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Biomedical subjects

A F Miranda

Publications and source records attributed to A F Miranda.

94 records · Page 6Linked to original sources
PubMed1974

Action of cytochalasin D on cells of established lines. II. Cortex and microfilaments.

Cells in culture exposed to cytochalasin D (CD) rapidly undergo a long-sustained tonic contraction. Coincident with this contracture the thin microfilaments of the cortex become compacted into feltlike masses. The ravelled filaments of these masses remain actinlike and bind heavy meromyosin; they are not disrupted or disaggregated, but rather, appear to represent a contracted state of the microfilament apparatus of the cell cortex. On continued exposure to CD, 'myoid' bundles, containing thick, dense filaments, and larger fusiform or ribbonlike, putatively myosinoid, aggregates may appear. These appearances are interpreted as consequences of a state of hypercontraction without relaxation induced by CD. They do not occur in CD-treated cells prevented from contracting by inhibitors of energy metabolism, and are readily reversible on withdrawal of CD. Extensive ordered arrays of thin microfilaments develop in cells which are reextending during early recovery.

Adenosine Triphosphate↗
PubMedDate not supplied

[Pain caused by brachial plexus injury during coronary revascularization. Report of 3 cases].

We report three cases of injury of the brachial plexus after coronary revascularization surgery. During the postoperative phase all patients presented plexopathy involving the left C8 and D1 roots. The symptoms were pain, paresthesia, and motor deficits. The proposed mechanisms for injury of the brachial plexus during cardiac surgery are: hyperabduction of the arm, direct traumatism produced by the needle during catheterization of the internal jugular vein, and traction and compression associated with sternal retraction. In the three patients we ruled out alterations during cannulation of the internal jugular vein and malposition of the arms. We think that in our cases the fundamental mechanism was an excessive and assymetrical opening of sternal and Favoloro's separators that were used in all cases during dissection of the left internal mammary artery. We conclude that injury of the brachial plexus can be minimized by reducing the opening of both separators and by placing Favaloro's separator in a lower position.

Aged↗
PubMedDate not supplied

[Retrospective study in hepatic biopsies, of hepatitis B surface antigen by the orcein method and indirect immunofluorescence methods].

A retrospective study of the HBsAg was done in 56 liver biopsies of children less than 12 year-old and 78 biopsies of adults. The study was performed by orcein stain and indirect immunofluorescent method. In 23 of the adults patients, the serological detection of HBsAg and antibodies (HbsAb) was determined by reverse passive haemagglutination technique. The adults patients' histological dianosis were variable and included acute or chronic hepatitis (20.5%) and cirrhosis (24.4%). Orcein was positive in 7 and IFI in 6 cases; 5 biopsies were positive by both methods. The highest incidence of HBsAg was seen in active cirrhosis (75%), including two cases of alcoholic cirrhosis. In the 23 serologically studied patients, 15 cases were HBsAg negative and 3 were HBsAg positive both in the liver and serum; only 2 cases showed discrepancy between these results. Three patients were HBsAb positive and HBsAg negative both in the liver and serum. All children biopsies were HBsAg negative. Among these patients, 26.8% had acute or chronic hepatitis and 10.7% cirrhosis. Serological and tissue techniques for HBsAg and HbsAb detection have different sensitivity. This should be kept in mind when studying the incidence of hepatitis B virus related to liver diseases.

Adult↗