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Biomedical subjects

A M Ubios

Publications and source records attributed to A M Ubios.

54 records · Page 3Linked to original sources
PubMed1984

Effects of acute intoxication with uranyl nitrate on bone formation.

The alteration of bone formation by an acute intoxication with uranyl nitrate is demonstrated by histologic and histometric methods. When compared with the controls, intoxicated animals showed a markedly lower density in healing sockets, while bone formation was reduced in healing sockets as well as in metaphyseal bone.

Animals↗
PubMed1984

Salivary gland tumors induced by 32P.

The oncogenic power of 32P was demonstrated in salivary glands. An intraglandular injection of 0.25 mCi of chromic colloidal phosphate (32P) was administered to young adult Wistar rats. Seven months post-injection, tumors began to appear in the neck region in 64% of the rats. The tumors were sarcomas (50%), carcinomas (35.70%), and carcino-sarcomas (14.28%).

Animals↗
PubMed1983

Radioactive-induced tumors by phosphorus-32 as colloidal compound.

Chromic colloidal phosphate labeled with 32P, which has been proposed for the treatment of several articular diseases, was injected intra-articularly in the knee joint of adult Wistar rats. After a 270 days minimum latent period, tumors began to appear in the injected zone, to a 70% frequency. Ten lung metastases were detected. In five cases, squamous cell carcinomas were induced in the injected area. The relevance of a sound evaluation of the risk involved in treatments with radioactive isotopes, is discussed.

Animals↗
PubMed1983

Freeze-fracture surface of salivary glands of rat observed by scanning electron microscopy.

The structure of parenchymal components of rat submandibular glands observed with scanning electron microscopy is presented. The glands were fixed, submerged in liquid nitrogen, cryofractured, dehydrated and critical-point-dried. The fracture surface displayed the acini, granular ducts and striated ducts. Acini exhibit a typical sponge-like pattern of irregular and empty cavities. Granular ducts are lined by bulging cells laden with numerous secretory granules. Their diameter ranged from 0.2 to 3.2 microns, with a mean value of 1.240.4 microns. Measurement of the actual granules was rendered possible by direct observation. Striated ducts exhibited a cribiform pattern near the basal cell region which corresponds to infoldings of the basal cell membrane.

Animals↗
PubMed1978

Total and local X-radiation effects on 18F uptake of bones.

Flourine uptake in rat bones under local and total-body X-irradiation was studied. Data were obtained by measurements with a scintillation crystal counter and in the case of limbs by means of macro and microautoradiographies. The autoradiographic studies showed a higher concentration of the isotope in the metaphyseal area of the endochondral plate. Irradiation produced a depression of 18F uptake in both cases. An alteration in the mineralization mechanism due to irradiation is presumed.

Animals↗
PubMed1978

Radiation effects produced by the intra-articular injection of 32P.

Colloidal forms of radioactive isotopes are being used for the treatment of some articular diseases. The radiation effects of intra-articular injection of 0.25 mCi of 32P in the form of colloidal chromic phosphate were investigated in one of the knee joints of adult Wistar rats. The contralateral knee was used as a control. The animals were sacrificed one, 7, 14, 28 and 56 days later. Destructive changes were found after 56 days. The articular cartilage was atrophied and covered by a fibrous pannus. The growth cartilage was severely disorganized and there were deleterious effects on both cells and matrix.

Animals↗
PubMedDate not supplied

Ethane 1-hydroxy-1, 1-diphosphonate (EHDP) counteracts the inhibitory effect of uranyl nitrate on bone formation.

The beneficial effect of ethane 1-hydroxy-1, 1-diphosphonate (EHDP) in restoring the inhibition of bone formation in cases of acute uranium intoxication is presented. Bone formation was studied histomorphometrically in a model of alveolar bone healing. After tooth extraction, 40 rats were divided into 4 groups that received (1) no further treatment, (2) 10 daily intraperitoneal injections of 7.5 mg/kg of body weight of EHDP, (3) an intraperitoneal injection of 2.0 mg/kg of body weight of uranyl nitrate, and (4) the same treatment as was provided rats in groups 2 and 3. The results showed that the healing of bone did not occur in exposed animals, whereas healing in EHDP-treated exposed animals did not differ from that of nonexposed controls. This effect might result from a blocking and/or competitive action of EHDP and/or the stimulation that EHDP elicits at the doses and in the administration period studied.

Animals↗
PubMedDate not supplied

Bone growth is impaired by uranium intoxication.

Acute and chronic uranium intoxication leads to the inhibition of bone formation and impaired bone modeling and remodeling. As these are processes directly involved in bone growth the aim of this paper is to present a biometric study of bone growth--tibiae and mandibles of rats intoxicated with uranium. Wistar ratios weighing 60-80 g were used as follows, a) one intraperitoneal injection (IPI, 2 mg/Kg of body weight)) of uranyl nitrate; b) 30 daily applications on the dorsal skin of aliquots of a mixture of U308, concentrated at 2% and at 4%--percutaneous absorption(PA)-. Tibia and mandible length were smaller in both experimental groups than in their respective controls. Some of the mandibular parameters were lower in intoxicated animals than their controls which in turn results in the alteration of the mandibular shape. We conclude that impairment in bone growth can be achieved by uranium intoxication.

Administration, Cutaneous↗