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Biomedical subjects

J Avila

Publications and source records attributed to J Avila.

At least 289 records · Page 16Linked to original sources
PubMed1978

Binding of microtubule proteins to DNA: specificity of the interaction.

Tubulin is detected among the DNA-binding proteins when an extract from fibroblasts is chromatographed on DNA-cellulose. Further purification of the colchicine-binding activity shows that purified tubulin from fibroblasts does not bind to DNA. Depolymerized brain microtubule proteins show a high affinity for DNA. The fraction bound is composed of tubulin and microtubule-associated proteins. Experiments with fractionated microtubule proteins indicate that tubulin-free microtubule associated proteins bind to DNA, while tubulin free of microtubule-associated proteins does not. Microtubule-associated proteins bind better to eukaryotic than to phage DNA suggesting a specificity of the interaction.

Animals↗
PubMed1978

Interaction of contractile proteins with DNA.

The interaction of contractile proteins (myosin, actin, tropomyosin and troponin) with DNA was studied in vitro using a nitrocellulose filter binding technique. The data indicate a high affinity of myosin and troponin for DNA, a lesser interaction between DNA and tropomyosin and the absence of binding of actin to DNA. When binding to DNA was detected, the interaction was higher with single-stranded DNA than with RNA or double-stranded DNA, although in some conditions myosin binds equally as well to native as to denatured eukaryotic DNA. Myosin binds better to eukaryotic than to phage native DNA.

Actins↗
PubMed1977

Carcinoma of the pinna.

Ninety-seven consecutive cases of carcinoma of the pinna are reviewed in this report. Fifty-six of the tumors were basal cell and thirty-nine squamous cell carcinoma. Fifty patients were surgically treated and forty-five irradiated. Small and/or peripheral lesions were excised and the large and/or centrally located lesions referred for irradiation. Analysis of the results shows no difference in tumor control rate, and the complication rate was also comparable with both modalities. Although chondritis was seen in three cases after irradiation, it also occurred in one case after excision. Our results indicate that neither modality should be used with total exclusion of the other. Initial resection would seem preferable in small lesions where primary closure is possible and in extensive lesions where a good cosmetic result is precluded by the destruction of normal tissue. Radiotherapy seems of value in those lesions in which resection would result in objectionable cosmetic defect.

Aged↗
PubMed1977

Autogenous cancellous-marrow bone grafts in irradiated dog mandibles.

A pilot study was conducted to investigate the osteogenic potential of autogenous cancellous-marrow grafts placed in irradiated tissue. Three dogs received 4,100 rads in ten treatments ooer 32 days. Postirradiation discontinuity mandibular defects were created. These defects were restored with cancellous-marrow autogenous bone supported in position by a titanium mesh basket. Bony union occurred in all the mandibles. The titanium mesh partially eroded through the oral mucosa in two animals. The quantity of new bone formed in the surgical defect varied. Two dogs had complete restoration of the resected mandible. Histologic observations were documented in both the graft area and the surgically uninvolved contralateral side of the mandible.

Animals↗
PubMed1977

Radiosensitization of normal tissue by chloroquine.

Severe radiation reaction with chest wall necrosis occurred following 5,000 rads of 60Co irradiation. The patient was arthritic and on chloroquine therapy. This delayed reaction was due to chloroquine radiosensitization. Rats treated with combined chloroquine and chest wall irradiation were compared to rats receiving irradiation alone. The acute radiation reaction was greater in the drug treated animals.

Animals↗
PubMed1976

Approaches to optimization of dose in radiation therapy of cervix carcinoma.

A treatment planning approach to radiation therapy for carcinoma of the cervix which attempts to maximize tumor dose and minimize the effect on normal tissue must include additonal dose reference points besides the standard ones (Manchester points A and B, mg-hrs.) A variety of loading configurations can be used to treat the tumor volume to a specified dose. In order to avoid inappropriate loading arrangements, dose at the tumor and at the vault must be carried to required therapeutic levels.

Female↗
PubMed1975

Calvarial-scalp compensator for radiotherapy.

A universal compensator for megavoltage cobalt-60 radiotherapy of the skull was constructed and applied to clinical radiotherapy use. This compensator allows the skull to be treated with a more uniform dose.

Adult↗
PubMed1974

Viral DNA synthesis in cells infected by temperature-sensitive mutants of simian virus 40.

Temperature-sensitive mutants of simian virus 40 (SV40) have been classified as those that are blocked prior to viral DNA synthesis at the restrictive temperature, "early" mutants, and those harboring a defect later in the replication cycle, "late" mutants. Mutants of the A and D complementation groups are early, those of the B, C, and BC groups are late. Our results confirm earlier reports that A mutants are defective in a function required for the initiation of each round of viral DNA synthesis. D mutants, on the other hand, continue viral DNA replication at the restrictive temperature after preincubation at the permissive temperature. The length of time required for D function to be expressed at the permissive temperature-after which infection proceeds unabated on shifting of the cultures to the restrictive temperature-is 10 to 20 h. The viral DNA synthesized in D mutants under these conditions progresses in normal fashion through replicative intermediate molecules to mature component I and II DNA molecules.

Animals↗