Experience of the combined use of the cusp-overlap projection and auricular pacing in transcatheter aortic-valve replacement with the self-expanding valves

Introduction

Need of permanent pacemaker implantation (PPI) continues to be an undesirable side-effect after transcatheter aortic-valve replacement (TAVR), mostly in self-expandable (SE) valves. Recently, different techniques have arisen, as the cusp-overlap projection (COP) to better control TAVR implantation depth, and the sequential atrial pacing (AP) after deployment to test atrioventricular (AV) conduction. However, the combination of both techniques has not been tested yet. We sought to determine if the combination of COP and AP can decrease the need of PPI after SE aortic prothesis.

Methods

We retrospectively studied 253 patients in sinus rhythm who underwent TAVR procedure with SE valves between 2018 and 2021, and compared standard implantation (n=143) with the combined use of COP and AP (n=110). Patients with permanent atrial fibrillation or previous pacemaker were excluded. Assessment included EKG, imaging, immediate and 30-day follow-up. AP was performed after TAVR in the absence of complete AV block at rates of 70 to 120 beats/min (or until AV Block was observed).

Results

Median patient age was 80 [75–85] years old and 52.2% were female. No significant differences could be appreciated in baseline demographics or treatment. Both cohorts had similar EKG intervals and similar rates of conduction disturbances (Table 1). Patients with CO+AP displayed bigger outflow tract perimeters (p=0.003). Also, the CO+AP cohort underwent more frequent predilation prior to valve deployment (p<0.001).

During TAVR complete AV block occurred in 4.6% of the CO+AP cohort vs 14.8% in the standard group (p=0.002). Among patients with transient or no conduction disturbances immediately after deployment, AP showed Wenckebach phenomenon in 22 subjects at a median heart rate of 110 bpm. PPI was considered within 24 hours when Wenckebach phenomenon developed below 90 bpm. Testing atrio-his conduction led to a significant decrease in the next 24-hour surveillance with a temporary pacemaker in the COP+AP cohort (23.1% vs 90.2% in the standard cohort, p<0.0001). Time of hospitalization was significantly reduce in the COP + AP cohort (mean stay 2 [1; 3] days vs 5 [4; 8] days in the standard cohort, p<0.0001), and the total amount of total PPI at that time was still lower CO+AP group (12.7% in CO+AP group vs 21.0% in the standard, p=0.121) (Figure 1).

On a 30-day follow-up, the rate of PPI after TAVR remained significantly decreased in the COP+AP cohort (p=0.039, Figure 1).

Conclusion

Combining COP with AP reduces the need of immediate and short-term PPI and reducing on-admission conduction surveillance and hospitalization stay after self-expandable TAVR.

Funding Acknowledgement

Type of funding sources: None.

Early results of a simplified protocol over standard in patients undergoing transcatheter aortic-valve replacement

Introduction

Transcatheter aortic-valve replacement (TAVR) procedure has been simplified, being now a less-invasive minimalist strategy the standard of treatment. Therefore, length of hospitalization has decreased, and early-discharge (ED) (<72 hour) protocols are in development.

Lately, additional techniques to optimize TAVR procedure have arisen, such as the use of radial approach as the secondary access, conscious sedation, cusp overlap projection (COP) to better control the implantation depth in self-expanding (SE) valves, or atrial pacing (AP) after deployment to test atrioventricular (AV) conduction. With the combination of these 4 maneuvers, we have developed an ED protocol, and hereby present the immediate results.

Methods

We prospectively studied 176 patients who underwent staged and transfemoral TAVR procedure with our novel protocol between May 2020 and December 2021 (Protocol) and compared them with a retrospective cohort of 175 patients who underwent standard TAVR between January 2018 and April 2020 (Standard). The protocol cohort included the use of conscious sedation with midazolam and fentanyl, routine radial approach as the secondary access, use of the CO projection, and AP after deployment in the absence of complete AV block, at rates of 70 to 120 beats/min (or until AV Block was observed) in 10 beats/min increments for a total of 20 beats at each increment. As part of this protocol, patients remained in general cardiology ward, avoiding ICU stay, with rapid recovery and early mobilization (After 6 hours in the absence of bleeding). In the absence of complications patients were discharged within 24–48 hours and reviewed a week and a month later in clinic. Initial assessment included EKG, echocardiogram, in hospital and 30-day follow-up.

Results

Median patient age was 80 years old and 49.9% were female. Despite higher rates of hypertension in the standard cohort (p=0.038), no significant differences could be appreciated in baseline demographics, EKG or imaging findings (Table).

Even with higher rates of predilation, CO and AP, the length of procedure and the use of contrast was lower in the protocol cohort. Rates of intraprocedural AV block were similar among groups (p=p.21), but AP led to a significant lower need of temporary pacemaker surveillance (p<0.0001). The use of radial access also tend to diminish immediate bleeding and vascular complications.

According to protocol, the median length of stay was reduced to 2 [1; 4] days (p<0.0001).

At a 30-day follow up, the incidence of major adverse cardiac events was low and similar among groups (p=0.67) (Figure), with no significant differences in the incidence of permanent pacemaker implantation, heart failure admission, bleeding o vascular complication (Figure)

Conclusion

A simplified TAVR protocol combining radial access, CO, AP can be adopted safely, leading to TAVR patients early discharge, with no major events on an immediate 30-day follow-up.

Funding Acknowledgement

Type of funding sources: None.

Transcatheter aortic-valve replacement with the self-expanding valve Portico in low-risk patients

Background

In the past years, transcatheter aortic-valve replacement (TAVR) has risen as a feasible and safe option for patients with aortic stenosis, been now an option of treatment in low-risk (Euroscore II <4%) patients over 75 years.1

Evidence of this treatment with self-expandable supraanular bioprothesis Evolut have widely proven to be no inferior to surgical valve replacement.2 Nevertheless, experience of the annular self-expandable prothesis Portico available in this population is scarce.

Purpose

We present our early experience with the annular self-expandable prothesis Portico in our low-risk population.

Methods

We retrospectively studied 219 symptomatic low-risk patients with who underwent TAVR procedure with self-expandable valves between 2018 and 2021. Assessment included echocardiogram, immediate and 30-day follow-up, as well as last clinical visit follow-up. 92 subjects received an annular Portico prothesis. Our reference group was the suprannular prothesis Evolut (n=127), already validated for low-risk patients in clinical trials.2

Results

The mean age of the patients was 79 years, 43.4% were women, and all the patients were at low surgical risk (2.2 [1.6; 3.0]). No significant differences could be appreciated in baseline demographics and echocardiographic characteristics except for body mass index (BMI), which was higher in the Portico group (p<0.001) (Table).

Procedure length was similar, with the particular need of higher predilation in the Portico group according to recommendations. Both self-expandable prothesis had similar rates of intraprocedural atrioventricular block, bleeding, vascular complications, stroke, and new onset atrial fibrillation.

Mean aortic-valve gradients before discharge were lower at the suprannular Evolut group than in the annular Portico group, and immediate residual aortic regurgitation was almost inexistent in both groups (Table 1).

At a 30-day follow up, the incidence of major adverse cardiac events was low and similar among groups (p=0.6) (Figure 1), with no significant differences in the incidence of permanent pacemaker implantation, heart failure admission, stroke, bleeding o vascular complication (Figure 1).

Conclusion

Annular aortic self-expandable prothesis Portico is a feasible alternative for patients with AS and low surgical risk who undergo TAVR procedure.

Funding Acknowledgement

Type of funding sources: None.

Analysis of co-isogenic prion protein deficient mice reveals behavioral deficits, learning impairment, and enhanced hippocampal excitability

Background

Cellular prion protein (PrP^C) is a cell surface GPI-anchored protein, usually known for its role in the pathogenesis of human and animal prionopathies. However, increasing knowledge about the participation of PrP^C in prion pathogenesis contrasts with puzzling data regarding its natural physiological role. PrP^C is expressed in a number of tissues, including at high levels in the nervous system, especially in neurons and glial cells, and while previous studies have established a neuroprotective role, conflicting evidence for a synaptic function has revealed both reduced and enhanced long-term potentiation, and variable observations on memory, learning, and behavior. Such evidence has been confounded by the absence of an appropriate knock-out mouse model to dissect the biological relevance of PrP^C, with some functions recently shown to be misattributed to PrP^C due to the presence of genetic artifacts in mouse models. Here we elucidate the role of PrP^C in the hippocampal circuitry and its related functions, such as learning and memory, using a recently available strictly co-isogenic Prnp^0/0 mouse model (Prnp^ZH3/ZH3).

Results

We performed behavioral and operant conditioning tests to evaluate memory and learning capabilities, with results showing decreased motility, impaired operant conditioning learning, and anxiety-related behavior in Prnp^ZH3/ZH3 animals. We also carried in vivo electrophysiological recordings on CA3-CA1 synapses in living behaving mice and monitored spontaneous neuronal firing and network formation in primary neuronal cultures of Prnp^ZH3/ZH3 vs wildtype mice. PrP^C absence enhanced susceptibility to high-intensity stimulations and kainate-induced seizures. However, long-term potentiation (LTP) was not enhanced in the Prnp^ZH3/ZH3 hippocampus. In addition, we observed a delay in neuronal maturation and network formation in Prnp^ZH3/ZH3 cultures.

Conclusion

Our results demonstrate that PrP^C promotes neuronal network formation and connectivity. PrP^C mediates synaptic function and protects the synapse from excitotoxic insults. Its deletion may underlie an epileptogenic-susceptible brain that fails to perform highly cognitive-demanding tasks such as associative learning and anxiety-like behaviors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12915-021-01203-0.

Deficits in coordinated neuronal activity and network topology are striatal hallmarks in Huntington's disease

Background

Network alterations underlying neurodegenerative diseases often precede symptoms and functional deficits. Thus, their early identification is central for improved prognosis. In Huntington’s disease (HD), the cortico-striatal networks, involved in motor function processing, are the most compromised neural substrate. However, whether the network alterations are intrinsic of the striatum or the cortex is not fully understood.

Results

In order to identify early HD neural deficits, we characterized neuronal ensemble calcium activity and network topology of HD striatal and cortical cultures. We used large-scale calcium imaging combined with activity-based network inference analysis. We extracted collective activity events and inferred the topology of the neuronal network in cortical and striatal primary cultures from wild-type and R6/1 mouse model of HD. Striatal, but not cortical, HD networks displayed lower activity and a lessened ability to integrate information. GABA_A receptor blockade in healthy and HD striatal cultures generated similar coordinated ensemble activity and network topology, highlighting that the excitatory component of striatal system is spared in HD. Conversely, NMDA receptor activation increased individual neuronal activity while coordinated activity became highly variable and undefined. Interestingly, by boosting NMDA activity, we rectified striatal HD network alterations.

Conclusions

Overall, our integrative approach highlights striatal defective network integration capacity as a major contributor of basal ganglia dysfunction in HD and suggests that increased excitatory drive may serve as a potential intervention. In addition, our work provides a valuable tool to evaluate in vitro network recovery after treatment intervention in basal ganglia disorders.

Development of two-photon polymerised scaffolds for optical interrogation and neurite guidance of human iPSC-derived cortical neuronal networks

Recent progress in the field of human induced pluripotent stem cells (iPSCs) has led to the efficient production of human neuronal cell models for in vitro study. This has the potential to enable the understanding of live human cellular and network function which is otherwise not possible. However, a major challenge is the generation of reproducible neural networks together with the ability to interrogate and record at the single cell level. A promising aid is the use of biomaterial scaffolds that would enable the development and guidance of neuronal networks in physiologically relevant architectures and dimensionality. The optimal scaffold material would need to be precisely fabricated with submicron resolution, be optically transparent, and biocompatible. Two-photon polymerisation (2PP) enables precise microfabrication of three-dimensional structures. In this study, we report the identification of two biomaterials that support the growth and differentiation of human iPSC-derived neural progenitors into functional neuronal networks. Furthermore, these materials can be patterned to induce alignment of neuronal processes and enable the optical interrogation of individual cells. 2PP scaffolds with tailored topographies therefore provide an effective method of producing defined in vitro human neural networks for application in influencing neurite guidance and complex network activity.

P5621Diagnostic accuracy of resting full-cycle ratio in the non-culprit artery of acute patients

Introduction

Resting full-cycle ratio (RFR) is a novel non-hyperemic index of coronary stenosis severity, independent of the timing within the cardiac cycle. Recent data has demonstrated good correlation between RFR and Fractional Flow Reserve (FFR) in stable coronary disease (SCD). However, there are no data regarding the reliability of RFR in non-culprit arteries of patients presenting with acute myocardial infarction (AMI).

Purpose

To study the diagnostic accuracy of RFR versus FFR in the non-culprit artery in AMI compared to stable lesions.

Methods

RFR, FFR, Coronary Flow Reserve (CFR), Index of Microcirculatory Resistance (IMR), and Resistance Reserve Ratio (RRR) were calculated in 67 patients with AMI and an intermediate lesion in a non-culprit artery (median time from primary PCI to study: 48 hours). Data were compared with those of a retrospective group of 66 patients with SCD.

Results

There was a higher proportion of males among patients of the AMI group (85% vs 62%, p=0.0026). Mean age was 64.5±11 years, being AMI cohort younger at presentation [62±11 vs 67±12 years in SCD cohort (p=0.04)]. Patients with AMI had a significantly lower prevalence of hypertension (52% vs 75%, p=0.006), diabetes (10% vs 32%), p=0.002) and hyperlipemia (37% vs 79%, p=0.002).

Coronary physiology parameters showed a non-normal distribution, and are expressed as median [IQR] (Table 1). In patients with AMI, FFR was lower than in patients with SCD. In contrast, RFR showed no significant difference. Both CFR and RRR were higher in the AMI group. No significant differences in IMR were found between cohorts.

Importantly, in the AMI group the correlation between RFR and FFR was 0.84 and the overall agreement 82%, with rates of false positive and negative of 15% and 3%, respectively. In SCD the correlation was 0.81 with a lower overall agreement of 69%, due mostly to a higher rate of false positive RFR (28%) (Figure 1).

Table 1. Microcirculatory parameters in non-culprit artery (AMI) and stable coronary disease (SCD) AMI (N=66) Stable (N=67) p value FFR 0.84 [0.76–0.9] 0.84 [0.76–0.9] 0.006 RFR 0.89 [0.82–0.94] 0,9 [0.84–0.94] 0.24 CFR 2.2 [1.7–3.1] 1.8 [1.1–2.6] 0.011 IMR 17 [14–27] 25 [14–38] 0.051 RRR 2.7 [2.17 - 3.9] 2.1 [1.4–3.1] 0.005 Median [IQR].

Figure 1. Correlation between RFR and FFR valueS

Conclusions

RFR shows a good correlation with FFR in AMI. Surprisingly, overall agreement is higher in the non-culprit artery in an acute setting, with a lower percentage of false positive results.

Acknowledgement/Funding

None

6115Influence of microvascular function and coronary flow in the diagnostic precision of resting full-cycle ratio

Introduction

Resting full-cycle ratio (RFR) has been recently described as a non-hyperemic index of coronary stenosis with good concordance with Fractional Flow Reserve (FFR). However, there is no information concerning the influence of microvascular function and coronary flow on RFR results.

Purpose

To determine if the accuracy of this novel parameter might be influenced by changes in microvascular function.

Methods

133 patients admitted in our center between July 2016 and December 2017 underwent coronary physiology study of an angiographically intermediate lesion. 67 subjects presented with AMI and an intermediate lesion in a non-culprit artery, and 66 subjects stable coronary disease. We performed FFR, Coronary Flow Reserve (CFR), Index of Microcirculatory Resistance (IMR) and Resistance Reserve Ratio (RRR) in all of them. We calculated RFR retrospectively from the pressure tracings.

Results

Coronary physiology parameters showed a non-normal distribution and are presented as median [IQR]: FFR 0.86 [0.79–0.92]; CFR 2.05 [1.4–2.95]; IMR 20.5 [14–32.55]; RRR 2.5 [1.85–3.63]; RFR 0.897 [0.83–0.94]. Patients with abnormal CFR displayed lower RFR values although FFR was not markedly affected (Table 1). These findings remained irrespective of the clinical scenario at presentation.

61 patients had a CFR lower than 2. Correlation between RFR and FFR was not significantly different in patients with abnormal CFR than in those with normal CFR (0,73 vs 0,88; p=0,067) (Figure 1); however, overall binary agreement between RFR and FFR was worse in patients with a low CFR (69% vs 83%; p=0,047).

48 patients had a high IMR (>25). Linear correlation between RFR and FFR was similar in patients with high and normal IMR (0,81 vs 0,83; p=0,784); likewise, binary concordance showed no significant difference between both groups (77% vs 75%, p=0,78).

The mean difference between RFR and FFR was 0,025. This was only influenced by CFR: patients with a low CFR had a smaller difference than those with a normal CFR (0,012 vs 0,035; p=0,019).

Physiology parameters by CFR group Normal CFR (≥2) Low CFR (<2) P-value FFR 0.88 [0.82–0.93] 0.84 [0.79–0.92] 0.14 RFR 0.91 [0.88–0.95] 0.86 [0.80–0.92] 0.0009 IMR 16.5 [13–27] 25 [16–45.5] 0.002 RRR 3.6 [2.7–4.9] 1.7 [1.3–2.1] <0.0001 Physiological coronary parameters (Median [IQR]) according to CFR.

Correlation between RFR and FFR by CFR

Conclusion

RFR has good overall correlation and concordance with FFR. However, RFR has a lower diagnostic accuracy in patients with a low CFR.

Acknowledgement/Funding

None

Aberrant expression of N-glycolyl GM3 ganglioside is associated with the aggressive biological behavior of human sarcomas

BACKGROUND

The aberrant expression of N-glycolyl GM3 ganglioside (NeuGcGM3) in patients with sarcomas was reevaluated by assessing the relation of this molecule with some clinicopathological features and overall survival (OS) of patients.

METHODS

Fifty formalin-fixed and paraffin-embedded specimens from patients diagnosed with sarcomas were included. For the evaluation of NeuGcGM3, the 14F7 monoclonal antibody followed by a peroxidase avidin-biotin system was used. Clinicopathological features were obtained from patient records. Survival rates were estimated by the Kaplan-Meier method and compared with the log-rank test. For multivariate analyses, the Cox regression model was used to identify independent prognostic factors for OS.

RESULTS

The majority of samples had high levels of NeuGcGM3 expression (66.0%) that showed statistical correlation with age (p = 0.014), TNM stage (p = 0.022), histological grade (p = 0.013) and proliferation rates (p = 0.012). In addition, a tendency for association with tumor depth (p = 0.070) was evidenced. In univariate survival analysis, TNM stage (p = 0.000), occurrence of metastasis (p = 0.000) and expression of NeuGcGM3 (p = 0.034) were significant prognostic factors for OS, while a tendency for association was evidenced for histological grade (p = 0.091). Among these variables, only the presence of metastasis (p = 0.001) was an independent prognostic factor on multivariate analysis.

CONCLUSIONS

The present research suggests the evaluation of NeuGcGM3 expression as a complementary prognostic factor in sarcoma, although our results need to be validated in a larger series and prospective studies. Moreover, our results could support the use of this molecule as a target for immunotherapy.

Multinuclear Ru(ii) and Ir(iii) decorated tetraphenylporphyrins as efficient PDT agents

Two novel multi-metallic porphyrin complexes were synthesised and evaluated as effective PDT agents against human breast epithelial cells (SKBR-3).

Biodegradable FeMnSi Sputter-Coated Macroporous Polypropylene Membranes for the Sustained Release of Drugs

Pure Fe and FeMnSi thin films were sputtered on macroporous polypropylene (PP) membranes with the aim to obtain biocompatible, biodegradable and, eventually, magnetically-steerable platforms. Room-temperature ferromagnetic response was observed in both Fe- and FeMnSi-coated membranes. Good cell viability was observed in both cases by means of cytotoxicity studies, though the FeMnSi-coated membranes showed higher biodegradability than the Fe-coated ones. Various strategies to functionalize the porous platforms with transferrin-Alexa Fluor 488 (Tf-AF488) molecules were tested to determine an optimal balance between the functionalization yield and the cargo release. The distribution of Tf-AF488 within the FeMnSi-coated PP membranes, as well as its release and uptake by cells, was studied by confocal laser scanning microscopy. A homogeneous distribution of the drug within the membrane skeleton and its sustained release was achieved after three consecutive impregnations followed by the addition of a layer made of gelatin and maltodextrin, which prevented exceedingly fast release. The here-prepared organic-inorganic macroporous membranes could find applications as fixed or magnetically-steerable drug delivery platforms.

Cell Death Mechanisms in Tumoral and Non-Tumoral Human Cell Lines Triggered by Photodynamic Treatments: Apoptosis, Necrosis and Parthanatos

Cell death triggered by photodynamic therapy can occur through different mechanisms: apoptosis, necrosis or autophagy. However, recent studies have demonstrated the existence of other mechanisms with characteristics of both necrosis and apoptosis. These new cell death pathways, collectively termed regulated necrosis, include a variety of processes triggered by different stimuli. In this study, we evaluated the cell death mechanism induced by photodynamic treatments with two photosensitizers, meso-tetrakis (4-carboxyphenyl) porphyrin sodium salt (Na-H₂TCPP) and its zinc derivative Na-ZnTCPP, in two human breast epithelial cell lines, a non-tumoral (MCF-10A) and a tumoral one (SKBR-3). Viability assays showed that photodynamic treatments with both photosensitizers induced a reduction in cell viability in a concentration-dependent manner and no dark toxicity was observed. The cell death mechanisms triggered were evaluated by several assays and cell line-dependent results were found. Most SKBR-3 cells died by either necrosis or apoptosis. By contrast, in MCF-10A cells, necrotic cells and another cell population with characteristics of both necrosis and apoptosis were predominant. In this latter population, cell death was PARP-dependent and translocation of AIF to the nucleus was observed in some cells. These characteristics are related with parthanatos, being the first evidence of this type of regulated necrosis in the field of photodynamic therapy.

Polysilicon-chromium-gold intracellular chips for multi-functional biomedical applications

The development of micro- and nanosystems for their use in biomedicine is a continuously growing field. One of the major goals of such platforms is to combine multiple functions in a single entity. However, achieving the design of an efficient and safe micro- or nanoplatform has shown to be strongly influenced by its interaction with the biological systems, where particle features or cell types play a critical role. In this work, the feasibility of using multi-material pSi-Cr-Au intracellular chips (MMICCs) for multifunctional applications by characterizing their interactions with two different cell lines, one tumorigenic and one non-tumorigenic, in terms of biocompatibility, internalization and intracellular fate, has been explored. Moreover, the impact of MMICCs on the induction of an inflammatory response has been assessed by evaluating TNFα, IL1b, IL6, and IL10 human inflammatory cytokines secretion by macrophages. Results show that MMICCs are biocompatible and their internalization efficiency is strongly dependent on the cell type. Finally as a proof-of-concept, MMICCs have been dually functionalized with transferrin and pHrodo™ Red, SE to target cancer cells and detect intracellular pH, respectively. In conclusion, MMICCs can be used as multi-functional devices due to their high biocompatibility, non-inflammatory properties and the ability of developing multiple functions.

Regulated necrosis in HeLa cells induced by ZnPc photodynamic treatment: a new nuclear morphology

Photodynamic therapy (PDT) is a cancer treatment modality based on the administration of a photosensitizer (PS), which accumulates preferentially in tumor cells. Subsequent irradiation of the neoplastic area triggers a cascade of photochemical reactions that leads to the formation of highly reactive oxygen species responsible for cell inactivation. Photodynamic treatments in vitro are performed with the PS, zinc-phthalocyanine (ZnPc). The PS is near the plasma membrane during uptake and internalization. Inactivation clearly occurs by a necrotic process, manifested by nuclear pyknosis, negative TUNEL and Annexin V assays and non-relocation of cytochrome c. In contrast, by increasing the incubation time, ZnPc is accumulated in the Golgi apparatus and produces cell inactivation with characteristics of apoptosis and necrosis: TUNEL positive, relocated cytochrome c and negative Annexin V assay. This type of death produces a still undescribed granulated nuclear morphology, which is different from that of necrosis or apoptosis. This morphology is inhibited by necrostatin-1, a specific inhibitor of regulated necrosis.

Percolation of spatially constrained Erdős-Rényi networks with degree correlations

Motivated by experiments on activity in neuronal cultures [ J. Soriano, M. Rodríguez Martínez, T. Tlusty and E. Moses Proc. Natl. Acad. Sci. 105 13758 (2008)], we investigate the percolation transition and critical exponents of spatially embedded Erdős-Rényi networks with degree correlations. In our model networks, nodes are randomly distributed in a two-dimensional spatial domain, and the connection probability depends on Euclidian link length by a power law as well as on the degrees of linked nodes. Generally, spatial constraints lead to higher percolation thresholds in the sense that more links are needed to achieve global connectivity. However, degree correlations favor or do not favor percolation depending on the connectivity rules. We employ two construction methods to introduce degree correlations. In the first one, nodes stay homogeneously distributed and are connected via a distance- and degree-dependent probability. We observe that assortativity in the resulting network leads to a decrease of the percolation threshold. In the second construction methods, nodes are first spatially segregated depending on their degree and afterwards connected with a distance-dependent probability. In this segregated model, we find a threshold increase that accompanies the rising assortativity. Additionally, when the network is constructed in a disassortative way, we observe that this property has little effect on the percolation transition.

Preoperative treatment with bevacizumab in combination with chemotherapy in patients with unresectable metastatic colorectal carcinoma

PURPOSE

This prospective observational study assessed the efficacy of bevacizumab in combination with chemotherapy as preoperative treatment to downsize tumours for radical resection in patients with unresectable metastatic colorectal cancer (mCRC).

PATIENTS/METHODS

Patients with mCRC initially unresectable according to predefined criteria were included. Preoperative treatment consisted of bevacizumab (5 mg/kg) combined with oxaliplatin- or irinotecan-based chemotherapy, which was followed by surgery in patients showing clinical benefit. Resection rate was the primary endpoint. Response rate (RR) and clinical benefit of preoperative chemotherapy, and overall survival (OS) were secondary endpoints.

RESULTS

A total of 120 eligible patients were included and received preoperative treatment. Chemotherapy was irinotecan-based in 73 (61 %) patients, oxaliplatin-based in 25 (21 %) and 22 (18 %) patients received more than one line. A RR of 30 % and a clinical benefit rate of 73 % were observed with preoperative chemotherapy. Metastatic resection was possible in 61 (51 %) patients. Median OS was 33 months (95 % CI 31-NA months) for patients undergoing surgery, and 15 months (95 % CI 11-25 months) in non-operated patients. Thirty-five patients experienced 59 postoperative complications (morbidity rate 57 %).

CONCLUSION

Preoperative bevacizumab-based chemotherapy offers a high surgical rescue rate in patients with initially unresectable mCRC.

Vehiculization determines the endocytic internalization mechanism of Zn(II)-phthalocyanine

It is generally accepted that compounds of nanomolecular size penetrate into cells by different endocytic processes. The vehiculization strategy of a compound is a factor that could determine its uptake mechanism. Understanding the influence of the vehicle in the precise mechanism of drug penetration into cells makes possible to improve or modify the therapeutic effects. In this study, using human A-549 cells, we have characterized the possible internalization mechanism of the photosensitizer Zn(II)-phthalocyanine (ZnPc), either dissolved in dimethylformamide (ZnPc-DMF) or included in liposomes of dipalmitoyl-phosphatidyl-choline. Specific inhibitors involved in the main endocytic pathways were used. Co-incubation of cells with ZnPc-liposomes and dynasore (dinamin-mediated endocytosis inhibitor) resulted in a significant decrease of photodamage, whereas other inhibitors did not alter the photodynamic effect of ZnPc. On the contrary, cells treated with ZnPc-DMF in the presence of dynasore, genistein (caveolin-mediated endocytosis inhibitor) or cytochalasin D (macropinocytosis and caveolin-mediated endocytosis inhibitor) showed a significant decrease in ZnPc uptake and photodynamic damage. These results suggest that ZnPc-DMF penetrates into cells mainly by caveolin-mediated endocytosis, whereas ZnPc-liposomes are internalized into cells preferentially by clathrin-mediated endocytosis. We conclude that using different drug vehiculization systems, it is possible to modify the internalization mechanism of a therapeutic compound, which could be of great interest in clinical research.

Nine steps towards a better water meter management

The paper provides a comprehensive perspective of the critical aspects to be taken into account when planning the long-term management of water meters in a utility. In order to facilitate their quick understanding and practical implementation, they have been structured into nine steps. Ranging from an initial audit up to the final periodic meter replacement planning, these steps cover three aspects of the problem - field work, laboratory work and management tasks; and each one is developed in detail paying attention to the particular data needed and noting the practical outcome it will yield.

Anomalous roughening of viscous fluid fronts in spontaneous imbibition

We report experiments on spontaneous imbibition of a viscous fluid by a model porous medium in the absence of gravity. The average position of the interface satisfies Washburn's law. Scaling of the interface fluctuations suggests a dynamic exponent z approximately 3, indicative of global dynamics driven by capillary forces. The complete set of exponents clearly shows that interfaces are not self-affine, exhibiting distinct local and global scaling, both for time (beta = 0.64 +/- 0.02, beta(*) = 0.33 +/- 0.03) and space (alpha = 1.94 +/- 0.20, alpha(loc) = 0.94 +/- 0.10). These values are compatible with an intrinsic anomalous scaling scenario.

A fungal phenoloxidase (tyrosinase) involved in pentachlorophenol degradation

Amylomyces rouxii eliminated 85% of initial pentachlorophenol (PCP) at 12.5 mg l(-1) when grown with 0.1 g tyrosine l(-1), but only 55% without tyrosine. Addition of tyrosine in the culture medium increased the monophenolase activity by 1.8-fold. Tyrosinase is thus indicated to be the phenoloxidase involved in PCP degradation by A. rouxii .

Occupational rhinitis and bronchial asthma due to TBTU and HBTU sensitization

Exposure to an increasing amount of products in the work environment is leading to new cases of occupational asthma among workers. We report the case of a worker at a pharmaceutical plant who developed occupational rhinitis and bronchial asthma due to HBTU: 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate and TBTU: 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate sensitization, two chemical products widely used in peptide synthesis and coupling. Skin tests (prick test) with HBTU and TBTU solutions in PBS were positive at a concentration of 1 mg/ml. Skin tests with the same solutions in 10 atopic controls yielded a negative result. Nasal challenge tests with these products were positive with HBTU at a concentration of 0.01 mg/ml and TBTU at a concentration of 1 mg/ml. In both cases PNIF (peak nasal inspiratory flow) decreased by more than 60% and severe sneezing and rhinorrhea were induced. Nasal challenge tests performed on 10 atopic controls with TBTU and HBTU at a concentration of 1 mg/ml were negative. We conclude that the patient presents occupational rhinitis and bronchial asthma due to TBTU and HBTU; the operational mechanism is probably immunological IgE-mediated given the positive prick tests and nasal challenge with these products.

Analysis of the −1438 G/A polymorphism of the 5-HT2A serotonin receptor gene in bulimia nervosa patients with or without a history of anorexia nervosa

A single nucleotide polymorphism (-1438 G/A) located 1438 base pairs upstream of the consensus start site of the 5-HT2A receptor gene has been reported. The hypothesis that this gene polymorphism may be a susceptibility factor in bulimia nervosa was explored in a female population of purgative bulimics. Bulimia nervosa patients who have suffered preceding anorexia nervosa episodes formed the so-called previous anorexia nervosa bulimic patient group. At variance with some previous reports, when the frequency distribution of genotypes and alleles was compared in patients and controls, no differences were detected regardless of whether the bulimia nervosa patients had suffered prior anorexia nervosa episodes.

Polymorphisms within the promoter and the intron 2 of the serotonin transporter gene in a population of bulimic patients

The serotonin transporter (5-HTT) gene is a firm candidate to explain eating disorders. In this association study, two different polymorphisms were analysed: a variable number of tandem repeat (VNTR) polymorphism in intron 2 and a deletion/insertion polymorphism (5-HTTLPR) in the promoter region. The hypothesis that these gene polymorphisms may be a susceptibility factor in bulimia nervosa (BN) was explored in a female population of 102 purgative bulimics. BN patients who have suffered preceding anorexia nervosa (AN) episodes formed the so-called previous AN bulimic patient group. In our sample of normal-eater controls and purging type bulimics, regardless of whether or not the BN patients had suffered prior AN episodes, no differences were found considering the frequencies of genotypes, alleles or haplotypes of both polymorphic regions of the 5-HTT gene.

Bilateral breast cancer associated with diffuse scleroderma

There is a strong evidence to suggest the association between breast cancer and diffuse scleroderma, though it is an infrequent occurrence. We describe the clinical and radiological findings in a patient who, over a period of 2 years, was diagnosed initially of diffuse scleroderma, next with right breast cancer and finally with left breast cancer. A review of the literature evidencing the relation between these two pathologies is provided. We suggest that special vigilance for tumoral pathology of the breast should be performed in patients with systemic scleroderma.

Anomalous roughening of Hele-Shaw flows with quenched disorder

The kinetic roughening of a stable oil-air interface moving in a Hele-Shaw cell that contains a quenched columnar disorder (tracks) has been studied. A capillary effect is responsible for the dynamic evolution of the resulting rough interface, which exhibits anomalous scaling. The three independent exponents needed to characterize the anomalous scaling are determined experimentally. The anomalous scaling is explained in terms of the initial acceleration and subsequent deceleration of the interface tips in the tracks coupled by mass conservation. A phenomenological model that reproduces the measured global and local exponents is introduced.

Facial edema associated with thyroid autoimmunity

BACKGROUND

There is growing evidence that some cases of chronic urticaria and angioedema are associated with thyroid autoimmunity. We present the case of a 42-year old woman with a two month long evolution of edema in the right hemiface associated with thyroid antibodies.

METHODS

Skin tests were performed with a standard series of aeroallergens and foods and were negative. Epicutaneous tests were performed with a series of contact allergens with a negative result. The chest X-ray was normal. A complete blood count was performed with ESR, biochemistry study, proteinogram, coagulation, complement, rheumatoid factor, anti-nuclear antibodies, hydatidosis and hepatitis serologies, urine sediment and stool parasitology, which were normal. The TSH was normal and, among the thyroid antibodies, the thyroglobulin ones (492 IU/mL) were positive and the microsomal ones were negative.

RESULTS

The edema remitted with the 2-month long thyroxin treatment. In spite of the clinical response, and although the thyroglobulin antibodies initially suffered a small decrease, they increased to values which greatly surpassed the initial ones, coinciding with a relapse of the facial edema, so that treatment was re-initiated with thyroxin, and the picture subsided again.

CONCLUSIONS

Some cases of localized edema can be associated with thyroid antibodies and respond to treatment with thyroxin.

Extraskeletical malformations in the Jarcho-Levin syndrome: postmortem study of three cases

We report on pathologic examination of three autopsied newborns with Jarcho-Levin syndrome. The most important abnormalities noted were multiple extraskeletical defects such as cardiovascular, urogenital, respiratory, and central nervous system malformations. These cases add new information to the multiple vertebral segmentation defects found in this syndrome.

[In-hospital major complications associated with rotational atherectomy: experience with 800 patients at a single center]

INTRODUCTION

Rotational atherectomy is usually performed in patients with angiographically determined high risk coronary lesions. The aim of this study was to evaluate the rate of major adverse cardiac events (death, Q-wave infarction or new revascularization) after rotational atherectomy, as well as to identify the clinical characteristics associated with this incidence.

PATIENTS AND METHODS

The study population included 800 patients treated with rotational atherectomy from 1993 to 1999: 512 (64%), for de novo lesions, and 288 (36%) for restenosis. Balloon dilation and coronary stenting was performed in 95% and 34% of patients, respectively.

RESULTS

During hospitalization, 17 patients (2.1%) died, 16 (2%) had a Q-wave infarction, 30 (3.8%) a non-Q infarction, and new revascularization was performed in 28 (3.5%). The incidence of major adverse cardiac events was 6.5% (n = 52), this incidence being higher in the presence of diabetes (8.9 vs. 4.4%; p = 0.01), unstable angina or acute/recent myocardial infarction (7.6 vs. 3.3%; p = 0.02), multivessel disease (8.6 vs. 3.3%; p < 0.01), treated vessel other than right coronary (7.0 vs. 1.7%; p = 0.01), procedure in > 1 vessel (10.7 vs. 4.7%; p < 0.01), angiographic failure (62.5 vs. 5.5%; p < 0.001), and de novo lesions (8.4 vs. 2.5%; p < 0.01), with diabetes and treatment of de novo lesions being independent predictors of major adverse cardiac events. However, age, previous infarction, and left ventricular dysfunction, were not associated with the rate of events.

CONCLUSION

Some simple variables are associated with a higher incidence of major adverse cardiac events after rotational atherectomy. Advanced age, previous infarction and left ventricular dysfunction, however, do not necessarily imply a poorer prognosis in these patients.

Long-term outcome of patients with proximal left anterior descending coronary artery in-stent restenosis treated with rotational atherectomy

Once a first interventional procedure has failed, patients with proximal left anterior descending in-stent restenosis are frequently sent for surgical revascularization. Data on long-term outcome in selected patients with proximal left anterior descending in-stent restenosis treated with RA are lacking. The study's objective was to evaluate the long-term outcome of patients with proximal left anterior descending artery in-stent restenosis treated with rotational atherectomy. The study population is constituted by 42 patients with proximal left anterior descending in-stent restenosis treated with rotational atherectomy. Patients were followed up for 2.1 +/- 0.9 years (range, 6--54). Restenosis length was 16.5 +/- 9.2 mm, and restenosis was diffuse (> 10 mm in length) in 30 (71.4%). The rotational atherectomy procedure was guided by intravascular ultrasound in 18 patients (42.9%). Maximum burr/artery ratio was > 0.7 in 24 (57.1%) patients. One patient suffered a periprocedural non--Q-wave infarction, but no deaths, Q-wave infarction, or new target vessel revascularization occurred during hospitalization. There were no deaths or myocardial infarctions after discharge. Sixteen patients (38.1%) needed a new revascularization, but only five (11.9%) underwent coronary bypass grafting at the end of the follow-up (2.1 +/- 0.9 years). The rate of surgical revascularization at 6 months, 1 year, and 3 years was 4.8%, 7.4%, and 18.4%, respectively. The rate of new target vessel revascularization at 6 months, 1 year, and 3 years was 16.7%, 36.5%, and 40.5%, respectively. Patients with < or = 5 months since stent implantation had a significantly higher rate of new target vessel revascularization. Patients with proximal left anterior descending in-stent restenosis may be safely treated with rotational atherectomy. This strategy is associated with a very good long-term outcome, with few patients undergoing surgical revascularization.

Early coronary angioplasty for acute myocardial infarction: predictors of poor outcome in a non-selected population

AIMS

The objective of this study was to report the experience in the treatment of acute myocardial infarction (AMI) with early coronary angioplasty (PTCA) in a single European center during one decade, attempting to identify the characteristics associated with a poor prognosis in these patients.

METHODS AND RESULTS

Eight hundred patients with AMI were treated with PTCA < 12 hours after symptom onset. Mean age was 64 +/- 13 years, 12% were in cardiogenic shock, AMI location was anterior in 61% and PTCA was performed after failed thrombolysis in 5%. Coronary stents and abciximab were used in 51% and 10%, respectively. An angiographic successful result was obtained in 93%, and final TIMI flow grade 3 was achieved in 83%. The overall in-hospital mortality rate was 12.5% (2.7%, 16.1%, 25.7% and 63.8% in patients in Killip class I, II, III and IV, respectively). Over the years, an improvement in the angiographic results and a reduction in the rates of reinfarction and target vessel revascularization were observed. The independent predictors of death were age > 70 years, absence of hyper-cholesterolemia, anterior location, cardiogenic shock, multi-vessel disease and unsuccessful PTCA. The leading causes of mortality were cardiogenic shock (63%) and ventricular free wall rupture (14%). The rates of non-fatal reinfarction, documented reocclusion and in-hospital repeated revascularization were 2%, 3% and 4%, respectively.

CONCLUSION

In most cases, PTCA performed in a non-selected patient population with AMI results in angiographic success. Mortality especially occurs in patients who are in cardiogenic shock at the beginning of the procedure. We have observed an improvement in the results throughout the course of the decade.

Family history influence on drug abuse severity and treatment outcome

Influence of parental alcohol/substance abuse on methadone maintenance therapy (MMT) outcome was examined in 164 DSM-III-R opioid dependent adults with no other current DSM Axis I disorder. Family history positive patients had more DSM-III-R opioid dependence symptoms and were more likely to be classified as severely dependent. However, when placed on identical daily doses of methadone (50 mg), they had lower rates of illicit opioid use but higher rates of cocaine use than family history negative patients. Both effects remained significant after adjusting for gender and race. These results suggest that common genetic factors may underlie both susceptibility to heroin dependence and response to therapeutic methadone treatment.

Early coronary angioplasty for acute myocardial infarction complicated by cardiogenic shock: have novel therapies led to better results?

Patients with acute myocardial infarction (MI) and cardiogenic shock constitute a very high risk subset despite an aggressive management. The objective of this study was to evaluate if the results of early coronary angioplasty in patients with acute myocardial infarction and cardiogenic shock have changed over the last years, and to address which role the recent adjuvant therapies have played in this evolution. From 1991 to April 1999, 94 patients with acute MI and cardiogenic shock were treated with coronary angioplasty within the first 12 hours from the onset of symptoms. Temporal changes of the utilization of adjuvant therapies and operators experience were studied over these years, as well as their impact on the angiographic results and in-hospital outcome. Over the years, a progressive and significant increase on the use of coronary stents and c7E3Fab was observed, as well as an increased number of primary angioplasties performed per month. The proportion of patients treated with intraaortic balloon pump did not changed significantly over the years. An angiographic successful result (< 50% residual stenosis and TIMI flow 2 or 3) and a final TIMI grade 3 flow were obtained in 76 (80.9%) and 61 (64.9%) patients, respectively. The angiographic success rate progressively increased over the years, from 72.3% in patients treated before 1994 to 94.1% in those admitted in 1998Eth 1999 (p for trend 0.0409). The proportion of patients with a final TIMI grade 3 flow also grew progressively over the years: from 36.4% before 1994 to 76.5% after 1997 (p for trend 0. 0209). The overall in-hospital mortality rate was 63.8% (60 patients), and there was no significant change in mortality rate over the years. Therefore, apart from the growing operators experience, we have observed an incremental change in the use of coronary stents and c7E3 Fab (abciximab) in patients with acute myocardial infarction and cardiogenic shock treated with early coronary angioplasty. All these factors have led to an improvement in the angiographic results, although this change has not meant a significant reduction of mortality.