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1.
Circulation ; 149(1): e157-e166, 2024 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-37970724

RESUMO

This 2023 focused update to the neonatal resuscitation guidelines is based on 4 systematic reviews recently completed under the direction of the International Liaison Committee on Resuscitation Neonatal Life Support Task Force. Systematic reviewers and content experts from this task force performed comprehensive reviews of the scientific literature on umbilical cord management in preterm, late preterm, and term newborn infants, and the optimal devices and interfaces used for administering positive-pressure ventilation during resuscitation of newborn infants. These recommendations provide new guidance on the use of intact umbilical cord milking, device selection for administering positive-pressure ventilation, and an additional primary interface for administering positive-pressure ventilation.


Assuntos
Reanimação Cardiopulmonar , Serviços Médicos de Emergência , Lactente , Criança , Recém-Nascido , Humanos , Estados Unidos , Ressuscitação , American Heart Association , Tratamento de Emergência
2.
J Physiol ; 602(8): 1791-1813, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38532618

RESUMO

Previous studies have suggested that an extended period of ventilation before delayed cord clamping (DCC) augments birth-related rises in pulmonary arterial (PA) blood flow. However, it is unknown whether this greater rise in PA flow is accompanied by increases in left ventricular (LV) output and systemic arterial perfusion or whether it reflects enhanced left-to-right shunting across the ductus arteriosus and/or foramen ovale (FO), with decreased systemic arterial perfusion. Using an established preterm lamb birth transition model, this study compared the effect of a short (∼40 s, n = 11), moderate (∼2 min, n = 11) or extended (∼5 min, n = 12) period of initial mechanical lung ventilation before DCC on flow probe-derived perinatal changes in PA flow, LV output, total systemic arterial blood flow, ductal shunting and FO shunting. The LV output was relatively stable during initial ventilation but increased after DCC, with similar responses in all groups. Systemic arterial flow patterns displayed only minor differences during brief and moderate periods of initial ventilation and were similar after DCC. However, an increase in PA flow was augmented with an extended initial ventilation (P < 0.001), owing to an earlier onset of left-to-right ductal and FO shunting (P < 0.001), and was accompanied by a pronounced reduction in total systemic arterial flow (P = 0.005) that persisted for 4 min after DCC (P ≤ 0.039). These findings suggest that, owing to increased left-to-right shunting and a greater reduction in systemic arterial perfusion, an extended period of ventilation before DCC does not result in greater perinatal circulatory benefits than shorter periods of initial ventilation in the birth transition. KEY POINTS: Previous studies suggest that an extended period of initial ventilation before delayed cord clamping (DCC) augments birth-related rises in pulmonary arterial (PA) blood flow. It is unknown whether this greater rise in PA flow is accompanied by an increased left ventricular output and systemic arterial perfusion or whether it reflects enhanced left-to-right shunting across the ductus arteriosus and/or foramen ovale, with decreased systemic arterial perfusion. Anaesthetized preterm fetal lambs instrumented with central arterial flow probes underwent a brief (∼40 s), moderate (∼2 min) or extended (∼5 min) period of ventilation before DCC. Perinatal changes in left ventricular output were similar in all groups, but extended initial ventilation augmented both perinatal increases in PA flow, owing to earlier onset and greater left-to-right ductal and foramen ovale shunting, and perinatal reductions in total systemic arterial perfusion. Extended ventilation before DCC does not confer a greater perinatal circulatory benefit than shorter periods of initial ventilation.


Assuntos
Canal Arterial , Hipertensão Pulmonar , Gravidez , Feminino , Ovinos , Animais , Clampeamento do Cordão Umbilical , Pulmão/irrigação sanguínea , Artéria Pulmonar/fisiologia , Canal Arterial/fisiologia , Perfusão , Constrição
3.
Eur J Neurosci ; 59(7): 1480-1499, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38169095

RESUMO

Dopaminergic (DA) neurons play pivotal roles in diverse brain functions, spanning movement, reward processing and sensory perception. DA neurons are most abundant in the midbrain (Substantia Nigra pars compacta [SNC] and Ventral Tegmental Area [VTA]) and the olfactory bulb (OB) in the forebrain. Interestingly, a subtype of OB DA neurons is capable of regenerating throughout life, while a second class is exclusively born during embryonic development. Compelling evidence in SNC and VTA also indicates substantial heterogeneity in terms of morphology, connectivity and function. To further investigate this heterogeneity and directly compare form and function of midbrain and forebrain bulbar DA neurons, we performed immunohistochemistry and whole-cell patch-clamp recordings in ex vivo brain slices from juvenile DAT-tdTomato mice. After confirming the penetrance and specificity of the dopamine transporter (DAT) Cre line, we compared soma shape, passive membrane properties, voltage sags and action potential (AP) firing across midbrain and forebrain bulbar DA subtypes. We found that each DA subgroup within midbrain and OB was highly heterogeneous, and that DA neurons across the two brain areas are also substantially different. These findings complement previous work in rats as well as gene expression and in vivo datasets, further questioning the existence of a single "dopaminergic" neuronal phenotype.


Assuntos
Neurônios Dopaminérgicos , Proteína Vermelha Fluorescente , Substância Negra , Camundongos , Ratos , Animais , Neurônios Dopaminérgicos/metabolismo , Substância Negra/metabolismo , Bulbo Olfatório , Mesencéfalo/metabolismo , Área Tegmentar Ventral/metabolismo
4.
Cell Tissue Res ; 396(3): 353-369, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38492001

RESUMO

Sour taste is detected by type III taste receptor cells that generate membrane depolarization with action potentials in response to HCl applied to the apical membranes. The shape of action potentials in type III cells exhibits larger afterhyperpolarization due to activation of transient A-type voltage-gated K+ currents. Although action potentials play an important role in neurotransmitter release, the electrophysiological features of A-type K+ currents in taste buds remain unclear. Here, we examined the electrophysiological properties of A-type K+ currents in mouse fungiform taste bud cells using in-situ whole-cell patch clamping. Type III cells were identified with SNAP-25 immunoreactivity and/or electrophysiological features of voltage-gated currents. Type III cells expressed A-type K+ currents which were completely inhibited by 10 mM TEA, whereas IP3R3-immunoreactive type II cells did not. The half-maximal activation and steady-state inactivation of A-type K+ currents were 17.9 ± 4.5 (n = 17) and - 11.0 ± 5.7 (n = 17) mV, respectively, which are similar to the features of Kv3.3 and Kv3.4 channels (transient and high voltage-activated K+ channels). The recovery from inactivation was well fitted with a double exponential equation; the fast and slow time constants were 6.4 ± 0.6 ms and 0.76 ± 0.26 s (n = 6), respectively. RT-PCR experiments suggest that Kv3.3 and Kv3.4 mRNAs were detected at the taste bud level, but not at single-cell levels. As the phosphorylation of Kv3.3 and Kv3.4 channels generally leads to the modulation of cell excitability, neuromodulator-mediated A-type K+ channel phosphorylation likely affects the signal transduction of taste.


Assuntos
Papilas Gustativas , Animais , Papilas Gustativas/metabolismo , Papilas Gustativas/citologia , Camundongos , Paladar/fisiologia , Masculino , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo , Canais de Potássio de Abertura Dependente da Tensão da Membrana/genética , Técnicas de Patch-Clamp , Ativação do Canal Iônico/efeitos dos fármacos
5.
Ann Surg Oncol ; 31(3): 1812-1822, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38038790

RESUMO

BACKGROUND: Hepatic pedicle clamping (HPC) is frequently utilized during hepatectomy to reduce intraoperative bleeding and diminish the need for intraoperative blood transfusion (IBT). The long-term prognostic implications of HPC following hepatectomy for hepatocellular carcinoma (HCC) remain under debate. This study aims to elucidate the association between HPC and oncologic outcomes after HCC resection, stratified by whether IBT was administered. PATIENTS AND METHODS: Prospectively collected data on patients with HCC who underwent curative resection from a multicenter database was studied. Patients were stratified into two cohorts on the basis of whether IBT was administered. The impact of HPC on long-term overall survival (OS) and recurrence-free survival (RFS) between the two cohorts was assessed by univariable and multivariable Cox regression analyses. RESULTS: Of 3362 patients, 535 received IBT. In the IBT cohort, using or not using HPC showed no significant difference in OS and RFS outcomes (5-year OS and RFS rates 27.9% vs. 24.6% and 13.8% vs. 12.0%, P = 0.810 and 0.530). However, in the non-IBT cohort of 2827 patients, the HPC subgroup demonstrated significantly decreased OS (5-year 45.9% vs. 56.5%, P < 0.001) and RFS (5-year 24.7% vs. 33.3%, P < 0.001) when compared with the subgroup without HPC. Multivariable Cox regression analysis identified HPC as an independent risk factor of OS and RFS [hazard ratios (HR) 1.16 and 1.12, P = 0.024 and 0.044, respectively] among patients who did not receive IBT. CONCLUSIONS: The impact of HPC on the oncological outcomes following hepatectomy for patients with HCC differed significantly whether IBT was administered, and HPC adversely impacted on long-term survival for patients without receiving IBT during hepatectomy.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/cirurgia , Hepatectomia , Neoplasias Hepáticas/cirurgia , Constrição , Estudos Retrospectivos , Prognóstico , Transfusão de Sangue
6.
Pancreatology ; 24(4): 584-591, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38693041

RESUMO

OBJECTIVES: We aimed to assess the diagnostic utility of an immunohistochemical panel including calcium-binding protein P, p53, Ki-67, and SMAD family member 4 and K-ras mutation for diagnosing pancreatic solid lesion specimens obtained by endoscopic ultrasound-guided fine-needle biopsy and to confirm their usefulness in histologically inconclusive cases. METHODS: Immunohistochemistry and peptide nucleic acid-clamping polymerase chain reaction for K-ras mutation were performed on 96 endoscopic ultrasound-guided fine-needle biopsy specimens. The diagnostic efficacy of each marker and the combination of markers was calculated. The diagnostic performances of these markers were evaluated in 27 endoscopic ultrasound-guided fine-needle biopsy specimens with histologically inconclusive diagnoses. A classification tree was constructed. RESULTS: K-ras mutation showed the highest accuracy and consistency. Positivity in more than two or three of the five markers showed high diagnostic accuracy (94.6 % and 93.6 %, respectively), and positivity for more than three markers showed the highest accuracy for inconclusive cases (92.0 %). A classification tree using K-ras mutation, Ki-67, S100P, and SMAD4 showed high diagnostic performance, with only two misclassifications in inconclusive cases. CONCLUSIONS: K-ras mutation detection via peptide nucleic acid-clamping polymerase chain reaction is a stable and accurate method for distinguishing between pancreatic ductal adenocarcinoma and non-pancreatic ductal adenocarcinoma lesions. A classification tree using K-ras mutation, Ki-67, S100P, and SMAD4 helps increase the diagnostic accuracy of cases that are histologically difficult to diagnose.


Assuntos
Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico , Antígeno Ki-67 , Mutação , Neoplasias Pancreáticas , Proteína Smad4 , Humanos , Proteína Smad4/genética , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/diagnóstico , Antígeno Ki-67/genética , Feminino , Masculino , Pessoa de Meia-Idade , Idoso , Reação em Cadeia da Polimerase/métodos , Adulto , Proteínas Proto-Oncogênicas p21(ras)/genética , Ácidos Nucleicos Peptídicos , Imuno-Histoquímica , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética
7.
Am J Obstet Gynecol ; 230(3S): S1046-S1060.e1, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38462248

RESUMO

The third stage of labor is defined as the time period between delivery of the fetus through delivery of the placenta. During a normal third stage, uterine contractions lead to separation and expulsion of the placenta from the uterus. Postpartum hemorrhage is a relatively common complication of the third stage of labor. Strategies have been studied to mitigate the risk of postpartum hemorrhage, leading to the widespread implementation of active management of the third stage of labor. Initially, active management of the third stage of labor consisted of a bundle of interventions including administration of a uterotonic agent, early cord clamping, controlled cord traction, and external uterine massage. However, the effectiveness of these interventions as a bundle has been questioned, leading to abandonment of some components in recent years. Despite this, upon review of selected international guidelines, we found that the term "active management of the third stage of labor" was still used, but recommendations for and against individual interventions were variable and not necessarily supported by current evidence. In this review, we: (1) examine the physiology of the third stage of labor, (2) present evidence related to interventions that prevent postpartum hemorrhage and promote maternal and neonatal health, (3) review current global guidelines and recommendations for practice, and (4) propose future areas of investigation. The interventions in this review include pharmacologic agents to prevent postpartum hemorrhage, cord clamping, cord milking, cord traction, cord drainage, early skin-to-skin contact, and nipple stimulation. Treatment of complications of the third stage of labor is outside of the scope of this review. We conclude that current evidence supports the use of effective pharmacologic postpartum hemorrhage prophylaxis, delayed cord clamping, early skin-to-skin contact, and controlled cord traction at delivery when feasible. The most effective uterotonic regimens for preventing postpartum hemorrhage after vaginal delivery include oxytocin plus ergometrine; oxytocin plus misoprostol; or carbetocin. After cesarean delivery, carbetocin or oxytocin as a bolus are the most effective regimens. There is inconsistent evidence regarding the use of tranexamic acid in addition to a uterotonic compared with a uterotonic alone for postpartum hemorrhage prevention after all deliveries. Because of differences in patient comorbidities, costs, and availability of resources and staff, decisions to use specific prevention strategies are dependent on patient- and system-level factors. We recommend that the term "active management of the third stage of labor" as a combined intervention no longer be used. Instead, we recommend that "third stage care" be adopted, which promotes the implementation of evidence-based interventions that incorporate practices that are safe and beneficial for both the woman and neonate.


Assuntos
Trabalho de Parto , Ocitócicos , Hemorragia Pós-Parto , Gravidez , Feminino , Recém-Nascido , Humanos , Hemorragia Pós-Parto/induzido quimicamente , Ocitocina/uso terapêutico , Ocitócicos/uso terapêutico , Prática Clínica Baseada em Evidências
8.
Dig Dis Sci ; 69(3): 961-968, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38340259

RESUMO

BACKGROUND: External biliary fistula, where the residual cyst is associated with the biliary tree, is one of the most common complications after liver hydatid cyst surgery. Surgical procedures become a consideration for patients in whom the biliary fistula persists despite all endoscopic procedures. However, reoperation for biliary fistula after hydatid cyst surgery leads to additional complications and increases morbidity and mortality. AIM: This study aims to treat persistent biliary fistulas that develop after liver hydatid cyst surgery using a simple noninvasive technique. MATERIALS AND METHODS: External drainage surgery was performed on 295 patients with liver hydatid cysts. Endoscopic treatment methods were used in patients who developed biliary fistula after surgery. Despite all endoscopic treatment methods, 14 patients developed persistent biliary fistulas. These patients were subsequently treated using the drain clamping technique. FINDINGS: All persistent fistulas occluded in 11.86 days (with a range of 8-20 days). No complications were observed in the one-year follow-up visits. CONCLUSION: Drain clamping, a novel approach to the treatment of persistent biliary fistulas developed despite all available endoscopic methods, can be safely used. This technique resulted in a complete recovery in patients without the need for surgical procedures.


Assuntos
Fístula Biliar , Equinococose Hepática , Humanos , Fístula Biliar/etiologia , Fístula Biliar/cirurgia , Colangiopancreatografia Retrógrada Endoscópica/métodos , Constrição , Equinococose Hepática/cirurgia , Equinococose Hepática/complicações , Drenagem , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/cirurgia , Estudos Retrospectivos
9.
Eur J Pediatr ; 183(6): 2791-2796, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38581461

RESUMO

Delayed cord clamping (DCC) is an established practice in perinatology with multiple benefits. However, in instances where the implementation of DCC is not viable, it needs alternatives, especially during caesarean deliveries. A non-inferiority randomized, non-blinded, trial was conducted at a tertiary care referral unit in South India among the preterm newborns (28-36 weeks) randomized to DCC as opposed to intact-umbilical cord milking (UCM). The primary objective was to compare the mean haemoglobin values between the two groups, and the secondary outcome was to compare death and/or major IVH (> Grade II). Of the 132 eligible newborn infants, 99 were randomized to two study groups. Of the 59 and 40 randomised to UCM and DCC, 54 and 36 received the allocated intervention respectively. Preterm infants who underwent UCM had significantly higher haemoglobin (19.97 ± 1.44) as compared to DCC group (18.62 ± 0.98) p-0.0001. The rates of mortality and/or major IVH were comparable between the two groups. CONCLUSION: UCM may be a feasible alternative to DCC especially in settings where the latter is not achievable, without increasing the risk of adverse effects to the preterm infants, this finding needing further confirmation with larger sample. TRIAL REGISTRATION: CTRI (Clinical Trial Registry-India) registration number: CTRI/2020/04/024566 (registered prospectively on 13/04/2020). WHAT IS KNOWN: • Delayed cord clamping (DCC) is recommended as a standard of care for all the stable term and preterm newborn babies at birth. WHAT IS NEW: • Intact umbilical cord milking may be a reasonable choice of cord management when DCC is unsuccessful, without increasing adverse effects for the new born.


Assuntos
Recém-Nascido Prematuro , Clampeamento do Cordão Umbilical , Humanos , Recém-Nascido , Feminino , Índia , Masculino , Clampeamento do Cordão Umbilical/métodos , Fatores de Tempo , Idade Gestacional , Gravidez , Cordão Umbilical , Hemoglobinas/análise , Constrição
10.
BMC Pregnancy Childbirth ; 24(1): 248, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38589786

RESUMO

BACKGROUND: Placental management strategies such as umbilical cord milking and delayed cord clamping may provide a range of benefits for the newborn. The aim of this review was to assess the effectiveness of umbilical cord milking and delayed cord clamping for the prevention of neonatal hypoglycaemia. METHODS: Three databases and five clinical trial registries were systematically reviewed to identify randomised controlled trials comparing umbilical cord milking or delayed cord clamping with control in term and preterm infants. The primary outcome was neonatal hypoglycaemia (study defined). Two independent reviewers conducted screening, data extraction and quality assessment. Quality of the included studies was assessed using the Cochrane Risk of Bias tool (RoB-2). Certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. Meta-analysis using a random effect model was done using Review Manager 5.4. The review was registered prospectively on PROSPERO (CRD42022356553). RESULTS: Data from 71 studies and 14 268 infants were included in this review; 22 (2 537 infants) compared umbilical cord milking with control, and 50 studies (11 731 infants) compared delayed with early cord clamping. For umbilical cord milking there were no data on neonatal hypoglycaemia, and no differences between groups for any of the secondary outcomes. We found no evidence that delayed cord clamping reduced the incidence of hypoglycaemia (6 studies, 444 infants, RR = 0.87, CI: 0.58 to 1.30, p = 0.49, I2 = 0%). Delayed cord clamping was associated with a 27% reduction in neonatal mortality (15 studies, 3 041 infants, RR = 0.73, CI: 0.55 to 0.98, p = 0.03, I2 = 0%). We found no evidence for the effect of delayed cord clamping for any of the other outcomes. The certainty of evidence was low for all outcomes. CONCLUSION: We found no data for the effectiveness of umbilical cord milking on neonatal hypoglycaemia, and no evidence that delayed cord clamping reduced the incidence of hypoglycaemia, but the certainty of the evidence was low.

11.
Nephrology (Carlton) ; 29(4): 188-200, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38173056

RESUMO

AIM: In two recent studies, we observed that a 30-min renal vein clamping caused formation of interstitial haemorrhagic congestion in ischaemic and ischaemic/reperfused kidney along with the development of severer acute kidney injury (AKI) than renal artery or pedicle clamping. It was suggested that the transmission of high arterial pressure into renal microvessels during vein occlusion probably causes the occurrence of interstitial haemorrhagic congestion that augments AKI. The present investigation aimed to evaluate this suggestion by reducing renal perfusion pressure (RPP) during renal venous occlusion. METHODS: Anaesthetized male Sprague-Dawley rats were divided into three groups (n = 8), which underwent a 2-h reperfusion period following 30-min bilateral renal venous clamping along with reduced RPP (VIR-rRPP group) or without reduced RPP (VIR group) and an equivalent period after sham-operation (Sham group). RESULTS: The VIR-rRPP group compared with VIR group had lower levels of kidney malondialdehyde and tissue damages as epithelial injuries of proximal tubule and thick ascending limb, vascular congestion, intratubular cast and oedema, along with the less reductions in renal blood flow, creatinine clearance, Na+ -reabsorption, K+ and urea excretion, urine osmolality and free-water reabsorption. Importantly, the formation of intensive interstitial haemorrhagic congestion in the VIR group was not observed in the VIR-rRPP group. CONCLUSION: These results indicate that the transmission of high arterial pressure into renal microvessels during venous occlusion leads to rupturing of their walls and the formation of interstitial haemorrhagic congestion, which has an augmenting impact on ischaemia/reperfusion-induced renal structural damages and haemodynamic, excretory and urine-concentrating dysfunctions.


Assuntos
Injúria Renal Aguda , Hipertensão , Traumatismo por Reperfusão , Ratos , Masculino , Animais , Pressão Arterial , Constrição , Ratos Sprague-Dawley , Rim , Injúria Renal Aguda/etiologia , Traumatismo por Reperfusão/complicações , Isquemia/complicações , Reperfusão/efeitos adversos , Microvasos
12.
Acta Paediatr ; 113(5): 931-938, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38293717

RESUMO

AIM: We investigated the influence of physiological-based cord clamping (PBCC) on cardiorespiratory stability in very low birth weight (VLBW) infants during the first 72 h of life. METHODS: This retrospective study comprised VLBW infants born at <32 + 0 weeks of gestation and admitted to the neonatal intensive care unit of the Medical University of Graz, Austria, from December 2014 to April 2021. VLBW infants delivered with PBCC were matched by gestational age and birth weight to delayed cord clamping controls. The PBCC group was stabilised after birth with an intact cord. Routine monitoring parameters were compared between the groups. RESULTS: We included 54 VLBW infants. The mean gestational ages of the PBCC group and controls were 27.4 ± 1.9 versus 27.4 ± 1.8 weeks (p = 0.87), and the mean birth weights were 912 ± 288 versus 915 ± 285 g (p = 0.96), respectively. The mean cord clamping time was 191 ± 78 s in the PBCC group. Heart rate was lower in the PBCC group during the first 3 days after birth, reaching significance by 10 h. Other monitoring parameters did not reveal any differences between the two groups. CONCLUSION: PBCC stabilised cardiorespiratory parameters in VLBW infants. The lower heart rate in the PBCC group suggested higher blood volume following intact cord resuscitation.


Assuntos
Recém-Nascido de muito Baixo Peso , Cordão Umbilical , Recém-Nascido , Lactente , Humanos , Constrição , Estudos Retrospectivos , Peso ao Nascer , Idade Gestacional , Cordão Umbilical/fisiologia
13.
Proc Natl Acad Sci U S A ; 118(7)2021 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-33579823

RESUMO

Human adult muscle-type acetylcholine receptors are heteropentameric ion channels formed from four different, but evolutionarily related, subunits. These subunits assemble with a precise stoichiometry and arrangement such that two chemically distinct agonist-binding sites are formed between specific subunit pairs. How this subunit complexity evolved and became entrenched is unclear. Here we show that a single historical amino acid substitution is able to constrain the subunit stoichiometry of functional acetylcholine receptors. Using a combination of ancestral sequence reconstruction, single-channel electrophysiology, and concatenated subunits, we reveal that an ancestral ß-subunit can not only replace the extant ß-subunit but can also supplant the neighboring δ-subunit. By forward evolving the ancestral ß-subunit with a single amino acid substitution, we restore the requirement for a δ-subunit for functional channels. These findings reveal that a single historical substitution necessitates an increase in acetylcholine receptor complexity and, more generally, that simple stepwise mutations can drive subunit entrenchment in this model heteromeric protein.


Assuntos
Substituição de Aminoácidos , Multimerização Proteica , Receptores Nicotínicos/genética , Linhagem Celular , Evolução Molecular , Humanos , Ligação Proteica , Domínios Proteicos , Subunidades Proteicas/química , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Receptores Nicotínicos/química , Receptores Nicotínicos/metabolismo
14.
J Perinat Med ; 52(5): 494-500, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38676940

RESUMO

OBJECTIVES: The University Hospital Basel implemented delayed umbilical cord clamping of 30-60 s in all laboring women on April 1, 2020. This practice has been widely researched showing substantial benefit for the neonate. Few studies focused on maternal blood loss. The objective of our retrospective comparative study was to assess the impact of immediate vs. delayed cord clamping on maternal blood loss in primary scheduled cesarean sections. METHODS: We analyzed data of 98 women with singleton gestations undergoing primary scheduled cesarean section at term. Data from procedures with early cord clamping (ECC) were compared to those after implementation of delayed cord clamping (DCC). Primary outcomes were perioperative change in maternal hemoglobin levels, estimated and calculated blood loss. Secondary outcomes included duration of cesarean section and neonatal data. RESULTS: There was a statistically significant difference in the mean perioperative decline of hemoglobin of 10.4 g/L (SD=7.92) and 18.7 g/L (SD=10.4) between the ECC and DCC group, respectively (p<0.001). The estimated (482 mL in ECC vs. 566 mL in DCC (p=0.011)) and the calculated blood loss (438 mL in ECC vs. 715 mL in DCC (p=0.002)) also differed significantly. Secondary outcomes showed no significant differences. CONCLUSIONS: In our study DCC resulted in a statistically significant higher maternal blood loss. In our opinion the widely researched neonatal benefit of DCC outweighs the risk of higher maternal blood loss in low-risk patients. However, maternal risks must be minimized, improvements to preoperative blood management and operative techniques are required.


Assuntos
Perda Sanguínea Cirúrgica , Cesárea , Clampeamento do Cordão Umbilical , Humanos , Feminino , Estudos Retrospectivos , Cesárea/efeitos adversos , Cesárea/métodos , Cesárea/estatística & dados numéricos , Gravidez , Adulto , Clampeamento do Cordão Umbilical/métodos , Perda Sanguínea Cirúrgica/estatística & dados numéricos , Perda Sanguínea Cirúrgica/prevenção & controle , Fatores de Tempo , Recém-Nascido , Hemoglobinas/análise , Cordão Umbilical/cirurgia
15.
J Obstet Gynaecol Res ; 50(3): 373-380, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38109908

RESUMO

OBJECTIVE: The present study aims to compare prophylactic common iliac artery (CIA) temporary clamping and preoperative balloon occlusion for managing placenta accreta spectrum (PAS) disorders. STUDY DESIGN: Between January 2019 and June 2020, 46 patients with PAS disorders were included. Of them, 26 patients were offered CIA balloon occlusion (Group A), while temporary CIA clamping was done for the other 20 patients (Group B). Primary outcomes were procedure-related complications, and secondary outcomes included intraoperative and postoperative complications, reoperation rates, total procedure time, blood loss, and amount of blood transfusion. RESULTS: Blood loss was statistically non-significant higher in group B than in group A (p-value = 0.143). Only one patient in group A and three in group B needed reoperation. The bleeding continued for a mean of 1.6 days in group A and 1.7 days in group B, with non-significant statistical differences between both groups p value = 0.71. Nine patients in group A (34.6%) and four in group B (20%) required ICU admission. The mean Apgar score was 7 and 6.6 in babies of group A and group B patients, respectively. The median number of allogeneic blood transfusions performed was two in patients in group A and 1 in group B (p-value = 0.001). CONCLUSION: Both techniques offer good choices for patients with PAS to decrease mortality and morbidity rates. The selection of a better technique depends on institutional references and physicians' experience.


Assuntos
Oclusão com Balão , Placenta Acreta , Doenças Placentárias , Lactente , Feminino , Gravidez , Humanos , Constrição , Artéria Ilíaca/cirurgia , Placenta Acreta/cirurgia , Estudos Prospectivos
16.
Arch Gynecol Obstet ; 309(1): 47-62, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-36988681

RESUMO

OBJECTIVE: This narrative review was performed to evaluate the correct timing of umbilical cord clamping for term infants. It was intended to determine any advantages or disadvantages from early or delayed cord clamping for newborns, infants or mothers. METHODS: A systematic search on two databases was conducted using the PICO pattern to define a wide search. Out of 43 trials, 12 were included in this review. Three of the included studies are meta-analyses, nine are randomized controlled trials. RESULTS: Early or delayed cord clamping was defined differently in all the included trials. However, there are many advantages from delayed cord clamping of at least > 60 s for newborns and infants up to 12 months of age. The trials showed no disadvantages for newborns or mothers from delayed cord clamping, except for a lightly increased risk of jaundice or the need for phototherapy. CONCLUSION: Delayed umbilical cord clamping for term infants should be performed. Further research is needed to improve knowledge on physiological timing of umbilical cord clamping in term infants, which also leads to the same advantages as delayed cord clamping.


Assuntos
Clampeamento do Cordão Umbilical , Feminino , Humanos , Lactente , Recém-Nascido , Gravidez , Mães , Fatores de Tempo , Cordão Umbilical
17.
Arch Gynecol Obstet ; 310(2): 991-999, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38753205

RESUMO

PURPOSE: To evaluate the effect of intravenous infusion versus intramyometrial injection of oxytocin on hemoglobin levels in neonates with delayed umbilical cord clamping during cesarean section. METHODS: The multi-centre randomized controlled trial was performed at three hospitals from February to June 2023. Women with term singleton gestations scheduled for cesarean delivery were allocated to receive an intravenous infusion of 10 units of oxytocin or a myometrial injection of 10 units of oxytocin during the surgery. The primary outcome was neonatal hemoglobin at 48 to 96 h after birth. Secondary outcomes were side-effects of oxytocin, postpartum haemorrhage, phototherapy for jaundice, feeding at 1 month, maternal and neonatal morbidity and re-admissions. RESULTS: A total of 360 women were randomized (180 women in each group). The mean neonatal hemoglobin did not show a significant difference between the intravenous infusion group (194.3 ± 21.7 g/L) and the intramyometrial groups (195.2 ± 24.3 g/L) (p = 0.715). Secondary neonatal outcomes, involving phototherapy for jaundice, feeding at 1 month and neonatal intensive care unit admission were similar between the two groups. The maternal outcomes did not differ significantly between the two groups, except for a 200 mL higher intraoperative infusion volume observed in the intravenous group compared to the intramyometrial group. CONCLUSION: Among women undergoing elective cesarean delivery of term singleton pregnancies, there was no significant difference in neonatal hemoglobin at 48 to 96 h after birth between infants with delayed cord clamping, whether the oxytocin was administrated by intravenous infusion or intramyometrial injection. TRIAL REGISTRATION: Chinese Clinical trial registry: ChiCTR2300067953 (1 February 2023).


Assuntos
Cesárea , Hemoglobinas , Ocitócicos , Ocitocina , Clampeamento do Cordão Umbilical , Humanos , Feminino , Ocitocina/administração & dosagem , Recém-Nascido , Gravidez , Hemoglobinas/análise , Adulto , Infusões Intravenosas , Ocitócicos/administração & dosagem , Hemorragia Pós-Parto/prevenção & controle , Fatores de Tempo , Cordão Umbilical , Injeções Intramusculares
18.
Aust N Z J Obstet Gynaecol ; 64(2): 120-127, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37775919

RESUMO

BACKGROUND: Placental cord drainage (PCD) after vaginal birth accelerates placental delivery by 2.85 minutes, but reduces blood loss by only 77 mL. AIMS: To determine if PCD at elective caesarean section accelerates placental delivery, compared to delayed cord clamping (DCC). MATERIALS AND METHODS: This randomised controlled trial randomised 100 women undergoing elective caesarean sections to receive either PCD for 60 sec after birth, or DCC for 60 sec. The primary outcome was time from birth until placental delivery. Secondary outcomes included estimated blood loss (EBL), postoperative haemoglobin drop, rates of postpartum haemorrhage (PPH), manual removal of placenta and blood transfusion. RESULTS: There was no significant difference in timing of placental delivery (PCD 122 sec vs DCC 123.5 sec, P = 0.717). There were no significant differences in EBL (PCD 425 mL vs DCC 400 mL, P = 0.858), postoperative haemoglobin drop (PCD 12 g/L vs DCC 15 g/L, P = 0.297), PPH rate (PCD 45.8% vs DCC 44.4%, P = 0.893, relative risk (RR) 1.03, 95% confidence interval (CI) 0.66-1.62), manual removal rate (PCD 2.1% vs DCC 4.4%, P = 0.609, RR 0.47, 95% CI 0.04-4.99) or transfusion rate (PCD 4.2% vs DCC 0%, P = 0.495). CONCLUSIONS: PCD did not accelerate placental delivery at caesarean compared with DCC. Given that both PCD and DCC groups had faster placental deliveries than quoted in the literature at caesarean (200 sec), it could be postulated that DCC is mimicking the effect of PCD through passive transfusion to the neonate. This supports routine use of DCC at elective caesarean section.


Assuntos
Cesárea , Hemorragia Pós-Parto , Recém-Nascido , Feminino , Gravidez , Humanos , Cesárea/efeitos adversos , Placenta , Clampeamento do Cordão Umbilical , Hemorragia Pós-Parto/prevenção & controle , Drenagem , Hemoglobinas , Cordão Umbilical/cirurgia
19.
Sensors (Basel) ; 24(9)2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38732849

RESUMO

Currently, the main solution for braking systems for underground electric trackless rubber-tired vehicles (UETRVs) is traditional hydraulic braking systems, which have the disadvantages of hydraulic pressure crawling, the risk of oil leakage and a high maintenance cost. An electro-mechanical-braking (EMB) system, as a type of novel brake-by-wire (BBW) system, can eliminate the above shortcomings and play a significant role in enhancing the intelligence level of the braking system in order to meet the motion control requirements of unmanned UETRVs. Among these requirements, the accurate control of clamping force is a key technology in controlling performance and the practical implementation of EMB systems. In order to achieve an adaptive clamping force control performance of an EMB system, an optimized fuzzy proportional-integral-differential (PID) controller is proposed, where the improved fuzzy algorithm is utilized to adaptively adjust the gain parameters of classic PID. In order to compensate for the deficiency of single-close-loop control and adjusting the brake gap automatically, a cascaded three-closed-loop control architecture with force/position switch technology is established, where a contact point detection method utilizing motor rotor angle displacement is proposed via experiments. The results of the simulation and experiments indicate that the clamping force response of the proposed multi-close-loop Variable Universe Fuzzy-PID (VUF-PID) controller is faster than the multi-closed-loop Fuzzy-PID and cascaded three-close-loop PID controllers. In addition, the chattering of braking force can be suppressed by 17%. This EMB system may rapidly and automatically finish the operation of the overall braking process, including gap elimination, clamping force tracking and gap recovery, which can obviously enhance the precision of the longitudinal motion control of UETRVs. It can thus serve as a BBW actuator of mine autonomous driving electric vehicles, especially in the stage of braking control.

20.
Zhongguo Dang Dai Er Ke Za Zhi ; 26(1): 25-30, 2024 Jan 15.
Artigo em Zh | MEDLINE | ID: mdl-38269455

RESUMO

In November 2023, the American Heart Association and the American Academy of Pediatrics jointly released key updates to the neonatal resuscitation guidelines based on new clinical evidence. This update serves as an important supplement to the "Neonatal resuscitation: 2020 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care". The aim of this paper is to outline the key updates and provide guidance on umbilical cord management and the selection of positive pressure ventilation equipment and its additional interfaces in neonatal resuscitation.


Assuntos
Serviços Médicos de Emergência , Ressuscitação , Estados Unidos , Humanos , Recém-Nascido , Criança , American Heart Association , Suplementos Nutricionais , Ventilação com Pressão Positiva Intermitente
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