[Evaluation of the response to vaccination against poliomyelitis and measles in malnourished children in Morocco]

We made a comparative survey of the poliovirus antibodies [anti-poliovirus type 1, anti-poliovirus type 2 and anti-poliovirus type 3] and the measles antibodies in malnourished but completely vaccinated children [37] and control children [34].The age range was 10 months to 5 years. Immunization in children with protein-energy malnutrition was low for both vaccines. Seroprevalence rates of the polio 1, polio 2, polio 3 antibodies and the measles antibodies in the control group were 94.1%, 97.1%, 91.2% and 82.4% respectively. In malnourished children the respective rates were in some cases significantly lower being: 40.5% [P = 0.001], 59.5% [P = 0.001], 40.5% and 35.1%. Malnutrition is a major determinant of the humoral response to oral polio and measles vaccines and must be given due consideration to prevent vaccination failure

Importance of mevalonate-derived products in the control of HMG-CoA reductase activity and growth of human lung adenocarcinoma cell line A549.

HMG-CoA reductase catalyzes the synthesis of mevalonate, a crucial intermediate in the biosynthesis of cholesterol and non-sterol isoprenoid compounds essential for cell growth. The HMG-CoA reductase activity of the A549 tumor cell line is higher than that of normal human fibroblasts. This deregulation in mevalonate needs was not due to an alteration in the activated state of the enzyme by short-term regulation. We show that the HMG-CoA reductase in A549 cell line was subject to a multivalent feedback control. A high fraction (40%) of the reductase activity was devoted to non-sterol products. In contrast, normal fibroblasts had only 15-20% of the reductase activity that generated non-sterol products. We also show that cholesterol and at least one of the non-sterol products are necessary for optimal cell growth of A549 cells. Our data strongly suggest that A549 cells produce more non-sterol substances which may be related to increased requirements of mevalonate for upregulated cell growth.

High density lipoprotein3 binding sites are related to DNA biosynthesis in the adenocarcinoma cell line A549.

The effect of high density (apoE-depleted HDL3) on cell growth of a human tumor cell line (A549) was studied and related to its binding on the plasma membrane. HDL3 were shown to stimulate the incorporation of [3H]thymidine into DNA and cell proliferation; these effects were dose-dependent. As HDL3, apoA-I and apoA-I-liposomes complexes (but not apoA-II) were able to stimulate DNA synthesis in serum-free conditions. This effect was maximum for 15-30 micrograms HDL3 protein/ml concentration. Binding of HDL3 on whole cells occurred by two mechanisms: the first was specific for HDL3; the second, of lower affinity, was phospholipid-dependent and was inhibited by low density lipoprotein or by phospholipid particles. Internalization and degradation of bound HDL3 were not observed. The specific sites (27.9 +/- 2.2 ng HDL3 protein/ng cell protein) accounted for only 2.5% of total (specific+phospholipid) binding sites and they bound HDL3 with a dissociation constant (KD) of 2.47 +/- 0.46 microgram HDL3 protein/ml (2.6 +/- 0.5 x 10(-8) M). The apparent KD value of total binding sites (specific+phospholipid) was eightfold higher (20.4 +/- 6.1 micrograms HDL3 protein/ml). Analysis of the membrane specific binding sites by ligand blotting with 125I-labeled HDL3 showed a single protein with an apparent molecular mass of 110 kDa. When HDL3 binding on phospholipid sites was inhibited by rigid phospholipid particles, the stimulation of [3H]thymidine incorporation related to HDL3 concentration did not show a maximum peak as previously observed but reached a plateau at a concentration as low as 5 micrograms HDL3 protein/ml. This low concentration also nearly saturated the specific binding sites with HDL3. When binding on specific protein sites was suppressed by tetranitromethane, DNA synthesis was not stimulated but, in contrast, inhibited. The stimulating effect of HDL3 on DNA biosynthesis is therefore likely dependent on HDL3 occupying specific binding sites.

[Renal oncocytoma. Retrospective study of 38 cases]. / Oncocytome rénal. Etude rétrospective de 38 cas.

38 cases of renal oncocytoma were recognized at Cochin's hospital from 1982 to 1991. Accurate diagnosis was not possible before performing surgery. However, a benign tumor appearance on the preoperative morphologic investigations and an evocative peroperative macroscopic aspect of renal oncocytoma, allowed us to realize a conservative surgery in 4 cases. Follow-up of 27 patients (11 lost to follow-up) showed a benign clinical behaviour in all cases, de spite of invasion of the perirenal fat in 2 cases, and tumoral thrombosis of a proximal branch of the renal vein in 1 case. No metastases occurred after a mean follow-up of 32.5 months, within range from 11 to 101. Our experience as well as the literature leads us to believe that renal oncocytoma is a benign tumor. We conclude that conservative surgery must be systematically considered when peroperative histological examination assert the diagnosis of renal oncocytoma, especially when the tumoral diameter is less than 5 cm.

Potassium monopersulfate and a water-soluble manganese porphyrin complex, [Mn(TMPyP)](OAc)5, as an efficient reagent for the oxidative cleavage of DNA.

Reported studies indicate that the association of potassium monopersulfate with [Mn(TMPyP)](OAc)5, a water-soluble manganese porphyrin complex, leads to an efficient reagent for the oxidative cleavage of DNA. Single-strand breaks (SSBs) are observed on double-stranded DNA at manganese porphyrin concentrations as low as 0.5 nM with a short incubation time of 1 min. The number of SSBs linearly varies with the concentration of the manganese complex, and potassium monopersulfate is at least 3 orders of magnitude more efficient as oxygen source than hydrogen peroxide. Cleavage efficiency is optimal in the pH range 7.5-9.0 for a NaCl concentration between 80 and 150 mM or for a MgCl2 concentration of 10 mM. At very low manganese porphyrin concentration and by increasing the incubation time a catalytic cleavage activity of the complex is evidenced: up to 5 SSBs per manganese porphyrin are observed. The high cleavage activity of the monopersulfate-manganese porphyrin system makes it a good candidate for DNA-footprinting experiments.