionnaires from EORTC (QLQ-C30 and QLQ-BLS24), stratifying results by gender, age and therapy at the start of the therapy (T0), at last instillation (T1) and at 3 months after T1 (T2). The persistence of QoL-related side effects after 3 months from the end of the induction cycle was evaluated. RESULTS: We enrolled 108 naïve patients and 103 patients self-completed the questionnaires. Treatment was well tolerated in both groups. Side effects were reported by 46.6% of patients at T1 and 47.5% of patients at T2. QoL dropped at T1, returning to the baseline at T2. Drop of QoL was greater in the physical, role, emotional and social functioning domains and in some clinical domains as pain, fatigue and insomnia. Our stratified analysis showed that patients > 70 years have a worsening of QoL, a higher incidence of patient-reported side effects or symptoms in the BCG arm as compared to MMC arm. CONCLUSIONS: Our study shows that intravesical instillations of BCG or MMC during the induction phase might have a relevant effect on HRQoL.

Performance Measurement and Quality Improvement Initiatives for Bladder Cancer Care.

PURPOSE OF REVIEW: Bladder cancer care is costly due to long surveillance periods for non-muscle-invasive bladder cancer (NMIBC) and comorbidities associated with the surgical treatment of muscle-invasive bladder cancer (MIBC). We reviewed current evidence-based practices and propose quality metrics for NMIBC and MIBC. RECENT FINDINGS: For patients with NMIBC, we propose four categories of candidate quality metrics: (1) appropriate use of imaging, (2) re-staging transurethral resection of bladder tumor, (3) perioperative intravesical chemotherapy, and (4) induction and maintenance BCG in high-risk NMIBC. For patients with MIBC, we propose eight candidate quality measures: (1) neoadjuvant chemotherapy, (2) multidisciplinary consultation, (3) urinary diversion teaching, (4) appropriate perioperative antibiotics, (5) venous thromboembolic prophylaxis, (6) lymphadenectomy, (7) monitoring of complications, and (8) inclusion of enhanced recovery after surgery protocols. Marked variation in evidence-based practice exists among patients with bladder cancer and represents opportunity for quality improvement. Regional and national physician-led collaboratives may be the best vehicle to achieve quality improvement in bladder cancer.

Assessment of the Airway Smooth Muscle Relaxant Effect of Drotaverine.

BACKGROUND: Drotaverine, a type 4 cyclic nucleotide phosphodiesterase (PDE4) inhibitor, blocks the degradation of 3',5'-cyclic adenosine monophosphate. However, published receptor binding data showed that drotaverin also binds to the L-type voltage-operated calcium channel (L-VOCC). Based on these molecular mechanisms of action, a direct and indirect (by blocking the constrictor response) relaxant effect on airway smooth muscle can be predicted, which has not yet been assessed. SUMMARY: Accordingly, drotaverine and reference agents were tested both on the histamine-, methacholine-, or KCl-induced contraction response and on precontracted guinea pig tracheal preparations. It was found that drotaverine not only relaxed the precontracted tracheal preparations but also decreased mediator-induced contraction. These effects of drotaverine were concentration dependent, with a significantly higher potency on the KCl-induced response, than on either the histamine or methacholine induced one. A similar result was noted for nifedipine. The PDE inhibitor, theophylline, also relaxed the precontracted preparations but was ineffective on the mediator-induced contraction in a physiologically relevant concentration range. Moreover, theophylline did not show selectivity and was the least potent relaxant among the 3 tested molecules. Key Message: These results show that drotaverine is a more potent airway smooth muscle relaxant molecule than theophylline. This enhanced potency on relaxation and inhibition of the constrictor response, at least partly, may be explained by the combined L-VOCC blocking and PDE inhibitory potential of drotaverine.

An impedance-based cell contraction assay using human primary smooth muscle cells and fibroblasts.

INTRODUCTION: Many cell types (including muscle cells and fibroblasts) can contract at physiological conditions and their contractility may change during tissue injury and repair or other diseases such as allergy and asthma. The conventional gel contraction assay is commonly used to monitor the cellular contractility. It is a manual assay and the experiment usually takes hours even days to complete. As its readout is not always accurate and reliable, the gel contraction assay is often used to qualitatively (but not quantitatively) characterize cellular contractility under various conditions. METHOD: To overcome the limits of the gel contraction assay, we developed an impedance-based contraction assay using the xCELLigence RTCA MP system. This technology utilizes special 96-well E-plates with gold microelectrode arrays printed in individual wells to monitor cellular adhesion by recording the electrical impedance in real time. The impedance change (percentage vs. control) can be used as the readout for cellular contraction. RESULTS: We demonstrated that the impedance-based contraction assay can be performed within 2h. Using this new method, we quantitatively characterized the effects of several contractile stimulators and inhibitors on human primary bronchial smooth muscle cells and primary lung fibroblasts. DISCUSSION: The impedance-based contraction assay can be applied to both basic research and drug discovery for characterizing cellular contraction quantitatively. Because it has high throughput capacity and high reproducibility, the impedance-based contraction assay is useful for high throughput functional screening in drug industry.

Bioaccumulation of Heavy Metals in Various Tissues of Some Fish Species and Green Tiger Shrimp (Penaeus semisulcatus) from Iskenderun Bay, Turkey, and Risk Assessment for Human Health.

In this study, concentrations of heavy metals were determined by ICP-MS in the edible tissues of common sole (Solea solea Linnaeus, 1758), whiting (Merlangius merlangus Linnaeus, 1758), silver sillago (Sillago sihama Forsskål, 1775) and muscle-exoskeleton of green tiger shrimp (Penaeus semisulcatus De Haan, 1844), from the seas of Iskenderun Bay, Eastern Mediterranean, Turkey, in January-February, 2016. The lowest and highest mean concentrations of Mn, Cr, Cd, Ni, Hg, As, Pb, and Co in fish and shrimp' muscles were found, respectively, as follows: 0.166-0.382, 0.134-0.336, 0.005-0.008, 0.091-0.140, 0.026-0.228, 1.741-29.254, 0.087-0.110, and <0.0005-0.027 mg kg-1; in the skin and exoskeleton, the values were found, respectively, as 0.103-15.819, 0.301-0.778, 0.007-0.026, 0.115-0.513, 0.021-0.243, 1.548-17.930, 0.148-0.295, and <0.0005-0.140 mg kg-1. According to the results, mean concentrations of all metals in the muscles of fish, except for arsenic and chromium, were found to be below certain legal limit values, especially arsenic levels in shrimp that were found to be above all the legal limit values. Also, the hazard quotients (HQ) of individual heavy metals in fish and shrimp, except for As, revealed safe levels for human consumption. However, the HQ values of estimated inorganic As exceeded 1 in the muscles of shrimp (P. semisulcatus), which may constitute a risk to public health.