[Use of metaphyseal stems «Proxima» DePuy: our experience to more than five years]

The total hip arthroplasty with short stems to preserve bone is a good choice in young patients that expected future revision surgery, it is also a good choice when we use approaches for minimal invasive surgeries. In this study, we have evaluated, clinically and radiologically, our experience in total hip arthroplasty with the use of short stems and metaphyseal anchorage. In total we have involved 23 patients with a mean age of 50.2 years (range 45 to 69 y/o) at the time of surgery. The median follow-up was greater than five years. There was a slight Varus femoral stem in three cases, one of them in severe varus. The latter presented continuous pain in the lateral aspect of the thigh that increased with time, with a diaphyseal reaction and an increase in radiolucencies around the stem that required revision surgery 12 months postoperative. A longer follow-up is required to analyze the results and confirm the durability of the observed clinical findings. Patients were evaluated radiological and clinically using the scale of Merle dAubigné (MD).

Influence of nitric oxide and vasoactive intestinal peptide on the spontaneous and triggered electrical and mechanical activities of the canine ileum

Modulation of canine ileal pacemaker activity by nitric oxide (NO) or vasoactive intestinal peptide (VIP) was studied during recording of the intracellular electrical and mechanical activity from the entire muscularis externa and from an isolated circular muscle preparation both cut in the long axis of the circular muscle. In the whole-thickness preparation with cholinergic and adrenergic nerve function blocked, the inhibitory junction potentials (IJPs) recorded near the myenteric plexus (MyP) or deep muscular plexus (DMP) were abolished by omega-conotoxin GVIA (omega-CTX, 10(-7) to 3 x 10(-7) M), tetrodotoxin (TTX, 1 microM), or the NO synthase (NOS) inhibitor N omega-nitro-L-arginine (L-NNA at 50 microM). IJPs from electrical field stimulation triggered slow waves (TSWs); after TTX or omega-CTX, TSWs still occurred, advanced in time and increased in amplitude after TTX. Addition of L-NNA advanced the onset of the TSWs after omega-CTX. TTX, L-NNA, or omega-CTX left the resting membrane potentials, the characteristics of spontaneous slow waves, or TSWs evoked by a long stimulating pulse unchanged. L-NNA at 100 microM enhanced the amplitude but not the frequency of spontaneous slow waves. TTX and NOS blockers all increased circular muscle contractions associated with the spontaneous slow waves and TSWs. In isolated circular muscle preparations, the NOS inhibitors N omega-nitro-L-arginine methyl ester (L-NAME at 300 microM) or L-NNA at 100 microM abolished the IJPs and increased the regularity and amplitude of spontaneous slow waves and associated contractions, but TSWs could not be evoked before or after NOS inhibition. The NO donor 3-morpholinosydnonimine hydrochloride (SIN-1) at 200 microM caused hyperpolarizations (10-15 mV) similar to the IJP mediator, attenuated the IJPs, and abolished mechanical activities. SIN-1 increased the slow wave frequency but decreased the amplitude and duration of spontaneous slow waves and TSWs. VIP (10(-6) M) decreased contraction and slow wave amplitude and prolonged IJP duration without affecting membrane potential or slow wave frequency. We conclude that spontaneous slow waves and TSWs originate independently of neural activity. Pacemaking regions possess inhibitory neural inputs that release NO to mediate IJPs and relaxation and influence the delay before a TSW. NO (not VIP) release from nerves inhibits initiation of spontaneous slow waves or TSWs near the MyP, and spontaneous NO release modulates pacemaking activity from the DMP.

A multicentric observational study of patients affected by advanced heart failure with implantable cardioverter defibrillator and left ventricular assist devices

Funding Acknowledgements

Type of funding sources: None.

Background

Left ventricular assist device (LVAD) implantation is increasingly used in patients with end-stage heart failure. Most patients already have an implantable defibrillator (ICD) at the time of L-VAD implantation. Studies on this patient population are limited by the small sample size and the short duration of follow-up.

Purpose

The aim of this study was to retrospectively describe the real-world management of patients implanted with both ICD and LVAD. The main objective was to evaluate the incidence and predictors of appropriate and inappropriate therapies of the ICD and the incidence and predictors of ICD related complications.

Methods

212 patients were enrolled in four Centers in the period between July 2006 and November 2020. The inclusion criteria were age> 18 years, advanced heart failure, patients with ICD and concomitant or subsequent continuous flow LVAD implantation. ICD therapy was defined as antitachycardia pacing therapy or shock.

The data available at the last visit with a median follow up of 21 months were analyzed.

Outcome predictors were assessed by univariate logistic regression and the variables of interest included in a multivariate model.

Results

The rate of appropriate ICD therapies was 29.7%, while the incidence of inappropriate therapies was 10.4%; in the multivariate analysis the presence of a zone therapy with low detection rate (VT zone with median detection rate of 164.5 bpm) was found to be an independent predictor of the composite of appropriate and inappropriate therapies (OR = 19.05; CI = 2.19-165.21; p = 0.007). Interference between ICD and LVAD occurred in 7.5% of cases; the incidence of infectious complications related to the ICD was 7.1% and bleeding complications of 5.2%; in the multivariate analysis, ICD generator replacement was an independent predictor of total complications related to the ICD (interference, infectious and bleeding; OR = 4.45; IC = 1.60-12.36; p = 0.004). 103 patients had CRT defibrillator (48,6%). At follow up there was no statistically significant difference in the incidence of appropriate therapies between those who had CRT-on (n=74) and those who had CRT-off (n=29; p = 0.61).

Conclusions

Patients with LVAD implanted with an ICD experience a high rate of appropriate and inappropriate ICD therapies. An active VT zone at low heart rate was found to be an independent predictor of ICD therapies. Of more, ICD generator replacement was found to be an independent predictor of total complications related to the ICD. Our findings suggest the importance of tailoring device programming in order to minimize the incidence of ICD therapies, thus sparing the need for generator replacement in this population.

Leadless left bundle branch pacing: feasibility in an animal model

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): EBR Systems Inc.

Introduction

Epicardial cardiac resynchronization therapy (CRT) is an established treatment for heart failure; left bundle branch (LBB) pacing has been proposed to overcome epicardial CRT limitations. In this study, we report on the first implants of a leadless electrode for endocardial pacing of the LBB in a porcine model.

Methods

The implant of the leadless, left ventricular endocardial pacing system (WiSE-CRT System) was attempted by transeptal approach in two porcines. Fluoroscopic and transoesophageal echocardiographic guidance were used to navigate the Delivery Sheath to the LBB area; the targeted implant site was selected by analysis of the electrograms from the implanting Electrode. At the end of the procedure, the animals were sacrificed and the hearts were isolated and analysed.

Results

In both animals, the Delivery System was successfully navigated to the LV septum. The target sites showed LBB electrograms preceding the far field ventricular electrogram by 15ms. The Electrode was successfully implanted on both animals with pacing threshold <2.0V @ 0.5ms. The implant of the pacing electrode was associated with minimal, multifocal haemorrhage; Purkinje fibers components of the LBB were observed in the on both sides of the site of implantation site. The lesion was 1.7 mm large and 2 mm deep.

Conclusions

This study supports the feasibility of leadless LBB pacing. Anatomical evaluation showed a close relationship between the Electrode and the LBB, with absence of significant damage to the conduction system from the implanted Electrode.

Configuración de redes locales en CD-ROM: el caso de la Universidad Carlos III de Madrid

Se describen unas nociones generales sobre la configuración de redes de área local, así como sobre la integración en red de aplicaciones en CD-ROM. Se analizan las características de los distintos productos disponibles en el mercado y se ofrecen pautas para su evaluación. Considerar las especificaciones de software y hardware necesarias es de gran importancia para lograr un buen funcionamiento de la red. El artículo se complementa con una exposición del proyecto llevado a cabo en la Universidad Carlos III de Madrid y con una reflexión sobre las consideraciones prioritarias y los problemas más frecuentes en un proyecto de estas características.

Mechanisms of action of cholecystokinin in the canine gastrointestinal tract: role of vasoactive intestinal peptide and nitric oxide

This study defined the cholecystokinin (CCK)/gastrin receptor subtypes at which CCK octapeptide (CCK8) and gastrin 17 (G17)act on motor functions of the intact canine gastrointestinal tract. In the antrum, studies of tachyphylaxis and effects of antagonists showed that i.a. G17 acted through CCKB receptors to activate contractions, whereas CCK8 acted through A and B receptor subtypes to produce contractions. In the duodenum, i.a. G17 caused dose-dependent inhibition of electrical field-stimulated contractions, apparently by release of nitric oxide [blocked by N-nitro-L-arginine (L-NNA) or NG-L-arginine methyl ester]. These inhibitory effects were abolished by YM022 (a CCKB antagonist) but not by L-364, 718 (a CCKA antagonist). However, i.a. CCK8 increased electrical field-stimulated contractions and L-364, 718 reversed this effect. In isolated perfused segments of distal intestine, CCK8 caused inhibition and excitation and released vasoactive intestinal peptide (VIP) into the venous effluent. CCK tetrapeptide and G17 had inconsistent effects. Excitation and VIP release were inhibited by L-364, 718. L-NNA potentiated excitatory responses and abolished inhibitory responses. Tetrodotoxin and atropine abolished and hexamethonium reduced excitatory responses to CCK8, but L-NNA restored contractions after atropine treatment. Hexamethonium or L-NNA (but not atropine) reduced VIP release; CCK8 still enhanced it. L-364, 718 abolished hexamethonium-resistant contractions and VIP release. Thus, CCK/gastrin peptides act on neural receptors in intact canine gastrointestinal tract. In antrum, activation of neural CCKA or CCKB receptors initiates contractions. In intestine, CCKA receptors at pre- and postjunctional sites in enteric nerves mediate acetylcholine and VIP release. CCKB receptors mediate release of an inhibitory mediator, apparently nitric oxide, from postjunctional sites.

Bronchodilator effect of the association ipratropium bromide plus fenoterol (low doses) versus terbutaline and salbutamol in bronchitic patients

In 12 chronic bronchitic out-patients, during 3 successive days, the variations of FEV1 and Vmax25 were studied at 15, 30, 45, 60, 120, and 180 min after inhalation of: [0.1 mg fenoterol (F) associated with 0.04 mg ipratropium bromide (IB)]; [0.2 mg salbutamol (S)], and [0.5 mg terbutaline (T)]. There were no secondary effects resulting from any treatment. Maximum effectiveness appeared on FEV1 at 60 min with F + IB, and at 45 min with S and T. On Vmax25, it was produced after 30 min with F + IB and no modifications in this parameter were observed either with S or with T. After 15 min, there were changes on FEV1 with the three products: P less than 0.001 for F + IB and S; p less than 0.01 for T. The variation persisted for up to 120 min with F + IB (p less than 0.001) and with S (p less than 0.05), and for up to 60 min with T (p less than 0.01). With F + IB, Vmax25 increased since after 15 min (p less than 0.001) and up to 60 min (p less than 0.01). In conclusion, the association of a small dose of F to IB provides as positive results as S, and better than T, in a group of chronic bronchitic out-patients.

Primary astrocytes retrovirally transduced with a tyrosine hydroxylase transgene driven by a glial-specific promoter elicit behavioral recovery in experimental parkinsonism

We used a retroviral-mediated gene transfer system to transduce primary rat astrocytes with a transgene in which the activity of a tyrosine hydroxylase (TH) cDNA is under the transcriptional control of a human promoter of the glial fibrillary acidic protein (GFAP). The engineered cells were tested for their therapeutic efficacy in a rodent model of Parkinson's disease (PD). The method is based both on the properties of astrocytes, as well as on those of the promoter. Astrocytes are an integral part of the neural tissue, have a long life span, are more resistant to oxidative stress than neurons, and possess an efficient secretory system. The GFAP promoter is active throughout postnatal life, and its activity is up-regulated by many insults to the brain, including PD. Transduced astrocytes were implanted into the striata of rats lesioned with 6-hydroxydopamine (6-OHDA), and the efficacy of grafted cells tested. Implanted astrocytes induced a significant reduction in the turning behavior that occurs in response to apomorphine for at least 4 weeks after grafting, and transgenic mRNA and protein could be detected in implanted brains. These results indicate that the gFa2-TH construct can be readily adapted to be used with a retroviral gene transfer system to obtain nontumorigenic cells that sustain a sufficient level of transgene activity to enable therapeutic effectiveness for prolonged periods. These results further endorse the use of astrocytes for gene therapy in the central nervous system.

Oral Health Research in the WHO African Region between 2011 and 2022: A Scoping Review

The status of oral health research in the World Health Organization (WHO) African region is unclear, yet the need for such information is central to moving an oral health agenda forward. Such an agenda is essential for effectively translating research into actionable practices and supporting regional strategies. The aim of this scoping review was to provide data on the scope and output of oral health research in the WHO African region to be used as a starting point for establishing a research agenda that can affect oral health in the region. We conducted a systematic search in PubMed; EMBASE; Epistemonikos; Scopus; the International Association for Dental, Oral, and Craniofacial Research General and Regional Sessions; ProQUEST; PROSPERO; and African regional databases such as Regional African Index Medicus and the African Journal Online. We included primary and secondary studies published in English, French, or Portuguese between January 1, 2011, and December 31, 2022, addressing oral health-related research having individuals, groups, or populations as units of analysis. These reports either addressed a topic relevant to the WHO African region assessed using the title and study objective or were conducted in a country in the region. We excluded in vitro and in vivo studies focusing on cells, biomarkers, or animals. We assessed 24,014 records, and 1,379 proved eligible. Our findings indicate a preference for particular research designs less suitable for evidence-informed practice guidelines and oral policies, a limited scope of oral health research topics, and important regional differences in research capacity. Furthermore, publications by researchers in the WHO African region tend to be published in journals with a limited readership. A discussion of our findings among oral health researchers at academic institutions in the WHO African region on how to create within- and across-country collaborations could potentially improve both health and oral health in the region.

Peripheral and central cholecystokinin receptors regulate postprandial intestinal motility in the rat

Postprandial cholecystokinin (CCK) has been suggested as an important mediator of disruption of migrating myoelectric complexes (MMC) after a meal. However, the role of CCK in regulating small intestinal motility in rats and the participation of central and/or peripheral CCK-A and B receptors in CCK actions, are still unclear. For this study, Sprague-Dawley rats were prepared with electrodes in the small intestine, a catheter in the jugular vein and an intracerebroventricular (i.c.v.) cannula. Postprandial disruption of the MMC was blocked by the i.v. infusion of the CCK-B antagonist L-365,260 (2 x 10(-7) mol/kg), but not by the infusion of the CCK-A antagonist L-364,718. When administered i.c.v., L-364,718 (2.25 x 10(-9) mol), but not L-365,260, restored the MMC pattern. The i.v. infusion of CCK-8 (1-3 x 10(-9) mol/kg) or CCK-4 (10(-7) mol/kg) disrupted the MMC pattern. CCK-8 effects where prevented by the i.v. infusion of either L-364,718 or L-365,260. Administered i.c.v., only the antagonist L-364,718 prevented CCK-8 disruption of the MMC. These results suggest that CCK-mediated motor changes after a meal are due to stimulation of peripheral CCK-B receptors. CCK also induces a release of central CCK that through CCK-A receptors participates on MMC disruption.