Identification of a minimal T cell epitope recognized by antinucleosome Th cells in the C-terminal region of histone H4.

Autoreactive T cells responding to systemic autoantigens have been characterized in patients and mice with autoimmune diseases and in healthy individuals. Using peptides covering the whole sequence of histone H4, we characterized several epitopes recognized by lymph node Th cells from nonsystemic lupus erythematosus-prone mice immunized with the same peptides, the H4 protein, or nucleosomes. Multiple T epitopes were identified after immunizing H-2d BALB/c mice with H4 peptides. They spanned residues 28-42, 30-47, 66-83, 72-89, and 85-102. Within the region 85-102, a minimal CD4+ T epitope containing residues 88-99 was characterized. Although Abs to peptide 88-99 recognized H4, this peptide does not contain a dominant B cell epitope recognized by anti-H4 Abs raised in BALB/c mice or Abs from NZB/NZW H-2d/z lupus mice. Th cells primed in vivo with H4 responded to H4, but not to peptide 88-99. However, this peptide was able to stimulate the proliferation and IL-2 secretion of Th cells generated after immunization with nucleosomes. H488-99 thus represents a cryptic epitope with regard to H4 and a supradominant epitope presented by nucleosome, a supramolecular complex that plays a key role in lupus. This study shows that in the normal repertoire of naive BALB/c mice, autoreactive Th cells specific for histones are not deleted. The reactivity of these Th cells seems to be relatively restricted and resembles that of Th clones generated from SNF1 ((SWR x NZB)F1; I-Ad/q) lupus mice described earlier.

[Surgery of aneurysms of the abdominal aorta. Clinical study and surgical results. Apropos of a series of 54 cases]. / La chirurgie des anévrysmes de l'aorte abdominale. Etude clinique et résultats chirurgicaux. A propos d'une série de 54 cas.

54 patients with an abdominal aortic aneurysm were hospitalized between 1969 and 1980 in the Clinic of Cardiovascular and Thoracic Surgery at Rennes (Pr. Y. Logeais): 35 were ruptured aneurysms, 19 non-ruptured. The average age of the patients was 70.6 years. 48% of patients showed signs of atheroma in at least one other site. 24% had arterial hypertension. Arteriography was carried out in 51.5% of the non-ruptured aneurysm cases and in 26% of the ruptured cases. Both ultrasound and tomography are regarded presently as very useful tests. The intervention carried out in 41 patients always involved the insertion of a by-pass graft (aortic only in 7 cases; aorto-biiliac in 19 cases; aorto-bifemoral in 15 cases). Mortality was 7.7% for the non-ruptured aneurysms. 59% for the ruptured aneurysms, the deaths above all being related to the degree of visceral ischaemia. Secondary mortality was comparable for all the aneurysms operated on. More than 80% of patients were surviving 5 years after surgery.

[Surgical treatment of constrictive pericarditis and life-threatening pericardic effusions (author's transl)]. / Principes du traitement chirurgical des péricardites constrictives et des épanchements péricardiques compressifs.

Total excision of both pericardic sac and epicardium is the basic surgical procedure for chronic constrictive pericarditis. Approach being through a vertical sternotomy. In case of either cardiac injury or poor haemodynamic of either cardiac injury or poor haemodynamic conditions, it is sometimes indicated to get help from an extracorporal circulation with femoro-femoral shunt. Surgery for acute pericarditis may vary according to local and general conditions. As soon as a pericardic effusion, whether or not infected, has occurred, drainage by means of an infraxiphoid incision seems to be a safe method. Where pericardic effusions relapse or densify to a constrictive pericarditis, pericardectomy is to be considered. Total pericardectomy is therefore regarded as the best procedure to prevent further disease.