Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 242
Filtrar
1.
J Dairy Sci ; 102(4): 3569-3583, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30738665

RESUMO

Lipopolysaccharide (LPS) administration causes immunoactivation, which negatively affects production and fertility, but experimental exposure via an acute bolus is unlikely to resemble natural infections. Thus, the objectives were to characterize effects of chronic endotoxemia on production parameters and follicular development in estrous-synchronized lactating cows. Eleven Holstein cows (169 ± 20 d in milk; 681 ± 16 kg of body weight) were acclimated to their environmental surroundings for 3 d and then enrolled in 2 experimental periods (P). During P1 (3 d) cows consumed feed ad libitum and baseline samples were obtained. During P2 (7 d), cows were assigned to continuous infusion of either (1) saline-infused and pair-fed (CON-PF; 40 mL/h of saline i.v.; n = 5) or (2) LPS infused and ad libitum fed (LPS-AL; Escherichia coli O55:B5; 0.017, 0.020, 0.026, 0.036, 0.055, 0.088, and 0.148 µg/kg of body weight/h i.v. on d 1 to 7, respectively; n = 6). Controls were pair-fed to the LPS-AL group to eliminate confounding effects of dissimilar nutrient intake. Infusing LPS temporally caused mild hyperthermia on d 1 to 3 (+0.49°C) relative to baseline. Dry matter intake of LPS-AL cows decreased (28%) on d 1 of P2, then progressively returned to baseline. Relative to baseline, milk yield from LPS-AL cows was decreased on d 1 of P2 (12%). No treatment differences were observed in milk yield during P2. Follicular growth, dominant follicle size, serum progesterone (P4), and follicular P4 and 17ß-estradiol concentrations were similar between treatments. Serum 17ß-estradiol tended to increase (115%) and serum amyloid A and LPS-binding protein were increased (118 and 40%, respectively) in LPS-AL relative to CON-PF cows. Compared with CON-PF, neutrophils in LPS-AL cows were initially increased (45%), then gradually decreased. In contrast, monocytes were initially decreased (40%) and progressively increased with time in the LPS-AL cows. Hepatic mRNA abundance of cytochrome P450 family 2 subfamily C (CYP2C) or CYP3A was not affected by LPS, nor was there a treatment effect on toll-like receptor 4 or LBP; however, acyloxyacyl hydrolase and RELA subunit of nuclear factor kappa B tended to be increased in LPS-AL cows. These data suggest lactating dairy cows become tolerant to chronic and exponentially increasing LPS infusion in terms of production and reproductive parameters.


Assuntos
Bovinos , Endotoxemia/veterinária , Lipopolissacarídeos/farmacologia , Folículo Ovariano/efeitos dos fármacos , Saúde Reprodutiva , Animais , Dieta/veterinária , Endotoxemia/fisiopatologia , Estradiol/sangue , Estro , Feminino , Fertilidade , Lactação , Fígado/metabolismo , Leite , Folículo Ovariano/metabolismo
2.
J Dairy Sci ; 102(4): 3584-3597, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30660419

RESUMO

Experimental objectives of this study were to characterize the systemic and intracellular metabolic response to continuous lipopolysaccharide (LPS) infusion in mid-lactation Holstein cows (169 ± 20 d in milk; 681 ± 16 kg of body weight). Following 3 d of acclimation, cows were enrolled in 2 experimental periods (P). During P1 (3 d), cows were fed ad libitum and baseline data were collected. In P2 (8 d), cows were assigned to 1 of 2 treatments: (1) saline-infused and pair-fed (CON-PF; i.v. sterile saline at 40 mL/h; n = 5) or (2) LPS-infused and fed ad libitum (LPS-AL; Escherichia coli O55:B5 at 0.017, 0.020, 0.026, 0.036, 0.055, 0.088, 0.148, and 0.148 µg/kg of body weight per hour for d 1 through 8, respectively; n = 6). During P2, CON-PF cows were pair-fed to LPS-AL cows to eliminate confounding effects of dissimilar nutrient intake. Blood samples were collected on d 1 and 2 of P1 and d 1, 3, 5, and 7 of P2. Following the P2 d 7 a.m. milking, adipose tissue, skeletal muscle, and liver biopsies were collected for reverse transcription quantitative PCR and Western blot analysis. To assess whole-body nutrient trafficking, an i.v. glucose tolerance test (GTT) was performed following the a.m. milking on P2 d 8; 4 h after the GTT, cows received an epinephrine challenge. During P2, there were no treatment differences in circulating glucose. Relative to P1, CON-PF cows had or tended to have decreased plasma ß-hydroxybutyrate and insulin (29 and 47%, respectively) during P2, whereas neither variable changed in LPS-AL cows, leading to an overall increase in ß-hydroxybutyrate and insulin (41 and 140%, respectively) relative to CON-PF cows. Circulating nonesterified fatty acids were increased from d 1 to 3 and subsequently decreased from d 3 to 7 in cows from both treatments. Blood urea nitrogen gradually decreased in CON-PF cows and increased in LPS-AL cows from d 1 to 5 of P2, resulting in an overall 25% increase in LPS-AL versus CON-PF cows. In response to the GTT, the glucose and insulin area under the curve were increased 33 and 56%, respectively, in LPS-AL compared with CON-PF cows; changes reflective of whole-body insulin resistance. However, protein abundance of insulin signaling markers within muscle, liver, and adipose tissue were similar between treatments. There were no observable treatment differences in the glucose or nonesterified fatty acids response to the epinephrine challenge. No treatment differences were observed in hepatic mRNA abundance of key gluconeogenic or lipid export enzymes. In conclusion, chronic LPS exposure altered multiple parameters of basal and stimulated metabolism, but did not appear to affect the molecular machinery evaluated herein.


Assuntos
Bovinos/metabolismo , Lactação , Lipopolissacarídeos/farmacologia , Ácido 3-Hidroxibutírico/sangue , Animais , Glicemia/metabolismo , Peso Corporal , Bovinos/sangue , Dieta , Ácidos Graxos não Esterificados/sangue , Feminino , Gluconeogênese , Teste de Tolerância a Glucose/veterinária , Insulina/sangue , Resistência à Insulina , Fígado , Leite
3.
Reproduction ; 155(4): R169-R181, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29363567

RESUMO

Endotoxemia can be caused by obesity, environmental chemical exposure, abiotic stressors and bacterial infection. Circumstances that deleteriously impact intestinal barrier integrity can induce endotoxemia, and controlled experiments have identified negative impacts of lipopolysaccharide (LPS; an endotoxin mimetic) on folliculogenesis, puberty onset, estrus behavior, ovulation, meiotic competence, luteal function and ovarian steroidogenesis. In addition, neonatal LPS exposures have transgenerational female reproductive impacts, raising concern about early life contacts to this endogenous reproductive toxicant. Aims of this review are to identify physiological stressors causing endotoxemia, to highlight potential mechanism(s) by which LPS compromises female reproduction and identify knowledge gaps regarding how acute and/or metabolic endotoxemia influence(s) female reproduction.


Assuntos
Endotoxemia/etiologia , Endotoxinas/efeitos adversos , Reprodução/efeitos dos fármacos , Animais , Feminino , Humanos
4.
J Dairy Sci ; 101(6): 5515-5530, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29550130

RESUMO

Activated immune cells are insulin sensitive and utilize copious amounts of glucose. Because chromium (Cr) increases insulin sensitivity and may be immunomodulatory, our objective was to evaluate the effect of supplemental Cr (KemTrace Cr propionate, 20 g/d; Kemin Industries Inc., Des Moines, IA) on immune system glucose utilization and immune system dynamics following an intravenous endotoxin challenge in lactating Holstein cows. Twenty cows (320 ± 18 d in milk) were randomly assigned to 1 of 4 treatments: (1) pair-fed (PF) control (PF-CON; 5 mL of saline; n = 5), (2) PF and Cr supplemented (PF-Cr; 5 mL of saline; n = 5), (3) lipopolysaccharide (LPS)-euglycemic clamp and control supplemented (LPS-CON; 0.375 µg/kg of body weight LPS; n = 5), and (4) LPS-euglycemic clamp and Cr supplemented (LPS-Cr; 0.375 µg/kg of body weight LPS; n = 5). The experiment was conducted serially in 3 periods (P). During P1 (3 d), cows received their respective dietary treatments and baseline values were obtained. At the initiation of P2 (2 d), either a 12-h LPS-euglycemic clamp was conducted or cows were PF to their respective dietary counterparts. During P3 (3 d), cows consumed feed ad libitum and continued to receive their respective dietary treatment. During P2, LPS administration decreased dry matter intake (DMI; 40%) similarly among diets, and by experimental design the pattern and magnitude of reduced DMI were similar in the PF cohorts. During P3, LPS-Cr cows tended to have decreased DMI (6%) relative to LPS-CON cows. Relative to controls, milk yield from LPS-challenged cows decreased (58%) during P2 and LPS-Cr cows produced less (16%) milk than LPS-CON cows. During P3, milk yield progressively increased similarly in LPS-administered cows, but overall milk yield remained decreased (24%) compared with PF controls. There were no dietary treatment differences in milk yield during P3. Circulating insulin increased 9- and 15-fold in LPS-administered cows at 6 and 12 h postbolus, respectively, compared with PF controls. Compared with LPS-CON cows, circulating insulin in LPS-Cr cows was decreased (48%) at 6 h postbolus. Relative to PF cows, circulating LPS binding protein and serum amyloid A from LPS-administered cows increased 2- and 5-fold, respectively. Compared with PF cows, blood neutrophil counts in LPS-infused cows initially decreased, then gradually increased 163%. Between 18 and 48 h postbolus, the number of neutrophils was increased (12%) in LPS-Cr versus LPS-CON cows. The 12-h total glucose deficit was 220 and 1,777 g for the PF and LPS treatments, respectively, but glucose utilization following immune activation was not influenced by Cr. In summary, supplemental Cr reduced the insulin response and increased circulating neutrophils following an LPS challenge but did not appear to alter the immune system's glucose requirement following acute and intense activation.


Assuntos
Glicemia/metabolismo , Bovinos/imunologia , Cromo/farmacologia , Lactação , Leucócitos/imunologia , Ração Animal , Animais , Dieta , Metabolismo Energético/efeitos dos fármacos , Metabolismo Energético/fisiologia , Feminino , Leite
5.
J Dairy Sci ; 100(11): 9402-9417, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28918138

RESUMO

Inadequate feed consumption reduces intestinal barrier function in both ruminants and monogastrics. Objectives were to characterize how progressive feed restriction (FR) affects inflammation, metabolism, and intestinal morphology, and to investigate if glucagon-like peptide 2 (GLP2) administration influences the aforementioned responses. Twenty-eight Holstein cows (157 ± 9 d in milk) were enrolled in 2 experimental periods. Period 1 [5 d of ad libitum (AL) feed intake] served as baseline for period 2 (5 d), during which cows received 1 of 6 treatments: (1) 100% of AL feed intake (AL100; n = 3), (2) 80% of AL feed intake (n = 5), (3) 60% of AL feed intake (n = 5), (4) 40% of AL feed intake (AL40; n = 5), (5) 40% of AL feed intake + GLP2 administration (AL40G; 75 µg/kg of BW s.c. 2×/d; n = 5), or (6) 20% of AL feed intake (n = 5). As the magnitude of FR increased, body weight and milk yield decreased linearly. Blood urea nitrogen and insulin decreased, whereas nonesterified fatty acids and liver triglyceride content increased linearly with progressive FR. Circulating endotoxin, lipopolysaccharide binding protein, haptoglobin, serum amyloid A, and lymphocytes increased or tended to increase linearly with advancing FR. Circulating haptoglobin decreased (76%) and serum amyloid A tended to decrease (57%) in AL40G relative to AL40 cows. Cows in AL100, AL40, and AL40G treatments were euthanized to evaluate intestinal histology. Jejunum villus width, crypt depth, and goblet cell area, as well as ileum villus height, crypt depth, and goblet cell area, were reduced (36, 14, 52, 22, 28, and 25%, respectively) in AL40 cows compared with AL100 controls. Ileum cellular proliferation tended to be decreased (14%) in AL40 versus AL100 cows. Relative to AL40, AL40G cows had improved jejunum and ileum morphology, including increased villus height (46 and 51%), villus height to crypt depth ratio (38 and 35%), mucosal surface area (30 and 27%), cellular proliferation (43 and 36%), and goblet cell area (59 and 41%). Colon goblet cell area was also increased (48%) in AL40G relative to AL40 cows. In summary, progressive FR increased circulating markers of inflammation, which we speculate is due to increased intestinal permeability as demonstrated by changes in intestinal architecture. Furthermore, GLP2 improved intestinal morphology and ameliorated circulating markers of inflammation. Consequently, FR is a viable model to study consequences of intestinal barrier dysfunction and administering GLP2 appears to be an effective mitigation strategy to improve gut health.


Assuntos
Bovinos/fisiologia , Privação de Alimentos , Peptídeo 2 Semelhante ao Glucagon/farmacologia , Inflamação/veterinária , Intestinos/efeitos dos fármacos , Animais , Biomarcadores/sangue , Peso Corporal , Bovinos/sangue , Dieta/veterinária , Ácidos Graxos não Esterificados/sangue , Feminino , Inflamação/sangue , Inflamação/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Intestinos/fisiologia , Lactação , Leite
6.
J Dairy Sci ; 100(5): 4113-4127, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28342610

RESUMO

Study objectives were to evaluate the effects of intentionally reduced intestinal barrier function on productivity, metabolism, and inflammatory indices in otherwise healthy dairy cows. Fourteen lactating Holstein cows (parity 2.6 ± 0.3; 117 ± 18 d in milk) were enrolled in 2 experimental periods. Period 1 (5 d) served as the baseline for period 2 (7 d), during which cows received 1 of 2 i.v. treatments twice per day: sterile saline or a gamma-secretase inhibitor (GSI; 1.5 mg/kg of body weight). Gamma-secretase inhibitors reduce intestinal barrier function by inhibiting crypt cell differentiation into absorptive enterocytes. During period 2, control cows receiving sterile saline were pair-fed (PF) to the GSI-treated cows, and all cows were killed at the end of period 2. Administering GSI increased goblet cell area 218, 70, and 28% in jejunum, ileum, and colon, respectively. In the jejunum, GSI-treated cows had increased crypt depth and reduced villus height, villus height-to-crypt depth ratio, cell proliferation, and mucosal surface area. Plasma lipopolysaccharide binding protein increased with time, and tended to be increased 42% in GSI-treated cows relative to PF controls on d 5 to 7. Circulating haptoglobin and serum amyloid A concentrations increased (585- and 4.4-fold, respectively) similarly in both treatments. Administering GSI progressively reduced dry matter intake (66%) and, by design, the pattern and magnitude of decreased nutrient intake was similar in PF controls. A similar progressive decrease (42%) in milk yield occurred in both treatments, but we observed no treatment effects on milk components. Cows treated with GSI tended to have increased plasma insulin (68%) and decreased circulating nonesterified fatty acids (29%) compared with PF cows. For both treatments, plasma glucose decreased with time while ß-hydroxybutyrate progressively increased. Liver triglycerides increased 221% from period 1 to sacrifice in both treatments. No differences were detected in liver weight, liver moisture, or body weight change. Intentionally compromising intestinal barrier function caused inflammation, altered metabolism, and markedly reduced feed intake and milk yield. Further, we demonstrated that progressive feed reduction appeared to cause leaky gut and inflammation.


Assuntos
Trato Gastrointestinal/microbiologia , Lactação , Ácido 3-Hidroxibutírico/sangue , Ração Animal , Animais , Bovinos , Dieta/veterinária , Ácidos Graxos não Esterificados/sangue , Feminino , Inflamação/metabolismo , Leite/metabolismo
7.
Ann Oncol ; 24(6): 1603-9, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23425946

RESUMO

BACKGROUND: The proportion of potentially eligible patients with transformed indolent non-Hodgkin lymphoma who undergo autologous stem-cell transplantation (ASCT) is unknown. There are limited data describing their outcome in the rituximab era. PATIENTS AND METHODS: We reviewed 105 consecutive patients with biopsy-proven transformation referred to Princess Margaret Hospital for consideration of ASCT during 1996-2009. Patients received anthracycline or platinum-based chemotherapy with or without rituximab. Responders proceeded to stem-cell mobilization and ASCT. RESULTS: The median age at transformation was 54 (range 30-65) years. Patients received a median of two chemotherapy regimens for transformation, including rituximab in 39%. Fifty patients (48%) proceeded with ASCT and 55 (52%) did not, mainly due to progressive disease (n = 42). Three-year overall (OS) and progression-free survival (PFS) post-ASCT were 54% and 42%, respectively. Patients receiving rituximab with chemotherapy before transplant had a 3-year post-ASCT OS of 71% versus 47% in those who received chemotherapy alone (P = 0.046). Patients transplanted after 2004 had a 3-year post-ASCT OS of 69% versus 39% in those receiving ASCT earlier (P = 0.009). CONCLUSIONS: About half of transplant-eligible patients with transformation are able to undergo ASCT. Outcomes following ASCT appear to have improved over recent years, although the role of rituximab in this patient population requires further evaluation.


Assuntos
Transformação Celular Neoplásica/patologia , Linfoma não Hodgkin/cirurgia , Encaminhamento e Consulta/tendências , Transplante de Células-Tronco/tendências , Adulto , Idoso , Estudos de Coortes , Feminino , Humanos , Linfoma não Hodgkin/diagnóstico , Linfoma não Hodgkin/mortalidade , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos , Transplante de Células-Tronco/mortalidade , Taxa de Sobrevida/tendências , Transplante Autólogo , Resultado do Tratamento
8.
Ann Oncol ; 24(10): 2601-2606, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23857959

RESUMO

BACKGROUND: This phase I/II study examined the safety and efficacy of Sepantronium Bromide (S), a small-molecule selective survivin suppressant, administered in combination with carboplatin (C) and paclitaxel (P). PATIENTS AND METHODS: Forty-one patients were treated on study. Twenty-two patients received escalating doses of S (3.6-12 mg/m(2)) and 19 with untreated stage IV non-small-cell lung cancer (NSCLC) were treated with the maximum tolerated dose of 10 mg/m(2) in combination with standard doses of C (AUC6) and P (200 mg/m(2)) for six cycles. S was administered as a continuous intravenous infusion (CIVI) over 72 h in 21-day treatment cycles. Study end points included safety and toxic effect, response rate, progression-free and overall survival (PFS and OS), as well as exploratory pharmacodynamic correlates. RESULTS: Treatment with S was well tolerated, and toxic effects were mostly hematological in the phase II study. Two (11%) partial responses were observed with a median PFS of 5.7 months and median OS 16.1 months. Pharmacodynamic analysis did not demonstrate an association with response. CONCLUSION: The combination of S (10 mg/m(2)/day 72-h CIVI) administered with C and P every 3 weeks exhibited a favorable safety profile but failed to demonstrate an improvement in response rate in advanced NSCLC. CLINICAL TRIAL NUMBER: NCT01100931.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Imidazóis/uso terapêutico , Proteínas Inibidoras de Apoptose/antagonistas & inibidores , Neoplasias Pulmonares/tratamento farmacológico , Naftoquinonas/uso terapêutico , Adulto , Idoso , Antineoplásicos Fitogênicos/efeitos adversos , Antineoplásicos Fitogênicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Apoptose/efeitos dos fármacos , Carboplatina/efeitos adversos , Carboplatina/uso terapêutico , Intervalo Livre de Doença , Feminino , Humanos , Imidazóis/efeitos adversos , Imidazóis/sangue , Masculino , Pessoa de Meia-Idade , Naftoquinonas/efeitos adversos , Naftoquinonas/sangue , Paclitaxel/efeitos adversos , Paclitaxel/uso terapêutico , Sobrevida , Survivina , Resultado do Tratamento
9.
Mol Reprod Dev ; 80(11): 948-58, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24038509

RESUMO

Dysregulation of immune cells and/or altered inflammatory signaling have been implicated with reproductive dysfunction. Physiological changes leading to perturbations in the profile of immune cells and/or pro-inflammatory cytokines in or around female reproductive tissue could potentially have profound effects on ovarian function. Obesity is associated with chronic low-grade inflammation due, in part, to increased immune cell infiltration and inflammation in visceral adipose depots. This study investigated the impact of diet-induced obesity on immune cell infiltration and inflammation in peri-ovarian adipose tissue and mRNA expression of key inflammatory markers and microRNAs (miRs) in ovarian tissue. Six-week-old female C57Bl/6J mice were fed a standard chow or high-fat diet (HFD; 60% kcal fat) for approximately 7 months, at which time peri-ovarian adipose tissue and ovarian tissues were collected. Histological analysis of peri-ovarian adipose tissue from obese mice revealed increased (P < 0.05) adipocyte size and the presence of crown-like structures, the morphological presentation of infiltrating immune cells in adipose tissue, along with increases (P < 0.05) in the mRNA levels of markers of T-cells, activated macrophages, inflammatory cytokines, and chemokines. Ovarian mRNA levels of Il1b, Il6, Tnfa, p55, p75, Ccl2, Ikbkb, and Rela were higher in obese tissue (P < 0.05), with a strong trend (P = 0.06) for an increase in Nos2 and RELA protein. Additionally, ovarian miR125b and miR143 levels were decreased (P = 0.1). These data demonstrate that diet-induced obesity elevates expression of inflammatory-mediator genes in both the ovary and surrounding adipose depot, potentially negatively affecting ovarian function.


Assuntos
Tecido Adiposo/efeitos dos fármacos , Citocinas/metabolismo , Gorduras na Dieta/farmacologia , Expressão Gênica/efeitos dos fármacos , Obesidade/metabolismo , Ovário/efeitos dos fármacos , Adipócitos/citologia , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Tecido Adiposo/química , Tecido Adiposo/citologia , Tecido Adiposo/metabolismo , Animais , Biomarcadores/análise , Biomarcadores/metabolismo , Tamanho Celular/efeitos dos fármacos , Citocinas/análise , Dieta Hiperlipídica , Gorduras na Dieta/administração & dosagem , Feminino , Inflamação , Camundongos , Camundongos Endogâmicos C57BL , Ovário/química , Ovário/metabolismo
10.
Ann Oncol ; 23(4): 968-73, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21859898

RESUMO

BACKGROUND: YM155, a small-molecule survivin suppressor, showed modest single-agent activity in a phase I study of heavily pretreated patients. This study was conducted to determine the activity of YM155 in patients with castration-resistant prostate cancer (CRPC) who received prior taxane therapy. PATIENTS AND METHODS: Patients received 4.8 mg/m(2)/day of YM155 over 168-h continuous i.v. infusion every 3 weeks. Study end points included prostate-specific antigen (PSA) response, objective tumor response, safety, progression-free survival (PFS) and overall survival (OS). RESULTS: Thirty-five patients were enrolled. Two of 32 (6.2%) assessable patients had a PSA response and 2 additional patients had PSA decrements >50% but not confirmed. One of 16 (6.2%) patients also had a partial response per RECIST V1. Median PFS and OS were 3.1 and 11.2 months, respectively. The most common adverse events were fatigue (63%), nausea (40%), anorexia (31%), constipation (31%), fever (26%) and vomiting (26%). CONCLUSIONS: YM155 has modest activity in taxane-pretreated CRPC with 25% of patients having prolonged stable disease (≥18 weeks). The regimen appears to be well tolerated. Based on the mechanism of action and preclinical evidence of synergy with docetaxel (Taxotere), YM155 combined with docetaxel is being evaluated in patients with CRPC.


Assuntos
Antineoplásicos/uso terapêutico , Hidrocarbonetos Aromáticos com Pontes/farmacologia , Resistencia a Medicamentos Antineoplásicos , Imidazóis/uso terapêutico , Proteínas Inibidoras de Apoptose/antagonistas & inibidores , Naftoquinonas/uso terapêutico , Neoplasias da Próstata/tratamento farmacológico , Taxoides/farmacologia , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/farmacologia , Hidrocarbonetos Aromáticos com Pontes/uso terapêutico , Humanos , Imidazóis/efeitos adversos , Imidazóis/farmacologia , Masculino , Pessoa de Meia-Idade , Naftoquinonas/efeitos adversos , Naftoquinonas/farmacologia , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/sangue , Neoplasias da Próstata/mortalidade , Survivina , Taxoides/uso terapêutico , Resultado do Tratamento
11.
Radiat Environ Biophys ; 51(3): 245-54, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22622994

RESUMO

The effects of cosmic radiation in single cells, organic tissues and electronics are a major concern for space exploration and manned missions. Standard heavy ions radiation tests employ ion cocktails with energy of the order of 10 MeV per nucleon and with a linear energy transfer ranging from a few MeV cm(2) mg(-1) to hundreds of MeV cm(2) mg(-1). In space, cosmic rays show significant fluxes at energies up to the order of GeV per nucleon. The present work aims at investigating single event damage due to low-, high- and very-high-energy ions. The European Space Agency reference single event upset monitor data are used to support the discussion. Finally, the effect of ionization induced directly by primary particles and ionization induced by recoils produced in an electronic device is investigated for different types of devices.


Assuntos
Radiação Cósmica , Equipamentos e Provisões Elétricas , Transferência Linear de Energia , Modelos Teóricos , Doses de Radiação
12.
Spinal Cord ; 49(9): 967-73, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21606931

RESUMO

STUDY DESIGN: Experimental investigation of intrathecal transplantation of stem cells by lumbar puncture (LP) in a rat model that simulates human thoracic spinal cord injury (SCI). OBJECTIVES: To examine the distribution and phenotype of spinal cord-derived neural stem/progenitor cells (NSPCs) and bone marrow-derived mesenchymal stromal cells (BMSCs) following LP transplantation in SCI rats. SETTING: Toronto Western Research Institute, Toronto, Ontario, Canada. METHODS: NSPCs or BMSCs were transplanted via LP at level L3-5 1 week after compression SCI at T8. Rats were killed at 3, 17 and 27 days after LP transplantation and the relative distribution of cells at C4, T8 and L3-5 was quantitated. The phenotype of the NSPC and BMSC was assessed with immunocytochemistry in vitro and following LP transplantation. RESULTS: By 4 weeks, more NSPC migrated to the lesion site relative to BMSC and uninjured animals. However, there was no preferential homing of either of these types of cells into the parenchyma of the injury site, and most of the transplanted cells remained in the intrathecal space. In vitro, spinal cord-derived NSPC proliferated and expressed nestin, but after LP transplantation, NSPC became post-mitotic and primarily expressed oligodendrocyte markers. In contrast, BMSC did not express any neural antigens in vivo. CONCLUSION: LP is a minimally invasive method of cell transplantation that produces wide dissemination of cells in the subarachnoid space of the spinal cord. This is the first study to report and quantify the phenotype and spatial distribution of LP transplanted NSPC and BMSC in the intact and injured spinal cord.


Assuntos
Injeções Espinhais/métodos , Transplante de Células-Tronco Mesenquimais , Células-Tronco Neurais/transplante , Traumatismos da Medula Espinal/cirurgia , Punção Espinal/métodos , Transplante de Células-Tronco/métodos , Animais , Células da Medula Óssea/citologia , Células da Medula Óssea/patologia , Células Cultivadas , Modelos Animais de Doenças , Feminino , Células-Tronco Mesenquimais/patologia , Células-Tronco Neurais/patologia , Ratos , Ratos Transgênicos , Ratos Wistar , Traumatismos da Medula Espinal/patologia , Vértebras Torácicas/lesões , Vértebras Torácicas/patologia
13.
Theriogenology ; 154: 73-83, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32531658

RESUMO

Unfavorable weather conditions are one of the largest constraints to maximizing farm animal productivity. Heat stress (HS), in particular, compromises almost every metric of profitability and this is especially apparent in the grow-finish and reproductive aspects of the swine industry. Suboptimal production during HS was traditionally thought to result from hypophagia. However, independent of inadequate nutrient consumption, HS affects a plethora of endocrine, physiological, metabolic, circulatory, and immunological variables. Whether these changes are homeorhetic strategies to survive the heat load or are pathological remains unclear, nor is it understood if they temporally occur by coincidence or if they are chronologically causal. However, mounting evidence suggest that the origin of the aforementioned changes lie at the gastrointestinal tract. Heat stress compromises intestinal barrier integrity, and increased appearance of luminal contents in circulation causes local and systemic inflammatory responses. The resulting immune activation is seemingly the epicenter to many, if not most of the negative consequences HS has on reproduction, growth, and lactation. Interestingly, thermoregulatory and production responses to HS are only marginally related. In other words, increased body temperature indices poorly predict decreases in productivity. Further, HS induced malnutrition is also a surprisingly inaccurate predictor of productivity. Thus, selecting animals with a "heat tolerant" phenotype based solely or separately on thermoregulatory capacity or production may not ultimately increase resilience. Describing the physiology and mechanisms that underpin how HS jeopardizes animal performance is critical for developing approaches to ameliorate current production issues and requisite for generating future strategies (genetic, managerial, nutritional, and pharmaceutical) aimed at optimizing animal well-being, and improving the sustainable production of high-quality protein for human consumption.


Assuntos
Transtornos de Estresse por Calor , Doenças dos Suínos , Animais , Biologia , Transtornos de Estresse por Calor/veterinária , Resposta ao Choque Térmico , Temperatura Alta , Reprodução , Suínos
14.
Science ; 273(5275): 627-9, 1996 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-8662548

RESUMO

Theoretical modeling of the dynamics of complexation and decomplexation of guest molecules by container molecules reveals that gating has a critical influence on the ease of formation and stability of host-guest complexes. Hosts equipped with gates can form very stable complexes with a variety of guests under readily achievable conditions. Gating involves conformational processes of the host molecule that alter the size of the portals through which guest molecules pass. "French door" and "sliding door" mechanisms of gate opening are identified.


Assuntos
Química Orgânica , Acetonitrilas/química , Benzeno/química , Fenômenos Químicos , Físico-Química , Conformação Molecular , Fenômenos de Química Orgânica , Software , Solventes , Termodinâmica
15.
Neuroscience ; 155(3): 760-70, 2008 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-18588947

RESUMO

We examined the effect of spinal cord-derived neural stem/progenitor cells (NSPCs) after delayed transplantation into the injured adult rat spinal cord with or without earlier transplantation of bone marrow-derived mesenchymal stromal cells (BMSCs). Either BMSCs or culture medium were transplanted immediately after clip compression injury (27 g force), and then, 9 days after injury, NSPCs or culture medium were transplanted. Cell survival and differentiation, functional recovery, retrograde axonal tracing, and immunoelectron microscopy were assessed. A significant improvement in functional recovery based on three different measures was seen only in the group receiving NSPCs without BMSCs, and the improved recovery was evident within 1 week of transplantation. In this group, NSPCs differentiated mainly into oligodendrocytes and astrocytes, there was ensheathing of axons at the injury site by transplanted NSPCs, an increase in host oligodendrocytes, and a trend toward an increase in retrogradely labeled supraspinal nuclei. Transplantation of the BMSC scaffold resulted in a trend toward improved survival of the NSPCs, but there was no increase in function. Thus, transplantation of adult rat NSPCs produced significant early functional improvement after spinal cord injury, suggesting an early neuroprotective action associated with oligodendrocyte survival and axonal ensheathment by transplanted NSPCs.


Assuntos
Células-Tronco Adultas/fisiologia , Células-Tronco Adultas/transplante , Recuperação de Função Fisiológica/fisiologia , Traumatismos da Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/cirurgia , Medula Espinal/citologia , Células-Tronco Adultas/ultraestrutura , Animais , Transplante de Medula Óssea/métodos , Diferenciação Celular/fisiologia , Células Cultivadas , Proteínas do Citoesqueleto/metabolismo , Modelos Animais de Doenças , Feminino , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Microscopia Imunoeletrônica/métodos , Proteínas do Tecido Nervoso/metabolismo , Ratos , Ratos Sprague-Dawley , Receptor de Fator de Crescimento Neural/metabolismo , Traumatismos da Medula Espinal/patologia , Fatores de Tempo , Transfecção/métodos
16.
Bone Marrow Transplant ; 42(1): 29-34, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18332908

RESUMO

Previous reports in Hodgkin's lymphoma (HL) patients undergoing autologous hematopoietic cell transplantation (AHCT) have demonstrated a significant association between the absolute lymphocyte count at day 15 (ALC-15) with survival. To evaluate this finding further, we analyzed 146 patients with relapsed/refractory HL who underwent AHCT to evaluate the relationship between lymphocyte counts at apheresis and at two time points (days 15 and 90) after AHCT with PFS. We found no association between the ALC-15 and the ALC-90 with PFS. We found lymphocyte counts at apheresis and disease sensitive to salvage chemotherapy were predictive of PFS. In conclusion, our study does provide some support for the theory that the immune system may be important in disease control but further and more detailed studies in this area are required.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Doença de Hodgkin/terapia , Contagem de Linfócitos , Adolescente , Adulto , Idoso , Remoção de Componentes Sanguíneos , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Condicionamento Pré-Transplante , Transplante Autólogo
17.
Bone Marrow Transplant ; 41(7): 635-42, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18084335

RESUMO

For adults with high-risk or recurrent ALL who lack a suitable sibling donor, the decision between autologous (Auto) and unrelated donor (URD) hematopoietic stem cell transplantation (HSCT) is difficult due to variable risks of relapse and treatment-related mortality (TRM). We analysed data from two transplant registries to determine outcomes between Auto and URD HSCT for 260 adult ALL patients in first (CR1) or second (CR2) CR. All patients received a myeloablative conditioning regimen. The median follow-up was 77 (range 12-170) months. TRM at 1 year post transplant was significantly higher with URD HSCT; however, there were minimal differences in TRM according to disease status. Relapse was higher with Auto HSCT and was increased in patients transplanted in CR2. Five-year leukemia-free (37 vs 39%) and overall survival (OS) rates (38 vs 39%) were similar for Auto HSCT vs URD HSCT in CR1. There were trends favoring URD HSCT in CR2. The long-term follow-up in this analysis demonstrated that either Auto or URD HSCT could result in long-term leukaemia-free survival and OS for adult ALL patients. The optimal time (CR1 vs CR2) and technique to perform HSCT remains an important clinical question for adult ALL patients.


Assuntos
Transplante de Medula Óssea/métodos , Recidiva Local de Neoplasia , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Sistema de Registros , Adolescente , Adulto , Intervalo Livre de Doença , Feminino , Sobrevivência de Enxerto , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Transplante Autólogo , Transplante Homólogo , Resultado do Tratamento
18.
J Anim Sci ; 96(3): 941-949, 2018 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-29617863

RESUMO

Identifying traits associated with susceptibility or tolerance to heat stress (HS) is a prerequisite for developing strategies to improve efficient pork production during the summer months. Study objectives were to determine the relationship between the thermoregulatory and production responses to acute HS in pigs. Prepubertal gilts (n = 235; 77.9 ± 1.2 kg BW) were exposed to a thermoneutral (TN) period (P1, 24 h; 21.9 ± 0.5 °C, 62 ± 13% RH; fed ad libitum) followed immediately by a subsequent acute HS period (P2, 24 h; 29.7 ± 1.3 °C, 49 ± 8% RH; fed ad libitum). Rectal temperature (TR), skin temperature (TS), and respiration rate (RR) were monitored and BW and feed intake (FI) were determined. All pigs had increased TR, TS, and RR (0.80 °C, 5.65 °C, and 61.2 bpm, respectively; P < 0.01) and decreased FI and BW (29% and 1.10 kg, respectively; P < 0.01) during P2 compared to P1. Interestingly, body temperature indices did not explain variation in FI during P2 (R2 ≤ 0.02). Further, the percent change in BW during P2 was only marginally explained by each body temperature index (R2 ≤ 0.06) or percent change in FI (R2 = 0.14). During HS, TR was strongly correlated with P1 TR (r = 0.72, P < 0.01), indicating a pig's body temperature during TN conditions predicts the severity of hyperthermia during HS. Additionally, the change in TR (ΔTR, HS TR - TN TR) was larger in pigs retrospectively classified as susceptible (SUS) as compared to tolerant (TOL) pigs (1.05 vs. 0.51 °C, respectively; P < 0.01). In summary, thermoregulatory responses and production variables during acute HS are only marginally related. Further, changes in BW and FI were unexpectedly poorly correlated during acute HS (r = 0.34; P < 0.01). Collectively, suboptimal growth is largely independent on the thermoregulatory response and hypophagia during acute HS. Consequently, incorporating solely body temperature indices into a genetic index is likely insufficient for substantial progress in selecting HS tolerant pigs.


Assuntos
Regulação da Temperatura Corporal , Resposta ao Choque Térmico/fisiologia , Suínos/fisiologia , Animais , Temperatura Corporal , Feminino , Temperatura Alta/efeitos adversos , Taxa Respiratória , Suínos/crescimento & desenvolvimento , Termotolerância
19.
Oncogene ; 25(45): 6092-100, 2006 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-16652142

RESUMO

Mer (MerTK) is a receptor tyrosine kinase important in platelet aggregation, as well as macrophage cytokine secretion and clearance of apoptotic cells. Mer is not normally expressed in thymocytes or lymphocytes; however, ectopic Mer RNA transcript and protein expression is found in a subset of acute lymphoblastic leukemia cell lines and patient samples, suggesting a role in leukemogenesis. To investigate the oncogenic potential of Mer in vivo, we created a transgenic mouse line (Mer(Tg)) that expresses Mer in the hematopoietic lineage under control of the Vav promoter. Ectopic expression and activation of the transgenic Mer protein was demonstrated in lymphocytes and thymocytes of the Mer(Tg) mice. At 12-24 months of age, greater than 55% of the Mer(Tg) mice, compared to 12% of the wild type, developed adenopathy, hepatosplenomegaly, and circulating lymphoblasts. Histopathological analysis and flow cytometry were consistent with T-cell lymphoblastic leukemia/lymphoma. Mer may contribute to leukemogenesis by activation of Akt and ERK1/2 anti-apoptotic signals, which were upregulated in Mer(Tg) mice. Additionally, a significant survival advantage was noted in Mer(Tg) lymphocytes compared to wild-type lymphocytes after dexamethasone treatment. These data suggest that Mer plays a cooperative role in leukemogenesis and may be an effective target for biologically based leukemia/lymphoma therapy.


Assuntos
Leucemia de Células T/genética , Linfoma de Células T/genética , Proteínas Proto-Oncogênicas/genética , Receptores Proteína Tirosina Quinases/genética , Animais , Apoptose , Sequência de Bases , Primers do DNA , Citometria de Fluxo , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/administração & dosagem , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Transdução de Sinais , c-Mer Tirosina Quinase
20.
J Clin Invest ; 79(4): 1153-9, 1987 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3470307

RESUMO

Monoclonal antibody L4F3 reacts with most acute myeloid leukemia (AML) cells and virtually all normal granulocyte/monocyte colony-forming cells (CFU-GM). Our objective was to determine whether lysis of AML cells with L4F3 and complement allowed expression of normal myeloid progenitors. The five glucose-6-phosphate dehydrogenase (G6PD) heterozygous patients with AML studied manifested only a single G6PD type in blast cells and in most or all granulocyte colony-forming cells, indicating that the leukemias developed clonally. The cells remaining after L4F3 treatment from two of the patients gave rise to granulocytic colonies that expressed the G6PD type not seen in the leukemic clone, indicating that they were derived from normal progenitors (CFU-GM). L4F3-treated cells from these two patients cultured over an irradiated adherent cell layer from normal long-term marrow cultures also gave rise to CFU-GM, which were shown by G6PD analysis to be predominantly nonleukemic. In the other three patients, the progenitor cells remaining after L4F3 treatment were derived mainly from the leukemic clone. The data suggest that in vitro cytolytic treatment with L4F3 of cells from certain patients with AML can enable normal, presumably highly immature progenitors to be expressed.


Assuntos
Anticorpos Monoclonais , Inibidores do Crescimento , Interleucina-6 , Leucemia Mieloide Aguda/imunologia , Linfocinas/imunologia , Células-Tronco/imunologia , Adolescente , Adulto , Criança , Pré-Escolar , Ensaio de Unidades Formadoras de Colônias , Glucosefosfato Desidrogenase/genética , Heterozigoto , Humanos , Técnicas In Vitro , Isoenzimas/genética , Fator Inibidor de Leucemia
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa