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1.
Can Urol Assoc J ; 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38587978

RESUMO

INTRODUCTION: Urologists observed reduced cancer consultations and surgeries during the SARS-CoV-2 pandemic, raising concern about treatment delays. Testicular cancer serves as a particularly sensitive marker of this phenomenon, as the clinical stage of testicular cancer at presentation is predictive of cancer-specific survival. We aimed to investigate whether COVID-related restrictions to primary care access resulted in increased incidence of metastatic germ cell testis cancer. METHODS: A retrospective chart review was conducted on all cases of testicular cancer managed surgically at our center from March 1, 2018, to February 28, 2023. Patients were categorized into temporal cohorts, representing before, during, and following the implementation of COVID-19 public health restrictions in the province of Newfoundland and Labrador. RESULTS: Forty-one cases of testicular germ cell tumors were identified during the study period. The mean age at diagnosis was 40.8 years (standard deviation ±13.7). Demographics did not vary across the cohorts. Clinical stage 3 disease remained stable before and during the pandemic at 10.5% and 9.1% of cases, respectively. In the post-pandemic period, there was an increase to 27.3% (p=0.617). Surgical wait times remained stable across the pandemic (p=0.151). CONCLUSIONS: There was a 16.8% rise in clinical stage III disease from the pre-pandemic to post-pandemic period. Our study failed to identify a statistically significant increase in metastatic testis cancer incidence upon lifting of pandemic restrictions. Further study is necessary to confirm suspicions that pandemic restrictions contributed to increased incidence of metastatic testis cancer.

2.
Can Urol Assoc J ; 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38587981

RESUMO

INTRODUCTION: A variety of procedures for the endoscopic surgical treatment of symptomatic benign prostatic hyperplasia (BPH) refractory to medical therapy have existed for decades. The present study examines trends in surgeon compensation for these treatments within Canada. METHODS: The physician fee schedule for BPH surgery across 10 Canadian provinces for the years 2010 and 2023 were obtained. A descriptive study examining first, the provincial reimbursement for transurethral resection of prostate (TURP) and laser ablative/enucleation surgery; second, the difference in TURP reimbursement between 2010 and 2023; and third, the annual change in TURP reimbursement juxtaposed with the annual change in the provincial Consumer Price Index (CPI) and annual salary for the working population aged 35-44. RESULTS: Seven of 10 Canadian provinces reimburse laser BPH surgery equally to TURP. The average provincial TURP reimbursement is $545, ranging from $451 in Ontario to $688 in Saskatchewan. Since 2010, TURP reimbursement has varied by province from a 0% net change in Ontario to an increase of 21% in Nova Scotia. Reimbursement for TURP has increased at a slower pace than the local CPI, and for half of the provinces at a slower pace than the annual salary for people aged 35-44. CONCLUSIONS: The compensation model for endoscopic BPH surgery does not have a unified structure in Canada that is consistent across provinces, nor does it keep up with inflation, possibly impacting future recruitment, increasing geographic disparities, and most importantly, limiting the adoption of new BPH therapies.

3.
ACS Chem Neurosci ; 14(22): 3986-3992, 2023 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-37879091

RESUMO

Prohormone-derived neuropeptides act as cell-cell signaling molecules to mediate a wide variety of biological processes in the animal brain. Mass spectrometry-based peptidomic experiments are valuable approaches to gain insight into the dynamics of individual peptides under different physiological conditions or experimental treatments. However, the use of anesthetics during animal procedures may confound experimental peptide measurements, especially in the brain, where anesthetics act. Here, we investigated the effects of the commonly used anesthetics isoflurane and sodium pentobarbital on the peptide profile in the rodent hypothalamus and cerebral cortex, as assessed by label-free quantitative peptidomics. Our results showed that neither anesthetic dramatically alters peptide levels, although extended isoflurane exposure did cause changes in a small number of prohormone-derived peptides in the cerebral cortex. Overall, our results demonstrate that acute anesthetic administration can be utilized in peptidomic experiments of the hypothalamus and cerebral cortex without greatly affecting the measured peptide profiles.


Assuntos
Anestésicos , Isoflurano , Ratos , Animais , Anestésicos/farmacologia , Anestésicos/análise , Peptídeos/química , Hipotálamo/química , Córtex Cerebral
4.
Angew Chem Int Ed Engl ; 62(50): e202313063, 2023 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-37906440

RESUMO

Traditional approaches to bio-orthogonal reaction discovery have focused on developing reagent pairs that react with each other faster than they are metabolically degraded. Glutathione (GSH) is typically responsible for the deactivation of most bio-orthogonal reagents. Here we demonstrate that GSH promotes a Cu-catalysed (3+2) cycloaddition reaction between an ynamine and an azide. We show that GSH acts as a redox modulator to control the Cu oxidation state in these cycloadditions. Rate enhancement of this reaction is specific for ynamine substrates and is tuneable by the Cu:GSH ratio. This unique GSH-mediated reactivity gradient is then utilised in the dual sequential bio-orthogonal labelling of peptides and oligonucleotides via two distinct chemoselective (3+2) cycloadditions.


Assuntos
Glutationa , Peptídeos , Peptídeos/química , Azidas/química , Catálise , Reação de Cicloadição
5.
ACS Chem Neurosci ; 14(14): 2569-2581, 2023 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-37395621

RESUMO

During the winter, hibernating mammals undergo extreme changes in physiology, which allow them to survive several months without access to food. These animals enter a state of torpor, which is characterized by decreased metabolism, near-freezing body temperatures, and a dramatically reduced heart rate. The neurochemical basis of this regulation is largely unknown. Based on prior evidence suggesting that the peptide-rich hypothalamus plays critical roles in hibernation, we hypothesized that changes in specific cell-cell signaling peptides (neuropeptides and peptide hormones) underlie physiological changes during torpor/arousal cycles. To test this hypothesis, we used a mass spectrometry-based peptidomics approach to examine seasonal changes of endogenous peptides that occur in the hypothalamus and pituitary of a model hibernating mammal, the thirteen-lined ground squirrel (Ictidomys tridecemlineatus). In the pituitary, we observed changes in several distinct peptide hormones as animals prepared for torpor in October, exited torpor in March, and progressed from spring (March) to fall (August). In the hypothalamus, we observed an overall increase in neuropeptides in October (pre-torpor), a decrease as the animal entered torpor, and an increase in a subset of neuropeptides during normothermic interbout arousals. Notable changes were observed for feeding regulatory peptides, opioid peptides, and several peptides without well-established functions. Overall, our study provides critical insight into changes in endogenous peptides in the hypothalamus and pituitary during mammalian hibernation that were not available from transcriptomic measurements. Understanding the molecular basis of the hibernation phenotype may pave the way for future efforts to employ hibernation-like strategies for organ preservation, combating obesity, and treatment of stroke.


Assuntos
Hibernação , Neuropeptídeos , Hormônios Peptídicos , Animais , Estações do Ano , Hibernação/fisiologia , Transdução de Sinais , Hipotálamo , Mamíferos
6.
Can Urol Assoc J ; 17(5): E134-E140, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36758180

RESUMO

INTRODUCTION: Penile carcinomas represent a rare malignancy associated with significant psychosocial impacts that deter afflicted individuals from seeking medical attention, thus, worsening prognosis. Following the dramatic shift in healthcare delivery to virtual platforms, it is suspected that prevalent psychosocial impacts have been further compounded by the COVID-19 pandemic, resulting in several late-stage presentations and engendering poorer outcomes. METHODS: A retrospective chart review of surgically managed cases of penile cancer was conducted from January 2020 to June 2022 to identify patients that may have been unduly impacted by the COVID-19 pandemic. Included cases were analyzed in quantifying diagnostic and treatment delays, along with patient outcomes. Relevant epidemiological and pathological markers were also examined. RESULTS: Ten patients met the inclusion criteria. Average time delay from first complaint of a penile lesion to surgical management was 75 days, with 60% of patients experiencing a time delay of two months or more. The average delay from first complaint to diagnosis was 62 days in 2020 and 18 days in 2021. Advanced-stage disease was present in six (60%) individuals at presentation, while four (40%) patients perished during the study period. CONCLUSIONS: In cases of concern for penile malignancy, virtual care cannot replace the necessity of physical exams in preventing diagnostic and treatment delays. The present study further highlights the necessity of initial physical examination of penile abnormalities in preventing fatal outcomes for those afflicted. Such consideration warrants urgent examination of referred males with genital abnormalities to prevent further exacerbation of delays.

7.
ACS Chem Neurosci ; 13(19): 2888-2896, 2022 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-36126283

RESUMO

Cell-cell signaling peptides (e.g., peptide hormones, neuropeptides) are among the largest class of cellular transmitters and regulate a variety of physiological processes. To identify and quantify the relative abundances of cell-cell signaling peptides in different physiological states, liquid chromatography-mass spectrometry-based peptidomics workflows are commonly utilized on freshly dissected tissues. In such animal experiments, the administration of general anesthetics is an important step for many research projects. However, acute anesthetic administration may rapidly change the measured abundance of transmitter molecules and metabolites, especially in the brain and endocrine system, which would confound experimental results. The aim of this study was to evaluate the effect of short-term (<5 min) anesthetic administration on the measured abundance of cell-cell signaling peptides, as evaluated by a typical peptidomics workflow. To accomplish this goal, we compared endogenous peptide abundances in the rat pituitary following administration of 5% isoflurane, 200 mg/kg sodium pentobarbital, or no anesthetic administration. Label-free peptidomics analysis demonstrated that acute use of isoflurane changed the levels of a small number of peptides, primarily degradation products of the hormone somatotropin, but did not influence the levels of most other peptide hormones. Acute use of sodium pentobarbital had negligible impact on the relative abundance of all measured peptides. Overall, our results suggest that anesthetics used in pituitary peptidomics studies do not dramatically confound observed results.


Assuntos
Anestésicos Gerais , Isoflurano , Neuropeptídeos , Hormônios Peptídicos , Animais , Hormônio do Crescimento , Neuropeptídeos/análise , Neuropeptídeos/farmacologia , Pentobarbital , Ratos , Sódio
8.
Can Urol Assoc J ; 16(6): E315-E320, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35099383

RESUMO

INTRODUCTION: Targeted biopsy approaches have been shown to increase the detection of clinically significant prostate cancer (csPCa) within index prostate lesions. We report our initial experience with magnetic resonance imaging-ultrasound fusion biopsies (MRI-TB) in a population of men who had a previously negative transrectal ultrasound (TRUS) biopsy, persistent prostate-specific antigen (PSA) elevation, and ongoing suspicion of PCa. Patients were followed prospectively to assess for changes in clinical management following targeted biopsy. METHODS: We prospectively followed the first 122 patients undergoing MRI-TB at our institution. All men had clinical suspicion of PCa, prior negative TRUS biopsies, and persistent PSA elevation. A total of 177 index lesions were identified on multiparametric MRI and reviewed using the Prostate Imaging Reporting and Data System (PI-RADS) v2 scoring system. Lesions classified as PI-RADS ≥3 received targeted biopsy. Biopsy-naive patients and those on active surveillance were excluded. The primary outcome was detection rate of csPCa, defined as International Society of Urological Pathology (ISUP) Grade Group (GG) ≥2. Multivariate analysis was used to determine predictors of csPCa on fusion biopsy. RESULTS: Prior to fusion biopsy, patients had a mean of 17.9±8.6 negative core biopsies per patient and a median PSA of 9.5 (standard deviation [SD] 6.2) ng/nl. MRI-TB resulted in diagnosis of csPCa in 42/122 (34.4%) patients. Clinically significant PCa was found in eight (13.1%), 14 (21.9%), and 25 (48.1%) of PI-RADS 3, 4, and 5 lesions, respectively. The location of csPCa was within the peripheral zone (55.3%), transitional zone (40.4%), and central zone (8.5%). Clinical outcomes of patients with newly diagnosed csPCa show 4.8%, 57.1%, and 38.1% receiving active surveillance, radiation treatment, and radical prostatectomy, respectively. Predictors for csPCa were presence of PI-RADS 5 lesions, age, length of time from MRI to biopsy, and smaller prostate volumes. CONCLUSIONS: MRI-TB yields high detection rates for csPCa in men with elusive PSA elevation and frequently guides a change in clinical management. Clinical decision-making based on MRI findings and PI-RADS lesion scores are best informed by an understanding of institutional reporting patterns.

9.
Front Chem ; 7: 204, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31024892

RESUMO

Gas-phase reaction of 1,3-dithiolane-2-thione over molybdenum trioxide supported on pumice stone results in efficient conversion into 1,3-dithiolan-2-one. The solid reagent is regenerated on exposure to air and thus acts as a catalyst for the overall conversion of the thione and oxygen from the air into the ketone and sulfur dioxide. The process can be carried out under either dynamic vacuum or atmospheric pressure flow conditions and using a solid reagent prepared either by physical mixing of MoO3 with the support or by solution impregnation, with an isolated yield of up to 67% obtained.

10.
J Comp Physiol B ; 187(5-6): 769-778, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28324159

RESUMO

A small-volume (1 ml/kg) resuscitation fluid based on metabolic adaptations in hibernating mammals was optimized using a rat model of hemorrhagic shock. A previous study of this therapy tested only one concentration of three specific components: 4 M D-stereoisomer of beta-hydroxybutyrate (BHB), 43 mM melatonin, and 20% DMSO. In this study, we considered the range of concentrations of BHB and melatonin seen during the physiological extremes of rapid arousal from hypothermic torpor in natural hibernators and applied these to the non-hibernating Sprague-Dawley rat model. These extremes normally result in ischemia and reperfusion injury in non-hibernating mammals. Dose-ranging studies were conducted for BHB and melatonin in rats with 60% blood loss. BHB was administered at either 4, 2, or 0.4 M concentration in conjunction with 4.3 mM melatonin and 10% DMSO. Subsequently, melatonin was administered at either 4.3, 0.43, 0.0043, 0.000043, or 0 mM in conjunction with 4 M BHB and 2% DMSO. 10-day mean survival showed a dose-dependent trend: rats survived longer with higher concentration of infused BHB (4 M BHB, 7.38 ± 1.75 days; 2 M BHB, 5.25 ± 2.22 days; 0.4 M BHB, 2.07 ± 2.05 days). Administering 4 M BHB without melatonin resulted in low mean survival times (4.38 ± 1.42 days). All treatments containing both 4 M BHB and melatonin, regardless of melatonin concentration, resulted in mean survival times of ~7.5 days. We conclude there is a dose-dependent trend in which higher BHB concentration resulted in improved survival over 10 days.


Assuntos
Ácido 3-Hidroxibutírico/uso terapêutico , Melatonina/uso terapêutico , Choque Hemorrágico/terapia , Animais , Dimetil Sulfóxido/uso terapêutico , Hidratação , Hibernação , Masculino , Ratos Sprague-Dawley , Ressuscitação
11.
Physiol Genomics ; 48(7): 513-25, 2016 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-27207617

RESUMO

Mammalian hibernators adapt to prolonged periods of immobility, hypometabolism, hypothermia, and oxidative stress, each capable of reducing bone marrow activity. In this study bone marrow transcriptomes were compared among thirteen-lined ground squirrels collected in July, winter torpor, and winter interbout arousal (IBA). The results were consistent with a suppression of acquired immune responses, and a shift to innate immune responses during hibernation through higher complement expression. Consistent with the increase in adipocytes found in bone marrow of hibernators, expression of genes associated with white adipose tissue are higher during hibernation. Genes that should strengthen the bone by increasing extracellular matrix were higher during hibernation, especially the collagen genes. Finally, expression of heat shock proteins were lower, and cold-response genes were higher, during hibernation. No differential expression of hematopoietic genes involved in erythrocyte or megakaryocyte production was observed. This global view of the changes in the bone marrow transcriptome over both short term (torpor vs. IBA) and long term (torpor vs. July) hypothermia can explain several observations made about circulating blood cells and the structure and strength of the bone during hibernation.


Assuntos
Hibernação/genética , Sciuridae/fisiologia , Transcriptoma/genética , Imunidade Adaptativa/genética , Adipócitos/metabolismo , Tecido Adiposo Branco/metabolismo , Animais , Nível de Alerta/genética , Medula Óssea/metabolismo , Eritrócitos/metabolismo , Matriz Extracelular/metabolismo , Proteínas de Choque Térmico , Imunidade Inata/genética , Mamíferos/genética , Mamíferos/metabolismo , Megacariócitos/metabolismo , Sciuridae/metabolismo , Estações do Ano , Torpor/genética
12.
Am J Physiol Regul Integr Comp Physiol ; 309(4): R368-77, 2015 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-26017496

RESUMO

The hearts of mammalian hibernators maintain contractile function in the face of severe environmental stresses during winter heterothermy. To enable survival in torpor, hibernators regulate the expression of numerous genes involved in excitation-contraction coupling, metabolism, and stress response pathways. Understanding the basis of this transition may provide new insights into treatment of human cardiac disease. Few studies have investigated hibernator heart performance during both summer active and winter torpid states, and seasonal comparisons of whole heart function are generally lacking. We investigated the force-frequency relationship and the response to ex vivo ischemia-reperfusion in intact isolated hearts from 13-lined ground squirrels (Ictidomys tridecemlineatus) in the summer (active, July) and winter (torpid, January). In standard euthermic conditions, we found that winter hearts relaxed more rapidly than summer hearts at low to moderate pacing frequencies, even though systolic function was similar in both seasons. Proteome data support the hypothesis that enhanced Ca(2+) handling in winter torpid hearts underlies the increased relaxation rate. Additionally, winter hearts developed significantly less rigor contracture during ischemia than summer hearts, while recovery during reperfusion was similar in hearts between seasons. Winter torpid hearts have an increased glycogen content, which likely reduces development of rigor contracture during the ischemic event due to anaerobic ATP production. These cardioprotective mechanisms are important for the hibernation phenotype and highlight the resistance to hypoxic stress in the hibernator.


Assuntos
Metabolismo Energético , Hibernação , Contração Miocárdica , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miocárdio/metabolismo , Sciuridae/metabolismo , Função Ventricular Esquerda , Adaptação Fisiológica , Trifosfato de Adenosina/metabolismo , Animais , Sinalização do Cálcio , Estimulação Cardíaca Artificial , Modelos Animais de Doenças , Feminino , Glicogênio/metabolismo , Masculino , Proteínas Musculares/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Fenótipo , Proteômica/métodos , Estações do Ano , Fatores de Tempo , Pressão Ventricular
13.
J Med Imaging Radiat Oncol ; 59(2): 200-3, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25043535

RESUMO

Subcutaneous venous port or 'portacath' devices are widely used, especially in oncology patients. Several potential complications of portacath devices have been well documented. We report a rare case of the spontaneous migration of the tip of a portacath into the azygos vein, with subsequent development of a tracheo-azygos fistula. This resulted in the patient receiving a dose of chemotherapy agent and saline directly into his lungs, which ultimately contributed to his death a few weeks later. To our knowledge, there have been only 10 previously reported cases of inadvertent intrathoracic (mediastinal, pleural or pulmonary) extravasation of chemotherapy agent as a result of central venous catheter malposition or perforation; this is the second reported case of extravasation of chemotherapy agent as a result of migration of a portacath device into the azygos vein.


Assuntos
Antineoplásicos/efeitos adversos , Veia Ázigos/anormalidades , Migração de Corpo Estranho/etiologia , Pneumonia Aspirativa/induzido quimicamente , Dispositivos de Acesso Vascular/efeitos adversos , Fístula Vascular/etiologia , Idoso , Antineoplásicos/administração & dosagem , Veia Ázigos/diagnóstico por imagem , Diagnóstico Diferencial , Extravasamento de Materiais Terapêuticos e Diagnósticos/diagnóstico , Extravasamento de Materiais Terapêuticos e Diagnósticos/etiologia , Evolução Fatal , Humanos , Masculino , Pneumonia Aspirativa/diagnóstico por imagem , Veia Porta/diagnóstico por imagem , Radiografia , Traqueia/irrigação sanguínea , Falha de Tratamento , Resultado do Tratamento , Fístula Vascular/diagnóstico
14.
PLoS One ; 8(1): e53574, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23301087

RESUMO

Hibernation is a natural adaptation that allows certain mammals to survive physiological extremes that are lethal to humans. Near freezing body temperatures, heart rates of 3-10 beats per minute, absence of food consumption, and depressed metabolism are characteristic of hibernation torpor bouts that are periodically interrupted by brief interbout arousals (IBAs). The molecular basis of torpor induction is unknown, however starved mice overexpressing the metabolic hormone fibroblast growth factor 21 (FGF21) promote fat utilization, reduce body temperature, and readily enter torpor-all hallmarks of mammalian hibernation. In this study we cloned FGF21 from the naturally hibernating thirteen-lined ground squirrel (Ictidomys tridecemlineatus) and found that levels of FGF21 mRNA in liver and FGF21 protein in serum are elevated during hibernation torpor bouts and significantly elevated during IBAs compared to summer active animals. The effects of artificially elevating circulating FGF21 concentrations 50 to 100-fold via adenoviral-mediated overexpression were examined at three different times of the year. This is the first time that a transgenic approach has been used in a natural hibernator to examine mechanistic aspects of hibernation. Surgically implanted transmitters measured various metrics of the hibernation phenotype over a 7-day period including changes in motor activity, heart rate and core body temperature. In April fed-state animals, FGF21 overexpression decreased blood insulin and free fatty acid concentrations, effects similar to those seen in obese mice. However, elevated FGF21 concentrations did not cause torpor in these fed-state animals nor did they cause torpor or affect metabolic parameters in fasted-state animals in March/April, August or October. We conclude that FGF21 is strongly regulated during torpor and IBA but that its overexpression is not sufficient to cause torpor in naturally hibernating ground squirrels.


Assuntos
Fatores de Crescimento de Fibroblastos/metabolismo , Regulação da Expressão Gênica , Hibernação , Sciuridae/metabolismo , Adipócitos/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Temperatura Corporal , Meios de Cultivo Condicionados/farmacologia , DNA Complementar/metabolismo , Frequência Cardíaca , Dados de Sequência Molecular , RNA Mensageiro/metabolismo , Estações do Ano , Homologia de Sequência de Aminoácidos
15.
J Trauma Acute Care Surg ; 73(4): 809-17, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23026915

RESUMO

OBJECTIVE: The hypothermia and hemostasis in severe trauma (HYPOSTAT): a new crossroads workshop was convened to evaluate the interplay among hypothermia, hemostasis, and severe trauma/hemorrhage. Trauma is the major cause of death in young individuals in the United States, with uncontrolled hemorrhage representing the major cause of preventable deaths. DATA SOURCES: This workshop organized by the National Heart, Lung, and Blood Institute and the US Army Medical Research and Material Command as a forum for exchange of ideas among experts from diverse fields. The specific workshop goals were to (1) identify state-of-the-art and needs in knowledge of biology of hypothermia and hemostasis in the setting of significant traumatic injury; (2) provide an interdisciplinary forum to enhance knowledge regarding early detection of traumatic shock and monitoring of the level and effect of controlled hypothermia in severe trauma settings; and (3) identify future research directions of the role of therapeutic-oriented hypothermia and hemostasis in trauma with severe blood loss. STUDY SELECTION: Not applicable. DATA EXTRACTION: Expert opinion and literature review. CONCLUSION: This document provides a summary of the expert opinion and highlights the recommendations that came out of the discussions at this workshop to guide scientific efforts in basic, translational, and clinical research in this area.


Assuntos
Pesquisa Biomédica , Hemorragia/etiologia , Hemostasia , Hipotermia/etiologia , Ferimentos e Lesões/complicações , Hemorragia/sangue , Humanos , Hipotermia/sangue , Índices de Gravidade do Trauma , Ferimentos e Lesões/sangue , Ferimentos e Lesões/diagnóstico
16.
J Neurochem ; 101(6): 1505-15, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17437538

RESUMO

The brain of a hibernating mammal withstands physiological extremes that would result in cerebral damage and death in a non-hibernating species such as humans. To examine the possibility that this neuroprotection results from alterations in cerebral metabolism, we used in vivo(1)H NMR spectroscopy at high field (9.4 T) to measure the concentration of 18 metabolites (neurochemical profile) in the brain of 13-lined ground squirrels (Spermophilus tridecemlineatus) before, during, and after hibernation. Resolved in vivo(1)H NMR spectra were obtained even at low temperature in torpid hibernators ( approximately 7 degrees C). The phosphocreatine-to-creatine ratio was increased during torpor (+143%) indicating energy storage, and remained increased to a lesser extent during interbout arousal (IBA) (+83%). The total gamma-aminobutyric acid concentration was increased during torpor (+135%) and quickly returned to baseline during IBA. Glutamine (Gln) was decreased (-54%) during torpor but quickly returned to normal levels during IBA and after terminal arousal in the spring. Glutamate (Glu) was also decreased during torpor (-17%), but remained decreased during IBA (-20% compared with fall), and returned to normal level in the spring. Our observation that Glu and Gln levels are depressed in the brain of hibernators suggests that the balance between anaplerosis and loss of Glu and Gln (because of glutamatergic neurotransmission or other mechanisms) is altered in hibernation.


Assuntos
Encéfalo/metabolismo , Metabolismo Energético/fisiologia , Hibernação/fisiologia , Sciuridae/fisiologia , Transmissão Sináptica/fisiologia , Animais , Ácido Ascórbico/metabolismo , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Química Encefálica , Colina/metabolismo , Temperatura Baixa , Creatina/metabolismo , Etanolaminas/metabolismo , Glucose/metabolismo , Ácido Glutâmico/metabolismo , Glutamina/metabolismo , Glutationa/metabolismo , Inositol/metabolismo , Ácido Láctico/metabolismo , Espectroscopia de Ressonância Magnética , Fosfocreatina/metabolismo , Taurina/metabolismo , Ácido gama-Aminobutírico/metabolismo
17.
Biochem J ; 403(3): 409-20, 2007 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-17223797

RESUMO

Bacterial infection triggers an acute inflammatory response that might alter phospholipid metabolism. We have investigated the acute-phase response of murine lung epithelia to Pseudomonas aeruginosa infection. Ps. aeruginosa triggered secretion of the pro-inflammatory lipase, sPLA2 IB (phospholipase A2 IB), from lung epithelium. Ps. aeruginosa and sPLA2 IB each stimulated basolateral PtdCho (phosphatidylcholine) efflux in lung epithelial cells. Pre-treatment of cells with glyburide, an inhibitor of the lipid-export pump, ABCA1 (ATP-binding cassette transporter A1), attenuated Ps. aeruginosa and sPLA2 IB stimulation of PtdCho efflux. Effects of Ps. aeruginosa and sPLA2 IB were completely abolished in human Tangier disease fibroblasts, cells that harbour an ABCA1 genetic defect. Ps. aeruginosa and sPLA2 IB induced the heterodimeric receptors, PPARa (peroxisome-proliferator-activated receptor-a) and RXR (retinoid X receptor), factors known to modulate ABCA1 gene expression. Ps. aeruginosa and sPLA2 IB stimulation of PtdCho efflux was blocked with PD98059, a p44/42 kinase inhibitor. Transfection with MEK1 (mitogen-activated protein kinase/extracellular-signal-regulated kinase kinase 1), a kinase upstream of p44/42, increased PPARa and RXR expression co-ordinately with increased ABCA1 protein. These results suggest that pro-inflammatory effects of Ps. aeruginosa involve release of an sPLA2 of epithelial origin that, in part, via distinct signalling molecules, transactivates the ABCA1 gene, leading to export of phospholipid.


Assuntos
Transportadores de Cassetes de Ligação de ATP/fisiologia , MAP Quinases Reguladas por Sinal Extracelular/fisiologia , PPAR alfa/fisiologia , Fosfatidilcolinas/metabolismo , Fosfolipases A/fisiologia , Infecções por Pseudomonas/fisiopatologia , Receptores X de Retinoides/fisiologia , Transportador 1 de Cassete de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Animais , Células Cultivadas , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Flavonoides/farmacologia , Glibureto/farmacologia , Fosfolipases A2 do Grupo IB , Humanos , Pulmão/metabolismo , MAP Quinase Quinase 1/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fosfolipases A/metabolismo , Fosfolipases A2 , Pseudomonas aeruginosa , Doença de Tangier/fisiopatologia , Transfecção , Regulação para Cima
18.
Arch Biochem Biophys ; 447(1): 23-33, 2006 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-16466687

RESUMO

CTP:phosphocholine cytidylyltransferase (CCTalpha) is a rate-regulatory enzyme required for phosphatidylcholine (PtdCho) synthesis. CCTalpha is also a phosphoenzyme, but the physiologic role of kinases on enzyme function remains unclear. We report high-level expression of two major isoforms of the c-Jun N-terminal kinase family (JNK1 and JNK2) in murine lung epithelia. Further, JNK1 and JNK2 phosphorylated purified CCTalpha in vitro, and this was associated with a dose-dependent decrease (approximately 40%) in CCT activity. To evaluate JNK in vivo, lung epithelial cells were infected with a replication defective adenoviral vector encoding murine JNK2 (Adv-JNK2) or an empty vector. Adv-JNK2 infection, unlike the empty vector, markedly increased JNK2 expression concomitant with increased incorporation of [32P]orthophosphate into endogenous CCTalpha. Although Adv-JNK2 infection only modestly reduced CCT activity, it reduced PtdCho synthesis by approximately 30% in cells. These observations suggest a role for JNK kinases as negative regulators of phospholipid synthesis in murine lung epithelia.


Assuntos
Colina-Fosfato Citidililtransferase/metabolismo , Regulação Enzimológica da Expressão Gênica/fisiologia , Pulmão/enzimologia , Proteína Quinase 8 Ativada por Mitógeno/metabolismo , Proteína Quinase 9 Ativada por Mitógeno/metabolismo , Mucosa Respiratória/enzimologia , Animais , Linhagem Celular , Coenzimas/metabolismo , Pulmão/citologia , Camundongos
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