A study of allergens in celery with cross-sensitivity to mugwort and birch pollens

Sixty-one sera with positive RAST to mugwort pollen ( Artemisiae vulgaris ) were submitted to RASTs for birch pollen ( Betula verrucosa) and celery ( Apium graveolens ). In 36 cases RAST results were positive for celery. In addition, 23 sera presented specific IgE to birch pollen. The binding of specific IgE to individual allergens in celery, mugwort pollen and birch pollen was studied by the immunoblotting technique. This involved electrophoretic separation of allergenic extracts, electrotransfer of proteins onto nitrocellulose sheets and sensitive immunoenzymatic detection. Eighteen sera had specific IgE binding to two celery components of molecular weight around 15 kD. All these sera also detected a 15 kD allergen in mugwort and two allergens in birch of 14 kD and 16 kD molecular weight. The sera that did not detect the 15 kD bands in celery failed to react with both the 15 kD mugwort component and the 14 and 16 kD birch components. Specific cross-inhibitions of the detection of these allergens on immunoblots were obtained by pre-incubation of the sera with crude extract of the three species. These results strongly suggest that such allergens display some structural identity and that they could be at the origin of some cases of crossed hypersensitivity to celery, mugwort pollen and birch pollen.     

Unclassified Haemolytic Anaemia with Splenomegaly and Erythrocyte Cation Abnormalities – A Disease of the Spleen?

An unclassified case of haemolytic anaemia with voluminous splenomegaly is reported. This anaemia was normocytic without any specific morphologic aspect of red blood cells (RBC); Coombs test was negative; the osmotic fragility was normal; the increased autohaemolysis was not affected by the presence of glucose; Hb studies were normal; no RBC enzyme deficiency was found; RBC lipids and membrane proteins were normal; there was a marked reduction in RBC survival with exclusive splenic uptake of erythrocytes. Before splenectomy, RBC cations and water content were abnormal: 1) the RBC water was decreased moderately; 2) the RBC sodium was about twice the normal mean with an increased ²²Na turn-over; 3) the RBC potassium was markedly reduced and ⁴²K influx was twice the normal mean; 4) the RBC calcium content was increased. Splenectomy was followed by rapid disappearance of haemolysis and RBC water and cation disturbances. Because of this extremely rapid disappearance after splenectomy the authors suggest this case of haemolytic anaemia could be a primary disease of the spleen.     

Revisiting host/parasite interactions: molecular analysis of parasites collected during longitudinal and cross-sectional surveys in humans

This paper summarizes the first conclusions arising from an analysis of parasite diversity in blood samples collected during longitudinal surveys conducted in Senegal. Parasite typing was carried out using a PCR-based molecular analysis of allelic polymorphism. The parasite populations circulating in the village of Dielmo during periods of intense transmission (when the inoculation rate was 0.5–1 infective bite/night) are characterized by a considerable allelic diversity of the MSP-1, MSP-2 and TRAP loci. A large proportion of blood samples contained several MSP-1 or MSP-2 alleles. In asymptomatic carriers, the complexity of the infections (number of alleles and genetic diversity of these alleles) was age-dependent. In children, the trend was for a reduced complexity during clinical episodes. Molecular typing showed that successive clinical episodes experienced by children were caused by genetically distinct parasites. Longitudinal analysis of asymptomatic carriers indicated that in the absence of transmission, the same parasite types were carried for long periods, while rapidly changing profiles were observed during intense transmission season. The consequences of these findings on our understanding of acquired anti-parasite immunity in humans living in endemic are discussed.     

14-Membered cyclic opioids related to dermorphin and their partially retro-inverso modified analogues II. Preferred conformations in solution as studied by 1H-NMR spectroscopy

The ¹H-NMR studies were extensively carried out to elucidate preferred conformations of a series of 14-membered cyclic dermorphin analogues containing two phenylalanines at both the third and fourth positions, e.g., Tyr-c[D-A₂bu-Phe-Phe-(l and d )-Leu], Tyr-c[d -A₂bu-Phe-gPhe-(S and R)-mLeu], and Tyr-c[d -Glu-Phe-gPhe-(L and D)-rLeu]. The temperature coefficients of the amide proton chemical shifts, vicinal ¹H-¹H coupling constants for the NH-CH groupings, and nuclear Overhauser effects provided information regarding the preferred conformations of the backbones. The conformational preferences and flexibility of the side chains were also estimated from the vicinal ¹H-¹H coupling constants around the C-Cβ and C-Cβ bonds in the articulated side chains. A comparison of the results obtained was made with the results previously obtained for the corresponding enkephalin analogues containing a glycine at the third position. It was found that the replacement of the glycine with the phenylalanine at the third position increases the conformational flexibility of the molecules with an l -, or S-, residue at the fifth position but reduces the flexibility of the molecules with d -, or R-, residue at the same position. The rotating frame nuclear Overhauser experiments gave direct evidence for compact conformations, with the Tyr side chain folding back over the 14-membered ring in Tyr-c[d -Glu-Phe-gPhe-rLeu], which displays relatively high selectivity for the δ-receptor over the μ-receptor. This observation is in agreement with our model proposed for the cyclic enkephalin analogues: folded forms with close aromatic ring placement are required for the activity at the δ-receptor.     

Improved Dual Chamber Pacing Mode in Paroxysmal Atrioventricular Conduction Disorders

GIRODO, S., ET AL.: Improved Dual Chamber Pacing Mode in Paroxysmal Atrioventricular Conduction Disorders. Dual chamber pacing may sometimes be directly indicated for carotid sinus hypersensitivity, vasovagal syndrome, and certain cases of sinoatrial block and intermittent atrioventricular (AV) block, although AV conduction is dominantly normal. At times of normal AV conduction, competition between ventricular pacing and spontaneous ventricular depolarization may occur, with its adverse hemodynamic effects on ventricular function and unnecessary drainage of pacemaker battery energy. A new mode of stimulation is described, called automatic DDD mode, which functions in 'pseudo-AAI' mode during normal AV conduction and reverts to classical DDD function during episodes of AV blocks. Furthermore, during pseudo-AAI function, the pacemaker measures certain physiological parameters that serve to automatically program certain parameters used in DDD mode. Preliminary clinical evaluation has shown that this new mode functions satisfactorily.     

Reactive Oxygen Species Are Necessary for High Flow (Shear Stress)‐induced Diameter Enlargement of Rat Resistance Arteries

Objectives: Chronic increases in blood flow induce remodeling associated with increases in diameter and endothelium‐mediated dilation. Remodeling requires cell growth and migration, which may involve reactive oxygen species (ROS). Nevertheless, the role of ROS in flow‐mediated remodeling in resistance arteries is not known. Materials and Methods: Rat mesenteric resistance arteries (MRAs) were exposed to high flow (HF) by sequentially ligating second‐order MRAs in vivo. After three weeks, arteries were collected for structural, pharmacological, and biochemical analysis. Results: In HF arteries, luminal diameter (431±12 to 553±14 μm; n=10), endothelium (acetylcholine)‐mediated vasodilatation (61±6 to 77±6% relaxation) and NAD(P)H subunit (gp91phox and p67phox) expression levels, and ROS (dihydroethydine microphotography) and peroxynitrite (3‐nitro‐tyrosine) production were higher than in normal flow arteries. Acute ROS scavenging with tempol improved acetylcholine‐dependent relaxation (92±4% relaxation), confirming that ROS are produced in HF arteries. Chronic treatment with tempol prevented the increase in diameter, reduced ROS and peroxynitrite production, and improved endothelium‐mediated relaxation in HF arteries. Thus, ROS and NO were involved in HF‐induced diameter enlargement, possibly through the formation of peroxynitrite, while ROS reduced the increase in endothelium‐dependent relaxation. Conclusions: ROS production is necessary for flow‐mediated diameter enlargement of resistance arteries. However, ROS counteract, in part, the associated improvement in endothelium‐mediated relaxation.     

Intradermal immunization of rats with plasmid DNA encoding Schistosoma mansoni 28 kDa glutathione S-transferase

Direct administration of plasmid DNA encoding an antigen represents an attractive approach to vaccination against infectious diseases, particularly in developing countries where easy-to-handle and cost-effective vaccines are needed. We have investigated the potential of DNA immunization to induce a specific antibody response against Schistosoma mansoni , using plasmid-DNA encoding the protective antigen, S. mansoni 28 kDa glutathione S-transferase (Sm28GST). Since S. mansoni parasite penetrates into its host through the skin, this tissue was chosen for plasmid DNA delivery. Following plasmid DNA administration into the skin of rats, the parasite antigen was detected in skin cells by immunohistochemistry. Three administrations of 200 μg plasmid at 14 day intervals led to the induction of a long-lasting specific IgG antibody response in the sera of immunized rats, with a predominance of IgG2a and IgG2b subclasses. Sera of immunized animals were able to mediate antibody-dependent cellular cytotoxicity in vitro , leading to the specific killing of parasite larvae. A parasite challenge performed on plasmid DNA-immunized animals induced a strong and rapid boosting effect on the specific IgG antibody response. These results demonstrate the potential of genetic immunization via the skin with plasmid DNA encoding Sm28GST for inducing immune responses with protective patterns against an S. mansoni infection .     

Cross–reactive antigenic determinants present on different Plasmodium falciparum blood–stage antigens

A gene encoding a previously undescribed antigen of Plasmodium falciparum has been isolated from a genomic expression library by use of a pool of human immune sera. Northern blot analysis indicated that the gene is expressed at the late stages of the intra-erythrocytic cycle. This antigen, 332, contains a series of degenerated amino acid repeats. Human antibodies affinity-purified on the 332 recombinant antigen reacted with a family of parasite proteins that are products of different genes. We identified antigens 11.1 and Pf155-RESA as members of this family and confirmed, using a human monoclonal antibody, the presence of cross-reacting determinants. The sequences of these antigens also share some structural homologies. The significance of this family of blood-stage antigens is discussed.     

BILATERAL NON FUNCTIONNING THECOMA OF THE OVARY IN EPILEPTIC CHILDREN UNDER ANTICONVULSANT THERAPY

The peculiar features of two bilateral thecoma of the ovary are described. They were discovered because of a rapid enlargement of the abdomen with hemorrhagic ascites, but without any sign of precocious puberty. They occurred in young females treated with anti-convulsant therapy for epilepsy. They have been cured with surgery alone. A third case has been found in the literature. Discussion is raised about the meaning of this association. The possible relationship with side-effect of anti-epileptic drugs is suggested.