Neurodegeneration Biomarkers in Adult Spinal Muscular Atrophy (SMA) Patients Treated with Nusinersen

The objective of this study is to evaluate biomarkers for neurodegenerative disorders in adult SMA patients and their potential for monitoring the response to nusinersen. Biomarkers for neurodegenerative disorders were assessed in plasma and CSF samples obtained from a total of 30 healthy older adult controls and 31 patients with adult SMA type 2 and 3. The samples were collected before and during nusinersen treatment at various time points, approximately at 2, 6, 10, and 22 months. Using ELISA technology, the levels of total tau, pNF-H, NF-L, sAPPβ, Aβ40, Aβ42, and YKL-40 were evaluated in CSF samples. Additionally, plasma samples were used to measure NF-L and total tau levels using SIMOA technology. SMA patients showed improvements in clinical outcomes after nusinersen treatment, which were statistically significant only in walkers, in RULM (p = 0.04) and HFMSE (p = 0.05) at 24 months. A reduction in sAPPβ levels was found after nusinersen treatment, but these levels did not correlate with clinical outcomes. Other neurodegeneration biomarkers (NF-L, pNF-H, total tau, YKL-40, Aβ40, and Aβ42) were not found consistently changed with nusinersen treatment. The slow progression rate and mild treatment response of adult SMA types 2 and 3 may not lead to detectable changes in common markers of axonal degradation, inflammation, or neurodegeneration, since it does not involve large pools of damaged neurons as observed in pediatric forms. However, changes in biomarkers associated with the APP processing pathway might be linked to treatment administration. Further studies are warranted to better understand these findings.

Serum neurofilament levels correlate with electrodiagnostic evidence of axonal loss in paclitaxel-induced peripheral neurotoxicity

INTRODUCTION

Paclitaxel-induced peripheral neurotoxicity (PIPN) typically manifests as a predominantly sensory axonopathy. Nerve conduction studies (NCS) represent the gold standard method to quantify axonal impairment in PIPN. Serum neurofilament light chain (sNfL) levels are emerging biomarkers for quantifying axonal damage in peripheral neuropathies. To date, the association between NCS abnormalities and sNfL levels during paclitaxel-based chemotherapy has not been specifically addressed.

METHODS

We prospectively conducted longitudinal measurement of sNfL levels in 27 chemotherapy-naïve breast cancer patients and correlated conventional NCS recordings with sNfL in 22 of them, before (T0) and after (T1) 12 cycles of weekly paclitaxel-based therapy.

RESULTS

PIPN was diagnosed in 24/27 patients (88%) after completion of the 12-week paclitaxel-based chemotherapy regimen. Serum NfL levels (pg/mL) were significantly higher at T1 compared to T0 (T0: 18.50 ± 12.88 vs T1: 255.80 ± 194.16; p < 0.001). The increase of sNfL levels at T1 significantly correlated with the decrease or abolishment of amplitudes recorded from the sural nerve (r = 0.620; p = 0.0035), sensory radial (r = 0.613; p = 0.005), sensory ulnar (r = 0.630; p = 0.005), and peroneal motor (r = 0.568; p = 0.024) nerves.

CONCLUSION

sNfL levels proportionally increase during chemotherapy administration and significantly correlate with NCS axonal abnormalities in patients with PIPN. A multimodal testing approach employing both sNfL and NCS might improve the PIPN diagnostic accuracy.

Validation of motor and functional scales for the evaluation of adult patients with 5q spinal muscular atrophy

BACKGROUND AND PURPOSE

Mos scales currently used to evaluate spinal muscular atrophy (SMA) patients have only been validated in children. The aim of this study was to assess the construct validity and responsiveness of several outcome measures in adult SMA patients.

METHODS

Patients older than 15 years and followed up in five referral centres for at least 6 months, between October 2015 and August 2020, with a motor function scale score (Hammersmith Functional Motor Scale Expanded [HFMSE], Revised Upper Limb module [RULM]) were included. Bedside functional scales (Egen Klassification [EK2], Revised Amyotrophic Lateral Sclerosis Functional Rating Scale [ALSFRS-R]) were also collected when available. Spearman's rho correlations (rs) and Bangdiwala's concordance test (B) were used to evaluate the scales' construct validity. Monthly slopes of change were used to calculate their responsiveness of the scales.

RESULTS

The study included 79 SMA patients, followed up for a mean of 16 months. All scales showed strong correlations with each other (rs &gt; 0.70). A floor effect in motor function scales was found in the weakest patients (HFMSE &lt; 5 and RULM &lt; 10), and a ceiling effect was found in stronger patients (HFMSE &gt; 60 and RULM &gt; 35). The ALSFRS-R (B = 0.72) showed a strong ability to discriminate between walkers, sitters and non-sitters, and the HFMSE (B = 0.86) between walkers and sitters. The responsiveness was low overall, although in treated patients a moderate responsiveness was found for the ALSFRS-R and HFMSE in walkers (0.69 and 0.61, respectively) and for EK2 in sitters (0.65) and non-sitters (0.60).

CONCLUSIONS

This study shows the validity and limitations of the scales most frequently used to assess adult SMA patients. Overall, bedside functional scales showed some advantages over motor scales, although all showed limited responsiveness.

Nusinersen in adult patients with 5q spinal muscular atrophy: A multicenter observational cohorts' study

BACKGROUND AND PURPOSE

The aim was to assess the safety and efficacy of nusinersen in adult 5q spinal muscular atrophy (SMA) patients.

METHODS

Patients older than 15 years and followed for at least 6 months with one motor scale (Hammersmith Functional Motor Scale Expanded, HFMSE; Revised Upper Limb Module, RULM) in five referral centers were included. The clinical and patients' global impression of change (CGI-C and PGI-C) were recorded in treated patients at the last visit. Functional scales (Egen Klassification, EK2; Revised Amyotrophic Lateral Sclerosis Functional Rating Scale, ALSFRS-R) and the percentage predicted forced vital capacity were collected when available.

RESULTS

Seventy-nine SMA patients (39 treated with nusinersen) were included. Compared with untreated patients, treated patients showed a significant improvement of 2 points (±0.46) in RULM (p &lt; 0.001) after 6 months. After a mean follow-up of 16 months, nusinersen treatment was associated with a significant improvement in HFMSE (odds ratio [OR] 1.15, p = 0.006), the 6-min walk test (OR = 1.07, p &lt; 0.001) and the EK2 (OR = 0.81, p = 0.001). Compared with untreated patients, more treated patients experienced clinically meaningful improvements in all scales, but these differences were statistically significant only for RULM (p = 0.033), ALSFRS-R (p = 0.005) and EK2 (p &lt; 0.001). According to the CGI-C and PGI-C, 64.1% and 61.5% of treated patients improved with treatment. Being a non-sitter was associated with less response to treatment, whilst a longer time of treatment was associated with better response. Most treated patients (77%) presented at least one adverse event, mostly mild.

CONCLUSIONS

Nusinersen treatment is associated with some improvements in adult SMA patients. Most severely affected patients with complex spines are probably those with the most unfavorable risk-benefit ratio.

P14.02.A Serum neurofilaments correlate with axonal loss in paclitaxel-induced peripheral neurotoxicity

Background

Paclitaxel-induced peripheral neuropathy (PIPN) is a dose-limiting axonal polyneuropathy. Nerve conduction studies (NCS) are unique for the assessment of axonal impairment in PIPN. Neurofilaments (NFs), constituent of the neuronal cytoskeleton, are emerging as axonal damage biomarker. To date, the association between changes in NCS and NfL quantification across paclitaxel treatment in breast cancer patients has not been specifically addressed.

MATERIAL AND METHODS: Prospective longitudinal measurement of sNfL levels and NCS in 27 chemotherapy-naïve breast cancer patients before (V0) and after completion (V1) of 12 cycles of weekly paclitaxel-based therapy.

Results

Serum NfL levels (in pg/mL) increased over the course of treatment in the whole of patients (T0: 18,509 +/- 12,886 vs T1:255,805 +/- 194,165, p&lt;0.001). The increase in sNfL levels at T1 showed a significant moderate correlation with the percentage of decrease in the amplitude of the sural (ρ = 0.6205 (p=0.0035), radial (r=0.6134, p=0.005)), ulnar (ρ = 0.6298 (p=0.005)) and peroneal motor (ρ = 0.5676, p=0.024)) nerve in NCS across treatment.

Conclusion

sNfL levels increase proportionally to the degree of paclitaxel-induced neuroaxonal damage, revealing being a promising blood biomarker able to detect the severity of large nerve fiber degeneration and, therefore, improving the diagnostic accuracy in PIPN.

Prevalence of the Frank's sign by aetiopathogenic stroke subtype: A prospective analysis

BACKGROUND AND PURPOSE

The Frank's sign is a diagonal earlobe crease running from the tragus to the edge of the auricle at an angle of 45°. Many studies have associated this sign with coronary artery disease and some with cerebrovascular disease. The objective of this study was to analyse the prevalence of the Frank's sign in patients suffering from acute stroke with a particular focus on its prevalence in each of the five aetiopathogenic stroke subtypes. Special interest is given to embolic stroke of undetermined source (ESUS), correlating the sign with clinical and radiological markers that support an underlying causal profile in this subgroup.

METHODS

Cross-sectional descriptive study including 124 patients admitted consecutively to a stroke unit after suffering an acute stroke. The Frank's sign was evaluated by the same blinded member of the research team from photographs taken of the patients. The stroke subtype was classified following SSS-TOAST criteria and the aetiological study was performed following the ESO guidelines.

RESULTS

The Frank's sign was present in 75 patients and was more prevalent in patients with an ischaemic stroke in comparison with haemorrhagic stroke (63.9 vs. 37.5, p<0.05). A similar prevalence was found in the different ischaemic stroke subtypes. The Frank's sign was significantly associated with age, particularly in patients older than 70 who had vascular risk factors. Atherosclerotic plaques found in carotid ultrasonography were significantly more frequent in patients with the Frank's sign (63.6%, p<0.05). Analysing the ESUS, we also found an association with age and a higher prevalence of the Frank's sign in patients with vascular risk factors and a tendency to a high prevalence of atherosclerosis markers.

CONCLUSION

The Frank's sign is prevalent in all aetiopathogenic ischaemic stroke subtypes, including ESUS, where it could be helpful in suspecting the underlying cardioembolic or atherothrombotic origin and guiding the investigation of atherosclerosis in patients with ESUS and the Frank's sign.

Increased C-X-C Motif Chemokine Ligand 12 Levels in Cerebrospinal Fluid as a Candidate Biomarker in Sporadic Amyotrophic Lateral Sclerosis

Sporadic amyotrophic lateral sclerosis (sALS) is a fatal progressive neurodegenerative disease affecting upper and lower motor neurons. Biomarkers are useful to facilitate the diagnosis and/or prognosis of patients and to reveal possible mechanistic clues about the disease. This study aimed to identify and validate selected putative biomarkers in the cerebrospinal fluid (CSF) of sALS patients at early disease stages compared with age-matched controls and with other neurodegenerative diseases including Alzheimer disease (AD), spinal muscular atrophy type III (SMA), frontotemporal dementia behavioral variant (FTD), and multiple sclerosis (MS). SWATH acquisition on liquid chromatography-tandem mass spectrometry (LC-MS/MS) for protein quantitation, and ELISA for validation, were used in CSF samples of sALS cases at early stages of the disease. Analysis of mRNA and protein expression was carried out in the anterior horn of the lumbar spinal cord in post-mortem tissue of sALS cases (terminal stage) and controls using RTq-PCR, and Western blotting, and immunohistochemistry, respectively. SWATH acquisition on liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed 51 differentially expressed proteins in the CSF in sALS. Receiver operating characteristic (ROC) curves showed CXCL12 to be the most valuable candidate biomarker. We validated the values of CXCL12 in CSF with ELISA in two different cohorts. Besides sALS, increased CXCL12 levels were found in MS but were not altered in AD, SMA, and FTD. Therefore, increased CXCL12 levels in the CSF can be useful in the diagnoses of MS and sALS in the context of the clinical settings. CXCL12 immunoreactivity was localized in motor neurons in control and sALS, and in a few glial cells in sALS at the terminal stage; CXCR4 was in a subset of oligodendroglial-like cells and axonal ballooning of motor neurons in sALS; and CXCR7 in motor neurons in control and sALS, and reactive astrocytes in the pyramidal tracts in terminal sALS. CXCL12/CXCR4/CXCR7 axis in the spinal cord probably plays a complex role in inflammation, oligodendroglial and astrocyte signaling, and neuronal and axonal preservation in sALS.

AB0163 ANTI-KU ANTIBODIES: MUCH MORE THAN SCLEROMYOSITIS

Background:

Initially, anti-Ku antibodies (Ab) were described in patients with overlap syndrome with systemic sclerosis (SSc) and inflammatory myophaty (scleromyositis), although later they have been linked to a wide variety of systemic autoimmune diseases (SAD) questioning its diagnostic value. Recently, the possible existence of 2 different clinical phenotypes associated with these Ab has been described: one with myositis and high risk of intersticial lung disease (ILD) and another with positive anti-dsDNA Ab and glomerulonephritis.

Objectives:

To analyze the clinical relevance and the main diagnosis of a serie of patients with positive anti-Ku Ab.

Methods:

Descriptive observational study of patients with anti-Ku Ab in two third level hospitals between 2011 and 2019. Their determination was made at the criteria of the requesting physician.

Results:

Twenty-three patients (20 women) with a median age of 59 ± 14 years (range, 24-83) and a follow up time (median) of 37 months (1-208) were identified. The main clinical and analytical characteristics, as well as the final clinical diagnosis of these patients are shown in Table 1. In the cluster analysis we could not identify clinical phenotypes, perhaps because of the small sample size. Only 50% of patients with myositis developed ILD. Regarding the final diagnosis, only 1 patient (5%) was diagnosed of scleromyositis. Besides detecting them in patients with SSc (39%) and idiopathic inflammatory myopathy (9%), anti-Ku Ab were detected in other SAD, the most frequent were systemic lupus erythematosus, rheumatoid arthritis (RA) and overlap syndrome of SSc + RA.

Table 1.

Main clinical-analytical manifestations and final diagnosis of pacientes with anti-Ku Ab.

FINAL CLINICAL DIAGNOSiSScleromyositis: 1Idiopahtic inflammatory myopathy: 1Systemic sclerosis (SSc): 6 (Pre-scleroderma: 3, limited SSc: 3).Systemic lupus erythematosus: 2Rheumatoid arthritis: 2Overlap syndrome RA + limited SSc: 2Primary Sjögren’s syndrome: 1 (Secondary Sjögren’s syndrome: 3)Mixed connective tissue disease: 1Polymyalgia rheumatica: 1Undifferentiated connective tissue disease: 1Acute hepatitis due to HEV: 1Autoimmune thrombocytopenia (ITP): 1Drug-induced fibrosing ILD: 1Systemic graft versus host disease (GVHD) in a patient with acute lymphoblastic leukemia who received and autologous haematopoietic progenitor transplant: 1Primary biliary cirrhosis: 1CLINICAL MANIFESTATIONS(patients could have more than one):Raynaud’s phenomenon: 61% (14/23).Inflammatory arthralgia/arthritis: 52% (12).Lung involvement: 30.5% (7: NSIP 3, UIP 2, other patterns 2).Serositis: 26% (6: pericarditis 4, pleuritis 1, pleuropericarditis 1).Cardiac involvement: 26% (6: PHT by echocardiogram 3, myocarditis 2, arrhytmia 1).Dry syndrome: 17% (4)Myositis: 17% (4).Esophageal involvement: 17% (4).Autoimmune cytopenias: leucolinfopenia: 17% (4) / thrombocytopenia: 13% (3).Telangiectasias: 13% (3).Photosensitivity: 13% (3).Other: non-androgenic alopecia: 9% (2); sensory-motor polyneuropathy: 4.5% (1);Puffy hands: 4.5% (1); fever: 4.5% (1); lymphadenitis: 4.5% (1); cold sores: 4.5% (1), and retinal hemorrhage: 4.5% (1).OTHER ASSOCIATED ANTIBODIES:ANA: 91% (21/23)anti Ro60/SSA Ab: 30.5% (7)Anti Ro52 Ab: 30.5% (7)Anti RNP Ab: 22% (5)Anti-dsDNA: 17% (4)Anti-La/SSB Ab: 17% (4)Anticentromer Ab: 17% (4)Anti Mi-2 Ab: 13% (3)Other: anti Sm Ab: 9% (2); anticardiolipin Ab(IgG): 4.5% (1); PM/Scl: 4.5% (1); nucleosomes: 4.5% (1); Scl70: 4.5% (1); PL12: 4.5% (1); anti-U1-RNP: 4.5% (1) and NOR90: 4.5% (1).

Conclusion:

Anti-Ku Ab are related to a great variety of SAD, without being a specific marker of any of them, nor being associated with any specific clinical manifestation. We couldn’t confirm the existence of clinical phenotypes associated with the presence of these antibodies.

Disclosure of Interests:

L Montolio-Chiva: None declared, J. Narváez: None declared, Francisco Morandeira: None declared, Jordi Bas: None declared, Carla Marco: None declared, Xavier González: None declared, Juanjo J Alegre-Sancho Consultant of: UCB, Roche, Sanofi, Boehringer, Celltrion, Paid instructor for: GSK, Speakers bureau: MSD, GSK, Lilly, Sanofi, Roche, UCB, Actelion, Pfizer, Abbvie, Novartis, Eduardo Flores: None declared, I Vázquez-Gómez: None declared, Jose María López: None declared, Joan Miquel Nolla: None declared

AB0594 EFFECTIVENESS OF RITUXIMAB IN CSDMARDS-RESISTANT ACTIVE MIXED CONNECTIVE TISSUE DISEASE

Background:

Objectives:

To evaluate rituximab (RTX) effectiveness and safety in treating patients with refractory mixed connective tissue disease (MCTD).

Methods:

Open observational study including patients with refractory MCTD (active disease despite treatment with glucocorticoids and csDMARDs) from two third-level hospitals who had been treated with RTX (off-label use) from January 2001 to December 2019.

Results:

Thirteen patients (all women) were included, with a mean age of 32 years (SD: 10, range 17-50) and a median time of evolution of the disease of 55 months (SD: 34.3; range 5-98 months). The main indication for initiating treatment with RTX was refractory arthritis (100%), most of the times accompanied by other features of the disease including shrinking lung syndrome (2), fibrosing progressive non-specific interstitial pneumonia (FP-NSIP) (1), recurrent serositis (2), glomerulonephritis (GMN) (2), lymphadenitis (1) and immune thrombocytopenic purpura (ITP) (1). All patients were treated with RTX at rheumatoid arthritis dosage while the baseline immunosuppressive treatment (methotrexate, azathioprine, mycophenolate, leflunomide or tacrolimus) remained unchanged. Hydroxychloroquine was also associated in 8 of the patients. The follow-up time (median) after starting RTX was 118 months (range, 65-177 months, with a total of 132.6 patient-years of follow-up) and the mean number of cycles of treatment was 4.2 (range, 1-15), with a variable interval (from 6 to 12 months). After the first RTX cycle, a partial or complete response was achieved in 92% of the patients. A significant improvement in the mean DAS28-ESR was observed (initial: 4.56 ± 1.6 / final: 2.21 ± 0.85; p=0.008). In all but one patient, who had previously failed to 2 anti-TNFα DAS28-ESR clinical remission or low activity was achieved, generally from week 16 to 20, although relapses were frequent and all cases need retreatment after 6-9 months. In 4 patients, RTX retreatment dosage was optimized to 1 g/cycle. The 3 patients with pulmonary involvement showed stabilization (2 cases) or improvement (1) of the lung function(as defined by the American Thoracic Society). In patients with GMN, renal response to RTX treatment was complete in a patient and partial in the other. The patient with ITP entered remission after the first RTX cycle and no more cycles were needed. Response in patients with serositis and lymphadenitis was also complete and maintained. Moreover, the glucocorticoid doses were reduced to less than half of the initial dose in all cases. At the end of the follow-up, 7 out of the 13 patients (54%) were still being treated with RTX. For the remaining 6 patients, RTX was withdrawn because of primary failure (1), recurrent bacterial infections (2), gestational desire (2) sustained remission (1).

Conclusion:

According to our preliminary results, RTX seems to be effective and relatively safe in patients with csDMARDs-resistant active MCTD.

Disclosure of Interests:

L Montolio-Chiva: None declared, J. Narváez: None declared, Juanjo J Alegre-Sancho Consultant of: UCB, Roche, Sanofi, Boehringer, Celltrion, Paid instructor for: GSK, Speakers bureau: MSD, GSK, Lilly, Sanofi, Roche, UCB, Actelion, Pfizer, Abbvie, Novartis, J Lluch Pons: None declared, Ana V Orenes Vera: None declared, I Vázquez-Gómez: None declared, Maribel Mora: None declared, Xavier González: None declared, Carla Marco: None declared, Jesús Rodriguez: None declared, Montserrat Romera: None declared, Joan Miquel Nolla: None declared

Anatomical causes of compression of the sciatic nerve in the pelvis. Piriform syndrome

OBJECTIVE

The piriformis syndrome is one of the etiologies of pelvic pain due to the sciatic nerve's entrapment by the piriformis muscle. Nowadays this syndrome might be difficult to be diagnosed. The aim of this study is to know the prevalence of anatomic variations in our population that may contribute to the appearance of piriformis syndrome. Furthermore, anthropometric measurements of the piriformis muscle and the sciatic nerve procedures are studied for a possible application in the gluteal region.

MATERIAL AND METHOD

The study was carried out in 59 pelvis of 32 cryopreserved bodies. The anatomical variations of piriformis and sciatic nerve founded were described following the Beaton and Anson's classification. Anthropometric measurements of both structures with reference to the greater trochanter of the femur were performed.

RESULTS

The sciatic nerve and the piriformis had an anatomical variation in a 28.13%. The most frequent variation found was tipus II (21.64%) and tipus III (6.49%).Insertion most frequently observed was an independent piriformis tendon inserted into the trochanteric fossa with 53.85%.

CONCLUSION

The anatomic variations' incidence in the population studied indicates that those have to be evaluated as a differential diagnosis of gluteal region pain due to the symptoms and signs resemblance with the vertebral disc pathology involving nerve root injury. In addition, anatomical knowledge of this region can be useful for the interpretation of imaging techniques, especially when ultrasound-guided injections are performed.

Identification of components of health complexity on internal medicine units by means of the INTERMED method

BACKGROUND

The INTERMED was developed for the early identification of biological, psychological, social and health system factors considered interacting in health complexity. This is defined as the interference with the achievement of expected or desired health and service use outcomes when patients are exposed to standard care.

OBJECTIVE

The aim of this study was to test the INTERMED's ability to identify 'case' and 'care' complexity, identifying patients that would especially benefit from integrated care.

METHODS

Observational longitudinal study of Internal medicine in patients in two National Health System hospitals in Spain using the INTERMED (patients scoring ≥ 21 were considered to be 'complex'); the Cumulative Illness Rating Scale (CIRS), a severity of illness assessment; and standard clinical variables.

RESULTS

Six hundred and fifteen consecutives were included, and the prevalence of health complexity was 27.6%. The greatest differences between patients with and without health complexity were observed in the non-biological domains. Eighty-five per cent of patients with health complexity had non-biological items considered to require timely (immediately or soon) assistance or intervention compared to 30% of those without, nearly a threefold difference. Complex patients had a significantly higher number of medical diagnoses (p = 0.002) and number of psychiatric referrals (p = 0.041), but there were no differences in CIRS scores or lengths of stay.

CONCLUSION

The INTERMED has the potential to identify a considerable subset of complex internal medicine inpatients for which timely corrective action related to non-biological risk factors not typically uncovered during standard medical evaluations would be considered beneficial.

Choline kinase active site provides features for designing versatile inhibitors

Choline kinase (CK) is a homodimeric enzyme that catalyses the transfer of the ATP γ-phosphate to choline, generating phosphocholine and ADP in the presence of magnesium. Several isoforms of CK are present in humans but only the HsCKα has been associated with cancer and validated as a drug target to treat this disease. As a consequence a large number of compounds based on Hemicholinium (HC-3) have been described. Two compounds, previously reported to inhibit the human enzyme, have recently been shown to inhibit P. falciparum CK (PfCK) and therefore their potential applications might be anticipated to other pathogens. Herein, using molecular dynamic simulations, we have firstly observed that the ATP and the choline binding site of different CK in pathogens and human are conserved, suggesting that previous compounds inhibiting the human enzyme may also interact with CKs from different pathogens. We have substantiated such observation with experimental assays showing that HsCKα1, PfCK and CpCK bind to two compounds with distinct structural features in the low μM range. Collectively, these results uncover similarities among the choline kinase binding site from different pathogenic species and the human enzyme, highlighting the feasibility of designing novel inhibitors based on the choline binding pocket.

[Foreseeable variation in parameters measured at implant and follow-up of permanent pacemaker active fixation electrodes]

OBJECTIVES

To analyze the variations in the parameters relative to active fixation electrodes at the time of implantation and over subsequent follow-up during 6 months of the acute phase of implantation.

DESIGN

A descriptive, analytical, prospective, observational cohort study was made of consecutive cases over a period of 8 months (April-December 2010).

SETTING

Pacing unit of an Intensive Care Unit.

PATIENTS OR PARTICIPANTS

Patients undergoing permanent pacemaker implantation with active fixation electrodes, implanted in both atrium and ventricle, Interventions: Measurement of variables described with a threshold analyzer during electrode fixation and at different times during the study, Main compared variables: threshold, impedance and intrinsic activity (both atrial and ventricular) before and after fixation, at 48 hours, at one month and 6 months, Comparisons were made using the Student t-test for paired data, assuming significance for p<0,05, and ANOVA to analyze the successive changes over ambulatory follow-up.

RESULTS

We analyzed 40 patients, with 19 atrial and 40 ventricular electrodes, In fixation, the electrodes showed significant variation in the impedance values of the atrial lead (1,188,53 ± 397,26 vs 610,69 ± 326,30 ohms, p<0,0001) and ventricular lead (1,512,93 ± 718,07 vs 768,80 ± 224,90 ohms, p>0,0001), In the first 48 hours it was coupled with a decrease in ventricular (0,86 ± 0,35 vs 0,48 ± 0,23 volts, p = 0,0001) and atrial pacing threshold (1,10 ± 0,39 vs 0,43 ± 0,23 volts, p = 0,0003), and p-wave sensing (3,61 ± 2,25 vs 2,32 ± 1,09 mV, p = 0,0463), Over follow-up we found the parameters to be stable, with no significant changes.

CONCLUSIONS

After active lead fixation, a fall in impedance of the antrial and ventricular is expected, Over the next 48 hours improvement in atrial and ventricular threshold may occur, in contrast to the sensitivity of the intrinsic activity, which reached significance at the P wave measured after 48 hours, These values stabilize over patient follow-up and do not differ significantly in the studied acute patient course.

Crystalline transformations in nylon-6/single-walled carbon nanotube nanocomposites

Nylon-6/single-walled carbon nanotube (SWNT) nanocomposites with different SWNTs loadings were prepared by melt-blending. An efficient dispersion of SWNTs into the nylon-6 matrix was confirmed by scanning electron microscopy. DSC and time-resolved synchrotron X-ray diffraction were used to provide detailed information on the effect of SWNTs on the crystalline phase transition of nylon-6 in the nanocomposites. The incorporation of SWNTs accelerated the crystallization rate of nylon-6 due to a nucleating effect. The variable-temperature WAXS experiments, in both neat nylon-6 and nylon-6 nanocomposites, showed that the crystallization from the melt occured through the formation of the pseudo-hexagonal crystal form (gamma) and its transformation to the monoclinic form (alpha) on cooling. Additionally, this crystalline transition was reversible as observed upon heating. The alpha-gamma crystalline transformation temperature of nylon-6 was dependent on heating rate and, more importantly, on the SWNT content.

The influence of a compatibilizer on the thermal and dynamic mechanical properties of PEEK/carbon nanotube composites

The effect of polyetherimide (PEI) as a compatibilizing agent on the morphology, thermal, electrical and dynamic mechanical properties of poly(ether ether ketone) (PEEK)/single-walled carbon nanotube (SWCNT) nanocomposites, has been investigated for different CNT loadings. After a pre-processing step based on ball milling and pre-mixing under mechanical treatment in ethanol, the samples were prepared by melt extrusion. A more homogeneous distribution of the CNTs throughout the matrix is found for composites containing PEI, as revealed by scanning electron microscopy. Thermogravimetric analysis demonstrates an increase in the matrix degradation temperatures under dry air and nitrogen atmospheres with the addition of SWCNTs; the level of thermal stability of these nanocomposites is maintained when PEI is incorporated. Both differential scanning calorimetry and synchrotron x-ray scattering studies indicate a slight decrease in the crystallization temperatures of the compatibilized samples, and suggest the existence of reorganization phenomena during the heating, which are favoured in the composites incorporating the compatibilizer, due to their smaller crystal size. Dynamic mechanical studies show an increase in the glass transition temperature of the nanocomposites upon the addition of PEI. Furthermore, the presence of PEI causes an enhancement in the storage modulus, and hence in the rigidity of these systems, attributed to an improved interfacial adhesion between the reinforcement and the matrix. The electrical and thermal conductivities of these composites decrease with the incorporation of PEI. Overall, the compatibilized samples exhibit improved properties and are promising for their use in industrial applications.

A comparison of glycaemic variability in CSII vs. MDI treated type 1 diabetic patients using CGMS

OBJECTIVE

To evaluate and compare glucose variability, hypoglycaemic events and daily glycaemic control in well-controlled (HbA1c <or= 7%), type 1 diabetic patients treated with either continuous subcutaneous insulin infusion (CSII) using lispro or multiple daily insulin injection (MDI) using glargine once daily and lispro with meals.

RESEARCH DESIGN AND METHODS

A total of 16 patients with type 1 diabetes receiving treatment with either CSII (eight patients) or MDI (eight patients), all with HbA1c levels < 7%, wore a continuous glucose monitoring system sensor for 3 days to compare the number, duration, timing and severity of hyperglycaemic and hypoglycaemic episodes.

RESULTS

There were several more episodes of hyperglycaemic [blood glucose (BG) >or= 180 mg/dl] and hypoglycaemic (BG <or= 60 mg/dl) excursions observed in patients treated with CSII than MDI. Glycaemic exposure over 150 mg/dl was similar between the two groups. Maintenance of near-euglycaemia as determined by the average amount of time spent within the glucose range of 80-140 mg/dl was marginally significantly better for the MDI than for the CSII group. Although the CSII group had significantly more hypoglycaemic episodes below 60 mg/dl, the average duration of hypoglycaemia was not significantly different for the two groups. Similar percentages of nocturnal hypoglycaemia were seen. There were no reported major adverse events throughout the duration of the study.

CONCLUSION

Well-controlled type 1 diabetic patients treated with MDI had fewer hyperglycaemic and hypoglycaemic excursions than patients treated with CSII.

Outcome of unresected gastric cancer after laparoscopic diagnosis of peritoneal carcinomatosis

BACKGROUND

Most gastric adenocarcinomas in western countries are locally advanced, and these tumours are often associated with metastatic spread at the time of diagnosis. It is controversial whether palliative surgery can improve symptom control in gastric cancer patients with peritoneal carcinomatosis.

OBJECTIVE

To determine the need of palliative procedures and survival in patients affected by gastric cancer with peritoneal carcinomatosis managed without resection. Methods and materials After standard preoperative staging, 160 patients were diagnosed with resectable gastric adenocarcinoma. Laparoscopy was performed in 107 patients (66.9%), finding peritoneal spread in 22 of them (21%). Seventeen of these patients were not submitted to any additional surgical procedure. Data regarding postoperative morbidity and mortality, need of endoscopic, percutaneous or surgical procedures to palliate symptoms, hospital stay and survival were collected. The same data were collected for the 6 non-resected patients who were diagnosed with carcinomatosis by laparotomy.

RESULTS

In the "laparoscopy alone" group, there were 2 minor complications and no postoperative mortality. Mean postoperative stay was 6 days. Eight patients had to be readmitted to hospital for symptoms derived from tumour progression, and 10 palliative endoscopic procedures were performed. Surgical interventions were not needed in any case. Mean survival was 11.5 months. Patients submitted only to laparotomy presented higher morbidity and mortality rates, with a longer postoperative stay and survival of less than 5 months.

CONCLUSIONS

Laparoscopic staging of gastric cancer can help to avoid unnecessary laparotomies. In patients with peritoneal carcinomatosis diagnosed by laparoscopy, nonsurgical treatment has low morbidity and mortality and permits good symptom relief with no shortening of survival.

Metastatic lymph node ratio as a prognostic factor in gastric cancer

BACKGROUND

There is an association between the number of resected lymph node and the number of metastatic lymph nodes in gastric cancer, suggesting that pN category could be influenced by the extension of the lymphadenectomy. This study evaluates this association and proposes a comprehensive use of the ratio as prognostic factor.

METHOD

Review of 183 consecutive patients with gastric adenocarcinoma. The association between the number of resected lymph nodes and the number of metastatic lymph nodes was analysed and evaluated with other prognostic factors.

RESULTS

The number of lymph node metastases increased with the number of resected lymph nodes. The lymph node ratio was a better prognostic factor than the number of metastatic lymph nodes.

CONCLUSIONS

The metastatic lymph node ratio seems to be a good prognostic factor, but needs further evaluation.

[Laparoscopic resection of hepatic hydatid cyst under general anesthesia with remifentanil infusion]

We report the case of a 52-year-old woman who underwent scheduled laparoscopic resection of a hydatid liver cyst under general anesthesia by infusion of remifentanil and sevoflurane. Surgery was uneventful, although invasive monitoring was required, just as it would have been in major open abdominal surgery, given the risk of bleeding secondary to organ manipulation, the risk of anaphylactic shock related to the etiology of the cyst and the possibility of gas embolism related to laparoscopy. The concept of "minimally invasive" surgery has developed thanks to continued progress in laparoscopy. The considerable advantages of such procedures in comparison with "open" or "conventional" surgery has led to their use with organs such as the liver, which in principle require caution. In such cases, the anesthesiologist must take an approach that is not as simple or minimalist as the term "minimally invasive" might lead us to expect.