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1.
J Vasc Access ; : 11297298241261146, 2024 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-39096211

RESUMO

INTRODUCTION: Short peripheral catheters (SPCs) are affected by a high complication rate that leads to catheter failure. Currently, the Visual Infusion Phlebitis score (VIP) is the most used tool to verify the presence of inflammatory complications (phlebitis and thrombophlebitis). However, ultrasound signs (US) may be an attractive alternative. OBJECTIVE: This study aims to evaluate the sensitivity and specificity of US and VIP score = 1 in identifying and recognizing early signs of SPC failure. The time to positivity for US and VIP scores was assessed as a secondary outcome. METHODS: An observational prospective study was conducted. In each patient, US (subcutaneous edema; fibroblastic sleeve; thrombophlebitis) and VIP of the exit site were performed every 24 h until 96 h after insertion. Compared to catheter failure, Sensitivity, Specificity, and Predictive values in both US and VIP were calculated. RESULTS: Two hundred patients were enrolled. The presence of ultrasonic pattern suggestive of edema at 72 h (p = 0.018), fibroblastic sleeve at 24, 48, 72, and 96 h (p < 0.001), thrombosis at 48 (p < 0.001) and 72 h (p = 0.005), and at least one of an abovementioned US at all checkpoints (p < 0.001) were highly significant predictors of complications. Both US and VIP effectively detect inflammatory events; however, the US showed better sensitivity in overall checkpoints and earlier predictive ability than VIP (1.9 vs 0.47 days). CONCLUSIONS: An ultrasound inflammatory pattern is correlated with SPC failure. An ultrasound protocol-requiring minimal training-is more effective than VIP in recognizing early signs of device failure.

2.
Nurs Rep ; 14(1): 455-467, 2024 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-38391080

RESUMO

INTRODUCTION: Situations involving increased workloads and stress (i.e., the COVID-19 pandemic) underline the need for healthcare professionals to minimize patient complications. In the field of vascular access, tunneling techniques are a possible solution. This systematic review and meta-analysis aimed to compare the effectiveness of tunneled Peripherally Inserted Central Catheters (tPICCs) to conventional Peripherally Inserted Central Catheters (cPICCs) in terms of bleeding, overall success, procedural time, and late complications. METHODS: Randomized controlled trials without language restrictions were searched using PUBMED®, EMBASE®, EBSCO®, CINAHL®, and the Cochrane Controlled Clinical Trials Register from August 2022 to August 2023. Five relevant papers (1238 patients) were included. RESULTS: There were no significant differences in overall success and nerve or artery injuries between the two groups (p = 0.62 and p = 0.62, respectively), although cPICCs caused slightly less bleeding (0.23 mL) and had shorter procedural times (2.95 min). On the other hand, tPICCs had a significantly reduced risk of overall complications (p < 0.001; RR0.41 [0.31-0.54] CI 95%), catheter-related thrombosis (p < 0.001; RR0.35 [0.20-0.59] IC 95%), infection-triggering catheter removal (p < 0.001; RR0.33 [0.18-0.61] IC 95%), wound oozing (p < 0.001; RR0.49 [0.37-0.64] IC 95%), and dislodgement (p < 0.001; RR0.4 [0.31-0.54] CI 95%). CONCLUSIONS: The tunneling technique for brachial access appears to be safe concerning intra-procedural bleeding, overall success, and procedural time, and it is effective in reducing the risk of late complications associated with catheterization.

3.
Infez Med ; 31(4): 553-559, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38075418

RESUMO

Background: Catheter-related bloodstream infections (CRBSIs) are a major cause of morbidity and mortality among hospitalized patients. Different studies suggest that the use of disinfectant caps (DCs) significantly reduces the rate of CRBSIs. The first purpose of this study is to analyze, through an in-vitro-model, the antiseptic effect of DCs produced by two manufacturers; the second aim is to assess potential differences in terms of effectiveness between the two manufacturers' products. Methods: A know concentration of thirteen different microorganisms was incubated with the sponge drenched in antimicrobial fluid inside DCs and cultured through several assays to investigate the disinfectant effectiveness of some commercially available caps. Disinfectant properties were evaluated under two different conditions: baseline (DCs placed on the needle-free connectors (NFCs) and stress test (DCs directly applied to the catheter hub). Results: Both manufacturers overcame the basal tests (fourteen different assays). Regarding stress tests: the only significant bacterial load was found for Serratia marcescens (104 CFU/mL in ICU Medical™), both at 90 and 180 minutes after incubation; due to the low load, MDR Acinetobacter baumannii was not considered significant (<103 CFU/mL in BD PureHub™). Conclusions: Our results confirm what was reported in BD PureHub™ datasheet and add data not previously shown by ICU Medical™. Moreover, no difference was observed between the two manufacturers products: the use of both DCs on NFCs was able to reclaim the catheter lumen. These findings support the routine use of DCs with NFCs, as part of a structured bundle of interventions, to reduce the incidence of CRBSIs.

4.
Antibiotics (Basel) ; 12(8)2023 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-37627758

RESUMO

Most antimicrobial drugs need an intravenous (IV) administration to achieve maximum efficacy against target pathogens. IV administration is related to complications, such as tissue infiltration and thrombo-phlebitis. This systematic review aims to provide practical recommendations about diluent, pH, osmolarity, dosage, infusion rate, vesicant properties, and phlebitis rate of the most commonly used antimicrobial drugs evaluated in randomized controlled studies (RCT) till 31 March 2023. The authors searched for available IV antimicrobial drugs in RCT in PUBMED EMBASE®, EBSCO® CINAHL®, and the Cochrane Controlled Clinical trials. Drugs' chemical features were searched online, in drug data sheets, and in scientific papers, establishing that the drugs with a pH of <5 or >9, osmolarity >600 mOsm/L, high incidence of phlebitis reported in the literature, and vesicant drugs need the adoption of utmost caution during administration. We evaluated 931 papers; 232 studies were included. A total of 82 antimicrobials were identified. Regarding antibiotics, 37 reach the "caution" criterion, as well as seven antivirals, 10 antifungals, and three antiprotozoals. In this subgroup of antimicrobials, the correct vascular access device (VAD) selection is essential to avoid complications due to the administration through a peripheral vein. Knowing the physicochemical characteristics of antimicrobials is crucial to improve the patient's safety significantly, thus avoiding administration errors and local side effects.

5.
J Vasc Access ; : 11297298231188150, 2023 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-37464763

RESUMO

INTRODUCTION: Venous catheters inserted in superficial femoral vein and with mid-thigh exit site have emerged as a feasible and safe technique for central or peripheral tip's venous access, especially in agitated, delirious patients. The spread of multidrug-resistant bacterial (MDR) strains is an emerging clinical problem and more and more patients are being colonized by these types of bacteria. The aim of this study is to evaluate the incidence of central line associated bloodstream infections (CLABSI) or catheter related bloodstream infections (CRBSI) in mid-thigh catheters in patients with positive rectal swabs to evaluate the safety of this procedure and the real infection risk. METHODS: In this retrospective observational study, we analyzed data on patients with mid-tight catheters inserted from May 2021 to November 2022. All surveillance rectal swabs were recorded. In addition, to collect data on CLABSI and CRBSI, the results of all blood and catheter tip cultures performed during the hospital stay were acquired. RESULTS: Six hundred two patients were enrolled, 304 patients (50.5%) had a rectal swab; 128 (42.1%) swabs were positive for MDR. Nine CLABSI (only two in patients with a positive rectal swab) and three CRBSI were detected. No statistical difference in the absolute number of CLABSI and CRBSI and in the number of infections per 1000 catheter days emerged between the overall population and patients with positive rectal swabs (respectively p = 0.45 and p = 0.53). Similarly, no statistical difference in the number of CLABSI and CRBSI was found among patients with a negative swab and patients with a positive one (respectively p = 0.43 and p = 0.51). CONCLUSIONS: According to our data, cannulation of the superficial femoral vein represents a safe location in patients with positive rectal swabs.

6.
Sensors (Basel) ; 22(5)2022 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-35270877

RESUMO

Timely and reliable identification of control phases is functional to the control of a powered robotic lower-limb prosthesis. This study presents a commercial energy-store-and-release foot prosthesis instrumented with a multimodal sensory system comprising optoelectronic pressure sensors (PS) and IMU. The performance was verified with eight healthy participants, comparing signals processed by two different algorithms, based on PS and IMU, respectively, for real-time detection of heel strike (HS) and toe-off (TO) events and an estimate of relevant biomechanical variables such as vertical ground reaction force (vGRF) and center of pressure along the sagittal axis (CoPy). The performance of both algorithms was benchmarked against a force platform and a marker-based stereophotogrammetric motion capture system. HS and TO were estimated with a time error lower than 0.100 s for both the algorithms, sufficient for the control of a lower-limb robotic prosthesis. Finally, the CoPy computed from the PS showed a Pearson correlation coefficient of 0.97 (0.02) with the same variable computed through the force platform.


Assuntos
Procedimentos Cirúrgicos Robóticos , Fenômenos Biomecânicos , , Marcha , Humanos , Transdutores de Pressão
7.
J Neuroeng Rehabil ; 18(1): 111, 2021 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-34217307

RESUMO

BACKGROUND: Transfemoral amputation is a serious intervention that alters the locomotion pattern, leading to secondary disorders and reduced quality of life. The outcomes of current gait rehabilitation for TFAs seem to be highly dependent on factors such as the duration and intensity of the treatment and the age or etiology of the patient. Although the use of robotic assistance for prosthetic gait rehabilitation has been limited, robotic technologies have demonstrated positive rehabilitative effects for other mobility disorders and may thus offer a promising solution for the restoration of healthy gait in TFAs. This study therefore explored the feasibility of using a bilateral powered hip orthosis (APO) to train the gait of community-ambulating TFAs and the effects on their walking abilities. METHODS: Seven participants (46-71 years old with different mobility levels) were included in the study and assigned to one of two groups (namely Symmetry and Speed groups) according to their prosthesis type, mobility level, and prior experience with the exoskeleton. Each participant engaged in a maximum of 12 sessions, divided into one Enrollment session, one Tuning session, two Assessment sessions (conducted before and after the training program), and eight Training sessions, each consisting of 20 minutes of robotically assisted overground walking combined with additional tasks. The two groups were assisted by different torque-phase profiles, aiming at improving symmetry for the Symmetry group and at maximizing the net power transferred by the APO for the Speed group. During the Assessment sessions, participants performed two 6-min walking tests (6mWTs), one with (Exo) and one without (NoExo) the exoskeleton, at either maximal (Symmetry group) or self-selected (Speed group) speed. Spatio-temporal gait parameters were recorded by commercial measurement equipment as well as by the APO sensors, and metabolic efficiency was estimated via the Cost of Transport (CoT). Additionally, kinetic and kinematic data were recorded before and after treatment in the NoExo condition. RESULTS: The one-month training protocol was found to be a feasible strategy to train TFAs, as all participants smoothly completed the clinical protocol with no relevant mechanical failures of the APO. The walking performance of participants improved after the training. During the 6mWT in NoExo, participants in the Symmetry and Speed groups respectively walked 17.4% and 11.7% farther and increased walking speed by 13.7% and 17.9%, with improved temporal and spatial symmetry for the former group and decreased energetic expenditure for the latter. Gait analysis showed that ankle power, step width, and hip kinematics were modified towards healthy reference levels in both groups. In the Exo condition metabolic efficiency was reduced by 3% for the Symmetry group and more than 20% for the Speed group. CONCLUSIONS: This study presents the first pilot study to apply a wearable robotic orthosis (APO) to assist TFAs in an overground gait rehabilitation program. The proposed APO-assisted training program was demonstrated as a feasible strategy to train TFAs in a rehabilitation setting. Subjects improved their walking abilities, although further studies are required to evaluate the effectiveness of the APO compared to other gait interventions. Future protocols will include a lighter version of the APO along with optimized assistive strategies.


Assuntos
Amputados , Robótica , Idoso , Marcha , Humanos , Pessoa de Meia-Idade , Aparelhos Ortopédicos , Projetos Piloto , Qualidade de Vida , Caminhada
8.
J Thromb Haemost ; 19(1): 194-201, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33078502

RESUMO

Essentials Increase in serum uric acid (SUA) levels has been widely associated with higher risk of cardiovascular disease. We investigated the link between SUA levels and the risk of venous thromboembolism (VTE) recurrence. Patients with SUA levels ≥ 4.38 mg/dL showed a three-fold increase in the risk of VTE recurrence. Elevated SUA levels are associated with increased risk of recurrent VTE independently from traditional risk factors. ABSTRACT: Background The link between serum uric acid (SUA) and the risk of cardiovascular disease is well established. However, the impact of SUA levels on the risk of venous thromboembolism (VTE) recurrence is unknown. Objectives To investigate the association between SUA and the risk of VTE recurrence. Patients and Methods We performed a monocenter, prospective study on 280 patients with a previous episode of VTE that completed the oral anticoagulant period. SUA levels at enrollment were correlated with the risk of VTE recurrence (mean follow-up 71.1 ± 29.2 months). Results Patients were stratified according to SUA tertiles distribution at baseline (tertiles cut-off: I ≤ 4.37 mg/dL, II 4.38--5.54 mg/dL, III ≥ 5.55 mg/dL). Fifty episodes of VTE recurrence occurred during the follow-up and Kaplan-Meier survival analysis showed that subjects in the lower tertile of SUA distribution had significantly lower risk of future VTE recurrence (P = .003). No differences were seen among patients belonging to the second and the third tertile of SUA distribution. A multivariate Cox regression analysis showed that higher tertiles of SUA distribution had about three-fold increase in the risk of VTE recurrence as compared to subjects with SUA ≤ 4.37, independently from potential confounders (hazard ratio [HR] 3.04, 95% confidence interval [CI] 1.15--8.05 P = .025). Moreover, we observed that the adjusted hazard of VTE recurrence increased by 30% for each additional unit of SUA (mg/dL; HR 1.30, 95% CI 1.01--1.22, P = .040). Conclusion Elevated SUA levels are associated with increased risk of future VTE recurrence independently from traditional risk factors.


Assuntos
Ácido Úrico , Tromboembolia Venosa , Anticoagulantes , Humanos , Estudos Prospectivos , Recidiva , Fatores de Risco , Tromboembolia Venosa/diagnóstico , Tromboembolia Venosa/epidemiologia
9.
Artigo em Inglês | MEDLINE | ID: mdl-33125331

RESUMO

Gait asymmetry in lower-limb amputees can lead to several secondary conditions that can decrease general health and quality of life. Including augmented sensory feedback in rehabilitation programs can effectively mitigate spatiotemporal gait irregularities. Such benefits can be obtained with non-invasive haptic systems representing an advantageous choice for usability in overground training and every-day life. In this study, we tested a wearable tactile feedback device delivering short-lasting (100ms) vibrations around the waist syncronized to gait events, to improve the temporal gait symmetry of lower-limb amputees. Three above-knee amputees participated in the study. The device provided bilateral stimulations during a training program that involved ground-level gait training. After three training sessions, participants showed higher temporal symmetry when walking with the haptic feedback in comparison to their natural walking (resulting symmetry index increases of +2.8% for Subject IDA, +12.7% for Subject IDB and +2.9% for Subject IDC). One subject retained improved symmetry (Subject IDB,+14.9%) even when walking without the device. Gait analyses revealed that higher temporal symmetry may lead to concurrent compensation strategies in the trunk and pelvis. Overall, the results of this pilot study confirm the potential utility of sensory feedback devices to positively influence gait parameters when used in supervised settings. Future studies shall clarify more precisely the training modalities and the targets of rehabilitation programs with such devices.


Assuntos
Amputados , Fenômenos Biomecânicos , Retroalimentação , Marcha , Humanos , Projetos Piloto , Qualidade de Vida , Caminhada
10.
Sensors (Basel) ; 20(5)2020 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-32155828

RESUMO

Wearable robotic devices require sensors and algorithms that can recognize the user state in real-time, in order to provide synergistic action with the body. For devices intended for locomotion-related applications, shoe-embedded sensors are a common and convenient choice, potentially advantageous for performing gait assessment in real-world environments. In this work, we present the development of a pair of pressure-sensitive insoles based on optoelectronic sensors for the real-time estimation of temporal gait parameters. The new design makes use of a simplified sensor configuration that preserves the time accuracy of gait event detection relative to previous prototypes. The system has been assessed relatively to a commercial force plate recording the vertical component of the ground reaction force (vGRF) and the coordinate of the center of pressure along the so-called progression or antero-posterior plane (CoPAP) in ten healthy participants during ground-level walking at two speeds. The insoles showed overall median absolute errors (MAE) of 0.06 (0.02) s and 0.04 (0.02) s for heel-strike and toe-off recognition, respectively. Moreover, they enabled reasonably accurate estimations of the stance phase duration (2.02 (2.03) % error) and CoPAP profiles (Pearson correlation coefficient with force platform ρCoP = 0.96 (0.02)), whereas the correlation with vGRF measured by the force plate was lower than that obtained with the previous prototype (ρvGRF = 0.47 (0.20)). These results confirm the suitability of the insoles for online sensing purposes such as timely gait phase estimation and discrete event recognition.


Assuntos
Sistemas Computacionais , Pé/fisiologia , Marcha/fisiologia , Pressão , Algoritmos , Fenômenos Biomecânicos , Eletricidade , Humanos
11.
Sci Rep ; 9(1): 7157, 2019 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-31073188

RESUMO

Robotic exoskeletons are regarded as promising technologies for neurological gait rehabilitation but have been investigated comparatively little as training aides to facilitate active aging in the elderly. This study investigated the feasibility of an exoskeletal Active Pelvis Orthosis (APO) for cardiopulmonary gait training in the elderly. Ten healthy elderly volunteers exhibited a decreased (-26.6 ± 16.1%) Metabolic Cost of Transport (MCoT) during treadmill walking following a 4-week APO-assisted training program, while no significant changes were observed for a randomly assigned control group (n = 10) performing traditional self-paced overground walking. Moreover, robot-assisted locomotion was found to require 4.24 ± 2.57% less oxygen consumption than free treadmill walking at the same speed. These findings support the adoption of exoskeletal devices for the training of frail individuals, thus opening new possibilities for sustainable strategies for healthy aging.


Assuntos
Exoesqueleto Energizado , Caminhada , Idoso , Exercício Físico , Feminino , Quadril/fisiologia , Humanos , Masculino , Consumo de Oxigênio , Pelve/fisiologia , Avaliação de Programas e Projetos de Saúde
12.
Front Neurorobot ; 11: 25, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28611621

RESUMO

Restoring locomotion functionality of transfemoral amputees is essential for early rehabilitation treatment and for preserving mobility and independence in daily life. Research in wearable robotics fostered the development of innovative active mechatronic lower-limb prostheses designed with the goal to reduce the cognitive and physical effort of lower-limb amputees in rehabilitation and daily life activities. To ensure benefits to the users, active mechatronic prostheses are expected to be aware of the user intention and properly interact in a closed human-in-the-loop paradigm. In the state of the art various cognitive interfaces have been proposed to online decode the user's intention. Electromyography in combination with mechanical sensing such as inertial or pressure sensors is a widely adopted solution for driving active mechatronic prostheses. In this framework, researchers also explored targeted muscles re-innervation for an objective-oriented surgical amputation promoting wider usability of active prostheses. However, information kept by the neural component of the cognitive interface deteriorates in a prolonged use scenario due to electrodes-related issues, thereby undermining the correct functionality of the active prosthesis. The objective of this work is to present a novel controller for an active transfemoral prosthesis based on whole body awareness relying on a wireless distributed non-invasive sensory apparatus acting as cognitive interface. A finite-state machine controller based on signals monitored from the wearable interface performs subject-independent intention detection of functional tasks such as ground level walking, stair ascent, and sit-to-stand maneuvres and their main sub-phases. Experimental activities carried out with four transfemoral amputees (among them one dysvascular) demonstrated high reliability of the controller capable of providing 100% accuracy rate in treadmill walking even for weak subjects and low walking speeds. The minimum success rate was of 94.8% in performing sit-to-stand tasks. All the participants showed high confidence in using the transfemoral active prosthesis even without training period thanks to intuitiveness of the whole body awareness controller.

13.
Ig Sanita Pubbl ; 68(3): 411-20, 2012.
Artigo em Italiano | MEDLINE | ID: mdl-23064138

RESUMO

Long wait times for access to Nuclear Magnetic resonance imaging (MRI) examinations are a concern and for this reason the project "Appropriateness of referrals for MRI examinations" has been launched in Latium (Italy). The aim of this preliminary study was to describe the main characteristics of MRI referrals in the region. Findings highlight a large variation in referral rates across the region, with 80% of MRI referrals being ordered by general practitioners and family pediatricians. The latter points to the possibility of inappropriate referrals for MRI imaging in Latium.


Assuntos
Medicina de Família e Comunidade/estatística & dados numéricos , Imageamento por Ressonância Magnética/estatística & dados numéricos , Padrões de Prática Médica/estatística & dados numéricos , Padrões de Prática Médica/normas , Encaminhamento e Consulta/estatística & dados numéricos , Encaminhamento e Consulta/normas , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Medicina de Família e Comunidade/normas , Feminino , Humanos , Lactente , Recém-Nascido , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Qualidade da Assistência à Saúde , Reprodutibilidade dos Testes , Medição de Risco , Procedimentos Desnecessários/estatística & dados numéricos
14.
Hum Reprod ; 23(11): 2570-6, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18664470

RESUMO

BACKGROUND: Ovarian stimulation gives rise to supraphysiological estradiol levels, which may affect oocyte quality. This study aims to investigate whether ovarian stimulation deranges the homocysteine pathway thereby affecting the pre-ovulatory follicle. METHODS: Blood samples were collected on cycle day 2 and the day of hCG administration in 181 women undergoing ovarian stimulation for IVF. In each subject, the diameter of the two leading follicles was measured and the corresponding follicular fluids were collected. In blood and follicular fluid samples, total homocysteine (tHcy), folate, cobalamin and pyridoxal'5-phosphate (PLP) were determined. According to the blood folate levels, women were classified as either folic acid supplemented (n = 113) or non-supplemented (n = 32). RESULTS: Ovarian stimulation resulted in a significant decrease in blood tHcy and cobalamin levels (both P

Assuntos
Homocisteína/metabolismo , Folículo Ovariano/metabolismo , Folículo Ovariano/fisiologia , Indução da Ovulação/métodos , Adulto , Biomarcadores/metabolismo , Gonadotropina Coriônica/metabolismo , Estradiol/metabolismo , Feminino , Fertilização in vitro/métodos , Ácido Fólico/metabolismo , Líquido Folicular/metabolismo , Humanos , Fosfato de Piridoxal/metabolismo , Inquéritos e Questionários , Vitamina B 12/metabolismo
15.
BMC Dev Biol ; 8: 34, 2008 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-18377649

RESUMO

BACKGROUND: about 15% to 30% of the DNA in human sperm is packed in nucleosomes and transmission of this fraction to the embryo potentially serves as a mechanism to facilitate paternal epigenetic programs during embryonic development. However, hitherto it has not been established whether these nucleosomes are removed like the protamines or indeed contribute to paternal zygotic chromatin, thereby potentially contributing to the epigenome of the embryo. RESULTS: to clarify the fate of sperm-derived nucleosomes we have used the deposition characteristics of histone H3 variants from which follows that H3 replication variants present in zygotic paternal chromatin prior to S-phase originate from sperm. We have performed heterologous ICSI by injecting human sperm into mouse oocytes. Probing these zygotes with an antibody highly specific for the H3.1/H3.2 replication variants showed a clear signal in the decondensed human sperm chromatin prior to S-phase. In addition, staining of human multipronuclear zygotes also showed the H3.1/H3.2 replication variants in paternal chromatin prior to DNA replication. CONCLUSION: these findings reveal that sperm-derived nucleosomal chromatin contributes to paternal zygotic chromatin, potentially serving as a template for replication, when epigenetic information can be copied. Hence, the execution of epigenetic programs originating from transmitted paternal chromatin during subsequent embryonic development is a logical consequence of this observation.


Assuntos
Cromatina/genética , Histonas/genética , Injeções de Esperma Intracitoplásmicas/métodos , Animais , Cromatina/química , Criopreservação , Replicação do DNA , Feminino , Histonas/química , Humanos , Masculino , Camundongos , Nucleossomos/química , Nucleossomos/genética , Oócitos/química , Interações Espermatozoide-Óvulo , Espermatozoides/química , Zigoto
16.
Fertil Steril ; 89(6): 1766-70, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17923130

RESUMO

OBJECTIVE: To investigate the influence of folic acid supplementation on the follicular fluid concentrations of folate and total homocysteine and their relationship to the diameter of the follicle. DESIGN: Observational study. SETTING: Tertiary referral fertility clinic at the Erasmus MC, University Medical Center, Rotterdam, The Netherlands. PATIENT(S): Thirty-seven women undergoing IVF or intracytoplasmic sperm injection treatment. INTERVENTION(S): No interventions other than routine stimulation treatment and the recommendation of folic acid supplementation. MAIN OUTCOME MEASURE(S): Concentrations of folate and total homocysteine in monofollicular and pooled follicular fluid and the diameter of the follicle. RESULT(S): Folic acid supplementation significantly increased folate and decreased total homocysteine concentrations in pooled follicular fluid. In monofollicular fluid, folate concentrations only were significantly increased in supplemented women. The total homocysteine concentration appeared to be significantly correlated with the diameter of the follicle (r = 0.27). Samples from single follicles were less prone to artifacts in the measurements of the folate and total homocysteine concentration. CONCLUSION(S): Preconception folic acid supplementation significantly alters both folate and total homocysteine concentrations in follicular fluid. The correlation between the diameter of the follicle and total homocysteine concentration in follicular fluid warrants further investigation.


Assuntos
Ácido Fólico/uso terapêutico , Oócitos/fisiologia , Adulto , Suplementos Nutricionais , Feminino , Fertilização in vitro , Líquido Folicular/efeitos dos fármacos , Líquido Folicular/fisiologia , Homocisteína/metabolismo , Humanos , Recuperação de Oócitos , Oócitos/efeitos dos fármacos , Folículo Ovariano/citologia , Folículo Ovariano/efeitos dos fármacos , Injeções de Esperma Intracitoplásmicas
17.
Hum Reprod ; 22(4): 980-8, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17204525

RESUMO

BACKGROUND: To test whether ovarian stimulation for in-vitro fertilization (IVF) affects oocyte quality and thus chromosome segregation behaviour during meiosis and early embryo development, preimplantation genetic screening of embryos was employed in a prospective, randomized controlled trial, comparing two ovarian stimulation regimens. METHODS: Infertile patients under 38 years of age were randomly assigned to undergo a mild stimulation regimen using gonadotrophin-releasing hormone (GnRH) antagonist co-treatment (67 patients), which does not disrupt secondary follicle recruitment, or a conventional high-dose exogenous gonadotrophin regimen and GnRH agonist co-treatment (44 patients). Following IVF, embryos were biopsied at the eight-cell stage and the copy number of 10 chromosomes was analysed in 1 or 2 blastomeres. RESULTS: The study was terminated prematurely, after an unplanned interim analysis (which included 61% of the planned number of patients) found a lower embryo aneuploidy rate following mild stimulation. Compared with conventional stimulation, significantly fewer oocytes and embryos were obtained following mild stimulation (P < 0.01 and < 0.05, respectively). Consequently, both regimens generated on average a similar number (1.8) of chromosomally normal embryos. Differences in rates of mosaic embryos suggest an effect of ovarian stimulation on mitotic segregation errors. CONCLUSIONS: Future ovarian stimulation strategies should avoid maximizing oocyte yield, but aim at generating a sufficient number of chromosomally normal embryos by reduced interference with ovarian physiology.


Assuntos
Aneuploidia , Blastocisto , Indução da Ovulação/métodos , Adulto , Biópsia , Blastômeros/ultraestrutura , Cromossomos/ultraestrutura , Embrião de Mamíferos/metabolismo , Feminino , Fertilização in vitro , Humanos , Hibridização in Situ Fluorescente , Modelos Genéticos , Diagnóstico Pré-Implantação , Resultado do Tratamento
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