Is skin autofluorescence a marker of metabolic memory in pregnant women with diabetes?

AIM: To determine whether skin autofluorescence can help to detect those who have previously had abnormal glucose levels among women referred for diabetes during pregnancy. METHODS: Using an advanced glycation end product reader (AGE Reader(tm) (;) DiagnOptics BV, Groningen, the Netherlands), we measured forearm skin autofluorescence at 24-30 weeks of gestation in all women who were referred to our Nutrition Diabetology unit for diabetes during pregnancy. RESULTS: The study included 230 women (200 with gestational diabetes and 30 with pre-gestational diabetes, of whom 21 had Type 1 and nine had Type 2 diabetes) and a reference group of 22 normoglycaemic non-pregnant women. Skin autofluorescence was significantly higher in women with pre-gestational diabetes (1.97 ± 0.44 arbitary units) compared with gestational diabetes (1.77 ± 0.32 arbitary units; P = 0.003) and lower in the reference group (1.60 ± 0.32 arbitary units; P = 0.009 vs all pregnant women). Among women with gestational diabetes, 71 had a history of hyperglycaemia (i.e. gestational diabetes or macrosomia in a previous pregnancy or discovery of diabetes before 24th gestational week in the present pregnancy). These women had higher levels of skin autofluorescence (1.83 ± 0.35 arbitary units) than women with gestational diabetes without previous history of hyperglycaemia (1.73 ± 0.30 arbitary units; P = 0.04, non-significant, adjusted for age). Skin autofluorescence increased with the number of criteria present for previous hyperglycaemia (P for trend = 0.008) and was significantly associated with having two or three criteria for hyperglycaemia after adjusting for age (P = 0.02). CONCLUSIONS: Skin autofluorescence could reflect previous long-term hyperglycaemia in pregnant women, and could therefore be a marker of metabolic memory.

Control and prediction of the course of brewery fermentations by gravimetric analysis.

A simple, fast and cheap test suitable for predicting the course of brewery fermentations based on mass analysis is described and its efficiency is evaluated. Compared to commonly used yeast vitality tests, this analysis takes into account wort composition and other factors that influence fermentation performance. It can be used to predict the shape of the fermentation curve in brewery fermentations and in research and development projects concerning yeast vitality, fermentation conditions and wort composition. It can also be a useful tool for homebrewers to control their fermentations.

[A Nematode Nobel Prize: Caenorhabditis elegans]. / Un Nématode Prix Nobel: Caenorhabditis elegans.

The Nematode Caenorhabditis elegans (C. elegans) is an established model increasingly used for studying human disease pathogenesis. C. elegans models are based on the mutagenesis of human disease genes conserved in this Nematode or on the transgenesis with disease genes not conserved in C. elegans. Genetic examinations will give new insights on the cellular and molecular mechanisms that are altered in some neurodegenerative diseases like Duchenne's muscular dystrophy, Huntington's disease and Alzheimer's disease. C. elegans may be used for primary screening of new compounds that may be used as drugs in these diseases.

Longitudinal study of the cellular response to Pf155/RESA and circumsporozoite protein in Madagascar.

In a community follow-up conducted in the Central Highlands of Madagascar, the cellular responses to synthetic peptides from the immunodominant regions of Pf155/RESA and the repeat region of the circumsporozoite protein were studied. Seasonal variations of the T cell response were measured at the individual level; the relationship between this response and the presence of parasites in blood was assessed; the question of the possible protective value of the lymphocyte proliferation in presence of a specific antigen was addressed.

Antibodies to the PF155 antigen of Plasmodium falciparum: measurement by cell-ELISA and correlation with expected immune protection.

Plasmodium falciparum polypeptide Pf155 is one of the main candidates for a vaccine against asexual blood stages of P. falciparum. Antibodies against Pf155 can be detected by a cell-ELISA technique with glutaraldehyde-fixed and air dried P. falciparum-infected erythrocytes as antigen. Using this assay, we measured the level of antibodies in sera from 230 subjects with various degrees of past exposure to P. falciparum. Significant levels of antibodies (OD492 greater than 0.5) were detected in 41/50 sera from Central African adults and in 34/50 sera from West African adults. All sera from 50 European adults suffering primary malarial attack and 28/30 sera from West African children (10 to 12 years old) were negative. Intermediate results were obtained with 50 sera from West African adults living in France for greater than or equal to 2 years (12 positive). Mean OD values of the sera of these five groups of subjects varied in the same direction as the positivity rates. These preliminary results suggest that the level of anti-Pf155 antibodies as detected by cell-ELISA might provide an assessment of protective immunity against P. falciparum which could complement clinical or epidemiological criteria.

Lymphoproliferative responses to synthetic peptides from merozoite ring-infected erythrocyte surface antigen and circumsporozoite protein: a longitudinal study during a falciparum malaria episode.

Proliferative responses of peripheral blood lymphocytes to synthetic peptides representing major epitopes of two malaria antigens (the merozoite ring-infected erythrocyte surface antigen and the sporozoite circumsporozoite protein) were investigated in Madagascar during a clinical Plasmodium falciparum episode. Thirty-seven patients greater than 10 years of age were enrolled at the beginning of the malaria transmission season and followed for four weeks. At enrollment, when the subjects presented with an acute infection, lymphocytes recovered from approximately 30% of them proliferated after peptide stimulation. These proliferative responses decreased sharply one and two weeks after treatment, with less than 10% responding to each peptide. Four weeks after treatment, the responses were only partially restored. The amplitude of these variations was not related to the initial parasitemia. At the individual level, proliferative response to each peptide varied greatly during the followup period, and this variation was unrelated to the presence of parasites in the blood.

Humoral and cell-mediated immune responses to the Plasmodium falciparum antigens PF155/RESA and CS protein: seasonal variations in a population recently reexposed to endemic malaria.

Resurgence of falciparum malaria occurred in the Central Highlands of Madagascar in the 1980s and the disease is currently hyperendemic. We determined the humoral and cellular responses to synthetic peptides reproducing the repeat sequences of 2 major Plasmodium falciparum antigens: the Pf155/RESA and the circumsporozoite (CS) protein. Blood samples from 83 subjects living in a rural community near Antananarivo were obtained at the beginning and the end of the transmission season. At enrollment, 40 subjects presenting with and 43 without blood parasites had similar T cell proliferative response and antibody level to all antigens tested. However, P. falciparum-infected individuals exhibited a decrease in the absolute number of T lymphocytes, due to a diminished number of CD8+ and natural killer lymphocytes. The number of CD4+ cells was similar in both groups. In the overall population, 45% of subjects had a T cell response to at least 1 RESA peptide (29-35% responding to a given peptide) and 35% to the CS protein peptide. Thirty-two percent of the donors presented with RESA antibodies and 23% had CS protein antibodies. After 20 weeks, at the end of the transmission season, cellular proliferative responses to all antigens markedly decreased as evidenced by a decrease of both the number of responders and mean stimulation indexes. Humoral response to RESA, as detected by erythrocyte membrane immunofluorescence (number of responders and mean antibody titers) markedly increased. Humoral responses to the CS protein and RESA peptides were similar.(ABSTRACT TRUNCATED AT 250 WORDS)

Differential measurement of monomeric and polymeric IgA by one-directional immunoelectrodiffusion.

A technique to specifically quantify monomeric IgA and total IgA in colostrum has been developed using a modified one-dimensional immunoelectrophoretic assay. This method employed electrophoresis in antibody-containing polyacrylamide-agarose gel in the presence of a gel barrier which blocks polymeric IgA. The addition of PEG (polyethylene-glycol 6000) to the anodic gel increased the sharpness of the peaks, the height of which was proportional to the antigen concentration. This method proved to be sufficiently simple, precise, reproducible (CV less than 3%) and linear (from 20-300 mg/l) to measure the monomeric IgA: total IgA ratio rapidly (14 +/- 4.5% for 20 samples in duplicate). Immunoelectrodiffusion studies confirmed that human colostral and serum IgA standards could be used to determine directly monomeric IgA, total IgA and polymeric IgA levels (by difference) rather than to apply correction factors to estimate these IgA levels.

In vitro excystation of Giardia from humans: a scanning electron microscopy study.

The in vitro excystation of Giardia lamblia on cysts isolated from human feces was studied. After purification by sucrose gradient, cysts were incubated in a pepsin-acid solution, then placed in a modified HSP3 medium where excystation occurred within a few minutes. The excystation procedure was studied by continuous observations by light microscopy and sequential observations by scanning electron microscopy (SEM). The in vitro excystation was stopped at timed intervals during incubation by addition of a large amount of 1% glutaraldehyde. The excystation process began by the cyst wall opening at one pole. Flagella protruded rapidly, the parasite emerged progressively from the cyst envelope, posterior end first, the empty cyst collapsed and shrank. Although flagella emerging from the organism were distinguishable, the cell body had not yet shown all the morphological features of the G. lamblia trophozoite. A radical rearrangement of the organism occurred gradually: initially oval in shape, the parasite became round, then elongated, flattened, and underwent cytokinesis. The daughter trophozoites acquired their typical morphological features: the shape, the adhesive disc with the C-shaped structure distinctly visible on the ventral surface, and the definite placement of the flagella. These observations obtained on G. lamblia by SEM were comparable to those obtained with G. muris.

Antimalarial activity and cytotoxicity of Evodia fatraina stem bark extracts.

Stem bark extracts of Evodia fatraina (Rutaceae) were tested for antimalarial activity in vitro on Plasmodium falciparum using an isotopic semi-microtest and in vivo on Plasmodium berghei in mice. Ethyl acetate extract showed moderate antimalarial activity in vitro (IC50 = 8.5 micrograms ml-1). However, ethanolic extract exhibited significant potency in vivo (65% suppression of parasitaemia). Moreover, low toxicity against HeLa cells and L 929 fibroblasts was observed with ethanolic extract (IC50 = 95 micrograms ml-1 and 60 micrograms ml-1, respectively).

A high-yield outbred suckling mouse model of cryptosporidiosis.

Outbred suckling mice (NMRI strain) were used as hosts. They were initially inoculated with oocysts of human origin, and subsequently with parasites recovered from the mouse ileal mucosa. Cryptosporidia were counted in an aliquot of whole-ileum homogenate. Parasite load was expressed as cryptosporidia per centimeter of ileum. Serial passage of C. parvum in NMRI mouse litters led to a gradual amplification of parasite burden relative to animals initially inoculated with the human isolate.

[Cryptosporidiosis. II. Biological diagnosis]. / La cryptosporidiose. II. Diagnostic biologique.

The biological diagnosis of human cryptosporidiosis is made primarily by identifying Cryptosporidium oocysts in stool specimens under the microscope. It is advisable to fix and stain the fecal smears by the technique according to Henriksen. It is possible to examine fresh specimens and to carry out concentration techniques but this requires excellent knowledge of the cytology of the parasite. Cryptosporidium can also be identified from intestinal biopsies.

Biochemical and metabolic peculiarities of some parasites availing as targets for therapy.

Biochemical and metabolic peculiarities of some parasites involved in their interactions with their hosts are reviewed according to (1) carbohydrate metabolism comprising glycolysis, Pasteur effect, CO2 fixation and electron transport system; (2) amino acid and protein metabolism ; (3) purine and pyrimidine nucleotides metabolism. These peculiarities are becoming targets for treatment without affecting the host.

[Preparation of oxime, hydrazone and dichloroacetamide derivatives. Researches of antiparasitic activity]. / Préparation de dérivés d'oximes, d'hydrazones et de dichloroacétamides. Recherches d'activité antiparasitaire.

Several oximes, hydrazones and dichloroacétamides were synthesized. The antiparasitic properties of these compounds were evaluated in vitro against two Protozoaires Entamoeba histolytica and Trichomonas vaginalis.