The humoral immune response of 34 macaques experimentally infected with SIVmac-251 was studied using a combination of an epitope library and synthetic peptides. The course of the immune response was checked for up to 9 months postinfection with a panel of clones expressing SIV fragments. A systematic study was performed with synthetic peptides covering the whole transmembrane (TM) and external (SU) envelope proteins. Seven major immunodominant epitopes were characterized. Four are localized in the SU protein: one in the V1 region (111-130), one in the Cys loop of the V3 region (311-330) and two in the C-terminal end (501-520 and 511-530). Three are localized in the TM protein: one in the extracellular domain (601-619), one in the anchor domain (731-750) and one in the intracytoplasmic domain (861-881). Among these epitopes, only one, 601-619, was found to be reactive with all sera and can be defined as the principal immunodominant epitope.

Amino Acid Sequence↗

PubMedDate not supplied

Inhibition of prokaryotic cell growth by HIV1 Vpr.

We have cloned the nef, vif, vpr and vpu genes of HIV1 in the pGEX system to produce auxiliary proteins of HIV1 as N-terminal fusions with glutathione S-transferase (GST). Some GST proteins are difficult to obtain under standard conditions. The synthesis and solubility varied considerably from one protein to another. We investigated the reasons for the poor production of GST-Vpr, GST-Vpu and GST-Vif. Interestingly, using this GST prokaryotic model, we demonstrated that Vpr, which is known to block the cell cycle of mammalian and yeast cells at the G2 phase, is also bacteriostatic for Escherichia coli. The effect on E. coli was specific to Vpr, and was not linked to the expression of the other HIV1 proteins. This suggests that Vpr interferes with components of cell replication that are conserved from prokaryotes to eukaryotes. Thus, E. coli appears to be a convenient model system for studies on the function of Vpr.

Cell Division↗

PubMedDate not supplied

[Red cell indices in the aged. 1 726 patients over the age of 70 (author's transl)].

Statistical analysis of red cell constants in 1 726 patients over the age of 70 shows that red cell counts, hemoglobin and hematocrits are slightly lower than those in young adults. However, the quality of the red cells is normal, because the MCV (mean cell volume) and MCHC (mean cell hemoglobin concentration) are normal.

Aged↗

PubMedDate not supplied

[Frequency and etiology of anemia in patients over the age of 70 (author's transl)].

The study of 1 726 patients living in homes for the aged, or hospitalized shows that 20% of them have anemia. There is no increase in prevalence of the disease in females. A wide variety of mechanisms may cause anemia. However, chronic bleeding of essentially digestive origin is the most common. Several anemia-causing factors are particularly frequent in the aged: bleeding, inflammation, nutritional deficiencies, bone marrow failure. Diagnosis is complicated and may require examinations which are not always easily accepted by the aged.

Aged↗

PubMedDate not supplied

[Crohn's disease (acute regional colitis) (author's transl)].

This article reports the observation of acute form of Crohn's disease, limited to colonic involvement, in a 40-year old female. Diagnosis was based upon pathologic examination of biopsy. The patient died after four months of acute disease. Clinical and paraclinical justification of the diagnosis of Crohn's disease (colonic), as well as description of treatment are given.

Adult↗

PubMedDate not supplied

[Primary hydatic cyst of the lung. Diagnostic problems (author's transl)].

Diagnosis of primary cystic disease of the lung is often difficult, and because of this, in non-endemic regions, patients are often referred to the surgeon with an erroneous diagnosis. Clinical signs are completely non-specific. The most common one is hemoptysis; X-rays often fail to confirm hydatic cyst because of the volume, topography, or rupture of the cyst. Biological tests are often of little help. Serological reactions are negative in over one-half of the cases. The advantage of other complementary examinations (bronchiography, bronchoscopy, angiography, echotomography, scintigraphy) including transparietal punctions of the cyst, are discussed in light of the literature.

Biopsy↗

PubMedDate not supplied