Biomedical subjects

N M Martins

Publications and source records attributed to N M Martins.

3 recordsLinked to original sources

PubMed2007

Cisplatin-induced nephrotoxicity is associated with oxidative stress, redox state unbalance, impairment of energetic metabolism and apoptosis in rat kidney mitochondria.

The clinical use of cisplatin (cis-diamminedichloroplatinum II) is highly limited by its nephrotoxicity. The precise mechanisms involved in cisplatin-induced mitochondrial dysfunction in kidney have not been completely clarified. Therefore, we investigated in vivo the effects of cisplatin on mitochondrial bioenergetics, redox state, and oxidative stress as well as the occurrence of cell death by apoptosis in cisplatin-treated rat kidney. Adult male Wistar rats weighing 200-220 g were divided into two groups. The control group (n = 8) was treated only with an intraperitoneal (i.p.) injection of saline solution (1 ml per 100 g body weight), and the cisplatin group (n = 8) was given a single injection of cisplatin (10 mg/kg body weight, i.p.). Animals were sacrificed 72 h after the treatment. The cisplatin group presented acute renal failure characterized by increased plasmatic creatinine and urea levels. Mitochondrial dysfunction was evidenced by the decline in membrane electrochemical potential and the substantial decrease in mitochondrial calcium uptake. The mitochondrial antioxidant defense system was depleted, as shown by decreased GSH and NADPH levels, GSH/GSSG ratio, and increased GSSG level. Moreover, cisplatin induced oxidative damage to mitochondrial lipids, including cardiolipin, and oxidation of mitochondrial proteins, as demonstrated by the significant decrease of sulfhydryl protein concentrations and increased levels of carbonylated proteins. Additionally, aconitase activity, which is essential for mitochondrial function, was also found to be lower in the cisplatin group. Renal cell death via apoptosis was evidenced by the increased caspase-3 activity. Results show the central role of mitochondria and the intensification of apoptosis in cisplatin-induced acute renal failure, highlighting a number of steps that might be targeted to minimize cisplatin-induced nephrotoxicity.

Aconitate Hydratase↗

PubMed2001

Speech intelligibility after glossectomy and speech rehabilitation.

BACKGROUND: Oral tumor resections cause articulation deficiencies, depending on the site, extent of resection, type of reconstruction, and tongue stump mobility. OBJECTIVES: To evaluate the speech intelligibility of patients undergoing total, subtotal, or partial glossectomy, before and after speech therapy. PATIENTS AND METHODS: Twenty-seven patients (24 men and 3 women), aged 34 to 77 years (mean age, 56.5 years), underwent glossectomy. Tumor stages were T1 in 3 patients, T2 in 4, T3 in 8, T4 in 11, and TX in 1; node stages, N0 in 15 patients, N1 in 5, N2a-c in 6, and N3 in 1. No patient had metastases (M0). Patients were divided into 3 groups by extent of tongue resection, ie, total (group 1; n = 6), subtotal (group 2; n = 9), and partial (group 3; n = 12). Different phonological tasks were recorded and analyzed by 3 experienced judges, including sustained 7 oral vowels, vowel in a syllable, and the sequence vowel-consonant-vowel (VCV). The intelligibility of spontaneous speech (sequence story) was scored from 1 to 4 in consensus. All patients underwent a therapeutic program to activate articulatory adaptations, compensations, and maximization of the remaining structures for 3 to 6 months. The tasks were recorded after speech therapy. To compare mean changes, analyses of variance and Wilcoxon tests were used. RESULTS: Patients of groups 1 and 2 significantly improved their speech intelligibility (P<.05). Group 1 improved vowels, VCV, and spontaneous speech; group 2, syllable, VCV, and spontaneous speech. Group 3 demonstrated better intelligibility in the pretherapy phase, but the improvement after therapy was not significant. CONCLUSIONS: Speech therapy was effective in improving speech intelligibility of patients undergoing glossectomy, even after major resection. Different pretherapy ability between groups was seen, with improvement of speech intelligibility in groups 1 and 2. The improvement of speech intelligibility in group 3 was not statistically significant, possibly because of the small and heterogeneous sample.

Adult↗

PubMed2000

Video fluoroscopic evaluation after glossectomy.

BACKGROUND: The swallowing deficits that result from oral or oropharyngeal resections vary considerably depending on the site, extension of the resection, and type of reconstruction. Most patients will experience some degree of dysphagia despite the reconstructive effort. Furthermore, a glossectomy is frequently associated with voice and speech difficulties. OBJECTIVES: To characterize swallowing in patients who underwent a glossectomy and to define the limits and the compensatory movements using video fluoroscopic analysis. DESIGN AND SETTING: Video fluoroscopic evaluation of 15 patients who underwent glossectomies at the Centro de Tratamento e Pesquisa Hospital do Cancer A. C. Camargo, S*ao Paulo, Brazil. PATIENTS: We examined 15 patients: 5 who underwent a partial glossectomy, 2 who underwent a subtotal glossectomy, and 8 who underwent a total glossectomy with laryngeal preservation and reconstruction with myocutaneous flaps (9 pectoralis major flaps and 1 latissimus dorsi flap). The 15 patients were enrolled in a program that included voice, speech, and swallowing rehabilitation. RESULTS: All patients who underwent a partial glossectomy had difficulties with formation and anteroposterior propulsion of the bolus in the oral cavity and an increase in oral transit time, which was more evident with materials of thicker consistencies. All patients who underwent a total or subtotal glossectomy with laryngeal preservation had an increase in oral transit time and stasis of food in the oral cavity, the pharynx, and the superior esophageal sphincter. Of the 15 patients, 2 had moderate and asymptomatic aspiration. These 2 patients had swallowing compensations, such as increased buccal, mandibular, pharyngeal, and laryngeal activity and voluntary protection of the larynx during swallowing. CONCLUSIONS: This study demonstrates the effectiveness of swallowing in patients who were enrolled in voice, speech, and swallowing rehabilitation after undergoing a partial or total glossectomy. An increase in oral transit time was detected in all patients. Only 2 of the 10 patients who underwent a total glossectomy had persistent asymptomatic aspiration.

Adult↗