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Biomedical subjects

G Ambrosio

Publications and source records attributed to G Ambrosio.

At least 145 records · Page 8Linked to original sources
PubMed1982

The effects of iodination on the polypeptide heterogeneity of thyroglobulin.

19 S thyroglobulins from several mammals were prepared under conditions designed to minimize endogenous proteolytic activities. The purified iodoproteins were then fractionated by RbCl isopycnic gradient centrifugation and fractions of varying iodine content analyzed by SDS-polyacrylamide gel electrophoresis. The dependence on the iodination level of molecular dissociability, previously reported in preparations "markedly' differing in their iodination degree, has been now ultimately assessed in all species investigated and demonstrated even for fraction differing from each other only by a few iodine atoms. Upon reduction fractions across the isopycnic gradients showed the occurrence of discrete electrophoretic bands faster than the 300,000 Da subunit: the relative amount of these peptides has been found to be linearly related to the iodine content of the molecules analyzed. This behaviour has been observed in all animal species investigated. In conclusion, our data suggest that iodination, beside the well-documented effects on thyroglobulin conformational properties, may also affect its "apparent' polypeptide chain composition. The origin of such heterogeneity is discussed.

Animals↗
PubMed1982

The AC/A ratio and convergence in hypermetropia corrected with spectacles or contact lenses.

Some hypermetropes, when corrected with contact lenses, appear to have a much smaller AC/A ratio than when corrected with spectacle lenses. Ocular convergence measured with contact lenses is greater than that measured with spectacles. Studies were carried out to establish the cause of these effects. Theoretical considerations are compared with the experimental results obtained. This study emphasizes the importance of the different amounts of magnification induced by contact lenses as compared with spectacles.

Adolescent↗
PubMed1982

Further observations on the electrophysiologic effects of oral amiodarone therapy.

A case is presented of a reversible intra-Hisian block occurring under amiodarone treatment for atrial tachycardia in a patient without clear intraventricular conduction abnormalities. His bundle recordings showed an atrial tachycardia with intermittent exit block and greatly prolonged BH and HV intervals (40 and 100 msec, respectively). Thirty days after amiodarone discontinuation, His bundle electrograms showed atrial flutter without intra-Hisian or infra-Hisian delay. Amiodarone should be used with caution during long-term oral therapy in patients with or without clear intraventricular conduction defects.

Adult↗
PubMed1981

Polypeptide chain composition of thyroglobulin.

It is known that thyroglobulin can be dissociated into a component which appears to be a half molecule (12 S) of the undissociated molecule (19 S). In the present work, these two molecular species were isolated with a high degree of purity by preparative gel electrophoresis in sodium dodecyl sulfate and were individually reduced. The reduction pattern of the 12 S form displayed only two closely migrating bands, both having an apparent Mr near 330 000, whereas the undissociated (covalently linked) 19 S form showed a complex pattern consisting of, besides the 330 000 doublet, nonreducible material and several faster bands, resembling the pattern of the unfractionated protein. The origin of the faster-moving peptides is not known. These results have been obtained with both hog and rat thyroglobulin.

Animals↗
PubMed1979

[Remarks concerning a case of oculogyric crisis (author's transl)].

A case of intermittent spasm of the oculo-palpebral motility present features which permit its inclusion among oculogyric crisis. The therapy with clonazepam gave good results supporting the etiological hypothesis of an alteration of the neurons at level of the mesencephalic reticular system.

Brain Diseases↗
PubMed1978

[Long-term treatment of arterial hypertension with propranolol. Combination with diuretics and dihydrazinophthalazine].

The effect of long-term treatment of hypertension with propranolol, alone or in combination with hydrochlorothiazide and/or dihydralazine, was investigated in 93 patients with various types of hypertension. Normalisation of the B. P. was obtained within two-four weeks of treatment with propranolol alone in all cases with mild hypertension, and in 77% and 44% of moderate and severe forms respectively. These percentages were even higher when propranolol was employed with hydrochlorothiazide and/or dihydralazine. The rationale of this combination and the mechanism of the hypotensive effect of propranolol are discussed. The drug was well tolerated; major side effects did not occur.

Adult↗
PubMedDate not supplied

Trabeculectomy and extracapsular cataract extraction with posterior chamber lens implantation: a long term study.

Extracapsular cataract extraction with posterior chamber lens implantation and trabeculectomy was performed on 15 cataractous eyes in 15 patients: 5 were affected with chronic closed angle glaucoma and 10 with primary open angle glaucoma. This procedure offers the intraocular pressure control expected after trabeculectomy and, at the same time, gives the patients all visual benefits that cataract extraction with intraocular lens implantation warrants, without the introduction of new complications.

Aged↗