A 7-Week Summer Camp in Antarctica Induces Fluctuations on Human Oral Microbiome, Pro-Inflammatory Markers and Metabolic Hormones Profile.

Antarctic camps pose psychophysiological challenges related to isolated, confined, and extreme (ICE) conditions, including meals composed of sealed food. ICE conditions can influence the microbiome and inflammatory responses. Seven expeditioners took part in a 7-week Antarctic summer camp (Nelson Island) and were evaluated at Pre-Camp (i.e., at the beginning of the ship travel), Camp-Initial (i.e., 4th and 5th day in camp), Camp-Middle (i.e., 19th-20th, and 33rd-34th days), Camp-Final (i.e., 45th-46th day), and at the Post-Camp (on the ship). At the Pre-Camp, Camp-Initial, and Camp-Final, we assessed microbiome and inflammatory markers. Catecholamines were accessed Pre- and Post-Camp. Heart rate variability (HRV), leptin, thyroid stimulating hormone (TSH), and thyroxine (T4) were accessed at all time points. Students' t-tests or repeated-measures analysis of variance (one or two-way ANOVA) followed by Student-Newman-Keuls (post hoc) were used for parametric analysis. Kruskal-Wallis test was applied for non-parametric analysis. Microbiome analysis showed a predominance of Pseudomonadota (34.01%), Bacillota (29.82%), and Bacteroidota (18.54%), followed by Actinomycetota (5.85%), and Fusobacteria (5.74%). Staying in a long-term Antarctic camp resulted in microbiome fluctuations with a reduction in Pseudomonadota-a "microbial signature" of disease. However, the pro-inflammatory marker leptin and IL-8 tended to increase, and the angiogenic factor VEGF was reduced during camp. These results suggest that distinct Antarctic natural environments and behavioral factors modulate oral microbiome and inflammation.

Left ventricular assist device implantation via lateral thoracotomy: A systematic review and meta-analysis.

BACKGROUND: Left ventricular assist device (LVAD) implantation via lateral thoracotomy can offer similar effectiveness to conventional approaches with less perioperative adverse events. We performed a systematic review and meta-analysis to determine the potential benefits of lateral thoracotomy (LT) for LVAD implantation compared to median sternotomy. METHODS: We searched MEDLINE and Embase databases for studies comparing continuous-flow LVAD implantation using LT with conventional sternotomy. Main outcomes were perioperative mortality and complications. RESULTS: Twenty-five observational studies enrolling 3072 patients were included with a median follow-up of 10 months. Perioperative mortality (30 day or in-hospital) was 7% (LT) and 14% (sternotomy); however, mortality differences were no longer statistically significant in matched/adjusted studies (RR:0.86; 95%CI:0.52-1.44; p = 0.58). LT was associated with decreased need for blood product transfusions (mean difference[MD]: -4.7; 95%CI: -7.2 to -2.3 units; p < 0.001), reoperation for bleeding (RR:0.34; 95%CI:0.22-0.54; p < 0.001), postoperative RVAD implantation (RR:0.53; 95%CI:0.36-0.77; p < 0.001), days requiring inotropes (MD: -1.1; 95%CI: -2.1 to -0.03 inotrope days; p = 0.04), ICU (MD: -3.3; 95%CI: -6.0 to -0.7 ICU days; p = 0.01), and hospital length of stay (MD: -5.1; 95%CI: -10.1 to -0.1 hospital days; p = 0.04) in matched/adjusted studies. Overall mortality during follow-up was significantly lower for LT in unmatched/unadjusted studies but not statistically significantly lower in matched/adjusted studies (Hazard Ratio:0.82; 95%CI:0.59-1.14; p = 0.24). CONCLUSION: LVAD implantation via LT was associated with significantly decreased need for blood products, reoperation for bleeding, and postoperative RVAD implantation. Furthermore, days on inotropic support were also lower, likely contributing to the shorter length of stay. These findings support greater use of a LT approach for carefully selected patients.

Heart rate variability, thyroid hormone concentration, and neuropsychological responses in Brazilian navy divers: a case report of diving in Antarctic freezing waters.

Open-water diving in a polar environment is a psychophysiological challenge to the human organism. We evaluated the effect of short-term diving (i.e., 10 min) in Antarctic waters on autonomic cardiac control, thyroid hormone concentration, body temperatures, mood, and neuropsychological responses (working memory and sleepiness). Data collection was carried out at baseline, before, and after diving in four individuals divided into the supporting (n=2) and diving (n=2) groups. In the latter group, autonomic cardiac control (by measuring heart rate variability) was also assessed during diving. Diving decreased thyroid-stimulating hormone (effect size = 1.6) and thyroxine (effect size = 2.1) concentrations; these responses were not observed for the supporting group. Diving also reduced both the parasympathetic (effect size = 2.6) and sympathetic activities to the heart (ES > 3.0). Besides, diving reduced auricular (effect size > 3.0), skin [i.e., hand (effect size = 1.2) and face (effect size = 1.5)] temperatures compared to pre-dive and reduced sleepiness state (effect size = 1.3) compared to basal, without changing performance in the working memory test. In conclusion, short-term diving in icy waters affects the hypothalamic-pituitary-thyroid axis, modulates autonomic cardiac control, and reduces body temperature, which seems to decrease sleepiness.

Large-Animal Model of Donation after Circulatory Death and Normothermic Regional Perfusion for Cardiac Assessment.

The increase in demand for cardiac transplantation throughout the years has fueled interest in donation after circulatory death (DCD) to expand the organ donor pool. However, the DCD process is associated with the risk of cardiac tissue injury due to the inevitable period of warm ischemia. Normothermic regional perfusion (NRP) allows for an in situ organ assessment, allowing the procurement of hearts determined to be viable. Here, we describe a clinically relevant large-animal model of DCD followed by NRP. Circulatory death is established in anesthetized pigs by stopping mechanical ventilation. After a preset warm ischemia period, an extracorporeal membrane oxygenator (ECMO) is used for a NRP period lasting at least 30 min. During this reperfusion period, the model allows the collection of various myocardial biopsies and blood samples for initial cardiac evaluation. Once NRP is weaned, biochemical, hemodynamic, and echocardiographic assessments of cardiac function and metabolism can be performed before organ procurement. This protocol closely simulates the clinical scenario previously described for DCD and NRP in heart transplantation and has the potential to facilitate studies aimed at decreasing ischemia-reperfusion injury and enhance cardiac functional preservation and recovery.

Association Between Neurohormone Levels and Exercise Testing Measures in Patients with Mechanical Circulatory Supports.

Continuous-flow left ventricular assist device (CF-LVAD) recipients exhibit impaired exercise capacity. Long-term continuous blood flow also elevates norepinephrine (NE) and aldosterone (Aldo) levels. However, the relationship between exercise capacity and neurohormonal activation has not been elucidated. Our study objective was to assess the association between cardiopulmonary exercise testing (CPT) measures and neurohormonal levels in CF-LVAD recipients. Symptom-limited CPT on a treadmill, using the modified Bruce protocol was performed in 15 CF-LVAD recipients. Norepinephrine and Aldo levels were measured, and the association between their levels and CPT measures were assessed. Peak VO2 (13.6 ml/kg/min) and percent age, sex predicted VO2 max (49.4%), and oxygen pulse (O2 pulse) (9.0 ± 4.0 ml/beat) were low, whereas minute ventilation/carbon dioxide output (VE/VCO2) slope (35) was elevated. In addition, VO2 at anaerobic threshold (VO2 AT), and O2 pulse values negatively correlated with NE levels. Norepinephrine levels positively correlated with chronotropic responses and heart rate (HR) recovery. Aldo levels in CF-LVAD recipients were not related to any CPT measures. Continuous-flow left ventricular assist device recipients exhibited impaired exercise capacity and chronotropic incompetence (CI). Despite the association of NE levels with chronotropic responses at peak exercise, neither NE levels nor chronotropic responses predicted peak VO2. This suggests that CI may not be the primary factor responsible for the low peak VO2. O2 pulse, which is a combined measure for stroke volume and peripheral oxygen extraction during exercise, was an independent predictor of peak VO2. Future studies should examine the contribution of peripheral factors to exercise capacity limitations.

Hormonal, autonomic cardiac and mood states changes during an Antarctic expedition: From ship travel to camping in Snow Island.

We evaluated the influence of an Antarctic expedition, consisting of 26-day ship travel followed by 24-day camping in the Antarctic field during the summer season, on hormonal responses, autonomic cardiac control, and mood states in individuals that live in tropical regions. Data collection was carried out in 10 individuals on the 2nd, 16th, and 26th days aboard the ship (characterized by exposure to low-luminosity and temperature-controlled environments) and on the 4th, 11th, and 23rd days of camping in the Antarctic field (prolonged exposure to natural luminosity and cold environments). Morning samples of saliva (to determine testosterone and cortisol concentrations) and blood [to determine thyroid-stimulating hormone (TSH) and thyroxine (T4) concentrations] were obtained. Next, resting heart rate variability (HRV) was recorded, and the volunteers answered a mood questionnaire. Samples of saliva for measurement of melatonin concentration were obtained at night. At the end of ship travel, blood TSH and salivary melatonin increased by 15.6% and 72.3%, respectively, whereas salivary cortisol reduced by 37.1% compared to initial values and T4 reduced by 12.2% compared to 16th day. These hormonal changes occurred alongside increased depression score and biphasic changes in HRV parameters; for example, the RMSSD, a parasympathetic-related parameter, initially decreased by 47.8% and then returned towards baseline values by the end of the ship travel. In contrast, during the camp period, blood TSH and T4 reduced by 26.5% and 34.1%, respectively, and salivary cortisol increased by 72.1%, without concomitant changes in melatonin and HRV. Also, tension score transiently reduced and then increased towards the pre-camp score by the end of the field period. Testosterone remained unaltered throughout the expedition. In conclusion, ship travel and camping in Antarctica induced distinct neuroendocrine changes, cardiac autonomic regulation, and mood states. These specific changes most likely resulted from exposure to different natural luminosity, degrees of confinement, and ambient temperature in these environments.

Human leukocyte antigen-G donor-recipient matching of the 14-base pair polymorphism protects against cancer after heart transplant.

BACKGROUND: After a transplant, cancer is a leading cause of morbidity and mortality. Human leukocyte antigen-G (HLA-G)-an immune checkpoint molecule-reduces allograft rejection by dampening host immune responses. Reports suggest malignant cells utilize HLA-G to evade the immune system and promote cancer development. Our objective was to evaluate HLA-G donor-recipient polymorphism matching and development of cancer after a heart transplant. METHODS: Recipients (n = 251) and corresponding donors (n = 196) were genotyped retrospectively to identify HLA-G polymorphisms in the 5' regulatory (-725, -201), 3' untranslated (+3,197, +3,187, +3,142, 14-base pair insertion-deletion polymorphism [14-bp indel]) and coding regions (Haplotypes I-VI). Associations between donor-recipient polymorphism matching and development of cancer were assessed through multivariate proportional hazard regression models. RESULTS: Recipient and donor (48.2 ± 12.1 and 35.5 ± 14.3 years, respectively) mean follow-up was 7.2 ± 4.6 years. Overall, 42 (16.7%) recipients developed de novo post-transplant cancer. 14-bp polymorphism matching significantly reduced the proportion of cancer, revealing an independent protective effect (hazard ratio [95% CI]: 0.26 [0.10-0.75]; p = 0.012). Recipients with the 14-bp insertion sequence, whether homozygous or heterozygous, had a lower proportion of cancer (p > 0.008), matching the INS sequence (INS/INS and INS/DEL) protected against cancer (p = 0.002). No differences were seen between matched vs unmatched cohorts regarding all donor-recipient pre-transplant and post-transplant characteristics. No other polymorphisms showed significant associations. CONCLUSIONS: We investigated donor-recipient HLA-G polymorphism matching and development of cancer following a heart transplant. Donor-recipient 14-bp matching was an independent protective factor against cancer development. HLA-G may have a role in therapeutic and diagnostic strategies against cancer. Identifying relevant HLA-G polymorphisms may warrant alterations in immunotherapy to reduce post-transplant cancer risk.

Supplemental Cardioplegia During Donor Heart Implantation: A Systematic Review and Meta-Analysis.

BACKGROUND: The optimal donor heart preservation and management strategy during heart transplantation remains controversial. We report the results of a systematic review and meta-analysis of the effect of supplemental cardioplegia administration during donor heart implant for transplantation. METHODS: We searched MEDLINE and Embase databases until February 2019 for studies comparing patients who received transplants with the donor heart given supplemental cardioplegia or not. Data were extracted by 2 independent investigators. The main outcomes were early morbidity and mortality. RESULTS: Included were 7 retrospective observational studies (4 comparing to historical controls) and 3 randomized controlled trials enrolling 1125 patients. Supplemental cardioplegia included crystalloid and blood cardioplegia given continuous retrograde or as terminal "hot shots." Supplemental cardioplegia was associated with improved early mortality (risk ratio [RR], 0.55; 95% confidence interval [CI], 0.35-0.87; P < .01), greater rates of spontaneous return of sinus rhythm (RR, 2.62; 95% CI, 1.50-4.56; P < .01), shorter intensive care stay (mean difference, -3.4 days; 95% CI, -5.1 to -1.6; P < .01), and lower incidence of ischemic changes seen on endomyocardial biopsy specimens (RR, 0.49; 95% CI, 0.35-0.69; P < .01) compared with controls. Midterm mortality was not different between groups (incident rate ratio, 0.80; 95% CI, 0.51-1.26; P = .34). CONCLUSIONS: Administration of supplemental cardioplegia may be associated with a reduction in organ ischemic injury and shorter intensive care stay as well as improvement in early survival after transplantation. This strategy may be a simple and cost-effective adjunct to improve outcomes of heart transplantation, especially in an era of increasing use of marginal donor organs. Further investigation will be needed to confirm the findings of this hypothesis-generating study.

HLA-G +3196 polymorphism as a risk factor for cell mediated rejection following heart transplant.

BACKGROUND: Rejection is a leading cause of mortality following heart transplantation. Human leukocyte antigen-G (HLA-G) is an immune checkpoint which dampens the immune response. Reports suggest elevated HLA-G expression is associated with reduced allograft rejection. Our objective was to evaluate HLA-G polymorphisms and cell mediated rejection (CMR) development. METHODS: Recipients (n = 123) were genotyped to identify relevant HLA-G polymorphisms in the 5'regulatory (-725, -201), 3'untranslated (+3197, +3187, +3142, 14-bp indel) and coding regions (haplotypes 1-6). CMR was evaluated via endomyocardial biopsy (grade ≥ 2R). Univariate/adjusted analyses were conducted via Kaplan Meier and proportional hazard models. RESULTS: Mean recipient age was 48 (±12) years, with a median time to CMR of 4.6 years. 55 (45%) recipients had a biopsy grade ≥ 2R. Adjusted analysis revealed the +3196 G allele as a risk factor for CMR (p = 0.03). Compared to the minor GG genotype, CG had a 47.2% reduction in CMR risk (HR[95% CI] = 0.528 [0.235, 1.184]), while CC had a 66.9% reduction (0.331 [0.144, 0.761]). The recessive effect significantly increased CMR likelihood (2.388 [1.128, 5.059], p = 0.02). CONCLUSION: The HLA-G +3196 G allele was identified as a risk factor for CMR diagnosis. HLA-G may have a role in therapeutic/diagnostic strategies against transplant rejection.

Clinical outcomes of mitral valve intervention in patients with mitral annular calcification: A systematic review and meta-analysis.

BACKGROUND: Mitral valve (MV) disease with mitral annular calcification (MAC) poses a surgical challenge and the clinical outcomes of MV surgery as well as transcatheter mitral valve replacement (TMVR) remain relatively unexplored. We performed a systematic review and meta-analysis to assess the effects of MAC on clinical outcomes following MV surgery and TMVR. METHODS: We searched MEDLINE and EMBASE databases until February 2019 for studies comparing clinical outcomes of MV surgery or TMVR in patients with and without MAC. Data were extracted by two independent investigators. Outcomes were perioperative and midterm complications and mortality. RESULTS: Seven observational studies enrolling 2902 patients were included. MAC patients were older, more likely to be female with greater chronic lung disease and kidney failure. Perioperative mortality was similar between patients with and without MAC undergoing MV surgery (risk ratio [RR], 1.15; 95% confidence interval [CI], 0.50-2.65; P = .74). MAC was associated with a higher risk of bleeding, permanent pacemaker implantation, and periprosthetic leak. Midterm mortality was greater in MAC patients undergoing MV surgery (incident rate ratio [IRR], 1.32; 95% CI, 1.05-1.67; P = .02). MAC patients undergoing TMVR had higher perioperative (RR, 4.65; 95% CI, 2.93-7.38; P < .01) and 1-year (RR, 5.44; 95% CI, 3.49-8.49; P < .01) mortality, decreased procedural success, greater left ventricular outflow tract obstruction and need for conversion to surgery when compared with patients undergoing TMVR for dysfunction of a bioprosthetic valve or annuloplasty ring. CONCLUSION: MV procedures in patients with MAC are associated with higher mortality and morbidity. This is largely driven by the high-risk patient profile associated with MAC. TMVR holds promise but has important limitations and should be reserved for select patients.

A Pre-Clinical Porcine Model of Orthotopic Heart Transplantation.

Fifty-years following the first successful report, cardiac transplantation remains the gold-standard treatment for eligible patients with advanced heart failure. Multiple small-animal models of heart transplantation have been used to study the acute and long-term effects of novel therapies. However, few are tested and demonstrated success in clinical trials. It is of critical importance to evaluate new therapies in a clinically relevant large-animal model for efficient and reliable translation of basic studies' findings. Here, we describe a pre-clinical large-animal (porcine) model of orthotopic heart transplantation that has been firmly established and previously used to investigate novel cardioprotective strategies. This procedure focuses on acute ischemia-reperfusion injury and is a reliable method to investigate novel interventions which have been tested and validated in smaller experimental models, such as the murine model. We demonstrate its usefulness in assessing cardiac performance during the early post-transplantation period and other potential possibilities enabled by the model.

Hearts Donated After Circulatory Death and Reconditioned Using Normothermic Regional Perfusion Can Be Successfully Transplanted Following an Extended Period of Static Storage.

BACKGROUND: There has been an increased interest in donation after circulatory death (DCD) to expand donor pool for cardiac transplantation. Normothermic regional perfusion (NRP) allows in situ assessment of DCD hearts, allowing only acceptable organs to be procured. We sought to determine if extended cold storage was possible for DCD hearts following NRP and to compare hearts stored using standard cold storage with a novel cardioprotective solution designed for room temperature storage. METHODS AND RESULTS: Donor pigs underwent hypoxic cardiac arrest (DCD) followed by 15 minutes of warm ischemia and resuscitation on NRP. They were then randomly assigned to static storage with histidine-tryptophan-ketoglutarate (HTK) at 4°C (HTK group, n=5) or SOM-TRN-001 at 21°C (SOM group, n=5). Conventional beating-heart donations were used as controls (n=4). Fourteen transplants were successfully performed. HTK hearts showed initial dysfunction following reperfusion; however, they demonstrated significant recovery up to 3 hours post-transplant. No significant differences were seen between HTK and control hearts post-transplantation (cardiac index: control 49.5±6% and HTK 48.5±5% of baseline). SOM improved myocardial preservation; hearts showed stable contractility after transplantation (cardiac index: 113.0±43% of NRP function) and improved diastolic function compared with HTK. Preservation in SOM also significantly reduced proinflammatory cytokine production and release following transplantation and partially prevented endothelial dysfunction. CONCLUSIONS: DCD hearts stored using a standard preservation solution demonstrated comparable post-transplantation myocardial function to standard controls. Thus, short periods of cold storage following successful NRP and documented adequate function is an acceptable strategy for DCD hearts. Preservation in SOM at room temperature is feasible and can improve cardiac recovery by minimizing endothelial dysfunction and tissue injury.

Recipient hypertonic saline infusion prevents cardiac allograft dysfunction.

OBJECTIVE: Hypertonic saline (HTS) has potent immune and vascular effects. We assessed recipient pretreatment with HTS on allograft function in a porcine model of heart transplantation and hypothesized that HTS infusion would limit endothelial and left ventricular (LV) dysfunction following transplantation. METHODS: Heart transplants were performed after 6 hours of cold ischemic storage. Recipient pigs were randomized to treatment with or without HTS (7.5% NaCl) before cardiopulmonary bypass (CPB). Using a myograft apparatus, coronary artery endothelial-dependent (Edep) and -independent (Eind) relaxation was assessed. LV performance was determined using pressure-volume loop analysis. Pulmonary interleukin (IL)-2, IL-6, and tumor necrosis factor (TNF)-α expression was measured. RESULTS: Weaning from CPB and LV performance after transplantation were improved in HTS-treated animals. Successful weaning from CPB was greater in the HTS-treated hearts (8 of 8 vs 2 of 8; P < .05). Mean LV functional recovery was improved in the HTS-treated animals, as assessed by preload recruitable stroke work (65 ± 10% vs 27 ± 10%; P < .001) and end-systolic elastance (55 ± 7% vs 37 ± 4%; P < .001). Treatment with HTS resulted in improved Edep (mean maximum elastance [Emax], 56 ± 5% vs 37 ± 7%; P < .001) and Eind (mean Emax%, 77 ± 6% vs 52 ± 4%; P < .001) vasorelaxation compared with control. Pulmonary expression of IL-2, IL-6, and TNF-α increased following transplantation, whereas HTS therapy attenuated IL production (P < .001). Transplantation increased plasma TNF-α levels and LV TNF-α expression, whereas HTS prevented this up-regulation (P < .001). CONCLUSIONS: Recipient HTS pretreatment preserves allograft vasomotor and LV function, and HTS therapy limits CPB-induced injury. HTS may be a novel recipient intervention to prevent graft dysfunction.

Left ventricular assist device exchange: the Toronto General Hospital experience.

BACKGROUND: As support times for left ventricular assist devices (LVADs) become longer, several complications requiring device exchange may occur. To our knowledge, this is the first Canadian report regarding implantable LVAD exchange. METHODS: We retrospectively reviewed the cases of consecutive, unique patients implanted with an LVAD between June 2006 and October 2015 at Toronto General Hospital. RESULTS: In total, 122 patients were impanted with an LVAD during the study period. Eight patients required LVAD exchange, and 1 patient had 2 replacements (9 of 122, 7.3%). There were 7 HeartMate II (HMII), 1 HVAD and 1 DuraHeart pumps exchanged. Two of these exchanges occurred early at the time of initial implant, whereas 7 occurred late (range 8-623 d). Six exchanges were made owing to pump thrombosis. Of the 3 exchanges made for other causes, 1 HMII exchange was owing to a driveline fracture, 1 DuraHeart patient had early inflow obstruction requiring exchange to HMII at the initial implant, and the third had a suspected inflow obstruction with no evidence of thrombosis at the time of the procedure. The mean support time before exchange was 225 days, and time from exchange to transplant, death or ongoing support was 245 days. Three patients were successfully bridged to transplant, and at the time of data collection 2 were supported awaiting transplant. Three patients died after a mean duration of 394.3 days (range 78-673 d) of support postreplacement. Four cases were successfully performed using a subcostal approach. CONCLUSION: Pump thrombosis is the most common cause for LVAD exchange, which can be performed with acceptable morbidity and mortality. The subcostal approach may be the preferred procedure for an HMII exchange when indicated.

CONTEXTE: À mesure que la durée d'utilisation des dispositifs d'assistance ventriculaire gauche (DAVG) augmente, plusieurs complications nécessitant un remplacement du dispositif peuvent survenir. À notre connaissance, il s'agit du premier rapport canadien concernant le remplacement des DAVG implantables. MÉTHODES: Nous avons passé en revue de manière rétrospective les cas individuels consécutifs de patients à qui on a implanté un DAVG entre juin 2006 et octobre 2015 à l'Hôpital Général de Toronto. RÉSULTATS: En tout, 122 patients ont reçu un DAVG pendant la période de l'étude. Huit patients ont eu besoin d'un remplacement de DAVG et 1 patient a eu besoin de 2 remplacements (9 sur 122, 7,3 %). Sept dispositifs HeartMate II (HMII), 1 dispositif HVAD et 1 dispositif DuraHeart ont été remplacés. Deux de ces remplacements sont survenus peu de temps après la pose initiale du dispositif, tandis que les 7 autres se sont produits plus tardivement (dans les 8 à 623 jours suivants). Six remplacements ont été effectués en raison d'une thrombose de la pompe. Parmi les 3 remplacements effectués pour d'autres raisons, 1 dispositif HMII a été remplacé en raison d'un bris de la ligne d'activation, 1 dispositif DuraHeart a présenté une obstruction précoce du flux entrant nécessitant la pose d'un HMII dès l'implantation initiale, et le troisième présentait une obstruction présumée du flux entrant sans signe de thrombose au moment de l'intervention. La durée moyenne d'utilisation avant le remplacement du dispositif a été de 225 jours, et l'intervalle entre le remplacement et la transplantation, le décès ou la décision de maintenir l'assistance a été de 245 jours. L'appareil a permis une transition réussie jusqu'à la transplantation chez 3 patients, et au moment de la collecte des données, 2 patients porteurs d'un DAVG étaient en attente d'une transplantation. Trois patients sont décédés après une durée moyenne de 394,3 jours (entre 78 et 673 jours) d'assistance post-remplacement. Quatre remplacements ont été effectués avec succès par une approche sous-costale. CONCLUSION: La thrombose de la pompe est la cause la plus fréquente de remplacement d'un DAVG; le remplacement peut être effectué avec des taux de morbidité et de mortalité acceptables. L'approche sous-costale serait à privilégier lorsqu'un remplacement de HMII est indiqué.

High Incidence of Biotinidase Deficiency from a Pilot Newborn Screening Study in Minas Gerais, Brazil.

OBJECTIVE: To assess the incidence of biotinidase deficiency among newborns and their clinical outcome up to one year of age in a large pilot screening study in Minas Gerais, Brazil. METHODS: A prospective cohort study was conducted from September 2007 to June 2008 with heel-prick blood samples collected on filter paper for the purpose of newborn screening. A qualitative colorimetric test was used as the primary screening method. Colorimetric-positive cases were further tested with a serum confirmatory assay. Gene sequencing was performed for eight children suspected with biotinidase deficiency and for some of their parents. Positive cases were daily supplemented with oral biotin and were followed up for approximately six years. RESULTS: Out of 182,891 newborns screened, 129 were suspected of having biotinidase deficiency. Partial deficiency was confirmed in seven children (one was homozygous for p.D543E) and profound deficiency in one child (homozygous p.H485Q). Thus the incidence was one in 22,861 live births (95% confidence interval 1:13,503 to 1:74,454) for profound and partial biotinidase deficiency combined. Two novel mutations were detected: p.A281V and p.E177K. In silico analysis and estimation of the enzyme activity in the children and their parents showed that p.A281V is pathogenic and p.E177K behaves like p.D444H. CONCLUSION: The incidence of biotinidase deficiency in newborn screening in Minas Gerais was higher than several international studies. The sample size should be larger for final conclusions. Oral daily biotin apparently precluded clinical symptoms, but it may have been unnecessary in some newborns.

Evidence for the conservation of miR-223 in zebrafish (Danio rerio): Implications for function.

MicroRNAs (miRNAs) are an abundant and conserved class of small RNAs, which play important regulatory functions by interacting with the 3' untranslated region (UTR) of target mRNAs. Through this mechanism, miR-223 was shown to regulate genes involved in mammalian haematopoiesis, both in physiological and pathological contexts. MiR-223 is essential for normal myelopoiesis in mammals, promoting granulocyte, osteoclast and megakaryocyte differentiation and suppressing erythropoiesis. However, there is a general lack of knowledge regarding miR-223 function in other vertebrates, which could help to clarify its role in other processes, such as development. In this work, we explored the functional conservation of miR-223 using zebrafish as a model. We show that miR-223 gene structure and genomic context have been maintained between human and zebrafish. In addition, we identified 22 novel sequences of miR-223 precursor and demonstrate that it contains domains highly conserved among vertebrates, suggesting function preservation throughout evolution. Furthermore, collected evidences show that miR-223 expression is highly correlated with haematopoietic events and osteoclastogenesis throughout zebrafish development. In adults, expression of miR-223 in zebrafish tissues mimics the distribution in mice, with high levels found in the major fish haematopoietic organ, the head kidney. These results suggest a conservation of miR-223 role in haematopoiesis, and osteoclastogenesis between zebrafish and human. Accordingly, validated targets of miR-223 in mammalian models were investigated and defined as putative targets in zebrafish, by in silico and gene expression analysis. Our data compiles critical evidence showing that miR-223, a highly conserved miRNA, appears to have kept similar regulatory functions throughout evolution.

MiR-29a is an enhancer of mineral deposition in bone-derived systems.

MicroRNAs (miRNAs) provide a mechanism for fine-tuning of intricate cellular processes through post-transcriptional regulation. Emerging evidences indicate that miRNAs play key roles in regulation of osteogenesis. The miR-29 family was previously implicated in mammalian osteoblast differentiation by targeting extracellular matrix molecules and modulating Wnt signaling. Nevertheless, the function of miR-29 in bone formation and homeostasis is not completely understood. Here, we provide novel insights into the biological effect of miR-29a overexpression in a mineralogenic cell system (ABSa15). MiR-29a gain-of-function resulted in significant increase of extracellular matrix mineralization, probably due to accelerated differentiation. We also demonstrated for the first time that miR-29a induced ß-catenin protein levels, implying a stimulation of canonical Wnt signaling. Our data also suggests that SPARC is a conserved target of miR-29a, and may contribute to the phenotype observed in ABSa15 cells. Finally, we provide evidences for miR-29a conservation throughout evolution based on sequence homology, synteny analysis and expression patterns. Concluding, miR-29a is a key player in osteogenic differentiation, leading to increased mineralization in vitro, and this function seems to be conserved throughout vertebrate evolution by interaction with canonical Wnt signaling and conservation of targets.

Estudio morfológico e histoquímico de las glándulas cefálicas de Bothrops alternatus (Ophidia, Viperidae) / Morphological and histochemical study of the cephalic glands of bothrops alternatus (Ophidia, Viperidae)

El objetivo del presente trabajo fue estudiar la histología de las glándulas cefálicas de la víbora de la cruz (Bothrops alternatus), identificar los tipos celulares y caracterizar histoquimicamente el producto de secreción. Con esta finalidad fueron usados ejemplares machos adultos de B. alternatus. Después del sacrificio, las glándulas cefálicas fueron fijadas en formol neutro al 10 por ciento e incluidas en parafina. Los cortes, de 6 µm de espesor, fueron teñidos con hematoxilina y eosina, tricrómico de Masson y con técnicas histoquímicas para identificación de mucopolisacáridos y proteínas. Los resultados histológicos demostraron que las glándulas linguales, de veneno y accesorias son de tipo tubular, las glándulas labiales y premaxilar son tubuloacinares y la glándula de Harder es tubuloacinar compuesta. Las células mucosas de los adenómeros y conductos secretores de las glándulas linguales, labiales y premaxilar, así como las células de los conductos de la glándula de Harder, secretan sulfosialomucinas y mucopolisacáridos neutros. Las células mucoserosas de las glándulas linguales, labiales y premaxilar sintetizan mucopolisacáridos neutros, ácido siálico y radicales tirosina, cistina, cisteína, arginina y triptófano. Las células seromucosas de las glándulas de veneno, accesorias y de Harder producen polisacáridos neutros y radicales cistina, cisteína y triptófano, mientras que la glándula de Harder también sintetiza tirosina.

The aim of this paper was to studythe histology of the cephalic glands of the snake Bothropsalternatus, identifying the cell types and characterize histochemically the secretion product. For this purpose we used male adult specimens of B. alternatus. After slaughter, the cephalic gland was fixed in 10 percent neutral formalin and embedded in paraffin-wax. Histological sections, 6 µm thick, were stained with hematoxylin and eosin, Masson trichrome and histochemical techniques to identify mucosubstances and proteins. Histologically they were identified tubuloacinar composed glands (Harderian gland), tubuloacinar glands (upper and lower lip and premaxillary glands) and tubular (supralingual, sublingual, venom, and accessory glands). The mucous cells of the acini of the upper and lower lip glands and of the premaxillary gland, the secretory ducts of these glands and ducts of the Harderian gland secrete sulfosialomucins and neutral mucosubstances. Mucoserous cells of upper and lower lip glands and premaxillary gland secrete neutral mucosubstances, sialic acid and protein radicals tyrosine, cystine, cysteine, arginine and tryptophane. Seromucous cells of venom, accessories and Harderian glands secrete neutral mucosubstances and protein radicals cystine, cysteine and tryptophan, whereas the seromucous cells of the Harderian gland also secrete the tyrosine radical.

Estudio morfológico, morfométrico e histoquímico de los epitelios de revestimiento y glandular de la lengua de la rana toro, rana catesbeiana / Morphological, morphometrical and histochemical study of the lining and glandular epithelia of the tongue of the tullfrog rana catesbeiana

La superficie dorsal de la lengua de la rana toro, Rana catesbeiana, presenta un epitelio simple cilíndrico, constituido por células caliciformes y raras células ciliadas. El dorso de la lengua posee numerosas papilas filiformes y algunas fungiformes. Las primeras poseen un epitelio simple cilíndrico, con células secretoras, mientras que las segundas poseen en la región apical, un disco sensorial con epitelio estratificado cilíndrico, con células basales, periféricas, glandulares y receptoras. A lo largo del dorso de la lengua existen numerosas glándulas tubulares, que penetran en profundidad, entremezclándose con las fibras musculares. El epitelio glandular es simple cilíndrico, con células secretoras y de sostén. Las primeras son las únicas en la base de la glándula y las segundas solo se encuentran en número escaso en el tercio superior. La superficie ventral de la lengua posee un epitelio estratificado, con células caliciformes y, entre éstas, células ciliadas. La morfometría de las glándulas mostró que son más cortas en la región anterior de la lengua (330 um) que en la región posterior (450 um). Las células secretoras de las glándulas linguales anteriores son menores (1457,7 um3) que en las posteriores (2645,9 um3). Lo mismo ocurre con los núcleos celulares: 130,0 um3 en las glándulas anteriores y 202,3 um3 en las posteriores. Las células secretoras de las glándulas linguales sintetizan producto rico en proteínas y mucopolisacáridos neutros, pudiendo caracterizarse como seromucoso. Las células caliciformes de las superficies dorsal y ventral secretan proteínas y mucopolisacáridos neutros, clasificándose como del tipo G1, mientras que las células de sostén de las glándulas superficiales de las papilas fungiformes secretan moco rico en mucopolisacáridos neutros, sulfomucinas y sialomucinas.

The dorsal surface of the tongue of the bullfrog, Rana catesbeiana, has simple columnar epithelium with a few ciliated cells and goblet cells. The entire surface is covered with numerous filiform papillae and few fungiform. Filiform papillae have a simple columnar epithelium with secretory cells, while the fungiform have a sensory disc on their upper surface the lined by a stratified columnar epithelium with basal, peripheral, glandular and receptor cells. Over the dorsal lingual surface there are numerous winding tubular glands, which penetrate deeply into the muscle of the tongue, mingling with the fibers. The gland epithelium is cylindrical with secretory and supporting cells. The first are absolute on the basis of the gland and the latter are rare in the upper third. The ventral surface of the tongue is lined by a stratified epithelium, with the presence of goblet cells, with ciliated cells among them. Morphometrically, lingual glands varies in length, according to their location: shorter in the anterior region of the tongue (330 um) than in the posterior region (450 um). Secretory cells of the anterior lingual glands are smaller (1457.7 mm3) than the posterior ones (2645.9 um3). The same can be said of the cell nuclei, 130.0 um3 for the anterior glands and 202.3 um3 for the posterior ones. Secretory cells of the lingual glands contain substances rich in protein and neutral mucopolysaccharides, which characterize the seromucous type. Goblet cells of the dorsal and ventral surface epithelia secrete neutral mucopolysaccharides and proteins, and can be characterized as type G1 cells, and the supporting cells of the superficial glands of the fungiform papillae secrete a mucus rich in neutral mucopolysaccharides, sulfomucins and sialomucins.