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1.
Can J Nurs Res ; : 8445621241255419, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38772564

RESUMO

BACKGROUND: Nurses experience elevated rates of operational stress injuries (OSIs). This can necessitate taking leave from work and subsequently engaging in a workplace reintegration process. An unsuccessful process can have long term impacts on a nurse's career, affecting the individual, their family, and broader community, while contributing to nursing shortages. A knowledge gap regarding the workplace reintegration of nurses experiencing mental health challenges, impedes the development and implementation of initiatives that might increase the success of nurses reintegrating into the workplace. This scoping review explored the existing literature concerning workplace reintegration for nurses experiencing OSIs. METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) reporting guidelines were utilized. Three key search terms across six databases were employed followed by a qualitative content analysis of the resulting literature. RESULTS: Eight documents were included. The literature exhibited high heterogeneity in objectives, content, and article types. The content analysis revealed five themes: (1) recognizing stigma, (2) elements of successful workplace reintegration, (3) considerations for military nurses, (4) considerations for nurses with substance use disorders, and (5) gaps in the existing literature. CONCLUSION: A paucity of programs, policies, procedures, and research exists regarding workplace reintegration for nurses facing mental health challenges. It is imperative to recognize that nurses may experience OSIs, necessitating mental health support, time off work, and operationally/culturally-specific assistance in returning to work. Innovative and evidence-based approaches to workplace reintegration are needed to enhance the retention of a skilled, experienced, compassionate, and healthy nursing workforce.

2.
Artigo em Inglês | MEDLINE | ID: mdl-37681804

RESUMO

BACKGROUND: Nurses are engaged in an unpredictable and dynamic work environment where they are exposed to events that may cause or contribute to physical and/or psychological injuries. Operational stress injury (OSI) may lead to an extended time away from work or nurses leaving the profession altogether. A deliberate focus on the workplace reintegration phase of the mental health recovery process may lead to the increased retention of nurses in their profession. Prior to the creation and implementation of potential solutions to address workplace reintegration, it is imperative to explore the experiences and perceptions of nurses affected by OSI. This qualitative study aims to investigate the experiences and perceptions of nurses (N = 7) employed within a Canadian provincial healthcare system who have attempted workplace reintegration after being off of work with an OSI. METHODS: Nurses were recruited via social media, unit emails, and word of mouth. Data were collected through recorded semi-structured interviews conducted over videoconferencing. Once transcribed, the data were thematically analyzed using an inductive approach. RESULTS: The resulting themes included (1) heroes to zeros, (2) changing the status quo, (3) connection is key, and (4) post-traumatic growth: advocacy and altruism. Study participants indicated both that nursing culture and a cumulation of events contributed to a need for a leave of absence from work and that a formalized process was desired by nurses to assist in returning to work. CONCLUSIONS: The development, implementation, and exploration of innovative policies, procedures, and initiatives to bridge the gap from clinical interventions to workplace reintegration are needed for nurses experiencing OSI. Further research is also needed regarding mental health impacts and appropriate resources to support nurses in their workplace reintegration process after experiencing psychological and/or physical injury.


Assuntos
Enfermeiras e Enfermeiros , Local de Trabalho , Humanos , Escuridão , Canadá , Altruísmo
3.
Artigo em Inglês | MEDLINE | ID: mdl-37297641

RESUMO

BACKGROUND: Nurses are exposed to potentially psychologically traumatic events which can lead to operational stress injuries (OSI). Workplace reintegration after an OSI can be challenging, especially with repeated exposure to potentially traumatic scenarios and workplace demands. A workplace reintegration program (RP) originally developed for police officers may be of benefit for nurses returning to work after an OSI. The purpose of this study is to investigate the perceived need for an RP for nurses, and its potential contextualization and implementation in the nursing context using an implementation science approach. METHODS: This mixed-methods study collected data via questionnaires and focus groups from acute care nurses in Canada (N = 19). Data analysis was conducted using descriptive statistics, thematic analysis, and an organizational readiness assessment. RESULTS: Study participants indicated that formalized processes were rarely used to support nurses returning to work after time off due to mental health challenges. Themes included (1) "The Perfect Storm": the current state of return-to-work, (2) Integral Needs, and (3) A Break in the Clouds: hope for health. CONCLUSIONS: Exploration of innovative programs such as the RP may provide additional support to nurses affected by OSIs. Further research is needed regarding workplace reintegration for nurses, and contextualization and evaluation of the RP.


Assuntos
Enfermeiras e Enfermeiros , Local de Trabalho , Humanos , Local de Trabalho/psicologia , Grupos Focais , Saúde Mental , Canadá
4.
JMIR Res Protoc ; 12: e33492, 2023 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-37223981

RESUMO

BACKGROUND: Law enforcement officers are routinely exposed to hazardous, disturbing events that can impose severe stress and long-term psychological trauma. As a result, police and other public safety personnel (PSP) are at increased risk of developing posttraumatic stress injuries (PTSIs) and disruptions to the autonomic nervous system (ANS). ANS functioning can be objectively and noninvasively measured by heart rate (HR), heart rate variability (HRV), and respiratory sinus arrhythmia (RSA). Traditional interventions aimed at building resilience among PSP have not adequately addressed the physiological ANS dysregulations that lead to mental and physical health conditions, as well as burnout and fatigue following potential psychological trauma. OBJECTIVE: In this study, we will investigate the efficacy of a web-based Autonomic Modulation Training (AMT) intervention on the following outcomes: (1) reducing self-reported symptoms of PTSI, (2) strengthening ANS physiological resilience and wellness capacity, and (3) exploring how sex and gender are related to baseline differences in psychological and biological PTSI symptoms and response to the AMT intervention. METHODS: The study is comprised of 2 phases. Phase 1 involves the development of the web-based AMT intervention, which includes 1 session of baseline survey measures, 6 weekly sessions that integrate HRV biofeedback (HRVBF) training with meta-cognitive skill practice, and 1 session of follow-up survey measures. Phase 2 will use a cluster randomized control design to test the effectiveness of AMT on the following prepost outcomes: (1) self-report symptoms of PTSI and other wellness measures; (2) physiological indicators of health and resilience including resting HR, HRV, and RSA; and (3) the influence of sex and gender on other outcomes. Participants will be recruited for an 8-week study across Canada in rolling cohorts. RESULTS: The study received grant funding in March 2020 and ethics approval in February 2021. Due to delays related to COVID-19, phase 1 was completed in December 2022, and phase 2 pilot testing began in February 2023. Cohorts of 10 participants in the experimental (AMT) and control (prepost assessment only) groups will continue until a total of 250 participants are tested. Data collection from all phases is expected to conclude in December 2025 but may be extended until the intended sample size is reached. Quantitative analyses of psychological and physiological data will be conducted in conjunction with expert coinvestigators. CONCLUSIONS: There is an urgent need to provide police and PSP with effective training that improves physical and psychological functioning. Given that help-seeking for PTSI is reduced among these occupational groups, AMT is a promising intervention that can be completed in the privacy of one's home. Importantly, AMT is a novel program that uniquely addresses the underlying physiological mechanisms that support resilience and wellness promotion and is tailored to the occupational demands of PSP. TRIAL REGISTRATION: ClinicalTrials.gov NCT05521360; https://clinicaltrials.gov/ct2/show/NCT05521360. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/33492.

5.
Springerplus ; 3: 522, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25279313

RESUMO

Absence of the appendix is rare. Isolated cases are usually discovered in adult patients or cadavers. We report the case of a 14 year old boy who was found to have no appendix on laparotomy for assumed acute appendicitis and use this opportunity to highlight the growing surgical uses of this vestigial structure.

6.
Pediatr Surg Int ; 28(11): 1101-7, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23011491

RESUMO

PURPOSE: To discuss the presentation, management and outcomes of penetrating anorectal injuries at the Bustamante Hospital for Children. METHODS: A retrospective review over an 11-year period (January 2001-December 2011) was undertaken. The data analysed were extracted from patients' case notes which were pulled based on the hospital's admission database. RESULTS: Over the study period a total of 14 children presented with penetrating anorectal injuries. The medical records for one child were missing. The mean age at presentation was 6 years. Impalement by a metal spike was the mechanism of injury in 12 children, with one case of sexual assault. Three of the children had associated urogenital injuries. Ten rectal injuries were extraperitoneal. Five of the 13 cases (38 %) were managed with a colostomy-average time to closure was 6 months. There was one case of perineal wound infection and dehiscence. There was no mortality. CONCLUSION: Selective fecal diversion in the form of a sigmoid loop colostomy is a safe and acceptable management option for children with penetrating anorectal injuries. The perineal wound itself can be closed primarily except in cases of delayed presentation.


Assuntos
Canal Anal/lesões , Traumatismo Múltiplo/cirurgia , Reto/lesões , Ferimentos Penetrantes/cirurgia , Canal Anal/cirurgia , Criança , Pré-Escolar , Protocolos Clínicos , Feminino , Humanos , Lactente , Jamaica , Masculino , Reto/cirurgia , Estudos Retrospectivos
9.
Am J Physiol Endocrinol Metab ; 293(6): E1804-9, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17911341

RESUMO

Acute physiological hyperinsulinemia increases skeletal muscle capillary blood volume (CBV), presumably to augment glucose and insulin delivery. We hypothesized that insulin-mediated changes in CBV are impaired in type 2 diabetes mellitus (DM) and are improved by angiotensin-converting enzyme inhibition (ACE-I). Zucker obese diabetic rats (ZDF, n = 18) and control rats (n = 9) were studied at 20 wk of age. One-half of the ZDF rats were treated with quinapril (ZDF-Q) for 15 wk prior to study. CBV and capillary flow in hindlimb skeletal muscle were measured by contrast-enhanced ultrasound (CEU) at baseline and at 30 and 120 min after initiation of a euglycemic hyperinsulinemic clamp (3 mU.min(-1).kg(-1)). At baseline, ZDF and ZDF-Q rats were hyperglycemic and hyperinsulinemic vs. controls. Glucose utilization in ZDF rats was 60-70% lower (P < 0.05) than in controls after 30 and 120 min of hyperinsulinemia. In ZDF-Q rats, glucose utilization was impaired at 30 min but similar to controls at 120 min. Basal CBV was lower in ZDF and ZDF-Q rats compared with controls (13 +/- 4, 7 +/- 3, and 9 +/- 2 U, respectively). With hyperinsulinemia, CBV increased by about twofold in control animals at 30 and 120 min, did not change in ZDF animals, and increased in ZDF-Q animals only at 120 min to a level similar to controls. Anatomic capillary density on immunohistology was not different between groups. We conclude that insulin-mediated capillary recruitment in skeletal muscle, which participates in glucose utilization, is impaired in animals with DM and can be partially reversed by chronic ACE-I therapy.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Capilares/efeitos dos fármacos , Diabetes Mellitus Tipo 2/fisiopatologia , Insulina/farmacologia , Músculo Esquelético/irrigação sanguínea , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Animais , Glicemia/metabolismo , Pressão Sanguínea/efeitos dos fármacos , Volume Sanguíneo/efeitos dos fármacos , Capilares/fisiopatologia , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Deformação Eritrocítica/efeitos dos fármacos , Técnica Clamp de Glucose , Membro Posterior/irrigação sanguínea , Membro Posterior/efeitos dos fármacos , Membro Posterior/fisiopatologia , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Insulina/sangue , Insulina/uso terapêutico , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/fisiopatologia , Poliúria/urina , Quinapril , Ratos , Ratos Mutantes , Ratos Zucker , Fluxo Sanguíneo Regional/efeitos dos fármacos , Tetra-Hidroisoquinolinas/farmacologia , Tetra-Hidroisoquinolinas/uso terapêutico , Ultrassonografia Doppler em Cores
10.
Diabetes ; 56(9): 2194-200, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17563063

RESUMO

We examined whether contraction-induced muscle microvascular recruitment would expand the surface area for insulin and nutrient exchange and thereby contribute to insulin-mediated glucose disposal. We measured in vivo rat hindlimb microvascular blood volume (MBV) using contrast ultrasound and femoral blood flow (FBF) using Doppler ultrasound in response to a stimulation frequency range. Ten minutes of 0.1-Hz isometric contraction more than doubled MBV (P < 0.05; n = 6) without affecting FBF (n = 7), whereas frequencies >0.5 Hz increased both. Specific inhibition of nitric oxide (NO) synthase with N(omega)-l-nitro-arginine-methyl ester (n = 5) significantly elevated mean arterial pressure by approximately 30 mmHg but had no effect on basal FBF or MBV. We next examined whether selectively elevating MBV without increasing FBF (0.1-Hz contractions) increased muscle uptake of albumin-bound Evans blue dye (EBD). Stimulation at 0.1 Hz (10 min) elicited more than twofold increases in EBD content (micrograms EBD per gram dry tissue) in stimulated versus contralateral muscle (n = 8; 52.2 +/- 3.8 vs. 20 +/- 2.5, respectively; P < 0.001). We then measured muscle uptake of EBD and (125)I-labeled insulin (dpm per gram dry tissue) with 0.1-Hz stimulation (n = 6). Uptake of EBD (19.1 +/- 3.8 vs. 9.9 +/- 1; P < 0.05) and (125)I-insulin (5,300 +/- 800 vs. 4,244 +/- 903; P < 0.05) was greater in stimulated muscle versus control. Low-frequency contraction increases muscle MBV by a NO-independent pathway and facilitates muscle uptake of albumin and insulin in the absence of blood flow increases. This microvascular response may, in part, explain enhanced insulin action in exercising skeletal muscle.


Assuntos
Insulina/fisiologia , Microcirculação/fisiologia , Contração Muscular/fisiologia , Músculo Esquelético/metabolismo , Óxido Nítrico/farmacologia , Animais , Volume Sanguíneo , Membro Posterior , Masculino , Microcirculação/efeitos dos fármacos , Microscopia Confocal , Músculo Esquelético/irrigação sanguínea , Músculo Esquelético/citologia , NG-Nitroarginina Metil Éster/farmacologia , Ratos , Ratos Sprague-Dawley
11.
Am J Physiol Endocrinol Metab ; 290(6): E1191-7, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16682488

RESUMO

Intense exercise and insulin each increases total limb blood flow and recruits muscle capillaries, presumably to facilitate nutrient exchange. Whether mixed meals or light exercise likewise recruits capillaries is unknown. We fed 18 (9 M, 9 F) healthy volunteers a 480-kcal liquid mixed meal. Plasma glucose, insulin, brachial artery flow, and forearm muscle microvascular blood volume were measured before and after the meal. Brachial artery flow and microvascular volume were also examined with light (25% max), moderate (50%), and heavy (80%) forearm contraction every 20 s in 5 (4 M, 1 F) healthy adults. After the meal, glucose and insulin rose modestly (to approximately 7 mM and approximately 270 pM) and peaked by 30 min, whereas brachial artery blood flow (P < 0.05) and the microvascular volume (P < 0.01) each increased significantly by 60 min, and microvascular flow velocity did not change. For exercise, both 50 and 80%, but not 25% maximal handgrip, increased average forearm and brachial artery blood flow (P < 0.01). Flow increased immediately after each contraction and declined toward basal over 15 s. Exercise at 25% max increased microvascular volume threefold (P < 0.01) without affecting microvascular flow velocity or total forearm blood flow. Forearm exercise at 80% maximal grip increased both microvascular volume and microvascular flow velocity (P < 0.05 each). We conclude that light exercise and simple meals each markedly increases muscle microvascular volume, thereby expanding the endothelial surface for nutrient exchange, and that capillary recruitment is an important physiological response to facilitate nutrient/hormone delivery in healthy humans.


Assuntos
Capilares/fisiologia , Exercício Físico , Alimentos , Músculos/irrigação sanguínea , Adulto , Animais , Velocidade do Fluxo Sanguíneo , Glicemia/metabolismo , Volume Sanguíneo , Artéria Braquial/fisiologia , Feminino , Antebraço/irrigação sanguínea , Humanos , Insulina/sangue , Masculino , Microcirculação , Músculos/fisiologia , Fluxo Sanguíneo Regional , Ultrassonografia Doppler
12.
Diabetes ; 55(5): 1436-42, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16644702

RESUMO

We have previously shown that skeletal muscle capillaries are rapidly recruited by physiological doses of insulin in both humans and animals. This facilitates glucose and insulin delivery to muscle, thus augmenting glucose uptake. In obese rats, both insulin-mediated microvascular recruitment and glucose uptake are diminished; however, this action of insulin has not been studied in obese humans. Here we used contrast ultrasound to measure microvascular blood volume (MBV) (an index of microvascular recruitment) in the forearm flexor muscles of lean and obese adults before and after a 120-min euglycemic-hyperinsulinemic (1 mU . min(-1) . kg(-1)) clamp. We also measured brachial artery flow, fasting lipid profile, and anthropomorphic variables. Fasting plasma glucose (5.4 +/- 0.1 vs. 5.1 +/- 0.1 mmol/l, P = 0.05), insulin (79 +/- 11 vs. 38 +/- 6 pmol/l, P = 0.003), and percent body fat (44 +/- 2 vs. 25 +/- 2%, P = 0.001) were higher in the obese than the lean adults. After 2 h of insulin infusion, whole-body glucose infusion rate was significantly lower in the obese versus lean group (19.3 +/- 3.2 and 37.4 +/- 2.6 mumol . min(-1) . kg(-1) respectively, P < 0.001). Compared with baseline, insulin increased MBV in the lean (18.7 +/- 3.3 to 25.0 +/- 4.1, P = 0.019) but not in the obese group (20.4 +/- 3.6 to 18.8 +/- 3.8, NS). Insulin increased brachial artery diameter and flow in the lean but not in the obese group. We observed a significant, negative correlation between DeltaMBV and BMI (R = -0.482, P = 0.027) in response to insulin. In conclusion, obesity eliminated the insulin-stimulated muscle microvascular recruitment and increased brachial artery blood flow seen in lean individuals.


Assuntos
Velocidade do Fluxo Sanguíneo/fisiologia , Artéria Braquial/fisiopatologia , Antebraço/irrigação sanguínea , Microcirculação/fisiologia , Músculo Esquelético/irrigação sanguínea , Músculo Esquelético/fisiopatologia , Obesidade/fisiopatologia , Adulto , Velocidade do Fluxo Sanguíneo/efeitos dos fármacos , Glicemia/metabolismo , Índice de Massa Corporal , Artéria Braquial/diagnóstico por imagem , Técnica Clamp de Glucose , Humanos , Insulina/sangue , Insulina/farmacologia , Cinética , Lipídeos/sangue , Músculo Esquelético/efeitos dos fármacos , Obesidade/sangue , Valores de Referência , Ultrassonografia
13.
J Pediatr Surg ; 41(2): 413-7, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16481261

RESUMO

OBJECTIVE: The physiological range of gastric emptying in healthy children has not previously been documented. The aim of this study was to establish the range of normal gastric emptying in children aged between 5 and 10 years with a Tc 99m-labelled solid meal acceptable to most of the children. METHODS: A list of 7 child-friendly foods was compiled. Thirty-one children aged 5 to 10 years completed a questionnaire, ranking their favourite food choices. A volume survey, to decide the weight of solid meal for the study, was carried out in 20 children. After ethical approval, gastric emptying was monitored in healthy children aged 5 to 10 years with a 99mTc-labelled solid meal selected by the methodology given hereinabove. Geometric mean counts were obtained from anterior and posterior gamma camera images, and data were used to produce normal emptying curves. In each case, a T1/2 gastric emptying time (time taken to empty half the stomach contents) was calculated. RESULTS: The overall preference was a chocolate Technecrispy cake, and the volume survey suggested a 30-g weight for the study. Twenty-four subjects consumed the meal and completed the study. The mean T1/2 gastric emptying time was 107.2 minutes (2 SD; range, 54.6-159.8 minutes). CONCLUSIONS: Chocolate Technecrispy cake was acceptable to most healthy children between 5 and 10 years of age and gave mean T1/2 gastric emptying time of 107.2 minutes. This meal can now be used for paediatric patients with transit problems.


Assuntos
Alimentos , Esvaziamento Gástrico/fisiologia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Valores de Referência
14.
J Pediatr Surg ; 40(12): 1941-4, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16338324

RESUMO

PURPOSE: It has not been possible so far to differentiate slow transit constipation from functional fecal retention because the existing medical literature lacks data on rectal dimensions for healthy children or children with chronic idiopathic constipation (CIC). We, for the first time, describe the use of pelvic ultrasound (US) to achieve this. METHODS: A pelvic US was carried out on 82 children with a full or partially full bladder and with no history of bowel problems and on 95 children with CIC. The rectal crescent seen behind the bladder was measured. All children also had documentation of their age, weight, and height. RESULTS: The median age, weight, and height for the healthy children were comparable with those of the children with CIC. The median rectal crescent size in children with constipation was 3.4 cm (range, 2.10-7.0; IQR, 1.0), as compared with 2.4 cm (range, 1.3-4.2; IQR, 0.72) in the healthy children, and this difference is statistically significant on multiple regressions of log for rectal diameter, adjusted for height, weight, and age (P value< .001). CONCLUSION: Pelvic US is a quick child-friendly investigation, which can be used to document the presence of megarectum. It should be the first line investigation for all the children with CIC.


Assuntos
Constipação Intestinal/complicações , Reto/diagnóstico por imagem , Reto/patologia , Adolescente , Criança , Pré-Escolar , Diagnóstico Diferencial , Dilatação Patológica , Feminino , Humanos , Lactente , Masculino , Pelve/diagnóstico por imagem , Ultrassonografia
15.
J Pediatr Surg ; 40(4): 709-12, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15852285

RESUMO

OBJECTIVE: The aim of this study was to assess the effectiveness of using topical steroid-based creams in the management of clinically diagnosed balanitis xerotica obliterans (BXO) in boys. METHODS: The response in 56 boys to locally applied steroid-based creams was studied retrospectively. All had been referred by their general practitioners with symptoms of penile pathology and then subsequently had a clinical diagnosis of BXO made. The boys were initially assessed after 3 months of treatment and then at various intervals depending on their response. RESULTS: The mean age at presentation of the boys was 8.9 (4 to 15) years. After the initial 3-month assessment, 10 (17.9%) boys had complete resolution. When the treatment period was prolonged by an average of 14 months, the total number of boys showing resolution increased to 17 (30.4%). All boys showing resolution had clinically mild BXO limited to the prepuce only. Those patients with established scar formation on the foreskin showed no significant improvement. CONCLUSIONS: Topical steroids seem to offer a reliable option only in the management of mild BXO limited to the prepuce in boys with minimal scar formation. Steroid-based creams can be offered to such patients provided they and their families are realistic as to the likelihood of success. This treatment is ineffective in the face of established scarring.


Assuntos
Anti-Inflamatórios/uso terapêutico , Balanite (Inflamação)/tratamento farmacológico , Betametasona/uso terapêutico , Hidrocortisona/uso terapêutico , Líquen Escleroso e Atrófico/tratamento farmacológico , Administração Tópica , Adolescente , Anti-Inflamatórios/administração & dosagem , Betametasona/administração & dosagem , Criança , Pré-Escolar , Humanos , Hidrocortisona/administração & dosagem , Masculino , Estudos Retrospectivos , Resultado do Tratamento
16.
Clin Exp Pharmacol Physiol ; 32(4): 302-7, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15810996

RESUMO

1. In the 80+ years since insulin's discovery, an enormous amount of literature has accumulated relating to its actions on body fat, glucose and protein metabolism. In particular, skeletal muscle has been extensively studied because of its major role as a site of insulin-mediated glucose disposal. Liver and adipose tissue are two other extensively studied sites of insulin action. Much less investigation has been directed towards delineating insulin's actions on cells other than myocytes, adipocytes and hepatocytes. 2. Over the past 5-10 years it has become increasingly evident that insulin exerts important actions on vascular cells. Here, we review evidence that insulin's action within muscle may be very much regulated by its ability to transit the vasculature to access the interstitial fluid (and hence the myocyte insulin receptor). Surprisingly little is known regarding the regulation of vascular events that first bring insulin to the capillary endothelium within muscle, whence presumably it transits from the vascular to the interstitial space. Recent studies suggest that insulin can increase blood flow and also influence the distribution of blood flow within skeletal muscle, potentially therefore regulating its own delivery to the capillary endothelium. Beyond insulin's ability to access the vascular lumen within skeletal muscle microvasculature lies the issue of its passing the endothelial barrier. Even less is known about the processes involved in insulin's actual transit across the endothelium. Available data do not clearly indicate whether this is a saturable, receptor-mediated process or a passive-diffusion pathway. Also, whether insulin in any manner regulates its own transit across the endothelium or its clearance via the lymphatic system is entirely unknown. 3. The aim of the present review is to identify areas where knowledge is deficient and highlight hypotheses which may lead to a better understanding of the coordinated relationship between insulin's vascular actions within muscle and its metabolic actions in that tissue. Even so, there is now sufficient evidence to indicate that insulin's vascular action within skeletal muscle is a major regulatory locus for its insulin mediated glucose disposal.


Assuntos
Permeabilidade Capilar/fisiologia , Insulina/metabolismo , Músculo Esquelético/metabolismo , Animais , Transporte Biológico/fisiologia , Capilares/metabolismo , Capilares/fisiologia , Glucose/metabolismo , Humanos , Insulina/sangue , Insulina/fisiologia , Modelos Biológicos , Músculo Esquelético/irrigação sanguínea , Fluxo Sanguíneo Regional/fisiologia
17.
NMR Biomed ; 18(4): 226-34, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15674816

RESUMO

This work discusses the strengths, limitations and validity of a novel arterial spin labeling technique when used specifically to measure perfusion in limb skeletal muscle. The technique, flow-driven arterial water stimulation with elimination of tissue signal (FAWSETS), offers several advantages over existing arterial spin labeling techniques. The primary goal of this study was to determine the perfusion signal response to changes in net hind limb flow that were independently verifiable. The range of perfusate flow was relevant to skeletal muscle during mild to moderate exercise. Localized, single voxel measurements were acquired from a 5 mm-thick slice in the isolated perfused rat hind limb at variable net flow rates. The results show that the perfusion signal is linearly proportional to net hind limb flow with a correlation coefficient of 0.974 (p = 0.0013). FAWSETS is especially well suited for studies of skeletal muscle perfusion, where it eliminates the need to compensate for magnetization transfer and arterial transit time effects. A conceptual discussion of the basic principles underlying these advantages is presented.


Assuntos
Algoritmos , Velocidade do Fluxo Sanguíneo/fisiologia , Imagem de Difusão por Ressonância Magnética/métodos , Interpretação de Imagem Assistida por Computador/métodos , Músculo Esquelético/irrigação sanguínea , Músculo Esquelético/fisiologia , Reologia/métodos , Animais , Artérias/fisiologia , Ratos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Água/metabolismo
18.
Pediatr Surg Int ; 20(7): 562-3, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15243777

RESUMO

On-table colonic lavage for preparing obstructed bowel prior to anastomosis or stoma formation is now routine in adults, but it is seldom used in paediatric practice. We describe a simple technique for intraoperative colonic lavage using inexpensive medical devices that are also readily available and disposable, a Replogle tube, a fine-bore sucker, and a 20-ml syringe. We have used this technique in infants with intestinal obstruction due to anorectal malformations, intestinal atresias, and post-NEC strictures, to good effect.


Assuntos
Colo/cirurgia , Cuidados Intraoperatórios , Intubação/instrumentação , Anus Imperfurado/cirurgia , Equipamentos Descartáveis , Humanos , Lactente , Obstrução Intestinal/cirurgia , Sucção/instrumentação , Seringas , Irrigação Terapêutica/instrumentação
19.
Diabetes ; 53(6): 1418-23, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15161743

RESUMO

Insulin increases glucose disposal into muscle. In addition, in vivo insulin elicits distinct nitric oxide synthase-dependent vascular responses to increase total skeletal muscle blood flow and to recruit muscle capillaries (by relaxing resistance and terminal arterioles, respectively). In the current study, we compared the temporal sequence of vascular and metabolic responses to a 30-min physiological infusion of insulin (3 mU. min(-1). kg(-1), euglycemic clamp) or saline in rat skeletal muscle in vivo. We used contrast-enhanced ultrasound to continuously quantify microvascular volume. Insulin recruited microvasculature within 5-10 min (P < 0.05), and this preceded both activation of insulin-signaling pathways and increases in glucose disposal in muscle, as well as changes in total leg blood flow. Moreover, l-NAME (N(omega)-nitro-l-arginine-methyl ester), a specific inhibitor of nitric oxide synthase, blocked this early microvascular recruitment (P < 0.05) and at least partially inhibited early increases in muscle glucose uptake (P < 0.05). We conclude that insulin rapidly recruits skeletal muscle capillaries in vivo by a nitric oxide-dependent action, and the increase in capillary recruitment may contribute to the subsequent glucose uptake.


Assuntos
Glucose/metabolismo , Insulina/farmacologia , Músculo Esquelético/irrigação sanguínea , Músculo Esquelético/metabolismo , Animais , Vasos Sanguíneos/diagnóstico por imagem , Meios de Contraste , Inibidores Enzimáticos/farmacologia , Glucose/antagonistas & inibidores , Masculino , Microcirculação/efeitos dos fármacos , Microesferas , NG-Nitroarginina Metil Éster/farmacologia , Ratos , Ratos Sprague-Dawley , Ultrassonografia
20.
Diabetes Metab Res Rev ; 20(1): 3-12, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-14737741

RESUMO

Whether a discrete vascular action of insulin in skeletal muscle integrally participates in insulin-mediated glucose disposal has been extensively examined but remains a contentious issue. Here, we review some of the data both supporting and questioning the role of insulin-mediated increases in limb blood flow in glucose metabolism. We advance the hypothesis that controversy has arisen, at least in part, from a failure to recognize that insulin exerts at least three separate actions on the peripheral vasculature, each with its own characteristic dose and time responsiveness. We summarize how, viewed in this manner, certain points of contention can be resolved. We also advance the hypothesis that an action on the precapillary arteriole may play the dominant role in mediating perfusion-dependent effects of insulin on glucose metabolism in muscle.


Assuntos
Arteríolas/fisiologia , Glucose/metabolismo , Insulina/fisiologia , Músculo Esquelético/metabolismo , Resistência Vascular/fisiologia , Vasodilatação/fisiologia , Animais , Arteríolas/efeitos dos fármacos , Transporte Biológico , Endotélio Vascular/fisiologia , Humanos , Insulina/farmacologia , Microcirculação , Músculo Esquelético/irrigação sanguínea , Resistência Vascular/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos
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