RESUMO
Sixty previously untreated patients with newly diagnosed advanced-stage lung cancer (21 small-cell, 39 non-small-cell) received chemotherapy with cisplatin and etoposide. Bleomycin was also used in the patients with non-small-cell lung cancer. During the first cycle of chemotherapy, 30 patients received antiemetic therapy with intermittent metoclopramide (regimen A), and the other 30 patients received continuous infusion metoclopramide (regimen B). During the second course of chemotherapy, patients were switched to the alternate regimen. Regimen A consisted of lorazepam, 1 mg, orally; dexamethasone, 10 mg, intravenously (IV) every four hours for three doses; diphenhydramine, 0.5 mg/kg, IV every four hours for three doses; metoclopramide, 1 mg/kg, IV bolus every two hours for six doses. Regimen B was identical to A except metoclopramide was administered as 1 mg/kg, IV bolus followed by 0.5 mg/kg/h for ten hours. Fifty-eight patients completed both antiemetic regimens. Thirty-nine of the 58 patients had total control of acute nausea and vomiting (0-1 episodes) with regimen A or B. Fourteen patients had poor control of acute nausea and vomiting (more than one episode) with regimen A but total control with regimen B. Five patients had poor control with either regimen. Dystonic reactions, akathisia, or diarrhea occurred in 20 of the 58 patients on regimen A, but in only eight of the 58 patients on regimen B. Compared with intermittent bolus, continuous infusion metoclopramide is more effective in total control of acute nausea and vomiting and has less toxicity.
Assuntos
Cisplatino/efeitos adversos , Metoclopramida/administração & dosagem , Náusea/prevenção & controle , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma de Células Pequenas/tratamento farmacológico , Dexametasona/administração & dosagem , Difenidramina/administração & dosagem , Esquema de Medicação , Quimioterapia Combinada , Humanos , Lorazepam/administração & dosagem , Neoplasias Pulmonares/tratamento farmacológico , Pessoa de Meia-Idade , Náusea/induzido quimicamente , Distribuição AleatóriaRESUMO
PURPOSE: To assess the antiemetic effects and safety profile of four different doses of granisetron (Kytril; SmithKline Beecham Pharmaceuticals, Philadelphia, PA) when administered as a single intravenous (IV) dose for prophylaxis of cisplatin-induced nausea and vomiting. PATIENTS AND METHODS: One hundred eighty-four chemotherapy-naive patients receiving high-dose cisplatin (81 to 120 mg/m2) were randomized to receive one of four granisetron doses (5, 10, 20, or 40 micrograms/kg) administered before chemotherapy. Patients were observed on an inpatient basis for 18 to 24 hours, and vital signs, nausea, vomiting, retching, and appetite were assessed. Safety analyses included incidence of adverse experiences and laboratory parameter changes. RESULTS: After granisetron doses of 5, 10, 20, and 40 micrograms/kg, a major response (< or = two vomiting or retching episodes, and no antiemetic rescue) was recorded in 23%, 57%, 58%, and 60% of patients, respectively, and a complete response (no vomiting or retching, and no antiemetic rescue) in 18%, 41%, 40%, and 47% of patients, respectively. There was a statistically longer time to first episode of nausea (P = .0015) and vomiting (P = .0001), and fewer patients were administered additional antiemetic medication in the 10-micrograms/kg dosing groups than in the 5-micrograms/kg dosing group. As granisetron dose increased, appetite return increased (P = .040). Headache was the most frequently reported adverse event (20%). CONCLUSION: A single 10-, 20-, or 40-micrograms/kg dose of granisetron was effective in controlling vomiting in 57% to 60% of patients who received cisplatin at doses greater than 81 mg/m2 and totally prevented vomiting in 40% to 47% of patients. There were no statistically significant differences in efficacy between the 10-micrograms/kg dose and the 20- and 40-micrograms/kg doses. Granisetron was well tolerated at all doses.
Assuntos
Cisplatino/efeitos adversos , Granisetron/uso terapêutico , Náusea/prevenção & controle , Vômito/prevenção & controle , Adolescente , Adulto , Idoso , Cisplatino/administração & dosagem , Constipação Intestinal/induzido quimicamente , Diarreia/induzido quimicamente , Método Duplo-Cego , Feminino , Granisetron/administração & dosagem , Granisetron/efeitos adversos , Cefaleia/induzido quimicamente , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Náusea/induzido quimicamente , Neoplasias/tratamento farmacológico , Serotonina/metabolismo , Estados Unidos , Vômito/induzido quimicamenteRESUMO
PURPOSE: To investigate the efficacy and safety of oral ondansetron in the control of cisplatin-induced delayed emesis in patients who do not require rescue antiemetic therapy for acute emesis. PATIENTS AND METHODS: Five hundred thirty-eight chemotherapy-naive patients who received cisplatin chemotherapy (> or = 70 mg/m2), and who were not rescued for acute emesis, were eligible to be randomized to receive one of the three oral regimens to control delayed emesis. Group I received placebo on days 2 to 6; group II received ondansetron 8 mg twice daily on days 2 and 3 and placebo on days 4 to 6; group III received ondansetron 8 mg twice daily on days 2 to 6. All patients received intravenous ondansetron (0.15 mg/kg every 4 hours for three doses) for the control of acute emesis on day 1. The number of emetic episodes on days 2 and 3 combined (days 2/3, when incidence and severity of delayed emesis were expected to be greatest) was considered the primary measure of efficacy. RESULTS: Patients who received odansetron had significantly fewer emetic episodes on days 2/3, 4, and 5 than those who received placebo (P < or = .002 on each day). Additionally, significantly more patients who received ondansetron had a complete plus major response (C+MR; < or = two two emetic episodes) than those who received placebo on days 2/3 (56% v 37%, P = .001), 4 (94% v 85%, P = .005), and 5 (98% v 88%, P = .006). Patients who received ondansetron had significantly less nausea on day 2/3 when day-1 nausea was used as the baseline score (P = .025). Patients who received ondansetron also had significantly less nausea on day 4 (P = .042) and the results approached significance on day 5 (P = .066). CONCLUSION: Oral ondansetron had a significant effect in the control of cisplatin-induced delayed emesis and nausea in patients who had not required rescue antiemetics during the acute emesis period. The control of delayed nausea and vomiting was most notable in the immediate 2 days following cisplatin administration, with the clinical difference narrowing between the two treatment arms on subsequent days.
Assuntos
Cisplatino/efeitos adversos , Ondansetron/uso terapêutico , Vômito/tratamento farmacológico , Administração Oral , Adulto , Idoso , Idoso de 80 Anos ou mais , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Náusea/induzido quimicamente , Náusea/tratamento farmacológico , Ondansetron/administração & dosagem , Ondansetron/efeitos adversos , Satisfação do Paciente , Prognóstico , Estados Unidos , Vômito/induzido quimicamenteRESUMO
PURPOSE: To compare the antiemetic efficacy of a single dose of an oral antiemetic (granisetron 2 mg) with a single dose of an intravenous (i.v.) antiemetic (ondansetron 32 mg) given before cisplatin-based chemotherapy. PATIENTS AND METHODS: This was a multicenter, randomized, double-blind, parallel-group study. Patients (N = 1,054) scheduled to receive cisplatin (> or = 60 mg/m2)-based chemotherapy were randomized to receive either 2 mg of oral granisetron tablets 1 hour before chemotherapy (n = 534) or i.v. ondansetron (32 mg) 30 minutes before chemotherapy (n = 520). The primary efficacy end point was total control (no emesis, no nausea, and no use of antiemetic rescue medication) over the initial 24 hours after the start of chemotherapy. Dexamethasone or methylprednisolone were permitted, but not required, as concomitant prophylactic antiemetics. RESULTS: Total control was equivalent 24 hours after cisplatin chemotherapy for single-dose oral granisetron (54.7%) and i.v. ondansetron (58.3%) (95% confidence interval [CI], -9.6 to 2.4). Similar proportions of patients remained nausea-free in the granisetron group (55.4%) and the ondansetron group (59%) (95% CI, -9.6 to 2.4). The rate of complete control of emesis was 61.2% in the granisetron group and 67.1% in the ondansetron group (95% CI, -11.7 to -0.1). Both treatment regimens were well tolerated, with similar patterns of adverse reactions, generally of a mild degree. The most common side effects included constipation (14%), headache (15%), and diarrhea (10%). CONCLUSION: Oral granisetron, administered as a single 2-mg dose, provided equivalent total antiemetic control when compared with i.v. ondansetron (32 mg) in patients who received highly emetogenic, cisplatin-based chemotherapy.
Assuntos
Antieméticos/administração & dosagem , Cisplatino/efeitos adversos , Granisetron/administração & dosagem , Náusea/induzido quimicamente , Náusea/prevenção & controle , Ondansetron/administração & dosagem , Administração Oral , Corticosteroides/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-IdadeRESUMO
PURPOSE: This study compares the efficacy and safety of two single-dose regimens with the approved three-dose regimen of ondansetron in the prevention of cisplatin-induced emesis. PATIENTS AND METHODS: This multicenter study was a stratified, randomized, double-blind, and parallel group design. Chemotherapy-naive inpatients were randomized to receive intravenous (IV) ondansetron (Zofran; Glaxo Inc, Research Triangle Park, NC) 0.15 mg/kg times three doses, every 4 hours or a single 8-mg or 32-mg dose followed by two saline doses that began 30 minutes before cisplatin administration. Cisplatin (high-dose > or = 100 mg/m2 or medium-dose 50 to 70 mg/m2) was given as a single infusion (< or = 3 hours). Patients were monitored for emetic episodes, adverse events, and laboratory safety parameters for 24 hours after cisplatin administration. RESULTS: A total of 699 patients (359 high-dose, 340 medium-dose) were enrolled. Of these, 618 were assessable for efficacy (15 ineligible, 66 protocol deviations). The 32-mg dose was superior to the 8-mg single dose with regard to total number of emetic episodes (high-dose, P = .015; medium-dose, P < .001), complete response (no emetic episodes: high-dose, 48% v 35%; P = .048; medium-dose, 73% v 50%; P = .001) and failure rate (> 5 emetic episodes, withdrawn or rescued: high-dose, 20% v 34%; P = .018; medium-dose, 9% v 23%; P = .005). The 32-mg single dose was also superior to the 0.15 mg/kg times three dose regimen with regard to total number of emetic episodes (medium-dose, P = .033) and failure rate (high-dose, 20% v 36%; P = .009; medium-dose, 9% v 22%; P = .011). Ondansetron was well tolerated. The most common adverse event was headache. An approximate 10-fold increase in the incidence of clinically significant transaminase elevations was observed in the high-dose versus medium-dose cisplatin strata (aspartate aminotransferase [AST], 6.5% v 0.7%; serum alanine aminotransferase [ALT], 5.0% v 0.3%). CONCLUSION: A 32-mg single dose of ondansetron is more effective than a single 8-mg dose and is at least as effective as the standard regimen of 0.15 mg/kg times three doses in the prevention of cisplatin-induced acute emesis.
Assuntos
Cisplatino/efeitos adversos , Náusea/prevenção & controle , Ondansetron/administração & dosagem , Vômito/prevenção & controle , Adulto , Idoso , Idoso de 80 Anos ou mais , Método Duplo-Cego , Esquema de Medicação , Feminino , Humanos , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Náusea/induzido quimicamente , Vômito/induzido quimicamenteRESUMO
PURPOSE: Dolasetron is a 5-HT3 antagonist antiemetic with active oral and intravenous formulations. The effects of this class are enhanced when combined with dexamethasone. This study tested the ability of the combination of oral dolasetron 200 mg and oral dexamethasone 20 mg to prevent acute emesis in cancer patients receiving initial cisplatin at doses > or = 70 mg/m2. Additionally, patients were randomly assigned to receive a second dosage of the regimen 16 hours later to improve control of acute symptoms. PATIENTS AND METHODS: A total of 75 patients were entered, with 38 randomized to the two-dose regimen. Thirty-five percent were women and 77% had lung cancer. RESULTS: Overall, the regimen prevented acute vomiting in 76% (95% confidence interval, 65% to 85%), including 74% of 35 patients who received cisplatin at doses > or = 100 mg/m2. There was no observed difference in emesis prevention between the one-dose (76%) and two-dose (76%) regimens (95% confidence interval for the difference, -20% to 19%). The median time to the onset of emesis was 19 hours for the one-dose regimen and 17 hours for the two-dose regimen in those patients with emesis. Headache occurred in 11% who received one dose and 16% who received two doses. CONCLUSION: The combination of oral dolasetron 200 mg and dexamethasone 20 mg given only once prevented acute emesis in 76% of patients who received cisplatin > or = 70 mg/m2. Administration of a second dose of the regimen did not improve the observed prevention rate or delay the time to emesis. This one-dose oral regimen has comparable or better effectiveness than reported results of intravenous combination regimens in preventing cisplatin-induced vomiting and merits further study and use.
Assuntos
Antieméticos/uso terapêutico , Antineoplásicos/efeitos adversos , Cisplatino/efeitos adversos , Dexametasona/uso terapêutico , Indóis/uso terapêutico , Quinolizinas/uso terapêutico , Vômito/prevenção & controle , Doença Aguda , Administração Oral , Antieméticos/administração & dosagem , Antineoplásicos/administração & dosagem , Cisplatino/administração & dosagem , Dexametasona/administração & dosagem , Quimioterapia Combinada , Feminino , Humanos , Indóis/administração & dosagem , Masculino , Pessoa de Meia-Idade , Náusea/induzido quimicamente , Náusea/prevenção & controle , Neoplasias/tratamento farmacológico , Quinolizinas/administração & dosagem , Vômito/induzido quimicamenteRESUMO
CGS 16949A (fadrozole hydrochloride), a potent cytochrome P450-mediated steroidogenesis inhibitor, blocks aromatase at low doses, but other biosynthetic steps at higher concentrations. Recent studies demonstrated inhibition of C11-hydroxylase, corticosterone methyloxidase-II, and deoxycorticosterone to corticosterone conversion with this agent at some-what higher concentrations than those required for blockade of aromatase. Based upon phase I studies, we postulated that relatively selective inhibition of aromatase might be possible if sufficiently low doses of CGS 16949A were used. A phase II study in 54 postmenopausal women with metastatic breast cancer examined the effects of low dose CGS 16949A on estrogen, mineralocorticoid, and glucocorticoid secretion. Two dose schedules and two dose levels were chosen based upon our prior dose escalation protocol study. Plasma estrone, estradiol, and estrone sulfate as well as urinary estrone and estradiol fell equally with 1.8-4 mg CGS 16949A given either on a twice daily or three times daily dose schedule. Isotopic kinetic studies demonstrated an 84% decrease in the rate of conversion of androstenedione to estrone to 0.40 +/- 0.07% (patients receiving 1.8-4 mg CGS 16949A daily). With these three regimens, basal levels of aldosterone and cortisol did not change significantly over a 12-week period of observation. Clinical examination, plasma electrolytes, and urinary sodium/potassium ratios suggested no biological evidence of mineralo-corticoid deficiency. ACTH-stimulated cortisol concentrations, however, were blunted at each dose level compared to pretreatment values. Nonetheless, peak responses exceeded 550 nmol/L, or a basal to peak difference of 190 nmol/L or greater, in 97% of instances. This probably reflected inhibition of C11-hydroxylase, since basal and ACTH-stimulated levels of 11-deoxycortisol were increased in response to CGS 16949A. Androstenedione and 17 alpha-hydroxyprogesterone also exhibited an upward trend in response to drug treatment. ACTH-stimulated aldosterone levels were blunted to a greater extent than those of cortisol, probably as a reflection of corticosterone methyloxidase type II blockade. Overall, the results suggest that CGS 16949A, at doses of 1.8-2 mg daily, blocks aromatase effectively and does not produce clinically important inhibition of cortisol or aldosterone biosynthesis. Thus, this agent can probably be used safely without glucocorticoid or mineralocorticoid supplementation.
Assuntos
Inibidores da Aromatase , Neoplasias da Mama/metabolismo , Imidazóis/farmacologia , Nitrilas/farmacologia , 17-alfa-Hidroxiprogesterona , Hormônio Adrenocorticotrópico , Aldosterona/sangue , Androstenodiona/sangue , Estradiol/sangue , Estradiol/urina , Estrona/análogos & derivados , Estrona/sangue , Estrona/urina , Fadrozol , Feminino , Humanos , Hidrocortisona/sangue , Hidroxiprogesteronas/sangue , Imidazóis/administração & dosagem , Cinética , Menopausa , Nitrilas/administração & dosagemRESUMO
One hundred one patients with severe aplastic anemia underwent allogeneic marrow transplantation and received one of three forms of infection prophylaxis: oral nonabsorbable antibiotics and isolation and decontamination in a laminar airflow room (36 patients); prophylactic granulocyte transfusions from a single family member donor (33 patients); or conventional treatment in single rooms with hand-washing and mask precautions (31 patients). During the period of granulocytopenia, patients in the laminar airflow rooms acquired fewer infections than either of the other groups, but this difference was statistically significant only when compared with the group receiving conventional treatment. Patients in the laminar airflow rooms had significantly fewer infections after engraftment as compared with the other two groups. Incidence of interstitial pneumonia and graft rejection was not different among the three groups. Acute graft-versus-host disease occurred later (Day 47) in the group in the laminar airflow rooms as compared with the group receiving prophylactic granulocyte transfusions (Day 23) or the group receiving conventional treatment (Day 20). The incidence of grades II to IV acute graft-versus-host disease was less in the patients in the laminar airflow rooms but only reached borderline significance (p = 0.08) when compared with the conventionally treated patients. The survival at Day 100 was 92 percent for the group in the laminar airflow rooms, 79 percent for the group receiving prophylactic granulocyte transfusions, and 64 percent for the group receiving conventional treatment.
Assuntos
Anemia Aplástica/terapia , Transplante de Medula Óssea , Controle de Infecções , Adolescente , Adulto , Antibacterianos/uso terapêutico , Transfusão de Sangue , Criança , Pré-Escolar , Ambiente Controlado , Rejeição de Enxerto , Doença Enxerto-Hospedeiro/etiologia , Granulócitos/transplante , Humanos , Pessoa de Meia-Idade , Fibrose Pulmonar/etiologiaRESUMO
Bone marrow transplant recipients undergo ablation of host immune defenses with total-body irradiation or high dose chemotherapy, or both. Over a 5.6-year period, mycobacterial infections were observed in 7 of 682 patients with leukemia who received marrow grafts. Four patients had pulmonary and three extrapulmonary infection. Granulomas were observed in the lungs of three patients, in the liver of one patient, and in the skin of one patient. Cultures revealed Mycobacterium tuberculosis in two patients, Mycobacterium fortuitum in two patients, and Mycobacterium kansasii in one patient. In the six patients treated with antimycobacterial therapy in either the pretransplant or posttransplant period, complete resolution of the infection was achieved. Pretransplant chest radiograph abnormalities suggesting mycobacterial infections should be aggressively evaluated in these immunocompromised hosts. Prophylaxis should be considered in marrow graft recipients with a well-established history of inadequately treated tuberculosis, previous Bacille Calmette-Guerin immunotherapy, known family contacts, recent skin test conversion, or past skin test positivity.
Assuntos
Transplante de Medula Óssea , Tuberculose Pulmonar/etiologia , Adolescente , Adulto , Feminino , Humanos , Terapia de Imunossupressão/métodos , Leucemia/complicações , Leucemia/terapia , Masculino , Pessoa de Meia-Idade , Infecções por Mycobacterium não Tuberculosas/etiologia , Infecções por Mycobacterium não Tuberculosas/patologia , Tuberculoma/etiologia , Tuberculoma/patologia , Tuberculose Pulmonar/patologiaRESUMO
Understanding the extent to which changes in whole-body protein kinetics contribute to the commonly observed weight loss and decrease in lean body mass (LBM) in patients with cancer is currently obscured by conflicting reports in the literature. While several studies have reported significant increases in whole-body protein turnover (WBPT), synthesis (WBPS), and catabolism (WBPC) in patients with cancer, others have failed to confirm these observations. We have measured whole-body protein kinetics using a primed constant infusion of 15N-glycine in a homogenous group of 32 newly diagnosed advanced lung cancer patients with comparable staging and before any antineoplastic treatment, and in 19 normal healthy volunteer controls. Urinary urea and ammonia 15N enrichment was determined in individually collected urine samples obtained during the 24-hour study period and averaged for the determination of protein kinetics. During the last 6 hours of urine collection, samples were obtained hourly for determination of 15N plateau enrichment. Twenty-four-hour urinary nitrogen and creatinine excretion was determined from 24-hour pooled urine samples. Resting metabolic expenditure (RME) was determined by indirect calorimetry and LBM was estimated from deuterium oxide dilution. Age body weight, LBM, RME, and 24-hour urinary nitrogen excretion did not differ between cancer and control subjects. WBPT, WBPC, and WBPS (g/kg/d) were significantly increased in lung cancer patients. However, when the same results were expressed either per kilogram LBM or per gram 24-hour urinary creatinine excretion, WBPT, WBPC, and WBPS rates were not statistically different from those of the controls.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Adenocarcinoma/metabolismo , Carcinoma de Células Escamosas/metabolismo , Neoplasias Pulmonares/metabolismo , Proteínas/metabolismo , Adenocarcinoma/patologia , Adenocarcinoma/fisiopatologia , Idoso , Nitrogênio da Ureia Sanguínea , Índice de Massa Corporal , Peso Corporal/fisiologia , Calorimetria , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/fisiopatologia , Cloretos/sangue , Creatinina/urina , Feminino , Glicina/metabolismo , Glicina/farmacocinética , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Potássio/sangue , Sódio/sangue , Fatores de Tempo , Redução de PesoRESUMO
This study surveyed medical school admission deans about the desirability of international study. Most agreed that an international study program in the premedical years was beneficial, but most were neutral concerning science courses taken in international programs.
Assuntos
Atitude do Pessoal de Saúde , Educação Pré-Médica , Intercâmbio Educacional Internacional , Coleta de Dados , Humanos , Critérios de Admissão Escolar , Faculdades de Medicina/normasRESUMO
Although it is generally accepted that altered nutrient intake and metabolism are responsible for the progressive loss of body weight observed in most advanced cancer patients, there is still considerable controversy regarding the contributory role of changes in both resting energy expenditure (REE) and glucose metabolism. Several studies suggest increases in both REE and glucose appearance in advanced cancer patients compared with healthy control subjects, whereas others revealed no changes in either metabolic parameter. We measured REE with indirect calorimetry and glucose kinetics with a primed constant infusion of D-[U-14C]glucose and D-[6-3H]glucose over the last 4 h of a 24-h fast in 32 advanced lung cancer patients immediately after diagnosis and before any chemotherapy or radiotherapy and in 19 healthy volunteer subjects. REE for the lung cancer group was not significantly different from that in the control group (1535.8 +/- 78.0 vs. 1670.2 +/- 53.9 kcal/day, respectively, p = 0.151). When REE was expressed as a function of body weight, or lean body mass, no differences between the two groups were observed. The rate of glucose appearance was 9.88 +/- 0.36 mumol.kg-1.min-1 in the cancer patients and 10.15 +/- 0.53 mumol.kg-1.min-1 in control subjects (p = 0.667), of which 50.4 versus 58.2%, respectively, was oxidized. The amount of glucose recycled was 13.54 +/- 1.22% in cancer patients and 15.08 +/- 0.99% in control subjects (p = 0.394). The amount of VCO2 from direct oxidation of glucose was 23.39 +/- 0.74% in cancer patients and 27.45 +/- 1.36% in control subjects (p = 0.006).(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Glucose/metabolismo , Neoplasias Pulmonares/metabolismo , Idoso , Glicemia/metabolismo , Calorimetria Indireta , Dióxido de Carbono/metabolismo , Creatinina/urina , Metabolismo Energético , Feminino , Humanos , Cinética , Masculino , Pessoa de Meia-Idade , Estado Nutricional , Oxirredução , Consumo de Oxigênio , Redução de PesoRESUMO
In the continuing search for effective cancer treatments, we report the rational engineering of a multifunctional nanoparticle that combines traditional chemotherapy with cell targeting and anti-adhesion functionalities. Very late antigen-4 (VLA-4) mediated adhesion of multiple myeloma (MM) cells to bone marrow stroma confers MM cells with cell-adhesion-mediated drug resistance (CAM-DR). In our design, we used micellar nanoparticles as dynamic self-assembling scaffolds to present VLA-4-antagonist peptides and doxorubicin (Dox) conjugates, simultaneously, to selectively target MM cells and to overcome CAM-DR. Dox was conjugated to the nanoparticles through an acid-sensitive hydrazone bond. VLA-4-antagonist peptides were conjugated via a multifaceted synthetic procedure for generating precisely controlled number of targeting functionalities. The nanoparticles were efficiently internalized by MM cells and induced cytotoxicity. Mechanistic studies revealed that nanoparticles induced DNA double-strand breaks and apoptosis in MM cells. Importantly, multifunctional nanoparticles overcame CAM-DR, and were more efficacious than Dox when MM cells were cultured on fibronectin-coated plates. Finally, in a MM xenograft model, nanoparticles preferentially homed to MM tumors with â¼10 fold more drug accumulation and demonstrated dramatic tumor growth inhibition with a reduced overall systemic toxicity. Altogether, we demonstrate the disease driven engineering of a nanoparticle-based drug delivery system, enabling the model of an integrative approach in the treatment of MM.
Assuntos
Nicotina , Química/educação , Humanos , Nicotina/análise , Plantas Tóxicas , Nicotiana/análiseRESUMO
The oxygen consumption of rat bronchioles suspended in a physiological salt solution containing plasma proteins was measured with the Cartesian diver microrespirometer. The oxygen consumption of the bronchiolar tissue 100-300 and 300-400 micrometer in diam was significantly (P greater than 0.01) reduced as the protein concentration of the suspending solution was increased from the low to the high extreme of the normal plasma physiological range and as the diffusion distance through the suspending medium was increased from 25 to 50 micrometer. The reduction in the bronchiolar oxygen consumption was significantly (P greater than 0.01) reversed by using 95% oxygen-5% nitrogen instead of air as the diffusing gas in the Cartesian diver. Measurements of the oxygen diffusivity in the protein solutions using a diaphragm diffusion cell showed a large decrease in the diffusivity as the plasma protein concentration was increased over the same concentration range used in the oxygen consumption studies. These results suggest that the reduction in oxygen consumption was secondary to a decrease in oxygen diffusion and may provide at least a partial explanation for the diffusion abnormalities which exist in noncardiogenic pulmonary edema in which there is an increase in microvascular membrane permeability to proteins.
Assuntos
Proteínas Sanguíneas/fisiologia , Brônquios/fisiologia , Consumo de Oxigênio , Animais , Difusão , Técnicas In Vitro , Masculino , Ratos , Respiração , SoluçõesRESUMO
2 patients with premortem marrow necrosis in acute leukemia are discussed. A review of the course of each patient plus those in the literature suggests that premortem marrow necrosis may not be a poor prognostic sign in acute lymphoblastic leukemia but generally precedes a prolonged and fatal pancytopenia in acute myelogenous leukemia. The technetium-99m rhenium sulfur colloid marrow scan was found to be of value in assessing the extent and degree of necrosis of the marrow as well as in documenting and predicting marrow recovery following chemotherapy.