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1.
J Gastrointest Surg ; 28(7): 1145-1150, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38657729

RESUMEN

BACKGROUND: Symptomatic cholelithiasis is a common surgical problem, with many patients requiring multiple gallstone-related emergency department (ED) visits before cholecystectomy. The Social Vulnerability Index (SVI) identifies vulnerable patient populations. This study aimed to assess the association between social vulnerability and outpatient management of symptomatic cholelithiasis. METHODS: Patients with symptomatic cholelithiasis-related ED visits were identified within our health system from 2016 to 2022. Clinical outcomes data were merged with SVI census track data, which consist of 4 SVI subthemes (socioeconomic status, household characteristics, racial and ethnic minority status, and housing type and transportation). Multivariate analysis was used for statistical analysis. RESULTS: A total of 47,292 patients presented to the ED with symptomatic cholelithiasis, of which 6103 patients (13.3 %) resided in vulnerable census tract regions. Of these patients, 13,795 (29.2 %) underwent immediate cholecystectomy with a mean time to surgery of 35.1 h, 8250 (17.4 %) underwent elective cholecystectomy at a mean of 40.6 days from the initial ED visit, and 2924 (6.2 %) failed outpatient management and returned 1.26 times (range, 1-11) to the ED with recurrent biliary-related pain. Multivariate analysis found social vulnerability subthemes of socioeconomic status (odds ratio [OR], 1.29; 95 % CI, 1.09-1.52) and racial and ethnic minority status (OR, 2.41; 95 % CI, 2.05-2.83) to be associated with failure of outpatient management of symptomatic cholelithiasis. CONCLUSION: Socially vulnerable patients are more likely to return to the ED with symptomatic cholelithiasis. Policies to support this vulnerable population in the outpatient setting with timely follow-up and elective cholecystectomy can help reduce delays in care and overutilization of ED resources.


Asunto(s)
Colecistectomía , Colelitiasis , Servicio de Urgencia en Hospital , Poblaciones Vulnerables , Humanos , Femenino , Masculino , Persona de Mediana Edad , Poblaciones Vulnerables/estadística & datos numéricos , Colelitiasis/cirugía , Colelitiasis/complicaciones , Adulto , Colecistectomía/estadística & datos numéricos , Servicio de Urgencia en Hospital/estadística & datos numéricos , Anciano , Clase Social , Atención Ambulatoria/estadística & datos numéricos , Tiempo de Tratamiento/estadística & datos numéricos , Procedimientos Quirúrgicos Electivos/estadística & datos numéricos , Estudios Retrospectivos
2.
Am J Surg ; 228: 258-263, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37923660

RESUMEN

BACKGROUND: Therapeutic lymphadenectomy (TLND) is still performed in most melanoma patients to treat nodal recurrences after initial negative lymph node biopsy (-SLNB), despite the lack of evidence for survival benefit. We sought to compare melanoma-specific survival (MSS) and distant metastasis-free survival (DMFS) of patients who underwent TLND versus no TLND using our institutional and MSTL-1 databases. METHODS: We identified 146 patients with nodal recurrence following -SLNB: 132 underwent TLND and 14 did not. DMFS and MSS were evaluated for the cohorts followed by a matched-pair analysis between the cohorts. RESULTS: No difference was observed in five-year DMFS (p â€‹= â€‹0.454) and five-year MSS (p â€‹= â€‹0.945) between the two groups. The matched-pair analysis showed similar results (p â€‹= â€‹0.329 and p â€‹= â€‹0.363 for DMSF and MSS, respectively). CONCLUSIONS: From this limited retrospective study, TLND for nodal recurrence after a -SLNB does not appear to improve DMFS or MSS in melanoma patients compared to no TLND.


Asunto(s)
Melanoma , Neoplasias Cutáneas , Humanos , Melanoma/patología , Neoplasias Cutáneas/patología , Biopsia del Ganglio Linfático Centinela/métodos , Estudios Retrospectivos , Metástasis Linfática/patología , Escisión del Ganglio Linfático/métodos , Ganglios Linfáticos/cirugía , Ganglios Linfáticos/patología , Recurrencia Local de Neoplasia/patología
4.
J Surg Oncol ; 127(7): 1187-1195, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36938777

RESUMEN

BACKGROUND AND OBJECTIVES: Melanoma mutational burden is high and approximately 50% have oncogenic mutations in BRAF. We sought to evaluate age-related mutational differences in melanoma. METHODS: We analyzed melanoma samples in the Genomics Evidence Neoplasia Information Exchange database. Targetable mutations were identified using the Precision Oncology Knowledge Base (OncoKB). RESULTS: We found 1194 patients with a common set of 30 genes. The top mutated genes in patients <40 years old (y/o) (n = 98) were BRAF (59%), TP53 (31%), NRAS (17%), and PTEN (14%); in 40-59 y/o (n = 354) were BRAF (51%), NRAS (30%), TP53 (26%), and APC (13%); and in ≥60 y/o (n = 742) were BRAF (38%), NRAS (33%), TP53 (26%), and KDR (19%). BRAF mutations were almost mutually exclusive from NRAS mutations in <40 y/o (58/59). Mutational burden increased with age, with means of 2.39, 2.92, and 3.67 mutations per sample in patients <40, 40-59, and ≥60 y/o, respectively (p < 0.0001). There were 10 targetable mutations meeting OncoKB criteria for melanoma: BRAF (level 1), RET (level 1), KIT (level 2), NRAS (level 3A), TP53 (level 3A), and FGFR2, MET, PTEN, PIK3CA, and KRAS (level 4). CONCLUSIONS: Mutations in melanoma have age-related differences and demonstrates potential targetable mutations for personalized therapies.


Asunto(s)
Melanoma , Neoplasias Cutáneas , Humanos , Adulto , Proteínas Proto-Oncogénicas B-raf/genética , Medicina de Precisión , Melanoma/genética , Mutación , Secuenciación de Nucleótidos de Alto Rendimiento , Análisis Mutacional de ADN , Neoplasias Cutáneas/genética
6.
Curr Med Res Opin ; 39(3): 417-423, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36617959

RESUMEN

BACKGROUND: The 31-gene expression profile test (Class 1A: low-risk; 1B/2A: intermediate-risk; 2B: high-risk) is validated to identify patients with cutaneous melanoma who can safely forego sentinel lymph node biopsy (SLNB). The objective of the current study is to quantify SLNB reduction by clinicians using 31-GEP. METHODS: Patients with T1-T2 tumors eligible for SLNB were seen by surgical oncologists (89.1%), dermatologists (7.8%), and medical oncologists (3.1%). After receiving 31-GEP results but before SLNB, clinicians were asked which clinical and pathological features influenced SLNB decisions (n = 191). The Exact binomial test was used to compare SLNB procedure rates to a contemporary study (78% SLNB baseline rate). Logistic regression modeling (odds ratio [OR], 95% CI) was used to identify features associated with SLNB procedure rates. RESULTS: One hundred clinical decisions (52.4%) were influenced by the 31-GEP to forego SLNB and 70% (70/100) were not performed. Of the 30 performed, 0% (0/30) were positive. The 31-GEP influenced sixty-three clinical decisions (33.0%) to perform SLNB, and 92.1% (58/63) were performed. There was a clinically meaningful 29.4% reduction of SLNBs performed in patients with a Class 1A result relative to the baseline rate of 78.0% (p < .01). In patients ≥55 or ≥65-year-old, SLNB reduction was 32.3% (p < .01), 28.3% (p < .01), respectively. Overall, 85.3% of decisions relating to SLNB were influenced by 31-GEP results. CONCLUSION: In this prospective, multicenter study, clinicians demonstrated clinically meaningful use of the 31-GEP test to forego or pursue SLNB in patients with T1-T2 tumors resulting in a significant, risk appropriate decrease in SLNBs.


Asunto(s)
Melanoma , Neoplasias Cutáneas , Humanos , Anciano , Melanoma/genética , Melanoma/cirugía , Melanoma/patología , Neoplasias Cutáneas/genética , Neoplasias Cutáneas/cirugía , Neoplasias Cutáneas/patología , Biopsia del Ganglio Linfático Centinela , Transcriptoma , Estudios Prospectivos , Pronóstico , Melanoma Cutáneo Maligno
7.
Am J Surg ; 225(1): 212-219, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36058752

RESUMEN

BACKGROUND: Due to the aging population, the number of older patients diagnosed with pancreatic ductal adenocarcinoma (PDAC) will continue to rise. STUDY DESIGN: Utilizing the NCDB from 2010 to 2016, patients with early stage, clinically node negative PDAC who were ≥70 years old and had a Whipple were identified. Multivariable logistic regressions were used to determine independent factors for R0 resection and NAT. Cox-proportional-hazards regression analyses examined for the impact of NAT on the risk of death. RESULTS: Of 5086 patients, 51.7% received upfront surgery + adjuvant therapy (UFS + AT), followed by 29.9% UFS only, and the remainder NAT. NAT significantly improved OS compared to a combined cohort of those that had UFS ± AT. NAT retained its independent survival benefit when compared to only patients that had UFS + AT. CONCLUSION: For older patients diagnosed with early stage PDAC, NAT was associated with improved R0 resection rates and a significant survival benefit when compared to the current standard of care.


Asunto(s)
Adenocarcinoma , Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Anciano , Neoplasias Pancreáticas/cirugía , Adenocarcinoma/cirugía , Pancreatectomía , Terapia Neoadyuvante , Carcinoma Ductal Pancreático/cirugía , Estudios Retrospectivos , Neoplasias Pancreáticas
8.
JAMA Surg ; 157(11): e224456, 2022 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-36169964

RESUMEN

Importance: The number of older patients (80 years and older) diagnosed with locally advanced rectal cancer (LARC) is expected to increase. Although current guidelines recommend neoadjuvant chemoradiation therapy (NACRT) followed by resection, little is known about management and outcomes in this older population. Objective: To assess the trends in management of older patients diagnosed with LARC who had a surgical resection. Design, Setting, and Participants: Patients 80 years and older who had a surgical resection for LARC were identified in the 2004-2016 National Cancer Database. Patients were grouped based on therapy sequence: (1) surgery followed by adjuvant therapy (AT), ie, chemotherapy or radiation; (2) surgery alone; or (3) NACRT followed by surgical resection. Data were analyzed in May 2021. Exposures: NACRT followed by surgery, and surgery with or without AT. Main Outcomes and Measures: Overall survival (OS) was assessed using Kaplan-Meier analyses with inverse probability of treatment weighting (IPTW) and Cox proportional hazards regression were performed to examine the association of NACRT with the risk of death. Results: Of 3868 patients with LARC who underwent surgical resection, 2042 (52.8%) were male, and the mean (SD) age was 83.4 (3.0) years. A total of 2273 (58.8%) received NACRT followed by surgical resection. Factors independently associated with NACRT were more recent diagnosis, age 80 to 85 years (vs 86 years and older), fewer comorbidities, larger tumors, and node-positive disease. The Kaplan-Meier analyses with IPTW showed that 3-year and 5-year OS for NACRT (3-year: 68.9%; 95% CI, 67.0-70.8; 5-year: 51.1%; 95% CI, 49.0-53.4) vs surgery with AT (3-year: 64.4%; 95% CI, 59.0-70.2; 5-year: 43.0%; 95% CI, 37.4-49.5) vs surgery alone (3-year: 55.8%; 95% CI, 52.0-60.0; 5-year: 34.7%; 95% CI, 30.8-39.0) was significantly different (P < .001). After adjusting for confounders, patients who received NACRT were more likely to undergo an R0 resection (adjusted odds ratio, 2.16; 95% CI, 1.62-2.88), which independently improved OS (P < .001). Moreover, receipt of NACRT was independently associated with a 25% decreased risk of death (adjusted hazard ratio, 0.75; 95% CI, 0.69-0.82) compared with alternative treatment sequences. Conclusions and Relevance: Approximately 40% of older patients with LARC did not receive the current standard of care. In this cohort, NACRT was associated with a higher likelihood of an R0 resection and improved OS. Clinicians should advocate for receipt of NACRT in older patients with LARC.


Asunto(s)
Neoplasias Primarias Secundarias , Neoplasias del Recto , Humanos , Masculino , Anciano , Anciano de 80 o más Años , Femenino , Terapia Neoadyuvante , Neoplasias del Recto/cirugía , Neoplasias del Recto/patología , Resultado del Tratamiento , Estudios Retrospectivos , Recto , Neoplasias Primarias Secundarias/etiología
10.
Ann Surg Oncol ; 29(13): 8469-8477, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35989390

RESUMEN

BACKGROUND: The Multicenter Selective Lymphadenectomy Trial II (MSLT-II) led to a change in the management of tumor-positive sentinel lymph nodes (SLNs) from completion node dissection (CLND) to nodal observation. This study aimed to evaluate prognostic factors for predicting sentinel node basin recurrence (SNBR) using data from MSLT-II trial participants. METHODS: In MSLT-II, 1076 patients were treated with observation. Patients were included in the current study if they had undergone a post-sentinel node basin ultrasound (PSNB-US) within 4 months after surgery. The study excluded patients with positive SLN by reverse transcription-polymerase chain reaction (RT-PCR) or incomplete SLN pathologic data. Primary tumor, patient, PSNB-US, and SLN characteristics were evaluated. Multivariable regression analyses were performed to determine independent prognostic factors associated with SNBR. RESULTS: The study enrolled 737 patients: 193 (26.2%) patients with SNBR and 73 (9.9%) patients with first abnormal US. The patients with an abnormal first US were more likely to experience SNBR (23.8 vs. 5.0%). In the multivariable analyses, increased risk of SNBR was associated with male gender (adjusted hazard ratio [aHR], 1.38; 95% confidence interval [CI], 1.00-1.9; p = 0.049), increasing Breslow thickness (aHR, 1.10; 95% CI, 1.01-1.2; p = 0.038), presence of ulceration (aHR, 1.93; 95% CI, 1.42-2.6; p < 0.001), sentinel node tumor burden greater than 1 mm (aHR, 1.91; 95% CI, 1.10-3.3; p = 0.022), lymphovascular invasion (aHR, 1.53; 95% CI, 1.00-2.3; p = 0.048), and presence of abnormal PSNB-US (aHR, 4.29; 95% CI, 3.02-6.1; p < 0.001). CONCLUSIONS: The first postoperative US together with clinical and pathologic factors may play an important role in predicting SNBR.


Asunto(s)
Linfadenopatía , Melanoma , Ganglio Linfático Centinela , Neoplasias Cutáneas , Masculino , Humanos , Ganglio Linfático Centinela/diagnóstico por imagen , Ganglio Linfático Centinela/cirugía , Ganglio Linfático Centinela/patología , Biopsia del Ganglio Linfático Centinela , Neoplasias Cutáneas/diagnóstico por imagen , Neoplasias Cutáneas/cirugía , Neoplasias Cutáneas/patología , Pronóstico , Melanoma/diagnóstico por imagen , Melanoma/cirugía , Melanoma/patología , Ganglios Linfáticos/diagnóstico por imagen , Ganglios Linfáticos/cirugía , Ganglios Linfáticos/patología , Escisión del Ganglio Linfático , Linfadenopatía/cirugía , Síndrome
11.
J Surg Res ; 279: 682-691, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35940046

RESUMEN

INTRODUCTION: Histologic characteristics cannot adequately predict which patients are at risk of developing metastatic disease after excision of primary cutaneous melanoma. The aim of this study was to identify immunomodulatory genes in primary tumors associated with development of distant metastases. MATERIALS AND METHODS: Thirty-seven patients with primary melanoma underwent surgical excision. RNA was extracted from the primary tumor specimens. cDNA was synthesized and used with Human Gene Expression microarray. Differential expression of 74 immunomodulatory genes was compared between patients who developed distant metastases and those who did not. RESULTS: Six of 37 patients developed distant metastases during the time of the study. Differential expression of microarray data showed upregulation of four immunomodulatory genes in this group. These four genes-c-CBL, CD276, CXCL1, and CXCL2-were all significantly overexpressed in the metastatic group with differential expression fold change of 1.15 (P = 0.01), 1.16 (P = 0.04), 2.51 (P < 0.001), and 1.68 (P < 0.02), respectively. CXCL1 had particularly high predictive value with an area under the curve of 0.80. Multivariate analysis showed only expression of CXCL1 (P = 0.01) remains predictive of distant metastases in melanoma patients. This result was confirmed using quantitative real-time polymerase chain reaction. CONCLUSIONS: CXCL1, CXCL2, c-CBL, and CD276 are immunomodulatory genes present in primary melanoma that are strongly associated with development of metastatic disease. Identification of their presence, particularly CXCL1, in the primary tumor could be used as a predictor of future risk of metastatic disease and thereby to identify patients who might benefit early from immunotherapy.


Asunto(s)
Melanoma , Neoplasias Cutáneas , Antígenos B7 , ADN Complementario , Humanos , Metástasis Linfática , Melanoma/patología , ARN , Neoplasias Cutáneas/patología
12.
Sci Adv ; 8(24): eabn1104, 2022 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-35704574

RESUMEN

Miniaturization has evolved repeatedly in frogs in the moist leaf litter environments of rainforests worldwide. Miniaturized frogs are among the world's smallest vertebrates and exhibit an array of enigmatic features. One area where miniaturization has predictable consequences is the vestibular system, which acts as a gyroscope, providing sensory information about movement and orientation. We investigated the vestibular system of pumpkin toadlets, Brachycephalus (Anura: Brachycephalidae), a clade of miniaturized frogs from Brazil. The semicircular canals of miniaturized frogs are the smallest recorded for adult vertebrates, resulting in low sensitivity to angular acceleration due to insufficient displacement of endolymph. This translates into a lack of postural control during jumping in Brachycephalus and represents a physical constraint resulting from Poiseuille's law, which governs movement of fluids within tubes.

14.
J Surg Oncol ; 122(2): 254-262, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32297324

RESUMEN

BACKGROUND: Merkel cell carcinoma is an uncommon malignancy often requiring multidisciplinary management. The purpose of this study was to determine whether high-volume facilities have improved outcomes in patients with Merkel cell carcinoma relative to lower-volume facilities. METHODS: A total of 5304 patients from the National Cancer Database with stage I-III Merkel cell carcinoma undergoing surgery were analyzed. High-volume facilities were the top 1% by case volume. Multivariable Cox regression and propensity score-matching were performed to account for imbalances between groups. RESULTS: Treatment at high-volume facilities (hazard ratio: 0.74; 95% confidence interval: 0.65-0.84, P < .001) was independently associated with improved overall survival (OS) in multivariable analyses. In propensity score-matched cohorts, 5-year OS was 62.3% at high-volume facilities vs 56.8% at lower-volume facilities (P < .001). Median OS was 111 months at high-volume facilities vs 79 months at lower-volume facilities. CONCLUSION: Treatment at high-volume facilities is associated with improved OS in Merkel cell carcinoma. Given the impracticality of referring all elderly patients with Merkel cell carcinoma to a small number of facilities, methods to mitigate this disparity should be explored.


Asunto(s)
Carcinoma de Células de Merkel/mortalidad , Carcinoma de Células de Merkel/cirugía , Neoplasias Cutáneas/mortalidad , Neoplasias Cutáneas/cirugía , Anciano , Instituciones Oncológicas/estadística & datos numéricos , Carcinoma de Células de Merkel/patología , Bases de Datos Factuales , Femenino , Humanos , Masculino , Estadificación de Neoplasias , Puntaje de Propensión , Modelos de Riesgos Proporcionales , Neoplasias Cutáneas/patología , Tasa de Supervivencia , Estados Unidos/epidemiología
15.
J Cutan Pathol ; 46(4): 261-266, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30632191

RESUMEN

BACKGROUND: Distinguishing benign nodal nevus from metastatic melanoma can be diagnostically challenging, with important clinical consequences. Recently, the loss of epigenetic marker, 5-hydroxymethylcytosine (5-hmC) expression by immunohistochemistry has been found in melanomas and atypical melanocytic neoplasms. METHODS: About 41 metastatic melanomas and 20 nodal nevi were retrieved. Nuclear 5-hmC (brown) and cytoplasmic Melan-A Red (red) double immunohistochemical staining was performed. RESULTS: Total or partial loss of nuclear expression of 5-hmC was noted in 40/41 metastatic melanomas; these tumor cells were strongly positive for Melan-A Red, except in one case of desmoplastic melanoma. All cases of nodal nevus showed uniformly retained nuclear expression of 5-hmC accompanied by strong Melan-A Red cytoplasmic staining. In two cases containing both nodal nevus and metastatic melanoma, all tumor cells were positive for Melan-A Red, but a nuclear expression of 5-hmC was selectively absent only in the melanoma tumor cells. CONCLUSION: Dual 5-hmC/Melan-A Red immunohistochemistry is highly specific in distinguishing nodal nevus from metastatic melanoma. Our protocol for brown and red chromogens used in this study provides excellent color contrast and is easy to interpret. Furthermore, this dual staining method allows the preservation of limited tumor tissue, which could be used for potential molecular studies.


Asunto(s)
5-Metilcitosina/análogos & derivados , Biomarcadores de Tumor/análisis , Metástasis Linfática/diagnóstico , Melanoma/diagnóstico , Nevo Pigmentado/diagnóstico , Ganglio Linfático Centinela/patología , Neoplasias Cutáneas/diagnóstico , 5-Metilcitosina/análisis , 5-Metilcitosina/biosíntesis , Diagnóstico Diferencial , Humanos , Inmunohistoquímica , Antígeno MART-1/análisis , Biopsia del Ganglio Linfático Centinela , Coloración y Etiquetado/métodos , Melanoma Cutáneo Maligno
16.
J Morphol ; 277(12): 1539-1558, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27577689

RESUMEN

Although the anuran pelvis is thought to be adapted for jumping, the function of the iliosacral joint has seen little direct study. Previous work has contrasted the basal "lateral-bender" pelvis from the "rod-like" pelvis of crown taxa hypothesized to function as a sagittal hinge to align the trunk with take-off forces. We compared iliosacral movements and pelvic motor patterns during jumping in the two pelvic types. Pelvic muscle activity patterns, iliosacral anteroposterior (AP) movements and sagittal bending of the pelvis during the take-off and landing phases were quantified in lateral bender taxa Ascaphus (Leiopelmatidae) and Rhinella (Bufonidae) and the rod-like Lithobates (Ranidae). All three species exhibit sagittal extension during take-off, therefore, both pelvic types employ a sagittal hinge. However, trunk elevation occurs significantly earlier in the anuran rod-like pelvis. Motor patterns confirm that the piriformis muscles depress the urostyle while the longissimus dorsi muscles elevate the trunk during take-off. However, the coccygeoiliacus muscles also produce anterior translation of the sacrum on the ilia. A new model illustrates how AP translation facilitates trunk extension in the lateral-bender anurans that have long been thought to have limited sagittal bending. During landing, AP translation patterns are similar because impact forces slide the sacrum from its posterior to anterior limits. Sagittal flexion during landing differs among the three taxa depending on the way the species land. AP translation during landing may dampen impact forces especially in Rhinella in which pelvic function is tuned to forelimb-landing dynamics. The flexibility of the lateral-bender pelvis to function in sagittal bending and AP translation helps to explain the retention of this basal configuration in many anurans. The novel function of the rod-like pelvis may be to increase the rate of trunk elevation relative to faster rates of energy release from the hindlimbs enabling them to jump farther. J. Morphol. 277:1539-1558, 2016. © 2016 Wiley Periodicals, Inc.


Asunto(s)
Anuros/fisiología , Ilion/fisiología , Locomoción/fisiología , Actividad Motora/fisiología , Pelvis/fisiología , Rango del Movimiento Articular , Sacro/fisiología , Animales , Fenómenos Biomecánicos , Electromiografía , Músculo Esquelético/fisiología , Músculos/fisiología , Especificidad de la Especie
17.
J Morphol ; 277(3): 379-93, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26711888

RESUMEN

Ancestral frogs underwent anatomical shifts including elongation of the hindlimbs and pelvis and reduction of the tail and vertebral column that heralded the transition to jumping as a primary mode of locomotion. Jumping has been hypothesized to have evolved in a step-wise fashion with basal frogs taking-off with synchronous hindlimb extension and crash-landing on their bodies, and then their limbs move forward. Subsequently, frogs began to recycle the forelimbs forward earlier in the jump to control landing. Frogs with forelimb landing radiated into many forms, locomotor modes, habitats, and niches with controlled landing thought to improve escape behavior. While the biology of take-off behavior has seen considerable study, interspecific comparisons of take-off and landing behavior are limited. In order to understand the evolution of jumping and controlled landing in frogs, data are needed on the movements of the limbs and body across an array of taxa. Here, we present the first description and comparison of kinematics of the hindlimbs, forelimbs and body during take-off and landing in relation to ground reaction forces in four frog species spanning the frog phylogeny. The goal of this study is to understand what interspecific differences reveal about the evolution of take-off and controlled landing in frogs. We provide the first comparative description of the entire process of jumping in frogs. Statistical comparisons identify both homologous behaviors and significant differences among species that are used to map patterns of trait evolution and generate hypotheses regarding the functional evolution of take-off and landing in frogs.


Asunto(s)
Especiación Genética , Locomoción , Ranidae/fisiología , Animales , Fenómenos Biomecánicos , Miembro Anterior/anatomía & histología , Miembro Anterior/fisiología , Miembro Posterior/anatomía & histología , Miembro Posterior/fisiología , Ranidae/clasificación , Ranidae/genética
18.
Ann Surg Oncol ; 23(Suppl 5): 9020-9027, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-16865592

RESUMEN

BACKGROUND: Positron emission tomography (PET) has become an invaluable part of patient evaluation in surgical oncology. PET is less than optimal for detecting lesions <1 cm, and the intraoperative localization of small PET-positive lesions can be challenging as a result of difficulties in surgical exposure. We undertook this investigation to assess the utility of a handheld high-energy gamma probe (PET-Probe) for intraoperative identification of 18F-deoxyglucose (FDG)-avid tumors. METHODS: Forty patients underwent a diagnostic whole-body FDG-PET scan for consideration for surgical exploration and resection. Before surgery, all patients received an intravenous injection of 7 to 10 mCi of FDG. At surgery, the PET-Probe was used to determine absolute counts per second at the known tumor site(s) demonstrated by whole-body PET and at adjacent normal tissue (at least 4 cm away from tumor-bearing sites). Tumor-to-background ratios were calculated. RESULTS: Thirty-two patients (80%) underwent PET-Probe-guided surgery with therapeutic intent in a recurrent or metastatic disease setting. Eight patients underwent surgery for diagnostic exploration. Anatomical locations of the PET-identified lesions were neck and supraclavicular (n = 8), axilla (n = 5), groin and deep iliac (n = 4), trunk and extremity soft tissue (n = 3), abdominal and retroperitoneal (n = 19), and lung (n = 2). PET-Probe detected all PET-positive lesions. The PET-Probe was instrumental in localization of lesions in 15 patients that were not immediately apparent by surgical exploration. CONCLUSIONS: The PET-Probe identified all lesions demonstrated by PET scanning and, in selected cases, was useful in localizing FDG-avid disease not seen with conventional PET scanning.


Asunto(s)
Rayos gamma , Recurrencia Local de Neoplasia/diagnóstico por imagen , Recurrencia Local de Neoplasia/cirugía , Neoplasias/diagnóstico por imagen , Neoplasias/cirugía , Adolescente , Adulto , Anciano , Femenino , Fluorodesoxiglucosa F18 , Humanos , Periodo Intraoperatorio , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Neoplasias/patología , Tomografía de Emisión de Positrones , Estudios Prospectivos , Radiometría/instrumentación , Radiometría/métodos , Radiofármacos , Adulto Joven
19.
Behav Processes ; 121: 43-53, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26449314

RESUMEN

Movements and locomotor behaviour were studied in the most basal living frog family (Leiopelmatidae: Ascaphus+Leiopelmatidae), which includes two stream-dwelling species and several that have transitioned into terrestrial niches. These cryptic frogs remain immobile over 99.6% of the time above ground as they sit in wait of prey and only rarely use jumping to escape. Walking is their primary mode of locomotion. The two stream species, which are separated by deep time and extreme geographic distance, have nearly identical behavioural repertoires and locomotor performance, which included occasional jumping as a means to change foraging positions. The terrestrial species, one of which has become semi-arboreal, rarely jump in nature and rely on chemical and postural antipredator behaviours to avoid predation. If early frogs resembled leiopelmatids, they were not well versed in jumping. Locomotor behaviour and performance of leiopelmatid frogs do not support the hypothesis that frog jumping originally evolved primarily as a means to rapidly escape into water. Given the basal position of the leiopelmatids, the locomotor strategy of these cryptic, cold-adapted, belly-flopping anurans that usually walk may represent a successful initial step in the evolution of saltatorial locomotion in frogs.


Asunto(s)
Anuros/fisiología , Movimiento/fisiología , Conducta Predatoria/fisiología , Animales , Conducta Animal , Conducta Alimentaria , Locomoción/fisiología
20.
Ann Surg Oncol ; 18(13): 3593-600, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21647761

RESUMEN

BACKGROUND: Numerous predictive factors for cutaneous melanoma metastases to sentinel lymph nodes have been identified; however, few have been found to be reproducibly significant. This study investigated the significance of factors for predicting regional nodal disease in cutaneous melanoma using a large multicenter database. METHODS: Seventeen institutions submitted retrospective and prospective data on 3463 patients undergoing sentinel lymph node (SLN) biopsy for primary melanoma. Multiple demographic and tumor factors were analyzed for correlation with a positive SLN. Univariate and multivariate statistical analyses were performed. RESULTS: Of 3445 analyzable patients, 561 (16.3%) had a positive SLN biopsy. In multivariate analysis of 1526 patients with complete records for 10 variables, increasing Breslow thickness, lymphovascular invasion, ulceration, younger age, the absence of regression, and tumor location on the trunk were statistically significant predictors of a positive SLN. CONCLUSIONS: These results confirm the predictive significance of the well-established variables of Breslow thickness, ulceration, age, and location, as well as consistently reported but less well-established variables such as lymphovascular invasion. In addition, the presence of regression was associated with a lower likelihood of a positive SLN. Consideration of multiple tumor parameters should influence the decision for SLN biopsy and the estimation of nodal metastatic disease risk.


Asunto(s)
Melanoma/patología , Recurrencia Local de Neoplasia/patología , Biopsia del Ganglio Linfático Centinela , Adulto , Anciano , Femenino , Estudios de Seguimiento , Humanos , Metástasis Linfática , Masculino , Persona de Mediana Edad , Invasividad Neoplásica , Estadificación de Neoplasias , Pronóstico , Estudios Prospectivos , Estudios Retrospectivos
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