Experimental pseudo-equivalent deterministic excitation method extension for low frequency domain applications

In transport engineering applications, flow-induced vibrations is an interesting topic to address since it may negatively affect the operation and the response of the system. Wind tunnel facilities are mandatory to test the structure design efficiency or to analyse new material performances under aerodynamic load. However, these experimental tests can be expensive and take a long time to set up and operate; hence, alternative methods for the reproduction of the structural response to a turbulent boundary layer excitation are required to accelerate and improve the experimental setups and provide more data for uncertainty analysis. In this paper, an alternative approach, the eXperimental Pseudo-Equivalent Deterministic Excitation method (X-PEDEM), is here extended for applications in the low frequency domain. An investigation about the applicability of the method in the low frequency domain is conducted, together with an analysis of its main properties. The reliability of the method is then tested numerically by considering different conditions: two different panels, two different boundary conditions, and different asymptotic flow velocities are considered.

Series and parallel coupling of 3D printed micro-perforated panels and coiled quarter wavelength tubes

Micro-perforated panel sound absorbers are widely used in noise control applications in the fields of architectural acoustics and transport acoustics. Combining micro-perforated panels with other resonant or sound absorbing systems may broaden the frequency range in which they absorb sound while ensuring that large sound absorption values are reached. In this work, a hybrid sound absorber that combines a micro-perforated panel and a coiled quarter wavelength tube is proposed. Series and parallel configurations of these two systems are studied from analytical, numerical, and experimental point of views. A comparison of two three-dimensional (3D) printing techniques for the production of samples highlights the main challenges for the practical implementation of the proposed design. The advantages and limitations of series and parallel arrangements are discussed and while the parallel configuration is more complex to setup in practice, it provides an improved sound-absorbing performance compared with the series configuration. Finally, the reproducibility of the hybrid absorber in parallel configuration is confirmed by testing samples that were produced with two different 3D printers and in two different laboratories.

Pseudo-equivalent deterministic excitation method application for experimental reproduction of a structural response to a turbulent boundary layer excitation

In the transportation engineering field, the turbulent boundary layer over a structure is one of the most relevant sources of structural vibration and emitted noise. Wind tunnels are still one of the best options for vibroacoustic experimental analyses for this specific problem. However, it is also true that this experimental method is not always affordable, due to several limitations-settings hard to control, time and money consumption, discrepancies among laboratories-that wind tunnel facilities present. It has already developed different methodologies to address this necessity, most of them based on the use of loudspeakers or shakers. In this work, an existing numerical method, called the pseudo-equivalent deterministic excitation method (PEDE_M), is further developed for the experimental purpose of reproducing the experimental structural response of a panel subjected to a turbulent boundary layer (TBL) excitation, by using an equivalent rain-on-the-roof excitation instead; different formulations are used for the application of this approximated TBL excitation. The experimental application of PEDE_M, here called X-PEDE_M, is validated by comparison with experimental results of two different panels analysed in two different wind tunnel facilities.

Monocentric case-series of mesenteric vascular disease occurred in the first month of the COVID-19 pandemic

Objectives

Methods

Results

Conclusions

Non Monotonous Effects of Noncovalently Functionalized Graphene Addition on the Structure and Sound Absorption Properties of Polyvinylpyrrolidone (1300 kDa) Electrospun Mats

Graphene is an attractive component for high-performance stimuli-responsive or 'smart' materials, shape memory materials, photomechanical actuators, piezoelectric materials and flexible strain sensors. Nanocomposite fibres were produced by electrospinning high molecular weight Polyvinylpyrrolidone (PVP-1300 kDa) in the presence of noncovalently functionalised graphene obtained through tip sonication of graphite alcoholic suspensions in the presence of PVP (10 kDa). Bending instability of electrospun jet appears to progressively increase at low graphene concentrations with the result of greater fibre stretching that leads to lower fibre diameter and possibly conformational changes of PVP. Further increase of graphene content seams having the opposite effect leading to greater fibre diameter and Raman spectra similar to the pure PVP electrospun mats. All this has been interpreted on the basis of currently accepted model for bending instability of electrospun jets. The graphene addition does not lower the very high sound absorption coefficient, α, close to unity, of the electrospun PVP mats in the frequency range 200⁻800 Hz. The graphene addition affects, in a non-monotonous manner, the bell shaped curves of α versus frequency curves becoming sharper and moving to higher frequency at the lower graphene addition. The opposite is observed when the graphene content is further increased.

Idiopathic SIADH in young patients: don't forget the nose

Olfactory neuroblastoma (ONB) is an uncommon neuroendocrine sinonasal cancer associated by many authors to ectopic production of several biologically active substances. We report a case of a 31-year-old male patient who presented with idiopathic syndrome of inappropriate secretion of antidiuretic hormone (SIADH). During diagnostic work-up, a CT scan of the head was performed and an ethmoidal ONB was detected. Endoscopical surgery followed by radiotherapy was carried out. Immediately after surgery natraemia levels normalised. Five years later the patient is disease-free. To our knowledge, 17 cases of SIADH associated to ONB have been published. In nine reports, idiopathic SIADH promptly led to the diagnosis of the sinonasal mass as in our clinical case, however, in many reports, correct diagnosis was accomplished months to years later. In young patients with idiopathic inappropriate antidiuretic hormone secretion, a neuroendocrine malignancy of the sinonasal area must be excluded.

Effects of Surgical Techniques on Long-Term Results in Patients with Degenerative Mitral Valve Bileaflet Prolapse

BACKGROUND AND AIM OF THE STUDY

The study aim was to evaluate the long-term results in patients with degenerative mitral valve bileaflet prolapse (DMVBLP) undergoing mitral valve repair (MVr) or mitral valve replacement (MVR), and to compare the consequences of survival related to each technique.

METHODS

Between 2001 and 2012, a total of 421 patients underwent isolated primary surgery for DMVBLP. MVr was performed in 146 patients (34.7%), and MVR in 275 (65.3%). MVR patients were allocated to two subgroups. Subgroup A were operated on in routine fashion, preserving the posterior subvalvular apparatus, and in selected cases the anterior or both apparatus (n = 119; 43.3%). In subgroup B, surgery was performed without preservation of the subvalvular apparatus (n = 156; 56.7%).

RESULTS

There were no intraoperative deaths in all patient groups. The median length of follow up was 5.96 ± 3.28 years. Five patients (3.4%) in the MVr group died, while 11 in MVR subgroup A (9.2%) died, and 29 in MVR subgroup B (18.6%). Patients in the MVr group demonstrated significant and persistent postoperative decreases in left ventricular end-diastolic diameter (LVEDD) and left ventricular end-systolic diameter (LVESD) during the follow up, while the left ventricular ejection fraction (LVEF) showed a trend to improve. In MVR subgroup A, preservation of the mitral subvalvular structures resulted in a decrease in LVEDD; this resulted in a lesser worsening of the LVEF, as occurs when subvalvular structures are resected. In MVR subgroup B, the LVEDD and LVESD were each increased constantly, which resulted in a statistically significant worsening of the LVEF.

CONCLUSIONS

MVr in DMVBLP patients achieved a better preservation of left ventricular systolic indices than MVR, and guaranteed better shortand long-term survivals. When MVr is not feasible, it is recommended that subvalvular preservation be performed during MVR, in order to reduce the risk of early and late mortality and to improve left ventricular function.

Early Results of Rheumatic Mitral Valve Repair

BACKGROUND AND AIM OF THE STUDY

Mitral valve repair (MVr) in rheumatic heart disease (RHD) remains challenging. The present authors' surgical experience of MVr in 56 patients with RHD operated in between January 2011 and September 2014 is reported.

METHODS

Among the patients (mean age 32 ± 11 years), 11 were in NYHA functional class II, 32 in class III, and seven in class IV. An adequate or oversized autologous pericardial patch was sutured to extend the coaptating edge of both the anterior leaflet (in 18 patients) and the posterior leaflet (in 30 patients). Neochordae were implanted as needed (n = 43), and leaflet thinning (n = 13), commissurotomy (n = 15) and chordal splitting (n = 9) were also performed. A rigid annuloplasty ring was implanted in 32 patients, and in 24 patients a complete flexible annuloplasty ring made from pericardium, 4 mm Gore-Tex tube graft or a Dacron patch was constructed. Repair was not attempted in 16 patients, with replacement using a mechanical bileaflet prosthesis being considered the only option.

RESULTS

Intraoperative post-repair transesophageal echocardiography demonstrated competency, with trivial mitral regurgitation (MR) up to grade I in all patients and a minimum coaptation depth ≥5 mm. There were no intraoperative or in-hospital deaths. Clinical and echocardiographic evaluations were performed up to six weeks after surgery, at which time 51 patients were in NYHA classes I-II and five were in class III. Residual mild MR up to grade I was identified in six patients. No recurrence of MR was observed in any of the patients, and no patients were reoperated on.

CONCLUSIONS

The lack of adequate access to anticoagulation medication and monitoring, in addition to religious/cultural bias to the type of prosthetic valve used in low-income countries, necessitates an increase in the numbers of rheumatic MVr.

Degenerazione dell'unità disco-somatica lombare

Gli autori, attraverso una revisione della letteratura ed uno studio retrospettivo su 125 esami RM, descrivono le alterazioni degenerative del rachide lombare in pazienti anziani, focalizzan-do l'attenzione sulla ricca semeiologia RM della patologia del complesso disco-somatico. Scopo del lavoro e quello di poter discernere le alterazioni a carattere francamente patologico da quelle che possono essere considerate segni del fisiologico invecchiamento rachideo. Viene in particolare evidenziato come la fissurazione radiale dell'anulus sia risultata, in base alla sua presenza significativamente più frequente nel gruppo dei pazienti sintomatici, il miglior segno predittivo di patologia estrusiva discale tra quelli esaminati.

A multidisciplinary approach to the study of cultural heritage environments: Experience at the Palatina Library in Parma

The aim of this paper is to describe a multidisciplinary approach including biological and particle monitoring, and microclimate analysis associated with the application of the Computational Fluid Dynamic (CFD). This approach was applied at the Palatina historical library in Parma. Monitoring was performed both in July and in December, in the absence of visitors and operators. Air microbial monitoring was performed with active and passive methods. Airborne particles with a diameter of ≥0.3, ≥0.5, ≥1 and ≥5 μm/m3, were counted by a laser particle counter. The surface contamination of shelves and manuscripts was assessed with nitrocellulose membranes. A spore trap sampler was used to identify both viable and non-viable fungal spores by optical microscope. Microbiological contaminants were analyzed through cultural and molecular biology techniques. Microclimatic parameters were also recorded. An infrared thermal camera provided information on the surface temperature of the different building materials, objects and components. Transient simulation models, for coupled heat and mass-moisture transfer, taking into account archivist and general public movements, combined with the related sensible and latent heat released into the environment, were carried out applying the CFD-FE (Finite Elements) method. Simulations of particle tracing were carried out. A wide variability in environmental microbial contamination, both for air and surfaces, was observed. Cladosporium spp., Alternaria spp., Aspergillus spp., and Penicillium spp. were the most frequently found microfungi. Bacteria such as Streptomyces spp., Bacillus spp., Sphingomonas spp., and Pseudoclavibacter as well as unculturable colonies were characterized by molecular investigation. CFD simulation results obtained were consistent with the experimental data on microclimatic conditions. The tracing and distribution of particles showed the different slice planes of diffusion mostly influenced by the convective airflow. This interdisciplinary research represents a contribution towards the definition of standardized methods for assessing the biological and microclimatic quality of indoor cultural heritage environments.

The 2010 WHO classification of digestive neuroendocrine neoplasms: a critical appraisal four years after its introduction

This paper briefly illustrates the basis, rules of application, and present outcome of the current World Health Organization (WHO) classification for neuroendocrine neoplasms. Established in 2010 upon the proposal from the European Neuroendocrine Tumor Society (ENETS), the WHO 2010 fostered some definitional changes (most notably the use of neuroendocrine tumor (NET) instead of carcinoid) and indicated the tools of grading and staging. Specific rules for its application were also defined. The data generated from the use of WHO 2010 classification substantially endorsed its rules and prognostic efficacy. In addition, the application demonstrated some issues, among which are the possible re-definition of the cutoff for grading G1 vs G2, as well as the possible identification of cases with somewhat different clinical behavior within the G3 neuroendocrine cancer class. Overall, since the recent introduction of WHO 2010 grading and staging, it appears wise to keep the current descriptors to avoid unnecessary confusion and to generate comparable data. Homogenous data on large series are ultimately needed to solve such issues.

25 Years of neuroendocrine neoplasms of the gastrointestinal tract

This paper provides a personal pathologist's view of how neuroendocrine tumors (NET) were perceived and defined in the last quarter of a century. In years when the Helicobacter pylori, omeprazole and the adenoma-carcinoma sequence in colon carcinogenesis significantly impacted on gastrointestinal (GI) pathology daily practice, neuroendocrine neoplasms of the GI tract passed from the original carcinoid definition to the current NET and neuroendocrine carcinoma (NEC) definitions. The development of different concepts, basic tumor biology knowledge, tools for pathology diagnosis and the various World Health Organization (WHO) classifications from 1980 through 2010 are briefly reviewed and discussed.

Towards an individualized approach to bicuspid aortopathy: different valve types have unique determinants of aortic dilatation

OBJECTIVES

Bicuspid aortic valve (BAV)-related aortopathy is increasingly recognized to be a heterogeneous disease entity, although the surgical approach, from indications to techniques, is still standard rather than individualized. We aimed to define the determinants of aortic dilatation in BAV patients stratified according to the valve morphotype.

METHODS

A consecutive echocardiographic series of 622 BAV patients was analysed. Among demographic (age, sex), anthropometric (height, weight, body surface area, body mass index), clinical (associated diseases) and echocardiographic variables (valve function, ventricular parameters), the determinants of aortic root and ascending tract diameter were assessed by multivariate regression models, as well as the predictors of aortic dilatation (size index >2.1 cm/m(2)) both in the overall population and separately in groups of different valve morphotypes (RL, right-left fusion; RN, right-non-coronary fusion).

RESULTS

Independent determinants of aortic root diameter (at sinuses) were age (P < 0.001), significant aortic regurgitation (P < 0.001), sex (female protective, P < 0.001) and valve morphotype (RN protective, P < 0.001). Independent determinants of ascending aortic diameter (tubular tract) were age (P < 0.001), RN morphotype (P < 0.001), body mass index (P = 0.005) and chronic obstructive pulmonary disease (P < 0.001). In univariate analysis, the RL morphotype was associated with dilatation (ASI > 2.1 cm/m(2)) at sinuses in 41% cases vs 22% for RN (P < 0.001), and the RN morphotype was associated with dilatation at the tubular tract in 68 vs 56% for RL (P = 0.007). The presence of root dilatation was predicted by age and absence of significant stenosis in the RL morphotype subgroup, and by severe regurgitation in the RN subgroup. In the RL-type subgroup, non-regurgitant aortic valve and chronic lung disease predicted dilatation at the ascending level; and in the RN-type subgroup, age and obesity.

CONCLUSIONS

The two most common BAV morphotypes are associated with aortic dilatation at two different tracts (RL at the root; RN at the tubular ascending tract) independently of valve function. Moreover, the determinants of aortic dilatation were at least in part different between the two morphotypes: this may provide stratification criteria for individualized methods of follow-up and treatment.

Endoscopic snare papillectomy: a possible radical treatment for a subgroup of T1 ampullary adenocarcinomas

Pancreaticoduodenectomy is the standard care for invasive ampullary adenocarcinomas. However, endoscopic snare papillectomy (ESP) might play a curative role in very selected patients. We studied a series of 15 patients with T1 ampullary adenocarcinoma who were treated by ESP alone and followed up for a mean of 29.6 ± 21.9 months (range 8 - 81 months). ESP was curative for eight patients (57.1 %). No tumor-related death was observed in patients with a cancer infiltration depth of ≤ 4 mm. According to this preliminary experience, we suggest that this measurable variable threshold should be considered as a possible basis for future large-scale studies.

EUS-guided fine needle tissue acquisition for the diagnosis of pleural metastases from endometrial cancer

Transesophageal EUS-FNA have become a useful tool in the evaluation of the mediastinum, especially during the staging work-up examination of patients with non-small-cell lung cancer (NSCLC) or other malignancies. We report a challenging case of a 53 years-old woman with an endometrial adenocarcinoma who subsequently presented with right pleural effusion, diffuse pleural thickening with few pleural lesions. The patient referred a long history of exposure to amiantum, this posing a differential diagnosis between primary pleural tumour (mesothelioma) and neoplastic pleural localization of the endometrial cancer. The cytological examination of the pleural effusion (sampled via thoracenthesis) was not adequate to reach a diagnosis. Although a right-video-assisted thoracoscopy was considered the gold standard in this clinical setting to achieve a tissue acquisition of the pleura, an EUS (as the least invasive procedure) was attempted to reach a definitive diagnosis. EUS-FNTA of the pleura was done using a 19-Gauge needle and the pathological and immunophenotypic features were diagnostic for a pleural metastasis of high-grade endometrial serous carcinoma. The patient received adjuvant chemotherapy with a complete regression of the pleural lesions. We take the opportunity of this challenging case to discuss the efficacy and safety of EUS-FNAT to sample the pleural lesions with the use of a large calibre needle if the lesion lies just under the EUS cursor. We may assume that, in selected patients, this technique could be presented as a viable option to the more invasive surgical procedure, which has been previously the gold standard for the pleural tissue acquisition.

Elastofibroma dorsi: clinicopathological analysis of 71 cases

INTRODUCTION

Elastofibroma dorsi (ELD) is a rare soft tissue benign tumor of the chest wall. So far, only a few large series have been reported in the English literature and, to the best of our knowledge, radiological assessment and clinical management remain without consensus. The aim of this study is to provide, on the basis of a single-institutional, homogeneous and large experience, ample evidences to support etiological and "clinical-usefulness-grade" classification hypotheses.

MATERIALS AND METHODS

We report observational information on 71 ELD cases and, on the basis of these, we discuss the clinical onset features, radiological and surgical characteristics, as well as pathological and immunohistochemical evidences.

RESULTS

In the period between January 1994 and September 2009, 71 consecutive patients (23 male and 48 female; mean age: 60.2 years; standard deviation [SD] ± 8.3 years) with ELD diagnosis were surgically treated at our institution. ELD was right sided in 34 patients (47.9%), left in 25 (35.2%), and bilateral in 12 (16.9%). In nine patients, ELD were diagnosed synchronously and three metachronously. Thirty-eight patients (53.5%) had no significant symptoms; 33 (46.5%) reported a clunking sensation or a localized scapular swelling during the shoulder movements. Sixty-six (93%) patients underwent surgical excision with radical intent while in five patients, a biopsy-only procedure was undertaken. Mean hospital stay was 3.0 days (SD ± 1.2 days) with a morbidity of 10.6% (one case of major postoperative bleeding requested a surgical revision of the hemostasis). At the univariate analysis, the probability of occurrence of morbidity increases with tumor size. All operated patients are alive and well at follow-up with no sign of recurrence and complete resolution of the symptomatology.

CONCLUSIONS

ELD is relatively uncommon, benign, and well controlled by radical surgery.

Pulmonary malacoplakia at early stage: use of polymerase chain reaction for detection of Rhodococcus equi

Malacoplakia is a rare inflammatory condition characterized by the accumulation of benign macrophages associated with pathognomonic Michaelis-Gutmann bodies (MGBs). It is usually found in the genito-urinary tract, and has been associated with immunocompromised states. In this short report, we present 5 patients with pulmonary nodules clinically suspicious for primary or metastatic lung cancer. The histologic examination of the surgical specimens revealed a nonspecific granulomatous chronic disease, and despite the paucity of classical MGBs, a pulmonary malacoplakia was suspected. In all cases the opportunistic pathogen Rhodococcus equi (R. equi) was identified by 16S rRNA gene sequence analysis, leading to the final pathological diagnosis of malacoplakia. We conclude that pulmonary malacoplakia associated with R. equi is a rare disease affecting also immunocompetent patients. The pathogenesis and the diagnostic problems are discussed. Since infection by R. equi is treatable, the importance of its early recognition should be emphasized.

Synovial sarcoma of the parotid gland: a case report and review of the literature

Parotid gland tumours are very heterogeneous, being benign in 80% of cases, and generally arising from epithelial cells. Nevertheless, a small group of non-epithelial tumours representing just 5% of all salivary gland neoplasms has also been reported, the most common of these being haemangioma, especially in children. However, lymphomas, neuromas, neurofibromas, lipomas and sarcomas can also be found. Synovial cell sarcoma is a high grade histological variety of sarcoma and is generally located near large joints and bursae of the lower extremities, such as knee, tendon sheaths and bursal structures. It is rarely found in the head and neck region due to its lack of synovioblastic tissue. Herewith, the case of a young female, affected by a synovial sarcoma of the left parotid gland, is presented and a review is made of the literature on this rare specific localization focusing on management and outcome.

Diffusion-weighted imaging in breast cancer: relationship between apparent diffusion coefficient and tumour aggressiveness

AIM

To assess the utility of diffusion-weighted imaging in diagnosing and characterizing breast malignancy.

MATERIALS AND METHODS

From April 2006 to April 2009, all consecutive patients with breast cancer undergoing breast magnetic resonance imaging (MRI) and subsequent surgery in our hospital were enrolled in this study. MRI was performed using a 1.5 T MRI unit using a dedicated, bilateral, four-channel breast coil. The MRI protocol included a diffusion sequence acquired using b values of 0 and 1000 s/mm(2). For each malignant lesion the relationships between tumour grade and histology and the relative value of the apparent diffusion coefficient (ADC) were analysed.

RESULTS

There were 136 female patients with 162 lesions. Histology revealed 149 invasive carcinomas and 13 ductal carcinomas in situ. There were 34 grade 1, 61 grade 2, and 67 grade 3 lesions. The mean ADC value of all malignant lesions was 1.03×10(-3) mm(2)/s. The mean ADC values for invasive and in situ carcinomas were 1.03×10(-3) mm(2)/s and 1.05×10(-3) mm(2)/s, respectively. The mean ADC values for grade 1, 2, and 3 tumours were 1.25×10(-3) mm(2)/s, 1.02×10(-3) mm(2)/s, and 0.92×10(-3) mm(2)/s, respectively. A statistically significant (p<0.001) inverse correlation was disclosed between the ADC value and the tumour grading. The mean ADC value of the "less aggressive" group of disease (G1 and in situ lesions) was 1.19×10(-3) mm(2)/s, whereas the mean ADC value of the "more aggressive" group (G2-G3 invasive carcinomas) was 0.96×10(-3) mm(2)/s (p<0.001).

CONCLUSION

The study confirms the usefulness of diffusion imaging in assessing the aggressiveness of breast tumours. ADC appears to be a promising parameter in the evaluation of the degree of malignancy of breast cancer tissue.

4-Amino-3(2H)-pyridazinones bearing arylpiperazinylalkyl groups and related compounds: synthesis and antinociceptive activity

A series of 4-amino-3(2H)-pyridazinones substituted at position 2 with arylpiperazinylalkyl groups and analogues were synthesized and their antinociceptive effect was evaluated in the mouse abdominal constriction model. Preliminary SARs studies were performed. Several of the novel compounds dosed at 100 mg/kg s.c. significantly reduced the number of writhes induced by the noxious stimulus. Compound 12e showed 100% inhibition of writhes and was able to protect all the treated animals from the effect of the chemical stimulus. Subsequent dose-response studies revealed 12e to be almost 40-fold more potent than the structurally related Emorfazone.

Modification of Nociception and Morphine Tolerance by the Selective Opiate Receptor-Like Orphan Receptor Antagonist (–)-cis-1-Methyl-7-[[4-(2,6-dichlorophenyl)piperidin-1-yl]methyl]-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-ol (SB-612111)

(-)-cis-1-Methyl-7-[[4-(2,6-dichlorophenyl)piperidin-1-yl]methyl]-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-ol (SB-612111) is a novel human opiate receptor-like orphan receptor (ORL-1) antagonist that has high affinity for the clonal human ORL-1 receptor (hORL-1 K(i) = 0.33 nM), selectivity versus mu-(174-fold), delta-(6391-fold), and kappa (486-fold)-opioid receptors and is able to inhibit nociceptin signaling via hORL-1 in a whole cell gene reporter assay. SB-612111 has no measurable antinociceptive effects in vivo in the mouse hot-plate test after intravenous administration but is able to antagonize the antimorphine action of nociceptin [ED(50) = 0.69 mg/kg, 95% confidence limit (CL) = 0.34-1.21]. SB-62111 administration can also reverse tolerance to morphine in this model, established via repeated morphine administration. In addition, intravenous SB-612111 can antagonize nociceptin-induced thermal hyperalgesia in a dose-dependent manner (ED(50) = 0.62 mg/kg i.v., 95% CL = 0.22-1.89) and is effective per se at reversing thermal hyperalgesia in the rat carrageenan inflammatory pain model. These data show that an ORL-1 receptor antagonist may be a useful adjunct to chronic pain therapy with opioids and can be used to treat conditions in which thermal hyperalgesia is a significant component of the pain response.

Evidence for a selective role of the delta-opioid agonist [8R-(4bS*,8aalpha,8abeta, 12bbeta)]7,10-Dimethyl-1-methoxy-11-(2-methylpropyl)oxycarbonyl 5,6,7,8,12,12b-hexahydro-(9H)-4,8-methanobenzofuro[3,2-e]pyrrolo[2,3-g]isoquinoline hydrochloride (SB-235863) in blocking hyperalgesia associated with inflammatory and neuropathic pain responses

The specific involvement of the delta-opioid receptor in the control of nociception was explored by investigating the pharmacological activity in vivo of a selective, orally active, and centrally penetrant delta-opioid agonist. [8R-(4bS*,8aalpha,8abeta,12bbeta)]7,10-dimethyl-1-methoxy-11-(2-methylpropyl)oxycarbonyl 5,6,7,8,12,12b-hexahydro-(9H)-4,8-methanobenzofuro[3,2-e]pyrrolo[2,3-g]isoquinoline hydrochloride (SB-235863) is a new pyrrolomorphinan with high affinity (Ki = 4.81 +/- 0.39 nM) for the delta-opioid receptor, full agonist activity, and binding selectivity versus the mu- and kappa-opioid receptors of 189-fold and 52-fold, respectively. Perorally administered SB-236863 was inactive in the rat tail-flick and hot-plate tests of acute pain response, but potently reversed thermal hyperalgesia in rats resulting from a carrageenan-induced inflammatory response. This activity could be blocked by the delta-opioid antagonist naltrindole (3 mg/kg s.c.), but selective mu- and kappa-opioid antagonists were ineffective. Naltrindole (1 microg i.c.v.) also blocked the activity of 10 mg/kg (p.o.) SB-235863, showing that the compound activates delta-opioid receptor sites in the central nervous system. SB-235863 was additionally effective at reversing chronic hyperalgesia in the Seltzer rat model of partial sciatic nerve ligation after peroral administration. These data show that the delta-opioid receptor plays a selective role in regulating evoked and lasting changes in nociceptive pain signaling. Classical side effects of mu- and kappa-opioid receptor activation (slowing of gastrointestinal transit and motor incoordination, respectively) were not observed after administration of 70 mg/kg (p.o.) SB-235863, nor was evoked seizure activity affected. These results suggest a selective and limited role of delta-opioid receptors in the modulation of nociception.

Detection of Listeria monocytogenes in Italian-style soft cheeses

AIMS

A rapid detection system specific for Listeria monocytogenes and based on the polymerase chain reaction (PCR) was developed.

METHODS AND RESULTS

Primers annealing to the coding region of the actA gene, critically involved in virulence and capable of discrimination between two different alleles naturally occurring in L. monocytogenes, have been utilized. The procedure was applied to recover L. monocytogenes cells in artificially contaminated fresh Italian soft cheeses (mozzarella, crescenza and ricotta). Low levels of L. monocytogenes were detected in mozzarella and crescenza homogenates (0.04-0.4 and 4 CFU g(-1), respectively) whereas in ricotta the detection limit was higher (40 CFU g(-1)).

CONCLUSIONS

This PCR-based assay is highly specific as primers used recognize the DNA from different L. monocytogenes strains of clinical and food origin, while no amplification products result with any other Listeria spp. strains.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study highlighted a low-cost and rapid procedure that can be appropriated for the detection in real time of low L. monocytogenes levels in soft cheese.

Localized ridge augmentation using titanium micromesh

Guided bone regeneration (GBR) has been used recently for the regeneration of bone in conjunction with the placement of dental implants, for augmentation of resorbed alveolar crests, and to treat localized ridge deformities. Twenty-two patients with alveolar crest defects or peri-implant dehiscences participated in this study. Titanium implants were inserted, and the defects were covered with a titanium micromesh, above which was positioned an e-PTFE membrane. After healing, the 2 membranes were removed and a small specimen of the underlying tissues was retrieved with a small trephine. The postoperative healing was mostly uneventful, and only a few dehiscences with membrane exposure were observed. The space under the membranes was, in all patients, filled by a tissue with the macroscopic features of newly formed bone. No residual bone defects were observed and an increase of the alveolar width or height was observed. No untoward effects on bone regeneration were observed in the cases with membrane exposure. Histology showed that the underlying regenerated tissues were composed, in all cases, by newly formed bone. In conclusion, our results show that very satisfactory results concerning GBR techniques can be obtained even without the use of grafts under barrier membranes.

Implant periapical lesion: a clinical and histologic case report

A new pathologic entity called implant periapical lesion has been recently described. This lesion could be produced by contamination of the implant surface, overheating of bone, overloading of the implant, presence of a pre-existing bone pathology, presence of residual root fragments and foreign bodies in bone, implant placement in an infected maxillary sinus, implant placement in a poor bone quality site, or lack of biocompatibility. A 49-year-old female patient underwent the placement of a screw-shaped titanium dental implant in the premolar region of the right mandible Six months after implant insertion, the patient presented with a persistent pain resistant to analgesics. No fistula was present at a clinical intraoral examination. A periapical x-ray showed the presence of a radiolucency at the apical portion of the implant; this image was confirmed by a CT Scan. The implant was removed. After implant removal, the pain disappeared completely. The specimen was processed to obtain thin ground sections. The histologic examination showed the presence of necrotic bone in the external and apical portion of the antirotational hole of the implant. The etiology of the implant failure in this instance could be related, probably, to an implant contamination of the apical portion of the implant.

Immediate postextraction implants: a histologic and histometric analysis in monkeys

The aim of this study was to evaluate the reaction of peri-implant tissues to immediately placed titanium plasma-sprayed implants into extraction sockets. Six macaca fascicularis monkeys were used in the study. A total of 36 titanium plasma-sprayed implants (PHI, Legnano, Italy) were inserted in both arches (18 in the posterior maxilla and 18 in the posterior mandible). The two premolars and the first molars of the maxilla and the mandible of all animals were extracted, and immediate postextraction implants were placed. After a releasing periosteal incision, the flap was coronally repositioned and sutured. No barrier membranes were used, and the only graft material used was autogenous bone chips. The implants were loaded after 2 months. Six months after implant loading, a block section was carried out, the remaining defects were filled with nonresorbable hydroxyapatite, and all 36 implants were retrieved. The implants were treated with the Precise System (Assing, Rome, Italy), to obtain thin ground sections. A total of three slides were cut for each implant and were examined under normal and polarized light. A histomorphometrical analysis was done. All implants were covered by compact, mature bone under examination in light microscopy. A very high bone-implant contact percentage (65-70%) was observed. No bone loss was present after the loading period. These results indicate that implants placed into fresh extraction sites grafted with autogenous bone chips will heal in a predictable way.

Infection of human enterocyte-like cells with rotavirus enhances invasiveness of Yersinia enterocolitica and Y. pseudotuberculosis

Mixed infection with rotavirus and either Yersinia enterocolitica or Y. pseudotuberculosis was analysed in Caco-2 cells, an enterocyte-like cell line highly susceptible to these pathogens. Results showed an increase of bacterial adhesion and internalisation in rotavirus-infected cells. Increased internalisation was also seen with Escherichia coli strain HB101 (pRI203), harbouring the inv gene from Y. pseudotuberculosis, which is involved in the invasion process of host cells. In contrast, the superinfection with bacteria of Caco-2 cells pre-infected with rotavirus resulted in decreased viral antigen synthesis. Transmission electron microscopy confirmed the dual infection of enterocytes. These data suggest that rotavirus infection enhances the early interaction between host cell surfaces and enteroinvasive Yersinia spp.

Acid tolerance in Listeria monocytogenes influences invasiveness of enterocyte-like cells and macrophage-like cells

Clinical and food Listeria monocytogenes isolates, pre-exposed to mild acidic conditions, were able to readily develop acid tolerance, irrespective of their origin. We attempted to investigate the influence of acid tolerance mechanisms, either constitutive or induced, on the invasive behaviour of this facultative food-borne pathogen. Entry efficiency and intracellular growth of acid-tolerant strains were evaluated in in vitro cell models capable to mimic in vivo target cells, such as enterocytes and macrophages. An acid-adapted L. monocytogenes wild-type strain and a constitutively acid-tolerant mutant were able to enter enterocyte-like (Caco-2) cells as well as to survive and proliferate intracellularly in lipopolysaccharide-treated macrophage-like (J774.A1) cells, at a significant increased extent by respect of the non acid-adapted wild-type strain. These findings add new information about the influence of the acid tolerance response on L. monocytogenes virulence, suggesting that in acid-adapted bacteria the early events of pathogenesis which allow the colonization and the spread of bacteria in the host may be highly promoted.

Modulation of actA gene expression in Listeria monocytogenes by iron

This study analysed the invasiveness of Listeria monocytogenes into enterocyte-like Caco-2 cells in which iron depletion was achieved by picolinic acid treatment. Both entry and intracellular multiplication varied depending on the endogenous iron content of bacterial and eukaryotic cells. The behaviour within enterocytes was correlated with a 10-fold increased transcription of the actA gene observed in bacterial cells grown under conditions of iron stress.

Immediate one-stage postextraction implant: a human clinical and histologic case report

The placement of an implant immediately after tooth extraction may have the following advantages: reduction in morbidity, treatment time, and treatment costs; preservation of the residual ridge width and height; optimal esthetic result; and easier definition of implant position. The aim of the present study was the presentation of a human clinical and histologic report involving a nonsubmerged implant placed in a mandibular postextraction site and removed because of persistent pain. At low-power magnification, it was possible to see that newly formed bone with wide osteocyte lacunae was present around the implant. A 1.5-mm sulcular epithelium was visible on one side of the implant, with a 0.5-mm epithelial attachment. The thickness of the supracrestal connective tissue was 3.2 mm. This connective tissue was dense, had few cells, was well vascularized, and showed no evidence of an inflammatory infiltrate. Under polarized light, it was possible to observe that the connective fibers were arranged perpendicular to the implant surface and that these fibers became parallel near the implant. These results show that human immediate postextraction implants can have a high percentage of bone-implant contact.

Tissue reactions, fluids, and bacterial infiltration in implants retrieved at autopsy: a case report

A 72-year-old patient underwent the placement of 2 screw-type implants. After 5 months the patient died of a massive stroke, and a block section of the portion of the mandible containing the implants was done. The specimen was treated to obtain thin ground sections. A 1- to 5-micron gap was present between the implant and the healing cover screw, and this space was filled by bacteria and calculus; bacteria were also present in the most apical portion of the hollow part of the implant. An inflammatory infiltrate was present in the connective peri-implant tissues. The spaces between all implant components (implant, abutment, and healing screw) can act as conduits and reservoirs for bacteria, which could cause inflammation of the peri-implant soft tissues. In conclusion, the histologic data from this autopsy case may help to confirm the penetration by fluids and bacteria into the internal portion of the implants, obtained from previous in vitro and in vivo studies.

The anti-invasive effect of bovine lactoferrin requires an interaction with surface proteins of Listeria Monocytogenes

The anti-invasive effect of bovine lactoferrin (BLf) and of bovine transferrin (BTf) towards L. monocytogenes, an intracellular facultative food-borne pathogen, was assayed in the enterocyte-like cell line Caco-2. When 0.5 mg/ml BLf were added during the infection time or preincubated with bacteria the number of internalized bacteria was noticeably decreased whereas BLf was ineffective when preincubated with the enterocytes or added post infection. BTf was deprived of any effect. Results from direct binding and Western blotting assays provided evidence that two L. monocytogenes surface proteins, of approximately 80 and 60 kDa, specifically reacted with BLf. These findings strongly support the hypothesis that the antiinvasive mechanism of BLf is due to its interaction with bacterial surfaces, but not to its binding with eukaryotic cells.

Invasion of human cultured cells by Prevotella nigrescens

Invasion of gingival and junctional epithelial cells has been recently proposed as a potentially relevant mechanism in the pathogenesis and recurrence of periodontal disease. The gram negative anaerobe Prevotella nigrescens was shown to be involved in the development of periodontal lesions in man, suggesting a possible involvement of invasivity as a mean to circumvent the host immune surveillance and other hostile factors. Appropriately designed invasion assays demonstrated that P. nigrescens efficiently invades human epithelial cells, through a mechanism whose efficiency is influenced by the phase of growth, by the multiplicity of infection, and by the cell line used, and that requires microfilament integrity, but is not affected by an impairment of microtubule organization. Intracellular replication assays suggested that P. nigrescens probably multiplies within Kb epithelial cells, causing extensive cell alterations. Invasion of gingival epithelial cells could consequently be a basic step in the virulence mechanism of the species.

Natural milk fatty acids affect survival and invasiveness of Listeria monocytogenes

The effects of 12 fatty acids, naturally occurring in milk from several mammalian species, on the survival and invasion ability of Listeria monocytogenes, a food-borne pathogen, were determined. The survival was tested in the presence of 200 micrograms ml-1 fatty acids suspended in brain hearth infusion broth or in storage conditioning solution (NaCl 1%) of Mozzarella cheese, an Italian soft unripened cheese, at pH 7.0 or 5.0. Lauric (C12:0), linoleic (C18:2) and linolenic (C18:3) acids exerted the strongest bactericidal activity. The invasive efficiency of L. monocytogenes, determined in the Caco-2 enterocyte-like cell line, was strongly decreased in the presence of the fatty acids tested (from about 20 to 500-fold). This research suggests that naturally occurring fatty acids of milk, supplemented in milk derivatives, could affect both bacterial growth and invasiveness and consequently, could serve as barriers towards L. monocytogenes infection.

Extradural hematomas in children

BACKGROUND

Extradural hematomas are rate complications of head injures in children often resulting from minor head traumas. Therefore the management of these ordinary traumas remains controversy since in many asymptomatic cases the intracranial bleeding is detected only by CT scan.

METHODS

During the study period between January 1991 and September 1995 sixty-one patients ranging in age from 5 months to 12 years were operated on for epidural hematomas. They represent about the 3% of all patients admitted for head injury in the same period in our Division. According to the age, children were divided in three groups (G1, G2, G3). Males predominate over females in each group of age. The mechanism of injury, the clinical findings, the neurological assessment on admission, the site of hematoma and the presence of skull fracture were examined in order to identify clinical and diagnostic parameters predicting developing intracranial complications.

RESULTS

The most common cause of head trauma was accidental falls in children under 5 years of age. Otherwise bicycle, pedestrian and car accidents are the main type of injury in older patients. A skull fracture was identified in 49 cases with a homogeneous distribution among the groups of age. Recurrent vomiting was found in about 70% of cases. A loss of consciousness was frequently reported (78%) in older children. Outcome mainly depended on Glasgow or Children Coma Score on admission. In our series the overall mortality rate was 4.9%.

CONCLUSIONS

Our data according with the literature suggest that localized skull traumas, suspected fractures, a loss of consciousness after trauma and recurrent vomiting can be recommended as indications for intracranial complications.

Giant intracavernous carotid aneurysm in a child. Case report

The occurrence of intracranial aneurysm in the pediatric population is a rare phenomenon. A case of giant aneurysm of the intracavernous carotid artery in a child is reported. Clinicoradiological findings are presented and the surgical procedure is illustrated. Authors stress the value of monitoring the cerebral collateral blood flow before and during the operation.