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1.
JBJS Case Connect ; 13(3)2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-37543730

RESUMO

CASE: A 37-year-old man with a right obturator foramen hip dislocation underwent closed reduction under spinal anesthesia with the use of a fracture traction table. CONCLUSION: This novel technique provides surgeons and anesthesiologists an alternative method of treating obturator foramen hip dislocations that provides a more controlled reduction and less need for assistants.


Assuntos
Raquianestesia , Fraturas Ósseas , Luxação do Quadril , Masculino , Humanos , Adulto , Raquianestesia/efeitos adversos , Luxação do Quadril/diagnóstico por imagem , Luxação do Quadril/cirurgia , Luxação do Quadril/etiologia , Fraturas Ósseas/complicações , Tração/métodos
2.
J Orthop Case Rep ; 13(6): 16-19, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37398534

RESUMO

Introduction: Acute compartment syndrome (ACS) occurs due to decreased perfusion of an osseofascial space due to increased compartmental pressure. Due to its potentially devastating sequelae, emphasis is placed on its prompt diagnosis. While fractures continue to be the most common cause of ACS, mechanisms such as crush injuries and even surgical positioning are described etiologies of compartment syndrome. ACS of the well-leg from hemilithotomy positioning has been previously depicted in medical literature; however, there have been no illustrations of this complication after elective arthroscopic-assisted posterior cruciate ligament (PCL) reconstruction. Case Report: This report discusses a patient undergoing PCL reconstruction who developed an ACS in the non-operative extremity that was positioned in hemilithotomy in a leg positioner. Conclusion: ACS is an uncommon but serious complication that can occur from hemilithotomy positioning. Surgeons should be mindful of risk factors that can place a patient at higher risk, including length of the case, body habitus, height of elevation of the leg, and method of leg support. The prompt recognition and surgical management of ACS can prevent the devastating long-term complications.

3.
Obstet Gynecol ; 137(1): 1-2, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33278282
4.
Pediatr Surg Int ; 36(1): 93-101, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31435734

RESUMO

PURPOSE: Pediatric cervical spine injuries are rare events. Missed injuries must be weighed against radiation exposure and excess resource utilization in a young population. A universal pediatric cervical spine clearance algorithm does not exist. The study objective is to determine if care improved after the implementation of a standardized cervical spine clearance pathway by evaluating imaging rates, length of stay, speciality consultation, and injury detection. METHODS: A multidisciplinary group reviewed relevant literature to develop an algorithm for cervical spine clearance in pediatric trauma patients. We reviewed patient charts 15 months before and after implementation. Categorical comparisons were tested with Chi-square. A p value less than 0.05 was considered statistically significant. RESULTS: The pre- and post-implementation groups were homogenous when comparing demographics, mechanism and severity of injury. Using the cervical spine clearance pathway, patients received fewer plain cervical spine radiographs (34% vs 16%), fewer spine speciality consults (28% vs 13%), and more patients were cleared clinically (44% vs 62%) (p < 0.05). There were 2 (1.7%) documented injuries in the pre-implementation group and 3 (3%) documented injuries in the post-implementation group. There were no missed injuries. CONCLUSIONS: Use of a standardized pathway allows more patients' cervical spines to be cleared clinically and better utilizes resources without compromising patient care. LEVEL OF EVIDENCE: Level III. TYPE OF STUDY: Care Management Study.


Assuntos
Vértebras Cervicais/lesões , Procedimentos Clínicos , Traumatismos da Coluna Vertebral/diagnóstico , Algoritmos , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Michigan , Avaliação de Programas e Projetos de Saúde , Estudos Prospectivos , Radiografia/estatística & dados numéricos , Encaminhamento e Consulta/estatística & dados numéricos , Medição de Risco , Centros de Traumatologia
5.
J Pediatr Surg ; 54(1): 189-193, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30355460

RESUMO

BACKGROUND/PURPOSE: We initiated a pediatric surgical program including a caregiver for the induction of anesthesia. We measured preoperative midazolam administration, preoperative time, induction time, and program satisfaction. METHODS: Families with children undergoing surgery during the study period were included. Preoperative midazolam administration, preoperative time, and induction time were compared between participants and controls. Satisfaction surveys were given to participating caregivers and staff. RESULTS: The rate of preoperative midazolam use decreased from 41% (392/964) to 13% (16/118) among participants vs controls (p < 0.0001). After linear regression analysis, this difference persisted as an adjusted odds ratio of 0.29 (95% CI = 0.16-0.52). Preoperative and induction times (minutes) were similar between groups (76.2 vs 82.2, 13.8 vs 16.2, p = nonsignificant). Based on 5-point Likert surveys, the program was rated as "beneficial" or "very beneficial" to the patient by caregivers (99.2%) and staff (77.5%). Caregivers stated it "reduced" or "greatly reduced" anxiety for them (87.1%) and their child (93.2%). CONCLUSIONS: Opponents of similar programs suggest familial presence slows care and is disruptive. Our program decreased utilization of preoperative anxiolytics with no effect on operating room efficiency. Both hospital staff and participants felt the program was beneficial to the patient. Perceived caregiver and child anxiety was reduced. TYPE OF STUDY: Treatment study. LEVEL OF EVIDENCE: Level III.


Assuntos
Adjuvantes Anestésicos/administração & dosagem , Anestesia/métodos , Midazolam/administração & dosagem , Assistência Centrada no Paciente/métodos , Atitude do Pessoal de Saúde , Criança , Pré-Escolar , Família , Feminino , Humanos , Lactente , Masculino , Satisfação do Paciente/estatística & dados numéricos , Estudos Retrospectivos , Inquéritos e Questionários
7.
Obstet Gynecol ; 132(2): 507-512, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29995749

RESUMO

OBJECTIVE: To evaluate observational research manuscripts submitted to Obstetrics & Gynecology to determine the level of adherence to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist and highlight specific areas that could be improved. METHODS: A scoring system based on the STROBE checklist was developed and validated for consistency by volunteer medical students or doctors. Using this scoring system, we performed a cross-sectional analysis on 198 observational research manuscripts submitted to Obstetrics & Gynecology from 2008 to 2016. Each manuscript was given a score based on the STROBE checklist. Comparisons were made among acceptance status, country of origin, and study type. Descriptive statistics (means, medians, and frequencies) were calculated for each manuscript category. The t test or Wilcoxon rank-sum test was used to compare differences between two groups and analysis of variance or the Kruskal-Wallis test was used to compare differences among three or more groups. RESULTS: There was a statistically significant difference between the mean score for accepted (23.2±2.7) compared with rejected (19.7±4.1) manuscripts (P<.001). This difference was not seen when comparing country of origin and study type. Poor reporting was seen among all manuscript categories for objectives, study size, missing data, study participants, and translation of risk. Additionally, rejected manuscripts had poor reporting for eligibility criteria, variables, bias and confounding, statistical methods, unadjusted and adjusted estimates, and category boundaries. CONCLUSION: Overall, accepted manuscripts show better adherence to the STROBE checklist, but there are several critical items that are poorly reported in all manuscripts.


Assuntos
Fidelidade a Diretrizes/estatística & dados numéricos , Estudos Observacionais como Assunto/normas , Obstetrícia/normas , Controle de Qualidade , Projetos de Pesquisa/normas , Lista de Checagem , Estudos Transversais , Políticas Editoriais , Feminino , Guias como Assunto , Humanos , Estudos Observacionais como Assunto/estatística & dados numéricos , Obstetrícia/estatística & dados numéricos , Publicações Periódicas como Assunto , Projetos de Pesquisa/estatística & dados numéricos
8.
Obstet Gynecol ; 130(6): 1385, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29189687
9.
Obstet Gynecol ; 129(2): 243-248, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28079780

RESUMO

OBJECTIVE: To evaluate whether quality of peer review and reviewer recommendation differ based on reviewer subspecialty in obstetrics and gynecology and to determine the role of experience on reviewer recommendation. METHODS: We performed a retrospective cohort study of reviews submitted to Obstetrics & Gynecology between January 2010 and December 2014. Subspecialties were determined based on classification terms selected by each reviewer and included all major obstetrics and gynecology subspecialties, general obstetrics and gynecology, and nonobstetrics and gynecology categories. Review quality (graded on a 5-point Likert scale by the journal's editors) and reviewer recommendation of "reject" were compared across subspecialties using χ, analysis of variance, and multivariate logistic regression. RESULTS: There were 20,027 reviews from 1,889 individual reviewers. Reviewers with family planning subspecialty provided higher-quality peer reviews compared with reviewers with gynecology only, reproductive endocrinology and infertility, gynecologic oncology, and general obstetrics and gynecology specialties (3.61±0.75 compared with 3.44±0.78, 3.42±0.72, 3.35±0.75, and 3.32±0.81, respectively, P<.05). Reviewers with gynecology-only subspecialty recommended rejection more often compared with reviewers with a nonobstetrics and gynecology subspecialty (57.7% compared with 38.7%, P<.05). Editorial Board members recommended rejection more often than new reviewers (68.0% compared with 41.5%, P<.05). Increased adjusted odds of manuscript rejection recommendation were associated with reproductive endocrinology, female pelvic medicine and reconstructive surgery, and gynecology-only reviewer subspecialty (adjusted odds ratio [OR] 1.23 [1.07-1.41], 1.21 [1.05-1.39], and 1.11 [1.02-1.20]). Manuscript rejection recommendation rate was also increased for reviewers who had completed the highest quintile of peer reviews (greater than 195) compared with the lowest quintile (one to seven) (adjusted OR 2.85 [2.60-3.12]). CONCLUSION: Peer review quality differs based on obstetrics and gynecology subspecialty. Obstetrics and gynecology subspecialty and reviewer experience have implications for manuscript rejection recommendation. Reviewer assignment is pivotal to maintaining a rigorous manuscript selection process.


Assuntos
Ginecologia , Medicina , Obstetrícia , Revisão da Pesquisa por Pares/métodos , Humanos , Fator de Impacto de Revistas , Variações Dependentes do Observador , Estudos Retrospectivos
10.
Obstet Gynecol ; 129(2): 237-238, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28079782
11.
Am J Surg ; 208(3): 480-4; discussion 483-4, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24462172

RESUMO

BACKGROUND: Complex ventral hernias remain a challenge. We present a study evaluating outcomes of complex ventral hernia repair using human-derived acellular dermal matrix (AlloDerm) and porcine-derived acellular dermal sheet (Permacol). METHODS: A retrospective review of 251 patients undergoing complex hernia repair was performed. Primary outcome was hernia recurrence; and secondary outcomes included early and late complications and mortality. RESULTS: Recurrence for Permacol versus AlloDerm was 32% versus 47% (P = .02). There was a difference in early complications (48% vs 30%, P = .007) and also late complications (30% vs 21%, P = .16) of Permacol versus AlloDerm. Overall survival was 85% for the Permacol group versus 78% for the AlloDerm group (P = .23). Recurrence for Permacol versus AlloDerm for underlay technique was 19% versus 22% and that for bridging technique was 44% versus 57%. CONCLUSION: There exists a high complication rate from both Permacol and AlloDerm in complex ventral hernia repair especially when used as a fascial bridge.


Assuntos
Parede Abdominal/cirurgia , Colágeno , Herniorrafia/instrumentação , Telas Cirúrgicas , Adulto , Idoso , Feminino , Hérnia Ventral/cirurgia , Herniorrafia/métodos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Modelos de Riscos Proporcionais , Recidiva , Estudos Retrospectivos , Resultado do Tratamento
12.
Clin Pediatr (Phila) ; 53(1): 51-9, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24002047

RESUMO

OBJECTIVE: To assess the impact of the 16-duty hour restriction on pediatric interns' neonatal education. METHOD: Survey of interns clinical and educational experiences during their neonatal rotations. RESULTS: A total of 316 respondents in 2011, who worked >16 hours, were compared with 509 respondents in 2012, who worked ≤16 hours. The average work week decreased from 67.3 ± 9.6 to 59.3 ± 8.1 hours (P < .0001). The 2012 cohort attended fewer didactic lectures (-16%, P < .0001), grand rounds (-27%, P < .0001), and mock resuscitations (-16%, P < .005). There were no significant differences in the number of (1) patients on service, (2) deliveries attended, or (3) procedures. There was no significant difference in the median number of correct responses (4) on 10 knowledge-based multiple-choice questions. CONCLUSIONS: The decrease in duty hours was achieved without significantly affecting interns' knowledge or clinical experience.


Assuntos
Competência Clínica , Educação de Pós-Graduação em Medicina/normas , Internato e Residência/normas , Neonatologia/educação , Pediatria/educação , Carga de Trabalho/normas , Adulto , Coleta de Dados , Educação de Pós-Graduação em Medicina/métodos , Educação de Pós-Graduação em Medicina/estatística & dados numéricos , Feminino , Humanos , Internato e Residência/métodos , Internato e Residência/estatística & dados numéricos , Masculino , Estados Unidos , Carga de Trabalho/estatística & dados numéricos
13.
Dis Colon Rectum ; 57(1): 110-4, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24316954

RESUMO

BACKGROUND: Sedation with propofol is gaining popularity. It is unclear whether sedation with propofol is associated with colonoscopic perforation. OBJECTIVE: The purpose of this study was to compare perforation rates during colonoscopy using sedation with or without propofol. DESIGN: This was a retrospective case series study. SETTINGS: Data from a tertiary center were analyzed. Demographics, method of sedation, and type of endoscopic procedure performed were collected. PATIENTS: Patients who underwent a colonoscopy from January 2003 to October 2012 were analyzed. MAIN OUTCOME MEASURES: Perforation rate expressed per 10,000 colonoscopies was measured. RESULTS: A total of 118,004 colonoscopies were performed during the study period, with 48 perforations (0.041% or 4.1 per 10,000). Overall, the use of propofol was associated with a 2.5 times increased rate of perforation (6.9 vs 2.7 per 10,000; p = 0.0015). Similarly, in patients undergoing therapeutic colonoscopies, there was a 3.4-times increased risk of perforation associated with the use of propofol (8.7 vs 2.6 per 10,000; p = 0.0016). However, in patients undergoing diagnostic colonoscopies, there was no significantly increased risk of perforation with the use of propofol (4.2 vs 2.9 per 10,000; p = 0.64). In univariate and multivariate analyses, there were no differential perforation risks on the basis of sex, but each decade increase in age was associated with an increased risk of perforation. In those patients having a therapeutic colonoscopy, age (per decade) and propofol use were independently and significantly associated with an increased perforation risk, with adjusted ORs of 1.32 (p = 0.04) and 3.38 (p = 0.001). LIMITATIONS: This was a retrospective study with the potential for selection bias. CONCLUSIONS: This study shows that propofol administration is associated with an increased risk of colonoscopic perforation among patients undergoing a therapeutic colonoscopy; however, this association was not evident in patients undergoing a diagnostic colonoscopy. Further studies, such as a prospective, randomized clinical trial, should be done to further evaluate this association.


Assuntos
Doenças do Colo/etiologia , Colonoscopia/efeitos adversos , Sedação Profunda/efeitos adversos , Hipnóticos e Sedativos , Perfuração Intestinal/etiologia , Propofol , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças do Colo/epidemiologia , Doenças do Colo/prevenção & controle , Colonoscopia/métodos , Sedação Profunda/métodos , Feminino , Humanos , Perfuração Intestinal/epidemiologia , Perfuração Intestinal/prevenção & controle , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
14.
J Matern Fetal Neonatal Med ; 25(10): 1933-40, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22494346

RESUMO

OBJECTIVES: (1) Develop reference ranges of neonatal adiposity using air displacement plethysmography. (2) Use new reference ranges for neonatal adiposity to compare two different methods of evaluating neonatal nutritional status. METHODS: Three hundred and twenty-four normal neonates (35-41 weeks post-menstrual age) had body fat (%BF) and total fat mass (FM, g) measured using air displacement plethysmography shortly after delivery. Results were stratified for 92 of these neonates with corresponding fetal biometry using two methods for classifying nutritional status: (1) population-based weight percentiles; and (2) a modified neonatal growth assessment score (m(3)NGAS(51)). RESULTS: At the 50th percentile, %BF varied from 7.7% (35 weeks) to 11.8% (41 weeks), while the corresponding 50th percentiles for total FM were 186-436 g. Among the subset of 92 neonates, no significant differences in adiposity were found between small for gestational age (SGA), appropriate for gestational age (AGA), and large for gestational age (LGA) groups using population-based weight standards. Classification of the same neonates using m(3)NGAS(51) showed significant differences in mean %BF between corresponding groups. CONCLUSIONS: Population-based weight criteria for neonatal nutritional status can lead to misclassifications on the basis of adiposity. A neonatal growth assessment score, that considers the growth potential of several anatomic parameters, appears to more effectively classify under- and over-nourished newborns.


Assuntos
Adiposidade , Peso ao Nascer , Desenvolvimento Fetal , Macrossomia Fetal/diagnóstico , Recém-Nascido Pequeno para a Idade Gestacional , Avaliação Nutricional , Adulto , Estudos Transversais , Diabetes Gestacional , Feminino , Macrossomia Fetal/etiologia , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Modelos Lineares , Masculino , Estado Nutricional , Pletismografia , Gravidez , Gravidez em Diabéticas , Estudos Prospectivos , Valores de Referência , Ultrassonografia Pré-Natal
15.
Am J Surg ; 204(2): 193-8, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22464444

RESUMO

BACKGROUND: Although fine-needle aspiration (FNA) is an established tool in the biopsy of breast masses, there has been a trend toward using core-needle biopsy (CNB). The aim of this study was to determine whether FNA has comparable predictive value with CNB and whether FNA is more cost effective. METHODS: A retrospective review was conducted on 162 patients who underwent either FNA or CNB of palpable breast lesions and had histologic confirmation with surgical biopsy in calendar year 2005. RESULTS: There were no false-positives or false-negatives in either group. The sensitivity, specificity, and positive predictive value for FNA were 89%, 98%, and 94%, respectively. CNB had sensitivity, specificity, and positive predictive value of 100%, 90%, and 93%, respectively. The cost to perform FNA was $166.34, compared with $477.92 for CNB. CONCLUSIONS: FNA and CNB had comparable predictive value, with FNA being more cost effective.


Assuntos
Biópsia por Agulha Fina/economia , Biópsia por Agulha Fina/métodos , Neoplasias da Mama/diagnóstico , Mama/patologia , Neoplasias da Mama/cirurgia , Custos e Análise de Custo , Feminino , Humanos , Masculino , Mamografia , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade , Ultrassonografia de Intervenção
16.
Arch Surg ; 147(7): 600-5, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22430091

RESUMO

OBJECTIVES: To determine the risk factors in diabetic patients that are associated with increased postcolectomy mortality and anastomotic leak. DESIGN: A prospectively acquired statewide database of patients who underwent colectomy was reviewed. Primary risk factors were diabetes mellitus, hyperglycemia (glucose level ≥ 140 mg/dL), steroid use, and emergency surgery. Categorical analysis, univariate logistic regression, and multivariate regression were used to evaluate the effects of these risk factors on outcomes. SETTING: Participating hospitals within the Michigan Surgical Quality Collaborative. PATIENTS: Database review of patients from hospitals within the Michigan Surgical Quality Collaborative. MAIN OUTCOME MEASURES: Anastomotic leak and 30- day mortality rate. RESULTS: Of 5123 patients, 153 (3.0%) had leaks and 153 (3.0%) died. Preoperative hyperglycemia occurred in 15.6% of patients, only 54% of whom were known to have diabetes. Multivariate analysis showed that the risk of leak for patients with and without diabetes increased only by preoperative steroid use (P<.05). Mortality among diabetic patients was associated with emergency surgery (P<.01) and anastomotic leak (P<.05); it was not associated with hyperglycemia. Mortality among nondiabetic patients was associated with hyperglycemia (P<.005). The presence of an anastomotic leak was associated with increased mortality among diabetic patients (26.3% vs 4.5%; P<.001) compared with nondiabetic patients (6.0% vs 2.5%; P<.05). CONCLUSIONS: The presence of diabetes did not have an effect on the presence of an anastomotic leak, but diabetic patients who had a leak had more than a 4-fold higher mortality compared with nondiabetic patients. Preoperative steroid use led to increased rates of anastomotic leak in diabetic patients. Mortality was associated with hyperglycemia for nondiabetic patients only. Improved screening may identify high-risk patients who would benefit from perioperative intervention.


Assuntos
Fístula Anastomótica/etiologia , Fístula Anastomótica/mortalidade , Colectomia/efeitos adversos , Colectomia/mortalidade , Diabetes Mellitus/mortalidade , Idoso , Distribuição de Qui-Quadrado , Feminino , Humanos , Laparoscopia , Laparotomia , Modelos Logísticos , Masculino , Michigan/epidemiologia , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Estatísticas não Paramétricas
17.
J Immunol ; 184(6): 2873-85, 2010 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-20154206

RESUMO

Generating adaptive immunity postinfection or immunization requires physical interaction within a lymph node T zone between Ag-bearing dendritic cells (DCs) and rare cognate T cells. Many fundamental questions remain regarding the dynamics of DC-CD4+ T cell interactions leading to priming. For example, it is not known how the production of primed CD4+ T cells relates to the numbers of cognate T cells, Ag-bearing DCs, or peptide-MHCII level on the DC. To address these questions, we developed an agent-based model of a lymph node to examine the relationships among cognate T cell frequency, DC density, parameters characterizing DC-T cell interactions, and the output of primed T cells. We found that the output of primed CD4+ T cells is linearly related to cognate frequency, but nonlinearly related to the number of Ag-bearing DCs present during infection. This addresses the applicability of two photon microscopy studies to understanding actual infection dynamics, because these types of experiments increase the cognate frequency by orders of magnitude compared with physiologic levels. We found a trade-off between the quantity of peptide-major histocompatibility class II on the surface of individual DCs and number of Ag-bearing DCs present in the lymph node in contributing to the production of primed CD4+ T cells. Interestingly, peptide-major histocompatibility class II t(1/2) plays a minor, although still significant, role in determining CD4+ T cell priming, unlike the primary role that has been suggested for CD8+ T cell priming. Finally, we identify several pathogen-targeted mechanisms that, if altered in their efficiency, can significantly effect the generation of primed CD4+ T cells.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Simulação por Computador , Linfonodos/imunologia , Ativação Linfocitária/imunologia , Modelos Imunológicos , Simulação de Dinâmica Molecular , Imunidade Adaptativa , Animais , Anticorpos/metabolismo , Antígenos/imunologia , Infecções Bacterianas/imunologia , Infecções Bacterianas/patologia , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/imunologia , Adesão Celular/imunologia , Comunicação Celular/imunologia , Movimento Celular/imunologia , Células Dendríticas/citologia , Células Dendríticas/imunologia , Células Dendríticas/microbiologia , Endotélio Linfático/irrigação sanguínea , Endotélio Linfático/citologia , Endotélio Linfático/imunologia , Linfonodos/citologia , Linfonodos/metabolismo , Linfonodos/microbiologia , Camundongos , Fase de Repouso do Ciclo Celular/imunologia
18.
J Theor Biol ; 250(4): 732-51, 2008 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-18068193

RESUMO

Generating adaptive immunity after infection or immunization requires physical interactions within a lymph node (LN) T-zone between antigen-bearing dendritic cells (DCs) that arrive from peripheral tissues and rare cognate T cells entering via high endothelial venules (HEVs). This interaction results in activation of cognate T cells, expansion of that T cell lineage and their exit from the LN T-zone via efferent lymphatics (ELs). How antigen-specific T cells locate DCs within this complex environment is controversial, and both random T cell migration and chemotaxis have been proposed. We developed an agent-based computational model of a LN that captures many features of T cell and DC dynamics observed by two-photon microscopy. Our simulations matched in vivo two-photon microscopy data regarding T cell speed, short-term directional persistence of motion and cell motility. We also obtained in vivo data regarding density of T cells and DCs within a LN and matched our model environment to measurements of the distance from HEVs to ELs. We used our model to compare chemotaxis with random motion and showed that chemotaxis increased total number of T cell DC contacts, but decreased unique contacts, producing fewer activated T cells. Our results suggest that, within a LN T-zone, a random search strategy is optimal for a rare cognate T cell to find its DC match and maximize production of activated T cells.


Assuntos
Quimiotaxia de Leucócito/imunologia , Células Dendríticas/imunologia , Modelos Imunológicos , Subpopulações de Linfócitos T/imunologia , Animais , Apresentação de Antígeno/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Comunicação Celular/imunologia , Movimento Celular/imunologia , Linfonodos/imunologia , Ativação Linfocitária/imunologia , Sensibilidade e Especificidade
19.
Immunol Rev ; 216: 93-118, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17367337

RESUMO

A functioning immune system and the process of antigen presentation in particular encompass events that occur at multiple length and time scales. Despite a wealth of information in the biological literature regarding each of these scales, no single representation synthesizing this information into a model of the overall immune response as it depends on antigen presentation is available. In this article, we outline an approach for integrating information over relevant biological and temporal scales to generate such a representation for major histocompatibility complex class II-mediated antigen presentation. In addition, we begin to address how such models can be used to answer questions about mechanisms of infection and new strategies for treatment and vaccines.


Assuntos
Apresentação de Antígeno , Células Apresentadoras de Antígenos/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Imunidade Celular , Modelos Imunológicos , Animais , Humanos
20.
Am J Perinatol ; 24(2): 107-15, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17304424

RESUMO

Our aims were to identify the range of blood pressure values during the first postnatal week in infants born between 23 and 25 weeks postmenstrual age who were not considered in need of treatment for hypotension, and to describe the clinical course of these untreated infants compared with those who were treated for hypotension. We reviewed retrospectively the charts of 142 consecutive inborn infants over a 6-year period. For 86 infants who survived the first postnatal week without being treated for hypotension, the mean arterial pressure (MAP) increased 0.3 mm Hg/h during the first 24 hours, 0.1 mm Hg/h from the 25th to the 48th hour, and then stabilized for the remainder of the week. MAP values < or = 25 mm Hg were not uncommon and were not associated with apparent consequences. Thirty-five infants treated for hypotension differed significantly from untreated infants in several clinical variables present at birth, suggesting a different degree of fetal compromise. Treated infants were less likely to survive (43 versus 85%; P < 0.001) or survive without a major morbidity (29 versus 53%; P = 0.013) than untreated infants. It was not apparent from our data that the treatment of hypotension was helpful.


Assuntos
Pressão Sanguínea/fisiologia , Recém-Nascido Prematuro/fisiologia , Feminino , Idade Gestacional , Humanos , Hipotensão/tratamento farmacológico , Hipotensão/epidemiologia , Hipotensão/mortalidade , Recém-Nascido , Doenças do Prematuro/epidemiologia , Masculino , Valores de Referência , Estudos Retrospectivos , Análise de Sobrevida , Resultado do Tratamento
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