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R P Santos

Publications and source records attributed to R P Santos.

9 recordsLinked to original sources
PubMed2006

Endoscopic endonasal approach for cerebrospinal fluid fistulae.

Different techniques have been proposed to repair cerebrospinal fluid rhinorrhea. Advances in nasal surgery led to a high success rate and low morbidity for the endonasal approach. It has become the favorite route for treating cerebrospinal fluid leaks of the anterior skull base. Better results have been obtained with the improvement of rigid endoscopes and intrathecal sodium fluorescein. In a prospective study, twenty-four patients with cerebrospinal fluid rhinorrhea were evaluated and treated by endoscopic endonasal surgery. In all cases intrathecal sodium fluorescein enabled a precise localization of the bone defect. The most common causes of CSF rhinorrhea were traumatic (8 cases, 33 %), spontaneous (6 cases, 25 %), and iatrogenic (5 cases, 20.8 %). Preoperative radiological evaluations (plane CT, CT cisternogram and MRI) showed the exact site and size of the defect in all patients. The most common site of leakage was the ethmoidal roof-cribriform plate. Primary closure was achieved in all patients. There were no major operative or postoperative complications. The endoscopic endonasal approach can be considered the first choice in the treatment of cerebrospinal fluid rhinorrhea.

Abdominal Fat↗
PubMed2002

Protective effect of early and late administration of pralidoxime against organophosphate muscle necrosis.

The objective of the present investigation was to study the protection afforded by a single administration of pralidoxime against the muscle necrosis induced by the organophosphate compound metamidophos at different times after intoxication. The fiber necrosis of the diaphragm muscle was quantified by a morphometric technique, comparing the area fraction occupied by necrotic muscle fibers in animals that received pralidoxime at different times after intoxication, i.e., 0, 1, 3, 6, and 12 h. Pralidoxime administration protected metamidophos-induced muscle necrosis in all groups studied except for the 12-h group. The earlier the administration of pralidoxime the greater the protection against muscle necrosis. This protection was not accompanied by complete reactivation of plasma cholinesterase activity. Results support the current opinion that pralidoxime should be administered as soon as possible after organophosphate intoxication, because in addition to reversing the muscarinic effects, early administration of pralidoxime also prevents muscle necrosis--which could impair muscular function and respiratory condition. The time difference between recovery of plasma cholinesterase activity and muscle necrosis protection indicates that this method is not completely trustworthy for patient follow-up, since some improvement may occur in spite of the low plasma cholinesterase activity.

Animals↗
PubMed2001

Ki-67 expression in anal intraepithelial neoplasia in AIDS.

CONTEXT: AIDS is one of the most important risk factors for progression and recurrence of anogenital condyloma. In a previous work, we observed that patients with warts and high-grade AIN (HAIN) had recurrences more frequently than did patients with warts without AIN. The mechanisms of this increased incidence of high-grade lesions in AIDS are not known. OBJECTIVE: We studied the expression of the proliferative marker Ki-67 by immunohistochemical methods, in specimens of anal condyloma from HIV+ patients to clarify whether its expression can be associated to the grade of AIN. DESIGN: A retrospective study of histological specimens. SETTING: University referral unit. SAMPLE: 34 patients were divided into two groups: (1) condylomas with low grade AIN (LAIN), with 25 patients; and (2) condylomas with HAIN, with 9 patients. In this latter group we examined two areas: 2A (HAIN area) and 2B (LAIN area). MAIN MEASUREMENTS: The immunohistochemical reaction for Ki-67 was done on histological sections. Slices were lightly stained with hematoxylin, to help us in Ki-67 positive cell counting. The percentage of Ki-67 marked nuclei was calculated. We applied one-way variance analysis for statistics. RESULTS: The mean number of Ki-67 positive cells in group 1 was 19.68 +/- 10.99; in group 2 (area A) it was 46.73 +/- 10.409; and in area B it was 36.43 +/- 14.731. There were statistical differences between groups 1 and 2A and between groups 1 and 2B. Ki-67 positive cells predominated in the lower layer in LAIN. Positive Ki-67 cells were found in all layers in group 2A, and in group 2B they predominated in the two lower or in all layers of the epithelium. CONCLUSIONS: Our results suggest that LAIN areas (using routine staining techniques) in HAIN can have a biological behavior more similar to HAIN.

Adult↗
PubMed2000

Histologic peripheral nerve changes in rats induced by deltamethrin.

Synthetic pyrethroid insecticides have been used in the last two decades largely because of their high activity as an insecticide and low mammalian toxicity. Some studies have demonstrated that these products, especially compounds with an alpha-cyano group, are toxic to the mammalian central nervous system (CNS) in acute intoxications. However, morphological studies are scarce. In the present work the histopathologic changes of the sciatic and tibial nerves of rats submitted to acute intoxication with the cyanopyrethroid deltamethrin were studied. For 3 consecutive days male Wistar rats received by oral gavage deltamethrin at a dose of 45 mg/kg body wt. On the 4th day fragments of sciatic and tibial nerves were studied by transmission electron microscopy (TEM) and teasing of individual nerve fibers. In addition, another group of rats were allowed to recover until the 10th day. Teasing of nerves of animals sacrificed on the 4th day revealed myelin ovoids, which are indicative of axonal damage. TEM demonstrated rare degenerated axons completely filled with organelles, in particular mitochondria, and with electron-dense lamellar bodies that resemble myelin figures. In addition, great cytoplasmic vacuolization caused by proliferation and dilation of the rough and smooth endoplasmic reticulum and Golgi apparatus was observed in some Schwann cells. No lesion was found 7 days after discontinuation of the treatment (group2). Since these histologic changes are transitory and scarce, the question arises: Are they related to the changes in NA(+), K(+)-ATPase activity or Na(+) channels caused by pyrethroid compounds?

Animals↗
PubMedDate not supplied

Hantavirus pulmonary syndrome in Brazil: clinical aspects of three new cases.

Hantavirus pulmonary syndrome (HPS) has been recognized recently in Brazil, where 28 cases have been reported as of September 1999. We report here the clinical and laboratory findings of three cases whose diagnoses were confirmed serologically. All the patients were adults who presented a febrile illness with respiratory symptoms that progressed to respiratory failure that required artificial ventilation in two of them. Laboratory findings were most of the time consistent with those reported in the United States in patients infected with the Sin Nombre virus, and included elevated hematocrit and thrombocytopenia; presence of atypical lymphocytes was observed in one patient. The chest radiological findings observed in all the patients were bilateral, diffuse, reticulonodular infiltrates. Two patients died. Histopathological examination of the lungs of these patients revealed interstitial and alveolar edema, alveolar hemorrhage, and mild interstitial pneumonia characterized by infiltrate of immunoblasts and mononuclear cells. In the epidemiologic investigation of one of the cases, serologic (ELISA) tests were positive in 3 (25%) out of 12 individuals who shared the same environmental exposure. HPS should be included in the differential diagnosis of interstitial pneumonia progressing to acute respiratory failure.

Adult↗