RESUMEN
Background: This study evaluated the antineoplastic and immunostimulatory effects of inhaled (IH) submicron particle paclitaxel (NanoPac®) in an orthotopic non-small cell lung cancer rodent model. Methods: Male nude rats were whole body irradiated, intratracheally instilled with Calu-3 cancer cells and divided into six treatment arms (n = 20 each): no treatment (Group 1); intravenous nab-paclitaxel at 5.0 mg/kg once weekly for 3 weeks (Group 2); IH NanoPac at 0.5 or 1.0 mg/kg, once weekly for 4 weeks (Groups 3 and 4), or twice weekly for 4 weeks (Groups 5 and 6). Upon necropsy, left lungs were paraffin embedded, serially sectioned, and stained for histopathological examination. A subset was evaluated by immunohistochemistry (IHC), anti-pan cytokeratin staining AE1/AE3+ tumor cells and CD11b+ staining dendritic cells, natural killer lymphocytes, and macrophage immune cells (n = 2, Group 1; n = 3 each for Groups 2-6). BCL-6 staining identified B lymphocytes (n = 1 in Groups 1, 2, and 6). Results: All animals survived to scheduled necropsy, exhibited no adverse clinical observations due to treatment, and gained weight at the same rate throughout the study. Histopathological evaluation of Group 1 lung samples was consistent with unabated tumor growth. Group 2 exhibited regression in 10% of animals (n = 2/20). IH NanoPac-treated groups exhibited significantly higher tumor regression incidence per group (n = 11-13/20; p < 0.05, χ2). IHC subset analysis revealed tumor-nodule cluster separation, irregular borders between tumor and non-neoplastic tissue, and an increased density of infiltrating CD11b+ cells in Group 2 animals (n = 2/3) and in all IH NanoPac-treated animals reviewed (n = 3/3 per group). A single animal in Group 4 and Group 6 exhibited signs of pathological complete response at necropsy with organizing stroma and immune cells replacing areas presumed to have previously contained adenocarcinoma nodules. Conclusion: Tumor regression and immune cell infiltration were observed in all treatment groups, with an increased incidence noted in animals receiving IH submicron particle paclitaxel treatment.
Asunto(s)
Antineoplásicos Fitogénicos/administración & dosificación , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Paclitaxel/administración & dosificación , Administración por Inhalación , Albúminas/administración & dosificación , Animales , Antineoplásicos Fitogénicos/farmacología , Carcinoma de Pulmón de Células no Pequeñas/patología , Línea Celular Tumoral , Relación Dosis-Respuesta a Droga , Humanos , Neoplasias Pulmonares/patología , Masculino , Paclitaxel/farmacología , Ratas , Ratas DesnudasRESUMEN
BACKGROUND: Inhaled chemotherapeutics may enhance pulmonary drug exposure to malignant lesions in the lung without substantially contributing to systemic toxicities. The pharmacokinetic profile of inhaled submicron particle paclitaxel (NanoPac®) in healthy rodent plasma and lung tissue is evaluated here to determine administration proof-of-principle. METHODS: Healthy male Sprague Dawley rats received paclitaxel in one of three arms: intravenous nab-paclitaxel at 2.9 mg/kg (IVnP), inhaled NanoPac low dose (IHNP-LD) at 0.38 mg/kg, or inhaled NanoPac high dose (IHNP-HD) at 1.18 mg/kg. Plasma and lung tissue paclitaxel concentrations were determined using ultraperformance liquid chromatography tandem mass spectrometry from animals sacrificed at 10 time points ranging up to 2 weeks after administration. Peak concentration (Cmax), apparent residence half-life (T1/2), exposure (AUC(last)), and dose-normalized exposure (AUCD(last)) were determined. Pulmonary histopathology was performed on rats sacrificed at the 336-hour time point. RESULTS: Paclitaxel was detectable and quantifiable in the rat lung for both inhaled NanoPac arms sampled at the final necropsy, 336 hours postadministration. Substantial paclitaxel deposition and retention resulted in an order of magnitude increase in dose-normalized pulmonary exposure over IVnP. Inhaled NanoPac arms had an order of magnitude lower plasma Cmax than IVnP, but followed a similar plasma T1/2 clearance (quantifiable only to 72 hours postadministration). Pulmonary histopathology found all treated animals indistinguishable from treatment-naive rats. CONCLUSION: In the rodent model, inhaled NanoPac demonstrated substantial deposition and retention of paclitaxel in sampled lung tissue. Further research to determine NanoPac's toxicity profile and potential efficacy as lung cancer therapy is underway.
Asunto(s)
Antineoplásicos Fitogénicos/administración & dosificación , Pulmón/metabolismo , Paclitaxel/administración & dosificación , Administración por Inhalación , Albúminas/administración & dosificación , Albúminas/farmacocinética , Animales , Antineoplásicos Fitogénicos/farmacocinética , Área Bajo la Curva , Relación Dosis-Respuesta a Droga , Semivida , Masculino , Paclitaxel/farmacocinética , Ratas , Ratas Sprague-Dawley , Factores de Tiempo , Distribución TisularRESUMEN
BACKGROUND AND PURPOSE: Small vessel disease is the major cause of white matter injury in patients with vascular cognitive impairment. Matrix metalloproteinase (MMP)-mediated inflammation may be involved in the white matter damage with oligodendrocyte (Ol) death. Therefore, we used spontaneously hypertensive stroke-prone rats to study the role of neuroinflammation in white matter damage. METHODS: Permanent unilateral carotid artery occlusion was performed at 12 weeks of age in spontaneously hypertensive stroke-prone rats. Following surgery, rats were placed on a Japanese permissive diet and received 1% NaCl in drinking water. MRI, histology, biochemistry, and ELISA characterized white matter lesions, and cognitive impairment was tested by Morris water maze. RESULTS: White matter damage was observed 4 to 5 weeks following permanent unilateral carotid artery occlusion/Japanese permissive diet. Immunoblotting showed marked reduction in myelin basic protein and upregulation of immature Ols. Mature Ols underwent caspase-3-mediated apoptosis. Morris water maze showed cognitive impairment. Abnormally appearing vessels were observed and surrounded by inflammatory-like cells. IgG extravasation and hemorrhage, indicating blood-brain barrier (BBB) disruption, was closely associated with MMP-9 expression. Lesions in white matter showed reactive astrocytosis and activated microglia that expressed tumor necrosis factor-α. MMP-3 and MMP-9 were significantly increased, and MMP-2 was reduced in both astrocytes and Ol. CONCLUSIONS: We found apoptosis of mature Ols with an increase in immature Ols. Increased MMP-3, MMP-9, and tumor necrosis factor-α were associated with myelin breakdown and BBB disruption. Neuroinflammation is an important factor in white matter damage and Ol death, and studies using this new model can be performed to assess agents to block inflammation.
Asunto(s)
Apoptosis , Corteza Cerebral/metabolismo , Proteína Básica de Mielina/metabolismo , Vaina de Mielina/metabolismo , Animales , Astrocitos/metabolismo , Astrocitos/patología , Barrera Hematoencefálica/metabolismo , Barrera Hematoencefálica/patología , Caspasa 3/biosíntesis , Corteza Cerebral/patología , Humanos , Inflamación/metabolismo , Inflamación/patología , Masculino , Metaloproteinasa 2 de la Matriz/biosíntesis , Metaloproteinasa 3 de la Matriz/biosíntesis , Metaloproteinasa 9 de la Matriz/biosíntesis , Microglía/metabolismo , Microglía/patología , Vaina de Mielina/patología , Ratas , Ratas Endogámicas SHR , Factor de Necrosis Tumoral alfa/biosíntesisRESUMEN
This 2-year study examined the effects of early second language exposure on phonological awareness skills. Syllable, onset-rime and phoneme awareness skills of 72 anglophone children attending English or French immersion programs in primary and grade 1 were investigated. Three-way mixed ANOVAS revealed the following effects and interactions. In terms of grade effect, grade 1 students performed significantly better than primary students on phoneme and onset-rime tasks. A stimulus language effect was observed for the three levels of phonological awareness. All children performed better on English tasks than on French ones. Interaction effects of stimulus language by program were revealed for phoneme as well as syllable tasks. Posthoc analyses revealed that French students performed better on English phoneme and syllable tasks than on French, while English students performed better than French immersion students on French syllable tasks. Correlational analyses revealed significant relationships between reading and phoneme and onset-rime phonological awareness tasks regardless of program of instruction (English, French immersion) or language of reading test (English, French). Syllable awareness was only significantly correlated with the French non-word reading task for the French immersion students.