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1.
PLoS One ; 15(7): e0235315, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32634172

RESUMO

BACKGROUND: The effect of paramedic crew size in the resuscitation of patients with out-of-hospital cardiac arrest (OHCA) remains inconclusive. We hypothesised that teams with a larger crew size have better resuscitation performance including chest compression fraction (CCF), advanced life support (ALS), and teamwork performance than those with a smaller crew size. METHODS: We conducted a randomized controlled study in a simulation setting. A total of 140 paramedics from New Taipei City were obtained by stratified sampling and were randomly allocated to 35 teams with crew sizes of 2, 3, 4, 5, and 6 (i.e. 7 teams in every paramedic crew size). A scenario involving an OHCA patient who experienced ventricular fibrillation and was attached to a cardiopulmonary resuscitation (CPR) machine was simulated. The primary outcome was the overall CCF; the secondary outcomes were the CCF in manual CPR periods, time from the first dose of epinephrine until the accomplishment of intubation, and teamwork performance. Tasks affecting the hands-off time during CPR were also analysed. RESULTS: In all 35 teams with crew sizes of 2, 3, 4, 5, and 6, the overall CCFs were 65.1%, 64.4%, 70.7%, 72.8%, and 71.5%, respectively (P = 0.148). Teams with a crew size of 5 (58.4%, 61.8%, 68.9%, 72.4%, and 68.7%, P<0.05) had higher CCF in manual CPR periods and better team dynamics. Time to the first dose of epinephrine was significantly shorter in teams with 4 paramedics, while time to completion of intubation was shortest in teams with 6 paramedics. Troubleshooting of M-CPR machine decreased the hands-off time during resuscitation (39 s), with teams comprising 2 paramedics having the longest hands-off time (63s). CONCLUSION: Larger paramedic crew size (≧4 paramedics) did not significantly increase the overall CCF in OHCA resuscitation but showed higher CCF in manual CPR period before the setup of the CPR machine. A crew size of ≧4 paramedics can also shorten the time of ALS interventions, while teams with 5 paramedics will have the best teamwork performance. Paramedic teams with a smaller crew size should focus more on the quality of manual CPR, teamwork, and training how to troubleshoot a M-CPR machine.


Assuntos
Pessoal Técnico de Saúde/estatística & dados numéricos , Reanimação Cardiopulmonar/métodos , Serviços Médicos de Emergência/métodos , Parada Cardíaca Extra-Hospitalar/prevenção & controle , Adulto , Cuidados Críticos/métodos , Auxiliares de Emergência , Medicina de Emergência/métodos , Epinefrina/administração & dosagem , Feminino , Humanos , Intubação/métodos , Masculino , Parada Cardíaca Extra-Hospitalar/epidemiologia , Parada Cardíaca Extra-Hospitalar/patologia , Fibrilação Ventricular/fisiopatologia , Fibrilação Ventricular/prevenção & controle
2.
Med Oral Patol Oral Cir Bucal ; 25(5): e634-e643, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32683388

RESUMO

BACKGROUND: Hemostasis is of critical importance in endodontic surgery. Studies on bleeding control in maxillary molars are scarce. The present study compares the efficacy of two hemostatic techniques in controlling bleeding in endodontic surgery. MATERIAL AND METHODS: A randomized two-arm pilot study involving 30 patients with peri-radicular lesions in maxillary molars (first and second molars) was carried out including the following hemostatic agents: polytetrafluoroethylene (PTFE) strips as an adjunct to epinephrine impregnated gauze (test group; n = 15) and aluminum chloride (Expasyl™) (control; n = 15). Bleeding control was independently assessed by the surgeon and by two blinded observers before and after application of the hemostatic agent, and was classified as either adequate (complete bleeding control) or inadequate (incomplete bleeding control). RESULTS: Bleeding control was similar in both groups. Simple binary logistic regression analysis failed to identify variables affecting bleeding control. Only the height of the keratinized mucosal band (≥ 2 mm) suggested a decreased risk of inadequate bleeding control of up to 89% (OR=0.11; p=0.06). CONCLUSIONS: No difference in the efficacy of bleeding control was observed between PTFE strips as an adjunct to epinephrine impregnated gauze and aluminum chloride in maxillary molars.


Assuntos
Cloreto de Alumínio , Hemostáticos , Epinefrina , Técnicas Hemostáticas , Humanos , Dente Molar , Projetos Piloto , Politetrafluoretileno
3.
Pediatrics ; 146(1)2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32532791

RESUMO

BACKGROUND: Neonatal-perinatal medicine (NPM) fellowship programs must provide adequate delivery room (DR) experience to ensure that physicians can independently provide neonatal resuscitation to very low birth weight (VLBW) infants. The availability of learning opportunities is unknown. METHODS: The number of VLBW (≤1500 g) and extremely low birth weight (ELBW) (<1000 g) deliveries, uses of continuous positive airway pressure, intubation, chest compressions, and epinephrine over 3 years at accredited civilian NPM fellowship program delivery hospitals were determined from the Vermont Oxford Network from 2012 to 2017. Using Poisson distributions, we estimated the expected probabilities of fellows experiencing a given number of cases over 3 years at each program. RESULTS: Of the 94 NPM fellowships, 86 programs with 115 delivery hospitals and 62 699 VLBW deliveries (28 703 ELBW) were included. During a 3-year fellowship, the mean number of deliveries per fellow ranged from 14 to 214 (median: 60) for VLBWs and 7 to 107 (median: 27) for ELBWs. One-half of fellows were expected to see ≤23 ELBW deliveries and 52 VLBW deliveries, 24 instances of continuous positive airway pressure, 23 intubations, 2 instances of chest compressions, and 1 treatment with epinephrine. CONCLUSIONS: The number of opportunities available to fellows for managing VLBW and ELBW infants in the DR is highly variable among programs. Fellows' exposure to key, high-risk DR procedures such as cardiopulmonary resuscitation is low at all programs. Fellowship programs should track fellow exposure to neonatal resuscitations in the DR and integrate supplemental learning opportunities. Given the low numbers, the number of new and existing NPM programs should be considered.


Assuntos
Neonatologia/educação , Ressuscitação/educação , Pressão Positiva Contínua nas Vias Aéreas , Epinefrina/uso terapêutico , Bolsas de Estudo , Humanos , Recém-Nascido , Recém-Nascido de muito Baixo Peso , Intubação , Ressuscitação/métodos , Vermont
4.
Plast Reconstr Surg ; 146(1): 54e-60e, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32590653

RESUMO

BACKGROUND: The wide-awake local anesthesia no tourniquet (WALANT) technique in hand surgery is gaining popularity. The authors aimed to prospectively analyze the frequency and type of arrhythmias in patients undergoing hand surgery under local anesthesia and to examine whether the addition of adrenaline affects their incidence. METHODS: Adult patients undergoing hand surgery under local anesthesia were randomized into two groups: group 1, local anesthesia with lidocaine and tourniquet; and group 2, local anesthesia with lidocaine and adrenaline (WALANT). Patients with a history of arrhythmias were excluded. Patients were connected to Holter electrocardiographic monitoring before surgery and up until discharge. The records were blindly compared between the groups regarding types of arrhythmias, and frequency and timing relative to injection and tourniquet inflation. RESULTS: One hundred two patients were included between August of 2018 and August of 2019 (age, 59.7 ± 13.6 years; 71 percent women; 51 in each group). No major arrhythmia (ventricular tachycardia, ventricular fibrillation, atrial fibrillation) or arrhythmia-related symptoms were recorded for either group. Minor arrhythmias (including atrial premature beats, ventricular premature beats, and atrial tachycardia) were recorded in 68 patients (66.6 percent), with no statistical difference between the groups. There were three patients with minor arrhythmias during inflation of the tourniquet. Patients in the adrenaline group had 2 percent sinus tachycardia during injection and 4 percent asymptomatic bradyarrhythmias. These findings do not require any further treatment. CONCLUSIONS: The authors' results show that hand operations using WALANT technique in patients with no history of arrhythmia are safe and are not arrhythmogenic; therefore, there is no need for routine perioperative continuous electrocardiographic monitoring. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.


Assuntos
Agonistas Adrenérgicos beta/efeitos adversos , Anestesia Local/métodos , Arritmias Cardíacas , Epinefrina/efeitos adversos , Mãos/cirurgia , Vasoconstritores/efeitos adversos , Adulto , Idoso , Anestesia Local/efeitos adversos , Arritmias Cardíacas/induzido quimicamente , Arritmias Cardíacas/epidemiologia , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
5.
J Oral Sci ; 62(3): 314-317, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32581178

RESUMO

Administration of local anesthetics with adrenaline can cause tachycardia and hypertension. This study assessed whether combined administration of landiolol with adrenaline and lidocaine would induce local anesthesia without causing hemodynamic changes. Normal saline (NS), lidocaine with adrenaline (LA), and lidocaine with adrenaline and landiolol (LLA) were injected into Wistar Kyoto (WKY/Izm) or spontaneously hypertensive (SHR/Izm) rats, followed by measurement of the pulse rate (PR), and the systolic, diastolic and mean blood pressures (SBP, DBP and MBP). In the LLA group, the increase in PR was significantly suppressed in both SHR/Izm and WKY/Izm rats relative to those in the LA group. Although SBP was significantly reduced in WKY/Izm rats given LLA, relative to those given NS or LA, it was elevated in SHR/Izm rats given LLA. Landiolol-induced changes in PR may be due to blockade of adrenaline-induced ß1 receptor stimulation, which suppresses cardiac hyperactivity, whereas the early surge of blood pressure in SHR/Izm rats given LLA may be due to the dominant alpha-adrenergic effects of ß1 receptor inhibition. The anti-adrenergic effects of LLA were safe and effective in WKY/Izm rats, although the unexpected early hypertensive surge in SHR/Izm rats indicates the need for caution.


Assuntos
Epinefrina , Lidocaína , Animais , Morfolinas , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Ureia/análogos & derivados
6.
Pediatr Rev ; 41(6): 283-292, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32482691

RESUMO

Urticaria and, to a lesser extent, angioedema are common occurrences in the pediatric population. There are multiple causes of acute and chronic urticaria and angioedema. Most causes are benign, although they can be worrisome for patients and their parents. An allergist should evaluate acute urticaria and/or angioedema if there are concerns of an external cause, such as foods or medications. Chronic urticaria and angioedema can severely affect quality of life and should be managed aggressively with antihistamines and immunomodulators if poorly controlled. Chronic symptoms are unlikely to be due to an external cause. Anaphylaxis is a more serious allergic condition characterized by a systemic reaction involving at least 2 organ systems. Anaphylaxis should be initially managed with intramuscular epinephrine. Patients who experience anaphylaxis should be evaluated by an allergist for possible causes; if found, avoidance of the inciting antigen is the best management. All patients should also be given an epinephrine autoinjector and an action plan. Foods are a common cause of anaphylaxis in the pediatric population. New evidence suggests that the introduction of highly allergic foods is safe in infancy and should not be delayed. In addition, the early introduction of foods such as peanuts may help prevent the development of food allergies.


Assuntos
Anafilaxia/etiologia , Angioedema/etiologia , Antialérgicos/uso terapêutico , Epinefrina/uso terapêutico , Hipersensibilidade Alimentar/diagnóstico , Antagonistas dos Receptores Histamínicos/uso terapêutico , Urticária/etiologia , Adolescente , Anafilaxia/tratamento farmacológico , Angioedema/tratamento farmacológico , Criança , Feminino , Hipersensibilidade Alimentar/complicações , Hipersensibilidade Alimentar/prevenção & controle , Humanos , Imunoterapia , Masculino , Omalizumab/uso terapêutico , Urticária/tratamento farmacológico
7.
J Anesth Hist ; 6(2): 42-48, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32593376

RESUMO

The name of Keizo Uenaka has not been documented in textbooks. However, Uenaka was the scientist who worked on ephedrine and played a practical role in the purification and crystallization of adrenaline. His handwritten memorandum, "On Adrenaline, Memorandum, July to December, 1900" is now stored in a Buddhist temple, Kyougyou-ji in Nashio, Japan. In the present report, we compared Uenaka's original description and Jokichi Takamine's published scientific reports, and examined how each statement in four documents are related to each other in terms of successful adrenaline crystallization. Uenaka's memorandum contained precise procedures and experimental tips for successful purification. The experimental steps were considered to transcribed in the first published document in The American Journal of Pharmacy by Takamine in 1901, and summarized in another document in ``Journal of Physiology'' in 1901. A Japanese version was published in ``Yakugakuzasshi'' in 1903 by translating the English paper in the American Journal of Pharmacy published in 1901. Reading Uenaka's memorandum, we realized that he tirelessly and diligently undertook routine experiments that to some of us might seem boring and laborious. Although the name of Uenaka is not globally well known, he was the main scientist who did the actual work of purifying adrenaline.


Assuntos
Epinefrina/história , Glândulas Suprarrenais/química , Efedrina/química , Efedrina/história , Epinefrina/química , Epinefrina/isolamento & purificação , História do Século XIX , História do Século XX , Japão , Estados Unidos
8.
Am Heart J ; 225: 78-87, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32474207

RESUMO

BACKGROUND: The severity of aortic coarctation (CoA) may be underestimated during cardiac catheterization. We aimed to investigate whether epinephrine stress testing improves clinical decision making and outcome in CoA. METHODS: We retrospectively evaluated CoA patients >50 kg with a peak systolic gradient (PSG) ≤20 mm Hg during cardiac catheterization who underwent epinephrine stress testing. Subsequent interventional management (stenting or balloon dilatation), complications, and medium-term clinical outcome were assessed. RESULTS: Fifty CoA patients underwent cardiac catheterization with epinephrine stress testing. Patients with a high epinephrine PSG (>20 mm Hg; n = 24) were younger and more likely to have a hypertensive response to exercise compared to patients with a low epinephrine PSG (≤20 mm Hg; n = 26). In total, 21 patients (88%) with a high epinephrine PSG underwent intervention, and 20 patients (77%) with a low epinephrine PSG were treated conservatively. After a mean follow-up of 25 ±â€¯18 months, there was a lower prevalence of hypertension in patients with a high epinephrine PSG who underwent intervention compared to patients with a low epinephrine PSG treated conservatively (19% vs. 76%; P = .001). In a multivariate model, intervention was independently associated with a 14.3-mm Hg reduction in systolic blood pressure (P = .001) and a decrease in the use of antihypertensive agents. CONCLUSIONS: In CoA patients with a low baseline PSG but high epinephrine PSG, percutaneous intervention is associated with a substantial reduction in systemic blood pressure and the use of antihypertensive medication. Accordingly, epinephrine stress testing may be a useful addition in the evaluation of CoA.


Assuntos
Agonistas Adrenérgicos beta/farmacologia , Coartação Aórtica/cirurgia , Pressão Sanguínea/efeitos dos fármacos , Cateterismo Cardíaco , Epinefrina/farmacologia , Adolescente , Adulto , Coartação Aórtica/diagnóstico , Coartação Aórtica/fisiopatologia , Tomada de Decisão Clínica , Teste de Esforço/métodos , Feminino , Humanos , Hipertensão/etiologia , Masculino , Estudos Retrospectivos , Sístole/fisiologia , Adulto Jovem
9.
PLoS One ; 15(5): e0233558, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32469977

RESUMO

Eye temperature measured using infrared thermography (IRT) can be used as a non-invasive measure of autonomic nervous system (ANS) activity in cattle. The objective of this study was to evaluate if changes in eye temperature (measured using IRT) can be used to non-invasively measure ANS activity in sheep. Twenty, 2 to 4-year-old, Romney ewes were randomly assigned to receive either epinephrine (EPI) or physiological saline (SAL) for 5 min administered via jugular catheter (n = 10 ewes/treatment). Eye temperature (°C) was recorded continuously using IRT for approximately 25 min before and 20 min after the start of infusion. Heart rate and heart rate variability, measured using the root mean square of successive differences (RMSSD) and the standard deviation of all inter-beat intervals (SDNN), were recorded for 5 min before and up to 10 min after the start of infusion. Blood samples were taken before and after the infusion period to measure plasma epinephrine, norepinephrine, cortisol and packed cell volume (PCV) concentrations. During the infusion period, maximum eye temperature was on average higher (P<0.05) in sheep that received epinephrine than those that received saline. On average, heart rate was higher (SAL: 87.5 beats/min, EPI: 123.2 beats/min, SED = 7.07 beats/min; P<0.05), and RMSSD (SAL: 55.3 ms, EPI: 17.3 ms, SED = 14.18 ms) and SDNN (SAL: 54.3 ms, EPI: 21.5 ms, SED = 10.00 ms) lower (P<0.05) in ewes during the 5 min post-infusion period compared with ewes that received saline. An infusion of epinephrine resulted in higher geometric mean epinephrine (P<0.05) and cortisol (P<0.05) but not norepinephrine (P>0.05) concentrations in ewes compared to an infusion of saline. PCV concentrations were higher (P<0.001) by 7 ± 1.0% (mean±SED) in ewes after an epinephrine infusion. These results suggest that heart rate variability is a sensitive, non-invasive method that can be used to measure ANS activity in sheep, whereas change in eye temperature measured using IRT is a less sensitive method.


Assuntos
Sistema Nervoso Autônomo/fisiologia , Temperatura Corporal/efeitos dos fármacos , Ovinos/fisiologia , Termografia/métodos , Animais , Sistema Nervoso Autônomo/efeitos dos fármacos , Epinefrina/farmacologia , Olho , Feminino , Frequência Cardíaca , Raios Infravermelhos
10.
PLoS One ; 15(5): e0230516, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32453770

RESUMO

Teaching practicals for receptor physiology/pharmacology in medical and veterinary schools have involved the use of in vitro experiments using tissues from laboratory animals, which have been killed for isolated vascular strip or ring preparations. However, the use of scavenged tissues has been advocated to reduce animal use. Utilising discarded tissues from routine surgical procedures, such as canine neutering, has not previously been investigated. Canine testicular and uterine tissues (discarded tissues) were obtained from routine neutering procedures performed by the veterinary team at a local animal neutering clinic for stray dogs. Rings of uterine and testicular artery were dissected and mounted on a Mulvany-Halpern wire myograph in order to characterize the adrenergic and serotonergic receptors mediating vasoconstriction. Cumulative contractile concentration-response curves were constructed for the alpha adrenoceptor agonists epinephrine (α1 and α2 receptors), phenylephrine (α1 selective) and UK14304 (α2 selective). Pre-treatment with the α1-selective antagonist, prazosin, was also investigated. The response to serotonin (5-HT) receptor agonists were also investigated, including 5-HT (acting at both 5-HT1 and 5-HT2 receptors), 5-carboxamidotryptamine (5-CT; 5-HT1 selective) and α-methyl 5-HT (5-HT2 selective). A contractile response was observed in both canine uterine and testicular arteries to epinephrine and phenylephrine, and prazosin caused a dose-dependent parallel rightward shift in the phenylephrine dose-response curve (pA2 values of 7.97 and 8.39, respectively). UK14304 caused a contractile response in canine testicular arteries but very little appreciable contractile response in uterine arteries. The maximum responses produced by the uterine arteries to 5-HT was significantly lower than those of the testicular arteries. In the testicular artery, the 5-HT2 receptor selective agonist, α-methyl 5-HT, produced a similar contractile response to 5-HT but the administration of 5-CT failed to produce a response in either the testicular or uterine artery segments. These results validate the use of discarded tissue from routine canine neutering procedures as a useful source of vascular tissue for pharmacological teaching, for characterizing alpha and 5-HT receptor contractile responses.


Assuntos
Contração Muscular/fisiologia , Músculo Liso Vascular/fisiologia , Ensino , Artéria Uterina/fisiologia , Animais , Animais de Laboratório , Cães , Epinefrina/farmacologia , Contração Muscular/efeitos dos fármacos , Músculo Liso Vascular/anatomia & histologia , Norepinefrina/farmacologia , Artéria Uterina/anatomia & histologia
12.
Isr Med Assoc J ; 22(4): 219-223, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32286023

RESUMO

BACKGROUND: In an effort to alter eye color during World War II, devout Nazi researcher Karin Magnussen had adrenaline eye drops administered to inmates at the concentration camp Auschwitz-Birkenau. A Sinti family, with a high prevalence of heterochromia iridis, was forced to participate in this study. Members of this family, as well as other victims, were later killed and had their eyes enucleated and sent to Magnussen for examination. Magnussen articulated the findings of these events in a manuscript that has never been published. The author is the first ophthalmologist to review this manuscript. The generation who experienced the atrocities of World War II will soon be gone and awareness of what happened during this tragic chapter of world history is fading. OBJECTIVES: To describe these events to raise awareness among future generations. METHODS: A literature review and archival search was conducted. RESULTS: Magnussen's research was based on an animal study published in 1937. For Magnussen's study, adrenaline drops were administered to inmates, including a 12-year-old girl from the Sinti family. As there was a reported case of deaf-mutism within the family, Waardenburg syndrome seems to be the most plausible explanation for this family's heritable heterochromia. CONCLUSIONS: The effort to change eye color was doomed to fail from the beginning because there was a probable diagnosis of Waardenburg syndrome. Extinction of humans for ophthalmological research is an insane act beyond imagination. For the sake of these victims, and for the generations who still feel their pain, it is imperative to tell their stories.


Assuntos
Campos de Concentração/história , Epinefrina/efeitos adversos , Cor de Olho , Experimentação Humana/história , Doenças da Íris/induzido quimicamente , Transtornos da Pigmentação/induzido quimicamente , Epinefrina/administração & dosagem , Feminino , Alemanha , História do Século XX , Experimentação Humana/ética , Humanos , Masculino , Prisioneiros , Violência/história , II Guerra Mundial
16.
Medicine (Baltimore) ; 99(11): e19040, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32176031

RESUMO

Traditional high ligation and stripping (THLS) is a routine operation for varicose veins. However, THLS is accompanied with postoperative subcutaneous ecchymosis and pain. In this current study, we aimed to explore the effect of tumescence solution (TS) combined with negative pressure wound therapy (NPWT) on the relief of subcutaneous ecchymosis and pain after THLS of great saphenous vein.A total of 180 patients receiving THLS were enrolled in group A, and 120 patients undergoing THLS and TS combined with NPWT were assigned into group B. The occurrences of subcutaneous ecchymosis and pain were recorded. Moreover, the total area of subcutaneous ecchymosis was estimated by the grid method. Visual analogue scale (VAS) score was used to assess the pain level of both groups.Preoperative characteristics were not significantly different between 2 groups. Postoperative ecchymosis occurred in 112 cases (62.2%) of group A and 41 cases (34.2%) of group B. The area of ecchymosis in group A (66.6 ±â€Š44.5) cm was larger than that in group B (25.2 ±â€Š19.9) cm. The number of patients without obvious pain in group A (57, 31.7%) was significantly less than that in group B (77, 64.2%) after operation. In addition, VAS score in group A (3.1 ±â€Š2.6) was higher than that in group B (2.2 ±â€Š1.9).In conclusion, the application of TS combined with NPWT in THLS can not only alleviate subcutaneous ecchymosis and pain, but also prevent the occurrence of subcutaneous ecchymosis and pain after operation. Therefore, it is conducive to postoperative recovery and is suitable for clinical application.


Assuntos
Equimose/terapia , Epinefrina/uso terapêutico , Tratamento de Ferimentos com Pressão Negativa/métodos , Ropivacaina/uso terapêutico , Veia Safena/cirurgia , Varizes/cirurgia , Adulto , Epinefrina/administração & dosagem , Feminino , Humanos , Masculino , Dor Pós-Operatória/terapia , Complicações Pós-Operatórias/terapia , Estudos Retrospectivos , Ropivacaina/administração & dosagem
17.
Nat Biomed Eng ; 4(3): 286-297, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32165736

RESUMO

The monitoring of vascular-targeted therapies using magnetic resonance imaging, computed tomography or ultrasound is limited by their insufficient spatial resolution. Here, by taking advantage of the intrinsic optical properties of haemoglobin, we show that raster-scanning optoacoustic mesoscopy (RSOM) provides high-resolution images of the tumour vasculature and of the surrounding tissue, and that the detection of a wide range of ultrasound bandwidths enables the distinction of vessels of differing size, providing detailed insights into the vascular responses to vascular-targeted therapy. Using RSOM to examine the responses to vascular-targeted photodynamic therapy in mice with subcutaneous xenografts, we observed a substantial and immediate occlusion of the tumour vessels followed by haemorrhage within the tissue and the eventual collapse of the entire vasculature. Using dual-wavelength RSOM, which distinguishes oxyhaemoglobin from deoxyhaemoglobin, we observed an increase in oxygenation of the entire tumour volume immediately after the application of the therapy, and a second wave of oxygen reperfusion approximately 24 h thereafter. We also show that RSOM enables the quantification of differences in neoangiogenesis that predict treatment efficacy.


Assuntos
Diagnóstico por Imagem/métodos , Neovascularização Patológica/diagnóstico , Técnicas Fotoacústicas/métodos , Ultrassonografia/métodos , Neoplasias Vasculares/diagnóstico por imagem , Animais , Encéfalo/diagnóstico por imagem , Neoplasias do Ventrículo Cerebral/diagnóstico por imagem , Neoplasias do Colo/diagnóstico por imagem , Neoplasias do Colo/patologia , Craniotomia , Modelos Animais de Doenças , Endotelina-1 , Epinefrina , Feminino , Xenoenxertos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional , Lasers , Camundongos , Camundongos Endogâmicos BALB C , Oxigênio , Neoplasias da Bexiga Urinária/diagnóstico por imagem , Neoplasias da Bexiga Urinária/patologia , Neoplasias Vasculares/patologia , Vasoconstrição
20.
Am J Physiol Endocrinol Metab ; 318(5): E779-E790, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32208001

RESUMO

Glucagon's effect on hepatic glucose production (HGP), under hyperglycemic conditions, is time dependent such that after an initial burst of HGP, it slowly wanes. It is not known whether this is also the case under hypoglycemic conditions, where an increase in HGP is essential. This question was addressed using adrenalectomized dogs to avoid the confounding effects of other counterregulatory hormones. During the study, infusions of epinephrine and cortisol were given to maintain basal levels. Somatostatin and insulin (800 µU·kg-1·min-1) were infused to induce hypoglycemia. After 30 min, glucagon was infused at a basal rate (1 ng·kg-1·min-1, baGGN group, n = 5 dogs) or a rate eightfold basal (8 ng·kg-1·min-1, hiGGN group, n = 5 dogs) for 4 h. Glucose was infused to match the arterial glucose levels between groups (≈50 mg/dL). Our data showed that glucagon has a biphasic effect on the liver despite hypoglycemia. Hyperglucagonemia stimulated a rapid, transient peak in HGP (4-fold basal production) over ~60 min, which was followed by a slow reduction in HGP to a rate 1.5-fold basal. During the last 2 h of the experiment, hiGGN stimulated glucose production at a rate fivefold greater than baGGN (2.5 vs. 0.5 mg·kg-1·min-1, respectively), indicating a sustained effect of the hormone. Of note, the hypoglycemia-induced rises in norepinephrine and glycerol were smaller in hiGGN compared with the baGGN group despite identical hypoglycemia. This finding suggests that there is reciprocity between glucagon and the sympathetic nervous system such that when glucagon is increased, the sympathetic nervous response to hypoglycemia is downregulated.


Assuntos
Glucagon/farmacocinética , Gluconeogênese/efeitos dos fármacos , Hipoglicemia/metabolismo , Fígado/efeitos dos fármacos , Sistema Nervoso Simpático/efeitos dos fármacos , Adrenalectomia , Animais , Cães , Epinefrina/farmacologia , Feminino , Hidrocortisona/farmacologia , Hipoglicemia/induzido quimicamente , Insulina , Fígado/metabolismo , Masculino , Somatostatina , Sistema Nervoso Simpático/metabolismo
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