Ultrasound as the first line investigation for midgut malrotation: a UK tertiary centre experience

AIM

To present the first 22-months experience of transitioning to an ultrasound-first pathway for suspected midgut malrotation.

MATERIALS AND METHODS

An "ultrasound-first" imaging pathway was initiated in October 2021. Twenty-two-months later, a search was undertaken of all <1-year-old patients with "bilious", "malrotation," or "volvulus" as the imaging indication. Reports and images from upper gastrointestinal fluoroscopy (UGI) and ultrasound were reviewed, and diagnoses and outcomes were documented.

RESULTS

The search yielded 101 eligible cases between October 2021 and July 2023. Of the patients, 63/101 (62%) had both ultrasound and UGI: 47/63 (75%) ultrasound first, 16/63 (25%) UGI first. Thirty-one per cent (31/101) had ultrasound only and 7/70 (10%) UGI only. The pathway diagnosed 7/8 (88%) infants with midgut malrotation with or without volvulus and one infant who had an inconclusive ultrasound examination with a suspected an internal hernia and who was found to have malrotation volvulus at surgery. Twenty-one infants who had confidently normal ultrasound examinations and who also had UGI all had a normal duodenojejunal flexure position. Ultrasound detected alternative pathology in eight children. Duodenal visualisation improved with time: 6/15 (40%) in the first 6 months to 23/34 (68%) after the first year.

CONCLUSION

The transition to ultrasound as the first diagnostic test for midgut malrotation can be done safely and effectively in a UK centre, which previously relied solely on UGI.

Thoracoscopic oesophageal atresia/tracheo-oesophageal fistula (OA/TOF) repair is associated with a higher stricture rate: a single institution’s experience

PURPOSE

Thoracoscopic OA/TOF repair was first described in 1999. Currently, less than 10% of surgeons routinely employ minimally access surgery. Our primary aim was to review our immediate-, early- and long-term outcomes with this technique compared with the open approach.

METHODS

A retrospective review of all patients undergoing primary OA/TOF (Type C) repair at our institution from 2009 was conducted. Outcome measures included length of surgery, conversion rate from thoracoscopy, early complications such as anastomotic leak and post-operative complications such as anastomotic strictures needing dilatations. Fisher's exact and Kruskal-Wallis tests were used for statistical analysis.

RESULTS

95 patients in total underwent OA/TOF repair during the study period of which 61 (64%) were completed via an open approach. 34 were attempted thoracoscopically of which 11 (33%) were converted. There was only one clinically significant anastomotic leak in our series that took place in the thoracoscopic group. We identified a significantly higher stricture rate in our thoracoscopic cohort (72%) versus open surgery (43%, P < 0.05). However, the median number of dilations (3) performed was not significantly different between the groups. There was one recurrent fistula in the thoracoscopic converted to open group. Our median follow-up was 60 months across the groups.

CONCLUSION

In our experience, the clinically significant leak rate for both open and thoracoscopic repair as well as recurrent fistula is much lower than has been reported in the literature. We do not routinely perform contrast studies and are, thus, reporting clinically significant leaks only. The use of post-operative neck flexion, ventilation and paralysis is likely to be protective towards a leak. Thoracoscopic OA/TOF repair is associated with a higher stricture rate compared with open surgery; however, these strictures respond to a similar number of dilatations and are no more refractory. Larger, multicentre studies may be useful to investigate these finding further.

THU0097 PREDICTIVE VALUE OF IMMUNOLOGICAL AND IMAGING BIOMARKERS ON ACHIEVING GOOD CLINICAL RESPONSE AT 6 MONTHS IN RHEUMATOID ARTHRITIS PATIENTS TREATED BY INTRAVENOUS BDMARDS

Background:

RA is the most prevalent chronic inflammatory rheumatism, responsible of functional impairment.

Objectives:

To investigate the value of biological and imaging biomarkers on predicting good clinical response at 6 months, in RA patients initiating IV bDMARD.

Methods:

From 2008 to 2017, 317 RA patients fulfilling ACR 1987 and/or ACR-EULAR 2010 criteria for RA, initiated IV bDMARDs in our department of Rheumatology. Patients were excluded in cases of lack of information on disease activity assessment before and at 6 months of treatment and on immunological status and titers (ACPA, RF, ANA) at baseline. For patients receiving successive IV bDMARDs during this time period (n=30), a randomization permitted to select 1 treatment sequence for the analysis. On 173 patients eligible to the study, 4 were loss to follow-up and 14 stopped treatment due to adverse events before 6 months. Clinical, biological and imaging (US and RX) data were collected when available at baseline. US examination was performed on 12 joints (wrist, MCP2-3-5 and MTP2-3-5) with qualitative and quantitative evaluation on B mode and Power Doppler (PD) for synovitis, tenosynovitis and erosion. The modified Sharp/van der Heijde erosion score was performed by 2 independent readers blindly from clinical and US informations. Good clinical response was defined by a DAS 28 < 3.2 and/ or DAS 28 decrease > 1.2 at 6 months. Only variables with a p<0.2 in univariate analysis were included in the multivariate model.

Results:

On 155 RA patients, 11 present a disease duration < 2 year, 44 (28.3%) were on first line of IV bDMARDs and 111 patients received at least one IV bDMARD (mean 2.5 (1.3)).

Table 1.

Characteristics of the patients (n=155) at baseline

VariablesN (%)Mean (SD)Clinical characteristicsAge (years)54.8 (12.2)Female113 (72.9)Disease duration (months)166.9 (118.8)DAS 285.2 (1)TreatmentCorticosteroids / dose (mg/day)99 (85.3)10.9 (6)Monotherapy56 (36.1)IV bDMARDAbatacept27 (17.4)Infliximab11 (7.1)Rituximab84 (54.2)Tocilizumab33 (21.3)ImmunologyACPA + /titer(IU)132 (85.2)618.5 (791.0)RF + /titer (IU/ml)114 (74.5)184.7 (351.3)ANA + / level87 (56.1)1453 (3836)RadiographySharp’s erosion score (n=110)49.4 (46.2)USNb Erosion (n=95)3.0 (2.3)Nb B mode Synovitis (n=128)6.0 (4.1)Nb PD+ Synovitis (n=130)4.8 (3.8)Nb B mode Tenosynovitis (n=129)1.6 (2)Nb PD+ Tenosynovitis (n=129)1.3 (2.1)

At 6 months, 87 patients (56.1%) were in good clinical response. Predictive values of biomarkers are presented in table 2.

Table 2.

Variables predictive of a good clinical response at 6 months

BiomarkersResponseMultivariate Logistic regression AnalysisAllN = 101Response(N=60)OR (CI95%)P valueImmunology RF +7551 (68.0%)5.1 (1.8-14.4)0.002 ACPA +8756 (64.4%) ANA +5536 (65.5%)Radiography Erosive RA7448 (64.9%)Ultrasonography Erosive RA8855 (62.5%) Nb B mode synovitis10160 (59.4%)1.2 (1.1-1.4)0.002 Nb PD+ synovitis10160 (59.4%)

All qualitative variables with a p value <0.2 on bivariate analysis were incorporated in the multivariate model (RF +, ACPA +, US erosive RA, Nb B mode synovitis, Nb PD+ synovitis, RX erosive RA). Only patients with all data available are incorporated in the multivariate logistic regression analysis (n=101/155)

Conclusion:

We showed that positive RF was predictive of good clinical response to IV bDMARDs. For the first time, we demonstrated that number of US B-mode synovitis was also predictive to good clinical response.

Disclosure of Interests:

Stephane Giuliani Grant/research support from: BMS, Benjamin Laurent Grant/research support from: BMS, Hella MEZGHANI Employee of: BMS, Isabelle Duprat-Lomon Employee of: BMS, Amandine Luc Grant/research support from: BMS, Marcelo De carvalho Bittencourt Grant/research support from: BMS, Cedric BAUMANN Grant/research support from: BMS, Isabelle CHARY VALCKENAERE: None declared, Damien LOEUILLE: None declared

SAT0042 PREDICTIVE VALUE OF IMMUNOLOGICAL AND IMAGING BIOMARKERS ON ACHIEVING REMISSION AT 6 MONTHS IN RHEUMATOID ARTHRITIS PATIENTS TREATED BY INTRAVENOUS BDMARDS

Background:

RA is the most prevalent chronic inflammatory rheumatism, responsible of functional impairment.

Objectives:

To investigate the value of biological and imaging biomarkers on predicting DAS 28 remission at 6 months, in RA patients initiating IV bDMARD.

Methods:

From 2008 to 2017, 317 RA patients fulfilling ACR 1987 and/or ACR-EULAR 2010 criteria for RA, initiated IV bDMARDs in our department of Rheumatology. Patients were excluded in cases of lack of information on disease activity assessment before and at 6 months of treatment and on immunological status and titers (ACPA, RF, ANA) at baseline. For patients receiving successive IV bDMARDs during this time period (n=30), a randomization permitted to select 1 treatment sequence. On 173 patients eligible to the study, 4 were lost to follow-up and 14 stopped treatment due to adverse events before 6 months. Clinical, biological and imaging (US and RX) data, were collected when available at treatment initiation. US examination was performed on 12 targeted joints (wrist, MCP2-3-5 and MTP2-3-5) with qualitative and quantitative evaluation on B mode and Power Doppler (PD) for synovitis, tenosynovitis and erosion. The modified Sharp/van der Heijde erosion score was performed by 2 independent readers blindly from clinical and US informations. Remission was defined by a DAS 28 < 2.6 at 6 months. Only variables with a p<0.2 in univariate analysis were included in the multivariate model.

Table 1.

Characteristics of the patients (n=155) at baseline

Table 2.

Variables predictive of a DAS 28 remission at 6 months for IV bDMARDs

BiomarkersUnivariateAnalysisBivariate Logistic regression AnalysisDAS 28 remission(n= 33)No Remission(n=122)p valueOR (CI95%)Clinical dataNb of sequence >119 (57.6%)92 (75.4%)0.0520.4 (0.2-1.0)Radiography (n=110)Erosive RA22 (88.0%)61 (71.8%)0.1180.3 (0.1-1.3)US (n=127)Erosive RA28 (96.6%)82 (83.7%)0.1170.2 (0.0-1.4)Nb B mode synovitis7.7 (4.5)5.5 (3.9)0.0130.9 (0.8-1.0)Nb PD+ synovitis6.5 (5.0)4.3 (3.3)0.0310.9 (0.8-1.0)

All qualitative variables with a p value <0.2 on bivariate analysis were incorporated in the multivariate model (RF +, ACPA +, US erosive RA, Nb B mode synovitis, Nb PD+ synovitis, RX erosive RA). Only patients with all data available were incorporated in the multivariate logistic regression analysis (n=103/155). In multivariate analysis only the number of B mode synovitis was still significant with OR =1.1 (CI 95%: 1.0-1.3) (p<0,019).

Results:

On 155 RA patients, 11 had a disease duration < 2 year, 44 (28.3%) were on first line of IV bDMARDs and 111 patients received at least one IV bDMARD (mean 2.5 (1.3)).

Conclusion:

In RA patients treated by IV bDMARDs, number of PD+ synovitis on ultrasonography was the only predictive biomarker of DAS 28 remission.

Disclosure of Interests:

Benjamin Laurent Grant/research support from: BMS, Stephane Giuliani Grant/research support from: BMS, Hella MEZGHANI Employee of: BMS, Isabelle Duprat-Lomon Employee of: BMS, Amandine Luc Grant/research support from: BMS, Marcelo De carvalho Bittencourt Grant/research support from: BMS, Cedric BAUMANN Grant/research support from: BMS, Isabelle CHARY VALCKENAERE: None declared, Damien LOEUILLE: None declared

One-year outcomes for congenital diaphragmatic hernia

Background

Congenital diaphragmatic hernia (CDH) is a congenital anomaly with high mortality and long‐term morbidity. The aim of this study was to benchmark trends in 1‐year and hospital volume outcomes for this condition.

Methods

This study included all infants born with CDH in England between 2003 and 2016. This was a retrospective analysis of the Hospital Episode Statistics database. The main outcomes were: 1‐year mortality, neonatal length of hospital stay (nLOS), total bed‐days at 1 year and readmission rate. The association between hospital volume and outcomes was assessed for specialist paediatric surgery centres.

Results

A total of 2336 infants were included (incidence 2·5 per 10 000 live births). No significant time trends were found in incidence and main outcomes. Some 1491 infants (63·8 per cent) underwent surgical repair. The 1‐year mortality rate was 31·2 per cent. Median nLOS and total bed‐days were 17 and 19 days respectively. The readmission rate in specialist paediatric centres was 6·3 per cent. Higher mortality was associated with birthweight lower than 1 kg (OR 5·90, 95 per cent c.i. 1·03 to 33·75), gestational age of 36 weeks or less (OR 1·75, 1·12 to 2·75) and black ethnicity (OR 2·13, 1·03 to 4·48). Only 4·0 per cent had extracorporeal membrane oxygenation, which was associated with higher mortality (OR 5·34, 3·01 to 9·46), longer nLOS (OR 3·70, 2·14 to 6·14) and longer total bed‐days (OR 3·87, 2·19 to 6·83). Specialist paediatric centres showed variation in 30‐day mortality (4·6 per cent with 84 per cent coefficient of variation), nLOS (median 25 (i.q.r. 15–42) days) and total bed‐days (median 28 (i.q.r. 16–51) days), but no significant volume–outcome relationship.

Conclusion

Key outcomes for CDH were similar to those of other developed countries. High variation among specialist paediatric centres was found and should be investigated further to explore the value of regionalization of care.

The impact of the 1999 Mw 7.4 event in the İzmit Bay (Turkey) on anthropogenic contaminant (PCBs, PAHs and PBDEs) concentrations recorded in a deep sediment core

The 1999 Mw 7.4 earthquake triggered a tremendous human tragedy and had a great social impact over the population of the İzmit Bay, one of the most industrialized area of Turkey. Although the successive environmental disasters were well documented, information on its sedimentary record is lacking. The present research aims at filling this gap, through the analysis of organic contaminants (PCBs, PAHs, and PBDEs) in a dated sediment core collected in the depocenter of the Karamürsel Basin in 2005. Profiles of total PCBs and total PAHs overlap the timing of industrialization in the area (starting in the 1960s) with values increasing as the population and the number of industrial plants grew larger. Profiles for PBDEs are in accordance with increasing urban inputs but are probably affected by processes of natural formation and post-depositional mixing. The continuous sedimentary record is interrupted at a level dating back to 1980 due to the erosion caused by the 1999 earthquake, having removed a 5-7cm thick sediment layer. Contaminant concentrations in the deepest 10-15cm of a 30cm thick seismo-turbidite unit, triggered by the 1999 event, increase with the progressive fining up and evidence massive transport of sediments from coastal, more polluted sites of the north-eastern Karamürsel shelves and shores. Additional inputs of PAHs are also evident, originating from a fire at the oil refinery that followed the shaking. The effects of the earthquake generated tsunami, its backwash fluxes and the following seiches are not uniquely displayed by each class of contaminants, and they could probably reflect successive inputs deriving from different parts of the basin that are subject to anthropogenic impacts of different nature. Concentrations measured at the top of the core are consistent with an unvaried input of pollutants in the period 1980-2005.

Thirty-days readmissions in pediatric surgery: The first U.K. experience

INTRODUCTION

The aim of this study was to investigate readmissions within 30days of operation (ReAd) in the setting of a tertiary pediatric surgical practice in the UK.

METHODS

Using Hospital Episode Statistics, cases that were readmitted within 30days of primary operation were identified retrospectively. Demographics including age, gender, preexisting comorbidities, diagnosis on primary admission and the treatment, length of stay, and diagnosis on readmission with treatment, including further surgical intervention, were collected from discharge summaries and hospital notes. Neonates were excluded from this study. Comorbidities, involving one or more systems, were also identified for each case of readmission. ReAds were classified into emergency and elective cohort depending on the nature of the primary operation. Outcomes were compared between these two groups. Data were quoted as median (range) unless indicated otherwise. Data were analyzed using SPSS software Desktop 22.0, using Mann-Whitney U and Chi-Squared tests, with a consideration that a P≤0.05 was significant.

RESULTS

A total of 2378 procedures were performed during the study period. Elective cases, including day cases, accounted for 77% (n=1837) of all cases. The remaining 23% (n=541) were emergency cases. Total unplanned readmission rate within 30days (ReAd) was 2%. Further surgical procedures were required in 38%. Having excluded neonates, the most common primary procedure leading to readmission within 30days was appendicectomy (26%). Overall, the most common cause for readmission within 30days was postoperative infection (30%). The ReAd in emergency cohort was 3.5% in comparison to 1.5% in elective, which was significantly different (P value=0.007).

CONCLUSION

Readmission within thirty days of primary procedure in pediatric surgery has little published data. An efficient discharge planning may play a vital role in preventing unwanted readmission. Elective operations had a significantly lower readmission rate than emergency operations. Having excluded neonates, appendicectomy was found to be the most common operation associated with readmission in the pediatric surgical practice. Although widely used as quality care indicator in adults, more studies are required to validate readmission rate as a quality of care indicator in pediatric surgery practice.

Length of stay and cost analysis of neonates undergoing surgery at a tertiary neonatal unit in England

Introduction There is a lack of knowledge on the average length of stay (LOS) in neonatal units after surgical repair of common congenital anomalies. There are few if any publications reporting the activity performed by units undertaking neonatal surgery. Such activity is important for contracting arrangements, commissioning specialist services and counselling parents. The aim of this study was to describe postnatal LOS for infants admitted to a single tertiary referral neonatal unit with congenital malformations requiring surgery. Methods Data on nine conditions were collected prospectively for babies on the neonatal unit over a five-year period (2006-2011). For those transferred back to their local unit following surgery, the local unit was contacted to determine the total LOS. Only those babies who had surgery during their first admission to our unit and who survived to discharge were included in the study. Cost estimates were based on the tariffs agreed for neonatal care between our trust and the London specialised commissioning group in 2011-2012. Results The median LOS for the conditions studied was: gastroschisis 35 days (range: 19-154 days), oesophageal atresia 33 days (range: 9-133 days), congenital diaphragmatic hernia 28 days (range: 7-99 days), intestinal atresia 24 days (range: 6-168 days), Hirschsprung's disease 21 days (range: 15-36 days), sacrococcygeal teratoma 17 days (range: 12-55 days), myelomeningocoele 15.5 days (range: 8-24 days), anorectal malformation 15 days (range: 6-90 days) and exomphalos 12 days (range: 3-228 days). The total neonatal bed day costs for the median LOS ranged from £8,701 (myelomeningocoele) to £23,874 (gastroschisis). The cost of surgery was not included. Conclusions There is wide variation in LOS for the same conditions in a single neonatal unit. This can be explained by different types and severity within the same congenital anomalies, different surgeons and other clinical confounders (eg sepsis, surgical complications, associated anomalies). These data will enable us to give more detailed information to families following prenatal or postnatal diagnosis. They also allow more detailed planning of resource allocation for neonatal admissions.

Exploring the possibility to detect recent temporal changes in highly disturbed sedimentary records through sampling repetitions and core comparisons of porosity and sand content

Dating of sediment cores in dynamic environments (such as tropical coastal lagoons) is often impossible to achieve, due to the difficulty to recover continuous and undisturbed records. Detailed temporal definition of environmental changes cannot be assured, but there is the possibility that information retained in such sediments can still provide useful insights on local or large-scale sedimentary dynamics, when a specific strategy is adopted. This latter consists in repeated core samplings at the same location and in the comparison of core profiles for basic and easily measurable parameters (porosity and sand content). This approach was tested on sediment cores, collected repeatedly during the period 2005-2010, at the same site of the Thi Nai Lagoon (central Vietnam). The proposed procedure was able to evidence the impact on lagoon sediments of activities linked to the construction of industrial settlements in the area, with dredging removing a consistent sediment layer from 2005 to 2008 and waste dumping providing additional sediment input in the following period. Simple statistic confirmed this scenario, together with core profiles of PCBs, As, Cd, Pb, and Zn. The procedure represents a simple tool to study coastal dynamics in places where the level of accuracy of traditional sediment radiodating cannot be reached. Several ameliorations are suggested in order to help developing the monitoring of sedimentary processes in poorly studied areas.

Accuracy of prenatal ultrasound in detecting jejunal and ileal atresia: systematic review and meta-analysis

OBJECTIVE

The accuracy of prenatal ultrasound examination in detecting jejunal and ileal atresia has been reported in the literature to be highly variable, at 25-90%. The aim of this systematic review was to evaluate the accuracy of prenatal ultrasound in detecting non-duodenal small bowel atresia (ND-SBA).

METHODS

MEDLINE, EMBASE and The Cochrane Library, including The Cochrane Database of Systematic Reviews (CDSR), Database of Abstracts of Reviews of Effects (DARE) and The Cochrane Central Register of Controlled Trials (CENTRAL), were searched electronically. The overall detection rate of jejunal or ileal atresia using ultrasound was reported. The accuracy of using polyhydramnios and dilated loops of bowel as diagnostic signs was also explored.

RESULTS

Sixteen studies involving 640 fetuses were included in this review. The detection rate of ND-SBA by prenatal ultrasound was highly variable, with values ranging from 10 to 100%, with an overall prediction of 50.6% (95% CI, 38.0-63.2%). When analyzed separately, the detection rates of jejunal and ileal atresia were 66.3%, (95% CI, 33.9-91.8%) and 25.9% (95% CI, 4.0-58.0%), respectively. Both dilated loops of bowel and polyhydramnios as diagnostic signs for ND-SBA provided a low overall detection rate.

CONCLUSIONS

The diagnostic performance of prenatal ultrasound in identifying ND-SBA is extremely variable. Large studies are needed in order to identify objective and combined criteria for the diagnosis of these anomalies.

Blockade of nociceptive sensory afferent activity of the rat knee joint by the bradykinin B2 receptor antagonist fasitibant

OBJECTIVE

The aim of this study was to determine in intact and inflamed knee joints of the rat, the effect of the bradykinin (BK) B2 receptor antagonist fasitibant (MEN16132) on nociceptor mechanosensitivity and hyperalgesia.

METHODS

Joint afferent sensory fibers of the medial articular nerve of anesthetized animals were electrophysiologically recorded, measuring nerve impulse activity evoked by passive innocuous and noxious movements of the joint, in intact and kaolin and carrageenan-injected joints. Knee joints of rats were also acutely inflamed by intra-articular injection of carrageenan alone. Long term duration of fasitibant antinociceptive effects were behaviorally evaluated using the incapacitance test.

RESULTS

BK (100 μM) injected into the saphenous artery, induced excitation and sensitization of multi- and single unit recordings. Fasitibant (300 μM) injected prior to BK, reduced its excitatory effects as well as the overall increase of movement-evoked activity resulting from repeated injections of BK. Fasitibant did not affect movement-evoked activity of sensory fibers of intact, non-inflamed knee joints. Intra-articular fasitibant (100 μg/knee) significantly reduced the carrageenan-induced inflammatory hyperalgesia measured with the incapacitance test up to four days after treatment. This antinociceptive effect was not obtained with systemic endovenous injection of the drug.

CONCLUSIONS

Fasitibant prevents B2 receptor-mediated activation and sensitization of peripheral joint afferents and the ensuing inflammatory hyperalgesia, and may be a useful, novel drug for arthritis pain treatment.

Frequency of estrogen receptor (ER)-negative, progesterone receptor (PR)-negative, and HER2-negative invasive breast cancer, the so-called triple-negative phenotype: a population-based study from Trentino, North East Italy

OBJECTIVE

Triple negative breast carcinomas (TNT) are infiltrating breast carcinomas (BC) with negative oestrogen receptor (ER), progesterone receptor (PgR) and human epidermal growth factor receptor 2 (HER-2) expression, and are associated with frequent BRCA1/BRCA2 mutations. The aim of the present study is to analyze the frequency and distribution of TNT in our population where a breast cancer screening program for women aged between 50 and 69 years is effective since 2001 with 85% accrual.

METHODS

We investigated the records of 2112 consecutive BC and 153 interval BC (i.e. BC detected in the screened negative women in the interval between screening rounds). Tumours with complete negative expression of ER, PgR and Her2 were considered TNT; tumours with negative ER and PgR status and faint Her2 expression (score 1) were considered as possible TNT (pTNT).

RESULTS

We identified 82 (3.8%) TNT and 20 (0.9%) pTNT in the series of 2112 consecutive BC and 7 TNT and 1 pTNT (5.2%) in the series of 153 interval BC. In the consecutive series, TNT/ pTNT were observed in 6.5% patients below 50 years and in 4.3% of patients above 50 years. A high proliferation rate (Ki-67 labelling > 36%) was observed in 87.8% of TNT (median labelling 56.3%) and in 60% of pTNT (median labelling 48.4%).

CONCLUSIONS

Since TNT/pTNT occurring in women < 50 years is a criterion for selecting patients whom genetic counselling and BRCA1 testing should be offered, our study is of help in foreseeing the workload of the Unit of Medical Genetics and the Laboratory of Molecular Pathology.

Control of odour emission in wastewater treatment plants by direct and undirected measurement of odour emission capacity

Odour emissions from wastewater treatment plants (WWTPs) are considered to be the main causes of disturbance noticed by the exposed population and have relevant impacts on both tourism economy and land costs. Odour impact from WWTPs is generated by primary and secondary odour emissions. Primary odour emissions are related especially to the wastewater type and variability discharged into the sewer and directed to the WWTP, and to the wastewater collection and sewage system. Secondary odours are related to the treatment units of the plant. Several studies describe the key role of primary odour emissions and how they are strongly related to odour impacts of WWTPs. In this way, a opportune characterization of the emission capacity of primary odour could be an effective way to control odour emission in the WWTPs. In this study the odour emission capacity (OEC) of different domestic sewers was described and investigated; a correlation between the OEC and the main physical-chemical parameters of wastewater quality was also carried out. Results of this study identify the optimum conditions for sampling and measuring OEC in wastewaters and define its dependence by wastewater quality. These results can contribute to setting the standards for the maximum odourant content of wastewater that are discharged into the publicly owned sewage system.

Bradykinin and B₂ receptor antagonism in rat and human articular chondrocytes

BACKGROUND AND PURPOSE

In osteoarthritis (OA), bradykinin (BK) is known to contribute to pain and synovitis, but not to cartilage degradation. Here, we investigated effects of BK and its antagonists on chondrocytes, cells involved in cartilage homeostasis.

EXPERIMENTAL APPROACH

BK receptor density and affinities of BK, its analogues and antagonists were measured in cultured human and rat chondrocytes by radioligand binding. Effects of BK were assessed by accumulation of inositol phosphates (IP) and release of interleukin (IL)-6 and IL-8.

KEY RESULTS

Density of [³H]-BK binding sites was higher (13-30-fold) and BK evoked a greater (48-fold) IP production, in human than in rat chondrocytes. The BK B₂ receptor antagonists MEN16132 and icatibant displayed similar binding affinity. MEN16132 was 40-fold more potent than icatibant in the IP assay. In human chondrocytes, BK increased release (over 24 h) of IL-6 and IL-8, effects blocked by MEN16132 but not by the B₁ receptor antagonist Lys-[Leu⁸][desArg⁹]BK. BK-induced release of IL-6, but not of IL-8, was partially inhibited by indomethacin (10 µM) and nordihydroguaiaretic acid (10 µM). Antagonists for the prostanoid EP receptors (AH6809 10 µM; L-798,196, 200 nM; L-161,982, 1 µM) were ineffective. Dexamethasone (100 nM) partially inhibited release of both IL-6 and IL-8. Inhibitors of intracellular downstream signalling pathways (SB203580 10 µM; PD98059, 30 µM; SP600125, 30 µM; BAY-117085, 5 µM) indicated the involvement of p38 MAPK and the activation of NF-κB.

CONCLUSION AND IMPLICATIONS

BK mediated inflammatory changes and cartilage degradation and B₂ receptor blockade would, therefore, be a potential treatment for OA.

Anti-inflammatory synergy of MEN16132, a kinin B(2) receptor antagonist, and dexamethasone in carrageenan-induced knee joint arthritis in rats

BACKGROUND AND PURPOSE

Bradykinin, through its B(2) receptor, is involved in inflammatory processes related to arthropathies. In carrageenan and lipopolysaccharide (LPS)-induced arthritis in rat, the anti-inflammatory activity of MEN16132, a potent and selective kinin B(2) receptor antagonist, was compared with that of steroidal and nonsteroidal anti-inflammatory drugs. The interaction between MEN16132 and dexamethasone was also investigated.

EXPERIMENTAL APPROACH

Drugs, alone or in combination, were injected into the knee joint 30min before intra-articular administration of carrageenan or LPS, in pentobarbital anaesthetized rats. Effects on incapacitation, oedema, neutrophil recruitment and kallikrein system activation, in the knee joint, were assessed.

KEY RESULTS

MEN16132 and dexamethasone (10-300µg per knee) dose-dependently reduced carrageenan-induced joint pain, oedema and neutrophil infiltration, reaching a maximal inhibition of about 50%. Dexketoprofen exerted a similar analgesic activity, whereas it did not affect the other inflammatory responses. MEN16132 showed a partial inhibition of LPS-induced joint pain, whereas dexamethasone produced a full analgesic effect. Combination of MEN16132 and dexamethasone showed a strong synergistic interaction in inhibiting both carrageenan and LPS-induced knee joint inflammation. Dexamethasone did not prevent the contact activation of prekallikrein by carrageenan and the subsequent release of kallikreins and bradykinin in the synovium.

CONCLUSIONS AND IMPLICATIONS

Steroids and kinin B(2) receptor antagonists appear to relieve arthritic symptoms induced by carrageenan or LPS and act synergistically to inhibit joint inflammation. This could have interesting therapeutic implications, possibly opening the way for combination therapies in the control of inflammatory arthropathies.

Comparison of the molecular interactions of two antagonists, MEN16132 or icatibant, at the human kinin B₂ receptor

BACKGROUND AND PURPOSE

Icatibant is a well-known kinin B₂ receptor antagonist currently used for angiooedema attacks. MEN16132 is a non-peptide B₂ receptor antagonist, more potent and long lasting than icatibant in different models. Here we studied the reasons for these differences between the two antagonists.

EXPERIMENTAL APPROACH

Rate of reversibility (over about 3 h) of the functional receptor blockade exerted by the antagonists was compared (inositol phosphates accumulation assay) in CHO cells expressing the human B₂ receptor and in human synovial cells. Antagonist pretreated cells were washed with medium and the time taken to restore bradykinin (BK) response measured. Antagonist affinity was measured by radioligand binding to wild type and mutated B₂ receptors.

KEY RESULTS

Recovery of BK-induced responses was slower in cells pretreated with MEN16132 than in those treated with icatibant. The affinity of icatibant (for the [³H]-BK or the B₂ receptor antagonist [³H]-MEN11270 binding site) was compared to that of MEN16132 using a panel of point-mutated receptors with mutations located at the transmembrane regions of the B₂ receptor, previously shown to decrease MEN16132 high affinity interaction. No consistent decrease of icatibant affinity was observed. From the different affinity of MEN16132 derivatives at wild type and W86A (transmembrane 2 region) receptors, and by evaluating its antagonist profile at the D266A/D284A double mutant receptor, a model of the MEN16132-B₂ receptor complex is proposed.

CONCLUSIONS AND IMPLICATIONS

MEN16132 dissociated from the B₂ receptor compartment more slowly than icatibant and interacted at a deeper level in transmembrane regions of the receptor.

Intestinal epithelial barrier dysfunction in disease and possible therapeutical interventions

The intestinal epithelial monolayer constitutes a physical and functional barrier between the organism and the external environment. It regulates nutrients absorption, water and ion fluxes, and represents the first defensive barrier against toxins and enteric pathogens. Epithelial cells are linked together at the apical junctional complex by tight junctions that reduce the extracellular space and the passage of charge entities while forming a physical barrier to lipophilic molecules. Cultured intestinal epithelial cells have been extensively used to study intestinal absorption of newly synthesized drugs and the regulation of tight junctions structure and function. In vitro mild irritants, proinflammatory cytokines, toxins and pathogens, and adverse environmental conditions open tight junctions and increase paracellular permeability, an effect often accompanied by immune activation of the enterocytes. Conversely, inhibition of proinflammatory cytokines, exposure to growth factors and probiotics, among others, exert a protective effect. Impaired barrier function results from activation of signalling pathways that lead to alteration of junctional proteins expression and/or distribution. In vivo, intestinal barrier dysfunction is associated with various intestinal and non-intestinal disorders including inflammatory bowel disease, celiac disease, and diarrhoeal infection. This review will describe the current knowledge of the mechanisms regulating tight junctions and intestinal permeability, how these findings have lead to a better understanding of barrier alteration in human intestinal disorders, and what the emerging therapies to treat these pathologies are.

Human Bone Marrow-Derived CD133+ Cells Delivered to a Collagen Patch on Cryoinjured Rat Heart Promote Angiogenesis and Arteriogenesis

Transplanting hematopoietic and peripheral blood-derived stem/progenitor cells can have beneficial effects in slowing the effects of heart failure. We investigated whether human bone marrow CD133+-derived cells (BM-CD133+ cells) might be used for cell therapy of heart injury in combination with tissue engineering. We examined these cells for: 1) their in vitro capacity to be converted into cardiomyocytes (CMs), and 2) their potential for in vivo differentiation when delivered to a tissue-engineered type I collagen patch placed on injured hearts (group II). To ensure a microvascular network ready for use by the transplanted cells, cardiac injury and patching were scheduled 2 weeks before cell injection. The cardiovascular potential of the BM-CD133+ cells was compared with that of a direct injection (group I) of the same cells in heart tissue damaged according to the same schedule as for group II. While a small fraction (2 ± 0.5%) of BM-CD133+cells cocultured with rat CMs switched in vitro to a CM-like cell phenotype, in vivo—and in both groups of nude rats transplanted with BM-CD133+—there was no evidence of any CM differentiation (as detected by cardiac troponin I expression), but there were signs instead of new capillaries and small arterioles. While capillaries prevailed over arterioles in group II, the opposite occurred in group I. The transplanted cells further contributed to the formation of new microvessels induced by the patch (group II) but the number of vessels did not appear superior to the one developed after directly injecting the BM-CD133+cells into the injured heart. Although chimeric human–rat microvessels were consistently found in the hearts of both groups I and II, they represented a minority (1.5–2.3%) compared with those of rat origin. Smooth muscle myosin isoform expression suggested that the arterioles achieved complete differentiation irrespective of the presence or absence of the collagen patch. These findings suggest that: 1) BM-CD133+ cells display a limited propensity for in vitro conversion to CMs; 2) the preliminarily vascularized bioscaffold did not confer a selective homing and differentiation advantage for the phenotypic conversion of BM-CD133+ cells into CMs; and 3) combined patching and cell transplantation is suitable for angiogenesis and arteriogenesis, but it does not produce better results, in terms of endothelial and smooth muscle cell differentiation, than the “traditional” method of cell injection into the myocardium.

Influence of tachykinin NK2 receptors on intestinal sensitivity and motility in newborn rats

The effect of tachykinin neurokinin NK(2) receptors activation on intestinal propulsion and colorectal sensitivity was studied in 7-15 days old newborn rats. In a first set of experiments investigating the intestinal transit, the selective NK(2) receptor agonist, [betaAla(8)]NKA-(4-10) was used. It produced an increase of the small intestinal transit measured by charcoal test of 54%, that was inhibited in a dose-dependent manner by nepadutant ([N(4)-(2-acetamido-2-deoxy-beta-D-glucopyranosyl)-L-asparaginyl-L-aspartyl-L-tryptophyl-L-phenylalanyl-L-2,3-diaminopropionyl-L-leucyl]-C-4.2-N-3.5-lactam-C-1.6-N-2.1-lactam), a known selective NK(2) receptor antagonist, orally administered 2-48 h before the challenge with the NK(2) receptor agonist. Nepadutant did not affect the basal intestinal propulsion and showed a good oral bioavailability and long duration of action. In another set of experiments investigating visceral sensitivity, a fixed distension volume of a balloon inserted intrarectally in 14-15 days old newborns rats produced abdominal contractions (AC) that were increased after colonic application of acetic acid (50 microl, 0.5%). In this latter condition nepadutant, at 0.5 and 2.5 mg/kg p.o., significantly reduced the resulting AC. In control rats, untreated with acetic acid, nepadutant did not affect AC evoked by colorectal distension. These findings show for the first time two models to assess intestinal motility and visceral sensitivity in newborn rats and indicate nepadutant as a valuable tool to assess the role of NK(2) receptors in the intestinal propulsive and nociceptive activity in infants.

Novel effects mediated by bradykinin and pharmacological characterization of bradykinin B2 receptor antagonism in human synovial fibroblasts

BACKGROUND AND PURPOSE

Bradykinin (BK) and B2 receptors have been implicated in the pathophysiology of osteoarthritis (OA), and synovitis is one of its hallmarks. Here, the selective B2 receptor antagonists MEN16132 and icatibant have been pharmacologically characterized in human synovial cells.

EXPERIMENTAL APPROACH

Radioligand and functional studies (inositol phosphate (IP) accumulation, interleukin (IL)-6 and IL-8 release) were performed in cultured synoviocytes.

KEY RESULTS

[3H]-BK saturation studies indicated receptor density (Bmax) and K(d) values of 121,550 sites per cell and 1.14 nM respectively. In synoviocytes, MEN16132 (pK(I) 8.9) was threefold more potent than icatibant (pK(I) 8.4). Both antagonists showed competitive antagonism in the BK-induced IP assay (control EC50 0.45 nM), with pK(B) values of 9.9 (MEN16132) and 8.1 (icatibant). 24h incubation with BK induced IL-6 (EC50 216 nM) and IL-8 (EC50 53 nM) release. Both MEN16132 (IL-6: pIC50 8.1; IL-8: pIC50 8.4) and icatibant (IL-6: pIC50 6.6; IL-8: pIC50 6.7) completely prevented this BK-induced release. Indomethacin did not affect the basal or the IL-6/IL-8 release induced by BK, whereas nordihydroguaiaretic acid decreased the basal release, although BK still increased IL-6 and IL-8 production. BK-induced IL-8 release was attenuated by inhibitors of phospholipase C (U73122), p38 (SB203580), JNK (SP600125), ERK 1/2 (PD98059) MAPKs, phosphoinositide 3-kinase (LY294002), NF-kappaB (BAY-117085) and by the glucocorticoid dexamethasone.

CONCLUSIONS AND IMPLICATIONS

Bradykinin via B2 receptors can participate in inflammatory events in synovitis. MEN16132 is a highly potent B2 receptor antagonist capable of blocking pro-inflammatory responses to BK evoked in human synoviocytes.

Contaminant fate and transport in the Venice Lagoon: results from a multi-segment multimedia model

Contaminant loadings to the Venice Lagoon peaked from 1950s-1980s and although they have since declined, contaminant concentrations remain elevated in sediment and seafood. In order to identify the relative importance of contaminant sources, inter-media exchange and removal pathways, a modified 10-segment fugacity/aquivalence-based model was developed for octachlorodibenzodioxin/furan (OCDD/F), PCB-180, Pb and Cu in the Venice Lagoon. Results showed that in-place pollution nearby the industrial area, current industrial discharges, and tributary loadings were the main sources of contaminants to the lagoon, with negligible contributions from the atmosphere. The fate of these contaminants was governed by sediment-water exchange with simultaneous advective transport by water circulation. Contaminants circulated amongst the northern and central basins with a small fraction reaching the far southern basin and the Chioggia inlet. As a consequence, we estimated limited contaminant transfer to the Adriatic Sea, trapping the majority of contaminants in the sediment in this "average" circulation scenario which does not account for periodic flooding events.

Examination of the uncertainty in contaminant fate and transport modeling: a case study in the Venice Lagoon

A Monte Carlo analysis is used to quantify environmental parametric uncertainty in a multi-segment, multi-chemical model of the Venice Lagoon. Scientific knowledge, expert judgment and observational data are used to formulate prior probability distributions that characterize the uncertainty pertaining to 43 environmental system parameters. The propagation of this uncertainty through the model is then assessed by a comparative analysis of the moments (central tendency, dispersion) of the model output distributions. We also apply principal component analysis in combination with correlation analysis to identify the most influential parameters, thereby gaining mechanistic insights into the ecosystem functioning. We found that modeled concentrations of Cu, Pb, OCDD/F and PCB-180 varied by up to an order of magnitude, exhibiting both contaminant- and site-specific variability. These distributions generally overlapped with the measured concentration ranges. We also found that the uncertainty of the contaminant concentrations in the Venice Lagoon was characterized by two modes of spatial variability, mainly driven by the local hydrodynamic regime, which separate the northern and central parts of the lagoon and the more isolated southern basin. While spatial contaminant gradients in the lagoon were primarily shaped by hydrology, our analysis also shows that the interplay amongst the in-place historical pollution in the central lagoon, the local suspended sediment concentrations and the sediment burial rates exerts significant control on the variability of the contaminant concentrations. We conclude that the probabilistic analysis presented herein is valuable for quantifying uncertainty and probing its cause in over-parameterized models, while some of our results can be used to dictate where additional data collection efforts should focus on and the directions that future model refinement should follow.

Spontaneous release of acetylcholine from autonomic nerves in the bladder

BACKGROUND AND PURPOSE

Bladder contractility is regulated by intrinsic myogenic mechanisms interacting with autonomic nerves. In this study, we have investigated the physiological role of spontaneous release of acetylcholine in guinea pig and rat bladders.

EXPERIMENTAL APPROACH

Conventional isotonic or pressure transducers were used to record contractile activity of guinea pig and rat bladders.

KEY RESULTS

Hyoscine (3 micromol x L(-1)), but not tetrodotoxin (TTX, 1 micromol x L(-1)), reduced basal tension, distension-evoked contractile activity and physostigmine (1 micromol x L(-1))-evoked contractions of the whole guinea pig bladder and muscle strips in vitro. omega-Conotoxin GVIA (0.3 micromol x L(-1)) did not affect physostigmine-induced contractions when given either alone or in combination with omega-agatoxin IVA (0.1 micromol x L(-1)) and SNX 482 (0.3 micromol x L(-1)). After 5 days in organotypic culture, when extrinsic nerves had significantly degenerated, the ability of physostigmine to induce contractions was reduced in the dorso-medial strips, but not in lateral strips (which have around 15 times more intramural neurones). Most muscle strips from adult rats lacked intramural neurones. After 5 days in culture, physostigmine-induced or electrical field stimulation-induced contractions of the rat bladder strips were greatly reduced. In anaesthetized rats, topical application of physostigmine (5-500 nmol) on the bladder produced a TTX-resistant tonic contraction that was abolished by atropine (4.4 micromol x kg(-1) i.v.).

CONCLUSIONS AND IMPLICATIONS

The data indicate that there is spontaneous TTX-resistant release of acetylcholine from autonomic cholinergic extrinsic and intrinsic nerves, which significantly affects bladder contractility. This release is resistant to blockade of N, P/Q and R type Ca(2+) channels.

A major QTL for durable leaf rust resistance widely exploited in durum wheat breeding programs maps on the distal region of chromosome arm 7BL

A recombinant inbred line (RIL) population and a set of advanced lines from multiple crosses were used to investigate the leaf rust (Puccinia triticina Eriks.) resistance carried by the durum wheat cultivar Creso and its derivatives (Colosseo and Plinio). One hundred seventy-six RILs from the cross Colosseo x Lloyd were tested under artificial rust inoculation in the field. The response at the seedling stage was also investigated. A major QTL (QLr.ubo-7B.2) for leaf rust resistance controlling both the seedling and the adult open field based-response was mapped on 7BL, with the favourable allele inherited from Colosseo. QLr.ubo-7B.2 showed R2 and LOD peak values for the area under disease progress curve (AUDPC) equal to 72.9% and 44.5, respectively. The presence and location of QLr.ubo-7B.2 was validated by a linkage disequilibrium-based test using two-year field data of 62 advanced lines from 21 crosses with Creso, Colosseo or Plinio as resistance donors. QLr.ubo-7B.2 maps in a gene-dense region (7BL10-0.78-1.00) carrying several genes/QTLs in wheat and barley for resistance to rusts and other fungal diseases.

Renal differentiation of amniotic fluid stem cells

OBJECTIVES

The role of stem cells in regenerative medicine is evolving rapidly. Here, we describe the application, for kidney regeneration, of a novel non-genetically modified stem cell, derived from human amniotic fluid. We show that these pluripotent cells can develop and differentiate into de novo kidney structures during organogenesis in vitro.

MATERIALS AND METHODS

Human amniotic fluid-derived stem cells (hAFSCs) were isolated from human male amniotic fluid obtained between 12 and 18 weeks gestation. Green fluorescent protein and Lac-Z-transfected hAFSCs were microinjected into murine embryonic kidneys (12.5-18 days gestation) and were maintained in a special co-culture system in vitro for 10 days. Techniques of live microscopy, histology, chromogenic in situ hybridization and reverse transcriptase polymerase chain reaction were used to characterize the hAFSCs during their integration and differentiation in concert with the growing organ.

RESULTS

Green fluorescent protein and Lac-Z-transfected hAFSCs demonstrated long-term viability in organ culture. Histological analysis of injected kidneys revealed that hAFSCs were capable of contributing to the development of primordial kidney structures including renal vesicle, C- and S-shaped bodies. Reverse transcriptase polymerase chain reaction confirmed expression of early kidney markers for: zona occludens-1, glial-derived neurotrophic factor and claudin.

CONCLUSIONS

Human amniotic fluid-derived stem cells may represent a potentially limitless source of ethically neutral, unmodified pluripotential cells for kidney regeneration.

Metal content and toxicity of produced formation water (PFW): study of the possible effects of the discharge on marine environment

A preliminary chemical and ecotoxicological assessment was performed on the produced formation water (PFW) and superficial sediment around a gas platform (Fratello Cluster), located in the Adriatic Sea (Italy), in order to evaluate the effects of PFW discharged from the installation. The ecotoxicological bioassays, with the marine bacterium Vibrio fischeri and the sea urchin Paracentrotus lividus, were associated with chemical data to estimate the possible effects on living organisms. PFW collected on the platform was toxic, but no significant effect was recorded on marine sediment. Only the sediment station nearest to the discharge point showed higher values of some contaminants (zinc and arsenic) in comparison to other sites and only some stations showed low toxicity.

Heterogeneous effect of leucotriene CysLT1receptor antagonists on antigen-induced motor and inflammatory responses in guinea-pig airways

1. The effect of montelukast or MEN91507, selective leucotriene CysLT1 receptor antagonists, on antigen-induced airway inflammation and bronchoconstriction were compared in anaesthetized guinea-pigs. 2. In sensitized animals, ovalbumin (0.3 mg kg(-1), i.v.)-induced microvascular leakage in trachea, intrapulmonary airways, total lung (parenchyma and intrapulmonary airways) and urinary bladder was reduced by MEN91507 (0.01-1 micromol kg(-1), i.v.), whereas montelukast (0.01-1 micromol kg(-1), i.v.) antagonized the effect of the antigen only in the lung and urinary bladder. 3. Ovalbumin (1 mg kg(-1), i.v.)-induced bronchoconstriction was dose dependently antagonized by MEN91507 (10-30 micromol kg(-1), i.v.), whereas the effect of montelukast (0.1-30 micromol kg(-1), i.v.) was marginal (15-30% inhibition). Neither MEN91507 nor montelukast (30 micromol kg(-1), i.v.) affected the bronchoconstrictor response induced by acetylcholine (0.3 micromol kg(-1), i.v.) in sensitized animals. 4. It is concluded that montelukast and MEN91507 display a differential activity against the effect of endogenous leucotrienes, despite the fact that both compounds show a similar antagonist profile against exogenous leucotrienes acting through CysLT1 receptors.

Root-ABA1 QTL affects root lodging, grain yield, and other agronomic traits in maize grown under well-watered and water-stressed conditions

A major QTL affecting root traits and leaf ABA concentration was identified in maize (Zea mays L.) and named root-ABA1. For this QTL, back-cross-derived lines (BDLs) homozygous either for the (+) or for the (-) allele increasing or decreasing, respectively, root size and leaf ABA concentration, were developed. This study was conducted to evaluate the QTL effects in various genetic backgrounds and at different water regimes. The (+/+) and (-/-) BDLs were crossed with five or 13 inbred tester lines of different origin, thus producing two sets of test-crosses that were evaluated in Italy and China, respectively. Testing was conducted under both well-watered and water-stressed conditions. In Italy, the test-crosses derived from (+/+) BDLs, as compared with those derived from (-/-) BDLs, showed, across both water regimes, higher leaf ABA concentration (on average 384 versus 351 ng g(-1) DW) and lower root lodging (28.0 versus 52.5%), and lower grain yield under water-stressed conditions (4.88 versus 6.27 Mg ha(-1)). In China, where root lodging did not occur, the test-crosses derived from (+/+) BDLs were less productive at both water regimes (on average, 6.83 versus 7.49 Mg ha(-1)). The lower grain yield of the test-crosses derived from (+/+) BDLs was due to a lower number of ears per plant and to lower kernel weight. The results indicate that the (+) root-ABA1 allele confers not only a consistently lower susceptibility to root lodging but also a lower grain yield, especially when root lodging does not occur.

Comparative antagonist pharmacology at the native mouse bradykinin B2 receptor: radioligand binding and smooth muscle contractility studies

BACKGROUND AND PURPOSE

The aim was to characterize the recently discovered non-peptide antagonist MEN16132 at the mouse B2 receptor, relative to other antagonists.

EXPERIMENTAL APPROACH

[3H]-BK binding experiments used mouse lung and ileum tissue membranes and antagonist potency was measured in the isolated ileum contractility assay.

KEY RESULTS

Two BK binding sites resulted from saturation and homologous competition experiments. A role for the B1 receptor was excluded because of the poor affinity of B1 receptor ligands (pIC50<5). MEN16132, and the other reference antagonists, inhibited only one portion of BK specific binding, and the rank order of potency was (pIC50): Icatibant (lung 10.7; ileum 10.2)=MEN11270 (lung 10.4; ileum 9.9)=MEN16132 (lung 10.5; ileum 9.9).>LF16-0687 (lung 8.9; ileum 8.8)>FR173657 (lung 8.6; ileum 8.2). BK homologous curves performed with lung membranes after treatment with the antagonist MEN16132 or Icatibant (10 nM) displayed only the low affinity site. The functional antagonism by MEN16132 (pA2 9.4) and Icatibant (pA2 9.1), towards BK (control EC50 6.1 nM) induced ileum contractions, was concentration-dependent and surmountable, but the Schild plot slope was less than unity.

CONCLUSIONS AND IMPLICATIONS

In mouse tissue, radiolabelled BK recognizes two binding sites and B2 receptor antagonists can compete only for the higher affinity one. The pharmacological profile of the novel non-peptide antagonist MEN16132 indicates that it exhibits subnanomolar affinity and potency for the mouse B2 receptor and is suitable for further characterization in in vivo pathophysiological models.

Mucilage impact on gorgonians in the Tyrrhenian sea

The mucilage phenomenon has affected the Tuscan Archipelago since its first appearance (1991) in the Tyrrhenian Sea (Mediterranean Sea) [Innamorati M, Raddi E, Buzzichelli A, Melley S, Demoulin M. Le mucillaggini nel Mar Tirreno. Biol Mar Suppl Notiz 1992;1:23-26; Sartoni G, Sonni C. Tribonema marinum J. Feldmann e Acinetospora crinita (Carmichael) Sauvageau nelle formazioni mucillaginose bentoniche osservate sulle coste toscane nell'estate 1991. Inf Bot Ital 1991;23:23-30; Sartoni G, Cinelli F, Boddi S. Ruolo di Tribonema marinum J. Feldmann ed Acinetospora crinita (Carmichael) Sauvageau negli aggregati mucillaginosi bentonici delle coste toscane. Biol Mar Suppl Notiz 1993;1:31-34]. Seasonally, these mucous aggregates become very common in the benthic domain. The gorgonians are the most exposed organisms because they provide the best support for mucilage growth; indeed, their long branches positioned in orthogonally with respect to the current so as to capture plankton, also trap the filamentous mucilage present in the water. A 3-year monitoring programme at Capo Calvo (Island of Elba) was carried out in order to study the appearance of the mucilage phenomenon and its impact on three species of gorgonians (Eunicella cavolinii, Eunicella singularis, and Paramuricea clavata). The composition of mucilage and the gorgonian recovery capacity, when damaged, were investigated. During the first year of study (1999), no relevant interactions between gorgonians and mucilages were recorded. Instead, massive presence of mucilages causing different types of damage to the different gorgonian species investigated was recorded during the second (2000) and third year (2001). The type and the extent of the impact of mucilages also depend on the season. Three species of algae (Nematochrysopsis marina, Chrysonephos lewisii and Acinetospora crinita) constitute the principal components of the mucilaginous aggregates. In general, the first two species occur during the spring season, down to 20 m, while A. crinita occurs at greater depths. In July, when the mucilages reach their maximum development, C. lewisii is the predominant species. This species mainly affects E. cavolinii and E. singularis while A. crinita mainly affects P. clavata, which colonizes greater depths.

Cardiovascular effects of peptide kinin B2 receptor antagonists in rats

Bradykinin (BK) is a vasoactive peptide reputed to play an important role in cardiovascular homeostasis. In this study, we describe the cardiovascular changes (mean blood pressure (BP) and heart rate (HR)) induced by the i.v. administration (left jugular vein) of two selective kinin B2 receptor antagonist, namely icatibant (0.1-1 micromol/kg as a bolus) and MEN1 1270 (0.1-1 micromol/kg as a bolus or 1 micromol/kg infused in 15 or 60 min), in urethane-anaesthetized or conscious rats with an indwelling catheter implanted in the right carotid artery for BP measurements. In conscious rats, icatibant at 0.1 or 0.3 micromol/kg did not change BP but at 0.1 micromol/kg increased HR at 30 min from administration. MEN1 1270 at 0.1 or 0.3 micromol/kg induced a dose-related increase in BP and a concomitant bradycardia (significant at 0.3 micromol/kg) lasting for 5 or 30 min, respectively. Icatibant at 1 micromol/kg induced a slight (P < 0.05) increase in BP that resolved in 5 min and a biphasic tachycardia (peaks at 30 and 90 min from administration). MEN1 1270 at 1 micromol/kg induced a triphasic change in HR (tachycardia in the first 5 min, bradycardia at 30 min, and tachycardia at 90 and 120 min) and a biphasic change in BP (hypotension at 15 min and hypertension at 30 min). The i.v. infusion of MEN1 1270 (1 micromol/kg in 15 or 60 min) produced hypertension, whereas HR was increased only following the 15-min infusion. In urethane-anaesthetized rats, both icatibant and MEN1 1270 (0.1 micromol/kg as a bolus) increased BP and the onset for this effect was correlated with the time course of the antagonism of BK-induced hypotension, where the effect of MEN1 1270 was more rapid than that of icatibant. These results indicate that kinin B2 receptor antagonists can induce acute cardiovascular effects, and the reason for the different haemodynamic profile between icatibant and MEN1 1270 could be putatively attributed to kinetic characteristics.

In vitro and in vivo activity of analogues of the kinin B2 receptor antagonist MEN1 1270

In this study, we describe the in vitro and in vivo activities of a series of cyclic peptide analogues of the selective kinin B2 receptor antagonist MEN11270 on Chinese hamster ovary cells expressing the human B2 receptor (hB2R), the human isolated umbilical vein (hUV), the isolated guinea pig ileum (gpI), and bradykinin (BK) induced bronchoconstriction (BC) and hypotension in anaesthetized guinea pigs. Substitutions in the backbone of MEN1 1270 (H-DArg-Arg-Pro-Hyp-Gly-Thi-c(Dab-DTic-Oic-Arg)c(7gamma-10alpha)) aimed to increase the potency in inhibiting bronchospasm versus hypotension following the topical (intratracheal (i.t.)) or systemic (intravenous (i.v.)) application of these antagonists. A series of analogues were left unprotected from N-terminal cleavage by aminopeptidases (MEN12739, MEN13052, MEN13346, and MEN13371): these compounds maintained sizeable affinities for the hB2R (pKi = 9.4, 9.6, 9.7, and 8.6, respectively) and antagonist activities toward BK in the hUV (pA2 = 7.9, 8.3, 8.2, and 7.5) and gpI assays (pK(B) = 7.4, 7.8, 7.9, and 7.9), but the inhibition of BK-induced BC and hypotension in vivo was negligible following either i.v. or i.t. administration. Two analogues (MEN12388 and MEN13405) could be potential substrates of angiotensin-converting enzyme: these have good activity in the hB2R (pKi = 9.5 and 8.9, respectively), hUV (pA2 = 8.2 for MEN12388), and gpI assays (pK(B) = 8.4 and 8.0) but an in vivo activity 10- to 30-fold lower than the parent compound MEN1 1270 (pKi = 9.4, pA2 = 8.1, pKB = 8.3) when given by either the i.v. or the i.t. route. Other analogues were functionalized with a quaternary ammonium Lys derivative (MEN13031, MEN12374, and the previously mentioned MEN13052) or with an ethyl group on Arg (MEN13655 and the previously mentioned MEN13346 and MEN13405) in order to hinder or facilitate local absorption. MEN13346 and MEN13031 (pKi = 9.7and 9.5, pA2 = 8.2 and 7.9, pKB = 7.9 and 8.5, respectively) were 10- to 30-fold less active in vivo than MEN1 1270, without improving the discrimination between BK-induced BC and hypotension after either systemic or topical administration. It is concluded that the decreased in vivo activities of cyclic analogues of MEN11270 on BK-induced BC and hypotension following either their intratracheal or their intravenous routes of administration might be due in large part to metabolic degradation.

Nepadutant pharmacokinetics and dose-effect relationships as tachykinin NK2 receptor antagonist are altered by intestinal inflammation in rodent models

Tachykinin NK2 receptor antagonists could reduce motility and symptoms during gastrointestinal diseases characterized by local inflammation such as diarrhea or colitis; however, how these conditions change pharmacodynamic and pharmacokinetic characteristics of NK2 receptor antagonists is unknown. We investigated the effect of the peptide NK2 receptor antagonist nepadutant on spontaneous intestinal motility or [betaAla8]NKA(4-10)-induced colonic and bladder contractions in rodent models of intestinal inflammation (enteritis induced by castor oil and rectocolitis induced by local instillation of acetic acid in rats, enteritis induced by bacterial toxins in mice). In the castor oil model, the oral/intraduodenal bioavailability of nepadutant was also determined. The intrarectal (i.r.) administration of nepadutant (100 nmol/kg) did not reduce [betaAla8]NKA(4-10) (10 nmol/kg i.v.)-induced colonic and bladder contractions in normal animals, but the same dose of nepadutant produced an inhibitory effect in the two organs following rectocolitis; in contrast, nepadutant is equieffective by the intravenous route in normal and colitic animals. In this model, nepadutant (100 nmol/kg i.r. or i.v.) decreased spontaneous colonic hypermotility, without affecting motility in controls. The intraduodenal administration of nepadutant (30 nmol/kg), which was ineffective on [betaAla8]NKA(4-10) (10 nmol/kg i.v.)-induced colonic and bladder contractions in control animals, abolished bladder contractions in castor oil-pretreated animals. In this latter group, the oral and intraduodenal bioavailability of nepadutant showed a 7- to 9-fold increase with respect to controls. Oral administration of nepadutant, in nanomolar or subnanomolar dosage, reduced diarrhea induced by bacterial toxins in mice. It is concluded that intestinal inflammation increases nepadutant absorption in the intestine, enhancing its activity. These results suggest that a drug with a limited oral bioavailability could be used for treating gastrointestinal diseases associated with a local inflammation.

The role of sensory neuropeptides in motor innervation of the hamster isolated urinary bladder

In this study we have characterized the role of sensory fibers and of the sensory peptides, neurokinin A (NKA) and calcitonin gene-related peptide (CGRP), on the contractile responses evoked by single pulse electrical field stimulation (EFS) in the hamster urinary bladder. EFS of the hamster isolated urinary bladder produced twitch contractions which were unaffected by atropine but abolished by tetrodotoxin. The P2 purinoreceptor antagonist PPADS (30 microM) inhibited twitches by 66+/-4% on its own and by 78+/-3% in the presence of atropine. The selective tachykinin NK2 receptor antagonist nepadutant produced a slight but consistent reduction of twitch amplitude (-21+/-3%) at 1 microM. Addition of nepadutant to atropine and PPADS did not further increase their inhibitory effect. The application of hCGRP (10-300 nM) produced a concentration-dependent inhibition of twitches (Emax -38+/-3%, EC50=12 nM) and a small reduction of tone (0.5+/-0.09 mN). Similar effects were obtained with capsaicin (0.1-10 microM) which inhibited EFS-evoked contractions with an EC50 of 100.0 nM and a maximal effect of 34+/-4% inhibition at 1 microM. Under submaximal parameters of stimulation NKA (10 nM) increased the amplitude of twitches by 45+/-6% and produced a concentration-dependent tonic contraction (EC50=55.9 nM). The CGRP1 receptor subtype antagonist, hCGRP(8-37), increased by 29+/-8% the EFS-evoked contractions and significantly reduced the response to 0.1 microM CGRP. Capsaicin (10 microM) increased both CGRP-LI and NKA-LI release from superfused slices of hamster urinary bladder by about sixfold and by about 70%, over baseline, respectively. A second application of capsaicin was ineffective, indicating a complete desensitization of sensory nerve efferent function. In the hamster urinary bladder the sensory neuropeptides NKA and CGRP are co-released by sensory fibers after stimulation either by EFS or capsaicin. However, the role of CGRP appears functionally predominant.

Urodynamic effects induced by intravesical capsaicin in rats and hamsters

This study compared the effect of acute intravesical capsaicin administration on transvesical cystometries in urethane-anesthetized rats and hamsters, and aimed to assess whether sensory neuropeptides (tachykinins; calcitonin gene-related peptide, CGRP) play a role in the urodynamic effects of capsaicin in these species. The following urodynamic parameters were evaluated: the mean micturition interval (MI), the pressure threshold for micturition (PT), and the mean amplitude of micturition contractions (MAC). Two concentrations of capsaicin (10 and 100 microM) were evaluated in both species. Here, we demonstrate that 10-microM capsaicin decreased the PT in both rats and hamsters, and 100-microM capsaicin decreased the PT in hamsters and decreased the MI in both species. In addition, 100-microM capsaicin increased the MAC in rats but decreased the MAC in hamsters. Administration of CGRP (10 nmol kg(-1) , i.v.) significantly decreased both MAC and PT in hamsters only, while capsaicin-induced desensitization of neuropeptide-containing afferents antagonized the urodynamic effects of intravesical capsaicin. In addition, administration of the tachykinin NK2 receptor antagonist, Nepadutant (100 nmol kg(-1), i.v.), reduced the effects of capsaicin (100 microM) only in rats. These results indicate that capsaicin induces bladder hyperactivity in both rats and hamsters, but the urodynamic characteristics of this hyperactivity markedly differ in these two species. The differences observed may be due to differential expression of sensory neuropeptides in capsaicin-sensitive bladder afferents or neuropeptide receptors in smooth muscle cells and in nerve fibers.

Tachykinin NK(2) receptors and enhancement of cholinergic transmission in the inflamed rat colon: an in vivo motility study

In the gastrointestinal tract, tachykinin NK(2) receptors are localized both on smooth muscle and nerve fibres. NK(2) receptor antagonists reduce exaggerated intestinal motility in various diarrhoea models but the site of action contributing to this effect is unknown. In this study we investigated the effects of atropine (1.4 micromol kg(-1), i.v.), hexamethonium (13.5 micromol kg(-1), i.v.), and nepadutant (0.1 micromol kg(-1), i.v.), a selective tachykinin NK(2) receptor antagonist, on distension (0.5 and 1 ml)-, or irritation (acetic acid, 0.5 ml of 7.5% v v(-1))-induced motility in the rat distal colon in vivo. The effects of atropine, hexamethonium or N(omega)-nitro-L-argininemethylester (L-NAME, 1.85 micromol kg(-1), i.v.) on [betaAla(8)]NKA(4-10) (10 nmol kg(-1), i.v.)-induced colonic contractions were also investigated. When the colonic balloon was filled with a subthreshold volume (0.5 ml), the intraluminal instillation of acetic acid triggered a high-amplitude phasic colonic motility which was partially reduced by nepadutant and suppressed by either hexamethonium or atropine. Filling of the balloon with 1 ml evoked reflex (hexamethonium-sensitive), atropine-sensitive phasic colonic motility: nepadutant had no significant effect on the distension-evoked motility. Neither hexamethonium nor atropine significantly reduced [betaAla(8)]NKA(4-10)-induced colonic contractions, whereas nepadutant suppressed them. Following L-NAME pretreatment, [betaAla(8)]NKA(4-10)-induced colonic contractions were inhibited by both atropine and hexamethonium. In hexamethonium-pretreated animals, an atropine-sensitive component of [betaAla(8)]NKA(4-10)-induced colonic contractions was also evident. These results indicate that the application of irritants onto the colonic mucosa induces the release of endogenous tachykinins which enhance excitatory cholinergic mechanisms through the stimulation of NK(2) receptors.

Effect of a tachykinin NK(2) receptor antagonist, nepadutant, on cardiovascular and gastrointestinal function in rats and dogs

The effect of the tachykinin NK(2) receptor antagonist, nepadutant (MEN 11420 or (c[[(beta-D-GlcNAc)Asn-Asp-Trp-Phe-Dpr-Leu]c(2beta-5beta)])) was assessed on cardiovascular function (unanaesthetized rats and anaesthetized dogs) and gastrointestinal motor activity (fasted unanaesthetized dogs). The selective tachykinin NK(2) receptor agonist, [betaAla(8)]neurokinin A (4-10), up to 100 nmol/kg, i.v., did not produce changes on mean blood pressure or heart rate in unanaesthetized rats. Nepadutant did not affect blood pressure and heart rate up to 10 micromol/kg, whereas saredutant (SR 48968 or ((S)-N-methyl-N[4-(4-acetylamino-4-phenyl piperidino)-2-(3,4-dichlorophenyl)butyl] benzamide), a nonpeptide antagonist, produced a transient reduction of mean blood pressure and heart rate. Nepadutant up to 20 micromol/kg, i.v. neither caused changes of cardiovascular and respiratory parameters in anaesthetized dogs nor induced any changes in left ventricular systolic pressure, left ventricular dP/dt or of electrocardiogram (lead II) waveforms. Intravenous administration of neurokinin A (9 nmol/kg) in unanaesthetized dogs stimulated gastrointestinal motility for 20-25 min. Nepadutant at 0.1 micromol/kg suppressed the stimulant effects of neurokinin A but, up to a dose of 10 micromol/kg, did not produce significant changes in the basal migrating motor complexes. We conclude that tachykinin NK(2) receptors do not participate in the physiologic regulation of resting cardiovascular and respiratory functions and that they do not regulate the fasted pattern of gastrointestinal motility. The cardiovascular changes induced by the nonpeptide tachykinin NK(2) receptor antagonist, saredutant, likely arise from nonspecific effects unrelated to tachykinin NK(2) receptor blockade.

Differences between peptide and nonpeptide B(2) bradykinin receptor antagonists in blocking bronchoconstriction and hypotension induced by bradykinin in anesthetized Guinea pigs

We have compared the in vivo activity of the bradykinin B(2) receptor peptide antagonists MEN 11270 and Icatibant versus the nonpeptide antagonist FR 173657, after intravenous (i.v.) and intratracheal (i.t.) administration, on the bradykinin (BK)-induced bronchoconstriction and hypotension in anesthetized guinea pigs. We have also assessed the affinity of these antagonists for B(2) receptors in guinea pig lung membranes by radioligand binding and the metabolic stability of peptide antagonists in guinea pig plasma and tissue homogenates. The i.v. administration of MEN 11270, Icatibant, or FR 173657 induced a dose-dependent (10-100 nmol/kg) inhibition of both hypotension and bronchoconstriction induced by bradykinin (10 nmol/kg i.v.). The inhibitory effect of MEN 11270 and Icatibant was comparable both in terms of potency and time course, whereas FR 173657 was less potent and shorter acting. After i.t. administration MEN 11270 and Icatibant (10-100 nmol/kg) dose dependently inhibited both bronchoconstriction and hypotension, whereas FR 173657 (10-100 nmol/kg) reduced bronchoconstriction without affecting hypotension. The antibronchoconstrictor effect of MEN 11270 was more prolonged than that of Icatibant and FR 173657, whereas no differences were found between the peptide antagonists in inhibiting hypotension. These findings indicated that, in vivo, the peptide antagonists are more potent and longer lasting than FR 173657 acting on bradykinin B(2) receptors in guinea pig airways and in the vascular system. The greater efficacy of the antagonists in blocking airway compared with vascular B(2) receptors after topical administration suggests that they can block airway B(2) receptors with little systemic effects.

Peripheral actions of tachykinins

Tachykinins mediate a variety of physiological processes in the gastrointestinal, pulmonary and genito-urinary tract mainly through the stimulation of NK1 and NK2 receptors. Preclinical evidence obtained through the use of selective tachykinin receptor antagonists indicates that endogenous tachykinins are involved in augmented smooth muscle contraction, vasodilatation, chemotaxis and activation of immune cells, mucus secretion, water absorption/secretion. Recent evidence also suggests that endogenous tachykinins released at the peripheral level may play a role in visceral inflammation, hyperreflexia and hyperalgesia. Possible mechanisms underlying the stimulation of primary afferent neurons by tachykinins may involve a direct excitation of these neurons and the release of mediators which sensitise or stimulate sensory nerves. Tachykinin receptor antagonists could have a clinical utility in several human diseases such as irritable bowel syndrome, asthma, and in micturition disturbances characterized by a hyperactive bladder.