Biomedical subjects
Publications and source records attributed to C Lisbona.
A right subclavian artery pseudoaneurysm caused by blunt trauma is described. CT and digital subtraction angiography helped us to establish a correct diagnosis. Radiologic features of subclavian artery aneurysms and relevant literature are briefly discussed.
tpl-2 is a rat gene that encodes a serine/threonine protein kinase that can act as a novel mitogen-activated protein (MAP) kinase kinase kinase. Tpl-2 is activated in Moloney murine leukemia virus-induced rat T lymphomas, due to a truncation in the C-terminal region of the protein. cot is a very closely related gene, if not the human homologue. The truncated form of Cot has been shown to have a higher transforming activity than the nontruncated form. In this paper we show that an increase in truncated Cot kinase expression correlates with an increase in IL-2 production in anti-CD3-treated Jurkat cells. Truncated Cot expression also cooperates with PHA or phorbol 12,13-dibutyrate (PDBu) and calcium ionophore for IL-2 production in Jurkat cells. Both the truncated and nontruncated Cot forms increased IL-2 transcription because they enhanced transcription of a reporter gene linked to the IL-2 promoter. The expression of a dominant negative form of Cot inhibits transcription directed by the IL-2 promoter in Jurkat cells stimulated by PDBu and ionophore. These data suggest a role of Tpl-2/Cot kinase in IL-2 production during T lymphocyte activation and could also explain its role in Moloney murine leukemia virus-induced lymphomagenesis.
Rat T lymphoblasts arrested in the G1 phase of the cell cycle by interleukin-2 (IL-2) deprivation can be forced to proceed to the S phase when they are stimulated with IL-2 or the phorbol ester phorbol 12,13-dibutyrate (PDBu). When PDBu is used as a stimulus, extracellular regulated kinase 2 (ERK2) is activated by threonine and tyrosine phosphorylation by the dual-specificity kinase MEK. Here we have studied the regulation of ERK2 dephosphorylation as a mechanism for inactivation of this kinase. In vivo inhibition of ERK2 dephosphorylation observed after preincubation with translation or transcription inhibitors (cycloheximide or actinomycin, respectively) indicates the involvement of at least one inducible phosphatase, the best candidate for which is the dual-specificity phosphatase PAC-1. Other noninducible phosphatases must act as well, however, because sodium orthovanadate is a more effective dephosphorylation blocker than cycloheximide. In addition, the okadaic acid effect in ERK2 dephosphorylation indicates that Ser/Thr phosphatases are also involved, directly and/or indirectly.
Rat lymphoblasts are arrested in the G1 phase of the cell cycle and can be promoted to proceed up to the S phase, when they are stimulated by phorbol ester. In this work, we have studied some details of the phorbol 12,13-dibutyrate (PBu2)-stimulated proliferation. We show that in response to PBu2 at least four different protein kinase C (PKC) isoforms translocate to the membrane. A specific PKC zeta antibody recognizes two bands of 75 and 82 kDa. These two activities are separated using a Mono Q chromatography and we show that p75 is the classical PKC zeta isoform, while p82 might be a related isoform which is PBu2 sensitive. Our data show that there is a correlation between the ability of PBu2 to promote mitogenesis and to activate ERK2 kinase, suggesting that ERK2 kinase might be the limiting step of the process. We also show that ERK kinase activation precedes Raf-1 kinase hyperphosphorylation, suggesting that Raf-1 kinase activation is not required for ERK kinase activation. This idea was checked using a Raf-1 kinase antisense (AS) oligonucleotide. The results obtained with the Raf-1 AS oligonucleotide indicate that this serine/threonine kinase is dispensable for ERK kinase activation, but needed for the PBu2 mitogenic signaling even as late as 7 h after the delivery of the signal.
We present our experience with arterio-venous traumatic fistulas. Seven cases, between 6 patients are reviewed. Respective etiologies were: 4 cases after an accidental traumatism, 2 cases produced by iatrogenicity and 1 case of idiopathic etiology. Respective localizations were: 6 cases at lower limbs (85.7%) and one case at cervical column (14.2%). All patients underwent surgical treatment. There was any case of mortality and treatment results were satisfactory in all cases. Patients were followed and, up to now, no recidives have been registered. follow-time ranged from 1.5 to more than 6 years.
Retrospective study about the frequency of hemorrhagic complications (258 patients) in the treatment of venous thrombosis and/o pulmonary embolism, with heparin. Heparin was intermittently administered by endovenous way and controlled during the ten first days. Mostly of the big hemorrhages happened between the seventh and the tenth day, in digestive and urinary system mainly.
Three cases demonstrating the possible venous system compression by some neoplasias, feigning an nonexistent thrombosis, are presented. Author stands out the fitness of to investigate possible neoplasias in thrombosis without apparent causality.
A case of arteriosclerotic aneurysm of the inferior mesenteric artery, in which obliteration of both the coeliac axis and the superior mesenteric artery was found by chance in a patient with chronic ischaemia of the lower extremities and without digestive vascular trouble is reported. The surgical treatment is discussed and the reasons for its applications analysed. A review of world literature revealed only two previously published cases, which are quoted.
We present a retrospective review of a series of patients from our Service submitted to surgical extra-anatomical grafts. Correlation between diverse variants and ulterior obliteration by thrombosis or infection of the surgical wounds is analyzed. The series included 133 patients surgically treated between 1986 and 1991. The studied variants were: sex, age, type of graft, the material used, length and type of anesthesia, presentation of hypotension during the surgical intervention, diabetes, platelet recount. Fourteen patients (11%) presented early graft obliteration and 15 (11%) presented an infection of their surgical wound. Only the platelet variant showed statistical differences in patients presenting infection. A high recount of platelets could be a factor risk of infection.
Results from 9 complete reconstructions without intermediate anastomosis (8 patients) are presented. In five cases a by-pass from femoral artery to the contralateral popliteal (infra or supra-rotuliar) arterial prosthesis was performed. In other case a by-pass from the aorta artery to the third popliteal section was placed. Other by-pass was performed from the branches of an axillo-bifemoral by-pass to the third popliteal section. The last case was an axillo-bi-popliteal by-pass. All the patients presented a severe ischemia (III and IV Fontaine stadii). Eight millimeter PTFE grafts were used. The distal anastomosis should always be performed in vessels with a low distal resistance.