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Biomedical subjects

J Rodriguez

Publications and source records attributed to J Rodriguez.

352 records · Page 20Linked to original sources
PubMedDate not supplied

Ultrastructural study of the osteointegration of bioceramics (whitlockite and composite beta-TCP + collagen) in rabbit bone.

Study examines the osteointegration of two porous ceramic implants, beta-tricalcium phosphate (beta-TCP) and a composite (beta-TCP-collagen), in femur and tibias of 20 New Zealand white rabbits, which were sacrificed 1 week and 1, 4, and 12 months postimplant so that radiological, optical microscopic, and ultrastructural studies could be carried out. The results show a progressive degradation and resorption of both implant materials by means of a macrophagic reaction, which is at its most intense 1 month postimplant. The materials are substituted by newly formed bone tissue starting at the host bone-implant interface, the substitution being almost total by the end of the study, although less completely and earlier than in the case of the composite. Both materials can be considered as potential substitutes for bone tissue since they are biocompatible, bioreabsorbable, and osteogenic.

Animals↗
PubMedDate not supplied

Immunohistochemical characterization of pineocytomas.

The immunoreactivity of a panel of poly- and monoclonal antibodies raised against different neuronal and glial antigens, was studied in paraffin-embedded specimens of five pineocytomas. Antibodies against neuron-specific enolase (NSE), S-100 protein, neurofilaments protein (NFP), glial fibrillar acidic protein (GFAP), myelin basic protein (MBP), Synaptophysin (SYN) and vimentin were used. NSE immunoreactivity was detectable in nearly all tumoral cells. S-100 expression was present in all tumors, but a significant variation in the number of S-100 positive cells was noted in the different specimens; they ranged from 3% of S-100 positive cells in some areas of case 1, to 30% in other areas of case 4. The number of GFAP-positive cells detected in four of the five tumors was minimal. In the remaining tumor, 10% to 14% the positively GFAP antisera-stained cells could be seen in some areas; this tumor was considered a pineocytoma with astrocytic differentiation. MBP immunoreactivity was found in isolated cells only in one tumor. Neurofilaments or vimentin expression could not be found in tumoral cells. Synaptophysin was studied in two tumors (cases 4 and 5). Both tumors showed a fine granular neuropil pattern of immunoreactivity, but only in isolated cells of case 5, occasional cytoplasmic positivity could be determined. Based upon our results we can conclude that NSE and synaptophysin are markers that may be applied in the diagnosis of pineocytomas. Further, our results support the hypothesis that the tumoral cells in these neoplasms are of neuroendocrine origin.

Adolescent↗
PubMedDate not supplied

Continuous infusion epidural anesthesia during labor: a randomized, double-blind comparison of 0.0625% bupivacaine/0.002% butorphanol and 0.125% bupivacaine.

The efficacy of pain relief and the maternal and neonatal effects of continuous epidural infusion of 0.0625% bupivacaine/0.002% butorphanol was compared with the infusion of 0.125% bupivacaine alone in a randomized, double-blind study of 32 women in labor. A test dose of 2 ml 0.5% bupivacaine was given to every patient and followed by two epidural regimens in randomized, double-blind manner. Group B-B (bupivacaine/butorphanol) patients received 7.5 ml 0.125% bupivacaine plus 1 mg butorphanol (0.5 ml) followed by an infusion of 0.0625% bupivacaine/0.002% butorphanol at a rate of 12 ml/hour; Group B (bupivacaine alone) patients received 8 ml 0.25% bupivacaine followed by an infusion of 0.125% bupivacaine at a rate of 12 ml/hour. A bolus of 5 ml 0.125% bupivacaine or 0.0625% bupivacaine was given to Group B or B-B, respectively, if additional pain relief was required. Infusion of B-B combination resulted in similar pain relief and fewer patients with motor block than bupivacaine alone; 12% versus 38% in Groups B-B and B, respectively, had motor weakness. A smaller dose of bupivacaine was used in the B-B group compared to the B group; 71 +/- 14 versus 99 +/- 13 mg (mean +/- SEM; p less than 0.05). Progress of labor and the mode of delivery did not differ significantly between the two groups. All infants were vigorous and had normal acid-base status and neurologic adaptive capacity scores. Butorphanol appears to be useful as an adjunct to epidural bupivacaine for continuous epidural infusion during labor without adversely affecting the mother or the neonate.

Adult↗
PubMedDate not supplied

Pontoneocerebellar hypoplasia--a probable consequence of prenatal destruction of the pontine nuclei and a possible role of phenytoin intoxication.

The autopsy findings of a 21/2-year-old microcephalic, mentally retarded girl, with tetraparesis, and dysmorphic features are reported. Neuropathologic findings, typical of the ponto-neocerebellar hypoplasia described by Brun [1917], suggest that this abnormality was the result of a prenatally acquired destruction of the pontine nuclei, with a secondary retrograde degeneration of the dentatopontine tract. The possible role of phenytoin, taken by the mother during pregnancy, is discussed.

Abnormalities, Drug-Induced↗
PubMedDate not supplied

The Bernese periacetabular osteotomy for the treatment of adult hip dysplasia.

The Bernese periacetabular osteotomy was developed for precise spatial reorientation of the adult dyplastic acetabulum and improvement of the femoral head coverage. The osteotomy has a large correction potential (average decrease of acetabular index: 22 degrees) but is technically demanding. With appropriate patient selection, the results obtained are promising. Therefore, the technique described should be considered in the treatment plan for the acetabular dysplasia of the young adult.

Acetabulum↗